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Sample records for after-heat

  1. After-heat removing device

    International Nuclear Information System (INIS)

    Air cooling devices of a plurality of loops are arranged, each of the cooling device comprises a damper and a vane therein, and a heat transfer tube is inserted between the damper and the vane. The minimum limit value for the opening degree of each of the damper and the vane is changed stepwise for each of the loops. After reactor shutdown, the opening degree of the damper and the vane for each of the loops is simultaneously fixed to the minimum opening degree set for each of the loops. Since the amount of inflown air to the loop having the damper and the vane of the maximum opening degree is greater compared with that of other loops, and the amount of heat removal is maximum, coolants in a heat transfer tube portion are frozen in a short period of time and heat removal is impossible. Then, after heat is successively removed by other loops set to smaller opening degree for the damper and the vane. With such procedures, degradation of reliability due to erroneous closure of the damper and the vane can be eliminated with no requirement for an operator's control for the opening degree. (I.N.)

  2. Computer programme for prediction steel parameters after heat treatment

    OpenAIRE

    J. Trzaska; L.A Dobrzanski; A. Jagiełło

    2007-01-01

    Purpose: The purpose of this paper is presentation of the computer program for calculating the Continuous Cooling Transformation diagrams for constructional and engineering steels.Design/methodology/approach: The computer program uses the artificial neural networks for prediction steel properties after heat treatment. Input data are chemical composition and austenitizing temperature. Results of calculation consist of temperature of the beginning and the end of transformation...

  3. Computer programme for prediction steel parameters after heat treatment

    Directory of Open Access Journals (Sweden)

    J. Trzaska

    2007-10-01

    Full Text Available Purpose: The purpose of this paper is presentation of the computer program for calculating the Continuous Cooling Transformation diagrams for constructional and engineering steels.Design/methodology/approach: The computer program uses the artificial neural networks for prediction steel properties after heat treatment. Input data are chemical composition and austenitizing temperature. Results of calculation consist of temperature of the beginning and the end of transformation in the cooling rate function, the volume fraction of structural components and hardness of steel cooled from austenitizing temperature with a fixed rate.Findings: The algorithm can be use in designing new chemical compositions of steels with assumed hardness after heat treatment.Research limitations/implications: The created method for designing chemical compositions is limited by ranges of mass concentrations of elements. The methodology demonstrated in the paper makes possibility to add new steels to the system.Practical implications: The method may be used in computer steel selection systems for machines parts manufactured from constructional or engineering steels subjected to heat treatment.Originality/value: The presented computer program can be used for selecting steel with required structure after heat treatment.

  4. After-heat removing device in nuclear reactor

    International Nuclear Information System (INIS)

    This invention concerns an FBR type reactor power generation plant equipped with a once-through steam generator and it is an object thereof to enable to operate the steam generator under a once-through mode in a usual operation state and at a recycling mode capable of stable operation under an extremely low load upon after-heat removing operation after the reactor shutdown. That is, a recycling system used only upon starting/shutdown is added to the once-through steam generator and a lower limit value demanded from the stable operation of the steam generator to feed water flow rate demand signal upon after-heat removing operation, thereby preventing the reduction of feed water flow rate to less than the limit level. Further, by starting the recycling pump again at the instance when the water level is formed in a liquid/water separator, the operation is shifted smoothly from the once-through mode to the recycling mode. In this way, since thermal shocks to important equipments such as nuclear reactors can be moderated, it is possible to improve the reliability and safety, as well as attain a cost-saving plant. (I.S.)

  5. Oligonol Supplementation Affects Leukocyte and Immune Cell Counts after Heat Loading in Humans

    Directory of Open Access Journals (Sweden)

    Jeong Beom Lee

    2014-06-01

    Full Text Available Oligonol is a low-molecular-weight form of polyphenol and has antioxidant and anti-inflammatory activity, making it a potential promoter of immunity. This study investigates the effects of oligonol supplementation on leukocyte and immune cell counts after heat loading in 19 healthy male volunteers. The participants took a daily dose of 200 mg oligonol or a placebo for 1 week. After a 2-week washout period, the subjects were switched to the other study arm. After each supplement, half-body immersion into hot water was made, and blood was collected. Then, complete and differential blood counts were performed. Flow cytometry was used to enumerate and phenotype lymphocyte subsets. Serum concentrations of interleukin (IL-1β and IL-6 in blood samples were analyzed. Lymphocyte subpopulation variables included counts of total T cells, B cells, and natural killer (NK cells. Oligonol intake attenuated elevations in IL-1β (an 11.1-fold change vs. a 13.9-fold change immediately after heating; a 12.0-fold change vs. a 12.6-fold change 1h after heating and IL-6 (an 8.6-fold change vs. a 9.9-fold change immediately after heating; a 9.1-fold change vs. a 10.5-fold change 1h after heating immediately and 1 h after heating in comparison to those in the placebo group. Oligonol supplementation led to significantly higher numbers of leukocytes (a 30.0% change vs. a 21.5% change immediately after heating; a 13.5% change vs. a 3.5% change 1h after heating and lymphocytes (a 47.3% change vs. a 39.3% change immediately after heating; a 19.08% change vs. a 2.1% change 1h after heating relative to those in the placebo group. Oligonol intake led to larger increases in T cells, B cells, and NK cells at rest (p < 0.05, p < 0.05, and p < 0.001, respectively and immediately after heating (p < 0.001 in comparison to those in the placebo group. In addition, levels of T cells (p < 0.001 and B cells (p < 0.001 were significantly higher 1 h after heating in comparison to those in

  6. Inflammatory cytokines and plasma redox status responses in hypertensive subjects after heat exposure

    Directory of Open Access Journals (Sweden)

    S.F. Fonseca

    2016-03-01

    Full Text Available Hypertension is characterized by a pro-inflammatory status, including redox imbalance and increased levels of pro-inflammatory cytokines, which may be exacerbated after heat exposure. However, the effects of heat exposure, specifically in individuals with inflammatory chronic diseases such as hypertension, are complex and not well understood. This study compared the effects of heat exposure on plasma cytokine levels and redox status parameters in 8 hypertensive (H and 8 normotensive (N subjects (age: 46.5±1.3 and 45.6±1.4 years old, body mass index: 25.8±0.8 and 25.6±0.6 kg/m2, mean arterial pressure: 98.0±2.8 and 86.0±2.3 mmHg, respectively. They remained at rest in a sitting position for 10 min in a thermoneutral environment (22°C followed by 30 min in a heated environmental chamber (38°C and 60% relative humidity. Blood samples were collected before and after heat exposure. Plasma cytokine levels were measured using sandwich ELISA kits. Plasma redox status was determined by thiobarbituric acid reactive substances (TBARS levels and ferric reducing ability of plasma (FRAP. Hypertensive subjects showed higher plasma levels of IL-10 at baseline (P<0.05, although levels of this cytokine were similar between groups after heat exposure. Moreover, after heat exposure, hypertensive individuals showed higher plasma levels of soluble TNF receptor (sTNFR1 and lower TBARS (P<0.01 and FRAP (P<0.05 levels. Controlled hypertensive subjects, who use angiotensin-converting-enzyme inhibitor (ACE inhibitors, present an anti-inflammatory status and balanced redox status. Nevertheless, exposure to a heat stress condition seems to cause an imbalance in the redox status and an unregulated inflammatory response.

  7. Experimental research on the mechanical property of prestressing steel wire during and after heating

    Institute of Scientific and Technical Information of China (English)

    ZHENG Wenzhong; HU Qiong; ZHANG Haoyu

    2007-01-01

    The mechanical property of prestressing steel wire during and after heating is the key factor in the design of fire resistance and after-fire damage evaluation of prestressed structures. Tensile experiment of 16 prestressing steel wires (fptk= 1770 N/mm2, d = 5 mm, low relaxation of stress) at high temperature and tensile experiment of 14 prestressed steel wires after heating are carried out. According to the experiment, the shapes of stress-strain curves of steel wire at high temperature go smooth and the mechanical property indexes of the steel wire such as strength, modulus of elastic- ity, etc., degenerate continuously as temperature increased. According to the experiment after heating, the mechanical property of steel wire varies little when the highest tempera- ture that the steel wire has ever been heated to is lower than 300℃; while the stress-strain curves of steel wire become more ductile and the mechanical property indexes of the steel wire degenerate gradually when the highest temperature is higher than 300℃. By applying the theory of viscoelastic mechanics, stress-strain curves of steel wire at high tempera- tures without loading rate influence are obtained. The law of mechanical property indexes of the wire is presented. The mathematical models of the stress-strain relationship of the pre-stressed steel wire are established. All can serve as basic data for the analysis of fire resistance and after-fire damage evaluation ofpre-stressed structures.

  8. Network analysis of oyster transcriptome revealed a cascade of cellular responses during recovery after heat shock.

    Directory of Open Access Journals (Sweden)

    Lingling Zhang

    Full Text Available Oysters, as a major group of marine bivalves, can tolerate a wide range of natural and anthropogenic stressors including heat stress. Recent studies have shown that oysters pretreated with heat shock can result in induced heat tolerance. A systematic study of cellular recovery from heat shock may provide insights into the mechanism of acquired thermal tolerance. In this study, we performed the first network analysis of oyster transcriptome by reanalyzing microarray data from a previous study. Network analysis revealed a cascade of cellular responses during oyster recovery after heat shock and identified responsive gene modules and key genes. Our study demonstrates the power of network analysis in a non-model organism with poor gene annotations, which can lead to new discoveries that go beyond the focus on individual genes.

  9. Physical and mechanical characteristics of poor-quality wood after heat treatment

    Directory of Open Access Journals (Sweden)

    Romagnoli M

    2015-12-01

    Full Text Available Poor-quality Corsican pine (Pinus nigra subsp. laricio (Poir. Maire and Douglas fir (Pseudotsuga menziesii (Mirb. Franco wood samples were heat treated with the aim of testing the improvement of wood quality that could increase their economic value. Wood properties were measured to assess quality in treated and non-treated materials, including density, hardness, anti-swelling efficiency (ASE, modulus of elasticity (MOE, modulus of rupture (MOR, and compression strength. The results showed higher dimensional stability in heat-treated wood, yet mechanical performance in compression and bending strength were only marginally affected by loss of density. Despite having a re­latively low density after heat treatment, Corsican pine sapwood has potential in manufacturing higher-value products. In contrast, heat treatment applied to Douglas fir wood did not appear economically viable; insufficient differences were detected between the naturally desirable characteristics of this species and heat-treated samples.

  10. Investigation of structural modification and thermal characteristics of lignin after heat treatment.

    Science.gov (United States)

    Kim, Jae-Young; Hwang, Hyewon; Oh, Shinyoung; Kim, Yong-Sik; Kim, Ung-Jin; Choi, Joon Weon

    2014-05-01

    Milled wood lignin was subjected to heat treatment between 150 and 300°C to understand the pattern of its structural modification and thermal properties. When the temperature was elevated with interval of 50°C, the color of the lignin became dark brown and the lignin released various forms of phenols from terminal phenolic groups in the lignin, leading to two physical phenomena: (1) gradual weight loss of the lignin, up to 19% based on dry weight and (2) increase in the carbon content and decrease in the oxygen content. Nitrobenzene oxidation and (13)C NMR analyses confirmed a cleavage of β-O-4 linkage (depolymerization) and reduction of methoxyl as well as phenolic hydroxyl group were also characteristic in the lignin structure during heat treatment. Simultaneously with lignin depolymerization, GPC analysis provided a possibility that condensation between lignin fragments could also occur during heat treatment. TGA/DTG/DSC data revealed that thermal stability of lignin obviously increased after heat treatment, implicating the structural rearrangement of lignin to reduction of β-O-4 linkage as well as accumulation of CC bonds. PMID:24530642

  11. Structural characteristics of nickel super alloy INCONEL 713LC after heat treatment

    Directory of Open Access Journals (Sweden)

    A. Hernas

    2007-04-01

    Full Text Available Purpose: Aircraft industry often uses nickel super-alloys for blades of jet engine turbines. This paper summarises analysis of influence of heat treatment on structural characteristics of nickel super-alloy INCONEL 713LC.Design/methodology/approach: Experimental investigation castings made of commercially produced nickel super-alloy INCONEL 713LC. Material was after heat treatment subjected to detailed structural analysis with use of methods of light microscopy (LM, or scanning electron microscopy (SEM on microscopes OLYMPUS IX71 and JEOL JSM 50A.Findings: Mode of optimum heat treatment was proposed. On the basis of obtained results it is possible to recommend a heat treatment, which would consist of heating and dwell at the temperature exceeding 1240°C (min. 1260°C, so that precipitates at the grain boundaries dissolve completely, with subsequent slow cooling down to the temperature of approx. 940-950°C, so that there occurs intensive intra-granular precipitation of inter-metallic phase γ’.Research limitations/implications: The experiment was limited by occurrence a void in cast alloys.Practical implications: Aircraft industry often uses nickel super-alloys for blades of jet engine turbines.Originality/value: On the basis of obtained results it is possible to recommend the most suitable heat treatment, which produce intensive intra-granular precipitation of inter-metallic phase γ’. It was received a new know-how in this field.

  12. Investigation of structural modification and thermal characteristics of lignin after heat treatment.

    Science.gov (United States)

    Kim, Jae-Young; Hwang, Hyewon; Oh, Shinyoung; Kim, Yong-Sik; Kim, Ung-Jin; Choi, Joon Weon

    2014-05-01

    Milled wood lignin was subjected to heat treatment between 150 and 300°C to understand the pattern of its structural modification and thermal properties. When the temperature was elevated with interval of 50°C, the color of the lignin became dark brown and the lignin released various forms of phenols from terminal phenolic groups in the lignin, leading to two physical phenomena: (1) gradual weight loss of the lignin, up to 19% based on dry weight and (2) increase in the carbon content and decrease in the oxygen content. Nitrobenzene oxidation and (13)C NMR analyses confirmed a cleavage of β-O-4 linkage (depolymerization) and reduction of methoxyl as well as phenolic hydroxyl group were also characteristic in the lignin structure during heat treatment. Simultaneously with lignin depolymerization, GPC analysis provided a possibility that condensation between lignin fragments could also occur during heat treatment. TGA/DTG/DSC data revealed that thermal stability of lignin obviously increased after heat treatment, implicating the structural rearrangement of lignin to reduction of β-O-4 linkage as well as accumulation of CC bonds.

  13. Radiological considerations on multi-MW targets Part II After-heat and temperature distribution in packed tantalum spheres

    CERN Document Server

    Magistris, M

    2005-01-01

    CERN is designing a Superconducting Proton Linac (SPL) to provide a 2.2GeV, 4MW proton beam to feed facilities like, for example, a future Neutrino Factory or a Neutrino SuperBeam. One of the most promising target candidates is a stationary consisting of a Ti container filled with small Ta pellets. The power deposited as heat by the radioactive nuclides (the so-called after-heat) can considerably increase the target temperature after ceasing operation, if no active cooling is provided. An estimate of the induced radioactivity and after-heat was performed with the FLUKA Monte Carlo code. To estimate the highest temperature reached inside the target, the effective thermal conductivity of packed spheres was evaluated using the basic cell method. A method for estimating the contribution to heat transmission from radiation is also discussed1).

  14. The effect of pre- versus postinjury infiltration with lidocaine on thermal and mechanical hyperalgesia after heat injury to the skin

    DEFF Research Database (Denmark)

    Dahl, J B; Brennum, J; Arendt-Nielsen, L;

    1993-01-01

    The aim of the study was to evaluate the effects of pre- and postinjury infiltration with lidocaine on alterations in mechanical and thermal sensitivity after heat injury to the skin. In the first part of the study, burn injuries (15 x 25 mm rectangular thermode, 50 degrees C, 7 min) were produced...... twice in each subject on the medial side of the left and right calves at least 24 h apart in 8 healthy, unmedicated male volunteers, in order to investigate the effects of the injury on sensitivity in untreated skin. In the second part of the study, burn injuries (15 x 25 mm rectangular thermode, 50...

  15. Time course changes of NADPH-d positive neuron counts in the cortex of mice after heat stress

    Institute of Scientific and Technical Information of China (English)

    Yan Wang; Ling Chen; Yu-Zhong Jin

    2016-01-01

    Objective:To discuss the time course changes of NADPH-d positive neuron counts in the cortex of mice after acute heat stress.Methods:Models of mice after acute heat stress were duplicated. Shuttle box test was used to observe the learning and memory function of mice at 6 h, 12 h, 24 h, respectively after heat stress. NADPH-d histochemical staining test was used to observe the time course changes of NADPH-d positive neuron counts in the cortex of mice at 6 h, 12 h, 24 h respectively after heat stress.Results:Compared with control group, mistakes in heat stress (HS) group was significantly increased while escape latency was significantly shortened at 6 h, 12 h respectively (P<0.05). Compared with control group, NADPH-d positive neuron counts in HS group were significantly increased at 6 h (P<0.05). NADPH-d positive neuron counts in HS group were significantly decreased at 12 h.Conclusions:Acute heat stress could result in obvious damages on learning and memory function of mice, which is possibly related with the increased NADPH-d positive neuron expression.

  16. Changes in time course of NADPH-d positive neuron counts in the cortex of mice after heat stress

    Institute of Scientific and Technical Information of China (English)

    Yan Wang; Ling Chen; Yuzhong Jin

    2016-01-01

    Objective:To discuss the time course changes of NADPH-d positive neuron counts in the cortex of mice after acute heat stress. Methods:Model of mice after acute heat stress were duplicated. Shuttle box test was used to observe the learning and memory function of mice at 6 h, 12 h, 24 h respectively after heat stress. NADPH-d histochemical staining test was used to observe the time course changes of NADPH-d positive neuron counts in the cortex of mice at 6 h, 12 h, 24 h respectively after heat stress. Results:(1) Shuttle box test indicated that:Compared with control group, mistakes (M) in HS (heat stress) group was significantly increased while escape latency (EL) was significantly shortened at 6 h, 12 h respectively. (2) NADPH-d histochemical staining test indicated that:Compared with control group, NADPH-d positive neuron counts in HS group were significantly increased at 6 h, and difference had statistical significance. NADPH-d positive neuron counts in HS group were significantly decreased at 12 h. Conclusion:Acute heat stress could result in obvious damages on learning and memory function of mice, which was possibly related with the increased NADPH-d positive neuron expression.

  17. Energy-supply-independent after-heat removal in nuclear propulsion plants for ships in combination with sinking and cuntering

    International Nuclear Information System (INIS)

    The energy-supply-independent after-heat-removal in nuclear propulsion plants for ships in combination with sinking and cantering are analysed with a numeric simulation model. Inclination on the seaground are 0 to the vertical. Different heat-transfer-mechanism in and out of the reactor vessel and at the structures of the containment are analysed. The computer calculation shows that in the course of the accident melting of the core at each inclination occurs. Nevertheless no melting of the reactor vessel occurs due to good cooling of the outer wall of the vessel with seawater. The accident sequenz has at inclinations of 500 to 600 to the vertical a maximum in time. (orig.)

  18. The Microstructure And Mechanical Properties Of The AlSi17Cu5 Alloy After Heat Treatment

    Directory of Open Access Journals (Sweden)

    Piątkowski J.

    2015-09-01

    Full Text Available In the paper results of the microstructure and mechanical properties (HB, Rm and R0,2 of AlSi17Cu5 alloy, subjected by solution heat treatment (500ºC/6h/woda and aging (200ºC/16h/piec are presented. In next step the alloy was modified and heated significantly above the Tliq temperature (separately and together. It was found that the increase in the strength properties of the tested alloy after heat treatment compared to alloys without solution heat treatment and aging was due to precipitation hardening. The applied aging treatment of ingots (preceded by solution heat treatment, causes not only increase in concentration in α(Al solid solution, but also a favorable change of the primary Si crystals morphology. During stereological measurements significant size reduction and change in the morphology of hypereutectic silicon crystals ware found. This effects can be further enhanced by overheating the alloy to a temperature of 920ºC and rapid cooling before casting of the alloy.

  19. Morphological and Structural Studies of Titanate and Titania Nanostructured Materials Obtained after Heat Treatments of Hydrothermally Produced Layered Titanate

    Directory of Open Access Journals (Sweden)

    Mohd Hasmizam Razali

    2012-01-01

    Full Text Available Different types of titanate and titania nanostructured materials have been successfully synthesised and characterized using field emission scanning electron microscopy (FESEM, transmission electron microscopy (TEM, X-ray diffraction (XRD and raman spectroscopy. Elemental analysis was determined by energy dispersive X-ray spectroscopy (EDX analyzer while thermogravimetric-differential scanning calorimetry (TG-DSC was used to determine thermal stability. In this study, we found that nanotubes were formed during the washing treatment stage with HCl and distilled water. When the pH of the washing solution was 12, sodium titanate nanotubes were obtained, while when the pH of the washing solution was 7, hydrogen titanate nanotubes were obtained. Sodium titanate nanotubes were thermally stable up to 500°C; however, at 700°C, the nanotubes structure transform to solid nanorods. Meanwhile, hydrogen titanate nanotubes decomposed to produce titania nanotubes after heat treatment at 300°C for 2 hours. At 500°C, the tubular structure broke to small segments due to destruction of the nanotube. Further heat treatment at 700°C, led to the destruction and collapse of the nanotubes structure produce titania nanoparticles.

  20. Small-angle X-ray scattering studies of metastable intermediates of beta-lactoglobulin isolated after heat-induced aggregation

    DEFF Research Database (Denmark)

    Carrotta, R.; Arleth, L.; Pedersen, J.S.;

    2003-01-01

    Small-angle x-ray scattering was used for studying intermediate species, isolated after heat-induced aggregation of the A variant of bovine P-lactoglobulin. The intermediates were separated in two fractions, the heated metastable dimer and heated metastable oligomers larger than the dimer. The pa...

  1. Bark- and wood-borer colonization of logs and lumber after heat treatment to ISPM 15 specifications: the role of residual bark.

    Science.gov (United States)

    Haack, Robert A; Petrice, Toby R

    2009-06-01

    Wood packaging material (WPM) is a major pathway for international movement of bark- and wood-infesting insects. ISPM 15, the first international standard for treating WPM, was adopted in 2002 and first implemented in the United States in 2006. ISPM 15 allows bark to remain on WPM after treatment, raising concerns that insects could infest after treatment, especially if bark were present. We conducted field studies to evaluate insect infestation of green logs and lumber with varying amounts of bark after heat treatment. In a log study, Cerambycidae and Scolytinae (ambrosia beetles and bark beetles) readily infested and developed in logs with bark after heat treatment. In a lumber study, Cerambycidae and bark beetles laid eggs in all sizes of bark patches tested (approximately 25, 100, 250, and 1,000 cm2) after heat treatment but did not infest control or heat-treated lumber without bark. Cerambycidae completed development only in boards with bark patches of 1,000 cm2, whereas bark beetles completed development on patches of 100, 250, and 1,000 cm2. Survival of bark beetles was greater in square patches (10 by 10 cm) versus rectangular patches (2.5 by 40 cm) of the same surface area (100 cm2). In surveys at six U.S. ports in 2006, 9.4% of 5,945 ISPM 15-marked WPM items contained bark, and 1.2% of 564 ISPM 15-marked WPM items with bark contained live insects of quarantine significance under the bark. It was not possible to determine whether the presence of live insects represented treatment failure or infestation after treatment.

  2. Simulation Analysis of Mechanical Properties for Wheel Rim After Heat Treatement%汽车轮辋热处理后的力学性能仿真分析

    Institute of Scientific and Technical Information of China (English)

    向东

    2013-01-01

    对汽车轮辋结构进行整体建模,分别对热处理前后的汽车轮辋进行了静结构分析,并利用子模型法建立轮辋应力集中区域的子模型.仿真结果表明:最大应力出现在轮辐和轮毂相连接的倒角处,子模型中汽车轮辋的最大等效应力相对于整体模型升高了约9%:经热处理后轮辋强度有一定的提高,但不明显.%The overall modelling on wheel rim was made, and static structural of wheel rim before and after heat treatment were analyzed, respectively. Submodeling was used to model the region of stress concentration in the wheel rim. The simulation results show that the maximum stresses occur in the fillet where the spoke connects to the hub, and maximum stress in the submodel is raised by about 9% than that in overall modelling. The strength of wheel rim after heat treatment raises to a certain extent, but it is not obvious.

  3. Operation method for after-heat removal

    International Nuclear Information System (INIS)

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

  4. Failures of tool steels after heat treatments

    International Nuclear Information System (INIS)

    The main objective of the work was to determine the most common defects occuring in tool steels of the AISI D-2, S-1, 0-1 and W-2 series during thermal treatment. Defects were evaluated by metallographic analyses, a method used to determine and recognize micro structural defects and their origin in order to be able to eliminate and correct some of the stages that are caused by heat treatment. Results show a large number of defects due to irregularities during thermal heating such as excess or lack of temperature, heating time, and atmosphere, rectifying and handling in service and, to a lesser extent, poor design. In conclusion, with the results obtained for each of the thermal treatments it is necessary to define, particularly the values each of these variables should have since they affect the material properties. (Author)

  5. Material selection,hardness after heat treatment and use specification of steel extrusion toolings%钢挤压工模具材质选择、热处理硬度及使用规范

    Institute of Scientific and Technical Information of China (English)

    包进平; 赵云路; 薛荣敬

    2012-01-01

    For the high temperature strength and toughness of the traditional hot working die steel materials can not meet the requirement of the steel extrusion toolings, and their comprehensive costs are high, so the hot working die steel material 1. 2367 suiting for steel extrusion toolings was proposed. And the differences between them and the traditional hot working die steel materials were compared. The material selection, suitable hardness after heat treatment and use specification of each steel extrusion toolings were described in detail. The frequently water cooling usually resulted in the die steel thermal fatigue, so the viewpoint of water cooling replaced by several toolings cycle use and natural cooling was proposed.%由于传统热作模具钢的高温强韧性不能满足钢挤压工模具的要求以及综合成本较高等原因,提出了适合用于钢挤压工模具的热作模具钢材质1.2367,并将其与传统热作模具钢进行对比;对各种钢挤压工模具材质选择、适宜的热处理硬度及使用规范进行了较为详细的叙述;对频繁水冷容易造成模具钢热疲劳的问题,提出了利用多件工模具循环使用并采取自然冷却的方法代替水冷的观点.

  6. Microstructure and mechanical properties of 08Ni3DR cryogenic steel after heat treatment%低温用08 Ni3 DR钢热处理后的组织与力学性能

    Institute of Scientific and Technical Information of China (English)

    王彩焕

    2013-01-01

    采用Gleeble 3800热模拟试验机测定了08Ni3DR钢的CCT曲线,观察了不同冷却速度下钢的显微组织,并对其热处理后的组织与性能进行了分析。结果表明,08Ni3DR钢奥氏体化后,冷却速度稍高于8℃/s时,淬火组织中会出现贝氏体;当冷却速度高于15℃/s时,组织逐渐变为马氏体+贝氏体,晶粒均匀细小。08Ni3DR钢加热到850℃,快速水冷到300℃以下,之后进行650℃回火处理后,晶粒细小均匀,组织为回火索氏体,综合力学性能良好。%CCT curves of 08Ni3DR steel were measured by Gleeble 3800 thermal simulation testing machine , and microstructure of the steel was observed under different cooling temperature , and microstructure and mechanical properties of the 08Ni3DR steel after heat treatment was analyzed.The results show that austenitized and cooled with the speed above 8℃/s, bainite appears in the quenched microstructure .When the cooling speed is above 15℃/s, the microstructure is composed of martensite and bainitic , and the crystal line grain is uniform and fine . When 08Ni3DR steel is heated to 850 ℃and then rapidly cooled to 300 ℃, and tempered at 650 ℃, the crystal is uniform and fine , the microstructure is tempered sorbite and the comprehensive mechanical properties is preferable .

  7. Translation Regulation and RNA Granule Formation after Heat Shock of Procyclic Form Trypanosoma brucei: Many Heat-Induced mRNAs Are also Increased during Differentiation to Mammalian-Infective Forms

    Science.gov (United States)

    Minia, Igor; Merce, Clementine; Terrao, Monica

    2016-01-01

    African trypanosome procyclic forms multiply in the midgut of tsetse flies, and are routinely cultured at 27°C. Heat shocks of 37°C and above result in general inhibition of translation, and severe heat shock (41°C) results in sequestration of mRNA in granules. The mRNAs that are bound by the zinc-finger protein ZC3H11, including those encoding refolding chaperones, escape heat-induced translation inhibition. At 27°C, ZC3H11 mRNA is predominantly present as an untranslated cytosolic messenger ribonucleoprotein particle, but after heat shocks of 37°C—41°C, the ZC3H11 mRNA moves into the polysomal fraction. To investigate the scope and specificities of heat-shock translational regulation and granule formation, we analysed the distributions of mRNAs on polysomes at 27°C and after 1 hour at 39°C, and the mRNA content of 41°C heat shock granules. We found that mRNAs that bind to ZC3H11 remained in polysomes at 39°C and were protected from sequestration in granules at 41°C. As previously seen for starvation stress granules, the mRNAs that encode ribosomal proteins were excluded from heat-shock granules. 70 mRNAs moved towards the polysomal fraction after the 39°C heat shock, and 260 increased in relative abundance. Surprisingly, many of these mRNAs are also increased when trypanosomes migrate to the tsetse salivary glands. It therefore seems possible that in the wild, temperature changes due to diurnal variations and periodic intake of warm blood might influence the efficiency with which procyclic forms develop into mammalian-infective forms. PMID:27606618

  8. Research on Wear-resisting Performance of 9SiCr Steel after Heat Treatment%热处理对9SiCr钢耐磨性能影响的研究

    Institute of Scientific and Technical Information of China (English)

    谢晓利

    2016-01-01

    对9SiCr钢试件进行了热处理,对比分析了试件热处理前后的金相组织、硬度及韧性等特征,以湿砂为磨料进行了磨料磨损试验,通过磨损失重、磨损表面形貌分析了9SiCr钢热处理前后的磨损性能.结果表明,9SiCr钢经热处理后,其组织形态由合金渗碳体为主变为以马氏体和下贝氏体为主,硬度及韧性显著加强,以磨损失重为指标的耐磨性提高了20.6%,磨损表面磨沟、凹坑、剥落等磨损特征减弱.%The heat treatment for 9SiCr steel has been deal,and the microstructure,hardness and ductile were compared and analyzed,the abrasive wear test was conducted by wet sand in order to research the change in wear behavior.The results show that,after heat treatment,the structure form of 9SiCr steel turns alloying cementite into martensite and lower bainite,the hardness and ductile improves significantly,the wear resistance characterized by wear weight loss is increased by 20.6%,the grinding groove,indentation,and peeling on wear surface is reduceed.

  9. 热射病对大鼠空间学习记忆能力远期损害的研究%Long-term Impairment of Spatial Learning and Memory in Rats after Heat Stroke

    Institute of Scientific and Technical Information of China (English)

    张云; 万明胜; 董会; 吴士文

    2016-01-01

    目的:比较热射病大鼠不同阶段的空间学习记忆能力,探讨其远期影响。方法 Sprague-Dawley大鼠42只,建立热射病大鼠模型,将造模成功后的大鼠随机分为热射病7 d组(HS7,n=21)和热射病21 d组(HS21,n=21);另取18只大鼠麻醉后行股动脉插管作为手术对照组(Sham,n=18)。3组分别于造模后7 d、21 d行Morris水迷宫实验5 d,记录逃避潜伏期,跨越平台的次数和目标象限停留时间。结果逃避潜伏期各个时间点HS7组均较Sham组延长(P0.05)。结论热射病大鼠空间学习记忆障碍在发病7d后最严重,并可遗留远期损害。%Objective To compare the spatial learning and memory function of heat stroke rats in different periods, to explore the long-term impairment. Methods 42 Sprague-Dawley rats were randomly divided into heat stroke 7 days group (HS7, n=21), heat stroke 21 days group (HS21, n=21), and another 18 rats were performed femoral artery intubation as surgery control group (sham, n=18). They were tested with Morris water maze 7 days and 21 days after modeling respectively for 5 days. The escaping latency, the frequency of crossing the platform area and the duration in the target quadrant were recorded. Results Compared with the sham group, the escaping latency prolonged in HS7 group in all the time (P0.05). Conclusion The impairment of spatial learning and memory is the most seriously 7 days after heat stroke in rats, and it may remain for long time.

  10. 热处理前后壮药“国虾薄”中皂苷类化合物研究%Saponins from Zhuang-medicine Gocaekmbaw before and after Heat-processing

    Institute of Scientific and Technical Information of China (English)

    刘慧敏; 陈道金; 朴香兰

    2013-01-01

    Objective:Isolation and identification of saponins from Gocaekmbaw before and after heatprocessing was studied.Method:The leaves of Gocaekmbaw were steam-heated at 125 ℃ and 0.24 MPa for 3 h,then extracted with 80% ethanol for 3 h.The extracts were isolated with chromatography using HP-20,silica gel and reversed ODS column.The constituents isolated from Gocaekmbaw before and after heat-processing were identified with 1H-NMR,13 C-NMR and LCMS-IT-TOF spectra.Result:Two dammarane-type saponins were isolated from the original Gocaekmbaw.And four different compounds were got from the heat processed Gocaekmbaw.They were identified as gypenoside XLVI,gypenoside LVI,gypenoside L,gypenoside LI,damulin B and damulin A,respectively.Conclusion:Sugar chains in C20 position of gypenoside XLVI and gypenoside LVI were hydrolyzed by heat-processing to change the constituents of Gocaekmbaw.%目的:分离、鉴定热处理前后国虾薄中皂苷类化合物.方法:国虾薄在温度125℃、压力0.24 MPa的条件下,加热处理3h,用80%乙醇加热回流提取3h,通过大孔树脂HP-20、硅胶柱及反相柱色谱等分离手段对热处理前后的国虾薄成分进行分离,并用核磁共振波谱、离子阱飞行时间质谱(LCMS-IT-TOF)等数据鉴定其成分.结果:从壮药国虾薄原药材中分离得到2个达玛烷类皂苷成分,经热处理后得另外4个达玛烷类皂苷成分,分别鉴定为绞股蓝皂苷gypenoside XLVI,gypenoside LVI,gypenoside L,gypenoside LI,damulin B和damulin A.结论:热处理能够使国虾薄中达玛烷型皂苷gypenoside XLVI,gypenoside LVI的20位上连有的糖链被水解,为国虾薄热处理产物的成分变化提供实验依据.

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

    International Nuclear Information System (INIS)

    Highlights: • Oxide layers prepared via PEO of zirconium were subjected to heat treatment. • Surface characteristics were determined for the obtained oxide coatings. • Heat treatment led to the partial destruction of the anodic oxide layer. • Pitting corrosion resistance of zirconium was improved after the modification. - Abstract: 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

  12. Phase transformations of pyrophyllite clay mineral after heat treatment

    International Nuclear Information System (INIS)

    The termal transformation of the Pyrophyllite clay mineral, given by the equations: AL sub(2) O sub(3).4SiO sub(2).H sub(2) O → Al sub(2) O sub(3).4SiO sub(2) + H sub(2) O Pyrophyllite Anhydride Water vapour. 3 (Al sub(2) O sub(3).4SiO sub(2)) → 3 Al sub(2) O sub(3). 2SiO sub(2) + 10 (SiO sub(2)) Pyrophyllite Anhydride Mullite Cristobalite, were studied by Transmission Electron Microscopy (TEM) associated to Selected Area Electron Diffraction (SAD), applied to a very pure sample, colected at Diamantina, M.G. Some other tgechniques were also used, as X-ray Diffraction (XRD), Differential Thermal Analysis (DTA) and Thermogravimetric Analysis (TGA), applied to other different Pyrophyllite samples. A thermodynamical theoretical study was undertaken to estimate the values for the entropyu of formation, enthalpy and molar thermal capacity for the Pyrophyllite Anhydride. (author)

  13. Expression of aquaporins in intestine after heat stroke.

    Science.gov (United States)

    Wang, Yuan-Hung; Liu, Tsung-Ta; Kung, Woon-Man; Chen, Chun-Chi; Wen, Ya-Ting; Lin, I-Chan; Huang, Chi-Chang; Wei, Li

    2015-01-01

    Heat stroke (HS) has been shown to induce intestinal barrier dysfunction during whole body hyperthermia. HS-induced intestinal permeability change may result from modulation of aquaporin (AQP) expression, which subsequently regulates water homeostasis. This study aimed to evaluate AQP expression in the intestine of rats with HS at different recovery time points. Sprague-Dawley (SD) rats were exposed to an ambient temperature of 40 ± 0.5°C until a maximum core temperature of 40.5°C was attained. The small intestine was surgically removed and histologically examined, and AQP expression was determined by reverse transcription polymerase chain reaction and immunohistochemical staining. H&E staining revealed those intestinal villi were destroyed from HS0 to HS1 and rebuilt from HS3 to HS12. We further stain with activated caspase 3 found expressed at HS0 and back to normal at HS3. Investigation of AQP mRNA expression identified 10 genes. PCR results of AQP1, 3, 7, 8, and 11 transcripts were significantly higher in the HS group than in the sham group. Immunohistochemical staining showed a more than 11-fold increase in AQP3 and 11 expressions at HS0. AQP1 and 8 increased at HS1 and AQP7 increased at HS3 compared with those in the sham group. In this study, we found HS induced jejunum damage and cell apoptosis. AQPs were upregulation/downregulation after HS in different time point suggested that water/glycerol transport was important when hyperthermia occurred. Furthermore, the biological function of the AQP needs more exploration in response to HS. PMID:26464618

  14. Nuclear phenotype changes after heat shock in Panstrongylus megistus (Burmeister

    Directory of Open Access Journals (Sweden)

    Garcia Simone L

    2000-01-01

    Full Text Available The nuclear phenotypes of Malpighian tubule epithelial cells of male nymphs of the blood-sucking insect, Panstrongylus megistus, subjected to short- and long-duration heat shocks at 40ºC were analyzed immediately after the shock and 10 and 30 days later. Normal nuclei with a usual heterochromatic body as well as phenotypes indicative of survival (unravelled heterochromatin, giants and death (apoptosis, necrosis responses were observed in control and treated specimens. However, all nuclear phenotypes, except the normal ones, were more frequent in shocked specimens. Similarly altered phenotypes have also been reported in Triatoma infestans following heat shock, although at different frequencies. The frequency of the various nuclear phenotypes observed in this study suggests that the forms of cell survival observed were not sufficient or efficient enough to protect all of the Malpighian tubule cells from the deleterious effects of stress. In agreement with studies on P. megistus survival following heat shock, only long-duration shock produced strongly deleterious effects.

  15. Change of ears creation of AHSS steels after heat treatment of zinc coating

    Directory of Open Access Journals (Sweden)

    E. Spišák

    2014-10-01

    Full Text Available The article deals with the normal anisotropy, the earring evaluation of deep-drawing steels DC06, micro-alloyed steel H220 and steel with transformation induced plasticity TRIP RAK 40/70 and deals with the influence of annealing temperature to ears creation of H220 steel and TRIP RAK 40/70 steel. The evaluation of normal anisotropy has been made by tensile test on TIRA test 2300 according standards STN EN 10002-1+AC1 and STN 42 0321. The evaluation of earring degree has been carried out on the cups, which have been drawn on a hydraulic press Fritz Muller 100.

  16. MECHANICAL PROPERTIES OF A PRESSED PIECE EN AW 2618A Al–ALLOY AFTER HEAT TREATMENT

    Directory of Open Access Journals (Sweden)

    Karol Oravec

    2009-06-01

    Full Text Available The aim of this contribution is to find out the influence of thermal treatment and small cold work on the microstructure and mechanical properties in the cross section of the EN AW 2618A Al – alloy. Four types of secondary particles were identified in the experimental alloy. Major portion in secondary particles is occupied by Al3NiFe particles, which are up to 5 µm large. Secondary particles Al3NiFe and AlCuNi are not soluble enough during the thermal treatment. The strength properties of the experimental Al - alloy are influenced most of all by precipitation hardening - ageing. The thermal treatment containing solution annealing and next artificial ageing increased the tensile strength 52% above the prime state value. The combined treatment containing solution annealing, cold work and artificial ageing resulted the increase of strength 59.4 %.

  17. Flow adsorption calorimetry of coals before and after heat and oxidation treatment

    Energy Technology Data Exchange (ETDEWEB)

    Groszek, A.J.; Templer, C.E.

    1988-12-01

    Flow microcalorimetry has been used to determine the heats of preferential adsorption of n-butanol and ammonium hydroxide on a number of coals immersed in n-heptane and water respectively. The determinations have also been carried out on the coals subjected to heating in air to temperatures ranging from 100 degrees C to 200 degrees C, to illustrate how the calorimetric technique can detect changes in the surface properties of the coals subjected to various treatments. The heats of adsorption have provided information on the relative surface acidities and hydrophobicities of the coals. 6 refs., 5 figs., 4 tabs.

  18. Method for restoring the resistance of indium oxide semiconductors after heating while in sealed structures

    Energy Technology Data Exchange (ETDEWEB)

    Seager, Carleton H. (1304 Onava Ct., NE., Albuquerque, NM 87112); Evans, Jr., Joseph Tate (13609 Verbena Pl., NE., Albuquerque, NM 87112)

    1998-01-01

    A method for counteracting increases in resistivity encountered when Indium Oxide resistive layers are subjected to high temperature annealing steps during semiconductor device fabrication. The method utilizes a recovery annealing step which returns the Indium Oxide layer to its original resistivity after a high temperature annealing step has caused the resistivity to increase. The recovery anneal comprises heating the resistive layer to a temperature between 100.degree. C. and 300.degree. C. for a period of time that depends on the annealing temperature. The recovery is observed even when the Indium Oxide layer is sealed under a dielectric layer.

  19. Surface roughness of Ti6Al4V after heat treatment evaluated by artificial neural networks

    International Nuclear Information System (INIS)

    The study examines how, using wire electrical discharge machining (WEDM), the microstructural, mechanical and conductivity characteristics of the titanium alloy Ti6Al4V are changed as a result of heat treatment and the effect they have on machinability. Scanning electron microscope (SEM), optical microscope and X-ray diffraction (XRD) examinations were performed to determine various characteristics and additionally related microhardness and conductivity measurements were conducted. L18 Taquchi test design was performed with three levels and six different parameters to determine the effect of such alterations on its machinability using WEDM and post-processing surface roughness (Ra) values were determined. Micro-changes were ensured successfully by using heat treatments. Results obtained with the optimization technique of artificial neural network (ANN) presented minimum surface roughness. Values obtained by using response surface method along with this equation were completely comparable with those achieved in the experiments. The best surface roughness value was obtained from sample D which had a tempered martensite structure.

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    The AE42 magnesium alloy was developed for high pressure die casting (HPDC) from low-aluminum magnesium alloys. In this alloy the rare earth (RE) elements were shown to increase creep resistance by forming AlxREy intermetallics along the grain boundaries. The present work investigates...

  1. Hsp27 enhances recovery of splicing as well as rephosphorylation of SRp38 after heat shock

    OpenAIRE

    Marin Vinader, L.; Shin, C.; Onnekink, C; Manley, J L; Lubsen, N H

    2005-01-01

    A heat stress causes a rapid inhibition of splicing. Exogenous expression of Hsp27 did not prevent that inhibition but enhanced the recovery of splicing afterward. Another small heat shock protein, αB-crystallin, had no effect. Hsp27, but not αB-crystallin, also hastened rephosphorylation of SRp38—dephosphorylated a potent inhibitor of splicing—after a heat shock, although it did not prevent dephosphorylation by a heat shock. The effect of Hsp27 on rephosphorylation of SRp38 required phosphor...

  2. Measurement of after-heat production and dose rates of spent AVR fuel elements

    International Nuclear Information System (INIS)

    Data on the afterheat production and dose rate of spent AVR fuel elements prepared by the ORIGEN computer program are verified by measurements. Individual measurements of afterheat and dose rate were implemented on 17 AVR fuel elements with decay periods of 150 days and more than four years, and burnups between 4.1 and 16.4% fima were implemented in the HOT CELLS at the Juelich Nuclear Research Centre. The radiation energy absorbed in the fuel elements and converted into heat was measured with a calorimeter, whereas the emitted radiation fraction was determined via dose rate measurements. The measured results for fuel elements with decay periods of more than one year are in good agreement with the data from ORIGEN. In the case of fuel elements with shorter decay periods (approx. 150 days) in part considerably lower values were measured which can be explained by the fact that the power gradient in time of the fuel elements in the reactor can vary considerably whereas mean are included in the ORIGEN computations assuming full-load operation. (orig./HP))

  3. Nickel super alloy INCONEL 713LC - structural characteristics after heat treatment

    Directory of Open Access Journals (Sweden)

    A. Hernas

    2007-06-01

    Full Text Available Purpose: Nickel super alloy’s products are mainly using for construction parts of jet engines, gas turbines and turbo-blowers.Design/methodology/approach: Super alloy was commercially produced and was investigated by using the light microscopy (OLYMPUS IX 71 and local chemical microanalysis and by the scanning electron microscopy (JEOL JSM 50AFindings: We found a mode of optimum heat treatment. On the basis of obtained results it is possible to recommend a following regime of heat treatment: heating and dwell at the temperature exceeding 1240 °C (min. 1260 °C, so that precipitates at the grain boundaries dissolve completely, with subsequent slow cooling down to the temperature of approx. 940-950 °C, so that there occurs intensive intra-granular precipitation of intermetallic phase γ’.Research limitations/implications: The experiment was limited by occurrence a void in cast alloys.Practical implications: Nickel super alloy’s products are mainly using for construction parts of jet engines, gas turbines and turbo-blowers.Originality/value: Mode of optimum heat treatment was proposed. On the basis of obtained results it is possible to recommend the most suitable heat treatment, which produce intensive intra-granular precipitation of inter-metallic phase γ’. It was received a new know-how in this field.

  4. Satellite DNA Modulates Gene Expression in the Beetle Tribolium castaneum after Heat Stress.

    Science.gov (United States)

    Feliciello, Isidoro; Akrap, Ivana; Ugarković, Đurđica

    2015-08-01

    Non-coding repetitive DNAs have been proposed to perform a gene regulatory role, however for tandemly repeated satellite DNA no such role was defined until now. Here we provide the first evidence for a role of satellite DNA in the modulation of gene expression under specific environmental conditions. The major satellite DNA TCAST1 in the beetle Tribolium castaneum is preferentially located within pericentromeric heterochromatin but is also dispersed as single repeats or short arrays in the vicinity of protein-coding genes within euchromatin. Our results show enhanced suppression of activity of TCAST1-associated genes and slower recovery of their activity after long-term heat stress relative to the same genes without associated TCAST1 satellite DNA elements. The level of gene suppression is not influenced by the distance of TCAST1 elements from the associated genes up to 40 kb from the genes' transcription start sites, but it does depend on the copy number of TCAST1 repeats within an element, being stronger for the higher number of copies. The enhanced gene suppression correlates with the enrichment of the repressive histone marks H3K9me2/3 at dispersed TCAST1 elements and their flanking regions as well as with increased expression of TCAST1 satellite DNA. The results reveal transient, RNAi based heterochromatin formation at dispersed TCAST1 repeats and their proximal regions as a mechanism responsible for enhanced silencing of TCAST1-associated genes. Differences in the pattern of distribution of TCAST1 elements contribute to gene expression diversity among T. castaneum strains after long-term heat stress and might have an impact on adaptation to different environmental conditions.

  5. Satellite DNA Modulates Gene Expression in the Beetle Tribolium castaneum after Heat Stress.

    Directory of Open Access Journals (Sweden)

    Isidoro Feliciello

    2015-08-01

    Full Text Available Non-coding repetitive DNAs have been proposed to perform a gene regulatory role, however for tandemly repeated satellite DNA no such role was defined until now. Here we provide the first evidence for a role of satellite DNA in the modulation of gene expression under specific environmental conditions. The major satellite DNA TCAST1 in the beetle Tribolium castaneum is preferentially located within pericentromeric heterochromatin but is also dispersed as single repeats or short arrays in the vicinity of protein-coding genes within euchromatin. Our results show enhanced suppression of activity of TCAST1-associated genes and slower recovery of their activity after long-term heat stress relative to the same genes without associated TCAST1 satellite DNA elements. The level of gene suppression is not influenced by the distance of TCAST1 elements from the associated genes up to 40 kb from the genes' transcription start sites, but it does depend on the copy number of TCAST1 repeats within an element, being stronger for the higher number of copies. The enhanced gene suppression correlates with the enrichment of the repressive histone marks H3K9me2/3 at dispersed TCAST1 elements and their flanking regions as well as with increased expression of TCAST1 satellite DNA. The results reveal transient, RNAi based heterochromatin formation at dispersed TCAST1 repeats and their proximal regions as a mechanism responsible for enhanced silencing of TCAST1-associated genes. Differences in the pattern of distribution of TCAST1 elements contribute to gene expression diversity among T. castaneum strains after long-term heat stress and might have an impact on adaptation to different environmental conditions.

  6. Gender differences in pain and secondary hyperalgesia after heat/capsaicin sensitization in healthy volunteers

    DEFF Research Database (Denmark)

    Jensen, Magnus Thorsten; Petersen, Karin Lottrup

    2006-01-01

    , but not total pain, during prolonged noxious thermal stimulation was higher in women. There was no gender difference in pain ratings during capsaicin sensitization or in heat pain detection thresholds. The results provided only limited support to the hypothesis that gender differences in clinical pain syndromes....../capsaicin sensitization, and heat pain detection thresholds. There was a trend toward smaller areas of secondary hyperalgesia in women. After adjusting for estimated gender differences in forearm surface area, areas to brush but not von Frey hair stimulation after capsaicin sensitization were larger in women. Peak pain...... can be explained by enhanced central sensitization in women. PERSPECTIVE: Our findings suggest that gender differences in nociceptive transmission and neuronal sensitization are small and provide only limited support to the hypothesis that gender differences in acute and chronic pain syndromes can...

  7. A Study of the Surface Quality of High Purity Copper after Heat Treatment

    CERN Document Server

    Aicheler, M; Atieh, S; Calatroni, S; Riddone, G; Lebet, S; Samoshkin, A

    2011-01-01

    Themanufacturing flow of accelerating structures for the compact linear collider, based on diamond-machined high purity copper components, include several thermal cycles (diffusion bonding, brazing of cooling circuits, baking in vacuum, etc.). The high temperature cycles may be carried out following different schedules and environments (vacuum, reducing hydrogen atmosphere, argon, etc.) and develop peculiar surface topographies which have been the object of extended observations. This study presents and discusses the results of scanning electron microscopy (SEM) and optical microscopy investigations.

  8. Microstructural characterisation of vacuum sintered T42 powder metallurgy high-speed steel after heat treatments

    Energy Technology Data Exchange (ETDEWEB)

    Trabadelo, V. [CEIT and TECNUN, Paseo Manuel de Lardizabal 15, 20018 San Sebastian (Spain)], E-mail: vtrabadelo@tekniker.es; Gimenez, S.; Iturriza, I. [CEIT and TECNUN, Paseo Manuel de Lardizabal 15, 20018 San Sebastian (Spain)

    2009-01-15

    High-speed steel powders (T42 grade) have been uniaxially cold-pressed and vacuum sintered to full density. Subsequently, the material was heat treated following an austenitising + quenching + multitempering route or alternatively austenitising + isothermal annealing. The isothermal annealing route was designed in order to attain a hardness value of {approx}50 Rockwell C (HRC) (adequate for structural applications) while the multitempering parameters were selected to obtain this value and also the maximum hardening of the material ({approx}66 HRC). Microstructural characterisation has been carried out by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The microstructure consists of a ferrous (martensitic or ferritic) matrix with a distribution of second phase particles corresponding to nanometric and submicrometric secondary carbides precipitated during heat treatment together with primary carbides. The identification of those secondary precipitates (mainly M{sub 3}C, M{sub 6}C and M{sub 23}C{sub 6} carbides) has allowed understanding the microstructural evolution of T42 high-speed steel under different processing conditions.

  9. Microstructure and mechanical properties of Elektron 21 alloy after heat treatment

    Directory of Open Access Journals (Sweden)

    A. Kiełbus

    2007-01-01

    Full Text Available Purpose: Elektron 21 is new magnesium based casting alloy contains neodymium, gadolinium and zinc for usedto at 200°C. It is a Mg-RE-Zn-Zr alloy designed for aerospace and specialty application ns. This alloy has highstrength, good corrosion resistance and excellent castability. The aim of the research was to determine the effectof heat treatment parameters on the microstructure and mechanical properties of Elektron 21 magnesium alloyDesign/methodology/approach: Solution treatment was performed at 520°C/8h with water cooling. Ageingtreatments were performed at 200°C/4÷96h and then quenched in air. The microstructure was characterized byJEM 2010 ARP microscope The examination of the mechanical properties was conducted on an MTS-810 servohydraulic machine at two temperatures: ambient (ca. 20°C and 200°C. Hardness measurements by Vickersmethod were performed on a ZWICK/ZHV50 hardness tester.Findings: The microstructure of the cast alloy consists of α-Mg phase matrix with precipitates of intermetallicphase Mg12(Ndx,Gd1-x at grain boundaries. After solution treatment the Mg12(Ndx,Gd1-x phase dissolvesin the matrix. The aging treatment applied after solution treatment with air-cooling caused precipitation of a β”,β’ and β intermetallic phases. The best mechanical properties (Rm=308MPa, R0.2=170MPa, A5=9.5% has aalloy with β’ intermetallic phase.Research limitations/implications: The future research will contain microstructural investigations of Elektron21 alloy after creep tests.Practical implications: Elektron 21 magnesium alloy is used in the aircraft industry for engine casings, gearbox casings and rotor heads in helicopters. Results of investigation may be useful for preparing heat treatmenttechnology of the Mg-Nd-Gd alloys.Originality/value: The results of the researches make up a basis for the next investigations of magnesium alloyswith addition of Gd and Nd designed to exploitation at temperature to 300°C.

  10. Measurement and Analysis on Hardness and Residual Stress of Heavy Forging after Heat Treatment

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The hardness and residual stress in the forging for cold roller during low temperature tempering, and the relationship of residual stress and cooling temperature of high temperature tempering for heavy forgings were studied. The stress relaxation constant at low temperature tempering and the elasto-plastisity inversion temperature at high temperature tempering were found. The results are of great importance to determine rational tempering cooling process of heavy forgings.

  11. Wettability, Shrinkage and Color Changes of Araucaria angustifolia After Heating Treatment

    Directory of Open Access Journals (Sweden)

    Rodrigo Marques de Oliveira

    2010-09-01

    Full Text Available The effects of thermal treatment on the wettability and shrink resistance of Araucaria angustifolia (Parana pine were studied from 20 to 200 °C. The contact angles of water droplets on untreated and heat-treated samples were measured by the sessile drop method in the grain of heartwood and sapwood cut in the radial, longitudinal, and tangential directions. A significant increase of the contact angles was verified for the samples from room temperature to 120 °C, in particular in the radial and tangential directions; at higher temperatures, the contact angles assumed almost constant values. From 120 to 200 °C, the sapwood of Araucaria angustifolia showed better dimensional stability and lower thermal resistance when compared to the heartwood. Variations of color were also studied by using the CIELab system, which showed to be capable of accurately distinguishing samples treated at different temperatures.

  12. Surface roughness of Ti6Al4V after heat treatment evaluated by artificial neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Altug, Mehmet [Inonu Univ., Malataya (Turkey). Dept. of Machine and Metal Technologies; Erdem, Mehmet; Bozkir, Oguz [Inonu Univ., Malataya (Turkey); Ozay, Cetin [Univ. of Firat Elazig (Turkey). Faculty of Tech. Education

    2016-05-01

    The study examines how, using wire electrical discharge machining (WEDM), the microstructural, mechanical and conductivity characteristics of the titanium alloy Ti6Al4V are changed as a result of heat treatment and the effect they have on machinability. Scanning electron microscope (SEM), optical microscope and X-ray diffraction (XRD) examinations were performed to determine various characteristics and additionally related microhardness and conductivity measurements were conducted. L{sub 18} Taquchi test design was performed with three levels and six different parameters to determine the effect of such alterations on its machinability using WEDM and post-processing surface roughness (Ra) values were determined. Micro-changes were ensured successfully by using heat treatments. Results obtained with the optimization technique of artificial neural network (ANN) presented minimum surface roughness. Values obtained by using response surface method along with this equation were completely comparable with those achieved in the experiments. The best surface roughness value was obtained from sample D which had a tempered martensite structure.

  13. Ge nanoclusters in PECVD-deposited glass after heat treating and electron irradiation

    DEFF Research Database (Denmark)

    Ou, Haiyan; Rørdam, Troels Peter; Rottwitt, Karsten;

    2007-01-01

    This paper reports the formation of Ge nanoclusters in silica glass thin films deposited by plasma-enhanced chemical vapor deposition (PECVD). We studied the samples by transmission electron microscopy (TEM) and Raman spectroscopy after annealing. TEM investigation shows that the Ge nanoclusters at...... two areaswere formed by different mechanisms. The Ge nanoclusters formed in a single row along the interface of a silicon substrate and the silica glass film by annealing during high-temperature heat treatment. Ge nanoclusters did not initially form in the bulk of the film but could be subsequently...

  14. The first HF table, after heat treatment and ready to be machined in HEPCO, Arak (IRAN)

    CERN Multimedia

    Tiziano Camporesi

    2003-01-01

    The first HF support table 'load' tested by the team of people who have contributed to it from design to welding. This table will support the 240 tons of 1 HF detector and will integrate the raisers which will push it up to the beam line level. It is the first Iranian contribution to an HEP experiment.

  15. Time course of primary and secondary hyperalgesia after heat injury to the skin

    DEFF Research Database (Denmark)

    Møiniche, S; Dahl, J B; Kehlet, H

    1993-01-01

    We have examined the time course of, and relationship between, primary and secondary hyperalgesia after thermal injury to the skin in humans. Burn injuries (15 x 25 mm rectangular thermode, 49 degrees C, 5 min) were produced in eight healthy, unmedicated male volunteers, on the medial side...... of the right calf, on two occasions at least 8 days apart. Heat pain detection thresholds (HPDT), heat pain tolerance (HPT), mechanical pain detection threshold (MPDT) and the intensity of burn-injury induced erythema (skin erythema index, SEI) were assessed inside the burn injury. HPT was assessed only in one...... study period. Areas of hyperalgesia to pinprick and brush were determined outside the injury. Assessments were made before and regularly for 72 h after the burn injury. There was a decrease in heat pain and mechanical thresholds, an increase in SEI inside the injury and development of mechanical...

  16. Microstructural changes in padding welds made from the 713C alloy after heat treatment

    OpenAIRE

    M.B. Lachowicz

    2010-01-01

    The following paper presents the results of the metallographic research of the padding welds made from cast alloy Inconel 713C that had undergone heat treatment in four different time and temperature variants. Annealing was applied at temperatures 1150oC and 950oC. Theresults of the research showed a strong coalescence of precipitation of the intermetalic γ’ phase (Ni3Al), resulting in formation ofsubgrains. The coalescence of the γ’ particles ran simultaneously with a diffusive decomposition...

  17. Stress strain relationship of Tempcore steel after heating up to 650°C and cooling

    OpenAIRE

    Franssen, Jean-Marc

    1993-01-01

    Reinforcing bars of 12 mm and 25 mm have been tested, at room temperature, at elevated temperatures (steady state and transient conditions), and after cooling from elevated temperatures. No decrease of the residual strength was observed as long as the elevated temperature has not exceeded 600°C. A slight decrease seems to appear for elevated temperatures beyond 600°C. Additional test for elevated temperatures higher than 680°C should ideally be performed to confirm this trend.

  18. Microstructural changes in padding welds made from the 713C alloy after heat treatment

    Directory of Open Access Journals (Sweden)

    M. B. Lachowicz

    2010-07-01

    Full Text Available The following paper presents the results of the metallographic research of the padding welds made from cast alloy Inconel 713C that had undergone heat treatment in four different time and temperature variants. Annealing was applied at temperatures 1150oC and 950oC. Theresults of the research showed a strong coalescence of precipitation of the intermetalic γ’ phase (Ni3Al, resulting in formation ofsubgrains. The coalescence of the γ’ particles ran simultaneously with a diffusive decomposition of carbides (NbTiC, which caused thesupersaturation of the γ’ phase with niobium, and the loss of its coherence with austenite γ. The phenomenon of the formation of subgrains intensified with the lengthening of the time of annealing. The analysis of the results showed that heating the alloy that had undergone pad welding to the temperatures used in the research is detrimental to the alloy because of the loss of the strengthening of the coherent γ’ phase and the increase of the brittleness.

  19. Glucose-6-phosphate dehydrogenase of Saccharomyces cervisiae decreased in presence of titanium dioxide nanoparticles after heat-shock treatment

    OpenAIRE

    Capela-Pires, JM; I. Alves-Pereira; Ferreira, Rui

    2011-01-01

    The in vivo toxicity of titanium nanoparticles is manifested by the induction of inflammatory states or by the occurrence of geno toxic and cytotoxic effects that usually depend on the particle size and, therefore its surface area, photocatalytic activity and their tendency to aggregate. However we not found studies in the literature on the importance of temperature on the biological effects of nanoparticles in unicellular eukaryotes. Consequently, the main purpose of this work was to evaluat...

  20. Induction of Heat Shock Protein 72 in RGCs of Rat Acute Glaucoma Model after Heat Stress or Zinc Administration

    Institute of Scientific and Technical Information of China (English)

    Guoping Qing; Xuanchu Duan; Youqin Jiang

    2004-01-01

    Purpose :To investigate the dynamics of heat shock protein 72 (HSP72) expression in retinal ganglion cells (RGCs) in rat model of acute glaucoma treated with heat stress or intraperitoneal injection of zinc sulfate.Methods: Twenty-seven male Wistar rats were used to make acute glaucoma models. Five others served as normal control. Acute glaucoma models were made by intracameral irrigation in the right eyes with balanced salt saline (BSS) at 102 mmHg for 2 hours. Nine model rats were killed at different intervals after intracameral irrigation without treatment, which served as damage control. Ten were treated with heat stress 40℃~42℃, and 8 were used for zinc sulfate administration 2 days posterior to intracameral irrigation.Treated model rats were sacrificed at designed intervals after treatment. Right eyes were enucleated immediately, and the retinas were dissected for Western blot.Results: No HSP72 was found in RGCs of normal Wistar rats. In damage control group,slight HSP72 was detected during 6~36 hours posterior to intracameral irrigation. HSP72was detected significantly expressed in RGCs of both heat shock group and zinc sulfate group. But the dynamics of HSP72 production were quite different in these two treated groups. In heat shock group, HSP72 appeared at the sixth hour after treatment, and increased gradually until its peak production emerged at the 48th hour. HSP72 vanished 8days later after treatment. In zinc sulfate group, HSP72 expression began 24 hours later after zinc administration, and reached its highest level at the 72th hour posterior to treatment. HSP72 expression then decreased slowly, and disappeared 21 days later after treatment.Conclusion:HSP72 can be induced in RGCs of rat acute glaucoma models with heat stress or zinc sulfate adddministration. But the dynamics of the HSP72 induction in those two groups were quite different. Eye Science 2004;20:30-33.

  1. I’m Not Dead Yet:Bacterial Tales from the Crypt and Survival After Heat Treatment

    Science.gov (United States)

    Heat stress has been used as a method of killing bacteria for many years, and is one approach promulgated by federal regulations to reduce pathogens in biosolids (40 CFR 503). However, recent studies have suggested that heat stressed organisms may be able to recover and re-grow ...

  2. qPCR based mRNA quality score show intact mRNA after heat stabilization

    Directory of Open Access Journals (Sweden)

    Oskar Karlsson

    2016-03-01

    Full Text Available Analysis of multiple analytes from biological samples can be challenging as different analytes require different preservation measures. Heat induced enzymatic inactivation is an efficient way to preserve proteins and their modifications in biological samples but RNA quality, as measured by RIN value, has been a concern in such samples. Here, we investigate the effect of heat stabilization compared with standard snap freezing on RNA quality using two RNA extraction protocols, QiaZol with and without urea pre-solubilization, and two RNA quality measurements: RIN value, as defined by the Agilent Bioanalyzer, and an alternative qPCR based method. DNA extraction from heat stabilized brain samples was also examined. The snap frozen samples had RIN values about 1 unit higher than heat stabilized samples for the direct QiaZol extraction but equal with stabilized samples using urea pre-solubilization. qPCR based RNA quality measurement showed no difference in quality between snap frozen and heat inactivated samples. The probable explanation for this discrepancy is that the RIN value is an indirect measure based on rRNA, while the qPCR score is based on actual measurement of mRNA quality. The DNA yield from heat stabilized brain tissue samples was significantly increased, compared to the snap frozen tissue, without any effects on purity or quality. Hence, heat stabilization of tissues opens up the possibility for a two step preservation protocol, where proteins and their modifications can be preserved in the first heat based step, while in a second step, using standard RNA preservation strategies, mRNA be preserved. This collection strategy will enable biobanking of samples where the ultimate analysis is not determined without loss of sample quality.

  3. Starch gelatinization and in vitro digestibility behaviour after heat treatment: Comparison between plantain paste and piece of pulp.

    Science.gov (United States)

    Giraldo Toro, A; Gibert, O; Briffaz, A; Ricci, J; Dufour, D; Tran, T; Bohuon, P

    2016-08-20

    Over the 65-100°C range and at a water content of 1.6kgkg(-1)db, a comparison was conducted between plantain paste (dispersion made of flour and water) and pulp pieces after cooking to evaluate their respective degree of starch gelatinization (α) and in vitro digestibility. Below 76°C and at 100°C, the gelatinization behaviour of starch into pulp pieces and paste was similar, whereas at 85°C a significant mean relative difference was observed in between. For α in the 0-1 range, pieces of plantain pulp exhibited a lower rapidly digestible starch fraction (30%) and a higher resistant starch fraction (33%) than the flour paste, suggesting some structural effects. Both Weibull and exponential models showed a good fit for α over temperature range and starch digestibility fractions over α. Although no explicit relationship was established between the intact pulp structure and grinded flour state of plantain, the evaluation of the degree of starch gelatinization and digestibility of a plantain flour paste, could be used to predict the gelatinization and digestibility behaviour of plantain starch in entire pieces of pulp. PMID:27178949

  4. Living in cold homes after heating improvements: Evidence from Warm-Front, England's Home Energy Efficiency Scheme

    International Nuclear Information System (INIS)

    Objective: To investigate explanatory factors for persistent cold temperatures in homes which have received heating improvements. Design: Analysis of data from a national survey of dwellings and households (in England occupied by low-income residents) that had received heating improvements or repairs under the Warm Front Scheme. Methods: Over the winters of 2001-02 and 2002-03, householders recorded living room and main bedroom temperatures in a diary. Entries were examined for 888 households, which had received high level heating interventions. Two hundred and twenty-two households were identified as occupying cold homes, with mean bedroom temperature below 16 deg. C or mean living room temperatures below 18 deg. C. Binary logistic regression was used to model dwelling and household features and then occupants' behaviour and attitudes in the 'cold homes' sub-set compared with the remainder of the high intervention group. Seventy-nine supplementary, structured telephone interviews explored reasons given for lower temperatures. Using graphical and tabular methods, householders preferring cooler homes were distinguished from those who felt constrained in some way. Results: Cold homes predominate in pre-1930 properties where the householder remains dissatisfied with the heating system despite major improvements funded by Warm Front. Residents of cold homes are less likely to have long-standing illness or disability, but more likely to experience anxiety or depression. A small sample of telephone interviews reveals those preferring lower temperatures for health or other reasons, report less anxiety and depression than those with limited control over their home environment. Their 'thermal resistance' to higher temperatures challenges orthodox definitions of comfort and fuel poverty

  5. Aroma characterisation and retention after heat treatment and drying of fruits using extraction and GC-MS analysis

    OpenAIRE

    Ráice, Rui

    2015-01-01

    This study concerns the identification and characterisation of volatile components of fruits, and evaluation of the effect of heat treatment and drying on retention or loss of volatiles of fruits. The investigation included developing a procedure to extract volatile components from the fruit matrix, a purification step, separation, identification and quantification. Initial experiments with Vangueria infausta L. showed that some components, especially sugars, degrade during ...

  6. Living in cold homes after heating improvements: Evidence from Warm-Front, England's Home Energy Efficiency Scheme

    Energy Technology Data Exchange (ETDEWEB)

    Critchley, Roger [Centre for Regional Economic and Social Research, Sheffield Hallam University, City Campus, Howard Street, Sheffield, S1 1WB (United Kingdom); Gilbertson, Jan [Centre for Regional Economic and Social Research, Sheffield Hallam University, City Campus, Howard Street, Sheffield, S1 1WB (United Kingdom)]. E-mail: J.M.Gilbertson@shu.ac.uk; Grimsley, Michael [Centre for Regional Economic and Social Research, Sheffield Hallam University, City Campus, Howard Street, Sheffield, S1 1WB (United Kingdom); Green, Geoff [Centre for Regional Economic and Social Research, Sheffield Hallam University, City Campus, Howard Street, Sheffield, S1 1WB (United Kingdom)

    2007-02-15

    Objective: To investigate explanatory factors for persistent cold temperatures in homes which have received heating improvements. Design: Analysis of data from a national survey of dwellings and households (in England occupied by low-income residents) that had received heating improvements or repairs under the Warm Front Scheme. Methods: Over the winters of 2001-02 and 2002-03, householders recorded living room and main bedroom temperatures in a diary. Entries were examined for 888 households, which had received high level heating interventions. Two hundred and twenty-two households were identified as occupying cold homes, with mean bedroom temperature below 16 deg. C or mean living room temperatures below 18 deg. C. Binary logistic regression was used to model dwelling and household features and then occupants' behaviour and attitudes in the 'cold homes' sub-set compared with the remainder of the high intervention group. Seventy-nine supplementary, structured telephone interviews explored reasons given for lower temperatures. Using graphical and tabular methods, householders preferring cooler homes were distinguished from those who felt constrained in some way. Results: Cold homes predominate in pre-1930 properties where the householder remains dissatisfied with the heating system despite major improvements funded by Warm Front. Residents of cold homes are less likely to have long-standing illness or disability, but more likely to experience anxiety or depression. A small sample of telephone interviews reveals those preferring lower temperatures for health or other reasons, report less anxiety and depression than those with limited control over their home environment. Their 'thermal resistance' to higher temperatures challenges orthodox definitions of comfort and fuel poverty.

  7. F-center mechanism of long-term relaxation in lead zirconate-titanate-based piezoelectric ceramics. 1. After-heating relaxation

    Science.gov (United States)

    Ishchuk, V. M.; Kuzenko, D. V.

    2015-12-01

    Results of experimental investigation of relaxation aging processes in Pb(Zr,Ti)O3-based solid solutions after termination of external actions are presented. Heating, DC electric field, uniaxial pressure and some of their combinations were taken as external actions. In the main part of the present paper, we use heating as external action. The said processes are long-time one and are described by the logarithmic function of time. Reversible and nonreversible relaxation processes take place depending on the action intensity. The relaxation rate depends on the action intensity also, and the said dependence has nonlinear and nonmonotonic form if external action leads to domain disordering. The oxygen vacancies-based model for description of the long-time relaxation processes is suggested. The model takes into account oxygen vacancies on the sample’s surface ends, their conversion into F+- and F0-centers under external effects (due to the liberation of the pyroelectric charge) and subsequent relaxation of these centers into the simple oxygen vacancies after the actions termination. The initial sample’s state is electroneutrality one. F-center formation leads to the violation of the original sample’s electroneutrality, and generates DC electric field into the sample. Relaxation of F-centers is accompanied by decreasing of electric field, induced by them, and dielectric constant relaxation as consequent effect.

  8. An investigation of the microstructure and durability of a fluidized bed fly ash–metakaolin geopolymer after heat and acid exposure

    International Nuclear Information System (INIS)

    Highlights: • A geopolymer is proposed based on fluidized bed fly ash–metakaolin. • Geopolymer shows relatively lower mass loss and strength loss compared to ordinary Portland cement. • Geopolymer possesses good heat resistance and acid resistance compared to ordinary Portland cement. • A model is proposed for microstructure development. • Durability of geopolymer is demonstrated by monitoring the pore structure. - Abstract: This study aims to investigate durability and microstructure of fluidized bed fly ash and metakaolin based geopolymer exposed to elevated temperatures and acid attack. Geopolymer specimens were prepared by combination of fly ash and metakaolin activated by sodium silicate and sodium hydroxide solutions and were cured in microwave radiation environment plus a heat curing period. Compressive strength and several key durability parameters for geopolymer and ordinary Portland cement (OPC) were assessed and compared. Microstructure formation and development was characterized in terms of morphology and pore structure as well as simulation. The experimental results reveal a dense microstructure of geopolymer compared to OPC. In terms of resistance to the acidic solution and elevated temperatures, geopolymer is superior to OPC as indicated by the relatively lower strength loss and lower mass change. Compressive strength shows a dramatic drop in OPC while geopolymer shows a strength increase after 400 °C. The mass loss curves of geopolymer are similar to OPC, but it shows relatively lower mass loss compared to OPC. The result of saturated water absorption after 28 days curing indicates less water absorption in geopolymer before and after thermal and acid exposure. Durability of geopolymer is demonstrated by monitoring the pore structure

  9. Microstructure of Welded Joints of X5CrNiCuNb16-4 (17-4 PH Martensitic Stainlees Steel After Heat Treatment

    Directory of Open Access Journals (Sweden)

    Ziewiec A.

    2014-10-01

    Full Text Available The paper presents rezults of microstructure (LM, TEM investigation and hardness measurments of welded joints in martensitic precipitation hardened stainless steel containing copper, subjected to heat treatment. For the aging temperature up to 540 °C even for the very long times, the microstructure of the welded joints is similar to this one at lower temerature aging. After aging at 620 °C a distinct change of the microstructure was observed. Non-equilibrium solidification conditions of the weld metal, segregation and the diffusion of copper and the elements stablilizing the austenite cause the occurrence of the reverse transformation of the martensite into austenite as fast as just 1 hour at 620 °C. TEM investigations revealed the differences in dispersion of hardening copper precipitates after aging at temperature 620 °C for 1 and 4 hours.

  10. Structures and properties of the multi-component hot work tool steels of the 47CrMoWVTiCeZr16-26-8 type after heat treatment

    International Nuclear Information System (INIS)

    The paper presents structure and properties of the newly developed multi component hot work steel of the 47CrMoWVTiCeZr16-26-8 type. It has been found out that the 47CrMoWVTiCeZr16-26-8 steel after quenching and tempering has the lath martensite structure, partially twinned, with alloy carbides of the MC and M2C3 type, partially dissolved in the solid solution, and also of the dispersive carbides of the M4C3 and M7C3 responsible for the secondary hardness effect during tempering. Results of the tests of mechanical properties, thermal fatigue resistance, and structural examinations have been referred in part to the X40CrMoV5-1 standard hot work tool steel. Both austenitizing temperature and tempering temperature have a great influence on structure and properties of investigated steel. The highest values of the ultimate tensile strength, impact strength, and hardness are attained by the investigated steel after quenching from the temperature of 1120 oC and tempering at 540 oC, where as the maximum thermal fatigue resistance - after quenching and tempering at 600 oC. (author)

  11. Microstructure and properties of low carbon CuNiCrMnMo steel after heat treatment%低碳CuNiCrMnMo钢热处理后的组织与性能

    Institute of Scientific and Technical Information of China (English)

    程丙贵; 罗咪; 刘东升

    2011-01-01

    设计了一种低碳CuNiCrMnMo钢,并研究了3种热处理工艺(油淬+回火、水淬+回火和轧后直接淬火回火)条件下试验钢的组织与性能.试验钢经油淬和600 ℃回火1 h,屈服强度Rp0.2=645 MPa,抗拉强度Rm=745 MPa,-60 ℃冲击吸收能量为138 J;经水淬和650 ℃回火1 h,屈服强度Rp0.2= 668 MPa,抗拉强度Rm=721 MPa,-80 ℃下冲击吸收能量为216 J.经直接淬火和650 ℃回火1 h,达到最佳的强韧性匹配,即屈服强度Rp0.2=700 MPa,抗拉强度Rm=764 MPa,-80 ℃下冲击吸收能量为182 J.%A low carbon CuNiCrMnMo steel was designed and the microstructure and mechanical properties of the test steel processed by three different heat treatment conditions (oil quenching & tempering, water quenching & tempering as well as direct quenching after rolling & tempering) were investigated.The Rp0.2 of 668 MPa,Rm of 721 MPa, and impact absorbed energy (KV2 )of 138 J at -60 ℃ were achieved by oil quenching and tempering at 600 ℃ for 1 h,while the Rp0.2 of 668 MPa,Rm of 721 MPa and KV2 of 216 J at -80 ℃ were achieved by water quenching and tempering at 650 ℃ for 1 h.As expected, the best combination of strength and low temperature toughness was obtained in the direct quenched and tempered samples with the Rp0.2of 700 MPa,Rm of 764 MPa and KV2 of 182 J even at -80 ℃.

  12. The non-ohmic and dielectric behavior evolution of CaCu{sub 3}Ti{sub 4}O{sub 12} after heat treatments in oxygen-rich atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Qiaoli [College of Mathematics and Information Science, North China University of Water Resources and Electric Power, Zhengzhou 450011 (China); Li Tao, E-mail: hnlt529@163.com [Department of Technology and Physics, Zhengzhou University of Light Industry, Zhengzhou 450002 (China); Chen Zhenping; Xue Renzhong; Wang Yongqiang [Department of Technology and Physics, Zhengzhou University of Light Industry, Zhengzhou 450002 (China)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Heat-treating in oxygen-rich atmosphere can improve the percent of oxygen at grain boundaries of CCTO ceramics. Black-Right-Pointing-Pointer Heat-treating in oxygen-rich atmosphere can improve the dielectric properties of CCTO ceramics. Black-Right-Pointing-Pointer Heat-treating in oxygen-rich atmosphere can improve the non-ohmic behaviors of CCTO ceramics. Black-Right-Pointing-Pointer Heat-treating in oxygen-rich atmosphere can enhance the potential barrier of CCTO ceramics. Black-Right-Pointing-Pointer We have explained behavior between the permittivity and the non-ohmic characteristics of CCTO ceramics by the Schottky potential barrier theory. - Abstract: CaCu{sub 3}Ti{sub 4}O{sub 12} (CCTO) ceramics pellets were prepared using the solid-state reaction method, and then they were heat-treated at different temperatures in oxygen-rich atmosphere. The effect of heat treatments on the non-ohmic behaviors and dielectric properties were investigated. EDS analysis results indicate that the percent of oxygen at grain boundaries of CCTO ceramics heat-treated in oxygen-rich atmosphere increases markedly with the rise of temperature and approaches saturation state at about 850 Degree-Sign C. The breakdown voltage and nonlinear coefficient also exhibit an increase trend with the rise of temperature. In addition, the calculated results manifest that the height of Schottky potential barrier is closely related to the oxygen content at the grain boundaries. The permittivity and dielectric loss of samples heat-treated present a relatively intense decrease with the rise of temperature. But the permittivity has a behavior just reverse to the non-ohmic characteristics, which can be explained by the Schottky potential barrier theory.

  13. A comparative study of platinum nanodeposits on HOPG , MnO(100) and MnOx/MnO(100) surfaces by STM and AFM after heat treatment in UHV, O2 , CO and H2

    NARCIS (Netherlands)

    Tsybukh, Roman

    2010-01-01

    This thesis aimed at preparing and characterizing two different model catalysts after their exposure at different temperatures to oxygen, carbon monoxide and hydrogen. The experiments were performed in an ultra-high vacuum (UHV) set-up using a range of techniques including scanning tunneling and ato

  14. Thermal elongation of concrete during heating up to 700°C and cooling; Stress-strain relationship of Tempcore steel after heating up to 650°C and cooling

    OpenAIRE

    Franssen, Jean-Marc

    1993-01-01

    Experimental tests are reported on the thermal elongation of unloaded concrete specimen during heating and cooling. Steel reinforcing bars of Tempcore with diameters of 12 and 25 mm were tested at elevated temperature (steady state as well as transient situation) and also after cooling down to 20°C.

  15. Cr13马氏体不锈钢热处理后的显微组织和硬度%Microstructure and hardness of Cr13 martensite stainless steel after heat treatment

    Institute of Scientific and Technical Information of China (English)

    纪显彬; 李具仓; 王建泽; 钱张信

    2016-01-01

    20Cr13, 30Cr13 and 40Cr13 martensitic stainless steel were heated at different temperatures and then air-cooled, and effects of heat temperature and carbon content on microstructure and hardness were investigated .The results show that the martensite laths become coarse, trigeminal grain boundary appears and the hardness increases along with the increase of heating temperature .With the increase of carbon content , martensite and carbide increase , the lath martensite gradually transforms to plate martensite , and the hardness increases .%通过对20 Cr13、30 Cr13、40 Cr13马氏体不锈钢进行不同温度下空冷,研究了加热温度和碳含量对马氏体不锈钢显微组织和硬度的影响。结果表明:随加热温度升高,马氏体板条开始粗大,出现了枝状晶界,并且硬度增加;随碳含量增加,马氏体和碳化物增加,马氏体板条逐渐向片状过渡,并且硬度增加。

  16. Safety and environmental aspects of fusion reactors

    International Nuclear Information System (INIS)

    This paper deals with those problems concerning safety and environmental aspects of the future fusion reactors (e.g. fuel cycle, magnetic failure, after heat disturbances, radioactive waste and magnetic field)

  17. Thermal treatment of dissimilar steels' welded joints

    Science.gov (United States)

    Nikulina, A. A.; Denisova, A. S.; Gradusov, I. N.; Ryabinkina, P. A.; Rushkovets, M. V.

    2016-04-01

    In this paper combinations of chrome-nickel steel and high-carbon steel, produced by flash butt welding after heat treatment, are investigated. Light and electron microscopic studies show that the welded joints after heat treatment have a complex structure consisting of several phases as initial welded joints. A martensite structure in welded joints after thermal treatment at 300... 800 °C has been found.

  18. FATIGUE LIFE AND CRACK GROWTH BEHAVIOR IN ANNEALED AND NORMALIZED 0.83% CARBON STEEL

    OpenAIRE

    CHOBIN MAKABE; SHINYA YAMAZAKI; TATSUJIRO MIYAZAKI; MASAKI FUJIKAWA

    2015-01-01

    The variations of fatigue limit and fatigue life of a plain specimen of annealed and normalized 0.83% carbon steel were investigated. This material is used for cutting tools and the original microstructure includes a spherical microstructure. After heat treatment under some conditions, the microstructure changed to a lamellar microstructure. However, the fatigue lives of the plain specimens of this material showed almost the same tendency even after heat treatment under some conditions. In th...

  19. Cell proliferation in the murine epidermis and subcutaneous vascular endothelium after hyperthermia

    International Nuclear Information System (INIS)

    The proliferation characteristics of the vascular endothelial cells in the subepidermal stoma were investigated after heat treatment using [3H] thymidine labelling and labelling of epidermal basal cells studied and compared with endothelium cells. The stimulated proliferation of subcutaneous endothelial cells after heating for 30 and 60 min at 440C correlated well with the finding that these heat treatments, given after or shortly before X-irradiation, led to a greatly reduced (X-ray induced) tumour bed effect. (author)

  20. Effect of TRIPLEX heat treatment on tensile properties of in situ synthesized (TiB + La2O3)/Ti composite

    International Nuclear Information System (INIS)

    The effects of β and TRIPLEX heat treatment on the microstructure and on the tensile properties of in situ synthesized (TiB + La2O3)/Ti composite were studied. The phases were identified by X-ray diffraction. The microstructures of titanium matrix composite before and after heat treatment were characterized by optical microscopy. The reinforcements (TiB whiskers and La2O3) after heat treatment were observed by transmission electron microscopy (TEM). Both room temperature and high temperature (600 deg. C, 650 deg. C and 700 deg. C) tensile properties of the specimens were tested. The results showed that the microstructures of specimens after both β and TRIPLEX heat treatment were laminar α. The room temperature and high temperature ductility of TRIPLEX heat treatment was better than that of β heat treatment. Both TiB whiskers and La2O3 particles were stable after heat treatment.

  1. Effect of Heating on Hydrogen Retention in C-SiC Coatings

    Institute of Scientific and Technical Information of China (English)

    DU Jifu; REN Ding; ZHANG Ruiqian; LIU Ning; HUANG Ningkang

    2008-01-01

    C-SiC coatings were prepared on stainless steel with magnetron sputtering deposition followed by Argon ion bombardment. These samples were implanted by 5 keV hydrogen ion beam.SEM, SIMS and IR transmission were utilized to study the mechanism and the stability of hydrogen retention of C-SiC coatings. Comparison was made between the samples with and without removing Argon by heating then followed by H+ ion implantation. The results show that removal of argon by heating can improve the hydrogen retention of the C-SiC coatings. The thermal stability of hydrogen barrier for the C-SiC coatings was investigated, it is found that the property of hydrogen retention for the C-SiC coatings is still good after heating at 573 K, but it becomes worse after heating at 873 K, and it loses after heating at 1 173 K.

  2. Influence of heat treatment on microstructures and micro-hardness of n-SiO2/Ni composite coating

    Institute of Scientific and Technical Information of China (English)

    XU Bin-shi; WANG Hai-dou; DONG Shi-yun; JIANG Bin; TU Wei-yi

    2004-01-01

    The n-SiO2/Ni composite electro-brush plating coating was prepared on the 1045 steel substrate. SEM and TEM were utilized to analyze the surface and cross-section morphologies or the microstructures of the composite coating before and after heat treatment, as well as a micro-hardness tester was used to measure the micro-hardness before and after heat treatment. The results show that the entrance of nano SiO2 particles into composite coating makes the micro-hardness higher. After heat treatment, due to the obstruction to growth of Ni crystals from nano particles, the composite coating still possesses a higher micro-hardness than that of common Ni-base coating.

  3. Effect of using heat-inactivated serum with the Abbott human T-cell lymphotropic virus type III antibody test.

    OpenAIRE

    Jungkind, D. L.; DiRenzo, S A; Young, S J

    1986-01-01

    The Abbott enzyme immunoassay (Abbott Laboratories, North Chicago, Ill.) for human T-cell lymphotropic virus type III (HTLV-III) antibody was evaluated to determine the effect of using heat-inactivated (56 degrees C for 30 min) serum as the sample. Each of 58 nonreactive serum samples gave a higher A492 value when tested after heat inactivation. Ten of the samples became reactive after heating. Heat-inactivated serum should not be used in the current Abbott HTLV-III antibody test, because thi...

  4. Nanofibre growth from cobalt carbide produced by mechanosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Barriga-Arceo, L [Instituto Mexicano del Petroleo, Programa de Ingenieria Molecular, Eje Central Lazaro Cardenas 152, Colonia San Bartolo Atepehuacan, Mexico DF, 07730 (Mexico); Orozco, E [Instituto de Fisica UNAM, Apartado Postal 20-364 CP 01000, DF (Mexico); Garibay-Febles, V [Instituto Mexicano del Petroleo, Programa de Ingenieria Molecular, Eje Central Lazaro Cardenas 152, Colonia San Bartolo Atepehuacan, Mexico DF, 07730 (Mexico); Bucio-Galindo, L [Instituto de Fisica UNAM, Apartado Postal 20-364 CP 01000, DF (Mexico); Mendoza Leon, H [FM-UPALM, IPN, Apartado Postal 75-395 CP 07300, DF (Mexico); Castillo-Ocampo, P [UAM-Iztapalapa, Apartado Postal 55-334 CP 09340, DF (Mexico); Montoya, A [Instituto Mexicano del Petroleo, Programa de Ingenieria Molecular, Eje Central Lazaro Cardenas 152, Colonia San Bartolo Atepehuacan, Mexico DF, 07730 (Mexico)

    2004-06-09

    Mechanical alloying was used to prepare cobalt carbide. Microstructural characterization of samples was performed by x-ray diffraction, differential scanning calorimetry and transmission electron microscopy methods. In order to produce carbon nanotubes, the cobalt carbide was precipitated after heating at 800 and 1000 deg. C for 10 min. Nanofibres of about 10-50 nm in diameter, 0.04-0.1 {mu}m in length and 20-200 nm in diameter and 0.6-1.2 {mu}m in length were obtained after heating at 800 and 1000 deg. C, respectively, by means of this process.

  5. Influência da quantidade de amônio na síntese de nanopartículas de óxido de ferro por microemulsão The influence of ammonium quantity on the synthesis of iron oxide nanoparticles in microemulsion

    Directory of Open Access Journals (Sweden)

    Maria Tereza Cortez Fernandes

    2010-01-01

    Full Text Available Iron oxide nanoparticles were synthesized in microemulsion systems composed by Triton X-100/hexyl alcohol/cyclohexane/aqueous solution. The nanoparticles were synthesized in microemulsions containing different amounts of ammonium, in order to evaluate the influence of this parameter on the size of the nanoparticles and on the phase transformation after heat treatment. Powder materials were obtained after centrifugation, washing and drying, and they were analyzed as synthesized and after heating at 350, 500 and 1000 °C. It was observed that the higher amount of ammonium induced smaller particles and minor phase transformation, possibly due to a preferential nucleation process.

  6. Transient thermography for structural investigation of concrete and composites in the near surface region

    Science.gov (United States)

    Maierhofer, Ch.; Brink, A.; Röllig, M.; Wiggenhauser, H.

    2002-06-01

    The cooling down process of building structures after heating up with an external radiation source was analysed to detect voids inside and below the surface of a concrete test specimen containing voids with different sizes at various depth or covered with carbon fibre reinforcing laminates. These experimental investigations were compared to the results of simulations performed with a finite difference program.

  7. Efficiency of inherent protection mechanisms for an improved HTR safety concept

    International Nuclear Information System (INIS)

    For a preliminary design of a 350 MWsub(th) annular core derived from AVR-reactor the efficiency of inherent protection mechanisms is discussed. After-heat removal and auto-shut down potential are demonstrated for intact and complete failure of core heat sinks

  8. Acoustical-Levitation Chamber for Metallurgy

    Science.gov (United States)

    Barmatz, M. B.; Trinh, E.; Wang, T. G.; Elleman, D. D.; Jacobi, N.

    1983-01-01

    Sample moved to different positions for heating and quenching. Acoustical levitation chamber selectively excited in fundamental and second-harmonic longitudinal modes to hold sample at one of three stable postions: A, B, or C. Levitated object quickly moved from one of these positions to another by changing modes. Object rapidly quenched at A or C after heating in furnace region at B.

  9. ASSOCIATION OF HSP72 WITH THE NUCLEAR (TX-100-INSOLUBLE) FRACTION UPON HEATING TOLERANT AND NONTOLERANT HELA S3 CELLS

    NARCIS (Netherlands)

    KAMPINGA, HH; MULLER, E; BRUNSTING, JF; HEINE, L; KONINGS, AWT; ISSELS, RD

    1993-01-01

    HSP72 levels in the cellular and the nuclear (TX-insoluble) fraction before and after heating of heat- and sodium arsenite-induced thermotolerant and non-tolerant HeLa S3 cells have been investigated by ID- and 2D-electrophoresis, followed by Western blotting and immunostaining, using a newly develo

  10. Surface characterisation of dextran-coated iron oxide nanoparticles prepared by laser pyrolysis and coprecipitation

    Energy Technology Data Exchange (ETDEWEB)

    Carmen Bautista, M. [Instituto de Ciencia de Materiales de Madrid, CSIC, C Sor Juana Ines de la Cruz 3, Cantoblanco, 28049 Madrid (Spain); Bomati-Miguel, Oscar [Instituto de Ciencia de Materiales de Madrid, CSIC, C Sor Juana Ines de la Cruz 3, Cantoblanco, 28049 Madrid (Spain); Puerto Morales, Maria del [Instituto de Ciencia de Materiales de Madrid, CSIC, C Sor Juana Ines de la Cruz 3, Cantoblanco, 28049 Madrid (Spain); Serna, Carlos J. [Instituto de Ciencia de Materiales de Madrid, CSIC, C Sor Juana Ines de la Cruz 3, Cantoblanco, 28049 Madrid (Spain); Veintemillas-Verdaguer, Sabino [Instituto de Ciencia de Materiales de Madrid, CSIC, C Sor Juana Ines de la Cruz 3, Cantoblanco, 28049 Madrid (Spain)]. E-mail: sabino@icmm.csic.es

    2005-05-15

    The favoured mechanism of adsorption of dextran on the surface of maghemite nanoparticles (5 nm) prepared by laser pyrolysis seems to be the collective hydrogen bonding between dextran hydroxyl groups and iron oxide particle surface. After heating, the formation of a surface complex between the polysaccharide oxygen atoms and the surface iron atoms gave rise to a stronger bonding.

  11. Trehalose degradation and glucose efflux precede cell ejection during germination of heat-resistant acospores of Talaromyces macrosporus

    NARCIS (Netherlands)

    Dijksterhuis, J.; Driel, van K.G.A.; Sanders, M.G.; Molenaar, D.; Houbraken, J.A.M.P.; Samson, R.A.; Kets, E.P.W.

    2002-01-01

    Talaromyces macrosporus forms ascospores that survive pasteurization treatments. Ascospores were dense (1.3 g ml-1), relatively dry [0.6 g H2O (g dry weight)-1] and packed with trehalose (9-17␏resh weight). Trehalose was degraded to glucose monomers between 30 and 100 min after heat activation of th

  12. Trehalose degradation and glucose efflux precede cell ejection during germination of heat-resistant ascospores of Talaromyces macrosporus

    NARCIS (Netherlands)

    Dijksterhuis, Jan; van Driel, Kenneth G A; Sanders, Mark G; Molenaar, Douwe; Houbraken, Jos A M P; Samson, Rob A; Kets, Edwin P W

    2002-01-01

    Talaromyces macrosporus forms ascospores that survive pasteurization treatments. Ascospores were dense (1.3 g ml(-1)), relatively dry [0.6 g H(2)O (g dry weight)(-1)] and packed with trehalose (9-17% fresh weight). Trehalose was degraded to glucose monomers between 30 and 100 min after heat activati

  13. Corrosion resistance of electrodeposited RE-Ni-W-P-SiC composite coating

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Immersion experiment results show that corrosion rate of the as-deposited RE-Ni-W-P-SiC composite coating in HCl solutions increases with the rise of HCl concentration. On the contrary, the corrosion rate of the composite coating after heat treatment decreases with increasing HCl concentration. The corrosion rates of the composite coatings in as-deposited state and after heat treatment in H2SO4 and H3PO4 solutions respectively decrease with the rise of H2SO4 and H3PO4 concentrations. The corrosion rate of the composite coating as-deposited in FeCl3 solutions decreases with increasing FeCl3 concentration, while the rate of the composite coating after heat treatment increases with the rise of FeCl3 concentration. The corrosion rate of 316L stainless steel in the corrosion media of H2SO4, HCl, H3PO4 and FeCl3 solutions at different concentrations increases with rising concentration. In addition, the corrosion rate of 316L stainless steel in the corrosion media of H2SO4, HCl, H3PO4 and FeCl3 solutions respectively is much greater than that of the RE-Ni-W-P-SiC composite coating as-deposited and after heat treatment in the same corrosion media.

  14. Composition-Dependent Luminescent Properties of GeO2-Eu2O3-Ag Films

    Science.gov (United States)

    Bokshyts, Yu. V.

    2013-05-01

    An effect of Eu3+-precursor on the luminescent properties of GeO2-Eu2O3-Ag films was studied. This effect can be attributed to the different phase compositions of europium compounds after heat treatment and the change of structural parameters of the environment for europium ions.

  15. Physiological effects after exposure to heat : A brief literature review

    NARCIS (Netherlands)

    Bogerd, C.P.; Daanen, H.A.M.

    2011-01-01

    Many employees are exposed to heat stress during their work. Although the direct effects of heat are well reported, the long term physiological effects occurring after heat exposure are hardly described. The present manuscript addresses these issues in the form of a brief literature review. Repeated

  16. Sequence Classification: 890087 [

    Lifescience Database Archive (English)

    Full Text Available eric mitochondrial matrix chaperone that cooperates with Ssc1p in mitochondrial thermotolerance after heat shock; prevents the aggreg...ation of misfolded matrix proteins; component of the mitochondrial proteolysis system; Hsp78p || http://www.ncbi.nlm.nih.gov/protein/6320464 ...

  17. Sequence Classification: 892661 [

    Lifescience Database Archive (English)

    Full Text Available ecameric mitochondrial chaperonin required for ATP-dependent folding of precursor polypeptides and complex assembly; prevents aggrega...tion and mediates protein refolding after heat shock; role in mtDNA transmission; similarity to groEL; Hsp60p || http://www.ncbi.nlm.nih.gov/protein/6323288 ...

  18. 49 CFR 178.37 - Specification 3AA and 3AAX seamless steel cylinders.

    Science.gov (United States)

    2010-10-01

    ... diameter in inches; d = inside diameter in inches. (g) Heat treatment. The completed cylinders must be uniformly and properly heat treated prior to tests. Heat treatment of cylinders of the authorized analyses...) Intermediate manganese steels may be tempered at temperatures not less than 1150 °F., and after heat...

  19. Physical-mechanical properties and bonding quality of heat treated poplar (I-214 clone and ceiba plywood

    Directory of Open Access Journals (Sweden)

    Goli G

    2015-10-01

    Full Text Available The present paper investigates the physical and mechanical modifications of both poplar (I-214 clone and ceiba veneers and plywood after heat treatments of different intensities (5 and 7 % of dry mass losses. Plywood panels were glued before and after heat treatment with urea-formaldehyde (UF and melamine-urea-formaldehyde (MUF resins. In order to assess the treatments’ effects on both the wood and the glues, the dry mass, the density, the bending strength, the Young’s modulus and the bonding quality were measured before and after heat treatment. The results of the different treatments were compared as well. Results showed that the loss in cell wall polymers due to the heat treatment caused a significant reduction of the equilibrium moisture content of the samples. From a mechanical point of view the treatment resulted in an important reduction of strength and in a small reduction of stiffness. Bonding quality as well as mechanical properties were widely affected by the heat treatment. The different intensities of the treatments (the treatment range was up to 5% and 7% of dry mass loss did not show significant differences for most of the features assessed. The mechanical performance as well as the bonding quality of treated samples suggested that veneers should be glued after heat treatment. Apparent cohesive wood failure showed that different degradations affect wood and glues with a prominent effect on the glues for UF resins and a prominent effect on the wood for MUF resins.

  20. Niobium phosphates as an intermediate temperature proton conducting electrolyte for fuel cells

    DEFF Research Database (Denmark)

    Huang, Yunjie; Li, Qingfeng; Jensen, Annemette Hindhede;

    2012-01-01

    A new proton conductor based on niobium phosphates was synthesized using niobium pentoxide and phosphoric acid as precursors. The existence of hydroxyl groups in the phosphates was confirmed and found to be preserved after heat treatment at 500 °C or higher, contributing to an anhydrous proton...

  1. Enhanced upconversion emission in crystallization-controllable glass-ceramic fiber containing Yb3+-Er3+ codoped CaF2 nanocrystals

    Science.gov (United States)

    Peng, Wencai; Fang, Zaijin; Ma, Zhijun; Qiu, Jianrong

    2016-10-01

    Functional nanocrystal-containing materials have been a hot topic in recent years. However, few researches have focused on functional nanocrystals contained in optical glass fibers. In this research, transparent CaF2 glass-ceramic was prepared by a melt-quenching method. Greatly enhanced upconversion luminescence was observed after heat treatment. By applying a novel method called melt-in-tube, precursor fiber free of crystals was fabricated at the drawing temperature where the clad was softened while the core was melted. Glass-ceramic fiber with fiber core containing Yb3+-Er3+ codoped CaF2 nanocrystals was obtained after heat treatment at a relatively low temperature. Electron probe micro-analyzer measurement shows no obvious element diffusion between the core and clad. Greatly enhanced upconversion emission was detected in the glass-ceramic fiber excited by a 980 nm laser, suggesting the developed glass-ceramic fiber is a promising material for upconversion laser.

  2. Fluorescent Comparison of Sr2CeO4 Prepared from Carbonate and Oxalate Precursor

    Institute of Scientific and Technical Information of China (English)

    石士考; 栗俊敏; 王继业; 王瑞芬; 周济

    2004-01-01

    A blue-emitting phosphor powder, Sr2CeO4, was synthesized after heat-treatment to carbonate and oxalate precursors, which were obtained by co-precipitation reactions with respective ammonium compounds as precipitants. The phase formation and chemical purity of Sr2CeO4 powders were studied on XRD, TGA and XPS techniques. Their fluorescent performances were investigated and compared. The photoluminescence emission spectra for the phosphor prepared from respective precursors are similar, having a broad band with the peak at about 470 nm. However, their fluorescent intensities are different after heat-treatment at same conditions. The optimum condition to achieve superior Sr2CeO4 phosphor is confirmed.

  3. Development of methodology for measurements of residual stresses in welded joint based on displacement of points in a coordinated table

    Directory of Open Access Journals (Sweden)

    Aníbal Veras Siqueira Filho

    2013-04-01

    Full Text Available Residual stresses in a welded joint of ASTM A131 grade AH32 steel was measured either by the X-ray diffraction or by displacements of referenced points measured on a coordinate measuring machine before and after heat treatment. For all tests, the welding was performed with Shielded Metal Arc Welding, vertical-up position, by a certified welder. After welding, some specimens were subjected to marking, made through small holes evenly spaced and mapped on a coordinate measuring machine. After labeling, the samples were subjected to heat treatment at temperatures nearby recrystallization. After heat treatment, the samples were subjected to new measurements by coordinate measuring machine to evaluate the displacements of the points produced by the recrystallization. In parallel, residual stress measurements were made by XRD for validation of this new methodology. The results obtained either by X-ray or by coordinate measuring machine showed a good correlation between the two measurement methodologies employed.

  4. Self-healing of cracks in Ag joining layer for die-attachment in power devices

    Science.gov (United States)

    Chen, Chuantong; Nagao, Shijo; Suganuma, Katsuaki; Jiu, Jinting; Zhang, Hao; Sugahara, Tohru; Iwashige, Tomohito; Sugiura, Kazuhiko; Tsuruta, Kazuhiro

    2016-08-01

    Sintered silver (Ag) joining has attracted significant interest in power devices modules for its ability to form stable joints with a porous interconnection layer. A function for the self-healing of cracks in sintered porous Ag interlayers at high temperatures is discovered and reported here. A crack which was prepared on a Ag joining layer was closed after heating at 200 °C in air. The tensile strength of pre-cracked Ag joining layer specimens recovers to the value of non-cracked specimens after heating treatment. Transmission electron microscopy (TEM) was used to probe the self-healing mechanism. TEM images and electron diffraction patterns show that a large quantity of Ag nanoparticles formed at the gap with the size less than 10 nm, which bridges the crack in the self-healing process. This discovery provides additional motivation for the application of Ag as an interconnection material for power devices at high temperature.

  5. Influence of cold work and sigma phase on the pitting corrosion behavior of 25 chromium super duplex stainless steel in 3.5% sodium chloride solution.

    Energy Technology Data Exchange (ETDEWEB)

    Elhoud, A.; Deans, W. [School of Engineering, Kings College, University of Aberdeen (United Kingdom); Ezuber, H. [College of Engineering, University of Bahrain (Bahrain)

    2010-03-15

    The effect of cold work (up to 16% strain) and sigma phase precipitation (at 850 C for 10 and 60 min) on the pitting resistance of 25 chromium super duplex stainless steel were investigated in 3.5% sodium chloride solution at 70 and 90 C. Anodic polarization scans for cold worked samples revealed immunity to pitting attack at 70 C even with 16% strain. At 90 C, the alloy still showed high pitting resistance, pitting occurring at about 600 mV (SCE) for the 16% plastic strain samples. A serious deterioration of the pitting corrosion resistance was found after heating the alloy at 850 C for 10 min resulting in a clear drop in the pitting potential at 90 C. After heating for 60 min, the material showed rapid deterioration of pitting corrosion resistance at 70 C. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  6. Proton dynamics in Rb{sub 3}H(SO{sub 4}){sub 2} doped with Mn{sup 2+} studied by EPR and impedance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ostrowski, A; Bednarski, W [Institute of Molecular Physics, Polish Academy of Sciences, M Smoluchowskiego 17, PL-60-179 Poznan (Poland)], E-mail: ostrowski@ifmpan.poznan.pl

    2009-05-20

    The temperature dependence of the linewidth {delta}B{sub pp} and spin Hamiltonian parameters of Rb{sub 3}H(SO{sub 4}){sub 2} (RHS) crystals were studied by X-band continuous-wave electron paramagnetic resonance. Direction cosines of the zero-field-splitting (ZFS) tensor and the coordination of the Mn{sup 2+} impurities in the crystal lattice were determined in the temperature range 20-450 K. The EPR spectra of crystalline samples and their irreversible changes into pseudo-powder spectra after heating above the superprotonic phase transition temperature were found. Our studies of electric conductivity have shown that, for crystals doped with Mn{sup 2+} ions, the conductivity values increase after heating by about one order of magnitude at intermediate temperatures (below the transition temperature to the superionic phase) in comparison with those of the pure RHS.

  7. Thermostability of bovine submaxillary mucin (BSM) in bulk solution and at a sliding interface

    DEFF Research Database (Denmark)

    Madsen, Jan Busk; Pakkanen, Kirsi I.; Lee, Seunghwan

    2014-01-01

    as characterized by circular dichroism (CD) spectroscopy, but this change was fully reversible upon lowering temperature. Extended heating up to 120min at 80°C did not make any appreciable changes in the structure of BSM when it was cooled to room temperature. The hydrodynamic size of BSM, as studied by dynamic...... light scattering (DLS), showed a slight increase after heating at high temperature (80°C). Optical waveguide lightmode spectroscopy (OWLS) studies showed facile adsorption of BSM onto poly(dimethylsiloxane) (PDMS) surface (>180ng/cm2) at room temperature due to its amphiphilic characteristics. Adsorbed...... mass of BSM was noticeably reduced after heating at 80°C, possibly resulting from its aggregation. BSM showed excellent lubricity at self-mated sliding contacts between PDMS at room temperature or lower (friction coefficient≈0.02), even when BSM solution was pre-heated up to 120min at 80°C. Gradual...

  8. Influence of Heating on the Structure of Hyaluronan

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Hyaluronan may be used in tissue engineering as a scaffold, and since the scaffold should degrade after the cells have proliiferated, and heat treatment is a method to achieve low molecular weight material.In this essay, we developed a new method to choose the characteristic heat treatment temperature, and applied a simple method to prepare the hyaluronan scaffold. We have acquired the TG and DTA curves of hyaluronan by thermal analysis, according to which we selected 310 ℃ ,375 ℃ and 500 ℃ as the heat treatment points. After heat treatment, test the infrared spectrum of the powder respectively. In conclusion, the scaffold formed by lyophilization exhibits a porous structure, and the occurrence of new groups after heating assumes the change of the molecular chain.

  9. A new approach for hydrogen generation from sewage sludge.

    Science.gov (United States)

    Zhang, Qiwu; Kano, Junya

    2016-02-01

    A new process to produce hydrogen efficiently from sewage sludge (SWS) was developed with co-grinding operation of the dried SWS with calcium and nickel hydroxides (Ca(OH)2 and Ni(OH)2) and subsequent heating of the ground mixture at relatively low temperature below 600°C. A set of analytical methods were used to characterize the ground samples before heating and the gaseous and solid products after heating. Thermo-mass spectroscopic (TG-MS) analysis showed hydrogen occurrence around 450°C. Hydrogen yield over 70g per kg SWS with concentration of 93.6% was obtained with the hydroxide additions of Ca to C from SWS at 1:1 and Ni to C at 1:6, respectively. X-ray diffraction (XRD) analysis of the solid residues after heating confirmed the existences of calcium carbonate and nickel metal. Based on the obtained results, possible reaction pathway was proposed. PMID:26642224

  10. Oesophageal heat transfer properties indication of segmental blood flow changes during distension

    DEFF Research Database (Denmark)

    Liao, Donghua; Frøkjær, Jens Brøndum; Brock, Christina;

    2008-01-01

    on measurement of heat transfer. A bag was distended in the distal oesophagus of six healthy subjects followed by cooling or heating of the bag fluid to 5 or 60 degrees C. After equilibrium, the temperature was allowed to change back to body temperature. The temperature was recorded together with intraluminal...... ultrasound imaging, allowing assessment of the heat transfer properties at different bag volumes. The heat transfer constants were higher after heating the bag than after cooling the bag (Tukey, P heat transfer constants after heating the bag decreased as function of bag volumes whereas the heat...... transfer during cooling was not affected by the bag volume (F = 0.9, P = 0.4). The findings indicate that segmental blood flow can be assessed indirectly by calculating the heat transfer properties. Distension induced a drop in regional blood flow. Hence, ischaemia may contribute to distension-induced pain...

  11. Study of solid-state reaction in Fe/Zr layer systems by 97Fe Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    The paper examines, under UHV conditions, vapour-deposited, polycrystalline Fe/Zr multiple layers after heat treatment ex situ and in situ by means of the Moessbauer spectroscopy. It shows that, as a consequence of solid-state reaction, an amorphous Fe-Zr-phase is formed. From the Moessbauer spectra the mean Fe concentration of the amorphous phase was determined. In contrast to that no amorphization was observed after heat treatment under similar conditions at a polycrystalline Fe layer which had been vapour-deposited on a surface-physically relatively clean and orderly Zr(0001) monocrystal surface, instead the formation of the crystalline intermetallic compound FeZr3 was observed. The result proves that grain boundaries of the polycrystalline Zr layers at the Fe/Zr interface act as nucleation on centers for the amorphous Fe-Zr phase. (orig.)

  12. Heat stress and recovery of photosystem II efficiency in wheat (Triticum aestivum L.) cultivars acclimated to different growth temperatures

    DEFF Research Database (Denmark)

    Haque, Sabibul; Kjær, Katrine Heinsvig; Rosenqvist, Eva;

    2014-01-01

    at different growth stages. The secondary aim was to investigate whether a pre-acclimation of plants to elevated temperature during the growth period induces a better tolerance to heat stress than for plants grown in ambient temperature or not. The plants were grown in two growth temperature conditions (15 °C...... compared to plants grown at 15 °C. The relative leaf chlorophyll content decreased significantly after heat stress in all cultivars at all growth stages. The elevated growth temperature (25 °C) accelerated plant growth resulting in early heading and reduced grain yield in comparison to ambient temperature...... and 25 °C) and subjected to heat stress (40 °C) for two days at early tillering and three days at anthesis and early grain development stages. The plants were returned to their original growth conditions after heat stress and recovery was observed for three days. The maximum photochemical efficiency (Fv...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Effect of Sm Volatilization on Magnetic Microstructures of Sintered Sm(Co,Fe,Cu,Zr)z Magnets at High Temperatures

    Institute of Scientific and Technical Information of China (English)

    XIA Ai-Lin; FANG Yi-Kun; GUO Zhao-Hui; LI Wei; HAN Bao-Shan

    2006-01-01

    @@ We present a magnetic force microscopy study of surface magnetic microstructure changes at high temperatures in 2:17-type Sm( Co, Fe, Cu,Zr)z (z ~ 7.4) magnets. Surface magnetic microstructures are found to change greatly in parallel and vertical specimens after heat-treatment at 400℃ for one hour in vacuum of 10-5 Torr with Ar gas as protecting atmosphere. Changes of microstructures are attributed to the formation of a soft-magnetic surfaces layer in the specimens, resulting from Sm volatilization due to high temperature. This hypothesis is further confirmed by the heat-treatment experiments at 400℃ for 0.5 h and 2 h. Finally, the existence of the soft-magnetic layers, which consist primarily of Fe-Co compounds, is verified by the results of both XRD and XPS of the vertical specimens before and after heat-treatment.

  15. Effect of Microstructure on Wear Behavior of Iron Aluminide Based Coatings

    Institute of Scientific and Technical Information of China (English)

    ZHUZi-xin; LIUYan; XUBin-shi; ZHANGWei; MAShi-ning

    2004-01-01

    An experimental study has been carried out to investigate the effect of microstructure on sliding wear behavior of Fe-Al coatings and Fe-Al/WC composite coatings produced by high velocity arc spraying (HVAS) and cored wires. After heat treatment at 300℃, 450℃, 550℃, 650℃ and 800℃, the microstructure of the coatings will be changed. The changes of microstructure have obvious effects on the microhardness of the coatings, which may be the most important factor influencing the coatings sliding wear behavior. After heat treated at 450℃-650℃, increasing of the amounts of iron aluminides (including Fe3Al and FeAl ) and dispersion strengthening of FeEWEC and Fe6W6C will lead to a rise of microhardness of the coatings. Increasing the microhardness through heat treatment would improve the sliding wear resistance of the iron aluminide based coatings coatings.

  16. Effect of Microstructure on Wear Behavior of Iron Aluminide Based Coatings

    Institute of Scientific and Technical Information of China (English)

    ZHU Zi-xin; LIU Yan; XU Bin-shi; ZHANG Wei; MA Shi-ning

    2004-01-01

    An experimental study has been carried out to investigate the effect of microstructure on sliding wear behavior of Fe-Al coatings and Fe-Al/WC composite coatings produced by high velocity arc spraying (HVAS) and cored wires. After heat treatment at 300℃, 450℃, 550℃, 650℃ and 800℃, the microstructure of the coatings will be changed. The changes of microstructure have obvious effects on the microhardness of the coatings, which may be the most important factor influencing the coatings sliding wear behavior. After heat treated at 450℃-650℃, increasing of the amounts of iron aluminides (including Fe3Al and FeAl ) and dispersion strengthening of Fe2W2C and Fe6W6C will lead to a rise of microhardness of the coatings. Increasing the microhardness through heat treatment would improve the sliding wear resistance of the iron aluminide based coatings coatings.

  17. Microstructure of MCMgAl12Zn1 magnesium alloy

    Directory of Open Access Journals (Sweden)

    Dobrzański L. A.

    2007-01-01

    Full Text Available In this paper is presented the structure of the cast magnesium alloys as cast state and after heat treatment cooled with different cooling rate, depending on the cooling medium (furnace, water, air. For investigations samples in shape of 250x150x25 mm plates were used. The structure have been study in the light microscope, scanning electron microscope equipped with an electron back scattering facility. The effects of the addition of Al on the microstructure were also studied. In the analysed alloys a structure of α solid solution and fragile phase β(Mg17Al12 occurred mainly on grain borders as well as eutectic and phase with Mn, Fe and Si. Investigation are carried out for the reason of chemical composition influence and precipitation processes influence to the structure and mechanical properties of the magnesium cast alloys with different chemical composition in as cast alloys and after heat treatment.

  18. Interfacial Shear Strength Measurements of SiC Fiber-Reinforced Titanium Composites

    Institute of Scientific and Technical Information of China (English)

    Yanhua LI; Nanlin SHI; Dezhi ZHANG; Rui YANG

    2005-01-01

    A continuous loading push-out test technique was used to measure the interfacial shear strength of SiC fiber reinforced Ti matrix composites. The interracial shear strength of samples as-fabricated and after heat exposed at 700 and 800℃ for 50 h was successfully determined. It has been found that the interfacial shear strength of the specimen exposed at 700℃ was higher than that of as-prepared and exposed samples at 800℃. The shear strength of the as-prepared samples was about 112.45 MPa, and increased to about 153.77 MPa after heat-treating at 700℃ for 50 h, but decreased to 133.11 MPa after treating at 800℃ for 50 h. Scanning electron microscope (SEM) was used to investigate the interfacial morphology of the samples. The brittle phase was the main products of interface for samples exposed at 800℃, and the interface was easily peeled off.

  19. Crystallization Kinetics of Calcium-magnesium Aluminosilicate (CMAS) Glass

    Science.gov (United States)

    Wiesner, Valerie L.; Bansal, Narottam P.

    2015-01-01

    The crystallization kinetics of a calcium-magnesium aluminosilicate (CMAS) glass with composition relevant for aerospace applications, like air-breathing engines, were evaluated using differential thermal analysis (DTA) in powder and bulk forms. Activation energy and frequency factor values for crystallization of the glass were evaluated. X-ray diffraction (XRD) was used to investigate the onset of crystallization and the phases that developed after heat treating bulk glass at temperatures ranging from 690 to 960 deg for various times. Samples annealed at temperatures below 900 deg remained amorphous, while specimens heat treated at and above 900 deg exhibited crystallinity originating at the surface. The crystalline phases were identified as wollastonite (CaSiO3) and aluminum diopside (Ca(Mg,Al) (Si,Al)2O6). Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were employed to examine the microstructure and chemical compositions of crystalline phases formed after heat treatment.

  20. Process and container for storage and/or transport of radioactive fuel elements and bulk goods for use in the process

    International Nuclear Information System (INIS)

    In order to improve the after-heat removal during the transport of fuel elements to a reprocessing plant, the space between one or more fuel elements and the wall of the container is filled up with small particles of stainless steel. This fill glass powder, Hf or B is added to. The filling can be effected below water surface. Moreover, the hollow spaces of the fill are evacuated and then made up with He or N. (DG)

  1. Production chain of CMS pixel modules

    CERN Multimedia

    2006-01-01

    The pictures show the production chain of pixel modules for the CMS detector. Fig.1: overview of the assembly procedure. Fig.2: bump bonding with ReadOut Chip (ROC) connected to the sensor. Fig.3: glueing a raw module onto the baseplate strips. Fig.4: glueing of the High Density Interconnect (HDI) onto a raw module. Fig.5: pull test after heat reflow. Fig.6: wafer sensor processing, Indium evaporation.

  2. Heterogeneity of mitochondrial DNA from Saccharomyces carlsbergensis. Denaturation mapping by electron microscopy.

    DEFF Research Database (Denmark)

    Christiansen, Gunna; Christiansen, C; Bak, AL

    1975-01-01

    Electronmicroscopic observation of the denaturation pattern of 130 partially denaturated linear mitochondrial DNA molecules from Saccharomyces carlsbergensis was used to investigate the distribution of AT-rich sequences within the mitochondrial genome. The molecules were observed after heating...... denaturated sequences in the mitochondrial DNA. These sequences which presumably correspond to the very AT-rich regions, known to exist in the yeast mitochondrial DNA, were found at intervals of about 0.5 - 3 mum on the map....

  3. Influence of Heat Treatment on Residual Stress in Cold-Forged Parts

    OpenAIRE

    Frederico Ozanan Neves; Thiago Luis Lara Oliviera; Durval Uchoas Braga; Alex Sander Chaves da Silva

    2014-01-01

    Residual stresses are those stresses that remain in a body when there is no external load applied. Numerous factors can induce residual stresses in the material, including cold forming. Thermal treatments of steel are widely used because they can improve the mechanical properties of the steel, such as toughness, tenacity, and resistance; however, thermal treatments can also produce residual stresses. This study aims to analyze the residual stresses present in a cold-forged part after heat tre...

  4. Efecto de la temperatura sobre películas de un aislado proteico del suero bovino (WPI) adsorbidas sobre la interfase aceite-agua

    OpenAIRE

    Rodríguez Patino, Juan M.; Carrera Sánchez, Cecilio; Rodríguez Niño, Mª Rosario

    2002-01-01

    Heat-induced interfacial aggregation of a whey protein isolate (WPI) with a high content of β-lactoglobulin, previously adsorbed at the oil-water interface, was studied by interfacial dynamic characteristics (interfacial tension and surface dilational properties) performed in a automatic drop tensiometer coupled with microscopic observation and image analysis of the drop after heat-treatment. The temperature, ranging between 20 and 80 ºC, and protein concentration in aqu...

  5. Transient Thermal Behavior of a Vertical Solar Storage Tank with a Mantle Heat Exchanger During No-Flow Operation

    OpenAIRE

    A. Barzegar; A. A. Dehghan

    2009-01-01

    Transient thermal behavior of a vertical storage tank of a domestic solar heating system with a mantle heat exchanger has been investigated numerically in the charging mode. It is assumed that the tank is initially filled with uniform cold water. At an instant of time, the hot fluid from collector outlet is uniformly injected in the upper section of the mantle heat exchanger and after heat transfer with the fluid inside the tank, withdrawn from the bottom part of the heat excha...

  6. Physiological responses of broiler chickens to heat stress and dietary electrolyte balance (sodium plus potassium minus chloride, milliequivalents per kilogram).

    Science.gov (United States)

    Borges, S A; Fischer da Silva, A V; Majorka, A; Hooge, D M; Cummings, K R

    2004-09-01

    Individually caged male Cobb broilers (24), 44 d of age, were used to evaluate effects of heat stress (1 d of data collection) and dietary electrolyte balance (DEB; Na + K - Cl, mEq/kg from 1 d of age). During summer rearing, mortality was variable, but DEB 240 improved growth, feed conversion ratio, water intake, and water:feed ratio vs. DEB 0. The temperature sequence for heat stress was 24 to 32 degrees C in 30 min, 32 to 36 degrees C in 30 min, 36 to 37 degrees C in 15 min, and 37 to 41 degrees C in 45 min. Maximum temperature was held for 15, 60, 90, or 360 min for data collection (relative humidity averaged 42 +/- 7%). Results from the same room before and after heat stress were analyzed by DEB (1-factor ANOVA) and before vs. after heat stress compared across DEB (2-sample t-test). Heat stress decreased blood Na, K, and pCO2, and lymphocytes but increased heterophils. Blood HCO3 rose, Cl declined, and hematocrit gave a concave pattern (lowest at DEB 120) as DEB increased. After heat stress, DEB 0 decreased blood Na and K, and DEB 0 and 120 levels decreased blood HCO3. After heat stress blood pCO2 and hemoglobin decreased with DEB 240, but it had highest pCO2, a key factor. The DEB 120 gave longest times to panting and prostration with DEB 0 and 240 results lower but similar statistically. In heat stress, DEB 360 was excessive, DEB 120 and 240 were favorable, and DEB 0 was intermediate based on hematology, panting, and prostration responses.

  7. Investigation on Behavior of Rare Earth Element Cerium in Aluminum-Lithium Alloys by Internal Friction Method

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The behavior of rare earth element Ce in 2090 Al-Li alloys was studied by the method of low frequency internal friction.The results showed that rare earth element Ce can increase the activation energy of grain boundary and improve the grain boundary strength of alloys.Rare earth element Ce can decrease the tendency of softening of elastic modulus of 2090 Al-Li alloys after heat cycle and keep high elastic modulus of initial state.

  8. Strong thermo-induced single and two-photon green luminescence in self-organized peptide microtubes.

    Science.gov (United States)

    Semin, S; van Etteger, A; Cattaneo, L; Amdursky, N; Kulyuk, L; Lavrov, S; Sigov, A; Mishina, E; Rosenman, G; Rasing, Th

    2015-03-01

    Diphenylalanine peptide nano- and microtubes formed by self-assembly demonstrate strongly enhanced and tunable single-photon and two-photon luminescence in the visible range, which appears after heat- or laser treatment of these self-organized peptide microtubes. This process significantly extends the functionality of these microstructures and can trigger a new interest in the optical properties of structures based on short peptides. PMID:25074710

  9. Experimental and numerical study of strength mismatch in cross-weld tensile testing

    OpenAIRE

    Acar, Murat O.; Gungor, Salih

    2015-01-01

    The mechanical properties of welded boiler tubes used in power plants can be significantly altered as a result of the fabrication history, such as pre-straining and heat treatment. The primary aim of the study was to determine the effect of fabrication history on local tensile properties across the welds. This was achieved by testing cross-weld specimens machined from welded thin-walled tubes (with unstrained or pre-strained base metal) before and after heat treatment. Digital image correlati...

  10. INHIBITION OF Salmonella BY ROSEMARY EXTRACTS (Rosmarinus officinalis): EFFECT OF WATER AND ETHANOL EXTRACTS INIBIÇÃO DE SALMONELLA POR EXTRATO DE ALECRIM (Rosmarinus officinalis): EFEITO DOS EXTRATOS ETANÓLICOS E AQUOSO

    OpenAIRE

    Paulo César Stringheta; Magdala Alencar Teixeiras; Alonso Salustiano Pereira; Maria Célia Lopes Torres

    2007-01-01

    Inhibitory effects presented by ethyl alcoholic and aquous extracts of rosemary were analyzed, obtained in Soxhlet and after heating at 121°C for 10 minutes, respectively, on seven species of Salmonella isolated from chicken. The presence of bactericidal active principle of rosemary in aquous and ethyl alcoholic extracts, its concentration with inhibitory effect on Salmonella, ";in vitro”, and the occurrence of a p...

  11. Pressureless bonding process using Ag nanoparticle paste for flexible electronics packaging

    International Nuclear Information System (INIS)

    We have developed a new method for preparing a paste containing a high concentration of Ag nanoparticles for pressureless bonding. A nanoscale layer of polyvinylpyrrolidone coated on the nanoparticles prevents the coalescence of Ag nanoparticles. After heating in air, sintering and bonding occur after the decomposition of polyvinylpyrrolidone. Joint strengths were increased significantly using this new Ag nanoparticle paste as bonding material. Robust joints with shear strength above 20 MPa were formed even without additional bonding pressure.

  12. Influence de la composition en acides gras du lait et des paramètres de fabrication sur la qualité de la crème glacée

    OpenAIRE

    Smet, Karen; Block, Jan; Van Der Meeren, Paul; Raes, Katleen; Dewettinck, Koen; Coudijzer, Katleen

    2010-01-01

    International audience There has been considerable interest in recent years in altering the fatty acid composition of milk fat in dairy products to improve the long-term health of consumers. The objective of this study was to investigate the influence of altering the fatty acid composition and varying two process parameters (homogenization pressure and ageing temperature) on the quality of ice cream. The quality of ice cream (8% fat) was monitored before and after heat shock by assessing f...

  13. Electrical doping of Hg Cd Te by ion implantation and heat treatments

    International Nuclear Information System (INIS)

    The general properties of junctions made by ion implantation in Hg Cd Te semiconductor are recalled structure of junctions made by implantation damage, defects, anneals, junctions made by active impurities. The effect of acceptor evolution in this semiconductor after heat treatments and a study of the kinetics are presented. Very high quality devices with very small size and large two-dimensional arrays are shown to be possibly achieved using ion implantation technique of junction formation in the semiconductor epilayers grown by LPE

  14. The heat shock-induced hyperphosphorylation of τ is estrogen-independent and prevented by androgens: Implications for Alzheimer disease

    OpenAIRE

    Papasozomenos, Sozos Ch.

    1997-01-01

    We have shown that heat shock induces rapid dephosphorylation of τ in both female and male rats followed by hyperphosphorylation only in female rats. To investigate the role of gonadal hormones, rats were ovariectomized (OVX), orchiectomized (ORX), or sham-gonadectomized and received replacement therapy with estradiol benzoate (EB), testosterone propionate (TP), or sesame oil (SO) vehicle for 2–3 weeks, respectively. At 0, 3, 6, and 12 hr after heat shock, immunoblot analysis of SDS cerebral ...

  15. Potentiodynamic Polarization Behaviour of Electroless Ni-P-W Coatings

    OpenAIRE

    Supriyo Roy; Prasanta Sahoo

    2012-01-01

    This paper deals with the synthesis of electroless Ni-P-W coatings on mild steel substrate followed by furnace-annealing process. Corrosion behaviors of the coatings after heat treatments at various annealing temperatures are evaluated by potentiodynamic polarization test using 3.5% sodium chloride solution. The electrochemical parameters, that is, corrosion potential and corrosion current density, are optimized for maximum corrosion resistance using Taguchi-based grey relational analysis, co...

  16. Flexural strength and microstructure of two lithium disilicate glass ceramics for CAD/CAM restoration in the dental clinic

    Science.gov (United States)

    Kang, Suk-Ho; Chang, Juhea

    2013-01-01

    Objectives There has been a growing interest in glass ceramic systems with good esthetics, high fracture resistance and bonding durability, and simplified fabrication techniques using CAD/CAM. The aim of this study is to compare flexural strength before and after heat treatment of two lithium disilicate CAD/CAM blocks, IPS e.max CAD (Ivoclar Vivadent) and Rosetta SM (Hass), and to observe their crystalline structures. Materials and Methods Biaxial flexural strength was tested according to ISO 6872 with 20 disc form specimens sliced from each block before and after heat treatment. Also, the crystalline structures were observed using field-emission scanning microscopy (FE-SEM, Hitachi) and x-ray diffraction (XRD, Rigaku) analysis. The mean values of the biaxial flexural strength were analyzed by the Mann-Whitney U test at a significance level of p = 0.05. Results There were no statistically significant differences in flexural strength between IPS e.max CAD and Rosetta SM either before heat treatment or after heat treatment. For both ceramics, the initial flexural strength greatly increased after heat treatment, with significant differences (p < 0.05). The FE-SEM images presented similar patterns of crystalline structure in the two ceramics. In the XRD analysis, they also had similar patterns, presenting high peak positions corresponding to the standard lithium metasilicate and lithium disilicate at each stage of heat treatment. Conclusions IPS e.max CAD and Rosetta SM showed no significant differences in flexural strength. They had a similar crystalline pattern and molecular composition. PMID:24010079

  17. MEASUREMENTS OF A STEEL CHARGE EMISSIVITY UNDER STRONG IRRADIANCE CONDITIONS

    OpenAIRE

    Agnieszka Benduch; Rafał Wyczółkowski

    2014-01-01

    Steel bars are manufactured in the rolling process, whereby they are characterized by strain hardening and poor plastic properties. In many application cases such properties are improper, therefore, additional heat treatment is required. Crucial influence on the products quality after heat treatment has an appropriate selection of process parameters. In many modern technologies of heat treatment the charge of porous structure is subjected to the heating process. Proper control of heat treatme...

  18. Biochar Systems for Smallholders in Developing Countries : Leveraging Current Knowledge and Exploring Future Potential for Climate-Smart Agriculture

    OpenAIRE

    Scholz, Sebastian M.; Sembres, Thomas; Roberts, Kelli; Whitman, Thea; Wilson, Kelpie; Lehmann, Johannes

    2014-01-01

    Biochar is the carbon-rich organic matter that remains after heating biomass under the minimization of oxygen during a process called pyrolysis. There are a number of reasons why biochar systems may be particularly relevant in developing-country contexts. This report offers a review of what is known about opportunities and risks of biochar systems. Its aim is to provide a state-of-the-art ...

  19. Technical note: Comparison of radial immunodiffusion and ELISA for quantification of bovine immunoglobulin G in colostrum and plasma.

    Science.gov (United States)

    Gelsinger, S L; Smith, A M; Jones, C M; Heinrichs, A J

    2015-06-01

    Historically, radial immunodiffusion (RID) has been the only method that directly measures IgG; however, recent studies have reported IgG concentrations in colostrum, milk, and plasma as measured using an ELISA. To our knowledge no comparison between RID and ELISA methods has been made for bovine colostrum or plasma. The objective of this study was to compare IgG concentrations measured by both methods in samples of bovine colostrum before and after heat treatment and bovine plasma. Concentration of IgG was quantified using a commercially available RID kit and a modified ELISA. Samples of bovine colostrum and plasma were collected from individual animals and colostrum was tested before and after heat treatment at 60°C for 30 min. All samples were tested using both methods. Pearson correlation coefficients were determined for RID and ELISA values from unheated colostrum, heat-treated colostrum, and plasma samples. Mixed models were used to determine the effect of assay on IgG measurement in colostrum and plasma and effect of heat treatment on IgG concentration in colostrum. A weak correlation was found between ELISA and RID results in plasma and unheated colostrum. Concentration of IgG was significantly lower in all sample types when measured by ELISA compared to RID. Thus, direct comparison of ELISA and RID results is not recommended. Colostrum IgG concentration significantly decreased after heat treatment as measured by ELISA, but means were not different when measured by RID. Correlation plots between colostrum values measured before and after heat treatment indicated changes in the colostrum protein matrix due to heat affected RID and ELISA assays differently. This investigation compared RID and ELISA results, but no conclusions could be drawn as to the accuracy of either assay. PMID:25841961

  20. Evidence for effective thermal boundary resistance from magnon/phonon disequilibrium

    OpenAIRE

    Langner, M. C.; Kantner, C.L.S.; Chu, Y. H.; Martin, L M; Yu, P.; Ramesh, R.; Orenstein, J

    2010-01-01

    We use the time-resolved magneto-optical Kerr effect (TRMOKE) to measure the local temperature and heat flow dynamics in ferromagnetic SrRuO3 thin films. After heating by a pump pulse, the film temperature decays exponentially, indicating that the heat flow out of the film is limited by the film/substrate interface. We show that this behavior is consistent with an effective boundary resistance resulting from disequilibrium between the spin and phonon temperatures in the film.

  1. Effective thermal boundary resistance from thermal decoupling of magnons and phonons in SrRuO3 thin films

    OpenAIRE

    Langner, M. C.

    2010-01-01

    We use the time-resolved magneto-optical Kerr effect (TRMOKE) to measure the local temperature and heat flow dynamics in ferromagnetic SrRuO3 thin films. After heating by a pump pulse, the film temperature decays exponentially, indicating that the heat flow out of the film is limited by the film/substrate interface. We show that this behavior is consistent with an effective boundary resistance resulting from disequilibrium between the spin and phonon temperatures in the film.

  2. Polyfluorerede forbindelser i mikrobølgeovnspopkornposer

    OpenAIRE

    Jensen, Diana Worm; Lehmann, Lisa Mølgaard; Høst-Madsen, William; Rimsø, Bjørk Anine

    2012-01-01

    We are exposed of fluorinated compounds by inhalation, dermal exposure and ingestion. Food intake is that type of exposure where we are exposed of the majority of the polyfluorinated compounds. The popcorn packing paper, by the manufacturer KiMs, was extracted with methanol before and after heating. From a visual comparison of the extracts’ 19F-NMR spectra with corresponding spectra shown in Trier et al. (2011b), and by using tables of literature values of relevant chemical Fluor shifts, w...

  3. EFFECT OF THE HEAT AND SURFACE LASER TREATMENT ON THE CORROSION DEGRADATION OF THE Mg-Al ALLOYS

    OpenAIRE

    Dobrzański, Leszek A.; Tomasz Tański; Szymon Malara

    2011-01-01

    In this paper there is presented the corrosion behavior of the cast magnesium alloys as cast state, after heat and laser treatment. Pitting corrosion resistance of the analyzed alloys was carried out using the potentiodynamic electrochemical method (direct current), based on a anodic polarization curve. On the basis of the achieved anodic polarization curves, using the Tefel extrapolation method near to the corrosion potential, the quantitative data were determined, which describe the electro...

  4. Application of artificial neural networks in modelling of normalised structural steels mechanical properties

    OpenAIRE

    L.A. Dobrzański; R. Honysz

    2009-01-01

    Purpose: This paper presents the application of artificial neural networks for mechanical properties prediction of constructional steels after heat treatment.Design/methodology/approach: On the basis of such input parameteres, such as the chemical composition, the ones of mechanical and heat treatment and dimensions of elements, mechanical properties such as strength, impact resistance or hardness are predicted.Findings: Results obtained in the given ranges of input parameters show very good ...

  5. Microstructure of MCMgAl12Zn1 magnesium alloy

    OpenAIRE

    Dobrzański L.A.; Tański T.; Čížek L.

    2007-01-01

    In this paper is presented the structure of the cast magnesium alloys as cast state and after heat treatment cooled with different cooling rate, depending on the cooling medium (furnace, water, air). For investigations samples in shape of 250x150x25 mm plates were used. The structure have been study in the light microscope, scanning electron microscope equipped with an electron back scattering facility. The effects of the addition of Al on the microstructure were also studied. In the analysed...

  6. Freeze-Etch of Emulsified Cake Batters During Baking

    OpenAIRE

    Cloke, J. D.; Gordon, J; Davis, E.A.

    1982-01-01

    Cryofixation, freeze-etch techniques were used to study the structure of cake batters made from a lean cake formulation before heating and after heating to temperatures up to l00-l02°C. Batters were prepared without added emulsifiers and with saturated and unsaturated monoglycerides replacing 5 and l 0% of the oil. Unsaturated monoglyceri des were more effective than saturated monoglycerides in dispersing oil droplets through the batter. Saturated monoglycerides formed liquid crystals during ...

  7. A Study on Properties of Electrical Conductive Bricks for Direct Current Electrical Arc Furnace

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    In this expeiment,the effects of temperature and graphite content on the electricl conductivity of MgO-C materials are studied,Experimental results indicated:the proper ontent of graphite is 10%-12%,The specific electrical resistance of MgO-C materials tends to decrease as the preheat treatment temerature rises.After heat treatment,the specific electrical resistance of MgO-C materials is nearly independent of temperature.

  8. Increased light intensity induces heat shock protein Hsp60 in coral species

    OpenAIRE

    Chow, Ari M.; Ferrier-Pagès, Christine; Khalouei, Sam; Reynaud, Stéphanie; Brown, Ian R.

    2009-01-01

    The effect of increased light intensity and heat stress on heat shock protein Hsp60 was examined in two coral species using a branched coral and a laminar coral, selected for their different resistance to environmental perturbation. Transient Hsp60 induction was observed in the laminar coral following either light or thermal stress. Sustained induction was observed when these stresses were combined. The branched coral exhibited comparatively weak transient Hsp60 induction after heat stress an...

  9. Effect of post-growth annealing on secondary phase formation in low-temperature-grown Mn-doped GaAs

    DEFF Research Database (Denmark)

    Kovács, A.; Sadowski, J.; Kasama, Takeshi;

    2013-01-01

    The microstructures of annealed GaAs layers containing 0.1%, 0.5% and 2% Mn are studied using aberration-corrected transmission electron microscopy (TEM). The layers were grown by molecular beam epitaxy at 270 °C. After heat treatment at 400, 560 and 630 °C, they are found to contain precipitate ...... in annealed GaMnAs layers doped with low Mn concentrations is proposed....

  10. Effects of sauna alone and postexercise sauna baths on blood pressure and hemodynamic variables in patients with untreated hypertension.

    Science.gov (United States)

    Gayda, Mathieu; Paillard, François; Sosner, Philippe; Juneau, Martin; Garzon, Mauricio; Gonzalez, Mariel; Bélanger, Manon; Nigam, Anil

    2012-08-01

    The effects of sauna alone vs exercise and sauna on ambulatory blood pressure monitoring and central hemodynamic variables were measured in 16 patients with untreated hypertension assigned to a control period, sauna, or exercise and sauna. Exercise and sauna had positive effects on 24-hour systolic and mean blood pressure in patients with untreated hypertension. Exercise and sauna and sauna alone reduce total vascular resistance, with positive effects lasting up to 120 minutes after heat exposure.

  11. Degradation behavior at elevated temperature of LaNisub5-xSnsubxHsubz for x between 0.20 and 0.25

    Science.gov (United States)

    Bowman, R. C., Jr.; Lindensmith, C. A.; Luo, S.; Flanagan, T. B.; Vogt, T.

    2000-01-01

    Systematic studies of the hydriding behavior of LaNi(sub 5-x)Sn(sub x)H(sub z) alloys with tin contents in the range between 0.20 and 0.25 have revealed changes in the pressure-composition-temperature (PCT) isotherms measured after heating the hydrides above 450 K. These changes are indications of degradation processes and increased disorder within the alloy structure.

  12. Mikrostruktura in mehanske lastnosti dupleks jekel

    OpenAIRE

    VEHOVAR, Leopold; Kosec, Ladislav; Gojić, Mirko

    2015-01-01

    In this work mechanical properties and microstructure of duplex steel after heat treatment are shown. Heat treatment of the steel consisted of water quenching from 1050°C. A ferrite-austenite microstructure was obtained and the brittle ▫$sigma$▫-phase was avoided. The results show that the impact energy depends on the direction of rolling. In rolling direction the share of ferrite and austenite was approximately equal.

  13. Mechanical and microstructural properties of duplex steel: Mikrostruktura in mehanske lastnosti dupleks jekel:

    OpenAIRE

    Gojić, Mirko; Kosec, Ladislav; VEHOVAR, Leopold

    1997-01-01

    In this work mechanical properties and microstructure of duplex steel after heat treatment are shown. Heat treatment of the steel consisted of water quenching from 1050°C. A ferrite-austenite microstructure was obtained and the brittle ?$\\sigma$?-phase was avoided. The results show that the impact energy depends on the direction of rolling. In rolling direction the share of ferrite and austenite was approximately equal.

  14. The heat treatment of Fermanal cast steel

    OpenAIRE

    F. Binczyk; A. Smoliński; J. Szymszal

    2007-01-01

    The study discloses the results of microstructural examinations, testing of magnetic properties and hardness measurements as cast and after heat treatment conducted on the Fermanal cast steel. A characteristic feature of this cast steel is its density lower by about 10% than the density of carbon cast steel [4]. It has been proved that the factor deciding about the composition of microstructure (fraction of ferrite and austenite) is the content of aluminium. The matrix totally austenitic is p...

  15. CHARACTERIZATION OF MICROSTRUCTURE AND DETERMINATION OF ELASTIC PROPERTIES IN SAF 2205 DUPLEX STAINLESS STEEL USING ULTRASONIC MEASUREMENTS

    OpenAIRE

    R. Jayachitra*

    2016-01-01

    Microstructural changes in duplex stainless steel due to changes in annealing temperature are characterized by ultrasonic pulse-echo technique and optical microscopy.  Duplex stainless steel was subjected to a series of heat treatments from 1100°C to 1350°C, followed by water quenching.  The microstructure after heat treatment at 1350°C resulted in coarse grained ferrite, which favored formation of Widmanstatan austenite with fast cooling.  Micro hardness and optica...

  16. Measurements and modelling of residual stresses during quenching of thick heat treatable aluminium components in relation to their precipitation state

    OpenAIRE

    Chobaut, Nicolas

    2015-01-01

    In the fabrication of heat treatable aluminium parts, solutionising and quenching are key steps in order to obtain the required mechanical characteristics. Fast quenching is necessary to avoid coarse precipitation as this one reduces the mechanical properties after heat treatment. However fast quenching gives birth to high residual stresses, which cause unacceptable distortions during machining and can reduce service life drastically. For this reason, plates and forgings such as those conside...

  17. Expression of mdr49 and mdr65 multidrug resistance genes in larval tissues of Drosophila melanogaster under normal and stress conditions

    OpenAIRE

    Tapadia, Madhu G.; Lakhotia, S. C.

    2005-01-01

    In situ expression of 2 multidrug resistance genes, mdr49 and mdr65, of Drosophila melanogaster was examined in wild-type third instar larval tissues under physiological conditions and after heat shock or colchicine feeding. Expression of these 2 genes was also examined in tumorous tissues of lethal (2) giant larvae l(2)gl4 mutant larvae. These 2 mdr genes show similar constitutive expression in different larval tissues under physiological conditions. However, they are induced differentially ...

  18. Determination of aqueous solubility by heating and equilibration: A technical note

    OpenAIRE

    Loftsson, Thorsteinn; Hreinsdôttir, Dagný

    2006-01-01

    A modified shake-flask solubility method, where the equilibration time was shortened through heating, was used to determine the solubility of 48 different drugs and pharmaceutical excipients in pure water at room temperature. The heating process accelerates dissolution of the solid compound and frequently results in supersaturated solution. Seeding with the solid compound after heating and cooling to room temperature promotes precipitation of the solid compound in its original stable form. Th...

  19. Flexural strength and microstructure of two lithium disilicate glass ceramics for CAD/CAM restoration in the dental clinic

    OpenAIRE

    Kang, Suk-Ho; Chang, Juhea; Son, Ho-Hyun

    2013-01-01

    Objectives There has been a growing interest in glass ceramic systems with good esthetics, high fracture resistance and bonding durability, and simplified fabrication techniques using CAD/CAM. The aim of this study is to compare flexural strength before and after heat treatment of two lithium disilicate CAD/CAM blocks, IPS e.max CAD (Ivoclar Vivadent) and Rosetta SM (Hass), and to observe their crystalline structures. Materials and Methods Biaxial flexural strength was tested according to ISO...

  20. Effect of Mg content on the density and critical properties of in-situ reacted MgB2 bulk superconductor

    International Nuclear Information System (INIS)

    The effects of Mg content on the pore formation, density and critical properties were investigated in in-situ reacted MgB2 superconductors. The Mg1+xB2, (x=-0.2, 0.0, 0.05, 0.3, 1.0) bulk samples with different Mg contents were heat-treated at 900 degrees C for 1 h in an Ar atmosphere. The dimensional changes of a pellet's mass and volume after heat-treatment were measured. After heat-treatment process, the sample mass was decreased by Mg evaporation, but the sample volume was expanded by pore formation at the Mg site; therefore, the apparent density was decreased. Spherical pores the same as Mg particles were developed after heat-treatment in all samples, and the pore density was increased with increasing Mg content. As the x of Mg content was increased to 1.0, the apparent density of Mg1+xB2 samples was decreased due to a relatively larger reduction in a mass change. The critical current density of Mg excessive sample of x=0.05 showed the highest values over the applied magnetic fields because the excessive Mg may compensate Mg loss and enhance grain connectivity

  1. Local structure and chemical reaction of C60 films on Si(111)7 x 7 studied by HREELS-STM

    International Nuclear Information System (INIS)

    We have investigated the thermal stability and the chemical reactions of C60 thin films on Si(111)7 x 7 surfaces by the combined measurements of the high-resolution electron-energy-loss spectroscopy (HREELS) and the scanning tunneling microscopy (STM), HREELS-STM. After heating the Si up to 400 C, the molecules did not align perfectly but made local arrangements. The energy shifts of the inelastic electrons indicate that the electrons in the Si dangling bond transfer to the C60 molecules. The value of the charge transfer is estimated to be 1+1 electron(s). After heating the Si up to 800 C, the smooth C60 monolayer film aggregates and forms islands. The nearest neighbouring distance between the C60 molecules is shortened from 10 A to 9.3 A. The intensity of the 92 and 101 meV peaks drastically increase. These results indicate the formation of a covalent bond between the C60 molecules. After heating the Si up to 1100 C, an SiC film grows. (orig.)

  2. Compounding of hydroxyapatite crystals to molecularly aligned crab tendon chitosan: the effect of heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Atsushi [Creative Research Initiative ' Sousei' , Hokkaido University, Sapporo, Hokkaido 001-0021 (Japan) and Biomaterials Research Center, National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044 (Japan)]. E-mail: Matsuda.Atsushi@nims.go.jp; Kasahara, Mayumi [School of Science and Engineering, Waseda University, Okubo 3-4-1, Shinjuku-ku, Tokyo 169-0072 (Japan); Kobayashi, Hisatoshi [Biomaterials Research Center, National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044 (Japan)]. E-mail: Kobayashi.Hisatoshi@nims.go.jp; Ichinose, Noboru [School of Science and Engineering, Waseda University, Okubo 3-4-1, Shinjuku-ku, Tokyo 169-0072 (Japan); Tanaka, Junzo [Creative Research Initiative ' Sousei' , Hokkaido University, Sapporo, Hokkaido 001-0021 (Japan); Biomaterials Research Center, National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044 (Japan)

    2004-12-01

    The aim of this study was to demonstrate the effect of heat treatment on the formation of hydroxyapatite crystals in molecularly aligned chitosan. Molecularly aligned chitosan was prepared from crab (Macrocheira Kaempferi) tendons by treatment with ethanol and a 4 wt.% NaOH solution to remove proteins and calcium phosphate, subsequently performed was deacetyl treatment using a 50 wt.% NaOH solution at 100 deg. C. The tendon chitosan (t-chitosan) obtained was compounded with hydroxyapatite (HAp) before and after heat treatment by applying an alternate soaking method. The amount of compounded HAp to t-chitosan before heat treatment was larger than that after heat treatment as shown by thermogravimetric and differential thermal analysis (TG-DTA) analysis. The HAp compounded to t-chitosan before heat treatment was distributed on the whole area as shown by energy dispersive X-ray spectroscopy (EDS) analysis. On the other hand, the compound after heat treatment was distributed only on the surface of t-chitosan. The compounded HAp crystals to t-chitosan before heat treatment were aligned in the horizontal direction to t-chitosan molecules as shown by transmission electron microscopy (TEM) and electron diffraction technique. These results suggest the control of crystallographic orientation in HAp by aligned amino groups.

  3. Additional heat treatment of non-porous coatings obtained on medium carbon steel substrates by electron beam cladding of a Ti-Mo-C powder composition

    Science.gov (United States)

    Mul, D. O.; Drobyaz, E. A.; Zimoglyadova, T. A.; Bataev, V. A.; Lazurenko, D. V.; Shevtsova, L. I.

    2016-04-01

    The structure and microhardness of surface layers, obtained by non-vacuum electron beam cladding of Ti-Mo-C powder mixture on a steel substrate after different types of heat treatment, were investigated. After cladding samples were heat treated in a furnace at 200...500 °C, as well as quenched at 860 ° C and then underwent high-temperature tempering. Heat treatment of cladded coatings induced tempering of martensite and precipitation of cementite particles (Fe3C). Transmission electron microscopy of the samples after heating and holding at 300 ° C revealed precipitation of nanosized cubical TiC particles. The formation of hard nanosized particles led to the surface layer microhardness growth. The highest level of microhardness (which was 1.2...1.5-fold higher in comparison with coating microhardness after heat treatment) was achieved after heating of the claded material at 300 °C and 400 °C Additional quenching of samples at 860 °C did not increase the microhardness level.

  4. Effect of thermal treatments on sputtered silver nanocluster/silica composite coatings on soda-lime glasses: ionic exchange and antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Ferraris, M.; Ferraris, S., E-mail: sara.ferraris@polito.it; Miola, M.; Perero, S.; Balagna, C.; Verne, E. [Politecnico di Torino, Department of Applied Science and Technology, Institute of Materials Physics and Engineering (Italy); Gautier, G. [IMAMOTER Institute for Agricultural and Earthmoving Machines (Italy); Manfredotti, Ch.; Battiato, A.; Vittone, E. [University of Torino, Physics Department, NIS Excellence Centre and CNISM (Italy); Speranza, G. [Fondazione Bruno Kessler FBK (Italy); Bogdanovic, I. [Ruder Boskovic Institute, Experimental Physics Department (Croatia)

    2012-12-15

    Silver nanocluster/silica composite coatings were deposited on both soda-lime and silica glasses by radio frequency (RF) co-sputtering. The effect of thermal treatments on the microstructure in the range of 150-450 Degree-Sign C were examined by UV-visible spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Time of Flight-Elastic Recoil Detection Analysis. Sodium/silver ionic exchange was evidenced for coatings sputtered on soda-lime substrates after heating at 450 Degree-Sign C; presence of silver ions and/or silver nanoclusters, nanocluster size and their position inside the sputtered layers will be discussed for as-deposited and heated coatings on both substrates. The antibacterial activity of all coatings was determined against Staphylococcus aureus and Candida albicans by disk diffusion method and colonies forming units count; in agreement with microstructural results, the antibacterial activity present on all coatings was slightly reduced after heating at 450 Degree-Sign C. All coatings have been submitted to humidity plus UV ageing and sterilization by autoclave, gamma ray and ethylene oxide gas. Tape resistance (ASTM D3359-97) tests have been done on each coating before and after ageing and sterilizations, revealing a good adhesion on soda-lime substrates, except for those aged in humidity plus UV and sterilized by autoclave. Scratch tests and nanoindentation tests have been done on each coating, as-deposited and after heating at 450 Degree-Sign C. The coating hardness was improved by heating only when coatings were deposited on silica. The heating of coatings deposited on soda-lime substrates gave opposite effect on their hardness.

  5. Removal of uranium(VI) from aqueous solutions by carboxyl-rich hydrothermal carbon spheres through low-temperature heat treatment in air

    International Nuclear Information System (INIS)

    Carboxyl-rich hydrothermal carbon spheres were prepared by simply heating pristine hydrothermal carbon spheres (HCSs) at lower temperature in air, and the textural properties were characterized using Boehm titrations, scanning electron microscopy, Fourier transform infrared spectrometer (FT-IR) and elemental-analysis. The result of Boehm titrations indicated that the content of carboxyl groups on HCSs increased significantly from 0.53 to 3.81 mmol/g after heat-treatment at 300 deg C, which was also confirmed by FT-IR and EA qualitatively. The ability of heat-treated HCSs has been explored for the removal and recovery of uranium from aqueous solutions, and the influences of different experimental parameters, such as heat-treatment temperature, contact time and ionic strength, on adsorption were investigated. The U(VI) sorption capacity of HCSs increased from 55.0 to 179.95 mg/g after heat-treatment at 300 deg C for 5 h. Selective adsorption studies showed that the heat-treated HCSs could selectively remove U(VI), and the selectivity coefficients were improved after heat-treatment in the presence of co-existing ions, Na(I), Ni(II), Sr(II), Mn(II), Mg(II) and Zn(II). The adsorbent HCSs could be effectively regenerated by 0.05 mol/L HCl solution for the removal and recovery of U(VI). Complete removal (99.0 %) of U(VI) from 1.0 L industry wastewater containing 15.0 mg U(VI) ions was possible with 5.0 g heat-treated HCSs. In addition, a reaction mechanism for newly generating carboxyl groups on pristine HCSs surface during heat-treatment process and uranyl ion interaction with carboxyl-rich hydrothermal carbon spheres were also supposed. (author)

  6. Aesthetic value improvement of the ruby stone using heat treatment and its synergetic surface study

    Energy Technology Data Exchange (ETDEWEB)

    Sahoo, Rakesh K.; Mohapatra, Birendra K., E-mail: bkmohapatra@immt.res.in; Singh, Saroj K.; Mishra, Barada K.

    2015-02-28

    Highlights: • Natural ruby is heated at high temperature with metal oxide additives (PbO and ZnO) to enhance its aesthetic value. • Changes in surface characteristics of these natural rubies before and after heat treatment are compared. • The R-line peak splitting in the PL spectra and the contrary shift of the Al 2p peaks in the XPS spectra are explicated. - Abstract: The surface behavior of the natural ruby stones before and after heat treatment with metal oxide additives like: zinc oxide (ZnO) and lead oxide (PbO) have been studied. The surface appearance of the ruby stones processed with the metal oxides changed whereas the bulk densities of the stones remained within the range of 3.9–4.0 g/cm{sup 3}. The cracks healing and pores filling by the metal oxides on the surface of the ruby have been examined using scanning electron microscopy. The chemical compositions based on the XPS survey scans are in good agreement with the expected composition. The phase and crystallinity of the ruby stones original and heat-treated were obtained from their X-ray diffraction patterns. The change in peak separation between R{sub 1} and R{sub 2} – peaks in photoluminescence spectra and the contrary binding energy shift of the Al 2p peaks in the X-ray photoelectron spectra have been explicated. Moreover, in this work we describe the change in surface chemical and physical characteristics of the ruby stone before and after heat treatment.

  7. Aesthetic value improvement of the ruby stone using heat treatment and its synergetic surface study

    International Nuclear Information System (INIS)

    Highlights: • Natural ruby is heated at high temperature with metal oxide additives (PbO and ZnO) to enhance its aesthetic value. • Changes in surface characteristics of these natural rubies before and after heat treatment are compared. • The R-line peak splitting in the PL spectra and the contrary shift of the Al 2p peaks in the XPS spectra are explicated. - Abstract: The surface behavior of the natural ruby stones before and after heat treatment with metal oxide additives like: zinc oxide (ZnO) and lead oxide (PbO) have been studied. The surface appearance of the ruby stones processed with the metal oxides changed whereas the bulk densities of the stones remained within the range of 3.9–4.0 g/cm3. The cracks healing and pores filling by the metal oxides on the surface of the ruby have been examined using scanning electron microscopy. The chemical compositions based on the XPS survey scans are in good agreement with the expected composition. The phase and crystallinity of the ruby stones original and heat-treated were obtained from their X-ray diffraction patterns. The change in peak separation between R1 and R2 – peaks in photoluminescence spectra and the contrary binding energy shift of the Al 2p peaks in the X-ray photoelectron spectra have been explicated. Moreover, in this work we describe the change in surface chemical and physical characteristics of the ruby stone before and after heat treatment

  8. Effect of thermal treatments on sputtered silver nanocluster/silica composite coatings on soda-lime glasses: ionic exchange and antibacterial activity

    International Nuclear Information System (INIS)

    Silver nanocluster/silica composite coatings were deposited on both soda-lime and silica glasses by radio frequency (RF) co-sputtering. The effect of thermal treatments on the microstructure in the range of 150–450 °C were examined by UV–visible spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Time of Flight-Elastic Recoil Detection Analysis. Sodium/silver ionic exchange was evidenced for coatings sputtered on soda-lime substrates after heating at 450 °C; presence of silver ions and/or silver nanoclusters, nanocluster size and their position inside the sputtered layers will be discussed for as-deposited and heated coatings on both substrates. The antibacterial activity of all coatings was determined against Staphylococcus aureus and Candida albicans by disk diffusion method and colonies forming units count; in agreement with microstructural results, the antibacterial activity present on all coatings was slightly reduced after heating at 450 °C. All coatings have been submitted to humidity plus UV ageing and sterilization by autoclave, gamma ray and ethylene oxide gas. Tape resistance (ASTM D3359-97) tests have been done on each coating before and after ageing and sterilizations, revealing a good adhesion on soda-lime substrates, except for those aged in humidity plus UV and sterilized by autoclave. Scratch tests and nanoindentation tests have been done on each coating, as-deposited and after heating at 450 °C. The coating hardness was improved by heating only when coatings were deposited on silica. The heating of coatings deposited on soda-lime substrates gave opposite effect on their hardness.

  9. Heating Quality and Stability of Aqueous Enzymatic Extraction of Fatty Acid-Balanced Oil in Comparison with Other Blended Oils

    Directory of Open Access Journals (Sweden)

    Yang Li

    2014-01-01

    Full Text Available The heating performance of enzyme-assisted aqueous processing-extracted blended oil (EAEPO, hexane-extracted blended oil (HEBO, and three kinds of blended oils was investigated by varying the heating times. Oil degradation was monitored by analysis of the acid value (AV, peroxide value (PV, p-anisidine value (p-AV, color, and trans-fatty acid composition. The fatty acid ratios of EAEPO, HEBO, and the three kinds of blended oils were very similar (0.27 : 1.03 : 0.96, 0.27 : 1.08 : 1.16, 0.27 : 0.65 : 0.8, 0.27 : 0.6 : 0.84, and 0.27 : 0.61 : 0.79, resp.. The AV and color increased in proportion to the heating time for all the oils. There was a rapid increase in the PV and p-AV of EAEPO and HEBO after heating for only 1 h, whereas the other three blended oils showed a rapid increase after heating for 2 h or 6 h. Despite the highest trans-fatty acid content found for HEBO, this content was relatively low and remained low up to a heating time of 8 h. It was found that after heating, a fatty acid ratio relatively close to its ideal value (0.27 : 0.48 : 0.49 was maintained by EAEPO, which indicates that EAEPO is tolerant to heat treatment and is suitable for maintaining a healthy diet.

  10. Novel Investigation on Nanostructured Multilayer and Functionally Graded Ni-P Electroless Coatings on Stainless Steel

    Science.gov (United States)

    Anvari, S. R.; Monirvaghefi, S. M.; Enayati, M. H.

    2015-06-01

    In this study, step-wise multilayer and functionally graded Ni-P coatings were deposited with electroless in which the content of phosphorus and nickel would be changed gradually and step-wise through the thickness of the coatings, respectively. To compare the properties of these coatings with Ni-P single-layer coatings, three types of coatings with different phosphorus contents were deposited. Heat treatment of coatings was performed at 400 °C for 1 h. The microstructure and phase transformation of coatings were characterized by SEM/EDS, TEM, and XRD. The mechanical properties of coatings were studied by nanoindentation test. According to the results of the single-layer coatings, low P coating had the maximum hardness and also the ratio of hardness ( H) to elasticity modulus ( E) for the mentioned coating was maximum. In addition, low and medium P coatings had crystalline and semi-crystalline structure, respectively. The mentioned coatings had texture and after heat treatment their texture didn't change. While high P coating had amorphous structure, after heat treatment it changed to crystalline structure with texture for nickel grains. Furthermore, the results showed that functionally graded and step-wise multilayer coatings were deposited successfully by using the same initial bath and changing the temperature and pH during deposition. Nanoindentation test results showed that the hardness of the mentioned coatings changed from 670 Hv near the substrate to 860 Hv near the top surface of coatings. For functionally graded coating the hardness profile had gradual changes, while step-wise multilayer coating had step-wise hardness profile. After heat treatment trend of hardness profiles was changed, so that near the substrate, hardness was measured 1400 Hv and changed to 1090 Hv at the top coat.

  11. Effect of heat treatment on antimycotic activity of Sahara honey

    Institute of Scientific and Technical Information of China (English)

    Moussa Ahmed; Saad Aissat; Noureddine Djebli

    2014-01-01

    Objective: To evaluate the influence of the temperature on honey colour, polyphenol contents and antimycotic capacity and to evaluate the correlation between these parameters. Methods:Sahara honey were heated up to 25, 50, 75 and 100 °C for 15, 30 and 60 min, and their colour intensity, polyphenol contents and antimycotic capacity. The Folin-Ciocalteu test was used to determine the total polyphenol contents (TPC). The antimycotic activity was evaluated both by agar diffusion method and micro wells dilution method against the Candida albicans (C. albicans) and Candida glabrata (C. glabrata). Results:Initial values for TPC in Sahara honey ranged from 0.55 to 1.14 mg of gallic acid per kg of honey, with the average value of 0.78 mg of gallic acid per kg of honey. The TPC values after heat-treatment were 0.54 to 1.54 with the average value of 1.49 mg. The minimal inhibitory concentrations before heat-treatment of Sahara honey against C. albicans and C. glabrata ranged from 3.06%-12.5% and 50% respectively. After heat-treatment the minimal inhibitory concentrations between 12.5% and 50% for C. albicans and C. glabrata, respectively. The diameters of inhibition zones of Sahara honey with 50% concentration varied from (12.67-15.00) mm by C. albicans to (14.33-15.67) mm by C. glabrata. The diameters of inhibition zones after heat-treatment at 25 and 50 °C for 15.30 and 60 min ranged from (2.00-18.67) mm by C. albicans to (8.00-16.67) mm by C. glabrata. Statistically significant relations between the TPC and the colour intensity of Sahara honey (r=0.99, P Conclusions:To our knowledge this is the first report on the antimycotic capacity of Sahara honey.

  12. Contribution of particulate brown carbon to light absorption in the rural and urban Southeast US

    Science.gov (United States)

    Devi, J. Jai; Bergin, Michael H.; Mckenzie, Michael; Schauer, James J.; Weber, Rodney J.

    2016-07-01

    Measurements of wavelength dependent aerosol light absorption coefficients were carried out as part of the Southern Oxidant and Aerosol Study (SOAS) during the summer of 2013 to determine the contribution of light absorbing organic carbon (BrC) to total aerosol light absorption in a rural location (Centreville, AL) and an urban area (Atlanta, GA). The light absorption coefficients in the near UV and visible wavelengths were measured for both ambient air, as well as ambient air heated in a thermal denuder to 200 °C to remove the semi-volatile organic compounds. Atlanta measurements show dominance of semi-volatile brown carbon with an average absorption angstrom exponent (AAE) of 1.4 before heating and about 1.0 after heating. In urban Atlanta, a decrease of about ∼35% in the light absorption coefficient at 370 nm after heating indicates that light absorbing organic compounds are a substantial fraction of the light absorption budget. Furthermore, a considerable increase in the fraction of light absorption by the semi-volatile aerosol occurs during the daytime, likely linked with photochemistry. Measurements at rural Centerville, on the other hand, do not show any major change in AAE with values before and after heating of 0.99 and 0.98, respectively. Overall the results suggest that photochemical aged urban emissions result in the presence of light absorbing BrC, while at rural locations which are dominated by aged aerosol and local biogenic emissions (based on measurements of Angstrom exponents) BrC does not significantly contribute to light absorption.

  13. Effect of chlorine in clay-mineral specimens prepared on silver metal-membrane mounts for X-ray powder diffraction analysis

    Science.gov (United States)

    Poppe, L.J.; Commeau, J.A.; Pense, G.M.

    1989-01-01

    Silver metal-membrane filters are commonly used as substrates in the preparation of oriented clay-mineral specimens for X-ray powder diffraction (XRD). The silver metal-membrane filters, however, present some problems after heat treatment if either the filters or the samples contain significant amounts of chlorine. At elevated temperature, the chloride ions react with the silver substrate to form crystalline compounds. These compounds change the mass-absorption coefficient of the sample, reducing peak intensities and areas and, therefore, complicating the semiquantitative estimation of clay minerals. A simple procedure that eliminates most of the chloride from a sample and the silver metal-membrane substrate is presented here.

  14. Slip lines in scandium and lithium containing aluminium alloys

    International Nuclear Information System (INIS)

    Intensive slip lines in cold rolled sheets of scandium or lithium containing aluminium base alloys are under study. Slip lines are shown to be the places of concentrated shear strain which arise due to the occurrence of secondary δ'(Al3Li) and Al3Sc particles completely coherent to the matrix. The formation of slip lines has a detrimental effect on cold rolled sheet mechanical properties after heat hardening. To avoid the appearance of slip lines it is necessary to roll sheets with low reductions in area and to choose appropriate conditions of intermediate heat treatments. 5 refs., 5 figs., 2 tabs

  15. Comment on "Ecological importance of the thermal emissivity of avian eggshells".

    Science.gov (United States)

    Jiménez-Muñoz, Juan C; Sobrino, José A

    2012-07-01

    Eggshell emissivity must be known to determine accurately the cooling rate of avian eggs when the parent, after heating by conduction during the incubation, is temporarily absent. We estimate possible values of eggshell emissivities from in-situ measurements and spectral libraries. Emissivity is near to 1 (probably higher than 0.95) and therefore its effect on cooling rate may be negligible, with differences between the temperature of the egg assuming a value of ε=0.95 and that of a blackbody (ε=1) below 0.2 °C.

  16. Effect of the Heat-treatment Temperature on the Mechanical Properties and Microstructural Evolution of Cold-rolled Twinning-induced Plasticity Steel

    Institute of Scientific and Technical Information of China (English)

    LI Dazhao; WEI Yinghui; SONG Jinlu; HOU Lifeng

    2015-01-01

    TWIP steels with 70%cold-rolled reduction were heated at 500, 600, 700, 800, 900, 1000, and 1100℃. Then, the properties before and after heating were examined through tensile and hardness experiments. The microstructures were also analyzed by optical microscopy and transmission electron microscopy. The relationship between the properties and microstructure was examined as well. Finally, the evolution process of cold-rolled microstructures during heating was discussed in detail. Moreover, some conclusions can be drawn, and the heating evolution characteristics are described.

  17. Mechanical Behavior of Sapphire Reinforced Alumina Matrix Composites at Elevated Temperatures

    Science.gov (United States)

    Jaskowiak, Martha H.; Eldridge, Jeffrey I.; Setlock, John A.; Gyekenyesi, John Z.

    1997-01-01

    Zirconia coated sapphire reinforced alumina matrix composites have been tested both after heat treatment to 1400 C and at temperatures ranging from 800 C to 1200 C in. air. Interfacial shear stress has also been measured with fiber pushout tests performed in air at room temperature, 800 C and 1OOO C. Matrix crack spacing was measured for the tensile tested composites and used to estimate interfacial shear stress up to 1200 C. Electron microscopy was used to determine the source of fiber fracture and to study interfacial failure within the composite.

  18. Mechanical and Corrosion Properties of Fe-Cr-Mn-C-N Austenitic Stainless Steels for Drill Collars

    Science.gov (United States)

    Lee, Eunkyung; Ryu, Jiseung; Jeon, Seol; Mishra, Brajendra; Palmer, Bruce R.

    2016-06-01

    The mechanical and corrosion properties of air/water-quenched CN66 (0.28/0.38 wt pct, C/N) and CN71 (0.27/0.44 wt pct, C/N) steels after heat treatment were investigated. The carbon condensed area of the water-quenched alloys decreased compared with the air-cooled alloys, and lattice expansions occurred, resulting in a strained region. The values of UTS and elongation of water-quenched CN71 were increased as 105 MPa and 25.2 pct compared with the air-cooled CN71, and decreased sour corrosion resistance (1.8 × 10-4 mm/year).

  19. High temperature indentation of helium-implanted tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, James S.K.-L., E-mail: james.gibson@materials.ox.ac.uk [Oxford University, Department of Materials, Parks Road, Oxford OX1 3PH (United Kingdom); Roberts, Steve G. [Oxford University, Department of Materials, Parks Road, Oxford OX1 3PH (United Kingdom); Culham Centre for Fusion Energy, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Armstrong, David E.J. [Oxford University, Department of Materials, Parks Road, Oxford OX1 3PH (United Kingdom)

    2015-02-11

    Nanoindentation has been performed on tungsten, unimplanted and helium-implanted to ~600 appm, at temperatures up to 750 °C. The hardening effect of the damage was 0.90 GPa at 50 °C, but is negligible above 450 °C. The hardness value at a given temperature did not change on re-testing after heating to 750 °C. This suggests that the helium is trapped in small vacancy complexes that are stable to at least 750 °C, but which can be bypassed due to increased dislocation mobility (cross slip or climb) above 450 °C.

  20. Retention of Rotavirus Infectivity in Mussels Heated by Using the French Recipe Moules Marinières.

    Science.gov (United States)

    Souza, Doris Sobral Marques; Miura, Takayuki; Le Mennec, Cécile; Barardi, Célia Regina Monte; Le Guyader, Françoise S

    2015-11-01

    To evaluate the persistence of infectious virus after heating, mussels contaminated with a rotavirus strain were prepared following the French recipe moules marinières (mariner's mussels). Rotavirus was then quantified by real-time quantitative PCR (RT-qPCR) and a cell culture infectivity assay. Results showed the persistence of infectious virus after 3 min of cooking. After 5 min, when no infectious virus could be detected, the RT-qPCR approach showed a 1-log decrease compared with concentrations detected after 1 min of cooking.

  1. Pelleted waste form for high-level ICPP wastes

    International Nuclear Information System (INIS)

    Simulated zirconia-type calcined waste is pelletized on a 41-cm diameter disc pelletizer using 5% bentonite, 2% metakaolin, and 2% boric acid as a solid binder and 7M phosphoric plus 4M nitric acid as a liquid binder. After heat treatment at 8000C for 2 hours the pellets are impact resistant and have a leach resistance of 10-4 g/cm2 . day, based on Soxhlet leaching for 100 hours at 950C with distilled water. An integrated pilot plant is being fabricated to verify the process. 1 figure, 4 tables

  2. Zwilag intermediate storage facility Wuerenlingen AG (CH). 25 years existence of the company, 15 years operational experience; Zwilag Zwischenlager Wuerenlingen AG (CH). 25 Jahre Firmenbestand, 15 Jahre Betriebserfahrung

    Energy Technology Data Exchange (ETDEWEB)

    Kasemeyer, Uwe [Zwilag Zwischenlager Wuerenlingen AG, Wuerenlingen (Switzerland)

    2015-07-01

    Wastes with high toxicity from chemistry, pharmaceutics, process engineering, automotive and electrical engineering that comply with the requirements of an underground disposal facility (UTD) can directly be delivered to the UTD for final disposal. Radioactive wastes may not be brought into the UTD for final disposal. Compared to chemical wastes the radioactive wastes lose their toxicity faster but the after-heat generation could damage the surrounding host rock. Therefore it is required that high-level radioactive wastes are stored in a so called intermediate storage facility. The article describes the intermediate storage and conditioning of radioactive wastes using the example of the Swiss Zwilag intermediate storage facility Wuerenlingen AG.

  3. Precipitation and Corrosion Behaviour of Nano-Structured Near-Surface Layers on an AA6111 Aluminium Alloy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y [Corrosion and Protection Centre, School of Materials, The University of Manchester, Manchester M60 1QD (United Kingdom); Zhou, X [Corrosion and Protection Centre, School of Materials, The University of Manchester, Manchester M60 1QD (United Kingdom); Thompson, G E [Corrosion and Protection Centre, School of Materials, The University of Manchester, Manchester M60 1QD (United Kingdom); Hashimoto, T [Corrosion and Protection Centre, School of Materials, The University of Manchester, Manchester M60 1QD (United Kingdom); Scamans, G M [Innoval Technology, Beaumont Close, Banbury, Oxon, OX16 1TQ (United Kingdom); Afseth, A [Novelis Technology and Management, 8212 Neuhausen (Switzerland)

    2006-02-22

    A nano-structured, near-surface layer has been generated by mechanically grinding an AA6111 alloy. After heat treatment at 180 deg. C for 30 minutes, Q phase particles, {approx}20 nm diameter, were precipitated preferentially at grain boundaries within the nano-structured nearsurface layer. No such precipitates were observed in the bulk alloy after this heat treatment. This preferential precipitation results in the near-surface layers having increased corrosion susceptibility than the bulk microstructure, due to the micro-galvanic coupling between the precipitates at grain boundary and the grain matrix. The localized attack is predominately intergranular.

  4. PREPARING Ni–W ALLOY FILMS WITH LOW INTERNAL STRESS AND HIGH HARDNESS BY HEAT TREATING

    OpenAIRE

    RUI LIU; HONG WANG; JIN-YUAN YAO; XUE-PING LI; GUI-FU DING

    2007-01-01

    In this paper, the internal stress and hardness of Ni–W alloy films with W contents in the range of 0–59 wt% were investigated. The amorphous Ni–W alloy films were electrodeposited with 59 wt% W content and the structure of crystalline alloy films was formed after heat treating. The experimental results showed that heat treating could prepare Ni–W alloy films with lower internal stress compared with low W content alloy films, and the heat treated alloy films still have high hardness. The inte...

  5. Clearance of serum solutes by hemofiltration in dogs with severe heat stroke

    OpenAIRE

    Chen, Guang-Ming; Lan, Yu-Ying; Wang, Cheng-Feng; Zhan, Hai-Xia; Wang, Wen-Rui; Chen, Jin-hua; Chen, Jian

    2014-01-01

    Background We have previously reported that hemofiltration (HF) may be an effective additional means of treating heat stroke when rapid cooling is not effective. Methods Dogs were assigned to a heat stroke (control) or heat stroke + hemofiltration (HF) group (n = 8 each group). After heat stroke induction, dogs in the HF group received HF for 3 h. Serum concentrations of interleukin (IL)-10, tumor necrosis factor (TNF)-α, IL-6, blood urea nitrogen (BUN) and creatinine were measured at baselin...

  6. Anodisation of sputter deposited aluminium–titanium coatings: Effect of microstructure on optical characteristics

    DEFF Research Database (Denmark)

    Aggerbeck, Martin; Junker-Holst, Andreas; Vestergaard Nielsen, Daniel;

    2014-01-01

    decreasedwith titaniumcontent in the as-deposited, and heat-treated states, and after anodisation of the as-deposited coatings. Specimens turned grey or blackwhen anodising after heat treatment. Partially anodised Al3Ti phaseswere found in the anodised layer, and the interface between substrate and anodised......-ray diffraction (XRD), and glow discharge optical emission spectroscopy (GDOES), while the optical appearance was investigated using photospectrometry. The microstructure of the coatings was varied by heat treatment, resulting in the precipitation of Al3Ti phases. The reflectance of the anodised surfaces...

  7. Fabrication of MgAl2O4 spinel/niobium laminar composites by plasma spraying

    International Nuclear Information System (INIS)

    The feasibility of plasma spray manufacturing of laminar ceramic matrix composites made of alternate thin layers of a ceramic oxide and a metal is demonstrated with a composite made of 7 layers, each 0.2 mm thick, of MgAl2O4 spinel and niobium. Microstructure and mechanical characteristics have been studied with both as-sprayed and heat-treated under vacuum at 1400 C conditions. It is shown that the as-sprayed composite is brittle but becomes pseudo-plastic after heat treatment. These laminar composites are very attractive for the manufacturing of large surface, few millimeter thick components. (from authors). 4 figs., 4 refs

  8. Transport du cuivre à travers un film mince d'or protecteur

    Science.gov (United States)

    Gillet, M.; Guglielmacci, J. M.; Benhenda, S.; Pech, T.

    Thin gold films were deposited by "sputtering" onto thick copper substrate. The crystalline structure and topography of the deposits were investigated by scanning and transmission electron microscopy. A scanning Auger microanalysis was performed on the surface and in depth on the gold deposit before and after heating. The observations reveal that the copper arrives at the gold surface especially via holes. The transport rate of the copper via theses holes is very fast compared to the diffusion via grain boundaries. The origin of the holes is discussed: they result of strains due to the gold epitaxial growth on copper grains.

  9. Compatibility of La26O27(BO3)8 electrolyte with

    OpenAIRE

    Kravchyk, K. V.; Quarez, E.; Caldes, M.; Le Gal La Salle, A.; Joubert, O.

    2011-01-01

    The chemical and mechanical compatibility of proton conducting La26O27(BO3)8 (LBO) electrolyte with standard cathode materials LSM, LSCM, La2NiO4 and BSCF was investigated. The results show that LSM, LSCM and La2NiO4 cathodes are chemically and mechanically stable with the LBO electrolyte, and BSCF reacts with LBO after heat-treatment of their mechanical ground mixtures at T=1150°C. Symmetrical cell tests based on LBO demonstrated that the values of the cathode ASR (area specif...

  10. Effect of hydrogen on the ductility and deformation resistance of VT1-0 commercial titanium at temperatures up to 750 C

    Energy Technology Data Exchange (ETDEWEB)

    Aksenov, IU.A.; Bashkin, I.O.; Kolmogorov, V.L.; Poniatovskii, E.G.; Taluts, G.G. (Institut Fiziki Tverdogo Tela, Moscow (USSR); Verkhnesaldinskoe Metallurgicheskoe Proizvodstvennoe Ob' edinenie, Verkhnyaya Salda (USSR))

    1989-05-01

    Specimens of VT1-0 titanium containing 0-1.54 percent hydrogen (by mass) were tested in tension and compression in the temperature range 20-750 C. It is found that the ductility of hydrated titanium increases significantly after heating above 300 C. It is further found that the anomalies of the ductile characteristics of titanium correlate with the location of the phase boundaries on the T-x diagrams of the Ti-H system. In the range 300-750 C, the alloying of titanium with hydrogen reduces its resistance to deformation, which is particularly noticeable at large deformations. 10 refs.

  11. Off-design temperature effects on nuclear fuel pins for an advanced space-power-reactor concept

    Science.gov (United States)

    Bowles, K. J.

    1974-01-01

    An exploratory out-of-reactor investigation was made of the effects of short-time temperature excursions above the nominal operating temperature of 990 C on the compatibility of advanced nuclear space-power reactor fuel pin materials. This information is required for formulating a reliable reactor safety analysis and designing an emergency core cooling system. Simulated uranium mononitride (UN) fuel pins, clad with tungsten-lined T-111 (Ta-8W-2Hf) showed no compatibility problems after heating for 8 hours at 2400 C. At 2520 C and above, reactions occurred in 1 hour or less. Under these conditions free uranium formed, redistributed, and attacked the cladding.

  12. Transparent glass-ceramics containing Eu3+ and Dy3+ ions for visible optoelectronics

    Science.gov (United States)

    Pisarska, Joanna; Żur, Lidia; Pisarski, Wojciech A.

    2011-06-01

    Selected oxyfluoride glasses containing Eu3+ and Dy3+ were heat treated in order to obtain transparent glass-ceramics. Visible emission spectra corresponding to 5D0 - 7FJ (J = 0, 1, 2, 3, 4) transitions of Eu3+ and 4F9/2 - 6HJ/2 (J = 11, 13, 15) transitions of Dy3+ in glass samples before and after heat treatment were registered. The luminescence intensity ratios R (Eu3+) and Y/B (Dy3+) have been analyzed in details. Their values are reduced due to part incorporation of rare earth ions into cubic β-PbF2 crystalline phase.

  13. Titania doped triaxial porcelain: Enhancement of strength by controlled heat treatment

    Indian Academy of Sciences (India)

    Sunipa Bhattacharyya; Swapan Kumar Das; Kausik Dana; Nirendra Krishna Mitra

    2007-06-01

    Titania doped vitrified triaxial porcelain samples were subjected to controlled heat treatment at different temperatures of 600, 800 and 1000°C with a specific heating schedule. The results revealed that flexural strength of 800°C heat treated sample was significantly enhanced to 60 MPa from its original value of 40 MPa. XRD pattern revealed the formation of mullite in the system both before and after heat treatment and the differences in their growth was ascertained through SEM analysis. The present heat treatment process may be useful to produce high strength porcelain body from a common triaxial system.

  14. Performance of underground heat storage system in a double-film-covered greenhouse

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    An underground heat storage system in a double-film-covered greenhouse and an adjacent greenhouse without the heat storage system were designed on the basis of plant physiology to reduce the energy consumption in greenhouses. The results indicated that the floor temperature was respectively 5.2 ℃, 4.6 ℃ and 2.0℃ higher than that of the soil in the adjacent reference greenhouse after heat storage in a clear, cloudy and overcast sky in winter. Results showed that the temperature and humidity were feasible for plant growth in the heat saving greenhouse.

  15. A heat shock element in the phosphoglycerate kinase gene promoter of yeast.

    OpenAIRE

    Piper, P W; Curran, B; Davies, M W; Hirst, K; Lockheart, A; Ogden, J E; Stanway, C A; Kingsman, A J; Kingsman, S M

    1988-01-01

    The phosphoglycerate kinase (PGK) promoter is often employed in yeast expression vectors due to its very high efficiency. Its activity in unstressed cells has been shown to be due to an upstream activator site (UASPGK) at -402 to -479. Since levels of PGK mRNA can sometimes be elevated by heat shock of yeast cultures this investigation determined how specific deletions of PGK promoter sequences effect levels of PGK mRNA both before and after heat shock. A series of PGK promoter deletions was ...

  16. Questions concerning safety and risk after the nuclear accidents in Japan. Deepened accident analysis for the Fukushima Daiichi power plant; Sicherheits- und Risikofragen im Nachgang zu den nuklearen Stoer- und Unfaellen in Japan. Vertiefte Ereignisanalyse zur Anlage Fukushima-Daini

    Energy Technology Data Exchange (ETDEWEB)

    Pistner, Christoph; Englert, Matthias [Oeko-Institut e.V. - Institut fuer Angewandte Oekologie, Darmstadt (Germany)

    2015-02-25

    The study questions concerning safety and risk in Japanese power plants following the disastrous nuclear accident covers the following issues: the nuclear facility Fukushima Daiichi, site characterization, important technical equipment, important electro-technical equipment, personal; description of the accident progression in the Fukushima nuclear power plant: impact of the earthquake, impact of the tsunami, short-term measures of the operating personnel, pressure and temperature situation in the containments, restoration of the after-heat cooling system in the units 1/2 and 4, fuel element storage pool, summarized parameters during the accident progress; comparative analysis of the accident progression at the Fukushima Daiichi site.

  17. Welding technique research between fuel element Zr-4 end and tantalum tube and its application

    International Nuclear Information System (INIS)

    The author introduces welding technique between fuel element cladding Zr-4 end and tantalum tube which is used to introduce the W/Re thermocouple and water pressure test and corrosion test of the weld. The results show that the welded surface takes form better, lacks metallurgical defect and the weld causes no leakage under 9.0 MPa pressure. There is the corrosion phenomenon in the weld after heating at 450 degree C for 100 h in melting PbBi alloy, but it can retard the corrosion in PbBi alloy after preoxidation film treatment. The adopted measures has been proposed in the design and assemble of irradiation capsule

  18. Temperature dependence of structural and optical properties of GeSbTe alloy thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chabli, A. E-mail: achabli@cea.fr; Vergnaud, C.; Bertin, F.; Gehanno, V.; Valon, B.; Hyot, B.; Bechevet, B.; Burdin, M.; Muyard, D

    2002-09-01

    Ge{sub 2}Sb{sub 2}Te{sub 5} films sandwiched by ZnS-SiO{sub 2} layers were studied by spectroscopic ellipsometry from room temperature up to 800 deg. C. An irreversible modification of both materials is pointed out. ZnS cubic phase precipitation occurs after heating at 650 deg. C, shown by grazing incidence X-ray diffraction. Chemical modification in phase change material is observed above 300 deg. C, revealed by a typical behavior of a transparent layer.

  19. Study on the Prevention of Rabbit Hair from Loss

    Institute of Scientific and Technical Information of China (English)

    刘世春; 张华鹏; 姚穆

    2001-01-01

    A new method is presented to solve the problem of loss of rabbit hair by using ES fiber blending with rabbit hair. ES fiber is used to bond the rabbit hair to prevent the rabbit hair from losing after heat setting. The factors affecting hair loss are heat setting temperature, rabbit hair/ES fiber blend ratio, fabric heating setting, twistsof yarn, etc. Temperature of heat setting and ES fiber content are the two key factors This method has almost no detrimental effect on the coziness of the fabric, which is better than other hair loss prevention methods.

  20. NMR-Based Metabonomic Investigation of Heat Stress in Myotubes Reveals a Time-Dependent Change in the Metabolites

    DEFF Research Database (Denmark)

    Straadt, Ida K; Young, Jette F; Bross, Peter;

    2010-01-01

    and separation of the control samples from the different time points after heat stress primarily are in the metabolites glucose, leucine, lysine, phenylalanine, creatine, glutamine, and acetate. In addition, PC scores revealed a maximum change in metabolite composition 4 h after the stress exposure; thereafter......, samples returned toward control samples, however, without reaching the control samples even 10 h after stress. The results also indicate that the myotubes efficiently regulate the pH level by release of lactate to the culture medium at a heat stress level of 42 degrees C, which is a temperature level...

  1. The Physicochemical Changes of Black Garlic during Thermal Processing

    Directory of Open Access Journals (Sweden)

    Mengmeng Lei

    2015-03-01

    Full Text Available To explore the physicochemical changes of black garlic during the thermal processing steps and further reveal the role of Maillard reaction in the formation mechanism of black garlic. The physicochemical changes including UV-Vis absorbance, fluorescence and color difference were determined. The UV absorbance at 294 nm and browning intensity at 420 nm gradually increased with increasing heating time, while the fluorescence intensity showed a maximum value at the heating time of 3 days. The color value of black garlic increased after heating at 70-80°C for 10 days. These results indicated Maillard reaction was primarily responsible for the formation of black garlic.

  2. The effects of heat treatment on microfluidic devices fabricated in silica glass by femtosecond lasers

    Institute of Scientific and Technical Information of China (English)

    Li Yan; Qu Shi-Liang

    2012-01-01

    We fabricated complex microfluidic devices in silica glass by water-assisted femtosecond laser ablation and sub-sequent heat treatment.The experimental results show that after heat treatment,the diameter of the microchannels is significantly reduced and the internal surface roughness is improved.The diameters of the fabricated microchannels can be modulated by changing the annealing temperature and the annealing time.During annealing,the temperature affects the diameter and shape of the protrusions in microfluidic devices very strongly,and these changes are mainly caused by uniform expansion and the action of surface tension.

  3. A Novel Training-Free Processed Fe-Mn-Si-Cr-Ni Shape Memory Alloy Undergoing δ → γ Phase Transformation

    Science.gov (United States)

    Peng, Huabei; Wang, Gaixia; Du, Yangyang; Wang, Shanling; Chen, Jie; Wen, Yuhua

    2016-07-01

    We not only suppress the formation of twin boundaries but also introduce a high density of stacking faults by taking advantage of δ → γ phase transformation in a processed Fe-19.38Mn-5.29Si-8.98Cr-4.83Ni shape memory alloy. As a result, its shape memory effect is remarkably improved after heating at 1533 K (1260 °C) (single-phase region of δ ferrite) and air cooling due to δ → γ phase transformation.

  4. Direct synthesis of thermochromic VO2 through hydrothermal reaction

    Science.gov (United States)

    Alie, David; Gedvilas, Lynn; Wang, Zhiwei; Tenent, Robert; Engtrakul, Chaiwat; Yan, Yanfa; Shaheen, Sean E.; Dillon, Anne C.; Ban, Chunmei

    2014-04-01

    Thermochromic VO2 was directly synthesized using hydrothermal techniques. The effects of formation conditions on the structure and morphology of the final product were studied through X-ray diffraction (XRD), and scanning electron microscopy (SEM). Unique hollow sphere morphology was observed for the synthesized VO2 powders. Ex-situ XRD studies after heat treatment confirmed the thermal stability of the VO2 structure. Thermochromic properties, as a consequence of the reversible structural transformation between monoclinic VO2 and tetragonal phases, were observed by Fourier transform infrared spectroscopy (FTIR).

  5. Synthesis, characterization and modelling of zinc and silicate co-substituted hydroxyapatite

    OpenAIRE

    Friederichs, Robert J.; Chappell, Helen F.; Shepherd, David V.; Best, Serena M.

    2015-01-01

    Experimental chemistry and atomic modelling studies were performed here to investigate a novel ionic co-substitution in hydroxyapatite (HA). Zinc, silicate co-substituted HA (ZnSiHA) remained phase pure after heating to 1100°C with Zn and Si amounts of 0.6 wt% and 1.2 wt%, respectively. Unique lattice expansions in ZnSiHA, silicate Fourier transform infrared peaks and changes to the hydroxyl IR stretching region suggested Zn and silicate co-substitution in ZnSiHA. Zn and silicate insertion in...

  6. Lactate threshold predicting time-trial performance: impact of heat and acclimation

    OpenAIRE

    Lorenzo, Santiago; Minson, Christopher T.; Babb, Tony G.; Halliwill, John R.

    2011-01-01

    The relationship between exercise performance and lactate and ventilatory thresholds under two distinct environmental conditions is unknown. We examined the relationships between six lactate threshold methods (blood- and ventilation-based) and exercise performance in cyclists in hot and cool environments. Twelve cyclists performed a lactate threshold test, a maximal O2 uptake (V̇o2max) test, and a 1-h time trial in hot (38°C) and cool (13°C) conditions, before and after heat acclimation. Eigh...

  7. Nuclear Reactor RA Safety Report, Vol. 16, Maximum hypothetical accident

    International Nuclear Information System (INIS)

    Fault tree analysis of the maximum hypothetical accident covers the basic elements: accident initiation, phase development phases - scheme of possible accident flow. Cause of the accident initiation is the break of primary cooling pipe, heavy water system. Loss of primary coolant causes loss of pressure in the primary circuit at the coolant input in the reactor vessel. This initiates safety protection system which should automatically shutdown the reactor. Separate chapters are devoted to: after-heat removal, coolant and moderator loss; accident effects on the reactor core, effects in the reactor building, and release of radioactive wastes

  8. Zwilag intermediate storage facility Wuerenlingen AG (CH). 25 years existence of the company, 15 years operational experience

    International Nuclear Information System (INIS)

    Wastes with high toxicity from chemistry, pharmaceutics, process engineering, automotive and electrical engineering that comply with the requirements of an underground disposal facility (UTD) can directly be delivered to the UTD for final disposal. Radioactive wastes may not be brought into the UTD for final disposal. Compared to chemical wastes the radioactive wastes lose their toxicity faster but the after-heat generation could damage the surrounding host rock. Therefore it is required that high-level radioactive wastes are stored in a so called intermediate storage facility. The article describes the intermediate storage and conditioning of radioactive wastes using the example of the Swiss Zwilag intermediate storage facility Wuerenlingen AG.

  9. Properties of Cross-Rolled Low Alloy White Cast Iron Grinding Ball

    Institute of Scientific and Technical Information of China (English)

    CHANG Li-min; LIU Lin; LIU Jian-hua

    2007-01-01

    The low-energy, multi-impact fracture resistance and the abrasiveness of the cross-rolled low alloy white cast iron grinding balls were studied after heat treatments at residual rolling temperature. Moreover, the means by which they are damaged and characters of the wear surface were analyzed. The results show that high resistance to impact fracture and high abrasiveness can be achieved after appropriate heat treatment at residual rolling temperature. This kind of heat treatment technology has several advantages under low impact and hard abrasive. These results are very useful for determining the optimized heat treatment technology at residual rolling temperatures.

  10. Novel processing of bioglass ceramics from silicone resins containing micro- and nano-sized oxide particle fillers.

    Science.gov (United States)

    Fiocco, L; Bernardo, E; Colombo, P; Cacciotti, I; Bianco, A; Bellucci, D; Sola, A; Cannillo, V

    2014-08-01

    Highly porous scaffolds with composition similar to those of 45S5 and 58S bioglasses were successfully produced by an innovative processing method based on preceramic polymers containing micro- and nano-sized fillers. Silica from the decomposition of the silicone resins reacted with the oxides deriving from the fillers, yielding glass ceramic components after heating at 1000°C. Despite the limited mechanical strength, the obtained samples possessed suitable porous architecture and promising biocompatibility and bioactivity characteristics, as testified by preliminary in vitro tests.

  11. Formation of Combined Surface Features of Protrusion Array and Wrinkles atop Shape-Memory Polymer

    Science.gov (United States)

    Sun, L.; Zhao, Y.; Huang, W. M.; Tong, T. H.

    We demonstrate a simple and cost-effective approach to realize two combined surface features of different scales together, namely submillimeter-sized protrusion array and microwrinkles, atop a polystyrene shape-memory polymer. Two different types of protrusions, namely flat-top protrusion and crown-shaped protrusion, were studied. The array of protrusions was produced by the Indentation-Polishing-Heating (IPH) process. Compactly packed steel balls were used for making array of indents. A thin gold layer was sputter deposited atop the polymer surface right after polishing. After heating for shape recovery, array of protrusions with wrinkles on the top due to the buckling of gold layer was produced.

  12. High temperature indentation of helium-implanted tungsten

    International Nuclear Information System (INIS)

    Nanoindentation has been performed on tungsten, unimplanted and helium-implanted to ~600 appm, at temperatures up to 750 °C. The hardening effect of the damage was 0.90 GPa at 50 °C, but is negligible above 450 °C. The hardness value at a given temperature did not change on re-testing after heating to 750 °C. This suggests that the helium is trapped in small vacancy complexes that are stable to at least 750 °C, but which can be bypassed due to increased dislocation mobility (cross slip or climb) above 450 °C

  13. Precipitation and Corrosion Behaviour of Nano-Structured Near-Surface Layers on an AA6111 Aluminium Alloy

    International Nuclear Information System (INIS)

    A nano-structured, near-surface layer has been generated by mechanically grinding an AA6111 alloy. After heat treatment at 180 deg. C for 30 minutes, Q phase particles, ∼20 nm diameter, were precipitated preferentially at grain boundaries within the nano-structured nearsurface layer. No such precipitates were observed in the bulk alloy after this heat treatment. This preferential precipitation results in the near-surface layers having increased corrosion susceptibility than the bulk microstructure, due to the micro-galvanic coupling between the precipitates at grain boundary and the grain matrix. The localized attack is predominately intergranular

  14. Pivalolactone, 3. Reactive blending of polypivalolactone with polycarbonate

    OpenAIRE

    Tijsma, Edze Jan; Does, van der, A.J.W.; Bantjes, Adriaan; Vulic, Ivan; Werumeus Buning, Gerard Hidde

    1994-01-01

    The occurrence of interchange reactions during heating of polypivalolactone (PPVL) with three polymers and their influence on the blend properties were studied. Physical blends of PPVL and bisphenol-A polycarbonate (PC) were found to be immiscible. By heating of PPVL/PC blends in the melt at 280°C, in diphenyl ether at 260°C and in a twin-screw extruder (TSE) at 280°C partial formation of copolymers was observed, provided that tetrabutyl orthotitanate (TnBT) was added. After heating of equimo...

  15. Molybdenum-boron-silicon coating on VN-3 niobium alloy

    International Nuclear Information System (INIS)

    Heat resistance of the complex molybdenum-boron-silicon coating on VN-3 niobium alloy is studied. The coating phase composition in the initial state and after heating in air at 1200 deg C during 100-1300 h is determined using X-ray diffraction, electron diffraction and X-ray spectrum analyses. It is shown that high heat resistance of the coating is ensured due to formation of an external film of silicon oxide and a boride sublayer between the metal and coating

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

    OpenAIRE

    Abdel-Wahab El-Morsy; 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...

  17. Heat shock response of the blue crab Portunus pelagicus:thermal stress and acclimation

    Institute of Scientific and Technical Information of China (English)

    Suhaila Qari

    2014-01-01

    Objective:To determine the effect of prior heat shock on the CTMax of differently acclimated Portunus pelagicus (P. pelagicus) as well as the time course of the changes in CTMax post heat shock. Methods: Crabs P. pelagicus were held in laboratory aquaria in tanks, which were supplied with filtered and aerated seawater. Crabs were acclimated at 20 °C, 25 °C, 30 °C and 35 °C for 3 weeks before their CTMax was determined. The CTMax was recorded for each crab as the median temperature during the 5 min period when a crab was not able to right itself, the average CTMax was calculated. The effect of heat shock on subsequent CTMax was measured. Crabs were heat shocked at temperature 1 °C lower than the CTMax for 20 min, followed by either 0.5 h, 1 h or 1.5 h recovery at 20 °C. The same procedure was repeated at other acclimation temperatures (25 °C, 30 °C and 35 °C). Results: Temperature acclimation of P. pelargicus from 20-35 °C progressively increased the CTMax. Acclimation at 35 °C the CTMax was 42.66 °C, whereas acclimation at 20 °C the CTMax was 39.8 °C. In P. pelagicus acclimated, at 20 °C the CTMax values after heat shock were significantly higher than crabs in control for 30 min, 1 h and 1.5 h after heat shock. In the 25 °C and 30 °C acclimated crabs, the CTMax values after heat shock were significantly higher than control only in 30 min and 1 h after heat shock. No significant differences in 35 °C acclimated crabs between control and heat shocked crabs were found after recovery for 30 min, 1 h, or 1.5 h. Conclusions: Heat shock caused significant rises in the CTMax, however, this increase was progressively reduced with longer recovery times at the acclimation temperature. For 20 °C acclimated crabs, the increased CTMax was still evident after 90 min, but for 25 °C and 30 °C crabs, the response was over after 90 min. Heat shock of 35 °C crabs was problematical, the CTMax gave no increased thermotolerance. It must be concluded that the

  18. Thermal expansion behavior of a β-LiA1SiO4/Cu composite

    Institute of Scientific and Technical Information of China (English)

    WANG Lidong; XUE Zongwei; LIU Zhe; FEI Weidong

    2009-01-01

    A copper matrix composite reinforced by β-LiAlSiO4 with negative thermal expansion coefficient was fabricated using vacuum hot-pressed sintering technique. The thermal expansion behavior of the composite was investigated, and the average residual stress in the matrix was analyzed by a simple model. The results indicate that the residual stress in the matrix affects the thermal expansion properties. After heat treatment, the coefficient of thermal expansion (CTE) of the composite decreases greatly. The CTE of the composite after thermal cycling between 50-350℃ is the lowest.

  19. Structural Evaluation and Performance of Portland Cement Concretes After Exposure to High Temperatures

    Directory of Open Access Journals (Sweden)

    Evandro Tolentino

    2002-03-01

    Full Text Available We evaluated the "residual" thermal conductivity of Portland cement concretes (with characteristic compressive strength at 28 days, f ck, of 20 MPa and 50 MPa at room temperature after heat-treating at 180 °C, 300 °C and 600 °C. The description of the geometry of the structure was carried out using mercury intrusion porosimetry and nitrogen sorption. The results showed a decreasing tendency of residual thermal conductivity, which we attributed to heat-induced concrete degradation. Furthermore, the results from mercury intrusion porosimetry and nitrogen sorption tests showed that a coarser pore structure is produced with the raise of heat-treatment temperatures.

  20. Structural Evaluation and Performance of Portland Cement Concretes After Exposure to High Temperatures

    OpenAIRE

    Evandro Tolentino; Fernando S. Lameiras; Abdias M. Gomes; Cláudio A. Rigo da Silva; Wander L. Vasconcelos

    2002-01-01

    We evaluated the "residual" thermal conductivity of Portland cement concretes (with characteristic compressive strength at 28 days, f ck, of 20 MPa and 50 MPa) at room temperature after heat-treating at 180 °C, 300 °C and 600 °C. The description of the geometry of the structure was carried out using mercury intrusion porosimetry and nitrogen sorption. The results showed a decreasing tendency of residual thermal conductivity, which we attributed to heat-induced concrete degradation. Furthermor...

  1. Bonding mechanism and performance of ceramic coatings by sol-gel process

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Thin alumina coatings were prepared on carbide tools to enhance their wear-resistant ability by dip coating from an aluminum alkoxide solution. The coating eventually obtained was perfectly integrated, without any macroscopic defect, and showed good performance in turning medium carbon steel, which presented a novel and promising coating method for cutting tools. The coating morphology before and after heat treatment was examined with the aid of a scanning electron microscope (SEM). The composition of coating and interface layer as well as the crystal structure of coating was characterized by X-ray diffraction (XRD). The elemental distribution near the interlayer was analyzed by electron probe microanalysis (EPMA).

  2. The Tribological Property and Microstructure of Ni-Ti Coating Prepared by Electrodeposition and Heat Treatment

    OpenAIRE

    Chufeng Sun; Yanbin Wang; Qiong Su; Zhiguang Guo; Lei Shi

    2016-01-01

    Ni-Ti coatings were fabricated by the electrodeposition in a Ni plating bath containing Ti power and heat treatment in nitrogen atmosphere. The surface morphology and microstructure of the Ni-Ti coating before and after heat treatment were analyzed by means of scanning electron microscopy and X-ray diffraction. The friction and wear behaviors of two different coatings were evaluated on a ball-on-disk UMT-2MT test rig. It was found that the phase structure of Ni-Ti coating heated in nitrogen w...

  3. Comment on "Ecological importance of the thermal emissivity of avian eggshells".

    Science.gov (United States)

    Jiménez-Muñoz, Juan C; Sobrino, José A

    2012-07-01

    Eggshell emissivity must be known to determine accurately the cooling rate of avian eggs when the parent, after heating by conduction during the incubation, is temporarily absent. We estimate possible values of eggshell emissivities from in-situ measurements and spectral libraries. Emissivity is near to 1 (probably higher than 0.95) and therefore its effect on cooling rate may be negligible, with differences between the temperature of the egg assuming a value of ε=0.95 and that of a blackbody (ε=1) below 0.2 °C. PMID:22484000

  4. Accumulation of gamma-aminobutyrate (GABA) caused by heat-drying and expression of related genes in immature vegetable soybean (edamame)

    OpenAIRE

    TAKAHASHI, Yukiko; Sasanuma, Tsuneo; Abe, Toshinori

    2013-01-01

    We studied the effects of drying of immature seeds of vegetable soybean (Glycine max L. Merrill) on the accumulation of gamma-aminobutyrate (GABA) in the seeds. GABA accumulated after heat-drying, with the maximum at 40°C. The GABA content (447.5 mg/100 g DW) increased to more than 5 times the value in untreated seeds (79.6 mg/100 g DW). In contrast, the glutamate content decreased rapidly to 1/3 the level in the untreated seeds. The GABA content increased early in the heat-drying treatment: ...

  5. Relationship between core temperature change during recovery and prognosis in classic heat stroke rat models

    OpenAIRE

    Liu, Ya-Nan; Geng, Yan; Fu, Wei; Na PENG; Zheng-tao GU; Su, Lei

    2013-01-01

    Objective To construct classic heat stroke rat models, and observe the changes of body temperature in the recovery period after heat stress to explore its relationship with prognosis. Methods Sixty male SD rats were randomly divided into heat stroke group (HS group, n=50) and control group (C group, n=10). Rats in HS group were exposed to 39℃ heat stress. Core temperature and systolic blood pressure (SBP) of rats were monitored until it reached diagnostic criteria of heat stroke. The core bod...

  6. Nanostructures obtained from a mechanically alloyed and heat treated molybdenum carbide

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Barriga Arceo, L. [Programa de Ingenieria Molecular, I.M.P. Lazaro Cardenas 152, C.P. 07730 D.F. Mexico (Mexico) and ESIQIE-UPALM, IPN Apdo Postal 118-395, C.P. 07051 D.F. Mexico (Mexico)]. E-mail: luchell@yahoo.com; Orozco, E. [Instituto de Fisica UNAM, Apdo Postal 20-364, C.P. 01000 D.F. Mexico (Mexico)]. E-mail: eorozco@fisica.unam.mx; Mendoza-Leon, H. [ESIQIE-UPALM, IPN Apdo Postal 118-395, C.P. 07051 D.F. Mexico (Mexico)]. E-mail: luchell@yahoo.com; Palacios Gonzalez, E. [Programa de Ingenieria Molecular, I.M.P. Lazaro Cardenas 152, C.P. 07730 D.F. Mexico (Mexico)]. E-mail: epalacio@imp.mx; Leyte Guerrero, F. [Programa de Ingenieria Molecular, I.M.P. Lazaro Cardenas 152, C.P. 07730 D.F. Mexico (Mexico)]. E-mail: fleyte@imp.mx; Garibay Febles, V. [Programa de Ingenieria Molecular, I.M.P. Lazaro Cardenas 152, C.P. 07730 D.F. Mexico (Mexico)]. E-mail: vgaribay@imp.mx

    2007-05-31

    Mechanical alloying was used to prepare molybdenum carbide. Microstructural characterization of samples was performed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) methods. Molybdenum carbide was heated at 800 {sup o}C for 15 min in order to produce carbon nanotubes. Nanoparticles of about 50-140 nm in diameter and nanotubes with diameters of about 70-260 nm and 0.18-0.3 {mu}m in length were obtained after heating at 800 {sup o}C, by means of this process.

  7. Wintertime aerosol chemical composition, volatility, and spatial variability in the greater London area

    Science.gov (United States)

    Xu, L.; Williams, L. R.; Young, D. E.; Allan, J. D.; Coe, H.; Massoli, P.; Fortner, E.; Chhabra, P.; Herndon, S.; Brooks, W. A.; Jayne, J. T.; Worsnop, D. R.; Aiken, A. C.; Liu, S.; Gorkowski, K.; Dubey, M. K.; Fleming, Z. L.; Visser, S.; Prévôt, A. S. H.; Ng, N. L.

    2016-02-01

    The composition of PM1 (particulate matter with diameter less than 1 µm) in the greater London area was characterized during the Clean Air for London (ClearfLo) project in winter 2012. Two high-resolution time-of-flight aerosol mass spectrometers (HR-ToF-AMS) were deployed at a rural site (Detling, Kent) and an urban site (North Kensington, London). The simultaneous and high-temporal resolution measurements at the two sites provide a unique opportunity to investigate the spatial distribution of PM1. We find that the organic aerosol (OA) concentration is comparable between the rural and urban sites, but the contribution from different sources is distinctly different between the two sites. The concentration of solid fuel OA at the urban site is about twice as high as at the rural site, due to elevated domestic heating in the urban area. While the concentrations of oxygenated OA (OOA) are well-correlated between the two sites, the OOA concentration at the rural site is almost twice that of the urban site. At the rural site, more than 70 % of the carbon in OOA is estimated to be non-fossil, which suggests that OOA is likely related to aged biomass burning considering the small amount of biogenic SOA in winter. Thus, it is possible that the biomass burning OA contributes a larger fraction of ambient OA in wintertime than what previous field studies have suggested. A suite of instruments was deployed downstream of a thermal denuder (TD) to investigate the volatility of PM1 species at the rural Detling site. After heating at 250 °C in the TD, 40 % of the residual mass is OA, indicating the presence of non-volatile organics in the aerosol. Although the OA associated with refractory black carbon (rBC; measured by a soot-particle aerosol mass spectrometer) only accounts for solid fuel OA and hydrocarbon-like OA, these three factors have similar volatility, which is inferred from the change in mass concentration after heating at 120 °C. Finally, we discuss the relationship

  8. Effect of Heat Treatment on Mechanical Property of High Cr-W Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Liu Jianping; Li Lixia

    2007-01-01

    The microstructure of high Cr-W cast iron after heat treatment were analyzed, and the effect of various heat treatment temperature and time on mechanical properties of high Cr-W cast iron were studied, and the best process parameter of heat treatment was provided in this paper. The results show that the heat treatment can improve the mechanical property of high Cr-W cast iron, and higher synthetic mechanical property of high Cr-W cast iron can be obtained when treated with normalization at 980℃ for 2h and tempered at 400℃ for 2h.

  9. Heat treatment of welded joints of steel 0.3С-1Cr-1Si produced by high-power fiber lasers

    Science.gov (United States)

    Kuryntsev, S. V.; Gilmutdinov, A. Kh.

    2015-11-01

    The effect of heat treatment on the welded joints of steel grade 0.3С-1Cr-1Si produced by 30 kW power fiber lasers was investigated in the paper. The speed of the welding process was 20 mm/s. Heat treatment was carried out on two levels, quenching with subsequent middle tempering and high tempering. The samples were examined before and after heat treatment, macro- and microstructure were studied using SEM, UTS, three points bent test, microhardness. The effect of heat treatment was significant: it allowed reduction of the weld hardness of considerably and enhancement of its ductility.

  10. Effect of Rare Earth Elements on Thermal Fatigue Property of Low Chromium Semi-Steel

    Institute of Scientific and Technical Information of China (English)

    常立民; 刘建华; 张瑞军; 邵利; 于升学; 谌岩

    2003-01-01

    The effect of rare earth elements on eutectic carbide′s morphology of low chromium semi-steel in as-cast state and after heat treatment was investigated, and accordingly, the thermal fatigue property of this material was studied. The results show that RE can improve the eutectic carbide′s morphology, inhibit the formation and propagation of thermal fatigue cracks, therefore, promote the thermal fatigue property, which is more noticeable in case of the RE modification in combination with heat treatment. The optimal thermal fatigue property can be obtained when treated with 0.2% RE modification as well as normalization at 950 ℃ for 3 h.

  11. slice of LEP beamtube with getter strip

    CERN Multimedia

    1989-01-01

    A section of the LEP beam pipe. This is the chamber in which LEP's counter-rotating electron and positron beams travel. It is made of lead-clad aluminium. The beams circulate in the oval cross-section part of the chamber. In the rectangular cross-section part, LEP's innovative getter-strip vacuum pump is installed. After heating to purify the surface of the getter, the strip acts like molecular sticky tape, trapping any stray molecules left behind after the accelerator's traditional vacuum pumps have done their job.

  12. Bone bonding ability of some borate bio-glasses and their corresponding glass-ceramic derivatives

    OpenAIRE

    Fatma H. Margha; Amr M. Abdelghany

    2012-01-01

    Ternary borate glasses from the system Na2O·CaO·B2O3 together with soda-lime-borate samples containing 5 wt.% of MgO, Al2O3, SiO2 or P2O5 were prepared. The obtained glasses were converted to their glass-ceramic derivatives by controlled heat treatment. X-ray diffraction was employed to investigate the separated crystalline phases in glass-ceramics after heat treatment of the glassy samples. The glasses and corresponding glass-ceramics after immersion in water or diluted phosphate solution f...

  13. Experimental plant for the physical-chemical treatment of groundwater polluted by Municipal Solid Waste (MSW) leachate, with ammonia recovery

    OpenAIRE

    Massimo Raboni; Vincenzo Torretta; Paolo Viotti; Giordano Urbini

    2013-01-01

    The paper documents the results of the experimental treatment of groundwater (flow rate: 300 m3 h-1) polluted by the leachate of an old MSW landfill (7 million tonnes) in northern Italy. The process consists of a coagulation-flocculation pre-treatment at pH > 11, and subsequent ammonia stripping, after heating the water to 35-38 °C by means of the biogas produced by the landfill. The stripped ammonia was recovered by absorption with sulfuric acid, producing a 30% solution of ammonium sulfate,...

  14. Preparation and characterization of haematite nanowire arrays

    CERN Document Server

    Xue, D S; Liu, Q F; Zhang, L Y

    2003-01-01

    Arrays of alpha-Fe sub 2 O sub 3 nanowires embedded in anodic alumina membranes were obtained after heat-treating beta-FeOOH nanowire arrays fabricated by electrochemical deposition. Haematite polycrystalline nanowires with maximum length of about 7 mu m and average diameter of about 120 nm were characterized by means of x-ray diffraction and transmission electron microscopy. The Morin temperature below 80 K and Neel temperature of about 350 K for the alpha-Fe sub 2 O sub 3 nanowire arrays, far lower than those of bulk material, were measured by Moessbauer spectroscopy and using a Magnetic Property Measurement System.

  15. Brute force nuclear orientaton of 87Y(met)

    International Nuclear Information System (INIS)

    87Y(met) produced by the Rb(α,2n) reaction and implanted into cubic Al and Au host has been oriented with 2-6T external magnetic fields at low temperature. The nuclear magnetic moment of the 9/2+ isomeric state is μ=6.10(+32 to -15)μsub(N) which inserts well in the systematics of 1gsub(9/2) nuclear monents. Attenuation of the orientation has been observed after heat treatment of samples, attributed to oxygen trapping by yttrium atoms

  16. Application of artificial intelligence methods for prediction of steel mechanical properties

    Directory of Open Access Journals (Sweden)

    Z. Jančíková

    2008-10-01

    Full Text Available The target of the contribution is to outline possibilities of applying artificial neural networks for the prediction of mechanical steel properties after heat treatment and to judge their perspective use in this field. The achieved models enable the prediction of final mechanical material properties on the basis of decisive parameters influencing these properties. By applying artificial intelligence methods in combination with mathematic-physical analysis methods it will be possible to create facilities for designing a system of the continuous rationalization of existing and also newly developing industrial technologies.

  17. Interface reaction between nickel-base self-fluxing alloy coating and steel substrate

    Science.gov (United States)

    Otsubo, F.; Era, H.; Kishitake, K.

    2000-06-01

    The interface reaction between a nickel-base, self-fluxing alloy coating and a steel substrate has been investigated to examine the formation of “pores,” which are observed along the interface of used boiler tubes. It was found that lumpy precipitates form along the interface instead of pores after heating at high temperatures and that the precipitates are of Fe2B boride. The adhesion strength of the coating is not decreased by the formation of Fe2B precipitates along the interface because of the increase of the adhesion due to interdiffusion.

  18. PREPARATION AND MICROSTRUCTURE CHARACTERIZATION OF Ni/TiO2 NANOCOMPOSITE

    Institute of Scientific and Technical Information of China (English)

    Yucheng WU; Xia Wu; Lide Zhang

    2003-01-01

    Homogeneous Ni2+-doped titania gel was synthesized by a sol-gel process, and the xerogel was then obtained through aging and drying, leading to the formation of Ni/TiO2 nanocomposite after heat treatment under a suitable reducing atmosphere. The resulting nanocomposite was characterized by TGA-DSC, TEM, XRD and BET methods. The results show that the structure and grain size of the nanocomposites could be manipulated by altering the heat-treatment conditions, and that the nanocomposite possesses a mesoporous structure with a pore radius of ca. 28 nm and a specific the anatase-rutile phase transformation.

  19. The structural and magnetic properties of barium ferrite powders prepared by the sol-gel method

    Institute of Scientific and Technical Information of China (English)

    Li Jie; Zhang Huai-Wu; Li Yuan-Xun; Liu Ying-Li; Ma Yan-Bing

    2012-01-01

    In this paper,M-type hexagonal barium ferrite powders are synthesized using the sol-gel method.A dried precursor heated in air is analyzed in the temperature range from 50 to 1200 ℃ using thermo-gravimetric analysis and differential scanning calorimetry. The effects of the additives and the cacinating temperature on the magnetic properties are investigated,and the results show that single-phase barium ferrite powders can be formed. After heat-treating at 950 ℃ for 4h with 3 wt% additive,the coercivity and saturation magnetization are found to be 440 Oe and 57.9 emu/g,respectively.

  20. Heat-shock-induced cellular responses to temperature elevations occurring during orthopaedic cutting

    OpenAIRE

    E.B Dolan; Haugh, M. G.; Tallon, D.; Casey, C.; McNamara, L. M.

    2012-01-01

    Severe heat-shock to bone cells caused during orthopaedic procedures can result in thermal damage, leading to cell death and initiating bone resorption. By contrast, mild heat-shock has been proposed to induce bone regeneration. In this study, bone cells are exposed to heat-shock for short durations occurring during surgical cutting. Cellular viability, necrosis and apoptosis are investigated immediately after heat-shock and following recovery of 12, 24 h and 4 days, in osteocyte-like MLO-Y4 ...

  1. The influence of molybdenum on stress corrosion in Ultra Low Carbon Steels with copper addition

    OpenAIRE

    Mazur, M.; R. Bogucki; Pytel, S.

    2010-01-01

    The influence of molybdenum content on the process of stress corrosion of ultra-low carbon structural steels with the addition of copper HSLA (High Strength Low Alloy) was analyzed. The study was conducted for steels after heat treatment consisting of quenching andfollowing tempering at 600°C and it was obtained microstructure of the tempered martensite laths with copper precipitates and the phaseLaves Fe2Mo type. It was found strong influence of Laves phase precipitate on the grain boundarie...

  2. Physical and mechanical properties of gamma radiation cross-linked polyethylene

    International Nuclear Information System (INIS)

    Granulated LDPE 2003 polyethylene was extruded and irradiated under nitrogen with 150, 200 and 300 kGy gamma rays doses to produce cross-linking. The study of the physical and mechanical properties shows that the product has a high degree of molecular cross-linking, can be heated up to 200 C for 2 hours without deformation and that the mechanical properties improve. Preliminary aging tests indicate that after heating at 60 C for 4 weeks no physical or mechanical deterioration can be observed. (author)

  3. Colorimetric determination of a paracetamole in raw material and in pharmaceutical dosage forms

    International Nuclear Information System (INIS)

    A rapid, accurate and simple method is proposed for the determination of p-acetaminophen (paracetamole) in raw material, tablets and syrups. The method is based on measuring the intensity of the yellow color that developed when acute acetaminophen is allowed to react with p-dimethylaminobenzaldehyde in 2M HCl after heating. The color which absorbs in the visible region of gamma 450 nm is stable for several hours and the intensity is directly proportional to the concentration of the drug, that is, Beer lambert law is obeyed. The method can be used to analyse paracetamole in raw material and in pharmaceutical dosage forms. (author)

  4. Reduction of Tb4+ions in luminescent Y2O3:Tb nanorods prepared by microwave hydrothermal method

    Institute of Scientific and Technical Information of China (English)

    Jarosaw Kaszewski; Bartomiej S Witkowski; ukasz Wachnicki; Hanka Przybyliska; Bolesaw Kozankiewicz; Ewa Mijowska; Marek Godlewski

    2016-01-01

    Terbium doped yttrium oxide was prepared with the microwave hydrothermal method. The Y2O3:Tb nanomaterial crystal-lized as needle-like grains. Bright luminescence in the green region was observed. Significant luminescence intensity increase was obtained after thermal treatment. Reduction of terbium ions was observed after heating in the air atmosphere. Tb4+ions were found to be stabilized by crystal impurities. Hydroxyl species were found to have impact on vacancies elimination. The terbium ions were used as optical and magnetic indicator of the material properties.

  5. Structural evolutions of the mechanically alloyed Al70Cu20Fe10 powders

    Indian Academy of Sciences (India)

    Musa Göğebakan; Bariş Avar

    2011-10-01

    Elemental mixtures of Al, Cu, Fe powders with the nominal composition of Al70Cu20Fe10 were mechanically alloyed in a planetary ball mill for 80 h. Subsequent annealing of the as-milled powders were performed at 600–800°C temperature range for 4 h. Structural characteristics of the mechanically alloyed Al70Cu20Fe10 powders with the milling time and the heat treatment were investigated by X-ray diffraction (XRD), differential scanning calorimeter (DSC) and differential thermal analysis (DTA). Mechanical alloying of the Al70Cu20Fe10 did not result in the formation of icosahedral quasicrystalline phase (i-phase) and a long time milling resulted in the formation of -Al(Cu,Fe) solid solution phase (-phase). The i-phase was observed only for short-time milled powders after heat treatment above 600°C. The -phase was one of the major phases in the Al70Cu20Fe10 alloy. The w-Al7Cu2Fe1 phase (w-phase) was obtained only after heat treatment of the short-time milled and unmilled samples. The present investigation indicated that a suitable technique to obtain a large amount of quasicrystalline powders is to use a combination of short-time milling and subsequent annealing.

  6. Melatonin in Arabidopsis thaliana acts as plant growth regulator at low concentrations and preserves seed viability at high concentrations.

    Science.gov (United States)

    Hernández, Ismaél Gatica; Gomez, Federico José Vicente; Cerutti, Soledad; Arana, María Verónica; Silva, María Fernanda

    2015-09-01

    Since the discovery of melatonin in plants, several roles have been described for different species, organs, and developmental stages. Arabidopsis thaliana, being a model plant species, is adequate to contribute to the elucidation of the role of melatonin in plants. In this work, melatonin was monitored daily by UHPLC-MS/MS in leaves, in order to study its diurnal accumulation as well as the effects of natural and artificial light treatments on its concentration. Furthermore, the effects of exogenous application of melatonin to assess its role in seed viability after heat stress and as a regulator of growth and development of vegetative tissues were evaluated. Our results indicate that melatonin contents in Arabidopsis were higher in plants growing under natural radiation when compared to those growing under artificial conditions, and its levels were not diurnally-regulated. Exogenous melatonin applications prolonged seed viability after heat stress conditions. In addition, melatonin applications retarded leaf senescence. Its effects as growth promoter were dose and tissue-dependent; stimulating root growth at low concentrations and decreasing leaf area at high doses.

  7. Silica-titania composite aerogel photocatalysts by chemical liquid deposition of titania onto nanoporous silica scaffolds.

    Science.gov (United States)

    Zu, Guoqing; Shen, Jun; Wang, Wenqin; Zou, Liping; Lian, Ya; Zhang, Zhihua

    2015-03-11

    Silica-titania composite aerogels were synthesized by chemical liquid deposition of titania onto nanoporous silica scaffolds. This novel deposition process was based on chemisorption of partially hydrolyzed titanium alkoxides from solution onto silica nanoparticle surfaces and subsequent hydrolysis and condensation to afford titania nanoparticles on the silica surface. The titania is homogeneously distributed in the silica-titania composite aerogels, and the titania content can be effectively controlled by regulating the deposition cycles. The resultant composite aerogel with 15 deposition cycles possessed a high specific surface area (SSA) of 425 m(2)/g, a small particle size of 5-14 nm, and a large pore volume and pore size of 2.41 cm(3)/g and 18.1 nm, respectively, after heat treatment at 600 °C and showed high photocatalytic activity in the photodegradation of methylene blue under UV-light irradiation. Its photocatalytic activity highly depends on the deposition cycles and heat treatment. The combination of small particle size, high SSA, and enhanced crystallinity after heat treatment at 600 °C contributes to the excellent photocatalytic property of the silica-titania composite aerogel. The higher SSAs compared to those of the reported titania aerogels (aerogels promising candidates as photocatalysts.

  8. Phenylnaphthalene as a Heat Transfer Fluid for Concentrating Solar Power: High-Temperature Static Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bell, Jason R [ORNL; Joseph III, Robert Anthony [ORNL; McFarlane, Joanna [ORNL; Qualls, A L [ORNL

    2012-05-01

    Concentrating solar power (CSP) may be an alternative to generating electricity from fossil fuels; however, greater thermodynamic efficiency is needed to improve the economics of CSP operation. One way of achieving improved efficiency is to operate the CSP loop at higher temperatures than the current maximum of about 400 C. ORNL has been investigating a synthetic polyaromatic oil for use in a trough type CSP collector, to temperatures up to 500 C. The oil was chosen because of its thermal stability and calculated low vapor and critical pressures. The oil has been synthesized using a Suzuki coupling mechanism and has been tested in static heating experiments. Analysis has been conducted on the oil after heating and suggests that there may be some isomerization taking place at 450 C, but the fluid appears to remain stable above that temperature. Tests were conducted over one week and further tests are planned to investigate stabilities after heating for months and in flow configurations. Thermochemical data and thermophysical predictions indicate that substituted polyaromatic hydrocarbons may be useful for applications that run at higher temperatures than possible with commercial fluids such as Therminol-VP1.

  9. Proteomic profiling of camel and cow milk proteins under heat treatment.

    Science.gov (United States)

    Felfoul, Imène; Jardin, Julien; Gaucheron, Frédéric; Attia, Hamadi; Ayadi, M A

    2017-02-01

    Cow and camel milk proteins before and after heat treatment at 80°C for 60min were identified using LC/MS and LC-MS/MS following monodimensional electrophoresis. The database used for the identification of camel and cow proteins was set from http://www.uniprot.org/. The obtained results showed that, after heating, camel milk at 80°C for 60min, camel α-lactalbumin (α-la) and peptidoglycan recognition protein (PGRP) were not detected while camel serum albumin (CSA) was significantly diminished. When heating cow milk at 80°C for 60min, α-lactalbumin (α-la) and β-lactoglobulin (β-lg) were not significantly detected. Moreover, 19 protein bands from SDS-PAGE were analyzed and a total of 45 different proteins were identified by LC-MS/MS. Casein fractions were kept intact under a heat treatment of 80°C during 60min of both camel and cow milks. Camel and bovine whey proteins were affected by a heat treatment of 80°C for 60min. PMID:27596405

  10. The influence of heat treatment on the microstructure of GA8 magnesium alloy

    Directory of Open Access Journals (Sweden)

    A. Kiełbus

    2007-01-01

    Full Text Available Purpose: GA8 magnesium alloy is a general purpose gravity sand casting alloy containing aluminum, zincand manganese. Typically, it is used in aerospace or commercial casting applications particularly where thereis no high temperature requirement. The aim of this paper is to present the results of investigations on themicrostructure of the GA8 magnesium alloy after heat treatment.Design/methodology/approach: The study was conducted on GA8 magnesium alloys in as-cast conditionand after heat treatment. The microstructure was characterized by optical microscopy (Olympus GX-70 and ascanning electron microscopy (Hitachi S3400 equipped with an electron dispersive detector EDS (VOYAGERof NORAN INSTRUMENTS. To measure the stereological parameters, an image analysis program“AnalysisPro®” was used.Findings: The microstructure of GA8 magnesium alloy has a solid solution structure α with α + d iscontinuous ßareas and continuous ß (Mg17Al12 phase at grain boundaries. After solution treatment a reduction of the number ofß precipitations was observed. Application of ageing treatment caused precipitation of discontinuous ß phase.Research limitations/implications: Future researches should involve investigations of the effect of heattreatment parameters on the mechanical properties of GA8 magnesium alloy.Practical implications: The established heat treatment parameters can be useful for preparing heat treatmenttechnology of the GA8 magnesium alloy.Originality/value: The relationship between the initial structure, heat treatment parameters and Mg17Al12 phasemorphology in GA8 magnesium alloy was specified.

  11. Aesthetic value improvement of the ruby stone using heat treatment and its synergetic surface study

    Science.gov (United States)

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

    2015-02-01

    The surface behavior of the natural ruby stones before and after heat treatment with metal oxide additives like: zinc oxide (ZnO) and lead oxide (PbO) have been studied. The surface appearance of the ruby stones processed with the metal oxides changed whereas the bulk densities of the stones remained within the range of 3.9-4.0 g/cm3. The cracks healing and pores filling by the metal oxides on the surface of the ruby have been examined using scanning electron microscopy. The chemical compositions based on the XPS survey scans are in good agreement with the expected composition. The phase and crystallinity of the ruby stones original and heat-treated were obtained from their X-ray diffraction patterns. The change in peak separation between R1 and R2 - peaks in photoluminescence spectra and the contrary binding energy shift of the Al 2p peaks in the X-ray photoelectron spectra have been explicated. Moreover, in this work we describe the change in surface chemical and physical characteristics of the ruby stone before and after heat treatment.

  12. Heat shock-induced interactions among nuclear HSFs detected by fluorescence cross-correlation spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Pack, Chan-Gi, E-mail: changipack@amc.seoul.kr [Asan Institute for Life Sciences, University of Ulsan, College of Medicine, Asan Medical Center, Seoul 138-736 (Korea, Republic of); Ahn, Sang-Gun [Dept. of Pathology, College of Dentistry, Chosun University, Seosuk-dong, Dong-gu, Gwangju 501-759 (Korea, Republic of)

    2015-07-31

    The cellular response to stress is primarily controlled in cells via transcriptional activation by heat shock factor 1 (HSF1). HSF1 is well-known to form homotrimers for activation upon heat shock and subsequently bind to target DNAs, such as heat-shock elements, by forming stress granules. A previous study demonstrated that nuclear HSF1 and HSF2 molecules in live cells interacted with target DNAs on the stress granules. However, the process underlying the binding interactions of HSF family in cells upon heat shock remains unclear. This study demonstrate for the first time that the interaction kinetics among nuclear HSF1, HSF2, and HSF4 upon heat shock can be detected directly in live cells using dual color fluorescence cross-correlation spectroscopy (FCCS). FCCS analyses indicated that the binding between HSFs was dramatically changed by heat shock. Interestingly, the recovery kinetics of interaction between HSF1 molecules after heat shock could be represented by changes in the relative interaction amplitude and mobility. - Highlights: • The binding interactions among nuclear HSFs were successfully detected. • The binding kinetics between HSF1s during recovery was quantified. • HSF2 and HSF4 strongly formed hetero-complex, even before heat shock. • Nuclear HSF2 and HSF4 bound to HSF1 only after heat shock.

  13. Effect of Sintering on Thermal Conductivity and Thermal Barrier Effects of Thermal Barrier Coatings

    Institute of Scientific and Technical Information of China (English)

    WANG Kai; PENG Hui; GUO Hongbo; GONG Shengkai

    2012-01-01

    Thermal barrier coatings (TBCs) are mostly applied to hot components of advanced turbine engines to insulate the components from hot gas.The effect of sintering on thermal conductivity and thermal barrier effects of conventional plasma sprayed and nanostructured yttria stabilized zirconia (YSZ) thermal barrier coatings (TBCs) are investigated.Remarkable increase in thermal conductivity occurs to both typical coatings after heat treatment.The change of porosity is just the opposite.The grain size of the nanostructured zirconia coating increases more drastically with annealing time compared to that of the conventional plasma sprayed coating,which indicates that coating sintering makes more contributions to the thermal conductivity of the nanostructured coating than that of the conventional coating.Thermal barrier effect tests using temperature difference technique are performed on both coatings.The thermal barrier effects decrease with the increase of thermal conductivity after heat treatment and the decline seems more drastic in low thermal conductivity range.The decline in thermal barrier effects is about 80 ℃for nanostructured coating after 100 h heat treatment,while the conventional coating reduces by less than 60 ℃ compared to the as-sprayed coating.

  14. Synthesis of biomedical composite scaffolds by laser sintering: Mechanical properties and in vitro bioactivity evaluation

    Science.gov (United States)

    Liu, Fwu-Hsing

    2014-04-01

    In this study, biomedical composite materials were employed to fabricate bone scaffolds using a self-developed rapid prototyping (RP) apparatus. The slurry formed by combining hydroxyapatite (HA), silica sol, and sodium tripolyphosphate (STPP) was heated by a CO2 laser. Under appropriate processing parameters, a biocomposite green body was subsequently fabricated. Its mechanical properties, including surface roughness, bending and compression strengths, volume shrinkage rate, and surface microstructure, were analyzed after heat treatment to 1200 °C, 1300 °C, and 1400 °C. The results showed that after heating the specimen to 1200 °C, its compression and bending strengths increased significantly to 43.26 MPa and 1.28 MPa, respectively; the surface roughness was 12 μm; and surface pores were of size 5-25 μm. Furthermore, the results of WST-1 and LDH assay indicate that the biocomposites showed no cytotoxicity on 3T3 fibroblast. An optical density (OD) of 1.1 was also achieved, and the specimen was suitable for the adhesion and growth of osteoblast-like cells (MG63). Therefore, the biocomposite bone scaffolds fabricated in this study have potential to be bone implants for developing hard tissue.

  15. Effect of grain orientation and heat treatment on mechanical properties of pure W

    International Nuclear Information System (INIS)

    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

  16. Sol-gel derived fluor-hydroxyapatite biocoatings on zirconia substrate.

    Science.gov (United States)

    Kim, Hae-Won; Kong, Young-Min; Bae, Chang-Jun; Noh, Yoon-Jung; Kim, Hyoun-Ee

    2004-07-01

    Fluor-hydroxyapatite (FHA) film was coated on a zirconia (ZrO(2)) substrate by a sol-gel method. An appropriate amount of F ions was incorporated into the hydroxyapatite (HA) during the preparation of the sols. The apatite phase began to crystallize after heat treatment at 400 degrees C, and increased in intensity above 500 degrees C. No decomposition was detected by X-ray diffraction analyses up to 800 degrees C, which illustrates the high thermal stability of the FHA films. The films showed a uniform and dense morphology with a thickness of approximately 1 microm after a precisely controlled heat treatment process. These FHA films adhered firmly to the zirconia substrate, representing notable adhesion strengths of approximately 70 MPa after heat treatment above 500 degrees C. The dissolution rate of the FHA coating layer varied according to the heat treatment temperature, which was closely related to the film crystallinity. The dissolution rate of the FHA film was lower than that of the HA film, suggesting the possibility of a functional gradient coating of HA and FHA. The MG63 cells seeded onto the FHA films proliferated in a similar manner to those seeded onto pure HA ceramic and a plastic control.

  17. Obtention, machining and wear of sintered alloys for automotive applications

    International Nuclear Information System (INIS)

    The aim of this work was the development of materials for automotive applications, in particular, valve seat inserts for gasoline combustion engines. The development involved the following activities: processing by powder metallurgy techniques, heat treatment, mechanical and microstructural characterization, machining and wear of materials. This work was undertaken aiming cost reduction of this component by the use of cheaper and less pollutant elements, eliminating the presence of Co and Pb due to their high cost and toxicological effects, respectively. The accomplishment of a thorough research into patents revealed that the materials studied here present particular compositions and were not yet produced. The results of hardness measurements and the transverse radial strength of the studied materials, after heat treatment, revealed superior properties than the commercial alloys applied at the moment. The machining tests of the material without heat treatment indicated a similar behaviour in comparison to the commercial alloy, suggesting that the new alloy chemistry composition was not deleterious in this sense. After heat treatment, the obtained alloys presented a cutting force increase in relation to the commercial alloy. Wear tests results of heat treated materials presented smaller friction coefficient and mass loss than the commercial alloy, in ali cases. This was especially achieved due to the advantages offered by heat treatment allied to the addition of NbC and Ti/W carbides. The materials obtained here showed to be potential candidates to substitute with advantages, valve seat inserts made of Fe-Co alloys for gasoline combustion engines. (author)

  18. Mechanical properties and microstructure evolution of the nano WC-Co coatings fabricated by detonation gun spraying with post heat treatment

    International Nuclear Information System (INIS)

    Effects of post heat treatment of thermally sprayed nano WC-Co coatings on their mechanical properties were studied. The thermal behavior of WC particles in the coatings was also investigated. WC-Co coatings containing nano carbide particles in the 100-200 nm range were fabricated by detonation gun spraying. Considerable phase decomposition of WC to W2C and amorphous phase was detected, which degrades the mechanical properties of coatings. In order to improve the mechanical properties of the coatings by recovery of dissociated carbide phases, post heat treatment was conducted in an Ar environment in the temperature range of 400-900 deg. C. Microhardness and fracture toughness were measured by Vickers indentation testing and wear resistance was also evaluated by using a scratch tester. Phase evolution and microstructural changes due to post heat treatment were investigated by optical microscopy, X-ray diffractometry and field-emission scanning electron microscopy. After heat treatment in all temperature ranges, microhardness increased. Fracture toughness and wear resistance of coatings were increased by increasing temperature to 800 deg. C but decreased after heat treatment at 900 deg. C. Amorphous phase disappeared and other carbide phases such as W3Co3C and W6Co6C formed during heat treatment above 700 deg. C. The improved properties were elucidated and discussed in terms of microstructural changes and the relationship between mechanical properties and carbide phase was also discussed

  19. Mechanical properties and microstructure evolution of the nano WC-Co coatings fabricated by detonation gun spraying with post heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.Y. [Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of); Kim, M.C. [Research Institute of Industrial Science and Technology, Pohang (Korea, Republic of); Park, C.G. [Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of)], E-Mail: cgpark@postech.ac.kr

    2007-03-25

    Effects of post heat treatment of thermally sprayed nano WC-Co coatings on their mechanical properties were studied. The thermal behavior of WC particles in the coatings was also investigated. WC-Co coatings containing nano carbide particles in the 100-200 nm range were fabricated by detonation gun spraying. Considerable phase decomposition of WC to W{sub 2}C and amorphous phase was detected, which degrades the mechanical properties of coatings. In order to improve the mechanical properties of the coatings by recovery of dissociated carbide phases, post heat treatment was conducted in an Ar environment in the temperature range of 400-900 deg. C. Microhardness and fracture toughness were measured by Vickers indentation testing and wear resistance was also evaluated by using a scratch tester. Phase evolution and microstructural changes due to post heat treatment were investigated by optical microscopy, X-ray diffractometry and field-emission scanning electron microscopy. After heat treatment in all temperature ranges, microhardness increased. Fracture toughness and wear resistance of coatings were increased by increasing temperature to 800 deg. C but decreased after heat treatment at 900 deg. C. Amorphous phase disappeared and other carbide phases such as W{sub 3}Co{sub 3}C and W{sub 6}Co{sub 6}C formed during heat treatment above 700 deg. C. The improved properties were elucidated and discussed in terms of microstructural changes and the relationship between mechanical properties and carbide phase was also discussed.

  20. The aggregation behavior and interactions of yak milk protein under thermal treatment.

    Science.gov (United States)

    Wang, T T; Guo, Z W; Liu, Z P; Feng, Q Y; Wang, X L; Tian, Q; Ren, F Z; Mao, X Y

    2016-08-01

    The aggregation behavior and interactions of yak milk protein were investigated after heat treatments. Skim yak milk was heated at temperatures in the range of 65 to 95°C for 10 min. The results showed that the whey proteins in yak milk were denatured after heat treatment, especially at temperatures higher than 85°C. Sodium dodecyl sulfate-PAGE analysis indicated that heat treatment induced milk protein denaturation accompanied with aggregation to a certain extent. When the heating temperature was 75 and 85°C, the aggregation behavior of yak milk proteins was almost completely due to the formation of disulfide bonds, whereas denatured α-lactalbumin and β-lactoglobulin interacted with κ-casein. When yak milk was heated at 85 and 95°C, other noncovalent interactions were found between proteins including hydrophobic interactions. The particle size distributions and microstructures demonstrated that the heat stability of yak milk proteins was significantly lowered by heat treatment. When yak milk was heated at 65 and 75°C, no obvious changes were found in the particle size distribution and microstructures in yak milk. When the temperature was 85 and 95°C, the particle size distribution shifted to larger size trend and aggregates were visible in the heated yak milk. PMID:27209140

  1. Influence of heat treatment on spray-dried mixtures of Amioca starch and Carbopol 974P used as carriers for nasal drug delivery.

    Science.gov (United States)

    Coucke, D; Pringels, E; Foreman, P; Adriaensens, P; Carleer, R; Remon, J P; Vervaet, C

    2009-08-13

    A mucoadhesive spray-dried starch/poly(acrylic acid) powder underwent different heat treatments in order to induce cross-linking between the functional groups of starch (Amioca) and poly(acrylic acid) (Carbopol 974P). After heat treatment the water-absorbing capacity, viscosity and elasticity of the mucoadhesive powder increased. NMR analysis in combination with FT-IR indicated that heat treatment induced a low degree of cross-linking between the polymers. Nasal administration of Amioca/Carbopol 974P powders without heat treatment resulted in an absolute bioavailability in rabbits of 8.2+/-3.0% for insulin. Due to the difference in water-absorbing capacity (which opened the tight junctions of the nasal mucosa), elasticity and plasticity (which reduced mucociliairy clearance and prolonged residence time) heat treatment at 120 degrees C improved the bioavailability: 26.4+/-21.9, 36.5+/-11.0 and 19.3+/-17.3% after heat treatment during 30 min, 1 h and 4 h, respectively. Heat treatment at 60 degrees C was less efficient. This study demonstrated that the nasal insulin absorption improved via heat treatment of the Amioca/Carbopol 974P powder (prior to the addition of insulin). The bioavailability-enhancing effect of a 1 h heat treatment at 120 degrees C was confirmed using the same polymer matrix in combination with different drugs (salmon calcitonin, human growth hormone and metoprolol tartrate). PMID:19477256

  2. Identification of proteins sensitive to thermal stress in human neuroblastoma and glioma cell lines.

    Directory of Open Access Journals (Sweden)

    Guilian Xu

    Full Text Available Heat-shock is an acute insult to the mammalian proteome. The sudden elevation in temperature has far-reaching effects on protein metabolism, leads to a rapid inhibition of most protein synthesis, and the induction of protein chaperones. Using heat-shock in cells of neuronal (SH-SY5Y and glial (CCF-STTG1 lineage, in conjunction with detergent extraction and sedimentation followed by LC-MS/MS proteomic approaches, we sought to identify human proteins that lose solubility upon heat-shock. The two cell lines showed largely overlapping profiles of proteins detected by LC-MS/MS. We identified 58 proteins in detergent insoluble fractions as losing solubility in after heat shock; 10 were common between the 2 cell lines. A subset of the proteins identified by LC-MS/MS was validated by immunoblotting of similarly prepared fractions. Ultimately, we were able to definitively identify 3 proteins as putatively metastable neural proteins; FEN1, CDK1, and TDP-43. We also determined that after heat-shock these cells accumulate insoluble polyubiquitin chains largely linked via lysine 48 (K-48 residues. Collectively, this study identifies human neural proteins that lose solubility upon heat-shock. These proteins may represent components of the human proteome that are vulnerable to misfolding in settings of proteostasis stress.

  3. Cytochrome c Is Released in a Reactive Oxygen Species-Dependent Manner and Is Degraded via Caspase-Like Proteases in Tobacco Bright-Yellow 2 Cells en Route to Heat Shock-Induced Cell Death1

    Science.gov (United States)

    Vacca, Rosa Anna; Valenti, Daniela; Bobba, Antonella; Merafina, Riccardo Sandro; Passarella, Salvatore; Marra, Ersilia

    2006-01-01

    To gain some insight into the mechanism of plant programmed cell death, certain features of cytochrome c (cyt c) release were investigated in heat-shocked tobacco (Nicotiana tabacum) Bright-Yellow 2 cells in the 2- to 6-h time range. We found that 2 h after heat shock, cyt c is released from intact mitochondria into the cytoplasm as a functionally active protein. Such a release did not occur in the presence of superoxide anion dismutase and catalase, thus showing that it depends on reactive oxygen species (ROS). Interestingly, ROS production due to xanthine plus xanthine oxidase results in cyt c release in sister control cultures. Maximal cyt c release was found 2 h after heat shock; later, activation of caspase-3-like protease was found to increase with time. Activation of this protease did not occur in the presence of ROS scavenger enzymes. The released cyt c was found to be progressively degraded in a manner prevented by either the broad-range caspase inhibitor (zVAD-fmk) or the specific inhibitor of caspase-3 (AC-DEVD-CHO), which have no effect on cyt c release. In the presence of these inhibitors, a significant increase in survival of the cells undergoing programmed cell death was found. We conclude that ROS can trigger release of cyt c, but do not cause cell death, which requires caspase-like activation. PMID:16531480

  4. Arbuscular mycorrhizal fungi modify nutrient allocation and composition in wheat (Triticum aestivum L.) subjected to heat-stress

    DEFF Research Database (Denmark)

    Cabral, Carmina Falcato; Ravnskov, Sabine; Tringovska, Ivanka;

    2016-01-01

    Aims To evaluate the role of the AM symbiosis on nutrient allocation in Triticum aestivum L. cv. 1110 at different growth stages before and after heat-stress at anthesis. Methods Measurements of plant biomass and grain yield at anthesis, grain-filling and maturity; determination of macro- and mic......Aims To evaluate the role of the AM symbiosis on nutrient allocation in Triticum aestivum L. cv. 1110 at different growth stages before and after heat-stress at anthesis. Methods Measurements of plant biomass and grain yield at anthesis, grain-filling and maturity; determination of macro......- and micronutrient concentrations in aboveground biomass; evaluation of AM fungal structures in roots and assessment of light-use efficiency of plants. Results AM increased grain number in wheat under heat-stress, and altered nutrient allocation and tiller nutrient composition. Heat increased number of arbuscules...... in wheat root, whereas number of vesicles and total colonization were unaffected. Heat increased photosystem II yield and the electron transfer rate, whereas non-photochemical quenching decreased during the first 2 days of heat-stress. Conclusions Nutrient allocation and –composition in wheat grown under...

  5. 磨球残余应力的数值模拟及分析%Simulation and Analysis of Residual Stress of Grinding Balls

    Institute of Scientific and Technical Information of China (English)

    袁允社; 张小博

    2009-01-01

    The distribution of residual stress of grinding balls in casting condition was simulated based on the software ProCAST. The stress distribution after heat treating was determined by X-ray diffraction instrument. The results indicate that grinding balls in the metal mould solidify first and then in the sand mould, and the interior structures of grinding balls are compact; there is mass of residual stress in the grinding ball in cast condition,although a definite residual stress can be eliminated after heat treating, an amount of stress still exists.%通过铸造数值模拟软件ProCAST模拟了磨球铸态下的残余应力分布情况,同时通过X射线衍射仪,测定了热处理后磨球试样上应力分布状态.结果表明,磨球金属型部位先凝固,砂型部位后凝固,磨球内部组织致密、无缺陷;铸态下在磨球内有大量的残余应力,热处理后可以消除一定的铸造残余应力,但仍有大量残余应力存在.

  6. Radiation-induced strand breaks in phiX174 replicative form DNA: an improved experimental and theoretical approach

    International Nuclear Information System (INIS)

    To determine the yield of radiation-induced single-strand, double-strand and potential breaks, oxygenated aqueous solutions of X174 super-coiled circular double-stranded (RFI)DNA were irradiated with increasing doses of γ-irradiation and subjected to electrophoresis on agarose gels both before and after heat treatment. A complete separation was obtained of RFI,RFII (relaxed circle due to one or more single-strand breaks) and RFIII (linear DNA due to one double-stand break). A computer-assisted spectrophotometric procedure was developed, enabling the accurate measurement of the amount of DNA present in the three DNA fractions. Quantitative changes of each fraction of DNA with dose could be fitted to a straightforward statistical model describing the dose-dependent formation of the different types of breaks and from which the D37-values of single-strand, potential single-strand and double-strand breaks could be calculated to be 0.42+-0.02, 1.40+-0.25 and 57+-36 Gy respectively. Potential double-strand breaks were not formed significantly. In addition the maximum distance between two independently introduced single-strand breaks in opposite strands resulting in a double-strand break could be determined. Values before and after heat treatment are shown to be 29+-6 and 102+-13 nucleotides, respectively. (U.K.)

  7. Gamma irradiation influence on physical properties of milk proteins

    Science.gov (United States)

    Cieśla, K.; Salmieri, S.; Lacroix, M.; Tien, C. Le

    2004-09-01

    Gamma irradiation was found to be an effective method for the improvement of both barrier and mechanical properties of the edible films and coatings based on calcium and sodium caseinates alone or combined with some globular proteins. Our current studies concern gamma irradiation influence on the physical properties of calcium caseinate-whey protein isolate-glycerol (1:1:1) solutions and gels, used for films preparation. Irradiation of solutions was carried out with Co-60 gamma rays applying 0 and 32 kGy dose. The increase in viscosity of solutions was found after irradiation connected to induced crosslinking. Lower viscosity values were detected, however, after heating of the solutions irradiated with a 32 kGy dose than after heating of the non-irradiated ones regarding differences in the structure of gels and resulting in different temperature-viscosity curves that were recorded for the irradiated and the non-irradiated samples during heating and cooling. Creation of less stiff but better ordered gels after irradiation arises probably from reorganisation of aperiodic helical phase and β-sheets, in particular from increase of β-strands, detected by FTIR. Films obtained from these gels are characterised by improved barrier properties and mechanical resistance and are more rigid than those prepared from the non-irradiated gels. The route of gel creation was investigated for the control and the irradiated samples during heating and the subsequent cooling.

  8. The aggregation behavior and interactions of yak milk protein under thermal treatment.

    Science.gov (United States)

    Wang, T T; Guo, Z W; Liu, Z P; Feng, Q Y; Wang, X L; Tian, Q; Ren, F Z; Mao, X Y

    2016-08-01

    The aggregation behavior and interactions of yak milk protein were investigated after heat treatments. Skim yak milk was heated at temperatures in the range of 65 to 95°C for 10 min. The results showed that the whey proteins in yak milk were denatured after heat treatment, especially at temperatures higher than 85°C. Sodium dodecyl sulfate-PAGE analysis indicated that heat treatment induced milk protein denaturation accompanied with aggregation to a certain extent. When the heating temperature was 75 and 85°C, the aggregation behavior of yak milk proteins was almost completely due to the formation of disulfide bonds, whereas denatured α-lactalbumin and β-lactoglobulin interacted with κ-casein. When yak milk was heated at 85 and 95°C, other noncovalent interactions were found between proteins including hydrophobic interactions. The particle size distributions and microstructures demonstrated that the heat stability of yak milk proteins was significantly lowered by heat treatment. When yak milk was heated at 65 and 75°C, no obvious changes were found in the particle size distribution and microstructures in yak milk. When the temperature was 85 and 95°C, the particle size distribution shifted to larger size trend and aggregates were visible in the heated yak milk.

  9. Serum erythropoietin levels by radioimmunoassay in polycythaemia

    Energy Technology Data Exchange (ETDEWEB)

    Birgegaard, G.; Miller, O.; Caro, J.; Erslev, A. (Cardeza Foundation for Hematological Research, Jefferson University, Philadelphia, Pa.)

    1982-01-01

    A radioimmunoassay (RIA) method for erythropoietin (Epo) was developed and validated against the polycythaemic mouse assay. The correlation was good, with a r=0.94. Several other criteria of specificity were also filled by the RIA, which had a lower detection limit of 5 mU/ml. The mean serum-Epo level in 6 patients with secondary polycythaemia, 50.2 +- 26.2 mU/ml, was significantly higher than in a group of 11 normal subjects, 28.7 +- 7.2 mU/ml (P<0.0002). However, the Epo level in 31 polycythaemia vera (PV) patients, M = 21.9 +- 6.6 mU/ml, was not significantly different from normal (P = 0.006). Since previous studies with bioassay of heat-treated and concentrated plasma samples have shown a decreased serum-Epo level in PV, Epo levels were measured before and after heat treatment and concentration of samples from normals and polycythaemics. It was found that the levels of immunoreactive material increased after heat treatment and 40 times concentration in samples from normals and patients with secondary polycythaemias, but decreased in PV. We conclude that the Epo levels in serum in the low range measured by our and previous RIA:s probably are not true Epo levels but are partly due to an unspecific serum effect, that was removed by heat treatment.

  10. Thermal stability of partially ordered Fe{sub 16}N{sub 2} film on non-magnetic Ag under layer

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiaowei; Wang, Jian-Ping, E-mail: jpwang@umn.edu [The Center for Micromagnetics and Information Technologies (MINT) and Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minnesota 55455 (United States); School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Yang, Meiyin; Jiang, Yanfeng [The Center for Micromagnetics and Information Technologies (MINT) and Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Allard, Lawrence F. [High Temperature Materials Laboratory, Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2014-05-07

    Partially ordered Fe{sub 16}N{sub 2} thin film with (001) texture is successfully grown on a Ag under layer using a facing target sputtering system. Fe{sub 16}N{sub 2} phase is formed after post-annealing, which is detected by X-ray diffraction (XRD). High saturation magnetization (M{sub s}) of Fe{sub 16}N{sub 2} thin films is observed by vibrating sample magnetometry. It is found that Fe{sub 16}N{sub 2} phase can be stable up to 225 °C, which is demonstrated by the Fe{sub 16}N{sub 2} finger print peak (002) in XRD. After heating to 250 °C, the Fe{sub 16}N{sub 2} phase decomposes, which leads to low M{sub s} and soft magnetic behavior. To further study Fe{sub 16}N{sub 2} decomposition, X-ray photoelectron spectroscopy is performed to detect the binding energy of nitrogen atoms. Differences of binding energy corresponding to before and after heat treatment show the variation of nitrogen atom in electronic state with surrounding Fe atoms, indicating nitrogen atomic migration during heat treatment.

  11. Preparation and characterization of Pt supported on graphene with enhanced electrocatalytic activity in fuel cell

    Science.gov (United States)

    Xin, Yuchen; Liu, Jian-guo; Zhou, Yong; Liu, Wenming; Gao, Jian; Xie, Yun; Yin, Ying; Zou, Zhigang

    Pt nanoparticles are deposited onto graphene sheets via synchronous reduction of H 2PtCl 6 and graphene oxide (GO) suspension using NaBH 4. Lyophilization is introduced to avoid irreversible aggregation of graphene (G) sheets, which happens during conventional drying process. Pt/G catalysts reveal a high catalytic activity for both methanol oxidation and oxygen reduction reaction compared to Pt supported on carbon black (Pt/C). The performance of Pt/G catalysts is further improved after heat treatment in N 2 atmosphere at 300 °C for 2 h, and the peak current density of methanol oxidation for Pt/G after heat treatment is almost 3.5 times higher than Pt/C. Transmission electron microscope (TEM) images show that the Pt particles are uniformly distributed on graphene sheets. X-ray photoelectron spectroscopy (XPS) results demonstrate that the interaction between Pt and graphene is enhanced during annealing. It suggests that graphene has provided a new way to improve electrocatalytic activity of catalyst for fuel cell.

  12. Using thermal and spectroscopic data to investigate the thermal behavior of epinephrine

    Energy Technology Data Exchange (ETDEWEB)

    Bannach, Gilbert; Cervini, Priscila [Instituto de Quimica de Sao Carlos - IQSC/USP, C.P. 780, CEP 13560-970, Sao Carlos, SP (Brazil); Cavalheiro, Eder Tadeu Gomes, E-mail: cavalheiro@iqsc.usp.br [Instituto de Quimica de Sao Carlos - IQSC/USP, C.P. 780, CEP 13560-970, Sao Carlos, SP (Brazil); Ionashiro, Massao [Instituto de Quimica, UNESP, C.P. 355, CEP 14801-970, Araraquara, SP (Brazil)

    2010-02-20

    Epinephrine is a neurotransmitter of the catecholamine class that acts in the mammalian central nervous system. The TG-DTA curves of epinephrine showed that the anhydrous compound starts decomposition at 165 {sup o}C, under the conditions used in this work. The reflectance FTIR spectra and X-ray powder diffraction patterns of epinephrine before and after heating up to 210 {sup o}C, as well as the TG-FTIR spectra of sample heated between 30 and 600 {sup o}C, were obtained and reveled that after heating, structural changes occurred in the sample. At temperatures higher than 205 {sup o}C the thermal decomposition took place with elimination of methylamine in agreement with the first mass loss observed in the TG curve in both air and N{sub 2} atmospheres (TG = 17.0%, calcd. = 17.0%). The melting was observed at 205 {sup o}C (DTA) or 203 {sup o}C (DSC) but this process occurred overlapped with decomposition characteristic of an incongruent melting process.

  13. Effect of heating on the behaviors of hydrogen in C-TiC films with auger electron spectroscopy and secondary ion mass spectroscopy analyses

    International Nuclear Information System (INIS)

    C-TiC films with a content of 75% TiC were prepared with magnetron sputtering deposition followed by Ar+ ion bombardment. Effect of heating on the behaviors of hydrogen in C-TiC films before and after heating was studied with Auger Electron Spectroscopy and Secondary Ion Mass Spectroscopy (SIMS) analyses. SIMS depth profiles of hydrogen after H+ ion implantation and thermal treatment show different hydrogen concentrations in C-TiC coatings and stainless steel. SIMS measurements show the existence of TiH, TiH2, CH3, CH4, C2H2 bonds in the films after H+ ion irradiation and the changes in the Ti LMM, Ti LMV and C KLL Auger line shape reveal that they have a good hydrogen retention ability after heating up to the temperature 393 K. All the results show that C-TiC coatings can be used as a hydrogen retainer or hydrogen permeable barrier on stainless steel to protect it from hydrogen brittleness

  14. High temperature annealing studies of strontium ion implanted glassy carbon

    Science.gov (United States)

    Odutemowo, O. S.; Malherbe, J. B.; Prinsloo, L.; Langa, D. F.; Wendler, E.

    2016-03-01

    Glassy carbon samples were implanted with 200 keV strontium ions to a fluence of 2 × 1016 ions/cm2 at room temperature. Analysis with Raman spectroscopy showed that ion bombardment amorphises the glassy carbon structure. Partial recovery of the glassy carbon structure was achieved after the implanted sample was vacuum annealed at 900 °C for 1 h. Annealing the strontium ion bombarded sample at 2000 °C for 5 h resulted in recovery of the glassy carbon substrate with the intensity of the D peak becoming lower than that of the pristine glassy carbon. Rutherford backscattering spectroscopy (RBS) showed that the implanted strontium diffused towards the surface of the glassy carbon after annealing the sample at 900 °C. This diffusion was also accompanied by loss of the implanted strontium. Comparison between the as-implanted and 900 °C depth profiles showed that less than 30% of the strontium was retained in the glassy carbon after heat treatment at 900 °C. The RBS profile after annealing at 2000 °C indicated that no strontium ions were retained after heat treatment at this temperature.

  15. Effect of severe environmental thermal stress on redox state in salmon.

    Science.gov (United States)

    Nakano, Toshiki; Kameda, Masumi; Shoji, Yui; Hayashi, Satoshi; Yamaguchi, Toshiyasu; Sato, Minoru

    2014-01-01

    Fish are exposed to many kinds of environmental stressors and the chances of succumbing to infectious diseases may be increased a result. For example, an acute increase in temperature can induce numerous physiological changes in the body. In the present study, we examined the redox state in response to a severe acute stress resulting from heat shock in teleost coho salmon (Oncorhynchus kisutch). The plasma lipid peroxides levels in fish gradually increased after heat shock treatment. By 2.5 h post-heat stress, plasma glutathione (GSH) levels had decreased, but they had returned to basal levels by 17.5 h post-stress. Plasma superoxide dismutase activities in stressed fish were significantly increased compared with those in control fish at 17.5 h post-stress, but had returned to basal levels by 48 h post-stress. Expression levels of hepatic GSH and heat shock protein 70 gradually increased after heat shock treatment. These results concerning the changing patterns of multiple important redox-related biomarkers suggest that severe thermal stressors can affect the redox state and induce oxidative stress in ectothermal animals, such as fish, in vivo. Hence, manipulation of appropriate thermal treatment may possibly be useful to control fish fitness.

  16. Effect of severe environmental thermal stress on redox state in salmon

    Directory of Open Access Journals (Sweden)

    Toshiki Nakano

    2014-01-01

    Full Text Available Fish are exposed to many kinds of environmental stressors and the chances of succumbing to infectious diseases may be increased a result. For example, an acute increase in temperature can induce numerous physiological changes in the body. In the present study, we examined the redox state in response to a severe acute stress resulting from heat shock in teleost coho salmon (Oncorhynchus kisutch. The plasma lipid peroxides levels in fish gradually increased after heat shock treatment. By 2.5 h post-heat stress, plasma glutathione (GSH levels had decreased, but they had returned to basal levels by 17.5 h post-stress. Plasma superoxide dismutase activities in stressed fish were significantly increased compared with those in control fish at 17.5 h post-stress, but had returned to basal levels by 48 h post-stress. Expression levels of hepatic GSH and heat shock protein 70 gradually increased after heat shock treatment. These results concerning the changing patterns of multiple important redox-related biomarkers suggest that severe thermal stressors can affect the redox state and induce oxidative stress in ectothermal animals, such as fish, in vivo. Hence, manipulation of appropriate thermal treatment may possibly be useful to control fish fitness.

  17. Thermal stability of nanocrystalline microstructures

    Science.gov (United States)

    Darling, Kris Allen

    The objective of the proposed research is to develop the experimental data and scientific basis that can optimize the thermodynamic stabilization of a nanoscale microstructure during consolidation of Fe powder particles through select solute diffusion to grain boundaries. Fe based alloys were high energy ball milled to produce supersaturated solid solutions with a nominal grain size of ˜10nm. Solutes such as Y, W, Ta, Ni and Zr were selected based on their propensity to grain boundary segregated in Fe. Based on preliminary heat treatments Zr was selected as the solute of choice. Upon further heat treating experiments and microstructural analysis it was found that Zr solute additions of contamination was high due to the extensive cold welding exhibited by this system. The as-milled alloy showed an increase in hardness from ˜6.5GPa to ˜10GPa after heat treating at 1000°C for 1 hour. Based on these hardness measurements this alloy exhibits high thermal stability up to 1000°C. However, after heat treating at 1273°C the formation of Zr oxides were detected. Occurring simultaneously with the secondary phase formation was a rapid decrease in Vickers hardness from ˜10GPa to ˜3GPa. Ion channeling contrast images reveled that a nanocrystalline microstructure was not maintained at 1273°C. While these results are in conflict with what was reported in literature additional work is needed to confirm the results, however a presentation of the collected data is presented.

  18. Dislocation generation related to micro-cracks in Si wafers: High temperature in situ study with white beam X-ray topography

    Energy Technology Data Exchange (ETDEWEB)

    Danilewsky, A., E-mail: a.danilewsky@krist.uni-freiburg.d [Kristallographie, Institut fuer Geowissenschaften, Universitaet, Freiburg (Germany); Wittge, J.; Hess, A.; Croell, A. [Kristallographie, Institut fuer Geowissenschaften, Universitaet, Freiburg (Germany); Allen, D.; McNally, P. [Research Institute for Networks and Communications Engineering, Dublin City University, Dublin (Ireland); Vagovic, P. [Institut fuer Synchrotronstrahlung, Research Centre Karlsruhe/KIT, Karlsruhe (Germany); Institute of Electrical Engineering, Slovak Academy Sciences, Bratislava (Slovakia); Cecilia, A. [Institut fuer Synchrotronstrahlung, Research Centre Karlsruhe/KIT, Karlsruhe (Germany); Li, Z. [Kristallographie, Institut fuer Geowissenschaften, Universitaet, Freiburg (Germany); Institut fuer Synchrotronstrahlung, Research Centre Karlsruhe/KIT, Karlsruhe (Germany); Baumbach, T. [Institut fuer Synchrotronstrahlung, Research Centre Karlsruhe/KIT, Karlsruhe (Germany); Gorostegui-Colinas, E.; Elizalde, M.R. [Centro de Estudios e Investigaciones Tecnicas de Gipuzkoa, CEIT and Tecnun (University of Navarra), San Sebastian (Spain)

    2010-02-15

    The generation and propagation of dislocations in Si at high temperature is observed in situ with white beam X-ray topography. For the heating experiments a double ellipsoidal mirror furnace was installed at the Topo-Tomo beamline of the ANKA synchrotron light source, Research Centre Karlsruhe, Germany. Details of the experimental set-up and the first results on the occurrence of dislocations are presented. Artificial damage was generated in commercial (1 0 0) Si wafers using a nanoindenter with various loads. The applied forces for each set of indents were varied from 100 to 500 mN, respectively. After heating to approx. 790 deg. C large area transmission topographs were taken every 30 min which were then compared to room temperature topographs before and after heating. At the outset straight 60 deg.-dislocations with b = a/2<1 1 0> originate from the 500 mN indents into the direction of the strongest temperature gradient. After 60 min at constant temperature an increase in the length and number of the dislocations in other directions is also observed. As a result of the continual thermal stressing dislocations develop from the 100 mN indents too.

  19. Obtention, machining and wear of sintered alloys for automotive applications; Processamento, usinagem e desgaste de ligas sinterizadas para aplicacoes automotivas

    Energy Technology Data Exchange (ETDEWEB)

    Jesus Filho, Edson Souza de

    2006-07-01

    The aim of this work was the development of materials for automotive applications, in particular, valve seat inserts for gasoline combustion engines. The development involved the following activities: processing by powder metallurgy techniques, heat treatment, mechanical and microstructural characterization, machining and wear of materials. This work was undertaken aiming cost reduction of this component by the use of cheaper and less pollutant elements, eliminating the presence of Co and Pb due to their high cost and toxicological effects, respectively. The accomplishment of a thorough research into patents revealed that the materials studied here present particular compositions and were not yet produced. The results of hardness measurements and the transverse radial strength of the studied materials, after heat treatment, revealed superior properties than the commercial alloys applied at the moment. The machining tests of the material without heat treatment indicated a similar behaviour in comparison to the commercial alloy, suggesting that the new alloy chemistry composition was not deleterious in this sense. After heat treatment, the obtained alloys presented a cutting force increase in relation to the commercial alloy. Wear tests results of heat treated materials presented smaller friction coefficient and mass loss than the commercial alloy, in ali cases. This was especially achieved due to the advantages offered by heat treatment allied to the addition of NbC and Ti/W carbides. The materials obtained here showed to be potential candidates to substitute with advantages, valve seat inserts made of Fe-Co alloys for gasoline combustion engines. (author)

  20. Antioxidants Inhibit Formation of 3-Monochloropropane-1,2-diol Esters in Model Reactions.

    Science.gov (United States)

    Li, Chang; Jia, Hanbing; Shen, Mingyue; Wang, Yuting; Nie, Shaoping; Chen, Yi; Zhou, Yongqiang; Wang, Yuanxing; Xie, Mingyong

    2015-11-11

    The capacities of six antioxidants to inhibit the formation of 3-monochloropropane-1,2 diol (3-MCPD) esters were examined in this study. Inhibitory capacities of the antioxidants were investigated both in chemical models containing the precursors (tripalmitoyl glycerol, 1,2-dipalmitoyl-sn-glycerol, monopalmitoyl glycerol, and sodium chloride) of 3-MCPD esters and in oil models (rapeseed oil and sodium chloride). Six antioxidants, butylated hydroxytoluene (BHT), butylated hydroxy anisole (BHA), tert-butyl hydroquinone (TBHQ), propyl gallate (PG), L-ascorbyl palmitate (AP), and α-tocopherol (VE), were found to exhibit inhibiting capacities on 3-MCPD ester formation both in chemical models and in oil models. TBHQ provided the highest inhibitory capacity both in chemical models and in oil models; 44% of 3-MCPD ester formation was inhibited in the presence of TBHQ (66 mg/kg of oil) after heating of rapeseed oil at 230 °C for 30 min, followed by PG and AP. BHT, BHA, and VE appeared to have weaker inhibitory abilities in both models. VE exhibited the lowest inhibition rate; 22% of 3-MCPD esters were inhibited in the presence of VE (172 mg/kg of oil) after heating of rapeseed oil at 230 °C for 30 min. In addition, the inhibition rates of PG and VE decreased dramatically with an increase in temperature or heating time. The results suggested that some antioxidants, such as TBHQ, PG, and AP, could be the potential inhibitors of 3-MCPD esters in practice. PMID:26478126

  1. Thermal stability of nitride solar selective absorbing coatings used in high temperature parabolic trough current

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This paper reports a new efficient solar selective surface in high temperature application.The influence of the monolayer’s microstructure and deposition rate was firstly discussed.Then the nitride nano-multilayer on the polished stainless steel (herein after referred as "SS") substrate was prepared with Ti and Al metal targets by DC.and R.F.magnetron co-sputtering.The samples were annealed in air at different temperatures ranging from 350 to 800°C for 2 h to evaluate their thermal stability.The samples’ surface and cross-section morphology,crystal structure,phase composition,optical properties were analyzed by scanning electron microscopy,X-ray diffraction,UV-VIS-NIR spectrophotometer and infrared emissivity tester.The results show that the coatings exhibit high solar selectivity (α/ε) of 0.943/0.08 even after heat-treatment up to 400°C for 2 h in air.After heat-treatment at 600°C in air,the solar selectivity decreases to 0.92/0.16.

  2. Ion irradiation effects on surface mechanical behavior and shrinkage of hybrid sol-gel derived silicate thin films

    Energy Technology Data Exchange (ETDEWEB)

    Ghisleni, R. [School of Mechanical and Aerospace Engineering, Oklahoma State University, 218 Engineering North, Stillwater, OK 74078 (United States); Lucca, D.A. [School of Mechanical and Aerospace Engineering, Oklahoma State University, 218 Engineering North, Stillwater, OK 74078 (United States)], E-mail: lucca@ceat.okstate.edu; Wang, Y.Q. [Division of Materials Science and Technology, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Lee, J.-K.; Nastasi, M. [Division of Materials Physics and Applications, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Dong, J.; Mehner, A. [Stiftung Institut fuer Werkstofftechnik, Badgasteiner Strasse 3, 28359 Bremen (Germany)

    2008-05-15

    A study of the effects of ion irradiation on the surface mechanical behavior and shrinkage of organic/inorganic modified silicate thin films was performed. The films were synthesized by sol-gel processing from tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTES) precursors and spin-coated onto Si substrates. The sol viscosity and the spin velocity were adjusted so that the films produced had a final thickness ranging from 580 to 710 nm after heat treatment. The ion species and incident energies used were selected such that the projected ion range was greater than the film thickness, resulting in fully irradiated films. After heat treatment at 300 deg. C for 10 min, the films were irradiated with 125 keV H{sup +}, 250 keV N{sup 2+} and 2 MeV Cu{sup +} ions with fluences ranging from 1 x 10{sup 14} to 1 x 10{sup 16} ions/cm{sup 2}. Both hardness and reduced elastic modulus were seen to exhibit a monotonic increase with fluence for all three ion species. Also, H loss was found to increase monotonically with increase in fluence, while the film thickness was found to decrease with increase in fluence.

  3. Influence of Microstructure, Produced by Heat Treatment and Sever Plastic Deformation, on Tribological Properties of Low-carbon Steel

    Directory of Open Access Journals (Sweden)

    V. I. Semenov

    2011-06-01

    Full Text Available This paper presents the results of tribological investigations conducted on steel 20 with the carbon content of up to 0.2%. The steel was studied in the three conditions: initial (hot-rolled, after heat-treatment (quenching+tempering and after heat treatment with subsequent severe plastic deformation (SPD performed by equal channel angular pressing technique (ECAP. It was stated that after various treatments the material acquires various structural conditions and possesses various strength properties and has a considerable difference in oxygen content in the surface layer. This influences the tribological properties during the contact with tool steel. The lowest values of adhesive bond shear strength, friction coefficient and wear rate are demonstrated in the material after martempering with subsequent SPD by ECAP technique. The surface of the investigated material after SPD treatment by the ECAP technique possesses a highest bearing capacity and requires more time for wearing-in in friction assemblies. Oxygen content increase in the form of metal oxides on the surface of low-carbon steels is accompanied by a decrease of the adhesive component of friction coefficien.

  4. Concurrent zero-dimensional and one-dimensional biomineralization of gold from a solution of Au3+ and bovine serum albumin

    International Nuclear Information System (INIS)

    A technique was developed for preparing a novel material that consists of gold nanoparticles trapped within a fiber of unfolded proteins. These fibers are made in an aqueous solution that contains HAuCl4 and the protein, bovine serum albumin (BSA). By changing the ratio of gold to BSA in solution, two different types of outcomes are observed. At lower gold to BSA ratios (30–120), a purple solution results after heating the mixture at 80 °C for 4 h. At higher gold to BSA ratios (130–170), a clear solution containing purple fibers results after heating the mixture at 80 °C for 4 h. UV–Vis spectroscopy and light scattering techniques show growth in nanocolloid size as gold to BSA ratio rises above 100. Data indicate that, for the higher gold to BSA ratios, the gold is sequestered within the solid material. The material mass, visible by eye, appears to be an aggregation of smaller individual fibers. Scanning electron microscopy and transmission electron microscopy indicate that these fibers are primarily one-dimensional aggregates, which can display some branching, and can be as narrow as 400 nm in size. The likely mechanism for the synthesis of the novel material is discussed. (paper)

  5. Characterization of W/Fe functionally graded materials manufactured by resistance sintering under ultra-high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Dandan [School of Materials Science and Engineering, University of Science and Technology Beijing, 100083 Beijing (China); Karlsruhe Institute of Technology, Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Zhou, Zhangjian, E-mail: zhouzhangjianustb@163.com [School of Materials Science and Engineering, University of Science and Technology Beijing, 100083 Beijing (China); Tan, Jun [School of Materials Science and Engineering, University of Science and Technology Beijing, 100083 Beijing (China); Aktaa, Jarir [Karlsruhe Institute of Technology, Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2015-02-15

    Highlights: • W/Fe functionally graded material (FGM) are fabricated well by resistance sintering under ultra-high pressure (RSUHP). • The whole sintering time is less than 3 min and cost-effective. • We research the W/Fe interface and the formation of intermetallic at the interface. In addition, we explain the possible method to avoid the formation of brittle intermetallic. • Vickers hardness of W/Fe FGM before and after heat treatment are investigated here. - Abstract: W/Fe-based components are considered as primary structural materials for the future fusion reactor. A five-layer W/Fe functional graded material (FGM) with W volume fraction of 0%, 25%, 50%, 75% and 100%, respectively, have been fabricated by a novel sintering method combining resistance sintering with ultra-high pressure. The sintering was carried out under pressures of 9 GPa and an input power of 11 kW for 60 s. The microstructure of cross-section observed by SEM shows a well-graded transition. The relative density of each layer is more than 97%. A brittle phase Fe{sub 7}W{sub 6} is formed at the interface of W particles and Fe particles, and this intermetallic phase coats Fe particles homogeneously with a thickness of 1–5 μm. It is possible to avoid the brittle phase by choosing appropriate particle size and sintering parameters. In addition, Vickers hardness of W/Fe FGM was investigated before and after heat treatment.

  6. THE EFFECT OF HEAT TREATMENT ON THE CHEMICAL AND COLOR CHANGE OF BLACK LOCUST (ROBINIA PSEUDOACACIA WOOD FLOUR

    Directory of Open Access Journals (Sweden)

    Yao Chen,

    2012-01-01

    Full Text Available The aim of this study was to investigate the effects of oxygen and moisture content (MC on the chemical and color changes of black locust (Robinia pseudoacacia wood during heat treatment. The wood flour was conditioned to different initial MCs and heated for 24 h at a constant temperature of 120ºC in either oxygen or nitrogen atmosphere. The pH values and chromaticity indexes were examined. Diffuse reflectance UV-Vis (DRUV and Fourier transform infrared (FTIR spectra were used to characterize the changes of chromophores upon heating. The study demonstrated that the pH values decreased after heat treatment, and it was lower when the heat treated was in oxygen than in nitrogen. The L* decreased significantly, while a* and b* increased. The total color difference ΔE* increased with increasing initial MC until a plateau was reached after 30% MC. The color change was greater in oxygen than in nitrogen. The hydroxyl groups decreased after heat treatment. The releases of acid and formation of quinoid compounds and carboxylic groups during heat treatment were confirmed. Discoloration of wood is due mainly to the condensation and oxidation reactions, which are accelerated by oxygen. Higher MCs are required to obtain the greatest color change of wood in inert atmosphere.

  7. Interfacial oxidations of pure titanium and titanium alloys with investments.

    Science.gov (United States)

    Ban, S; Watanabe, T; Mizutani, N; Fukui, H; Hasegawa, J; Nakamura, H

    2000-12-01

    External oxides of a commercially pure titanium (cpTi), Ti6Al4V alloy, and an experimental beta-type titanium alloy (Ti 53.4 wt%, Nb 29 wt%, Ta 13 wt%, and Zr 4.6 wt%) were characterized after heating to 600, 900, 1150, and 1400 degrees C in contact with three types of investments (alumina cement, magnesia cement, and phosphate-bonded) in air. XRD studies demonstrated that MgO, Li2TiO3 and/or Li2Ti3O7 were formed through reactions with the metal and the constituents in the magnesia cement-investment after heating to 900, 1150, and 1400 degrees C. Except for these conditions, TiO2 (rutile) was only formed on cpTi. For titanium alloys, the other components apart from Ti also formed simple and complex oxides such as Al2O3 and Al2TiO5 on Ti6Al4V, and Zr0.25Ti0.75Nb2O7 on the beta-type titanium alloy. However, no oxides containing V or Ta were formed. These results suggest that the constituents of titanium alloys reacted with the investment oxides and atmospheric oxygen to form external oxides due to the free energy of oxide formation and the concentration of each element on the metal surface.

  8. The Tribological Property and Microstructure of Ni-Ti Coating Prepared by Electrodeposition and Heat Treatment

    Directory of Open Access Journals (Sweden)

    Chufeng Sun

    2016-01-01

    Full Text Available Ni-Ti coatings were fabricated by the electrodeposition in a Ni plating bath containing Ti power and heat treatment in nitrogen atmosphere. The surface morphology and microstructure of the Ni-Ti coating before and after heat treatment were analyzed by means of scanning electron microscopy and X-ray diffraction. The friction and wear behaviors of two different coatings were evaluated on a ball-on-disk UMT-2MT test rig. It was found that the phase structure of Ni-Ti coating heated in nitrogen was much different from that of the as-deposited Ni-Ti coating. Namely, the new intermetallic compounds, including Ni3Ti, NiTi, and NiTi2, and TiN were detected in the coating after heat treatment by the XRD analysis and contributed to greatly increasing the hardness and tribological property of the Ni-Ti coating, owing to the strengthening effect of the hard intermetallic compounds and TiN phase. At the same time, a small amount of intermetallic compounds and TiN was transferred from the composite coating to the rubbing surface of the counterpart steel ball during the sliding, which also contributed to decreasing the friction coefficient and increasing the wear resistance.

  9. Gamma irradiation influence on physical properties of milk proteins

    International Nuclear Information System (INIS)

    Gamma irradiation was found to be an effective method for the improvement of both barrier and mechanical properties of the edible films and coatings based on calcium and sodium caseinates alone or combined with some globular proteins. Our current studies concern gamma irradiation influence on the physical properties of calcium caseinate-whey protein isolate-glycerol (1:1:1) solutions and gels, used for films preparation. Irradiation of solutions was carried out with Co-60 gamma rays applying 0 and 32 kGy dose. The increase in viscosity of solutions was found after irradiation connected to induced crosslinking. Lower viscosity values were detected, however, after heating of the solutions irradiated with a 32 kGy dose than after heating of the non-irradiated ones regarding differences in the structure of gels and resulting in different temperature-viscosity curves that were recorded for the irradiated and the non-irradiated samples during heating and cooling. Creation of less stiff but better ordered gels after irradiation arises probably from reorganisation of aperiodic helical phase and β-sheets, in particular from increase of β-strands, detected by FTIR. Films obtained from these gels are characterised by improved barrier properties and mechanical resistance and are more rigid than those prepared from the non-irradiated gels. The route of gel creation was investigated for the control and the irradiated samples during heating and the subsequent cooling

  10. Fatigue failure of micro-alloyed 23MnB4 steel

    Directory of Open Access Journals (Sweden)

    S. Rusz

    2008-12-01

    Full Text Available Purpose: In the following paper there have been the structure and fatigue properties of micro-alloyed 23MnB4 steel in initial state and after heat treatment evaluated.Design/methodology/approach: Fatigue test of micro-alloyed 23MnB4 steel was completed by metallographic and fracture analyses. For scope the methods of the light microscopy and SEM were used.Findings: Microstructure of examined alloy in initial state was characterized mostly by fine ferrite with pearlitic net and in state after heat treatment was formed by martensite or partly by bainite and after tempering was formed by tempered martensite. Objective of this work consisted in determination of fatigue characteristics of micro-alloyed 23MnB4 steel, including fracture analyze. Results of fatigue testing at various stress levels for the samples in initial state and after the heat treatment have confirmed that obtained values of cycles to rupture were at least 585 000 cycles. Change of fatigue properties in dependence on heat treatment of the used steel.Research limitations/implications: For define fracture area a samples must be provide with notch. The experiment was limited by occurrence a void in cast alloys.Practical implications: The results may be utilized for application of the investigated material in process of manufacturing.Originality/value: These results contribute to explanation of fracture mechanism of micro-alloyed 23MnB4 steel.

  11. Effect of the aging treatment in the fractures mechanics of welded joints of steel 316L

    International Nuclear Information System (INIS)

    The austenitic stainless steel 316L is widely used in nuclear industry because of its excellent mechanical properties and corrosion resistance. These properties must be evaluated in order to prevent failure and extend the life of equipment. The microstructure in the weld fusion zone consists on an austenite matrix with 5-12% of delta ferrite met stable at room temperature. However the pressurized water reactors operate at temperatures in the range 290-325 deg C, thus welds may be susceptible to thermal aging embrittlement after long service life. According to the literature, this occurs due to the spinodal decomposition. Therefore, the purpose of this study was to evaluate the mechanical properties of 316L stainless steel welds by hardness and tensile tests before and after heat treatment. In this regard, two steel plates were welded and part of the material was heat treated at 335 deg C for 1000 hours. The tests after heat treatment showed an increase of only 4% in ultimate tensile strength and an increase of 28% in hardness. No changes were observed in the material microstructure, however according to literature changes can be identified by transmission electron microscopy. The curves of impact energy vs. temperature showed little change but, it was not able to observe a ductile-brittle transition and images of microstructure from scanning electronic microscopy (SEM) did not show fragile behavior. (author)

  12. A Bottom-Up Engineered Broadband Optical Nanoabsorber for Radiometry and Energy Harnessing Applications

    Science.gov (United States)

    Kaul, Anupama B.; Coles, James B.; Megerian, Krikor G.; Eastwood, Michael; Green, Robert O.; Bandaru, Prabhakar R.

    2013-01-01

    Optical absorbers based on vertically aligned multi-walled carbon nanotubes (MWCNTs), synthesized using electric-field assisted growth, are described here that show an ultra-low reflectance, 100X lower compared to Au-black from wavelength lamba approximately 350 nm - 2.5 micron. A bi-metallic Co/Ti layer was shown to catalyze a high site density of MWCNTs on metallic substrates and the optical properties of the absorbers were engineered by controlling the bottom-up synthesis conditions using dc plasma-enhanced chemical vapor deposition (PECVD). Reflectance measurements on the MWCNT absorbers after heating them in air to 400deg showed negligible changes in reflectance which was still low, approximately 0.022 % at lamba approximately 2 micron. In contrast, the percolated structure of the reference Au-black samples collapsed completely after heating, causing the optical response to degrade at temperatures as low as 200deg. The high optical absorption efficiency of the MWCNT absorbers, synthesized on metallic substrates, over a broad spectral range, coupled with their thermal ruggedness, suggests they have promise in solar energy harnessing applications, as well as thermal detectors for radiometry.

  13. Formation of Diastereoisomeric Piperazine-2,5-dione from uc(dl)-Alanine in the Presence of Olivine and Water

    Science.gov (United States)

    Fuchida, Shigeshi; Naraoka, Hiroshi; Masuda, Harue

    2016-04-01

    uc(dl)-Alanine (Ala) was heated with/without powdered olivine and water at 120 °C for 8 days to investigate the formation of the diastereoisomers of piperazine-2,5-dione (diketopiperazine, DKP). When only uc(dl)-Ala was heated with a small amount of water, 3.0 % of uc(dl)-Ala changed to cis- and trans-DKP after 8 days. DKPs were not detected after heating when no water was added. The presence of a small amount of water is important factor controlling peptide production rates under thermal conditions. When DL-Ala was heated with olivine powder for 8 days, the yields of cis- and trans-DKP were 6.8 and 4.9 %, respectively. The high yield of cis-DKP compared with trans-DKP was attributed to greater thermal stability of cis-DKP. After heating for 8 days, the diastereoisomeric excess of cis-DKP without olivine was 7.3 %, whereas a much higher value of 16.3 % was obtained in the presence of olivine. Taken together, these results show that olivine is not only an efficient catalyst for the formation of DKPs but that it also play a significant role in determining the diastereoisomer selectivity of these cyclic dipeptides.

  14. Fabrication and Properties of Microencapsulated,n-octadecane and Paraffim

    Institute of Scientific and Technical Information of China (English)

    WANG Xue-chen; ZHANG Xing-xiang; WU Shi-zhen

    2008-01-01

    Microencapsulated n-alkanes as energy-storage materials have promising application prospects.The microcapsules containing 100-50 wt% of n-octadecane,0-20 wt% of paraffin and 0-30 wt% of cyciohexane were synthesized by in-situ polymerization using melamineformaldehyde polymer as shell.Cyclohexane was removed after heat-treated the microcapsules at 100℃.The morphologies,cell parameters,phase change properties,thermal stable temperatures of these micrecapsules were examined.The diameters of these mieroeapsules arc lower than 5 μm.The effect of paraffin in the microcapsules on the cell parameters of,n-octadecane is negligible.The paraffin is effectively used as a nucleating agent to decrease the degree of supercooling.The melting enthalpy is decreased from 132 J/g to 111 J/g due to the increase of the cyciohexane contents.The thermal stable temperature is enhanced 6-16℃ after heat-treated the microcales at 160℃ for 30 min.

  15. Production of bacteriocin by Virgibacillus salexigens isolated from "terasi": a traditionally fermented shrimp paste in Indonesia.

    Science.gov (United States)

    Kobayashi, Takeshi; Agustini, Tri Winarni; Ibrahim, Ratna; Kamei, Kaeko; Kondo, Akihiro; Kajiwara, Michika; Ooka, Yoshihiro; Nakamura, Hidetoshi; Terahara, Takeshi; Imada, Chiaki

    2016-03-01

    A natural antibacterial-substance-producing gram-positive bacterium was isolated from terasi shrimp paste, a popular fermented product in Indonesia. This strain, a spore-forming and strictly aerobic bacterium, was identified as Virgibacillus salexigens by 16S rRNA gene sequence analysis. The antibacterial substance purified from the precipitated product in the culture supernatant of the strain using ammonium sulfate showed a broad inhibition spectrum against gram-positive bacteria, including a typical foodborne bacterium, namely, Listeria monocytogenes. The antibacterial activity of the substance was inactivated by treatments with various proteolytic enzymes. It was stable after heating or pH treatment, and approximately 60% of the initial activity remained even after heating at 121 °C for 15 min. In addition, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis indicated that its monoisotopic mass weight was 5318.4 Da (M+H)(+). On the basis of the results obtained by the automated Edman degradation technique and MALDI-TOF MS analysis, the substance can be classified as a member of Class IId bacteriocins, but it could not be identified as any of the previously purified substances except for the putative bacteriocin predicted from the draft genome sequence data of gram-positive bacteria such as Virgibacillus and Bacillus strains. PMID:26873558

  16. The effect of the heat treatment on residual stresses in HVOF sprayed WC-Co coating

    Energy Technology Data Exchange (ETDEWEB)

    Khameneh Asl, S.; Heydarzadeh Sohi, M. [Dept. of Metallurgy and Materials Science, Faculty of Engineering, Univ. of Tehran (Iran); Hadavi, S.M.M. [Dept. of Metallic Materials, Faculty of Materials and Energy, Univ. of Malekashtar, Tehran (Iran)

    2004-07-01

    A WC-17Co coating was deposited onto ST37 mild steel substrate using HVOF spray technique and then heat treated at different temperatures in a vacuum chamber. The coatings were then evaluated in the as sprayed and heat treated conditions. The results indicated that substantial amount of amorphous phases was created during the HVOF spray process. Carbon and tungsten, liberated through the dissociation of WC, combined with cobalt in the spray powder to form amorphous material on solidification. X-ray analyses indicated that by increasing the heat treating temperature, the percentage of the desirable crystalline phases was increased and the less desirable amorphous phases were eliminated. Cross-sectional microhardness examination showed significant increases in the hardness of the coating after heat treatment. The residual stress of thermally sprayed WC-17Co deposits before and after heat treatment was also studied using X-ray diffraction technique. The heat treated coatings exhibited residual compressive stresses to varying degrees. The stress decreased in the carbide grains after the relaxation occurred by heat treatment. (orig.)

  17. 聚苯硫醚热氧化处理研究%Thermal oxidation of poly(p-phenylene sulfide)

    Institute of Scientific and Technical Information of China (English)

    周宇; 李振环; 程博闻

    2011-01-01

    The chemical modification of poly( p- phenylene sulfide) was studied after heat treatment in air atmosphere. Poly(p-phenylene sulfide) was characterized by high-temperature gel chromatography, photoelectron spectroscopy, thermogravimetric analysis, infrared spectrometry and high-pressure capillary rheometry. The results showed that the relative molecular mass of lowand high- relative molecular mass poly ( p- phenylene sulfide) both considerably increased after heat treatment. The oxidation,oxidative crosslinking, thermal crosslinking and chain extension reactions could simultaneously occur during the heat treatment of poly( p-phenylene sulfide).%研究了聚苯硫醚在空气环境下经过热处理的合成化学改性.采用高温凝胶渗透色谱、光电子能谱、热失重、红外光谱和高压毛细管流变技术对聚苯硫醚进行表征.结果表明:低相对分子质量的聚苯硫醚和高相对分子质量的聚苯硫醚经过热处理,相对分子质量都会大幅提高;聚苯硫醚经过热处理过程会同时发生氧化反应、氧化交联反应、热交联反应和链增长反应.

  18. Stress-dependent proteolytic processing of the actin assembly protein Lsb1 modulates a yeast prion.

    Science.gov (United States)

    Ali, Moiez; Chernova, Tatiana A; Newnam, Gary P; Yin, Luming; Shanks, John; Karpova, Tatiana S; Lee, Andrew; Laur, Oskar; Subramanian, Sindhu; Kim, Dami; McNally, James G; Seyfried, Nicholas T; Chernoff, Yury O; Wilkinson, Keith D

    2014-10-01

    Yeast prions are self-propagating amyloid-like aggregates of Q/N-rich protein that confer heritable traits and provide a model of mammalian amyloidoses. [PSI(+)] is a prion isoform of the translation termination factor Sup35. Propagation of [PSI(+)] during cell division under normal conditions and during the recovery from damaging environmental stress depends on cellular chaperones and is influenced by ubiquitin proteolysis and the actin cytoskeleton. The paralogous yeast proteins Lsb1 and Lsb2 bind the actin assembly protein Las17 (a yeast homolog of human Wiskott-Aldrich syndrome protein) and participate in the endocytic pathway. Lsb2 was shown to modulate maintenance of [PSI(+)] during and after heat shock. Here, we demonstrate that Lsb1 also regulates maintenance of the Sup35 prion during and after heat shock. These data point to the involvement of Lsb proteins in the partitioning of protein aggregates in stressed cells. Lsb1 abundance and cycling between actin patches, endoplasmic reticulum, and cytosol is regulated by the Guided Entry of Tail-anchored proteins pathway and Rsp5-dependent ubiquitination. Heat shock-induced proteolytic processing of Lsb1 is crucial for prion maintenance during stress. Our findings identify Lsb1 as another component of a tightly regulated pathway controlling protein aggregation in changing environments. PMID:25143386

  19. The Microstructure of Ni Layer on Single-Walled Carbon Nanotubes Prepared by an Electroless Coating Process

    Directory of Open Access Journals (Sweden)

    Weixue Li

    2011-01-01

    Full Text Available The single-walled carbon nanotubes (SWNTs, diameter: 2~3 nm, which were obtained in the suspension of purification solution, with Ni-P coating layers were obtained by an electroless deposition process. The SWNTs before and after coating were characterized by transmission electron microscopy (TEM and energy dispersive spectrometry (EDS. An Ni-P layer on individual nanotube with thickness of 20 nm can be obtained after the deposition process. The X-ray diffraction (XRD and selected area electron diffraction (SAED analysis of Ni-P SWNTs before and after heat treatment show that the heat treatment caused the transformation of the amorphous Ni-P layer to the nanocrystalline Ni-P (crystalline Ni and Ni3P intermetallic compound layer. The XRD pattern of SWNTs with Ni-P layers after heat treatment revealed that the crystal structures of Ni in plating layer contained: hexagonal close-packed (hcp structure and face-centered cubic (fcc structure. The lattice parameters of Ni (fcc and Ni3P are larger than the bulk's, indicting that the lattice expansion has taken place. However, the lattice parameter of Ni (hcp has no difference from the bulk's.

  20. Yogurt made from milk heated at different pH values.

    Science.gov (United States)

    Ozcan, Tulay; Horne, David S; Lucey, John A

    2015-10-01

    Milk for yogurt manufacture is subjected to high heat treatment to denature whey proteins. Low milk pH values (≤ 6.5) at heating result in most denatured whey proteins becoming associated with casein micelles, whereas high milk pH values (≥ 7.0) at heating result in the formation of mostly soluble (nonmicellar) denatured whey protein complexes. There are conflicting reports on the relative importance of soluble and casein-bound whey protein aggregates on the properties of acid gels. Prior studies investigating the effect of pH of milk at heating used model gels in which milk was acidified by glucono-δ-lactone; in this study, we prepared yogurt gels using commercial starter cultures. Model acid gels can have very different texture and physical properties from those made by fermentation with starter cultures. In this study, we investigated the effects of different pH values of milk at heating on the rheological, light backscatter, and microstructural properties of yogurt gels. Reconstituted skim milk was adjusted to pH values 6.2, 6.7, and 7.2 and heated at 85°C for 30 min. A portion of the heated milk samples was readjusted back to pH 6.7 after heating. Milks were inoculated with 3% (wt/wt) yogurt starter culture and incubated at 40°C until pH 4.6. Gel formation was monitored using dynamic oscillatory rheology, and parameters measured included the storage modulus (G') and loss tangent (LT) values. Light-backscattering properties, such as the backscatter ratio (R) and the first derivative of light backscatter ratio (R'), were also monitored during fermentation. Fluorescence microscopy was used to observe gel microstructure. The G' values at pH 4.6 were highest in gels made from milk heated at pH 6.7 and lowest in milk heated at pH 6.2, with or without pH adjustment after heating. The G' values at pH 4.6 were lower in samples after adjustment back to pH 6.7 after heating. No maximum in the LT parameter was observed during gelation for yogurts made from milk

  1. Assessment of the activation, decay heat, and waste disposal of the US helium-cooled ceramic breeder test blanket module in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Youssef, M.; Ying, A. [California Univ., Los Angeles, CA (United States)

    2007-07-01

    The radioactivity inventory and after heat in the U.S. helium-cooled ceramic breeder (HCCB) test blanket module (TBM) have been accessed at shut down and for several times thereafter. Also assessed is the waste disposal rating (WDR) of its various components. The objectives are: (1) to provide the information needed for further safety assessment of the generated radionuclides and their volatility, as well as after heat on the safety operation of ITER, and (2) to aid in determining the waiting cooling period prior to removing and transporting the TBM for further treatment outside ITER site. The TBM is proposed to be placed in one of the three dedicated test ports of ITER. The current proposal is that it will occupy 1/3 of the horizontal upper half of a port next to Japan and Korea sub-modules. The sub-module will have its own FW and structural container box that houses the breeder and beryllium pebble bed units, arranged in an edge-on-configuration. Helium is used to cool the FW, sides of the box, and the internal plates. Conventional ferritic steel (F82H) is used as the structure. The sub-module has 71 cm height, 38.9 cm wide and 60 cm depth in the radial direction. The breeder beds are made of Li{sub 2}TiO{sub 3} pebbles with 94% theoretical density and 62% packing factor (as the beryllium pebbles). Lithium-6 is enriched to 75%. A 2 mm thick beryllium layer is used as a plasma facing material on the FW area subjected to 0.78 MW/m{sup 2} neutron wall load. Pulsed operation mode is assumed. Each pulse is assumed to be 400 s full flat top followed by 1800 s dwell time, during which the decay of the generated radionuclides are accounted for. The 500 MW pulses are assumed to be generated one after another until a fluence limit of 0.3 MWa/m{sup 2} is reached without replacing the TBM. This gives upper conservative estimates for the radioactive inventory and decay heat. During operation in the D-T phase, the total heating rate in the TBM is {proportional_to}263 KW. The

  2. Effect of Extractives on Color Changes of Eucalyptus urophyll a ×Eucalyptus grandis and Its SpectrumA nalysis%溶剂抽提物对尾巨桉热变色的影响及光谱分析

    Institute of Scientific and Technical Information of China (English)

    高姗; 陈瑶; 高建民

    2015-01-01

    为探讨溶剂抽提物对尾巨桉热变色的影响,在过热蒸气条件下对抽提物进行热处理,之后采用冷水、热水、乙醇、甲醇、丙酮、正己烷等6种溶剂对热处理前后的尾巨桉木粉进行抽提,对热处理前后经过抽提的木粉进行色度指数的测定和红外光谱分析,并对抽提物进行紫外光谱分析。结果表明:①极性溶剂抽提物对尾巨桉颜色及其热处理后颜色变化影响较大,其中热水抽提物对颜色的影响最显著;②抽提物热处理后共轭结构增加,共轭体系能量降低,吸收带延伸至可见光范围,是木材受热后颜色加深的重要原因;③热处理后,尾巨桉木粉ΔL倡为负值,即颜色变深,木材颜色均匀美观,可提高利用价值。%Overheating steam treatment can darken the color of Eucalyptus urophylla×Eucalyptus grandis wood and make it look like precious wood, which can improve its utility value.For studying the effect of overheating steam treatment on discolora-tion of Eucalyptus urophylla ×Eucalyptus grandis wood, we extracted the wood powder before and after heating treatment with cold water, hot water, alcohol, methyl alcohol, and acetone and n-hexane, and measured the color parameters of the samples before and after extracted.We used ultraviolet absorption spectrum and the FTIR spectra to evaluate chemical changes of extractives and wood powder.Polar solvents extract was more effective on color and color changes of E.grandis wood powder after heat treatment.Hot water extraction had the most important influence on wood color.The important rea-sons of color deepen after heat treatment were:after heat treatment, the conjugated structures of extractives increased, and the energy of conjugated system decreased, and the absorption band extended to the visible light range.After heat treat-ment,ΔL* value of E.urpoh ylla×E.grandis wood powder was negative, which meant the color was deepen, and the

  3. Microstructural evolution of 2026 aluminum alloy during hot compression and subsequent heat treatment%2026铝合金热变形及热处理过程中的微观组织演变

    Institute of Scientific and Technical Information of China (English)

    张辉; 陈容; 黄旭东; 陈江华

    2011-01-01

    研究2026铝合金在温度为300-450℃和应变速率为0.01-10 s-1的变形条件与固溶时效热处理后微观组织之间的关系.结果表明:热处理后的再结晶和析出特性与热变形时的温度补偿应变速率Z有关.在低Z条件下,热处理后会形成少量细小的再结晶晶粒,热变形过程产生的高角度亚晶粒和粗大析出物被保留下来;高Z条件下,热处理后会产生大量细小等轴晶再结晶晶粒,热变形过程产生的高密度晶胞和相对细小的动态析出物被热处理后完整的亚晶粒和相对粗化的析出物所替代.热处理后的平均再结晶晶粒尺寸随着Z值的增加而减小.建立两者的定量关系式.%2026 aluminum alloy was compressed in a temperature range of 300-450 ℃ and strain rate range of 0.01-10 s-1. The correlation between compression conditions and microstructural evolution after solution and aging heat treatment was investigated. It is found that the recrystallization and precipitation behavior after heat treatment are associated with the temperature compensated strain rate Z value during hot deformation. Under low Z parameter condition, a small quantity of fine recrystallized grains are formed, and the well formed subgrains with clean high-angle boundaries and coarse precipitates seem to be remained during heat treatment. Under high Z parameter condition, a large number of fine equiaxed recrystallized grains are produced, and a high dislocation density with poorly developed cellularity and considerable fine dynamic precipitates are replaced by the well formed subgrains and relatively coarse precipitates after heat treatment. The average recrystallized grain size after heat treatment decreases with increasing Z value and a quantitative relation between the average grain size and the Z value is obtained.

  4. Partial purification and characterization of a bacteriocin produced by Enterococcus faecium 130 isolated from mozzarella cheese

    Directory of Open Access Journals (Sweden)

    Fabrício Luiz Tulini

    2011-03-01

    Full Text Available Lactic acid bacteria are important in foods as potential probiotics and also due to the ability to produce antimicrobial compounds that can contribute for biopreservation. In this work, the bacteriocin produced by the food isolate Enterococcus faecium 130 was partially purified and characterized. The compound was active against Gram-positive bacteria, including Listeria monocytogenes. It was produced after 4 days of storage at a broad temperature range (4 to 37 °C; it was stable at pH ranging from 2 to 10 with no loss of activity after heating at 100 °C for 15 minutes. Bacteriocin was partially purified by the adsorption-desorption technique, and the analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE showed a molecular mass of 3.5 to 6.5 kDa. These data encourage studies on application of this bacteriocin in food systems as an additional hurdle to microbial growth.

  5. Improvement of processing process on drill die used to make oblique oil hole in bearing ring%轴承套圈斜油孔钻模加工工艺改进

    Institute of Scientific and Technical Information of China (English)

    秦博; 陈述

    2012-01-01

      Drill die used to make oblique oil hole in bearing ring will deform after heat treatment, thus to cause inaccuracy when making hole. Aimed at the problem above, two improving methods have been taken to ensure drill die precision and drilling quality of the ring oblique oil hole.%  针对轴承套圈斜油孔钻模热处理后产生变形,影响其制造精度的问题,采用了两种改进方式,保证了钻模制造精度及套圈斜油孔钻削质量。

  6. Measurements of low-energy electron reflection at a plasma boundary

    International Nuclear Information System (INIS)

    It is demonstrated that low-energy (<3 eV) electron reflection from a solid surface in contact with a low-temperature plasma can have significant variation with time. An uncontaminated, i.e., “clean,” metallic surface (just after heating up to glow) in a plasma environment may have practically no reflection of low-energy incident electrons. However, a contaminated, i.e., “dirty,” surface (in some time after cleaning by heating) that has a few monolayers of absorbent can reflect low-energy incident electrons and therefore significantly affect the net electron current collected by the surface. This effect may significantly change plasma properties and should be taken into account in plasma experiments and models. A diagnostic method is demonstrated for measurements of low-energy electron absorption coefficient in plasmas with a mono-energetic electron group

  7. CDF modeling of flow and transport processes in the reactor core of a modular high temperature reactor during an air ingress accident; CFD-Modellierung der Stroemungs- und Transportprozesse im Reaktorkern eines modularen Hochtemperaturreaktors waehrend eines Lufteinbruchstoerfalls

    Energy Technology Data Exchange (ETDEWEB)

    Baggemann, Johannes

    2015-05-22

    Generation IV of reactor design is supposed to include inherent safety systems that allow accident management using passive processes (without external energy). The VTR (very high temperature reactor) is graphite moderated with helium cooling. The design concept assumes that in any operational situation the after heat is removed by thermal conduction and radiation. Air ingress is beyond-design accident assuming a leak in the primary circuit triggering oxygen reaction with the hot graphite that could damage the barriers for fission product release. Using 3D CFD (computational fluid dynamics) codes the air ingress scenario is simulated, the flow and transport processes in the reactor core are analyzed. For validation of the modeling heat transport processes were investigated in specific test facilities.

  8. Ultrasound-mediated intracellular drug delivery using microbubbles and temperature-sensitive liposomes.

    Science.gov (United States)

    Yudina, A; de Smet, M; Lepetit-Coiffé, M; Langereis, S; Van Ruijssevelt, L; Smirnov, P; Bouchaud, V; Voisin, P; Grüll, H; Moonen, C T W

    2011-11-01

    A novel two-step protocol for intracellular drug delivery has been evaluated in vitro. As a first step TO-PRO-3 (a cell-impermeable dye that displays a strong fluorescence enhancement upon binding to nucleic acids) encapsulated in thermosensitive liposomes was released after heating to 42°C. A second step consisted of ultrasound-mediated local permeabilization of cell membrane allowing TO-PRO-3 internalization observable as nuclear staining. Only the combination of two consecutive steps - heating and sonication in the presence of SonoVue microbubbles led to the model drug TO-PRO-3 release from the thermosensitive liposomes and its intracellular uptake. This protocol is potentially beneficial for the intracellular delivery of cell impermeable drugs that suffer from rapid clearance and/or degradation in blood and are not intrinsically taken up by cells.

  9. Bone bonding ability of some borate bio-glasses and their corresponding glass-ceramic derivatives

    Directory of Open Access Journals (Sweden)

    Fatma H. Margha

    2012-12-01

    Full Text Available Ternary borate glasses from the system Na2O·CaO·B2O3 together with soda-lime-borate samples containing 5 wt.% of MgO, Al2O3, SiO2 or P2O5 were prepared. The obtained glasses were converted to their glass-ceramic derivatives by controlled heat treatment. X-ray diffraction was employed to investigate the separated crystalline phases in glass-ceramics after heat treatment of the glassy samples. The glasses and corresponding glass-ceramics after immersion in water or diluted phosphate solution for extended times were characterized by the grain method (adopted by several authors and recommended by ASTM and Fourier-transform infrared spectra to justify the formation of hydroxyapatite as an indication of the bone bonding ability. The influence of glass composition on bioactivity potential was discussed too.

  10. Effect of vacuum heat treatment on microstructure and microhardness of cold sprayed Cu-4Cr-2Nb alloy coating

    Institute of Scientific and Technical Information of China (English)

    LI Wen-ya; GUO Xue-ping; L. DEMBINSKI; LIAO Han-lin; C.CODDET

    2006-01-01

    The effect of vacuum heat treatment on the microstructure and microhardness of cold-sprayed Cu-4%Cr-2%Nb alloy coating was investigated. The heat treatment was conducted under the temperatures from 250 ℃ to 950 ℃ with a step of 100 ℃ for 2 h. It was found that a dense thick Cu-4Cr-2Nb coating could be formed by cold spraying. After heat treatment,a Cr2Nb phase was uniformly distributed in the matrix,which was transferred from the gas-atomized feedstock. A little grain growth of Cr2Nb phase was observed accompanying with the healing-up of the incomplete interfaces between the deposited particles at the elevated temperatures. The coating microhardness increases a little with increasing the temperature to 350 ℃,and then decreases with further increasing temperature up to 950 ℃. This fact can be attributed to the microstructure evolution during the heat treatment.

  11. Studies on Behavior and Trend Controlling of Technetium in 1A and Scrubbing Extractor

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The effect of the concentration of HNO3 on distribution ratio of Tc (Ⅶ) between 30% TBP-kerosene and HNO3 solution at various ratio of U, Zr, Tc is determined. The trend and extraction behavior of Tc in 1A extractor with mixer-settler is studied. The results show that 14.4% and 27.0% of Tc is in 1AP, respectively while the concentrations of HNO3 in 1AF solution are 2 mol/L and 3 mol/L which prepared by chemicals. However after heating pretreatment of 1AF solution , 99.8% of Tc is in 1Ap while concentration of HNO3 in 1AF is 3 mol/L.Meanwhile, The HNO3 driving out method of U-Tc-Zr in efflux 1AP is studied. The aim is

  12. Palladium and ruthenium supported silver migration in 3C–silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    O’Connell, Jacques Herman, E-mail: jacques.oconnell@gmail.com [Center for High Resolution Electron Microscopy, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth 6031 (South Africa); Neethling, Johannes Henoch [Center for High Resolution Electron Microscopy, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa)

    2015-01-15

    Surrogate TRISO particles were infiltrated with a Pd Ag mixture and heat treated at 1000 °C to investigate the effect of Pd on Ag transport through current state of the art TRISO coatings for use in HTGRs. The experiment was repeated with Ru instead of Pd because of the similarities in the reaction between Pd and Ru with SiC. It was found that both Pd and Ru form their respective silicides after heat treatment together with the simultaneous precipitation of graphite. In both cases Ag was concentrated along the leading edge of the reaction zone which itself was concentrated along grain boundaries. However, the effect of Pd was much more pronounced than that of Ru making Ru at most a secondary contributor to Ag migration through SiC in TRISO fuel.

  13. Influence of the V microaddition on the structure and mechanical properties of 60CrV7 spring steel

    Directory of Open Access Journals (Sweden)

    M. Opiela

    2007-01-01

    Full Text Available Purpose: Influence of vanadium microaddition on structure and mechanical properties of the constructionalspring steel was investigated.Design/methodology/approach: Metallography, transmission electron microscope, tensile test, hardnessmeasurements have been used.Findings: Microaddition of V introduced to the steel allows to obtain the fine-grained structure, and gives elasticelements obtaining: apparent elastic limit Rp0.05 over 1800 MPa, proof stress Rp0.2 over 1900 MPa and ultimatetensile strength over 1960 MPa after tempering at 450 °C temperature.Research limitations/implications: TEM investigations on structure of the elastic elements after heat treatmentwere predicted.Practical implications: The carried out investigations showed a full suitability of the steel for production ofsprings and suspension springs witch high strength properties, operating under conditions of high elastic strains.Originality/value: Conditions of heat treatment of elastic elements with the high strength properties were presented.

  14. Effect of Heat Treatment on Silica Aerogels Prepared via Ambient Drying

    Institute of Scientific and Technical Information of China (English)

    Fei SHI; Lijiu WANG; Jingxiao LIU; Miao ZENG

    2007-01-01

    Silica aerogels were prepared at ambient drying by using ethanol/trimethylchlorosilane (TMCS)/heptane solution as pore water exchange and surface modification of the wet gel before drying. The obtained silica aerogels exhibit a sponge-like structure with uniform pore size distribution. The effects of heat-treatment on the hydrophobicity, specific surface area and other properties were investigated. The results indicated that the hydrophobicity of silica aerogels could be maintained up to 350℃. With increasing heating temperature, hydrophobicity decreased, and became completely hydrophilic after heat-treatment at 500℃. Brunaueremmitt-teller (BET) surface area results indicated that the specific surface area of silica aerogels increased with increasing heating temperature in the range of 150-500 ℃. The effects of heat-treatment on the morphology and chemical bonding state of silica aerogels were investigated by scanning electron microscopy (SEM),differential temperature analysis (DTA) and Fourier-transform infrared spectroscopy (FT-IR).

  15. Synthesis and characterization of laminated Si/SiC composites

    Directory of Open Access Journals (Sweden)

    Salma M. Naga

    2013-01-01

    Full Text Available Laminated Si/SiC ceramics were synthesized from porous preforms of biogenous carbon impregnated with Si slurry at a temperature of 1500 °C for 2 h. Due to the capillarity infiltration with Si, both intrinsic micro- and macrostructure in the carbon preform were retained within the final ceramics. The SEM micrographs indicate that the final material exhibits a distinguished laminar structure with successive Si/SiC layers. The produced composites show weight gain of ≈5% after heat treatment in air at 1300 °C for 50 h. The produced bodies could be used as high temperature gas filters as indicated from the permeability results.

  16. Forced convection to laminar flow of liquid egg yolk in circular and annular ducts

    Directory of Open Access Journals (Sweden)

    M. Bernardi

    2009-06-01

    Full Text Available The steady-state heat transfer in laminar flow of liquid egg yolk - an important pseudoplastic fluid food - in circular and concentric annular ducts was experimentally investigated. The average convection heat transfer coefficients, determined by measuring temperatures before and after heating sections with constant temperatures at the tube wall, were used to obtain simple new empirical expressions to estimate the Nusselt numbers for fully established flows at the thermal entrance of the considered geometries. The comparisons with existing correlations for Newtonian and non-Newtonian fluids resulted in excellent agreement. The main contribution of this work is to supply practical and easily applicable correlations, which are, especially for the case of annulus, rather scarce and extensively required in the design of heat transfer operations dealing with similar shear-thinning products. In addition, the experimental results may support existing theoretical analyses.

  17. Platinum containing amorphous hydrogenated carbon (a-C:H/Pt) thin films as selective solar absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Yung-Hsiang; Brahma, Sanjaya [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Tzeng, Y.H. [Department of Electrical Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Ting, Jyh-Ming, E-mail: jting@mail.ncku.edu.tw [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 701, Taiwan (China)

    2014-10-15

    We have investigated a double-cermet structured thin film in which an a-C:H thin film was used as an anti-reflective (AR) layer and two platinum-containing amorphous hydrogenated carbon (a-C:H/Pt) thin films were used as the double cermet layers. A reactive co-sputter deposition method was used to prepare both the anti-reflective and cermet layers. Effects of the target power and heat treatment were studied. The obtained films were characterized using X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy. The optical absorptance and emittance of the as deposited and annealed films were determined using UV–vis-NIR spectroscopy. We show that the optical absorptance of the resulting double-cermet structured thin film is as high as 96% and remains to be 91% after heat treatment at 400 °C, indicating the thermal stability of the film.

  18. Interim storage of solidified fission products from fuel element reprocessing with utilization of obtaining post-decay heat

    International Nuclear Information System (INIS)

    It is noted that the out-lined interim store for HRW with industrial utilization of decay heat (production of saturated steam and hydrogen) does include a certain risk potential like any technical plant but that it does not represent a danger to the population living nearby. All internal and external impacts on the store result in safely triggering natural convection cooling. A further emergency cooling system is provided by the water irrigation facility so that obtaining after-heat can be safely removed under all circumstances. Therefore, there are no safety-technology arguments against any realization of the concept presented for interim storage of solidified high-level radio-active wastes. An interim store of this type may be built and operated even in densely populated regions and urban agglomerations. (orig./HP)

  19. Hepatic Necrosis and Degenerative Myopathy Associated with Cassava Feeding in Pigs

    Directory of Open Access Journals (Sweden)

    Gloria Daniel-Igwe

    2014-01-01

    Full Text Available Forty-three deaths were recorded among pigs fed boiled cassava meal at a private piggery over a period of two years. There were signs of sudden death in some cases with blood exuding from the external nares, vomiting, muscular weakness and pain or reluctance to move, emaciation, and stunted growth. The necropsy lesions included skeletal and cardiac muscle degeneration and necrosis, icterus, hepatic necrosis, and oedema of the dependent parts. The deaths and clinical signs are thought to be due to a non cyanide toxic principle in cassava, possibly the coumarins (scopoletin, which is found in high levels in cassava diet even after heat treatment. Therefore, the use of proper processing technology to obtain cassava products of high quality is recommended.

  20. Modifications of the Dielectric Properties of Biological Membranes by Heating

    CERN Document Server

    Savescu, S B

    2004-01-01

    Biological cell suspensions are known to show dielectric dispersions due to the Maxwell-Wagner mechanism. Many examples are summarized in a number of papers by Schwan [7, 9, 10]. By the application of an appropriate analysis to the dielectric dispersion, it is possible to estimate electrical phase parameters related to protoplasm and cell membrane. A dielectric theory of interfacial polarization for a suspension of conducting particles (protoplasm) covered with poorly conducting shells (plasma membrane) was developed by Pauly and Schwan [7], and was satisfactory applied for low volume fractions of suspended particles (less than about 0.2). The purpose of this paper is to examine the change in yeast plasma membrane permittivity after heating treatment, by using the Pauly and Schwan's theory.

  1. Characterization and growth dynamics of barium titanate crystallite on nanometer scale

    Institute of Scientific and Technical Information of China (English)

    Sen Wang; Yue Zhang; Zhen Ji; Yousong Gu; Yunhua Huang; Cheng Zhou

    2005-01-01

    Barium titanate powder on nanometer scale was synthesized by means of co-precipitation. The thermal mass loss, crystal grain growth and phase transition of the barium titanate nanometer powder were investigated by TG (Thermogravimetric)-DTA (Differential scanning calorimetric) and XRD (X-ray powder diffractometer) at different heat treatment temperatures. The results show that amorphous barium titanate powder can transfer into tetragonal symmetry structure after heat treatment. When the heat treatment temperature is below 900℃, the grains grow rapidly because the activation energy at low temperature is greatly less than that at high temperature. By controlling theheat treatment temperature, the optimization of the barium titanate crystallite size and formation of tetragonal phase can be realized.

  2. Micro-structure of graphite-intercalated tin oxide and its influence on SnO2-based gas sensors

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yinhong; HE Yunqiu

    2007-01-01

    A nano-scaled graphite oxide(GO)was prepared with a micro-layer structure for intercalation.Graphite-intercalated SnO2 was obtained at temperatures lower than 100℃.The morphology,microstructure,crystalline phases and thermal property of this intercalative composite were studied by atomic force microscopy(AFM),field-emission scanning electron microscopy(FE-SEM),X-ray diffractometry(XRD) and differential scanning calorimetry-thermogravimetry(DSC-TG)doped with a proper amount of graphite-intercalated composites(GITs),GIT-SnO2 composite was obtained after heat treatment.This combined gas sensor reveals low resistance and high sensitivity to butane between 200℃ and 300℃.

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

    Directory of Open Access Journals (Sweden)

    Ping-zhou CAO

    2013-10-01

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

  4. Topologically Associating Domains: An invariant framework or a dynamic scaffold?

    Science.gov (United States)

    Cubeñas-Potts, Caelin; Corces, Victor G

    2015-01-01

    Metazoan genomes are organized into regions of topologically associating domains (TADs). TADs are demarcated by border elements, which are enriched for active genes and high occupancy architectural protein binding sites. We recently demonstrated that 3D chromatin architecture is dynamic in response to heat shock, a physiological stress that downregulates transcription and causes a global redistribution of architectural proteins. We utilized a quantitative measure of border strength after heat shock, transcriptional inhibition, and architectural protein knockdown to demonstrate that changes in both transcription and architectural protein occupancy contribute to heat shock-induced TAD dynamics. Notably, architectural proteins appear to play a more important role in altering 3D chromatin architecture. Here, we discuss the implications of our findings on previous studies evaluating the dynamics of TAD structure during cellular differentiation. We propose that the subset of variable TADs observed after differentiation are representative of cell-type specific gene expression and are biologically significant. PMID:26418477

  5. The Electrochemical Performance of Ml0.7Mm0.3Ni3.7Co0.7Mn0.4Al0.2 Nanocrystalline Hydrogen Storage Alloy as Metal Hydride Electrode

    Institute of Scientific and Technical Information of China (English)

    方守狮; 熊义辉; 等

    2002-01-01

    Ml0.7Mm0.3Ni3.7Co0.7Mn0.4Al0.2 nanocrystalline hydrogen storage materials are prepared by melt-spinning(MS).X-ray diffraction is used for the measurement of the nanocrystalline size.Compared to the electrode of polycrystalline alloys,the property of activation MH9metal hydride)electrode of the alloys with nanometer scale became worse and the inital discharge capacity decreased.It may be ascribed to the decrease of the total amount of rare earth metals and the increase of oxygen on the surface from the analysis of components of the alloys.After heat-treatment,the electrochemical performance of MH electrode of as-spun alloys could be improved,which could be attributed to the alleviation of the lattice strain.

  6. In-situ neutron diffraction measurement of stress redistribution in a dissimilar joint during heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Dodge, M.F., E-mail: michael.dodge@twi.co.uk [TWI Ltd., Great Abington, Cambridge CB21 6AL (United Kingdom); Gittos, M.F. [TWI Ltd., Great Abington, Cambridge CB21 6AL (United Kingdom); Dong, H. [Department of Engineering, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Zhang, S.Y.; Kabra, S.; Kelleher, J.F. [ISIS, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX (United Kingdom)

    2015-03-11

    Neutron diffraction is routinely used to monitor stress redistribution before and after heat treatment in dissimilar joints. However there remains a paucity of information concerning the evolution of strain throughout the process of heat treatment itself. Due to different mechanical properties between opposing sides, a competitive strain redistribution process occurs. Consequently, a novel in-situ measurement approach has been developed: strains at multiple points in a dissimilar joint have been measured during heat treatment. Thus, the described work elucidates areas within the thermal cycle in which competitive strain redistribution occurs, and where high residual stresses remain, following PWHT. The method may be used to characterise comparable material combinations, with a view to optimising the thermal cycles, and ultimately, the structural integrity of dissimilar joints.

  7. The influence of molybdenum on stress corrosion in Ultra Low Carbon Steels with copper addition

    Directory of Open Access Journals (Sweden)

    M. Mazur

    2010-07-01

    Full Text Available The influence of molybdenum content on the process of stress corrosion of ultra-low carbon structural steels with the addition of copper HSLA (High Strength Low Alloy was analyzed. The study was conducted for steels after heat treatment consisting of quenching andfollowing tempering at 600°C and it was obtained microstructure of the tempered martensite laths with copper precipitates and the phaseLaves Fe2Mo type. It was found strong influence of Laves phase precipitate on the grain boundaries of retained austenite on rate anddevelopment of stress corrosion processes. The lowest corrosion resistance was obtained for W3 steel characterized by high contents ofmolybdenum (2.94% Mo which should be connected with the intensity precipitate processes of Fe2Mo phase. For steels W1 and W2which contents molybdenum equals 1.02% and 1.88%, respectively were obtained similar courses of corrosive cracking.

  8. Into the open – or hidden away? – The construction of war children as a social category in post-war Norway and Germany

    Directory of Open Access Journals (Sweden)

    Eva Simonsen

    2006-01-01

    Full Text Available After World War II two groups of children fathered by foreign soldiers were assigned special political functions in the building of a future peaceful Europe. In Norway, the children of German soldiers and Norwegian women and in West Germany, the children of African-American soldiers and German women were constructed as specific categories to be handled in certain ways by state authorities. The Norwegian government, after heated debates, decided that the children were allowed to stay and to be silently and discreetly assimilated into society. In West Germany however, the children begotten to African-Americans came to serve as objects in a national public campaign for international recognition as a democratic state. The two cases demonstrate how social politics for children may serve political purposes, rather than being in the interest of the child.

  9. Negative Temperature Coefficient of Resistivity in Bulk Nanostructured Ag

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@The change of the temperature coefficient of resistivity (α) with the particle size, dp, and the grain size, dc, in the nanostructured Ag bulk samples was investigated, dp and de were controlled by heating the nano-Ag powders over the temperature range from 393 to 453 K. The electrical resistance measurements of the nanostructured Ag bulk samples obtained by compacting the Ag powders after heat treatments showed a change in the sign of α with dp and dc. When dp and dc are smaller or equal to 18 and 11 nm below room temperature or 20 and 12 nm above room temperature, respectively, the sign of the temperature coefficient of resistivity changes from positive to negative. The negative α arises mainly from the high resistivity induced by the particle interfaces with very lowly ordered or even disordered structure, a large volume fraction of interfaces and impurities existing in the interfaces, and the quantum size effect appearing in the nano-Ag grains.

  10. Reduced heat shock response in human mononuclear cells during aging and its association with polymorphisms in HSP70 genes

    DEFF Research Database (Denmark)

    Singh, Ripudaman; Kølvraa, Steen; Bross, Peter;

    2006-01-01

    Age-dependent changes in heat shock response (HSR) were studied in mononuclear cells (monocytes and lymphocytes) collected from young (mean age = 22.6 +/- 1.7 years) and middle-aged (mean age = 56.3 +/- 4.7 years) subjects after 1 hour of heat shock at 42 degrees C. Genotype-specific HSR was...... measured by genotyping the subjects for 3 single nucleotide polymorphisms, HSPA1A(A-110C), HSPA1B(A1267G), and HSPA1L(T2437C), 1 each in the 3 HSP70 genes. A significant age-related decrease in the induction of Hsp70 occurred after heat shock in both monocytes and lymphocytes. The noninducible and...

  11. Role of orientation of nucleus of crystal during the process of synthesis of fine crystalline oxides at high temperatures and pressure

    Energy Technology Data Exchange (ETDEWEB)

    Panasyuk, G P; Belan, V N; Voroshilov, I L; Shabalin, D G [IGIC RAS, N. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences (Russian Federation)], E-mail: Panasyuk@igic.ras.ru

    2008-07-15

    The structural transformations of hydrargillite Al(OH){sub 3} and boehmite AlOOH were studied on thermovaporous autoclaving and on heat treatment. A special attention was paid to the morphology of initial flocculated and loose hydrargillite crystals, of the again segregating flocculi boehmite intermediate phase, and to the morphology of the end product - corundum single - or polycrystals. It is shown that on thermovaporous autoclaving the intraflocculi orientation of the boehmite crystals is decisive in the corundum single crystals formation. The degree of identity of the boehmite crystals orientation qualifies the sizes of the growing corundum crystals. It is shown, that after heat treatment in air at <1200 deg. C alpha-alumina forms, the habitus of the initial crystals remains unchanged, but at 1400-1500 deg. C in vacuum it alters, and equally oriented alumina grains sinter. Influence of the mutual crystals orientation at different stages of structural transformations is explored. Keywords: autoclaving, hydrargillite, boehmite, corundum.

  12. Study on Thermal Expansion Coefficient of Sealing Materials for Ceramic Metal Halide Lamps

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    With Al2O3, Dy2O3, and SiO2 as starting materials, the basic glass of Al2O3-Dy2O3-SiO2 system was prepared by conventional melting technology, and their thermal expansion coefficients (TECs) at different anneal time were investigated. TECs of the basic glass, which were heat-treated under different temperature, were also investigated. The result showed that TECs of the basic glass gradually approached a fixed value as the anneal time was extended, which suggested that most of the inner stress had been eliminated. After heat treatment, the contents of Dy2O3, Dy2Si2O7, and a new crystal increased up to 1200 ℃ and decreased below 1250 ℃, which was consistent with the TEC change of crystallized samples. This suggests that the crystal has a direct effect on TECs of the crystallized samples.

  13. Conductivity of oriented bis-azo polymer films

    DEFF Research Database (Denmark)

    Apitz, D.; Bertram, R.P.; Benter, N.;

    2006-01-01

    The conductivity properties of electro-optic photoaddressable, dense bis-ozo chromophore polymer films are investigated by using samples corona poled at various temperatures. A dielectric spectrometer is applied to measure the frequency dependence of the conductivity at different temperatures...... before and after heating the material to above the glass transition temperature. The results show that the orientation of the chromophores changes the charge-carrier mobility. Ionic conductivity dominates in a more disordered configuration of the material, while the competing process of hole hopping...... takes over as a transition to a liquid-crystalline phase occurs when the material is heated to much higher than the gloss transition temperature. Such micro-crystallization strongly enhances the conductivity....

  14. In-situ neutron diffraction measurement of stress redistribution in a dissimilar joint during heat treatment

    International Nuclear Information System (INIS)

    Neutron diffraction is routinely used to monitor stress redistribution before and after heat treatment in dissimilar joints. However there remains a paucity of information concerning the evolution of strain throughout the process of heat treatment itself. Due to different mechanical properties between opposing sides, a competitive strain redistribution process occurs. Consequently, a novel in-situ measurement approach has been developed: strains at multiple points in a dissimilar joint have been measured during heat treatment. Thus, the described work elucidates areas within the thermal cycle in which competitive strain redistribution occurs, and where high residual stresses remain, following PWHT. The method may be used to characterise comparable material combinations, with a view to optimising the thermal cycles, and ultimately, the structural integrity of dissimilar joints

  15. Investigation of crystallization in glasses containing fission products

    International Nuclear Information System (INIS)

    Five potential solidification products for high-level waste (four borosilicate glasses and one celsian glass ceramic) have been investigated in terms of crystallization. In all glasses and in the glass ceramic, crystallization, and recrystallization, respectively, were observed by heating above 7730K, however, at very different periods of time (0.1d greater than or equal to 100d). The noble metals precipitated into various phases. Crystal growth proceeded at the phase boundary glass-noble metal. In all products rare earth phases crystallized. Silicate phases rarely formed. The leach resistance (by the grain titration and Soxhlet tests) decreased after heat treatment in all cases. The changes were found to be within one order of magnitude for all products. 2 figures, 4 tables

  16. Direct observation of Nd3+ and Tm3+ ion distributions in oxy-fluoride glass ceramics containing PbF2 nanocrystals

    International Nuclear Information System (INIS)

    Nd3+ and Tm3+, doped oxy-fluoride glasses and glass ceramics were prepared by conventional melt-quenching and subsequent heat-treatment, respectively. β-PbF2 nanocrystals with diameter 50 –100 nm formed in the glass matrix after heat treatment. The Stark splitting in absorption peaks, enhanced photoluminescence and prolonged lifetimes that β-PbF2 nanocrystal formation increased the luminescence of rare earth ions. Both Nd3+ and Tm3+ ions were incorporated into nanocrystals that were enriched in lead and fluorine, and deficient in oxygen. - Highlights: • EELS analysis for rare-earth ion distribution in oxy-fluoride glass ceramics • No significant changes in lifetimes of Nd3+, while obvious change for Tm3+ • Direct evidence of Nd3+ and Tm3+ aggregation into fluoride nanocrystals

  17. YSZ protective coatings elaborated by MOCVD on nickel-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, E.; Esteve, J. [Barcelona Univ. (Spain). Dept. de Fisica Aplicada i Electronica; Garcia, G.; Figueras, A. [ICMAB/CSIC, Campus U.A.B. 08193, Bellaterra (Spain); Llibre, J. [S.E. de, Carburos Metalicos S.A., Pl, Zona Franca 14-20, 08038, Barcelona (Spain)

    1998-03-01

    The aim of this work is to study both the mechanical and the structural properties of yttria-stabilized zirconia (YSZ) coatings prepared on metallic substrates. YSZ films were obtained in a hot wall MOCVD reactor using Zr(thd){sub 4} and Y(thd){sub 3} as organometallic precursors. The evaporation and the deposition temperatures were chosen in order to stabilize the cubic phase of the zirconia. The coatings were produced on different nickel and chromium alloys substrates. X-ray diffraction and SIMS techniques were used to characterize the influence of different experimental parameters, such as substrate nature, deposition temperature and thermal treatment, on the structure and composition of the YSZ film and the film/substrate interface. Mechanical properties of the coatings were also determined, before and after heat treatment, by means of microindentation tests. (orig.) 13 refs.

  18. Stability at comminution chopping temperatures of model chicken breast muscle emulsions.

    Science.gov (United States)

    Perchonok, M H; Regenstein, J M

    1986-01-01

    Mixtures of vegetable oil and protein solutions extracted from chicken breast muscle were heated to 10°C, 20°C and 30°C before or after the Omni-mixer step of timed emulsification. Emulsion stability (ES) was determined by placing the extracted cream layer between layers of filter paper and polyester mesh and measuring the weight loss after 96 h at 0-1°C. All natural actomyosin and exhaustively washed chicken breast muscle emulsions lost no more than 50% of their original weight after heating and were defined as being stable. Even excessive chopping temperatures (30°C) failed to effect timed emulsification or ES. This study suggests that any instability of finished commercial sausage-type products is not due to changes in the protein caused by excessively high chopping temperatures generated during comminution.

  19. Synthesis and characterization of nanocrystalline graphite from coconut shell with heating process

    Energy Technology Data Exchange (ETDEWEB)

    Wachid, Frischa M., E-mail: frischamw@yahoo.com, E-mail: adhiyudhaperkasa@yahoo.com, E-mail: afandisar@yahoo.com, E-mail: nurulrosyidah92@gmail.com, E-mail: darminto@physics.its.ac.id; Perkasa, Adhi Y., E-mail: frischamw@yahoo.com, E-mail: adhiyudhaperkasa@yahoo.com, E-mail: afandisar@yahoo.com, E-mail: nurulrosyidah92@gmail.com, E-mail: darminto@physics.its.ac.id; Prasetya, Fandi A., E-mail: frischamw@yahoo.com, E-mail: adhiyudhaperkasa@yahoo.com, E-mail: afandisar@yahoo.com, E-mail: nurulrosyidah92@gmail.com, E-mail: darminto@physics.its.ac.id; Rosyidah, Nurul, E-mail: frischamw@yahoo.com, E-mail: adhiyudhaperkasa@yahoo.com, E-mail: afandisar@yahoo.com, E-mail: nurulrosyidah92@gmail.com, E-mail: darminto@physics.its.ac.id; Darminto, E-mail: frischamw@yahoo.com, E-mail: adhiyudhaperkasa@yahoo.com, E-mail: afandisar@yahoo.com, E-mail: nurulrosyidah92@gmail.com, E-mail: darminto@physics.its.ac.id [Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Sepuluh Nopember, Campus ITS Sukolilo, Surabaya 60111 (Indonesia)

    2014-02-24

    Graphite were synthesized and characterized by heating process of coconut shell with varying temperature (400, 800 and 1000°C) and holding time (3 and 5 hours). After heating process, the samples were characterized by X-ray diffraction (XRD) and analyzed by X'pert HighScore Plus Software, Scanning Electron Microcope-Energy Dispersive X-Ray (SEM-EDX) and Transmission Electron Microscope-Energy Dispersive X-Ray (TEM-EDX). Graphite and londsdaelite phase were analyzed by XRD. According to EDX analysis, the sample was heated in 1000°C got the highest content of carbon. The amorphous carbon and nanocrystalline graphite were observed by SEM-EDX and TEM-EDX.

  20. Thermal stability of multi-spray deposition heat resistant Al-Fe-V-Si alloy

    Institute of Scientific and Technical Information of China (English)

    卢斌; 易丹青; 黎文献; 余志明; 周琳

    2002-01-01

    Rapidly solidified Al-8.4Fe-1.3V-1.7Si heat resistant alloy was made by using multi-layer spray deposition technique.Its thermal stability of mechanical properties was investigated by the means of tensile and hardness tests,thermal stability of microstructure by transmission electron microscopy (TEM),X-ray diffraction (XRD).The results show that after heat exposure (HE) at 753 K for 500 h the tensile strength and hardness of Al-Fe-V-Si alloy at 623 K maintains the same values as those at room-temperature.HE dose not obviously affect the thermal stabilities of Al12(Fe,V)3Si phase but the lattice constant of Al12(Fe,V)3Si phase decrease.

  1. Fabrication of Pd Doped WO3 Nanofiber as Hydrogen Sensor

    Directory of Open Access Journals (Sweden)

    Alireza Nikfarjam

    2013-01-01

    Full Text Available Pd doped WO3 fibers were synthesized by electro-spinning. The sol gel method was employed to prepare peroxopolytungstic acid (P-PTA. Palladium chloride and Polyvinyl pyrrolidone (PVP was dissolved in the sol Pd:WO3 = 10% molar ratio. The prepared sol was loaded into a syringe connected to a high voltage of 18.3 kV and electrospun fibers were collected on the alumina substrates. Scanning electron microscope (SEM, X-ray powder diffraction (XRD and X-ray photoelectron spectroscopy (XPS techniques were used to analyze the crystal structure and chemical composition of the fibers after heat treatment at 500 °C. Resistance-sensing measurements exhibited a sensitivity of about 30 at 500 ppm hydrogen in air, and the response and recovery times were about 20 and 30 s, respectively, at 300 °C. Hydrogen gas sensing mechanism of the sensor was also studied.

  2. Heat treatment process optimization for face gearsbased on deformation and residual stress control

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-zhong; LAN Zhou‡; HOU Liang-wei; ZHAO Hong-pu; ZHONG Yang

    2015-01-01

    In this paper, based on the principle of heat transfer and thermal elastic-plastic theory, the heat treatment process optimization scheme for face gearsis proposed according to the structural characteristics oftheface gear and material properties of 12Cr2Ni4 steel.To simulate the effect of carburizing and quenching process on tooth deformation and residual stress distribution,aheat treatment analysis model of face gearsis established, and the microstructure, stress and deformation of face gear teeth changing with time are analyzed. The simulation results show that face gear tooth hardness increases, tooth surface residual compressive stress increases and tooth deformation decreases after heat treatment process optimization.It is beneficialto improvingthe fatigue strength and performance of face gears.

  3. Growth of Co on Cu(111), Subsurface growth of trilayer Co islands

    DEFF Research Database (Denmark)

    Pedersen, M.Ø.; Bönicke, I.A.; Lægsgaard, E.;

    1997-01-01

    The growth of cobalt on Cu(lll) has been studied using a variable-temperature scanning tunneling microscope (STM). Al a deposition temperature of 150 K, one observes the growth of three-layer Co islands with one subsurface layer. The Co islands are surrounded by a brim of Cu. The distinction...... between Co and Cu is made by adsorption of CO which adsorbs only on Co at room temperature, resulting in a Co(lll)-(root 3 x root 3)R30 degrees-CO structure. After heating the surface, or depositing Co at higher temperatures, the Cu brims gradually disappear, and vacancy islands form in the Cu...... stable island configuration to be several cobalt layers capped with one copper layer. (C) 1997 Elsevier Science B.V....

  4. Reuse of waste foundry sand through interaction with sodium silicate binder; Reutilizacao da areia descartada da fundicao, a partir da sua interacao com agente ligante silicato de sodio

    Energy Technology Data Exchange (ETDEWEB)

    Souza, J.C.; Chinelatto, A.S.A.; Chinelatto, A.L., E-mail: josi3souza@gmail.com [Universidade Estadual de Ponta Grossa (UEPG), PR (Brazil); Oliveira, I.L. [Universidade Tecnologica Federal do Parana (UTFPR), Ponta Grossa, PR (Brazil)

    2012-07-01

    Green sand molds are used in metal casting process. However, after heating, activated bentonite present in green sand lose the binding properties, and part of the foundry sand has to be discarded from the process. The ABNT NBR 15.984/2011 establishes the management of waste foundry sand (WFS) avoiding disposal in landfills. The objective of this work was to investigate the possibility of reusing the WFS from the study of their interaction with sodium silicate binder. Studies with silica sand and new green sand was performed to compare the results obtained with the WFS. The characterizations of the samples were performed by measures the compressive strength, X-ray diffraction, optical microscopy and scanning electron microscopy. The results showed that there is interaction of the sodium silicate with the WFS as well as with the silica sand and green sand. (author)

  5. Research on Extruded Products of Mgalzn Alloys – Microstructure and Mechanical Properties / Badania Wyrobów Wyciskanych Ze Stopów Mgalzn – Mikrostruktura I Właściwości Mechaniczne

    Directory of Open Access Journals (Sweden)

    Płonka B.

    2015-12-01

    Full Text Available The aim of the study was to test and assess products extruded from the magnesium alloys type MgAlZn: AZ31, AZ61 and AZ80A alloys in the form of Ø35mm round bars and 80x15mm flat bars. The test material was extruded in a direct system with the ram feed speed of 1 mm/s and the extrusion ratio λ = 7 ÷ 9. The extruded bars were examined in as-extruded state and after heat treatment to the T5 temper and T6 temper. The strength properties were tested and microstructure was examined with calculation of the average grain size.

  6. Controlled Morphology and Mechanical Characterisation of Electrospun Cellulose Acetate Fibre Webs

    Directory of Open Access Journals (Sweden)

    B. Ghorani

    2013-01-01

    Full Text Available The purpose was to interpret the varying morphology of electrospun cellulose acetate (CA fibres produced from single and binary solvent systems based on solubility parameters to identify processing conditions for the production of defect-free CA fibrous webs by electrospinning. The Hildebrand solubility parameter ( and the radius of the sphere in the Hansen space ( of acetone, acetic acid, water, N,N-dimethylacetamide (DMAc, methanol, and chloroform were examined and discussed for the electrospinning of CA. The Hildebrand solubility parameter ( of acetone and DMAc were found to be within an appropriate range for the dissolution of CA. The suitability of the binary solvent system of acetone: DMAc (2 : 1 for the continuous electrospinning of defect-free CA fibres was confirmed. Electrospun webs exhibited improved tensile strength and modulus after heat and alkali treatment (deacetylation of the as-spun material, and no major fibre morphological degradation occurred during the deacetylation process.

  7. The Photoluminescence Spectra of the Aeschynite Group Minerals

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Raman and photoluminescence spectra of the metamict and annealing recrystallization titanoaeschynite-(Nd) and nioboaeschynite-(Ce), found in Baiyunobo mineral deposit in China, were measured and discussed. The peaks or bands in the spectra of the metamic minerals are weak, broad and diffuse, but sharpen notably after heating. The results show that the distortion of the structure and disorder state of the elements exists in the minerals when natural crystalline minerals transformed into metamict minerals after a long period of self-irradiation structure damaging. And all bands in the photoluminescence spectra of the aeschynite group mineral stem from emission transitions of Nd3+, when 514.5nm laser is used as the excitation source.

  8. The Electrochemical Performance of Ml0.7 Mm0.3 Ni3.7 Co0.7 Mn0.4 Al0.2 Nanocrystalline Hydrogen Storage Alloy as Metal Hydride Electrode%纳米储氢合金Ml0.7Mm0.3Ni3.7Co0.7Mn0.4Al0.2制作的储氢电极的电化学性能

    Institute of Scientific and Technical Information of China (English)

    方守狮; 熊义辉; 林根文; 张金龙; 葛建生

    2002-01-01

    Ml0.7Mm0.3Ni3.7Co0.7Mn0.4Al0.2 nanocrystalline hydrogen storage materials are prepared by melt-spinning (MS). X-ray diffraction is used for the measurement of the nanocrystalline size. Compared to the electrode of polycrystalline alloys, the property of activation MH (metal hydride) electrode of the alloys with nanometer scale became worse and the initial discharge capacity decreased.It may be ascribed to the decrease of the total amount of rare earth metals and the increase of oxygen on the surface from the analysis of components of the alloys. After heat-treatment, the electrochemical performance of MH electrode of as-spun alloys could be improved, which could be attributed to the alleviation of the lattice strain.

  9. Changes of Chemical Composition and Crystalline of Compressed Chinese Fir Wood in Heating Fixation

    Institute of Scientific and Technical Information of China (English)

    Tang Xiaoshu; Zhao Guangjie; Nakao Tetsuya

    2004-01-01

    The changes in relative crystalline, chemical composition and internal structure of compressed Chinese fir wood after different heating fixations were found strictly related to fixation conditions. The compressed wood powders were fixed either by heating at different temperatures all resulting in a 10% recovery, or by incubating at 180 °C for different periods with subsequent recovery levels. Both X-ray diffraction and infrared absorption of those samples have been measured. Relative crystalline increases at early stage of heating fixation, and then decreased gradually. Hemicellulose and lignin decomposition were induced by the fixation process, especially at 180 °C, and lignin was degraded actively. Furthermore, absorbed water was lost after heating, but cellulose did not change markedly. Although different fixation pathways can result in the same recovery level, the major chemical reactions underlying them vary, which is consistent with the difference of fixation mechanisms.

  10. Micro segregation and homogenization treatments of uranium-niobium alloys (U-Nb)

    International Nuclear Information System (INIS)

    In the following sections micro segregation results in 0-3,6 wt% Nb and U-6,1 wt% Nb alloys casted in no consumable electrode arc furnace are presented. The micro segregation is studied qualitatively by optical microscopy and quantitatively by electron microprobe. The degree of homogenization has been measured after 800 and 850 deg C heat treatments in tubular resistive furnace. The microstructures after heat treatments are quantitatively analysed to check effects on the casting structures, mainly the variations in solute along the dendrite arm spacing. Some solidification phenomena are then discussed on reference to theoretical models of dendritic solidification , including microstructure and micro segregation. The experimental results are compared to theoretical on basis of initial and residual micro segregation after homogenization treatments. The times required for homogenization of the alloys are also discussed in function of the micro segregation from casting structures and the temperatures of the treatments. (author)

  11. Jojoba seed meal proteins associated with proteolytic and protease inhibitory activities.

    Science.gov (United States)

    Shrestha, Madan K; Peri, Irena; Smirnoff, Patricia; Birk, Yehudith; Golan-Goldhirsh, Avi

    2002-09-25

    The jojoba, Simmondsia chinensis, is a characteristic desert plant native to the Sonoran desert. The jojoba meal after oil extraction is rich in protein. The major jojoba proteins were albumins (79%) and globulins (21%), which have similar amino acid compositions and also showed a labile thrombin-inhibitory activity. SDS-PAGE showed two major proteins at 50 kDa and 25 kDa both in the albumins and in the globulins. The 25 kDa protein has trypsin- and chymotrypsin-inhibitory activities. In vitro digestibility of the globulins and albumins resembled that of casein and soybean protein concentrates and was increased after heat treatment. The increased digestibility achieved by boiling may be attributed to inactivation of the protease inhibitors and denaturation of proteins.

  12. Hydrothermal route to Eu doped LuO(OH) and Lu2O3 nanorods

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A facile method was developed to synthesize Eu doped LuO(OH) nanorods through hydrothermal processing and Lu2O3 nanorods by subsequent calcining.The microstructural morphologies of the Lu-based nanostructures could be controlled by simply varying the concentration of NaOH in hydrothermal processing as mineralizer.TEM observation revealed that the obtained LuO(OH) nanorods after hydrothermal processing had a uniform diameter of 10-25 nm and a length around 100 nm.After heat treatment at 600-700°C for 2 h,the high length/diameter ratio was sustained in the obtained Lu2O3 nanorods with different sizes depending on the calcining temperatures.

  13. Grain size reduction in the 713C nickel superalloy as a result of heat treatment

    Directory of Open Access Journals (Sweden)

    M.B. Lachowicz

    2011-04-01

    Full Text Available The paper presents metallographic test results for the 713C nickel superalloy after heat treatment and crystallographic orientation analysis performed with the EBSD method. The 713C alloy was subjected to annealing in the temperature of 950 oC for 30 hours followed by aircooling. As a result of the applied heat treatment the local grain size reduction in the alloy was observed. It has been found that in the primary grains the new subgrains of different crystallographic orientation are created. Between the new grains and the primary grains the boundaries of high angle appear. Orientation change in the micro-areas is closely related to the carbides rebuilding and volume diffusion of elements dissolved in the γ - γ’ alloy matrix and the (NbTiC carbides.

  14. Irradiation in combination of heat treatment of mango puree

    International Nuclear Information System (INIS)

    The effect of irradiation with heat combination treatment on the shelf life and quality of mango puree was studied. Thermal inactivation of polyphenol oxidase enzyme at 80 degree C and 15 min. was used as a measure of adequacy of pre-heat treatment. Irradiation of mango puree after heat treatment at dosage of 0, 2, 4, 6 and 8 kGy showed no change in mc, pH, acidity, and TSS but during storage, growth of microorganisms brought changes in these values. Irradiation in combination with low temperature (5 degree C) reduced discoloration and darkening rate during storage. Irradiation dose from 0 to 8 kGy resulted in log linear reductions in microorganism levels but at 6 and 8 kGy, there was no growth of microorganisms. Products irradiated at 8 kGy showed no microorganism growth at both temperatures

  15. Chemical composition in relation with biomass ash structure

    Science.gov (United States)

    Holubcik, Michal; Jandacka, Jozef

    2014-08-01

    Biomass combustion can be more complicated like combustion of fossil fuels because it is necessary to solve problems with lower ash melting temperature. It can cause a lot of problems during combustion process. Chemical composition of biomass ash has great impact on sinters and slags creation in ash because it affects structure of heated ash. In this paper was solved relation between chemical composition and structure of heated ash from three types of biomass (spruce wood, miscanthus giganteus and wheat straw). Amount of SiO2, CaO, MgO, Al2O3 and K2O was determined. Structure of heated ash was optically determined after heating to 1000 °C or 1200 °C. Results demonstrated that chemical composition has strong effect on structure and color of heated ash.

  16. Synthesis and characterization of bulky mesoporous silica Pd-MCM-41

    International Nuclear Information System (INIS)

    Bulky palladium catalyst supported on mesoporous silica MCM-41 (Pd-MCM-41) was successfully synthesized by hydrothermal hot-pressing method. In this study, the structure of the palladium species in Pd-MCM-41 bulk before and after heat-treatment process was revealed by X-ray diffraction (XRD), X-ray absorption near edge structure (XANES) and transmission electron microscopy (TEM). Also, the microstructure and mesoporous property of Pd-MCM-41 bulk was discussed. As a result, it was revealed that these dense Pd-MCM-41 bulks possessed a high surface area of over 1000 m2/g and the structure of palladium of Pd-MCM-41 bulk is almost equal to palladium (0) metal. (author)

  17. Thermal inactivation kinetics of partially purified mango pectin methylesterase

    Directory of Open Access Journals (Sweden)

    Claudio Alonso DÍAZ-CRUZ

    2016-01-01

    Full Text Available Abstract Kinetic parameters of thermal inactivation of pectin methylesterase (PME in a partially purified mango enzyme extract were determined. The PME of mango partially purified by salting out showed different patterns of thermal inactivation, indicating the presence of a thermostable fraction at 70 °C and a thermolabile fraction at lower temperatures. The inactivation of the thermostable fraction exhibited a linear behavior that yielded a z-value of 9.44 °C and an activation energy (Ea of 245.6 kJ mol-1 K-1 using the Arrhenius model. The thermostable mango PME fraction represented 17% of total crude enzyme extract, which emphasizes the importance of residual enzyme activity after heat treatment.

  18. Material for hot rolling of high boron content austenite stainless steel, and hot rolling method

    International Nuclear Information System (INIS)

    A hot rolling material made of a high boron content austenite stainless steel of the present invention comprises a slab made of an austenite stainless steel containing from 0.6 to 2.0% by weight of B and a pad-welded metal layer formed on the side surface of the slab. The pad-welded metal layer has δ ferrite amount of from 3 to 12% by volume, B content up to 0.3% by weight, a thickness of 3mm or greater, and is subjected to hot rolling after heated to a temperature of from 1100 to 1200degC. This can prevent occurrence of peripheral cracking and the material can be industrially manufactured stably at a low cost. (T.M.)

  19. Low temperature synthesis of magnesium oxide and spinel powders by a sol-gel process

    Directory of Open Access Journals (Sweden)

    Li-Zhai Pei

    2010-09-01

    Full Text Available Magnesium oxide and magnesium aluminate (MgAl2O4 spinel (MAS powders have been synthesized by a simple aqueous sol-gel process using citrate polymeric precursors derived from magnesium chloride, aluminium nitrate and citrate. The thermal decomposition of the precursors and subsequent formation of cubic MgO and MAS were investigated by X-ray diffraction (XRD, scanning electron microscopy (SEM, thermogravimetry-differential scanning calorimetry (TG-DSC and Fourier transform infrared spectra (FTIR. The single phase cubic MgO powder and MAS powder form after heat treatment at 800 and 1200 °C, respectively. The particle size of the MgO and MAS powders is about 100 nm and several micrometers, respectively. Ball milling eliminates the size of MgO and MgAl2O4 spinel powders by decreasing the conglomeration of the powders.

  20. Magnetic Properties and Core Loss Behavior of Fe-6.5wt.%Si Ribbons Prepared by Melt Spinning

    Directory of Open Access Journals (Sweden)

    S. Wang

    2015-01-01

    Full Text Available Fe-6.5wt.%Si alloy is prepared in the form of continuous ribbons with 25 mm in width and 0.03 mm in thickness by using melt spinning technique. The ribbons are flexible and could be wounded into tapes. DC magnetic properties and core loss behaviors of the ribbons after heat treatment are investigated in this paper. The magnetic properties are compared with ribbons by cold rolling and CVD methods. The melt spinning ribbons exhibit much less core loss in the frequencies more than 10 kHz. The melt spinning ribbons are promising to be used for electric devices used in medium or higher frequencies.

  1. The Effect of the Solution Heat Treatment on the Mechanical Properties of Aluminum-Copper Alloy (2024-T3 Using Rolling Process

    Directory of Open Access Journals (Sweden)

    Khairia Salman Hassan

    2011-01-01

    Full Text Available The effect of solution heat treatment on the mechanical properties of Aluminum-Copper alloy. (2024-T3 by the rolling process is investigated. The solution heat treatment was implemented by heating the sheets to 480 C° and quenching them by water; then forming by rolling for many passes. And then natural aging is done for one month. Mechanical properties (tensile strength and hardness are evaluated and the results are compared with the metal without treatment during the rolling process. ANSYS analysis is used to show the stresses distribution in the sheet during the rolling process. It has been seen that good mechanical properties are evident in the alloy without heat treatment due to the strain hardening and also the mechanical properties are improved after heat treatment and rolling process but with lower forces and stresses when compared with the untreated.

  2. Electrophoretic deposition and reaction-bond sintering of Al2O3/Ti composite coating: evaluation of microstructure, phase and wear resistance

    Indian Academy of Sciences (India)

    M Mahmoudi; H Maleki-Ghaleh; M Kavanlouei

    2015-04-01

    In this study, Al2O3/Ti composite coating was deposited on TiAl6V4 substrate in various compositions using the electrophoretic deposition method. After the deposition, samples were dried at room temperature then the coated samples were sintered at 1050°C for 4 h. Scanning electron microscope and X-ray diffraction analysis were used to analyse the microstructure and morphology of coatings. The friction coefficient, wear (missing volume) and hardness of coatings have been studied in comparison with uncoated sample. The results demonstrate that the density of Al2O3/Ti composite coating increased considerably after heat treatment process. Moreover, wearing resistance of TiAl6V4 alloy escalated considerably, increasing its potential for application in orthopedic implants and artificial joints.

  3. Preparation of Dy-Bi alloy films by electrodeposition in organic bath

    Institute of Scientific and Technical Information of China (English)

    LI Gaoren; TONG Yexiang; LIU Guankun

    2004-01-01

    The cyclic voltammetry and potentiostatic electrolysis were used to investigate the preparing of Dy-Bi alloy films in LiCl-DMSO (dimethylsulfoxide) system. The effects of several factors including the potential of deposition, concentrations of main salts, and the concentration ratio of DyCl3 to Bi(NO3)3 were studied. Dy-Bi alloy films containing 4.82%-80.62% (mass fraction) dysprosium were prepared in DyCl3-Bi(NO3)3-LiCl-DMSO system by controlling the system composition and deposition conditions. The films are gray, uniform, metallic luster and adhere firmly to the copper substrates analyzed by SEM (scanning electron microscope), EDS (X-ray energy dispersive analysis), and XRD (X-ray diffraction). After heat treatment at 718 K for l h, the alloy phase of Dy-Bi was found in XRD patterns.

  4. Thermal decomposition and reconstruction of CaFe-layered double hydroxide studied by X-ray diffractometry and 57Fe Mössbauer spectroscopy

    Science.gov (United States)

    Bugris, Valéria; Ádok-Sipiczki, Mónika; Anitics, Tamás; Kuzmann, Ernő; Homonnay, Zoltán; Kukovecz, Ákos; Kónya, Zoltán; Sipos, Pál; Pálinkó, István

    2015-06-01

    In spite of numerous investigations on the various processes of the thermal decomposition and rehydration of layered double hydroxides (LDHs) by a variety sophisticated experimental means, many details are still unexplored and some contradictions are still unresolved. In this work, our efforts were focussed on clarifying the composition, structure and properties of thermally decomposed metaphases originating from CaFe-LDH, heat treated in the 373-973 K temperature range. The structure reconstruction ability of mixed metal oxide phases obtained after heat treatments was also investigated, mainly concentrating on the changes in the microenvironment of Fe(III), in the presence of controlled amount of water vapour (i.e., at different relative humidities). All samples were characterised by X-ray diffractometry, and the iron-containing phases were studied by 57Fe Mössbauer spectroscopy.

  5. A study on the performance valuation of small size water storage electric boiler

    International Nuclear Information System (INIS)

    We was made 150L a water storage electric boiler and obtained various performances of the storage, radiant and keeping by experimentation. The storage performance is that the heat were off about 50 minutes after heating start. Then the temperature of outlet was arrived the stead state at 91 deg. C and the storage performance was appeared 93.64%. In the radiant performance, the water temperature was decreased from 90 .deg. C to 44.8 deg. C after 960 minutes. Then the calorific value changed from 675kcal/h to 72kcal/h and the temperature decreased about 50%. The keeping performance showed mean temperature, 67.06 .deg. C according to progress 800 minutes and the maximum temperature drop were 0.2 .deg. C. By the results of the performance valuation, the water storage electric boiler was verified fitted quality on the test prescription of KERI (Korea Electrotechnology Research Institute.)

  6. Preparation and Spectroscopic Properties of Ce-Doped High-Silica Glass

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to develop a novel electric light source, the doped high-silica glass was studied on the preparation and spectroscopic properties. The porous glasses were made firstly and were then immersed in the solution containing Ce ion. Thereafter, the high-silica glasses containing Ce ion were prepared by sintering the porous preform. The spectroscopic properties were studied before and after heat-treatment in H2. The experimental results indicate that the suitable temperature schedules are the most important to prepare doped high-silica glass. The study of the spectra shows that Ce ion can be reduced to low valence state when it is heat-treated in H2. It can be used to adjust the UV cut-off wavelength of high-silica glass by changing the valence state of Ce ion.

  7. Conjugative plasmid in Corynebacterium flaccumfaciens subsp. oortii that confers resistance to arsenite, arsenate, and antimony(III)

    Energy Technology Data Exchange (ETDEWEB)

    Hendrick, C.A.; Haskins, W.P.; Vidaver, A.K.

    1984-07-01

    Gene transfer systems for phytopathogenic corynebacteria have not been reported previously. In this paper a conjugative 46-megadalton plasmid (pDG101) found in Corynebacterium flaccumfaciens subsp. oorii CO101 is described that mediates resistance to arsenite, arsenate, and antimony(III). Transfer of the plasmid from CO101 to four other strains from the C. flaccumfaciens group occurred between cells immobilized on nitrocellulose filters or on agar surfaces. Transconjugant strains expressed the same levels of metal resistance as the donor strain and were able to act as donor strains in subsequent matings. The physical presence of the plasmid was detected by agarose gel electrophoresis. Arsenite-sensitive derivatives of the donor and transconjugant strains were obtained after heat treatment; these were cured of pDG101.

  8. Processing Bi-Pb-Sr-Ca-Cu-O superconductors from amorphous state

    Science.gov (United States)

    Chiang, C. K.; Freiman, S. W.; Wong-Ng, W.; Hwang, N. M.; Shapiro, A. J.; Hill, M. D.; Cook, L. P.; Shull, R. D.; Swartzendruber, L. J.; Bennett, L. H.

    1990-01-01

    Researchers produced superconducting ceramics of the Bi-Pb-Sr-Ca-Cu-O system started from a glass. To form the glass, the mixed oxide powder was melted at 1200 C in air. The liquid was quenched rapidly by pouring it onto an aluminum plate and rapidly pressing with another plate. The quenched compound was in the form of black amorphous solid, whose x-ray powder pattern has no crystalline peaks. After heat treatment at high temperatures, the glass crystallized into a superconductor. The crystalline phases in the superconductor identified using x-ray diffraction patterns. These phases were that associated with the superconducting phases of T(sub c) = 80 K (Bi2Ca1Sr2Cu2Ox) and of T(sub c) = 110 K (Bi2Ca2Sr2Cu3Ox). The dc resistivity and the ac susceptibility of these superconductors were studied.

  9. Electrohydrodynamic coating of metal with nano-sized hydroxyapatite.

    Science.gov (United States)

    Li, Xiang; Huang, Jie; Ahmad, Zeeshan; Edirisinghe, Mohan

    2007-01-01

    Electrohydrodynamic spray deposition of a hydroxyapatite (HA) suspension consisting of nano-particles has been used to create a hydroxyapatite coating comprising of nanostructured surface topography. Preliminary coating experiments were carried out on an Al substrate and 30 s was found to be the most appropriate coating time. HA coating on titanium for this duration was found to be well-bonded to the substrate after heat-treatment. A thickness of 2 mum was achieved in 30 s and formation of a bone-like apatite on the surface was detected after incubation of the heat-treated coated Ti in simulated body fluid. Therefore, we have uncovered a new procedure by which nano-biomaterials can be deposited on real orthopedic substrates to prepare bioactive thin coatings in a simple and easy manner. PMID:18032815

  10. Temperature stability of AgCu nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sopoušek, Jiří, E-mail: sopousek@mail.muni.cz; Zobač, Ondřej; Vykoukal, Vít [Masaryk University, Department of Chemistry, Faculty of Science (Czech Republic); Buršík, Jiří; Roupcová, Pavla [Institute of Physics of Materials ASCR (Czech Republic); Brož, Pavel; Pinkas, Jiří [Masaryk University, Department of Chemistry, Faculty of Science (Czech Republic); Vřešťál, Jan [Masaryk University, Central European Institute of Technology, CEITEC (Czech Republic)

    2015-12-15

    The colloidal solutions of the Ag–Cu nanoparticles (NPs, 10–32 nm) were prepared by solvothermal reactions. The samples of dried AgCu NPs and the resulting microstructures after heat treatment in air were investigated by various methods including electron microscopy (TEM, SEM) and high-temperature X-ray powder diffraction (HTXRD). The AgCu randomly mixed, Cu-rich, and Ag-rich face centred cubic crystal lattices were detected during the experiments. The temperature induced sintering was observed experimentally by HTXRD at 250 °C. The phase transformations at high temperatures were monitored by differential scanning calorimetry. The formation of the Ag-rich grains during heating in air and evolution of copper oxide microstructure were detected.Graphical abstract.

  11. Combination of Heat Shock and Enhanced Thermal Regime to Control the Growth of a Persistent Legionella pneumophila Strain.

    Science.gov (United States)

    Bédard, Emilie; Boppe, Inès; Kouamé, Serge; Martin, Philippe; Pinsonneault, Linda; Valiquette, Louis; Racine, Jules; Prévost, Michèle

    2016-01-01

    Following nosocomial cases of Legionella pneumophila, the investigation of a hot water system revealed that 81.5% of sampled taps were positive for L. pneumophila, despite the presence of protective levels of copper in the water. A significant reduction of L. pneumophila counts was observed by culture after heat shock disinfection. The following corrective measures were implemented to control L. pneumophila: increasing the hot water temperature (55 to 60 °C), flushing taps weekly with hot water, removing excess lengths of piping and maintaining a water temperature of 55 °C throughout the system. A gradual reduction in L. pneumophila counts was observed using the culture method and qPCR in the 18 months after implementation of the corrective measures. However, low level contamination was retained in areas with hydraulic deficiencies, highlighting the importance of maintaining a good thermal regime at all points within the system to control the population of L. pneumophila. PMID:27092528

  12. Manganese in silicon carbide

    Science.gov (United States)

    Linnarsson, M. K.; Hallén, A.

    2012-02-01

    Structural disorder and relocation of implanted Mn in semi-insulating 4H-SiC has been studied. Subsequent heat treatment of Mn implanted samples has been performed in the temperature range 1400-2000 °C. The depth distribution of manganese is recorded by secondary ion mass spectrometry. Rutherford backscattering spectrometry has been employed for characterization of crystal disorder. Ocular inspection of color changes of heat-treated samples indicates that a large portion of the damage has been annealed. However, Rutherford backscattering shows that after heat treatment, most disorder from the implantation remains. Less disorder is observed in the [0 0 0 1] channel direction compared to [ 1 1 2¯ 3] channel direction. A substantial rearrangement of manganese is observed in the implanted region. No pronounced manganese diffusion deeper into the sample is recorded.

  13. Effect of carbon content on carbide morphology and mechanical properties of A.R. white cast iron with 10-12% tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Heydari, D. [Department of Materials Science and Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Skandani, A. Alipour [Department of Engineering Science and Mechanics, Virginia Tech, Blacksburg, VA 24061 (United States); Al Haik, M., E-mail: alhaik@vt.edu [Department of Engineering Science and Mechanics, Virginia Tech, Blacksburg, VA 24061 (United States)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer Effect of W and C variation in A.R. white cast iron was studied up to 12 wt% W. It never exceeded 10 wt% in previous investigations. Black-Right-Pointing-Pointer Carbide morphologies with 2.2-3.2 wt% carbon shows that W has dominating effect on carbide morphology. Black-Right-Pointing-Pointer New carbide microstructures (GA and IA) appear in some range of carbon and its volume fraction is function of carbon content. Black-Right-Pointing-Pointer After heat treatment, new carbide morphology turns to continuous chromium carbide. Black-Right-Pointing-Pointer Wear resistance and hardness of the new alloys depends on both IA appearance presence and tungsten carbide precipitation. - Abstract: Carbide morphologies of white cast iron containing 22% Cr and 10-12% tungsten with different carbon contents (2.34-3.20 wt.%) were investigated. Results indicated that for the as-cast alloys with no heat treatments, the addition of carbon changes the morphology of carbides during air-cooling in the presence of tungsten. Light microscopy analysis revealed that for an alloy with 2.3 wt% carbon, chromium carbides possess coarse gray appearance (GA). Increasing the carbon content reduced the coarse GA zones volume fraction while a finer GA zones emerged. The coexistence of coarse and fine GA phases came to an end at 2.8 wt% carbon, at which only fine GA zones spread throughout the chromium carbide phase. Scaling up the carbon content to 3.2 wt% led to the formation of tungsten carbide and austenite in a eutectic reaction. Both fine and coarse GA zones vanished while the tungsten carbides acquired fishbone-like morphology. Upon heat treatment, the coarse GA zones vanished completely and turned into island appearance (IA) of chromium carbide. On the contrary, the finer GA zones remained unchanged after heat treatment and they coexisted with the IA. After heat treatment, the fishbone morphology shattered apart, however, the hyper chromium carbides

  14. Temperature measurements and hydrogen transformation under dynamic compression up to 150 GPA.

    Science.gov (United States)

    Nikolaev, Dmitry; Pyalling, Alexey; Kvitov, Sergey; Fortov, Vladimir

    2012-03-01

    Lithium fluoride single crystal window was used for optical light emission registration during quasi-isentropic compression of hydrogen to the pressures 100-150 GPa. Initially gaseous hydrogen samples at 78 K temperature and different pressures in the range 3-30 MPa were investigated. Recorded brightness temperature profiles in near infrared range of wavelength were analyzed to evaluate optical and transport properties of the investigated hydrogen sample and window. Two EOS models of hydrogen, with and without metallic region were used for 1-D simulation of it's properties under dynamic compression and estimation of hydrogen temperature within compressed layer. The obtained data demonstrate abrupt change of final temperatures after heating higher then 3500K.

  15. Cyclotron instability in the afterglow mode of minimum-B ECRIS

    Energy Technology Data Exchange (ETDEWEB)

    Izotov, I., E-mail: izotov@ipfran.ru; Mansfeld, D. [Institute of Applied Physics, Russian Academy of Sciences (IAP RAS), 46 Ul’yanova St., 603950 Nizhny Novgorod (Russian Federation); Kalvas, T.; Koivisto, H.; Komppula, J.; Kronholm, R.; Laulainen, J.; Tarvainen, O. [Department of Physics, University of Jyvaskyla, P.O. Box 35 (YFL), 40500 Jyvaskyla (Finland); Skalyga, V. [Institute of Applied Physics, Russian Academy of Sciences (IAP RAS), 46 Ul’yanova St., 603950 Nizhny Novgorod (Russian Federation); Lobachevsky State University of Nizhny Novgorod (UNN), 23 Gagarina St., 603950 Nizhny Novgorod (Russian Federation)

    2016-02-15

    It was shown recently that cyclotron instability in non-equilibrium plasma of a minimum-B electron cyclotron resonance ion source (ECRIS) causes perturbation of the extracted ion current and generation of strong bursts of bremsstrahlung emission, which limit the performance of the ion source. The present work is devoted to the dynamic regimes of plasma instability in ECRIS operated in pulsed mode. Instability develops in decaying plasma shortly after heating microwaves are switched off and manifests itself in the form of powerful pulses of electromagnetic emission associated with precipitation of high energy electrons. Time-resolved measurements of microwave emission bursts are presented. It was found that even in various gases (helium and oxygen were studied) and at different values of magnetic field and heating power, the dynamic spectra demonstrate common features: decreasing frequency within a single burst as well as from one burst to another.

  16. Antireflection Pyrex envelopes for parabolic solar collectors

    Science.gov (United States)

    McCollister, H. L.; Pettit, R. B.

    1983-11-01

    Antireflective (AR) coatings, applied to the glass envelopes used in parabolic trough solar collectors around the receiver tube in order to reduce thermal losses, can increase solar transmittance by 7 percent. An AR surface has been formed on Pyrex by first heat treating the glass to cause a compositional phase separation, removing a surface layer after heat treatment through the use of a preetching solution, and finally etching in a solution that contains hydrofluorosilic and ammonium bifluoride acids. AR-coated samples with solar transmittance values of more than 0.97, by comparison to an untreated sample value of 0.91, have been obtained for the 560-630 C range of heat treatment temperatures. Optimum values have also been determined for the other processing parameters.

  17. Sulfur polymer cement, a solidification and stabilization agent for radioactive and hazardous wastes

    International Nuclear Information System (INIS)

    Sulfur polymer cement (SPC) is made by reacting 95% sulfur with 2.5 % dicyclopentadiene and 2.5% cyclopentadiene oligomers, to produce a product that is much better than unmodified sulfur. SPC is being tested as a solidifying and stabilizing agent for low-level radioactive and hazardous wastes. Heavy loadings (5 wt%) of eight toxic metals were combined individually with SPC and 7 wt% sodium sulfide nonahydrate. The leach rates for mercury, lead, chromium and silver oxides were reduced by six orders of magnitude, while those of arsenic and barium were reduced by four. SPC is good for stabilizing incinerator ash. Ion-exchange resins can be stabilized with SPC after heat treatment with asbestos or diatomite at 220-250 deg C. 19 refs

  18. Heat Pipe Systems

    Science.gov (United States)

    1993-01-01

    The heat pipe was developed to alternately cool and heat without using energy or any moving parts. It enables non-rotating spacecraft to maintain a constant temperature when the surface exposed to the Sun is excessively hot and the non Sun-facing side is very cold. Several organizations, such as Tropic-Kool Engineering Corporation, joined NASA in a subsequent program to refine and commercialize the technology. Heat pipes have been installed in fast food restaurants in areas where humid conditions cause materials to deteriorate quickly. Moisture removal was increased by 30 percent in a Clearwater, FL Burger King after heat pipes were installed. Relative humidity and power consumption were also reduced significantly. Similar results were recorded by Taco Bell, which now specifies heat pipe systems in new restaurants in the Southeast.

  19. Measurements of low-energy electron reflection at a plasma boundary

    Energy Technology Data Exchange (ETDEWEB)

    Demidov, V. I., E-mail: vladimir.demidov@mail.wvu.edu [Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506 (United States); Adams, S. F. [Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Kaganovich, I. D. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Koepke, M. E. [Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506 (United States); Kurlyandskaya, I. P. [Department of Optics and Spectroscopy, St. Petersburg State University, St. Petersburg 199034 (Russian Federation); International Laboratory “Nonlocal Plasma in Nanotechnology and Medicine,” ITMO University, St. Petersburg 197101 (Russian Federation)

    2015-10-15

    It is demonstrated that low-energy (<3 eV) electron reflection from a solid surface in contact with a low-temperature plasma can have significant variation with time. An uncontaminated, i.e., “clean,” metallic surface (just after heating up to glow) in a plasma environment may have practically no reflection of low-energy incident electrons. However, a contaminated, i.e., “dirty,” surface (in some time after cleaning by heating) that has a few monolayers of absorbent can reflect low-energy incident electrons and therefore significantly affect the net electron current collected by the surface. This effect may significantly change plasma properties and should be taken into account in plasma experiments and models. A diagnostic method is demonstrated for measurements of low-energy electron absorption coefficient in plasmas with a mono-energetic electron group.

  20. Selection of Cleaning Agents Used in Tractor Manufacture%拖拉机制造过程中清洗剂的选用研究

    Institute of Scientific and Technical Information of China (English)

    史小阳; 焦凤菊; 段华荣

    2011-01-01

    根据拖拉机制造过程中,大批量生产方式下的几个主要工序,如机加中间工序及装配前、热处理前后、涂装前等工序,以及清洗污垢类型、清洗工件的材质、清洗用水质、环保等,对清洗剂的选择原则进行了阐述。%According to the several main processes under mass production in tractor manufacture,such as mechanical intermediate process,before assembling,before and after heating treatment,before painting,and so on,fouling product type,material,water quality,environ

  1. Effect of indomethacin on hyperthermia induced by heat stress in broiler chickens

    Science.gov (United States)

    Furlan, R. L.; Macari, M.; Malheiros, E. B.; Secato, E. R.; Guerreiro, J. R.

    An investigation was carried out to verify whether the heat stress hyperthermia response of broilers is prostaglandin-dependent. Male broiler chickens of the Hubbard-Petterson strain, aged 35-49 days, were used. Chickens were injected with indomethacin (1 mg/kg intraperitoneally ) 15 min before or 2 h after heat exposure (at 35°C for 4 h), and rectal temperature was measured before injection and up to 4 h thereafter. Birds were separated into two groups with and without access to water during heat stress. The increase in rectal temperature was lower (Prectal temperature, irrespective of whether indomethacin was administered before or in the course of the rise in temperature. The results revealed that the increase in rectal temperature during heat exposure is not prostaglandin-dependent, and that the use of cyclooxigenase inhibitors is not recommended to attenuate heat stress hyperthermia in broiler chickens.

  2. Hardness and Microstructure of Binary and Ternary Nitinol Compounds

    Science.gov (United States)

    Stanford, Malcolm K.

    2016-01-01

    The hardness and microstructure of twenty-six binary and ternary Nitinol (nickel titanium, nickel titanium hafnium, nickel titanium zirconium and nickel titanium tantalum) compounds were studied. A small (50g) ingot of each compound was produced by vacuum arc remelting. Each ingot was homogenized in vacuum for 48 hr followed by furnace cooling. Specimens from the ingots were then heat treated at 800, 900, 1000 or 1100 degree C for 2 hr followed by water quenching. The hardness and microstructure of each specimen was compared to the baseline material (55-Nitinol, 55 at.% nickel - 45 at.% titanium, after heat treatment at 900 degC). The results show that eleven of the studied compounds had higher hardness values than the baseline material. Moreover, twelve of the studied compounds had measured hardness values greater 600HV at heat treatments from 800 to 900 degree C.

  3. Effect of Heat Treatment on Microstructures and Properties of Near-Isothermally Forged TiAl Alloy Containing Minor Ni

    Institute of Scientific and Technical Information of China (English)

    YUAN Zhi-shan; CHEN Sun-yuan; ZHOU Li; LIU Chang-sheng; ZHANG Ji; ZHANG Jian-wei

    2004-01-01

    The heat treatment, including two steps, was proposed to obtain Fine Fully Lamellar (FFL) microstructure on TiAl containing minor Ni. The first step was in (α+γ) phase region to get Duplex (DP) microstructure, and the second step was in α phase region transforming DP microstructure into FFL microstructure. The effect of heat treatment on microstructures and properties was studied. The results showed that the static recrystallization kinetics in (α+γ) phase region took the form of Avrami equitation, and the remnant lamellae in DP microstructure were detrimental to room temperature tensile properties. The FL microstructures were obtained after heat treatment in α phase region using DP microstructure, the uniform FFL microstructure was beneficial to comprehensive properties.

  4. Combination of Heat Shock and Enhanced Thermal Regime to Control the Growth of a Persistent Legionella pneumophila Strain

    Directory of Open Access Journals (Sweden)

    Emilie Bédard

    2016-04-01

    Full Text Available Following nosocomial cases of Legionella pneumophila, the investigation of a hot water system revealed that 81.5% of sampled taps were positive for L. pneumophila, despite the presence of protective levels of copper in the water. A significant reduction of L. pneumophila counts was observed by culture after heat shock disinfection. The following corrective measures were implemented to control L. pneumophila: increasing the hot water temperature (55 to 60 °C, flushing taps weekly with hot water, removing excess lengths of piping and maintaining a water temperature of 55 °C throughout the system. A gradual reduction in L. pneumophila counts was observed using the culture method and qPCR in the 18 months after implementation of the corrective measures. However, low level contamination was retained in areas with hydraulic deficiencies, highlighting the importance of maintaining a good thermal regime at all points within the system to control the population of L. pneumophila.

  5. Pyroelectric effect and polarization instability in self-assembled diphenylalanine microtubes

    Science.gov (United States)

    Esin, A.; Baturin, I.; Nikitin, T.; Vasilev, S.; Salehli, F.; Shur, V. Ya.; Kholkin, A. L.

    2016-10-01

    The natural ability of peptides and proteins to self-assemble into elongated fibrils is associated with several neurogenerative diseases. Diphenylalanine (FF) tubular structures that have the same structural motif as in Aβ-amyloid peptide (involved in Alzheimer's disease) are shown to possess remarkable physical properties ranging from piezoelectricity to electrochemical activities. In this work, we also discover a significant pyroelectric activity and measure the temperature dependence of the pyroelectric coefficient in the temperature range of 20-100 °C. Pyroelectric activity decreases with temperature contrary to most ferroelectric materials and significant relaxation of pyrocurrent is observed on cooling after heating above 50 °C. This unusual behavior is assigned to the temperature-induced disorder of water molecules inside the nanochannels. Pyroelectric coefficient and current and voltage figures of merit are estimated and future applications of pyroelectric peptide nanostructures in biomedical applications are outlined.

  6. Protein removal from fish mince washwater using ohmic heating

    Directory of Open Access Journals (Sweden)

    Kobsak Kanjanapongkul

    2008-05-01

    Full Text Available A static ohmic heating system was developed to remove protein from fish mince (threadfin bream washwatercollected from a surimi production plant in order to improve water quality. The samples were heated under different electricfield strengths (EFS, 20, 25, and 30 V/cm until reaching the desired temperature (50, 60, and 70oC, and further held at thattemperature for a certain time (0, 15, and 30 minutes. Heating the samples to 70oC resulted in a better protein removal whencompared to 50 and 60oC. After heating to 70oC, the samples were centrifuged. The analysis of the supernatant obtained showsthe reduction of protein, COD, BOD, TS, and TDS to 42%, 25%, 23%, 44%, and 61%, respectively. The electrical conductivityof the samples showed a linear relationship with temperature and the temperature demonstrated a parabolic relationshipwith heating time. EFS and holding time have no significant effect on protein removal.

  7. Non-dendritic structural 7075 aluminum alloy byliquidus cast and its semi-solid compression behavior

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Fine, equiaxed, non-dendritic structure needed by semi-solid processing was obtained by liquidus cast, i.e.7075 wrought aluminum alloy cast from liquidus temperature. The microstructures after heat treatment at different tem-peratures and time in the semi-solid range were observed, and the compression deformation behavior at different tempera-tures (490 ~ 600 C) and strain rates (5 × 10-3 ~ 5s-1) was investigated by means of Gleeble-1500 thermal-mechenicalsimulator. Thc results show that the deformation resistance of the non-dendritic structure attained by liquidus cast in semi-solid is remarkably lower than that of conventional dendritic structure. The formability of non-dendritic structure is betterthan that of dendritic structure

  8. Semi-solid squeeze casting process of a ZL109 alloy

    Institute of Scientific and Technical Information of China (English)

    ZHAI Yanbo; LIU Changming; HAN Zhaotang; WANG Kai

    2008-01-01

    The structure evolution of the ZL109 alloy in the process of semi-solid squeeze casting and the mechanical properties of the components were investigated. The results show that (1) the eutectic silicon phase in original billets is refined in the low super-heat casting process; (2) the eutectic structure in billets starts to fuse and the crystals of the eutectic silicon phase are refined further and sphericized in the remelting process of billets; (3) in the semi-solid ,squeeze casting process, the sphericity of the α phase and the refining of the silicon phase occur, owing to the friction between solid and liquid; (4) in the process of heat treatment, the eutectic α phase aggregates with the primary α phase and the eutectic silicon pieces aggregate together. The elongation of the semi-solid component after heat treatment rises to 1.42%.

  9. Characterization and Flocculating Properties of a Biopolymer Produced by Halomonas sp. Okoh.

    Science.gov (United States)

    Okaiyeto, Kunle; Nwodo, Uchechukwu U; Mabinya, Leonard V; Okoh, Anthony I

    2015-04-01

    The flocculating efficiency and physiochemical properties of purified bioflocculant produced by Halomonas sp. Okoh were investigated. Approximately 1.213 g/L of bioflocculant was recovered after fermentation under predetermined ambient conditions. Jar test experimentation revealed optimum bioflocculant concentration as 0.2 mg/mL with flocculation activity of 66.1%. The thermostable bioflocculant retained high flocculation activity after heat treatment at 100 °C for 30 minutes; flocculation activity of 74% was achieved. Chemical analysis showed that the bioflocculant was composed of sugar (26.5%), protein (2.64%), and uronic acid (13.3%). The Fourier infrared spectroscopy spectrum of the purified bioflocculant revealed the presence of hydroxyl and carboxylic functional groups. Thermogravimetric analyses showed a varied decomposition step, thus, an indication of varied composition. Scanning electron micrograph revealed the amorphous structure of the bioflocculant. These results suggest potential applicability of the bioflocculant produced by Halomonas sp. Okoh industrially. PMID:26462073

  10. Non-additive response of blends of rice and potato starch during heating at intermediate water contents: A differential scanning calorimetry and proton nuclear magnetic resonance study.

    Science.gov (United States)

    Bosmans, Geertrui M; Pareyt, Bram; Delcour, Jan A

    2016-02-01

    The impact of different hydration levels, on gelatinization of potato starch (PS), rice starch (RS) and a 1:1 blend thereof, was investigated by differential scanning calorimetry and related to nuclear magnetic resonance proton distributions of hydrated samples, before and after heating. At 20% or 30% hydration, the visual appearance of all samples was that of a wet powder, and limited, if any, gelatinization occurred upon heating. At 30% hydration, changes in proton distributions were observed and related to plasticization of amorphous regions in the granules. At 50% hydration, the PS-RS blend appeared more liquid-like than other hydrated samples and showed more pronounced gelatinization than expected based on additive behavior of pure starches. This was due to an additional mobile water fraction in the unheated PS-RS blend, originating from differences in water distribution due to altered stacking of granules and/or altered hydration of PS due to presence of cations in RS.

  11. Palladium and ruthenium supported silver migration in 3C–silicon carbide

    International Nuclear Information System (INIS)

    Surrogate TRISO particles were infiltrated with a Pd Ag mixture and heat treated at 1000 °C to investigate the effect of Pd on Ag transport through current state of the art TRISO coatings for use in HTGRs. The experiment was repeated with Ru instead of Pd because of the similarities in the reaction between Pd and Ru with SiC. It was found that both Pd and Ru form their respective silicides after heat treatment together with the simultaneous precipitation of graphite. In both cases Ag was concentrated along the leading edge of the reaction zone which itself was concentrated along grain boundaries. However, the effect of Pd was much more pronounced than that of Ru making Ru at most a secondary contributor to Ag migration through SiC in TRISO fuel

  12. Characterization and study of the behavior of wire Ti-Ni with shape memory effect enables manufacture of actuators; Estudo da caracterizacao e do comportamento de fios de Ti-Ni com efeito memoria de forma viabilizando fabricacao de atuadores

    Energy Technology Data Exchange (ETDEWEB)

    Pina, E.A.C.; Araujo Filho, O.O. de; Urtiga Filho, S.L.; Gonzalez, C.H., E-mail: kikipina@hotmail.co [Universidade Federal de Pernambuco (DEM/CTG/UFPE), Recife, PE (Brazil). Centro de Tecnologia e Geociencias. Dept. de Engenharia Mecanica

    2010-07-01

    This work aims to characterize the wire commercial Ti-Ni of 1.27 mm in diameter with shape memory effect for the development of helical springs with the function of sensor / actuator. After heat treatment, the transformation temperatures, the presence of precipitates, the degree of damping, maximum stress of rupture, modulus of elasticity, the presence of phase R, the behavior of the alloy under tension, will be analyzed and compared in each situation. For characterization we used several methods including: heat treatment, Differential Scanning Calorimetry (DSC), tensile, dynamic mechanical analysis (DMA), X-ray diffraction, thermomechanical cycling. The wires were cut into pieces and heat-treated at 400 deg C with variation of time in muffle furnaces and quenching in water at 25 deg C. (author)

  13. An application of Au thin-film emissivity barrier on Ni alloy

    Energy Technology Data Exchange (ETDEWEB)

    Huang Zhibin [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechincial University, Xi' an 710072 (China)], E-mail: huangzhibin83@163.com; Zhu Dongmei; Lou Fa; Zhou Wancheng [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechincial University, Xi' an 710072 (China)

    2008-12-30

    1000 nm-thick Au film was sputter-deposited on two groups of nickel alloy substrates, in which one group (Group A) was oxidated at 800 deg. C for 20 h to form a oxide film before coating gold while another group (Group B) was unoxidated. The gold thin-film is applied to serve as a low emissivity coating to reflect thermal radiation. The gold-coated samples were heated in air at 600 deg. C for 150 h to explore the effect of high-temperature environment on the emissivity of coated Au film. After heat-treatment, the average thermal emissivity at the wavelength of 3-14 {mu}m of Group B greatly increased from 0.18 to 0.82 while that of Group A only increased a little. The diffusion between Au and other nickel alloy elements at 600 deg. C also had been discussed in this paper.

  14. MEASUREMENTS OF A STEEL CHARGE EMISSIVITY UNDER STRONG IRRADIANCE CONDITIONS

    Directory of Open Access Journals (Sweden)

    Agnieszka Benduch

    2014-09-01

    Full Text Available Steel bars are manufactured in the rolling process, whereby they are characterized by strain hardening and poor plastic properties. In many application cases such properties are improper, therefore, additional heat treatment is required. Crucial influence on the products quality after heat treatment has an appropriate selection of process parameters. In many modern technologies of heat treatment the charge of porous structure is subjected to the heating process. Proper control of heat treatment parameters of bundles of rods requires knowledge on their thermal properties. However, it also requires accurate identification of complex heat transfer processes occurring in the porous material. Such analysis, with respect to bundles of bars, provide a response of qualitative nature of the heat exchange area of these charges. The article describes the emissivity measurements of samples of the steel charge using a thermal imaging camera.

  15. Effect of the heat treatment on the infrared emissivity of indium tin oxide (ITO) films

    International Nuclear Information System (INIS)

    Indium tin oxide (ITO) films were deposited on glass substrates at temperatures ranging from 100 deg. C to 400 deg. C by direct current magnetron sputtering. The mean infrared emissivities at the waveband of 8-14 μm were measured in process of heating and cooling between room temperature and 350 deg. C. Microstructure and phases of ITO films before (Group A) and after (Group B) heat treatment were characterized by SEM and XRD, respectively. Electrical properties were characterized with a four-point probe method and by Hall measurement system. During heat treatment, the infrared emissivity of the film increases with the increase of temperature, and decreases with the decrease of temperature. While, the infrared emissivity of the films decreases slightly around 250 deg. C in heating process. On the other hand, after heat treatment, the crystalline phases of the films have no obvious change. However, both the resistivity and the infrared emissivity of all films decrease.

  16. Effect of the heat treatment on the infrared emissivity of indium tin oxide (ITO) films

    Energy Technology Data Exchange (ETDEWEB)

    Sun Kewei, E-mail: sunkewei0616@163.com [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China); Zhou Wancheng; Tang Xiufeng; Huang Zhibin; Lou Fa; Zhu Dongmei [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China)

    2011-09-01

    Indium tin oxide (ITO) films were deposited on glass substrates at temperatures ranging from 100 deg. C to 400 deg. C by direct current magnetron sputtering. The mean infrared emissivities at the waveband of 8-14 {mu}m were measured in process of heating and cooling between room temperature and 350 deg. C. Microstructure and phases of ITO films before (Group A) and after (Group B) heat treatment were characterized by SEM and XRD, respectively. Electrical properties were characterized with a four-point probe method and by Hall measurement system. During heat treatment, the infrared emissivity of the film increases with the increase of temperature, and decreases with the decrease of temperature. While, the infrared emissivity of the films decreases slightly around 250 deg. C in heating process. On the other hand, after heat treatment, the crystalline phases of the films have no obvious change. However, both the resistivity and the infrared emissivity of all films decrease.

  17. Characterization of an extracellular polysaccharide produced by Bacillus sp.RL-2

    Institute of Scientific and Technical Information of China (English)

    LUO Ping; LUO Gu-yuan; JI Fang-ying; CAI Jiang-wei

    2005-01-01

    A strain secreting a strongly acidic polysaccharide flocculating agent was isolated from activated sludge, and identified as Bacillus brevis. The bioflocculant was produced by RL-2 during the late logarithmic growth in the batch culture and was recovered from supernatant by ethanol precipitation. The bioflocculant is thermo-stable as its activity remains stable after heated at 100℃ for 45 min. Its flocculating activity with kaolin suspensions was stimulated by the addition of Ca2+, Al3+ and Cu2+. The flocculant consists of glucose, mannose, and galacturonic acid. Its average molecular mass was estimated to be approximately 2.86×105 by the method of viscosity. The flocculant aggregates various inorganic and organic compounds in solution.

  18. Synthetic heat carrier oil compositions based on polyalkylene glycols

    International Nuclear Information System (INIS)

    The results of syntheses of heat carrier oils based on polyalkylene glycols (PAGs) using suitable additives have been reported. Polyalkylene glycols have been prepared by heating diethylene glycol, propylene oxide, glycols, adipic acid and 2-ethyhexanol in the presence of KOH and stannyl octoate as catalyst in the molar ratio to give proper physical properties and viscosity-temperature index. The prepared PAGs have been taken as basic components for heat carrier oil compositions. In order to improve the thermal stability and viscosity indices, as well as other specifications, anti-oxidant and anti-foaming additives were added to the base material to reach optimum compositions. Thermal stability, mass loss on vaporization at 250 oC, 350 oC and changing the specifications after heating at 300 oC for 10 h have also been investigated. The obtained heat carrier oils showed comparable improved properties in comparison with commercially available heat carriers

  19. Functional analysis of Drosophila HSP70 promoter with different HSE numbers in human cells.

    Science.gov (United States)

    Kust, Nadezda; Rybalkina, Ekaterina; Mertsalov, Ilya; Savchenko, Ekaterina; Revishchin, Alexander; Pavlova, Gali

    2014-01-01

    The activation of genetic constructs including the Drosophila hsp70 promoter with four and eight HSE sequences in the regulatory region has been described in human cells. The promoter was shown to be induced at lower temperatures compared to the human hsp70 promoter. The promoter activity increased after a 60-min heat shock already at 38 °C in human cells. The promoter activation was observed 24 h after heat shock for the constructs with eight HSEs, while those with four HSEs required 48 h. After transplantation of in vitro heat-shocked transfected cells, the promoter activity could be maintained for 3 days with a gradual decline. The promoter activation was confirmed in vivo without preliminary heat shock in mouse ischemic brain foci. Controlled expression of the Gdnf gene under a Drosophila hsp70 promoter was demonstrated. This promoter with four and eight HSE sequences in the regulatory region can be proposed as a regulated promoter in genetic therapeutic systems.

  20. A new sol-gel process for preparing Ba(Mg1/3Nb2/3)O3 nanopowders

    Institute of Scientific and Technical Information of China (English)

    Fang Lian; Lihua Xu; Fushen Li; Hailei Zhao

    2004-01-01

    Commercially available niobium (V) oxide [Nb2O5], with barium acetate [Ba(CH3COO)2] and magnesium acetate At first, Nb2O5 reacted with melting sodium hydroxide and transformed into dispersible oxide. The resulting glassy substance after cooling was dispersed and washed several times in distilled water to remove the Na+ ions. The as-prepared colloidal Nb2O5.nH2O was subsequently mixed with acetic solution of barium acetate and magnesium acetate according to the required molar proportions and followed by gelation. The ultrafine BMN powders were finally obtained after heat-treating the gel at 820℃ for 1 h, and the assintered nanoceramics revealed a high relative density of 98.2%, and a high microwave Q-factor, of 10397 at 1.45GHz.

  1. Improvement of field emission of graphite flakes using hydrogen thermal processing

    International Nuclear Information System (INIS)

    In order to improve the field electron emission properties of the graphite, the carbon nanoparticles (CNPs) are synthesized on the micrographite flakes by hydrogen thermal processing. We spin the graphite solution on the silicon wafer and desiccate it, then produce the CNPs on the graphite flakes using hydrogen thermal processing in the furnace. The processing parameters such as the processing temperature, hydrogen flow rate and processing time, were varied to find the optimal conditions for the improvement of the field emission properties of the graphite flakes. The experimental results show that the field emission properties of the graphite flakes have glaring improvement after heat treatment owing to the increase of the defect density and the CNPs on above. The turn-on field was decreased from 7.7 of the untreated sample to 4.3 V/μm of the treated sample at the optimal processing conditions.

  2. Magnetic Microstructures of 2:17 Type Sm(Co,Fe,Cu,Zr)z Magnets Detected by Magnetic Force Microscopy

    Institute of Scientific and Technical Information of China (English)

    Xia Ailin; Guo Zhaohui; Li Wei; Han Baoshan

    2006-01-01

    The magnetic microstructures of 2:17 type Sm(Co,Fe,Cu,Zr)z magnets were detected by magnetic force microscopy.Comparing the microstructures of the specimens coated with and without Ta thin film before and after heat-treatment, it is found that: (a) as a protection layer, Ta coating layer about 20 nm thick can effectively restrain Sm volatilization under high temperature;(b) the stress built in the 2:17 type Sm-Co magnets during specimen preparation only affects some local parts of the domain structures;(c) the magnetic microstructures vary largely for specimens heat-treated at high temperature without Ta film coating due to Sm volatilization.In addition, by comparing with high coercivity Fe-Pt point tips, it is found that the Co-Cr thin-film tips are not suitable for detecting the magnetic microstructures of strong permanent magnets.

  3. Microstructural characterization of titanium dental implants by electron microscopy and mechanical tests; Caracterizacao microestrutural de implantes dentarios de titanio por microscopia eletronica e ensaios mecanicos

    Energy Technology Data Exchange (ETDEWEB)

    Helfenstein, B.; Muniz, N.O.; Dedavid, B.A., E-mail: bruhelfenstein@hotmail.co [Pontificia Univ. Catolica do Rio Grande do Sul (FE/PUC/RS), Porto Alegre, RS (Brazil). Fac. de Engenharia; Gehrke, S.A. [Universidade Federal de Santa Maria (FE/UFSM), RS (Brazil). Fac. de Engenharia; Vargas, A.L.M. [Parque Tecnologico da PUCRS (TECNOPUC/GEPSI), Porto Alegre, RS (Brazil). Grupo de Estudos de Propriedades de Superficies e Interfaces

    2010-07-01

    Mini screw types for titanium implants, with differentiated design, were tested for traction and torsion for behavior analysis of the shape relative to the requirements of ASTM F136. All implants showed mechanical tensile strength above by the standard requirement, being that 83.3% of them broke above the doughnut, in support of the prosthesis. Distinct morphologies in ruptured by mechanical tests, were obtained. However, both fracture surfaces showed fragile comportments. Metallographic tests, x-ray diffraction (XRD) and microhardness were used for microstructural characterization of material, before and after heat treatment. The presences of {beta} phase in screw surface after quenching treatment proves that the thermal treatment can contribute for mechanical resistance in surface implants. (author)

  4. Fabrication of a Microtubular La0.6Sr0.4Ti0.2Fe0.8O3−δ Membrane by Electrophoretic Deposition for Hydrogen Production

    Directory of Open Access Journals (Sweden)

    Kyoung-Jin Lee

    2015-01-01

    Full Text Available Microtubular type La0.6Sr0.4Ti0.2Fe0.8O3−δ (LSTF membranes were prepared by electrophoretic deposition (EPD. The oxygen permeation and hydrogen production behavior of the membranes were investigated under various conditions. LSTF green layer was successfully coated onto a carbon rod and, after heat treatment at 1400°C in air, a dense LSTF tubular membrane with a thickness of 250 mm can be obtained. The oxygen permeation and hydrogen production rate were enhanced by CH4 in the permeate side, and the hydrogen production rate by water splitting was 0.22 mL/min·cm2 at 1000°C. It is believed that hydrogen production via water splitting using these tubular LSTF membranes is possible.

  5. Influence Of Heat Treathment On Caracteristics Of Inkjet Prints On Textile Material

    Directory of Open Access Journals (Sweden)

    Nemanja Kašiković

    2011-05-01

    Full Text Available This paper presents research regarding influence of heat treatment on changes of prints on textile material whichare obtained by inkjet printing technique. Research was done on three characteristic materials (100 % polyesteron which ware printed test chart. Test chart consisted of four colour fields each 100% of one of process colours(CMYK. Printing machine used was Mimaki JV22-160 with J-eco Subly nano inks. Variable factor was numberof ink layers, textile materials ware printed with one, two, three, four and five layers of ink. The analysis of heattreatment influence on prints was done according to SRPS F.S3.311 standard (temperature 110 0C. Total of 60samples were analyzed, 20 for each material used in this experiment. Resistance of colour to heat treatment andtransfer to cotton cloth was determined for characteristic temperatures by using the gray scale. The surface changesof textile material before and after heat treatment ware monitored by SEM analysis.

  6. Efecto de la naturaleza del precursor sobre las caracteristicas de las nanoparticulas de SnO2 sintetizadas Effect of the precursor's nature on characteristics of synthesized SnO2 nanoparticles

    Directory of Open Access Journals (Sweden)

    Carlos E. Ararat-Ibarguen

    2007-01-01

    Full Text Available Tin oxide (SnO2 is widely used in industry as raw material for electronic devices, plating of different types of materials, for dyes and pigments, for electroplating, heterogeneous catalysis, etc. In this work SnO2 was obtained by a controlled precipitation method with special attention to the effects the tin precursor has on the microstructure of the final product. The most appropriate pH for obtaining SnO2 with the rutile structure as the main phase is 6.25 for SnCl2 and 6.40 for SnSO4. After heat treatment at 600 °C, particles of nanometric order (~10 - 30 nm approx were obtained. The characterization of the solid phase was made by X-ray diffraction (XRD, thermal analysis (DTA/TG, transmission electron microscopy (TEM and Fourier transformed infrared spectroscopy (FTIR.

  7. Electrodeposition, Structure and Corrosion Resistance of Nanocrystalline Ni-W Alloy

    Institute of Scientific and Technical Information of China (English)

    YANG, Fang-Zu(杨防祖); GUO, Yi-Fei(郭逸飞); HUANG, Ling(黄令); XU, Shu-Kai(许书楷); ZHOU, Shao-Min(周绍民)

    2004-01-01

    Ni-W alloy was electrodeposited from the electrolyte solution containing sodium tungstate, nickel sulfate and ammonium citrate. The electrodeposition, heat treatment, structure, surface morphology and corrosion resistance in w=0.03 NaCl solution, of Ni-W alloys were studied by means of DSC, XRD, SEM and electrochemical techniques. The results showed that the obtained Ni-W alloy electrodeposit with W weight content (wW=0.471) was presented in more typical nanocrystalline. After heat treatment at 400 ℃ for 1 h, the phase structure of the deposits was not obviously changed whereas the agglomerate for the reunion of tiny grains on deposit surface caused the granule in a more smooth morphology, the microhardness was slightly increased and the corrosion resistance was enhanced.

  8. Aerosol Fe Nanoparticles with the Passivating Oxide Shell

    International Nuclear Information System (INIS)

    Structure, state, transformations and interactions of iron oxide shell with the iron metallic core in aerosol Fe nano-particles has been studied by X-ray and electron diffraction, TEM, Moessbauer spectroscopy and magnetization measurements. A strong influence of the state of nanoparticles oxide shell has been revealed on their magnetization, coercive force and hysteresis loop shift. A long-term passivation of the particles has been shown to be caused by the primary amorphous oxide. The passivation ability of the oxide shell becomes essentially worse after heat treatment of powder, resulting in its crystallization. Basing on the obtained results, a qualitative mechanism of passivation for nanoparticles covered with amorphous oxide shell has been suggested

  9. Properties and Application of Iron-based Shape Memory Alloy

    Institute of Scientific and Technical Information of China (English)

    Li Jian-chen; Jiang Qing; Dai Jun

    2005-01-01

    The properties of FeMnSiCrNi shape memory alloy were investigated. The results show that the best shape memory effect of Fel4Mn6Si9Cr5Ni alloy is 85%. The transformation amount of the ε→γ transformation is not complete after heating the alloy to 1000 K, As and Af points drop with increased transformation enthalpy ( △Hγ→ε) by thermal cycling and increased prestrain. The alloy shows also good creep and stress relaxation resistance. In addition, the alloy having a tensile force of 20 kN and a sealing pressure of 6 MPa can satisfy requirements for possible industrial application on pipe joints.

  10. Induction of the major heat-stress protein in purified rat glial cells

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, R.N.; Dwyer, B.E.; Welch, W.; Cole, R.; de Vellis, J.; Liotta, K.

    1988-05-01

    Cultured purified oligodendroglia and astroglia exposed to heat stress (45 degrees C, 10 or 20 min) synthesized a 68-kDa heat-stress protein, which migrates on two-dimensional gel electrophoresis and reacts with a specific monoclonal antibody suggesting it is similar to a major 72-kDa heat-shock protein previously reported in other cell types. This protein was not detected in control glial cultures. Actinomycin D prevented synthesis of this protein demonstrating an absolute requirement for newly synthesized mRNA. The response was prolonged by increasing the period of heat stress from 10 to 20 min. In addition to the 68-kDa HSP protein, the incorporation of radioactivity into 70-, 89-, and 97-kDa proteins was also increased after heating, but in contrast to the 68 kDa protein these proteins appeared to be made in control glial cultures.

  11. Effect of heat treatment on the inhibition of the acidic corrosion aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Khamis, E. (Alexandria Univ. (Egypt). Dept. of Chemistry); El-Gamal, M. (Alexandria Univ. (Egypt). Dept. of Material Science); El-Toukhy, A. (Alexandria Univ. (Egypt). Dept. of Material Science); Atea, M. (Alexandria Univ. (Egypt). Dept. of Material Science)

    1994-12-01

    The effect of heat treatment on the inhibition of acid corrosion of duralumin has been studied using gasometry, mass loss measurements and potentiodynamic technique. All the data reveal that the duralumin generally developed good corrosion resistance after heat treatment and the corrosion rate ranked as follows: Non treated > Naturally aged > quenched. This improvement in the corrosion resistance was attributed to the structural homogeneity of the heat-treated alloys. The presence of some selected aryl and alkyl triazoline derivatives at the threshold concentration of 5 x 10[sup -3] M indicate that these compounds retard the corrosion rate of duralumin and the extent of inhibition depends on the molecular structure of the inhibitors. Polarization curves show that the triazoline compounds act as mixed-type inhibitors affecting both the cathodic and anodic processes. Moreover, there is no noticeable difference in the degree by which the triazoline derivatives inhibit the corrosion of pure aluminium and heat treated duralumin alloy. (orig.)

  12. Preliminary comparative study of anti-inlfammatory effect of unheated and heat-treated Sahara honey:In vivo approach

    Institute of Scientific and Technical Information of China (English)

    Moussa Ahmed; Saad Aissat; Noureddine Djebli

    2015-01-01

    Objective:To investigate the effect of unheated and heat-treated of Sahara honey. Methods: A total of 24 Swiss albino mice weighing 25–35 g were divided into four groups (n = 6). Anti-inflammatory effect was assessed at 1, 2, 3, 4, 5 and 6 h after subplantar injection of carrageenan (0.5 mL of a 1% solution in normal saline). In addition, total phenolic content was determined by modified Folin-Ciocalteu method. Results: The total phenolic content capacity of the Sahara honey before and after heat treatment was between 72 and 97.9 mg of gallic acid equivalents/100 g of honey respectively. Administration of unheated honey (oral administration) reduced significantly (P Conclusions:Our results suggest that unheated Sahara honey has anti-inflammatory effects by reducing the mice paw edema size while heat-treated Sahara honey decreases the anti-inflammatory activity.

  13. Field experiment on coalmine heat disaster governance using cold source from surface water

    Institute of Scientific and Technical Information of China (English)

    Guo Pingye; Zhu Guolong; Liu Yuqing; Duan Mengmeng; Wu Junyin

    2014-01-01

    Regarding the lack of cold source for underground cooling systems from either mine inflow or return air, field experiments were taken in a high temperature deep coal mine with abundant cold source from surface water. Taking Sanhejian coal mine as an example, this paper introduced the technology scheme of heat disaster governance using surface water cold source. The paper presents the basics of this field experiment at the beginning, following by the design and site layout of the cooling system including the analysis and calculation of cold source. Numerical calculation method is also applied based on the operation parameters to simulate the influence to the surface river ecosystem. The results suggest that the temperature of surface water shall be lower than 34 ?C after heat exchange, and when more cooling capacities are needed in the future, increasing the water flow is more favorable than increasing the cooling range of water, which is better for the ecological environment protection.

  14. Observation of residual disorder in the centre of amorphous solid water films after pore collapse at 125 K

    International Nuclear Information System (INIS)

    The rapid structural re-organisation of porous amorphous solid water, grown to thicknesses in the range 2.5–70 μm by vapour deposition on a copper substrate at 75 K, after heating to 125 K has been found to leave a μm-wide band of residual disorder—for example, nm-sized closed pores—in the centre of the film. This layer was revealed by thinning the film by sublimation and continuously measuring the fraction of 1.5 keV positrons implanted into the film which forms ortho-positronium in the top 150 nm and decays into three gamma photons. (paper)

  15. On the sol-gel synthesis of strontium-titanate thin films and the prospects of their use in electronics

    Energy Technology Data Exchange (ETDEWEB)

    Sohrabi Anaraki, H.; Gaponenko, N. V., E-mail: nik@nano.bsuir.edu.by; Rudenko, M. V.; Guk, A. F.; Zavadskij, S. M.; Golosov, D. A.; Kolosnitsyn, B. S. [Belarusian State University of Informatics and Radioelectronics (Belarus); Kolos, V. V.; Pyatlitskij, A. N.; Turtsevich, A. S. [Integral Enterprise (Belarus)

    2014-12-15

    Strontium-titanate films obtained by the sol-gel technique are deposited onto silicon and silicon/oxide titanium/platinum substrates. The strontium-titanate phase is detected by the method of X-ray diffraction analysis after heat treatment at temperatures of 750 and 800°C. The thickness of the films obtained by the spin-on method increases from 50 to 250 nm as the number of deposited layers is increased and is accompanied with an increase in the grain size in the films. Prospects of the development of the sol-gel technique for the formation of film components of electronic devices based on SrTiO{sub 3} xerogels are discussed.

  16. Thermal mechanical behavior and microstructure characteristic of microalloyed CrMo steel under cross deformation

    International Nuclear Information System (INIS)

    Pipes with a diameter of 177.8 mm were prepared by the cross deformation of an Nb, V and Ti microalloyed CrMo steel. Equivalent strains of pipe making process and their effect on microstructure evolution were investigated. A thermal mechanical simulator was employed to simulate the conditions of the pipe making at different elevated temperatures. Microstructure was studied using a transmission electron microscope and an X-ray diffractometer. It was found that the (1 1 1) fiber formed after the pipe making has been inherited in the steel pipes after heat treatment, and austenite recrystallization of the steel begins at 1223 K, in good accordance with the predicted recrystallization start temperature.

  17. Phosphine-stabilised Au9 clusters interacting with titania and silica surfaces: The first evidence for the density of states signature of the support-immobilised cluster

    International Nuclear Information System (INIS)

    Chemically made, atomically precise phosphine-stabilized clusters Au9(PPh3)8(NO3)3 were deposited on titania and silica from solutions at various concentrations and the samples heated under vacuum to remove the ligands. Metastable induced electron spectroscopy was used to determine the density of states at the surface, and X-ray photoelectron spectroscopy for analysing the composition of the surface. It was found for the Au9 cluster deposited on titania that the ligands react with the titania substrate. Based on analysis using the singular value decomposition algorithm, the series of MIE spectra can be described as a linear combination of 3 base spectra that are assigned to the spectra of the substrate, the phosphine ligands on the substrate, and the Au clusters anchored to titania after removal of the ligands. On silica, the Au clusters show significant agglomeration after heat treatment and no interaction of the ligands with the substrate can be identified

  18. Effect of heat treatment on mechanical properties of heavily cold-rolled Fe-6.5wt%Si alloy sheet

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Fe-6.5wt%Si alloy has excellent soft magnetic properties,but it is hard to be cold-rolled due to appearance of ordered phases in this alloy.In this paper we report that ultra thin Fe-6.5wt%Si sheet of 0.05 mm thick was obtained by heavily cold rolling.By means of optical microscope,micro-hardness indenter,instron,SEM and X-ray diffraction,the effect of heat treatment on mechanical properties of this alloy sheet was investigated.The heavily cold-rolled sheet exhibits some extent of ductility.The ultimate tensile strength reaches 1.93 GPa.After heat treatment,micro-hardness is decreased and the ductility is lost,especially at temperature above 650℃ when recrystallization takes place.The reason for decreasing the ductility lies in the ordered DO3 phase transformation.

  19. Ice-Active Substances from the Infective Juveniles of the Freeze Tolerant Entomopathogenic Nematode, Steinernema feltiae.

    Directory of Open Access Journals (Sweden)

    Farman Ali

    Full Text Available Steinernema feltiae is a moderately freezing tolerant nematode, that can withstand intracellular ice formation. We investigated recrystallization inhibition, thermal hysteresis and ice nucleation activities in the infective juveniles of S. feltiae. Both the splat cooling assay and optical recrystallometry indicate the presence of ice active substances that inhibit recrystallization in the nematode extract. The substance is relatively heat stable and largely retains the recrystallization inhibition activity after heating. No thermal hysteresis activity was detected but the extract had a typical hexagonal crystal shape when grown from a single seed crystal and weak ice nucleation activity. An ice active substance is present in a low concentration, which may be involved in the freezing survival of this species by inhibiting ice recrystallization.

  20. Manufacturing of high (10 tesla) twin aperture superconducting dipole magnet for L.H.C

    International Nuclear Information System (INIS)

    The model magnet uses Nb Ti superconducting cables at 1.8 K, has a length of one meter with cross section of full scale superconducting dipoles for the large Hadron Collider (L.H.C.) In this paper the various steps of the manufacturing of the magnet are presented. The coils are wound with insulated superconducting cables and cured under pressure for polymerization. Collaring is achieved with stamped aluminum alloy collars. The magnetic circuit consists of two half yokes of laminated iron. A shrunk-fit cylinder is the external structural element. This cylinder which is made of aluminum alloy, is assembled after heating and then closed with an electron-beam welded flange. Details of the manufacturing process, electrical and mechanical measurements performed during fabrication and testing results are reported

  1. Chemical Characterization of Stabilized and Carbonized Polyacrylonitrile (PAN Fibers Treated with Oleic Acid.

    Directory of Open Access Journals (Sweden)

    Salleh Shahrul Nizam Md

    2014-07-01

    Full Text Available Polyacrylonitrile (PAN fiber is the best precursor for carbon fibers due to high carbon content after heat treatment. After the polymer was spun into fibers, the fibers will undergo pretreatment process with chemical solution known as post spinning treatment. Post spinning will directly affect conversion of PAN fiber to carbon fiber. Oleic acid was used as post spinning treatment chemical solution to PAN fibers. The pretreated PAN fiber will be heated at 250°C and 800°C. The fibers were studied using Fourier Transform Infra-Red (FTIR, X-ray Photoelectron Spectroscopy (XPS and DSC to study the chemical change during heat treatment. PAN fibers treated with oleic acid have reduced the cyclization energy and increase oxygen and carbon content leading to high performance carbon fibers.

  2. Developmentally and stress-induced small heat shock proteins in cork oak somatic embryos.

    Science.gov (United States)

    Puigderrajols, Pere; Jofré, Anna; Mir, Gisela; Pla, Maria; Verdaguer, Dolors; Huguet, Gemma; Molinas, Marisa

    2002-06-01

    The timing and tissue localization of small heat shock proteins (sHSPs) during cork oak somatic embryo development was investigated under normal growing culture conditions and in response to stress. Western blot analyses using polyclonal antibodies raised against cork oak recombinant HSP17 showed a transient accumulation of class I sHSPs during somatic embryo maturation and germination. Moreover, the amount of protein increased at all stages of embryo development in response to exogenous stress. The developmentally accumulated proteins localized to early differentiating, but not the highly dividing, regions of the root and shoot apical meristems. By contrast, these highly dividing regions were strongly immunostained after heat stress. Findings support the hypothesis of a distinct control for developmentally and stress-induced accumulation of class I sHSPs. The possible role of sHSPs is discussed in relation to their tissue specific localization.

  3. Structure and properties of electrodeposited Fe-Ni-W alloys with different levels of tungsten content: A comparative study

    International Nuclear Information System (INIS)

    Fe-Ni-W alloys with 18 wt%, 35 wt% and 55 wt% tungsten have been obtained by electrodeposition from an ammoniacal citrate bath. The deposits are smooth, of nice appearance, and adhere well to iron and steel. The morphology and structure of Fe-Ni-W alloys were studied by SEM and XRD, respectively. The structure of the as-plated deposits changed from crystalline to amorphous with increasing tungsten content. The amorphous structure crystallized under heat treatment condition. The wear and corrosion resistance of the deposits were tested by MPX-2000 wear-tear equipment and neutral salt spray test (NSS), respectively. The alloys with 55 wt% tungsten, after heat treatment at proper temperatures, appear to have good wear resistance and hardness. The alloys with 18 wt% tungsten are very corrosion-resistant

  4. Microstructure and Microhardness of Tempered Ni-A1 Alloyed Layer

    Institute of Scientific and Technical Information of China (English)

    Yue Yang; Hua Wu

    2012-01-01

    A Nd:YAG pulsed laser was used to alloy the Ni-P electroless deposited coating with aluminum substrate under the condition of scanning speed of 3.0 mm/s and power density of 5.36×10^9 W/m^2. Subsequently, the samples were heat treated at 300, 400 and 500 ℃ for 2.5 h, respectively. The phase composition and microstructure of the tempered layers treated at different temperature were identified by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the phase constituents of the alloyed zones were intermetallic compounds of NiAI, AI3Ni, Ni3P and AINi3. As a result, the microhardness of the alloyed layer after heat treatment was improved obviously compared to untreated samoles, and the laver obtained at teml0erature 400 ℃ reached HVn.1 430.

  5. Effect of heat treatment on the microstructure and yield strength of a cold-rolled enameling steel

    Science.gov (United States)

    Peng, D.; Yu, Q.; Lin, C.; An, D.; Dai, T.; Krakauer, B. W.; Zhu, M.

    2015-06-01

    The mechanisms of yield strength reduction of a cold-rolled enameling steel after enamel-fire annealing at 760°C by air cooling, and the effect of the tempering process on the microstructure and yield strength, are studied by combining experiments and thermodynamic calculations. The results show that after heat treatment at 760°C and air cooling, the lump phase, enriched with the element carbon, appears along the ferrite grain boundaries, which leads to yield strength reduction. After tempering at 200°C∼400°C, the lump phase disappears gradually and is transformed to lamellar pearlite as the tempering temperature increases, resulting in the yield strength increasing.

  6. Precision Measurement and Modeling of Quenching-Tempering Distortion in Low-Alloy Steel Components with Internal Threads

    Science.gov (United States)

    Nie, Zhenguo; Wang, Gang; Lin, Yongliang; Rong, Yiming (Kevin)

    2015-12-01

    Distortion resulting from heat treatment may cause serious problems for precision parts. A precision component made from 30CrNi3Mo steel with internal threads distorts slightly after quenching-tempering treatment. Such a small distortion results in serious difficulties in the subsequent assembly process. The distortion of the internal thread was measured using semi-destructive testing with video measuring system. Periodic wavy distortions emerged in the internal threads after heat treatment. Then both XRD analysis and hardness testing were conducted. A numerical simulation of the complete quenching-tempering process was conducted by DANTE, which is a set of user subroutines that link into the ABAQUS/STD solver. The results from the simulations are in good agreement with the measurement in distortion, microstructure field, and hardness. The effects of the technological parameters including quenchant, immersion orientation, and grooves were discussed on the basis of the simulation results. Finally, strategies to significantly decrease distortion and residual stress are proposed.

  7. EFFECTS OF CARBURIZING AND NITRIDING PROCESSES ON THE COST AND QUALITY OF GEARS PRODUCED WITH AISI 4140 AND 8620 STEELS

    Directory of Open Access Journals (Sweden)

    Claudio José Leitão

    2012-09-01

    Full Text Available This study compares the effects of nitriding and carburizing processes applied to gears subjected to contact stresses below 1300 MPa. The manufacturing cost, as well the depth of hardened layer and the distortion produced by two processes are analyzed. AISI 4140 gears quenched, tempered, liquid and gas nitriding and AISI 8620 gears after liquid carburizing, quenching and tempering are analyzed. The dimensional control of the gears was carried out before and after heat and thermochemical treatments. It is concluded that liquid or gas nitriding processes are about 30% more economical than liquid carburizing an also they reduce the dimensional changes. By the other hand liquid carburizing achieves greater case depth. Liquid nitriding process presents the lowest cost, dimensional changes and case depth.

  8. Influence of Heat Treatment on Residual Stress in Cold-Forged Parts

    Directory of Open Access Journals (Sweden)

    Frederico Ozanan Neves

    2014-01-01

    Full Text Available Residual stresses are those stresses that remain in a body when there is no external load applied. Numerous factors can induce residual stresses in the material, including cold forming. Thermal treatments of steel are widely used because they can improve the mechanical properties of the steel, such as toughness, tenacity, and resistance; however, thermal treatments can also produce residual stresses. This study aims to analyze the residual stresses present in a cold-forged part after heat treatments. Half-cylinder samples of AISI 1045 steel were cold-forged, and a wedge tool was pressed into their surface, causing a strain gradient. The samples were then heat-treated by annealing, normalizing, quenching, or quenching and tempering. A numerical simulation was also performed to aid in choosing the measurement points in the samples. The results show that residual stresses are dependent on the heat treatment and on the intensity and nature of previous residual stresses in the body.

  9. Quantitative analysis and morphological characterization of 6063 alloy. Microstructural and mechanical comparison between periphery and center of semi-continuous casting round billets; Analisis cuantitativo y caracterizacion morfologica de la aleacion 6063. Diferencias microestructurales y mecanicas entre la superficie y el nucleo de barras cilindricas de colada semicontinua

    Energy Technology Data Exchange (ETDEWEB)

    Asensio-Lozano, J.; Suarez-Pena, B.

    2012-11-01

    In the present work it has been studied the effect of microstructure on tensile properties of semi-continuously cast round billets manufactured in the industrial 6063 alloy either in the as cast state or after heat treatment. Relevant microstructural features were characterized by quantitative metallographic techniques, both in the periphery and centre of billets, and contrasted against the measured tensile properties at room temperature. Special attention in the study was paid to the way in which chemical non-homogeneities could be minimized. For such purpose the refinement and shape modification of second phase particles formed during solidification, thereafter transformed during the subsequent industrial heat treatment, were assessed. It was observed that the morphology of iron-rich intermetallic compounds developed during solidification was highly influenced by the solidification rate as seen in the billet cross section. It was also verified that the optimal elongation corresponded to the central portion of the billet once industrially homogenized. (Author) 50 refs.

  10. Changes in physical and chemical properties of a dental palladium-silver alloy during metal-porcelain bonding.

    Science.gov (United States)

    Payan, J; Moya, G E; Meyer, J M; Moya, F

    1986-07-01

    The hardening ability of a dental palladium-silver (Pd-Ag-Sn-In) bonding alloy has been investigated, and the distribution of the elements along the metal-ceramic interface have been studied by microprobe analysis. The alloy was found to be highly heterogeneous in its 'as-cast' condition, but homogenized alloy was obtained after heating the alloy at 1000 degrees C for 2 h. Hardening occurred after annealing at 650 degrees C for 1 h. A longer thermal treatment caused the hardness to decrease (over-ageing). The change in hardness could be attributed to an internal oxidation phenomenon. The additional elements tin and indium segregated towards the ceramic-metal interface, with a diffusion of indium only into the porcelain. Diffusion of silver in the ceramics, supposed to be the cause of the 'greening' of dental porcelains baked on silver-rich alloys, has not been detected by the microprobe across the interface. PMID:3531444

  11. Influence of niobium on the hardening phenomenon and wear in the manganese steel (12% Mn destined for the railway

    Directory of Open Access Journals (Sweden)

    Maouche Hichem

    2014-06-01

    Full Text Available This study relates to the manufacture of austenitic manganese steel for the heart switching crossings of railways in all industrial countries where heavy loads are moved by rail. This steel is characterized by a high surface hardness service yard caused by the phenomenon of hardening. According to the microstructure formed after quenching, the transformation of austenite into martensite during working, determine the operating life. The rate of transformation of austenite into martensite can force a compromise between ductility and wear resistance of the steel in order to withstand large forces without breaking. The objective of this study is to improve the resistance to abrasion and friction to cast state and after heat treatment by the addition of niobium. This study permitted to develop a new shade of manganese steel can be integrated into the production of heart of railway switches with better lifecycle.

  12. Improvement of carbon corrosion resistance through heat-treatment in polymer electrolyte membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Y.J.; Oh, H.S.; Kim, H. [Yonsei Univ., Seoul (Korea, Republic of). Dept. of Chemical and Biomolecular Engineering

    2010-07-01

    Electrochemical corrosion of carbon in the catalyst layer of polymer electrolyte membrane fuel cells (PEMFCs) is a critical factor in limiting their durability. The corrosion rate increases during the iterative abnormal operating conditions known as reverse current phenomenon. The corrosion causes a decrease of the active surface of the platinum (Pt) catalyst. The graphitization of carbon increases corrosion resistance, and the hydrophobicity of the carbon surface can also play an important role in decreasing carbon corrosion. This study investigated the effect of heat-treating carbon nanofibers (CNFs) for use in PEMFC applications. The aim of the study was to determine if heat treatments modified the carbon surface by eliminating the oxygen functional group and increasing hydrophobicity. The electrochemical carbon corrosion of CNFs were compared after heat treatments at various temperatures. Mass spectrometry was used to measure electrochemical carbon corrosion by monitoring the amounts of carbon dioxide (CO{sub 2}) produced during the electrochemical oxidation process. 2 refs.

  13. Synthesis Of NiCrAlC alloys by mechanical alloying; Sintese de ligas NiCrAlC por moagem de alta energia

    Energy Technology Data Exchange (ETDEWEB)

    Silva, A.K.; Pereira, J.I.; Vurobi Junior, S.; Cintho, O.M., E-mail: alissonkws@gmail.co [Universidade Estadual de Ponta Grossa (UEPG), PR (Brazil)

    2010-07-01

    The purpose of the present paper is the synthesis of nickel alloys (NiCrAlC), which has been proposed like a economic alternative to the Stellite family Co alloys using mechanical alloying, followed by sintering heat treatment of milled material. The NiCrAlC alloys consist of a chromium carbides dispersion in a Ni{sub 3}Al intermetallic matrix, that is easily synthesized by mechanical alloying. The use of mechanical alloying enables higher carbides sizes and distribution control in the matrix during sintering. We are also investigated the compaction of the processed materials by compressibility curves. The milling products were characterized by X-ray diffraction, and the end product was featured by conventional metallography and scanning electronic microscopy (SEM), that enabled the identification of desired phases, beyond microhardness test, which has been shown comparable to alloys manufactured by fusion after heat treating. (author)

  14. Investigation of carbonized layer on surface of NaAlSi glass fibers

    International Nuclear Information System (INIS)

    There are presented and discussed experimental results about carbonate shell on the sodium rich alumosilicate (NaAlSi) glass fibers and carbonization in wet air atmosphere and water uptake kinetic of such fiber fabrics. The analyzes of water uptake kinetic by regression technique, leaching and heating of carbonized glass fabrics helped to separate stages of fast and slow processes between fiber and carbonate shell and air atmosphere. The shell contains mixture of trona and hydrated sodium carbonate. Heating converts both substances to sodium carbonate. The weight uptake after heating encounters two fast exponential processes associated with water absorption on the surface of carbonated shell and its diffusion into volume. The slow process associates with CO2 and H2O absorption from air, hydration and sodium carbonate conversion to trona

  15. Bunias orientalis L. as a natural overwintering host OF Turnip mosaic virus

    Directory of Open Access Journals (Sweden)

    Tadeusz Kobyłko

    2012-12-01

    Full Text Available A virus was isolated, using mechanical inoculation, from hill mustard (Bunias orientalis L. plants exhibiting yellow mottling and blistering on leaves, which were frequently accompanied by asymmetric leaf narrowing. It systemically infected certain plants from the family Brassicaceae (Brassica rapa, Bunias orientalis, Hesperis matronalis, Sinapis alba as well as Cleome spinosa and Nicotiana clevelandii, and locally Atriplex hortensis, Chenopodium quinoa, Ch. amaranticolor, N. tabacum. In the sap, it maintained infectivity for 3-4 days and lost it after heating for 10 min. at a temperature of 55 - 60oC or when diluted with water at 10-3. Virus particles were thread- like with a length of 675 - 710 nm. Based on an analysis of biological properties of the pathogen, serological response, particle morphology and data from field observations, it was identified as an isolate of Turnip mosaic virus (TuMV, and hill mustard was recognised as a natural overwintering host for this pathogen.

  16. The Study on Weldability of Boron Steel and Hot-Stamped Steel by Using Laser Heat Source (Ⅲ) - Comparison on Laser Weldability of Boron Steel and Hot -Stamped Steel-

    Energy Technology Data Exchange (ETDEWEB)

    Choi, So Young; Kim, Jong Do [Korea Maritime and Ocean University, Busan (Korea, Republic of); Kim, Jong Su [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

    2015-01-15

    This study was conducted to compare the laser weldability of boron steel and hot-stamped steel. In general, boron steel is used in the hot-stamping process. Hot-stamping is a method for simultaneously forming and cooling boron steel in a press die after heating it to the austenitizing temperature. Hot-stamped steel has a strength of 1500 MPa or more. Thus, in this study, the laser weldability of boron steel and that of hot-stamped steel were investigated and compared. A continuous wave disk laser was used to produce butt and lap joints. In the butt welding, the critical cooling speed at which full penetration was obtained in the hot-stamped steel was lower than that of boron steel. In the lap welding, the joint widths were similar regardless of the welding speed when full penetration was obtained.

  17. Thermoresponsive Magnetic Nano-Biosensors for Rapid Measurements of Inorganic Arsenic and Cadmium

    Directory of Open Access Journals (Sweden)

    Isamu Maeda

    2012-10-01

    Full Text Available Green fluorescent protein-tagged sensor proteins, ArsR-GFP and CadC-GFP, have been produced as biosensors for simple and low-cost quantification of As(III or Cd(II. In this study, the sensor protein-promoter DNA complexes were reconstructed on the surfaces of magnetic particles of different sizes. After the surface modification all the particles could be attracted by magnets, and released different amounts of GFP-tagged protein, according to the metal concentrations within 5 min, which caused significant increases in fluorescence. A detection limit of 1 µg/L for As(III and Cd(II in purified water was obtained only with the nanoparticles exhibiting enough magnetization after heat treatment for 1 min. Therefore, thermoresponsive magnetic nano-biosensors offer great advantages of rapidity and sensitivity for the measurement of the toxic metals in drinking water.

  18. Detection of N-acetylglycine, N-acetylglycylglycine, and N-acetylglycylglycylglycine by paper chromatography

    International Nuclear Information System (INIS)

    This paper reports that the developing solvent of Kirchenmayer and Kuffner, n-butanol-acetic acid-water (8:1:10, v/v) can be used to separate and detect N-acetylglycine, N-acetylglycylglycine, and N-acetylglycylglycylglycine. The chromatographic procedure is described. After heating at 1000C, the spots could be seen under uv light; acetone-bromocresol green-morpholine can also be used to make the spots show up. The R/sub f/ values are 0.59, 0.43, and 0.33, respectively. This procedure was used to detect these compounds in aqueous solutions of diglycine, triglycine, and tetraglycine, which were used as gamma-radiolysis targets

  19. Effects of Annealing Temperature on Co30Cu70 Mechanical Alloys

    Directory of Open Access Journals (Sweden)

    Watcharee RATTANASAKULTH

    2006-06-01

    Full Text Available Physical properties of Co30Cu70 mechanical alloys prepared by ball milling were investigated. After milling for 50 h, the powder contained Co-rich, Cu-rich clusters as well as Co-Cu solid solution. Annealing at 200 - 300 °C for 30 min modified thermal behaviors but only slightly affected magnetic properties. Higher temperature annealing (400 - 500 °C led to substantial oxidation of Co and Cu and deteriorated magnetic properties. Pressed Co30Cu70 pellets exhibited 0.6 - 2 % giant magnetoresistance (GMR but showed modest GMR after heat treatment. GMR disappeared by annealing at 500 °C as large fractions of Co and Cu were converted into oxides.

  20. WOOD-WATER RELATIONSHIPS AND BIOLOGICAL DURABILITY OF HEAT-TREATED TAURUS FIR WOOD

    Directory of Open Access Journals (Sweden)

    Bekir Cihad BAL

    2015-09-01

    Full Text Available In this study, Taurus Fir (Abies cilicica wood was treated with hot air at temperatures of 160, 190 and 220°C for 2h durations. After heat treatment, some physical properties and wood-water relationships were evaluated, such as mass loss, density, tangential swelling, radial swelling, volumetric swelling, swelling anisotropy, and fiber saturation point. In addition, the biological durability of Taurus Fir wood was tested in the laboratory with the soil contact test, and determined weight loss. The relationships between mass loss and some of the tested properties were determined using regression analysis. The results showed that heat treatment at 220°C had significant effects on the physical properties and the biological durability of Taurus Fir wood. Further, it was determined that there was a linear-negative correlation between weight loss and mass loss.

  1. Effects of heat treatment on the physical properties of heartwood and sapwood of Cedrus libani

    Directory of Open Access Journals (Sweden)

    Bekir Cihad Bal

    2013-02-01

    Full Text Available Effects of heat treatment on the physical properties of heartwood and sapwood of Cedrus libani A. Richard, such as density, equilibrium moisture content, swelling, and fiber saturation point were investigated. Heartwood and sapwood samples were treated at 140, 160, 180, 200, and 220°C for 3 h. After heat treatment, the physical properties of the samples of wood were determined according to Turkish standards. The results showed that mass loss increased and physical properties decreased as the treatment temperature increased. As the treatment temperature was increased, the mass of the heartwood decreased more than that of the sapwood, which may be due to the fact that the heartwood had greater extractives content. Conversely, even though the mass of the heartwood decreased more than the mass of the sapwood at the treatment temperature of 220°C, its physical properties, such as equilibrium moisture content, swelling, and fiber saturation point, decreased less than those of the sapwood.

  2. Effect of the heat treatment on physical and chemical properties of Pinus caribaea wood

    Directory of Open Access Journals (Sweden)

    Dallyene da Silva Poubel

    2013-09-01

    Full Text Available This study evaluated the effect of the heat treatment on physical properties (density, equilibrium moisture content, mass loss, volumetric and linear swelling and shrinkage and chemical composition of normal (opposite side and compression wood of Pinus caribaea Morelet. Samples of 25 x 25 x 50 mm were heat-treated under two different temperatures: 200 and 220 ºC. The results indicated a reduction in equilibrium moisture content and swelling and shrinkage following heat treatment, independent of wood type. The compression wood showed higher longitudinal swelling than normal one, however, after heat treatment, the improvements were similar between both wood types. Samples heat-treated at 200 and 220 ºC had mass losses of 9.94 and 21.03 %, respectively. The heat treatment promoted a relative increase in lignin content and a decrease in holocellulose and α-cellulose contents, indicating the occurrence of thermal degradation of these components.

  3. Modification of the original color of the Eucalyptus grandis wood by heat treatments

    Directory of Open Access Journals (Sweden)

    Rosilei Aparecida Garcia

    2014-09-01

    Full Text Available The objective of this study was to determine the modification of original color of Eucalyptus grandis Hill ex. Maiden wood after heat-treatment. Wood samples were heat-treated under different temperatures (180, 200, 215 and 230ºC and time conditions (15 minutes, 2 and 4 hours. Color analysis were performed on the CIE L*a*b* system by using a Color Eye XTH-X-Rite 200d spectrophotometer. All heat treatments promoted an alteration of the original color of wood. Heat-treated woods presented lower L* (lightness values than untreated wood (control, characterizing the wood darkness, mainly for more severe conditions of temperature and time. Chromatic coordinates (a* and b* showed different behaviors depending on the temperature-time combination. The modification of the original color of the wood allowed the creation of new color patterns, which can add greater value to the studied wood.

  4. EFFECT OF HEAT TREATMENT ON THE CHANGE IN COLOR

    Directory of Open Access Journals (Sweden)

    Vu Manh Tuong

    2010-04-01

    Full Text Available Acacia hybrid (Acacia mangium x auriculiformis, a wood species of low dimensional stability which is used almost exclusively for pulp, paper, or as firewood, was heat treated in nitrogen at 210-230 ºC for 2 to 6 hours. The changes in color and anti-swelling efficiency (ASE of wood after heat treatment were determined for the different heat treatment conditions. The results show that heat treatment mainly resulted in the darkening of wood tissues, and heat-treated wood had better dimensional stability than those of the control samples. Chemical modifications of wood components were determined by FT-IR analysis. Spectra indicated that the hydroxyl group content was reduced by increased treatment intensity. This result coincides with the increase in dimensional stability of heat-treated wood. Heat treatment of acacia hybrid wood shows an interesting potential to improve the quality and value for solid wood products from plantation-grown wood species.

  5. Ice-Active Substances from the Infective Juveniles of the Freeze Tolerant Entomopathogenic Nematode, Steinernema feltiae.

    Science.gov (United States)

    Ali, Farman; Wharton, David A

    2016-01-01

    Steinernema feltiae is a moderately freezing tolerant nematode, that can withstand intracellular ice formation. We investigated recrystallization inhibition, thermal hysteresis and ice nucleation activities in the infective juveniles of S. feltiae. Both the splat cooling assay and optical recrystallometry indicate the presence of ice active substances that inhibit recrystallization in the nematode extract. The substance is relatively heat stable and largely retains the recrystallization inhibition activity after heating. No thermal hysteresis activity was detected but the extract had a typical hexagonal crystal shape when grown from a single seed crystal and weak ice nucleation activity. An ice active substance is present in a low concentration, which may be involved in the freezing survival of this species by inhibiting ice recrystallization. PMID:27227961

  6. Microstructural evolution of castable during firing; Evolucao microestrural de concretos refratarios durante a queima

    Energy Technology Data Exchange (ETDEWEB)

    Santos, E.M.B.; Ribeiro, S., E-mail: esoly@ppgem.eel.usp.br [Universidade de Sao Paulo (DEMAR/EEL/USP), Lorena, SP (Brazil). Escola de Engenharia. Departamento de Engenharia de Materiais; Almeida, B.A.; Lopes, A.B. [Universidade de Aveiro (Portugal). Departamento de Ceramica e do Vidro (DECV)

    2011-07-01

    Castable are materials used for high temperature industrial applications, containing one or more binding agents, aggregates and additives. Calcium aluminate cement (CAC) is one of the most used binding agents, mainly due to his abundance, low cost, refractoriness and high mechanical and chemical resistance. During high temperature processes, these materials exhibit microstructural evolution that changes their properties and affect the performance. The purpose of this work was to study the microstructural changes presented by a castable, containing CAC and alumina aggregates, during heat treatment. For that, was used X-ray diffraction, thermal analyses, electron microscopy and energy dispersive spectroscopy to characterize concretes after heat treatment up to 1000 deg C. The results allowed to understand the microstructural changes at high temperature and its influence in mechanical properties of the castable. (author)

  7. Heating effects on physicochemical characteristics and antioxidant activity of flaxseed hull oil (Linum usitatissimum L

    Directory of Open Access Journals (Sweden)

    Wahid HERCHI

    2016-01-01

    Full Text Available The aim of this study was to analyze the effects of heating on some quality characteristics and antioxidant activity of flaxseed hull oil. Polyunsaturated fatty acids (PUFA and Cox value decreased during heating. Heating process led to considerable increase in saponification value (SV, peroxide value (PV, p-anisidine value (p-AnV, oxidative value (OV and specific extinction at 232 and 270 nm. There was a significant decrease in oil stability during heating process (1.4-1.0 h. Fuel properties of flaxseed hull oil were also changed after heating treatment. Heating process caused loss of total phenolic acids, total flavanoids, carotenoids and chlorophyll pigments. Phospholipids (PL content were less changed compared to other bioactive compounds. Antioxidant activity of flaxseed hull oil decreased during heating process.

  8. Age and heat exposure-dependent changes in antioxidant enzymes activities in rat's liver and brain mitochondria: role of alpha-tocopherol.

    Science.gov (United States)

    Stojkovski, V; Hadzi-Petrushev, N; Ilieski, V; Sopi, R; Gjorgoski, I; Mitrov, D; Jankulovski, N; Mladenov, M

    2013-01-01

    To investigate the role of mitochondrial antioxidant capacity during increased susceptibility to heat accompanied by the aging, young and aged Wistar rats were exposed on heat for 60 min. After heat exposure, hepatic and brain mitochondria were isolated. Our results revealed changes in antioxidant enzyme activities in liver and brain mitochondria from young and to a greater extent in aged rats. Our measurements of MnSOD, GPx and GR activity indicate greater reactive oxygen species production from the mitochondria of aged heat exposed in comparison to young heat exposed rats. Also in the aged rats, the effect of alpha-tocopherol treatment in the prevention of oxidative stress occurred as a result of heat exposure, is less pronounced. Taken together, our data suggest that mitochondria in aged rats are more vulnerable and less able to prevent oxidative changes that occur in response to acute heat exposure.

  9. Influence of deformation and annealing on texture and anisotropy of the properties in VT23 alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zakharchenko, I.G.; Ivasishin, O.M.; Ivanij, V.S.; Kshnyakin, V.S. (AN Ukrainskoj SSR, Kiev. Inst. Metallofiziki; Sumskij Gosudarstvennyj Pedagogicheskij Inst. (Ukrainian SSR))

    The effect of cold rolling and following heat treatment on development of texture and anisotropy of physical properties in sheets of VT23 titanium alloy is investigated. It is shown that decrease of elastic anisotropy of hot-rolled sheets of VT23 alloy can be assured by cold rolling. Annealings at temperatures up to 500 deg C do not bring about essential changes in anisotropy. But orientated ..cap alpha.. reversible ..beta.. - transformations at annealing up to 750-800 deg C promoting development of prismatic and pyramidal components of texture result in increase of anisotropy of elastic properties. Essential decrease of anisotropy value of Young modulus takes place after heating in the ..beta..-region.

  10. Effect of heating rate on structure of VT23 and VT6 quenched alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ivasishin, O.M.; Oshkaderov, S.P. (AN Ukrainskoj SSR, Kiev. Inst. Metallofiziki)

    1982-01-01

    The grain and intergrain structures of two-phase VT23 and VT6 titanium alloys with an initial fine-grain structure quenched after heating with different rates in (..cap alpha..+..beta..) and ..beta..-regions were studied. The heating rate increase from 0.2 up to 200 deg/s is shown to result in the monotonic growth of a polymorphic transformation temperature, the decrease of grain size at a constant quenching temperature, the appearance of a grain size change jump, and the martensite grain refinement during heating up to ..beta..-region temperatures. The high-rate heating of VT23 and VT6 quenched alloys permits to build up dispersion intergranular structure and to control their properties.

  11. Preparation and properties of yttrium iron garnet microcrystal in $P_{2}O_{5}-MgO$ glass

    CERN Document Server

    Chen, G J; Chang, Y S; Lee, H M; Lin, Y J; 10.1016/j.jallcom.2004.07.041

    2005-01-01

    The fabrication of phosphorus-based glasses containing Y/sub 3/Fe/sub 5/O/sub 12/ crystals by the incorporation method was studied. From transmission electron microscopy observation, there is only one rod- like crystalline phase identified as Y/sub 3/Fe/sub 5/O/sub 12/ existing in the glass matrix. When the content of YIG is 30wt.%, the as-cast sample shows a Faraday rotation of 85 degrees /cm and a magnetization of 0.4emu/g in a field of 14kOe. After heat treatment, the magnetic and optical properties of the glass ceramic changed owing to the thermal diffusion of iron ions into the glass matrix.

  12. Shape memory alloys: New materials for future engineering

    Science.gov (United States)

    Hornbogen, E.

    1988-01-01

    Shape memory is a new material property. An alloy which experiences relative severe plastic deformation resumes its original shape again after heating by 10 to 100 C. Besides simple shape memory, in similar alloys there is the second effect where the change in shape is caused exclusively by little temperature change. In pseudo-elasticity, the alloy exhibits a rubber-like behavior, i.e., large, reversible deformation at little change in tension. Beta Cu and beta NiTi alloys have been used in practice. The probability is that soon alloys based on Fe will become available. Recently increasing applications for this alloy were found in various areas of technology, even medical technology. A review with 24 references is given, including properties, production, applications and fundamental principles of the shape memory effect.

  13. Effects of pulse current on properties of electrodeposited RE-Ni-W-P-SiC composite coating

    Institute of Scientific and Technical Information of China (English)

    GUO Zhong-cheng; ZHU Xiao-yun; XU Rui-dong

    2004-01-01

    Effects of pulse current on properties of electrodeposited RE-Ni-W-P-SiC composite coating were studied. The results show that hardness of the pulse current electrodeposited composite coatings is higher than that of the direct current electrodeposited composite coatings while other parameters are the same. Otherwise, the deposited velocity is higher, and wear resistance and corrosion resistance of the pulse current electrodeposited composite coatings are also improved when the average current density is 10 A/dm2 , pulse frequency is 800 Hz and duty ratio is 1: 5. The hardness of the coating as-deposited is HV500 - 700, and it reaches HV1300 after heat treatment at 400 ℃ for 1 h.

  14. Polysialates binders preparation and their influence to shear strength of foundry sand mixtures

    Directory of Open Access Journals (Sweden)

    R. Fridrich

    2008-07-01

    Full Text Available This paper deals with polysialates water-glasses preparation. There were used various procedures with the goal to create inorganic polymer on silicon and aluminum base. The one composed of SiO2 and AlO4 tetrahedron chains. For the preparation was concentrated NaOH solution used together with metakaolinite in a way low-temperature synthesis in the presence of alkaline silicate: higher pressure and temperature (autoclave to direct making of alkaline silicate made of sand, NaOH with metakaolinite addition and by melting fritted glass together with metakaolinite and dissolution in autoclave. The dissolving effectivity was evaluated by the concentration of aluminum in alkaline silicate and by the influence to reduce strengths after heat exposition with this inorganic binder.

  15. Determination of cholesterol and four phytosterols in foods without derivatization by gas chromatography-tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Yan-Zong Chen

    2015-12-01

    Full Text Available In this study, a method for determination of cholesterol and four phytosterols by gas chromatography coupled with electron impact ionization mode–tandem mass spectrometry without derivatization in general food was developed. The sample was saponified with 7.5% KOH in methanol. After heating on hot plate and reflux for 60 minutes, the saponified portion was extracted with n-hexane/petroleum ether (50:50, v/v. The extracts were evaporated with rotary evaporator and then redissolved with tetrahydrofuran. The tetrahydrofuran layer was transferred into an injection vial and analyzed by gas chromatography on a 30 m VF-5 column. Limit of quantification was 2 mg/kg. Recoveries of cholesterol and four phytosterols from general food were between 91% and 100%.

  16. Synthesis and characterization of nanocrystalline graphite from coconut shell with heating process

    International Nuclear Information System (INIS)

    Graphite were synthesized and characterized by heating process of coconut shell with varying temperature (400, 800 and 1000°C) and holding time (3 and 5 hours). After heating process, the samples were characterized by X-ray diffraction (XRD) and analyzed by X'pert HighScore Plus Software, Scanning Electron Microcope-Energy Dispersive X-Ray (SEM-EDX) and Transmission Electron Microscope-Energy Dispersive X-Ray (TEM-EDX). Graphite and londsdaelite phase were analyzed by XRD. According to EDX analysis, the sample was heated in 1000°C got the highest content of carbon. The amorphous carbon and nanocrystalline graphite were observed by SEM-EDX and TEM-EDX

  17. Remarkable improvement in microwave absorption by cloaking a micro-scaled tetrapod hollow with helical carbon nanofibers.

    Science.gov (United States)

    Jian, Xian; Chen, Xiangnan; Zhou, Zuowan; Li, Gang; Jiang, Man; Xu, Xiaoling; Lu, Jun; Li, Qiming; Wang, Yong; Gou, Jihua; Hui, David

    2015-02-01

    Helical nanofibers are prepared through in situ growth on the surface of a tetrapod-shaped ZnO whisker (T-ZnO), by employing a precursor decomposition method then adding substrate. After heat treatment at 900 °C under argon, this new composite material, named helical nanofiber-T-ZnO, undergoes a significant change in morphology and structure. The T-ZnO transforms from a solid tetrapod ZnO to a micro-scaled tetrapod hollow carbon film by reduction of the organic fiber at 900 °C. Besides, helical carbon nanofibers, generated from the carbonization of helical nanofibers, maintain the helical morphology. Interestingly, HCNFs with the T-hollow exhibit remarkable improvement in electromagnetic wave loss compared with the pure helical nanofibers. The enhanced loss ability may arise from the efficient dielectric friction, interface effect in the complex nanostructures and the micro-scaled tetrapod-hollow structure.

  18. A Study on the Microstructures and Toughness of Fe-B Cast Alloy Containing Rare Earth

    Science.gov (United States)

    Yi, Dawei; Zhang, Zhiyun; Fu, Hanguang; Yang, Chengyan; Ma, Shengqiang; Li, Yefei

    2015-02-01

    This study investigates the effect of cerium on the microstructures, mechanical properties of medium carbon Fe-B cast alloy. The as-cast microstructure of Fe-B cast alloy consists of the eutectic boride, pearlite, and ferrite. Compared with the coarse eutectic borides in the unmodified alloy, the eutectic boride structures in the modified alloy are greatly refined. Cerium promotes the formation of Ce2O3 phase. Ce2O3 can act as effective heterogeneous nuclei of primary austenite, and refine austenite and boride. After heat treatment, the impact toughness of the modified alloy is higher than that of the unmodified alloy because there are more broken borides in the modified alloy. Meanwhile, the fracture mechanism of medium carbon Fe-B alloy is depicted and analyzed by using fractography.

  19. Properties of yttria-tetragonal zirconia polycrystal (Y-TZP) materials after long-term exposure to elevated temperatures. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Swab, J.J. [Army Materials Research Agency, Watertown, MA (United States). Materials Technology Lab.

    1989-03-01

    Seven commercially available yttria-tetragonal zirconia polycrystal (Y-TZP) materials were evaluated. Room temperature properties were measured before and after heat treatments at 1000C. Microstructure and phase stability were also examined. In all but one case, the Y-TZPs showed very little change in room temperature properties after long times at this temperature. Results show that pressure-assisted processing greatly improves the strength by reducing porosity and keeping the grain size extremely fine, but this reduces the toughness because finer grains are more difficult to transform. In addition, a small amount of cubic zirconia appears to enhance the toughness of fine-grained Y-TZP while maintaining good strength. During processing, a small amount of cubic zirconia is formed and allowed to grow. This creates regions poor in yttria which can transform spontaneously in the presence of a crack-tip stress field.

  20. The Crack Self-healing Properties of Cement-based Material with EVA Heat-melt Adhesive

    Institute of Scientific and Technical Information of China (English)

    YUAN Xiongzhou; SUN Wei; ZUO Xiaobao; LI Hua

    2011-01-01

    An experimental program was carried out to investigate whether EVA(ethylene vinyl acetate copolymer)heat-melt adhesive can potentially act as a self-healing agent in cement-based material.The effects of incorporation of EVA and heating on the properties of mortar were studied.Self-healing capacity of EVA specimens was also verified.The experimental results show that the addition of EVA would not greatly affect original characteristics of the matrix when EVA content was less than 5%;the interface between EVA and cement matrix was well improved after heating,which allows a significant improvement in flexural strength and toughness of specimen;pre-damaged specimens in various degrees(30%,50% and 70%)were effectively repaired by EVA and the repair efficiency all exceeded 100%.

  1. Surface chemical composition analysis of heat-treated bamboo

    Science.gov (United States)

    Meng, Fan-dan; Yu, Yang-lun; Zhang, Ya-mei; Yu, Wen-ji; Gao, Jian-min

    2016-05-01

    In this study, the effect of heat treatment on the chemical composition of bamboo slivers was studied. The chemical properties of the samples were examined by chemical analysis. Results showed a decrease in the contents of holocellulose and α-cellulose, as well as an increase in the contents of lignin and extractives. Changes in the chemical structure of bamboo components were analyzed by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). FTIR spectroscopy results indicated that hemicellulose contents decrease, whereas lignin contents increase after heat treatment. Ester formation linked to lignin decreased the hygroscopicity of the bamboo samples and consequently improved their dimensional stability and durability. XPS spectroscopy results showed that hemicelluloses and celluloses are relatively more sensitive to the heating process than lignin. As a consequence, hemicellulose and cellulose contents decreased, whereas lignin contents increased during heat treatment. The results obtained in this study provide useful information for the future utilization of heat-treated bamboo.

  2. Effect of heat treatment on the mechanical properties of fluorine-free slag glasses

    Energy Technology Data Exchange (ETDEWEB)

    Minakova, A.A.; Kamarinda, L.P.; Parfenov, V.Z.; Tyutyunikov, N.P.

    1986-05-01

    The authors studied flourine-free sitall glasses of two compositions: with ZnO, and with ZnO and MnO. On the basis of the generalization of previously obtained results the authors selected the following heat-treatment temperatures: 850, 900, 925, 950, and 1000/sup 0/ C. For composition 1 the maximum ultimate strength values are reached at 850 and 1000/sup 0/ C and with heat treatment time of 2 h; the resiliance after heat treatment at 950-1000/sup 0/ C for 1-3 h. For composition 2 the high levels of strength and resilience are obtained at lower temperatures (900-1000/sup 0/ C) and with a shorter heat-treatment time (0.5-2 h). When the experimental composition were heat treated for more than 2 h, there was a significant lowering of strength and resilience.

  3. Effect of Addition of Al and Mg on properties of Periclase-Spinel-Carbon Brick

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Periclase-spinel-carbon brick was made from sintered spinel,fused magnesia and flake graphite as principal raw materials,the influence of Mg/Al(w/w) ratio and the addition of Al,Mg in the matrix of periclas-spinel-carbon brikc on the carbonization and thermal expansion coeffi-cient and the weight los of the brick after heating at 1500℃ in a flowing stream of dry N2for 1.5 h have been studied.The results show that to control Mg/Al(w/w) ration and to add both Al and Mg appropriately can obvi-ously improve the properties of the bricks.

  4. The plastid metalloprotease FtsH6 and small heat shock protein HSP21 jointly regulate thermomemory in Arabidopsis

    Science.gov (United States)

    Sedaghatmehr, Mastoureh; Mueller-Roeber, Bernd; Balazadeh, Salma

    2016-01-01

    Acquired tolerance to heat stress is an increased resistance to elevated temperature following a prior exposure to heat. The maintenance of acquired thermotolerance in the absence of intervening stress is called ‘thermomemory' but the mechanistic basis for this memory is not well defined. Here we show that Arabidopsis HSP21, a plastidial small heat shock protein that rapidly accumulates after heat stress and remains abundant during the thermomemory phase, is a crucial component of thermomemory. Sustained memory requires that HSP21 levels remain high. Through pharmacological interrogation and transcriptome profiling, we show that the plastid-localized metalloprotease FtsH6 regulates HSP21 abundance. Lack of a functional FtsH6 protein promotes HSP21 accumulation during the later stages of thermomemory and increases thermomemory capacity. Our results thus reveal the presence of a plastidial FtsH6–HSP21 control module for thermomemory in plants. PMID:27561243

  5. Comparison of code calculations with experiments on containment response during LOCA conditions

    International Nuclear Information System (INIS)

    A series of experiments were performed on a one-tenth scale model of PHWR containment, incorporating pressure suppression system. The pressure-temperature transients in the model containment observed during simulated LOCA (Loss of Coolant) blowdown conditions were compared against calculated results form computer code PACSR, for purposes of verification of the code. Comparison of results indicated that calculated values of peak pressure in various compartment were significantly higher than observed ones. This disagreement was attributed mainly to modelling for energy absorption from containment atmosphere to structural surfaces, this effect being particularly important in a scaled down model. Good agreement between calculation and experiment was obtained after heat transfer correlation for energy absorption on surfaces were modified in the code. The study demonstrates the conservatism of the results from the code. (author). 6 refs., 1 tab., 9 figs

  6. Combining Hydraulic and Phosphate Bonds to Improve Properties of Alumina-spinel Low Cement Castables

    Institute of Scientific and Technical Information of China (English)

    M.Paghandeh; A.Monshi; R.Emadi

    2009-01-01

    A basic alumina-spinel low cement castables (castables A) and another castables (castables B) with 5% addition of sodium hexametaphosphate were prepared and heat treated at 110 ℃,900 ℃ and 1 400 ℃.It is shown that after heat treating at 110 ℃,cold crushing strength (CCS) of castables B is more than 3 times of castables A and apparent porosity (AP) is less than half of castables A.The presence of 800-1 000 ℃ that hydraulic bond reverses to dehydrate condition and castables A becomes weak with high porosity,castables B shows a CCS more than 4 times of castables A.Needles of magnesium phosphate are responsible for reinforcing microstructure of castables B at 900 ℃.After firing at 1 400 ℃,castables B shows extra ordinary CCS of mare than 100 MPa.Reasons were discussed with X-ray diffraction and scanning electron microscopy.

  7. Influence of Size Effects on the Properties of Processed Iron Ore and Schungite Rock

    Directory of Open Access Journals (Sweden)

    Yu. Mirgorod

    2016-06-01

    Full Text Available Scanning electron microscopy, energy dispersion spectroscopy, X-ray diffractometry and magnetometry methods were used to investigate the structure and magnetic properties of iron ore and schungite rock. The results show the existence of external size effect in iron ore concentrate. It is related with the penetration of iron nanoparticles from equipment surfaces onto the powder surface, which increases specific magnetic saturation of the powder by 1.6 times compared with pure magnetite. As a result of internal size effect in schungite powder its reactivity decreases by 800 °С and after heat treatment of the powder its specific magnetic saturation increases by seven times. Considering the application of size effects the investigated powders and waste natural mineral powders are recommended to be used in the production of composite materials.

  8. Thermochemical behaviour of Ru(II) complex–SiO2 microcomposites

    Indian Academy of Sciences (India)

    S Anastasova; M Milanova; I Manolov; T Czeppe; D Todorovsky

    2007-10-01

    The results from DSC and thermogravimetric analysis of gels produced from a mixture of tetraethoxysilane (TEOS) and octyltriethoxysilane (OtEOS) both with and without immobilized Ru(II) tris(4,7-diphenyl-1,10-phenanthroline) dichloride as well as DSC and TG data for films deposited by deep- or spincoating from the same gels, are reported. The initial products are characterized by elemental analysis, IR, solid state NMR and mass spectroscopy. Elemental analysis and IR spectroscopy are applied for identification of some of the intermediates obtained after heating at different temperatures. The final products are characterized by X-ray diffractometry. A hypothesis for the thermodecomposition processes taking place is proposed. The results reported contribute to elucidation of the properties as well as the temperature intervals in which the studied microcomposites could be used as sensing components of oxygen sensors.

  9. Nanocrystalline Hydroxyapatite/Si Coating by Mechanical Alloying Technique

    Science.gov (United States)

    Hannora, Ahmed E.; Mukasyan, Alexander S.; Mansurov, Zulkhair A.

    2012-01-01

    A novel approach for depositing hydroxyapatite (HA) films on titanium substrates by using mechanical alloying (MA) technique has been developed. However, it was shown that one-hour heat treatment at 800°C of such mechanically coated HA layer leads to partial transformation of desired HA phase to beta-tri-calcium phosphate (β-TCP) phase. It appears that the grain boundary and interface defects formed during MA promote this transformation. It was discovered that doping HA by silicon results in hindering this phase transformation process. The Si-doped HA does not show phase transition to β-TCP or decomposition after heat treatment even at 900°C. PMID:22312324

  10. Point contact resistive switching memory based on self-formed interface of Al/ITO

    Science.gov (United States)

    Li, Qiuhong; Qiu, Linjun; Wei, Xianhua; Dai, Bo; Zeng, Huizhong

    2016-07-01

    Point contact resistive switching random access memory (RRAM) has been achieved by directly sputtering Al electrodes on indium tin oxide (ITO) conductive glasses. The room-temperature deposited Al/ITO shows an asymmetrical bipolar resistive switching (BRS) behavior after a process of initialization which induces a stable high resistive state (HRS). It might be caused by the in-situ formation of an ultra-thin layer (≈4 nm) at the interface. By comparison, the Al/ITO device after vacuum annealed exhibits typical symmetrical BRS without an initiation or electroforming process. This can be ascribed to the ex-situ thickening of the interfacial layer (≈9.2 nm) to achieve the stable HRS after heat treatment. This work suggests that the self-formed interface of active Al electrode/ITO would provide the simplest geometry to construct RRAM.

  11. Microstructural stability of ultrafine grained cold sprayed 6061 aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Rokni, M.R., E-mail: mohammadreza.rokni@mines.sdsmt.edu [Department of Materials and Metallurgical Engineering, Advanced Materials Processing Center, South Dakota School of Mines and Technology (SDSM and T), SD (United States); Widener, C.A. [Department of Materials and Metallurgical Engineering, Advanced Materials Processing Center, South Dakota School of Mines and Technology (SDSM and T), SD (United States); Champagne, V.R. [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, Aberdeen Proving Ground, MD (United States)

    2014-01-30

    The microstructural stability of ultrafine grained (UFG) cold spray 6061 aluminum deposits produced by high pressure cold spray were investigated by in situ heating to a fully annealed state via a hot-stage transmission electron microscope (TEM). It was possible to observe the precise locations and temperatures of different microstructural changes, like dislocation movement and other restoration processes. Even after heating up to the annealing temperature for this alloy, the deposited layer in the perpendicular direction was found to preserve the UFG structures, which were the result of different recrystallization mechanisms caused by the high strains present during cold spraying. Extensive solute segregation at the grain boundaries acted as an obstruction for grain boundary migration in this direction, thereby preventing grain growth. However, in the direction parallel to the deposited surface, the UFGs were not resistant to grain coursing like the other direction, since the grain boundaries had much less solute segregation.

  12. EFFECT OF THE HEAT AND SURFACE LASER TREATMENT ON THE CORROSION DEGRADATION OF THE Mg-Al ALLOYS

    Directory of Open Access Journals (Sweden)

    Leszek A. Dobrzański

    2011-09-01

    Full Text Available In this paper there is presented the corrosion behavior of the cast magnesium alloys as cast state, after heat and laser treatment. Pitting corrosion resistance of the analyzed alloys was carried out using the potentiodynamic electrochemical method (direct current, based on a anodic polarization curve. On the basis of the achieved anodic polarization curves, using the Tefel extrapolation method near to the corrosion potential, the quantitative data were determined, which describe the electrochemical corrosion process of the investigated alloys: value of the corrosion potential Ecorr (mV, polarization resistance RP (kohm.cm2, corrosion current density icorr (10-6A/cm2, corrosion rate Vcorr (mm/year as well the mass loss Vc (g/m2<.

  13. 焊后热处理对1Cr18Ni9Ti与2Cr13钢焊接接头组织和性能的影响%Effect of post-welding heat treatment on microstructure and mechanical properties of 1Crl8Ni9Ti and 2Cr13 steel welded joints

    Institute of Scientific and Technical Information of China (English)

    赵勇桃; 董俊慧; 刘宗昌; 周军伟

    2012-01-01

    By method of tungsten inert gas welding, 1Crl 8Ni9Ti and 2Cr13 steels were welded, and heat treatment was carried on the welded joint. By OM and SEM, the microstructure of 2Cr13 and 1Crl8Ni9Ti steels welded joints was analyzed before and after heat treatment. Mechanical properties of the welded joints were measured by micro-hardness tester and electronic universal tensile machine. The resuhs show that before heat treatment, 2Cr13 and 1Crl8NigTi steels welded joint is typical columnar crystal, the microstructure is lath martensite + restained austenite + carbide, After heat treatment, the microstructure changes from lath martensite into tempered sorbite, and carbide quantity also increases significantly. The position of fracture is at the heat affected zone of austenitic stainless steel. Before and after heat treatment, the tensile strength of welded joints is about 635.56,649.44 MPa respectively; micro-hardness of welded zone 1Crl8NigTi and 2Cr13 steels is about 276, 222 HV0.5 respectively. After heat treatment,the micro-hardness of all welded joint decreases obviously.%通过钨极氩弧焊方法,对1Cr18Ni9Ti与2Cr13钢实施焊接,并对焊接接头整体进行焊后热处理。采用OM、SEM对2Cr13与1Cr18Ni9Ti钢热处理前后的焊接接头组织进行分析,利用显微硬度计、电子万能拉伸机测量了焊接接头的力学性能。结果表明,1Cr18Ni9Ti和2Cr13钢焊接接头热处理前焊缝组织为典型的柱状晶,组织为板条马氏体+残留奥氏体+碳化物;热处理后焊缝组织为回火索氏体,而且碳化物析出量也明显增多。拉伸时,热处理前后焊接接头断裂的部位都发生在奥氏体不锈钢热影响区一侧,热处理前后焊接接头的抗拉强度分别约为635.56、649.44 MPa;焊缝区的显微硬度分别约为276、222 HV0.5,热处理后焊接接头的整体显微硬度比热处理前的明显降低。

  14. Effect of Heat Treatment on Fracture Microstructure and Image of 1Cr18Ni9Ti and 2Cr13 Steel Welded Joints%热处理对1Cr18Ni9Ti与2Cr13钢焊接接头断口组织形貌的影响

    Institute of Scientific and Technical Information of China (English)

    赵勇桃; 董俊慧; 刘宗昌; 周军伟

    2012-01-01

    By TIG, under certain welding craft conditions, lCrl8Ni9Ti and 2Crl3 was welded, and certain heat treatment was carried out to welded joint The fracture image and properties of 2Cr13 and lCrl8Ni9Ti welded joints before and after heat treatment were observed by OM, SEM, electronic universal tensile machine and tensile experiments. The results show that before heat treatment, 2Crl3 and lCrl8Ni9Ti welded joints is columnar crystal, the microstructure is lath martensite + austenite + carbide. After heat treatment, the structure changes from lath martensite into tempered sorbite. After tensile,the fracture position of welded joints is HAZ of austenitic stainless steel, belong to toughness fracture. Before heat treatment, the dimple size and distribution are not uniform; after heat treatment, they are uniform. Before heat treatment, the tensile strength of the welded joints is about 635 Mpa, elongation is 26%, reduction of area is 44%; after heat treatment, the tensile strength of the welded joints is about 645 Mpa, elongation is 24%, reduction of area is 44%.%通过钨极氩弧焊方法,在一定工艺条件下对1Cr18Ni9Ti与2Cr13实施焊接,后对焊接接头进行焊后热处理.通过万能拉伸机对热处理前后的焊接接头进行拉伸试验,采用OM、SEM对1Cr18Ni9Ti与2Cr13钢热处理前后的焊接接头进行断口组织形貌观察及分析.结果表明,1Cr18Ni9Ti和2Cr13焊接接头热处理前焊缝组织为典型的柱状晶,组织为板条马氏体+残余奥氏体+碳化物;热处理后焊缝组织转变为回火索氏体.拉伸时,热处理前后焊接接头断裂部位都发生在奥氏体不锈钢热影响区一侧,均属于韧性断裂,热处理前韧窝大小、分布不均匀;热处理后韧窝变小,分布均匀,大小尺寸均等.热处理前,焊接接头的抗拉强度约为635 MPa,伸长率约为26%,断面收缩率约为44%;热处理后,焊接接头的抗拉强度约为645 MPa,伸长率约为24%,断面收缩率约为44%.

  15. Prevention of experimental autoimmune encephalomyelitis in DA rats by grafting primary skin fibroblasts engineered to express transforming growth factor-beta1.

    Science.gov (United States)

    Zargarova, T; Kulakova, O; Prassolov, V; Zharmukhamedova, T; Tsyganova, V; Turobov, V; Ivanov, D; Parfenov, M; Sudomoina, M; Chernajovsky, Y; Favorova, O

    2004-08-01

    To determine whether primary fibroblasts producing latent transforming growth factor beta1 (TGF-beta1) are capable of down-regulating experimental autoimmune encephalomyelitis (EAE), a retroviral vector TGF-beta1-pBabe-neo (-5'UTR) was used for efficient gene transfer into primary skin fibroblasts of DA rats. After heat activation, conditioned medium from the transduced fibroblasts was found to inhibit significantly in vitro proliferation of lymphocytes from lymph nodes of DA rats with EAE. Intraperitoneal administration of TGF-beta1-transduced fibroblasts into DA rats during the priming phase of EAE resulted in a significant reduction in mortality and in the mean clinical and EAE scores versus the control immunized animals treated with non-transduced fibroblasts.

  16. Prevention of experimental autoimmune encephalomyelitis in DA rats by grafting primary skin fibroblasts engineered to express transforming growth factor-β1

    Science.gov (United States)

    Zargarova, T; Kulakova, O; Prassolov, V; Zharmukhamedova, T; Tsyganova, V; Turobov, V; Ivanov, D; Parfenov, M; Sudomoina, M; Chernajovsky, Y; Favorova, O

    2004-01-01

    To determine whether primary fibroblasts producing latent transforming growth factor β1 (TGF-β1) are capable of down-regulating experimental autoimmune encephalomyelitis (EAE), a retroviral vector TGF-β1-pBabe-neo (−5′UTR) was used for efficient gene transfer into primary skin fibroblasts of DA rats. After heat activation, conditioned medium from the transduced fibroblasts was found to inhibit significantly in vitro proliferation of lymphocytes from lymph nodes of DA rats with EAE. Intraperitoneal administration of TGF-β1-transduced fibroblasts into DA rats during the priming phase of EAE resulted in a significant reduction in mortality and in the mean clinical and EAE scores versus the control immunized animals treated with non-transduced fibroblasts. PMID:15270848

  17. Sorption and desorption of tritiated water vapor on piping materials of nuclear fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Satoru; Ohmori, Rumi [Tokyo Univ. (Japan). Faculty of Engineering

    1996-10-01

    Sorption and desorption of D{sub 2}O on Cr{sub 2}O{sub 3}, NiO, SS316 powders were studied at ambient temperature. When D{sub 2}O were contacted with samples after drying at 303K, broad peak was observed at 2100-2700cm{sup -1} on Cr{sub 2}O{sub 3} and NiO. Sorption and desorption rate depended on wave numbers. Isotope exchange rate with H{sub 2}O vapor was faster than dry desorption rate. By heating pretreatment, sorption amount and desorption rate for Cr{sub 2}O{sub 3} and NiO decreased. For SS316, broad peak was observed only after heating pretreatment at 673K. (author)

  18. Sol-gel synthesis and densification of aluminoborosilicate powders. Part 1: Synthesis

    Science.gov (United States)

    Bull, Jeffrey; Selvaduray, Guna; Leiser, Daniel

    1992-01-01

    Aluminoborosilicate powders high in alumina content were synthesized by the sol-gel process utilizing various methods of preparation. Properties and microstructural effects related to these syntheses were examined. After heating to 600 C for 2 h in flowing air, the powders were amorphous with the metal oxides comprising 87 percent of the weight and uncombusted organics the remainder. DTA of dried powders revealed a T(sub g) at approximately 835 C and an exotherm near 900 C due to crystallization. Powders derived from aluminum secbutoxide consisted of particles with a mean diameter 5 microns less than those from aluminum isopropoxide. Powders synthesized with aluminum isopropoxide produced agglomerates comprised of rod shaped particulates while powders made with the secbutoxide precursor produced irregular glassy shards. Compacts formed from these powders required different loadings for equivalent densities according to the method of synthesis.

  19. A low-cost BCC alloy prepared from a FeV80 alloy with a high hydrogen storage capacity

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Yigang; Chen, Yungui; Wu, Chaoling; Tao, Mingda; Liang, Hao [School of Materials Science and Engineering, Sichuan University, Chengdu 610064 (China)

    2007-02-10

    A V{sub 30}Ti{sub 32}Cr{sub 32}Fe{sub 6} alloy prepared from a FeV80 master alloy is reported. It has a high hydrogen absorption/desorption capacity, good activation performance and kinetics. Heat-treatment at 1673 K is an effective way to increase the capacity and flatten the plateau due to the homogenization of the compositions in the alloy and the disappearance of Laves phase after heat-treatment. The heat-treated alloy can absorb 3.76 wt.%H at 298 K. It desorbs 2.35 wt.%H at 298 K and 2.56 wt.%H at 373 K. The development of this alloy could be of great significance to the application of V-based BCC hydrogen storage alloys. (author)

  20. Effect of grinding and heat treatment on the mechanical behavior of zirconia ceramic.

    Science.gov (United States)

    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. PMID:26676188

  1. Effect of grinding and heat treatment on the mechanical behavior of zirconia ceramic

    Directory of Open Access Journals (Sweden)

    Gabriela Freitas RAMOS

    2016-01-01

    Full Text Available Abstract The present study investigated the effect of grinding on roughness, flexural strength, and reliability of a zirconia ceramic before and after heat treatment. Seven groups were tested (n = 15: a control group (labeled CG, untreated, and six groups of samples ground with diamond discs, simulating diamond burs, with grits of 200 µm (G80; 160 µm (G120, and 25 µm (G600, either untreated or heat-treated at 1200°C for 2 h (labeled A. Yttria tetragonal zirconia polycrystal discs were manufactured, ground, and submitted to roughness and crystalline phase analyses before the biaxial flexural strength test. There was no correlation between roughness (Ra and Rz and flexural strength. The reliability of the materials was not affected by grinding or heat treatment, but the characteristic strength was higher after abrasion with diamond discs, irrespective of grit size. The X-ray diffraction data showed that grinding leads to a higher monoclinic (m phase content, whereas heat treatment produces reverse transformation, leading to a fraction of m-phase in ground samples similar to that observed in the control group. However, after heat treatment, only the G80A samples presented strength similar to that of the control group, while the other groups showed higher strength values. When zirconia pieces must be adjusted for clinical use, a smoother surface can be obtained by employing finer-grit diamond burs. Moreover, when the amount of monoclinic phase is related to the degradation of zirconia, the laboratory heat treatment of ground pieces is indicated for the reverse transformation of zirconia crystals.

  2. Oxysterol content in selected meats and meat products

    Directory of Open Access Journals (Sweden)

    Dorota Derewiaka

    2009-09-01

    Full Text Available Background. High consumption of oxysterols contributes to the development of arteriosclerosis. Thus it is necessary to monitor changes of their concentration in foodstuffs. The aim of this study was to determine the content of oxysterols in selected meats and meat products before and after heat treatment. Material and methods. Meats and meat products were pan fried in rapeseed oil for 10 minutes. Oxysterols methodology applied for the study of fat extraction, saponification, derivatization and determination by gas chromatography coupled with mass spectrometer. Results. The content of cholesterol oxidation products in meats and meat products after heat treatment (17.5 to 34.9 µg/g of fat was statistically higher than before frying (2.2 to 10.7 µg/g of fat. Raw meats and processed meat products contained mainly cholesterol oxidation products which equalled from 1.0 to 8.3% of cholesterol content. In fried meats and meat products has been found phytosterol oxidation products (0.1-1.7 µg/g of fat but only in small amounts. Conclusions. The increase in the content of phytosterol oxidation products in analysed meat samples after frying was probably the result of intensive phytosterol oxidation included in the rapeseed oil, also induced by haeme dyes within meat. From the results of the samples analyzed, it seems that multiple parameters are associated with the formation of oxysterols. Further studies should be performed to identify the factors e.g. water content, pro-oxidants, exposure to light, storage time and conditions, that may affect oxysterol formation during home frying.

  3. Tritium permeation barrier based on self-healing composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Gao Jifeng; Zhang Dan [State Key Laboratory of Mould Technology, Institute of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Suo Jinping, E-mail: jpsuo@yahoo.com.cn [State Key Laboratory of Mould Technology, Institute of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2010-12-15

    Pores and cracks in ceramic coatings is one of the most important problems to be solved for the thermally sprayed tritium permeation barriers (TPBs) in fusion reactor. In this work, we developed a self-healing composite coating to address this problem. The coating composed of TiC + mixture(TiC/Al{sub 2}O{sub 3}) + Al{sub 2}O{sub 3} was deposited on martensitic steels by means of atmospheric plasma spraying (APS). Before and after heat treatment, the morphology and phase of the coating were comparatively investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). In the experiment, NiAl + Al{sub 2}O{sub 3}, mixture(TiC/Al{sub 2}O{sub 3}) + Al{sub 2}O{sub 3} and NiAl + TiC + mixture(TiC/Al{sub 2}O{sub 3}) + Al{sub 2}O{sub 3} films were also fabricated and studied, respectively. The results showed that the TiC + mixture(TiC/Al{sub 2}O{sub 3}) + Al{sub 2}O{sub 3} coating exhibited the best self-healing ability and good thermal shock resistance among the four samples after heat treatment under normal atmosphere. The SEM images analyzed by Image Pro software indicated that the porosity of the TiC + mixture(TiC/Al{sub 2}O{sub 3}) + Al{sub 2}O{sub 3} coating decreased more than 90% in comparison with the sample before heat treatment. This self-healing coating made by thermal spraying might be a good candidate for tritium permeation barrier in fusion reactors.

  4. Sterilization Resistance of Bacterial Spores Explained with Water Chemistry.

    Science.gov (United States)

    Friedline, Anthony W; Zachariah, Malcolm M; Middaugh, Amy N; Garimella, Ravindranath; Vaishampayan, Parag A; Rice, Charles V

    2015-11-01

    Bacterial spores can survive for long periods without nutrients and in harsh environmental conditions. This survival is influenced by the structure of the spore, the presence of protective compounds, and water retention. These compounds, and the physical state of water in particular, allow some species of bacterial spores to survive sterilization schemes with hydrogen peroxide and UV light. The chemical nature of the spore core and its water has been a subject of some contention and the chemical environment of the water impacts resistance paradigms. Either the spore has a glassy core, where water is immobilized along with other core components, or the core is gel-like with mobile water diffusion. These properties affect the movement of peroxide and radical species, and hence resistance. Deuterium solid-state NMR experiments are useful for examining the nature of the water inside the spore. Previous work in our lab with spores of Bacillus subtilis indicate that, for spores, the core water is in a more immobilized state than expected for the gel-like core theory, suggesting a glassy core environment. Here, we report deuterium solid-state NMR observations of the water within UV- and peroxide-resistant spores from Bacillus pumilus SAFR-032. Variable-temperature NMR experiments indicate no change in the line shape after heating to 50 °C, but an overall decrease in signal after heating to 100 °C. These results show glass-like core dynamics within B. pumilus SAFR-032 that may be the potential source of its known UV-resistance properties. The observed NMR traits can be attributed to the presence of an exosporium containing additional labile deuterons that can aid in the deactivation of sterilizing agents.

  5. XRD and EXAFS studies on the structure of Er{sup 3+}-doped SiO{sub 2}-HfO{sub 2} glass-ceramic waveguides: Er{sup 3+}-activated HfO{sub 2} nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Afify, N D; Dalba, G [Dipartimento di Fisica, Universita di Trento, Via Sommarive 14, I-38123 Povo (Trento) (Italy); Rocca, F [IFN-CNR, Istituto di Fotonica e Nanotecnologie del Consiglio Nazionale delle Ricerche, Sezione ' FBK-CeFSA' di Trento, Via alla Cascata 56/C, I-38123 Povo (Trento) (Italy)], E-mail: rocca@science.unitn.it

    2009-06-07

    This paper describes the structure of Er{sup 3+}-doped SiO{sub 2}-HfO{sub 2} waveguides containing nanocrystals of HfO{sub 2}. Pure and 1 mol% Er{sup 3+}-doped 70SiO{sub 2}-30HfO{sub 2} films were deposited by the sol-gel method on amorphous SiO{sub 2} substrates using the dip-coating technique. Each waveguide has experienced a single thermal treatment at temperatures ranging from 900 to 1200 deg. C, for either short (30 min) or long (24 h) durations. Crystallization and microstructure were studied by x-ray diffraction (XRD). The local environments of hafnium and erbium ions were determined, respectively, from Hf and Er L{sub 3}-edges extended x-ray absorption fine structure (EXAFS) experiments. Both XRD and EXAFS results demonstrate the substitution of Hf{sup 4+} by Er{sup 3+} ions in the crystalline structure. XRD shows the nucleation of tetragonal HfO{sub 2} nanocrystals after heat treatment at 1000 deg. C for 30 min in the pure waveguide, and at 900 deg. C for 24 h in the waveguide doped with Er{sup 3+}. In both series, partial transformation from tetragonal to monoclinic HfO{sub 2} nanocrystals starts after heat treatment at 1100 deg. C for 24 h. The average crystallite size and size distribution can be controlled by thermal annealing temperature and duration, respectively, with brief treatment yielding a more homogeneous nanocrystal size.

  6. Synthesis of biomedical composite scaffolds by laser sintering: Mechanical properties and in vitro bioactivity evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Fwu-Hsing, E-mail: fhliu@mail.lhu.edu.tw

    2014-04-01

    Graphical abstract: Synthesis of biomedical composite scaffold obtained by selective laser sintering. - Highlights: • A layer additive manufacturing technique for fabricating the bio-composites scaffolds is developed. • The slurry state biomaterials are solidified via a laser beam in a self-developed apparatus. • The osteoblast-like cells can be cultured on the scaffold. • This technology has potential for fabricating the bone scaffolds in tissue engineering. - Abstract: In this study, biomedical composite materials were employed to fabricate bone scaffolds using a self-developed rapid prototyping (RP) apparatus. The slurry formed by combining hydroxyapatite (HA), silica sol, and sodium tripolyphosphate (STPP) was heated by a CO{sub 2} laser. Under appropriate processing parameters, a biocomposite green body was subsequently fabricated. Its mechanical properties, including surface roughness, bending and compression strengths, volume shrinkage rate, and surface microstructure, were analyzed after heat treatment to 1200 °C, 1300 °C, and 1400 °C. The results showed that after heating the specimen to 1200 °C, its compression and bending strengths increased significantly to 43.26 MPa and 1.28 MPa, respectively; the surface roughness was 12 μm; and surface pores were of size 5–25 μm. Furthermore, the results of WST-1 and LDH assay indicate that the biocomposites showed no cytotoxicity on 3T3 fibroblast. An optical density (OD) of 1.1 was also achieved, and the specimen was suitable for the adhesion and growth of osteoblast-like cells (MG63). Therefore, the biocomposite bone scaffolds fabricated in this study have potential to be bone implants for developing hard tissue.

  7. Effect of gamma rays absorbed doses and heat treatment on the optical absorption spectra of silver ion-exchanged silicate glass

    Energy Technology Data Exchange (ETDEWEB)

    Farah, Khaled, E-mail: kafarah@gmail.com [Unité de recherche: Maîtrise et développement des techniques nucléaires à caractère pacifique, Centre National des Sciences et Technologie Nucléaires, 2020 Sidi-Thabet (Tunisia); ISTLS, University of Sousse (Tunisia); Hosni, Faouzi [Unité de recherche: Maîtrise et développement des techniques nucléaires à caractère pacifique, Centre National des Sciences et Technologie Nucléaires, 2020 Sidi-Thabet (Tunisia); Academie Militaire de Fondouk Jedid, 8012 Nabeul (Tunisia); Mejri, Arbi [Unité de recherche: Maîtrise et développement des techniques nucléaires à caractère pacifique, Centre National des Sciences et Technologie Nucléaires, 2020 Sidi-Thabet (Tunisia); Boizot, Bruno [Laboratoire des Solides Irradiés, Ecole Polytechnique, Route de Saclay, 91128 Palaiseau Cedex (France); Hamzaoui, Ahmed Hichem [Centre National de Recherche en Sciences des Matériaux, B.P. 95, Hammam-Lif 2050 (Tunisia); Ben Ouada, Hafedh [Laboratoire des Interfaces et Matériaux Avancés, Faculté des Sciences, University of Monastir, Avenue de l’environnement, 5019 Monastir (Tunisia)

    2014-03-15

    Samples of a commercial silicate glass have been subjected to ion exchange at 320 °C in a molten mixture of AgNO{sub 3} and NaNO{sub 3} with molar ratio of 1:99 and 5:95 for 60 min. The ion exchange process was followed by gamma irradiation in the dose range of 1–250 kGy and heating at the temperature of 550 °C for different time periods ranging from 10 to 582 min. The spectral absorption in UV–Vis range of the Ag–Na ion exchanged glass was measured and used to determine the states of silver prevailing in the glass during the ion exchange, the gamma irradiation and the heat treatment. The gamma irradiation induced holes and electrons in the glass structure leading to the creation of a brown colour, and silver ions trapped electrons to form silver atoms. We observed the first stage of aggregation after irradiation, as well as after heating. The silver atoms diffused and then aggregated to form nanoclusters after heating at 550 °C. A characteristic band at about 430 nm was induced. The surface Plasmon absorption of silver nanoclusters in the glass indicated that the nanoclusters radius grew between 0.9 and 1.43 nm with increasing of annealing time from 10 to 242 min and then saturated. We also found that the size of aggregates depends on the value of gamma radiation absorbed dose. Contrary to what was expected, we found that 20 kGy is the optimal absorbed dose corresponding to the larger size of the aggregates which decreases for absorbed doses above 20 kGy.

  8. Analysis of DNA Content of Various Types of Spermatogenic Cells in Rat after Testicular Heating with Flow Cytometry

    Institute of Scientific and Technical Information of China (English)

    Duo XU; Wei-jie ZHU; Zi-neng WANG; Da-nian QIN

    2005-01-01

    Objective To measure DNA contents of spermatogenic cells and analyze the efficiency of spermatogenesis aftef testicular heating in ratMethods Eighty adult male Sprague-Dawley rats were randomly divided into experimental group (43 ℃, 30 min) and control group (22 ℃, 30 min). According to day 0.5, 1, 3, 6, 10, 25, 35 and 50 after local testicular heating, every group was divided into 8 subgroups:experimental subgroups (n=6) and control subgroups (n=4). DNA contents of various types of germ cells were observed with flow cytometry (FCM) in all groups.Results Compared with control groups, percentages of 4C cell (primary spermatocyte)in 0. 5 -35 d groups and percentages of 1 C cell (spermatid and sperm) in 6-50 d groups significantly decreased in experimental groups (P<0. 05), and percentages of 2C cell (spermatogonium and second spermatocyte) in 3 -35 d experimental groups increased significantly after heating (P<0. 05). 4C:2C in all of 8 experimental groups and 1C:2C in 3-35 d experimental groups were down (P<0. 05), and in 1 d experimental group 1C:4C was up after heating (P<0. 05).Conclusions After being heated, the number of spermatocyte firstly decreased, and then that of spermatid and sperm decreased too. Heat influences several stages in spermatogenesis and results in suppression of spermatogenesis. Flow cytometry is an effective method for researching on the change of spermatogenesis and has significance on mechanism about changing of spermatogenic cells induced by heat.

  9. Li induced effects in the core level and π-band electronic structure of graphene grown on C-face SiC

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Leif I., E-mail: lij@ifm.liu.se; Xia, Chao; Virojanadara, Chariya [Department of Physics, Chemistry and Biology, Linköping University, SE-58183 Linköping (Sweden)

    2015-11-15

    Studies of the effects induced in the electronic structure after Li deposition, and subsequent heating, on graphene samples prepared on C-face SiC are reported. The as prepared graphene samples are essentially undoped, but after Li deposition, the Dirac point shifts down to 1.2 eV below the Fermi level due to electron doping. The shape of the C 1s level also indicates a doping concentration of around 10{sup 14 }cm{sup −2} after Li deposition, when compared with recent calculated results of core level spectra of graphene. The C 1s, Si 2p, and Li 1s core level results show little intercalation directly after deposition but that most of the Li has intercalated after heating at 280 °C. Heating at higher temperatures leads to desorption of Li from the sample, and at 1030 °C, Li can no longer be detected on the sample. The single π-band observable from multilayer C-face graphene samples in conventional angle resolved photoelectron spectroscopy is reasonably sharp both on the initially prepared sample and after Li deposition. After heating at 280 °C, the π-band appears more diffuse and possibly split. The Dirac point becomes located at 0.4 eV below the Fermi level, which indicates occurrence of a significant reduction in the electron doping concentration. Constant energy photoelectron distribution patterns extracted from the as prepared graphene C-face sample and also after Li deposition and heating at 280 °C look very similar to earlier calculated distribution patterns for monolayer graphene.

  10. The Effect of Anions on Structure and Catalytic Properties of the Fe-based High Temperature Shift Catalyst%阴离子环境对铁基高温变换催化剂结构与性能的影响

    Institute of Scientific and Technical Information of China (English)

    姜浩强; 何润霞; 武芳; 智科端; 周晨亮; 张万华; 刘全生

    2013-01-01

    The Fe -based high temperature shift catalysts were prepared by the wet co -precipitation method, which were characterized by XRD , SBET and TG-DTA and tested for water-gas shift reaction.The results showed that anions types had significant effects on the structure and performance of precursor which generated during the process of preparation , finally caused product catalyst performance vary widely .The catalytic activity of sample in the SO 2-4 environment was better , which was 24 .52% at 350℃ after heat resistance(500℃,180min);the catalytic activity of sample in the Cl -environment was lower, which was 6. 94%at 350℃after heating resistance(500℃,180min).%采用湿法共沉淀工艺制备了不同阴离子环境下的铁基高温变换催化剂,利用XRD、BET、TG-DTA、TEM和活性测试等对催化剂样品的结构和性能进行比较研究。结果表明,阴离子环境对催化剂制备过程中所生成前驱体的结构影响较大,最终导致成品催化剂性能相差很大。 SO2-4环境下制备的催化剂活性较好,500℃耐热180min后350℃的活性可达24.52%,而Cl -环境下制备的催化剂活性较差,500℃耐热后350℃的活性为6.94%。

  11. Synthesis of biomedical composite scaffolds by laser sintering: Mechanical properties and in vitro bioactivity evaluation

    International Nuclear Information System (INIS)

    Graphical abstract: Synthesis of biomedical composite scaffold obtained by selective laser sintering. - Highlights: • A layer additive manufacturing technique for fabricating the bio-composites scaffolds is developed. • The slurry state biomaterials are solidified via a laser beam in a self-developed apparatus. • The osteoblast-like cells can be cultured on the scaffold. • This technology has potential for fabricating the bone scaffolds in tissue engineering. - Abstract: In this study, biomedical composite materials were employed to fabricate bone scaffolds using a self-developed rapid prototyping (RP) apparatus. The slurry formed by combining hydroxyapatite (HA), silica sol, and sodium tripolyphosphate (STPP) was heated by a CO2 laser. Under appropriate processing parameters, a biocomposite green body was subsequently fabricated. Its mechanical properties, including surface roughness, bending and compression strengths, volume shrinkage rate, and surface microstructure, were analyzed after heat treatment to 1200 °C, 1300 °C, and 1400 °C. The results showed that after heating the specimen to 1200 °C, its compression and bending strengths increased significantly to 43.26 MPa and 1.28 MPa, respectively; the surface roughness was 12 μm; and surface pores were of size 5–25 μm. Furthermore, the results of WST-1 and LDH assay indicate that the biocomposites showed no cytotoxicity on 3T3 fibroblast. An optical density (OD) of 1.1 was also achieved, and the specimen was suitable for the adhesion and growth of osteoblast-like cells (MG63). Therefore, the biocomposite bone scaffolds fabricated in this study have potential to be bone implants for developing hard tissue

  12. Reaction selectivity studies on nanolithographically-fabricated platinum model catalyst arrays

    Energy Technology Data Exchange (ETDEWEB)

    Grunes, Jeffrey Benjamin

    2004-05-15

    In an effort to understand the molecular ingredients of catalytic activity and selectivity toward the end of tuning a catalyst for 100% selectivity, advanced nanolithography techniques were developed and utilized to fabricate well-ordered two-dimensional model catalyst arrays of metal nanostructures on an oxide support for the investigation of reaction selectivity. In-situ and ex-situ surface science techniques were coupled with catalytic reaction data to characterize the molecular structure of the catalyst systems and gain insight into hydrocarbon conversion in heterogeneous catalysis. Through systematic variation of catalyst parameters (size, spacing, structure, and oxide support) and catalytic reaction conditions (hydrocarbon chain length, temperature, pressures, and gas composition), the data presented in this dissertation demonstrate the ability to direct a reaction by rationally adjusting, through precise control, the design of the catalyst system. Electron beam lithography (EBL) was employed to create platinum nanoparticles on an alumina (Al{sub 2}O{sub 3}) support. The Pt nanoparticle spacing (100-150-nm interparticle distance) was varied in these samples, and they were characterized using x-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM), both before and after reactions. The TEM studies showed the 28-nm Pt nanoparticles with 100 and 150-nm interparticle spacing on alumina to be polycrystalline in nature, with crystalline sizes of 3-5 nm. The nanoparticle crystallites increased significantly after heat treatment. The nanoparticles were still mostly polycrystalline in nature, with 2-3 domains. The 28-nm Pt nanoparticles deposited on alumina were removed by the AFM tip in contact mode with a normal force of approximately 30 nN. After heat treatment at 500 C in vacuum for 3 hours, the AFM tip, even at 4000 nN, could not remove the platinum nanoparticles. The

  13. [Microstructure and spectral property of Er3+ doped transparent oxyfluoride glass ceramics with high fluorine contents].

    Science.gov (United States)

    Lin, Le-Jing; Ren, Guo-Zhong; Chen, Min-Peng; Liu, Yang

    2009-12-01

    The microstructure and spectral properties of Er3+ doped transparent oxyfluoride glass ceramics with high fluorine content were reported. Two samples with the same initial contents (50SiO2-45PbF2-5PbO-1ErF3) were prepared under the different preparation parameters. The final fluorine contents were detected by a fluoride ion selective electrode. The results shows that the final fluorine contents increase by covering crucibles with corundum lid during melt. The samples were characterized by X-ray diffraction, transmission electron microscopy (TEM), absorption spectra and upconversion luminescence spectra. The results show that PbF2 crystals were precipitated in the sample with high fluorine content before heat treatment. And the PbF2 crystals precipitated inside the glass matrix are spherical with diameters of approximately 10-15 nm in size from the high resolution TEM micrograph. The absorption spectra, J-O parameters and the upconversion spectra show that the Er3+ ions were located in crystalline and vitreous mixed states. It is different from the sample with low fluorine content which is completely amorphous. After heat treatment, Er3+ ions that remain in the glassy phase entered into fluoride nanocrystals in the sample with high fluorine content. The fluorine environment decreases non-radiative transfer which eases the upconversion processes. Hence, the upconversion luminescence intensity of Er3+ ions in the high fluorine content sample after heat treatment is much stronger than that in the precursor sample. PMID:20210134

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

    Science.gov (United States)

    Sakoda, Kazuki; Hirano, Masanori

    2015-08-01

    The compositional dependence of the structure and properties of spinel-type solid solutions, Zn(A,Ga)2O4 was investigated by comparison with samples hydrothermally prepared and those after heat treatment at 1000 °C in air. Nanocrystalline spinel-type solid solutions in the whole composition range in the ZnAl2O4-ZnGa2O4 system were directly formed from the aqueous precursor solutions of ZnSO4, Al(NO3)3 and Ga(NO3)3 under hydrothermal conditions at 180 °C for 5 h in the presence of tetramethylammonium hydroxide. The incorporation of aluminum into the lattice, Zn(AlxGa1-x)2O4, resulted in lower crystallinity of the spinel. The relationship between the lattice parameter of as-prepared samples and the Al atomic ratio in the spinel composition was slightly apart from the ideal linear relationship that was obtained in the samples after heat treatment at 1000 °C. The optical band gap of both as-prepared solid solutions and those heat treated linearly increased from 4.1~4.2 to 5.25 eV by the incorporation of aluminum ion into the lattice, Zn(AlxGa1-x)2O4. Two main broad-band emission spectra centered at around 360 and 430 nm in the range of 300-600 nm were observed in the spinel solid solutions under excitation at 270 nm, thought their broad-band emission spectra and their peak wavelengths subtly changed depending on the composition and heat treatment. PMID:26369200

  15. Acute microcirculatory changes after scalding of the rat paw.

    Science.gov (United States)

    Löfgren, O; Gazelius, B; Lundeberg, T

    1997-11-01

    A scalding model in the anaesthetized rat was used to measure acute circulatory reactions after heat exposure. Local blood flow of both hindpaws was recorded simultaneously and continuously by laser Doppler flowmetry before, during and for 2 hours following scalding. The scalding injury was inflicted by dipping the right hindpaw into hot water at 60 degrees C for 20 s. Concomitantly, the mean arterial blood pressure (MAP) was displayed on a chart recorder. MAP was obtained by cannulation of the common carotid artery. Oedema formation was calculated by measuring the volume changes of the hindpaws in a plethysmometer before and 30, 60 and 120 min after scalding. Scalding was followed by a biphasic increase of cutaneous circulation. During the first minute after heat provocation, an immediate increase in blood perfusion of about 400% was recorded, followed by a slow decrease of circulation. At 30 min after scalding, there was a secondary phase of increased microcirculation of approximately 230%. A slow decline of cutaneous circulation then followed, and after about 60 min the value was stabilized at approximately 100% above pre-burn level throughout the observation time. Almost no change of perfusion was observed on the contralateral unscalded paw. The scalding injury was followed by a progressive oedema formation on the scalded paw, measured by a volume increase of approximately 72% during the observation period, whereas the non-scalded paw showed no change. MAP remained at a stable level throughout the experiment except for a short-lasting transient increase of approximately 10% at the same time as the first peak of blood perfusion. We could thus confirm that scalding in the present model is accompanied by an immediate and marked increase in the peripheral circulation of the scalded paw followed by a later propagation of oedema, and that these inflammatory changes do not appear to be related to central haemodynamic alterations. PMID:9401580

  16. ADENOVIRUS-MEDIATED P53 GENE TRANSFER INCREASES THE THERMOSENSITIVITY OF HUMAN GASTRIC CARCINOMA CELL LINES (IN VITRO AND IN VIVO)

    Institute of Scientific and Technical Information of China (English)

    张珊文; 肖绍文; 吕有勇

    2003-01-01

    Objective: To investigate the effect of adenovirus- mediated p53 (Adp53) transfer on thermosensitivity of human gastric carcinoma cell lines (BGC823). Methods: Two human gastric carcinoma cell lines with different p53 status, BGC823-wtp53 cell (abbreviate W) bearing the wilt-type p53 and BGC823-mutp53 cell (abbreviate M) bearing the mutant p53, were cultured with DMEM medium and were infected with Adp53 at a viral multiplicity of infection of 100 (1:100MOI) for 48h before heating. Cell cycle redistribution and apoptosis of two human gastric carcinoma cell lines in 24h at 37℃ after heat treatment at 42℃ for 2h or 43℃ for 0.5h were analyzed by flow cytometry. Relative tumor volume growth curves were used in a nude mouse tumor model of the two cell lines following hyperthermia at 43℃ for 0.5h after 48h intratumoral injection of 1(108 pfu of Adp53 to evaluate thermoenhancemet effect in vivo. Results: In vitro study showed that both W and M cells infected with Adp53 and treated with heating had strong arrest in G2 (after heating at 42℃ for 2h, 34.0% of original population for W cells and 25.3% of original population for M cells) and produced obvious apoptotic response. The apoptosis rate showed 230% increased (for W cells) and 110% increase (for M cells) compared with heating only control. In vivo study showed that the growth of tumor of both W cells and M cells was significantly delayed by hyperthemia combining with Adp53 as compared to tumors receiving either treatment alone. Conclusion: This study demonstrated that Adp53 transfer increased cellular apoptosis and thermo- sensitivity in vitro and tumor thermosensitivity in vivo independent of cellular intrinsic p53 status. These results support the combined used of p53 gene therapy with hyperthermia in clinical trials.

  17. Enhanced apatite formation on Ti metal heated in PO2-controlled nitrogen atmosphere.

    Science.gov (United States)

    Hashimoto, Masami; Hayashi, Kazumi; Kitaoka, Satoshi

    2013-10-01

    The oxynitridation of biomedical titanium metal under a precisely regulated oxygen partial pressure (PO2) of 10(-14)Pa in nitrogen atmosphere at 973 K for 1 h strongly enhanced apatite formation compared with that on Ti heated in air. The factors governing the high apatite-forming ability are discussed from the viewpoint of the surface properties of Ti heated under a PO2 of 10(-14)Pa in nitrogen atmosphere determined from X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and zeta potential measurements. Nitrogen (N)-doped TiO2 (interstitial N) was formed on pure Ti heated under a PO2 of 10(-14)Pa in nitrogen atmosphere at 973 K. The XPS O1s main peak shifted toward a lower binding energy upon heating under a PO2 of 10(-14)Pa. This shift may be due to the formation of oxygen vacancies. This Ti surface had a positive zeta potential of approximately 20 mV. According to time-of-flight secondary ion mass spectroscopy results, PO4(3-) ions were predominantly adsorbed on Ti soaked in simulated body fluid (SBF) after heat treatment, followed by calcium ions. It was concluded that the apatite formation kinetics can be described using the Avrami-Erofeev equation with an Avrami index of n=2, which implies the instantaneous nucleation of apatite on the surface of Ti soaked in SBF after heat treatment at 973 K under a PO2 of 10(-14)Pa. PMID:23910327

  18. The optical absorption of gamma irradiated and heat-treated natural quartz

    Directory of Open Access Journals (Sweden)

    Eduardo Henrique Martins Nunes

    2005-09-01

    Full Text Available Quartz with aluminum as impurity absorbs energy from ionizing radiation and modifies its color. Colorless quartz becomes smoky or dark smoky (morion quartz when exposed to gamma rays. By heat-treatment, smoky quartz may become successively greenish, yellowish, or brownish as the irradiation dose increases. Natural, colorless quartz is routinely colored by irradiation with gamma rays and heat-treatment for jewelry production. The color formation in natural quartz through this procedure is explained based on EPR, UV-VIS, and IR studies of irradiated and irradiated and heat-treated samples. Smoky quartz shows absorption bands in the visible region and a strong EPR signal. After heat-treatment it shows absorption bands in the near UV region with extensions into the visible region and a weak EPR signal. The intensity of the absorption bands is proportional to the irradiation dose. These changes of color are explained by the model of Itoh, Stoneham, and Stoneham. [AlSi O4 /h+]0 centers are produced by irradiation, causing the EPR signal and the absorption bands in the visible region. [AlSi O4]- centers are created from [AlSi O4 /h+]0 centers by heat-treatment. They cannot cause an EPR signal and have absorption bands in the near UV region with extensions into the visible region. The highest concentration of [AlSi O4]- centers occurs when the charge compensators have medium mobility. Lithium should give the best condition for color formation. Sodium (low mobility and hydrogen (high mobility should make smoky quartz colorless after heat-treatment.

  19. Effects of Ce-rich RE additions and heat treatment on the microstructure and tensile properties of Mg-Li-Al-Zn-based alloy

    International Nuclear Information System (INIS)

    Research highlights: → Adding Ce-rich RE leads to the formation of Al2RE/Al3RE phases in LAZ532 alloy. → Ce-rich RE additions improve the tensile properties of the alloy. → The tensile properties of alloys processed by heat treatment are increased greatly. → Adding RE changes the fracture pattern of the alloy. - Abstract: As-cast Mg-5Li-3Al-2Zn-xRE (x = 0-2.5 wt.%) alloys were prepared under the ambient of pure argon, and the effects of Ce-rich rare earths (RE) and heat treatment on the microstructure and mechanical properties of Mg-Li-Al-Zn-based alloy were investigated. The results show that the main phase compositions of Mg-5Li-3Al-2Zn (LAZ532) alloy consist of α-Mg and AlLi. With the addition of RE, Al-RE precipitate forms, and increases gradually, whereas AlLi phase decreases. The room temperature tensile test reveals that the addition of RE could clearly improves the mechanical properties of alloys which are further improved after heat treatment. In more detail, excellent tensile strength and ductility are obtained in 1.5 wt.% RE containing alloy in as-cast state. After heat treatment, the 1.0 wt.% RE containing alloy attains superior tensile strength. The differences in tensile strength are related to the morphology, distribution of second phases and solid-solution strengthening in different alloy systems. In addition, the fracture pattern of the alloy is predominantly brittle cleavage and tends to be quasi-cleavage with RE addition.

  20. Effect of grinding and heat treatment on the mechanical behavior of zirconia ceramic.

    Science.gov (United States)

    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.