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Sample records for ageing heat treatments

  1. YIELD STRENGTH PREDICTION FOR RAPID AGE-HARDENING HEAT TREATMENT OF ALUMINUM ALLOYS

    SciTech Connect

    Yin, Hebi; Sabau, Adrian S; Ludtka, Gerard Michael; Skszek, Timothy; Niu, X

    2013-01-01

    A constitutive model has been developed to predict the yield strength aging curves for aluminum casting alloys during non-isothermal age-hardening processes. The model provides the specific relationship between the process variables and yield strength. Several aging heat treatment scenarios have been investigated using the proposed model, including two-step aging recipes. Two-step aging heat treatments involve a low temperature regime to promote nucleation of secondary phases and a second step at higher temperature for the growth of the secondary phases. The predicted results show that yield strength of approximately 300MPa might be obtained in shorter aging time, of approximately 30 minutes. Thus, better mechanical properties can be obtained by optimizing the time-temperature schedules for the precipitation hardening process of heat treatable aluminum alloys.

  2. Experimental heat treatment of silcrete implies analogical reasoning in the Middle Stone Age.

    PubMed

    Wadley, Lyn; Prinsloo, Linda C

    2014-05-01

    Siliceous rocks that were not heated to high temperatures during their geological formation display improved knapping qualities when they are subjected to controlled heating. Experimental heat treatment of South African silcrete, using open fires of the kind used during the Middle Stone Age, shows that the process needed careful management, notwithstanding recent arguments to the contrary. Silcrete blocks fractured when heated on the surface of open fires or on coal beds, but were heated without mishap when buried in sand below a fire. Three silcrete samples, a control, a block heated underground with maximum temperature between 400 and 500 °C and a block heated in an open fire with maximum temperature between 700 and 800 °C, were analysed with X-ray powder diffraction (XRD), X-ray fluorescence (XRF), optical microscopy, and both Fourier transform infrared (FTIR) and Raman spectroscopy. The results show that the volume expansion during the thermally induced α- to β-quartz phase transformation and the volume contraction during cooling play a major role in the heat treatment of silcrete. Rapid heating or cooling through the phase transformation at 573 °C will cause fracture of the silcrete. Successful heat treatment requires controlling surface fire temperatures in order to obtain the appropriate underground temperatures to stay below the quartz inversion temperature. Heat treatment of rocks is a transformative technology that requires skilled use of fire. This process involves analogical reasoning, which is an attribute of complex cognition.

  3. A previously undescribed organic residue sheds light on heat treatment in the Middle Stone Age.

    PubMed

    Schmidt, Patrick; Porraz, Guillaume; Bellot-Gurlet, Ludovic; February, Edmund; Ligouis, Bertrand; Paris, Céline; Texier, Pierre-Jean; Parkington, John E; Miller, Christopher E; Nickel, Klaus G; Conard, Nicholas J

    2015-08-01

    South Africa has in recent years gained increasing importance for our understanding of the evolution of 'modern human behaviour' during the Middle Stone Age (MSA). A key element in the suite of behaviours linked with modern humans is heat treatment of materials such as ochre for ritual purposes and stone prior to tool production. Until now, there has been no direct archaeological evidence for the exact procedure used in the heat treatment of silcrete. Through the analysis of heat-treated artefacts from the Howiesons Poort of Diepkloof Rock Shelter, we identified a hitherto unknown type of organic residue - a tempering-residue - that sheds light on the processes used for heat treatment in the MSA. This black film on the silcrete surface is an organic tar that contains microscopic fragments of charcoal and formed as a residue during the direct contact of the artefacts with hot embers of green wood. Our results suggest that heat treatment of silcrete was conducted directly using an open fire, similar to those likely used for cooking. These findings add to the discussion about the complexity of MSA behaviour and appear to contradict previous studies that had suggested that heat treatment of silcrete was a complex (i.e., requiring a large number of steps for its realization) and resource-consuming procedure.

  4. Combined heating and chemical treatment for oil recovery from aging crude oil.

    PubMed

    Hou, Chunjuan; Jiang, Qingzhe; Song, Zhaozheng; Tan, Guorong; Shi, Zhan

    2016-07-01

    With increasing use of chemical oil displacement agents in tertiary recovery and the application of various demulsifiers for crude oil dehydration, a large amount of aging crude oil containing a high ratio of water is produced, and it is very difficult for processing and utilisation. In this article, we chose aging crude oil samples from a union station in an oilfield in China. Sample composition was analysed to demonstrate that the key of aging crude oil dehydration is the removal of solid impurities. Thus, an efficient method of combining heating and chemical treatments was developed to treat aging crude oil. It includes two steps: The first step is washing of aging crude oil with hot water with sodium dodecylbenzene sulfonate; the second step is chemical demulsification of the above mixture with hydrochloric acid and sodium chloride solution. The result showed that 2.9% of solid impurities and 29.2% of water were removed in the first step; 27.2% of oil, 24.3% of water, and 3.47% of solid impurities in the aging crude oil were recycled in the second step. A total 87.07% of aging crude oil could be solved with this method. The present two-step treatment method can ensure that the dehydration process runs normally and efficiently in the union station, making it a promising method in the recycling of aging crude oil.

  5. Developing a two-step heat treatment for inactivating desiccation-adapted Salmonella spp. in aged chicken litter.

    PubMed

    Chen, Zhao; Wang, Hongye; Jiang, Xiuping

    2015-02-01

    The effectiveness of a two-step heat treatment for eliminating desiccation-adapted Salmonella spp. in aged chicken litter was evaluated. The aged chicken litter with 20, 30, 40, and 50% moisture contents was inoculated with a mixture of four Salmonella serotypes for a 24-h adaptation. Afterwards, the inoculated chicken litter was added into the chicken litter with the adjusted moisture content for a 1-h moist-heat treatment at 65 °C and 100% relative humidity inside a water bath, followed by a dry-heat treatment in a convection oven at 85 °C for 1 h to the desired moisture level (<10-12%). After moist-heat treatment, the populations of Salmonella in aged chicken litter at 20 and 30% moisture contents declined from ≈6.70 log colony-forming units (CFU)/g to 3.31 and 3.00 log CFU/g, respectively. After subsequent 1-h dry-heat treatment, the populations further decreased to 2.97 and 2.57 log CFU/g, respectively. Salmonella cells in chicken litter with 40% and 50% moisture contents were only detectable by enrichment after 40 and 20 min of moist-heat treatment, respectively. Moisture contents in all samples were reduced to <10% after a 1-h dry-heat process. Our results demonstrated that the two-step heat treatment was effective in reducing >5.5 logs of desiccation-adapted Salmonella in aged chicken litter with moisture content at or above 40%. Clearly, the findings from this study may provide the chicken litter processing industry with an effective heat treatment method for producing Salmonella-free chicken litter.

  6. Effects of double aging heat treatment on the microstructure, Vickers hardness and elastic modulus of Ti-Nb alloys

    SciTech Connect

    Lopes, E.S.N.; Cremasco, A.; Afonso, C.R.M.; Caram, R.

    2011-07-15

    Aging heat treatment can be a good way to optimize mechanical properties, changing the microstructure, and hence, the mechanical behavior of Ti alloys. The effects of aging heat treatments on {beta}-type Ti-30Nb alloy were investigated to evaluate the kinetics of {alpha}'' {yields} {alpha} + {beta} transformation. The results obtained from differential scanning calorimetry and high-temperature X-ray diffraction experiments indicated the complete decomposition of orthorhombic {alpha}'' phase at close to 300 deg. C, followed by {alpha} phase precipitation at 470 deg. C. The aging heat treatments also enabled us to observe a transformation sequence {alpha}'' {yields} {beta} + {omega} {yields} {beta} + {omega} + {alpha}, indicating martensite decomposition and {omega} phase precipitation at 260 deg. C after 2 h, followed by {alpha} phase nucleation after heating at 400 deg. C for 1 h. The elastic modulus and Vickers hardness of Ti-30Nb alloy were found to be very sensitive to the microstructural changes caused by heat treatment. - Highlights: {yields} DSC and XRD shed light on the {alpha}'' decomposition and nucleation of {omega} and {alpha} phases. {yields} Aging allows for {alpha}''{yields}{beta} transformation and nucleation of {omega} dispersed in the {beta} matrix. {yields} During aging, {alpha}'' interplanar distances are reduced to enable {beta} phase nucleation. {yields} Mechanical behavior is dependent on the microstructure and the phases in the alloy. {yields} It is not possible to obtain high strength and low elastic modulus by applying aging.

  7. Influence of homogenization and artificial aging heat treatments on corrosion behavior of Mg-Al alloys

    SciTech Connect

    Beldjoudi, T.; Fiaud, C.; Robbiola, L. . Lab. d'Etudes de la Corrosion)

    1993-09-01

    The influence of heat treatment on corrosion behavior of magnesium-aluminum (Mg-9Al) alloys was investigated by studying the electrochemical properties of Mg-9Al in the solution-treated (T4) and artificially aged (T6) conditions. The alloys' properties were compared to those of pure Mg, the intermetallic Mg[sub 17]Al[sub 12] phase, and different Mg-Al-based alloys (Mg-3Al, AZ91). The Mg-9Al alloy exhibited better corrosion resistance in the T6 condition than in the T4 condition because of the intermetallic Mg[sub 17]Al[sub 12] precipitates present n the T6 alloy. The mechanism responsible for this behavior was attributed to a more protective porous film on the T6 matrix alloy than on the T4 alloy. Addition of zinc did not modify these results. Localized corrosion testing showed the Mg-Al alloys were attacked preferentially in relation to magnesium silicide (Mg[sub 2]Si) precipitates which were characterized clearly using metallurgical examinations.

  8. Ti-Mo alloys employed as biomaterials: effects of composition and aging heat treatment on microstructure and mechanical behavior.

    PubMed

    Cardoso, Flavia F; Ferrandini, Peterson L; Lopes, Eder S N; Cremasco, Alessandra; Caram, Rubens

    2014-04-01

    The correlation between the composition, aging heat treatments, microstructural features and mechanical properties of β Ti alloys is of primary significance because it is the foundation for developing and improving new Ti alloys for orthopedic biomaterials. However, in the case of Ti-Mo alloys, this correlation is not fully described in the literature. Therefore, the purpose of this study was to experimentally investigate the effect of composition and aging heat treatments on the microstructure, Vickers hardness and elastic modulus of Ti-Mo alloys. These alloys were solution heat-treated and water-quenched, after which their response to aging heat treatments was investigated. Their microstructure, Vickers hardness and elastic modulus were evaluated, and the results allow us to conclude that stabilization of the β phase is achieved with nearly 10% Mo when a very high cooling rate is applied. Young's modulus was found to be more sensitive to phase variations than hardness. In all of the compositions, the highest hardness values were achieved by aging at 723K, which was attributed to the precipitation of α and ω phases. All of the compositions aged at 573K, 623K and 723K showed overaging within 80h.

  9. Effect of Double Aging Heat Treatment on the Short-Term Creep Behavior of the Inconel 718

    NASA Astrophysics Data System (ADS)

    Caliari, Felipe Rocha; Candioto, Kátia Cristiane Gandolpho; Couto, Antônio Augusto; Nunes, Carlos Ângelo; Reis, Danieli Aparecida Pereira

    2016-06-01

    This research studies the effect of double aging heat treatment on the short-term creep behavior of the superalloy Inconel 718. The superalloy, received in the solution treated state, was subjected to an aging treatment which comprises a solid solution at 1095 °C for 1 h, a first aging step of 955 °C for 1 h, then aged at 720 and 620 °C, 8 h each step. Creep tests at constant load mode, under temperatures of 650, 675, 700 °C and stress of 510, 625 and 700 MPa, were performed before and after heat treatment. The results indicate that after the double aging heat treatment creep resistance is increased, influenced by the presence of precipitates γ' and γ″ and its interaction with the dislocations, by grain size growth (from 8.20 to 7.23 ASTM) and the increase of hardness by approximately 98%. Creep parameters of primary and secondary stages have been determined. There is a breakdown relationship between dot{\\upvarepsilon }_{{s}} and stress at 650 °C of Inconel 718 as received, around 600 MPa. By considering the internal stress values, effective stress exponent, effective activation energy, and TEM images of Inconel 718 double aged, it is suggested that the creep mechanism is controlled by the interaction of dislocations with precipitates. The fracture mechanism of Inconel 718 as received is transgranular (coalescence of dimples) and mixed (transgranular-intergranular), whereas the Inconel 718 double aged condition crept surfaces evidenced the intergranular fracture mechanism.

  10. Characterization of Retrogression and Re-Aging Heat Treatment of AA7075-T6 Using Nonlinear Acoustics and Eddy Current

    SciTech Connect

    Ananthula, Rajeshwar; Ko, Ray T.; Sathish, Shamachary; Blodgett, Mark

    2004-02-26

    Nonlinear acoustic parameter and eddy current methods have been utilized to characterize the heat treatment process of retrogression and re-aging of aluminum 7075-T6. The results of nonlinear acoustic parameter measurements show two distinct peaks at 30 minutes and 45 minutes of retrogression time. The phase of the through-thickness eddy current signal shows a minimum at 42 minutes of retrogression time. Application of combined methods for identifying the optimized properties in the material is discussed.

  11. The effect of ageing and heat treatment on microstructure evolution of a commercial cement paste

    NASA Astrophysics Data System (ADS)

    Sabeur, Hassen; Platret, Gérard; Vincent, Julien

    2017-03-01

    This paper reports the microstructural changes on a 2 year-old cement paste, unprotected from contact with air, heated to various temperature regimes up to 1000 °C in steps of 100 °C for a constant period of 6 h. This work has been carried out using a thermal analysis technique and XRD. The parameter involved in this study is the state of the samples: powdered samples and blocks of paste. As a result, it is possible to monitor the major features of the experiments, i.e. the phase's existence domains and their growing of hydrated calcium silicate, portlandite, calcite as well as their decaying: alite, belite and lime. The result shows higher amounts of portlandite and carbonate calcium for the aged cement paste compared to fresh OPC. The carbonation is more marked for the blocks of paste while the crystallinity degree is higher for the powdered cement paste samples. The new portlandite formed during cooling continues to exist until the 1000 °C temperature plateau. Nevertheless, this portlandite is less crystalline than the original one, and its temperature of thermal decomposition gets lower. An increase in the total weight loss and in the crystallinity at 900 and 1000 °C, compared to 800 °C is also noted. The CSH dehydration to β-C2S and C3S become significant above 600 °C and the corresponding rate increases with increasing temperature.

  12. Effects of aging treatment and heat input on the microstructures and mechanical properties of TIG-welded 6061-T6 alloy joints

    NASA Astrophysics Data System (ADS)

    Peng, Dong; Shen, Jun; Tang, Qin; Wu, Cui-ping; Zhou, Yan-bing

    2013-03-01

    Aging treatment and various heat input conditions were adopted to investigate the microstructural evolution and mechanical properties of TIG welded 6061-T6 alloy joints by microstructural observations, microhardness tests, and tensile tests. With an increase in heat input, the width of the heat-affected zone (HAZ) increases and grains in the fusion zone (FZ) coarsen. Moreover, the hardness of the HAZ decreases, whereas that of the FZ decreases initially and then increases with an increase in heat input. Low heat input results in the low ultimate tensile strength of the welded joints due to the presence of partial penetrations and pores in the welded joints. After a simple artificial aging treatment at 175°C for 8 h, the microstructure of the welded joints changes slightly. The mechanical properties of the welded joints enhance significantly after the aging process as few precipitates distribute in the welded seam.

  13. Effect of Change of Aging Heat Treatment Pattern on the JK2LB Jacket for the ITER Central Solenoid

    NASA Astrophysics Data System (ADS)

    Ozeki, Hidemasa; Saito, Toru; Kawano, Katsumi; Takahashi, Yoshikazu; Nunoya, Yoshihiko; Yamazaki, Toru; Isono, Takaaki

    Following the recent improvement of the heat treatment pattern for the ITER CS conductor from 250 hour at 650 °C to 250 hour at 570 °C and then 100 hour at 650 °C, the mechanical properties at 4K and the material structure of the conductor jacketmade of JK2LB after heat treatment including the 570 °C phasewere studied. The mechanical test results at 4K showed no noticeable difference with the jacket heat-treated only at 650 °C to the one additionally heat-treatedat 570 °C.Both satisfied the ITER requirement. The metallographic test results also did not show large difference. In conclusion the 570 °C step does not affect noticeably the JK2LB jacket and the improved heat treatment pattern is applicable.

  14. Heat treatment furnace

    SciTech Connect

    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.

  15. Effects of aging and heat treatment on whole yeast cells and yeast cell walls and on adsorption of ochratoxin A in a wine model system.

    PubMed

    Nunez, Y P; Pueyo, E; Carrascosa, A V; Martínez-Rodríguez, A J

    2008-07-01

    A wine model was evaluated to determine the influence of aging on the ability of whole yeast cells (WY) and yeast cell walls (YCW) to remove ochratoxin A (OTA). Aging and autolysis were monitored for 214 h in the model wine. The original concentration of OTA in the model wine was 10 microg/liter, and WY and YCW were added at a final concentration of 1 g/liter. YCW mannoproteins were involved in the removal of OTA from the model wine through adsorption mechanisms. Aging affected the capacity of WY to remove OTA, but YCW removal capacity remained constant during aging. A previous heat treatment (85 degrees C for 10 min) of WY and YCW increased their removal capacity and increased the efficiency of the decontamination process.

  16. Single Point Incremental Forming of an Aged AL-Cu-Mg Alloy: Influence of Pre-heat Treatment and Warm Forming

    NASA Astrophysics Data System (ADS)

    Mohammadi, Amirahmad; Qin, Ling; Vanhove, Hans; Seefeldt, Marc; Van Bael, Albert; Duflou, Joost R.

    2016-06-01

    This research is aimed at enhancing the poor room temperature formability of heat-treatable aluminum alloy AA2024-T3, without deterioration of its post-forming properties. For this purpose, the influences of different heat-treatment conditions as well as warm forming on the single point incremental forming formability and post-forming properties of this material were investigated. Thermal pre-treatments were consisting of annealing (O-temper), solution treating and quenching (W-temper), and solution heat treating, quenching, and then cold working (T-temper). The formability results as well as forming forces of pre-heat-treated sheets were compared to those of the warm forming process results carried out using a laser-assisted single point incremental forming (LASPIF) setup. The post-forming properties of SPIF-formed parts were analyzed by hardness testing. The maximum forming angles of the blank formed under O-temper and W-temper conditions showed, respectively, 41 and 32% increases compared to the one under T-temper condition. LASPIF forming of this material at a temperature of about 360 °C resulted in 41% improvement in the maximum forming angle with respect to parts formed at room temperature from the T-temper sheet. The hardness of the material reduced significantly after annealing, while SPIF parts formed from W-temper blanks and under LASPIF condition regained their hardness after natural aging. The fracture surface characteristics of the failed parts showed that voids nucleate at the interface between intermetallic particles and matrix, and a dimple rupture fracture mode was identified under all heat-treatment conditions. Under O-temper condition, due to precipitation of particles along the grain boundary, an intergranular dimple rupture was observed. Finally, Energy dispersive x-ray (EDX) and electron backscattered diffraction (EBSD) were used to investigate the possible effects of the heat treatment and the deformation on the changes in the composition of

  17. Microstructural evolution and the variation of tensile behavior after aging heat treatment of precipitation hardened martensitic steel

    SciTech Connect

    Shin, Jong-Ho; Jeong, JaeSuk; Lee, Jong-Wook

    2015-01-15

    The effects of aging temperature on the microstructural evolution and the tensile behavior of precipitation hardened martensitic steel were investigated. Microscopic analysis using transmission electron microscope (TEM) was combined with the microstructural analysis using the synchrotron X-ray diffraction (XRD) to characterize the microstructural evolution with aging temperature. Peak hardness was obtained by precipitation of the Ni{sub 3}Al ordered phase. After aging at temperature range from 420 to 590 °C, spherical Ni{sub 3}Al precipitates and ellipsoidal M{sub 23}C{sub 6} carbides were observed within laths and at lath boundaries, respectively. Strain hardening behavior was analyzed with Ludwik equation. It is observed that the plastic strain regimes can be divided into two different stages by a rapid increase in strain hardening followed by a comparatively lower increase. At the first strain hardening stage, the aged specimen exhibited higher strain hardening exponent than the as-quenched specimen, and the exponent in the aged specimen was not changed considerably with increasing aging temperature. It is revealed that the strain hardening exponents at the first and the second stages were associated with the Ni{sub 3}Al precipitates and the domain size representing the coherent scattering area, respectively. - Highlights: • All of aged specimen exhibited higher strain hardening exponent than the as-quenched specimen at the first stage. • The value of strain hardening exponent in the aged specimen was nearly constant with aging temperature. • Ni{sub 3}Al precipitation dominantly influenced to the increase of strain hardening exponent at the first strain hardening stage. • Domain size was associated with strain hardening exponent at the second strain hardening stage.

  18. Heat treatment of investment cast PH 13-8 Mo stainless steel; Part 2: Isothermal aging kinetics

    SciTech Connect

    Robino, C.V.; Cieslak, M.J. . Physical and Joining Metallurgy Dept.); Hochanadel, P.W.; Edwards, G.R. . Dept. of Metallurgical and Materials Engineering)

    1994-04-01

    The hardening response of investment cast PH 13-8 Mo stainless steel has been evaluated by hardness measurements following aging in the temperature range normally specified for this alloy (510 C to 593 C). A new relationship between fraction transformed and hardness was developed, and analysis of the data in terms of the kinetics of precipitation, in a manner similar to that frequently applied to other precipitation-hardenable martensitic steels, yielded low time exponents and a low value for the apparent activation energy. The values of the time exponents were 0.49, 0.37, 0.56, and 0.53 at 510 C, 538 C, 566 C, and 593 C, respectively, and that for the apparent activation energy was 139 kJ/mole. As has been proposed for other maraging type steels, these estimates suggest that [beta]-NiAl precipitates along or near dislocations and that growth of the precipitates is dominated by dislocation pipe diffusion. However, these predictions were neither supported nor refuted by transmission electron microscopy (TEM) because of difficulties in imaging the [beta]-NiAl precipitates at the aging times and temperatures used. Further, analysis of the data using the formalism of Wert and Zener for the growth of precipitates with interfering diffusion fields indicated that the estimates of fraction transformed from hardness data are not fully appropriate for maraging type steels. Consideration of the nature of the Avrami analysis and the electron microscopy results suggests that other phenomena, including dislocation recovery and reversion of martensite to austenite, occur at rates sufficient to convolute the Avrami analysis. It is further suggested that these results cast doubt on the fundamental implications of previous analyses of precipitation kinetics in age-hardening martensitic steels.

  19. Heat treatment of investment cast PH 13-8 Mo stainless steel: Part II. Isothermal aging kinetics

    NASA Astrophysics Data System (ADS)

    Robino, C. V.; Cieslak, M. J.; Hochanadel, P. W.; Edwards, G. R.

    1994-04-01

    The hardening response of investment cast PH 13-8 Mo stainless steel has been evaluated by hardness measurements following aging in the temperature range normally specified for this alloy (510 °C to 593 °C). A new relationship between fraction transformed and hardness was developed, and analysis of the data in terms of the kinetics of precipitation, in a manner similar to that frequently applied to other precipitation-hardenable martensitic steels, yielded low time exponents and a low value for the apparent activation energy. The values of the time exponents were 0.49, 0.37, 0.56, and 0.53 at 510 °C, 538 °C, 566 °C, and 593 °C, respectively, and that for the apparent activation energy was 139 kJ/mole. As has been proposed for other maraging type steels, these estimates suggest that Β-NiAl precipitates along or near dislocations and that growth of the precipitates is dominated by dislocation pipe diffusion. However, these predictions were neither supported nor refuted by transmission electron microscopy (TEM) because of difficulties in imaging the Β-NiAl precipitates at the aging times and temperatures used. Further, analysis of the data using the formalism of Wert and Zener for the growth of precipitates with interfering diffusion fields indicated that the estimates of fraction transformed from hardness data are not fully appropriate for maraging type steels. Consideration of the nature of the Avrami analysis and the electron microscopy results suggests that other phenomena, including dislocation recovery and reversion of martensite to austenite, occur at rates sufficient to convolute the Avrami analysis. It is further suggested that these results cast doubt on the fundamental implications of previous analyses of precipitation kinetics in age-hardening martensitic steels. Although the Avrami analysis was found not to provide a tenable description of the precipitation kinetics, it does provide a reasonable methodology for portrayal of the hardening response

  20. Performance of weld repairs on service-aged 2{1/4}Cr-1Mo girth weldments utilizing conventional postweld heat treatment and temper-bead repair techniques

    SciTech Connect

    Gandy, D.W.; Viswanathan, R.; Findlan, S.J.

    1996-06-01

    Weld repair of service-damaged piping and header girth weldments has generated considerable interest within the fossil power plant arena over the past few years. The interest has stemmed in part from recent revisions to the National Board Inspection Code regarding welding repair of Cr-Mo steels and from the fact that many domestic utility power plants are nearing the end of their projected design life. EPRI is addressing a number of concerns expressed by utilities surrounding weld repair under a joint EPRI/utility program RP3484-01. The program is focused on procuring service-aged piping and header girth weldments, quantifying the level of damage associated with those weldments, performing weld repairs within the girth weldment region, testing the repair weldment mechanically and metallurgically, and comparing the increase or decrease in remaining life associated with the weld repair. This paper discusses four industry case histories along with two piping girth weld repairs performed under the EPRI program: (1) a repair performed with conventional postweld heat treatment and (2) a repair performed employing temper-bead welding repair technology.

  1. Hyperbaric post weld heat treatment

    SciTech Connect

    Saunderson, S.; Waller, D.

    1983-05-01

    This paper describes a sub-sea hyperbaric Post Weld Heat Treatment (PWHT) system developed jointly by SHELL UK EXPLORATION and PRODUCTION and COMEX DIVING. It discusses: assessment of power requirements and equipment, initial tests conducted in the COMEX hydrosphere and in shallow water in Marseille, and full scale North Sea trials at - 150 m, comparing the performance and results of two separate power sources and control units. Particular attention is drawn to the importance of the elements, insulation and controls used to achieve uniform distribution of heat at the required temperature in a HELIOX environment.

  2. Heat waves, aging, and human cardiovascular health.

    PubMed

    Kenney, W Larry; Craighead, Daniel H; Alexander, Lacy M

    2014-10-01

    This brief review is based on a President's Lecture presented at the Annual Meeting of the American College of Sports Medicine in 2013. The purpose of this review was to assess the effects of climate change and consequent increases in environmental heat stress on the aging cardiovascular system. The earth's average global temperature is slowly but consistently increasing, and along with mean temperature changes come increases in heat wave frequency and severity. Extreme passive thermal stress resulting from prolonged elevations in ambient temperature and prolonged physical activity in hot environments creates a high demand on the left ventricle to pump blood to the skin to dissipate heat. Even healthy aging is accompanied by altered cardiovascular function, which limits the extent to which older individuals can maintain stroke volume, increase cardiac output, and increase skin blood flow when exposed to environmental extremes. In the elderly, the increased cardiovascular demand during heat waves is often fatal because of increased strain on an already compromised left ventricle. Not surprisingly, excess deaths during heat waves 1) occur predominantly in older individuals and 2) are overwhelmingly cardiovascular in origin. Increasing frequency and severity of heat waves coupled with a rapidly growing at-risk population dramatically increase the extent of future untoward health outcomes.

  3. Heat shock proteins and Drosophila aging

    PubMed Central

    Tower, John

    2010-01-01

    Since their discovery in Drosophila, the heat shock proteins (Hsps) have been shown to regulate both stress resistance and life span. Aging is characterized by increased oxidative stress and the accumulation of abnormal (malfolded) proteins, and these stresses induce Hsp gene expression through the transcription factor HSF. In addition, a subset of Hsps is induced by oxidative stress through the JNK signaling pathway and the transcription factor Foxo. The Hsps counteract the toxicity of abnormal proteins by facilitating protein refolding and turnover, and through other mechanisms including inhibition of apoptosis. The Hsps are up-regulated in tissue-specific patterns during aging, and their expression correlates with, and sometimes predicts, life span, making them ideal biomarkers of aging. The tools available for experimentally manipulating gene function and assaying healthspan in Drosophila provides an unparalleled opportunity to further study the role of Hsps in aging. PMID:20840862

  4. Heat shock proteins and Drosophila aging.

    PubMed

    Tower, John

    2011-05-01

    Since their discovery in Drosophila, the heat shock proteins (Hsps) have been shown to regulate both stress resistance and life-span. Aging is characterized by increased oxidative stress and the accumulation of abnormal (malfolded) proteins, and these stresses induce Hsp gene expression through the transcription factor HSF. In addition, a subset of Hsps is induced by oxidative stress through the JNK signaling pathway and the transcription factor Foxo. The Hsps counteract the toxicity of abnormal proteins by facilitating protein refolding and turnover, and through other mechanisms including inhibition of apoptosis. The Hsps are up-regulated in tissue-specific patterns during aging, and their expression correlates with, and sometimes predicts, life span, making them ideal biomarkers of aging. The tools available for experimentally manipulating gene function and assaying healthspan in Drosophila provides an unparalleled opportunity to further study the role of Hsps in aging.

  5. 29 CFR 1919.80 - Heat treatment.

    Code of Federal Regulations, 2010 CFR

    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...

  6. 29 CFR 1919.36 - Heat treatment.

    Code of Federal Regulations, 2010 CFR

    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...

  7. 29 CFR 1919.36 - Heat treatment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 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...

  8. 29 CFR 1919.80 - Heat treatment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 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...

  9. Heat Treatment Procedure Qualification for Steel Castings

    SciTech Connect

    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.

  10. Heat Treatment Procedure Qualification for Steel Castings

    SciTech Connect

    Voigt, Robert C.; Charles, Mariol; Deskevich, Nicholas; Varkey, Vipin; Wollenburg, Angela

    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.

  11. 29 CFR 1919.16 - Heat treatment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Heat treatment. 1919.16 Section 1919.16 Labor Regulations...) GEAR CERTIFICATION Certification of Vessels' Cargo Gear § 1919.16 Heat treatment. (a) All chains (other... material other than wrought iron or steel shall be heat treated when necessary in accordance with §...

  12. Cholesterol transformations during heat treatment.

    PubMed

    Derewiaka, D; Molińska née Sosińska, E

    2015-03-15

    The aim of the study was to characterise products of cholesterol standard changes during thermal processing. Cholesterol was heated at 120°C, 150°C, 180°C and 220°C from 30 to 180 min. The highest losses of cholesterol content were found during thermal processing at 220°C, whereas the highest content of cholesterol oxidation products was observed at temperature of 150°C. The production of volatile compounds was stimulated by the increase of temperature. Treatment of cholesterol at higher temperatures i.e. 180°C and 220°C led to the formation of polymers and other products e.g. cholestadienes and fragmented cholesterol molecules. Further studies are required to identify the structure of cholesterol oligomers and to establish volatile compounds, which are markers of cholesterol transformations, mainly oxidation.

  13. Heat treatment of expressed breast milk is a feasible option for feeding HIV-exposed, uninfected children after 6 months of age in rural Zimbabwe.

    PubMed

    Mbuya, Mduduzi N N; Humphrey, Jean H; Majo, Florence; Chasekwa, Bernard; Jenkins, Alison; Israel-Ballard, Kiersten; Muti, Monica; Paul, Keriann H; Madzima, Rufaro C; Moulton, Lawrence H; Stoltzfus, Rebecca J

    2010-08-01

    In the context of a prevention of mother to child transmission of HIV program promoting exclusive breast-feeding (EBF) to 6 mo and offering HIV-PCR testing at approximately 6 mo, we ascertained the feasibility of expressing and heat-treating (EHT) all breast milk fed to HIV-exposed, uninfected infants following 6 mo of EBF. Twenty mother-baby pairs were enrolled from a hospital in rural Zimbabwe. Research nurses provided lactation, EHT, and complementary feeding counseling through 21 home visits conducted over an 8-wk period and collected quantitative and qualitative data on the mothers' EHT experiences, children's diets, and anthropometric measurements. Mothers kept daily logs of EHT volumes and direct breast-feeding episodes. Mothers successfully initiated and sustained EHT for 4.5 mo (range, 1-11 mo), feeding 426 +/- 227 mL/d (mean +/- SD). By wk 2 of follow-up, children were receiving EHT and Nutributter-enriched complementary foods that satisfied 100% of their energy requirements. During the 8-wk follow-up period, no growth faltering was experienced [changes in weight-for-age, weight-for-length, and length-for-age Z scores = +0.03 +/- 0.50; +0.77 +/- 1.59; and +0.02 +/- 0.85 (mean +/- SD), respectively]. Stigma was not a major deterrent, likely due to a social marketing campaign for EBF that promoted EHT as a practice to sustain breast-feeding for all women. This study provides evidence that resource-poor rural women can initiate and sustain EHT given family and health systems support. EHT provides a strategy for improving the diets of HIV-exposed but uninfected children after direct breast-feeding has ceased.

  14. Avoiding Aging? Social Psychology's Treatment of Age

    ERIC Educational Resources Information Center

    Barrett, Anne E.; Redmond, Rebecca; von Rohr, Carmen

    2012-01-01

    Population aging, in conjunction with social and cultural transformations of the life course, has profound implications for social systems--from large-scale structures to micro-level processes. However, much of sociology remains fairly quiet on issues of age and aging, including the subfield of social psychology that could illuminate the impact of…

  15. HEAT TREATMENT OF ELECTROPLATED URANIUM

    DOEpatents

    Hoglund, P.F.

    1958-07-01

    A method is described for improving electroplated coatings on uranium. Such coatings are often porous, and in an effort to remedy this, the coatings are heat treated by immersing the coated specimen ln a bath of fused salt or molten methl. Since the hase metal, uranium, is an active metal, such a procedure often results in reactions between the base metal and the heating medium. This difficulty can be overcome by using liquid organopolysiloxanes as the heating medium.

  16. 29 CFR 1919.16 - Heat treatment.

    Code of Federal Regulations, 2010 CFR

    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...

  17. Heat Treatment of Friction-Stir-Welded 7050 Aluminum Plates

    NASA Technical Reports Server (NTRS)

    Petter, George E.; Figert, John D.; Rybicki, Daniel J.; Burns, Timothy

    2006-01-01

    A method of heat treatment has been developed to reverse some of the deleterious effects of friction stir welding of plates of aluminum alloy 7050. This alloy is considered unweldable by arc and high-energy-density beam fusion welding processes. The alloy can be friction stir welded, but as-welded workpieces exhibit low ductility, low tensile and yield strengths, and low resistance to stress corrosion cracking. Heat treatment according to the present method increases tensile and yield strengths, and minimizes or eliminates stress corrosion cracking. It also increases ductility. This method of heat treatment is a superior alternative to a specification-required heat treatment that caused the formation of large columnar grains, which are undesired. Workpieces subjected to the prior heat treatment exhibited elongations <2 percent, and standard three-point bend specimens shattered. The development of the present heat treatment method was guided partly by the principles that (1) by minimizing grain sizes and relieving deformation stresses, one can minimize or eliminate stress corrosion cracking and (2) the key to maximizing strength and eliminating residual stresses is to perform post-weld solution heating for as long a time as possible while incurring little or no development of large columnar grains in friction stir weld nuggets. It is necessary to perform some of the solution heat treatment (to soften the alloy and improve machine welding parameters) before welding. The following is an example of thickness- dependent pre- and post-weld heat treatments according to the present method: For plates 0.270 in. (approx.6.86 mm) thick milled from plates 4.5 in. (114.3 mm) thick, perform pre-weld solution heating at 890 F (477 C) for 1 hour, then cool in air. After friction stir welding, perform solution heating for 10 minutes, quench, hold at room temperature for 96 hours, then age at 250 F (121 C) for 5 hours followed by 325 F (163 C) for 27 hours.

  18. Pre-weld heat treatment improves welds in Rene 41

    NASA Technical Reports Server (NTRS)

    Prager, M.

    1968-01-01

    Cooling of Rene 41 prior to welding reduces the incidence of cracking during post-weld heat treatment. The microstructure formed during the slow cooling rate favors elevated temperature ductility. Some vestiges of this microstructure are apparently retained during welding and thus enhance strain-age crack resistance in air.

  19. Heat treatment procedure to increase ductility of degraded nickel alloy

    NASA Technical Reports Server (NTRS)

    Prager, M.

    1968-01-01

    Tests demonstrate the room temperature ductility of degraded Rene 41 can be increased to acceptable values by solution heat treatment at a temperature of 2050 degrees to 2150 degrees F /1 to 2 hours/ and cooling through a controlled temperature range followed by normal aging in air /16 hours at 1400 degrees F/.

  20. The Effects of Heat Treatment and Microstructure Variations on Disk Superalloy Properties at High Temperature

    NASA Technical Reports Server (NTRS)

    Gabb, Timothy P.; Gayda, John; Telesman, Jack; Garg, Anita

    2008-01-01

    The effects of heat treatment and resulting microstructure variations on high temperature mechanical properties were assessed for a powder metallurgy disk superalloy LSHR. Blanks were consistently supersolvus solution heat treated and quenched at two cooling rates, than aged at varying temperatures and times. Tensile, creep, and dwell fatigue crack growth tests were then performed at 704 C. Gamma' precipitate microstructures were quantified. Relationships between heat treatment-microstructure, heat treatment-mechanical properties, and microstructure-mechanical properties were assessed.

  1. Maraging superalloys and heat treatment processes

    DOEpatents

    Korenko, Michael K.; Gelles, David S.; Thomas, Larry E.

    1986-01-01

    Described herein are nickel-chromium-iron maraging, gamma prime strengthened superalloys containing about 18 to 25 weight percent nickel, about 4 to 8 weight percent chromium, gamma prime forming elements such as aluminum and/or titanium, and a solid solution strengthening element, such as molybdenum. After heat treatment, which includes at least one ausaging treatment and at least one maraging treatment, a microstructure containing gamma prime phase and decomposed Fe-Ni-Cr type martensite is produced.

  2. 49 CFR 179.400-12 - Postweld heat treatment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Postweld heat treatment. 179.400-12 Section 179... and 107A) § 179.400-12 Postweld heat treatment. (a) Postweld heat treatment of the inner tank is not... be attached before postweld heat treatment. Welds securing the following need not be postweld...

  3. 49 CFR 179.220-11 - Postweld heat treatment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Postweld heat treatment. 179.220-11 Section 179... Postweld heat treatment. (a) Postweld heat treatment of the inner container is not a specification requirement. (b) Postweld heat treatment of the cylindrical portions of the outer shell to which the...

  4. What is an anti-aging treatment?

    PubMed

    Gems, David

    2014-10-01

    Key objectives of biogerontology are to understand the biology of aging and to translate scientific insight into interventions that improve late-life health - or anti-aging treatments. In this context, when considering the problem of how to effect translational research, it is useful to have a clear, consensus view on what exactly constitutes an anti-aging treatment. This essay critically assesses the understanding of this concept common among biogerontologists, and proposes a new definition. A current conception of anti-aging treatment imagines a primary cause of aging that is causally upstream of, and the cause of, all age-related pathology. Intervening in this aging process thus protects against the totality of age-related diseases. However, this underlying aging process remains an abstraction. By contrast, what is demonstrable is that interventions in model organisms can improve late-life health and extend lifespan. Furthermore, a safe deduction is that treatments that extend lifespan do so by reducing age-related pathology, both florid and subtle. What is currently identifiable about aging (i.e. senescence) is that it is a very complex disease syndrome, likely involving a number of biological mechanisms. Treatments that substantially extend lifespan must suppress multiple pathologies that otherwise limit lifespan, but whether they suppress the entire aging process remains undemonstrated. A more pragmatic and realistic definition of anti-aging treatment is any preventative approach to reduce late-life pathology, based on the understanding that senescence is a disease syndrome. This definition would encompass preventative approaches aimed at both broad and narrow spectra of age-related pathologies. Its adoption would facilitate translation, since it would shift the emphasis to medical practice, particularly the introduction of preventative approaches. Narrow spectrum anti-aging treatments (e.g. the cardiovascular polypill) could establish a practice that

  5. Aging impairs heat loss, but when does it matter?

    PubMed Central

    Stapleton, Jill M.; Poirier, Martin P.; Flouris, Andreas D.; Boulay, Pierre; Sigal, Ronald J.; Malcolm, Janine

    2014-01-01

    Aging is associated with an attenuated physiological ability to dissipate heat. However, it remains unclear if age-related impairments in heat dissipation only occur above a certain level of heat stress and whether this response is altered by aerobic fitness. Therefore, we examined changes in whole body evaporative heat loss (HE) as determined using whole body direct calorimetry in young (n = 10; 21 ± 1 yr), untrained middle-aged (n = 10; 48 ± 5 yr), and older (n = 10; 65 ± 3 yr) males matched for body surface area. We also studied a group of trained middle-aged males (n = 10; 49 ± 5 yr) matched for body surface area with all groups and for aerobic fitness with the young group. Participants performed intermittent aerobic exercise (30-min exercise bouts separated by 15-min rest) in the heat (40°C and 15% relative humidity) at progressively greater fixed rates of heat production equal to 300 (Ex1), 400 (Ex2), and 500 (Ex3) W. Results showed that HE was significantly lower in middle-aged untrained (Ex2: 426 ± 34; and Ex3: 497 ± 17 W) and older (Ex2: 424 ± 38; and Ex3: 485 ± 44 W) compared with young (Ex2: 472 ± 42; and Ex3: 558 ± 51 W) and middle-aged trained (474 ± 21; Ex3: 552 ± 23 W) males at the end of Ex2 and Ex3 (P < 0.05). No differences among groups were observed during recovery. We conclude that impairments in HE in older and middle-aged untrained males occur at exercise-induced heat loads of ≥400 W when performed in a hot environment. These impairments in untrained middle-aged males can be minimized through regular aerobic exercise training. PMID:25505030

  6. Behavior of Sandstones Under Heat Treatment

    NASA Astrophysics Data System (ADS)

    Keppert, M.; Fořt, J.; Trník, A.; Koňáková, D.; Vejmelková, E.; Pokorný, J.; Svora, P.; Pavlík, Z.; Černý, R.

    2017-04-01

    Knowledge of materials behavior under heat treatment is of high importance in construction and safety engineering; tunnels represent a special field because of their specific safety issues. In the case of fire, tunnel structure and surrounding rock are subjected to extreme temperatures which induces irreversible changes in the material's microstructure and consequently its mechanical properties. Significant portion of the Earth's crust is formed by sandstones; this group of sedimentary rocks is highly variable in structure, composition and engineering properties. Quartz grains (alternatively together with other minerals) form the clastic part of sandstones; the space between clasts is filled by variable amount of cement and matrix which can contain particularly clay minerals, quartz and calcite. The porosity of sandstones is again highly variable from a nearly compact material to a highly porous one. The paper aims to find out and explain differences in response of various kinds of sandstones to heat treatment. The behavior of a representative set of sandstones under heat treatment was studied by TG/DSC, thermodilatometry and residual strength measurement. These experiments were accompanied by SEM and porosimetry measurement. The effect of increased temperature on the compressive strength was found to be crucially dependent on the nature of the cement and matrix present in the individual rock. The rocks with calcite cement which had high initial strength and low porosity were damaged by calcite decomposition. The siliceous sandstones were damaged by cracking due to thermally induced volume changes. In contrary, the strength of the clayey sandstones was even improved after the heat treatment. It can be concluded that behavior of sandstone under heat treatment is controlled by its composition and diagenesis.

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

    DOEpatents

    Vinegar, Harold J.; Nguyen, Scott Vinh

    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.

  8. Aging management guideline for commercial nuclear power plants - heat exchangers

    SciTech Connect

    Booker, S.; Lehnert, D.; Daavettila, N.; Palop, E.

    1994-06-01

    This Aging Management Guideline (AMG) describes recommended methods for effective detection and mitigation of age-related degradation mechanisms in commercial nuclear power plant heat exchangers important to license renewal. The intent of this AMG is to assist plant maintenance and operations personnel in maximizing the safe, useful life of these components. It also supports the documentation of effective aging management programs required under the License Renewal Rule 10 CFR 54. This AMG is presented in a manner that allows personnel responsible for performance analysis and maintenance to compare their plant-specific aging mechanisms (expected or already experienced) and aging management program activities to the more generic results and recommendations presented herein.

  9. Improved Heat Treatment Of Steel Alloy 4340

    NASA Technical Reports Server (NTRS)

    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.

  10. Very high-vacuum heat treatment facility

    NASA Technical Reports Server (NTRS)

    Folkner, W. M.; Moody, M. V.; Richard, J.-P.

    1987-01-01

    A vacuum heat treatment facility, with hot zone dimensions of 12 x 19 x 19 cm, has been designed and constructed at a cost substantially below that of a commercial unit. The design incorporates efficient water cooling and a resistive heating element. A vacuum pressure of 1.5 x 10 to the -8th torr at room temperature has been obtained after baking. The temperature limit is approximately 1900 C. This limit results from the choice of niobium as the hot zone material.

  11. Assessment of NASA Dual Microstructure Heat Treatment Method for Multiple Forging Batch Heat Treatment

    NASA Technical Reports Server (NTRS)

    Gayda, John (Technical Monitor); Lemsky, Joe

    2004-01-01

    NASA dual microstructure heat treatment technology previously demonstrated on single forging heat treat batches of a generic disk shape was successfully demonstrated on a multiple disk batch of a production shape component. A group of four Rolls-Royce Corporation 3rd Stage AE2100 forgings produced from alloy ME209 were successfully dual microstructure heat treated as a single heat treat batch. The forgings responded uniformly as evidenced by part-to-part consistent thermocouple recordings and resultant macrostructures, and from ultrasonic examination. Multiple disk DMHT processing offers a low cost alternative to other published dual microstructure processing techniques.

  12. 7 CFR 305.29 - Vacuum heat treatment schedule.

    Code of Federal Regulations, 2010 CFR

    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...

  13. Effect of heat treatment and heat-to-heat variations in the fatigue-crack growth response of Alloy 718

    SciTech Connect

    James, L A; Mills, W J

    1980-04-01

    The fatigue-crack growth behavior of seven heats of Alloy 718 was studied at five different test temperatures. These seven heats represented at least four different producers, four different product forms, two melt practices, and most of the heats were tested in two different heat-treated conditions. Heat-to-heat variations were noted; these were most obvious in material given the conventional heat treatment. 8 figures, 5 tables.

  14. Effect of heat treatment and heat-to-heat variations in the fatigue-crack growth response of Alloy 718

    SciTech Connect

    James, L.A.; Mills, W.J.

    1980-04-01

    The fatigue-crack growth behavior of seven heats of Alloy 718 was studied at five different test temperatures. These seven heats represented at least four different producers, four different product forms, two melt practices, and most of the heat were tested in two different heat-treated conditions. Heat-to-heat variations were noted; these were most obvious in material given the conventional heat-treatment. 8 figs., 5 tabs.

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

    NASA Astrophysics Data System (ADS)

    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.

  16. 7 CFR 305.25 - Dry heat treatment schedules.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Dry heat treatment schedules. 305.25 Section 305.25 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE PHYTOSANITARY TREATMENTS Heat Treatments § 305.25 Dry heat...

  17. 49 CFR 179.220-11 - Postweld heat treatment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Postweld heat treatment. 179.220-11 Section 179... Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.220-11 Postweld heat treatment. (a) Postweld heat treatment of the inner container is not a specification requirement. (b)...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  19. 49 CFR 179.200-11 - Postweld heat treatment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Postweld heat treatment. 179.200-11 Section 179.200-11 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS... Postweld heat treatment. When specified in § 179.201-1, after welding is complete, postweld heat...

  20. 49 CFR 179.300-10 - Postweld heat treatment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Postweld heat treatment. 179.300-10 Section 179... Specifications for Multi-Unit Tank Car Tanks (Classes DOT-106A and 110AW) § 179.300-10 Postweld heat treatment. After welding is complete, steel tanks and all attachments welded thereto, must be postweld heat...

  1. [Treatment options for age-related infertility].

    PubMed

    Belaisch-Allart, Joëlle

    2010-06-20

    There has been a consistent trend towards delayed childbearing in most Western countries. Treatment options for age-related infertility includes controlled ovarian hyperstimulation with intrauterine insemination and in vitro fertilization (IVF). A sharp decline in pregnancy rate with advancing female age is noted with assisted reproductive technologies (ART) including IVF. Evaluation and treatment of infertility should not be delayed in women 35 years and older. No treatment other than oocyte donation has been shown to be effective for women over 40 and for those with compromised ovarian reserve, but its pratice is not easy in France hence the procreative tourism. As an increasing number of couples choose to postpone childbearing, they should be informed that maternal age is an important risk factor for failure to conceive.

  2. Aging results in an unusual expression of Drosophila heat shock proteins

    SciTech Connect

    Fleming, J.E.; Walton, J.K.; Dubitsky, R.; Bensch, K.G. )

    1988-06-01

    The authors used high-resolution two-dimensional polyacrylamide gel electrophoresis to evaluate the effect of aging on the heat shock response in Drosophila melanogaster. Although the aging process is not well understood at the molecular level, recent observations suggest that quantitative changes in gene expression occur as these fruit flies approach senescence. Such genetic alterations are in accord with our present data, which clearly show marked differences in the synthesis of heat shock proteins between young and old fruit flies. In 10-day-old flies, a heat shock of 20 min results in the expression of 14 new proteins as detectable by two-dimensional electrophoresis of ({sup 35}S)methionine-labeled polypeptides, whereas identical treatment of 45-day-old flies leads to the expression of at least 50 new or highly up-regulated proteins. In addition, there is also a concomitant increase in the rate of synthesis of a number of the normal proteins in the older animals. Microdensitometric determinations of the low molecular weight heat shock polypeptides on autoradiographs of five age groups revealed that their maximum expression occurs at 47 days for a population of flies with a mean life span of 33.7 days. Moreover, a heat shock effect similar to that observed in senescent flies occurs in young flies fed canavanine, an arginine analogue, before heat shock.

  3. Effects of heat treatment on the mechanical properties of SiC p/6061 Al composite

    NASA Astrophysics Data System (ADS)

    Aldun, D.; Martin, P.; Sun, J.

    1992-10-01

    Metal-matrix composites have been receiving considerable attention as light-weight materials for use in many advanced technology applications. Silicon carbide (SiC) particles and whiskers have several advantages over other discontinuous reinforcements. Studies have shown that heat treatment can change the mechanical properties of metal-matrix composites. Modified heat treatments were developed for SiC p/6061 Al composites through a series of heat treatment with varied solution temperatures and aging time. Mechanical tests were conducted to determine the mechanical properties of the composites in three conditions; as-received, annealed, and heat treated. The modified heat treatments resulted in increases in the yield strength of up to 12% over the manufacturer’s reported yield strength for the standard T6 heat treatment. The trends which occur during heat treatment of SiC p/6061 Al are simular to those which occur during heat treatment of aluminum alloys. In addition, the relationship between the mechanical properties and the heat treatment parameters was documented. Throughout this study, the values of elastic modules were rather erratic compared to the strength values. Scanning Electron Microscope fractographic analysis revealed various fracture initiation sites, such as particle clusters and iron inclusions.

  4. Pressurized heat treatment of glass ceramic

    DOEpatents

    Kramer, D.P.

    1984-04-19

    A method of producing a glass-ceramic having a specified thermal expansion value is disclosed. The method includes the step of pressurizing the parent glass material to a predetermined pressure during heat treatment so that the glass-ceramic produced has a specified thermal expansion value. Preferably, the glass-ceramic material is isostatically pressed. A method for forming a strong glass-ceramic to metal seal is also disclosed in which the glass-ceramic is fabricated to have a thermal expansion value equal to that of the metal. The determination of the thermal expansion value of a parent glass material placed in a high-temperature environment is also used to determine the pressure in the environment.

  5. [The golden age of rheumatoid arthritis treatment].

    PubMed

    Mercado, Ulises

    2014-01-01

    Today, we enjoy the golden age of rheumatology. In the 1970s, the paradigm for treating rheumatoid arthritis consisted in a pyramid. In the decade of the 1980s, and shortly after began a revolution in the understanding and treatment of rheumatic diseases. Methotrexate and tumor necrosis factor-blockers came on the scene.

  6. 7 CFR 305.8 - Heat treatment requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 5 2011-01-01 2011-01-01 false Heat treatment requirements. 305.8 Section 305.8 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE PHYTOSANITARY TREATMENTS § 305.8 Heat treatment requirements....

  7. 7 CFR 305.8 - Heat treatment requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Heat treatment requirements. 305.8 Section 305.8 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE PHYTOSANITARY TREATMENTS § 305.8 Heat treatment requirements....

  8. 49 CFR 179.100-10 - Postweld heat treatment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Postweld heat treatment. 179.100-10 Section 179...-10 Postweld heat treatment. (a) After welding is complete, steel tanks and all attachments welded... treatment is prohibited. (c) Tank and welded attachments, fabricated from ASTM A 240/A 240M (IBR, see §...

  9. Age-related differences in heat loss capacity occur under both dry and humid heat stress conditions

    PubMed Central

    Larose, Joanie; Boulay, Pierre; Wright-Beatty, Heather E.; Sigal, Ronald J.; Hardcastle, Stephen

    2014-01-01

    This study examined the progression of impairments in heat dissipation as a function of age and environmental conditions. Sixty men (n = 12 per group; 20–30, 40–44, 45–49, 50–54, and 55–70 yr) performed four intermittent exercise/recovery cycles for a duration of 2 h in dry (35°C, 20% relative humidity) and humid (35°C, 60% relative humidity) conditions. Evaporative heat loss and metabolic heat production were measured by direct and indirect calorimetry, respectively. Body heat storage was measured as the temporal summation of heat production and heat loss during the sessions. Evaporative heat loss was reduced during exercise in the humid vs. dry condition in age groups 20–30 (−17%), 40–44 (−18%), 45–49 (−21%), 50–54 (−25%), and 55–70 yr (−20%). HE fell short of being significantly different between groups in the dry condition, but was greater in age group 20–30 yr (279 ± 10 W) compared with age groups 45–49 (248 ± 8 W), 50–54 (242 ± 6 W), and 55–70 yr (240 ± 7 W) in the humid condition. As a result of a reduced rate of heat dissipation predominantly during exercise, age groups 40–70 yr stored between 60–85 and 13–38% more heat than age group 20–30 yr in the dry and humid conditions, respectively. These age-related differences in heat dissipation and heat storage were not paralleled by significant differences in local sweating and skin blood flow, or by differences in core temperature between groups. From a whole body perspective, combined heat and humidity impeded heat dissipation to a similar extent across age groups, but, more importantly, intermittent exercise in dry and humid heat stress conditions created a greater thermoregulatory challenge for middle-aged and older adults. PMID:24812643

  10. Circulating Heat Shock Protein 70 in Health, Aging and Disease

    PubMed Central

    2011-01-01

    Background Heat shock proteins (Hsp) are ubiquitously synthesised in virtually all species and it is hypothesised that they might have beneficial health effects. Recent studies have identified circulating Hsp as an important mediator in inflammation - the effects of low-grade inflammation in the aging process are overwhelming. While much is known about intracellular Hsp70, scant data exist on circulating Hsp70 in the aging context. Therefore, the objectives of this study were to investigate the effect of age and disease on circulating Hsp70 and, in particular, to evaluate the association between circulating Hsp70 and inflammatory parameters. Results Serum Hsp70, Interleukin (IL) -10, IL-6 and Tumor Necrosis Factor (TNF) alpha concentrations were determined in 90 hospitalised geriatric patients (aged 83 ± 6 years) and in 200 community-dwelling control subjects (100 elderly, aged 74 ± 5 years, and 100 young, aged 23 ± 3 years). In the community-dwelling elderly, serum Hsp70 and IL-10 concentrations were significantly lower and IL-6 was significantly higher when compared to healthy young control subjects. Elderly patients presenting inflammation (CRP serum levels ≥5 mg/L) showed significantly (p = 0.007) higher Hsp70 values; and Hsp70 correlated positively (p < 0.001) with IL-6 and CRP, but not with TNF-alpha or IL-10. A significant association was also noted between Hsp70 levels and the degree of dependency and cognitive decline in geriatric patients. Conclusions The present data provide new evidence that serum concentration of Hsp70 decreases with age in a normal population. Our study also shows that higher levels of Hsp70 are associated with inflammation and frailty in elderly patients. PMID:21443787

  11. 9 CFR 590.575 - Heat treatment of dried whites.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... and at such temperatures as will result in salmonella negative product. (a) The product to be heat... less than 7 days and until it is salmonella negative. (2) Pan dried albumen shall be heated throughout... days and until it is salmonella negative. (3) Methods of heat treatment of spray dried or pan...

  12. 9 CFR 590.575 - Heat treatment of dried whites.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... and at such temperatures as will result in salmonella negative product. (a) The product to be heat... less than 7 days and until it is salmonella negative. (2) Pan dried albumen shall be heated throughout... days and until it is salmonella negative. (3) Methods of heat treatment of spray dried or pan...

  13. 9 CFR 590.575 - Heat treatment of dried whites.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... and at such temperatures as will result in salmonella negative product. (a) The product to be heat... less than 7 days and until it is salmonella negative. (2) Pan dried albumen shall be heated throughout... days and until it is salmonella negative. (3) Methods of heat treatment of spray dried or pan...

  14. 9 CFR 590.575 - Heat treatment of dried whites.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... and at such temperatures as will result in salmonella negative product. (a) The product to be heat... less than 7 days and until it is salmonella negative. (2) Pan dried albumen shall be heated throughout... days and until it is salmonella negative. (3) Methods of heat treatment of spray dried or pan...

  15. 9 CFR 590.575 - Heat treatment of dried whites.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... and at such temperatures as will result in salmonella negative product. (a) The product to be heat... less than 7 days and until it is salmonella negative. (2) Pan dried albumen shall be heated throughout... days and until it is salmonella negative. (3) Methods of heat treatment of spray dried or pan...

  16. Detailed Specifications for Global Heat Treatment Sourcing and Materials

    NASA Astrophysics Data System (ADS)

    Sponzilli, Jared; Sponzilli, John

    2013-07-01

    The very nature of global sourcing means that components must carry clear and detailed specifications for material, heat treatment, and test methods. Qualified global heat treat facilities can achieve good control of not only the common features such as surface and gradient hardness, but also of microstructure, core hardness, residual stress, and other critical metallurgical parameters. This paper will discuss a new concept for material specifications and more detailed heat treatment specifications for the global marketplace.

  17. 49 CFR 179.300-10 - Postweld heat treatment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Postweld heat treatment. 179.300-10 Section 179.300-10 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS... Postweld heat treatment. After welding is complete, steel tanks and all attachments welded thereto, must...

  18. 49 CFR 179.400-12 - Postweld heat treatment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.400-12 Postweld heat treatment. (a) Postweld heat treatment of the inner tank is not required. (b)...

  19. 29 CFR 1919.17 - Exemptions from heat treatment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Exemptions from heat treatment. 1919.17 Section 1919.17... from heat treatment. Gear made of steel, or gear which contains (as in ball bearings swivels), or is permanently attached to (as with blocks) equipment made of materials which cannot be subjected to...

  20. 29 CFR 1919.17 - Exemptions from heat treatment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Exemptions from heat treatment. 1919.17 Section 1919.17... from heat treatment. Gear made of steel, or gear which contains (as in ball bearings swivels), or is permanently attached to (as with blocks) equipment made of materials which cannot be subjected to...

  1. Effects of heat treatment parameters on liquid whole egg proteins.

    PubMed

    Uysal, Reyhan Selin; Boyacı, İsmail Hakkı; Soykut, Esra Acar; Ertaş, Nusret

    2017-02-01

    The aim of this study was to analyse the effect of heat treatment parameters on liquid whole egg (LWE) proteins by using ultraviolet-visible (UV-VIS) spectroscopy and capillary electrophoresis (CE). Heat treatment (at 60-68°C for 1-5min) was applied to LWE. Treated LWE was centrifuged and supernatant was taken for measurement of UV-VIS spectroscopy and CE. The change in UV absorbance showed loss of protein solubility depending on heat treatments parameters. Electropherograms of samples demonstrated the effect of treatment parameters on composition of LWE proteins. It was found that conalbumin and lysozyme were influenced by the treatment, while ovalbumin and ovomucoid were not affected. CE combined with principal component analysis (PCA) was used for classification of samples untreated or treated and treated at different treatment parameters. The results of the study revealed that the extent of heat treatment in LWE samples could be determined with PCA of the CE measurements.

  2. Heat treatment of cobalt-chromium alloy wire.

    PubMed

    Fillmore, G M; Tomlinson, J L

    1976-04-01

    This study shows that the ability of cobalt-chromium wire to resist permanent deformation is definitely affected by the temperature of heat treatment. For each temperature of heat treatment up to 1200 degrees F there is progressively greater resistance to permanent deformation; at temperatures of heat treatment above 1200 degrees F, however, there is a rapid decline in resistance to permanent deformation due to partial annealing. The maximum resistance to permanent deformation occurs from heat treatment in the temperature range of 1100 degrees to 1200 degrees F. A clinician desiring maximum resistance to permanent deformation from a .016 inches x .022 inches cobalt-chromium archwire should heat-treat the wire at 1100 degrees to 1200 degrees F for 5 minutes in a dental furnace. If the wire was in a highly work-hardened condition as were the wire specimens of this study, he could expect an increase in resistance to permanent deformation of approximately 174 percent. Heat treatment at lower temperatures could be used in situations requiring less than maximum resistance to permanent deformation. Heat treatment at 900 degrees F would give approximately a 95 percent increase in resistance to permanent deformation. Of course, heat treatment would not be indicated when the desired level of resistance to permanent deformation was not greater than the amount exhibited in the untreated wires of this study. When an electrical resistance heat-treatment unit and 950 degrees F temper-indicating paste were used, the clinician would expect increased resistance to permanent deformation similar to that seen in the wires heat-treated with a dental furnace at 800 degrees and 900 degrees F, i.e., about half of that obtained by the 1200 degrees F treatment. This study has determined the effects that various temperatures of heat treatment have on the resistance to permanent deformation of cobalt-chromium wire specimens which were formed into a specific pattern of loops. The following

  3. Constraints on Pacific midplate swells from global depth-age and heat flow-age models

    NASA Astrophysics Data System (ADS)

    Stein, Carol A.; Stein, Seth

    Oceanic midplate swells are identified by shallow seafloor depths. In turn, models of the processes giving rise to these regions rely on assessments of how their depths, surface heat flow, and flexural properties differ from those for lithosphere which is presumed not to have been affected by these processes. Such comparisons have been inhibited because reference thermal models, which are assumed to describe unperturbed lithosphere, predict deeper depths and lower heat flow than typically observed for lithosphere older than 70 Ma. As a result, both depth and heat flow anomalies can be overestimated. To address this difficulty, we have derived model GDH1 (Global Depth and Heat flow) by joint fitting of heat flow and bathymetry. GDH1, which has a hotter and thinner lithosphere than previous models, fits the depth and heat flow data significantly better, including the data from older lithosphere previously treated as anomalous. It also provides an improved fit to depth-to-basement data for ocean drilling sites, and to geoid offsets across fracture zones. The improved fit occurs for depth-age data from both the DBDB-5 digital bathymetry, and from regional medians from ship tracks, which yield comparable depth-age curves. We use GDH1 to study three classes of midplate swells: the Hawaiian and other hot spot swells, the Darwin Rise area of widespread Cretaceous volcanism, and the Superswell, considered a present analogue to the Darwin Rise. Heat flow on the Hawaiian swell, though anomalously high with respect to previous reference models, is at most slightly high relative to GDH1. The situation is similar for the Bermuda, Cape Verde, and Crozet hot spots. The absence of a significant heat flow anomaly favors a primarily dynamic, rather than thermal, origin for these swells. Similarly, the present depths and heat flow for the Darwin Rise are consistent with GDH1, although they were anomalous with respect to previous reference models. The depth and heat flow data thus

  4. The effect of heat treatment on the morphology of D-Gun sprayed hydroxyapatite coatings.

    PubMed

    Erkmen, Z E

    1999-01-01

    In this study, the morphology of the Hydroxyapatite (HA) coatings sprayed on Ti alloy samples by Detonation Gun Spray (D-Gun) and the effect of aging before and after heat treatment in physiological solution were observed. Cross-sectional porosity and percentages of amorphous and crystal phase were measured using optical, electron microscopy, and X-ray diffraction analysis. Differential Thermogravimetric Analysis (DTA) was performed to estimate the glass-crystalline phase transformation temperatures. Heat-treatment at 300, 500, 700, 800 and 1200 degrees C were carried out to confirm DTA results. As a final analysis, the aging effect using Ringer's solution for 1 week on heat-treated and non-heat-treated samples was measured. It was observed that, in D-Gun sprayed samples, the cross-sectional porosity stayed in the accepted 5% range as reported for other spraying techniques.(1-5) On the other hand, surface porosity measured using the water immersion method remained in the conventional porosity limit of 15% for non-heat-treated samples. Heat-treatment had a small influence on the porosity while the crystallinity increased considerably; in addition, aging had little effect on HA crystallinity for heat treated samples. This work showed that D-gun sprayed HA coatings had lower porosity and better integrity than other coatings, due to which we can expect better performance during in vivo applications.

  5. Age, splanchnic vasoconstriction, and heat stress during tilting

    NASA Technical Reports Server (NTRS)

    Minson, C. T.; Wladkowski, S. L.; Pawelczyk, J. A.; Kenney, W. L.

    1999-01-01

    During upright tilting, blood is translocated to the dependent veins of the legs and compensatory circulatory adjustments are necessary to maintain arterial pressure. For examination of the effect of age on these responses, seven young (23 +/- 1 yr) and seven older (70 +/- 3 yr) men were head-up tilted to 60 degrees in a thermoneutral condition and during passive heating with water-perfused suits. Measurements included heart rate (HR), cardiac output (Qc; acetylene rebreathing technique), central venous pressure (CVP), blood pressures, forearm blood flow (venous occlusion plethysmography), splanchnic and renal blood flows (indocyanine green and p-aminohippurate clearance), and esophageal and mean skin temperatures. In response to tilting in the thermoneutral condition, CVP and stroke volume decreased to a greater extent in the young men, but HR increased more, such that the fall in Qc was similar between the two groups in the upright posture. The rise in splanchnic vascular resistance (SVR) was greater in the older men, but the young men increased forearm vascular resistance (FVR) to a greater extent than the older men. The fall in Qc during combined heat stress and tilting was greater in the young compared with older men. Only four of the young men versus six of the older men were able to finish the second tilt without becoming presyncopal. In summary, the older men relied on a greater increase in SVR to compensate for a reduced ability to constrict the skin and muscle circulations (as determined by changes in FVR) during head-up tilting.

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

    PubMed

    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.

  7. Investigation of anodic oxide coatings on zirconium after heat treatment

    NASA Astrophysics Data System (ADS)

    Sowa, Maciej; Dercz, Grzegorz; Suchanek, Katarzyna; Simka, Wojciech

    2015-08-01

    Herein, results of heat treatment of zirconium anodised under plasma electrolytic oxidation (PEO) conditions at 500-800 °C are presented. The obtained oxide films were investigated by means of SEM, XRD and Raman spectroscopy. The corrosion resistance of the zirconium specimens was evaluated in Ringer's solution. A bilayer oxide coatings generated in the course of PEO of zirconium were not observed after the heat treatment. The resulting oxide layers contained a new sublayer located at the metal/oxide interface is suggested to originate from the thermal oxidation of zirconium. The corrosion resistance of the anodised metal was improved after the heat treatment.

  8. The myocardial heat shock response following sodium salicylate treatment

    PubMed Central

    Locke, Marius; Atance, Joel

    2000-01-01

    In cultured cells, salicylate has been shown to potentiate the induction of Hsp72 so that a mild heat stress (40°C) in the presence of salicylate induces an Hsp72 response that is similar to a severe heat stress (42°C). To determine whether salicylate can potentiate the myocardial Hsp70 response in vivo and confer protection from an ischemic stress, male Sprague-Dawley rats (250–300 g) were placed into 5 groups: (1) control, (2) salicylate only (400 mg/kg), (3) mild heat stress (40°C for 15 minutes), (4) mild heat stress plus salicylate, and (5) severe heat stress (42°C for 15 minutes). Twenty-four hours following salicylate treatment and/or heat stress, animals were anesthetized, their hearts rapidly isolated, and hemodynamic function evaluated using the Langendorff technique. Hsp72 content was subsequently assessed by Western blotting. Although salicylate in combination with a mild heat stress induced heat shock factor activation, only the hearts from severely heat-stressed animals (42°C) demonstrated a significantly elevated myocardial Hsp72 content and a significantly enhanced postischemic recovery of left ventricular developed pressure and rates of contraction and relaxation. These results support the role for Hsp72 as a protective protein and suggest that neither salicylate treatment alone nor salicylate in combination with a mild heat stress potentiates the myocardial Hsp72 response. PMID:11048658

  9. 13. INTERIOR MIDDLE BAY DETAIL VIEW, FACING NORTHWEST. HEAT TREATMENT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. INTERIOR MIDDLE BAY DETAIL VIEW, FACING NORTHWEST. HEAT TREATMENT EQUIPMENT ABANDONED ON SITE. ALSO, TRACKS ALONG EQUIPMENT FOR MOVEMENT OF MATERIAL. - NASA Industrial Plant, Missile Research Laboratory, 12214 Lakewood Boulevard, Downey, Los Angeles County, CA

  10. 49 CFR 179.500-6 - Heat treatment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... III steel. Tempering temperatures shall not be less than 1000 °F. Heat treatment of alternate steels... sound metal by grinding and the surface exposed shall be blended smoothly into the surrounding area....

  11. Age alters the cardiovascular response to direct passive heating

    NASA Technical Reports Server (NTRS)

    Minson, C. T.; Wladkowski, S. L.; Cardell, A. F.; Pawelczyk, J. A.; Kenney, W. L.

    1998-01-01

    During direct passive heating in young men, a dramatic increase in skin blood flow is achieved by a rise in cardiac output (Qc) and redistribution of flow from the splanchnic and renal vascular beds. To examine the effect of age on these responses, seven young (Y; 23 +/- 1 yr) and seven older (O; 70 +/- 3 yr) men were passively heated with water-perfused suits to their individual limit of thermal tolerance. Measurements included heart rate (HR), Qc (by acetylene rebreathing), central venous pressure (via peripherally inserted central catheter), blood pressures (by brachial auscultation), skin blood flow (from increases in forearm blood flow by venous occlusion plethysmography), splanchnic blood flow (by indocyanine green clearance), renal blood flow (by p-aminohippurate clearance), and esophageal and mean skin temperatures. Qc was significantly lower in the older than in the young men (11.1 +/- 0.7 and 7.4 +/- 0.2 l/min in Y and O, respectively, at the limit of thermal tolerance; P < 0. 05), despite similar increases in esophageal and mean skin temperatures and time to reach the limit of thermal tolerance. A lower stroke volume (99 +/- 7 and 68 +/- 4 ml/beat in Y and O, respectively, P < 0.05), most likely due to an attenuated increase in inotropic function during heating, was the primary factor for the lower Qc observed in the older men. Increases in HR were similar in the young and older men; however, when expressed as a percentage of maximal HR, the older men relied on a greater proportion of their chronotropic reserve to obtain the same HR response (62 +/- 3 and 75 +/- 4% maximal HR in Y and O, respectively, P < 0.05). Furthermore, the older men redistributed less blood flow from the combined splanchnic and renal circulations at the limit of thermal tolerance (960 +/- 80 and 720 +/- 100 ml/min in Y and O, respectively, P < 0. 05). As a result of these combined attenuated responses, the older men had a significantly lower increase in total blood flow directed to

  12. Heat Treatment. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

    ERIC Educational Resources Information Center

    Filer, Herb; Broste, Dale

    This lesson was developed for a course in sludge treatment and disposal. The lesson describes the Porteous heat treatment method of sludge conditioning and compares that system to the Zimpro wet air oxidation process. The theory of heat treatment, system of components and functions, and concepts of operation are addressed in the lesson. The…

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    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.

  15. Low temperature catalytic oxidative aging of LDPE films in response to heat excitation.

    PubMed

    Luo, Xuegang; Zhang, Sizhao; Ding, Feng; Lin, Xiaoyan

    2015-09-14

    The waste treatment of polymer materials is often conducted using the photocatalytic technique; however, complete decomposition is frequently inhibited owing to several shortcomings such as low quantum yield and the requirement of ultraviolet irradiation. Herein, we report a strategy to implement moderate management of polymeric films via thermocatalytic oxidative route, which is responsive to heat stimulus. Diverse LDPE-matrix films together with as-prepared thermal catalysts (TCs) or initiators were synthesized to further investigate heat-dependent-catalytic degradation effects. After artificial ageing, structural textures of the as-synthesized films could be chemically deteriorated, followed by a huge increase in surface roughness values, and appreciable loss was also found in the average molecular weights and mechanical parameters. We found an emergent phenomenon in which crystallization closely resembled two-dimensional (2D) growth, which displayed rod-like or disc-type crystal shapes. New chemical groups generated on film surfaces were monitored, and led to a higher limiting oxygen index because of strong catalytic oxidation, thus demonstrating the success of catalytic oxidative ageing by heat actuation. The underlying mechanism responsible for thermocatalytic oxidative pattern is also discussed. Accordingly, these findings may have important implications for better understanding the development of polymeric-matrix waste disposal.

  16. Heat treatments to enhance the safety of mung bean seeds.

    PubMed

    Hu, Haijing; Churey, John J; Worobo, Randy W

    2004-06-01

    Salmonella enterica serovars and Escherichia coli O157:H7 have been associated with contaminated seed sprout outbreaks. The majority of these outbreaks have been traced to sprout seeds contaminated with low levels of pathogens. E. coli O157:H7 strains can grow an average of 2.3 log CFU/g over 2 days during seed germination, and Salmonella can achieve an average growth of 3.7 log CFU/g. Therefore, it is important to find an effective method to reduce possible pathogenic bacterial populations on the seeds prior to sprouting. Our objective was to assess the effectiveness of various dry heat treatments on reducing E. coli O157:H7 and Salmonella populations on mung beans intended for sprout production and to determine the effect of these treatments on seed germination. Mung beans were inoculated with five-strain cocktails of E. coli O157:H7 and of Salmonella serovars harboring the green fluorescent protein gene and then air dried overnight. Heat treatments were performed by incubating the seeds at 55 degrees C for various periods of time. Heat-treated seeds were then assessed for the efficacy of the heat treatment and the effects of heat treatment on germination rates. After inoculation and drying, 6 log CFU/g E. coli O157:H7 and 4 log CFU/g Salmonella were detected on the seeds. Following heat treatment, pathogenic bacterial populations on the seeds were below detectable levels (<1 log CFU/g), but the germination rate of the seed was not affected. Thus, the risk of contamination and the presence of pathogens in the finished sprouts were greatly reduced via the seed heat treatment process.

  17. Acute limb heating improves macro- and microvascular dilator function in the leg of aged humans.

    PubMed

    Romero, Steven A; Gagnon, Daniel; Adams, Amy N; Cramer, Matthew N; Kouda, Ken; Crandall, Craig G

    2017-01-01

    Local heating of an extremity increases blood flow and vascular shear stress throughout the arterial tree. Local heating acutely improves macrovascular dilator function in the upper limbs of young healthy adults through a shear stress-dependent mechanism but has no such effect in the lower limbs of this age group. The effect of acute limb heating on dilator function within the atherosclerotic prone vasculature of the lower limbs of aged adults is unknown. Therefore, the purpose of this study was to test the hypothesis that acute lower limb heating improves macro- and microvascular dilator function within the leg vasculature of aged adults. Nine young and nine aged adults immersed their lower limbs at a depth of ~33 cm into a heated (~42°C) circulated water bath for 45 min. Before and 30 min after heating, macro (flow-mediated dilation)- and microvascular (reactive hyperemia) dilator functions were assessed in the lower limb, following 5 min of arterial occlusion, via Doppler ultrasound. Compared with preheat, macrovascular dilator function was unchanged following heating in young adults (P = 0.6) but was improved in aged adults (P = 0.04). Similarly, microvascular dilator function, as assessed by peak reactive hyperemia, was unchanged following heating in young adults (P = 0.1) but was improved in aged adults (P < 0.01). Taken together, these data suggest that acute lower limb heating improves both macro- and microvascular dilator function in an age dependent manner.

  18. Heat in the treatment of patients with anorexia nervosa.

    PubMed

    Gutierrez, E; Vazquez, R

    2001-03-01

    The paper presents the results of heat treatment in three cases of anorexia nervosa (AN), in which marked overactivity and/or strenuous exercising were prominent clinical features. Heat was supplied in three ways: continuous exposure to a warm environment, wearing a thermal waistcoat, and sauna baths in an infrared cabin. The outcomes went far beyond what had been expected, as the disappearance of hyperactivity was followed by progressive recovery.

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

    ERIC Educational Resources Information Center

    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…

  20. Compositions produced using an in situ heat treatment process

    DOEpatents

    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.

  1. Compositions produced using an in situ heat treatment process

    DOEpatents

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

    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.

  2. Heat treatment study of the SiC/Ti-15-3 composite system

    NASA Technical Reports Server (NTRS)

    Lerch, Bradley A.; Gabb, Timothy P.; Mackay, Rebecca A.

    1990-01-01

    The oxidation and aging behaviors of a continuous fiber SiC/Ti-15V-3Cr-3Sn-3Al composite (SiC/Ti-15-3) were investigated. The aging characteristic of the composite were compared with those of the unreinforced Ti-15-3 matrix material, which was processed in the same manner as the composite. Various age hardened conditions of both the unreinforced matrix and the composite were evaluated by using optical microscopy, hardness measurements, and room temperature tensile tests (unreinforced matrix only). The Ti-15-3 material formed a thick surface oxide at temperature at or above 550 C when heat treated in air. The in situ composite matrix was softer than the unreinforced matrix for equivalent aging conditions. Both materials hardened to a maximum, then softened during overaging. The temperature at which peak aging occurred was approx. 450 C for both the in situ composite matrix and the unreinforced matrix. The room temperature elastic modulus and ultimate tensile strength of the unreinforced matrix varied as a function of aging treatment and paralleled the hardness behavior. The modulus and tensile strength showed little response to aging up to temperatures of 300 C; however, these properties increased after aging at 550 C. Aging at temperatures above 550 C resulted in a decrease in the modulus and tensile strength. The failure strain was a function of the precipitation state and of the amount of oxidation resulting from the heat treatment. Aging in air at the higher temperatures (greater than 550 C) caused the formation of a thick oxide layer and reduced the ductility. Aging in vacuum at these temperatures resulted in significantly higher ductilities. Long term exposures at 700 C caused the formation of a large grain boundary alpha-phase which reduced the ductility, even though the specimens were heat treated in vacuum.

  3. Effect of heat treatment and storage conditions on mead composition.

    PubMed

    Kahoun, David; Řezková, Soňa; Královský, Josef

    2017-03-15

    The effects of heat treatment and storage conditions on the composition of pure mead (honey wine) made from only honey and water were investigated. Heat treatment experiments were performed at 7 different temperatures ranging from 40°C to100°C with 10°C increments for 60min. Storage condition experiments were performed at room temperature (20-25°C) in daylight without direct sunlight and in darkness in a refrigerator at 4°C for 1, 2, 4 and 12weeks. The parameters evaluated were phenolic compounds, peak area of unidentified compounds, 5-hydroxymethylfurfural content and antioxidant capacity. Significant changes in compound content were observed in the case of 6 identified compounds and 9 unidentified compounds. However, the antioxidant activity was not affected by the heat treatments or storage at room temperature.

  4. Effect of heat treatment temperature on nitinol wire

    NASA Astrophysics Data System (ADS)

    Cai, S.; Schaffer, J. E.; Daymond, M. R.; Yu, C.; Ren, Y.

    2014-08-01

    In-situ synchrotron X-ray diffraction has been used to study the influence of the heat treatment temperature on the subsequent micromechanical behavior of nitinol wire. It was found that increase in the heat treatment temperature rotated the austenite texture from the {332}B2 fiber towards the {111}B2 fiber, and the texture of the Stress-Induced Martensite phase changed from the ( 1 ¯ 40)B19' to the ( 1 ¯ 20)B19' fiber accordingly. Heat treatment at a low temperature reduces the internal residual strains in the austenite during super-elastic deformation and therefore improves the materials fatigue performance. The development of internal residual strains in austenite is controlled by transformation induced plasticity and the reversal martensite to austenite transformation.

  5. Identification of heat treatments for better formability in an aluminum-lithium alloy sheet

    NASA Astrophysics Data System (ADS)

    Bairwa, M. L.; Desai, Sharvari G.; Date, P. P.

    2005-10-01

    Research in the weight of an automobile is a continuous process among auto manufacturers. The “body in white” (BIW, i.e., the body of the car) deserves attention, being a major contributor to the weight of the vehicle. By virtue of a high strength to weight ratio (density smaller than aluminum) and a higher Young’s modulus than aluminum, aluminum-lithium alloy sheet appears to hold promise as an autobody material. Because auto components are required in large numbers and are formed at room temperature, formability under these conditions becomes significant. Aluminum-lithium alloys acquire, because of aging over a short period of time, a good amount of strength and hence dent resistance. In principle, they can be given, through suitable heat treatments, a high formability as well as dent resistance, i.e., an ideal combination of properties. To this end, tensile properties have been determined for a number of heat treatments comprising three different solutionizing temperatures and for three aging times at each of the three aging temperatures. Considerable influence of heat treatment was observed on the mechanical properties (which in turn characterize both formability and dent resistance), such as the strain hardening exponent, average normal anisotropy, yield stress, ultimate tensile stress, and percentage elongation to failure. For each property, the best three heat treatments leading to a high formability were identified. Consequently, heat treatments that imparted the greatest formability for processes such as deep drawing and stretch forming have been identified. The investigations show that the best heat treatment for one property may not be the best for another property, calling for a compromise to obtain the most practicable heat treatment schedule. Results shed light on not only the biaxial formability but also springback behavior that is important in the BIW components. Further, the properties obtained from the heat treatment giving good formability

  6. Ultrasonic verification of microstructural changes due to heat treatment

    NASA Technical Reports Server (NTRS)

    Generazio, E. R.

    1986-01-01

    Ultrasonic attenuation was measured for polycrystalline samples of nickel and copper with various grain-size distributions produced by heat treatment. Attenuation as a function of frequency was determined for a sample having a known mean grain diameter. Once this function was determined, it could be scaled to determine the mean grain size of other samples of the same material with different mean grain diameters. These results were obtained by using broadband pulse-echo ultrasound in the 25 to 100 MHz frequency range. The results suggest an ultrasonic, nondestructive approach for verifying heat treatment of metals.

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

    DOEpatents

    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.

  8. Lethal effects of heat and use of localized heat treatment for control of bed bug infestations.

    PubMed

    Pereira, Roberto M; Koehler, Philip G; Pfiester, Margie; Walker, Wayne

    2009-06-01

    Bed bugs, Cimex lectularius L., hide in cracks and crevices in furniture and are difficult to control. The bed bug thermal death kinetics were examined to develop a heat treatment method to eliminate bed bug infestations in room contents. High temperatures caused temporary immobilization (knockdown) of bed bugs even with exposures that did not have lethal effects. Exposure of bed bug adults to 39 degrees C for 240 min caused no mortality; however, as temperatures increased from 41 to 49 degrees C, exposure times that caused 100% mortality decreased. The temperature difference to provide a 10-fold change in the mortality was estimated at 4 degrees C, and the estimated activation energy (EA) was between 484 and 488.3 kJ/mol. This demonstrates that bed bugs are not more resistant or susceptible to changes in temperature than other tested insects and that the temperatures needed to kill bed bugs are relatively low. In room treatment tests, heat treatment times varied from 2 to 7 h with complete mortality of exposed bed bugs within the treatment envelope created by surrounding the treated furniture with polystyrene sheathing boards. Containment and circulation of heat around the treated material were crucial factors in an efficient heat treatment for bed bug control. The room floor material greatly affected containment of the heat. The tested method for limited heat treatment of furniture and other room contents required equipment costing less than US$400 and provided opportunity for residual pesticide application around the room with minimal disruption in use of treated room.

  9. Effect of heat treatments on aminoglycosides in milk.

    PubMed

    Zorraquino, M A; Althaus, R L; Roca, M; Molina, M P

    2009-06-01

    The presence of antibiotic residues in milk not only is a potential consumer risk but also may cause serious problems in the fermentation processes used in the dairy industry. There is very limited information available on the effect of heat treatments on aminoglycoside activity in milk. For this reason, the objective of this study was to analyze the effect of different heat treatments (60 degrees C for 30 min, 120 degrees C for 20 min, and 140 degrees C for 10 s) on milk samples spiked with four aminoglycosides (gentamicin, 50, 100, and 200 microg/liter; kanamycin, 300, 600, and 1200 microg/liter, neomycin, 200, 400, and 800 microg/liter; and streptomycin, 200, 400, and 800 microg/liter). The method used was a bioassay based on the inhibition of Bacillus subtilis BGA. Statistical analysis of the three heat treatments studied showed that the one at 60 degrees C for 30 min did not inactivate the aminoglycosides, the treatment at 140 degrees C for 10 s produced inactivation levels of between 17% for kanamycin and 40% for neomycin, and the classic sterilization (120 degrees C for 20 min) showed a high heat inactivation (>95%) for all the concentrations of aminoglycosides tested with respect to the samples without treatment (control group).

  10. Effects of heat treatment on hair structure.

    PubMed

    Bories, M F; Martini, M C; Et, M F; Cotte, J

    1984-10-01

    Synopsis The influence of increasing temperature from 20 to 200 degrees C was studied at the superficial level by electron microscopy and in depth by differential colorimetry and X-ray defraction. The results have been related to moisture content in order to establish the influence of hair-drying treatment which would respect the integrity of the keratin fibre whilst encouraging the deformation of the hair. A critical temperature of 140 degrees C resulted from the studies. Below this temperature little modification of the hair structure was observed which was reversible and linked to the progressive loss of free water. Above 140 degrees C the structural modifications were profound and irreversible. This was accompanied by a change in the appearance of a folding of the cuticle and the gradual disappearance of the scale of the cuticle. After elimination of bound water, a total degradation of the structure was observed around 200 degrees C. From the point of view of these structure studies, a drying temperature of 60 degrees C would appear optimal since a subsequent moisture pick-up is slower, leaving the hair less sensitive to atmospheric humidity variations.

  11. Structural changes of synthetic opal by heat treatment

    NASA Astrophysics Data System (ADS)

    Arasuna, Akane; Okuno, Masayuki; Okudera, Hiroki; Mizukami, Tomoyuki; Arai, Shoji; Katayama, Shin'ichi; Koyano, Mikio; Ito, Nobuaki

    2013-10-01

    The structural changes of synthetic opal by heat treatment up to 1,400 °C were investigated using scanning electron microscopy, X-ray diffraction, and Fourier transform infrared and Raman spectroscopies. The results indicate that the dehydration and condensation of silanol in opal are very important factors in the structural evolution of heat-treated synthetic opal. Synthetic opal releases water molecules and silanols by heat treatment up to 400 °C, where the dehydration of silanol may lead to the condensation of a new Si-O-Si network comprising a four-membered ring structure of SiO4 tetrahedra, even at 400 °C. Above 600 °C, water molecules are lost and the opal surface and internal silanol molecules are completely dehydrated by heat effect, and the medium-temperature range structure of opal may begin to thermally reconstruct to six-membered rings of SiO4 tetrahedra. Above 1,000 °C, the opal structure almost approaches that of silica glass with an average structure of six-membered rings. Above 1,200 °C, the opal changes to low-cristobalite; however, minor evidence of low-tridymite stacking was evident after heat treatment at 1,400 °C.

  12. Impact Toughness and Heat Treatment for Cast Aluminum

    NASA Technical Reports Server (NTRS)

    Lee, Jonathan A (Inventor)

    2016-01-01

    A method for transforming a cast component made of modified aluminum alloy by increasing the impact toughness coefficient using minimal heat and energy. The aluminum alloy is modified to contain 0.55%-0.60% magnesium, 0.10%-0.15% titanium or zirconium, less than 0.07% iron, a silicon-tomagnesium product ratio of 4.0, and less than 0.15% total impurities. The shortened heat treatment requires an initial heating at 1,000deg F. for up to I hour followed by a water quench and a second heating at 350deg F. to 390deg F. for up to I hour. An optional short bake paint cycle or powder coating process further increase.

  13. Heat Treatment and Properties of Iron and Steel

    DTIC Science & Technology

    2007-11-02

    specified as an added element to a standard steel. • Silicon: Because of the technological nature of the process , acid bessemer steels are not...Heat treatment of steels 9 5.1. Annealing ~ 10 a. Full annealing I__ 10 b. Process annealing 10 c. Spheroidizing . 10 5.2. Normalizing 10...treatment of iron and steel and for directions and explanations of such processes . This Monograph has been prepared to answer such inquiries and to give

  14. Heat treatment giving a stable high temperature micro-structure in cast austenitic stainless steel

    DOEpatents

    Anton, Donald L.; Lemkey, Franklin D.

    1988-01-01

    A novel micro-structure developed in a cast austenitic stainless steel alloy and a heat treatment thereof are disclosed. The alloy is based on a multicomponent Fe-Cr-Mn-Mo-Si-Nb-C system consisting of an austenitic iron solid solution (.gamma.) matrix reinforced by finely dispersed carbide phases and a heat treatment to produce the micro-structure. The heat treatment includes a prebraze heat treatment followed by a three stage braze cycle heat treatment.

  15. Effect of the woman's age on discontinuation of IVF treatment.

    PubMed

    Soullier, Noémie; Bouyer, Jean; Pouly, Jean-Luc; Guibert, Juliette; de La Rochebrochard, Elise

    2011-05-01

    Treatment discontinuations are an important issue in IVF programmes. In the French context, financial constraint does not intervene in discontinuation until older ages. This study examined treatment discontinuation in IVF programmes, according to the woman's age and when there is no financial burden for couples. Medical records were collected for 3037 women who began their IVF programme between 1998 and 2002 in two French IVF units. Up to four attempts were taken into consideration. Cumulative success (delivery) rates were calculated, as well as discontinuation rates. Multiple imputation was applied to estimate a theoretical cumulative success rate as if no woman discontinued treatment before the end of the IVF programme without delivering. Cumulative discontinuation rates at the end of the IVF programme increased with the woman's age (41% for age <35, 56% for age 35-39, 80% for age ⩾40). The benefit in terms of delivery rates of pursuing treatment would be smaller for older women (∼10% for age <35, 7% for age 35-39, 4% for age ⩾40). Even when treatment is reimbursed, the discontinuation rate is high for older women, suggesting that the strong decrease in success rate with age induces older women to discontinue. Treatment discontinuations are an important issue in IVF programmes. In the French context, financial constraint does not intervene in discontinuation until older ages. We aimed to examine treatment discontinuation in IVF programmes, according to the woman's age and when there is no financial burden for couples. Medical records were collected for 3037 women who began their IVF programme between 1998 and 2002 in two French IVF units. Up to four attempts were taken into consideration. Cumulative success (delivery) rates were calculated, as well as discontinuation rates. Multiple imputation was applied to estimate a theoretical cumulative success rate as if no woman discontinued treatment before the end of the IVF programme without delivering. Cumulative

  16. The effect of heat treatment of wood on osteoconductivity.

    PubMed

    Rekola, J; Aho, A J; Gunn, J; Matinlinna, J; Hirvonen, J; Viitaniemi, P; Vallittu, P K

    2009-06-01

    Wood is a natural porous fibre composite, which has some structural similarities to bone. Recently, it has been used as a modelling material in developing synthetic fibre-reinforced composite to be used as load-bearing non-metallic artificial bone material. In this study, the behaviour of wood implanted into bone was studied in vivo in the femur bone of the rabbit. Wood was pre-treated by heat, which altered its chemical composition and structure, as well as the biomechanical properties. In the heat treatment, wood's dimensional stability is enhanced, equilibrium moisture content reduces and the biological durability increases. Cone-shaped implants were manufactured from heat-treated (at 200 and 140 degrees C) birch wood (Betula pubescens) and from untreated birch. A total of 62 implants were placed in the distal femur of 50 white New Zealand rabbits. The behaviour of the implants was studied at 4, 8 and 20 weeks with histological and histometrical analysis. Osteoconductive contact line and the presence of fibrous tissue and foreign body reaction were determined. The amount of fibrous tissue diminished with time, and the absence of foreign body reaction was found to be in correlation to the amount of heat treatment. Histologically found contact between the implant and the host bone at the interface was significantly more abundant in the 200 degrees C group (avg. 12.8%) vs. the 140 degrees C (avg. 2.7%) and the untreated groups (avg. 0.6%). It was observed that the heat treatment significantly modified the biological behaviour of the implanted wood. The changes of the wood by heat treatment showed a positive outcome concerning osteoconductivity of the material.

  17. 49 CFR 179.500-6 - Heat treatment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... proper inspection. (b) To check uniformity of heat treatment, Brinnel hardness tests shall be made at 18 inch intervals on the entire longitudinal axis. The hardness shall not vary more than 35 points in the length of the tank. No hardness tests need be taken within 12 inches from point of head to shell...

  18. 49 CFR 179.500-6 - Heat treatment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... proper inspection. (b) To check uniformity of heat treatment, Brinnel hardness tests shall be made at 18 inch intervals on the entire longitudinal axis. The hardness shall not vary more than 35 points in the length of the tank. No hardness tests need be taken within 12 inches from point of head to shell...

  19. 49 CFR 179.500-6 - Heat treatment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... proper inspection. (b) To check uniformity of heat treatment, Brinnel hardness tests shall be made at 18 inch intervals on the entire longitudinal axis. The hardness shall not vary more than 35 points in the length of the tank. No hardness tests need be taken within 12 inches from point of head to shell...

  20. Research Findings on Heat Treatment of Pathogens and Indicator Organisms

    EPA Science Inventory

    Heat or thermal treatment has been used for many years for reducing the densities of pathogens in food and beverages. Its application for disinfection of municipal sludges has occurred only recently. One method for achieving Class A biosolids is to thermally treat sludges either ...

  1. 7 CFR 58.236 - Pasteurization and heat treatment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... than 6.0 undenatured whey protein nitrogen per gram of non-fat dry milk as classified in the U.S... Service 1 Operations and Operating Procedures § 58.236 Pasteurization and heat treatment. All milk and buttermilk used in the manufacture of dry milk products and modified dry milk products shall be...

  2. 49 CFR 179.200-11 - Postweld heat treatment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Postweld heat treatment. 179.200-11 Section 179.200-11 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK...

  3. 49 CFR 179.100-10 - Postweld heat treatment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Postweld heat treatment. 179.100-10 Section 179.100-10 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK...

  4. 49 CFR 179.100-10 - Postweld heat treatment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Postweld heat treatment. 179.100-10 Section 179.100-10 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK...

  5. 49 CFR 179.200-11 - Postweld heat treatment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Postweld heat treatment. 179.200-11 Section 179.200-11 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK...

  6. 49 CFR 179.220-11 - Postweld heat treatment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Postweld heat treatment. 179.220-11 Section 179.220-11 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK...

  7. 49 CFR 179.100-10 - Postweld heat treatment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Postweld heat treatment. 179.100-10 Section 179.100-10 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK...

  8. 49 CFR 179.100-10 - Postweld heat treatment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Postweld heat treatment. 179.100-10 Section 179.100-10 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK...

  9. 49 CFR 179.200-11 - Postweld heat treatment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Postweld heat treatment. 179.200-11 Section 179.200-11 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK...

  10. Potential heat treatments for quarantine security of exotic tropical fruits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potential heat treatments (HT) were developed to control fruit flies in selected tropical fruits (avocado, guava, longan, passion fruit, and persimmon). Hawaii has three fruit flies of economic and quarantine importance, Mediterranean fruit fly (Medfly), oriental fruit fly, and melon fly. Previous r...

  11. 7 CFR 58.236 - Pasteurization and heat treatment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... than 6.0 undenatured whey protein nitrogen per gram of non-fat dry milk as classified in the U.S... Service 1 Operations and Operating Procedures § 58.236 Pasteurization and heat treatment. All milk and buttermilk used in the manufacture of dry milk products and modified dry milk products shall be...

  12. 7 CFR 58.236 - Pasteurization and heat treatment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... than 6.0 undenatured whey protein nitrogen per gram of non-fat dry milk as classified in the U.S... Service 1 Operations and Operating Procedures § 58.236 Pasteurization and heat treatment. All milk and buttermilk used in the manufacture of dry milk products and modified dry milk products shall be...

  13. 7 CFR 58.236 - Pasteurization and heat treatment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... than 6.0 undenatured whey protein nitrogen per gram of non-fat dry milk as classified in the U.S... Service 1 Operations and Operating Procedures § 58.236 Pasteurization and heat treatment. All milk and buttermilk used in the manufacture of dry milk products and modified dry milk products shall be...

  14. 7 CFR 58.236 - Pasteurization and heat treatment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... than 6.0 undenatured whey protein nitrogen per gram of non-fat dry milk as classified in the U.S... Service 1 Operations and Operating Procedures § 58.236 Pasteurization and heat treatment. All milk and buttermilk used in the manufacture of dry milk products and modified dry milk products shall be...

  15. Tool Steel Heat Treatment Optimization Using Neural Network Modeling

    NASA Astrophysics Data System (ADS)

    Podgornik, Bojan; Belič, Igor; Leskovšek, Vojteh; Godec, Matjaz

    2016-11-01

    Optimization of tool steel properties and corresponding heat treatment is mainly based on trial and error approach, which requires tremendous experimental work and resources. Therefore, there is a huge need for tools allowing prediction of mechanical properties of tool steels as a function of composition and heat treatment process variables. The aim of the present work was to explore the potential and possibilities of artificial neural network-based modeling to select and optimize vacuum heat treatment conditions depending on the hot work tool steel composition and required properties. In the current case training of the feedforward neural network with error backpropagation training scheme and four layers of neurons (8-20-20-2) scheme was based on the experimentally obtained tempering diagrams for ten different hot work tool steel compositions and at least two austenitizing temperatures. Results show that this type of modeling can be successfully used for detailed and multifunctional analysis of different influential parameters as well as to optimize heat treatment process of hot work tool steels depending on the composition. In terms of composition, V was found as the most beneficial alloying element increasing hardness and fracture toughness of hot work tool steel; Si, Mn, and Cr increase hardness but lead to reduced fracture toughness, while Mo has the opposite effect. Optimum concentration providing high KIc/HRC ratios would include 0.75 pct Si, 0.4 pct Mn, 5.1 pct Cr, 1.5 pct Mo, and 0.5 pct V, with the optimum heat treatment performed at lower austenitizing and intermediate tempering temperatures.

  16. The response of cobalt-free Udimet 700 type alloy to modified heat treatments

    NASA Technical Reports Server (NTRS)

    Harf, F. H.

    1986-01-01

    A superalloy based on Udimet 700, in which all of the cobalt was replaced by nickel, was prepared from hot isostatically pressed prealloyed powders. This material was given various heat treatments consisting of partial solutioning and aging in a sequence of four different temperatures. Comparisons were made of microstructures and mechanical properties. Best results were obtained by partially solutioning at 1145 deg C and aging through a sequence of 870, 1030, 650 and 760 deg C. This heat treatment also provided significantly improved properties for wrought material of the same composition. The results suggest that cobalt free Udimet 700 should be considered as a substitute for Udimet 700 with the standard 17 percent cobalt content.

  17. The response of cobalt-free Udimet 700 type alloy to modified heat treatments

    NASA Technical Reports Server (NTRS)

    Harf, F. H.

    1985-01-01

    A superalloy based on Udimet 700, in which all of the cobalt was replaced by nickel, was prepared from hot isostatically pressed prealloyed powders. This material was given various heat treatments consisting of partial solutioning and aging in a sequence of four different temperatures. Comparisons were made of microstructures and mechanical properties. Best results were obtained by partially solutioning at 1145 deg C and aging through a sequence of 870, 1030, 650 and 760 deg C. This heat treatment also provided significantly improved properties for wrought material of the same composition. The results suggest that cobalt free Udimet 700 should be considered as a substitute for Udimet 700 with the standard 17 percent cobalt content.

  18. Microwave heat treatment of natural ruby and its characterization

    NASA Astrophysics Data System (ADS)

    Swain, S.; Pradhan, S. K.; Jeevitha, M.; Acharya, P.; Debata, M.; Dash, T.; Nayak, B. B.; Mishra, B. K.

    2016-03-01

    Natural ruby (in the form of gemstone) collected from Odisha has been heat-treated by microwave (MW). A 3-kW industrial MW furnace with SiC susceptors was used for the heat treatment. The ruby samples showed noticeable improvements (qualitative), may be attributed to account for the improvement in clarity and lustre. Optical absorption in 200-800 nm range and photoluminescence peak at 693 nm (with 400 nm λ ex) clearly show that subtle changes do take place in the ruby after the heat treatment. Further, inorganic compound phases and valence states of elements (impurities) in the ruby were studied by X-ray diffraction, micro-Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The valence states of the main impurities such as Cr, Fe, and Ti, in the untreated and MW heat-treated ruby, as revealed from XPS, have been discussed in depth. The overall results demonstrate for the first time the effect of fast heating like MW on the microstructural properties of the gemstone and various oxidation states of impurity elements in the natural ruby.

  19. Age, Gender, and Treatment Attendance among Forensic Psychiatric Outpatients.

    ERIC Educational Resources Information Center

    Hadley, Dianne C.; Reddon, John R.; Reddick, Robert D.

    2001-01-01

    Uses the records of forensic psychiatry outpatients (N=6,299) to evaluate absenteeism from treatment in relation to age and gender. Results reveal that females had a significantly higher absentee rate than males in all age groups. For both males and females, missed appointments declined significantly with age. (Contains 34 references and 1 table.)…

  20. Heat treatment in high Cr white cast iron Nb alloy

    NASA Astrophysics Data System (ADS)

    Farah, A. F.; Crnkovic, O. R.; Canale, L. C. F.

    2001-02-01

    Wear resistance of high Cr white cast irons can be improved by means of heat treatment. This type of cast iron alloy may present a microstructure with retained austenite. The amount of retained austenite changes with the applied heat treatment, which will have an influence on wear properties. The purpose of this work was to study the influence of several parameters such as quenching and tempering temperatures and subzero treatment in the wear performance of the high Cr white cast iron Nb alloy. In this way, the performance was evaluated using pin-on-disc abrasion test. The worn surface was examined by scanning electron microscopy, and the main wear mechanisms were identified. The microstructural characterization was also performed with carbide identification. This Fe alloy has proven to be good for applications in mining and alcohol-sugar industries.

  1. Effect of Pre- and Post-weld Heat Treatments on Linear Friction Welded Ti-5553

    NASA Astrophysics Data System (ADS)

    Wanjara, Priti; Dalgaard, Elvi; Gholipour, Javad; Cao, Xinjin; Cuddy, Jonathan; Jonas, John J.

    2014-10-01

    Linear friction welding allows solid-state joining of near-beta ( β) titanium alloy Ti-5553 (Ti-5Al-5V-5Mo-3Cr). In the as-welded condition, the weld zone (WZ) exhibits β grain refinement and marked softening as compared with Ti-5553 in the solution heat treated and aged condition. The softening of the weldment is attributed to the depletion of the strengthening alpha ( α) phase in the WZ and the adjacent thermo-mechanically affected zone (TMAZ). Specifically, in near- β titanium alloys, the strength of the material mainly depends on the shape, size, distribution, and fraction of the primary α and other decomposition products of the β phase. Hence, a combination of pre- and post-weld heat treatments were applied to determine the conditions that allow mitigating the α phase depletion in the WZ and TMAZ of the welds. The mechanical response of the welded samples to the heat treatments was determined by performing microhardness measurements and tensile testing at room temperature with an automated 3D deformation measurement system. It was found that though the joint efficiency in the as-welded condition was high (96 pct), strain localization and failure occurred in the TMAZ. The application of post-weld solution heat treatment with aging was effective in restoring α, increasing the joint efficiency (97 to 99 pct) and inducing strain localization and failure in the parent material region.

  2. Sour gas injection for use with in situ heat treatment

    DOEpatents

    Fowler, Thomas David

    2009-11-03

    Systems, methods, and heaters for treating a subsurface formation are described herein. At least one method for providing acidic gas to a subsurface formation is described herein. The method may include providing heat from one or more heaters to a portion of a subsurface formation; producing fluids that include one or more acidic gases from the formation using a heat treatment process. At least a portion of one of the acidic gases may be introduced into the formation, or into another formation, through one or more wellbores at a pressure below a lithostatic pressure of the formation in which the acidic gas is introduced.

  3. Estimating risks of heat strain by age and sex: a population-level simulation model.

    PubMed

    Glass, Kathryn; Tait, Peter W; Hanna, Elizabeth G; Dear, Keith

    2015-05-18

    Individuals living in hot climates face health risks from hyperthermia due to excessive heat. Heat strain is influenced by weather exposure and by individual characteristics such as age, sex, body size, and occupation. To explore the population-level drivers of heat strain, we developed a simulation model that scales up individual risks of heat storage (estimated using Myrup and Morgan's man model "MANMO") to a large population. Using Australian weather data, we identify high-risk weather conditions together with individual characteristics that increase the risk of heat stress under these conditions. The model identifies elevated risks in children and the elderly, with females aged 75 and older those most likely to experience heat strain. Risk of heat strain in males does not increase as rapidly with age, but is greatest on hot days with high solar radiation. Although cloudy days are less dangerous for the wider population, older women still have an elevated risk of heat strain on hot cloudy days or when indoors during high temperatures. Simulation models provide a valuable method for exploring population level risks of heat strain, and a tool for evaluating public health and other government policy interventions.

  4. Melatonin and aging: prospects for human treatment.

    PubMed

    Bubenik, G A; Konturek, S J

    2011-02-01

    Human life span, with or without modern medicine is around 85-95 years. All living creatures have their inner clock that measures their daily (circadian) and their seasonal (circannual) time. These time changes are mediated by the alteration of levels of melatonin, an evolutionary ancient hormone, which is produced in many body tissues, including the pineal gland, retina and the gastrointestinal tract (GIT). Light is blocking the production of melatonin in the pineal gland, darkness is stimulating it. So, the diurnal changes of light intensity of melatonin, provide a "daily clock" and the seasonal changes provide a "seasonal clock". Finally, the reduction of melatonin observed with aging, may indicate the presence of an "age clock". Melatonin is a strong antioxidant (often it is called scavenger of free radicals), which protects the body from the effects of noxious compounds. Therefore it was hypothesized that the reduction of melatonin levels with age contributes to the aging process. So far, the only remedy to extend the life span was a 40% reduction in caloric intake, which prolonged the life in mice, rats, dogs and monkeys by 30-50%. A large group of people imitate these experiments performed on animals, but the results of these experiments will not be known for several decades. How is being hungry prolonging the life span? There is a connection between caloric reduction and melatonin levels in GIT. Several experiments indicate that fasting in animals substantially increased their production of GIT melatonin. Therefore, instead of being permanently hungry, a prolongation of human life could be achieved by a replacement melatonin therapy. A daily intake of melatonin before bed time might achieve the same effect as fasting e.g. an increase of body melatonin levels, which will protect the individual from the ravages of old age. That includes Parkinson's disease and Alzheimer's disease. There is a large group of people taking melatonin daily who believe that

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

    PubMed Central

    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 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.

  6. Effect of mechanical surface and heat treatments on erosion resistance

    NASA Technical Reports Server (NTRS)

    Salik, J.; Buckley, D. H.

    1980-01-01

    The effects of mechanical surface treatments as well as heat treatments on the erosion resistance of 6061 aluminum alloy and 1045 steel were studied. Mechanical surface treatments were found to have little or no effect on the erosion resistance. This is due to the formation by particle impact of a work hardened surface layer regardless of the initial surface condition. The erosion resistance of Al single crystals is found to be independent of orientation. This is due to destruction of the surface microstructure and formation of a polycrystalline surface layer by the impact of erodant particles as observed by X-ray diffraction. While upon solution treatment of annealed 6061 aluminum the increase in hardness is accompanied by an increase in erosion resistance, precipitation treatment which causes a further increase in hardness results in slightly lower erosion resistance. Using two types of erodant particles, glass beads and crushed glass, the erosion rate is found to be strongly dependent on erodant particle shape, being an order of magnitude higher for erosion with crushed glass as compared to glass beads. While for erosion with glass beads heat treatment of 1045 steel had a profound effect on its erosion resistance, little or no such effect was observed for erosion with crushed glass.

  7. Effect of Heat Treatment on Microstructure Characteristics of Laser Composites

    NASA Astrophysics Data System (ADS)

    Liu, Peng; Zhang, Yuanbin; Li, Yajiang; Yang, Qingqing; Liu, Yan; Ren, Guocheng

    2014-12-01

    In this paper, effect of heat treatment on the microstructures and wear properties of laser alloying (LA) composites is investigated. LA of the T-Co50/FeSi/TiC/TiN/CeO2 mixed powders on substrate of 45 steel can form the hard composites, which increased the wear resistance of substrate greatly. Such LA composites were investigated by means of a scanning electron microscope (SEM) and a transmission electron microscope (TEM). The tempering promoted the growth of the block-shape hard phases, favoring an enhancement of the integrity of block-shape hard phases; and tempering also improved greatly the formation mechanism, guarantying the composites to have enough ability of intensity transfer. This research provided essential experiment and theoretical basis to promote the application of the laser and heat treatment technologies in the field of surface modification.

  8. Feasibility of in situ controlled heat treatment (ISHT) of Inconel 718 during electron beam melting additive manufacturing

    DOE PAGES

    Sames, William J.; Unocic, Kinga A.; Helmreich, Grant W.; ...

    2016-10-07

    A novel technique was developed to control the microstructure evolution in Alloy 718 processed using Electron Beam Melting (EBM). In situ solution treatment and aging of Alloy 718 was performed by heating the top surface of the build after build completion scanning an electron beam to act as a planar heat source during the cool down process. Results demonstrate that the measured hardness (478 ± 7 HV) of the material processed using in situ heat treatment similar to that of peak-aged Inconel 718. Large solidification grains and cracks formed, which are identified as the likely mechanism leading to failure ofmore » tensile tests of the in situ heat treatment material under loading. Despite poor tensile performance, the technique proposed was shown to successively age Alloy 718 (increase precipitate size and hardness) without removing the sample from the process chamber, which can reduce the number of process steps in producing a part. Lastly, tighter controls on processing temperature during layer melting to lower process temperature and selective heating during in situ heat treatment to reduce over-sintering are proposed as methods for improving the process.« less

  9. Feasibility of in situ controlled heat treatment (ISHT) of Inconel 718 during electron beam melting additive manufacturing

    SciTech Connect

    Sames, William J.; Unocic, Kinga A.; Helmreich, Grant W.; Kirka, Michael M.; Medina, Frank; Dehoff, Ryan R.; Babu, Sudarsanam Suresh

    2016-10-07

    A novel technique was developed to control the microstructure evolution in Alloy 718 processed using Electron Beam Melting (EBM). In situ solution treatment and aging of Alloy 718 was performed by heating the top surface of the build after build completion scanning an electron beam to act as a planar heat source during the cool down process. Results demonstrate that the measured hardness (478 ± 7 HV) of the material processed using in situ heat treatment similar to that of peak-aged Inconel 718. Large solidification grains and cracks formed, which are identified as the likely mechanism leading to failure of tensile tests of the in situ heat treatment material under loading. Despite poor tensile performance, the technique proposed was shown to successively age Alloy 718 (increase precipitate size and hardness) without removing the sample from the process chamber, which can reduce the number of process steps in producing a part. Lastly, tighter controls on processing temperature during layer melting to lower process temperature and selective heating during in situ heat treatment to reduce over-sintering are proposed as methods for improving the process.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    Gelles, D.S.; Li, H.

    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.

  12. Effects of preincubation heating of broiler hatching eggs during storage, flock age, and length of storage period on hatchability.

    PubMed

    Gucbilmez, M; Ozlü, S; Shiranjang, R; Elibol, O; Brake, J

    2013-12-01

    The effects of heating of eggs during storage, broiler breeder age, and length of egg storage on hatchability of fertile eggs were examined in this study. Eggs were collected from Ross 344 male × Ross 308 broiler breeders on paper flats, held overnight (1 d) at 18°C and 75% RH, and then transferred to plastic trays. In experiment 1, eggs were obtained at 28, 38, and 53 wk of flock age. During a further 10 d of storage, eggs either remained in the storage room (control) or were subjected to a heat treatment regimen of 26°C for 2 h, 37.8°C for 3 h, and 26°C for 2 h in a setter at d 5 of storage. In experiment 2, eggs from a flock at 28 wk of age were heated for 1 d of a 6-d storage period. Eggs from a 29-wk-old flock were either heated at d 1 or 5 of an 11-d storage period in experiment 3. In experiment 4, 27-wk-old flock eggs were heated twice at d 1 and 5 of an 11-d storage period. Control eggs stored for 6 or 11 d were coincubated as appropriate in each experiment. Heating eggs at d 5 of an 11-d storage period increased hatchability in experiment 1. Although no benefit of heating 28-wk-old flock eggs during 6 d of storage in experiment 2 was observed, heating eggs from a 29-wk-old flock at d 1 or 5 of an 11-d storage period increased hatchability in experiment 3. Further, heating eggs from a 27-wk-old flock twice during 11 d of storage increased hatchability in experiment 4. These effects were probably due to the fact that eggs from younger flocks had been reported to have many embryos at a stage of development where the hypoblast had not yet fully developed (less than EG-K12 to EG-K13), such that heating during extended storage advanced these embryos to a more resistant stage.

  13. Heat Treatment of AZ91D Mg-Al-Zn Alloy: Microstructural Evolution and Dynamic Response

    NASA Astrophysics Data System (ADS)

    Luong, Dung D.; Shunmugasamy, Vasanth Chakravarthy; Cox, James; Gupta, Nikhil; Rohatgi, Pradeep K.

    2013-11-01

    Magnesium alloys are attracting great interest from the automotive industry because of the potential for weight reduction. An AZ91D cast alloy was studied in the current work to understand the effect of heat treatment on the microstructure and dynamic compressive properties. The selected heat treatments include solution treatment (T4) and solution treatment followed by aging (T6). The as-cast alloy microstructure consists of intermetallic β-phase (Mg17Al12) precipitates surrounded by α + β lamellar eutectic in α-Mg solid solution. The AZ91D-T4 specimens showed small β-phase precipitates along the grain boundaries and regions of eutectic mixture. The T6 heat treatment causes the β-phase platelets in the α + β eutectic to grow and develop into β-precipitates. The difference in the phase morphology reflects into the mechanical properties. The Vickers hardness of the T6 heat-treated specimens was 3.6% higher than the as-cast alloy. The compressive yield strengths of T4 and T6 treated specimens were 1.3% and 43.1% higher than those of as-cast specimens. The high strain rate compression testing resulted in increase in the strength with strain rate for the T4 and T6 specimens. A maximum increase of 42% was observed in T6 specimen tested at a strain rate of 4,000/s in comparison to the quasi-static compression. Under high strain rate compression testing, the T6 heat-treated specimens showed failure of the β-precipitates resulting in increased energy absorption in comparison to the quasi-static compression.

  14. Age-related macular degeneration: current treatment and future options.

    PubMed

    Moutray, Tanya; Chakravarthy, Usha

    2011-09-01

    Age-related macular degeneration is the leading cause of visual impairment among older adults in the developed world. Epidemiological studies have revealed a number of genetic, ocular and environmental risk factors for this condition, which can be addressed by disease reduction strategies. We discuss the various treatment options for dry and exudative age-related macular degeneration available and explain how the recommended treatment depends on the exact type, location and extent of the degeneration. Currently, vascular endothelial growth factor (VEGF) inhibition therapy is the best available treatment for exudative age-related macular degeneration but is limited by the need for repeated intravitreal injections. The current treatment regime is being refined through research on optimal treatment frequency and duration and type of anti-VEGF drug. Different modes of drug delivery are being developed and in the future other methods of VEGF inhibition may be used.

  15. Targeting Heat Shock Proteins Mitigates Ventilator Induced Diaphragm Muscle Dysfunction in an Age-Dependent Manner

    PubMed Central

    Ogilvie, Hannah; Cacciani, Nicola; Akkad, Hazem; Larsson, Lars

    2016-01-01

    Intensive care unit (ICU) patients are often overtly subjected to mechanical ventilation and immobilization, which leads to impaired limb and respiratory muscle function. The latter, termed ventilator-induced diaphragm dysfunction (VIDD) has recently been related to compromised heat shock protein (Hsp) activation. The administration of a pharmacological drug BGP-15 acting as a Hsp chaperone co-inducer has been found to partially alleviate VIDD in young rats. Considering that the mean age in the ICU is increasing, we aimed to explore whether the beneficial functional effects are also present in old rats. For that, we exposed young (7–8 months) and old (28–32 months) rats to 5-day controlled mechanical ventilation and immobilization with or without systemic BGP-15 administration. We then dissected diaphragm muscles, membrane–permeabilized bundles and evaluated the contractile function at single fiber level. Results confirmed that administration of BGP-15 restored the force-generating capacity of isolated muscle cells from young rats in conjunction with an increased expression of Hsp72. On the other hand, our results highlighted that old rats did not positively respond to the BGP-15 treatment. Therefore, it is of crucial importance to comprehend in more depth the effect of VIDD on diaphragm function and ascertain any further age-related differences. PMID:27729867

  16. Regeneration of pyrolyzed photoresist film by heat treatment.

    PubMed

    Gross, Andrew J; Downard, Alison J

    2011-03-15

    A simple, time-, and cost-effective procedure is described for regenerating film-modified or deactivated pyrolyzed photoresist film (PPF) surfaces. Heating for 30 min at 545 ± 25 °C in argon at a flow rate of 1 L min(-1) removes covalently bound thin organic films, attached via electrografting from aryldiazonium salt solutions. The heat-treated surfaces exhibit improved electrochemical characteristics compared to those prior to modification and can be reused for solution-based electrochemical measurements and for electrografting. The same treatment reactivates PPF electrodes that have been deactivated by exposure to adsorbates from air or solution. X-ray photoelectron spectroscopy (XPS), atomic force microscopy, and water contact angle measurements establish that the regeneration procedure does not lead to significant changes in oxygen content, roughness, or hydrophobicity of PPF surfaces. XPS measurements also confirm the complete removal of covalently attached organic films after heat treatment but reveal a specific interaction between grafted nitrophenyl films and PPF which results in a small amount of N incorporation in the surface.

  17. High temperature heat treatment of 3GHz niobium cavities

    SciTech Connect

    Diete, W. ); Rusnak, B.; Bennett, B.L.; Clark, W.L.; Maggs, R.G.; Shapiro, A.H.; Wright, P.V. )

    1992-01-01

    We applied high temperature heat treatment to 3GHz cavities to determine the preparation of niobium cavities using the titanium solid-state gettering process. Some preliminary results showed peak surface electric fields of up to 65MV/m at a Q-factor of 2{times}lO{sup 10}. We evaluated improvement in the purity of the niobium by measuring the residual resistance ratio (RRR) at 10K. The purest niobium we prepared reached a RRR of 670. To study the potential application to large-scale accelerator structures at lower frequencies, we are testing the possibility of heat treating the cavity half-cells before welding them. Therefore, we investigated the influence of electron beam welding on the RRR of high-purity niobium.

  18. Effects of heat treatment on shape-setting and non-linearmechanical properties of Nitinol stent

    NASA Astrophysics Data System (ADS)

    Liu, Xiaopeng; Wang, Yinong; Qi, Min; Yang, Dazhi

    2007-07-01

    NiTi shape memory alloy is a temperature sensitive material with non-linear mechanical properties and good biocompatibility, which can be used for medical devices such as stent, catheter guide wire and orthodontic wire. The majority of nitinol stents are of the self-expanding type basing on the superelasticity. Nitinol stents are shape set into the open condition and compressed and inserted into the delivery catheter. Additional the shape-setting treatment can be used as a tool to accurately tune the transformation temperatures and mechanical properties. In this study, different heat treatments have been performed on the Ti-50.7at%Ni alloy wires. And results of shape-setting, austenite transformation finish temperature and non-linear mechanical property of NiTi shape memory alloy at body temperature have been investigated. The experimental results show that the proper shape-setting temperature should be chosen between 450-550 °C. And the shape-setting results were stabilization when the NiTi wires were constrain-treated at 500 and 550°C and ageing time longer than 10 minutes. The austenite finish temperatures increased with ageing time and increased first and then decreased with ageing temperature. The peak values were obtained at 400°C. When the heat treatments was performed at the same temperature, both the upper plateau stresses and lower plateau stresses decreased with the ageing time. Most of treated nitinol wires owned good recovery ability at body temperature and the permanent sets were less than 0.05% when short time ageing treatment was performed at 500°C.

  19. Why Was Silcrete Heat-Treated in the Middle Stone Age? An Early Transformative Technology in the Context of Raw Material Use at Mertenhof Rock Shelter, South Africa

    PubMed Central

    2016-01-01

    People heat treated silcrete during the Middle Stone Age (MSA) in southern Africa but the spatial and temporal variability of this practice remains poorly documented. This paucity of data in turn makes it difficult to interrogate the motive factors underlying the application of this technique. In this paper we present data on heat treatment of silcrete through the Howiesons Poort and post-Howiesons Poort of the rock shelter site Mertenhof, located in the Western Cape of South Africa. In contrast to other sites where heat treatment has been documented, distance to rock source at Mertenhof can be reasonably well estimated, and the site is known to contain high proportions of a diversity of fine grained rocks including silcrete, hornfels and chert at various points through the sequence. Our results suggest the prevalence of heat treatment is variable through the sequence but that it is largely unaffected by the relative abundance of silcrete prevalence. Instead there is a strong inverse correlation between frequency of heat treatment in silcrete and prevalence of chert in the assemblage, and a generally positive correlation with the proportion of locally available rock. While it is difficult to separate individual factors we suggest that, at Mertenhof at least, heat treatment may have been used to improve the fracture properties of silcrete at times when other finer grained rocks were less readily available. As such, heat treatment appears to have been a component of the MSA behavioural repertoire that was flexibly deployed in ways sensitive to other elements of technological organisation. PMID:26867145

  20. Effect of Heat Treatment on Chemical Segregation in CMSX-4 Nickel-Base Superalloy

    NASA Astrophysics Data System (ADS)

    Szczotok, A.; Chmiela, B.

    2014-08-01

    Superalloys display a strong tendency toward chemical segregation during solidification. Therefore, it is of great importance to develop appropriate techniques for the melting and casting of superalloys. Elements partitioning between the γ and γ' phases in single crystal superalloys have been investigated by several authors using electron probe microanalysis (Hemmersmeier and Feller-Kniepmeier Mater Sci Eng A 248:87-97, 1998; Kearsey et al. Intermetallics 12:903-910, 2004; Kearsey et al. Superalloys 2004, pp 801-810, 2004; D'Souza et al. Mater Sci Eng A 490:258-265, 2008). We examined the effect of the particular stages of standard heat treatment (solution treatment and ageing) applied to CMSX-4 single crystal superalloy on chemical segregation that occurs between dendrites and interdendritic areas. Dendritic structures were observed using a scanning electron microscope. Analyses of the chemical composition were performed using energy dispersive x-ray spectroscopy. The obtained qualitative and quantitative results for the concentrations of elements enabled us to confirm the dendritic segregation in as-cast CMSX-4 superalloy. The concentrations of some refractory elements (tungsten, rhenium) were much greater in dendrites than in interdendritic areas. However, these differences in chemical composition gradually decreased during heat treatment. The results obtained in this study warrant further examination of the diffusion processes of elements during heat treatment of the investigated superalloy, and of the kinetics of diffusion.

  1. Growth of TiO2 nanoparticles under heat treatment

    NASA Astrophysics Data System (ADS)

    Bahadur, J.; Sen, D.; Mazumder, S.; Sastry, P. U.; Paul, B.

    2013-02-01

    The effect of heat treatment, on growth of NiO doped TiO2, have been investigated. The nanoparticle size has been estimated by small-angle x-ray scattering. The average particle size increases with increasing temperature. The growth of crystallite size has been probed by X-ray diffraction. A polymorphic phase transition of TiO2 is observed beyond 600°C due to growth of TiO2 nanoparticles beyond 14 nm of size.

  2. Preservation of Cognitive Performance with Age during Exertional Heat Stress under Low and High Air Velocity

    PubMed Central

    Wright Beatty, Heather E.; Keillor, Jocelyn M.; Hardcastle, Stephen G.; Boulay, Pierre; Kenny, Glen P.

    2015-01-01

    Older adults may be at greater risk for occupational injuries given their reduced capacity to dissipate heat, leading to greater thermal strain and potentially cognitive decrements. Purpose. To examine the effects of age and increased air velocity, during exercise in humid heat, on information processing and attention. Methods. Nine young (24 ± 1 years) and 9 older (59 ± 1 years) males cycled 4 × 15 min (separated by 15 min rest) at a fixed rate of heat production (400 W) in humid heat (35°C, 60% relative humidity) under 0.5 (low) and 3.0 (high) m·s−1 air velocity wearing coveralls. At rest, immediately following exercise (end exercise), and after the final recovery, participants performed an abbreviated paced auditory serial addition task (PASAT, 2 sec pace). Results. PASAT numbers of correct responses at end exercise were similar for young (low = 49 ± 3; high = 51 ± 3) and older (low = 46 ± 5; high = 47 ± 4) males and across air velocity conditions, and when scored relative to age norms. Psychological sweating, or an increased sweat rate with the administration of the PASAT, was observed in both age groups in the high condition. Conclusion. No significant decrements in attention and speeded information processing were observed, with age or altered air velocity, following intermittent exercise in humid heat. PMID:25874223

  3. Effect of heat treatments on the tensile and electrical properties of high-strength, high-conductivity copper alloys

    SciTech Connect

    Zinkle, S.J.; Eatherly, W.S.

    1997-08-01

    The unirradiated tensile properties of CuCrZr produced by two different vendors have been measured following different heat treatments. Room temperature electrical resistivity measurements were also performed in order to estimate the thermal conductivity of these specimens. The thermomechanical conditions studied included solution quenched, solution quenched and aged (ITER reference heat treatment), simulated slow HIP thermal cycle ({approximately}1{degrees}C/min cooling from solutionizing temperature) and simulated fast HIP thermal cycle ({approximately}100{degrees}C/min cooling from solutionizing temperature). Specimens from the last two heat treatments were tested in both the solution-cooled condition and after subsequent precipitate aging at 475{degrees}C for 2 h. Both of the simulated HIP thermal cycles caused a pronounced decreases in the strength and electrical conductivity of CuCrZr. The tensile and electrical properties were unchanged by subsequent aging in the slow HIP thermal cycles caused a pronounced decrease in the strength and electrical conductivity of CuCrZr. The tensile and electrical properties were unchanged by subsequent aging in the slow HIP thermal cycle specimens, whereas the strength and conductivity following aging in the fast HIP thermal cycle improved to {approximately}65% of the solution quenched and aged CuCrZr values. Limited tensile and electrical resistivity measurements were also made on two new heats of Hycon 3HP CuNiBe. High strength but poor uniform and total elongations were observed at 500{degrees}C on one of these new heats of CuNiBe, similar to that observed in other heats.

  4. Heating Location Control of HIFU Treatment Enhanced with Microbubbles

    NASA Astrophysics Data System (ADS)

    Nishihara, T.; Utashiro, H.; Ichiyanagi, M.; Yoshinaka, K.; Takagi, S.; Matsumoto, Y.

    2011-09-01

    High-intensity focused ultrasound (HIFU) treatment using ultrasound contrast microbubbles for enhancing the heating effect has been developed with the aim of realising a less invasive tumor therapy. The focused sound waves result in an increase in temperature and increased thermal absorption, which necroses tumor cells. In addition, microbubbles are used as contrast agents for ultrasound imaging, and, in a previous study, we used microbubbles to enhance the heating effect. However, when microbubbles exist in the ultrasound pathway, they disturb ultrasound propagation and distort the acoustic field. Distortion of the acoustic field leads to defocusing and causes unexpected damage to tissue in the body. The objective of the present study is to propose a method by which to destroy microbubbles in the ultrasound pathway and to focus the thermal energy only at the focal point. The proposed method consists of two steps. The first step is to use repetitive high-intensity, short-burst waves (20 waves) to destroy the microbubbles in the pathway. In the second step, low amplitude continuous waves are sent in order to heat the focal point. This method was successful for a gel containing microbubbles with a void fraction on the order of 10-4. The results of the present study indicate that more microbubbles were destroyed as the non-exposure time and the pulse number were increased during the first step.

  5. The interrealtionship between locally applied heat, ageing and skin blood flow on heat transfer into and from the skin.

    PubMed

    Petrofsky, Jerrold; Alshahmmari, Faris; Yim, Jong Eun; Hamdan, Adel; Lee, Haneul; Neupane, Sushma; Shetye, Gauri; Moniz, Harold; Chen, Wei-Ti; Cho, Sungkwan; Pathak, Kunal; Malthane, Swapnil; Shenoy, Samruddha; Somanaboina, Karunakar; Alshaharani, Mastour; Nevgi, Bhakti; Dave, Bhargav; Desai, Rajavi

    2011-07-01

    In response to a thermal stress, skin blood flow (BF) increases to protect the skin from damage. When a very warm, noxious, heat source (44 °C) is applied to the skin, the BF increases disproportionately faster than the heat stress that was applied, creating a safety mechanism for protecting the skin. In the present investigation, the rate of rise of BF in response to applied heat at temperatures between 32 °C and 40 °C was examined as well as the thermal transfer to and from the skin with and without BF in younger and older subjects to see how the skin responds to a non-noxious heat source. Twenty male and female subjects (10 - 20-35 years, 10 - 40-70 years) were examined. The arms of the subjects were passively heated for 6 min with and without vascular occlusion by a thermode at temperatures of 32, 36, 38 or 40 °C. When occlusion was not used during the 6 min exposure to heat, there was an exponential rise in skin temperature and BF in both groups of subjects over the 6-min period. However, the older subjects achieved similar skin temperatures but with the expenditure of fewer calories from the thermode than was seen for the younger subjects (p<0.05). BF was significantly less in the older group than the younger group at rest and after exposure to each of the three warmest thermode temperatures (p<0.05). As was seen for noxious temperatures, after a delay, the rate of rise of BF at the three warmest thermode temperatures was faster than the rise in skin temperature in the younger group but less in the older group of subjects. Thus, a consequence of ageing is reduced excess BF in response to thermal stress increasing susceptibility to thermal damage. This must be considered in modelling of BF.

  6. Effects of long-term atorvastatin treatment on cardiac aging

    PubMed Central

    HAN, LEI; LI, MINGGAO; LIU, XIN

    2013-01-01

    A number of studies have reported that atorvastatin (AVT) may have an important role in the delay of cardiac aging. However, the mechanism by which AVT affects cardiac aging has not been established. In this study, a series of experiments were performed to investigate the effects of AVT treatment on the cardiovascular system and the associated mechanism. Wistar rats were administered AVT or saline for 4 months. Age-related changes in the hearts were measured at the end of the experiment. The results showed that compared with young rats, the aged rats had significant changes indicative of myocardial aging, including increased blood lipid 1evelss, increased body weight, cardiac hypertrophy, larger myocardial cells, irregular muscle fibers, fewer deeply stained nuclei, smaller intercellular spaces, a larger number of apoptotic cells and increased levels of lipofuscin in myocardial tissue. However, long-term AVT treatment was able to significantly delay or even reverse these aging-related changes. In addition, these effects showed a certain dose-dependence. In general, long-term AVT treatment reduces blood lipids, inhibits cardiac hypertrophy, suppresses cardiomyocyte apoptosis and lowers the level of oxidative stress to protect the heart from aging. PMID:24137254

  7. Effect of Heat Treatment on Mechanical Properties and Microstructure of Four Different Heats of ASTM A710 Steel.

    DTIC Science & Technology

    1985-09-01

    HEAT TREATMENT ON MECHANICAL PROPERTIES t AND MICROSTRUCTURE OF FOUR DIFFERENT HEATS OF ASTM A710 STEEL by G.E. Hicho, C.H. Brady, L.C. Smith, and...Properties and Microstructure of Four Different Heats of ASTM A710 Steel I.E Hicho, C.H. Brady, L.C. Smith and R.J. Fields (" REPORT 13lb TIM E COVERED 14DATE...necessary and Identify by block number) iD GROUP SUBGROUP A710 HSLA Steel Heat Treatment Tensile Properties Grain Size Impact Properties Frnr-ngrphy Mi

  8. 46 CFR 56.80-15 - Heat treatment of bends and formed components.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... installation. (g) Austenitic stainless-steel pipe that has been heated for bending or other forming may be used... components. (a) Carbon-steel piping that has been heated to at least 1,650 °F (898 °C) for bending or other forming requires no subsequent heat treatment. (b) Ferritic alloy steel piping which has been heated...

  9. 46 CFR 56.80-15 - Heat treatment of bends and formed components.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... installation. (g) Austenitic stainless-steel pipe that has been heated for bending or other forming may be used... components. (a) Carbon-steel piping that has been heated to at least 1,650 °F (898 °C) for bending or other forming requires no subsequent heat treatment. (b) Ferritic alloy steel piping which has been heated...

  10. Microstructure Evolution and Mechanical Properties of 2219 Al Alloy During Aging Treatment

    NASA Astrophysics Data System (ADS)

    Wang, Huimin; Yi, Youping; Huang, Shiquan

    2017-03-01

    Hardness and tensile properties of 2219 Al alloys were tested at various temperature (150, 165, 175 °C) and subjected to T6 temper heat treatment to identify the peak aging time at various temperature. Microstructure evolution and precipitate behavior were analyzed with transmission electron microscope (TEM), differential scanning calorimetry (DSC) and x-ray diffraction (XRD). It is found that the peak aging time is 24 h at 150 °C and does not vary down to 165 °C. When the aging temperature rise to 175 °C, the peak aging time down to 12 h. Considering the strength and elongation, the optimum aging treatment is at 165 °C for 24 h after the solution treatment at 535 °C for 1.5 h. Compared with that of only water-quenched sample, after aged at 165 °C for 24 h, the tensile strength of the 2219 Al alloy increases from 324.5 to 411.8 MPa, yield strength from 168 to 310.8 MPa, respectively. The improvement in the mechanical performance is mainly attributed to the precipitation strengthening of the GP zones, θ″ and θ' phases.

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

    DOEpatents

    Kuhlman, Myron Ira; Vinegar; Harold J.; Baker, Ralph Sterman; Heron, Goren

    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.

  12. Spin-rolling, welding, and heat treatment of aluminium 2219 for Ariane 5 GAM high pressure vessel liners

    NASA Astrophysics Data System (ADS)

    Radtke, W.

    1992-10-01

    Cylindrical liners made of Al 2219 may be spinrolled if both recrystallization and metastable precipitates can be avoided during forging or preparatory heat treatment. So welding is to be limited to circumferential joints. Pore-free welds are attainable immediately after hydroxide layer removal by diamond cutting without grease application. The EB vacuum is favorable to porosity suppression. A complete heat treatment of the liner incorporating solutionizing, water quenching and ageing leads to 100 percent weld efficiency. Pressure stabilization avoids buckling. Subsequent carbon fiber winding, curing and plastic prestressing of the liner results in an efficient high pressure vessel for hydrogen service.

  13. Early-age heat exposure affects skeletal muscle satellite cell proliferation and differentiation in chicks.

    PubMed

    Halevy, O; Krispin, A; Leshem, Y; McMurtry, J P; Yahav, S

    2001-07-01

    Exposure of young chicks to thermal conditioning (TC; i.e., 37 degrees C for 24 h) resulted in significantly improved body and muscle growth at a later age. We hypothesized that TC causes an increase in satellite cell proliferation, necessary for further muscle hypertrophy. An immediate increase was observed in satellite cell DNA synthesis in culture and in vivo in response to TC of 3-day-old chicks to levels that were significantly higher than those of control chicks. This was accompanied by a marked induction of insulin-like growth factor-I (IFG-I), but not hepatocyte growth factor in the breast muscle. No significant difference between treatments in plasma IGF-I levels was observed. A marked elevation in muscle regulatory factors on day 5, followed by a decline in cell proliferation on day 6 together with continuous high levels of IGF-I in the TC chick muscle may indicate accelerated cell differentiation. These data suggest a central role for IGF-I in the immediate stimulation of satellite cell myogenic processes in response to heat exposure.

  14. Imprints of zero-age velocity dispersions and dynamical heating on the age-velocity dispersion relation

    NASA Astrophysics Data System (ADS)

    Kumamoto, Jun; Baba, Junichi; Saitoh, Takayuki R.

    2017-03-01

    Observations of stars in the the solar vicinity show a clear tendency of old stars to have larger velocity dispersions. This relation is called the age-velocity dispersion relation (AVR) and it is believed to provide insight into the heating history of the Milky Way galaxy. Here, in order to investigate the origin of the AVR, we performed smoothed particle hydrodynamic simulations of the self-gravitating multiphase gas disks in the static disk-halo potentials. Star formation from cold and dense gas is taken into account, and we analyze the evolution of these star particles. We find that exponents of simulated AVR and the ratio of the radial to vertical velocity dispersion are close to the observed values. We also find that the simulated AVR is not a simple consequence of dynamical heating. The evolution tracks of stars with different epochs evolve gradually in the age-velocity dispersion plane as a result of: (1) the decrease in velocity dispersion in star-forming regions, and (2) the decrease in the number of cold/dense/gas as scattering sources. These results suggest that the AVR involves not only the heating history of a stellar disk, but also the historical evolution of the ISM in a galaxy.

  15. Heat shock proteins: in vivo heat treatments reveal adipose tissue depot-specific effects.

    PubMed

    Rogers, Robert S; Beaudoin, Marie-Soleil; Wheatley, Joshua L; Wright, David C; Geiger, Paige C

    2015-01-01

    Heat treatments (HT) and the induction of heat shock proteins (HSPs) improve whole body and skeletal muscle insulin sensitivity while decreasing white adipose tissue (WAT) mass. However, HSPs in WAT have been understudied. The purpose of the present study was to examine patterns of HSP expression in WAT depots, and to examine the effects of a single in vivo HT on WAT metabolism. Male Wistar rats received HT (41°C, 20 min) or sham treatment (37°C), and 24 h later subcutaneous, epididymal, and retroperitoneal WAT depots (SCAT, eWAT, and rpWAT, respectively) were removed for ex vivo experiments and Western blotting. SCAT, eWAT, and rpWAT from a subset of rats were also cultured separately and received a single in vitro HT or sham treatment. HSP72 and HSP25 expression was greatest in more metabolically active WAT depots (i.e., eWAT and rpWAT) compared with the SCAT. Following HT, HSP72 increased in all depots with the greatest induction occurring in the SCAT. In addition, HSP25 increased in the rpWAT and eWAT, while HSP60 increased in the rpWAT only in vivo. Free fatty acid (FFA) release from WAT explants was increased following HT in the rpWAT only, and fatty acid reesterification was decreased in the rpWAT but increased in the SCAT following HT. HT increased insulin responsiveness in eWAT, but not in SCAT or rpWAT. Differences in HSP expression and induction patterns following HT further support the growing body of literature differentiating distinct WAT depots in health and disease.

  16. Hemodialysis Catheter Heat Transfer for Biofilm Prevention and Treatment

    PubMed Central

    Richardson, Ian P.; Sturtevant, Rachael; Heung, Michael; Solomon, Michael J.; Younger, John G.; VanEpps, J. Scott

    2016-01-01

    Central line-associated bloodstream infections (CLABSIs) are not easily treated and many catheters (e.g., hemodialysis catheters) are not easily replaced. Biofilms (the source of infection) on catheter surfaces are notoriously difficult to eradicate. We have recently demonstrated that modest elevations of temperature lead to increased staphylococcal susceptibility to vancomycin and significantly soften the biofilm matrix. In this study, using a combination of microbiological, computational, and experimental studies, we demonstrate the efficacy, feasibility, and safety of using heat as an adjuvant treatment for infected hemodialysis catheters. Specifically, we show that treating with heat in the presence of antibiotics led to additive killing of Staphylococcus epidermidis with similar trends seen for Staphylococcus aureus and Klebsiella pneumoniae. The magnitude of temperature elevation required is relatively modest (45-50°C) and similar to that used as an adjuvant to traditional cancer therapy. Using a custom-designed benchtop model of a hemodialysis catheter positioned with tip in the human vena cava as well as computational fluid dynamic simulations we demonstrate that these temperature elevations are likely achievable in situ with minimal increased in overall blood temperature. PMID:26501916

  17. Hemodialysis Catheter Heat Transfer for Biofilm Prevention and Treatment.

    PubMed

    Richardson, Ian P; Sturtevant, Rachael; Heung, Michael; Solomon, Michael J; Younger, John G; VanEpps, J Scott

    2016-01-01

    Central line-associated bloodstream infections (CLABSIs) are not easily treated, and many catheters (e.g., hemodialysis catheters) are not easily replaced. Biofilms (the source of infection) on catheter surfaces are notoriously difficult to eradicate. We have recently demonstrated that modest elevations of temperature lead to increased staphylococcal susceptibility to vancomycin and significantly soften the biofilm matrix. In this study, using a combination of microbiological, computational, and experimental studies, we demonstrate the efficacy, feasibility, and safety of using heat as an adjuvant treatment for infected hemodialysis catheters. Specifically, we show that treating with heat in the presence of antibiotics led to additive killing of Staphylococcus epidermidis with similar trends seen for Staphylococcus aureus and Klebsiella pneumoniae. The magnitude of temperature elevation required is relatively modest (45-50°C) and similar to that used as an adjuvant to traditional cancer therapy. Using a custom-designed benchtop model of a hemodialysis catheter, positioned with tip in the human vena cava as well as computational fluid dynamic simulations, we demonstrate that these temperature elevations are likely achievable in situ with minimal increased in overall blood temperature.

  18. Surface modification by alkali and heat treatments in titanium alloys.

    PubMed

    Lee, Baek-Hee; Do Kim, Young; Shin, Ji Hoon; Hwan Lee, Kyu

    2002-09-05

    Pure titanium and titanium alloys are normally used for orthopedic and dental prostheses. Nevertheless, their chemical, biological, and mechanical properties still can be improved by the development of new preparation technologies. This has been the limiting factor for these metals to show low affinity to living bone. The purpose of this study is to improve the bone-bonding ability between titanium alloys and living bone through a chemically activated process and a thermally activated one. Two kinds of titanium alloys, a newly designed Ti-In-Nb-Ta alloy and a commercially available Ti-6Al-4V ELI alloy, were used in this study. In this study, surface modification of the titanium alloys by alkali and heat treatments (AHT), alkali treated in 5.0M NaOH solution, and heat treated in vacuum furnace at 600 degrees C, is reported. After AHT, the effects of the AHT on the bone integration property were evaluated in vitro. Surface morphologies of AHT were observed by optical microscopy (OM) and scanning electron microscopy (SEM). Chemical compositional surface changes were investigated by X-ray diffractometry (XRD), energy dispersive spectroscopy (EDS), and auger electron spectroscopy (AES). Titanium alloys with surface modification by AHT showed improved bioactive behavior, and the Ti-In-Nb-Ta alloy had better bioactivity than the Ti-6Al-4V ELI alloy in vitro.

  19. Treatment of dry age-related macular degeneration with dobesilate

    PubMed Central

    Cuevas, P; Outeiriño, L A; Angulo, J; Giménez-Gallego, G

    2012-01-01

    The authors present anatomical and functional evidences of dry age-macular degeneration improvement, after intravitreal treatment with dobesilate. Main outcomes measures were normalisation of retinal structure and function, assessed by optical coherence tomography, fundus-monitored microperimetry, electrophysiology and visual acuity. The effect might be related to the normalisation of the outer retinal architecture. PMID:22729337

  20. Tolerance of Sitophilus zeamais (Coleoptera: Curculionidae) to heated controlled atmosphere treatments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Combination heat and controlled atmosphere (CA) postharvest phytosanitary treatments are environmentally friendly alternatives to chemical fumigants. A controlled atmosphere/ heating block system (CA-HBS) was used to rapidly assess tolerances of adult maize weevil, Sitophilus zeamais, both under reg...

  1. Influence of various heat treatment stages on evolution of microstructure and grain in H407 steel

    NASA Astrophysics Data System (ADS)

    Sun, Jian; Ji, Kai; Jiang, Chen Wei; Zhang, Yun Chang

    2016-09-01

    Regarding heat treatment as one of the main methods for improving property of die steel, dead annealing, quenching, once tempering, twice tempering, and thrice tempering treatment of H407 die steel were conducted in this thesis. Microstructure conversion and grain size development in various stages of heat treatment were analyzed, and then magnitude, shape, and distribution of secondary phase during heat treatment were investigated to explore the function mechanism of microalloyed elements on evolution of microstructure and grain during heat treatment. The steel achieves homogeneous microstructure and composition after this heat treatment. The final phase constituent is α and γ phase as well as the final microstructure consists of tempered martensite, trace retained austenite and granular carbides. A large number of fine and dispersive MC as well as M7C3 type granular carbides containing V, Mo and Cr precipitate in trice tempered microstructure. After this heat treatment grain is finer with grain size of 5.96 μm.

  2. Hardness and Second Phase Percentage of Ni-Ti-Hf Compounds After Heat Treatment at 700C

    NASA Technical Reports Server (NTRS)

    Stanford, Malcolm K.

    2017-01-01

    The Vickers hardness and second phase precipitation of three ternary intermetallic Ni-Ti-Hf compounds containing either 1, 3 or 5 at.% Hf were compared to 60-Nitinol (55 at.% Ni - 45 at.% Ti). Heat treatment either at 700 C or with a subsequent aging step, hardened the 3 and 5 at.% Hf-containing ternaries to approximately 620 HV (56 HRC). Heat treatment increased the hardness of the 1 at.% Hf compound by more than 25 percent. Average hardness of the 3 and 5 at.% Hf ternaries, though higher than that of the binary Ni-Ti or the Ni-Ti-Hf compound containing 1 at.% Hf, appeared to be fairly insensitive to the different heat treatments. There was a drastic reduction of fatigue-enhancing second phase precipitates for the 5 at.% Hf ternaries compared to the other compounds. These results should guide materials selection for development of aerospace componentry.

  3. Past and present seafloor age distributions and the temporal evolution of plate tectonic heat transport

    NASA Astrophysics Data System (ADS)

    Becker, T. W.; Conrad, C. P.; Buffett, B.; Muller, D.; Loyd, S.; Lithgow-Bertelloni, C.; Corsetti, F.

    2008-12-01

    Variations in the rates of seafloor generation and recycling have potentially far-reaching consequences for sea level, ocean chemistry and climate. A parameterized framework to describe such variations could guide the study of non-uniformitarian plate tectonic activity, but there is little agreement on the appropriate mechanical description of the surface boundary layer. A strong constraint on the statistics of oceanic convection systems comes from the preserved seafloor age distribution, and additional inferences are possible when paleo-seafloor is modeled based on plate motion reconstructions. Based on previously reconstructed seafloor ages, we recently inferred that oceanic heat flow was larger by ~15% at 60~Ma than today. This signal is mainly caused by the smaller plates that existed previously in the Pacific basin with relatively larger ridge-proximal area of young seafloor. The associated decrease in heat flow is larger than any plausible decrease due to cooling, and therefore hint at cyclic behavior in plate tectonics. We also consider area-per-age statistics for the present-day and back to 140~Ma from new paleo-age reconstructions. Using a simplified seafloor age evolution model we explore which physical parameterizations for the average behavior of the oceanic lithosphere are compatible with broad trends in the data. In particular, we show that a subduction probability based on lithospheric buoyancy ("sqrt(age)") leads to results that are comparable to, or better than, that of the probability distribution that is required to obtain the "triangular" age distribution with age-independent destruction of ocean floor. The current, near triangular distribution of ages and the relative lull in heat flow are likely only snapshots of a transient state during the Wilson cycle. Current seafloor ages still contain hints of a ≤sssim 60~Myr period, cyclic variation of seafloor production, and using paleo-ages for 140~Ma, we find a ~ 400~Myr best-fitting variation

  4. Mechanisms of protein modification during model anti-viral heat-treatment bioprocessing of beta-lactoglobulin variant A in the presence of sucrose.

    PubMed

    Smales, C M; Pepper, D S; James, D C

    2000-10-01

    To ensure the safety of plasma and recombinant therapeutic proteins, heat treatment is routinely applied to these biopharmaceuticals as a means of virus inactivation. However, to maintain protein integrity during heat treatment it is necessary to use high concentrations of thermostabilizing excipients, such as sucrose, in order to prevent protein damage. In this study we describe the covalent modifications inferred to a model protein, beta-lactoglobulin A, that occur during typical and extended anti-viral heat treatments. The chemical derivation and mechanisms by which these modifications arise are addressed. Heat treatment initiated hydrolysis of sucrose to glucose and fructose, which in turn were degraded to glyoxal. Glyoxal and the free reducing sugars reacted with free amino groups in beta-lactoglobulin A to yield Maillard glycation adducts and advanced glycation end products (AGEs). The major mechanism for AGE formation was via degradation of glucose-derived Schiff-base adducts. Heat treatment and glycation of beta-lactoglobulin A resulted in thiol-disulphide interchange reactions leading to protein oligomerization. A small population of beta-lactoglobulin A non-disulphide-linked dimers were also observed with increasingly harsh heat treatments. These findings have implications for (i) improvements in the safety and efficacy of heat-treated protein biopharmaceuticals and (ii) our understanding of the mechanisms of protein glycation and AGE adduct formation.

  5. Developments in age-related macular degeneration: Diagnosis and treatment.

    PubMed

    Kaufman, Steven R

    2009-03-01

    Age-related macular degeneration (ARMD) is the leading cause of legal blindness of Americans over age 65 years. Severe loss of vision is usually due to exudative ARMD, of which there are about 200,000 new cases in the United States annually. Until recently, only a small fraction of patients benefited from treatment, but advances in the early diagnosis of the disease and major developments in therapy have substantially improved the prognosis of patients with ARMD. Because visual loss substantially reduces quality of life, effective management of ARMD will have increasing public health importance as the population ages. The American Academy of Ophthalmology recommends that people over age 65 years should have a comprehensive eye examination every 1 to 2 years to check for cataracts, macular degeneration, glaucoma, and other conditions. Those who complain of difficulty reading, driving at night, or adapting from sunlight to indoor lighting might have macular degeneration.

  6. Age-velocity dispersion relations and heating histories in disc galaxies

    NASA Astrophysics Data System (ADS)

    Aumer, Michael; Binney, James; Schönrich, Ralph

    2016-10-01

    We analyse the heating of stellar discs by non-axisymmetric structures and giant molecular clouds (GMCs) in N-body simulations of growing disc galaxies. The analysis resolves long-standing discrepancies between models and data by demonstrating the importance of distinguishing between measured age-velocity dispersion relations (AVRs) and the heating histories of the stars that make up the AVR. We fit both AVRs and heating histories with formulae ∝tβ and determine the exponents βR and βz derived from in-plane and vertical AVRs and tilde{β }_R and tilde{β }_z from heating histories. Values of βz are in almost all simulations larger than values of tilde{β }_z, whereas values of βR are similar to or mildly larger than values of tilde{β }_R. Moreover, values of βz (tilde{β }_z) are generally larger than values of βR (tilde{β }_R). The dominant cause of these relations is the decline over the life of the disc in importance of GMCs as heating agents relative to spiral structure and the bar. We examine how age errors and biases in solar neighbourhood surveys influence the measured AVR: they tend to decrease β values by smearing out ages and thus measured dispersions. We compare AVRs and velocity ellipsoid shapes σz/σR from simulations to solar neighbourhood data. We conclude that for the expected disc mass and dark halo structure, combined GMC and spiral/bar heating can explain the AVR of the Galactic thin disc. Strong departures of the disc mass or the dark halo structure from expectation spoil fits to the data.

  7. Mild heat treatments induce long-term changes in metabolites associated with energy metabolism in Drosophila melanogaster.

    PubMed

    Sarup, Pernille; Petersen, Simon Metz Mariendal; Nielsen, Niels Chr; Loeschcke, Volker; Malmendal, Anders

    2016-11-01

    Heat-induced hormesis, the beneficial effect of mild heat-induced stress, increases the average lifespan of many organisms. Yet little is known about the mechanisms underlying this effect. We used nuclear magnetic resonance spectroscopy to investigate the long-term effects of repeated mild heat treatments on the metabolome of male Drosophila melanogaster. 10 days after the heat treatment, metabolic aging appears to be slowed down, and a treatment response with 40 % higher levels of alanine and lactate and lower levels of aspartate and glutamate were measured. All treatment effects had disappeared 16 days later. Metabolic reprogramming has been associated with the life extending effects of dietary restriction. The metabolite changes induced by the hormetic treatment suggest that the positive effects might not be limited to the repair pathways induced, but that there also is a change in energy metabolism. A possible direct link between changes in energy metabolism and heat induced increase in Hsp70 expression is discussed.

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

    PubMed

    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.

  9. Charpy impact toughness of martensitic steels irradiated in FFTF: Effect of heat treatment

    SciTech Connect

    Klueh, R.L.; Alexander, D.J.

    1992-12-31

    Charpy tests were made on plates of 9Cr-1MoVNb and 12Cr-1MoVW steels given four different normalizing-and-tempering treatments. One-third-size Charpy specimens from each steel were irradiated to 7.4-8 {times} 10{sup 26} n/m{sup 2} (about 34--37 dpa) at 420C in the Materials Open Test Assembly of the Fast Flux Test Facility. Specimens were also thermally aged to 20000 h at 400C to determine the effect of aging during irradiation. Previous work on these steels irradiated to 4--5 dpa at 365C in MOTA were reexamined in light of the new results. The tests indicated that prior austenite grain size, which was varied by different normalizing treatments, had an effect on impact behavior of the 9Cr-1MoVNb but not on the 12Cr-1MoVW. Tempering treatment had relatively little effect on the shift in DBTT for both steels. conclusions are presented on how heat treatment can be used to optimize properties.

  10. Charpy impact toughness of martensitic steels irradiated in FFTF: Effect of heat treatment

    SciTech Connect

    Klueh, R.L.; Alexander, D.J.

    1992-01-01

    Charpy tests were made on plates of 9Cr-1MoVNb and 12Cr-1MoVW steels given four different normalizing-and-tempering treatments. One-third-size Charpy specimens from each steel were irradiated to 7.4-8 [times] 10[sup 26] n/m[sup 2] (about 34--37 dpa) at 420C in the Materials Open Test Assembly of the Fast Flux Test Facility. Specimens were also thermally aged to 20000 h at 400C to determine the effect of aging during irradiation. Previous work on these steels irradiated to 4--5 dpa at 365C in MOTA were reexamined in light of the new results. The tests indicated that prior austenite grain size, which was varied by different normalizing treatments, had an effect on impact behavior of the 9Cr-1MoVNb but not on the 12Cr-1MoVW. Tempering treatment had relatively little effect on the shift in DBTT for both steels. conclusions are presented on how heat treatment can be used to optimize properties.

  11. Apparatus for microwave heat treatment of manufactured components

    DOEpatents

    Ripley, Edward B.

    2008-04-15

    An apparatus for heat treating manufactured components using microwave energy and microwave susceptor material. Heat treating medium such as eutectic salts may be employed. A fluidized bed introduces process gases which may include carburizing or nitriding gases. The process may be operated in a batch mode or continuous process mode. A microwave heating probe may be used to restart a frozen eutectic salt bath.

  12. Methods for microwave heat treatment of manufactured components

    DOEpatents

    Ripley, Edward B.

    2010-08-03

    An apparatus for heat treating manufactured components using microwave energy and microwave susceptor material. Heat treating medium such as eutectic salts may be employed. A fluidized bed introduces process gases which may include carburizing or nitriding gases. The process may be operated in a batch mode or continuous process mode. A microwave heating probe may be used to restart a frozen eutectic salt bath.

  13. Effect of heat treatment on stiffness and damping of SiC/Ti-15-3

    NASA Technical Reports Server (NTRS)

    Grady, Joseph E.; Lerch, Bradley A.

    1992-01-01

    The effect of heat treatment on material properties of SiC/Ti-15-3 was measured by vibration tests. Heat treatment changes the microstructure, which was found to stiffen the matrix and reduce its damping capacity. Test results indicate how these changes in the matrix affect the corresponding properties of the composite. Measurements show that heat treatment affects damping properties of the composite to a greater extent than stiffness properties. The extent of change in mechanical properties is shown to depend on heat treatment temperature and exposure time.

  14. Aging assessment of nuclear air-treatment system HEPA filters and adsorbers. Volume 1, Phase 1

    SciTech Connect

    Winegardner, W.K.

    1993-08-01

    A Phase I aging assessment of high-efficiency particulate air (HEPA) filters and activated carbon gas adsorption units (adsorbers) was performed by the Pacific Northwest Laboratory (PNL) as part of the US Nuclear Regulatory Commission`s (NRC) Nuclear Plant Aging Research (NPAR) Program. Information concerning design features; failure experience; aging mechanisms, effects, and stressors; and surveillance and monitoring methods for these key air-treatment system components was compiled. Over 1100 failures, or 12 percent of the filter installations, were reported as part of a Department of Energy (DOE) survey. Investigators from other national laboratories have suggested that aging effects could have contributed to over 80 percent of these failures. Tensile strength tests on aged filter media specimens indicated a decrease in strength. Filter aging mechanisms range from those associated with particle loading to reactions that alter properties of sealants and gaskets. Low radioiodine decontamination factors associated with the Three Mile Island (TMI) accident were attributed to the premature aging of the carbon in the adsorbers. Mechanisms that can lead to impaired adsorber performance include oxidation as well as the loss of potentially available active sites as a result of the adsorption of pollutants. Stressors include heat, moisture, radiation, and airborne particles and contaminants.

  15. Growth response of weanling rats to heated, aged, fractionated, and chemically treated yogurts.

    PubMed

    Hargrove, R E; Alford, J A

    1980-07-01

    Significance of viable cultures in yogurt at time of ingestion on rate of growth of weaning rats was determined. Fresh yogurts were compared with those in which cultures were treated with heat, hydrogen peroxide, and ethylene oxide. They also were aged and freeze-dried. Fractions of yogurt prepared by ultrafiltration were recombined to determine which fraction gave the highest rate of gain in weight. Cultures were inactivated and growth in rats was depressed when yogurt was heated at 60 C and above for 2 min. Hydrogen peroxide reduced the viable yogurt count and rate of gain but not feed consumption. Yogurts treated with ethylene oxide were toxic. Aging did not effect culture viability or feed efficiency, but growth response was reduced. Fractionation of yogurt into components of high and low molecular weight and recombinations with control milk fractions indicated that the growth stimulant remained in the component of high molecular weight.

  16. Influences of post-weld heat treatment on tensile properties of friction stir-welded AA6061 aluminum alloy joints

    SciTech Connect

    Elangovan, K.; Balasubramanian, V.

    2008-09-15

    This paper reports on studies of the influences of various post-weld heat treatment procedures on tensile properties of friction stir-welded AA6061 aluminum alloy joints. Rolled plates of 6-mm thick AA6061 aluminum alloy were used to fabricate the joints. Solution treatment, an artificial aging treatment and a combination of both were given to the welded joints. Tensile properties such as yield strength, tensile strength, elongation and joint efficiency were evaluated. Microstructures of the welded joints were analyzed using optical microscopy and transmission electron microscopy. A simple artificial aging treatment was found to be more beneficial than other treatment methods to enhance the tensile properties of the friction stir-welded AA6061 aluminum alloy joints.

  17. Temperature Profile Measurements During Heat Treatment of BSCCO 2212 Coils

    SciTech Connect

    Tollestrup, Alvin; /Fermilab

    2011-04-14

    The temperature profile of two different BSCCO 2212 coils has been analyzed. The profiles are obtained from thermocouples imbedded in the windings during the heat treatment that activates the 2212. The melting and freezing of the 2212 is clearly observed. A model that describes the data and can be used to guide the processing of new coils has been developed. We have obtained the thermal history of two BSCCO coils, one from NHMFL (1) that had 10 layers of 1 mm diameter wire with 0.15 mm insulation and a second coil from OST that had 24 layers with similar insulation and conductor size. Both coils had thermocouples imbedded in the windings and excellent recordings of the temperature over the whole reaction cycle were available for analysis. There are several features that we will address in this note. Measurements have shown that the I{sub c} of the conductor is a sensitive function of its thermal history. This brings up the question of the absolute accuracy of the thermometry in the range around 882 C, the MP of 2212. The reference for the treatment profile is really related to this MP and to small deviations around it. Since the heat of fusion of 2212 is rather large, it generates a clear signal during the melting and cooling transition that automatically generates the relative temperature markers. The physics is the same as the way ice in water maintains an isothermal environment until it is all melted. A related question is the thermal response time of the coil package. The temperature cycles that are being used to optimize strand and small coils can have rapid changes easily implemented whereas a large coil may have such a large thermal time constant that the optimum cycle may not be attainable. A simple analytical model that works well for small solenoids has been developed and an ANSYS (5) program that works for larger coils with more complicated geometry has been set up but will not be discussed in this note.

  18. A conservative treatment for plastic bronchitis in pediatric age.

    PubMed

    Berlucchi, Marco; Pelucchi, Francesca; Timpano, Silviana; Zorzi, Annalisa; Padoan, Rita

    2014-01-01

    Plastic bronchitis is a rare disorder in pediatric age. This disease can cause life-threatening episodes. Broncoscopy plus bronchial lavage is considered the gold standard therapeutic technique. Knowledge of this disease is mandatory to perform correct diagnosis and provide prompt treatment. The authors report the history of a 5-year-old girl affected by plastic bronchitis who was successfully treated by a conservative therapy avoiding the traditional more invasive management.

  19. Treatment Moderators and Predictors of Outcome in the Treatment of Early Age Mania (TEAM) Study

    ERIC Educational Resources Information Center

    Vitiello, Benedetto; Riddle, Mark A.; Yenokyan, Gayane; Axelson, David A.; Wagner, Karen D.; Joshi, Paramjit; Walkup, John T.; Luby, Joan; Birmaher, Boris; Ryan, Neal D.; Emslie, Graham; Robb, Adelaide; Tillman, Rebecca

    2012-01-01

    Objective: Both the diagnosis and treatment of bipolar disorder in youth remain the subject of debate. In the Treatment of Early Age Mania (TEAM) study, risperidone was more effective than lithium or divalproex in children diagnosed with bipolar mania and highly comorbid with attention-deficit/hyperactivity disorder (ADHD). We searched for…

  20. Effect of crystallization heat treatment on the microstructure of niobium-doped fluorapatite glass-ceramics.

    PubMed

    Denry, I; Holloway, J A; Gupta, P K

    2012-07-01

    Our goal was to study the effect of heat treatment temperature and heating rate on the microstructure and crystalline phases and assess the domain of existence of submicrometer fluorapatite crystals in niobium-doped fluorapatite glass-ceramics for biomedical applications. Glass-ceramic specimens were prepared by casting and heat treatment between 700 and 1200°C using a fast or a slow heating rate. The microstructure was characterized by atomic force microscopy and scanning electron microscopy. Crystalline phases were analyzed by x-ray diffraction. AFM of the as-cast glass revealed that amorphous phase separation occurred in this system. XRD confirmed the presence of fluorapatite in all specimens, together with forsterite and enstatite at higher temperatures. Both heating rate and heat treatment temperature strongly influenced microstructure and crystallinity. A dual microstructure with submicrometer fluorapatite crystals and polygonal forsterite crystals was obtained when slow heating rates and crystallization temperatures between 950 and 1100°C were used. Needle-shaped fluorapatite crystals appeared after heat treatment above 1100°C. Fast heating rates led to an increase in crystal size. Heat treatment temperatures should remain below 1100°C, together with slow heating rates, to prevent crystal dissolution, and preserve a dual microstructure of finely dispersed submicrometer crystals without growth of needle-shaped crystals.

  1. THE EFFECTS OF HYDROGEN, TRITIUM, AND HEAT TREATMENT ON THE DEFORMATION AND FRACTURE TOUGHNESS PROPERTIES OF STAINLESS STEEL

    SciTech Connect

    Morgan, M.; Tosten, M.; Chapman, G.

    2013-09-06

    The deformation and fracture toughness properties of forged stainless steels pre-charged with tritium were compared to the deformation and fracture toughness properties of the same steels heat treated at 773 K or 873 K and precharged with hydrogen. Forged stainless steels pre-charged with tritium exhibit an aging effect: Fracture toughness values decrease with aging time after precharging because of the increase in concentration of helium from tritium decay. This study shows that forged stainless steels given a prior heat treatment and then pre-charged with hydrogen also exhibit an aging effect: Fracture toughness values decrease with increasing time at temperature. A microstructural analysis showed that the fracture toughness reduction in the heat-treated steels was due to patches of recrystallized grains that form within the forged matrix during the heat treatment. The combination of hydrogen and the patches of recrystallized grains resulted in more deformation twinning. Heavy deformation twinning on multiple slip planes was typical for the hydrogen-charged samples; whereas, in the non-charged samples, less twinning was observed and was generally limited to one slip plane. Similar effects occur in tritium pre-charged steels, but the deformation twinning is brought on by the hardening associated with decay helium bubbles in the microstructure.

  2. Phase Transformation of Calcium Phosphates by Electrodeposition and Heat Treatment

    NASA Astrophysics Data System (ADS)

    Shih, Wei-Jen; Wang, Moo-Chin; Chang, Kuo-Ming; Wang, Cheng-Li; Wang, Szu-Hao; Li, Wang-Long; Huang, Hong-Hsin

    2010-12-01

    The effect of heat treatment on the calcium phosphate deposited on Ti-6Al-4V substrate using an electrolytic process is investigated. The calcium phosphate was deposited in a 0.04 M Ca(H2PO4)2·H2O (MCPM) solution on a Ti-6Al-4V substrate at 333 K (60 °C), 10 V, and 80 Torr for 1 hour, and calcined at various temperatures for 4 hours. The X-ray diffraction (XRD) results demonstrate that the phases are dicalcium phosphate (CaHPO4, DCPD) and hydroxyapatile [Ca(PO4)6 (OH)2, HAP] for the as-deposited samples. When the deposited sample was calcined at 873 K (600 °C) for 4 hours, the XRD results show that the transformation of DCPD to HAP occurs. Moreover, HAP converts to β-TCP, CPP, and CaO. For the sample calcined at 1073 K (800 °C) for 4 hours, the scanning electron microscopy (SEM) micrograph reveals that the crack of the calcined sample propagates with a width of about 3 μm. This result is due to HAP becoming decomposed and converting to β-TCP, CPP, CaO, and H2O. The vaporization of H2O within the calcined sample promotes the crack propagation and growth.

  3. Assessing heat treatment of chicken breast cuts by impedance spectroscopy.

    PubMed

    Schmidt, Franciny C; Fuentes, Ana; Masot, Rafael; Alcañiz, Miguel; Laurindo, João B; Barat, José M

    2017-03-01

    The aim of this work was to develop a new system based on impedance spectroscopy to assess the heat treatment of previously cooked chicken meat by two experiments; in the first, samples were cooked at different temperatures (from 60 to 90 ℃) until core temperature of the meat reached the water bath temperature. In the second approach, temperature was 80 ℃ and the samples were cooked for different times (from 5 to 55 min). Impedance was measured once samples had cooled. The examined processing parameters were the maximum temperature reached in thermal centre of the samples, weight loss, moisture and the integral of the temperature profile during the cooking-cooling process. The correlation between the processing parameters and impedance was studied by partial least square regressions. The models were able to predict the studied parameters. Our results are essential for developing a new system to control the technological, sensory and safety aspects of cooked meat products on the whole meat processing line.

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

    SciTech Connect

    Pawel, Steven J; Hsu, Julia

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

    NASA Astrophysics Data System (ADS)

    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 %.

  6. Anti-inflammatory peptide regulates the supply of heat shock protein 70 monomers: implications for aging and age-related disease.

    PubMed

    Cunningham, Timothy J; Greenstein, Jeffrey I; Loewenstern, Joshua; Degermentzidis, Elias; Yao, Lihua

    2015-04-01

    Reducing the levels of toxic protein aggregates has become a focus of therapy for disorders like Alzheimer's and Parkinson's diseases, as well as for the general deterioration of cells and tissues during aging. One approach has been an attempt to influence the production or activity of a class of reparative chaperones called heat shock proteins (HSPs), of which HSP70 is a promising candidate. Manipulation of HSP70 expression results in disposal of misfolded protein aggregates that accumulate in aging and disease models. Recently, HSP70 has been shown to bind specifically to an amino-terminal sequence of a human diffusible survival evasion peptide (DSEP), dermcidin. This sequence includes CHEC-9, an orally available anti-inflammatory and cell survival peptide. In the present study, we found that the CHEC-9 peptide also binds HSP70 in the cytosol of the cerebral cortex after oral delivery in normal rats. Western analysis of non-heat-denatured, unreduced samples suggested that peptide treatment increased the level of active HSP70 monomers from the pool of chaperone oligomers, a process that may be stimulated by potentiation of the chaperone's adenosine triphosphatase (ATPase). In these samples, a small but consistent gel shift was observed for glyceraldehyde 3-phosphate dehydrogenase (GAPDH), a multifunctional protein whose aggregation is influenced by HSP70. CHEC-9 treatment of an in vitro model of α-synuclein aggregation also results in HSP70-dependent dissolution of these aggregates. HSP70 oligomer-monomer equilibrium and its potential to control protein aggregate disease warrant increased experimental attention, especially if a peptide fragment of an endogenous human protein can influence the process.

  7. Diagnosis and Treatment of Dementia in the Aged

    PubMed Central

    Small, Gary W.; Jarvik, Lissy F.; Liston, Edward H.

    1981-01-01

    Dementia affects an estimated 5 percent of the population 65 years of age and older, with 20 percent being affected at 75 years or older. Although the most common forms, primary degenerative and multi-infarct dementia, currently lack specific treatments, it is estimated that a thorough diagnostic evaluation will uncover a treatable cause in 10 percent to 20 percent. The differential diagnosis includes benign senescent forgetfulness, depression, adjustment disorder, paranoid states, amnestic syndrome, delirium, drug effects, systemic illnesses and intracranial conditions. The approach to each patient involves a history, physical examination, mental status evaluation and laboratory tests that focus on identifying treatable conditions. When no specific treatments are available, however, symptomatic treatments, including pharmacotherapy, environmental management, family supports and psychotherapy, can offer relief for both patients and their families and improve the daily functioning of the elderly patient with dementia. PMID:6121426

  8. Weld repair of carbon-moly coke drums without postweld heat treatment

    SciTech Connect

    Moore, D.E.

    1996-06-01

    Investigations to evaluate weld repair of C-{1/2}Mo coke drums without postweld heat treatment (PWHT) are discussed in this paper. These investigations showed that shielded metal-arc welding (SMAW) without PWHT produced heat-affected zones (HAZ) and weld deposits with Charpy V-notch (CVN) impact toughness that exceeded the toughness of ex-service plate material. PWHT de-embrittles strain age-embrittled ex-service plate material. However, warming of drums to 200 F before putting in feed compensates for the omission of the de-embrittling PWHT. Additional testing showed that the de-embrittling PWHT did not significantly improve the fatigue properties of the ex-service plate material. As-welded SMAW repairs were found to be feasible for coke drums, and repairs have now been in service successfully for up to 2 years. The as-welded SMAW repairs were qualified on the basis of a 300 F preheat using small diameter electrodes for the first pass followed by larger diameter electrodes to temper the HAZ of the first pass. A half-bead technique was not used. Heat input is not precisely controlled as would be required for controlled deposition welding. Following the implementation of SMAW repairs without PWHT, the author extended the work to include as-welded repairs with automatic gas metal-arc welding (GMAW).

  9. Past and present seafloor age distributions and the temporal evolution of plate tectonic heat transport

    NASA Astrophysics Data System (ADS)

    Becker, Thorsten W.; Conrad, Clinton P.; Buffett, Bruce; Müller, R. Dietmar

    2009-02-01

    Variations in Earth's rates of seafloor generation and recycling have far-reaching consequences for sea level, ocean chemistry, and climate. However, there is little agreement on the correct parameterization for the time-dependent evolution of plate motions. A strong constraint is given by seafloor age distributions, which are affected by variations in average spreading rate, ridge length, and the age distribution of seafloor being removed by subduction. Using a simplified evolution model, we explore which physical parameterizations of these quantities are compatible with broad trends in the area per seafloor age statistics for the present-day and back to 140 Ma from paleo-age reconstructions. We show that a probability of subduction based on plate buoyancy (slab-pull, or "sqrt(age)") and a time-varying spreading rate fits the observed age distributions as well as, or better than, a subduction probability consistent with an unvarying "triangular" age distribution and age-independent destruction of ocean floor. Instead, we interpret the present near-triangular distribution of ages as a snapshot of a transient state of the evolving oceanic plate system. Current seafloor ages still contain hints of a ˜ 60 Myr periodicity in seafloor production, and using paleoages, we find that a ˜ 250 Myr period variation is consistent with geologically-based reconstructions of production rate variations. These long-period variations also imply a decrease of oceanic heat flow by ˜ - 0.25%/Ma during the last 140 Ma, caused by a 25-50% decrease in the rate of seafloor production. Our study offers an improved understanding of the non-uniformitarian evolution of plate tectonics and the interplay between continental cycles and the self-organization of the oceanic plates.

  10. Charpy impact toughness of martensitic steels irradiated in FFTF: Effect of heat treatment

    SciTech Connect

    Klueh, R.L.; Alexander, D.J.

    1992-12-31

    Plates of 9Cr-1MoVNb and 12Cr-1 MoVW steels were normalized and then tempered at two different tempering conditions. One-third-size Charpy specimens from each steel were irradiated to 7.4-8{times}10{sup 26} n/m{sup 2} (about {approximately}35 dpa) at 420{degrees}C in the Materials Open Test Assembly (MOTA) of the Fast Flux Test Facility. Specimens were also thermally aged to 20,000 h at 400{degrees}C to compare the effect of aging and irradiation. Previous work on the steels irradiated to 4-5 dpa at 365{degrees}C in MOTA were reexamined in light of the new results. The tests indicated that prior-austenite grain size, which was varied by different normalizing treatments, had an effect on impact behavior of the 9Cr-1MoVNb but not on the 12Cr-1MoVW. Tempering treatment had relatively little effect on the shift in DBTT for both steels. Conclusions are presented on how heat treatment can be used to optimize properties.

  11. Effect of Aging Treatment on the Damping Capacity and Mechanical Properties of Mg-6Al-1Zn Alloy

    PubMed Central

    El-Morsy, Abdel-Wahab; Farahat, Ahmed I. Z.

    2015-01-01

    The damping capacity and mechanical properties of Mg-6Al-1Zn alloy after heat treatment were investigated. The damping characteristics of un-heat-treated, solution treated, and aged Mg-6Al-1Zn specimens were determined by measuring the damping ratio and the logarithmic decrement of free vibrations of a bending beam clamped at one side. The microstructural evaluations confirmed that the β-Mg17Al12 phase was reprecipitated after aging and increased with an increase in aging time. The peak level of damping ratio and logarithmic decrement was obtained after 34 hr of aging time, over which the damping capacity declined according to increasing amount of strong pining points. PMID:25918738

  12. The Effect of the Heat Treatment on the Dust Emission During Machining of an Al-7Si-Mg Cast Alloys

    NASA Astrophysics Data System (ADS)

    Djebara, A.; Zedan, Y.; Kouam, J.; Songmene, V.

    2013-12-01

    This paper reports on the effect of artificial aging on the machinability of Al-7Si-Mg (A356) cast alloys for the as-received alloy, solution heat-treated (SHT) alloy and then aged SHT alloy at 155, 180, and 220 °C, respectively. The influence of heat treatment on the machinability of the alloys studied was considered using innovative criteria such as dust emission. The effect of various lubrication modes including dry, mist, and wet process, as well as cutting speed and feed rate, was also investigated. The results obtained from the statistically designed experiments indicate that at the same cutting conditions, the A356-T7 heat treatment generates less dust emission level compared to other various heat treatments (there is 32% less airborne swarf produced than with A356-T6). Aging at low temperature was observed to produce the greatest level of the dust emission while the aging at higher temperatures is accompanied by a reduction in the dust emission level. Fracture surface analysis using scanning electron microscope, has shown that dust emission levels were strongly dependent on the nature of the fracture surface of the alloys studied, with different heat treatments. A change in chip formation was also found to be a function of age hardening and dust emission during machining of the tested aluminum alloy. A correlation was established between the cutting speed, the feed rate, and the dust emission, which is useful for determining the conditions required for minimal dust emission.

  13. Promoting Bacillus cereus spore germination for subsequent inactivation by mild heat treatment.

    PubMed

    Løvdal, Irene Stranden; Hovda, Maria Befring; Granum, Per Einar; Rosnes, Jan Thomas

    2011-12-01

    Sublethal heat treatment may activate dormant spores and thereby potentiate the conversion of spores to vegetative cells. As the germinated spore is known to possess lower heat resistance than its dormant counterpart, it has been postulated that double heat treatment, i.e., spore heat activation followed by germination and then by heat inactivation, can be used to control spores in foods. Production of refrigerated processed foods of extended durability often includes more than one heat treatment of the food components. This work simulates conventional heat treatment procedures and evaluates double heat treatment as a method to improve spore control in model food matrixes of meat broth and cream sauce. Bacillus cereus NVH 1230-88 spores were supplemented in food model matrixes and heat activated at 70°C and then heat inactivated at 80 or 90°C. The samples were held at 29 to 30°C for 1 h between primary and secondary heat treatments, to allow spore germination. Nutrients naturally present in the food matrixes, e.g., amino acids and inosine, could act as germinants that induce germination. The levels of germinants could be too low to produce effective germination within 1 h. Following primary heat treatment, some samples were therefore supplemented with a combination of L-alanine and inosine, a germinant mixture known to be effective for B. cereus spores. In both matrixes, a combination of double heat treatment (heat activation, germination, and inactivation) and addition of germinants gave a reduction in spore counts equivalent to or greater than that obtained with a single heat treatment for 12 min at 90°C. Addition of germinants was essential to induce effective germination in cream sauce during 1 h at 29 to 30°C, and germinants were therefore a crucial supplement to obtain an effect of double heat treatment in this matrix. These data will be valuable when setting up temperature-time-germinant combinations for an optimized spore reduction in mild-heat

  14. Optimization of the Process of Carburizing and Heat Treatment of Low-Carbon Martensitic Steels

    NASA Astrophysics Data System (ADS)

    Ivanov, A. S.; Greben'kov, S. K.; Bogdanova, M. V.

    2016-05-01

    Steel 24Kh2G2NMFB is studied after carburizing and different heat treatments. The hardness and microhardness of the surface layer and of the matrix are measured. The content of retained austenite is determined by the method of x-ray diffraction analysis. Heat treatment modes improving the structure of the surface layer after carburizing are suggested.

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

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 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...

  16. 49 CFR 179.201-5 - Postweld heat treatment and corrosion resistance.

    Code of Federal Regulations, 2010 CFR

    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...

  17. 49 CFR 179.201-5 - Postweld heat treatment and corrosion resistance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 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...

  18. 49 CFR 179.201-5 - Postweld heat treatment and corrosion resistance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 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...

  19. 49 CFR 179.201-5 - Postweld heat treatment and corrosion resistance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 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...

  20. 46 CFR 56.80-15 - Heat treatment of bends and formed components.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... forming requires no subsequent heat treatment. (b) Ferritic alloy steel piping which has been heated for... ferritic-alloy pipe in nominal pipe sizes of 4 inches and larger, or one-half-inch wall thickness or heavier, will require a stress-relieving treatment. (d) Cold bending of carbon-steel and...

  1. 46 CFR 56.80-15 - Heat treatment of bends and formed components.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... forming requires no subsequent heat treatment. (b) Ferritic alloy steel piping which has been heated for... ferritic-alloy pipe in nominal pipe sizes of 4 inches and larger, or one-half-inch wall thickness or heavier, will require a stress-relieving treatment. (d) Cold bending of carbon-steel and...

  2. Protein carbonylation and heat shock proteins in human skeletal muscle: relationships to age and sarcopenia.

    PubMed

    Beltran Valls, Maria R; Wilkinson, Daniel J; Narici, Marco V; Smith, Kenneth; Phillips, Bethan E; Caporossi, Daniela; Atherton, Philip J

    2015-02-01

    Aging is associated with a gradual loss of muscle mass termed sarcopenia, which has significant impact on quality-of-life. Because oxidative stress is proposed to negatively impact upon musculoskeletal aging, we investigated links between human aging and markers of oxidative stress, and relationships to muscle mass and strength in young and old nonsarcopenic and sarcopenic adults. Sixteen young and 16 old males (further subdivided into "old" and "old sarcopenic") were studied. The abundance of protein carbonyl adducts within skeletal muscle sarcoplasmic, myofibrillar, and mitochondrial protein subfractions from musculus vastus lateralis biopsies were determined using Oxyblot immunoblotting techniques. In addition, concentrations of recognized cytoprotective proteins (eg, heat shock proteins [HSP], αβ-crystallin) were also assayed. Aging was associated with increased mitochondrial (but not myofibrillar or sarcoplasmic) protein carbonyl adducts, independently of (stage-I) sarcopenia. Correlation analyses of all subjects revealed that mitochondrial protein carbonyl abundance negatively correlated with muscle strength ([1-repetition maximum], p = .02, r (2) = -.16), but not muscle mass (p = .13, r (2) = -.08). Abundance of cytoprotective proteins, including various HSPs (HSP 27 and 70), were unaffected by aging/sarcopenia. To conclude, these data reveal that mitochondrial protein carbonylation increases moderately with age, and that this increase may impact upon skeletal muscle function, but is not a hallmark of (stage-I) sarcopenia, per se.

  3. The Effect of Heat Treatment on Residual Stress and Machining Distortions in Advanced Nickel Base Disk Alloys

    NASA Technical Reports Server (NTRS)

    Gayda, John

    2001-01-01

    This paper describes an extension of NASA's AST and IDPAT Programs which sought to predict the effect of stabilization heat treatments on residual stress and subsequent machining distortions in the advanced disk alloy, ME-209. Simple "pancake" forgings of ME-209 were produced and given four heat treats: 2075F(SUBSOLVUS)/OIL QUENCH/NO AGE; 2075F/OIL QUENCH/1400F@8HR;2075F/OIL QUENCH/1550F@3HR/l400F@8HR; and 2160F(SUPERSOLVUS)/OIL QUENCH/1550F@3HR/ 1400F@8HR. The forgings were then measured to obtain surface profiles in the heat treated condition. A simple machining plan consisting of face cuts from the top surface followed by measurements of the surface profile opposite the cut were made. This data provided warpage maps which were compared with analytical results. The analysis followed the IDPAT methodology and utilized a 2-D axisymmetric, viscoplastic FEA code. The analytical results accurately tracked the experimental data for each of the four heat treatments. The 1550F stabilization heat treatment was found to significantly reduce residual stresses and subsequent machining distortions for fine grain (subsolvus) ME209, while coarse grain (supersolvus) ME209 would require additional time or higher stabilization temperatures to attain the same degree of stress relief.

  4. Solar Injury and Heat Illness. Treatment and Prevention in Children.

    ERIC Educational Resources Information Center

    Gutierrez, Greg

    1995-01-01

    Children are especially vulnerable to solar injury and heat illness. Physicians can lower children's risk through education about short-term and long-term sequelae and through various prevention efforts. The paper discusses how to screen for risk factors and how to prevent and treat heat illness and solar injury. (SM)

  5. Predicting heat inactivation of Staphylococcus aureus under nonisothermal treatments at different pH.

    PubMed

    Hassani, Mounir; Mañas, Pilar; Condón, Santiago; Pagán, Rafael

    2006-05-01

    The aim was to assess whether heat resistance data obtained from isothermal treatments allow the estimation of survivors of Staphylococcus aureus under nonisothermal conditions and to find a model that accurately predicts its heat inactivation at constantly rising heating rates (0.5-9 degrees C/min) in media of different pH (4.0-7.4). S. aureus showed a higher heat resistance under isothermal treatments at pH 4.0 than at pH 5.5-7.4. However, under nonisothermal treatments S. aureus increased its heat resistance at pH 5.5-7.4 and became more thermotolerant than at pH 4.0. Estimations of survival curves under nonisothermal treatments obtained from heat resistance parameters of isothermal treatments did not adequately fit experimental values. Whereas the number of survivors was much higher than estimated at pH 5.5-7.4, that obtained at the slower heating rates at pH 4.0 was lower. An equation based on the Weibullian-like distribution (log10 S(t) = (t/delta)p) accurately described survival curves obtained under nonisothermal conditions. A nonlinear relationship was observed among the scale parameter (delta) and the heating rate which allowed the development of two equations capable of predicting the inactivation rate of S. aureus under nonisothermal treatments. This study might contribute to prevent public health risks in foods requiring long heating lag phases during their processing.

  6. Effect of heat treatment on nutritional quality of germinated legume seeds.

    PubMed

    Trugo, L C; Donangelo, C M; Trugo, N M; Bach Knudsen, K E

    2000-06-01

    The effect of heat treatment of germinated soybean, lupin, and black bean on chemical composition and protein utilization in rats was evaluated. Heat treatment caused complete inactivation of trypsin inhibitors whereas it did not affect phytic acid levels. Proximate components, minerals, and amino acids did not change, but low molecular weight sugars were affected by heat treatment differently for each germinated legume. The sugar digestibility ratio (total digestible sugars/total nondigestible sugars) in germinated black beans doubled after heat treatment. True protein digestibility (TD) increased with heat treatment only in germinated soybean. Net protein utilization was markedly improved (20%) with heat treatment in germinated soybean and lupin. Utilizable protein of heat-treated germinated legumes was 289, 236, and 132 g/kg of legume dry weight for soybean, lupin, and black bean, respectively. Supplementation with methionine did not alter TD but improved all other indices of protein utilization in the germinated legumes, particularly in black bean. All three germinated legumes become equivalent in protein quality when heating and supplementation with methionine are combined with germination. The use of germinated heat-treated soybean, lupin, and black bean on their own and/or as food ingredients is nutritionally advantageous due to the low content of nondigestible oligosaccharides and the high protein utilization.

  7. Synergetic Surface and Chemical Durability Study of the Aesthetically Enhanced Natural Quartz by Heat Treatment

    NASA Astrophysics Data System (ADS)

    Sahoo, Rakesh K.; Rout, Prajna P.; Singh, Saroj K.; Mishra, Barada K.; Mohapatra, Birendra K.

    2017-03-01

    The change in surface behavior of natural quartz stone before and after heat treatment with metal oxides such as: cobalt oxide (Co3O4) and copper oxide (Cu2O) under vacuum and open atmosphere has been investigated. The surface feature, bulk density and hardness value of quartz changed after heat treatment, converting to a high value product. Difference in crystallinity of quartz, pre- and post-heat treatment was obtained through X-ray diffraction (XRD) study. The electron probe microanalysis results clearly explicated the diffusion of metal ion in quartz matrix exposed under vacuum atmosphere but as coating on the surface under open atmosphere. The structural transformation of quartz after heat treatment has been observed from the XRD data and well corroborated with the nanoindentation results. Durability of such quartz to chemical hazardous environment was observed. Thus, this communication demonstrates the change in physical and chemical characteristics of natural quartz stone after heat treatment under different atmosphere.

  8. Synergetic Surface and Chemical Durability Study of the Aesthetically Enhanced Natural Quartz by Heat Treatment

    NASA Astrophysics Data System (ADS)

    Sahoo, Rakesh K.; Rout, Prajna P.; Singh, Saroj K.; Mishra, Barada K.; Mohapatra, Birendra K.

    2017-01-01

    The change in surface behavior of natural quartz stone before and after heat treatment with metal oxides such as: cobalt oxide (Co3O4) and copper oxide (Cu2O) under vacuum and open atmosphere has been investigated. The surface feature, bulk density and hardness value of quartz changed after heat treatment, converting to a high value product. Difference in crystallinity of quartz, pre- and post-heat treatment was obtained through X-ray diffraction (XRD) study. The electron probe microanalysis results clearly explicated the diffusion of metal ion in quartz matrix exposed under vacuum atmosphere but as coating on the surface under open atmosphere. The structural transformation of quartz after heat treatment has been observed from the XRD data and well corroborated with the nanoindentation results. Durability of such quartz to chemical hazardous environment was observed. Thus, this communication demonstrates the change in physical and chemical characteristics of natural quartz stone after heat treatment under different atmosphere.

  9. Heat Treatments of ZnSe Starting Materials for Physical Vapor Transport

    NASA Technical Reports Server (NTRS)

    Su, Ching-Hua; Palosz, W.; Feth, S.; Lehoczky, S. L.

    1998-01-01

    The effect of different heat treatments on stoichiometry and residual gas pressure in ZnSe physical vapor transport system was investigated. The dependence of the amount and composition of the residual gas on various heat treatment procedures is reported. Heat treatment of ZnSe starting materials by baking under the condition of dynamic vacuum to adjust its stoichiometry was performed and the effectiveness of the treatment was confirmed by the measurements of the partial pressure of Se2, P(sub Se2), in equilibrium with the heat treated samples. Optimum heat treatment procedures on the ZnSe starting material for the physical vapor transport process are discussed and verified experimentally.

  10. The Tensile Properties of Advanced Nickel-Base Disk Superalloys During Quenching Heat Treatments

    NASA Technical Reports Server (NTRS)

    Gabb, Timothy P.; Gayda, John; Kantzos, Pete T.; Biles, Tiffany; Konkel, William

    2001-01-01

    There is a need to increase the temperature capabilities of superalloy turbine disks. This would allow full utilization of higher temperature combustor and airfoil concepts under development. One approach to meet this goal is to modify the processing and chemistry of advanced alloys, while preserving the ability to use rapid cooling supersolvus heat treatments to achieve coarse grain, fine gamma prime microstructures. An important step in this effort is to understand the key high temperature tensile properties of advanced alloys as they exist during supersolvus heat treatments. This could help in projecting cracking tendencies of disks during quenches from supersolvus heat treatments. The objective of this study was to examine the tensile properties of two advanced disk superalloys during simulated quenching heat treatments. Specimens were cooled from the solution heat treatment temperatures at controlled rates, interrupted, and immediately tensile tested at various temperatures. The responses and failure modes were compared and related to the quench cracking tendencies of disk forgings.

  11. Heat Treatments of ZnSe Starting Materials for Physical Vapor Transport

    NASA Technical Reports Server (NTRS)

    Su, Ching-Hua; Palosz, W.; Feth, S.; Lehoczky, S. L.

    1997-01-01

    The effect of different heat treatments on stoichiometry and residual gas pressure in ZnSe physical vapor transport system was investigated. The dependence of the amount and composition of the residual gas on various heat treatment procedures is reported. Heat treatment of ZnSe starting materials by baking under the condition of dynamic vacuum to adjust its stoichiometry was performed and the effectiveness of the treatment was confirmed by the measurements of the partial pressure of Se2, P(sub Se2), in equilibrium with the heat treated samples. Optimum heat treatment procedures on the ZnSe starting material for the physical vapor transport process are discussed and verified experimentally.

  12. Influence of heat treatment on FVIII:C recovery from freeze dried cryoprecipitate.

    PubMed Central

    Benny, A G; Ockelford, P A; Johns, A S; Scott, R H; Woodfield, D G; Berry, E W

    1988-01-01

    A standard lyophilised triple cryoprecipitate preparation, stabilised by the addition of Synthamin 17, was heat treated at 60 degrees C for 48 hours. The total protein content, factor VIII concentration, and factor VIII recovery were not affected by the heat treatment procedure. Heat treatment did not influence the reconstitution characteristics of the freeze dried preparation and there were no side effects during or after administration. The mean in vivo rise of factor VIII from infused heat treated triple cryoprecipitate was 2.5 (SD 0.9)%/unit/kg with a half life of 13.1 (3.1) hours. These results compare favourably with those obtained using non-heated triple cryoprecipitate. Cryoprecipitate can be heat treated without adversely influencing factor VIII recovery, and the ability to prepare a heat treated cryoprecipitate means that a small pool high yield factor VIII preparation can again be used in routine clinical practice. PMID:3142936

  13. Treatment of aging oily wastewater by demulsification/flocculation.

    PubMed

    Yang, Jing Y; Yan, Liang; Li, Shao P; Xu, Xin R

    2016-08-23

    The aging oily wastewater (AOW) from Tarim oilfield in China was treated by demulsification/flocculation. A novel sewage treatment agent (YL-7) was developed using a cationic surfactant (LY) and flocculants (polydimethyl diallyl ammonium chloride (PDMDAAC)/polyaluminum chloride (PAC)). At an YL-7 dosage of 320 mg L(-1) at 323 K for 90 min, the oil content of AOW was reduced from 728.8 mg L(-1) to 23.7 mg L(-1), and oil removal efficiency reached 96.7%. Microorganism flocs (extracted from AOW) with high negative zeta potential enhanced the stability of oil/water emulsion. LY and PDMDAAC neutralized the negative charge on the oil droplet surface. PDMDAAC and PAC mainly bridged and swept flocs during the flocculation process. YL-7 was found to be a suitable sewage treatment agent in removing oil from AOW.

  14. Microstructural Evolution and Mechanical Properties of Cold-deformed Al-5Cu Alloy Samples After Isothermal Heat Treatments

    SciTech Connect

    Saklakoglu, Nursen; Gencalp, Simge

    2011-01-17

    Abstract.In this paper, the microscopic morphology of a semi solid Al5Cu alloy by strain induced melt activated (SIMA) process were investigated, and the effects of predeformation, microstructural evolution, aging response and hardness changes were determined. The microstructural observation shows that while the grain boundaries started to appear after 620 deg. C, globular grains surrounded wet boundaries needed for SSP were obtained at 650 deg. C. The grain sizes exhibited ununiformity from the outer surface to the center of the sample because of ununiform predeformation. Although isothermal heat treatments reduced hardness, age hardening gave back the hardness loss.

  15. HEAT INPUT AND POST WELD HEAT TREATMENT EFFECTS ON REDUCED-ACTIVATION FERRITIC/MARTENSITIC STEEL FRICTION STIR WELDS

    SciTech Connect

    Tang, Wei; Chen, Gaoqiang; Chen, Jian; Yu, Xinghua; Frederick, David Alan; Feng, Zhili

    2015-01-01

    Reduced-activation ferritic/martensitic (RAFM) steels are an important class of structural materials for fusion reactor internals developed in recent years because of their improved irradiation resistance. However, they can suffer from welding induced property degradations. In this paper, a solid phase joining technology friction stir welding (FSW) was adopted to join a RAFM steel Eurofer 97 and different FSW parameters/heat input were chosen to produce welds. FSW response parameters, joint microstructures and microhardness were investigated to reveal relationships among welding heat input, weld structure characterization and mechanical properties. In general, FSW heat input results in high hardness inside the stir zone mostly due to a martensitic transformation. It is possible to produce friction stir welds similar to but not with exactly the same base metal hardness when using low power input because of other hardening mechanisms. Further, post weld heat treatment (PWHT) is a very effective way to reduce FSW stir zone hardness values.

  16. Effects of long-term thermal aging on the tensile and creep properties of commercially heat-treated alloy 718

    SciTech Connect

    Booker, M.K.

    1984-01-01

    Alloy 718 is a structure material widely used in elevated-temperature applications. In particular, it was extensively used in the design of the upper internal system and control rod drive line of the proposed Clinch River Breeder Reactor. Its popularity is due to several excellent behavioral features, including high creep and creep-rupture strength, good oxidation resistance, and exceptional high-cycle fatigue strength. However, alloy 718 is extremely complex, and its microstructure can be significantly modified by thermal treatment. The stability of the alloy in long-term elevated-temperature service is therefore a substantial concern in any such application. This report presents tensile and creep data obtained on three heats of alloy 718 after thermal aging for up to 27,000 h from 593 to 76{degree}C. Implications of these results in terms of long-term stability of the alloy are discussed. 5 refs., 13 figs., 6 tabs.

  17. Carbonated aqueous media for quench heat treatment of steels

    NASA Astrophysics Data System (ADS)

    Nayak, U. Vignesh; Rao, K. M. Pranesh; Pai, M. Ashwin; Prabhu, K. Narayan

    2016-09-01

    Distilled water and polyalkylene glycol (PAG)-based aqueous quenchants of 5 and 10 vol.% with and without carbonation were prepared and used as heat transfer media during immersion quenching. Cooling curves were recorded during quenching of an inconel 600 cylindrical probe instrumented with multiple thermocouples. It was observed that the vapor stage duration was prolonged and the wetting front ascended uniformly for quenching with carbonated media. The cooling data were analyzed by determining the critical cooling parameters and by estimating the spatially dependent probe/quenchant interfacial heat flux transients. The study showed significantly reduced values of heat transfer rate for carbonated quenchants compared to quenchants without carbonation. Further, the reduction was more pronounced in the case of PAG-based carbonated quenchants than carbonated distilled water. The results also showed the dependence of heat transfer characteristics of the carbonated media on polymer concentration. The effect of quench uniformity on the microstructure of the material was assessed.

  18. 49 CFR 179.500-6 - Heat treatment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... quenching and tempering for Class III steel. Tempering temperatures shall not be less than 1000 °F. Heat.... Cracks shall be removed to sound metal by grinding and the surface exposed shall be blended smoothly...

  19. Cyclic Deformation Behavior of a Rare-Earth Containing Extruded Magnesium Alloy: Effect of Heat Treatment

    NASA Astrophysics Data System (ADS)

    Mirza, F. A.; Chen, D. L.; Li, D. J.; Zeng, X. Q.

    2015-03-01

    The present study was aimed at evaluating strain-controlled cyclic deformation behavior of a rare-earth (RE) element containing Mg-10Gd-3Y-0.5Zr (GW103K) alloy in different states (as-extruded, peak-aged (T5), and solution-treated and peak-aged (T6)). The addition of RE elements led to an effective grain refinement and weak texture in the as-extruded alloy. While heat treatment resulted in a grain growth modestly in the T5 state and significantly in the T6 state, a high density of nano-sized and bamboo-leaf/plate-shaped β' (Mg7(Gd,Y)) precipitates was observed to distribute uniformly in the α-Mg matrix. The yield strength and ultimate tensile strength, as well as the maximum and minimum peak stresses during cyclic deformation in the T5 and T6 states were significantly higher than those in the as-extruded state. Unlike RE-free extruded Mg alloys, symmetrical hysteresis loops in tension and compression and cyclic stabilization were present in the GW103K alloy in different states. The fatigue life of this alloy in the three conditions, which could be well described by the Coffin-Manson law and Basquin's equation, was equivalent within the experimental scatter and was longer than that of RE-free extruded Mg alloys. This was predominantly attributed to the presence of the relatively weak texture and the suppression of twinning activities stemming from the fine grain sizes and especially RE-containing β' precipitates. Fatigue crack was observed to initiate from the specimen surface in all the three alloy states and the initiation site contained some cleavage-like facets after T6 heat treatment. Crack propagation was characterized mainly by the characteristic fatigue striations.

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

    PubMed

    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.

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

    PubMed Central

    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. PMID:28316470

  2. Detection of heat shock protein 70 in choroidal neovascular membranes secondary to age related macular degeneration

    PubMed Central

    2011-01-01

    Background Heat shock proteins are acute phase proteins that are upregulated in inflammation or following thermal stress. We analyzed the presence of the heat shock protein 70 (Hsp 70) in choroidal neovascular (CNV) membranes secondary to AMD after treatment with verteporphin photodynamic therapy (PDT) or transpupillary thermo therapy (TTT) to determine whether treatment correlated with the presence of Hsp70. Results CNV membranes were removed by pars plana vitrectomy (ppV) and subretinal extraction. The membranes were analysed by light microscopy and the presence of Hsp 70 was examined using histochemistry. HeLa Cells served as controls. Of the 14 membranes analysed 11 were Hsp70 positive and 3 negative. In the no pre-treatment group of 8 membranes 6 were Hsp70 positive and 2 negative; in the PTD group all 4 membranes were positive and in the TTT group 1 membrane was positive and 1 membrane was negative for Hsp70. Conclusion Hsp70 is present in the most CNV membranes secondary to AMD. Pre-treatment of the membrane with PTD or TTT does not appear to influence the expression of Hsp70. PMID:21477309

  3. High-Temperature Heat Treatment Study on a Large-Grain Nb Cavity

    SciTech Connect

    G. Ciovati, P. Dhakal, R. Myneni, P. Maheshwari, F.A. Stevie

    2011-07-01

    Improvement of the cavity performance by a high-temperature heat-treatment without subsequent chemical etching have been reported for large-grain Nb cavities treated by buffered chemical polishing, as well as for a fine-grain cavity treated by vertical electropolishing. Changes in the quality factor, Q{sub 0}, and maximum peak surface magnetic field achieved in a large-grain Nb single-cell cavity have been determined as a function of the heat treatment temperature, between 600 °C and 1200 °C. The highest Q{sub 0} improvement of about 30% was obtained after heat-treatment at 800 °C-1000 °C. Measurements by secondary ion mass spectrometry on large-grain samples heat-treated with the cavity showed large reduction of hydrogen concentration after heat treatment.

  4. Effect of Melt Superheating Treatment on the Latent Heat Release of Sn

    NASA Astrophysics Data System (ADS)

    Xu, Junfeng; Dang, Bo; Fan, Dandan; Jian, Zengyun

    2016-12-01

    The accuracy of the baseline evaluation is of importance for calculating the transition enthalpy such as the latent heat of the crystallization. This study demonstrates the modified method of the equivalent non-latent heat baseline, by which the transition enthalpy can be measured accurately according to the transition peak in differential scanning calorimetric curve. With this method, the effect of melt superheating treatment time on the latent heat release upon the solidification of tin is investigated. The results show that the latent heat increases by increasing the treatment time, and is close to a constant when the treatment time is large enough, indicating the homogeneous system. And then, a simple model is established to describe the changes of the crystallization latent heat with the treatment time, which is confirmed by the experimental data of Sn.

  5. Effect of Melt Superheating Treatment on the Latent Heat Release of Sn

    NASA Astrophysics Data System (ADS)

    Xu, Junfeng; Dang, Bo; Fan, Dandan; Jian, Zengyun

    2017-03-01

    The accuracy of the baseline evaluation is of importance for calculating the transition enthalpy such as the latent heat of the crystallization. This study demonstrates the modified method of the equivalent non-latent heat baseline, by which the transition enthalpy can be measured accurately according to the transition peak in differential scanning calorimetric curve. With this method, the effect of melt superheating treatment time on the latent heat release upon the solidification of tin is investigated. The results show that the latent heat increases by increasing the treatment time, and is close to a constant when the treatment time is large enough, indicating the homogeneous system. And then, a simple model is established to describe the changes of the crystallization latent heat with the treatment time, which is confirmed by the experimental data of Sn.

  6. Potential of furan formation in hazelnuts during heat treatment.

    PubMed

    Senyuva, H Z; Gökmen, V

    2007-01-01

    The formation of furan as influenced by temperature and time of heating was studied in hazelnuts. Temperature was noted as the important processing parameter on the formation of furan in hazelnuts. The formation of furan was noticeably increased at temperatures exceeding 120 degrees C. Furan concentrations tended to increase linearly at 100 and 150 degrees C up to 60 min of heating. Detailed examination of the composition of different hazelnut varieties showed that certain precursors such as polyunsaturated fatty acids (linoleic acid), amino acids (threonine and alanine), and sugars (glucose) were present in hazelnut at amounts sufficient to generate significant amounts of furan upon heating. The composition of the lipid fraction in terms of relative percentages of fatty acids was relatively stable during heating at 150 degrees C for 30 min, but the concentrations of amino acids and sugars decreased significantly at the end of the heating period. This led to the conclusion that the Maillard reaction is possibly the primary mechanism responsible for the formation of furan in hazelnuts during heating.

  7. A study on the effect of heat treatment temperature on mesophase development in coal tar pitch

    NASA Astrophysics Data System (ADS)

    Soni, Neha; Shah, Raviraj K.; Shrivastava, Rakesh; Datar, Manoj

    2013-06-01

    In the present study, a zero quinoline insoluble (QI) isotropic coal tar pitch was taken for the preparation of mesophase pitch. The pitch was heated in inert atmosphere at different heat treatment temperatures keeping same heating rate and soaking time to study the formation, growth and coalescence of mesophase spheres in the pitch. Such pitches were characterized for insoluble content (QI & TI), mesophase content, sulphur content, weight loss in inert atmosphere, softening point, coking value (CVC), C/H ratio etc. Results show that the insoluble content (QI & TI) and mesophase content of pitch increase with increase of heat treatment temperature.

  8. The effects of heat treatments on the transport properties of Cu/x/S thin films

    NASA Astrophysics Data System (ADS)

    Hmurcik, L.; Allen, L.; Serway, R. A.

    1982-12-01

    The resistivity and Hall effect of Cu(x)S (x = 1.995-2) thin films, which are used in the CdS/Cu(x)S solar cell currently investigated as an alternate source of electrical energy, has been measured as a function of temperature and heat treatment time. It is found that initial heat treatments cause copper in grain boundaries to diffuse irreversibly into the bulk. Further heating in hydrogen causes the resistivity to increase and the charge density and the mobility to decrease as surface oxides break up and free copper diffuses into the copper sulfide. Heating in oxygen reverses this process.

  9. A Novel Combination of Thermal Ablation and Heat-Inducible Gene Therapy for Breast Cancer Treatment

    DTIC Science & Technology

    2007-04-01

    and Heat-Inducible Gene Therapy for Breast Cancer Treatment PRINCIPAL INVESTIGATOR: Yunbo Liu...Breast Cancer Treatment 5b. GRANT NUMBER W81XWH-06-1-0461 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Yunbo Liu Pei Zhong...therapy (via the control of hsp70B-heat shock promoter) to improve the overall efficiency of breast cancer treatment . In the first year of the project

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

    PubMed Central

    2011-01-01

    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. PMID:21711877

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

    PubMed

    Ramesh, Gopalan; Prabhu, Narayan Kotekar

    2011-04-14

    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.

  12. Functional properties of whey proteins affected by heat treatment and hydrodynamic high-pressure shearing.

    PubMed

    Dissanayake, M; Vasiljevic, T

    2009-04-01

    Two batches of native whey proteins (WP) were subjected to microfluidization or heat denaturation accompanied by microfluidization, followed by spray drying. Powders were assessed for their solubility, heat stability, coagulation time, and emulsifying and foaming properties. Effects of denaturation and shearing were examined by particle size analysis, differential scanning calorimetry, reducing and nonreducing sodium dodecyl sulfate-PAGE, and size exclusion-HPLC. Heat treatment significantly decreased solubility, whereas the number of microfluidization passes markedly improved solubility. The combined effect of heat and pressure significantly increased heat coagulation time. Emulsifying activity index substantially increased upon heat denaturation and was further enhanced by microfluidization. Emulsion stability appeared unaffected by the combined treatment, but the concentration of adsorbed protein on fat droplets was significantly increased. Foaming properties were diminished by heating. Particle size distribution patterns, sodium dodecyl sulfate-PAGE, and size exclusion-HPLC revealed disappearance of major WP and creation of relatively higher, as well as smaller, molecular weight aggregates as a result of the 2 treatments. The use of heat and microfluidization in combination could be used to stabilize WP against heat by producing microparticulated species that have different surface and colloidal properties compared with native WP. These results have implications for the use of WP as an additive in heat-processed foods.

  13. Expression of heat shock protein 70 is altered by age and diet at the level of transcription.

    PubMed Central

    Heydari, A R; Wu, B; Takahashi, R; Strong, R; Richardson, A

    1993-01-01

    Because heat shock proteins have been shown to play a critical role in protecting cells from hyperthermia and other types of physiological stresses, it was of interest to determine what effect age and caloric restriction have on the ability of cells to regulate the expression of heat shock protein 70 (hsp70), the most prominent and most evolutionarily conserved of the heat shock proteins. Caloric restriction is the only experimental manipulation known to retard aging and increase survival of mammals. The ability of hepatocytes isolated from young/adult (4- to 7-month-old) and old (22- to 28-month-old) male Fischer F344 rats fed ad libitum or a caloric restriction diet (60% of the content of the ad libitum diet) to express hsp70 was determined after a mild heat shock (42.5 degrees C for 30 min). We found that the induction of hsp70 synthesis and mRNA levels by heat shock was 40 to 50% lower in hepatocytes isolated from old rats than in hepatocytes isolated from young rats. Using in situ hybridization, we found that essentially all hepatocytes from the young/adult and old rats expressed hsp70 in response to heat shock; therefore, the age-related decrease in the induction of hsp70 expression was not due to an age-related accumulation of cells that do not respond to heat shock. Measurements of hsp70 mRNA stability and hsp70 transcription demonstrated that the age-related decline in hsp70 expression arose from a decline in hsp70 transcription. Interestingly, the age-related decline in the induction of hsp70 expression was reversed by caloric restriction; e.g., the induction of hsp70 synthesis, mRNA levels, and nuclear transcription were significantly higher in hepatocytes isolated from old rats fed the caloric restricted diet than in hepatocytes isolated from old rats fed ad libitum. The levels of the heat shock transcription factor in nuclear extracts isolated from heat-shocked hepatocytes were measured in a gel shift assay. Binding of the heat shock transcription

  14. Effect of T6 heat treatment on the microstructural and mechanical properties of Al-Si-Cu-Mg alloys

    NASA Astrophysics Data System (ADS)

    Patel, Dhruv; Davda, Chintan; Solanki, P. S.; Keshvani, M. J.

    2016-05-01

    In this communication, it is aimed to optimize the conditions for T6 heat treatment of permanent die cast Al-Si-Cu-Mg alloys. Various solutionizing temperatures, aging treatments and soaking times were used to improve / modify the mechanical properties of presently studied alloys. Formation mechanism of the particles was understood by carrying out optical microscopy and energy dispersive X-ray (EDX) spectroscopy measurements. Spherical particles of alloys were studied for their microstructural properties using scanning electron microscopy (SEM). Microhardness test was performed to investigate their mechanical properties. Dependence of cluster formation and microhardness of the alloys on the adequate solutionizing temperature, aging treatment and soaking time has been discussed in detail.

  15. Hormone Treatment and Muscle Anabolism during Aging: Androgens

    PubMed Central

    Dillon, E. Lichar; Durham, William J.; Urban, Randall J.; Sheffield-Moore, Melinda

    2010-01-01

    Aging is associated with a gradual decline in circulating testosterone concentrations and decreased musculature in men. While testosterone administration is often considered when symptoms of hypogonadism are presented, the long-term effects of androgen use on muscle physiology are not yet fully understood. The definition of hypogonadism in men remains obscure but is generally indicated by total testosterone concentrations less than a threshold value of 300-500 ng/dL. Androgen replacement therapy is generally safe in men and women with low endogenous testosterone concentrations. The development of selective androgen receptor modulators (SARMs) may provide additional options in treatment of hypogonadism while lowering the potential of side effects often associated with long-term androgen use. Androgen administration, either alone or in combination with other treatments, can be successful in improving muscle mass by increasing protein anabolism and reducing protein catabolism in men and women. Further research is necessary to optimize the anabolic and anticatabolic properties of androgens for treatment and prevention of muscle loss in men and women. PMID:20452103

  16. Local mean age measurements for heating, cooling, and isothermal supply air conditions

    SciTech Connect

    Han, H.; Kuehn, T.H.; Kim, Y.

    1999-07-01

    The objective of this paper is to investigate the effect on room ventilation of thermal buoyancy caused by temperature differences between surfaces and the supply air. Spatial distributions of local mean age were obtained in a half-scale environmental chamber under well-controlled temperature conditions simulating isothermal ventilation, cooling, and heating. Air was supplied and returned through slots in the ceiling. Sulfur hexafluoride (SF{sub 6}) tracer gas concentration was measured by an electron capture gas chromatograph. Tracer gas concentration was measured at various points in the chamber versus time after a pulse injection was applied in the supply air duct. The maximum local mean age (LMA) was obtained near the center of a large recirculation zone for isothermal conditions. The results for cooling conditions showed a relatively uniform LMA distribution in the space compared to the isothermal conditions, as the room air was well mixed by the cold downdraft from the supply. However, there was a large variation in local air change indices in the space for the heating condition because of stable thermal stratification. Warm supply air could not penetrate into the lower half of the space but short-circuited to the exhaust duct. The model results in the present study can be converted to full-scale situations using similitude and can be used for validating computational fluid dynamics codes.

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

    SciTech Connect

    Udell, K.S.

    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.

  18. Effect of heat treatment upon the fatigue-crack growth behavior of Alloy 718 weldments

    SciTech Connect

    James, L.A.; Mills, W.J.

    1981-05-01

    Gas-tungsten-arc weldments in Alloy 718 were studied in fatigue-crack growth test conducted at five temperatures over the range 24--649{degree}C. In general, crack growth rates increased with increasing temperature, and weldments given the conventional'' post-weld heat-treatment generally exhibited crack growth rates that were higher than for weldments given the modified'' (INEL) heat-treatment. Limited testing in the as-welded condition revealed crack growth rates significantly lower than observed for the heat-treated cases, and this was attributed to residual stresses. Three different heats of filler wire were utilized, and no heat-to-heat variations were noted. 23 refs., 9 figs., 6 tabs.

  19. Specific heat treatment of selective laser melted Ti-6Al-4V for biomedical applications

    NASA Astrophysics Data System (ADS)

    Huang, Qianli; Liu, Xujie; Yang, Xing; Zhang, Ranran; Shen, Zhijian; Feng, Qingling

    2015-12-01

    The ductility of as-fabricated Ti-6Al-4V falls far short of the requirements for biomedical titanium alloy implants and the heat treatment remains the only applicable option for improvement of their mechanical properties. In the present study, the decomposition of as-fabricated martensite was investigated to provide a general understanding on the kinetics of its phase transformation. The decomposition of asfabricated martensite was found to be slower than that of water-quenched martensite. It indicates that specific heat treatment strategy is needed to be explored for as-fabricated Ti-6Al-4V. Three strategies of heat treatment were proposed based on different phase transformation mechanisms and classified as subtransus treatment, supersolvus treatment and mixed treatment. These specific heat treatments were conducted on selective laser melted samples to investigate the evolutions of microstructure and mechanical properties. The subtransus treatment leaded to a basket-weave structure without changing the morphology of columnar prior β grains. The supersolvus treatment resulted in a lamellar structure and equiaxed β grains. The mixed treatment yielded a microstructure that combines both features of the subtransus treatment and supersolvus treatment. The subtransus treatment is found to be the best choice among these three strategies for as-fabricated Ti-6Al-4V to be used as biomedical implants.

  20. The Effect of Post-heat Treatment on the Microstructures of Single Crystal DD6 Superalloy

    NASA Astrophysics Data System (ADS)

    Li, Dongfan; Gao, Hangshan; Wen, Zhixun; Li, Zhenwei; Yue, Zhufeng

    2016-09-01

    Various thermal cycles at the end of solution heat treatment and their influences on microstructure of single crystal superalloy DD6 were studied by experiments. During various thermal cycles, the qualitative and quantitative microstructure of samples quenched of the transformations is microscopically characterized. This completely includes the large changes in volume fraction, size distribution and morphology of gamma prime precipitate experienced in the upper temperature transformation. Noticeable deviation from the equilibrium volume fraction of γ' phase is detected in both the dissolution and precipitation processes above 1,120°C for both moderate cooling and heating rate; differences were mainly attributed to the unsteady nature of the turbulent flow. The growth and alignment of the γ' precipitates are deeply influenced by several factors, e.g. ageing time, cooling rate and quenching temperature. In addition, interesting findings such as "labyrinth" and "cluster" morphologies were observed by scanning electron microscope. During precipitation processes, the complicated microstructure evolution is illustrated by considering the consecutive equilibrium shapes of a coherent precipitate, which grows under the interaction with its neighbors and the coherency of the precipitates improves their potential to resist dissolution.

  1. Phase transitions of hydroxyapatite coatings during post-heat treatment and their performances under ultrasonic tests.

    PubMed

    Tong, W; Li, X; Feng, J; Chen, J; Zhang, X

    2001-07-01

    Highly or completely crystalline hydroxyapatite (HA) coatings can be obtained by post-heat treatment. We have developed a high-temperature (490 degrees C) and a low-temperature (125 degrees C) heat treatment to improve the crystallinity of HA coatings. Both methods transform entirely the amorphous phase into crystalline HA. However, the microstructure of the coating is dependent on the post-heating method. Nanocrystalline HA is about half of the component of the low-temperature heated coating while highly crystalline HA dominates the high-temperature heated coating, as detected by X-ray diffraction. The effects of both methods on the disintegration of the coatings were tested by ultrasonic treatment. The high-temperature heated coatings exhibited poor integrity while the low-temperature heated coatings exhibited better integrity, possibly due to their different microstructure. SEM revealed that the coatings disintegrated via different mechanisms: the high-temperature heated coatings failed via crack initiation and propagation while the low-temperature heated coatings failed via pit formation and subsequent widening.

  2. Milk protein-gum tragacanth mixed gels: effect of heat-treatment sequence.

    PubMed

    Hatami, Masoud; Nejatian, Mohammad; Mohammadifar, Mohammad Amin; Pourmand, Hanieh

    2014-01-30

    The aim of this study was to investigate the role of the heat-treatment sequence of biopolymer mixtures as a formulation parameter on the acid-induced gelation of tri-polymeric systems composed of sodium caseinate (Na-caseinate), whey protein concentrate (WPC), and gum tragacanth (GT). This was studied by applying four sequences of heat treatment: (A) co-heating all three biopolymers; (B) heating the milk-protein dispersion and the GT dispersion separately; (C) heating the dispersion containing Na-caseinate and GT together and heating whey protein alone; and (D) co-heating whey protein with GT and heating Na-caseinate alone. According to small-deformation rheological measurements, the strength of the mixed-gel network decreased in the order: C>B>D>A samples. SEM micrographs show that the network of sample C is much more homogenous, coarse and dense than sample A, while the networks of samples B and D are of intermediate density. The heat-treatment sequence of the biopolymer mixtures as a formulation parameter thus offers an opportunity to control the microstructure and rheological properties of mixed gels.

  3. Effect of heating and aging of poultry litter on the persistence of enteric bacteria.

    PubMed

    Wilkinson, K G; Tee, E; Tomkins, R B; Hepworth, G; Premier, R

    2011-01-01

    Food-borne illnesses have rarely been associated with the reuse of poultry litter as an organic fertilizer and soil amendment in agriculture. Yet farming practices in many countries have come under increased scrutiny because of heightened consumer awareness of food safety and environmental issues. This study was conducted to determine whether simple on-farm management practices could improve the microbiological safety of poultry litter. First, the effects of heat and moisture on the survival of Escherichia coli and Salmonella enterica serovar Typhimurium in poultry litter were investigated under laboratory conditions. Second, the persistence and regrowth of enteric bacteria were examined in poultry litter that had been aged for up to 12 wk in either a turned or static (unturned) windrow. Escherichia coli and Salmonella counts in poultry litter were reduced by >99% in 1 h at 55 or 65°C under laboratory conditions. At 35°C, both persisted longer under moist (65% wt/wt, wet basis) than dry (30% wt/wt) conditions. Poultry litter aged for 3 wk in a turned windrow, and up to 6 wk in a static windrow, supported increased E. coli densities when incubated in the laboratory at 37°C for 21 d. Peak temperatures >65°C were observed in both windrows within the first 3 wk of aging; after this point, the turned windrow was more consistently exposed to temperatures >45°C than the static windrow. By 12 wk, however, E. coli counts were very similar (3 to 3.6 log(10)) in the outside edge of both windrows. This study highlights the need for a better understanding of the interrelationship between spontaneous heating in organic waste streams, organic matter stabilization, and pathogen reduction.

  4. Heat treatment effect on microstructure, hardness and wear resistance of Cr26 white cast iron

    NASA Astrophysics Data System (ADS)

    Zhou, Shaoping; Shen, Yehui; Zhang, Hao; Chen, Dequan

    2015-01-01

    High chromium cast iron(HCCI) is taken as material of coal water slurry pump impeller, but it is susceptible to produce serious abrasive wear and erosion wear because of souring of hard coal particles. The research on optimization of heat treatments to improve abrasive wear properties of HCCI is insufficient, so effect of heat treatments on the microstructure, hardness, toughness, and wear resistance of Cr26 HCCI is investigated to determine the optimal heat treatment process for HCCI. A series of heat treatments are employed. The microstructures of HCCI specimens are examined by using optical microscopy and scanning electron microscopy. The hardness and impact fracture toughness of as-cast and heat treated specimens are measured. The wear tests are assessed by a Type M200 ring-on block wear tester. The results show the following: With increase of the quenching temperature from 950 °C to 1050 °C, the hardness of Cr26 HCCI increased to a certain value, kept for a time and then decreased. The optimal heat treatment process is 2 h quenching treatment at 1000 °C, followed by a subsequent 2 h tempering at 400 °C. The hardness of HCCI is related to the precipitation and redissolution of secondary carbides in the process of heat treatment. The subsequent tempering treatment would result in a slight decrease of hardness but increase of toughness. The wear resistance is much related to the "supporting" effect of the matrix and the "protective" effect of the hard carbide embedded in the matrix, and the wear resistance is further dependent on the hardness and the toughness of the matrix. This research can provide an important insight on developing an optimized heat treatment method to improve the wear resistance of HCCI.

  5. [The influence of oil heat treatment on wood decay resistance by Fourier infrared spectrum analysis].

    PubMed

    Wang, Ya-Mei; Ma, Shu-Ling; Feng, Li-Qun

    2014-03-01

    Wood preservative treatment can improve defects of plantation wood such as easy to corrupt and moth eaten. Among them heat-treatment is not only environmental and no pollution, also can improve the corrosion resistance and dimension stability of wood. In this test Poplar and Mongolian Seoteh Pine was treated by soybean oil as heat-conducting medium, and the heat treatment wood was studied for indoor decay resistance; wood chemical components before and after treatment, the effect of heat treatment on wood decay resistance performance and main mechanism of action were analysed by Fourier infrared spectrometric. Results showed that the mass loss rate of poplar fell from 19.37% to 5% and Mongolian Seoteh Pine's fell from 8.23% to 3.15%, so oil heat treatment can effectively improve the decay resistance. Infrared spectrum analysis shows that the heat treatment made wood's hydrophilic groups such as hydroxyl groups in largely reduced, absorbing capacity decreased and the moisture of wood rotting fungi necessary was reduced; during the heat treatment wood chemical components such as cellulose, hemicellu lose were degraded, and the nutrient source of wood rotting fungi growth necessary was reduced. Wood decay fungi can grow in the wood to discredit wood is because of that wood can provide better living conditions for wood decay fungi, such as nutrients, water, oxygen, and so on. The cellulose and hemicellulose in wood is the main nutrition source of wood decay fungi. So the oil heat-treatment can reduce the cellulose, hemicellulose nutrition source of wood decay fungi so as to improve the decay resistance of wood.

  6. At What Level of Heat Load Are Age-Related Impairments in the Ability to Dissipate Heat Evident in Females?

    PubMed Central

    Stapleton, Jill M.; Poirier, Martin P.; Flouris, Andreas D.; Boulay, Pierre; Sigal, Ronald J.; Malcolm, Janine; Kenny, Glen P.

    2015-01-01

    Studies have reported that older females have impaired heat loss responses during work in the heat compared to young females. However, it remains unclear at what level of heat stress these differences occur. Therefore, we examined whole-body heat loss [evaporative (HE) and dry heat loss, via direct calorimetry] and changes in body heat storage (∆Hb, via direct and indirect calorimetry) in 10 young (23±4 years) and 10 older (58±5 years) females matched for body surface area and aerobic fitness (VO2peak) during three 30-min exercise bouts performed at incremental rates of metabolic heat production of 250 (Ex1), 325 (Ex2) and 400 (Ex3) W in the heat (40°C, 15% relative humidity). Exercise bouts were separated by 15 min of recovery. Since dry heat gain was similar between young and older females during exercise (p=0.52) and recovery (p=0.42), differences in whole-body heat loss were solely due to HE. Our results show that older females had a significantly lower HE at the end of Ex2 (young: 383±34 W; older: 343±39 W, p=0.04) and Ex3 (young: 437±36 W; older: 389±29 W, p=0.008), however no difference was measured at the end of Ex1 (p=0.24). Also, the magnitude of difference in the maximal level of HE achieved between the young and older females became greater with increasing heat loads (Ex1=10.2%, Ex2=11.6% and Ex3=12.4%). Furthermore, a significantly greater ∆Hb was measured for all heat loads for the older females (Ex1: 178±44 kJ; Ex2: 151±38 kJ; Ex3: 216±25 kJ, p=0.002) relative to the younger females (Ex1: 127±35 kJ; Ex2: 96±45 kJ; Ex3: 146±46 kJ). In contrast, no differences in HE or ∆Hb were observed during recovery (p>0.05). We show that older habitually active females have an impaired capacity to dissipate heat compared to young females during exercise-induced heat loads of ≥325 W when performed in the heat. PMID:25790024

  7. Dry heat and hot water treatments for disinfesting cottonseed of Fusarium oxysporum f. sp. vasinfectum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potential of low- and high-temperature dry heat, and hot water treatments, for disinfesting cottonseed of Fusarium oxysporum f. sp. vasinfectum was investigated. Naturally infected seeds from Louisiana were air-heated in incubators set at temperatures of 30, 35, and 40 degrees C for up to 24 we...

  8. Preparation, heat treatment, and mechanical properties of the uranium-5 weight percent chromium eutectic alloy

    SciTech Connect

    Townsend, A. B.

    1980-10-01

    The eutectic alloy of uranium-5 wt % chromium (U-5Cr) was prepared from high-purity materials and cast into 1-in.-thick ingots. This material was given several simple heat treatments, the mechanical properties of these heat-treated samples were determined; and the microstructure was examined. Some data on the melting point and transformation temperatures were obtained.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  10. Effects of heat treatment on the bioactivity of surface-modified titanium in calcium solution.

    PubMed

    Sultana, Razia; Hamada, Kenichi; Ichikawa, Tetsuo; Asaoka, Kenzo

    2009-01-01

    The purpose of this study was to determine the effects of heat treatment on the bioactivity of hydrothermal-modified titanium in CaO solution for improved bioactivity by immersion in simulated body fluid (SBF). The hydrothermal treatment of titanium in CaO solution was performed at 121 degrees C at 0.2 MPa for 1 h in an autoclave followed by 1 h heat treatments at 200, 400, 600 and 800 degrees C simultaneously. The bioactivity of titanium was evaluated by hydroxyapatite precipitation during immersion in SBF. Surface microstructure changes after the heat treatments and immersion in SBF were determined by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Heat treatments at high temperatures (600 and 800 degrees C) promoted the synthesis of anatase, increased the thickness of the titanium oxide layer on the modified titanium surface and promoted the synthesis of calcium titanate, which possibly promoted the precipitation of apatite in SBF. The extent of precipitations increased with the time of immersion in SBF and the temperature of the heat treatment. Island-like deposits of needle-like crystals were observed only on the surface of the 600 and 800 degrees C heat-treated specimens after two or four week immersions in SBF. The results suggested that treatments of the surface of hydrothermal-treated titanium specimens at high temperatures (600 and 800 degrees C) could be effective for the surface modification of titanium as an implant material offering better osseointegration.

  11. Preparation and Heat-Treatment of DWPF Simulants With and Without Co-Precipitated Noble Metals

    SciTech Connect

    Koopman, David C.:Eibling, Russel E

    2005-08-01

    simulants were visually very viscous compared to the traditional SB3 simulant. (4) Heat-treatment reduced the viscosity of the two new simulants with and without coprecipitated noble metals, though they were still more viscous than the traditional SB3. (5) The approach of using a 97 C heat-treatment step to qualitatively simulate tank farm aging may not be optimal. A significant change in the base equivalent molarities of both simulants was observed during heat-treatment. (6) Heat-treatment appeared to make phosphates insoluble in water. The following recommendations came out of the work: (1) Washed slurry should be checked for TIC and base equivalents before calculating the final trim chemical additions of sodium carbonate and sodium hydroxide. (2) Final insoluble trim chemicals should be added to the slurry in the cross-flow filtration unit mixing tank, since significant slurry is lost in the CUF equipment. Adding the chemicals here would keep them in the correct proportion relative to the precipitated insoluble solids. (3) A composite wash and decant sample should be prepared containing proportionally weighted masses of each aqueous stream removed during preparation of a co-precipitated noble metal simulant. This sample should then be checked for noble metal losses. This would reduce the sample load, while still confirming that there was no significant noble metal loss. (4) A study of the impact of heat-treatment on existing simulants should be undertaken. If there is a shift in base equivalents, then SRNL acid stoichiometries may be biased relative to real waste. The study should be extended to several real wastes as well.

  12. Studies of Standard Heat Treatment Effects on Microstructure and Mechanical Properties of Laser Net Shape Manufactured INCONEL 718

    NASA Astrophysics Data System (ADS)

    Qi, H.; Azer, M.; Ritter, A.

    2009-10-01

    Laser net shape manufacturing (LNSM) is a laser cladding/deposition based technology, which can fabricate and repair near-net-shape high-performance components directly from metal powders. Characterizing mechanical properties of the laser net shape manufactured components is prerequisite to the applications of LNSM in aircraft engine industrial productions. Nickel-based superalloys such as INCONEL 718 are the most commonly used metal materials in aircraft engine high-performance components. In this study, the laser deposition process is optimized through a set of designed experiments to reduce the porosity to less than 0.03 pct. It is found that the use of plasma rotating electrode processed (PREP) powder and a high energy input level greater than 80 J/mm are necessary conditions to minimize the porosity. Material microstructure and tensile properties of laser-deposited INCONEL 718 are studied and compared under heat treatment conditions of as deposited, direct aged, solution treatment and aging (STA), and full homogenization followed by STA. Tensile test results showed that the direct age heat treatment produces the highest tensile strength equivalent to the wrought material, which is followed by the STA-treated and the homogenization-treated tensile strengths, while the ductility exhibits the reverse trend. Finally, failure modes of the tensile specimens were analyzed with fractography.

  13. Effect of Prior and Post-Weld Heat Treatment on Electron Beam Weldments of (α + β) Titanium alloy Ti-5Al-3Mo-1.5V

    NASA Astrophysics Data System (ADS)

    Anil Kumar, V.; Gupta, R. K.; Manwatkar, Sushant K.; Ramkumar, P.; Venkitakrishnan, P. V.

    2016-06-01

    Titanium alloy Ti5Al3Mo1.5V is used in the fabrication of critical engine components for space applications. Double vacuum arc re-melted and (α + β) forged blocks were sliced into 10-mm-thick plates and subjected to electron beam welding (EBW) with five different variants of prior and post-weld heat treatment conditions. Effects of various heat treatment conditions on the mechanical properties of the weldments have been studied. The welded coupons were characterized for microstructure, mechanical properties, and fracture analysis. An optimized heat treatment and welding sequence has been suggested. Weld efficiency of 90% could be achieved. Weldment has shown optimum properties in solution treated and aged condition. Heat-affected zone adjacent to weld fusion line is found to have lowest hardness in all conditions.

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

    SciTech Connect

    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 of

  15. Heat Treatment Devices and Method of Operation Thereof to Produce Dual Microstructure Superalloys Disks

    NASA Technical Reports Server (NTRS)

    Gayda, John (Inventor); Gabb, Timothy P. (Inventor); Kantzos, Peter T. (Inventor)

    2003-01-01

    A heat treatment assembly and heat treatment methods are disclosed for producing different microstructures in the bore and rim portions of nickel-based superalloy disks, particu- larly suited for gas turbine applications. The heat treatment assembly is capable of being removed from the furnace and disassembled to allow rapid fan or oil quenching of the disk. For solutioning heat treatments of the disk, temperatures higher than that of this solvus temperature of the disk are used to produce coarse grains in the rim of each disk so as to give maximum creep and dwell crack resistance at the rim service temperature. At the same time, solution temperature lower than the solvus temperature of the disk are provided to produce fine grain in the bore of the disk so as to give maximum strength and low cycle fatigue resistance.

  16. Influence of heat treatment of rayon-based activated carbon fibers on the adsorption of formaldehyde.

    PubMed

    Rong, Haiqin; Ryu, Zhenyu; Zheng, Jingtang; Zhang, Yuanli

    2003-05-15

    The influence of heat treatment of rayon-based activated carbon fibers on the adsorption behavior of formaldehyde was studied. Heat treatment in an inert atmosphere of nitrogen for rayon-based activated carbon fibers (ACFs) resulted in a significant increase in the adsorption capacities and prolongation of breakthrough time on removing of formaldehyde. The effect of different heat-treatment conditions on the adsorption characteristics was investigated. The porous structure parameters of the samples under study were investigated using nitrogen adsorption at the low temperature 77.4 K. The pore size distributions of the samples under study were calculated by density functional theory. With the aid of these analyses, the relationship between structure and adsorption properties of rayon-based ACFs for removing formaldehyde was revealed. Improvement of their performance in terms of adsorption selectivity and adsorption rate for formaldehyde were achieved by heat post-treatment in an inert atmosphere of nitrogen.

  17. Heat-treatment of Colostrum on Commercial Dairy Farms: Effects on Colostrum Characteristics and Calf Health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction Colostrum provides immunoglobulins (Ig) and nutrients essential for calf health and performance. However, colostrum may be a source of exposure to significant pathogens including Mycobacterium avium subsp. paratuberculosis. Pilot studies have suggested that heat-treatment of colostrum...

  18. Development of the heat treatment system for the 40 T hybrid magnet superconducting outsert.

    PubMed

    Chen, W G; Chen, Z M; Chen, Z Y; Huang, P C; He, P; Zhu, J W

    2011-10-01

    The heat treatment of Nb(3)Sn coil with the glass fabric insulation is one of the key and critical processes for the outsert solenoids of the 40 T hybrid magnet, which could be wound with cable-in-conduit conductors using the insulation-wind-and-react technique. The manufacturing of the large vertical type vacuum/Ar atmosphere-protection heat treatment system has been completed and recently installed in the High Magnetic Filed Laboratory, Chinese Academy of Sciences. The heat treatment system composed mainly the furnace, the purging gas supply system, the control system, the gas impurities monitoring system, and so on. At present, the regulation and testing of the heat treatment system has been successfully finished, and all of technical parameters meet or exceed specifications.

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

    SciTech Connect

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

    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.

  20. [Cherubism: diagnosis and treatment in the pediatric age].

    PubMed

    Sánchez Burgos, R; Martín Pérez, M; Ramírez Piqueras, M; Gómez García, E; Burgueño García, M

    2012-01-01

    Cherubism is a benign bone dysplasia of childhood, exclusively involving maxillary bones and spontaneous resolving after puberty in different grades. Approximately, 280 cases have been reviewed in the literature. It is an autosomal dominant disorder in which the normal bone is replaced by cellular fibrous and immature bone, resulting in painless symmetrical enlargement of the jaws. Diagnosis is based in clinical and radiological findings, confirmed by histology. Treatment is a controversial issue, and it is recommended surgical management as conservative as possible during the rapid growth phases. An aggressive case of cherubism is reported, diagnosed and followed since early childhood until puberty, with progressive involvement of facial bones developing in a disruption of facial contours and occlusion. The patient is treated by several surgical interventions oriented to minimize the aesthetic impact of the disease being as conservative as possible. The highlights of this case are the great proportion of the lesions, the functional and emotional disturbances brought out by these lesions and the difficulty to choose the most appropriate age and form of treatment.

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

    PubMed

    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.

  2. Domestic central heating radiators: a cause for concern in all age groups.

    PubMed

    Harper, R D; Dickson, W A

    1996-05-01

    A retrospective analysis of all burns admitted to the Welsh Regional Burns and Plastic Surgery Unit, Chepstow, in the period 1 January 1990 to 1 October 1993, highlighted a group of 50 patients who had sustained contact burns from the radiators of domestic central heating systems. There was a male prevalence, with an average age of 43.4 years (range 6 months to 100 years). The mean TBSA burned was 1.58 per cent (range 0.13-6.0 per cent) and half of the injuries were full thickness depth. The forearm and hand were predominantly injured. Although the literature has indicated that the incidence of contact burns peaks at the extremes of the age spectrum, this study has shown that contact radiator burns can be sustained by all age groups. The aim of the audit was to investigate the mechanism of injury and link precipitating factors. The contribution of the high surface temperature of the radiator to the burn injury is alluded to. The various methods available to reduce this risk are discussed and the use of the low surface temperature radiator, already routinely used in health care premises, is advocated.

  3. Quality assessment of palm products upon prolonged heat treatment.

    PubMed

    Tarmizi, Azmil Haizam Ahmad; Lin, Siew Wai

    2008-01-01

    Extending the frying-life of oils is of commercial and economic importance. Due to this fact, assessment on the thermal stability of frying oils could provide considerable savings to the food processors. In this study, the physico-chemical properties of five palm products mainly palm oil, single-fractionated palm olein, double-fractionated palm olein, red palm olein and palm-based shortening during 80 hours of heating at 180 degrees C were investigated. Heating properties of these products were then compared with that of high oleic sunflower oil, which was used as reference oil. The indices applied in evaluating the quality changes of oils were free fatty acid, smoke point, p-anisidine value, tocols, polar and polymer compounds. Three palm products i.e. palm oil, single-fractionated palm olein and double-fractionated palm olein were identified to be the most stable in terms of lower formation of free fatty acid, polar and polymer compounds as well as preserving higher smoke point and tocols content compared to the other three oils. The low intensity of hydrolytic and oxidative changes due to prolonged heating, suggests that these palm products are inherently suitable for frying purposes.

  4. Nanoparticles for cancer treatment: role of heat transfer.

    PubMed

    Avedisian, C Thomas; Cavicchi, Richard E; McEuen, Paul L; Zhou, Xinjian

    2009-04-01

    An overview is presented of an approach for treating cancer that uses nanoparticles to deliver heat to diseased areas after absorbing energy from a laser of the appropriate wavelength. The implications are discussed of the relationship of parameters necessary to raise the temperature to therapeutically beneficial levels. Tight focusing is required for a continuous-wave laser to sufficiently heat individual nanoparticles because of heat loss to the surrounding fluid during the period of exposure. The natural thermal confinement of pulse lasers minimizes this effect because of the finite thermal diffusion time, which restricts the absorbed energy to a region around the particle, that offers the potential for achieving high temperatures that can promote phase change on the surface of a nanoparticle or even melting of the particle. A discussion of a way to potentially measure temperature on the scale of an individual nanoparticle is included based on using a single-walled nanotube (SWNT) of carbon as a thermistor. The challenges of this undertaking are that SWNTs do not always follow Ohm's law, they may exhibit metallic or semiconductor behavior with an often unpredictable result in manufacturing, and no two SWNTs behave identically, which necessitates calibration for each SWNT. Some results are presented that show the electrical characteristics of SWNTs and their potential for exploitation in this application.

  5. Tailoring of Microstructure and Properties of Titanium Parts with Local Rapid Heat Treatment

    DTIC Science & Technology

    2010-07-19

    frequency of specimens’ rotation during fatigue testing; 8) kWt – power of induction heating in kilowatts; 9) N sec – duration of LRHT in seconds...REFERENCES FR PAGE 47 List of Figures Fig.1 Installation for Local Rapid Heat Treatment (LRHT, induction heating method); (1) – 440 kHz, 5 kWt...types of specimens tested. FR PAGE 8 Fig.5 Influence of induction heating (5 kWt) duration on the relative thickness of treated layers. FR PAGE 9

  6. High pressure homogenization versus heat treatment: effect on survival, growth, and metabolism of dairy Leuconostoc strains.

    PubMed

    Guglielmotti, D M; Patrignani, F; Lanciotti, R; Guerzoni, M E; Reinheimer, J A; Quiberoni, A

    2012-09-01

    The effect of high pressure homogenization (HPH) with respect to a traditional heat treatment on the inactivation, growth at 8°C after treatments, and volatile profile of adventitious Leuconostoc strains isolated from Cremoso Argentino spoiled cheeses and ingredients used for their manufacture was evaluated. Most Leuconostoc strains revealed elevated resistance to HPH (eight passes, 100 MPa), especially when resuspended in skim milk. Heat treatment was more efficient than HPH in inactivating Leuconostoc cells at the three initial levels tested. The levels of alcohols and sulfur compounds increased during incubation at 8°C in HPH-treated samples, while the highest amounts of aldehydes and ketones characterized were in heated samples. Leuconostoc cells resuspended in skim milk and subjected to one single-pass HPH treatment using an industrial-scale machine showed remarkable reductions in viable cell counts only when 300 and 400 MPa were applied. However, the cell counts of treated samples rose rapidly after only 5 days of storage at 8°C. The Leuconostoc strains tested in this work were highly resistant to the inactivation treatments applied. Neither HPH nor heat treatment assured their total destruction, even though they were more sensitive to the thermal treatment. To enhance the inhibitory effect on Leuconostoc cells, HPH should be combined with a mild heat treatment, which in addition to efficient microbial inactivation, could allow maximal retention of the physicochemical properties of the product.

  7. Heat treatment mechanism and biodegradable characteristics of ZAX1330 Mg alloy.

    PubMed

    Lin, Da-Jun; Hung, Fei-Yi; Lui, Truan-Sheng; Yeh, Ming-Long

    2015-06-01

    Heat treatments are key processes in the development of biodegradable magnesium implants. The aim of this study is to investigate the factors of microstructures and metallurgical segregation on the functionality of biodegradable magnesium alloy. The solid solution heat treatment and strain induced melting activation heat treatment were employed to alter the microstructures of ZAX1330 alloy in this study. Heat treatments caused a significant change on grain size and distribution of secondary phases. The fine-grained microstructure enhanced the mechanical strength, corrosion resistance and achieved the lowest degradation rate in simulated body fluid solution. In coarse-grained microstructure systems, grain growth followed liquid phase formation. The corrosion rate increased due to a larger cathodic region. The status of micro-alloyed calcium (in solid solution or segregated) influenced the microstructural evolution mechanisms, mechanical strength, and degradation properties. A cytotoxicity test and a live/dead assay showed that ZAX1330 had good cytocompatibility, which varied with heat treatment, and no cell toxicity. The results suggest that heat treatment should be controlled precisely in order to improve the cytocompatibility of magnesium alloys for application in orthopedic implants.

  8. The effect of heat treatment on the hardness and impact properties of medium carbon steel

    NASA Astrophysics Data System (ADS)

    Mazni Ismail, Noor; Khatif, Nurul Aida Amir; Aliff Kamil Awang Kecik, Mohamad; Hanafiah Shaharudin, Mohd Ali

    2016-02-01

    This paper covers the effect of heat treatment on the mechanical properties of medium carbon steel. The main objective of this project is to investigate the hardness and impact properties of medium carbon steel treated at different heat treatment processes. Three types of heat treatment were performed in this project which are annealing, quenching and tempering. During annealing process, the specimens were heated at 900°C and soaked for 1 hour in the furnace. The specimens were then quenched in a medium of water and open air, respectively. The treatment was followed by tempering processes which were done at 300°C, 450°C, and 600°C with a soaking time of 2 hours for each temperature. After the heat treatment process completed, Rockwell hardness test and Charpy impact test were performed. The results collected from the Rockwell hardness test and Charpy impact test on the samples after quenching and tempering were compared and analysed. The fractured surfaces of the samples were also been examined by using Scanning Electron Microscope. It was observed that different heat treatment processes gave different hardness value and impact property to the steel. The specimen with the highest hardness was found in samples quenched in water. Besides, the microstructure obtained after tempering provided a good combination of mechanical properties due to the process reduce brittleness by increasing ductility and toughness.

  9. Smoothing of surface of silica glass by heat treatment in wet atmosphere

    SciTech Connect

    Osawa, Kenta; Katayama, Keiichi; Inoue, Hiroyuki; Masuno, Atsunobu; Zhang Yingjiu; Utsuno, Futoshi; Sugahara, Yoshiyuki; Koya, Kazuo; Fujinoki, Akira; Tawarayama, Hiromasa; Kawazoe, Hiroshi

    2011-05-15

    The effect of heat treatment on the surface morphology of fused silica glass substrates was investigated. It was found that the water vapor pressure during heat treatment had a strong influence on the flattening of the silica glass surface. The surface of the frosted glass changed into a transparent and lustrous surface after heat treatment with water vapor at 1200 deg. C for 48 h, whereas surface irregularities remained for heat treatment under a dry atmosphere. It was suggested that the difference in surface flattening was caused by changes in surface viscosity that depended on the concentration of OH groups on the surface. In order to quantitatively understand the effect of the heat treatment atmosphere, power spectral density (PSD) analysis and a novel peak and valley method were applied to the experimental results. From the PSD analysis, it was found that the Mullins' model could not explain the smoothing behavior by heat treatment. The peak and valley method, which could separate the surface morphology into the surface irregularities and the background undulation, revealed that the Mullins' model limitation was mainly for the surface and the background undulation could be understood within the model. These results indicate that there are different mechanisms between for the surface smoothing and for the relaxation of the background undulation.

  10. Gene expression changes in response to aging compared to heat stress, oxidative stress and ionizing radiation in Drosophila melanogaster.

    PubMed

    Landis, Gary; Shen, Jie; Tower, John

    2012-11-01

    Gene expression changes in response to aging, heat stress, hyperoxia, hydrogen peroxide, and ionizing radiation were compared using microarrays. A set of 18 genes were up-regulated across all conditions, indicating a general stress response shared with aging, including the heat shock protein (Hsp) genes Hsp70, Hsp83 and l(2)efl, the glutathione-S-transferase gene GstD2, and the mitochondrial unfolded protein response (mUPR) gene ref(2)P. Selected gene expression changes were confirmed using quantitative PCR, Northern analysis and GstD-GFP reporter constructs. Certain genes were altered in only a subset of the conditions, for example, up-regulation of numerous developmental pathway and signaling genes in response to hydrogen peroxide. While aging shared features with each stress, aging was more similar to the stresses most associated with oxidative stress (hyperoxia, hydrogen peroxide, ionizing radiation) than to heat stress. Aging is associated with down-regulation of numerous mitochondrial genes, including electron-transport-chain (ETC) genes and mitochondrial metabolism genes, and a sub-set of these changes was also observed upon hydrogen peroxide stress and ionizing radiation stress. Aging shared the largest number of gene expression changes with hyperoxia. The extensive down-regulation of mitochondrial and ETC genes during aging is consistent with an aging-associated failure in mitochondrial maintenance, which may underlie the oxidative stress-like and proteotoxic stress-like responses observed during aging.

  11. Oxidative stress in E. coli cells upon exposure to heat treatments.

    PubMed

    Marcén, María; Ruiz, Virginia; Serrano, Mª Jesús; Condón, Santiago; Mañas, Pilar

    2017-01-16

    Heat treatments are widely used by the food industry to inactivate microorganisms, however their mode of action on microbial cells is not fully known. In the last years, it has been proposed that the generation of oxidative species could be an important factor contributing to cell death by heat and by other stresses; however, investigations in this field are scarce. The present work studies the generation of reactive oxygen species (ROS) upon heat treatment in E. coli, through the use of cell staining with specific fluorochromes. Results obtained demonstrate that ROS are detected in E. coli cells when they are subjected to heat exposure, and the amount of fluorescence increases with temperature and time, as does the cellular inactivation. The addition of glutathione or tiron, a potent antioxidant and a superoxide quencher, respectively, to the heating medium protected E. coli against heat inactivation and concurrently reduced the detection of ROS, especially in the case of glutathione. Finally, recovery of heated cells under conditions that relief oxidative stress produced an increase in cell survival. Data presented in this work support the view that ROS generation and subsequent control in bacterial cells could be an essential factor determining inactivation and survival upon exposure to heat, and it could be a potential target to increase the efficacy of current treatments.

  12. Optimized postweld heat treatment procedures for 17-4 PH stainless steels

    SciTech Connect

    Bhaduri, A.K.; Sujith, S.; Srinivasan, G.; Gill, T.P.S.; Mannan, S.L.

    1995-05-01

    The postweld heat treatment (PWHT) procedures for 17-4 PH stainless steel weldments of matching chemistry was optimized vis-a-vis its microstructure prior to welding based on microstructural studies and room-temperature mechanical properties. The 17-4 PH stainless steel was welded in two different prior microstructural conditions (condition A and condition H 1150) and then postweld heat treated to condition H900 or condition H1150, using different heat treatment procedures. Microstructural investigations and room-temperature tensile properties were determined to study the combined effects of prior microstructural and PWHT procedures.

  13. Effects of heat treatment on chitosan nanocomposite film reinforced with nanocrystalline cellulose and tannic acid.

    PubMed

    Rubentheren, V; Ward, Thomas A; Chee, Ching Yern; Nair, Praveena; Salami, Erfan; Fearday, Christopher

    2016-04-20

    This article presents an analysis of the influence of heat treatment on chitosan nanocomposite film. A series of samples comprising: pure chitosan film, chitosan film embedded with nanocrystalline cellulose (NCC), chitosan film crosslinked with tannic acid and chitosan film with a blend of NCC and tannic acid were heat treated using a convection oven. Fourier-transform-infrared spectroscopy (FTIR) and X-ray diffraction test (XRD) shows the changes in chemical interaction of the heat treated films. The heat treated films show significant improvements in moisture absorption. Tensile strength and Young's Modulus were increased up to 7MPa and 259MPa, respectively when the samples were subjected to heat treatment. For the NCC particles, a transmission electron microscope (TEM) was used to inspect the structural properties of cellulose particle in suspension form.

  14. Effect of heat stress on age at first calving of Japanese Black cows in Okinawa.

    PubMed

    Oikawa, Takuro

    2017-03-01

    Calving records from birth certificates of cows were analyzed to investigate the effect of heat stress on age at first calving (AFC) of Japanese Black cows. The data set covered 20 years (1990-2009) of calving records. Total number of records was 9279. Daily weather information from weather stations in the vicinity of the farms was used. Temperature-humidity index (THI) fitted to a linear model covered 30 days pre-insemination to 61 days post-insemination. Statistical analysis was conducted with procedures of SAS/STAT. Preliminary analysis showed that THI of the lowest temperature and humidity was most conducive to AFC. Covariance analysis, including main effect of sire, farm and year of insemination and covariates of THI on days showed that regression coefficients of THI on day -7, day -2 and day +31 were statistically significant. The estimated piecewise regression line showed different responses of AFC to THI on days: roof-shasped downward trend on day -7, hockey-stick shaped upward trend on day -2 and day +31. The difference among the estimated regression lines may be caused by direct and indirect factors on reproduction: indirect effect of reduced feed intake, failure of conception at previous insemination, direct effect of heat stress on oocyte and embryo development.

  15. Effects of Pressure, Temperature, Treatment Time, and Storage on Rheological, Textural, and Structural Properties of Heat-Induced Chickpea Gels.

    PubMed

    Alvarez, María Dolores; Fuentes, Raúl; Canet, Wenceslao

    2015-04-15

    Pressure-induced gelatinization of chickpea flour (CF) was studied in combination with subsequent temperature-induced gelatinization. CF slurries (with 1:5 flour-to-water ratio) and CF in powder form were treated with high hydrostatic pressure (HHP), temperature (T), and treatment time (t) at three levels (200, 400, 600 MPa; 10, 25, 50 °C; 5, 15, 25 min). In order to investigate the effect of storage (S), half of the HHP-treated CF slurries were immediately analyzed for changes in oscillatory rheological properties under isothermal heating at 75 °C for 15 min followed by cooling to 25 °C. The other half of the HHP-treated CF slurries were refrigerated (at 4 °C) for one week and subsequently analyzed for changes in oscillatory properties under the same heating conditions as the unrefrigerated samples. HHP-treated CF in powder form was analyzed for changes in textural properties of heat-induced CF gels under isothermal heating at 90 °C for 5 min and subsequent cooling to 25 °C. Structural changes during gelatinization were investigated using microscopy. Pressure had a more significant effect on rheological and textural properties, followed by T and treatment t (in that order). Gel aging in HHP-treated CF slurries during storage was supported by rheological measurements.

  16. Effects of Pressure, Temperature, Treatment Time, and Storage on Rheological, Textural, and Structural Properties of Heat-Induced Chickpea Gels

    PubMed Central

    Alvarez, María Dolores; Fuentes, Raúl; Canet, Wenceslao

    2015-01-01

    Pressure-induced gelatinization of chickpea flour (CF) was studied in combination with subsequent temperature-induced gelatinization. CF slurries (with 1:5 flour-to-water ratio) and CF in powder form were treated with high hydrostatic pressure (HHP), temperature (T), and treatment time (t) at three levels (200, 400, 600 MPa; 10, 25, 50 °C; 5, 15, 25 min). In order to investigate the effect of storage (S), half of the HHP-treated CF slurries were immediately analyzed for changes in oscillatory rheological properties under isothermal heating at 75 °C for 15 min followed by cooling to 25 °C. The other half of the HHP-treated CF slurries were refrigerated (at 4 °C) for one week and subsequently analyzed for changes in oscillatory properties under the same heating conditions as the unrefrigerated samples. HHP-treated CF in powder form was analyzed for changes in textural properties of heat-induced CF gels under isothermal heating at 90 °C for 5 min and subsequent cooling to 25 °C. Structural changes during gelatinization were investigated using microscopy. Pressure had a more significant effect on rheological and textural properties, followed by T and treatment t (in that order). Gel aging in HHP-treated CF slurries during storage was supported by rheological measurements. PMID:28231191

  17. Dynamic strength and failure behavior of titanium alloy Ti-6Al-4V for a variation of heat treatments

    NASA Astrophysics Data System (ADS)

    Meyer, Lothar W.; Krüger, Lutz; Sommer, Kristin; Halle, Thorsten; Hockauf, Matthias

    2008-09-01

    In our study, samples of Ti-6Al-4V were subjected to modifications of an aging treatment where temperatures for solution annealing and final aging as well as the cooling rate were varied. The titanium alloy was annealed above and below the β-transus temperature followed by cooling in a vacuum furnace or by water quenching. Additionally, the final annealing temperature was varied. Compression tests under quasistatic and dynamic loading rates were performed to determine the flow stress and strain hardening behavior. Furthermore, instrumented Charpy impact tests on U-notch specimen were performed at room temperature to monitor the load-time response of deformation and fracturing. The obtained high rate mechanical properties are discussed and correlated with the present microstructure. Our results reveal a very strong effect of the microstructure on the material behavior and will assist to choose the appropriate heat treatment technology, especially if impact loaded or safety structures have to be considered.

  18. Testosterone treatment in the aging male: myth or reality?

    PubMed

    Nigro, Nicole; Christ-Crain, Mirjam

    2012-03-19

    The definition of late onset hypogonadism in the aging male is controversially debated, and according to the latest literature consists of at least three especially sexual symptoms such as loss of morning erection, low sexual desire and erectile dysfunction as well as a total testosterone <8-11 nmol/l. Testosterone replacement therapy in the aging male has been shown to have a beneficial effect on muscle and fat mass as well as on bone mineral density, with more conflicting effects observed on muscle strength, sexual function, mood and quality of life. The prescriptions for testosterone products for the aging male increased by over 170% in the previous five years. Furthermore, there is a lot of epidemiological data showing an inverse relationship between testosterone levels and obesity, insulin resistance, the metabolic syndrome and type 2 diabetes mellitus. However, only few small randomised placebo-controlled studies have investigated the effect of testosterone replacement therapy on insulin resistance and HbA1c levels, with controversial results. Importantly, so far the long-term safety and efficacy of testosterone replacement therapy has not been established. Although until now no clear evidence has been found that testosterone replacement therapy has a causative role in prostate cancer or indeed in changes of the biology of the prostate, in a recent meta-analysis a 4-fold increased risk of prostate-associated event rates in testosterone treated elderly men sounds a note of caution. Also the risk for cardiovascular events is still not clear and caution is warranted especially in elderly men with cardiovascular disease and limited mobility. In summary, the actual available evidence of long-term risks and outcome of testosterone replacement therapy is still very limited and carefully designed placebo-controlled trials of testosterone administration to assess the risks and benefits of such a therapy are required. Until then, testosterone treatment in elderly men

  19. UV-Heat Treatments for the Control of Foodborne Microbial Pathogens in Chicken Broth

    PubMed Central

    Gouma, M.; Gayán, E.; Raso, J.; Condón, S.; Álvarez, I.

    2015-01-01

    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. PMID:26539493

  20. Method for detecting pollutants. [through chemical reactions and heat treatment

    NASA Technical Reports Server (NTRS)

    Rogowski, R. S.; Richards, R. R.; Conway, E. J. (Inventor)

    1976-01-01

    A method is described for detecting and measuring trace amounts of pollutants of the group consisting of ozone, nitrogen dioxide, and carbon monoxide in a gaseous environment. A sample organic solid material that will undergo a chemical reaction with the test pollutant is exposed to the test environment and thereafter, when heated in the temperature range of 100-200 C., undergoes chemiluminescence that is measured and recorded as a function of concentration of the test pollutant. The chemiluminescence of the solid organic material is specific to the pollutant being tested.

  1. Effects of heat and high-pressure treatments on the solubility and immunoreactivity of almond proteins.

    PubMed

    Zhang, Yan; Zhang, Jieqiong; Sheng, Wei; Wang, Shuo; Fu, Tong-Jen

    2016-05-15

    The effects of dry and moist heat, autoclave sterilization and high-pressure treatment on the biochemical characteristics and immunological properties of almond proteins were investigated. Changes in the solubility and immunoreactivity of almond proteins extracted from treated almond flour were evaluated using a total protein assay, indirect competitive inhibition enzyme-linked immunosorbent assay (IC-ELISA), and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Almond proteins were stable during dry-heat treatment at temperatures below 250°C. Dry heat at 400°C, boiling, autoclave sterilization and high-pressure treatment in the presence of water at ⩾ 500 MPa greatly reduced the solubility and immunoreactivity of almond proteins. SDS-PAGE revealed that the protein profiles of almond flour samples treated under these conditions also changed significantly. The synergistic effects of heat, pressure and the presence of water contributed to significant changes in solubility and immunoreactivity of almond proteins.

  2. Effect of Heat-Treatment on Metallic Collection for Used Printed Circuit Board

    NASA Astrophysics Data System (ADS)

    Agawa, Ryuichi; Tsugita, Yasuhiro; Nishida, Minoru; Araki, Takao

    In this research, we examined the method that separates the material from the printed circuit board by the proof scale heat-treatment. The size of the printed circuit board (PCB) used for the examination was about 150 mm × 200 mm, and PCB was executed heat-treatment by two kinds of shape as received (Sample-A) and crushed (Sample-B) by hammarcrasher. The following result was obtained. The organic resin and also omine were removed by the heat treatment in both cases. In Sample-B heat-treatment, though combustion was done with stability, however, the temperature rises locally so that the organism in the board crushed by the high contact with oxygen may burn instantaneously and the combustion residue melted solidifies. In Sample-A heat-treatment, the metallic collection rate in the combustion residue was higher than Sample-B, especially Cu and Ni are collected by 90mass% or more, and Ag, Au and Pb collected were twice larger compared with Sample-B. The residue in Sample-A could be crushed comparatively easily with hammarcrasher. Therefore, to make the crushing combustion residue concentrated of the metal in the printed circuit board adjust to metallic refinement process, it is thought that we should heat-treat the printed circuit board near as received.

  3. Dependence of Dynamic Tensile Strength of Longyou Sandstone on Heat-Treatment Temperature and Loading Rate

    NASA Astrophysics Data System (ADS)

    Yao, Wei; Xu, Ying; Wang, Wei; Kanopolous, Patrick

    2016-10-01

    As a material for famous historical underground rock caverns, Longyou sandstone (LS) may fail under the combination of high loading rate and high temperature. The thermal damage induced by various heat-treatment temperatures (150, 250, 350, 450, 600 and 850 °C) is first characterized by X-ray Micro-computed tomography (CT) method. The damage variable derived from the average CT value for heat-treated LS specimen and reference specimen without heat treatment was used to quantify the thermal damage. The dynamic tensile strengths of these LS samples under different dynamic loading rates (ranging from 24 to 540 GPa/s) were then obtained using the split Hopkinson pressure bar (SHPB) system. The dynamic tensile strength of LS increases with the loading rate at a given heat-treatment temperature, and the tensile strength at the same loading rate decreases with the heat-treatment temperature except for 450 °C. Based on the experimental data, an empirical equation was established to relate the dynamic tensile strength of LS to the loading rate and the heat-treatment temperature.

  4. Heat treatment induced bacterial changes in irrigation water and their implications for plant disease management.

    PubMed

    Hao, W; Hong, C X

    2014-05-01

    A new heat treatment for recycled irrigation water using 48 °C for 24 h to inactivate Phytophthora and bacterial plant pathogens is estimated to reduce fuel cost and environmental footprint by more than 50 % compared to current protocol (95 °C for 30 s). The objective of this study was to determine the impact of this new heat treatment temperature regime on bacterial community structure in water and its practical implications. Bacterial communities in irrigation water were analyzed before and after heat treatment using both culture-dependent and -independent strategies based on the 16S ribosomal DNA. A significant shift was observed in the bacterial community after heat treatment. Most importantly, bacteria with biological control potential--Bacillus and Paenibacillus, and Pseudomonas species became more abundant at both 48 and 42 °C. These findings imply that the new heat treatment procedure not only controls existing plant pathogens but also may make the heat-treated irrigation water a more antagonistic environment against plant pathogens, promoting sustainable disease management.

  5. Comparison of the effectiveness of soil heating prior or during in situ chemical oxidation (ISCO) of aged PAH-contaminated soils.

    PubMed

    Ranc, Bérénice; Faure, Pierre; Croze, Véronique; Lorgeoux, Catherine; Simonnot, Marie-Odile

    2017-03-15

    Thermal treatments prior or during chemical oxidation of aged polycyclic aromatic hydrocarbon (PAH)-contaminated soils have already shown their ability to increase oxidation effectiveness. However, they were never compared on the same soil. Furthermore, oxygenated polycyclic aromatic hydrocarbons (O-PACs), by-products of PAH oxidation which may be more toxic and mobile than the parent PAHs, were very little monitored. In this study, two aged PAH-contaminated soils were heated prior (60 or 90 °C under Ar for 1 week) or during oxidation (60 °C for 1 week) with permanganate and persulfate, and 11 O-PACs were monitored in addition to the 16 US Environmental Protection Agency (US EPA) PAHs. Oxidant doses were based on the stoichiometric oxidant demand of the extractable organic fraction of soils by using organic solvents, which is more representative of the actual contamination than only the 16 US EPA PAHs. Higher temperatures actually resulted in more pollutant degradation. Two treatments were about three times more effective than the others: soil heating to 60 °C during persulfate oxidation and soil preheating to 90 °C followed by permanganate oxidation. The results of this study showed that persulfate effectiveness was largely due to its thermal activation, whereas permanganate was more sensitive to PAH availability than persulfate. The technical feasibility of these two treatments will soon be field-tested in the unsaturated zone of one of the studied aged PAH-contaminated soils.

  6. Green Chemical Treatments for Heating and Cooling Systems

    DTIC Science & Technology

    2006-09-01

    of condenser wa- ter treatment with a key ingredient being polyaspartate (PASP). Polyaspar- tic acid was the 1996 Presidential Green Chemistry Challenge...cooling water biocide tetrakis (hy- droxymethyl) phosphonium sulfate (THPS). THPS won the Presidential Green Chemistry Challenge Award in 1997. The...Legionella pneumophila bacterium, which causes Legion- naire’s Disease. 2.3 Steam Line Treatment The third and final product in the Green Chemistry project

  7. Menu driven heat treatment control of thin walled bodies

    DOEpatents

    Kothmann, Richard E.; Booth, Jr., Russell R.; Grimm, Noel P.; Batenburg, Abram; Thomas, Vaughn M.

    1992-01-01

    A process for controlling the heating of a thin-walled body according to a predetermined temperature program by means of electrically controllable heaters, comprising: disposing the heaters adjacent one surface of the body such that each heater is in facing relation with a respective zone of the surface; supplying heat-generating power to each heater and monitoring the temperature at each surface zone; and for each zone: deriving (16,18,20), on the basis of the temperature values obtained in the monitoring step, estimated temperature values of the surface at successive time intervals each having a first selected duration; generating (28), on the basis of the estimated temperature values derived in each time interval, representations of the temperature, THSIFUT, which each surface zone will have, based on the level of power presently supplied to each heater, at a future time which is separated from the present time interval by a second selected duration; determining (30) the difference between THSIFUT and the desired temperature, FUTREFTVZL, at the future time which is separated from the present time interval by the second selected duration; providing (52) a representation indicating the power level which sould be supplied to each heater in order to reduce the difference obtained in the determining step; and adjusting the power level supplied to each heater by the supplying step in response to the value of the representation provided in the providing step.

  8. Endothelial nitric oxide synthase mediates cutaneous vasodilation during local heating and is attenuated in middle-aged human skin.

    PubMed

    Bruning, Rebecca S; Santhanam, Lakshmi; Stanhewicz, Anna E; Smith, Caroline J; Berkowitz, Dan E; Kenney, W Larry; Holowatz, Lacy A

    2012-06-01

    Local skin heating is used to assess microvascular function in clinical populations because NO is required for full expression of the response; however, controversy exists as to the precise NO synthase (NOS) isoform producing NO. Human aging is associated with attenuated cutaneous vasodilation but little is known about the middle aged, an age cohort used for comparison with clinical populations. We hypothesized that endothelial NOS (eNOS) is the primary isoform mediating NO production during local heating, and eNOS-dependent vasodilation would be reduced in middle-aged skin. Vasodilation was induced by local heating (42°C) and during acetylcholine dose-response (ACh-DR: 0.01, 0.1, 1.0, 5.0, 10.0, 50.0, 100.0 mmol/l) protocols. Four microdialysis fibers were placed in the skin of 24 men and women; age cohorts were 12 middle-aged (53 ± 1 yr) and 12 young (23 ± 1 yr). Sites served as control, nonselective NOS inhibited [N(G)-nitro-l-arginine methyl ester (l-NAME)], inducible NOS (iNOS) inhibited (1400W), and neuronal NOS (nNOS) inhibited (N(ω)-propyl-l-arginine). After full expression of the local heating response, l-NAME was perfused at all sites. Cutaneous vascular conductance was measured and normalized to maximum (%CVC(max): Nitropress). l-NAME reduced %CVCmax at baseline, all phases of the local heating response, and at all ACh concentrations compared with all other sites. iNOS inhibition reduced the initial peak (53 ± 2 vs. 60 ± 2%CVC(max); P < 0.001); however, there were no other differences between control, nNOS-, and iNOS-inhibited sites during the phases of local heating or ACh-DR. When age cohorts were compared, NO-dependent vasodilation during local heating (52 ± 6 vs. 68 ± 4%CVC(max); P = 0.013) and ACh perfusion (50 mmol/l: 83 ± 3 vs. 93 ± 2%CVC(max); 100 mmol/l: 83 ± 4 vs. 92 ± 3%CVC(max); both P = 0.03) were reduced in middle-aged skin. There were no differences in NOS isoform expression obtained from skin biopsy samples between groups (all

  9. An Update on Inflamm-Aging: Mechanisms, Prevention, and Treatment

    PubMed Central

    Wu, Junzhen

    2016-01-01

    Inflamm-aging is a challenging and promising new branch of aging-related research fields that includes areas such as immunosenescence. Increasing evidence indicates that inflamm-aging is intensively associated with many aging diseases, such as Alzheimer's disease, atherosclerosis, heart disease, type II diabetes, and cancer. Mounting studies have focused on the role of inflamm-aging in disease progression and many advances have been made in the last decade. However, the underlying mechanisms by which inflamm-aging affects pathological changes and disease development are still unclear. Here, we review studies of inflamm-aging that explore the concept, pathological features, mechanisms, intervention, and the therapeutic strategies of inflamm-aging in disease progression. PMID:27493973

  10. Phase composition of heat-resisting alloy modified by ageing and alloyed by rhenium

    NASA Astrophysics Data System (ADS)

    Koneva, Nina; Nikonenko, Elena; Popova, Natalya; Gibert, Ivan; Kozlov, Eduard

    2016-11-01

    The paper presents the transmission electron microscope (TEM) investigations of the structure of Ni-Al-Cr-based superalloy which is obtained by directional crystallization technique. The structural TEM investigations are carried out in two stages: 1) annealing at 1150°C for 1 h and 2) annealing at 1100°C for 480 h. The qualitative and quantitative analysis is given for the structure, phase composition and morphology of heat-resisting alloy additionally alloyed by rhenium Re both in the original state and after thermal treatment. The heat-resisting alloy comprises ˜70 at % Ni, ˜17 at % Al and ˜5 at % Cr. The total amount of the primary alloying elements of Mo, W, Ta, Ti, Co, La was ˜7 at % and 0.4 at % Re. It is shown that the structure of the superalloy is represented by (γ + γ')-phase mixture which has a morphologically correct crystallographic orientation and quasi-monocrystalline structure. σ-phase is formed in this superalloy due to rhenium. Since Re distribution in the alloy is not uniform, only a part of (γ + γ')-phase quasi-cuboids is distorted. It is shown that Re modification distorts the ideal structure of (γ + γ')-phase quasi-cuboids and results in the formation of β-, χ-and σ-phases.

  11. Shortening the Time of Heat Treatment of Silumins of the Al - Si - Cu System by Modifying their Structure

    NASA Astrophysics Data System (ADS)

    Nikitin, K. V.; Chikova, O. A.; Amosov, E. A.; Nikitin, V. I.

    2016-11-01

    The possibility of shortening the heat treatment hold of silumins of the Al - Si - Cu system by changing the parameters of the structure under chill casting is considered and a criterion for their evaluation is suggested. Alloys AK6M2 and AK8M3ch are used to demonstrate experimentally that decrease in the sizes of the crystals of primary silicon and in the transverse size of the α-Al secondary dendrite arms can halve the time of holding for quenching and aging at a guaranteed margin of the strength properties.

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

    SciTech Connect

    Mamum, Md Abdullah A.; Elmustafa, Abdelmageed A,; Stutzman, Marcy L.; Adderley, Philip A.; Poelker, Matthew

    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.

  13. Effects of heat treatment on microbial communities of granular sludge for biological hydrogen production.

    PubMed

    Alibardi, Luca; Favaro, Lorenzo; Lavagnolo, Maria Cristina; Basaglia, Marina; Casella, Sergio

    2012-01-01

    Dark fermentation shares many features with anaerobic digestion with the exception that to maximize hydrogen production, methanogens and hydrogen-consuming bacteria should be inhibited. Heat treatment is widely applied as an inoculum pre-treatment due to its effectiveness in inhibiting methanogenic microflora but it may not exclusively select for hydrogen-producing bacteria. This work evaluated the effects of heat treatment on microbial viability and structure of anaerobic granular sludge. Heat treatment was carried out on granular sludge at 100 °C with four residence times (0.5, 1, 2 and 4 h). Hydrogen production of treated sludges was studied from glucose by means of batch test at different pH values. Results indicated that each heat treatment strongly influenced the granular sludge resulting in microbial communities having different hydrogen productions. The highest hydrogen yields (2.14 moles of hydrogen per mole of glucose) were obtained at pH 5.5 using the sludge treated for 4 h characterized by the lowest CFU concentration (2.3 × 10(3)CFU/g sludge). This study demonstrated that heat treatment should be carefully defined according to the structure of the sludge microbial community, allowing the selection of highly efficient hydrogen-producing microbes.

  14. Previous heat shock treatment inhibits Mayaro virus replication in human lung adenocarcinoma (A549) cells.

    PubMed

    Virgilio, P L; Godinho-Netto, M C; Carvalho Mda, G

    1997-01-01

    Human lung adenocarcinoma cells (A549) were submitted to mild or severe heat shock (42 degrees C or 44 degrees C) for 1 h, while another group of cells was double-heat-shocked (submitted to 42 degrees C for 1 h, returned to 37 degrees C for 3 h, then exposed to 44 degrees C for 1 h). After each heat treatment, the cells were infected with Mayaro virus for 24 h and incubated at 37 degrees C. The results showed that the double-heat-shocked thermotolerant cells exhibited a 10(4)-fold virus titre inhibition, despite the recovery of protein synthesis and original morphology 24 h post-infection. In contrast, cells submitted to mild or severe heat shock exhibited weaker inhibition of Mayaro virus titre (10(2)-fold). The mildly heat-shocked cells also presented a full recovery in protein synthesis, which was not observed in severely heat-shocked cells. These results indicate that exposure of A549 cells to a mild or to a double heat shock treatment before Mayaro virus infection induces an antiviral state.

  15. Design and performance of a new induction furnace for heat treatment of superconducting radiofrequency niobium cavities

    NASA Astrophysics Data System (ADS)

    Dhakal, Pashupati; Ciovati, Gianluigi; Rigby, Wayne; Wallace, John; Myneni, Ganapati Rao

    2012-06-01

    Superconducting radio frequency (SRF) cavities made of high purity niobium (Nb) are the building blocks of many modern particle accelerators. The fabrication process includes several cycles of chemical and heat treatment at low (˜120 °C) and high (˜800 °C) temperatures. In this contribution, we describe the design and performance of an ultra-high-vacuum furnace which uses an induction heating system to heat treat SRF cavities. Cavities are heated by radiation from the Nb susceptor. By using an all-niobium hot zone, contamination of the Nb cavity by foreign elements during heat treatment is minimized and allows avoiding subsequent chemical etching. The furnace was operated up to 1400 °C with a maximum pressure of ˜1 × 10-5 Torr and the maximum achievable temperature is estimated to be higher than 2000 °C. Initial results on the performance of a single cell 1.5 GHz cavity made of ingot Nb heat treated at 1200 °C using this new induction furnace and without subsequent chemical etching showed a reduction of the RF losses by a factor of ˜2 compared to cavities made of fine-grain Nb which underwent standard chemical and heat treatments.

  16. Design and performance of a new induction furnace for heat treatment of superconducting radiofrequency niobium cavities.

    PubMed

    Dhakal, Pashupati; Ciovati, Gianluigi; Rigby, Wayne; Wallace, John; Myneni, Ganapati Rao

    2012-06-01

    Superconducting radio frequency (SRF) cavities made of high purity niobium (Nb) are the building blocks of many modern particle accelerators. The fabrication process includes several cycles of chemical and heat treatment at low (∼120 °C) and high (∼800 °C) temperatures. In this contribution, we describe the design and performance of an ultra-high-vacuum furnace which uses an induction heating system to heat treat SRF cavities. Cavities are heated by radiation from the Nb susceptor. By using an all-niobium hot zone, contamination of the Nb cavity by foreign elements during heat treatment is minimized and allows avoiding subsequent chemical etching. The furnace was operated up to 1400 °C with a maximum pressure of ∼1 × 10(-5) Torr and the maximum achievable temperature is estimated to be higher than 2000 °C. Initial results on the performance of a single cell 1.5 GHz cavity made of ingot Nb heat treated at 1200 °C using this new induction furnace and without subsequent chemical etching showed a reduction of the RF losses by a factor of ∼2 compared to cavities made of fine-grain Nb which underwent standard chemical and heat treatments.

  17. Design and performance of a new induction furnace for heat treatment of superconducting radiofrequency niobium cavities

    SciTech Connect

    Dhakal, Pashupati; Ciovati, Gianluigi; Myneni, Ganapati Rao; Rigby, Wayne; Wallace, John

    2012-06-15

    Superconducting radio frequency (SRF) cavities made of high purity niobium (Nb) are the building blocks of many modern particle accelerators. The fabrication process includes several cycles of chemical and heat treatment at low ({approx}120 Degree-Sign C) and high ({approx}800 Degree-Sign C) temperatures. In this contribution, we describe the design and performance of an ultra-high-vacuum furnace which uses an induction heating system to heat treat SRF cavities. Cavities are heated by radiation from the Nb susceptor. By using an all-niobium hot zone, contamination of the Nb cavity by foreign elements during heat treatment is minimized and allows avoiding subsequent chemical etching. The furnace was operated up to 1400 Degree-Sign C with a maximum pressure of {approx}1 Multiplication-Sign 10{sup -5} Torr and the maximum achievable temperature is estimated to be higher than 2000 Degree-Sign C. Initial results on the performance of a single cell 1.5 GHz cavity made of ingot Nb heat treated at 1200 Degree-Sign C using this new induction furnace and without subsequent chemical etching showed a reduction of the RF losses by a factor of {approx}2 compared to cavities made of fine-grain Nb which underwent standard chemical and heat treatments.

  18. Design and performance of a new induction furnace for heat treatment of superconducting radiofrequency niobium cavities

    SciTech Connect

    Pashupati Dhakal, Gianluigi Ciovati, Wayne Rigby, John Wallace, Ganapati Rao Myneni

    2012-06-01

    Superconducting radio frequency (SRF) cavities made of high purity niobium (Nb) are the building blocks of many modern particle accelerators. The fabrication process includes several cycles of chemical and heat treatment at low ({approx}120 deg C) and high ({approx}800 deg C) temperatures. In this contribution, we describe the design and performance of an ultra-high-vacuum furnace which uses an induction heating system to heat treat SRF cavities. Cavities are heated by radiation from the Nb susceptor. By using an all-niobium hot zone, contamination of the Nb cavity by foreign elements during heat treatment is minimized and allows avoiding subsequent chemical etching. The furnace was operated up to 1400 deg C with a maximum pressure of {approx}1 x 10{sup -5} Torr and the maximum achievable temperature is estimated to be higher than 2000 deg C. Initial results on the performance of a single cell 1.5 GHz cavity made of ingot Nb heat treated at 1200 deg C using this new induction furnace and without subsequent chemical etching showed a reduction of the RF losses by a factor of {approx}2 compared to cavities made of fine-grain Nb which underwent standard chemical and heat treatments.

  19. Combined heat transfer and kinetic models to predict cooking loss during heat treatment of beef meat.

    PubMed

    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.

  20. Particle Size of Gamma Prime as a Result of Vacuum Heat Treatment of INCONEL 738 Super Alloy

    NASA Astrophysics Data System (ADS)

    Guzman, I.; Granda, E.; Mendez, R.; Lopez, G.; Acevedo, J.; Gonzalez, D.

    2013-04-01

    In this paper, the influence of the cooling rate and cooling media after a standard solution heat treatment on the size and distribution of the gamma prime phase (γ') in the nickel-based super alloy INCONEL 738 in over-aged conditions is described. The volume fraction of the gamma prime depends on the chemical composition of the alloy, the solution treatment temperature and the cooling rate; in over-aged alloys (i.e., with more than 25,000 h of service) the volume fraction of γ' is about 78.8%. However, it has been demonstrated that in order to maintain excellent creep strength a volume fraction of at least 60% or lower is required. In this work the volume fraction was optimized between 40 and 55% by means of a standard solution heat treatment at 1120 °C using different cooling gases. A γ' volume fraction of 54.8% was obtained by using argon as the cooling medium at a cooling rate of 87 °C/min, producing a precipitate of partial distribution of primary and secondary γ'. Better results were obtained in a nitrogen atmosphere at a cooling rate of 287 °C/min, leading to a volume fraction of 40% and obtaining a total re-precipitation of primary and secondary γ'.

  1. Bone-bonding properties of Ti metal subjected to acid and heat treatments.

    PubMed

    Kawai, Toshiyuki; Takemoto, Mitsuru; Fujibayashi, Shunsuke; Neo, Masashi; Akiyama, Haruhiko; Yamaguchi, Seiji; Pattanayak, Deepak K; Matsushita, Tomiharu; Nakamura, Takashi; Kokubo, Tadashi

    2012-12-01

    The effects of surface treatment on the bone-bonding properties of Ti metal were examined by both mechanical detaching test and histological observation after implantation into rabbit tibiae for various periods ranging from 4 to 26 weeks. The bone-bonding ability of Ti metal, which is extremely low as it is abraded, was hardly increased by simple heat treatment at 600 °C or treatment with H(2)SO(4)/HCl mixed acid alone, but was markedly increased by the heat treatment after the acid treatment. Even Ti metal that had been previously subjected to NaOH treatment showed considerably high bone-bonding ability after acid and heat treatments. Such high bonding abilities were attributed to their high apatite-forming ability in the body environment. Their high apatite-forming abilities were attributed to a high positive surface charge, and not to the type of crystalline phase or specific roughness of their surfaces. The present study has demonstrated that acid and subsequent heat treatments are effective for conferring stable fixation properties on Ti metal implants.

  2. Aging Will Amplify the Heat-related Mortality Risk under a Changing Climate: Projection for the Elderly in Beijing, China

    NASA Astrophysics Data System (ADS)

    Li, Tiantian; Horton, Radley M.; Bader, Daniel A.; Zhou, Maigeng; Liang, Xudong; Ban, Jie; Sun, Qinghua; Kinney, Patrick L.

    2016-06-01

    An aging population could substantially enhance the burden of heat-related health risks in a warming climate because of their higher susceptibility to extreme heat health effects. Here, we project heat-related mortality for adults 65 years and older in Beijing China across 31 downscaled climate models and 2 representative concentration pathways (RCPs) in the 2020s, 2050s, and 2080s. Under a scenario of medium population and RCP8.5, by the 2080s, Beijing is projected to experience 14,401 heat-related deaths per year for elderly individuals, which is a 264.9% increase compared with the 1980s. These impacts could be moderated through adaptation. In the 2080s, even with the 30% and 50% adaptation rate assumed in our study, the increase in heat-related death is approximately 7.4 times and 1.3 times larger than in the 1980s respectively under a scenario of high population and RCP8.5. These findings could assist countries in establishing public health intervention policies for the dual problems of climate change and aging population. Examples could include ensuring facilities with large elderly populations are protected from extreme heat (for example through back-up power supplies and/or passive cooling) and using databases and community networks to ensure the home-bound elderly are safe during extreme heat events.

  3. Aging Will Amplify the Heat-related Mortality Risk under a Changing Climate: Projection for the Elderly in Beijing, China

    PubMed Central

    Li, Tiantian; Horton, Radley M.; Bader, Daniel A.; Zhou, Maigeng; Liang, Xudong; Ban, Jie; Sun, Qinghua; Kinney, Patrick L.

    2016-01-01

    An aging population could substantially enhance the burden of heat-related health risks in a warming climate because of their higher susceptibility to extreme heat health effects. Here, we project heat-related mortality for adults 65 years and older in Beijing China across 31 downscaled climate models and 2 representative concentration pathways (RCPs) in the 2020s, 2050s, and 2080s. Under a scenario of medium population and RCP8.5, by the 2080s, Beijing is projected to experience 14,401 heat-related deaths per year for elderly individuals, which is a 264.9% increase compared with the 1980s. These impacts could be moderated through adaptation. In the 2080s, even with the 30% and 50% adaptation rate assumed in our study, the increase in heat-related death is approximately 7.4 times and 1.3 times larger than in the 1980s respectively under a scenario of high population and RCP8.5. These findings could assist countries in establishing public health intervention policies for the dual problems of climate change and aging population. Examples could include ensuring facilities with large elderly populations are protected from extreme heat (for example through back-up power supplies and/or passive cooling) and using databases and community networks to ensure the home-bound elderly are safe during extreme heat events. PMID:27320724

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

    PubMed

    Sarup, P; Sørensen, P; Loeschcke, V

    2014-02-01

    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<0.01). This result was unexpected as the major Drosophila heat shock protein, Hsp70, is reported to return to normal levels of expression shortly after heat stress. We conclude that the heat shock response, and Hsp70 in particular, may be central to the heat-induced increase in the average lifespan in flies that are exposed to mild heat stress early in life.

  5. Effects of 35 C Heat Treatments on Photosensitive Grand Rapids Lettuce Seed Germination 1

    PubMed Central

    Carpita, Nicholas C.; Nabors, Murray W.

    1976-01-01

    Grand Rapids lettuce (Lactuca sativa L.) seeds were given 35 C heat treatments to increase photodormancy in a subsequent 20 C dark period. Short heat treatments (1-5 hours) induced a significant germination percentage increase of from 16% to over 50% depending on seed lot. With longer heat treatments dark germination percentage was gradually reduced to zero. If given at the end of 35 C, far red or red followed by far red further increased the amount of dark germination. Thermodormancy also delayed red-stimulated germination by 10 hours or more when red was given following a long 35 C treatment. The presence of Pfr was required during this time since far red light remained effective in reversing at least 50% of the red stimulation for up to 16 hours compared to only 4 hours in nonheat-treated seeds. PMID:16659537

  6. Increased prevalence of Dirofilaria immitis antigen in canine samples after heat treatment.

    PubMed

    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.

  7. The (safety-related) heat exchangers aging management guideline for commercial nuclear power plants, and developments since 1994

    SciTech Connect

    Clauss, J.M.

    1998-08-01

    The US Department of Energy (DOE), in cooperation with the Electric Power Research Institute (EPRI) and US nuclear power plant utilities, is preparing a series of aging management guidelines (AMGs) for commodity types of components (e.g., heat exchangers, electrical cable and terminations, pumps). Commodities are included in this series based on their importance to continued nuclear plant operation and license renewal. The AMGs contain a detailed summary of operating history, stressors, aging mechanisms, and various types of maintenance and surveillance practices that can be combined to create an effective aging management program. Each AMG is intended for use by the systems engineers and plant maintenance staff (i.e., an AMG is intended to be a hands-on technical document rather than a licensing document). The heat exchangers AMG, published in June 1994, includes the following information of interest to nondestructive examination (NDE) personnel: aging mechanisms determined to be non-significant for all applications; aging mechanisms determined to be significant for some applications; effective conventional programs for managing aging; and effective unconventional programs for managing aging. Since the AMG on heat exchangers was published four years ago, a brief review has been conducted to identify emerging regulatory issues, if any. The results of this review and lessons learned from the collective set of AMGs are presented.

  8. Effect of long-term aging on microstructure and local behavior in the heat-affected zone of a Ni–Cr–Mo–V steel welded joint

    SciTech Connect

    Zhu, Ming-Liang Wang, De-Qiang; Xuan, Fu-Zhen

    2014-01-15

    Evolution of microstructure, micro-hardness and micro-tensile strength behavior was investigated in the heat-affected zone of a Ni–Cr–Mo–V steel welded joint after the artificial aging at 350 °C for 3000 h. After detailed characterization of microstructures in optical microscopy, scanning electron microscopy and transmission electron microscopy, it is revealed that the change of martensite–bainite constituent promotes more homogeneous microstructure distribution. The aging treatment facilitates redistribution of carbon and chromium elements along the welded joint, and the micro-hardness is increased slightly through the welds due to enrichment of carbon. The types of precipitates in the weldment mainly include M{sub 3}C, MC, M{sub 2}C and M{sub 23}C{sub 6}. The carbides in base metal, weld metal and coarse-grained heat-affected zone are prone to change from ellipsoidal to platelet form whereas more uniform spherical carbides are observed in the fine-grained zone. Precipitation and coarsening of M{sub 23}C{sub 6} near the fusion line, and formation of MC and M{sub 2}C, are responsible for the tensile strength decrease and its smooth distribution in the aged heat-affected zone. This implies that the thermal aging can relieve strength mismatch in the weldments. - Highlights: • Microstructure homogeneity improved in HAZ after long-term aging. • Tensile strength decreased in HAZ due to precipitation and coarsening of M{sub 23}C{sub 6}. • Strength mismatch in NiCrMoV steel welds was relieved after aging at 350 °C × 3000 h.

  9. 7 CFR 305.24 - Vapor heat treatment schedules.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... must be sized before treatment. Temperature probes must be placed in the center of the largest fruits.... Temperature probes must be placed in the center of the largest fruits. (2) The temperature of the fruit must... placed in the approximate center of the largest fruits at the seed's surface. (2) The......

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

    NASA Astrophysics Data System (ADS)

    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.

  11. Substance Abuse Treatment Admissions Aged 12 to 14. The TEDS Report

    ERIC Educational Resources Information Center

    Substance Abuse and Mental Health Services Administration, 2011

    2011-01-01

    This report uses data from the Treatment Episode Data Set (TEDS) for 2008 to provide information on the characteristics of youths aged 12 to 14 admitted to substance abuse treatment. In 2008, approximately 23,770 substance abuse treatment admissions were adolescents aged 12 to 14. The two most frequently reported primary substances of abuse among…

  12. Effect of Heat Treatment on the Microstructure and Microhardness of Nanostructural Al2O3 Coatings

    NASA Astrophysics Data System (ADS)

    Kovaleva, M.; Tyurin, Yu.; Vasilik, N.; Kolisnichenko, O.; Prozorova, M.; Arseenko, M.; Sirota, V.; Pavlenko, I.

    2014-10-01

    Nanostructural Al2O3 coatings were formed on a steel substrate surface using a multichamber detonation sprayer. The Al2O3 coatings were characterized by a dense microstructure with porosity below 1% and hardness of 1300 ± 25 HV0.3. The transition layer between the coating and substrate was up to 15 μm thick, containing Fe-Al-type intermetallic compounds (FeAl3, Fe2Al5). Postdeposition heat treatment of the samples at 850 °C for 3 h was carried out in air and argon environments. The effect of heat treatment on the microstructure and microhardness of the Al2O3 coatings was investigated by optical microscopy, scanning and transmission electron microscopy, scanning probe microscopy, x-ray phase analysis, and Vickers hardness testing. A positive impact of postcoating heat treatment on the coating microstructure and microhardness was observed. Heat treatment resulted in an increase in the coating hardness from 1300, to 1350 ± 25 HV0.3 and 1600 ± 25 HV0.3 after annealing in air and argon, respectively. Heat treatment in argon led to a more significant increase in the α-Al2O3 phase from 47 to 81%.

  13. Effect of heat treatment on caustic stress corrosion cracking behavior of alloy 600

    SciTech Connect

    Sung, J.K.

    1999-12-01

    Constant elongation rate tests (CERT) were conducted to evaluate the effect of heat treatment on intergranular stress corrosion cracking (IGSCC) susceptibility of alloy 600 (UNS NO6600) in 140 C and 50% caustic solution at {minus}900 mV vs saturated calomel electrode (SCE). Results showed: (1) Heat treatment at low temperature for a long time (600 C for 260 h) led to a material that was not susceptible to caustic intergranular (IG) cracking. Increase in heat treatment temperature enhanced IG cracking susceptibility. Caustic IGSCC susceptibility was at maximum near the carbon solubility limit. However, when the heat treatment temperature was higher than the carbon solubility limit, a significant decrease in crack growth rate was observed. (2) Grain boundaries acted as a preferential crack path when grain boundary carbon segregation was likely. Thermodynamic considerations suggested that severe caustic IGSCC susceptibility near the carbon solubility limit could be explained in terms of carbon segregation at the grain boundaries. (3) IGSCC in caustic solution did not seem to be caused by chromium depletion. (4) Although formation of semi-continuous IG carbides and IGSCC resistance seemed to exhibit a similar chronological response with heat treatment, it was unlikely that grain boundary IG carbides played a role in caustic IGSCC susceptibility.

  14. Effect of heat-moisture treatment on the structural, physicochemical, and rheological characteristics of arrowroot starch.

    PubMed

    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.

  15. Numerical Modeling of Vacuum Heat Treatment of Nickel-based Superalloys

    NASA Astrophysics Data System (ADS)

    Cosentino, Francesco; Warnken, Nils; Gebelin, Jean-Christophe; Reed, Roger C.

    2013-11-01

    Numerical modeling is carried out of the heat transfer effects arising during heat treatment of single-crystal nickel-based superalloys, of the type used for high pressure turbine blades in jet engines. For these components, fine control of the thermal history during processing is needed to avoid incipient melting and to develop the properties needed for service applications. Computational fluid dynamics methods are employed for the analysis. The modeling is used to predict the temporal evolution of the temperature distribution inside the treated component, to calculate heat transfer coefficients, and to analyze the homogeneity of heat transfer. The impact of the boundary conditions is investigated with particular emphasis on the temperature of the heating elements. Its value was derived from an analytical model of the furnace using effective view factors. The predictions of the modeling are tested against measurements made on laboratory-scale apparatus containing features of production-scale equipment.

  16. Heat-treatment studies on thin-film CdS/Cu/x/S solar cells

    NASA Astrophysics Data System (ADS)

    Hmurcik, L.; Serway, R. A.

    1982-12-01

    CdS/CuS polycrystalline solar cells were heat treated in different mixtures of hydrogen and oxygen and examined for the resultant I-V curves. Ten cells were studied, six which were heat treated, then kept in storage for one year. Monitoring was also carried out on the short-circuit current density, the open circuit voltage, the fill factor, and the cell efficiency. Several episodes of heat treatment were performed, with measurements carried out after each. It was determined that changes in the copper-sulfide stoichiometry were the cause of changes in the short-circuit current. Monitoring the changes in the short-circuit current during heating in a hydrogen atmosphere permitted optimization of the cell efficiency to within 5% of its theoretical value. The hydrogen-atmosphere heating is noted to increase the CuS layer stoichiometry.

  17. Heat Distribution in the Lower Leg from Pulsed Short-Wave Diathermy and Ultrasound Treatments

    PubMed Central

    Garrett, Candi L.; Draper, David O.; Knight, Kenneth L.

    2000-01-01

    Objective: To compare tissue temperature rise and decay after 20-minute diathermy and ultrasound treatments. Design and Setting: We inserted 3 26-gauge thermistor microprobes into the medial aspect of the anesthetized triceps surae muscle at a depth of 3 cm and spaced 5 cm apart. Eight subjects received the diathermy treatment first, followed by the ultrasound treatment. This sequence was reversed for the remaining 8 subjects. The diathermy was applied at a frequency of 27.12 MHz at the following settings: 800 bursts per second, 400-microsecond burst duration, 850-microsecond interburst interval, peak root mean square amplitude of 150 W per burst, and an average root mean square output of 48 W per burst. The ultrasound was delivered at a frequency of 1 MHz and an intensity of 1.5 W/cm2 in the continuous mode for 20 minutes over an area of 40 times the effective radiating area. The study was performed in a ventilated research laboratory. Subjects: Sixteen (11 men, 5 women) healthy subjects (mean age = 23.56 ± 4.73 years) volunteered to participate in this study. Measurements: We recorded baseline, final, and decay temperatures for each of the 3 sites. Results: The average temperature increases over baseline temperature after pulsed short-wave diathermy were 3.02°C ± 1.02°C in site 1, 4.58°C ± 0.87°C in site 2, and 3.28°C ± 1.64°C in site 3. The average temperature increases over baseline temperature after ultrasound were only 0.17°C ± 0.40°C, 0.09°C ± 0.56°C, and -0.43°C ± 0.41°C in sites 1, 2, and 3, respectively. The temperature dropped only 1°C in 7.65 ± 4.96 minutes after pulsed short-wave diathermy. Conclusions: We conclude that pulsed short-wave diathermy was more effective than 1-MHz ultrasound in heating a large muscle mass and resulted in the muscles' retaining heat longer. ImagesFigure 1.Figure 2.Figure 3.Figure 4.Figure 5. PMID:16558608

  18. Heat Exchange through Cutaneous Vasodilation After Atropine Treatment in Two Environments

    DTIC Science & Technology

    1987-10-01

    anticholinergic effect of systemic atropine treatment on the eccrine sweat gland is well known and the inhibition of sweat secretion during exercise and heat...anticholinergic, dry heat exchange, sweating , I thermoregulation, vasodilation 19 ABSTRACT (Continue on reverse if necessary and identify by block...local sweating rate (-60%) occurred in both environments in the atropine treated subjects.’ During exercise, FBF was 85% greater at 30C and 95% greater at

  19. New Treatment Greatly Improves Prognosis for Patients with AMD (Age-Related Macular Degeneration)

    MedlinePlus

    ... turn JavaScript on. Feature: Age-related Macular Degeneration New Treatment Greatly Improves Prognosis for Patients with AMD ... Eye Institute Photo Courtesy of: NEI In a new study of nearly 650 people with age-related ...

  20. Alpha/Beta Heat Treatment of a Titanium Alloy with a Non-Uniform Microstructure (Preprint)

    DTIC Science & Technology

    2006-08-01

    Experiments comprising induction heating to a peak temperature of 971 or 982 °C followed by cooling at a rate of 11 or 42 °C/min revealed that the...starting microstructure of equiaxed + remnant lamellar alpha was established. Experiments comprising induction heating to a peak temperature of 971...were met via a series of induction heat treatments and accompanying diffusion analyses using Ti-6Al-2Sn-4Zr-2Mo-0.1Si (Ti6242Si) as the program

  1. Heat Stress and Hormetin-Induced Hormesis in Human Cells: Effects on Aging, Wound Healing, Angiogenesis, and Differentiation

    PubMed Central

    Rattan, Suresh I. S.; Fernandes, Ricardo A.; Demirovic, Dino; Dymek, Barbara; Lima, Cristovao F.

    2009-01-01

    Accumulation of molecular damage and increased molecular heterogeneity are hallmarks of cellular aging. Mild stress-induced hormesis can be an effective way for reducing the accumulation of molecular damage, and thus slowing down aging from within. We have shown that repeated mild heat stress (RMHS) has anti-aging effects on growth and various other cellular and biochemical characteristics of normal human skin fibroblasts and keratinocytes undergoing aging in vitro. RMHS given to human cells increased the basal levels of various chaperones, reduced the accumulation of damaged proteins, stimulated proteasomal activities, increased the cellular resistance to other stresses, enhanced the levels of various antioxidant enzymes, enhanced the activity and amounts of sodium-potassium pump, and increased the phosphorylation-mediated activities of various stress kinases. We have now observed novel hormetic effects of mild heat stress on improving the wound healing capacity of skin fibroblasts and on enhancing the angiogenic ability of endothelial cells. We have also tested potential hormetins, such as curcumin and rosmarinic acid in bringing about their beneficial effects in human cells by inducing stress response pathways involving heat shock proteins and hemeoxygenase HO-1. These data further support the view that mild stress-induced hormesis can be applied for the modulation, intervention and prevention of aging and age-related impairments. PMID:19343114

  2. Aging Will Amplify the Heat-Related Mortality Risk Under a Changing Climate: Projection for the Elderly in Beijing, China

    NASA Technical Reports Server (NTRS)

    Li, Tiantian; Horton, Radley M.; Bader, Daniel A.; Zhou, Maigeng; Liang, Xudong; Ban, Jie; Sun, Qinghua; Kinney, Patrick L.

    2016-01-01

    An aging population could substantially enhance the burden of heat-related health risks in a warming climate because of their higher susceptibility to extreme heat health effects. Here, we project heatrelated mortality for adults 65 years and older in Beijing China across 31 downscaled climate models and 2 representative concentration pathways (RCPs) in the 2020s, 2050s, and 2080s. Under a scenario of medium population and RCP8.5, by the 2080s, Beijing is projected to experience 14,401 heat-related deaths per year for elderly individuals, which is a 264.9% increase compared with the 1980s. These impacts could be moderated through adaptation. In the 2080s, even with the 30% and 50% adaptation rate assumed in our study, the increase in heat-related death is approximately 7.4 times and 1.3 times larger than in the 1980s respectively under a scenario of high population and RCP8.5. These findings could assist countries in establishing public health intervention policies for the dual problems of climate change and aging population. Examples could include ensuring facilities with large elderly populations are protected from extreme heat (for example through back-up power supplies and/or passive cooling) and using databases and community networks to ensure the home-bound elderly are safe during extreme heat events.

  3. Effect of Heat Treatment on Silicon Carbide Based Joining Materials for Fusion Energy

    SciTech Connect

    Lewinsohn, Charles A.; Jones, Russell H.; Nozawa, T.; Kotani, M.; Kishimoto, H.; Katoh, Y.; Kohyama, A.

    2001-10-01

    Two general approaches to obtaining silicon carbide-based joint materials were used. The first method relies on reactions between silicon and carbon to form silicon carbide, or to bond silicon carbide powders together. The second method consists of pyrolysing a polycarbosilane polymer to yield an amorphous, covalently bonded material. In order to assess the long-term durability of the joint materials, various heat treatments were performed and the effects on the mechanical properties of the joints were measured. Although the joints derived from the polycarbosilane polymer were not the strongest, the value of strength measured was not affected by heat treatment. On the other hand, the value of the strength of the reaction-based joints was affected by heat treatment, indicating the presence of residual stresses or unreacted material subsequent to processing. Further investigation of reaction-based joining should consist of detailed microscopic studies; however, continued study of joints derived from polymers is also warranted.

  4. Variation of Mechanical Properties of High RRR And Reactor Grade Niobium With Heat Treatments

    SciTech Connect

    Ganapati Myneni; H. Umezawa

    2003-06-01

    Superconducting rf cavities used as accelerating structures in particle accelerators are made from high purity niobium with residual resistance ratios greater than 250. Reactor grade niobium is also used to make wave-guide and/or end group components for these accelerating structures. The major impurities in this type of niobium are interstitially dissolved gases such as hydrogen, nitrogen, and oxygen in addition to carbon. After fabricating the niobium accelerating structures, they are subjected to heat treatments for several hours in vacuum at temperatures of up to 900 C for degassing hydrogen or up to 1400 C for improving the thermal conductivity of niobium considerably. These heat treatments are affecting the mechanical properties of niobium drastically. In this paper the variation of the mechanical properties of high purity and reactor grade niobium with heat treatments in a vacuum of {approx} 10{sup -6} Torr and temperatures from 600 C to 1250 C for periods of 10 to 6 hours are presented.

  5. Fffect of heat treatment conditions on structure and properties of high-speed steel

    NASA Astrophysics Data System (ADS)

    Nikolaeva, E. P.; Vlasov, D. B.

    2017-02-01

    High-speed steels made by powder and traditional metallurgical technology have been investigated. These steels are used for manufacturing of metalworking tools. Powder high-speed steels have a large safety margin and a high level of mechanical properties. Mechanical properties and the structure of steels S390 MICROCLEAN® and Fe-9%W-4%Mo-8%Co were compared after their hardening heat treatment. The composition of the carbides was determined by x-ray phase analysis. Residual stresses of the finished cutters were determined. It was shown that the mechanical properties of steels have been determined by the phase composition and the degree of carbides dispersion. The dependence of the microstructure and the high-speed steels phase composition on heat treatment conditions was identified. The conclusion about structure control effectiveness in the adjustment of heat treatment conditions of high speed steels was made.

  6. Effects of heat treatment on crystallographic and magnetic properties of magnetic steels

    NASA Astrophysics Data System (ADS)

    Battistini, L.; Benasciutti, R.; Tassi, A.

    1994-05-01

    The keeper and the head of a modern electrovalve for electronic injection can be succesfully realized using AISI 430 ferromagnetic steel. Important improvements in the performance of the device, mainly in terms of its regularity and energy savings, are possible by means of a better comprehension of the origins of the steel's magnetic properties. The magnetic behaviour of the AISI 430 steel upon different heat treatments was investigated, looking for the best compromise between time saving in the heat treatments and the ensuing magnetic properties of the material. In particular, the relationships between the structural effects of the heat treatments and the magnetic behaviour of the samples were studied. Values of the coercive force Hc, residual induction Br, maximum permeability μ max and the approach to saturation values for H and B were determined by mean of a computerized permeameter, based on a Sanford-Bennet closed yoke for differently shaped samples.

  7. Hydrogen Degassing Study During the Heat Treatment of 1.3-GHZ SRF Cavities

    SciTech Connect

    Joung, Mijoung; Kim, H. J.; Rowe, A.; Wong, M.

    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.

  8. Effect of heat treatment time on microstructure and electrical conductivity in LATP glass ceramics

    SciTech Connect

    Sonigra, Dhiren E-mail: ajit.kulkarni@iitb.ac.in; Soman, Swati E-mail: ajit.kulkarni@iitb.ac.in; Kulkarni, Ajit R. E-mail: ajit.kulkarni@iitb.ac.in

    2014-04-24

    Glass-ceramic is prepared by heat treatment of melt quenched 14Li{sub 2}O−9Al{sub 2}O{sub 3}−38TiO{sub 2}−39P{sub 2}O{sub 5} glass in the vicinity of crystallization temperature. Growth of ceramic phase is controlled by tuning heat treatment time at fixed temperature. Ceramic phase was identified to be LiTi{sub 2}(PO{sub 4}){sub 3} from X Ray Diffraction analysis. Microstructural evolution of this phase with hold time was observed under high resolution Scanning Electron Microscope. DC conductivity is observed to increase by 4-5 orders of magnitude in this glass-ceramic compared to parent glass. However, formation of pores and cracks with very large heat treatment time seem to hinder further increase of conductivity.

  9. Effect of heat treatment time on microstructure and electrical conductivity in LATP glass ceramics

    NASA Astrophysics Data System (ADS)

    Sonigra, Dhiren; Soman, Swati; Kulkarni, Ajit R.

    2014-04-01

    Glass-ceramic is prepared by heat treatment of melt quenched 14Li2O-9Al2O3-38TiO2-39P2O5 glass in the vicinity of crystallization temperature. Growth of ceramic phase is controlled by tuning heat treatment time at fixed temperature. Ceramic phase was identified to be LiTi2(PO4)3 from X Ray Diffraction analysis. Microstructural evolution of this phase with hold time was observed under high resolution Scanning Electron Microscope. DC conductivity is observed to increase by 4-5 orders of magnitude in this glass-ceramic compared to parent glass. However, formation of pores and cracks with very large heat treatment time seem to hinder further increase of conductivity.

  10. Effect of foam on temperature prediction and heat recovery potential from biological wastewater treatment.

    PubMed

    Corbala-Robles, L; Volcke, E I P; Samijn, A; Ronsse, F; Pieters, J G

    2016-05-15

    Heat is an important resource in wastewater treatment plants (WWTPs) which can be recovered. A prerequisite to determine the theoretical heat recovery potential is an accurate heat balance model for temperature prediction. The insulating effect of foam present on the basin surface and its influence on temperature prediction were assessed in this study. Experiments were carried out to characterize the foam layer and its insulating properties. A refined dynamic temperature prediction model, taking into account the effect of foam, was set up. Simulation studies for a WWTP treating highly concentrated (manure) wastewater revealed that the foam layer had a significant effect on temperature prediction (3.8 ± 0.7 K over the year) and thus on the theoretical heat recovery potential (30% reduction when foam is not considered). Seasonal effects on the individual heat losses and heat gains were assessed. Additionally, the effects of the critical basin temperature above which heat is recovered, foam thickness, surface evaporation rate reduction and the non-absorbed solar radiation on the theoretical heat recovery potential were evaluated.

  11. Effects of heat treatment and moisture contents on interactions between lauric acid and starch granules.

    PubMed

    Chang, Fengdan; He, Xiaowei; Fu, Xiong; Huang, Qiang; Jane, Jay-lin

    2014-08-06

    This study aimed to understand the effects of the moisture content of granular normal cornstarch (NC), heat treatment at 80 °C, and order of adding lauric acid (LA) to starch before or after the heat treatment on the physicochemical properties and digestibility of the starch. LA was added to NC priority heated with different moisture contents (10, 20, 30, 40, and 50%) or added to dried NC and then heated with different moisture contents. The hydrothermal/LA treatments increased the pasting temperature but decreased the peak viscosity of the NC. Light and scanning electron microscopy revealed that the addition of LA retarded gelatinization. The hydrothermal/LA treatments changed the X-ray pattern of the NC to a mixture of A- and V-type patterns. The thermal property and digestibility analysis showed that 40% was the optimum moisture content for the formation of the amylose-LA complex and adding LA prior to heating the NC favored the formation of slowly digestible starch.

  12. Detailed near-infrared study of the `water'-related transformations in silcrete upon heat treatment

    NASA Astrophysics Data System (ADS)

    Schmidt, Patrick; Lauer, Christoph; Buck, Gerald; Miller, Christopher E.; Nickel, Klaus G.

    2017-01-01

    In archaeology, lithic heat treatment is the process of modifying a rock for stone tool production using fire. Although the earliest known cases of heat treatment come from South Africa and involved silcrete, a microcrystalline pedogenic silica rock, its thermal transformations remain poorly understood. We investigate the `water'-related transformations in silcrete using direct transmission near-infrared spectroscopy. We found that SiOH is noticeably lost between 250 and 450 °C and hydroxyl reacts with H2O, part of which is trapped in the structure of the rocks. This water can only be evaporated through heat-induced fracturing at high temperatures, imposing maximum temperatures for silcrete heat treatment of approximately 500 °C. Between 250 and 450 °C new siloxane bonds are formed according to the reaction 2SiOH → Si-O-Si + H2O, which can be expected to transform the rock's mechanical properties. The tolerance of silcrete for relatively fast ramp rates can be explained by its pore volume and low SiOH content, ensuring good water evaporation. These results shed light on the processes taking place in silcrete during heat treatment and allow for a better understanding of the parameters needed for it.

  13. Effect of heat treatments on biomolecular profile of Sardinian apple cultivars.

    PubMed

    Ciavatta, M L; Gavagnin, M; Serra, M; Sanna, D; Palma, A; Barberis, A; Schirra, M; Fadda, A

    2013-01-01

    Postharvest heat treatments (hot water or hot air treatment) may be applied to horticultural crops to control fungal diseases, insect infestation and to reduce chilling injury in cultivars susceptible to low storage temperatures. The present study investigated the influence of hot water (53 degrees C for 60s) and hot air treatment (38 degrees C for 24h) applied to two typical Sardinian apple varieties, cvs. Miali and Caddina, on the composition of the lipophilic extracts of the peel as well as on the antioxidant activity of ethanolic extracts of both peel and pulp. The lipophilic extracts of the peel of the two varieties were almost similar and resulted to be dominated by the presence of triterpenes being ursolic and oleanoic acids the main metabolites in both analysed fruits. The chemical analysis of the extracts obtained from the different heat-treated samples for each variety revealed no significant difference in the relative distribution of triterpene components with respect to untreated control samples. This strongly suggested that heat treatment does not affect the composition of terpene metabolite profile of the fruit peel. On the other hand, the antioxidant activity of the ethanolic extracts of the peel and the pulp of heat treated was significantly different from that of control In particular, on Caddina variety the antioxidant activity levels of the peel were consistently higher than in the pulp and were affected by storage conditions. Differently, on Miali variety the antioxidant activity of heat-treated samples was higher than control sample in both peel and pulp.

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

    SciTech Connect

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

    1995-05-01

    The effects of heat treatments of the industrial type 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 1,000 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 {gamma}{double_prime} Ni{sub 3}Nb 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 {delta} Ni{sub 3}(Nb, Mo, Cr, Fe, Ti) phase. At 1,000 C, the ductility and impact strength are restored. However, the higher the beat 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 1,000 C are the sole treatments to avoid embrittlement and impairment of the corrosion resistance characteristics of alloy 625.

  15. Early Evidence for the Extensive Heat Treatment of Silcrete in the Howiesons Poort at Klipdrift Shelter (Layer PBD, 65 ka), South Africa

    PubMed Central

    Douze, Katja; Wurz, Sarah; Bellot-Gurlet, Ludovic; Conard, Nicholas J.; Nickel, Klaus G.; van Niekerk, Karen L.; Henshilwood, Christopher S.

    2016-01-01

    Heating stone to enhance its flaking qualities is among the multiple innovative adaptations introduced by early modern human groups in southern Africa, in particular during the Middle Stone Age Still Bay and Howiesons Poort traditions. Comparatively little is known about the role and impact of this technology on early modern human behaviors and cultural expressions, due, in part, to the lack of comprehensive studies of archaeological assemblages documenting the heat treatment of stone. We address this issue through an analysis of the procedure used for heating and a technological analysis of a lithic assemblage recovered from one Howiesons Poort assemblage at Klipdrift Shelter (southern Cape, South Africa). The resulting data show extensive silcrete heat treatment, which adds a new dimension to our understanding of fire-related behaviors during the Howiesons Poort, highlighting the important role played by a heat treatment stage in the production of silcrete blades. These results are made possible by our new analytical procedure that relies on the analysis of all silcrete artifacts. It provides direct evidence of a controlled use of fire which took place during an early stage of core exploitation, thereby impacting on all subsequent stages of the lithic chaîne opératoire, which, to date, has no known equivalent in the Middle Stone Age or Middle Paleolithic record outside of southern Africa. PMID:27760210

  16. Early Evidence for the Extensive Heat Treatment of Silcrete in the Howiesons Poort at Klipdrift Shelter (Layer PBD, 65 ka), South Africa.

    PubMed

    Delagnes, Anne; Schmidt, Patrick; Douze, Katja; Wurz, Sarah; Bellot-Gurlet, Ludovic; Conard, Nicholas J; Nickel, Klaus G; van Niekerk, Karen L; Henshilwood, Christopher S

    2016-01-01

    Heating stone to enhance its flaking qualities is among the multiple innovative adaptations introduced by early modern human groups in southern Africa, in particular during the Middle Stone Age Still Bay and Howiesons Poort traditions. Comparatively little is known about the role and impact of this technology on early modern human behaviors and cultural expressions, due, in part, to the lack of comprehensive studies of archaeological assemblages documenting the heat treatment of stone. We address this issue through an analysis of the procedure used for heating and a technological analysis of a lithic assemblage recovered from one Howiesons Poort assemblage at Klipdrift Shelter (southern Cape, South Africa). The resulting data show extensive silcrete heat treatment, which adds a new dimension to our understanding of fire-related behaviors during the Howiesons Poort, highlighting the important role played by a heat treatment stage in the production of silcrete blades. These results are made possible by our new analytical procedure that relies on the analysis of all silcrete artifacts. It provides direct evidence of a controlled use of fire which took place during an early stage of core exploitation, thereby impacting on all subsequent stages of the lithic chaîne opératoire, which, to date, has no known equivalent in the Middle Stone Age or Middle Paleolithic record outside of southern Africa.

  17. Heat treatment of investment cast PH 13-8 Mo stainless steel: Part I. Mechanical properties and microstructure

    NASA Astrophysics Data System (ADS)

    Hochanadel, P. W.; Edwards, G. R.; Robino, C. V.; Cieslak, M. J.

    1994-04-01

    The microstructure of investment cast PH 13-8 Mo stainless steel heat-treated to various conditions was studied using light and electron microscopy, electron probe microanalysis, and Mössbauer spectroscopy. The mechanical properties were investigated by using uniaxial tensile testing, hardness testing, and Charpy impact testing. The Β-NiAl strengthening precipitates, though detectable by electron diffraction, were difficult to resolve by transmission electron microscopy (TEM) in specimens aged at low temperatures (566 °C and below). A high dislocation density was observed in the lath martensitic structure. The higher strength and lower ductility observed at low aging temperatures was attributed to both the high dislocation density and the precipitation of Β-NiAl. When samples were aged at high temperatures (> 566 °C), a lower dislocation density and a reverted austenite fraction on the order of 15 pct were observed. Spherical Β-NiAl precipitates were observed in the overaged condition. The decrease in strength and corresponding increase in ductility observed in samples aged at temperatures above 566 °C were attributed to the reverted austenite and recovery. Mechanical properties were improved when the homogenizing temperature and time were increased. Electron probe microanalysis quantified the increased homogeneity realized by increasing homogenizing temperature and time. Elimination of the refrigeration step, which normally follows the solution treatment, did not degrade the mechanical properties. Mössbauer spectroscopy showed only minor decreases in the fraction of retained austenite when refrigeration followed the solution treatment.

  18. Recommendations for the treatment of aging in standard technical specifications

    SciTech Connect

    Orton, R.D.; Allen, R.P.

    1995-09-01

    As part of the US Nuclear Regulatory Commission`s Nuclear Plant Aging Research Program, Pacific Northwest Laboratory (PNL) evaluated the standard technical specifications for nuclear power plants to determine whether the current surveillance requirements (SRs) were effective in detecting age-related degradation. Nuclear Plant Aging Research findings for selected systems and components were reviewed to identify the stressors and operative aging mechanisms and to evaluate the methods available to detect, differentiate, and trend the resulting aging degradation. Current surveillance and testing requirements for these systems and components were reviewed for their effectiveness in detecting degraded conditions and for potential contributions to premature degradation. When the current surveillance and testing requirements appeared ineffective in detecting aging degradation or potentially could contribute to premature degradation, a possible deficiency in the SRs was identified that could result in undetected degradation. Based on this evaluation, PNL developed recommendations for inspection, surveillance, trending, and condition monitoring methods to be incorporated in the SRs to better detect age- related degradation of these selected systems and components.

  19. Revised conceptualization of the North China Basin groundwater flow system: Groundwater age, heat and flow simulations

    NASA Astrophysics Data System (ADS)

    Cao, Guoliang; Han, Dongmei; Currell, Matthew J.; Zheng, Chunmiao

    2016-09-01

    Groundwater flow in deep sedimentary basins results from complex evolution processes on geological timescales. Groundwater flow systems conceptualized according to topography and/or groundwater table configuration generally assume a near-equilibrium state with the modern landscape. However, the time to reach such a steady state, and more generally the timescales of groundwater flow system evolution are key considerations for large sedimentary basins. This is true in the North China Basin (NCB), which has been studied for many years due to its importance as a groundwater supply. Despite many years of study, there remain contradictions between the generally accepted conceptual model of regional flow, and environmental tracer data. We seek to reconcile these contractions by conducting simulations of groundwater flow, age and heat transport in a three dimensional model, using an alternative conceptual model, based on geological, thermal, isotope and historical data. We infer flow patterns under modern hydraulic conditions using this new model and present the theoretical maximum groundwater ages under such a flow regime. The model results show that in contrast to previously accepted conceptualizations, most groundwater is discharged in the vicinity of the break-in-slope of topography at the boundary between the piedmont and central plain. Groundwater discharge to the ocean is in contrast small, and in general there are low rates of active flow in the eastern parts of the basin below the central and coastal plain. This conceptualization is more compatible with geochemical and geothermal data than the previous model. Simulated maximum groundwater ages of ∼1 Myrs below the central and coastal plain indicate that residual groundwater may be retained in the deep parts of the basin since being recharged during the last glacial period or earlier. The groundwater flow system has therefore probably not reached a new equilibrium state with modern-day hydraulic conditions. The

  20. Conjugate heat transfer analysis of an ultrasonic molten metal treatment system

    NASA Astrophysics Data System (ADS)

    Zhu, Youli; Bian, Feilong; Wang, Yanli; Zhao, Qian

    2014-09-01

    In piezoceramic ultrasonic devices, the piezoceramic stacks may fail permanently or function improperly if their working temperatures overstep the Curie temperature of the piezoceramic material. While the end of the horn usually serves near the melting point of the molten metal and is enclosed in an airtight chamber, so that it is difficult to experimentally measure the temperature of the transducer and its variation with time, which bring heavy difficulty to the design of the ultrasonic molten metal treatment system. To find a way out, conjugate heat transfer analysis of an ultrasonic molten metal treatment system is performed with coupled fluid and heat transfer finite element method. In modeling of the system, the RNG model and the SIMPLE algorithm are adopted for turbulence and nonlinear coupling between the momentum equation and the energy equation. Forced air cooling as well as natural air cooling is analyzed to compare the difference of temperature evolution. Numerical results show that, after about 350 s of working time, temperatures in the surface of the ceramic stacks in forced air cooling drop about 7 K compared with that in natural cooling. At 240 s, The molten metal surface emits heat radiation with a maximum rate of about 19 036 W/m2, while the heat insulation disc absorbs heat radiation at a maximum rate of about 7922 W/m2, which indicates the effectiveness of heat insulation of the asbestos pad. Transient heat transfer film coefficient and its distribution, which are difficult to be measured experimentally are also obtained through numerical simulation. At 240 s, the heat transfer film coefficient in the surface of the transducer ranges from -17.86 to 20.17 W/(m2 · K). Compared with the trial and error method based on the test, the proposed research provides a more effective way in the design and analysis of the temperature control of the molten metal treatment system.

  1. Influences of post weld heat treatment on tensile properties of friction stir welded AA2519-T87 aluminium alloy joints

    NASA Astrophysics Data System (ADS)

    Sabari, S. Sree; Balasubramanian, V.; Malarvizhi, S.; Reddy, G. Madusudhan

    2015-12-01

    AA 2519-T87 is an aluminium alloy that principally contains Cu as an alloying element and is a new grade of Al-Cu alloy system. This material is a potential candidate for light combat military vehicles. Fusion welding of this alloy leads to hot cracking, porosity and alloy segregation in the weld metal region. Friction stir welding (FSW) is a solid state joining process which can overcome the above mentioned problems. However, the FSW of age hardenable aluminium alloys results in poor tensile properties in the as-welded condition (AW). Hence, post weld heat treatment (PWHT) is used to enhance deteriorated tensile properties of FSW joints. In this work, the effect of PWHT, namely artificial ageing (AA) and solution treatment (ST) followed by ageing (STA) on the microstructure, tensile properties and microhardness were systematically investigated. The microstructural features of the weld joints were characterised using an optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The tensile strength and microhardness of the joints were correlated with the grain size, precipitate size, shape and its distribution. From the investigation, it was found that STA treatment is beneficial in enhancing the tensile strength of the FSW joints of AA2519-T87 alloy and this is mainly due to the presence of fine and densely distributed precipitates in the stir zone.

  2. Influences of post weld heat treatment on tensile strength and microstructure characteristics of friction stir welded butt joints of AA2014-T6 aluminum alloy

    NASA Astrophysics Data System (ADS)

    Rajendran, C.; Srinivasan, K.; Balasubramanian, V.; Balaji, H.; Selvaraj, P.

    2016-08-01

    Friction stir welded (FSWed) joints of aluminum alloys exhibited a hardness drop in both the advancing side (AS) and retreating side (RS) of the thermo-mechanically affected zone (TMAZ) due to the thermal cycle involved in the FSW process. In this investigation, an attempt has been made to overcome this problem by post weld heat treatment (PWHT) methods. FSW butt (FSWB) joints of Al-Cu (AA2014-T6) alloy were PWHT by two methods such as simple artificial aging (AA) and solution treatment followed by artificial aging (STA). Of these two treatments, STA was found to be more beneficial than the simple aging treatment to improve the tensile properties of the FSW joints of AA2014 aluminum alloy.

  3. Improvement of Mechanical Properties of Spheroidized 1045 Steel by Induction Heat Treatment

    NASA Astrophysics Data System (ADS)

    Kim, Minwook; Shin, Jung-Ho; Choi, Young; Lee, Seok-Jae

    2016-04-01

    The effects of induction heat treatment on the formation of carbide particles and mechanical properties of spheroidized 1045 steel were investigated by means of microstructural analysis and tensile testing. The induction spheroidization accelerated the formation of spherical cementite particles and effectively softened the steel. The volume fraction of cementite was found to be a key factor that affected the mechanical properties of spheroidized steels. Further tests showed that sequential spheroidization by induction and furnace heat treatments enhanced elongation within a short spheroidization time, resulting in better mechanical properties. This was due to the higher volume fraction of spherical cementite particles that had less diffusion time for particle coarsening.

  4. Effect of heat-treatment temperatures on density and porosity in MgB 2 superconductor

    NASA Astrophysics Data System (ADS)

    Liu, C. F.; Yan, G.; Du, S. J.; Xi, W.; Feng, Y.; Zhang, P. X.; Wu, X. Z.; Zhou, L.

    2003-04-01

    The density, porosity, and microstructures of MgB 2 samples are very important factors for transition critical current density. The effect of heat-treatment temperatures on density and porosity in MgB 2 superconductors has been investigated. The open porosity increases with increasing heat-treatment temperatures, but close porosity decreases. The calculated theory densities from the lattice parameters of the measured samples are 2.6-2.63 g/cm 3. The average measured total porosity (including open and close porosity) is about 50%.

  5. The effect of post-heat treatment on the ion dissolution behavior of nanotubular titanium alloys

    NASA Astrophysics Data System (ADS)

    Saji, Viswanathan S.; Choe, Han Cheol

    2011-04-01

    Recently, nanoscale tubular oxide layers on titanium alloys have attracted considerable research interest due to their potential application in various fields such as implant engineering, solar energy conversion, etc. In the present study, we have investigated the ion dissolution behavior of titanium alloys coated with a layer of nanotubular oxide in Ringer's solution as a function of post-heat treatment temperature. The results of the study showed that post-heat treatment had significant influence on the ion dissolution behavior of nanotubular titanium alloys.

  6. Investigating the effect of heat treatment on hydrogen permeation behavior of API X-70 steel

    NASA Astrophysics Data System (ADS)

    Shirband, Zeynab; Shishesaz, Mohammad Reza; Ashrafi, Ali

    2012-06-01

    Pipeline steels absorb different amounts of hydrogen during transportation of sour oil and gas. Since hydrogen-related damages such as hydrogen-induced cracking are strongly affected by hydrogen permeation behavior of steels, the purpose of this study determined to investigate hydrogen permeation behavior in API X-70 pipeline steel using electrochemical permeation method. The effect of heat treatment was also considered. It was found that hydrogen diffusivity increased by annealing the X-70 and it was decreased by normalizing. The condition was reverse for hydrogen apparent solubility. Finally, it was concluded that change in hydrogen diffusivity can be attributed to changes in grain size due to heat treatment.

  7. Physical aspects of thermotherapy: A study of heat transport with a view to treatment optimisation

    NASA Astrophysics Data System (ADS)

    Olsrud, Johan Karl Otto

    1998-12-01

    Local treatment with the aim to destruct tissue by heating (thermotherapy) may in some cases be an alternative or complement to surgical methods, and has gained increased interest during the last decade. The major advantage of these, often minimally-invasive methods, is that the disease can be controlled with reduced treatment trauma and complications. The extent of thermal damage is a complex function of the physical properties of tissue, which influence the temperature distribution, and of the biological response to heat. In this thesis, methods of obtaining a well-controlled treatment have been studied from a physical point of view, with emphasis on interstitial laser-induced heating of tumours in the liver and intracavitary heating as a treatment for menorrhagia. Hepatic inflow occlusion, in combination with temperature-feedback control of the output power of the laser, resulted in well defined damaged volumes during interstitial laser thermotherapy in normal porcine liver. In addition, phantom experiments showed that the use of multiple diffusing laser fibres allows heating of clinically relevant tissue volumes in a single session. Methods for numerical simulation of heat transport were used to calculate the temperature distribution and the results agreed well with experiments. It was also found from numerical simulation that the influence of light transport on the damaged volume may be negligible in interstitial laser thermotherapy in human liver. Finite element analysis, disregarding light transport, was therefore proposed as a suitable method for 3D treatment planning. Finite element simulation was also used to model intracavitary heating of the uterus, with the purpose of providing an increased understanding of the influence of various treatment parameters on blood flow and on the depth of tissue damage. The thermal conductivity of human uterine tissue, which was used in these simulations, was measured. Furthermore, magnetic resonance imaging (MRI) was

  8. Influence of Heat Treatment on Mechanical Properties of DLC Deposited by FIB-CVD

    NASA Astrophysics Data System (ADS)

    Sakamoto, Naomichi; Kogo, Yasuo; Yasuno, Takuya; Taniguchi, Jun; Miyamoto, Iwao

    The influence of heat treatment on the mechanical properties of DLC deposited by FIB-CVD was examined. To evaluate the mechanical properties, Young’s modulus and Vickers hardness were measured by the nano indentation tester. For the characterization of DLC structure, Raman scattering was used. The microstructures of samples were characterized by HRTEM equipped with EELS. From results of the indentation experiments, it was found that Young’s modulus and Vickers hardness decreased with increasing heat treatment temperature. Analysis of Raman and EELS spectra indicated that the decrease of Young’s modulus and hardness was caused by the decrease of sp3 fraction.

  9. Diabetes technology and treatments in the paediatric age group.

    PubMed

    Shalitin, S; Peter Chase, H

    2011-02-01

    Type 1 diabetes (T1D) is one of the most common chronic childhood diseases and its incidence has doubled during the last decade. The goals of intensive management of diabetes were established in 1993 by the Diabetes Control and Complications Trial (DCCT) (1). Children with T1D and their caregivers continue to face the challenge to maintain blood glucose levels in the near-normal range. It is important to prevent sustained hyperglycaemia which is associated with long-term microvascular and macrovascular complications and to avoid recurrent episodes of hypoglycaemia or hyperglycaemia, especially in young children, which may have adverse effects on cognitive function and impede efforts to achieve the recommended glycaemic targets. Advances in the use of technology that may help maintain the metabolic control goals for young people with T1D were centred on continuous subcutaneous insulin infusion (CSII) (2-4), continuous glucose monitoring (CGM) (5-7), and combining both technologies into a closed-loop system (8-10). The dilemma in paediatrics of patient selection for insulin pump therapy was found to be most successful in those with more frequent self-monitoring of blood glucose (SMBG) and younger age prior to pump initiation (2). Similarly, those who used a dual-wave bolus probably paid closer attention to their management and had lower HbA1c levels (3). The advantage of using a pre-meal bolus to improve postprandial glucose levels was shown to offer another potential method to improve glycaemic control (4). SMBG is an important component of therapy in patients with diabetes, especially in the paediatric age group. Standard use of glucose meters for SMBG provides only intermittent single blood glucose levels, without giving the 'whole picture' of glucose variability during the 24 h, and especially during the night, when blood glucose levels are seldom measured. Therefore, the use of a device such as real-time continuous glucose monitoring (RT-CGM) that provides

  10. Effect of heat treatment duration on tribological behavior of electroless Ni-(high)P coatings

    NASA Astrophysics Data System (ADS)

    Biswas, A.; Das, S. K.; Sahoo, P.

    2016-09-01

    Electroless nickel coating occurs through an autocatalytic chemical reaction and without the aid of electricity. From tribological perspective, it is recommended due to its high hardness, wear resistance, lubricity and corrosion resistance properties. In this paper electroless Ni-P coatings with high phosphorous weight percentages are developed on mild steel (AISI 1040) substrates. The coatings are subjected to heat treatment at 300°C and 500°C for time durations up to 4 hours. The effect of heat treatment duration on the hardness as well as tribological properties is discussed in detail. Hardness is measured in a micro hardness tester while the tribological tests are carried out on a pin-on-disc tribotester. Wear is reported in the form of wear rates of the sample subjected to the test. As expected, heat treatment of electroless Ni-P coating results in enhancement in its hardness which in turn increases its wear resistance. The present study also finds that duration of heat treatment has quite an effect on the properties of the coating. Increase in heat treatment time in general results in increase in the hardness of the coating. Coefficient of friction is also found to be lesser for the samples heat treated for longer durations (4 hour). However, in case of wear, similar trend is not observed. Instead samples heat treated for 2 to 3 hour display better wear resistance compared to the same heat treated for 4 hour duration. The microstructure of the coating is also carried out to ensure about its proper development. From scanning electron microscopy (SEM), the coating is found to possess the conventional nodular structure while energy dispersive X-ray analysis (EDX) shows that the phosphorous content in the coating to be greater than 9%. This means that the current coating belongs to the high phosphorous category. From X-ray diffraction analysis (XRD), it is found that coating is amorphous in as-deposited condition but transforms into a crystalline structure with

  11. [Treatment with nonsteroidal anti-inflammatory agents in the aged].

    PubMed

    Krajcík, S; Salamonová, H; Cápová, L

    1995-07-01

    Some 13--33,7% old people use non-steroid antiphlogistics. The authors mention undesirable effects, their incidence being higher in advanced age, as well as differences between effects of different non-steroid antiphlogistics.

  12. IMPACT OF COMPOSITION AND HEAT TREATMENT ON PORE SIZE IN POROUS WALLED HOLLOW GLASS MICROSPHERES

    SciTech Connect

    Raszewski, F; Erich Hansen, E; Ray Schumacher, R; David Peeler, D

    2007-12-04

    The Savannah River National Laboratory (SRNL) developed a new geometric form: hollow glass microspheres (HGMs), with unique porous walls. The new geometric form combines the existing technology of HGMs with basic glass science knowledge in the realm of glass-in-glass phase separation. Conceptually, the development of a HGM with porous walls (referred to as a PWHGM) provides a unique system in which various media or filling agents can be incorporated into the PWHGM (via transport through the porous walls) and ultimately has the capacity to serve as a functional delivery system in various industrial applications. Applications of these types of systems could range from hydrogen storage, molecular sieves, drug and bioactive delivery systems, to environmental, chemical and biological indicators, relevant to Energy, Environmental Processing and Homeland Security fields. As a specific example, previous studies at SRNL have introduced materials capable of hydrogen storage (as well as other materials) into the interior of the PWHGMs. The goal of this project was to determine if the microstructure (i.e., pore size and pore size distribution) of a PWHGM could be altered or tailored by varying composition and/or heat treatment (time and/or temperature) conditions. The ability to tailor the microstructure through composition or heat treatments could provide the opportunity to design the PWHGM system to accommodate different additives or fill agents. To meet this objective, HGMs of various alkali borosilicate compositions were fabricated using a flame forming apparatus installed at the Aiken County Technical Laboratory (ACTL). HGMs were treated under various heat treatment conditions to induce and/or enhance glass in glass phase separation. Heat treatment temperatures ranged from 580 C to 620 C, while heat treatment times were either 8 or 24 hours. Of the two primary variables assessed in this study, heat treatment temperature was determined to be most effective in changing the

  13. Effect of heat treatment on structure, surface composition, infrared emission and surface electrical properties of tourmaline

    NASA Astrophysics Data System (ADS)

    He, Dengliang; Liu, Shuxin

    2017-02-01

    Crystal structure, surface composition, infrared emission properties and surface electrical properties of tourmaline from Guangxi of China, when subjected to heat treatment in air atmosphere had been studied by some methods, including X-ray fluorescence spectrum (XRF), X-ray diffraction (XRD) meter, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), energy dispersion spectroscopy (EDS), scanning electron microscope (SEM) and Zeta potential analyzer, etc. Experimental results show that the unit cell of tourmaline would shrink during heat treatment because Fe2+ were oxidized. Moreover, the Fe3+/Fetotal inside tourmaline can be raised after treatment. Infrared normal total emissivity of tourmaline reaches 0.87, and infrared radiation energy density is 4.56 × 102W/m2. It can maintain excellent infrared emission properties at high temperature. Simultaneously, tourmaline presents negative Zeta potential in the aqueous solution, and its Zeta potential reaches ‑18.04 mV. Zeta potential of tourmaline was increased to ‑24.83 mV after heat treatment at 400∘C, and decrease to ‑11.78 mV after heat treatment at 600∘C. These findings may provide reference data for tourmaline’s application in the field of functional materials.

  14. Randomized 5-treatment crossover study to assess the effects of external heat on serum fentanyl concentrations during treatment with transdermal fentanyl systems.

    PubMed

    Moore, Kenneth T; Sathyan, Gayatri; Richarz, Ute; Natarajan, Jaya; Vandenbossche, Joris

    2012-08-01

    This randomized, open-label, 5-treatment, 5-sequence crossover study was designed to evaluate the effects of a heating pad on serum fentanyl concentrations with reservoir and matrix transdermal fentanyl systems. Subjects were randomized to 1 of 5 treatment sequences, receiving 5 fentanyl treatments (1 per period) for 36 hours: 25 µg/h reservoir without heat, 25 µg/h reservoir with heat, 25 µg/h matrix without heat, 25 µg/h matrix with heat, and a 50 µg/h reservoir without heat. The 25 µg/h systems with heat had a heating pad applied from 0 to 10 and 26 to 36 hours post application. Washout periods between treatments were 5 to 14 days. Naltrexone was given to block the opioid effects of fentanyl. Study results indicate that external heat had a similar effect on both matrix and reservoir systems, with heat applied during the first 10 hours of treatment increasing fentanyl exposure by approximately 61% to 81% at 10 hours (observed serum concentration at 10 hours) and overall exposure (area under the curve from 0 to 10 hours) by approximately 120% to 184%, but had minimal effect from 26 to 36 hours. The increased exposure observed with heat in both 25 µg/h systems, between 0 and 10 hours, was higher than that obtained with the 50 µg/h reservoir system applied without heat.

  15. Proteomic Profiling Comparing the Effects of Different Heat Treatments on Camel (Camelus dromedarius) Milk Whey Proteins.

    PubMed

    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 < 0.05 and a fold change of ≥1.2) between the non-heated and heated 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.

  16. Effect of grinding and heat treatment on the mechanical behavior of zirconia ceramic.

    PubMed

    Ramos, Gabriela Freitas; Pereira, Gabriel Kalil Rocha; Amaral, Marina; Valandro, Luiz Felipe; Bottino, Marco Antonio

    2016-01-01

    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.

  17. Proteomic profiling of camel and cow milk proteins under heat treatment.

    PubMed

    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.

  18. Improvement in the mechanical properties of PTFE bonded NdFeB magnets by heat treatment

    NASA Astrophysics Data System (ADS)

    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. Effect of alkali and heat treatments for bioactivity of TiO2 nanotubes

    NASA Astrophysics Data System (ADS)

    Kim, Seo young; Kim, Yu kyoung; Park, Il song; Jin, Guang chun; Bae, Tae sung; Lee, Min ho

    2014-12-01

    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 TiO2 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 TiO2 nanotubes (PNA) and alkali and heat-treated TiO2 nanotubes (PNAH) groups. Cell proliferation was decreased due to the formation of amorphous sodium titanate (Na2TiO3) 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.

  20. Heat Treatment Effect on Fracture Toughness of F82H Irradiated in HFIR

    SciTech Connect

    Stoller, Roger E; Sokolov, Mikhail A; Tanigawa, Hiroyasu; Hirose, Takanori; Odette, G.R.; Okubo, N.; Jitsukawa, Shiro; Sawai, T.

    2011-01-01

    Irradiation hardening and fracture toughness of reduced-activation ferritic/martensitic steel F82H after irradiation were investigated with a focus on changing the fracture toughness transition temperature as a result of several heat treatments. The specimens were standard F82H-IEA (IEA), F82H-IEA with several heat treatments (Mod1 series) and a heat of F82H (Mod3) containing 0.1 % tantalum. The specimens were irradiated up to 20 dpa at 300oC in the High Flux Isotope Reactor under a collaborative research program between JAEA/US-DOE. The results of hardness tests showed that irradiation hardening of IEA was comparable with that of Mod3. However, the fracture toughness-transition temperature of Mod3 was lower than that of IEA. The transition temperature of Mod1 was also lower than that of the IEA heat. These results suggest that optimization of specifications on the heat treatment condition and modification of the minor alloying elements seem to be effective to reduce the fracture toughness-transition temperature after irradiation.

  1. Heat treatment effect on fracture toughness of F82H irradiated in HFIR

    NASA Astrophysics Data System (ADS)

    Okubo, N.; Sokolov, M. A.; Tanigawa, H.; Hirose, T.; Jitsukawa, S.; Sawai, T.; Odette, G. R.; Stoller, R. E.

    2011-10-01

    Irradiation hardening and fracture toughness of reduced-activation ferritic/martensitic steel F82H after irradiation were investigated with a focus on changing the fracture toughness transition temperature as a result of several heat treatments. The specimens were standard F82H-IEA (IEA), F82H-IEA with several heat treatments (Mod1 series) and a heat of F82H (Mod3) containing 0.1% tantalum. The specimens were irradiated up to 20 dpa at 300 °C in the High Flux Isotope Reactor under a collaborative research program between JAEA/US-DOE. The results of hardness tests showed that irradiation hardening of IEA was comparable with that of Mod3. However, the fracture toughness-transition temperature of Mod3 was lower than that of IEA. The transition temperature of Mod1 was also lower than that of the IEA heat. These results suggest that optimization of specifications on the heat treatment condition and modification of the minor alloying elements seem to be effective to reduce the fracture toughness-transition temperature after irradiation.

  2. Water treatment capacity of forward osmosis systems utilizing power plant waste heat

    DOE PAGES

    Zhou, Xingshi; Gingerich, Daniel B.; Mauter, Meagan S.

    2015-06-11

    Forward osmosis (FO) has the potential to improve the energy efficiency of membrane-based water treatment by leveraging waste heat from steam electric power generation as the primary driving force for separation. In this study, we develop a comprehensive FO process model, consisting of membrane separation, heat recovery, and draw solute regeneration (DSR) models. We quantitatively characterize three alternative processes for DSR: distillation, steam stripping, and air stripping. We then construct a mathematical model of the distillation process for DSR that incorporates hydrodynamics, mass and heat transport resistances, and reaction kinetics, and we integrate this into a model for the fullmore » FO process. Finally, we utilize this FO process model to derive a first-order approximation of the water production capacity given the rejected heat quantity and quality available at U.S. electric power facilities. We find that the upper bound of FO water treatment capacity using low-grade heat sources at electric power facilities exceeds process water treatment demand for boiler water make-up and flue gas desulfurization wastewater systems.« less

  3. Water treatment capacity of forward osmosis systems utilizing power plant waste heat

    SciTech Connect

    Zhou, Xingshi; Gingerich, Daniel B.; Mauter, Meagan S.

    2015-06-11

    Forward osmosis (FO) has the potential to improve the energy efficiency of membrane-based water treatment by leveraging waste heat from steam electric power generation as the primary driving force for separation. In this study, we develop a comprehensive FO process model, consisting of membrane separation, heat recovery, and draw solute regeneration (DSR) models. We quantitatively characterize three alternative processes for DSR: distillation, steam stripping, and air stripping. We then construct a mathematical model of the distillation process for DSR that incorporates hydrodynamics, mass and heat transport resistances, and reaction kinetics, and we integrate this into a model for the full FO process. Finally, we utilize this FO process model to derive a first-order approximation of the water production capacity given the rejected heat quantity and quality available at U.S. electric power facilities. We find that the upper bound of FO water treatment capacity using low-grade heat sources at electric power facilities exceeds process water treatment demand for boiler water make-up and flue gas desulfurization wastewater systems.

  4. Effects of post-deposition heat treatment on the optical characteristics of ZnTe thin films

    SciTech Connect

    Prepelita, P.; Rusu, G. I.; Pirghie, C.

    2007-04-23

    Zinc telluride (ZnTe) thin films (d=0.15 {mu}m - 2.40 {mu}m) were deposited by quasi-closed volume technique under vacuum. X-ray diffraction patterns indicated that the films are polycrystalline and have a zinc blende structure. After a heat treatment, a significant increase of peak intensities, corresponding to (220) plane take place. The heat treatment determines a greater dispersion of crystallite height as compare to the not treated once. After heat treatment the transmission coefficient strongly decreases. The values of optical bandgap ranged between 1.95 eV and 2.40 eV, due to heat treatment.

  5. Vacuum evaporation treatment of digestate: full exploitation of cogeneration heat to process the whole digestate production.

    PubMed

    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.

  6. The Effect of Solution Heat Treatment on an Advanced Nickel-Base Disk Alloy

    NASA Technical Reports Server (NTRS)

    Gayda, J.; Gabb, T. P.; Kantzos, P. T.

    2004-01-01

    Five heat treat options for an advanced nickel-base disk alloy, LSHR, have been investigated. These included two conventional solution heat treat cycles, subsolvus/oil quench and supersolvus/fan cool, which yield fine grain and coarse grain microstructure disks respectively, as well as three advanced dual microstructure heat treat (DMHT) options. The DMHT options produce disks with a fine grain bore and a coarse grain rim. Based on an overall evaluation of the mechanical property data, it was evident that the three DMHT options achieved a desirable balance of properties in comparison to the conventional solution heat treatments for the LSHR alloy. However, one of the DMHT options, SUB/DMHT, produced the best set of properties, largely based on dwell crack growth data. Further evaluation of the SUB/DMHT option in spin pit experiments on a generic disk shape demonstrated the advantages and reliability of a dual grain structure at the component level.

  7. Fluxless Brazing and Heat Treatment of a Plate-Fin Sandwich Actively Cooled Panel

    NASA Technical Reports Server (NTRS)

    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.

  8. Effect of dry heat treatment with xanthan on waxy rice starch.

    PubMed

    Li, Yue; Zhang, Huien; Shoemaker, Charles F; Xu, Zhiting; Zhu, Song; Zhong, Fang

    2013-02-15

    Waxy rice starch was impregnated with xanthan and heat-treated in a dry state. The effects on the pasting and rheological properties of the treated starch-xanthan mixture were evaluated. Swelling of the granule was restricted, and a continuous rise of the viscosity during pasting was provided for the treated sample. After pasting, the gel forming ability of the treated starch was strengthened, as both storage and loss modulus increased and tan δ decreased. The paste also owned the highest zero order Newtonian viscosity and yield stress. An increase in starch particle size of the dry heated starch-xanthan mixture suggested a cross linking of the starch granules by the xanthan polymers. An increase of crystallinity was observed for the starch after dry heat treatment, but with the addition of xanthan the amorphous region of the granule became more resistant to dry-heating. The melting enthalpy was found to be correlated with the crystallinity.

  9. On post-weld heat treatment cracking in tig welded superalloy ATI 718Plus

    NASA Astrophysics Data System (ADS)

    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.

  10. Investigation of laser heating effect of metallic nanoparticles on cancer treatment

    NASA Astrophysics Data System (ADS)

    Shan, G. S.; Liu, X. M.; Chen, H. J.; Yu, J. S.; Chen, X. D.; Yao, Y.; Qi, L. M.; Chen, Z. J.

    2016-07-01

    Metallic nanoparticles can be applied for hyperthermia therapy of cancer treatment to enhance the efficacy because of their high absorption rate. The absorption of laser energy by metallic nanoparticles is strongly dependent on the concentration, shape, material of nanoparticles and the wavelength of the laser. However, there is no systematic investigation on the heating effect involving different material, concentration and laser wavelength. In this paper, gold nanoparticles (AuNPs), sliver nanoparticles (AgNPs) and sliver nanowires (AgNWs) with different concentrations are heated by 450nm and 532nm wavelength laser to investigate the heating effect. The result shows that the temperature distribution of heated metallic nanoparticles is non-uniform.

  11. Anorexia of Aging: Risk Factors, Consequences, and Potential Treatments.

    PubMed

    Landi, Francesco; Calvani, Riccardo; Tosato, Matteo; Martone, Anna Maria; Ortolani, Elena; Savera, Giulia; Sisto, Alex; Marzetti, Emanuele

    2016-01-27

    Older people frequently fail to ingest adequate amount of food to meet their essential energy and nutrient requirements. Anorexia of aging, defined by decrease in appetite and/or food intake in old age, is a major contributing factor to under-nutrition and adverse health outcomes in the geriatric population. This disorder is indeed highly prevalent and is recognized as an independent predictor of morbidity and mortality in different clinical settings. Even though anorexia is not an unavoidable consequence of aging, advancing age often promotes its development through various mechanisms. Age-related changes in life-style, disease conditions, as well as social and environmental factors have the potential to directly affect dietary behaviors and nutritional status. In spite of their importance, problems related to food intake and, more generally, nutritional status are seldom attended to in clinical practice. While this may be the result of an "ageist" approach, it should be acknowledged that simple interventions, such as oral nutritional supplementation or modified diets, could meaningfully improve the health status and quality of life of older persons.

  12. Anorexia of Aging: Risk Factors, Consequences, and Potential Treatments

    PubMed Central

    Landi, Francesco; Calvani, Riccardo; Tosato, Matteo; Martone, Anna Maria; Ortolani, Elena; Savera, Giulia; Sisto, Alex; Marzetti, Emanuele

    2016-01-01

    Older people frequently fail to ingest adequate amount of food to meet their essential energy and nutrient requirements. Anorexia of aging, defined by decrease in appetite and/or food intake in old age, is a major contributing factor to under-nutrition and adverse health outcomes in the geriatric population. This disorder is indeed highly prevalent and is recognized as an independent predictor of morbidity and mortality in different clinical settings. Even though anorexia is not an unavoidable consequence of aging, advancing age often promotes its development through various mechanisms. Age-related changes in life-style, disease conditions, as well as social and environmental factors have the potential to directly affect dietary behaviors and nutritional status. In spite of their importance, problems related to food intake and, more generally, nutritional status are seldom attended to in clinical practice. While this may be the result of an “ageist” approach, it should be acknowledged that simple interventions, such as oral nutritional supplementation or modified diets, could meaningfully improve the health status and quality of life of older persons. PMID:26828516

  13. Effect of specimen size on ductile to brittle transition behavior of martensitic 9Cr steels after various heat treatments

    NASA Astrophysics Data System (ADS)

    Abe, Fujio; Kayano, Hideo

    1996-09-01

    The effect of specimen size on the ductile to brittle transition behavior has been investigated using the full-size and 1/3-size Charpy V-notch specimens of martensitic 9Cr-WVTa steels after quenching, tempering and subsequent prolonged aging treatments. The upper shelf energy (USE) and ductile to brittle transition temperature (DBTT) were widely changed by the heat treatments; the USE varied from 90 to 292 J, and the DBTT from 188 to 325 K. The nominal volume ( Bb) {3}/{2}, where B is the specimen thickness and b the ligament size, was effective as a normalization factor for the USE only in the large USE region above 210 and 8.5 J for the full-size and 1/3-size specimens, respectively. A new normalization factor depending on the USE level was proposed. Although the relationship between the DBTT for the full-size and 1/3-size specimens was different from steel to steel, the shift in DBTT caused by the heat treatments was described by Δ DBTT{1}/{3}- size = (1.2 ± 0.1) ΔDBTT full-size for all the steels examined.

  14. Thermal treatments of foods: a predictive general-purpose code for heat and mass transfer

    NASA Astrophysics Data System (ADS)

    Barba, Anna Angela

    2005-05-01

    Thermal treatments of foods required accurate processing protocols. In this context, mathematical modeling of heat and mass transfer can play an important role in the control and definition of the process parameters as well as to design processing systems. In this work a code able to simulate heat and mass transfer phenomena within solid bodies has been developed. The code has been written with the ability of describing different geometries and it can account for any kind of different initial/boundary conditions. Transport phenomena within multi-layer bodies can be described, and time/position dependent material parameters can be implemented. Finally, the code has been validated by comparison with a problem for which the analytical solution is known, and by comparison with a differential scanning calorimetry signal that described the heating treatment of a raw potato (Solanum tuberosum).

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Implantable polymer/metal thin film structures for the localized treatment of cancer by Joule heating

    NASA Astrophysics Data System (ADS)

    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.

  17. Heat Tolerance and Aging of the Anhydrobiotic Seed Gall Nematode with SEM Observations.

    PubMed

    Eisenback, J D; Wei, Ma; Roane, C W

    2013-03-01

    The seed gall nematode, Anguina agrostis, feeds and reproduces within the developing ovaries of bentgrass seeds and overwinters in seed galls as anhydrobiotic juveniles. These dormant juveniles can survive within the seed gall for many years. In this dehydrated state, they are more tolerant to extreme environmental conditions than are their hydrated counterparts. Nematodes in seed galls were exposed to various high temperatures (80 to 160°C) for time intervals of 5 to 30 min. Survival decreased as time and temperature increased. Remarkably, these nematodes survived exposure to 155°C for 5 min, higher than that recorded for any other metazoan. In contrast, seed galls that had been stored at room temperature and humidity for 5 yr also survived exposure to extreme temperatures; however, their survival rates were not as high as those for freshly collected galls. Juveniles within the seed gall were coiled and grouped together conforming to the shape of the seed gall. The gross morphology of the cuticle of the juveniles was very smooth and relatively undistorted by the shrinkage from the loss water from their body tissues. Wherever the nematodes were cut with a razor blade, a small amount of their contents oozed out of the opening and coalesced with that of other nearby specimens and appeared gel-like. Elucidation of the mechanisms that enable these nematodes to remain viable after exposure to extreme heat remains a mystery. Understanding the changes that occur in these nematodes as they rehydrate and return to life from an ametabolic state may have major impacts on the life sciences, including insights into the answer of the age-old question: "What is life?"

  18. Syllable-Timed Speech Treatment for School-Age Children Who Stutter: A Phase I Trial

    ERIC Educational Resources Information Center

    Andrews, Cheryl; O'Brian, Sue; Harrison, Elisabeth; Onslow, Mark; Packman, Ann; Menzies, Ross

    2012-01-01

    Purpose: This clinical trial determined the outcomes of a simple syllable-timed speech (STS) treatment for school-age children who stutter. Method: Participants were 10 children, ages 6-11 years, who stutter. Treatment involved training the children and their parents to use STS at near normal speech rates. The technique was practiced in the clinic…

  19. Effect of Weight Loss and Microstructure by Heat Treatment and Fabrication of Lps-Sic Ceramics

    NASA Astrophysics Data System (ADS)

    Yoon, Han-Ki; Park, Joon Soo; Kohyama, Akira

    In the present work, monolithic LPS-SiC was fabricated by hot press method with the addition of Al2O3, Y2O3 and SiO2 and annealed at different temperatures to observe microstructure evolution. Process temperature was varied from 1760°C to 1800°C. Process pressure and maturing time are 20MPa and 1h respectively. Hot pressed samples were cut into rectangular bars. Three-point flexural strength was measured at room temperature in air with a cross-head speed of 0.1 mm/min and a lower span of 18 mm. Flexural strength and elastic modulus measurement was performed using a universal test machine (INSTRON 5581, USA). The apparent density of the sintered body was measured by the Archimedes method. The specimen dimension of the heat treatments is 4W×25L×1.5T mm. The specimens used for weight-loss measurement were set into an open carbon crucible to avoid nonuniform temperature distribution within the furnace. Post-fabrication heat treatment was performed in vacuum atmosphere (PO2 ≈ 0.01 Pa). The temperature was increased at a rate of 20 K/min to the heat-treatment temperature and maintained for 10 hours, after which the specimens were furnace cooled. After heat-treatment, weight of heat-treated specimens was carefully measured by an electronic balance. In order to reveal the microstructural change in heat-treated specimen, X-ray diffractometry and microstructure observation were performed and compared with those of the as-fabricated one.

  20. 9 CFR 590.548 - Drying, blending, packaging, and heat treatment rooms and facilities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Drying, blending, packaging, and heat treatment rooms and facilities. 590.548 Section 590.548 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION INSPECTION OF EGGS AND EGG...

  1. Survey of research and applications of laser heat treatment in China

    NASA Astrophysics Data System (ADS)

    Qian, Hongbin; Su, Baorong

    1996-09-01

    This paper reports the fruits of the research on fundamental theory, application basis and application of laser heat treatment since 1979 in China. Also the technical development and spreading of laser heat treatment is reported. Over 20 academic exchange activities home or abroad were organized by our country. In China, there are near 1,000 units and about 5,000 intermediate and senior scientists and engineers engaged in the research, development and production of laser heat treatment. More than 3,000 academia articles have been published home and abroad. About 2,000 Bachelors, Masters and Doctors whose major is laser application have been cultivated. In domestic plants, near 1,000 production lines of laser heat treatment on the cylinder bodies and covers of automobiles and tractors have been set up, which were deeply welcomed by the automobile makers and repairmen. There are other production lines running in some factories and making good effects, such as laser glazing production line for steel ring, laser quenching production line for master reed in elastic shaft coupling and laser quenching production line for big gears, etc.

  2. 46 CFR 52.05-15 - Heat treatment (modifies PW-10).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Requirements for Boilers Fabricated by Welding § 52.05-15 Heat treatment (modifies PW-10). (a) Vessels and... of the ASME Boiler and Pressure Vessel Code (incorporated by reference; see 46 CFR...

  3. 46 CFR 52.05-15 - Heat treatment (modifies PW-10).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Requirements for Boilers Fabricated by Welding § 52.05-15 Heat treatment (modifies PW-10). (a) Vessels and... of the ASME Boiler and Pressure Vessel Code (incorporated by reference; see 46 CFR...

  4. 46 CFR 52.05-15 - Heat treatment (modifies PW-10).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Requirements for Boilers Fabricated by Welding § 52.05-15 Heat treatment (modifies PW-10). (a) Vessels and... of the ASME Boiler and Pressure Vessel Code (incorporated by reference; see 46 CFR...

  5. 46 CFR 52.05-15 - Heat treatment (modifies PW-10).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Requirements for Boilers Fabricated by Welding § 52.05-15 Heat treatment (modifies PW-10). (a) Vessels and... of the ASME Boiler and Pressure Vessel Code (incorporated by reference; see 46 CFR...

  6. 46 CFR 52.05-15 - Heat treatment (modifies PW-10).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Requirements for Boilers Fabricated by Welding § 52.05-15 Heat treatment (modifies PW-10). (a) Vessels and... of the ASME Boiler and Pressure Vessel Code (incorporated by reference; see 46 CFR...

  7. Heat treatment temperature influence on ASTM A890 GR 6A super duplex stainless steel microstructure

    SciTech Connect

    Martins, Marcelo; E-mail: marcelo.martins@sulzer.com; Casteletti, Luiz Carlos

    2005-09-15

    Duplex and super duplex stainless steels are ferrous alloys with up to 26% chromium, 8% nickel, 5% molybdenum and 0.3% nitrogen, which are largely used in applications in media containing ions from the halogen family, mainly the chloride ion (Cl{sup -}). The emergence of this material aimed at substituting Copper-Nickel alloys (Cupro-Nickel) that despite presenting good corrosion resistance, has mechanical properties quite inferior to steel properties. The metallurgy of duplex and super duplex stainless steel is complex due to high sensitiveness to sigma phase precipitation that becomes apparent, due to the temperatures they are exposed on cooling from solidification as well as from heat treatment processes. The objective of this study was to verify the influence of heat treating temperatures on the microstructure and hardness of ASTM A890/A890M Gr 6A super duplex stainless steel type. Microstructure control is of extreme importance for castings, as the chemical composition and cooling during solidification inevitably provide conditions for precipitation of sigma phase. Higher hardness in these materials is directly associated to high sigma phase concentration in the microstructure, precipitated in the ferrite/austenite interface. While heat treatment temperature during solution treatment increases, the sigma phase content in the microstructure decreases and consequently, the material hardness diminishes. When the sigma phase was completely dissolved by the heat treatment, the material hardness was influenced only due to ferrite and austenite contents in the microstructure.

  8. High pressure and heat treatments effects on pectic substances in guava juice.

    PubMed

    Yen, G C; Lin, H T

    1998-01-01

    Effects of high pressure treatment on changes in pectic substances in guava juice were investigated and compared with those of heat treated samples. The viscosity and turbidity of guava juice pressurized at 6000 atm and 25 degrees C for 10 min increased slightly, whereas the viscosity of juice heated at 95 degrees C for 5 min decreased from 362 to 285 cps while turbidity increased from 0.87 to 1.15 (OD 600 nm). There were no apparent changes in water soluble, oxalate soluble and alkali soluble pectins in the pressurized juice. However, heat treated juice exhibited a decrease in its water and alkali soluble pectins and a slight increase in oxalate soluble pectin. The DEAE-cellulose profiles of pectic substances in guava juice were apparently unchanged after high pressure treatment while they were markedly changed by heat treatment, due to coagulation or degradation. During thermal processing, the degradation of pectin in guava juice caused a decrease in viscosity while the coagulation of pectin resulted in an increase in turbidity and cloud content. High pressure treatment showed no marked changes in pectic substances and cloud content in guava juice and maintained its natural viscous properties.

  9. Marketing research for EE G Mound Applied Technologies' heat treatment process of high strength materials

    SciTech Connect

    Shackson, R.H.

    1991-10-09

    This report summarizes research conducted by ITI to evaluate the commercialization potential of EG G Mound Applied Technologies' heat treatment process of high strength materials. The remainder of the report describes the nature of demand for maraging steel, extent of demand, competitors, environmental trends, technology life cycle, industry structure, and conclusion. (JL)

  10. Grain refinement of 2Mn-0.1C steel by repetitive heat treatment and recrystallization

    NASA Astrophysics Data System (ADS)

    Park, M. H.; Shibata, A.; Tsuji, N.

    2015-08-01

    Grain refinement in metals is well-known as one of the most effective methods to enhance their strength without addition of other elements. In this study, repetitive heat treatment combined with subsequent cold-rolling and recrystallization were investigated to obtain ultrafine-grained ferrite. Ultrafine-grained (UFG) ferritic structure having a mean grain size smaller than 1 μm was fabricated by repetitive heat treatment at 810 °C for 180 s and cold rolling by 90% plus a recrystallization heat treatment at 600 °C. Starting from this UFG ferrite, finegrained dual phase (DP) steel composed of ferrite and martensite phases with grain sizes smaller than 3 pm could be also obtained by intercritical heat treatment at 740 °C for 30 minutes followed by water-quenching. The mechanical properties of the ultrafine-grained ferritic and DP structured specimens were evaluated by tensile test. Results of the tensile test showed that finegrained ferritic and DP structures had higher yield and tensile strength than the coarse-grained ferritic and DP structures of the same steel.

  11. Deposition, Heat Treatment And Characterization of Two Layer Bioactive Coatings on Cylindrical PEEK.

    PubMed

    Durham, John W; Rabiei, Afsaneh

    2016-09-15

    Polyether ether ketone (PEEK) rods were coated via ion beam asssited deposition (IBAD) at room temperature. The coating consists of a two-layer design of yttria-stabilized zirconia (YSZ) as a heat-protection layer, and hydroxyapatite (HA) as a top layer to increase bioactivity. A rotating substrate holder was designed to deposit an even coating on the cylindrical surface of PEEK rods; the uniformity is verified by cross-sectional measurements using scanning electron microscopy (SEM). Deposition is followed by heat treatment of the coating using microwave annealing and autoclaving. Transmission electron microscopy (TEM) showed a dense, uniform columnar grain structure in the YSZ layer that is well bonded to the PEEK substrate, while the calcium phosphate layer was amorphous and pore-free in its as-deposited state. Subsequent heat treatment via microwave energy introduced HA crystallization in the calcium phosphate layer and additional autoclaving further expanded the crystallization of the HA layer. Chemical composition evaluation of the coating indicated the Ca/P ratios of the HA layer to be near that of stoichiometric HA, with minor variations through the HA layer thickness. The adhesion strength of as-deposited HA/YSZ coatings on smooth, polished PEEK surfaces was mostly unaffected by microwave heat treatment, but decreased with additional autoclave treatment. Increasing surface roughness showed improvement of bond strength.

  12. Influence of deformation ageing treatment on microstructure and properties of aluminum alloy 2618

    SciTech Connect

    Wang Jianhua Yi Danqing; Su Xuping; Yin Fucheng

    2008-07-15

    The effects of deformation ageing treatment (DAT) on the microstructure and properties of aluminum alloy 2618 were investigated. The alloy was subjected to deformation ageing treatment which included solution treating at 535 deg. C quenching into water at room-temperature, cold rolling (10%) and further ageing to peak hardness level at 200 deg. C. The electron microscopic studies revealed that the treatment affects the ageing characteristics and the coarsening of ageing phase (S') at elevated-temperature. The dislocation-precipitate tangles substructure couldn't be found in alloy 2618. The tensile and hardness tests showed that deformation-ageing treatment causes a significant improvement in tensile strength and hardness to alloy 2618 at room- and elevated-temperature.

  13. Grape powder treatment prevents anxiety-like behavior in a rat model of aging.

    PubMed

    Patki, Gaurav; Ali, Quaisar; Pokkunuri, Indira; Asghar, Mohammad; Salim, Samina

    2015-06-01

    Earlier, we have reported that grape powder (GP) treatment prevented pharmacologic and psychological stress-induced anxiety-like behavior and memory impairment in rats. Protective effects of GP were attributed to its antioxidant effects. In this study, we tested the hypothesis that age-associated behavioral and cognitive deficits such as anxiety and memory impairment will be ameliorated with GP treatment. Using a National Institute of Aging recommended rodent model of aging, we examined a potentially protective role of antioxidant-rich GP in age-associated anxiety-like behavior and memory impairment. Male Fischer 344 rats were randomly assigned into 4 groups: young rats (3 months old) provided with tap water or with 15 g/L GP dissolved in tap water for 3 weeks, aged rats (21 months old) provided with tap water or with GP-treated tap water for 3 weeks (AG-GP). Anxiety-like behavior was significantly greater in aged rats compared with young rats, GP-treated young rats, or aged control rats (P < .05). Also, GP treatment prevented age-induced anxiety-like behavior in AG-GP rats (P < .05). Neither short-term nor long-term age-associated memory deficits improved with GP treatment in AG-GP rats. Furthermore, aged rats showed increased level of physiological stress (corticosterone) and increased oxidative stress in the plasma (8-isoprostane) as well as in selected brain areas (protein carbonylation). Grape powder treatment prevented age-induced increase in corticosterone levels and plasma 8-isoprostane levels in aged rats (P < .05), whereas protein carbonylation was recovered in the amygdala region only (P < .05). Grape powder by regulating oxidative stress ameliorates age-induced anxiety-like behavior in rats, whereas age-associated memory deficits seem unaffected with GP treatment.

  14. Durable polyorganosiloxane superhydrophobic films with a hierarchical structure by sol-gel and heat treatment method

    NASA Astrophysics Data System (ADS)

    Jiang, Zhenlin; Fang, Shuying; Wang, Chaosheng; Wang, Huaping; Ji, Chengchang

    2016-12-01

    For a surface to be superhydrophobic a combination of surface roughness and low surface energy is required. In this study, polyorganosiloxane superhydrophobic surfaces were fabricated using a sol-gel and heat treatment process followed by coating with a nanosilica (SiO2) sol and organosiloxane 1, 1, 1, 3, 5, 5, 5-heptamethyl-3-[2-(trimethoxysilyl)ethyl]-trisiloxane (β-HPEOs). The nano-structure was superimposed using self-assembled, surface-modified silica nanoparticles, forming two-dimensional hierarchical structures. The water contact angle (WCA) of polyorganosiloxane superhydrophobic surface was 143.7 ± 0.6°, which was further increased to 156.7 ± 1.1° with water angle hysteresis of 2.5 ± 0.6° by superimposing nanoparticles using a heat treatment process. An analytical characterization of the surface revealed that the nano-silica and polyorganosiloxane formed a micro/nano structure on the films and the wetting behaviour of the films changed from hydrophilic to superhydrophobic. The WCA of these films were 143.7 ± 0.6° and at heat treatment temperatures of less than 400 °C, the WCA increased from 144.5 ± 0.7° to 156.7 ± 1.1°. The prepared superhydrophobic films were stable even after heat treatment at 430 °C for 30 min and their superhydrophobicity was durable for more than 120 days. The effects of heat treatment process on the surface chemistry structure, wettability and morphology of the polyorganosiloxane superhydrophobic films were investigated in detail. The results indicated that the stability of the chemical structure was required to yield a thermally-stable superhydrophobic surface.

  15. Effects of heat treatment of calcium hydroxyapatite particles on the protein adsorption behavior.

    PubMed

    Kandori, Kazuhiko; Mizumoto, Saki; Toshima, Satoko; Fukusumi, Masao; Morisada, Yoshiaki

    2009-08-06

    The effects of heat treatment of calcium hydroxyapatite (Hap) on the protein adsorption behavior were examined using typical proteins of bovine serum albumin (BSA: isoelectric point (iep) = 4.7, molecular mass (Ms) = 67,200 Da, acidic protein), myoglobin (MGB: iep = 7.0, Ms = 17,800 Da, neutral protein), and lysozyme (LSZ: iep = 11.1, Ms = 14,600 Da, basic protein). The TEM, XRD, and gas adsorption measurements ascertained that all of the Hap particles examined were highly crystallized and nonporous. The Hap single phase was continued up to the heat treatment temperature of 600 degrees C. However, after treatment above 800 degrees C in air, the beta-Ca3(PO4)2 (beta-TCP) phase slightly appeared. TG and ICP-AES measurements suggested that all of the Hap particles are Ca2+-deficient. Also, it was indicated from FTIR and XPS measurements that a partially dehydrated oxyhydroxyapatite (pd-OHap) was formed after treatment at high temperature. The saturated amounts of adsorbed BSA (nsBSA) did not vary on the Hap particles after heat treatment at 200 and 400 degrees C. However, nsBSA values were increased by raising the heat treatment temperature above 600 degrees C. The adsorption coverage of BSA was increased up to ca. 1.4. This adsorption coverage of BSA (thetaBSA) over unity suggests that the BSA molecules densely adsorbed and a part of BSA molecules adsorbed as end-on type on the Hap particle surface or BSA molecules became contracted. Similar adsorption behavior was observed on the LSZ system, but the adsorption coverage of LSZ (thetaLSZ) values are much less than thetaBSA. On the other hand, no effect of the heat treatment of Hap particles was observed on the adsorption of MGB. The increases of nsBSA and nsLSZ were explained by the increase of calcium and phosphate ions in the solutions dissolved from beta-TCP formed after heat treatment of Hap, especially treated at high temperature. The dissolved Ca2+ and PO(4)3 - ions may act as binders between proteins and Hap

  16. The effects of heat treatment on technological properties in Red-bud maple (Acer trautvetteri Medw.) wood.

    PubMed

    Korkut, Süleyman; Kök, M Samil; Korkut, Derya Sevim; Gürleyen, Tuğba

    2008-04-01

    Heat treatment is often used to improve the dimensional stability of wood. In this study, the effects of heat treatment on technological properties of Red-bud maple (Acer trautvetteri Medw.) wood were examined. Samples obtained from Düzce Forest Enterprises, Turkey, were subjected to heat treatment at varying temperatures (120 degrees C, 150 degrees C and 180 degrees C) and for varying durations (2h, 6h and 10h). The technological properties of heat-treated wood samples and control samples were tested. Compression strength parallel to grain, bending strength, modulus of elasticity in bending, janka-hardness, impact bending strength, and tension strength perpendicular to grain were determined. The results showed that technological strength values decreased with increasing treatment temperature and treatment times. Red-bud maple wood could be utilized by using proper heat treatment techniques with minimal losses in strength values in areas where working, and stability such as in window frames, are important factors.

  17. Denaturation and Oxidative Stability of Hemp Seed (Cannabis sativa L.) Protein Isolate as Affected by Heat Treatment.

    PubMed

    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.

  18. Titanium metals form direct bonding to bone after alkali and heat treatments.

    PubMed

    Nishiguchi, S; Kato, H; Fujita, H; Oka, M; Kim, H M; Kokubo, T; Nakamura, T

    2001-09-01

    In this article we evaluated the bone-bonding strengths of titanium and titanium alloy implants with and without alkali and heat treatments using the conventional canine femur push-out model. Four kinds of smooth cylindrical implants, made of pure titanium or three titanium alloys, were prepared with and without alkali and heat treatments. The implants were inserted hemitranscortically into canine femora. The bone-bonding shear strengths of the implants were measured using push-out test. At 4 weeks all types of the alkali- and heat-treated implants showed significantly higher bonding strength (2.4-4.5 MPa) than their untreated counterparts (0.3-0.6 MPa). At 12 weeks the bonding strengths of the treated implants showed no further increase, while those of the untreated implants had increased to 0.6-1.2MPa. Histologically, alkali- and heat-treated implants showed direct bonding to bony tissue without intervening fibrous tissue. On the other hand, untreated implants usually had intervening fibrous tissue at the interface between bone and the implant. The early and strong bonding to bone of alkali- and heat-treated titanium and its alloys without intervening fibrous tissue may be useful in establishing cementless stable fixation of orthopedic implants.

  19. Graphene transport properties upon exposure to PMMA processing and heat treatments

    NASA Astrophysics Data System (ADS)

    Gammelgaard, Lene; Caridad, José M.; Cagliani, Alberto; Mackenzie, David M. A.; Petersen, Dirch H.; Booth, Timothy J.; Bøggild, Peter

    2014-12-01

    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 of graphene while PMMA residues are found to be surprisingly benign. In accordance with this picture, graphene devices with initially high carrier mobility tend to suffer a decrease in carrier mobility, while in contrast an improvement is observed for low carrier mobility devices. We explain this by noting 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.

  20. Small molecule SIRT1 activators for the treatment of aging and age-related diseases

    PubMed Central

    Hubbard, Basil P.; Sinclair, David A.

    2014-01-01

    Recent studies in mice have identified single molecules that can delay multiple diseases of aging and extend lifespan. In theory, such molecules could prevent dozens of diseases simultaneously, significantly extending healthy years of life. In this review we discuss recent advances, controversies, opportunities, and challenges surrounding the development of SIRT1 activators, molecules with the potential to delay aging and age-related diseases. Sirtuins comprise a family of NAD+-dependent deacylases that are central to the body’s response to diet and exercise. New studies indicate that both natural and synthetic sirtuin activating compounds (STACs) work via a common allosteric mechanism to stimulate sirtuin activity, thereby conferring broad health benefits in rodents, primates, and possibly humans. The fact that the two-thirds of people in the USA who consume multiple dietary supplements consume resveratrol, a SIRT1 activator, underscores the importance of understanding the biochemical mechanism, physiological effects, and safety of STACs. PMID:24439680

  1. Opportunities for Combined Heat and Power at Wastewater Treatment Facilities: Market Analysis and Lessons from the Field

    EPA Pesticide Factsheets

    This report presents the opportunities for combined heat and power (CHP) applications in the municipal wastewater treatment sector, and it documents the experiences of the wastewater treatment facility (WWTF) operators who have employed CHP.

  2. Behavior of Fe-ODS Alloys After Thermal Aging Treatments

    NASA Astrophysics Data System (ADS)

    Serrano Garcia, Marta; Hernández-Mayoral, Mercedes; Esparraguera, Elvira Oñorbe

    2016-06-01

    Oxide dispersion alloys are one of the candidates as cladding materials for Gen IV fast reactors, due to their high strength at high temperature, good creep properties, and swelling resistance. This good performance is mainly due to a fine dispersion of nano-oxide particles on the microstructure and to non-grained structure. The microstructural stability and the mechanical properties of a Fe-ODS alloy are studied after different thermal aging experiments at 973 K (700 °C), 5000 hours; 973 K (700 °C), 10,000 hours; and 1123 K (850 °C), 10,000 hours. SEM/EBSD and TEM together with tensile and impact tests on the as-received and thermally aged material have been carried out. In general, for all the tested conditions, a slight softening effect is observed attributed to the changes in the grain structure as well as to the changes in the amount and size of nano-oxide particles. In addition, the aged material shows a lower impact USE value while the DBTT is maintained.

  3. Laser surface heat treatment of electroless Ni-P-SiC coating on Al356 alloy

    NASA Astrophysics Data System (ADS)

    Hashemi, Sayed Hamid; Shoja-Razavi, Reza

    2016-11-01

    Electroless Ni-P-SiC coatings are recognized for their hardness and wear resistance. In the present study, electroless Ni-P coatings containing SiC particles were co-deposited on Al356 substrate. Laser surface heat treatment was performed using 700 W Nd:YAG pulsed laser. Effects of different laser operating parameters, such as laser scan rate, laser average power and defocusing distance on microstructures were investigated by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectrometer (EDS). The results of microstructural characterization indicated that the laser treatment under different operating conditions produced composite coating contained nanocrystallined Ni-based matrix with SiC particles Ni3P, Ni12P5, Ni5P2, Ni8P3 precipitates. The microhardness measurements showed that the hardness of the coating was increased up to 60%, due to laser heat treatment, without effect on base metal.

  4. Functional Properties of Glutinous Rice Flour by Dry-Heat Treatment

    PubMed Central

    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 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. PMID:27537844

  5. Process Integrated Heat Treatment of a Microalloyed Medium Carbon Steel: Microstructure and Mechanical Properties

    NASA Astrophysics Data System (ADS)

    Herbst, Sebastian; Schledorn, Mareike; Maier, Hans Jürgen; Milenin, Andrij; Nürnberger, Florian

    2016-04-01

    Air-water spray cooling was employed during a heat treatment to enhance the mechanical properties of microalloyed medium carbon steel test cylinders (38MnVS6, 88 mm diameter). Using appropriate cooling times and intensities, the test cylinders' surfaces could be quenched and subsequently self-tempered by the residual heat of the core. Simultaneously, it was possible to keep the core regions of the cylinders in the bainitic regime and carry out a quasi-isothermal holding. The resulting microstructures consisted of tempered martensite (near-surface) and bainite with pearlite and ferrite (core). Compared to the standard heat treatment (controlled air cooling), the tensile properties (proof stress and ultimate tensile strength) could be improved for both near-surface and core regions with the adapted spray cooling. A hardness profile with 450 HV10 surface hardness and a hardening depth of more than 11 mm could be realized. In addition, an increase of the impact toughness for the core was achieved, resulting in approximately 25 J charpy impact energy. This is a substantial improvement compared to standard heat treatment procedure and values reported in the literature and can be attributed to the reduced pearlite volume fraction and the increased amount of fine bainite.

  6. Effect of grain orientation and heat treatment on mechanical properties of pure W

    NASA Astrophysics Data System (ADS)

    Noto, Hiroyuki; Taniguchi, Shuichi; Kurishita, Hiroaki; Matsuo, Satoru; Ukita, Takashi; Tokunaga, Kazutoshi; Kimura, Akihiko

    2014-12-01

    The effect of grain orientation, heat-treatment temperature and test temperature on the mechanical properties of tungsten (W), which vary depending on plastic working and fabrication process, was investigated by mechanical testing of tensile or bending. Heavily worked W samples (1.5-2.0 mm in the final thickness) exhibit degradation of fracture strength due to recrystallization embrittlement after heat-treatment at 1240 °C (temperature of diffusion bonding between W and a candidate material of the Fe base support structure). On the other hand, W samples with lower thickness reduction rates do not suffer degradation of fracture strength after heating up to around 1300 °C, and show somewhat higher fracture strength by heat-treatment below 1300 °C than the samples in the as-received state. The observed behavior is a reflection of recovery of dislocations introduced by plastic working. High temperature tensile testing of ITER grade W with an anisotropic grain structure and S-TUN with an equiaxed grain structure revealed that both W grades exhibit plastic elongation at temperatures higher than 200 °C with essentially the same temperature dependence of yield strength, which is relatively insensitive to grain orientation in the structure at 200-1300 °C.

  7. Temperature and Time Requirements for Controlling Bed Bugs (Cimex lectularius) under Commercial Heat Treatment Conditions.

    PubMed

    Kells, Stephen A; Goblirsch, Michael J

    2011-08-29

    Developing effective alternative approaches for disinfesting bed bugs from residential spaces requires a balance between obtaining complete insect mortality, while minimizing costs and energy consumption. One method of disinfestation is the application of lethal high temperatures directly to rooms and contents within a structure (termed whole-room heat treatments). However, temperature and time parameters for efficacy in whole-room heat treatments are unknown given the slower rate of temperature increase and the probable variability of end-point temperatures within a treated room. The objective of these experiments was to explore requirements to produce maximum mortality from heat exposure using conditions that are more characteristic of whole-room heat treatments. Bed bugs were exposed in an acute lethal temperature (LTemp) trial, or time trials at sub-acute lethal temperatures (LTime). The lethal temperature (LTemp99) for adults was 48.3 °C, while LTemp99 for eggs was 54.8 °C. Adult bed bugs exposed to 45 °C had a LTime99 of 94.8 min, while eggs survived 7 h at 45 °C and only 71.5 min at 48 °C. We discuss differences in exposure methodologies, potential reasons why bed bugs can withstand higher temperatures and future directions for research.

  8. Temperature and Time Requirements for Controlling Bed Bugs (Cimex lectularius) under Commercial Heat Treatment Conditions

    PubMed Central

    Kells, Stephen A.; Goblirsch, Michael J.

    2011-01-01

    Developing effective alternative approaches for disinfesting bed bugs from residential spaces requires a balance between obtaining complete insect mortality, while minimizing costs and energy consumption. One method of disinfestation is the application of lethal high temperatures directly to rooms and contents within a structure (termed whole-room heat treatments). However, temperature and time parameters for efficacy in whole-room heat treatments are unknown given the slower rate of temperature increase and the probable variability of end-point temperatures within a treated room. The objective of these experiments was to explore requirements to produce maximum mortality from heat exposure using conditions that are more characteristic of whole-room heat treatments. Bed bugs were exposed in an acute lethal temperature (LTemp) trial, or time trials at sub-acute lethal temperatures (LTime). The lethal temperature (LTemp99) for adults was 48.3 °C, while LTemp99 for eggs was 54.8 °C. Adult bed bugs exposed to 45 °C had a LTime99 of 94.8 min, while eggs survived 7 h at 45 °C and only 71.5 min at 48 °C. We discuss differences in exposure methodologies, potential reasons why bed bugs can withstand higher temperatures and future directions for research. PMID:26467736

  9. Design of Water-Drip Cooling Facilities for Heat Treatment of Mill Rollers

    NASA Astrophysics Data System (ADS)

    Yudin, Yu. V.; Maisuradze, M. V.; Anufriev, N. P.

    2013-07-01

    Water-drip cooling devices based on centrifugal jet atomizers are studied experimentally. Their main operating characteristics such as the irrigation density, the uniformity of the distribution of irrigation over the cooled surface, the dependence of the heat transfer factor on the surface temperature, etc. are determined. The effect of the design and production parameters of the quenching facilities on their operating characteristics and mode of cooling of large steel articles is considered for mill rollers as an example. The results of the tests are used to design cooling facilities and heat treatment processes for mill rollers with the use of water-drip quenching.

  10. Heat stress stimulates hepcidin mRNA expression and C/EBPα protein expression in aged rodent liver.

    PubMed

    Bloomer, Steven A; Kregel, Kevin C; Brown, Kyle E

    2014-01-01

    Elevations in hepatic iron content occur with aging and physiological stressors, which may promote oxidative injury to the liver. Since dysregulation of the iron regulatory hormone, hepcidin, can cause iron accumulation, our goal was to characterize the regulation of hepcidin in young (6 mo) and old (24 mo) Fischer 344 rats exposed to environmental heat stress. Liver and blood samples were taken in the control condition and after heating. Hepcidin expression did not differ between young and old rats in the control condition, despite higher levels of hepatic iron and IL-6 mRNA in the latter. Following heat stress, pSTAT3 increased in both groups, but C/EBPα and hepcidin mRNA increased only in old rats. Despite this, serum iron decreased in both age groups 2 h after heat stress, suggesting hepcidin-independent hypoferremia in the young rats. The differential regulation of hepcidin between young and old rats after hyperthermia may be due to the enhanced expression of C/EBPα protein in old rats. These data support the concept of "inflammaging" and suggest that repeated exposures to stressors may contribute to the development of anemia in older individuals.

  11. The influence of heat treatments on several types of base-metal removable partial denture alloys.

    PubMed

    Morris, H F; Asgar, K; Rowe, A P; Nasjleti, C E

    1979-04-01

    Four removable partial denture alloys, Vitallium (Co-Cr alloy), Dentillium P.D. (Fe-Cr alloy), Durallium L.G. (Co-Cr-Ni alloy), and Ticonium 100 (Ni-Cr alloy), were evaluated in the as-cast condition and after heat treatment for 15 minutes at 1,300 degrees, 1,600 degrees, 1,900 degrees, and 2,200 degrees F followed by quenching in water. The following properties were determined and compared for each alloy at each heat treatment condition: the yield strengths at 0.01%, 0.1%, and 0.2% offsets, the ultimate tensile strength, the percent elongation, the modulus of elasticity, and the Knoop microhardness. The results were statistically analyzed. Photomicrographs were examined for each alloy and test condition. The following conclusions were made: 1. The "highest values" were exhibited by the as-cast alloy. 2. Heat treatment of the partial denture alloys tested resulted in reductions in strength, while the elongations varied. This study demonstrates that, in practice, one should avoid (a) prolonged "heat-soaking" while soldering and (b) grinding or polishing of the casting until the alloy is "red hot". 3. Durallium L.G. was the least affected by the various heat treatment conditions. 4. Conventional reporting of the yield strength at 0.2% offset, the ultimate tensile strength, and percent elongation are not adequate to completely describe and compare the mechanical behavior of alloys. The reporting of the yield strength at 0.01% offset, in addition to the other reported properties, will provide a more complete description of the behavior of the dental alloys.

  12. Argon-40/Argon-39 Age Spectra of Apollo 17 Highlands Breccia Samples by Laser Step Heating and the Age of the Serenitatis Basin

    NASA Technical Reports Server (NTRS)

    Dalrymple, G. Brent; Ryder, Graham

    1996-01-01

    We have obtained high-resolution (21-63 steps) Ar-40/Ar-39 age spectra using a continuous laser system on 19 submilligram samples of melt rocks and clasts from Apollo 17 samples collected from the pre-Imbrian highlands in the easternmost part of the Serenitatis basin. The samples include poikilitic melt rocks inferred to have been formed in the Serenitatis basin-forming impact, aphanitic melt rock whose compositions vary and whose provenance is uncertain, and granulite, gabbro, and melt clasts. Three of the poikilitic melts have similar age spectrum plateau ages (72395,96, 3893 +/- 16 Ma (2sigma); 72535,7, 3887 +/- 16 Ma; 76315,150, 3900 +/- 16 Ma) with a weighted mean age of 3893 +/- 9 Ma, which we interpret as the best age for the Serenitatis basin- forming impact. Published Ar-40/Ar-39 age spectrum ages of Apollo 17 poikilitic melts are consistent with our new age but are much less precise. Two poikilitic melts did not give plateaus and the maxima in their age spectra indicate ages of greater than or equal to 3869 Ma (72558,7) and greater than or equal to 3743 Ma (77135,178). Plateau ages of two poikilitic melts and two gabbro clasts from 73155 range from 3854 +/- 16 Ma to 3937 +/- 16 Ma and have probably been affected by the ubiquitous (older?) clasts and by post- formation heating (impact) events. Plateau ages from two of the aphanitic melt 'blobs' and two granulites in sample 72255 fall in the narrow range of 3850 q 16 Ma to 3869 q 16 Ma with a weighted mean of 3862 +/- 8 Ma. Two of the aphanitic melt blobs from 72255 have ages of 3883 +/- 16 Ma and greater than or equal to 3894 Ma, whereas a poikilitic melt clast (of different composition from the 'Serenitatis' melts) has an age of 3835 +/- 16 Ma, which is the upper limit for the accretion of 72255. These data suggest that either the aphanitic melts vary in age, as is also suggested by their varying chemical compositions, or they formed in the 72255 accretionary event about 3.84-3.85 Ga and older relict

  13. Antioxidant Supplementation in the Treatment of Aging-Associated Diseases

    PubMed Central

    Conti, Valeria; Izzo, Viviana; Corbi, Graziamaria; Russomanno, Giusy; Manzo, Valentina; De Lise, Federica; Di Donato, Alberto; Filippelli, Amelia

    2016-01-01

    Oxidative stress is generally considered as the consequence of an imbalance between pro- and antioxidants species, which often results into indiscriminate and global damage at the organismal level. Elderly people are more susceptible to oxidative stress and this depends, almost in part, from a decreased performance of their endogenous antioxidant system. As many studies reported an inverse correlation between systemic levels of antioxidants and several diseases, primarily cardiovascular diseases, but also diabetes and neurological disorders, antioxidant supplementation has been foreseen as an effective preventive and therapeutic intervention for aging-associated pathologies. However, the expectations of this therapeutic approach have often been partially disappointed by clinical trials. The interplay of both endogenous and exogenous antioxidants with the systemic redox system is very complex and represents an issue that is still under debate. In this review a selection of recent clinical studies concerning antioxidants supplementation and the evaluation of their influence in aging-related diseases is analyzed. The controversial outcomes of antioxidants supplementation therapies, which might partially depend from an underestimation of the patient specific metabolic demand and genetic background, are presented. PMID:26903869

  14. Aging With HIV in the Era of Antiretroviral Treatment

    PubMed Central

    Nideröst, Sibylle; Imhof, Christoph

    2016-01-01

    The aim of this cross-sectional study was to identify the living conditions and the quality of life of people aged more than 50 who were living with HIV in Switzerland. Participants were consecutively sampled through different HIV-specific sites. Seventy-two HIV-positive persons filled in an anonymous standardized questionnaire, either paper-pencil or online. Descriptive and inferential statistics were calculated. Quality of life was rated quite high (M = 14.9, SD = 4.14). The multivariate regression analyses showed that mental and physical health problems, long-term living with HIV, having a high degree of needed support, and financial problems decreased quality of life, and perceived available social support was an important predictor in maintaining quality of life. In addition to current offers to support mental health and social networks, efforts to integrate people of working age into the labor market and efforts to reduce stigma and the social marginalization of older HIV-positive people should be fostered. PMID:28138489

  15. Additive Manufacturing of 17-4 PH Stainless Steel: Post-processing Heat Treatment to Achieve Uniform Reproducible Microstructure

    NASA Astrophysics Data System (ADS)

    Cheruvathur, Sudha; Lass, Eric A.; Campbell, Carelyn E.

    2016-03-01

    17-4 precipitation hardenable (PH) stainless steel is a useful material when a combination of high strength and good corrosion resistance up to about 315°C is required. In the wrought form, this steel has a fully martensitic structure that can be strengthened by precipitation of fine Cu-rich face-centered cubic phase upon aging. When fabricated via additive manufacturing (AM), specifically laser powder-bed fusion, 17-4 PH steel exhibits a dendritic structure containing a substantial fraction of nearly 50% of retained austenite along with body centered cubic/martensite and fine niobium carbides preferentially aligned along interdendritic boundaries. The effect of post-build thermal processing on the material microstructure is studied in comparison to that of conventionally produced wrought 17-4 PH with the intention of creating a more uniform, fully martensitic microstructure. The recommended stress relief heat treatment currently employed in industry for post-processing of AM 17-4 PH steel is found to have little effect on the as-built dendritic microstructure. It is found that, by implementing the recommended homogenization heat treatment regimen of Aerospace Materials Specification 5355 for CB7Cu-1, a casting alloy analog to 17-4 PH, the dendritic solidification structure is eliminated, resulting in a microstructure containing about 90% martensite with 10% retained austenite.

  16. The Effect of Stabilization Heat Treatments on the Tensile and Creep Behavior of an Advanced Nickel-Based Disk Alloy

    NASA Technical Reports Server (NTRS)

    Gayda, John

    2003-01-01

    As part of NASA s Advanced Subsonic Technology Program, a study of stabilization heat treatment options for an advanced nickel-base disk alloy, ME 209, was performed. Using a simple, physically based approach, the effect of stabilization heat treatments on tensile and creep properties was analyzed in this paper. Solutions temperature, solution cooling rate, and stabilization temperature/time were found to have a significant impact on tensile and creep properties. These effects were readily quantified using the following methodology. First, the effect of solution cooling rate was assessed to determine its impact on a given property. The as-cooled property was then modified by using two multiplicative factors which assess the impact of solution temperature and stabilization parameters. Comparison of experimental data with predicted values showed this physically based analysis produced good results that rivaled the statistical analysis employed, which required numerous changes in the form of the regression equation depending on the property and temperature in question. As this physically based analysis uses the data for input, it should be noted that predictions which attempt to extrapolate beyond the bounds of the data must be viewed with skepticism. Future work aimed at expanding the range of the stabilization/aging parameters explored in this study would be highly desirable, especially at the higher solution cooling rates.

  17. Viability of Clostridium perfringens, Escherichia coli, and Listeria monocytogenes surviving mild heat or aqueous ozone treatment on beef followed by heat, alkali, or salt stress.

    PubMed

    Novak, John S; Yuan, James T C

    2003-03-01

    The threat of pathogen survival following ozone treatment of meat necessitates careful evaluation of the microorganisms surviving under such circumstances. The objective of this study was to determine whether sublethal aqueous ozone treatment (3 ppm of O3 for 5 min) of microorganisms on beef surfaces would result in increased or decreased survival with respect to subsequent heat, alkali, or NaCl stress. A mild heat treatment (55 degrees C for 30 min) was used for comparison. Reductions in three-strain cocktails of Clostridium perfringens, Escherichia coli O157:H7, and Listeria monocytogenes on beef following the heat treatment were 0.14, 0.77, and 1.47 log10 CFU/g, respectively, whereas reductions following ozone treatment were 1.28, 0.85, and 1.09 log10 CFU/g, respectively. C. perfringens cells exhibited elevated heat resistance at 60 degrees C (D60 [time at 60 degrees C required to reduce the viable cell population by 1 log10 units or 90%] = 17.76 min) following heat treatment of beef (55 degrees C for 30 min) but exhibited reduced viability at 60 degrees C following ozone treatment (D60 = 7.64 min) compared with the viability of untreated control cells (D60 = 13.84 min). The D60-values for L. monocytogenes and E. coli O157:H7 following heat and ozone exposures were not significantly different (P > 0.05). C. perfringens cells that survived ozone treatment did not exhibit increased resistance to pH (pH 6 to 12) relative to non-ozone-treated cells when grown at 37 degrees C for 24 h. The heat treatment also resulted in decreased numbers of surviving cells above and below neutral pH values for both E. coli O157:H7 and L. monocytogenes relative to those of non-heat-treated cells grown at 37 degrees C for 24 h. There were significant differences (P < 0.05) in C. perfringens reductions with increasing NaCl concentrations. The effects of NaCl were less apparent for E. coli and L. monocytogenes survivors. It is concluded that pathogens surviving ozone treatment of beef

  18. Non-lethal heat treatment of cells results in reduction of tumor initiation and metastatic potential

    SciTech Connect

    Kim, Yoo-Shin; Lee, Tae Hoon; O'Neill, Brian E.

    2015-08-14

    Non-lethal hyperthermia is used clinically as adjuvant treatment to radiation, with mixed results. Denaturation of protein during hyperthermia treatment is expected to synergize with radiation damage to cause cell cycle arrest and apoptosis. Alternatively, hyperthermia is known to cause tissue level changes in blood flow, increasing the oxygenation and radiosensitivity of often hypoxic tumors. In this study, we elucidate a third possibility, that hyperthermia alters cellular adhesion and mechanotransduction, with particular impact on the cancer stem cell population. We demonstrate that cell heating results in a robust but temporary loss of cancer cell aggressiveness and metastatic potential in mouse models. In vitro, this heating results in a temporary loss in cell mobility, adhesion, and proliferation. Our hypothesis is that the loss of cellular adhesion results in suppression of cancer stem cells and loss of tumor virulence and metastatic potential. Our study suggests that the metastatic potential of cancer is particularly reduced by the effects of heat on cellular adhesion and mechanotransduction. If true, this could help explain both the successes and failures of clinical hyperthermia, and suggest ways to target treatments to those who would most benefit. - Highlights: • Non-lethal hyperthermia treatment of cancer cells is shown to cause a reduction in rates of tumor initiation and metastasis. • Dynamic imaging of cells during heat treatment shows temporary changes in cell shape, cell migration, and cell proliferation. • Loss of adhesion may lead to the observed effect, which may disproportionately impact the tumor initiating cell fraction. • Loss or suppression of the tumor initiating cell fraction results in the observed loss of metastatic potential in vivo. • This result may lead to new approaches to synergizing hyperthermia with surgery, radiation, and chemotherapy.

  19. Degradation of Anthocyanin Content in Sour Cherry Juice During Heat Treatment

    PubMed Central

    Szalóki-Dorkó, Lilla; Ladányi, Márta; Ficzek, Gitta; Stéger-Máté, Mónika

    2015-01-01

    Summary Sour cherry juices made from two sour cherry cultivars (Érdi bőtermő and Kántorjánosi 3) were investigated to determine their total anthocyanin content and half-life of anthocyanins during heat treatment at different temperatures (70, 80 and 90 °C) for 4 h. Before the heat treatment, Érdi bőtermő juice had higher anthocyanin concentration (812 mg/L) than Kántorjánosi 3 juice (513 mg/L). The greatest heat sensitivity of anthocyanins was measured at 90 °C, while the treatments at 80 and 70 °C caused lower thermal degradation. The loss of anthocyanins in Érdi bőtermő juice after treatment was 38, 29 and 18%, respectively, while in Kántorjánosi 3 juice losses of 46, 29 and 19% were observed, respectively. At 90 °C sour cherry Érdi bőtermő juice had higher half-life (t1/2) of anthocyanins, while the Kántorjánosi 3 juice had higher t1/2 values at 70 °C. Cyanidin-3-glucosyl-rutinoside was present in higher concentrations in both cultivars (Érdi bőtermő: 348 and Kántorjánosi 3: 200 mg/L) than cyanidin-3-rutinoside (177 and 121 mg/L) before treatment. However, during the experiment, cyanidin-3-rutinoside was proved to be more resistant to heat. Comparing the two varieties, both investigated pigment compounds were more stable in Kántorjánosi 3 than in Érdi bőtermő. Degradation rate of anthocyanins was cultivar-dependent characteristic, which should be taken into account in the food production. PMID:27904369

  20. Comprehensive treatment of the aging face--cutaneous and structural rejuvenation.

    PubMed

    Sherris, D A; Otley, C C; Bartley, G B

    1998-02-01

    As people age, characteristic changes occur in the skin, the soft tissue envelope, and the bony skeleton of the face and result in the aging face syndrome. An understanding of the pertinent biomechanical and histologic changes is necessary for developing an appropriate treatment plan. The advent of many new techniques, including cosmetic exfoliation, laser skin resurfacing, open rhinoplasty, and endoscopic, multiplane plastic surgical procedures, has enhanced therapy for the aging face syndrome. Treatment protocols should be individualized for each patient's needs and desires. Several of these recent treatments for facial rejuvenation are reviewed herein.

  1. Characterization and dissolution behavior of sputtered calcium phosphate coatings after different postdeposition heat treatment temperatures.

    PubMed

    Yang, Y; Agrawal, C M; Kim, K H; Martin, H; Schulz, K; Bumgardner, I D; Ong, J L

    2003-01-01

    There is a lack of correlation between specific properties of hydroxyapatite coating surfaces, osseointegration processes, and implant success. The aim of this study was to evaluate the relationship between well-characterized structural and chemical properties of radio-frequency sputtered calcium phosphate (CaP) coatings and their dissolution behavior. Sputtered CaP coatings were evaluated as-sputtered (non-heat treated) or after 1 hour of postsputter heat treatments at 400 degrees C or 600 degrees C. All coatings were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and contact angle measurement. The dissolution behavior of CaP coatings in the presence and absence of proteins was also investigated. It was observed from this study that as-sputtered CaP coatings were amorphous. The 400 degrees C heat-treated CaP coatings exhibited low crystallinity (1.9% +/- 0.4%), whereas the 600 degrees C heat-treated CaP coatings were highly crystalline (67.0% +/- 2.4%). The increase of Ca/P ratio, PO4/HPO4 ratio, and the number of PO4 peaks were observed to be consistent with the increase in heating temperature and the degrees of coating crystallinity. Phosphorus ions released from CaP coatings decreased with the increase of crystallinity of CaP coatings. In addition, immersion of CaP coatings in media containing proteins resulted in an increase in P ions released as compared with coatings immersed in media without proteins. It was concluded that the degree of CaP coating crystallinity can be controlled by varying the postdeposition heat-treatment temperature. It was also concluded that, aside from coating crystallinity, dissolution and reprecipitation of the coatings can be controlled by knowing the presence of proteins in the media and PO4/HPO4 ratio within the coatings.

  2. Mutagenicity of an aged gasworks soil during bioslurry treatment

    PubMed Central

    Lemieux, Christine L; Lynes, Krista D; White, Paul A; Lundstedt, Staffan; Öberg, Lars; Lambert, Iain B

    2009-01-01

    This study investigated changes in the mutagenic activity of organic fractions from soil contaminated with polycyclic aromatic hydrocarbons (PAHs) during pilot-scale bioslurry remediation. Slurry samples were previously analyzed for changes in PAH and polycyclic aromatic compound content, and this study examined the correspondence between the chemical and toxicological metrics. Nonpolar neutral and semipolar aromatic fractions of samples obtained on days 0, 3, 7, 24, and 29 of treatment were assayed for mutagenicity using the Salmonella mutation assay. Most samples elicited a significant positive response on Salmonella strains TA98, YG1041, and YG1042 with and without S9 metabolic activation; however, TA100 failed to detect mutagenicity in any sample. Changes in the mutagenic activity of the fractions across treatment time and metabolic activation conditions suggests a pattern of formation and transformation of mutagenic compounds that may include a wide range of PAH derivatives such as aromatic amines, oxygenated PAHs, and S-heterocyclic compounds. The prior chemical analyses documented the formation of oxygenated PAHs during the treatment (e.g., 4-oxapyrene-5-one), and the mutagenicity analyses showed high corresponding activity in the semipolar fraction with and without metabolic activation. However, it could not be verified that these specific compounds were the underlying cause of the observed changes in mutagenic activity. The results highlight the need for concurrent chemical and toxicological profiling of contaminated sites undergoing remediation to ensure elimination of priority contaminants as well as a reduction in toxicological hazard. Moreover, the results imply that remediation efficacy and utility be evaluated using both chemical and toxicological metrics. Environ. Mol. Mutagen. 2009. © 2009 Wiley-Liss, Inc. PMID:19274766

  3. Silver: an age-old treatment modality in modern times.

    PubMed

    Spear, Marcia

    2010-01-01

    The use of silver as an antimicrobial for infection spans hundreds of years. The ancient Greeks and Romans used silver to disinfect their water and food supplies. Silver was also used in ancient times to treat burns and wounds as a wound dressing. Silver solutions were approved by the U.S. Food and Drug Administration in the 1920s. Since that time, silver has established itself as an effective and well-known treatment modality for and in the prevention of high-risk infection in clinical wound care (http://int.hansaplast.com/med-info/wound-care-beautiful-healing/silver-tech.html).

  4. The Microstructural Evolution of Inconel Alloy 740 During Solution Treatment, Aging, and Exposure at 760 °C

    SciTech Connect

    Cowen, Christopher J.; Danielson, Paul E.; Jablonski, Paul D.

    2010-08-10

    In this study, the microstructural evolution of Inconel alloy 740 during solution treatment and aging was characterized using optical and scanning electron microscopy. During double solution heat treatment, carbon is liberated from the dissolution of MC carbides during the first solution treatment at 1150 °C, and fine MC carbides are precipitated on gamma grain boundaries during the second solution treatment at 1120 °C. Due to the concurrent decrease in carbon solubility and the increase in the contribution of grain boundary diffusion at lower temperatures, the MC carbides on the gamma grain boundaries provide a localized carbon reservoir that aids in M23C6 carbide precipitation on gamma grain boundaries during exposure at 760 °C. The γ' phase, which is the key strengthening phase in alloy 740, is incorporated into the alloy microstructure during aging at 850 °C. Finally, the main source of microstructural instability observed during exposure at 760 °C was the coarsening of the γ' phase.

  5. Xylanase Treatment Suppresses Light- and Heat-Induced Yellowing of Pulp

    PubMed Central

    Zhang, Daolei; Li, Xuezhi; Wang, Meimei; Ye, Yanxin; Du, Jian; Lu, Xianqin; Zhao, Jian

    2016-01-01

    Xylanase is commonly applied in pulp and paper industries to ease cost-related and environmental pressures. The effect of xylanase treatment on pulp bleaching is well-established, however, few studies were conducted on the effects of xylanase treatment in pulp yellowing, especially the mechanism of pulp yellowing inhibition by xylanase treatment. In this study, pure xylanase (EC 3.2.1.8) was applied to treat wheat straw chemical pulp (CP) and poplar chemi-thermo-mechanical pulp (CTMP) to determine their effects on pulp brightness and on light- and heat-induced yellowing. The xylanase treatment decreased the post-color number of the pulps during light- and heat-induced yellowing. However, differences were observed in the yellowing inhibition between the wheat straw CP and poplar CTMP. The changes in chemical components of pulps after the xylanase treatment, for example, lignin, hemicellulose, and HexA contents, and analysis of UV–vis absorption spectra and Fourier transform infrared-attenuated total reflectance spectrum were used to explore the pulp yellowing inhibition causes by the xylanase treatment. PMID:27917912

  6. Biochemical and proteomic analysis of 'Dixiland' peach fruit (Prunus persica) upon heat treatment.

    PubMed

    Lara, María V; Borsani, Julia; Budde, Claudio O; Lauxmann, Martin A; Lombardo, Verónica A; Murray, Ricardo; Andreo, Carlos S; Drincovich, María F

    2009-01-01

    Shipping of peaches to distant markets and storage require low temperature; however, cold storage affects fruit quality causing physiological disorders collectively termed 'chilling injury' (CI). In order to ameliorate CI, different strategies have been applied before cold storage; among them heat treatment (HT) has been widely used. In this work, the effect of HT on peach fruit quality as well as on carbon metabolism was evaluated. When fruit were exposed to 39 degrees C for 3 d, ripening was delayed, with softening inhibition and slowing down of ethylene production. Several differences were observed between fruit ripening at ambient temperature versus fruit that had been heat treated. However, the major effects of HT on carbon metabolism and organoleptic characteristics were reversible, since normal fruit ripening was restored after transferring heated peaches to ambient temperature. Positive quality features such as an increment in the fructose content, largely responsible for the sweetness, and reddish coloration were observed. Nevertheless, high amounts of acetaldehyde and low organic acid content were also detected. The differential proteome of heated fruit was characterized, revealing that heat-induced CI tolerance may be acquired by the activation of different molecular mechanisms. Induction of related stress proteins in the heat-exposed fruits such as heat shock proteins, cysteine proteases, and dehydrin, and repression of a polyphenol oxidase provide molecular evidence of candidate proteins that may prevent some of the CI symptoms. This study contributes to a deeper understanding of the cellular events in peach under HT in view of a possible technological use aimed to improve organoleptic and shelf-life features.

  7. Surface analysis of TFTR vacuum vessel samples subjected to the post-weld heat treatment

    SciTech Connect

    Moore, R.L.; Cohen, S.A.; Cecchi, J.L.; Dylla, H.F.

    1980-11-01

    To ensure the dimensional stability of the Tokamak Fusion Test Reactor (TFTR) vacuum vessel, it is necessary to perform a post-weld heat treatment (PWHT). This process consists of heating the vessel segments to approx. 450/sup 0/C for 1.5 h. The large size of the segments precludes a vacuum bake previous to installation. Effects of the PWHT on the vacuum vessel surface were studied using small samples of vessel material which were subjected to a variety of PWHT procedures, including inert gas purges and different oven designs. Changes in topography and near-surface chemistry were investigated with SEM and sputter-Auger electron spectroscopy. These samples were compared with the surface properties of non-baked UHV-quality stainless steel. The primary difference noted between the PWHT samples and the non-baked control was the thickness of the passivation oxide layer. The thickness of this mixed oxide (FeO/Cr/sub 2/O/sub 3//NiO) on the control sample was less than or equal to 100 A. The thickness of the oxide layer on the heat-treated samples ranged between 230 to 350 A, depending on the method of the PWHT. The effect of hydrogen glow discharge cleaning on these thicker oxide layers, and the consequences of such heat treatment procedure relative to oxygen impurity production in fusion devices are discussed.

  8. The effect of heat treatment and skimming on precipitate formation in caprine and bovine milks.

    PubMed

    Miloradovic, Zorana N; Kljajevic, Nemanja V; Jovanovic, Snezana T; Vucic, Tanja R; Macej, Ognjen D

    2015-02-01

    Caprine and bovine milks have a similar overall gross composition, but vary considerably in the ratios of their casein components. These differences in colloidal casein micelles could affect directly or indirectly the heat stability of caprine and bovine milks at their natural pH. In the present work, the differences in colloidal stability of caprine and bovine milk have been studied by analysing the effect of heat treatment and skimming on precipitation of proteins. Raw and heated milk samples (70 °C/5 min, 80°C/5 min and 90°C/5 min) were centrifuged at 600, 2000, and 4500  g . The amount of precipitate formed after skimming was measured and the protein composition of both precipitates and supernatants analysed using the SDS-PAGE (sodium dodecyl sulphate polyacrylamide gel electrophoresis) and densitometry. In caprine milk, the heat treatment prior to skimming had a statistically significant effect on protein precipitation. Centrifugal force had a statistically significant effect on amount of precipitate for both milks, but the amount was 2 to 4 times higher for caprine milk. When defatting the milk for electrophoresis, a centrifugal force of 600  g appeared to be the most appropriate, in order to avoid protein loss and a possible error in the interpretation of results. Results of this study could also serve as the basis for further investigations on adjusting the skimming conditions for caprine milk in industrial dairy processing environment.

  9. Resistant starch improvement of rice starches under a combination of acid and heat-moisture treatments.

    PubMed

    Hung, Pham Van; Vien, Ngo Lam; Lan Phi, Nguyen Thi

    2016-01-15

    The effects of a combination of acid and heat-moisture treatment on formation of resistant starch (RS) and characteristics of high-amylose, normal and waxy rice starches were investigated in this study. The degrees of polymerization of the rice starches treated with citric acid, lactic acid or acetic acid were significantly reduced as compared to the native starches. The RS contents of acid and heat-moisture treated rice starches were in a range of 30.1-39.0%, significantly higher than those of native rice starches (6.3-10.2%) and those of heat-moisture treated rice starches (18.5-23.9%). The acid and heat-moisture treatments reduced swelling power and viscosity, but increased solubility of the starches, while the crystalline structure did not change. Among the organic acids used, citric acid had the most impact on starch characteristics and RS formation, followed by lactic acid and acetic acid. The results are useful in production of RS for functional food application.

  10. Using Finite Element Simulation to Optimize the Heat Treatment of Tire Protection Chains

    NASA Astrophysics Data System (ADS)

    Eck, S.; Prevedel, P.; Marsoner, S.; Ecker, W.; Illmeier, M.

    2014-04-01

    The heat treatment of tire protection chains has a major influence on the final product because the high local stresses that arise during quenching may lead to material failure, i.e., quench cracks. The investigations presented in this paper aim at the identification of critical areas in the design of a tire chain link made of 50CrV4 (DIN 1.8159) steel. Parametric studies were conducted by means of finite element (FE) simulation. The FE model enables the calculation of the stress evolution in the chain link during heat treatment. The position of the cracks produced in laboratory quench experiments coincided with the position where the FE simulation model predicted the maximum tensile stress at the end of the quench. Hence, geometry optimization of the chain links is now possible by means of parametric FE studies aiming to minimize these tensile stresses. To identify the influence of the various input parameters on the calculated stress evolution during the quenching, a sensitivity analysis was performed. The influence of the mesh size, the heat transfer at the surface, and the thermo-mechanical properties of the material phases on the stress calculation was evaluated and trends were identified. Temperature measurements during quenching experiments were used to determine the heat transfer parameters. X-ray residual stress measurements on pre-defined positions after an instrumented laboratory quenching were used to validate the simulation results.

  11. Effects of heat treatment on oil-binding ability of rice flour.

    PubMed

    Tabara, Aya; Nakagawa, Mariko; Ushijima, Yuki; Matsunaga, Kotaro; Seguchi, Masaharu

    2015-01-01

    Heat-treated (120 °C for 120 min) rice flour showed high affinity to oil (oil-binding ability). This oil-binding ability could be observed by shaking the heat-treated rice flour (2.0 g), oil (4.0 mL), and water (20 mL) vigorously in a test tube, and the oil bound to the rice flour sank into the water. To examine the time-dependent levels of the oil-binding ability, rice flour was heat-treated at 120 °C for 10, 20, 40, 60, and 120 min, and the precipitated volume of oil/rice flour complex increased with an increase of the heating time. The oil-binding ability of the rice flour was not affected by the treatments with diethyl ether or boiled chloroform/methanol (2:1) solutions, which suggested no relationship to the oil in the rice flour, but was lost upon alkali (0.2% NaOH solution) or pepsin treatment, which suggested its relationship to the rice proteins.

  12. Heat treatment's effects on hydroxyapatite powders in water vapor and air atmosphere

    NASA Astrophysics Data System (ADS)

    Karabulut, A.; Baştan, F. E.; Erdoǧan, G.; Üstel, F.

    2015-03-01

    Hydroxyapatite (HA; Ca10(PO4)6(OH)2) is the main chemical constituent of bone tissue (~70%) as well as HA which is a calcium phosphate based ceramic material forms inorganic tissue of bone and tooth as hard tissues is used in production of prosthesis for synthetic bone, fractured and broken bone restoration, coating of metallic biomaterials and dental applications because of its bio compatibility. It is known that Hydroxyapatite decomposes with high heat energy after heat treatment. Therefore hydroxyapatite powders that heated in water vapor will less decomposed phases and lower amorphous phase content than in air atmosphere. In this study high purity hydroxyapatite powders were heat treated with open atmosphere furnace and water vapor atmosphere with 900, 1000, 1200 °C. Morphology of same powder size used in this process by SEM analyzed. Chemical structures of synthesized coatings have been examined by XRD. The determination of particle size and morphological structure of has been characterized by Particle Sizer, and SEM analysis, respectively. Weight change of sample was recorded by thermogravimetric analysis (TGA) during heating and cooling.

  13. Effect of heat treatment upon the fatigue-crack growth behavior of Alloy 718 weldments

    SciTech Connect

    Mills, W.J.; James, L.A.

    1981-05-01

    The microstructural features that influenced the room and elevated temperature fatigue-crack growth behavior of as-welded, conventional heat-treated, and modified heat-treated Alloy 718 GTA weldments were studied. Electron fractographic examination of fatigue fracture surfaces revealed that operative fatigue mechanisms were dependent on microstructure, temperatures and stress intensity factor. All specimens exhibited three basic fracture surface appearances at temperatures up to 538{degrees}C: crystallographic faceting at low stress intensity range ({Delta}K) levels, striation, formation at intermediate values, and dimples coupled with striations in the highest ({Delta}K) regime. At 649{degrees}C, the heat-treated welds exhibited extensive intergranular cracking. Laves and {delta} particles in the conventional heat-treated material nucleated microvoids ahead of the advancing crack front and caused on overall acceleration in crack growth rates at intermediate and high {Delta}K levels. The modified heat treatment removed many of these particles from the weld zone, thereby improving its fatigue resistance. The dramatically improved fatigue properties exhibited by the as-welded material was attributed to compressive residual stresses introduced by the welding process. 19 refs., 16 figs.

  14. Distinguishing between heating power and hyperthermic cell-treatment efficacy in magnetic fluid hyperthermia.

    PubMed

    Munoz-Menendez, Cristina; Conde-Leboran, Ivan; Serantes, David; Chantrell, Roy; Chubykalo-Fesenko, Oksana; Baldomir, Daniel

    2016-11-04

    In the magnetic fluid hyperthermia (MFH) research field, it is usually assumed that achieving a uniform temperature enhancement (ΔT) of the entire tumour is a key-point for treatment. However, various experimental works reported successful cell apoptosis via MFH without a noticeable ΔT of the system. A possible explanation of the success of these negligible-ΔT experiments is that a local ΔT restricted to the particle nanoenvironment (i.e. with no significant effect on the global temperature T) could be enough to trigger cell death. Shedding light on such a possibility requires accurate knowledge of heat dissipation at the local level in relation to the usually investigated global (average) one. Since size polydispersity is inherent to all synthesis techniques and the heat released is proportional to the particle size, heat dissipation spots with different performances - and thus different effects on the cells - will likely exist in every sample. In this work we aim for a double objective: (1) to emphasize the necessity to distinguish between the total dissipated heat and hyperthermia effectiveness, and (2) to suggest a theoretical approach on how to select, for a given size polydispersity, a more adequate average size so that most of the particles dissipate within a desired heating power range. The results are reported in terms of Fe3O4 nanoparticles as a representative example.

  15. The effect of age on the synthesis of two heat shock proteins in the hsp70 family.

    PubMed

    Wu, B; Gu, M J; Heydari, A R; Richardson, A

    1993-03-01

    Hepatocytes isolated from male F344 rats were exposed to elevated temperatures (40 degrees C to 45 degrees C), and the incorporation of [35S]-L-methionine into proteins was measured from fluorograms of two-dimensional polyacrylamide gels. The synthesis of two proteins was induced by temperatures of 40 degrees C to 42.5 degrees C; however, 45 degrees C inhibited the synthesis of all proteins. Based on their apparent molecular weights and pI values and their recognition by a monoclonal antibody to the HSP70 gene family, the two proteins induced by hyperthermia were found to be the highly heat-inducible hsp70 and the constitutive hsc70. Because a heat shock of 42.5 degrees C for 30 minutes had very little effect on cell viability and induced the synthesis of hsp70 and hsc70, this heat shock was used to study the effect of age on the ability of hepatocytes to respond to the stress of hyperthermia. Neither hepatocytes isolated from young adult (5-7 months) nor old (25-27 months) rats synthesized detectable amounts of hsp70 when incubated at 37 degrees C. However, heat shock induced the synthesis of both hsp70 and hsc70 in hepatocytes isolated from young adult and old rats. The induction of hsp70 synthesis was significantly lower (37%) for hepatocytes isolated from old rats compared to hepatocytes isolated from young adult rats. However, neither the basal level nor the induced level of hsc70 synthesis changed significantly with age. Thus, aging resulted in a decrease in the ability of hepatocytes to synthesize hsp70 in response to hyperthermia; this effect, however, was specific for hsp70.

  16. Dry-heat treatment process for enhancing viral safety of an antihemophilic factor VIII concentrate prepared from human plasma.

    PubMed

    Kim, In Seop; Choi, Yong Woon; Kang, Yong; Sung, Hark Mo; Shin, Jeong Sup

    2008-05-01

    Viral safety is a prerequisite for manufacturing clinical antihemophilic factor VIII concentrates from human plasma. With particular regard to the hepatitis A virus (HAV), a terminal dry-heat treatment (100 degrees for 30 min) process, following lyophilization, was developed to improve the virus safety of a solvent/detergent-treated antihemophilic factor VIII concentrate. The loss of factor VIII activity during dry-heat treatment was of about 5%. No substantial changes were observed in the physical and biochemical characteristics of the dry-heat-treated factor VIII compared with those of the factor VIII before dry-heat treatment. The dry-heat-treated factor VIII was stable for up to 24 months at 4oC. The dry-heat treatment after lyophilization was an effective process for inactivating viruses. The HAV, murine encephalomyocarditis virus (EMCV), and human immunodeficiency virus (HIV) were completely inactivated to below detectable levels within 10 min of the dry-heat treatment. Bovine herpes virus (BHV) and bovine viral diarrhea virus (BVDV) were potentially sensitive to the treatment. However porcine parvovirus (PPV) was slightly resistant to the treatment. The log reduction factors achieved during lyophilization and dry-heat treatment were > or =5.55 for HAV, > or =5.87 for EMCV, > or =5.15 for HIV, 6.13 for BHV, 4.46 for BVDV, and 1.90 for PPV. These results indicate that dry-heat treatment improves the virus safety of factor VIII concentrates, without destroying the activity. Moreover, the treatment represents an effective measure for the inactivation of non-lipid-enveloped viruses, in particular HAV, which is resistant to solvent/detergent treatment.

  17. In situ heat treatment of a tar sands formation after drive process treatment

    DOEpatents

    Vinegar, Harold J.; Stanecki, John

    2010-09-21

    A method for treating a tar sands formation includes providing a drive fluid to a hydrocarbon containing layer of the tar sands formation to mobilize at least some hydrocarbons in the layer. At least some first hydrocarbons from the layer are produced. Heat is provided to the layer from one or more heaters located in the formation. At least some second hydrocarbons are produced from the layer of the formation. The second hydrocarbons include at least some hydrocarbons that are upgraded compared to the first hydrocarbons produced by using the drive fluid.

  18. Fluorine redistribution in a chemical vapor deposited tungsten/polycrystalline silicon gate structure during heat treatment

    NASA Astrophysics Data System (ADS)

    Eriksson, Th.; Carlsson, J.-O.; Keinonen, J.; Petersson, C. S.

    1988-09-01

    Fluorine redistribution during heat treatment of chemical vapor deposited tungsten/polycrystalline silicon gate structures was analyzed by the nuclear resonance broadening technique. The tungsten layer was deposited from a hydrogen/tungsten hexafluoride gas mixture. Upon heat treatment in the temperature range 1020-1325-K tungsten disilicide formation was observed using Rutherford backscattering spectrometry. In the as-deposited sample, the fluorine was accumulated at the tungsten/polycrystalline silicon interface. After silicide formation the fluorine was observed at the tungsten disilicide/polycrystalline silicon interface. At temperatures above 1120 K fluorine starts to diffuse through the polycrystalline silicon layer. A variation in the total fluorine content between the samples was also observed. The origin of the fluorine redistribution as well as the variation in the total fluorine content is discussed in connection to conceivable mechanisms.

  19. Fluorine redistribution in a chemical vapor deposited tungsten/polycrystalline silicon gate structure during heat treatment

    SciTech Connect

    Eriksson, T.; Carlsson, J.; Keinonen, J.; Petersson, C.S.

    1988-09-15

    Fluorine redistribution during heat treatment of chemical vapor deposited tungsten/polycrystalline silicon gate structures was analyzed by the nuclear resonance broadening technique. The tungsten layer was deposited from a hydrogen/tungsten hexafluoride gas mixture. Upon heat treatment in the temperature range 1020--1325-K tungsten disilicide formation was observed using Rutherford backscattering spectrometry. In the as-deposited sample, the fluorine was accumulated at the tungsten/polycrystalline silicon interface. After silicide formation the fluorine was observed at the tungsten disilicide/polycrystalline silicon interface. At temperatures above 1120 K fluorine starts to diffuse through the polycrystalline silicon layer. A variation in the total fluorine content between the samples was also observed. The origin of the fluorine redistribution as well as the variation in the total fluorine content is discussed in connection to conceivable mechanisms.

  20. Influence of Heat Treatment Conditions on the Properties of Vanadium Oxide Thin Films for Thermochromic Applications.

    PubMed

    Kim, Donguk; Kwon, Samyoung; Park, Young; Boo, Jin-Hyo; Nam, Sang-Hun; Joo, Yang Tae; Kim, Minha; Lee, Jaehyeong

    2016-05-01

    In present work, the effects of the heat treatment on the structural, optical, and thermochromic properties of vanadium oxide films were investigated. Vanadium dioxide (VO2) thin films were deposited on glass substrate by reactive pulsed DC magnetron sputtering from a vanadium metal target in mixture atmosphere of argon and oxygen gas. Various heat treatment conditions were applied in order to evaluate their influence on the crystal phases formed, surface morphology, and optical properties. The films were characterized by an X-ray diffraction (XRD) in order to investigate the crystal structure and identify the phase change as post-annealing temperature of 500-600 degrees C for 5 minutes. Surface conditions of the obtained VO2(M) films were analyzed by field emission scanning electron microscopy (FE-SEM) and the semiconductor-metal transition (SMT) characteristics of the VO2 films were evaluate by optical spectrophotometry in the UV-VIS-NIR, controlling temperature of the films.

  1. Effects of erodant particle shape and various heat treatments on erosion resistance of plain carbon steel

    NASA Technical Reports Server (NTRS)

    Salik, J.; Buckley, D. H.

    1981-01-01

    Erosion tests were conducted on 1045 steel samples which had been subjected to different heat treatments. The weight of material removed upon erosion with glass beads and crushed glass was measured. The data show that there is no correlation between hardness and erosion resistance. The erosion rate was strongly dependent on the shape of erodant particles, being an order of magnitude higher for erosion with crushed glass than with glass beads. Heat treatment had a profound effect on the erosion resistance when the erodant particles were glass beads but little or no effect when the particles were crushed glass. It is thus concluded that different mechanisms of material removal are involved with these two erodants. This conclusion is supported by the surface morphology of annealed 1045 steel samples which had been eroded by these two types of erodant particles. SEM micrographs of the eroded surfaces show that for erosion with glass beads it is deformation induced fracture of surface layers.

  2. SO2 gas adsorption by modified kaolin clays: influence of previous heating and time acid treatments.

    PubMed

    Volzone, Cristina; Ortiga, Jose

    2011-10-01

    Modified kaolin clays were used as adsorbents for SO(2) gas adsorptions. The clays were heated up to 900 °C previous to acid treatments with 0.5 N sulfuric acid solutions at boiling temperature during different times up to 1440 min. Equilibrium adsorption at 25 °C and 0.1 MPa was carried out by using a volumetric apparatus. The samples were characterized by chemical analysis, X-ray diffraction and infrared analysis. The heating of the clays followed by acid treatment improved the adsorption capacity of the kaolin clays. The presence of amorphous silica and hydroxyl in the final products improved SO(2) adsorption capacity. Better properties for SO(2) adsorption were found in kaolin rich in not well ordered kaolinite clay mineral.

  3. The effects of heat treatment on physical properties and surface roughness of red-bud maple (Acer trautvetteri Medw.) wood.

    PubMed

    Korkut, Derya Sevim; Guller, Bilgin

    2008-05-01

    Heat treatment is often used to improve the dimensional stability of wood. In this study, the effects of heat treatment on physical properties and surface roughness of red-bud maple (Acer trautvetteri Medw.) wood were examined. Samples obtained from Düzce Forest Enterprises, Turkey, were subjected to heat treatment at varying temperatures and durations. The physical properties of heat-treated samples were compared against controls in order to determine their; oven-dry density, air-dry density, and swelling properties. A stylus method was employed to evaluate the surface characteristics of the samples. Roughness measurements, using the stylus method, were made in the direction perpendicular to the fiber. Three main roughness parameters; mean arithmetic deviation of profile (Ra), mean peak-to-valley height (Rz), and maximum roughness (Rmax) obtained from the surface of wood, were used to evaluate the effect of heat treatment on the surface characteristics of the specimens. Significant differences were determined (p>0.05) between surface roughness parameters (Ra, Rz, Rmax) at three different temperatures and three periods of heat treatment. The results showed that the values of density, swelling and surface roughness decreased with increasing temperature treatment and treatment times. Red-bud maple wood could be utilized successfully by applying proper heat treatment techniques without any losses in investigated parameters. This is vital in areas, such as window frames, where working stability and surface smoothness are important factors.

  4. New approaches and potential treatments for dry age-related macular degeneration.

    PubMed

    Damico, Francisco Max; Gasparin, Fabio; Scolari, Mariana Ramos; Pedral, Lycia Sampaio; Takahashi, Beatriz Sayuri

    2012-01-01

    Emerging treatments for dry age-related macular degeneration (AMD) and geographic atrophy focus on two strategies that target components involved in physiopathological pathways: prevention of photoreceptors and retinal pigment epithelium loss (neuroprotection induction, oxidative damage prevention, and visual cycle modification) and suppression of inflammation. Neuroprotective drugs, such as ciliary neurotrophic factor, brimonidine tartrate, tandospirone, and anti-amyloid β antibodies, aim to prevent apoptosis of retinal cells. Oxidative stress and depletion of essential micronutrients are targeted by the Age-Related Eye Disease Study (AREDS) formulation. Visual cycle modulators reduce the activity of the photoreceptors and retinal accumulation of toxic fluorophores and lipofuscin. Eyes with dry age-related macular degeneration present chronic inflammation and potential treatments include corticosteroid and complement inhibition. We review the current concepts and rationale of dry age-related macular degeneration treatment that will most likely include a combination of drugs targeting different pathways involved in the development and progression of age-related macular degeneration.

  5. The ability of lens alpha crystallin to protect against heat-induced aggregation is age-dependent

    NASA Technical Reports Server (NTRS)

    Horwitz, J.; Emmons, T.; Takemoto, L.; Spooner, B. S. (Principal Investigator)

    1992-01-01

    Alpha crystallin was prepared from newborn and aged bovine lenses. SDS-PAGE and tryptic peptide mapping demonstrated that both preparations contained only the alpha-A and alpha-B chains, with no significant contamination of other crystallins. Compared with alpha crystallin from the aged lens, alpha crystallin from the newborn lens was much more effective in the inhibition of beta L crystallin denaturation and precipitation induced in vitro by heat. Together, these results demonstrate that during the aging process, the alpha crystallins lose their ability to protect against protein denaturation, consistent with the hypothesis that the alpha crystallins play an important role in the maintenance of protein native structure in the intact lens.

  6. Integrated modelling of transitions in mechanical conditions during casting and heat treatment

    NASA Astrophysics Data System (ADS)

    Thorborg, J.; Klinkhammer, J.; Heitzer, M.

    2015-06-01

    The mechanical material behaviour of a cast component changes significantly during casting and heat treatment. The big difference in temperature levels during the different process steps causes different deformation mechanisms to be active. The thermal gradients promote transient stresses that can lead to inelastic deformations, residual stresses and in some cases to defects in the final part. It is a big challenge to make a reasonable transition in the mechanical model, and hence material data, when modelling several different coupled process steps. It is important to use an integrated approach where the transition is included in the full load history of the part. When industrial examples are considered, the sequence of process steps typically also changes the thermal and mechanical boundary conditions significantly e.g. going from being mechanically constrained during casting to being supported point-wise during the heat treatment process. This change includes mapping of results and obtaining equilibrium in a new global system, where the further reaction forces from the supports must be handled with contact conditions to e.g. predict deformations due to gravity during solution heat treatment. The work presented in this paper is focused on modelling the mechanical fields, taking into account the changes in the mechanical material model at different temperature levels, and the transition in mechanical behaviour when the microstructure is changing during the different steps of the heat treatment process. The approach used is based on a unified model where creep effects are considered at high temperature and rate effects are included in general during cooling. Proposals are made to include cooling rate sensitivity, annealing and precipitation hardening via modification of mechanical properties in the different process steps.

  7. Induction heat treatment and technique of bioceramic coatings production on medical titanium alloys

    NASA Astrophysics Data System (ADS)

    Fomin, Aleksandr A.; Rodionov, Igor V.; Fomina, Marina A.; Poshivalova, Elena Y.; Krasnikov, Aleksandr V.; Petrova, Natalia N.; Zakharevich, Andrey M.; Skaptsov, Alexander A.; Gribov, Andrey N.; Atkin, Vsevolod S.

    2015-03-01

    Prospective composite bioceramic titania coatings were obtained on intraosseous implants fabricated from medical titanium alloy VT16 (Ti-2.5Al-5Mo-5V). Consistency changes of morphological characteristics, physico-mechanical properties and biocompatibility of experimental titanium implant coatings obtained by oxidation during induction heat treatment are defined. Technological recommendations for obtaining bioceramic coatings with extremely high strength on titanium items surface are given.

  8. Numerical simulation of thermal disposition with induction heating used for oncological hyperthermic treatment.

    PubMed

    Dughiero, F; Corazza, S

    2005-01-01

    Hyperthermia plays an important role in oncological therapies, most often being used in combination with radiotherapy, chemotherapy and immunotherapy. The success of this therapy is strongly dependent on the precision and control of thermal deposition. Hyperthermia based on induction heating, with thermally self-regulating thermoseeds inserted into the tumorous mass, is used for interstitial treatment. The technique was the subject of the numerical study presented in the paper. The analysis was carried out using coupled electromagnetic heating and thermo-fluid dynamic FEM simulations. During thermal deposition by induction heating of inserted seeds, the simulations estimated the thermal field inside and outside the tumour, as well as the sensitivity of the thermal field to variations regarding seed temperature, configuration and proximity to vessels. The method, for which accurate anatomical patient's information is essential, is suitable for providing useful qualitative and quantitative information about thermal transients and power density distribution for hyperthermic treatment. Several grid steps were analysed and compared. A 1 cm seed grid was resulted in good homogeneity and effectiveness of the thermal deposition. The cold spot effect caused by large vessels was demonstrated and quantified. Simulations of the heating of a tumorous mass in the liver showed that an indcutor generator operating at 200 kHz frequency and 500 A current, producing a pulsating magnetic field of H = 60 A cm(-1), was adequate for the treatment. The seeds that perform best among those tested (Nicu (28% Cu), PdNi (27.2% Ni), PdCo (6.15% Co) and ferrite core) were the PdNi (1 mm radius, 10 mm length), as they have a low Curie temperature (52 degrees C), which is the closest to the desired treatment temperature and thus reduces the risk of hot spots.

  9. Physicomechanical properties of spring steel 70S2KhA after different heat treatments

    SciTech Connect

    Kuznetsov, I.A.; Rodionova, S.S.; Nikiforov, A.P.

    1995-10-01

    We have studied the magnetic, electrical, thermoelectric, and mechanical properties of steel 70S2KhA as a function of various quenching and tempering conditions. We examine the effect of a change in the chemical composition (within the grade limits) on the physical properties of the steel and the conditions for monitoring the heat treatment for the example of the coercive force, the relaxation coercive force, and the magnetic susceptibility.

  10. The effect of heat treatment on the resistivity of polycrystalline silicon films

    NASA Technical Reports Server (NTRS)

    Fripp, A. L., Jr.

    1975-01-01

    The resistivity of doped polycrystalline silicon films has been studied as a function of post deposition heat treatments in an oxidizing atmosphere. It was found that a short oxidation cycle may produce a resistivity increase as large as three orders of magnitude in the polycrystalline films. The extent of change was dependent on the initial resistivity and the films' doping level and was independent of the total oxidation time.

  11. Endotoxin inactivation via steam-heat treatment in dilute simethicone emulsions used in biopharmaceutical processes.

    PubMed

    Britt, Keith A; Galvin, Jeffrey; Gammell, Patrick; Nti-Gyabaah, Joseph; Boras, George; Kolwyck, David; Ramirez, José G; Presente, Esther; Naugle, Gregory

    2014-01-01

    Simethicone emulsion is used to regulate foaming in cell culture operations in biopharmaceutical processes. It is also a potential source of endotoxin contamination. The inactivation of endotoxins in dilute simethicone emulsions was assessed as a function of time at different steam temperatures using a Limulus amebocyte lysate kinetic chromogenic technique. Endotoxin inactivation from steam-heat treatment was fit to a four-parameter double exponential decay model, which indicated that endotoxin inactivation was biphasic, consisting of fast and slow regimes. In the fast regime, temperature-related effects were dominant. Transitioning into the slow regime, the observed temperature dependence diminished, and concentration-related effects became increasingly significant. The change in the Gibbs free energy moving through the transition state indicated that a large energy barrier must be overcome for endotoxin inactivation to occur. The corresponding Arrhenius pre-exponential factor was >10(12) s(-1) suggesting that endotoxins in aqueous solution exist as aggregates. The disorder associated with the endotoxin inactivation reaction pathway was assessed via the change in entropy moving through the transition state. This quantity was positive indicating that endotoxin inactivation may result from hydrolysis of individual endotoxin molecules, which perturbs the conformation of endotoxin aggregates, thereby modulating the biological activity observed. Steam-heat treatment decreased endotoxin levels by 1-2 logarithm (log) reduction (LRV), which may be practically relevant depending on incoming raw material endotoxin levels. Antifoam efficiency and cell culture performance were negligibly impacted following steam-heat treatment. The results from this study show that steam-heat treatment is a viable endotoxin control strategy that can be implemented to support large-scale biopharmaceutical manufacturing.

  12. Age-related changes of antioxidant enzyme activities, glutathione status and lipid peroxidation in rat erythrocytes after heat stress.

    PubMed

    Oztürk, Oğuz; Gümüşlü, Saadet

    2004-08-13

    The aim of this study was to determine whether exposure to heat stress would lead to oxidative stress and whether this effect varied with different exposure periods. We kept 1-, 6- and 12-month-old male Wistar rats at an ambient temperature of either 22 degrees C or 40 degrees C for 3 and 7 days and measured glucose-6-phosphate dehydrogenase (G-6-PD), Cu,Zn-superoxide dismutase (Cu,Zn-SOD), catalase (CAT), selenium-dependent glutathione peroxidase (Se-GSH-Px) and glutathione-S-transferase (GST) activities and levels of thiobarbituric acid-reactive substances (TBARS), reduced glutathione (GSH) and oxidized glutathione (GSSG) in erythrocytes and determined GSH/GSSG ratio, total glutathione and the redox index. G-6-PD and CAT activities were found to be significantly increased in 1- and 6-month-old rats after 3 and 7 days of heat stress, but G-6-PD activities decreased in 12-month-old rats. Cu, Zn-SOD activity decreased in 1-month-old rats after heat stress, whereas it increased in 6- and 12-month-old rats. GST activity increased in all groups. GSH and total GSH levels and GSH/GSSG ratios decreased in 1- and 6-month-old rats but they increased in 12-month-old rats after heat stress. GSSG levels increased in 1- and 6-month-old rats but decreased in 12-month-old rats after heat stress. TBARS levels increased in all groups. Seven days of stress is more effective in altering enzyme activities and levels of GSH, GSSG and TBARS. When the effects of both heat stress and aging were examined together, it was interesting to note that they mostly influenced G-6-PD activity.

  13. The influence of heat treatment on properties of cold rolled alloyed steel and nickel superalloys sheets used in aircraft industry

    NASA Astrophysics Data System (ADS)

    Zaba, K.; Dul, I.; Puchlerska, S.

    2017-02-01

    Superalloys based on nickel and selected steels are widely used in the aerospace industry, because of their excellent mechanical properties, heat resistance and creep resistance. Metal sheets of these materials are plastically deformed and applied, inter alia, to critical components of aircraft engines. Due to their chemical composition these materials are hardly deformable. There are various methods to improve the formability of these materials, including plastic deformation at an elevated or high temperature, or a suitable heat treatment before forming process. The paper presents results of the metal sheets testing after heat treatment. For the research, sheets of two types of nickel superalloys type Inconel and of three types of steel were chosen. The materials were subjected to multivariate heat treatment at different temperature range and time. After this step, mechanical properties were examined according to the metal sheet rolling direction. The results were compared and the optimal type of pre-trial softening heat treatment for each of the materials was determined.

  14. Simple Heat Treatment of Zirconia Ceramic Pre-Treated with Silane Primer to Improve Resin Bonding.

    PubMed

    Ha, Jung-Yun; Son, Jun Sik; Kim, Kyo-Han; Kwon, Tae-Yub

    2015-01-01

    Establishing a strong resin bond to dental zirconia ceramic remains difficult. Previous studies have shown that the conventional application of silane does not work well with zirconia. This paper reports that a silane pre-treatment of dental zirconia ceramic combined with subsequent heat treatment has potential as an adhesive cementation protocol for improving zirconia-resin bonding. Among the various concentrations (0.1 to 16 vol%) of experimental γ-methacryloxypropyltrimethoxysilane (γ-MPTS) primers assessed, the 1% solution was found to be the most effective in terms of the shear bond strength of the resin cement to dental zirconia ceramic. A high shear bond strength (approx. 30 MPa) was obtained when zirconia specimens were pre-treated with this primer and then heat-treated in a furnace for 60 min at 150 degrees C. Heat treatment appeared to remove the hydrophilic constituents from the silane film formed on the zirconia ceramic surface and accelerate the condensation reactions between the silanol groups of the hydrolyzed silane molecules at the zirconia/resin interface, finally making a more desirable surface for bonding with resin. This estimation was supported by Fourier transform infrared spectroscopy of the silanes prepared in this study.

  15. Microstructural Evaluation of KM4 and SR3 Samples Subjected to Various Heat Treatments

    NASA Technical Reports Server (NTRS)

    Ellis, David; Gabb, Timothy; Garg, Anita

    2004-01-01

    The gamma-gamma microstructures of two advanced powder metallurgy disk alloys, KM4 and SR3, were quantified after a series of heat treatments using transmission electron microscopy and image analysis. Relationships between the heat treatments and the resulting gamma distributions were evaluated. Statistical correlations between the gamma distributions and the reported tensile strengths, creep resistances, and dwell crack growth resistances were separately assessed for each alloy. To avoid the effects of grain size related mechanisms, the grain size of the samples used in the correlations for each alloy were limited to narrow ranges of about 1.5 in ASTM grain size number. In both alloys, yield and tensile strength increased with increasing fraction of medium sized gamma. The strength increased as the size of the medium gamma decreased and the size of the fine gamma increased. Time to 0.2 percent creep in SR3 increased with increasing medium gamma volume fraction, and decreasing fine gamma sizes. However, 0.2 percent creep time was not clearly correlated with the gamma microstructures of KM4 specimens, apparently due to effects of stabilization heat treatments which greatly suppress creep resistance. Dwell fatigue crack growth rate decreased with increasing medium gamma volume fraction, indicating more medium gamma is beneficial. The crack growth rate also decreased with decreasing gamma size, indicating finer gamma is better.

  16. Effects of heat treatment on physical, microstructural and optical characteristics of PbS luminescent nanocrystals

    NASA Astrophysics Data System (ADS)

    Mozafari, Masoud; Moztarzadeh, Fathollah; Vashaee, Dayoosh; Tayebi, Lobat

    2012-04-01

    The oxidation of lead sulfide (PbS) luminescent nanocrystals (NCs) considerably changes their luminescence characteristics. Hence, an understanding of the oxidation mechanism, the structure and properties of oxidized moieties is important. In this research, well-defined spherical PbS NCs were synthesized via a simple, effective and surfactant-free method and characterized. Then, the effects of heat treatment (at 250, 350, 450 and 550 °C) on the PbS NCs were investigated. The transmission electron microscope (TEM) micrographs of the synthesized PbS NCs revealed that they had a well-defined spherical morphology. In addition, the average crystallite size using Scherrer's formula was about 13 nm and the calculated lattice constant using Bragg's equation was 0.5950 nm, which was very close to the value in the standard card (JCPDS No. 5-592). Furthermore, the X-ray diffraction (XRD) revealed that the heat treatment of samples at temperatures of 250, 350,450 and 550 °C in air results in the formation of oxide sulfate phase of the compositions PbSO4 and PbO·PbSO4. The lattice parameter, crystallite size, average internal stress, micro-strain and optical properties of PbS NCs were calculated and correlated with the heat-treatment temperature.

  17. Histone modifications change with age, dietary restriction and rapamycin treatment in mouse brain

    PubMed Central

    Gong, Huan; Qian, Hong; Ertl, Robin; Astle, Clinton M.; Wang, Gang G.; Harrison, David E.; Xu, Xiangru

    2015-01-01

    The risk of developing neurodegenerative disorders such as Alzheimer's disease (AD) increases dramatically with age. Understanding the underlying mechanisms of brain aging is crucial for developing preventative and/or therapeutic approaches for age-associated neurological diseases. Recently, it has been suggested that epigenetic factors, such as histone modifications, maybe be involved in brain aging and age-related neurodegenerations. In this study, we investigated 14 histone modifications in brains of a cohort of young (3 months), old (22 months), and old age-matched dietary restricted (DR) and rapamycin treated BALB/c mice. Results showed that 7 out of all measured histone markers were changed drastically with age. Intriguingly, histone methylations in brain tissues, including H3K27me3, H3R2me2, H3K79me3 and H4K20me2 tend to disappear with age but can be partially restored by both DR and rapamycin treatment. However, both DR and rapamycin treatment also have a significant impact on several other histone modifications such as H3K27ac, H4K16ac, H4R3me2, and H3K56ac, which do not change as animal ages. This study provides the first evidence that a broad spectrum of histone modifications may be involved in brain aging. Besides, this study suggests that both DR and rapamycin may slow aging process in mouse brain via these underlying epigenetic mechanisms. PMID:26021816

  18. Impact of heat treatment and oxidation of Carbon-carbon composites on microstructure and physical properties

    NASA Astrophysics Data System (ADS)

    Iqbal, Sardar Sarwat

    Carbon-carbon (C/C) composites are notable among engineering materials in aerospace and defense industries possessing excellent specific mechanical, thermal, frictional and wear properties. C/C maintain their properties at temperatures where most of the high end alloys give in, and maintain their dimensional stability at temperatures above 2000 °C. C/C is frequently used in aircraft and automotive industries as brake materials. However, frictional performance is dependent on various parameters: microstructure, fiber type, fiber orientation distribution, fiber/matrix interfacial bond, heat treatment, and oxidation. The present study in dissertation provides an insight into the impact of heat treatment, and oxidation on microstructure, mechanical and thermal properties. The heat treatment (performed at 1800, 2100, 2400 °C in argon) of two-directional (2-D) pitch-fiber with charred resin carbon matrix, and three-directional (3-D) PAN-fiber with CVI carbon matrix influenced microstructure, mechanical and thermal properties. Microstructure characterized by polarized light microscopy (PLM), XRD, and Raman spectroscopy changed with increasing heat treatment temperature. The RL microstructure of 3-D C/C progressively highly organized, whereas ISO microstructure of 2-D C/C's charred resin hardly organized into an ordered structure as evident from Raman spectroscopy and Raman profiling of polished samples. Pitch-fiber organized more than the ISO microstructure of charred resin matrix. On the other, PAN-fiber became more ordered, but was organization was lower than pitch-fiber. Thermal conductivity increased for both (2-D, 3-D C/C) materials in comparison to non-heat treated (NHT) C/Cs. Thermal conductivity of oxidized samples decreased significantly than non-oxidized samples. In-plane thermal conductivity of 3-D C/C was much higher than that of 2-D C/C, and was attributed to the rough laminar (RL) microstructure of carbon matrix and continuous PAN-fiber when compared to

  19. Heat treatment following surface silanization in rebonded tribochemical silica-coated ceramic brackets: shear bond strength analysis

    PubMed Central

    SILVA, Emilia Adriane; TRINDADE, Flávia Zardo; RESKALLA, Hélcio Nagib José Feres; de QUEIROZ, José Renato Cavalcanti

    2013-01-01

    Objective This study aimed to evaluate the effects of heat treatment on the tribochemical silica coating and silane surface conditioning and the bond strength of rebonded alumina monocrystalline brackets. Material and Methods Sixty alumina monocrystalline brackets were randomly divided according to adhesive base surface treatments (n=20): Gc, no treatment (control); Gt, tribochemical silica coating + silane application; Gh, as per Gt + post-heat treatment (air flux at 100ºC for 60 s). Brackets were bonded to the enamel premolars surface with a light-polymerized resin and stored in distilled water at 37ºC for 100 days. Additionally, half the specimens of each group were thermocycled (6,000 cycles between 5-55ºC) (TC). The specimens were submitted to the shear bond strength (SBS) test using a universal testing machine (1 mm/min). Failure mode was assessed using optical and scanning electron microscopy (SEM), together with the surface roughness (Ra) of the resin cement in the bracket using interference microscopy (IM). 2-way ANOVA and the Tukey test were used to compare the data (p>0.05). Results The strategies used to treat the bracket surface had an effect on the SBS results (p=0.0), but thermocycling did not (p=0.6974). Considering the SBS results (MPa), Gh-TC and Gc showed the highest values (27.59±6.4 and 27.18±2.9) and Gt-TC showed the lowest (8.45±6.7). For the Ra parameter, ANOVA revealed that the aging method had an effect (p=0.0157) but the surface treatments did not (p=0.458). For the thermocycled and non-thermocycled groups, Ra (µm) was 0.69±0.16 and 1.12±0.52, respectively. The most frequent failure mode exhibited was mixed failure involving the enamel-resin-bracket interfaces. Conclusion Regardless of the aging method, Gh promoted similar SBS results to Gc, suggesting that rebonded ceramic brackets are a more effective strategy. PMID:24037072

  20. Effects of Solution and Aging Treatments on Corrosion Resistance of As-cast 60NiTi Alloy

    NASA Astrophysics Data System (ADS)

    Qin, Qiuhui; Wen, Yuhua; Wang, Gaixia; Zhang, Lanhui

    2016-12-01

    60NiTi alloy has become a competitive candidate for bearing applications due to its shape memory effect, superelasticity, high strength, hardness, excellent abrasion resistance and corrosion resistance, etc. However, the relationship between its corrosion resistance and heat treatment is not clearly understood. Therefore, we used OM, XRD, SEM and EDS to study the evolution of microstructure in as-cast, solution-treated and aged 60NiTi alloy. Besides, the potentiodynamic polarization and salt spray test were used to compare corrosion resistance of 60NiTi alloy and 316 stainless steel and to study the effect of microstructures on corrosion resistance of 60NiTi alloy. The results show that the corrosion resistance of as-cast 60NiTi alloy is comparable to that of 316 stainless steel, but the corrosion resistance of solution-treated and aged 60NiTi alloys is much superior. The significantly reduced Ni3Ti phase after the solution and aging treatments is responsible for the remarkable improvement in the corrosion resistance of as-cast 60NiTi alloy.

  1. Development of HIFU treatment in which the heating location is controlled using microbubbles

    NASA Astrophysics Data System (ADS)

    Kajiyama, Kenichi; Iida, Naoyuki; Hasegawa, Keisuke; Yoshizawa, Shin; Yoshinaka, Kiyoshi; Takagi, Shu; Matsumoto, Yoichiro

    2009-04-01

    High-intensity focused ultrasound (HIFU) treatment that employs microbubbles to provide enhanced heating has been investigated in order to develop a less invasive and more rapid tumor therapy. Previous studies by us have demonstrated that ultrasound propagation is disturbed when there are microbubbles in front of the focus. In this study, we develop a method for obtaining enhanced heating by using microbubbles just at the focus, thus avoiding heating on the transducer side. In this method, microbubbles are destroyed in front of the HIFU focus (on the transducer side) by irradiating a very short burst wave of microsecond order, before irradiating the ultrasound waves for heating the focus. The experiment is conducted in a medium of a gel containing microbubbles, and a temperature-sensing liquid crystal sheet is set in the focus to observe the temperature distribution. The ultrasound frequency was 2.2 MHz and the intensity was 5000 W/cm2, and 20 burst wave waves were irradiated at pulse repetition frequency of 1 kHz. The number of wave pulses was varied. The continuous-wave frequency, intensity and irradiation time are 2.2 MHz, 1000 W/cm2 and 60 sec, respectively. As the number of pulses increased, the heating region moves from the transducer side to the focus. This is because microbubbles in front of the focus are destroyed and the ultrasound propagates around the target position effectively. These results suggest that the microbubble distribution and the heating position in the developed HIFU system can be controlled.

  2. Microstructural evolution of delta ferrite in SAVE12 steel under heat treatment and short-term creep

    SciTech Connect

    Li, Shengzhi; Eliniyaz, Zumrat; Zhang, Lanting; Sun, Feng; Shen, Yinzhong; Shan, Aidang

    2012-11-15

    This research focused on the formation and microstructural evolution of delta ferrite phase in SAVE12 steel. The formation of delta ferrite was due to the high content of ferrite forming alloy elements such as Cr, W, and Ta. This was interpreted through either JMatPro-4.1 computer program or Cr{sub eq} calculations. Delta ferrite was found in bamboo-like shape and contained large amount of MX phase. It was surrounded by Laves phases before creep or aging treatment. Annealing treatments were performed under temperatures from 1050 Degree-Sign C to 1100 Degree-Sign C and various time periods to study its dissolution kinetics. The result showed that most of the delta ferrite can be dissolved by annealing in single phase austenitic region. Dissolution process of delta ferrite may largely depend on dissolution kinetic factors, rather than on thermodynamic factors. Precipitation behavior during short-term (1100 h) creep was investigated at temperature of 600 Degree-Sign C under a stress of 180 MPa. The results demonstrated that delta ferrite became preferential nucleation sites for Laves phase at the early stage of creep. Laves phase on the boundary around delta ferrite showed relatively slower growth and coarsening rate than that inside delta ferrite. - Highlights: Black-Right-Pointing-Pointer Delta ferrite is systematically studied under heat treatment and short-term creep. Black-Right-Pointing-Pointer Delta ferrite contains large number of MX phase and is surrounded by Laves phases before creep or aging treatment. Black-Right-Pointing-Pointer Formation of delta ferrite is interpreted by theoretical and empirical methods. Black-Right-Pointing-Pointer Most of the delta ferrite is dissolved by annealing in single phase austenitic region. Black-Right-Pointing-Pointer Delta ferrite becomes preferential nucleation sites for Laves phase at the early stage of creep.

  3. Effects of Various Heat Treatments on the Ballistic Impact Properties of Inconel 718 Investigated

    NASA Technical Reports Server (NTRS)

    Pereira, J. Michael; Lerch, Bradley A.

    2000-01-01

    Uncontained failures of aircraft engine fan blades are serious events that can cause equipment damage and loss of life. Federal Aviation Administration (FAA) certification requires that all engines demonstrate the ability to contain a released fan blade with the engine running at full power. However, increased protection generally comes at the expense of weight. Proper choice of materials is therefore imperative to an optimized design. The process of choosing a good casing material is done primarily through trial and error. This costly procedure could be minimized if there was a better understanding of the relationships among static material properties, impact properties, and failure mechanisms. This work is part of a program being conducted at the NASA Glenn Research Center at Lewis Field to study these relationships. Ballistic impact tests were conducted on flat, square sheets of Inconel 718 that had been subjected to different heat treatments. Two heat treatments and the as-received condition were studied. In addition, results were compared with those from an earlier study involving a fourth heat treatment. The heat treatments were selected on the basis of their effects on the static tensile properties of the material. The impact specimens used in this study were 17.8-cm square panels that were centered and clamped over a 15.2-cm square hole in a 1.27-cm-thick steel plate. Three nominal plate thickness dimensions were studied, 1.0, 1.8, and 2.0 mm. For each thickness, all the specimens were taken from the same sheet of material. The projectile was a Ti-6Al-4V cylinder with a length of 25.4 mm, a diameter of 12.7 mm, and a mass ranging from 14.05 to 14.20 g. The projectiles were accelerated toward the specimens at normal incidence using a gas gun with a 2-m-long, 12.7-mm inner-diameter barrel. The ballistic limit for each heat treatment condition and thickness was determined by conducting a number of impact tests that bracketed as closely as possible the velocity

  4. Large size superelastic SMA bars: heat treatment strategy, mechanical property and seismic application

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Fang, Cheng; Liu, Jia

    2016-07-01

    This paper reports a comprehensive study on the mechanical performance of large size superelastic shape memory alloy (SMA) bars, with the main focus given to their potential applications for seismic-resistant connections. A series of practical issues, including heat treatment, mechanical property assessment, and connection design/evaluation, were discussed aiming to benefit both material and civil engineering communities. The study commenced with a detailed discussion on the heat treatment strategy for SMA bars and the resulting mechanical properties including strength/stiffness, self-centring ability, energy dissipation, and fractural resistance. It was observed that the mechanical performance of the bars were quite sensitive to both annealing temperature and duration, and size effect was also evident, resulting in different appropriate heat treatment procedures for the bars with varying diameters. The optimally heat-treated SMA bars were machined to the bolt form and were then used for two types of practical self-centring connections, namely, connection with all SMA bars and that with combined angles and SMA bars. Through conducting full-scale tests, both connections were shown to have stable and controllable hysteretic responses till 5% loading drift. Up to 3% drift, the self-centring performance was satisfactory for both connection types, but beyond that the presence of the angles could lead to accumulated residual rotation. Importantly, for both connections, the deformation was accommodated by the SMA bolts or angles, whereas no plastic deformation was observed at any other structural members. This confirmed the feasibility of using such connections for highly resilient structures where minimal repair work is required after earthquakes.

  5. Effects of extrusion and heat treatment on the mechanical properties and biocorrosion behaviors of a Mg-Nd-Zn-Zr alloy.

    PubMed

    Zhang, Xiaobo; Yuan, Guangyin; Mao, Lin; Niu, Jialin; Fu, Penghuai; Ding, Wenjiang

    2012-03-01

    Mechanical properties at room temperature and biocorrosion behaviors in simulated body fluid (SBF) at 37 °C of a new type of patented Mg-3Nd-0.2Zn-0.4Zr (hereafter, denoted as JDBM) alloy prepared at different extrusion temperatures, as well as heat treatment, were studied. The mechanical properties of this magnesium alloy at room temperature were improved significantly after extrusion and heat treatment compared to an as-cast alloy. The results of mechanical properties show that the yield strength (YS) decreases with increasing extrusion temperature. The tensile elongation decreases a little while the ultimate tensile strength (UTS) has no obvious difference. The yield strength and ultimate tensile strength were improved clearly after heat treatment at 200 °C for 10 h compared with that at the extrusion state, which can be mainly contributed to the precipitation strengthening. The biocorrosion behaviors of the JDBM alloy were studied using immersion tests and electrochemical tests. The results reveal that the extruded JDBM alloy and the aging treatment on the extruded alloy show much better biocorrosion resistance than that at solid solution state (T4 treatment), and the JDBM exhibited favorable uniform corrosion mode in SBF.

  6. Aerodynamic and heat transfer aspects of tip and casing treatments used for turbine tip leakage control

    NASA Astrophysics Data System (ADS)

    Gumusel, Baris

    Axial flow turbine stages are usually designed with a gap between the tips of the rotating blades and a stationary outer casing. The presence of a strong pressure gradient across this gap drives flow from the pressure side of the blade to the suction side. This leakage flow creates a significant amount of energy loss of working fluid in the turbine stage. In a modern gas turbine engine the outer casing of the high-pressure turbine is also exposed to a combination of high flow temperatures and heat transfer coefficients. The casing is consequently subjected to high levels of convective heat transfer, a situation that is aggravated by flow unsteadiness caused by periodic blade-passing events. An experimental investigation of the aerodynamic and heat transfer effect of tip and casing treatments used in turbine tip leakage control was conducted in a large scale, low speed, rotating research turbine facility. The effects of casing treatments were investigated by measuring the total pressure field at the exit of the rotor using a high frequency response total pressure probe. A smooth wall as a baseline case was also investigated. The test cases presented include results of casing treatments with varying dimensions for tip gap height of t/h=2.5%. The results of the rotor exit total pressure indicate that the casing treatment significantly reduced the leakage mass flow rate and the momentum deficit in the core of the tip vortex. The reductions obtained in the tip vortex size and strength influenced the tip-side passage vortex and other typical core flow characteristics in the passage. Casing treatments with the highest ridge height was the most effective in reducing the total pressure loss in the leakage flow of the test blades. This was observed at a radius near the core of the tip vortex. It appears that casing treatments with the highest ridge height is also the most effective from a global point of view, as shown by the passage averaged pressure coefficient obtained in

  7. Effect of Thermo-Mechanical Processing and Heat Treatment on the Tribological Characteristics of Al Based MMC's

    NASA Astrophysics Data System (ADS)

    Keshavamurthy, R.; Madhu Sudhan, J.; Gowda, Narasimhe; Krishna, R. Ananda

    2016-09-01

    This paper reports on effect of forging and Heat Treatment on Tribological characteristics of aluminium alloy-silicon nitride. Cast aluminium alloy and composite were subjected to open die hot forging process. Alloy and its composites were examined to characteristics hardness and wear test under both primary and secondary processing conditions. Effect of heat treatment on hardness and tribological behaviour were also studied. Microstructure shows even spreading of particles in cast & forged conditions. hot forged alloy and composite shows a noticeable improvement in wear resistance and COF compare to their primary counter parts. Heat treatment has a considerable effect on hardness, friction and wear characteristics of composites.

  8. In situ post-weld heat treatment on martensitic stainless steel turbine runners using a robotic induction heating process to control temperature distribution

    NASA Astrophysics Data System (ADS)

    Boudreault, E.; Hazel, B.; Côté, J.; Godin, S.

    2014-03-01

    A new robotic heat treatment process is developed. Using this solution it is now possible to perform local heat treatment on large steel components. Crack, cavitation and erosion repairs on turbine blades and Pelton buckets are among the applications of this technique. The proof of concept is made on a 13Cr-4Ni stainless steel designated "CA6NM". This alloy is widely used in the power industry for modern system components. Given the very tight temperature tolerance (600 to 630 °C) for post-weld heat treatment on this alloy, 13Cr-4Ni stainless steel is very well suited for demonstrating the possibilities of this process. To achieve heat treatment requirements, an induction heating system is mounted on a compact manipulator named "Scompi". This robot moves a pancake coil in order to control the temperature distribution. A simulator using thermal finite element analysis is first used for path planning. A feedback loop adjusts parameters in function of environmental conditions.

  9. Effect of heat treatment upon the fatigue-crack growth behavior of Alloy 718 weldments. Part I. Macroscopic behavior

    SciTech Connect

    James, L A; Mills, W J

    1981-05-01

    Gas-tungsten-arc weldments in Alloy 718 were studied in fatigue-crack growth tests conducted at five temperatures over the range 24 to 649{sup 0}C. In general, crack growth rates increased with increasing temperature, and weldments given the conventional post-weld heat-treatment generally exhibited crack growth rates that were higher than for weldments given the modified (INEL) heat-treatment. Limited testing in the as-welded condition revealed crack growth rates significantly lower than observed for the heat-treated cases, and this was attributed to residual stresses. Three different heats of filler wire were utilized, and no heat-to-heat variations were noted. 9 figures, 6 tables.

  10. Enhanced immunomodulatory activity and stability in simulated digestive juices of Lactobacillus plantarum L-137 by heat treatment.

    PubMed

    Fujiki, Takashi; Hirose, Yoshitaka; Yamamoto, Yoshihiro; Murosaki, Shinji

    2012-01-01

    This study reports the effect of heat treating Lactobacillus plantarum L-137 on its in vitro cytokine-inducing activity, on the stability of this activity in simulated digestive juices, and on its in vivo immunomodulatory properties. L-137 cells were harvested at the stationary phase with or without the subsequent heat treatment and then lyophilized. Heat-killed L-137 cells stimulated mouse spleen cells to produce more interleukin-12p40 than unheated L-137. The interleukin-12p40-inducing activity of unheated L-137 was significantly lower when incubated with simulated intestinal juice, but the activity of heat-killed L-137 cells was maintained. Furthermore, heat-killed L-137 was more protective than unheated L-137 in a mouse model of dextran sulfate sodium-induced colitis. A heat treatment may therefore be effective for enhancing the immunomodulatory activity of L-137 cells.

  11. Microstructure Evolution During Spray Rolling and Heat Treatment of 2124 Al

    SciTech Connect

    K.M. McHugh; Y. Lin; Y. Zhou; S.B. Johnson; J.P. Delplanque; E.J. Lavernia

    2006-09-01

    Spray rolling is a strip casting technology that combines elements of spray forming and twin-roll casting. It consists of atomizing molten metal with a high velocity inert gas, quenching the resultant droplets in flight, and directing the spray between mill rolls. In-flight convection heat transfer from atomized droplets and conduction heat transfer at the rolls rapidly move an alloy’s latent heat. Hot deformation of the semi-solid material in the rolls results in fully consolidated, rapidly-solidified product. While similar in many ways to twin-roll casting, spray rolling is able to process a broader range of alloys and operates at a higher production rate. A laboratory-scale strip caster has been constructed at INL and used to evaluate the interplay of processing parameters and strip quality while producing strips up to 200 mm wide and 1.6 – 6.4 mm thick. Plans are underway to scale to 600 mm width and demonstrate steady-state operation. As-spray-rolled strip is characterized by a flat, uniformly thick profile with minimal porosity or segregation. This paper examines how processing parameters influence the microstructure transformations that take place during spray rolling and post-deposition heat treatment of 2124 Al.

  12. Intermittent cryogen spray cooling for optimal heat extraction during dermatologic laser treatment.

    PubMed

    Majaron, Boris; Svaasand, Lars O; Aguilar, Guillermo; Nelson, J Stuart

    2002-09-21

    Fast heat extraction is critically important to obtain the maximal benefit of cryogen spray cooling (CSC) during laser therapy of shallow skin lesions, such as port wine stain birthmarks. However, a film of liquid cryogen can build up on the skin surface, impairing heat transfer due to the relatively low thermal conductivity and higher temperature of the film as compared to the impinging spray droplets. In an attempt to optimize the cryogen mass flux, while minimally affecting other spray characteristics, we apply a series of 10 ms spurts with variable duty cycles. Heat extraction dynamics during such intermittent cryogen sprays were measured using a custom-made metal-disc detector. The highest cooling rates were observed at moderate duty cycle levels. This confirms the presence, and offers a practical way to eliminate the adverse effect of liquid cryogen build-up on the sprayed surface. On the other hand, lower duty cycles allow a substantial reduction in the average rate of heat extraction, enabling less aggressive and more efficient CSC for treatment of deeper targets, such as hair follicles.

  13. Assessment of heat treatment of dairy products by MALDI-TOF-MS.

    PubMed

    Meltretter, Jasmin; Birlouez-Aragon, Inès; Becker, Cord-Michael; Pischetsrieder, Monika

    2009-12-01

    The formation of the Amadori product from lactose (protein lactosylation) is a major parameter to evaluate the quality of processed milk. Here, MALDI-TOF-MS was used for the relative quantification of lactose-adducts in heated milk. Milk was heated at a temperature of 70, 80, and 100 degrees C between 0 and 300 min, diluted, and subjected directly to MALDI-TOF-MS. The lactosylation rate of alpha-lactalbumin increased with increasing reaction temperature and time. The results correlated well with established markers for heat treatment of milk (concentration of total soluble protein, soluble alpha-lactalbumin and beta-lactoglobulin at pH 4.6, and fluorescence of advanced Maillard products and soluble tryptophan index; r=0.969-0.997). The method was also applied to examine commercially available dairy products. In severely heated products, protein pre-purification by immobilized metal affinity chromatography improved spectra quality. Relative quantification of protein lactosylation by MALDI-TOF-MS proved to be a very fast and reliable method to monitor early Maillard reaction during milk processing.

  14. Effects of Post-Weld Heat Treatment on the Mechanical Properties of Similar- and Dissimilar-Alloy Friction Stir Welded Blanks

    SciTech Connect

    Zadpoor, Amir Abbas; Sinke, Jos

    2011-01-17

    Friction stir welding is a solid state joining process with relatively low welding temperatures. Nevertheless, the mechanical properties of friction stir welded blanks are degraded after welding. Indeed, both strength and ductility of the welds are decreased after welding. Often, the resulting friction stir welded blanks need to be formed to their final structural shape. Therefore, the formability of friction stir welded blanks is of primary importance in the manufacturing of structural parts. This paper studies how the mechanical properties and particularly formability of friction stir welded blanks can be improved by applying a post weld heat treatment. Two aluminum alloys from 2000 and 7000 series, namely 2024-T3 and 7075-T6, are selected for the study. The sheet thickness of both materials is 2,0 mm. The selected alloys are welded in three configurations: 2024-T3 and 2024-T3, 7075-T6 and 7075-T6, and 2024-T3 and 7075-T6. The resulting welds are naturally aged for a few months. Three sets of standard dog bone shape tensile test specimens are then machined from the welds. The first set of the specimens is tested without any heat treatment. The second set of the specimens is solution heat treated and quenched before testing. The third set of the specimens is solution heat treated, quenched, and naturally aged for a week before testing. The mechanical properties of the three different sets of specimens are compared with each other. It is shown that careful selection of post weld heat-treatment can greatly improve the formability of friction stir welded blanks.

  15. Ar-40/Ar-39 ages of six Apollo 15 impact melt rocks by laser step heating

    NASA Technical Reports Server (NTRS)

    Dalrymple, G. B.; Ryder, Graham

    1991-01-01

    Fifteen high resolution (21-51 step) Ar-40/Ar-39 age spectra are obtained for six Apollo 15 impact melt rocks of different compositions, using a continuous laser system on submilligram subsamples and on single crystal plagioclase clasts. Four of the six samples gave reproducible age spectra with well-defined intermediate temperature plateaus over 48 percent or more of the Ar-39 released; the plateaus are interpreted as crystallization ages. Samples 15304,7,69, 15294,6,21 and 15314,26,156 gave virtually identical plateau ages whose weighted mean is 3870 + or - 6 Ma. These three melt rocks differ in composition and likely formed in three separate impact events.

  16. Aging and aerobic fitness affect the contribution of noradrenergic sympathetic nerves to the rapid cutaneous vasodilator response to local heating.

    PubMed

    Tew, Garry A; Saxton, John M; Klonizakis, Markos; Moss, James; Ruddock, Alan D; Hodges, Gary J

    2011-05-01

    Sedentary aging results in a diminished rapid cutaneous vasodilator response to local heating. We investigated whether this diminished response was due to altered contributions of noradrenergic sympathetic nerves by assessing 1) the age-related decline and 2) the effect of aerobic fitness. Using laser-Doppler flowmetry, we measured skin blood flow (SkBF) in young (24 ± 1 yr) and older (64 ± 1 yr) endurance-trained and sedentary men (n = 7 per group) at baseline and during 35 min of local skin heating to 42°C at 1) untreated forearm sites, 2) forearm sites treated with bretylium tosylate (BT), which prevents neurotransmitter release from noradrenergic sympathetic nerves, and 3) forearm sites treated with yohimbine + propranolol (YP), which antagonizes α- and β-adrenergic receptors. SkBF was converted to cutaneous vascular conductance (CVC = SkBF/mean arterial pressure) and normalized to maximal CVC (%CVC(max)) achieved by skin heating to 44°C. Pharmacological agents were administered using microdialysis. In the young trained group, the rapid vasodilator response was reduced at BT and YP sites (P < 0.05); by contrast, in the young sedentary and older trained groups, YP had no effect (P > 0.05), but BT did (P > 0.05). Neither BT nor YP affected the rapid vasodilator response in the older sedentary group (P > 0.05). These data suggest that the age-related reduction in the rapid vasodilator response is due to an impairment of sympathetic-dependent mechanisms, which can be partly attenuated with habitual aerobic exercise. Rapid vasodilation involves noradrenergic neurotransmitters in young trained men and nonadrenergic sympathetic cotransmitters (e.g., neuropeptide Y) in young sedentary and older trained men, possibly as a compensatory mechanism. Finally, in older sedentary men, the rapid vasodilation appears not to involve the sympathetic system.

  17. Chronic social stress during adolescence: interplay of paroxetine treatment and ageing.

    PubMed

    Scharf, Sebastian H; Sterlemann, Vera; Liebl, Claudia; Müller, Marianne B; Schmidt, Mathias V

    2013-09-01

    Exposure to chronic stress during developmental periods is a risk factor for a number of psychiatric disorders. While the direct effects of stress exposure have been studied extensively, little is known about the long-lasting effects and the interaction with ageing. The same holds true for the treatment with selective serotonin reuptake inhibitors (SSRIs), which have been shown to prevent or reverse some stress-induced effects. Here, we studied the direct and long-lasting impact of chronic social stress during adolescence and the impact of chronic treatment with the SSRI paroxetine in adulthood and aged animals. Therefore, male CD1 mice at the age of 28 days were subjected to 7 weeks of chronic social stress. Treatment with paroxetine was performed per os with a dosage of 20 mg/g BW. We were able to reverse most of the effects of chronic social stress in adult mice (4 months old) and to some extend in aged animals (15 months old) with the SSRI treatment. Especially the regulation of the HPA axis seems to be affected in aged mice with a shift to the use of vasopressin. Our results demonstrate that chronic stress exposure and antidepressant treatment at the end of the developmental period can have a significant and long-lasting impact, highly relevant for healthy ageing.

  18. Phonon scattering in the thermal conductivity of large-grain superconducting niobium as a function of heat treatment temperature

    NASA Astrophysics Data System (ADS)

    Chandrasekaran, Saravan Kumar; Bieler, Tom; Compton, Chris; Wright, Neil T.

    2012-06-01

    Production of niobium ingots and subsequent fabrication and processing of superconducting radio frequency (SRF) cavities affect the thermal conductivity of superconducting niobium in an as yet unknown way. Here, parameters of a theoretically-based model are used to relate thermal conductivity to the heat treatment temperature of niobium. Temperature and heat flux measurements on large grain niobium specimens with different heat treatment histories are used to estimate the parameters in the model. The parameter associated with the scattering of phonons by normal conducting electrons, β3, deviates from its theoretical value at cooler heat treatment temperatures, but converges to the theoretical value at hotter heat treatment temperatures. The parameter associated with the scattering of phonons by lattice defects and boundaries, β4, correlates well with the heat treatment temperature. The parameter associated with the condensation of electrons to form Cooper pairs, β5, is shown to be unaffected by the heat treatment temperature. These results show promise for relating thermal conductivity to the material processing of niobium.

  19. Kinetic analysis of cooking losses from beef and other animal muscles heated in a water bath--effect of sample dimensions and prior freezing and ageing.

    PubMed

    Oillic, Samuel; Lemoine, Eric; Gros, Jean-Bernard; Kondjoyan, Alain

    2011-07-01

    Cooking loss kinetics were measured on cubes and parallelepipeds of beef Semimembranosus muscle ranging from 1 cm × 1 cm × 1 cm to 7 cm × 7 cm × 28 cm in size. The samples were water bath-heated at three different temperatures, i.e. 50°C, 70°C and 90°C, and for five different times. Temperatures were simulated to help interpret the results. Pre-freezing the sample, difference in ageing time, and in muscle fiber orientation had little influence on cooking losses. At longer treatment times, the effects of sample size disappeared and cooking losses depended only on the temperature. A selection of the tests was repeated on four other beef muscles and on veal, horse and lamb Semimembranosus muscle. Kinetics followed similar curves in all cases but resulted in different final water contents. The shape of the kinetics curves suggests first-order kinetics.

  20. Dry vs soaked wood: modulating the volatile extractible fraction of oak wood by heat treatments.

    PubMed

    Duval, Charlie J; Sok, Nicolas; Laroche, Jérémy; Gourrat, Karine; Prida, Andréi; Lequin, Sonia; Chassagne, David; Gougeon, Régis D

    2013-05-01

    The aim of this study was to analyze the impact of the water content of wood on the concentrations of volatile compounds which can be extracted after heat treatments. Head Space-Solid Phase Micro Extraction Gas Chromatography coupled to Mass Spectrometry (HS-SPME GC-MS) has been used to compare the concentrations of six aroma compounds (vanillin, furfural, eugenol, guaïacol and cis- and trans-whisky lactones) in hydroalcoholic extracts of heated oak wood samples either previously soaked in hot water or not. Except for eugenol, concentrations of extracted aromas appeared to be lower in soaked woods than in dry woods for temperatures up to 200 °C. If a delaying effect of water could explain such overall lower extracted concentrations from soaked woods, a PCA analysis revealed that for the longer duration (25 min of heat treatment), the adsorbed water could promote a higher impact of furfural, eugenol and both whisky lactones on the composition of hydroalcoholic extracts, suggesting that alternative mechanisms of thermal modifications of the wood macromolecular network could exist at high temperatures in presence of adsorbed water.