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Sample records for heat treatment techniques

  1. Post-Heat Treatment and Mechanical Assessment of Polyvinyl Alcohol Nanofiber Sheet Fabricated by Electrospinning Technique

    Directory of Open Access Journals (Sweden)

    Mahir Es-saheb

    2014-01-01

    Full Text Available Polyvinyl alcohol (PVA sheets based nanofibers were produced by electrospinning technique. Postheat treatment of the produced PVA sheets with temperatures both below and above Tg to improve the mechanical properties of this material is conducted. The morphology, microstructures, and thermal degradation of the nanofibers sheets produced were investigated using scanning electron microscopy (SEM, transmission electron microscope (TEM, and thermal gravimetric analysis (TGA. Produced nanofibers are compact, and entangled with each other, with diameters from around 150 to 210. Some mechanical characteristics of the successfully produced PVA sheets, and heat-treated, are then conducted and assessed employing uniaxial tensile tests at different speeds ranging from 1 mm/min to 100 mm/min. The tensile test results obtained show that the PVA sheets are strain rate sensitive with increasing strength as the speed (i.e., strain rate increases. The yield tensile stress ranges from 2.411 to 6.981 MPa, the ductility (i.e., elongation percent from ∼21 to 60%, and Young modulus ranges from 103 to 0.137 KPa. However, for heat-treated samples, it is found that the yield strength increases almost by ∼35–40% more than the values of untreated cases with values reaching up to about 3.627–9.63 MPa.

  2. Effects of heat treatment on morphological, optical and electrical properties of ITO films by sol-gel technique

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-hua; KE Yu-peng; REN Dong-yan

    2008-01-01

    Indium-tin-oxide(ITO) films were prepared on the quarts glass by sol-gel technique. Effects of different heat treatment temperatures and cooling methods on the morphological, optical and electrical properties of ITO films were measured by TG/DTA, IR, XRD, SEM, UV-VIS spectrometer and four-probe apparatus. It is found that the crystallized ITO films exhibit a polycrystalline cubic bixbyite structure. The heat treatment process has significant effects on the morphological, optical and electrical properties of ITO films. Elevating the heat treatment temperature can perfect the crystallization process of ITO films, therefore the optical and electrical properties of ITO films are improved. But the further increasing of heat treatment temperature results in the increment of ITO films' resistivity. Compared with ITO films elaborated by furnace cooling, those prepared through air cooling have following characteristics as obviously decreased crystalline size, deeply declined porosity, more compact micro-morphology, improved electrical property and slightly decreased optical transmission.

  3. Heat treatment deformations

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-02-01

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

  4. Heat Treatment Parameters to Optimize Friction and Wear behavior of Novel Hybrid Aluminium Composites Using Taguchi Technique

    Directory of Open Access Journals (Sweden)

    V.C.Uvaraja

    2014-05-01

    Full Text Available In the present study, an Al 7075 alloy is used as the matrix and varying weight percentage of Silicon Carbide (SiC and constant weight percentage of Boron Carbide (B4C as the reinforcing material. The composite is produced using stir casting technique. The composite thus formed is termed as hybrid composite. The samples are prepared for heat treatment process by subjecting to solutionizing temperature of 530o C for 1 hr followed by quenching in water. Further the specimens are subjected to artificial aging for durations of 4, 6 and 8 hr at a temperature of 175°C. The mechanical and tribological properties of composites before and after heat treatment are examined by Vickers hardness test machine and pin-on-disc test machine respectively. The wear rate and friction co-efficient of heat treatment parameters are evaluated based on Taguchi technique. The analysis is further extended to the optimization of test parameters using Design of Experiment (DoE based on L9 orthogonal array. The developed Analysis of Variance (ANOVA and the regression equations is obtained through MINITAB R16 are used to investigate the influence of parameters like sliding speed, applied load, sliding time, and percentage of reinforcement on the dry sliding wear and friction co-efficient of the composites. The wear surface morphology and wear mechanism of the pins are investigated using Scanning Electron Microscope (SEM and are correlated them with wear test results. Finally, confirmation tests are carried out to verify the experimental results.

  5. Optimisasi Suhu Pemanasan dan Kadar Air pada Produksi Pati Talas Kimpul Termodifikasi dengan Teknik Heat Moisture Treatment (HMT (Optimization of Heating Temperature and Moisture Content on the Production of Modified Cocoyam Starch Using Heat Moisture Treatment (HMT Technique

    Directory of Open Access Journals (Sweden)

    I Nengah Kencana Putra

    2016-12-01

    Full Text Available One of the physically starch modification technique is heat-moisture treatment (HMT. This technique can increase the resistance of starch to heat, mechanical treatment, and acid during processing.  This research aimed to find out the influence of heating temperature and moisture content in the modification process of cocoyam starch  with HMT techniques on the characteristic of product, and then to determine the optimum heating temperature and moisture content in the process. The research was designed with a complete randomized design (CRD with two factors factorial experiment.  The first factor was temperature of the heating consists of 3 levels namely 100 °C, 110 °C, and 120 °C. The second factor was the moisture content of starch which consists of 4 levels, namely 15 %, 20 %, 25 %, and 30 %. The results showed that the heating temperature and moisture content significantly affected water content, amylose content and swelling power of modified cocoyam starch product, but the treatment had no significant effect on the solubility of the product. HMT process was able to change the type of cocoyam starch from type B to type C. The optimum heating temperature and water content on modified cocoyam starch production process was 110 °C and 30 % respectively. Such treatment resulted in a modified cocoyam starch with moisture content of 6.50 %, 50,14 % amylose content, swelling power of 7.90, 0.0009% solubility, paste clarity of 96.310 % T, and was classified as a type C starch.   ABSTRAK Salah satu teknik modifikasi pati secara fisik adalah teknik Heat Moisture Treatment (HMT. Teknik ini dapat meningkatkan ketahanan pati terhadap panas, perlakuan mekanik, dan asam selama pengolahan. Penelitian ini bertujuan untuk mengetahui pengaruh suhu dan kadar air pada proses modifikasi pati talas kimpul dengan teknik HMT terhadap karakteristik produk, dan selanjutnya menentukan suhu dan kadar air yang optimal dalam proses tersebut. Penelitian ini dirancang

  6. Heat treatment furnace

    Science.gov (United States)

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

    2014-10-21

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

  7. Overview of waste heat utilization techniques

    Energy Technology Data Exchange (ETDEWEB)

    Olszewski, M.

    1979-04-01

    Power plants annually reject about 11 x 10/sup 9/ GJ (11 x 10/sup 15/ Btu) of low-grade heat to the atmosphere. Typically, this heat is found in the large quantities of cooling water necessary to condense the steam in the power-generating cycle. Such cooling water is generally discharged in the range of 15 to 43/sup 0/C (60 to 110/sup 0/F) depending on the temperature of the available inlet water, quantity circulated, plant load, and heat-rejection system used. A number of possible uses have been suggested for this low-grade heat, including: greenhouse horticulture; soil heating (both open field and in greenhouses); spray irrigation for frost protection; organic waste treatment (particularly for algae or biomass production); and aquaculture/mariculture. To date greenhouse and aquaculture/mariculture systems have received the most attention and have, therefore, progressed farthest. This paper describes several innovative techniques that utilize power-plant reject heat for these applications. Schematic descriptions are given for these techniqes and a brief review of the project status is provided. The major efforts to utilize reject heat for agricultural purposes are described not only for the U.S., but efforts in Canada, France, West Germany, and the USSR are noted.

  8. Effects of heat treatment on characteristics of porous Ni-rich NiTi SMA prepared by SHS technique

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The effects of heat treatment on the microstructure and compressive properties of porous Ni-rich NiTi shape memory alloy (SMA) fabricated by self-propagating high-temperature synthesis (SHS) were investigated. The solution treatment at 1050℃ has little effects on stable Ti2Ni second phase, however, it decreases the amount of Ni4Ti3 phase derived from the SHS process and results in the improvement of the ductility of porous NiTi SMA. The subsequent aging treatment after solution treatment could lead to the precipitation of the discrete Ni4Ti3 phase in NiTi matrix grains, which increases the brittleness of porous NiTi SMA. Porous NiTi SMA presents a composite fracture behavior consisting of a ductile fracture of NiTi matrix and a cleavage fracture of second phase particles. Many cracks existing on the interfaces indicate that the bonding of the matrix with second phase particles is weak.

  9. Alternating Current Heating Technique of Hollow Rod

    Institute of Scientific and Technical Information of China (English)

    Na Weisheng; Shi Tonghao

    1995-01-01

    @@ In recent years, wellbore heat tracing technique is widely used in development of high viscosity and high pour point crude oil. Theory and experiences show that wellbore heat tracing has obvious effect on increasing liquid yield of oil wells.

  10. Research on ground heat exchanger of Ground Source Heat Pump technique

    Institute of Scientific and Technical Information of China (English)

    LIU Dong-sheng; SUN You-hong; GAO Ke; WU Xiao-hang

    2004-01-01

    Ground Source Heat Pump technique and its operating principle are described in this paper. Ground heat exchanger is the key technique of ground source heat pump and its pattems are discussed. Software is helpful to design ground heat exchanger. A project of Chinese Ground Source Heat Pump is introduced and its market is more and more extensive.

  11. Heat Treatment Procedure Qualification -- Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Robert C. Voigt

    2004-10-15

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

  12. Heat Treatment Procedure Qualification for Steel Castings

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-04-29

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

  13. 29 CFR 1919.80 - Heat treatment.

    Science.gov (United States)

    2010-07-01

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

  14. 29 CFR 1919.36 - Heat treatment.

    Science.gov (United States)

    2010-07-01

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

  15. Industrial heating principles, techniques, materials, applications, and design

    CERN Document Server

    Deshmukh, Yeshvant V

    2005-01-01

    Industry relies on heating for a wide variety of processes involving a broad range of materials. Each process and material requires heating methods suitable to its properties and the desired outcome. Despite this, the literature lacks a general reference on design techniques for heating, especially for small- and medium-sized applications. Industrial Heating: Principles, Techniques, Materials, Applications, and Design fills this gap, presenting design information for both traditional and modern heating processes and auxiliary techniques.The author leverages more than 40 years of experience int

  16. Study Of Gear Teeth Distortions Due To Heat Treatment

    Directory of Open Access Journals (Sweden)

    V. Khade

    2015-02-01

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

  17. 29 CFR 1919.16 - Heat treatment.

    Science.gov (United States)

    2010-07-01

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

  18. Advances in the heat treatment of steels

    Energy Technology Data Exchange (ETDEWEB)

    Morris, J.W. Jr.; Kim, J.I.; Syn, C.K.

    1978-06-01

    A number of important recent advances in the processing of steels have resulted from the sophisticated uses of heat treatment to tailor the microstructure of the steels so that desirable properties are established. These new heat treatments often involve the tempering or annealing of the steel to accompish a partial or complete reversion from martensite to austenite. The influence of these reversion heat treatments on the product microstructure and its properties may be systematically discussed in terms of the heat treating temperature in relation to the phase diagram. From this perspective, four characteristic heat treatments are defined: (1) normal tempering, (2) inter-critical tempering, (3) intercritical annealing, and (4) austenite reversion. The reactions occurring during each of these treatments are described and the nature and properties of typical product microstructures discussed, with specific reference to new commercial or laboratory steels having useful and exceptional properties.

  19. Heat detection techniques in cattle and buffalo

    Directory of Open Access Journals (Sweden)

    Thakur Krishna Shankar Rao

    2013-12-01

    Full Text Available Proper heat detection to achieve appropriate timing of insemination is the biggest restriction in attaining high conception rate in dairy herd. The estrus detection is the key issue to be considered on priority basis. Inefficient heat detection reduces the fertility status of herd. Interventions in existing management practices in farm can manifest estrus with clarity. Manifestation of estrus is due to effect of estrogen on Central Nervous System (CNS. The standing to be ridden is the best reliable sign of estrus. Ovulation time is well estimated by standing heat. Different factors are responsible which affect estrous behavior, out of which feeding and management interventions are one of the most important factors. For improving efficiency of heat detection in animal visual observation is best method, if it is done thrice a day for 30 minutes every time. However heat detection aids, if used in combination give better results as compared to visual observation. The progesterone (P4 estimation in milk and ultrasound monitoring of ovary and reproductive tracts for estimation of ovulation time are other important methods. Ovulation is very important point in dairy reproduction management. The optimum time for insemination is before the actual ovulation. It is already established that, estrus detection alone contributes considerably to reproductive status of the herd, therefore the need of the hour is critical observation of dairy herd to reduce incidence of unnoticed estrus. [Vet World 2013; 6(6.000: 363-369

  20. WOOD MODIFICATION BY HEAT TREATMENT: A REVIEW

    Directory of Open Access Journals (Sweden)

    Bruno M. Esteves

    2009-02-01

    Full Text Available Wood heat treatment has increased significantly in the last few years and is still growing as an industrial process to improve some wood properties. The first studies on heat treatment investigated mainly equilibrium mois-ture, dimensional stability, durability and mechanical properties. Mass loss, wettability, wood color, and chemical transformations have been subsequently extensively studied, while recent works focus on quality control, modeling, and study the reasons for the improvements. This review explains the recent interest on the heat treatment of wood and synthesizes the major publications on this subject on wood properties, chemical changes, wood uses, and quality control.

  1. Heat Transfer and Cooling Techniques at Low Temperature

    CERN Document Server

    Baudouy, B

    2014-07-17

    The first part of this chapter gives an introduction to heat transfer and cooling techniques at low temperature. We review the fundamental laws of heat transfer (conduction, convection and radiation) and give useful data specific to cryogenic conditions (thermal contact resistance, total emissivity of materials and heat transfer correlation in forced or boiling flow for example) used in the design of cooling systems. In the second part, we review the main cooling techniques at low temperature, with or without cryogen, from the simplest ones (bath cooling) to the ones involving the use of cryocoolers without forgetting the cooling flow techniques.

  2. Literature survey of heat transfer enhancement techniques in refrigeration applications

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, M.K.; Shome, B. [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Mechanical Engineering, Aeronautical Engineering and Mechanics

    1994-05-01

    A survey has been performed of the technical and patent literature on enhanced heat transfer of refrigerants in pool boiling, forced convection evaporation, and condensation. Extensive bibliographies of the technical literature and patents are given. Many passive and active techniques were examined for pure refrigerants, refrigerant-oil mixtures, and refrigerant mixtures. The citations were categorized according to enhancement technique, heat transfer mode, and tube or shell side focus. The effects of the enhancement techniques relative to smooth and/or pure refrigerants were illustrated through the discussion of selected papers. Patented enhancement techniques also are discussed. Enhanced heat transfer has demonstrated significant improvements in performance in many refrigerant applications. However, refrigerant mixtures and refrigerant-oil mixtures have not been studied extensively; no research has been performed with enhanced refrigerant mixtures with oil. Most studies have been of the parametric type; there has been inadequate examination of the fundamental processes governing enhanced refrigerant heat transfer, but some modeling is being done and correlations developed. It is clear that an enhancement technique must be optimized for the refrigerant and operating condition. Fundamental processes governing the heat transfer must be examined if models for enhancement techniques are to be developed; these models could provide the method to optimize a surface. Refrigerant mixtures, with and without oil present, must be studied with enhancement devices; there is too little known to be able to estimate the effects of mixtures (particularly NARMs) with enhanced heat transfer. Other conclusions and recommendations are offered.

  3. Hydrogen heat treatment of hydrogen absorbing materials

    Science.gov (United States)

    Park, Choong-Nyeon

    2000-12-01

    This study introduces the hydrogen heat treatment of hydrogen absorbing materials and its applicability for practical use. This treatment is somewhat different from normal heat treatment because of the interaction between metal atoms and hydrogen. Since hydrogen can be removed very fast by pumping it out the hydrogen-induced new lattice phase which can not be obtained without hydrogen can be preserved in a meta-stable state. A thermodynamic interpretation of the hydrogen heat treatment established previously was reformulated for graphical and analytical methods and applied to Pd-Pt-H and Pd-Ag-H alloy systems and a fair correlation between the calculation and experimental results was shown. The feasibility of applying the thermodynamic interpretation to intermetallic compounds-hydrogen systems was also discussed.

  4. Transformation of coals at the heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    S.A. Aipshtein; V.I. Minaev; O.V. Barabanova; V.A. Novikova [Moscow State University of Mining (MSMU), Moscow (Russian Federation)

    2007-07-01

    The coals (from Kuznetsk and Donetsk basins) were selected with the following criteria: a) different rank; b) different genetic types. The substantial and chemical compositions of the coals were determined. Experimental works on coal heat treatment were carried out at temperatures 423K, 473K, 523K, 573K and different times of processing in the conditions excluding oxidation of coals. It was shown, that the prevailing contribution of destruction or cross-linking in the general process of coal transformation at the heat treatment depends on temperature and time of thermal treatment. It was shown that the depth and direction of coals transformations at the heat treatment essentially depended on the genetic type of coals. 7 refs., 3 figs., 1 tab.

  5. Study of automatic designing of line heating technique parameters

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Based on experimental data of line heating, the methods of vector mapping, plane projection, and coordinate converting are presented to establish the spectra for line heating distortion discipline which shows the relationship between process parameters and distortion parameters of line heating. Back-propagation network (BP-net) is used to modify the spectra.Mathematical models for optimizing line heating techniques parameters, which include two-objective functions,are constructed. To convert the multi-objective optimization into a single-objective one, the method of changing weight coefficient is used, and then the individual fitness function is built up. Taking the number of heating lines, distance between the heating lines' border (line space), and shrink quantity of lines as three restrictive conditions,a hierarchy genetic algorithm (HGA) code is established by making use of information provided by the spectra, in which inner coding and outer coding adopt different heredity arithmetic operators in inherent operating. The numerical example shows that the spectra for line heating distortion discipline presented here can provide accurate information required by techniques parameter prediction of line heating process and the technique parameter optimization method based on HGA provided here can obtain good results for hull plate.

  6. Laser Heat Treatment on Gear Surface and Its Practical Application

    Institute of Scientific and Technical Information of China (English)

    MA Chun-yin; DAI Zhong-sen; SU Bao-rong

    2004-01-01

    Making gears with hardened tooth flank is one of the important developments in gear manufacturing. However, the conventional heat treating methods have a common shortcoming--producing big deformation. In this work, we demonstrate, by study, experiment and practical use, that not only has the laser heat treatment solved the difficult problems in conventional technique, but also it has great superiority. The use cases proved that the laser-treated gears are able to substitute for all the gears including gears with complicated shape, high precision and high performance imported gears and all those gears that cannot be manufactured by conventional methods. Moreover, our laser-treated gears have won quite good economic benefit.Obviously, the laser heat treatment for gears is a highly competitive technique having good prospects.

  7. Comparison of corrosion monitoring techniques in district heating systems

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Nielsen, Lars Vendelbo; Thorarinsdottir, R.I.

    2004-01-01

    Investigations aimed at evaluating monitoring techniques as a function of the specific water chemistry has been conducted as a part of a Nordic project focused on improving the quality of corrosion monitoring in municipal district heating. A combination of techniques has been selected to measure...

  8. Cast functional accessories for heat treatment furnaces

    Directory of Open Access Journals (Sweden)

    A. Drotlew

    2010-10-01

    Full Text Available The study gives examples of the cast functional accessories operating in furnaces for the heat treatment of metals and alloys. The describeddesign solutions of castings and their respective assemblies are used for charge preparation and handling. They were put in systematicorder depending on furnace design and the technological purpose of heat treatment. Basic grades of austenitic cast steel, used for castings of this type, were enumerated, and examples of general guidelines formulated for their use were stated. The functional accessories described in this study were designed and made by the Foundry Research Laboratory of West Pomeranian University of Technology.

  9. 49 CFR 179.500-6 - Heat treatment.

    Science.gov (United States)

    2010-10-01

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

  10. 49 CFR 179.400-12 - Postweld heat treatment.

    Science.gov (United States)

    2010-10-01

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

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

    Science.gov (United States)

    2010-10-01

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

  12. Local Laser Heat Treatments of Steel Sheets

    Science.gov (United States)

    Järvenpää, A.; Jaskari, M.; Hietala, M.; Mäntyjärvi, K.

    In this work UHS structural and abrasion resistant (AR) steels were heat treated with a single 4 kW Yb: YAG-laser beam. Aim of the softening heat treatments was to enhance the formability locally with minimized strength lose. 1.8 mm thick B24CR boron steel was used for hardening tests. Study presents the possibilities and limitations in laser processing showing that a single laser beam is suitable for heat treating of sheets through the whole cross-section up to the thickness of 6 mm. In the case of the 6 mm thick sheets, the achieved maximum temperature in the cross-section varies as a function of the depth. Consequently, the microstructure and mechanical properties differ between the surfaces and the center of the cross-section (layered microstructure). For better understanding, all layers were tested in tensile tests. The 10 mm thick sheet was heat treated separately on the both surfaces by heating to a lower temperature range to produce a shallow tempered layer. The tensile and bendability tests as well as hardness measurements indicated that laser heat treatment can be used to highly improve the bendability locally without significant strength losses. Laser process has been optimized by transverse scanning movement and with a simple FE-model.

  13. A laser-induced heat flux technique for convective heat transfer measurements in high speed flows

    Science.gov (United States)

    Porro, A. R.; Keith, T. G., Jr.; Hingst, W. R.

    1991-01-01

    A technique is developed to measure the local convective heat transfer coefficient on a model surface in a supersonic flow field. The technique uses a laser to apply a discrete local heat flux at the model test surface, and an infrared camera system determines the local temperature distribution due to the heating. From this temperature distribution and an analysis of the heating process, a local convective heat transfer coefficient is determined. The technique was used to measure the local surface convective heat transfer coefficient distribution on a flat plate at nominal Mach numbers of 2.5, 3.0, 3.5, and 4.0. The flat plate boundary layer initially was laminar and became transitional in the measurement region. The experimentally determined convective heat transfer coefficients were generally higher than the theoretical predictions for flat plate laminar boundary layers. However, the results indicate that this nonintrusive optical measurement technique has the potential to measure surface convective heat transfer coefficients in high-speed flowfields.

  14. Measurement of thermophysical properties by a pulse-heating technique

    Institute of Scientific and Technical Information of China (English)

    Peng Xiao; Jingmin Dai; Qingwei Wang

    2007-01-01

    A technique is described for the dynamic measurement of selected thermophysical properties of electrically conducting solids in the temperature range from 1100 K to the melting point. Based on rapid resistive self-heating of the specimen from room temperature to any desired high temperature in several seconds by the passage of an electical current pulse through it, this technique measures the pertinent quantities such as current, voltage, randiance temperature, with sub-millisecond time resolution. The pulse-heating technique is applied to strip specimens. The radiance temperature is measured by high-speed pyrometry,normal spectral emissivity of the strips is measured by integrating sphere reflectometry. The normal spectral emissivity results are used to compute the true temperature of the specimens. The heat capacity,electrical resistivity, total hemispherical emissivity are evaluated in the temperature range from 1100 K to the melting point.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-12-07

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

  16. A biological treatment technique for wool textile

    Directory of Open Access Journals (Sweden)

    Yu Xiao-Wei

    2005-09-01

    Full Text Available A biological treatment technique for wool textile was carried out by enzymes degradation coupled with H2O2 oxidation. The results demonstrated that the technique had ideal effects on wool textile such as better softness, plump and less loss of bursting stress. Because of mild reaction conditions, less textile damage and less environmental pollution, this technique for wool textile treatment could have promising prospect.

  17. Extraction treatment using Invisalign Technique.

    Science.gov (United States)

    Giancotti, Aldo; Greco, Mario; Mampieri, Gianluca

    2006-01-01

    The Invisalign method is gaining an increasing interest as an alternative treatment option in adult patients and in difficult orthodontic cases. The aim of this work is to show a class II malocclusion with severe crowding in the upper and lower arches treated with the extraction of the upper first premolars performed by means of Invisalign. The alignment phase was successfully completed but the space closure achieved with crown tipping and without correct root inclination making a further fixed appliance phase necessary.

  18. Heat Treatment of the Photonic Crystal Fiber

    Institute of Scientific and Technical Information of China (English)

    Joo; Beom; Eom; Seongwoo; Yoo; Jinchae; Kim; Hokyung; Kim; Un-Chul; Paek; Byeong; Ha; Lee

    2003-01-01

    We report heat treatment of the photonic crystal fiber. As the temperature was increased, the transmission of the photonic crystal fiber was increased, unlike conventional single mode fiber. The transmission increase at short wavelength region was larger than long wavelength region for the various temperatures. After crystallization of the silica glass, the spectra of the photonic crystal fiber were just decreased at all wavelength regions, but, in case of the single mode fiber, the absorption in visibl...

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

    Science.gov (United States)

    1982-05-01

    AD-A1uG 385 COLD RE61ONS RESEARCH AND ENGINEERING LAS HANOVER NH F/e 13/1 EVALUATING THE HEAT PUMP ALTERNATIVE FOR HEATING ENCLOSED WASTE--ETC(U) NAT...1982Enginee Cold Regions Research & Engineering Laboratory Evaluating the heat pump alternative for heating enclosed wastewater treatment facilities in...COVERED EVALUATING; THlE HEAT PUMP ALTERNATIVE FOR HEATING ENCLOSED WASTEWATER TREATMENT FACI~IITIES IN COLD REGIONS 6 PERFORMING ORG. REPORT NUMBER 7

  20. Fullerenes synthesis by combined resistive heating and arc discharge techniques.

    Science.gov (United States)

    Kyesmen, Pannan Isa; Onoja, Audu; Amah, Alexander Nwabueze

    2016-01-01

    The two main electrode techniques for fullerenes production; the direct arc technique and the resistive heating of graphite rod were employed in this work. One of the electrodes was resistively heated to high temperature and subjected to arc discharge along its length by the second graphite rod. Fullerenes solid were extracted from carbon soot samples collected from an installed arc discharge system using the solvent extraction method. The fullerenes solid obtained from carbon soot collected for 2 min of arc discharge run when one of the electrodes was resistively heated at different voltages all gave higher yields (maximum of 67 % higher, at 150 A arc current and 200 Torr chamber pressure) compared to when no resistive heating was carried out. Scanning electron microscopy and ultraviolet visible spectroscopy analysis carried out on all fullerenes solid indicated the presence of fullerenes. The enhancement of fullerenes production by combined resistive and direct arc techniques shows prospect for possible use at industrial level for large scale production.

  1. Comparison of corrosion monitoring techniques in district heating systems

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Nielsen, Lars Vendelbo; Thorarinsdottir, R.I.

    2004-01-01

    Investigations aimed at evaluating monitoring techniques as a function of the specific water chemistry has been conducted as a part of a Nordic project focused on improving the quality of corrosion monitoring in municipal district heating. A combination of techniques has been selected to measure...... both general and localised corrosion. Electrochemical techniques (LPR, EIS) as well as direct techniques (high sensitive ER, weight loss, local crevice corrosion current) have been applied. The data show that the water quality in Danish systems is high resulting in low corrosion rates, but changes...... in the water quality induce localised corrosion. Useful monitoring results have been obtained with high sensitive ER technique (MetriCorr) and crevice corrosion measurements with the LOCORR cell (FORCE TECHNOLOGY)....

  2. Optimization of Heat-Sink Cooling Structure in EAST with Hydraulic Expansion Technique%Optimization of Heat-Sink Cooling Structure in EAST with Hydraulic Expansion Technique

    Institute of Scientific and Technical Information of China (English)

    许铁军; 黄生洪; 谢韩; 宋云涛; 张平; 戢翔; 高大明

    2011-01-01

    Considering utilization of the original chromium-bronze material, two processing techniques including hydraulic expansion and high temperature vacuum welding were proposed for the optimization of heat-sink structure in EAST. The heat transfer performance of heat-sink with or without cooling tube was calculated and different types of connection between tube and heat-sink were compared by conducting a special test. It is shown from numerical analysis that the diameter of heat-sink channel can be reduced from 12 mm to 10 mm. Compared with the original sample, the thermal contact resistance between tube and heat-sink for welding sample can reduce the heat transfer performance by 10%, while by 20% for the hydraulic expansion sample. However, the welding technique is more complicated and expensive than hydraulic expansion technique. Both the processing technique and the heat transfer performance of heat-sink prototype should be further considered for the optimization of heat-sink structure in EAST.

  3. Open palm technique in Dupuytren's disease treatment

    Directory of Open Access Journals (Sweden)

    Marcio Carpi Malta

    2013-06-01

    Full Text Available OBJECTIVE: To evaluate the results of the open palm technique for the treatment of Dupuytren's disease. METHOD: The authors used the technique described by McCash. Twelve patients (13 hands were surgically treated, between october 2002 and september 2011. RESULTS: The wounds healed in a medium of 25 days (variation of 17 to 30 days. There were no complications, such as infection, haematoma formation, skin necrosis, residual edema. CONCLUSION: The open palm technique remains a safe alternative for the treatment of Dupuytren's disease, with satisfactory results and low risk of complications.

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

    Science.gov (United States)

    Verhave, Jan Peter

    2016-01-01

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

  5. High resolution temperature measurement technique for measuring marine heat flow

    Institute of Scientific and Technical Information of China (English)

    QIN; YangYang; YANG; XiaoQiu; WU; BaoZhen; SUN; ZhaoHua; SHI; XiaoBin

    2013-01-01

    High resolution temperature measurement technique is one of the key techniques for measuring marine heat flow. Basing on Pt1000 platinum resistance which has the characteristics of high accuracy and good stability, we designed a bridge reversal excitation circuit for high resolution temperature measurement. And the deep ocean floor in-situ test results show that: (1) temperature deviation and peak-to-peak resolution of the first version circuit board (V1) are 1.960-1.990 mK and 0.980-0.995 m Kat 1.2-2.7°C, respectively; and temperature deviation and peak-to-peak resolution of the second circuit board (V2) are 2.260mK and 1.130 mK at 1.2-1.3°C, respectively; (2) During the 2012NSFC-IndOcean cruise, seafloor geothermal gradient at Ind2012HF03,-07 and-12 stations (water depth ranges from 3841 to 4541 m) were successfully measured, the values are 59.1,75.1 and 71.6°C/km, respectively. And the measurement errors of geothermal gradient at these three stations are less than 3.0% in terms of the peak-to-peak resolution. These indicate that the high resolution temperature measurement technique based on Pt1000 platinum resistance in this paper can be applied to marine heat flow measurement to obtain high precision geothermal parameters.

  6. 49 CFR 179.200-11 - Postweld heat treatment.

    Science.gov (United States)

    2010-10-01

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

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

    Science.gov (United States)

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

  8. Research on radon detecting technique for locating inaccessible underground heatings

    Institute of Scientific and Technical Information of China (English)

    XIE Jun; XUE Sheng; WANG Gang

    2011-01-01

    The identification of the exact location of the heatings that occur in often inaccessible locations several hundred meters deep in goaf areas is a key to allowing effective control measures to be taken.Radon technique provides the only solution for remotely locating underground sponcom from surface.The results of Chaili mine indicated that a total area of 66 000 m2 has been surveyed and exact locations of spontaneous combustion have been detected.This has enabled the successful implementation of various control measures against spontaneous combustion.

  9. Induction heat treatment of laser welds

    DEFF Research Database (Denmark)

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

    2003-01-01

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

  10. Induction heat treatment of laser welds

    DEFF Research Database (Denmark)

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

    2003-01-01

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

  11. Cast construction elements for heat treatment furnaces

    Directory of Open Access Journals (Sweden)

    B. Piekarski

    2011-07-01

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

  12. 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.

  13. The use of fluidized sand bed as an innovative technique for heat treating aluminum based castings

    Science.gov (United States)

    Ragab, Khaled

    The current study was carried out to arrive at a better understanding of the influences of the fluidized sand bed heat treatment on the tensile properties and quality indices of A356.2 and B319.2 casting alloys. For the purposes of validating the use of fluidized sand bed furnaces in industrial applications for heat treatment of 356 and 319 castings, the tensile properties and the quality indices of these alloys were correlated with the most common metallurgical parameters, such as strontium modification, grain refining, solutionizing time, aging parameters and quenching media. Traditional heat treatment technology, employing circulating air convection furnaces, was used to establish a relevant comparison with fluidized sand beds for the heat treatment of the alloys investigated, employing T6 continuous aging cycles or multi-temperature aging cycles. Quality charts were used to predict and/or select the best heat treatment conditions and techniques to be applied in industry in order to obtain the optimum properties required for particular engineering applications. The results revealed that the strength values achieved in T6-tempered 319 and 356 alloys are more responsive to fluidized bed (FB) heat treatment than to conventional convection furnace (CF) treatment for solution treatment times of up to 8 hours. Beyond this solution time, no noticeable difference in properties is observed with the two techniques. A significant increase in strength is observed in the FB heat-treated samples after short aging times of 0.5 and 1 hour, the trend continuing up to 5 hours. The 319 alloys show signs of overaging after 8 hours of aging using a conventional furnace, whereas with a fluidized bed, overaging occurs after 12 hours. Analysis of the tensile properties in terms of quality index charts showed that both modified and non-modified 319 and 356 alloys display the same, or better, quality, after only a 2-hr treatment in an FB compared to 10 hours when using a CF. The quality

  14. 49 CFR 179.100-10 - Postweld heat treatment.

    Science.gov (United States)

    2010-10-01

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

  15. Heat Treatment of Die and Mould Oriented Concurrent Design

    Institute of Scientific and Technical Information of China (English)

    LI Xiong; ZHANG Hong-bing; RUAN Xue-yu; LUO Zhong-hua; ZHANG Yan

    2006-01-01

    Many disadvantages exist in the traditional die design method which belongs to serial pattern. It is well known that heat treatment is highly important to the dies. A new idea of concurrent design for heat treatment process of die and mould was developed in order to overcome the existent shortcomings of heat treatment process. Heat treatment CAD/CAE was integrated with concurrent circumstance and the relevant model was built. These investigations can remarkably improve efficiency, reduce cost and ensure quality of R and D for products.

  16. Heat treatment process of new NdFeB magnet prepared by spark plasma sintering

    Institute of Scientific and Technical Information of China (English)

    李涛; 岳明; 张久兴; 王公平; 肖耀福; 王润

    2003-01-01

    In recent years, spark plasma sintering technique(SPS) has been a focus in the field of material preparation due to its advantages. SPS technique is first introduced for preparation of high quality NdFeB magnets. The effects of heat treatment process on the magnetic properties of SPS NdFeB magnet were investigated. Meanwhile, the effects of heat treatment process on the microstructure, tropism and dimensional precision of the SPS NdFeB magnets were also studied. The high quality NdFeB magnets with fine grains were prepared under proper heat treatment process. The results show that the magnetic properties of SPS NdFeB can be further improved through proper heat treatment process. Meanwhile, the experiment also demonstrates that it is feasible to prepare near-net-shape NdFeB magnets with fine grains and high magnetic property by spark plasma sintering.

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

    Directory of Open Access Journals (Sweden)

    Kamran Amini

    2017-03-01

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

  18. Enhancing the crystalline degree of carbon nanotubes by acid treatment, air oxidization and heat treatment

    Institute of Scientific and Technical Information of China (English)

    Chensha Li; Baoyou Zhang; Xingjuan Chen; Xiaoqing Hu; Ji Liang

    2005-01-01

    Three approaches of treating carbon nanotubes (CNTs) including acid treatment, air oxidization and heat treatment at high temperature were studied to enhance the crystalline degree of carbon nanotubes. High temperature heat-treatment elevates the crystalline degree of carbon nanotubes. Acid treatment removes parts of amorphous carbonaceous matter through its oxidization effect.Air oxidization disperses carbon nanotubes and amorphous carbonaceous matter. The treatment of combining acid treatment with heat-treatment further elevates the crystalline degree of carbon nanotubes comparing with acid treatment or heat-treatment. The combination of the three treatments creates the thorough effects of enhancing the crystalline degree of carbon nanotubes.

  19. PECULIAR FEATURES OF ELECTROLYTIC-PLASMA HEATING DURING ELECTROCHEMICAL HEAT-TREATMENT OF STEEL

    Directory of Open Access Journals (Sweden)

    Yu. Alekseev

    2013-01-01

    Full Text Available Thermo-physical peculiar features of  anode electrolytic-plasma heating applied for heat and chemical heat-treatment have been investigated in the paper. The paper presents  results of the investigations pertaining  to influence of the operating voltage on current density, temperature and heating rate, heating power and  changes in heat portion passing to the anode. Peculiar features of layer formation which are hardened  by electrolytic-plasma carburizing  have been presented in the paper.

  20. 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.

  1. Control Techniques in Heating, Ventilating and Air Conditioning Systems

    Directory of Open Access Journals (Sweden)

    H. Mirinejad

    2008-01-01

    Full Text Available Problem statement: Heating, Ventilating and Air Conditioning (HVAC systems are among the main installations in residential, commercial and industrial buildings. The purpose of the HVAC systems is normally to provide a comfortable environment in terms of temperature, humidity and other environmental parameters for the occupants as well as to save energy. Achieving these objectives requires a suitable control system design. Approach: In this overview, thermal comfort level and ISO comfort field is introduced, followed by a review and comparison of the main existing control techniques used in HVAC systems to date. Results: The present overview shows that intelligent controllers which are based on the human sensation of thermal comfort have a better performance in providing thermal comfort as well as energy saving than the traditional controllers and those based on a model of the HVAC system. Conclusion: Such an overview provides an insight into current control methods in HVAC systems and can help scholars and HVAC learners to have the comprehensive information about a variety of control techniques in the field of HVAC and therefore to better design a proper controller for their work

  2. Towards convective heat transfer enhancement: surface modification, characterization and measurement techniques

    NARCIS (Netherlands)

    Taha, T.J.; Thakur, D.B.; van der Meer, Theodorus H.

    2012-01-01

    In this work, heat transfer surface modification and heat transfer measurement technique is developed. Heat transfer investigation was aimed to study the effect of carbon nano fibers (extremely high thermal conductive material) on the enhancement level in heat transfer. Synthesis of these carbon nan

  3. Towards convective heat transfer enhancement: surface modification, characterization and measurement techniques

    NARCIS (Netherlands)

    Taha, T.J.; Thakur, D.B.; Meer, van der T.H.

    2012-01-01

    In this work, heat transfer surface modification and heat transfer measurement technique is developed. Heat transfer investigation was aimed to study the effect of carbon nano fibers (extremely high thermal conductive material) on the enhancement level in heat transfer. Synthesis of these carbon nan

  4. 49 CFR 179.300-10 - Postweld heat treatment.

    Science.gov (United States)

    2010-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Sowa, Maciej [Faculty of Chemistry, Silesian University of Technology, B. Krzywoustego Street 6, 44-100 Gliwice (Poland); Dercz, Grzegorz [Institute of Materials Science, University of Silesia, 75 Pułku Piechoty Street 1 A, 41-500 Chorzów (Poland); Suchanek, Katarzyna [The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego Street 152, 31-342 Krakow (Poland); Simka, Wojciech, E-mail: wojciech.simka@polsl.pl [Faculty of Chemistry, Silesian University of Technology, B. Krzywoustego Street 6, 44-100 Gliwice (Poland)

    2015-08-15

    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.

  6. Sterilization techniques without heating (ultraviolet ray, radiation and ozone)

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hitoshi (Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment)

    1991-01-01

    The recent demand of consumers for processed foods is characterized by the intention for health and nature, besides, the demand for low sweetness, salt reduction, no additive and freshness becomes strong. In view of the control of microorganisms in products, all these become the negative factors. Accordingly, in order to overcome them, it is urgently desired to develop new technology or to improve conventional methods. As to heating sterilization, the uniform temperature treatment to the inside of foods is difficult, and it cannot be applied to perishables. The high temperature sterilization above 120degC causes the change in nutrition composition and physical properties. Ultraviolet ray and ozone can be used for the sterilization of food surface and powder and liquid foods. Radiation treatment can be applied to packed foods and frozen foods as well as food surface. The principle and the fields of application of ultraviolet ray sterilization, radiation sterilization and ozone sterilization are reported. In the mechanism of these methods, the action to DNA and oxidation are common. (K.I.).

  7. Optimal Heating in Heat-Treatment Process Based on Grey Asynchronous Particle Swarm Optimization

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    To ensure plate heating quality and reduce energy consumption in heat-treatment process, optimal heating for plates in a roller hearth furnace was investigated and a new strategy for heating procedure optimization was developed. During solving process, plate temperature forecast model based on heat transfer mechanics was established to calculate plate temperature with the assumed heating procedure. In addition, multi-objective feature of optimal heating was analyzed. And the method, which is composed of asynchronous particle swarm optimization and grey relational analysis, was adopted for solving the multi-objective problem. The developed strategy for optimizing heating has been applied to the mass production. The result indicates that the absolute plate discharging temperature deviation between measured value and target value does not exceed ± 8 ℃, and the relative deviation is less than ± 0.77%.

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

    Directory of Open Access Journals (Sweden)

    A. F. Demirova

    2013-01-01

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

  9. Effect of heat treatments in the silicon eutectic crystal evolution in Al-Si alloys

    Energy Technology Data Exchange (ETDEWEB)

    Forn, A.; Baile, M.T.; Martin, E.; Ruperez, E. [Light Alloys and Surface Treatments Design Centre (CDAL), Univ. Politecnica de Catalunya, Vilanova I la Geltru (Spain)

    2005-07-01

    This paper describes the heat treatment effect on the eutectic silicon evolution in the A357 alloy, obtained by semisolid forming process (SSM). The coarsening rate of the silicon was determined by image analysis technique in specimens from rheocasting ingots and thixocasting components. The study was realized in the temperature range from 450 to 550 C by applying heating times between 1 and 24 hours. The results show that during the heat treatment the coarsening and sphereodization of the silicon particles is produced and the fragmentation stages, which are observed in conventional alloys, do not appear. Kinetic silicon growth has been adjusted to the Oswald's ripening equation. (orig.)

  10. New Nomenclatures for Heat Treatments of Additively Manufactured Titanium Alloys

    Science.gov (United States)

    Baker, Andrew H.; Collins, Peter C.; Williams, James C.

    2017-07-01

    The heat-treatment designations and microstructure nomenclatures for many structural metallic alloys were established for traditional metals processing, such as casting, hot rolling or forging. These terms do not necessarily apply for additively manufactured (i.e., three-dimensionally printed or "3D printed") metallic structures. The heat-treatment terminology for titanium alloys generally implies the heat-treatment temperatures and their sequence relative to a thermomechanical processing step (e.g., forging, rolling). These designations include: β-processing, α + β-processing, β-annealing, duplex annealing and mill annealing. Owing to the absence of a thermomechanical processing step, these traditional designations can pose a problem when titanium alloys are first produced via additive manufacturing, and then heat-treated. This communication proposes new nomenclatures for heat treatments of additively manufactured titanium alloys, and uses the distinct microstructural features to provide a correlation between traditional nomenclature and the proposed nomenclature.

  11. Quality assurance of a conformal treatment technique

    Energy Technology Data Exchange (ETDEWEB)

    Kroes, A.P.G.; Bruinvis, I.A.D.; Lanson, J.H.; Uiterwaal, G.J. [Nederlands Kanker Inst. `Antoni van Leeuwenhoekhuis`, Amsterdam (Netherlands)

    1995-12-01

    For a parotid gland irradiation technique with a pair of oblique wedged photon beams the target coverage near the surface was investigated. The planning target volume extends to 5 millimetres under the skin; a minimum target dose of 95% is required when the dose at the centre is set to 100%. The treatment technique was simulated on a water phantom with a beam of 45 degree gantry angle, 55 degree wedge, 8 x 10 cm{sup 2} field size and the isocentre at 2 cm depth. Beam energies of 4, 6 and 8 MV were used. The dose distributions were measured in two orthogonal planes through the isocentre perpendicular to the water surface with p-type silicon diodes along lines through the isocentre every 45 degrees. Dose distributions were calculated in these planes with our 3-D planning system (U-Mplan, University of Michigan planning system), with model parameters are fitted to depth dose curves and profiles of open and wedged normally incident beams. The location of the 95% isodose was determined in five points near the surface. For 4, 6 and 8 MV the depths of the 95% isodose were 6.0, 10.3 and 11.0 mm, respectively. The depths of the 95% points of single normally incident open fields were 6.0, 9.0 and 11.5 mm, respectively. The treatment planning system (TPS) calculated the 95% isodose for the parotid technique at 5.5, 7.3 and 11.5 mm depths, for 4, 6 and 8 MV, respectively. Thus for 6 MV the 95% was 3 mm deeper than calculated by the TPS; 2 mm were caused by the inaccuracy of the open field depth dose curve fit in the build-up region. The depth near the surface of the 95% isodose for this treatment technique can be estimated from single open field depth dose curves with acceptable accuracy. This result is not obvious because the effects of the wedge and oblique incidence on the dose distribution are also involved. The TPS performed well for the 4 and 8 MV beams, but for treatments with 6 MV target under dosage could have remained undetected. (Abstract Truncated)

  12. Computer-aided simulation of the heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Arola, R.; Martikainen, H.; Virta, J. [Technical Research Centre of Finland, Espoo (Finland). Metallurgy Lab.

    1993-12-31

    Computer-aided simulation of the heat treatment of components and charges is examined. Existing programs for the simulation of heat treatment are reviewed. Test simulations including calculation of temperature, phase composition and stresses and strains during heating and cooling are performed with selected programs. The results of the simulations are compared with the results of heat treating experiments. Heat transfer during heating-up varies considerably between different treatments, components of the charge and surfaces of the component. Therefore, heat transfer data defined on the basis of the measurements has to be used in exact simulation instead of literature data. According to the simulation results non-uniform temperature distribution, plastic straining and residual stresses after heating can be formed in an AISI 316 bar heated up at the edge of a charge in a pit furnace. Permanent bending of these bars as a result of heating is not observed. In the oil quenching of a 42CrMo4 cylinder, where martensite and bainite are formed in austenite decomposition, the simulation results (especially amounts of phases and residual stresses) are crucially dependent on the TTT-diagram describing the kinetics of the phase transformations. Several TTT-diagrams for the steel grade are found, leading to different simulation results

  13. Heat treatment modelling using strongly continuous semigroups.

    Science.gov (United States)

    Malek, Alaeddin; Abbasi, Ghasem

    2015-07-01

    In this paper, mathematical simulation of bioheat transfer phenomenon within the living tissue is studied using the thermal wave model. Three different sources that have therapeutic applications in laser surgery, cornea laser heating and cancer hyperthermia are used. Spatial and transient heating source, on the skin surface and inside biological body, are considered by using step heating, sinusoidal and constant heating. Mathematical simulations describe a non-Fourier process. Exact solution for the corresponding non-Fourier bioheat transfer model that has time lag in its heat flux is proposed using strongly continuous semigroup theory in conjunction with variational methods. The abstract differential equation, infinitesimal generator and corresponding strongly continuous semigroup are proposed. It is proved that related semigroup is a contraction semigroup and is exponentially stable. Mathematical simulations are done for skin burning and thermal therapy in 10 different models and the related solutions are depicted. Unlike numerical solutions, which suffer from uncertain physical results, proposed analytical solutions do not have unwanted numerical oscillations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Development of a laser-induced heat flux technique for measurement of convective heat transfer coefficients in a supersonic flowfield

    Science.gov (United States)

    Porro, A. Robert; Keith, Theo G., Jr.; Hingst, Warren R.; Chriss, Randall M.; Seablom, Kirk D.

    1991-01-01

    A technique is developed to measure the local convective heat transfer coefficient on a model surface in a supersonic flow field. The technique uses a laser to apply a discrete local heat flux at the model test surface, and an infrared camera system determines the local temperature distribution due to heating. From this temperature distribution and an analysis of the heating process, a local convective heat transfer coefficient is determined. The technique was used to measure the load surface convective heat transfer coefficient distribution on a flat plate at nominal Mach numbers of 2.5, 3.0, 3.5, and 4.0. The flat plate boundary layer initially was laminar and became transitional in the measurement region. The experimental results agreed reasonably well with theoretical predictions of convective heat transfer of flat plate laminar boundary layers. The results indicate that this non-intrusive optical measurement technique has the potential to obtain high quality surface convective heat transfer measurements in high speed flowfields.

  15. Generic vapor heat treatments to control Maconellicoccus hirsutus (Homoptera: Pseudococcidae).

    Science.gov (United States)

    Follett, Peter A

    2004-08-01

    Vapor heat treatments were developed against life stages of the mealybug Maconellicoccus hirsutus (Green) (Homoptera: Pseudococcidae). Treatments tested were 47 degrees C for 5-50 min in 5-min increments and 49 degrees C for 3, 5, 8, 10, and 12 min. All tests were conducted with mixed age M. hirsutus on Chinese pea, Pisum sativum L. Treatment at 47 degrees C required 45 min to kill all M. hirsutus, whereas treatment at 49 degrees C required 10 min. The adult female and nymphal stages were the most heat tolerant at 47 degrees C, but the egg stage was the most heat tolerant at 49 degrees C. Use of the vapor heat treatments on other commodities will require achieving or exceeding the proper temperature and duration at all locations on the host where M. hirsutus may reside.

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

    Science.gov (United States)

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

    2013-04-01

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

  17. Study on heat treatment blister of squeeze casting parts

    Institute of Scientific and Technical Information of China (English)

    TONG Wen-jun; QI Lin; QI Pi-xiang

    2007-01-01

    Heat treatment blister is one of the common defects found in squeeze casting parts, which is related to squeeze mode, process and mold. For direct squeeze-casting parts, solution heat treatment can be performed smoothly as long as oil-based paint is not used and air exhaust is well arranged. For indirect squeeze casting parts,solution heat treatment can also be applied when additional factors are taken into consideration, including well designed internal feeding system and strictly controlled liquid metal filling velocity to prevent from inclusions.

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

    Directory of Open Access Journals (Sweden)

    Hájek J.

    2016-09-01

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

  19. Protection of phosphatidylcholine to photosystemⅡ membrane during heat treatment

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Photosystem Ⅱ membrane was reconstituted with phosphatidylcholine (PC) with different kinds of fatty acyl chains and the protection of PC to photosystem Ⅱ (PSⅡ) membrane during heat treatment was investigated using oxygen electrode, variable fluorescence and circular dichroism (CD) spectroscopy. Heat treatment decreased the oxygen evolution rate and the F′v/Fm′ ratio of PSⅡ membrane and influenced CD spectra of PSⅡ membrane, but PC inhibited the effect of heat treatment on the oxygen evolution rate, the F′v/F′m ratio and CD spectra of PSⅡ membrane. The results indicate that PC can protect PSⅡ membrane against heat treatment and the alterations in the unsaturated fatty acid extent in PC can cause the changes of the protection ability.

  20. Towards convective heat transfer enhancement: surface modification, characterization and measurement techniques

    Science.gov (United States)

    Taha, T. J.; Thakur, D. B.; Van der Meer, T. H.

    2012-11-01

    In this work, heat transfer surface modification and heat transfer measurement technique is developed. Heat transfer investigation was aimed to study the effect of carbon nano fibers (extremely high thermal conductive material) on the enhancement level in heat transfer. Synthesis of these carbon nano structures is achieved using thermal catalytic chemical vapor deposition process (TCCVD) on a 50 μm pure nickel (Ni270) wire. The micro wire samples covered with CNF layers were subjected to a uniform flow from a nozzle. Heat transfer measurement was achieved by a controlled heat dissipation through the micro wire to attain a constant temperature during the flow. This measurement technique is adopted from hot wire anemometry calibration method. Synthesis of carbon nano structures, heat transfer surface characterization and measurement technique are evaluated. Preliminary results indicate that an average enhancement in Nusselt Number of 17% is achieved.

  1. Techniques of endoscopic airway tumor treatment.

    Science.gov (United States)

    Guibert, Nicolas; Mhanna, Laurent; Droneau, Sylvain; Plat, Gavin; Didier, Alain; Mazieres, Julien; Hermant, Christophe

    2016-11-01

    Interventional bronchoscopy has a predominant role in the management of both early and advanced-stage airway tumors. Given the very poor prognosis of lung cancer, there is a need for new tools to improve early detection and bronchoscopic treatment of endo-bronchial precancerous lesions. In more advanced stages, interventional bronchoscopy plays an important role, as nearly a third of lung cancers lead to proximal airway obstruction. This will cause great discomfort or even life-threatening symptoms related to local extension, such as dyspnea, post-obstructive pneumonia, and hemoptysis. Surgery for very locally advanced disease is only effective for a limited number of patients and the effects of conventional antitumor therapies, like radiation therapy or chemotherapy, are inconstant and are too delayed in a palliative context. In this review, we aim to provide pulmonologists with an exhaustive technical overview of (I) the bronchoscopic management of benign endobronchial lesions; (II) the bronchoscopic management of malignant tumors, including the curative treatment of localized lesions and palliative management of malignant proximal airway stenosis; and (III) descriptions of the emerging endoscopic techniques used to treat peripheral lung tumors.

  2. Modular Heat Dissipation Technique for a CubeSat

    Science.gov (United States)

    2015-07-28

    box dimensions are decided, the heat dissipater was modeled in SOLIDWORKS ® and frequency analysis was conducted computationally by Mr. Philip D...Technical Drawing of the Heat Dissipater Box SolidWorks Educational License Instructional Use Only 3 . 819 PC1e4 layout CO!IITJACr: 0«!. ~~~1h...First Edge of the Heat Dissipater Box 3. 819 l-----l3 . 819f------l~PCle4 layout rT-----------------,~·~I.2sel ~--------------~---r SolidWorks

  3. Modeling and Simulation of Heat Transfer in Loaded Continuous Heat Treatment Furnace

    Institute of Scientific and Technical Information of China (English)

    KANG Jin-wu; HUANG Tian-you; PURUSHOTHAMAN Radhakrishnan; WANG Wei-wei; RONG Yi-ming

    2004-01-01

    Continuous furnaces are widely used in the heat treatment of mass-produced parts. However, the heating up process of parts in continuous furnace is still decided by experience. In this paper the heat transfer in the continuous furnace is formulated firstly. The heat balance in each zone is discussed and equations are given. Coupled with the model for heat transfer between workpieces and furnace and the heat transfer in the workload as well presented in the former developed CHT-bf for batch furnaces, a program CHT-cf for continuous furnaces was developed. The model deals with two typical movements of parts: continuous or step by step. The moving speed of parts and load pattern can be optimized based on the calculated temperature distributions and curves, especially, the fastest heated and slowest-heated temperature-distance profiles. A case study is carried out for the heat treatment of a kind of hook-shaped part. The calculated results are analyzed and in good agreement with the measured ones.

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

    Science.gov (United States)

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

    2010-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-12-31

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

  6. 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.

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

    Science.gov (United States)

    Opit, G P; Arthur, F H; Bonjour, E L; Jones, C L; Phillips, T W

    2011-08-01

    Field experiments were conducted in 2007 and 2008 to evaluate heat treatment for disinfestations of empty concrete elevator silos. A Mobile Heat Treatment Unit was used to introduce heat into silos to attain target conditions of 50 degrees C for at least 6 h. Ventilated plastic containers with a capacity of 100 g of wheat, Triticum aestivum L., held Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) and Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). Polyvinyl chloride containers with a capacity of 300 g of wheat held adults of Liposcelis corrodens (Heymons) (Psocoptera: Liposcelididae) and Liposcelis decolor (Pearman), which were contained in 35-mm Petri dishes within the grain. Containers were fastened to a rope suspended from the top of the silo at depths of 0 m (just under the top manhole), 10 m, 20 m, and 30 m (silo floor). When the highest temperature achieved was approximately 50 degrees C for 6 h, parental mortality ofR. dominica and T. castaneum, and both psocid species was 98-100%. Progeny production of R. dominica occurred when there was parental survival, but in general R. dominica seemed less impacted by the heat treatment than T. castaneum. There was 100% mortality of L. corrodens at all depths in the heat treatments but only 92.5% mortality for L. decolor, with most survivors located in the bioassay containers at the top of the silo. Results show wheat kernels may have an insulating effect and heat treatment might be more effective when used in conjunction with sanitation and cleaning procedures.

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

    Directory of Open Access Journals (Sweden)

    Younsi Ramdane

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    K. Raghu Ram Mohan Reddy

    2017-01-01

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

  10. Autoclave heat treatment for prealloyed powder products

    Science.gov (United States)

    Freche, J. C.; Ashbrook, R. L.

    1973-01-01

    Technique could be applied directly to loose powders as part of hot pressing process of forming them to any required shapes. This would eliminate initial extrusion step commonly applied to prealloyed powders, substantially reduce cost of forming operation, and result in optimum properties.

  11. COLOR CHANGE OF CHINESE FIR THROUGH STEAM-HEAT TREATMENT

    Directory of Open Access Journals (Sweden)

    Yongjian Cao,

    2012-05-01

    Full Text Available Dark brown wood color is a current trend and widely appreciated by consumers in the furniture and decoration markets. Heat treatment is one of the most effective methods to darken wood’s appearance. The influence of steam-heat treatment on color change of Chinese fir (Cunninghamia lanceolata (Lamb. Hook. was investigated within the temperature range from 170 to 230 oC and time from 1 to 5 hours in an air-tight chamber within an atmosphere comprising less than 2 percent oxygen. Saturated steam was used as a heating medium and a shielding gas. The results showed that the chroma difference (△C* decreased gradually, while the color difference (△E* and hue difference (△H* increased with an increase in temperature and length of time. An analysis of variance (ANOVA and a multi-comparison analysis revealed that the treatment temperature plays a more important role in darkening wood color during the process of steam-heat treatment in comparison with the treatment time. The results suggest that a more desirable wood color can be achieved with the technology of steam-heat treatment.

  12. Laser heating: a minimally invasive technique for studying fire-generated heating in building stone

    Directory of Open Access Journals (Sweden)

    Ocaña, José Luis

    2008-06-01

    Full Text Available Due to the irreparable damage it can cause, fire is one of the major risks to buildings. Recent studies on the effects of fire tend to focus on micro-scale analysis, addressing questions such as micro-cracking or mineralogical or chemical changes that are particularly relevant to listed buildings.The fire simulation techniques employed to date (convection heating laboratory furnaces and real flame tests are subject to a series of limitations including non-repeatability, the lack of combustion by-products and, most importantly, the need to work with large samples. In this final context, techniques must be found that require only minimal sample sizes.This paper introduces laser irradiation as a technique suitable for simulating the “combustion” of building materials, since it mimics the physics of fire, is repeatable, yields combustion products and, most importantly, can be applied to small specimens. Indeed, as laser irradiation concentrates high amounts of energy in small areas, it can be used for micro-scale testing.El fuego es una de las amenazas más importantes para los edificios debido a la escala de pérdidas irreparables que genera. Los estudios sobre los efectos del fuego se han dirigido recientemente hacia escalas de observación más detalladas, que son más adecuadas para el estudio de muestras de edificios patrimoniales, como microfisuración y cambios mineralógicos y químicos.Las técnicas de simulación de fuegos empleadas hasta ahora (ensayos con hornos y llamas reales presentan varias limitaciones como, por ejemplo, la falta de repetibilidad, ausencia de sub-productos de combustión o, especialmente, el uso de muestras de gran tamaño. Por esta última razón, es importante encontrar técnicas en las que se pueda usar cantidades mínimas de muestra.Este artículo presenta la irradiación láser como una técnica adecuada para simular el “quemado” de materiales de construcción, ya que ofrece una física de

  13. A genetic algorithm technique to optimize the configuration of heat storage in DH networks

    Directory of Open Access Journals (Sweden)

    Amru Rizal Razani

    2016-12-01

    Full Text Available The technical and economical evaluation of heat storage layout and configuration in the DH network is one of important aspect for optimizing the heat production from the heat supplier’s point of view in one side as well as to satisfy the heat customer demand in the other side. Generally, the state of the art technique has considered three optional planning layouts for DH network. A classical network with centralized heat storage at Combined Heat and Power (CHP plant, decentralized storages in the network, and decentralized small storages at the substations or in the customer building. In this paper, through the use of genetic algorithm technique, comparison of three different scenarios is presented to evaluate the optimal planning of heat storage layout in CHP based DH supply system according to economical and technical aspects in the network.

  14. The effects of heat treatment on technological properties in Red-bud maple (Acer trautvetteri Medw.) wood.

    Science.gov (United States)

    Korkut, Süleyman; Kök, M Samil; Korkut, Derya Sevim; Gürleyen, Tuğba

    2008-04-01

    Heat treatment is often used to improve the dimensional stability of wood. In this study, the effects of heat treatment on technological properties of Red-bud maple (Acer trautvetteri Medw.) wood were examined. Samples obtained from Düzce Forest Enterprises, Turkey, were subjected to heat treatment at varying temperatures (120 degrees C, 150 degrees C and 180 degrees C) and for varying durations (2h, 6h and 10h). The technological properties of heat-treated wood samples and control samples were tested. Compression strength parallel to grain, bending strength, modulus of elasticity in bending, janka-hardness, impact bending strength, and tension strength perpendicular to grain were determined. The results showed that technological strength values decreased with increasing treatment temperature and treatment times. Red-bud maple wood could be utilized by using proper heat treatment techniques with minimal losses in strength values in areas where working, and stability such as in window frames, are important factors.

  15. 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.)

  16. Effect of heat treatment on stainless steel orthodontic wires

    Directory of Open Access Journals (Sweden)

    Osmar Aparecido Cuoghi

    2011-04-01

    Full Text Available This study evaluated the effect of heat treatment on CrNi stainless steel orthodontic archwires. Half of forty archwires of each thickness - 0.014" (0.35 mm, 0.016" (0.40 mm, 0.018" (0.45 mm and 0.020" (0.50 mm (totalling 160 archwires - were subjected to heat treatment while the remainder were not. All of the archwires had their individual thickness measured in the anterior and posterior regions using AutoCad 2000 software before and after compressive and tensile strength testing. The data was statistically analysed utilising multivariance ANOVA at a 5% significance level. All archwires without heat treatment that were subjected to tensile strength testing presented with anterior opening, which was more accentuated in the 0.020" archwires. In the posterior region, the opening produced by the tensile force was more accentuated in the archwires without heat treatment. There was greater stability in the thermally treated archwires, especially those subjected to tensile strength testing, which indicates that the heat treatment of orthodontic archwires establishes a favourable and indispensable condition to preserve the intercanine width.

  17. Heat Shock Proteins, Autoimmunity, and Cancer Treatment

    Directory of Open Access Journals (Sweden)

    Stuart K. Calderwood

    2012-01-01

    Full Text Available Heat shock proteins (HSPs have been linked to the therapy of both cancer and inflammatory diseases, approaches that utilize contrasting immune properties of these proteins. It would appear that HSP family members Hsp60 and Hsp70, whether from external sources or induced locally during inflammation, can be processed by antigen-presenting cells and that HSP-derived epitopes then activate regulatory T cells and suppress inflammatory diseases. These effects also extend to the HSP-rich environments of cancer cells where elevated HSP concentrations may participate in the immunosuppressive tumor milieu. However, HSPs can also be important mediators of tumor immunity. Due to their molecular chaperone properties, some HSPs can bind tumor-specific peptides and deliver them deep into the antigen-processing pathways of antigen-presenting cells (APCs. In this context, HSP-based vaccines can activate tumor-specific immunity, trigger the proliferation and CTL capabilities of cancer-specific CD8+ T cells, and inhibit tumor growth. Further advances in HSP-based anticancer immunotherapy appear to involve improving the properties of the molecular chaperone vaccines by enhancing their antigen-binding properties and combating the immunosuppressive tumor milieu to permit programming of active CTL capable of penetrating the tumor milieu and specifically targeting tumor cells.

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

    Science.gov (United States)

    Alberta Advanced Education and Technology, 2008

    2008-01-01

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

  19. A New Technique for Measuring the Heat Loss Coefficient

    DEFF Research Database (Denmark)

    Svendsen, Sv Aa Højgaard; Rose, Jørgen

    1996-01-01

    To measure the effect of linear cold bridges in building envelope constructions the guarded hot box technique is used. A new method based on a guarded hot plate technique has been proposed and investigated with respect to errors. The results are promising and further development of the method is ...

  20. PINE WOOD MODIFICATION BY HEAT TREATMENT IN AIR

    Directory of Open Access Journals (Sweden)

    Bruno Esteves

    2008-02-01

    Full Text Available Maritime pine (Pinus pinaster wood has low dimensional stability and durability. Heat treatment was made in an oven using hot air during 2 to 24 h and at 170-200 ºC. A comparison was made against steam heat treatment. The equilibrium moisture content and the dimensional stability (ASE in radial and tangential directions were evaluated at 35%, 65%, and 85% relative humidity. MOE, bending strength and wettability were also determined. At the same mass loss, improvements of equilibrium moisture content and dimensional stability were higher for oven heat treatment, but the same was true for mechanical strength degradation. A 50% decrease in hemicellulose content led to a similar decrease in bending strength.

  1. Effect of heat treatment temperature on nitinol wire

    Energy Technology Data Exchange (ETDEWEB)

    Cai, S.; Schaffer, J. E. [Fort Wayne Metals Research Products Corporation, 9609 Ardmore Ave., Fort Wayne, Indiana 46809 (United States); Daymond, M. R. [Department of Mechanical and Materials Engineering, Queen' s University, Nicol Hall, 60 Union Street, Kingston, Ontario K7L 3N6 (Canada); Yu, C. [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, 102249 Beijing (China); Ren, Y. [Argonne National Laboratory, 9700 S. Cass Ave, 433/D008, Argonne, Illinois 60439 (United States)

    2014-08-18

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

  2. Effect of heat treatment temperature on nitinol wire

    Science.gov (United States)

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

    2014-08-01

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

  3. Control Techniques in Heating, Ventilating and Air Conditioning Systems

    OpenAIRE

    H. Mirinejad; Sadati, S.H.; M Ghasemian; H. Torab

    2008-01-01

    Problem statement: Heating, Ventilating and Air Conditioning (HVAC) systems are among the main installations in residential, commercial and industrial buildings. The purpose of the HVAC systems is normally to provide a comfortable environment in terms of temperature, humidity and other environmental parameters for the occupants as well as to save energy. Achieving these objectives requires a suitable control system design. Approach: In this overview, thermal comfort level and ISO comfort fiel...

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

    Science.gov (United States)

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

    2010-06-08

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

  5. Influence of Heat Treatment on Color Change of Poplar

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this paper, Populus tomentosa was used as samples for heat treatment in order to find the initial effect rule of color change, when the temperature rose to180, 200 and 220 oC and the time was kept for 1, 2 and 3 h, respectively. The results are shown as follows: The color of treated wood can be changed obviously by the heat treatment. Under the same temperature, the color saturation becomes smaller and the difference of color becomes more obvious with the increase of the keeping time. Lightness and color...

  6. Limiting current technique in the research of mass/heat transfer in nanofluid

    Science.gov (United States)

    Wilk, J.; Grosicki, S.

    2016-09-01

    In the paper the authors focused on the application of the electrochemical limiting diffusion current technique to the study of mass transfer in nanofluid flow. As mass and heat transfer are analogical phenomena, analysing mass transfer helps understand heat transfer processes in nanofluids. The paper begins with a short review of the available literature on the subject followed by the authors' results of mass transfer coefficient measurements and the conclusions concerning mass/heat transfer enhancement in nanofluids.

  7. Mathematical Model of ComputerHeat Treatment and Its Simulation

    Institute of Scientific and Technical Information of China (English)

    PanJiansheng; ZhangWeimin; TianDong; GuJianfeng; HuMingjuan

    2004-01-01

    Computer simulation on heat treatment is the foundation of intelligent heat treatment. The simulations of temperature field,phase transformation, stress/strain complicate quenching operation were realized by using the model of three dimensional non-linear finite element method and the treatment methods of abruptly changing interface conditions. The simulation results basically fit those measured in experiments. The intelligent sealed multipurpose furnace production line has been developed based on the combination of computer simulation on gaseous carburizing and computer control technology. More than 3000 batches of workpieces have been processed on this production line, and all are up to standard. The application of computer simulation technology can significantly improve the loading ability and reliability of nitriding and carburizing workpieces, reduce heat treatment distortion, and shorten carburizing duration. It is recommended that the reliable product design without redundancy should be performed with the combination of the CAD of mechanical products, the CAE of materials selection and heat treatment, and the dynamic evaluation technology of product reliability.

  8. Potential of rapid heat treatment of titanium alloys and steels

    Energy Technology Data Exchange (ETDEWEB)

    Ivasishin, O.M.; Teliovich, R.V. [Institute of Metal Physics, Kiev (Ukraine)

    1999-05-15

    Rapid heat treatment (RHT) of titanium alloys and steels, which includes rapid heating into the single-phase field, {beta} and {gamma} of titanium alloys and steels, respectively, is reviewed. Heating rate is an important parameter that affects the mechanism and kinetics of phase and/or structural transformation. Refinement of grain structure, formation of micro-chemical inhomogeneity and substructure in the high temperature phase following RHT are addressed. Thermo-kinetic effects during rapid heating of material with an initial metastable (quenched or deformed) microstructure are discussed. The response of titanium alloys and steels to RHT is compared. The improvement in mechanical properties of both material system following RHT is also presented. (orig.) 48 refs.

  9. Impact Toughness and Heat Treatment for Cast Aluminum

    Science.gov (United States)

    Lee, Jonathan A (Inventor)

    2016-01-01

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

  10. Structural changes of synthetic opal by heat treatment

    Science.gov (United States)

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

    2013-10-01

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

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

    Science.gov (United States)

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

    2009-06-01

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

  12. Reviewing efficacy of alternative water treatment techniques.

    Science.gov (United States)

    Hambidge, A

    2001-06-01

    synergistic effect in the inactivation of coliphage MS-2 and poliovirus. Other techniques: There are a number of other techniques. We have conducted trials of most of these in the control of Legionella sp., but these fall out of the scope of this article, and as such less emphasis has been placed on them here. Ozonation: Ozone [O3] is an oxidising gas, generated electrically from oxygen [O2]. L. pneumophila can be killed at ozone [Edelstien et al 1982]. Muraca et al [1987] found that 1-2 mg/L of continuous ozone over a six hour contact time, produced a 5 logarithm decrease of L. pneumophila. The effectiveness of ozone treatment against a range of bacteria and coliphages has been studied Botzenhart et al [1993]. E. coli was least resistant to ozone, followed by MS 2-coliphage and PhiX 174-coliphage, with L. pneumophila and Bacillus subtilis spores being the most resistant. (ABSTRACT TRUNCATED)

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

    CERN Document Server

    ,

    2012-01-01

    The temperature profile of two different BSCCO 2212 coils has been analyzed. The profiles are obtained from thermocouples imbedded in the windings during the heat treatment that activates the 2212. The melting and freezing of the 2212 is clearly observed. A model that describes the data and can be used to guide the processing of new coils has been developed.

  14. Integrated modeling and heat treatment simulation of austempered ductile iron

    Science.gov (United States)

    Hepp, E.; Hurevich, V.; Schäfer, W.

    2012-07-01

    The integrated modeling and simulation of the casting and heat treatment processes for producing austempered ductile iron (ADI) castings is presented. The focus is on describing different models to simulate the austenitization, quenching and austempering steps during ADI heat treatment. The starting point for the heat treatment simulation is the simulated microstructure after solidification and cooling. The austenitization model considers the transformation of the initial ferrite-pearlite matrix into austenite as well as the dissolution of graphite in austenite to attain a uniform carbon distribution. The quenching model is based on measured CCT diagrams. Measurements have been carried out to obtain these diagrams for different alloys with varying Cu, Ni and Mo contents. The austempering model includes nucleation and growth kinetics of the ADI matrix. The model of ADI nucleation is based on experimental measurements made for varied Cu, Ni, Mo contents and austempering temperatures. The ADI kinetic model uses a diffusion controlled approach to model the growth. The models have been integrated in a tool for casting process simulation. Results are shown for the optimization of the heat treatment process of a planetary carrier casting.

  15. 7 CFR 58.236 - Pasteurization and heat treatment.

    Science.gov (United States)

    2010-01-01

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

  16. Heat transfer monitoring by means of the hot wire technique and finite element analysis software.

    Science.gov (United States)

    Hernández Wong, J; Suarez, V; Guarachi, J; Calderón, A; Rojas-Trigos, J B; Juárez, A G; Marín, E

    2014-01-01

    It is reported the study of the radial heat transfer in a homogeneous and isotropic substance with a heat linear source in its axial axis. For this purpose, the hot wire characterization technique has been used, in order to obtain the temperature distribution as a function of radial distance from the axial axis and time exposure. Also, the solution of the transient heat transport equation for this problem was obtained under appropriate boundary conditions, by means of finite element technique. A comparison between experimental, conventional theoretical model and numerical simulated results is done to demonstrate the utility of the finite element analysis simulation methodology in the investigation of the thermal response of substances.

  17. Tool Steel Heat Treatment Optimization Using Neural Network Modeling

    Science.gov (United States)

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

    2016-11-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-08-01

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

  19. A new paradigm for heat treatment of alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ustinovshikov, Y., E-mail: ust@ftiudm.ru

    2014-11-25

    Highlights: • The sign of the ordering energy in alloys varies with the temperature. • Each temperature of heating leads to formation of its characteristic microstructure. • Quenching of alloys is a totally unnecessary and useless operation. - Abstract: The article considers the consequences in the field of heat treatment of alloys that could follow the introduction of the concept of phase transition ordering-phase separation into common use. By example of the Fe{sub 50}Cr{sub 50} alloy, industrial carbon tool steel and Ni{sub 88}Al{sub 12} alloy, it is shown that this transition occurs at a temperature, which is definite for each system, that the change of the sign of the chemical interaction between component atoms reverses the direction of diffusion fluxes in alloys, which affects changes in the type of microstructures. The discovery of this phase transition dramatically changes our understanding of the solid solution, changes the ideology of alloy heat treatment. It inevitably leads to the conclusion about the necessity of carrying out structural studies with the help of TEM in order to adjust the phase diagrams of the systems where this phase transition has been discovered. Conclusions have been made that quenching of alloys from the so-called region of the solid solution, which is usually performed before tempering (aging) is a completely unnecessary and useless operation, that the final structure of the alloy is formed during tempering (aging) no matter what the structure was before this heat treatment.

  20. Heat treatment of scallop adductor muscle using superheated steam.

    Science.gov (United States)

    Abe, T; Miyashita, K

    2007-08-01

    Scallop (Patinopecten yessoensis) adductor muscles were heated using superheated steam (150 and 200 degrees C), boiling (98 degrees C), and normal steaming (95 degrees C). The amounts of amino acids, water-soluble peptides, and nucleotides, expressed as extractive nitrogen in scallop products, are very important elements of quality and taste. After 15-min heating of scallop muscles with normal steaming and boiling, respective losses of 50% and 64% of the extractive nitrogen were observed. However, most extractive nitrogen (> 86%) remained in the scallop muscles treated with superheated steam at 150 and 200 degrees C. Protective effects of superheated steam against elution loss of nitrogen compounds were also observed in amino acid analyses of the heated products. The scallop-muscle surface temperature during treatment with superheated steam increased more quickly than that with normal steaming and boiling. The rapid water loss and the surface protein denaturation engendered formation of a 30-mum-thick film covering the surface, which prevented extractive nitrogen loss from internal tissues. Superheated steam treatment at 200 degrees C caused browning, surface shrinkage, and 47% weight loss. In marked contrast, the appearance and the weight loss of sample treated at 150 degrees C were almost the same as those of normal steaming and boiling-treated samples. These results suggested that superheated steaming at 150 degrees C is an optimal heat treatment of scallop adductor muscles.

  1. Effects of heat treatment on properties of boron nitride fiber

    Institute of Scientific and Technical Information of China (English)

    LI Duan; ZHANG ChangRui; LI Bin; CAO Feng; WANG SiQing

    2012-01-01

    The boron nitride fibers were heated at the range of 600-1400°C in flowing nitrogen and air,respectively,and the effects of heat treatment on the structure,composition and morphology of BN fibers were studied.The results showed that BN fibers exhibited smooth surfaces,and that t-BN was the main phase with a little B2O3 included.After heat treatment at 1400°C in nitrogen atmosphere,the fibers displayed rough surfaces with little change in mass.Better crystallinity was obtained with the increasing temperature.During heat treatment in air,the fibers were oxidized severely as the temperature went up,especially at 1400°C.The volatilization of B2O3,HBO2 and H3BO3 led to the pores on the surfaces of the fibers,while the boron oxide glaze and nitrogen gas produced during the oxidation process protected the fibers from further oxidation.

  2. 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.

  3. 40 CFR 142.46 - Alternative treatment techniques.

    Science.gov (United States)

    2010-07-01

    ... grant a variance from any treatment technique requirement of a national primary drinking water... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Alternative treatment techniques. 142... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS IMPLEMENTATION Variances Issued by the...

  4. [Treatment of atherosclerosis. New percutaneous intraluminal techniques].

    Science.gov (United States)

    Lablanche, J M

    1990-10-06

    Balloon-catheter angioplasty was introduced by Gruntzig in 1977 and has since proved effective, but 3 problems are still encountered: immediate reobstruction, restenosis during the first 3 months and extension of the procedure to a greater number of cases. In an attempt to solve these problems, other percutaneous/technics, associated or not with balloon angioplasty, have been devised. They are: (1) intraluminal stents which perfectly keep the vessel open after balloon angioplasty; (2) vaporization of atheromatous plaques by laser, and notably excimer laser which results in immediate recanalization, later completed by balloon angioplasty; (3) heating balloons which stick dissections and improve the immediate success rate; (4) atheroma-cutting and storing systems, such as Simpson's atherocath, cutting and aspirating systems, such as Stack's transluminal extraction catheter, or erasing systems, such as Auth's rotablator; (5) other sources of energy, such as ultrasounds, microwaves and radiofrequencies, will perhaps, be used in the near future. None of these new technics has solved the restenosis problem, but all have proved effective in suppressing the obstacle, there by giving hopes of reducing immediate complications and gradually widening the indications of percutaneous revascularization.

  5. Effect of heat treatment on an AISI 304 austenitic stainless steel evaluated by the ultrasonic attenuation coefficient

    Energy Technology Data Exchange (ETDEWEB)

    Moghanizadeh, Abbas; Farzi, Abolfazl [Islamic Azad Univ., Esfarayen (Iran, Islamic Republic of). Dept. of Civil Engineering

    2016-07-01

    The properties of metals can be substantially changed by various methods, one of them is using heat treatment processes. Moreover, ultrasonic testing is the most preferred and effective, nondestructive testing technique for characterization of mechanical material properties. Austenitic stainless steel AISI 304 serves in many applications due to high strength and corrosion resistance. In certain applications, it is important to evaluate the mechanical properties of AISI 304 stainless steel. In this study, the ultrasonic method (attenuation measurement technique) is used to evaluate the hardness of AISI 304 stainless steel samples which were heat treated at different levels. Due to the heat treatment process, each sample has its specific microstructure and hardness which attenuate ultrasonic waves appropriately. The ultrasonic and hardness test show that it is possible to evaluate the hardness of AISI 304 stainless steel by ultrasonic attenuation coefficient. In addition, the relationship between ultrasonic attenuation coefficients and time of heat treatment is investigated.

  6. The influence of applied heat treatments on whey protein denaturation

    Directory of Open Access Journals (Sweden)

    Fetahagić Safet

    2002-01-01

    Full Text Available Reconstituted skim milk with 8.01% DM was standardized with 3% skim milk powder and with 3% demineralized whey powder (DWP, respectively. Gained milk samples are named as 8%, 11% and 8%+3%DWP. All samples were heat treated at 85ºC/10 min, 90ºC/10 min and 95ºC/10 min, respectively. Untreated milk was used as control. Milk samples were coagulated by glucono-d-lactone (GDL at the temperature of 45ºC until pH 4.60 was reached. Milk nitrogen matter content decreased during heat treatments, but linear relationship between applied heat treatments and nitrogen matter decreasing was not found. Nitrogen matter content of sera gained from both untreated and heat treated milk increased with the increase of milk dry matter content and with the addition of DWP. The higher temperature of applied heat treatment, the smaller sera nitrogen matter content. Nitrogen matter content in sera obtained from untreated milk were 64.90 mg%, 96.80 mg% and 117.3 mg% for milk 8%, 11% and 8%+3.0% DWP, respectively. Sera samples obtained from milk 8% heat treated at 85ºC/10 min, 90ºC/10 min and 95ºC/10 min had 38.70 mg% 38.30 mg% and 37.20 mg% of nitrogen matter, respectively. Sera samples obtained from milk 11% heat treated at 85ºC/10 min, 90ºC/10 min and 95ºC/10 min had 55.90 mg%, 52.80 mg% and 51.30 mg% of nitrogen matter, respectively. Sera samples obtained from milk 8% heat treated at 85ºC/10 min, 90ºC/10 min and 95ºC/10 min had 69.50 mg%, 66.20 mg% and 66.00 mg% of nitrogen matter respectively. Distribution of nitrogen matter from untreated milk to milk sera were 12.01%, 11.14% and 17.69% for milk 8%, 11% and 8%+3.0% DWP respectively. Distribution of nitrogen matter from milk 8% heat treated at 85ºC/10 min, 90ºC/10 min and 95ºC/10 min to sera samples were 6.99%, 6.72% and 6.59%, respectively. Distribution of nitrogen matter from milk 11% heat treated at 85ºC/10 min, 90ºC/10 min and 95ºC/10 min to sera samples, were 6.02%, 5.32% and 5.21%, respectively

  7. The effects of heat treatment on physical properties and surface roughness of red-bud maple (Acer trautvetteri Medw.) wood.

    Science.gov (United States)

    Korkut, Derya Sevim; Guller, Bilgin

    2008-05-01

    Heat treatment is often used to improve the dimensional stability of wood. In this study, the effects of heat treatment on physical properties and surface roughness of red-bud maple (Acer trautvetteri Medw.) wood were examined. Samples obtained from Düzce Forest Enterprises, Turkey, were subjected to heat treatment at varying temperatures and durations. The physical properties of heat-treated samples were compared against controls in order to determine their; oven-dry density, air-dry density, and swelling properties. A stylus method was employed to evaluate the surface characteristics of the samples. Roughness measurements, using the stylus method, were made in the direction perpendicular to the fiber. Three main roughness parameters; mean arithmetic deviation of profile (Ra), mean peak-to-valley height (Rz), and maximum roughness (Rmax) obtained from the surface of wood, were used to evaluate the effect of heat treatment on the surface characteristics of the specimens. Significant differences were determined (p>0.05) between surface roughness parameters (Ra, Rz, Rmax) at three different temperatures and three periods of heat treatment. The results showed that the values of density, swelling and surface roughness decreased with increasing temperature treatment and treatment times. Red-bud maple wood could be utilized successfully by applying proper heat treatment techniques without any losses in investigated parameters. This is vital in areas, such as window frames, where working stability and surface smoothness are important factors.

  8. The Effects of Heat Treatment on the Physical Properties and Surface Roughness of Turkish Hazel (Corylus colurna L. Wood

    Directory of Open Access Journals (Sweden)

    Nevzat Çakıcıer

    2008-09-01

    Full Text Available Heat treatment is often used to improve the dimensional stability of wood. In this study, the effects of heat treatment on the physical properties and surface roughness of Turkish Hazel (Corylus colurna L. wood were examined. Samples obtained from Kastamonu Forest Enterprises, Turkey, were subjected to heat treatment at varying temperatures and for different durations. The physical properties of heat-treated and control samples were tested, and oven-dry density, air-dry density, and swelling properties were determined. A stylus method was employed to evaluate the surface characteristics of the samples. Roughness measurements, using the stylus method, wereb made in the direction perpendicular to the fiber. Four main roughness parameters, mean arithmetic deviation of profile (Ra, mean peak-to-valley height (Rz, root mean square roughness (Rq, and maximum roughness (Ry obtained from the surface of wood were used to evaluate the effect of heat treatment on the surface characteristics of the specimens. Significant difference was determined (p = 0.05 between physical properties and surface roughness parameters (Ra,Rz, Ry, Rq for three temperatures and three durations of heat treatment. The results showed that the values of density, swelling and surface roughness decreased with increasing temperature treatment and treatment times. Turkish Hazel wood could be utilized successfully by applying proper heat treatment techniques without any losses in investigated parameters. This is vital in areas, such as window frames, where working stability and surface smoothness are important factors.

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

    Science.gov (United States)

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

    2008-09-01

    Heat treatment is often used to improve the dimensional stability of wood. In this study, the effects of heat treatment on the physical properties and surface roughness of Turkish Hazel (Corylus colurna L.) wood were examined. Samples obtained from Kastamonu Forest Enterprises, Turkey, were subjected to heat treatment at varying temperatures and for different durations. The physical properties of heat-treated and control samples were tested, and oven-dry density, air-dry density, and swelling properties were determined. A stylus method was employed to evaluate the surface characteristics of the samples. Roughness measurements, using the stylus method, were made in the direction perpendicular to the fiber. Four main roughness parameters, mean arithmetic deviation of profile (Ra), mean peak-to-valley height (Rz), root mean square roughness (Rq), and maximum roughness (Ry) obtained from the surface of wood were used to evaluate the effect of heat treatment on the surface characteristics of the specimens. Significant difference was determined (p = 0.05) between physical properties and surface roughness parameters (Ra,Rz, Ry, Rq) for three temperatures and three durations of heat treatment. The results showed that the values of density, swelling and surface roughness decreased with increasing temperature treatment and treatment times. Turkish Hazel wood could be utilized successfully by applying proper heat treatment techniques without any losses in investigated parameters. This is vital in areas, such as window frames, where working stability and surface smoothness are important factors.

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

    Directory of Open Access Journals (Sweden)

    N. V. Kolebina

    2015-01-01

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

  11. Development of Radiation Technique for Environmental Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myun Joo; Kuk, Il Hiun; Jin, Joon Ha (and others)

    2007-02-15

    The purpose of this research is to development of technologies for 1) the removal of toxic organic chemicals in sewage sludges and the volume reduction of the sewage sludge 2) the recycling/reuse of sewage sludge 3) the reconvey of resource from fishery waste by using radiation technologies. This research project focused on the study of treatment, disposal, and recycling/reuse of sewage sludge by radiation technology, and recovery of highly value-added resources from the wastes. As basic studies with a radiation technology, an enhancement of dewaterbilities of sewage sludge, development of dewatering conditioner, reduction of trace toxic organic chemicals, and the toxicities of the byproducts were studied. Based on the basic experimental results, we developed the pilot-scale system with the continuous e-beam and dewatering unit and the advanced treatment system with the use of carbon source recovered from sewage sludge.

  12. Pulse Mitigation and Heat Transfer Enhancement Techniques. Volume 5. Transient Liquid Movement in Heat Pipe Wicks

    Science.gov (United States)

    1992-08-01

    pipe wall. This is not likely to be the case in the thin wicks used in most heat pipes unless severe dryout occurs. Eninger [7] studied the capillary...balance on a randomly oriented fibecr. The theoretical model required an empirical constant obtained from the experimental results. Eninger also 6...structure was utilized for this experimpnt. The two-component wick structure was utilized previously by Eninger [7], who was able to measure slight

  13. Hydrothermal treatment of sorption materials. Implications on adsorption heat pumps

    Energy Technology Data Exchange (ETDEWEB)

    Henninger, S.K.; Mueller, S.; Ratzsch, K.F.; Schossig, P.; Henning, H.M. [Fraunhofer-Institut fuer Solare Energiesysteme (ISE), Freiburg im Breisgau (Germany). Dept. of Thermal Systems and Buildings; Munz, G. [PSE AG, Freiburg (Germany)

    2010-07-01

    Material stability of adsorbents for thermally driven systems like heat storage and heat transformation plays a key role. In particular high power-density applications like adsorption heat pumps and chillers in combination with recently developed adsorption materials lead to a significant increased number of cycles over the lifetime (<100'000) making cycle stability crucial. With regard to current developments on composite structures improving the heat and mass transfer, additional stability analysis like thermo-mechanical properties are now getting into focus. This contribution gives a broad overview on the stability of current available sorption materials like silica gels and zeolites, recently developed (silica-) aluminophosphates (AIPO/SAPO) and most novel synthesized metal organic framework (MOF) materials under hydrothermal treatment. The results give a first indication on the suitability of these materials for the use in heat storage, thermally driven sorption heat pumps and cooling machines. Pure powders as well as composites have been analysed under continuous cycling conditions. Whereas the stability of powders and granules have been analysed in-situ by thermogravimetric cycle measurements, a cycling-test rig has been developed in order to realise a lifetime stress of composites consisting of active sorption material and a support structure. The need for a first stage short-cycle analysis is demonstrated impressively by the dramatic loss of more than 50% in sorption capacity of a SAPO-34 sample within the first 10 cycles. Several composite samples have passed a treatment of 30'000 cycles or more and show continuous degradation effects leading to a reduction in sorption capacity of 20% compared to the initial value. (orig.)

  14. A heat transfer model for biological wastewater treatment system

    Science.gov (United States)

    Lin, S. H.

    A heat transfer model for predicting the water temperature of aeration tank in a biological wastewater treatment plant is presented. The heat transfer mechanisms involved in the development of the heat transfer model include heat gains from solar radiation and biochemical reaction and heat losses from evaporation, aeration, wind blowing and conduction through tank walls. Several empirical correlations were adopted and appropriate assumptions made to facilitate the model development. Experiments were conducted in the biological wastewater treatment plant of a chemical fiber company over a year's period. The operational, weather and temperature data were registered. The daily water temperature data were averaged over a month period and compared with the theoretical prediction. Excellent agreement has been obtained between the predicted and measured temperatures, verifying the proposed heat transfer model. Zusammenfassung Es wird ein Wärmeübergangsmodell zur Berechnung der Wassertemperatur im Belüftungstank einer Anlage zur biologischen Abwasserbehandlung vorgestellt. Die in das Modell eingehenden Wärmeübergangsmechanismen umfassen: solare Wärmeeinstrahlung, biochemische Reaktion, Wärmeverluste durch Verdampfung, Belüftung, Windeinfluß und Leitung durch die Behälterwände. Mehrere empirische Beziehungen sowie vertretbare Annahmen tragen zur Modellvereinfachung bei. An der biologischen Abwasser-Kläranlage einer Chemiefaserfirma wurden ein Jahr lang Experimente durchgeführt und dabei Betriebs-, Wetter- und Temperaturdaten aufgezeichnet. Die täglichen Wassertemperaturen, gemittelt über einen Monat, zeigten ausgezeichnete Übereinstimmung mit den theoretischen Vorausberechnungen und bestätigten so die Brauchbarkeit des vorgeschlagenen Wärmeübergangsmodells.

  15. A low-computational-cost inverse heat transfer technique for convective heat transfer measurements in hypersonic flows

    Science.gov (United States)

    Avallone, F.; Greco, C. S.; Schrijer, F. F. J.; Cardone, G.

    2015-04-01

    The measurement of the convective wall heat flux in hypersonic flows may be particularly challenging in the presence of high-temperature gradients and when using high-thermal-conductivity materials. In this case, the solution of multidimensional problems is necessary, but it considerably increases the computational cost. In this paper, a low-computational-cost inverse data reduction technique is presented. It uses a recursive least-squares approach in combination with the trust-region-reflective algorithm as optimization procedure. The computational cost is reduced by performing the discrete Fourier transform on the discrete convective heat flux function and by identifying the most relevant coefficients as objects of the optimization algorithm. In the paper, the technique is validated by means of both synthetic data, built in order to reproduce physical conditions, and experimental data, carried out in the Hypersonic Test Facility Delft at Mach 7.5 on two wind tunnel models having different thermal properties.

  16. Techniques for the estimation of Heats of Explosion (HEX) using thermochemical codes

    Science.gov (United States)

    Fifer, Robert A.; Morris, Jeffrey B.

    1993-09-01

    Procedures are outlined for calculating the heats of explosion (HEX) of neat energetic materials or propellant/explosive formulations using thermochemical codes. The 'exact' method and three approximate techniques are described; the approximate techniques either eliminate the need to sum the internal energies of the predicted products, or eliminate the need to specify a freeze-out temperature. The various techniques are illustrated for HMX and a nitrocellulose/nitroglycerine (NC/NG) mixture.

  17. Infrared evaluation of the heat-sink bipolar diathermy dissection technique.

    Science.gov (United States)

    Allan, J; Dusseldorp, J; Rabey, N G; Malata, C M; Goltsman, D; Phoon, A F

    2015-08-01

    The use of the bipolar diathermy dissection technique is widespread amongst surgeons performing flap perforator dissection and microvascular surgery. The 'heat-sink' modification uses a DeBakey forcep as a heat sinking interposition between the bipolar tip and the main (vascular or flap) pedicle aiming to protect it from the thermal effects of the bipolar diathermy. This study examines the thermal effects of bipolar cautery upon the microvasculature and investigates the efficacy of heat sinking as a thermally protective technique in microsurgical dissection. A chicken thigh microsurgical training model was used to examine the effects of bipolar cautery. The effects of bipolar were examined using high definition, real-time infrared thermographic imaging (FLIR Systems) and temperature quantitatively assessed at various distances away from the point of bipolar cautery. Comparison was made using the heat sink technique to determine if it conferred a thermoprotective effect compared to the standard technique without heat sink. Using paired t-test analysis (SPSS) the heat sink modification of the bipolar dissection technique was found to have a highly statistically significant effect (P < 0.000000001) in reducing the conductive temperature along the vascular pedicle. This protective effect kept temperatures comparable to controls. Bipolar cautery is an extremely safe method of electrosurgery, however when its use is required within 3 mm of important vascular architecture, the heat-sink method is a viable and easy technique to prevent thermal spread and limit potential coagulopathic changes. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  18. Microstructural evolvement of wrought magnesium alloy sheet during heat treatment

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Magnesium alloy is the lightest structural metal material. As its ductility is usually limited because of its hexagonal closest packing (hcp) structure, it is significant to improve its forming performance. The primary way to achieve this goal is by grain refinement. This study explores new ways of grain refinement for cold-rolled sheet of magnesium alloy AZ31B by probing into its structural evolvement in heat treatment. It is found that recrystallization mostly takes place in the cold-rolled sheet in heattreatment, and refined and equiaxial recrystallization grains with an average diameter of (14 to 15) μm can be obtained by heattreatment at 260 °C for (60 to 90) min, which is an effective method to obtain refined symmetrical grains of magnesium alloy by heat treatment at a lower recrystallization temperature after cold-rolling.

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

    Science.gov (United States)

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

    2014-12-01

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

  20. Theoretical Prediction and Experimental Determination of Heating Time During High-Temperature Heat Treatment of Wood

    Directory of Open Access Journals (Sweden)

    LIU Xin-you

    2011-06-01

    Full Text Available Theoretical prediction provides basic understanding and guidance to correctly implement a certaintechnology in the production process. The present study uses a differential equation to predict the heattransfer time between the surface and core layer of wood during the heat treatment, with applicability inestimating the duration of heat treatments at high temperatures. The obtained prediction was compared withthe result of an experimental study performed on Chinese poplar wood with various thicknesses (20, 40 and60mm. During this experiment, the time necessary for the core of wood to reach a temperature of 100°C,130°C and finally 180°C was monitored and the recorded values were compared with the predicted ones.The result of this comparison proved that the experimental values matched the theoretically predicted times,validating thus the applicability of the proposed equation as prediction tool.

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

    Directory of Open Access Journals (Sweden)

    A. P. Nesenchuk

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Hoemberg, Dietmar; Kern, Daniela

    2009-07-21

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

  3. Adapted Cuing Technique for Use in Treatment of Dyspraxia.

    Science.gov (United States)

    Klick, Susan L.

    1985-01-01

    The Adapted Cuing Technique (ACT) was created to accompany oral stimulus presentation in treatment of dyspraxia. ACT is consistent with current treatment theory, emphasizing patterns of articulatory movement, manner of production, and multimodality facilitation. A case study describes the use of ACT in the treatment of a five-year-old child.…

  4. Heuristic algorithms for scheduling heat-treatment furnaces of steel casting industries

    Indian Academy of Sciences (India)

    M Mathirajan; V Chandru; A I Sivakumar

    2007-10-01

    This paper addresses a research problem of scheduling parallel, nonidentical batch processors in the presence of dynamic job arrivals, incompatible job-families and non-identical job sizes. We were led to this problem through a realworld application involving the scheduling of heat-treatment operations of steel casting. The scheduling of furnaces for heat-treatment of castings is of considerable interest as a large proportion of the total production time is the processing times of these operations. In view of the computational intractability of this type of problem, a few heuristic algorithms have been designed for maximizing the utilization of heat-treatment furnaces of steel casting manufacturing. Extensive computational experiments were carried out to compare the performance of the heuristics with the estimated optimal value (using the Weibull technique) and for relative effectiveness among the heuristics. Further, the computational experiments show that the heuristic algorithms proposed in this paper are capable of obtaining near (statistically estimated) optimal utilization of heat-treatment furnaces and are also capable of solving any large size real-life problems with a relatively low computational effort.

  5. Review of current status of high flux heat transfer techniques. Volume I. Text + Appendix A

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, W.H.; Gordon, H.S.; Lackner, H.; Mettling, J.R.; Miller, J.E.

    1980-09-01

    The scope of this work comprised two tasks. The first was to review high heat flux technology with consideration given to heat transfer panel configuration, diagnostics techniques and coolant supply. The second task was to prepare a report describing the findings of the review, to recommend the technology offering the least uncertainty for scale-up for the MFTF-B requirement and to recommend any new or perceived requirements for R and D effort.

  6. Effect of Combustion Air Pre-Heating In Carbon Monoxide Emission in Diesel Fired Heat Treatment Furnace

    Directory of Open Access Journals (Sweden)

    E B Muhammed Shafi,

    2015-09-01

    Full Text Available This paper describes the effect of combustion air pre- heating in Diesel fired heat Treatment Furnace. The main heat treatment processes are Normalizing, Tempering, Hardening, Annealing, Solution Annealing and Stress Relieving. The emission of carbon monoxide is measured with combustion air pre-heating and without preheating. The results are then compared and it is found that the emission of CO is reduced by 29.12%. With the Combustion air pre-heating a considerable reduction in Specific Furnace Fuel Consumption (SFFC is obtained. The test was caaried out at Peekay Steels Casting (P ltd, Nallalam, Calicut.

  7. Extension and application of a scaling technique for duplication of in-flight aerodynamic heat flux in ground test facilities

    NARCIS (Netherlands)

    Veraar, R.G.

    2009-01-01

    To enable direct experimental duplication of the inflight heat flux distribution on supersonic and hypersonic vehicles, an aerodynamic heating scaling technique has been developed. The scaling technique is based on the analytical equations for convective heat transfer for laminar and turbulent bound

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-04-01

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

  9. Assessment of Haar Wavelet-Quasilinearization Technique in Heat Convection-Radiation Equations

    Directory of Open Access Journals (Sweden)

    Umer Saeed

    2014-01-01

    Full Text Available We showed that solutions by the Haar wavelet-quasilinearization technique for the two problems, namely, (i temperature distribution equation in lumped system of combined convection-radiation in a slab made of materials with variable thermal conductivity and (ii cooling of a lumped system by combined convection and radiation are strongly reliable and also more accurate than the other numerical methods and are in good agreement with exact solution. According to the Haar wavelet-quasilinearization technique, we convert the nonlinear heat transfer equation to linear discretized equation with the help of quasilinearization technique and apply the Haar wavelet method at each iteration of quasilinearization technique to get the solution. The main aim of present work is to show the reliability of the Haar wavelet-quasilinearization technique for heat transfer equations.

  10. Some Aspects Concerning Convective Circulation Mode of Heat Transfer in Furnace to Wood Heat Treatment

    Directory of Open Access Journals (Sweden)

    Nadia Potoceanu

    2007-10-01

    Full Text Available The paper presented the most aspects of convective circulate mode of heat transfer : heat transfer through the boundary layer formed at the surface of the heat generator; heat transfer in the heat carrier and heat transfer through the boundary layer formed at the heated surface

  11. Influence of Heat Treatment on Microstructures and Properties of Nd8Fe78B6Co4 Alloy

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Melt-spun Nd8Fe78B6Co4 magnetic powders and their bonded magnets were prepared with the optimization of compositions and preparation techniques. The microstructure change of alloy NdFeB and the relation between microstructure and heat-treatment were studied. The heat-treatment temperature is 200~700 ℃. The as-cast structure of the alloy is typically amorphous. Different melt-spun speed and different heat treatment could result in different magnetic properties of NdFeB magnets. Magnetic properties of NdFeB increase with the addition of element Co. The magnetic properties of magnet alloy get the best when the melt-spun speed reaches 23~26 m·s-1, heat treatment temperature is 690 ℃ and time is 30 min.

  12. Structural ordering of coal char during heat treatment and its impact on reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Feng, B.; Bhatia, S.K.; Barry, J.C.

    2002-07-01

    The effect of heat treatment on the structure of an Australian semi-anthracite char was studied between 850-1150{sup o}C using XRD, HRTEM, and electrical resistivity techniques. It was found that the carbon crystallite size in the char does not change during heat treatment, for both the raw coal and its ash-free derivative obtained by acid treatment. However, the fraction of the organized carbon in the raw coal chars, determined by XRD, increased with increase of heat treatment time and temperature, while that for the ash-free coal chars remained unchanged. This suggests the occurrence of catalytic ordering during heat treatment. Electrical resistivity of the raw coal chars decreased with heat treatment, while that of the ash-free coal chars did not vary. High resolution transmission electron micrographs depicted well-organized carbon layers surrounding iron particles. The fraction of organized carbon attains an apparent equilibrium value that increases with increase in temperature. Good temperature-independent correlation was found between the electrical resistivity and the organized carbon fraction, indicating that electrical resistivity is structure sensitive. These results suggest that the thermal deactivation is the result of a crystallite-perfecting process, which is effectively catalyzed by the inorganic matter in the coal char. It is concluded that the process is diffusion controlled, most likely involving transport of iron in the inter-crystallite nanospaces in the temperature range studied. The activation energy of this transport process is found to be low, which is corroborated by model-free correlation of the temporal variation of organized carbon fraction as well as electrical resistivity data using the superposition method, and is suggestive of surface transport of iron.

  13. Production of amorphous tin oxide thin films and microstructural transformation induced by heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Z.W.; Lai, J.K.L.; Shek, C.H.; Chen, H.D. [City University of Hong Kong, Department of Physics and Materials Science, Kowloon Tong, Hong Kong (China)

    2005-10-01

    X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and high resolution transmission electron microscopy were used to study tin oxide thin films deposited on Si(100) substrates at room temperature using pulsed laser deposition techniques with a sintered cassiterite SnO{sub 2} target and subsequently heat-treated. X-ray diffraction and scanning electron microscopy results demonstrated that the as-prepared thin films consisted of an amorphous matrix as well as plume-like features, which are shown many micropores. The thin films that were heat treated for 2 h at 150 C had tetragonal rutile nanocrystalline SnO{sub 2} structures. The microstructural evolution of the tin oxide thin films during the heat treatment is discussed in the paper. (orig.)

  14. Effect of heat treatment on microstructures and mechanical behavior of porous Sr-Ca-P coatings on titanium

    Energy Technology Data Exchange (ETDEWEB)

    Kung, Kuan-Chen [Department of Materials Science and Engineering, National Cheng Kung University, Tainan, Taiwan (China); Yuan Kuo [Institute of Oral Medicine, National Cheng Kung University, Tainan, Taiwan (China); Lee, Tzer-Min, E-mail: tmlee@mail.ncku.edu.tw [Institute of Oral Medicine, National Cheng Kung University, Tainan, Taiwan (China); Medical Device Innovation Center, National Cheng Kung University, Tainan, Taiwan (China); Lui, Truan-Sheng [Department of Materials Science and Engineering, National Cheng Kung University, Tainan, Taiwan (China)

    2012-02-25

    Highlights: Black-Right-Pointing-Pointer We used an efficient technique to coat porous Sr-Ca-P coatings on titanium. Black-Right-Pointing-Pointer The heat treatment method accelerates mechanical properties and crystallinity of the coatings. Black-Right-Pointing-Pointer After heat treatment at various temperatures, all specimens show the same morphologies. Black-Right-Pointing-Pointer Adhesion strength between the coating and the substrate increases with increasing heat treatment temperature. Black-Right-Pointing-Pointer The heat treatment is beneficial method for improving coatings adhesion in medical applications. - Abstract: Titanium and its alloys are widely used in dental and orthopedic fields due to their excellent chemical stability. The micro-arc oxidation (MAO) technique is an effective method for coating strontium, calcium, and phosphorus onto titanium. In clinical application, the adhesion between the coating and the substrate is important factor for dental implants and artificial joint prosthesis. The present study investigates the effects of heat treatment on the properties of MAO coatings. The physicochemical characteristics are investigated using scanning electron microscopy (SEM) observation, thin film X-ray diffraction (TF-XRD) analysis, and the scratch test. After heat treatment, the TF-XRD results indicate that the tricalcium phosphate phase appears at a temperature of 800 Degree-Sign C. SEM results show that the surface morphology does not change. The scratch test results reveal that the adhesion strength between the coatings and the substrate increases with increasing heat treatment temperature. Consequently, all findings in this study indicated that MAO coatings with heat treatment have good mechanical properties for clinical applications.

  15. Modeling heat and mass transfer in the heat treatment step of yerba maté processing

    Directory of Open Access Journals (Sweden)

    J. M. Peralta

    2007-03-01

    Full Text Available The aim of this research was to estimate the leaf and twig temperature and moisture content of yerba maté branches (Ilex paraguariensis Saint Hilaire during heat treatment, carried out in a rotary kiln dryer. These variables had to be estimated (modeling the heat and mass transfer due to the difficulty of experimental measurement in the dryer. For modeling, the equipment was divided into two zones: the flame or heat treatment zone and the drying zone. The model developed fit well with the experimental data when water loss took place only in leaves. In the first zone, leaf temperature increased until it reached 135°C and then it slowly decreased to 88°C at the exit, despite the gas temperature, which varied in this zone from 460°C to 120°C. Twig temperature increased in the two zones from its inlet temperature (25°C up to 75°C. A model error of about 3% was estimated based on theoretical and experimental data on leaf moisture content.

  16. HARDENING OF THE ELECTRODESIEGED IRON CHEMICAL HEAT TREATMENT

    Directory of Open Access Journals (Sweden)

    V. I. Serebrovskii

    2015-01-01

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

  17. Surgical Treatment of Epiphrenic Diverticulum: Technique and Controversies.

    Science.gov (United States)

    Andolfi, Ciro; Wiesel, Ory; Fisichella, P Marco

    2016-11-01

    The goal of this article is to illustrate the current minimal invasive approaches to patients with epiphrenic diverticulum in terms of preoperative evaluation, surgical technique, and outcomes. Two techniques will be presented: a laparoscopic and a video-assisted thoracic repair. Indications for each technique will be discussed as well as proper patient selection and management. Current controversies in the treatment of patients with this rare disease will be addressed.

  18. Changes in hydroxyapatite powder properties via heat treatment

    Indian Academy of Sciences (India)

    Y M Z Ahmed; S M El-Sheikh; Z I Zaki

    2015-12-01

    The properties of hydroxyaptite (HA) powder, especially its physical one, are largely influenced by the heat treatment process. Controlling of these changes is vital in deciding the suitability of applying this powder in wet processing routes for green body fabrication. Chemically, the crystallinity of the HA powder was found to be largely enhanced with the increase in calcination temperatures. In contrary, a high retardation in the carbonate ion content was found. Physically, all the powder properties in terms of particle size, its distribution, pore volume, pore size and surface area are considerably varied with calcination temperatures. It was found that HA powder calcined at both 1000 and 1100°C possesses reasonable physico-chemical properties for being applied in wet processing routes. Using heat-treated powder at 1000 and 1100°C with 0.3 wt% sodium polyacrylate (as a dispersing agent) turned out to be beneficial in developing a low viscosity and high turbidity suspensions.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-05-15

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

  20. Novel localized heating technique on centrifugal microfluidic disc with wireless temperature monitoring system.

    Science.gov (United States)

    Joseph, Karunan; Ibrahim, Fatimah; Cho, Jongman

    2015-01-01

    Recent advances in the field of centrifugal microfluidic disc suggest the need for electrical interface in the disc to perform active biomedical assays. In this paper, we have demonstrated an active application powered by the energy harvested from the rotation of the centrifugal microfluidic disc. A novel integration of power harvester disc onto centrifugal microfluidic disc to perform localized heating technique is the main idea of our paper. The power harvester disc utilizing electromagnetic induction mechanism generates electrical energy from the rotation of the disc. This contributes to the heat generation by the embedded heater on the localized heating disc. The main characteristic observed in our experiment is the heating pattern in relative to the rotation of the disc. The heating pattern is monitored wirelessly with a digital temperature sensing system also embedded on the disc. Maximum temperature achieved is 82 °C at rotational speed of 2000 RPM. The technique proves to be effective for continuous heating without the need to stop the centrifugal motion of the disc.

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

    Directory of Open Access Journals (Sweden)

    V. A. Pokhol’chenko

    2015-01-01

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

  2. Estimating Heat Fluxes by Merging Profile Formulae and the Energy Budget with a Variational Technique

    Institute of Scientific and Technical Information of China (English)

    张述文; 邱崇践; 张卫东

    2004-01-01

    A variational technique (VT) is applied to estimate surface sensible and latent heat fluxes based on observations of air temperature, wind speed, and humidity, respectively, at three heights (1 m, 4 m, and 10m), and the surface energy and radiation budgets by the surface energy and radiation system (SERBS). The method fully uses all information provided by the measurements of air temperature, wind, and humidity profiles, the surface energy budget, and the similarity profile formulae as well. Data collected at Feixi experiment station installed by the China Heavy Rain Experiment and Study (HeRES) Program are used to test the method. Results show that the proposed technique can overcome the well-known unstablility problem that occurs when the Bowen method becomes singular; in comparison with the profile method, it reduces both the sensitivities of latent heat fluxes to observational errors in humidity and those of sensible heat fluxes to observational errors in temperature, while the estimated heat fluxes approximately satisfy the surface energy budget. Therefore, the variational technique is more reliable and stable than the two conventional methods in estimating surface sensible and latent heat fluxes.

  3. Effects of heat treatment on some physical properties of Douglas fir (Pseudotsuga menziesii) wood

    Science.gov (United States)

    Xianjun Li; Zhiyong Cai; Qunying Mou; Yiqiang Wu; Yuan Liu

    2011-01-01

    In this study the effect of heat treatment on some physical properties of Douglas fir (Pseudotsuga menziesii) was investigated. Wood specimens were subjected to heat treatment at 160, 180, 200 and 220°C for 1, 2, 3 and 4h. The results show that heat treatment resulted in a darkened color, decreased moisture performance and increased dimensional stability of...

  4. Experimental Technique and Assessment for Measuring the Convective Heat Transfer Coefficient from Natural Ice Accretions

    Science.gov (United States)

    Masiulaniec, K. Cyril; Vanfossen, G. James, Jr.; Dewitt, Kenneth J.; Dukhan, Nihad

    1995-01-01

    A technique was developed to cast frozen ice shapes that had been grown on a metal surface. This technique was applied to a series of ice shapes that were grown in the NASA Lewis Icing Research Tunnel on flat plates. Nine flat plates, 18 inches square, were obtained from which aluminum castings were made that gave good ice shape characterizations. Test strips taken from these plates were outfitted with heat flux gages, such that when placed in a dry wind tunnel, can be used to experimentally map out the convective heat transfer coefficient in the direction of flow from the roughened surfaces. The effects on the heat transfer coefficient for both parallel and accelerating flow will be studied. The smooth plate model verification baseline data as well as one ice roughened test case are presented.

  5. On-Line Life Monitoring Technique for Tube Bundles of Boiler High-Temperature Heating Surface

    Institute of Scientific and Technical Information of China (English)

    Yang Dong; Wang Zhongyuan

    2005-01-01

    High-temperature heating surface such as superheater and reheater of large-sized utility boiler all experiences a relatively severe working conditions. The failure of boiler tubes will directly impact the safe and economic operation of boiler. An on-line life monitoring model of high-temperature heating surface was set up according to the well-known L-M formula of the creep damages. The tube wall metal temperature and working stress was measured by on-line monitoring, and with this model, the real-time calculation of the life expenditure of the heating surface tube bundles were realized. Based on the technique the on-line life monitoring and management system of high-temperature heating surface was developed for a 300 MW utility boiler. An effective device was thus suggested for the implementation of the safe operation and the condition-based maintenance of utility boilers.

  6. Electroless-plating technique for fabricating thin-wall convective heat-transfer models

    Science.gov (United States)

    Avery, D. E.; Ballard, G. K.; Wilson, M. L.

    1984-01-01

    A technique for fabricating uniform thin-wall metallic heat-transfer models and which simulates a Shuttle thermal protection system tile is described. Two 6- by 6- by 2.5-in. tiles were fabricated to obtain local heat transfer rates. The fabrication process is not limited to any particular geometry and results in a seamless thin-wall heat-transfer model which uses a one-wire thermocouple to obtain local cold-wall heat-transfer rates. The tile is relatively fragile because of the brittle nature of the material and the structural weakness of the flat-sided configuration; however, a method was developed and used for repairing a cracked tile.

  7. Heat treatment of AlSi9Mg alloy

    Directory of Open Access Journals (Sweden)

    J. Pezda

    2008-04-01

    Full Text Available Processes of crystallization of alloys have decisive impact on structure of castings, and the same their utility characteristics. Knowledge about those processes constitutes a source of information to development of preparation of liquid metal and control of alloy preparation process within industry. Method of Thermal-Voltage-Derivative Analysis (ATND, developed by Faculty of Chipless Forming Technology enables registration of temperature and voltage curves, on which one can observe thermal and voltage effects being result of crystallization of phases and eutectic mixtures present on these curves in form of characteristic “peaks”. Temperature value read offs for these characteristic points become a basis to taking regression analysis aimed at obtaining of mathematical dependences illustrating effect of changes of these values on change of impact resistance of dispersion hardened AK9 alloy. The paper presents an attempt of implementation of Thermal-Voltage-Derivative Analysis method to determination of temperature of hyperquenching and ageing processes of AK9 (AlSi9Mg silumin. Investigated alloy had undergone typical treatments of refining and modification, and next the heat treatment. Temperature range for the heat treatment has been determined on base of ATND melting curves.

  8. Hypersonic aerospace vehicle leading edge cooling using heat pipe, transpiration and film cooling techniques

    Science.gov (United States)

    Modlin, James Michael

    An investigation was conducted to study the feasibility of cooling hypersonic vehicle leading edge structures exposed to severe aerodynamic surface heat fluxes using a combination of liquid metal heat pipes and surface mass transfer cooling techniques. A generalized, transient, finite difference based hypersonic leading edge cooling model was developed that incorporated these effects and was demonstrated on an assumed aerospace plane-type wing leading edge section and a SCRAMJET engine inlet leading edge section. The hypersonic leading edge cooling model was developed using an existing, experimentally verified heat pipe model. Two applications of the hypersonic leading edge cooling model were examined. An assumed aerospace plane-type wing leading edge section exposed to a severe laminar, hypersonic aerodynamic surface heat flux was studied. A second application of the hypersonic leading edge cooling model was conducted on an assumed one-quarter inch nose diameter SCRAMJET engine inlet leading edge section exposed to both a transient laminar, hypersonic aerodynamic surface heat flux and a type 4 shock interference surface heat flux. The investigation led to the conclusion that cooling leading edge structures exposed to severe hypersonic flight environments using a combination of liquid metal heat pipe, surface transpiration, and film cooling methods appeared feasible.

  9. COMPUTERIZED HEAT-TREATMENT IN A ZIMBABWEAN FACTORY

    Directory of Open Access Journals (Sweden)

    M. Collier

    2012-01-01

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

  10. Growth of TiO2 nanoparticles under heat treatment

    Science.gov (United States)

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

    2013-02-01

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

  11. Intercritical heat treatments in ductile iron and steel

    Science.gov (United States)

    Aristizabal, Ricardo E.

    Materials such as dual phase (DP) steels, transformation induced plasticity (TRIP) steels and dual phase ductile irons are produced by intercritical heat treatments. These materials can provide significant weight savings in the automotive industry. The goal of this dissertation is to study intercritical heat treatments in ductile iron and steel to optimize the production parameters. Three different aspects were addressed. First, common steels were intercritically austenitized and austempered (intercritically austempered) under a variety conditions. The results showed that common grade steels that were intercritically austempered exhibited tensile properties in the same range as DP and TRIP steels. The second study consisted of determining the effect of heat treatment conditions on the tensile properties of intercritically austenitized, quenched and tempered ductile iron (IAQ&TDI). The results showed that (1) ultimate tensile strength (UTS) and yield strength (YS) were determined by the volume fraction of martensite, (2) tempering improved the elongation 1.7-2.5 times with only a slight decrease in strength, (3) the carbon in austenite formed during the intercritical heat treatment of ductile iron with a ferritic-pearlitic matrix came from the carbon available in the matrix and that carbon diffusion from the graphite nodules was restricted, and (4) limited segregation of substitutional elements occurred during intercritical austenitizing. Finally, intercritically austempered ductile iron (IADI) alloyed with different amounts of manganese and nickel was produced. Tensile properties and microstructure were determined. Also, the stability of the austenite during deformation and the lattice strains of the ferrite and the austenite phases were determined using x-ray diffraction (XRD) and neutron diffraction. The results indicated that: 1) high manganese concentrations produced materials with large blocky, low carbon austenite particles at the intercellular boundaries

  12. 1983-2004 Heat Treatment Embraces Surface Engineering

    Institute of Scientific and Technical Information of China (English)

    Tom Bell

    2004-01-01

    The origins of surface engineering lie in antiquity, with the practices in ancient Greece and China of hardening,tempering and crude form of case hardening using solid organic materials. The formation of the International Federation for Heat Treatment in 1971 later to include Surface Engineering has been pre-eminent in the globalisation of the rapidly developing discipline of surface engineering. The dominant effect of environmental aspects of surface engineering are discussed regarding the impact for change to light weight materials and the adoption of environmentally friendly plasma technologies.

  13. In situ post-weld heat treatment on martensitic stainless steel turbine runners using a robotic induction heating process to control temperature distribution

    Science.gov (United States)

    Boudreault, E.; Hazel, B.; Côté, J.; Godin, S.

    2014-03-01

    A new robotic heat treatment process is developed. Using this solution it is now possible to perform local heat treatment on large steel components. Crack, cavitation and erosion repairs on turbine blades and Pelton buckets are among the applications of this technique. The proof of concept is made on a 13Cr-4Ni stainless steel designated "CA6NM". This alloy is widely used in the power industry for modern system components. Given the very tight temperature tolerance (600 to 630 °C) for post-weld heat treatment on this alloy, 13Cr-4Ni stainless steel is very well suited for demonstrating the possibilities of this process. To achieve heat treatment requirements, an induction heating system is mounted on a compact manipulator named "Scompi". This robot moves a pancake coil in order to control the temperature distribution. A simulator using thermal finite element analysis is first used for path planning. A feedback loop adjusts parameters in function of environmental conditions.

  14. Assessment of heat treatment of various types of milk.

    Science.gov (United States)

    Sakkas, Lambros; Moutafi, Alexandra; Moschopoulou, Ekaterini; Moatsou, Golfo

    2014-09-15

    Raw milk (RM), reconstituted condensed milk (CM) and three types of reconstituted milk powders (SMPs) were heated indirectly at 80-140°C for 4 s. Native β-lactoglobulin after 90°C treatment of RM was 1132±167 mg/L but no reliable quantities were estimated at temperatures >100°C, whereas 218±43 mg/L residual α-lactalbumin were found at 130°C. Average lactulose contents from 51 to 1549 mg/L were detected at ⩾100°C; average furosine was 1.9 and 126.5 mg/L in raw and 140°C treated milks respectively. The behaviour of heated CM was similar to that of heated RM except for higher furosine concentration. Reconstituted SMPs contained high quantities of lactulose and furosine, the ratio of which was lower than in similarly treated RM. Among the market milks analysed, the group of high-pasteurised milks was highly variable; i.e. native β-lactoglobulin was 69-2831 mg/L, lactulose 0-824 mg/L and furosine 3.3-68.8 mg/L.

  15. Assessment of the effectiveness of two heat removal techniques for permafrost protection

    DEFF Research Database (Denmark)

    Jørgensen, Anders Stuhr; Doré, Guy; Voyer, Érika;

    2008-01-01

    Two mitigation techniques, an air convection embankment and an embankment of a granular material with an integrated heat drain, have been tested for the implementation in the shoulders of road and airfield embankments in permafrost regions. Both techniques will allow cold air to penetrate...... that the effectiveness of the air convection embankment technique can be increased during winter conditions by ventilating the top and the bottom of the embankment shoulders. Installation of air intakes along the shoulders will facilitate air flow info the system during winter and will trap the cold air in the bottom...

  16. Thermal performance of plate-fin heat exchanger using passive techniques: vortex-generator and nanofluid

    Science.gov (United States)

    Khoshvaght-Aliabadi, Morteza

    2016-04-01

    This experimental study investigates the effects of vortex-generator (VG) and Cu/water nanofluid flow on performance of plate-fin heat exchangers. The Cu/water nanofluids are produced by using a one-step method, namely electro-exploded wire technique, with four nanoparticles weight fractions (i.e. 0.1, 0.2, 0.3, and 0.4 %). Required properties of nanofluids are systematically measured, and empirical correlations are developed. A highly precise test loop is fabricated to obtain accurate results of the heat transfer and pressure drop characteristics. Experiments are conducted for nanofluids flow inside the plain and VG channels. Based on the experimental results, utilizing the VG channel instead of the plain channel enhances the heat transfer rate, remarkably. Also, the results show that the VG channel is more effective than the nanofluid on the performance of plate-fin heat exchangers. It is observed that the combination of the two heat transfer enhancement techniques has a noticeably high thermal-hydraulic performance, about 1.67. Finally, correlations are developed to predict Nusselt number and friction factor of nanofluids flow inside the VG channel.

  17. Modernization and efficiency of heat treatment and heating up plants; Modernisierung und Effizienz von Thermoprozessanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Wendt, Peter [LOI Thermprocess GmbH, Essen (Germany); Kuehn, Friedhelm [Ingenieurbuero fuer Waermebehandlung, Industrieoefen und Energieberatung, Muelheim (Germany)

    2010-10-15

    A goal of this contribution is to show, using examples of the thermal heat treatment industry and the thermal processing units used there (Beltype plants, routary hearth, walking hearth, walking beam, pusher type furnaces and gas carburizing plants as well as case hardening plants), which increases in efficiency within and outside of the actual thermal treatment process and the necessary thermal processing units for the order are available today. From the possibilities of the reduction of energy employment resulting from that, a high potential for the discharge of the environment can be derived. The economic effect concerning energy employment and saving possibilities will also be considered. Concluding, examples of case-hardening show which variants of a change of process present themselves partially in the future, in order to achieve substantial production increases and thus energy cost reductions. (orig.)

  18. Pengaruh Heat Treatment untuk Mengembalikan Sifat Mekanik Kawat T-loop Segmental Stainless Steel terhadap Besaran Gaya yang Dihasilkan

    Directory of Open Access Journals (Sweden)

    Avi Laviana

    2015-09-01

    Full Text Available Heat-treatment procedure with precise temperature and technique on the stainless-steel segmental T-loop retraction spring can restore the mechanical properties that decreases after a wire-bending process. The goal of this study was to compare the force produced by a stainless-steel segmental T-loop spring without and with heat-treatment on 4500C for 15 minutes, with various activation distance and gable. The design of the study was in-vitro laboratory experimental design. This study was performed at the Chemistry Laboratory of the Faculty of Science, ITB in 2006. Sample included 50 segmental T-loop springs with α and β angle of 0°–0°, 7.5°–7.5°, 15°–15°, and 22.5°–22.5°, and 30°–30° which consisted of 25 springs without heat-treatment and 25 springs with heat-treatment. Force was measured using autograph with a retraction distance of 1, 2, and 3 mm and the results were gained from ANOVA statistics analysis with a factorial design of 2x3x5 and 5 replications for each cell and posthoc Student Newman Keuls and Tukey test. The result of the statistic test showed that heat-treatment compared to no heat-treatment and interaction between heat-treatment and gable gives significant effect to the force created (p-value <0.05. In conclusion, the heat-treatment on the stainless steel T-loop produces an effect to decrease the created force.

  19. Analyses of Effects of Cutting Parameters on Cutting Edge Temperature Using Inverse Heat Conduction Technique

    Directory of Open Access Journals (Sweden)

    Marcelo Ribeiro dos Santos

    2014-01-01

    Full Text Available During machining energy is transformed into heat due to plastic deformation of the workpiece surface and friction between tool and workpiece. High temperatures are generated in the region of the cutting edge, which have a very important influence on wear rate of the cutting tool and on tool life. This work proposes the estimation of heat flux at the chip-tool interface using inverse techniques. Factors which influence the temperature distribution at the AISI M32C high speed steel tool rake face during machining of a ABNT 12L14 steel workpiece were also investigated. The temperature distribution was predicted using finite volume elements. A transient 3D numerical code using irregular and nonstaggered mesh was developed to solve the nonlinear heat diffusion equation. To validate the software, experimental tests were made. The inverse problem was solved using the function specification method. Heat fluxes at the tool-workpiece interface were estimated using inverse problems techniques and experimental temperatures. Tests were performed to study the effect of cutting parameters on cutting edge temperature. The results were compared with those of the tool-work thermocouple technique and a fair agreement was obtained.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-11-30

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

  1. Numerical Simulation of Vacuum Heat Treatment Thermal Hysteresis Time of GH4169 Superalloy Workpiece

    Institute of Scientific and Technical Information of China (English)

    WANGMing-wei; ZHANGLi-wen; JIANGGuo-dong; ZHANGFan-yun; LiChen-hui; ZHANGLi-sheng; ZHANGZun-li

    2004-01-01

    A nonlinear finite element model of vacuum heat treatment process was developed. In this model, influence of many factors, such as nonlinear heat radiation, temperature-dependent thermal physical properties of material are considered. The temperature field of GH4169 alloy workpiece during vacuum heat treatment process was calculated using finite element software MSC.Marc, and the thermal hysteresis time of the workpiece was predicted. An experiment of vacuum heat treatment of GH4169 superalloy workpiece was carried out to verify the calculation. The experimental results of temperature profile agree well with the simulated results. This work lays a theoretical foundation for optimizing technical parameter of vacuum heat treatment process.

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

    Science.gov (United States)

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

    2015-01-01

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

  3. Endovascular treatment of traumatic carotid cavernous fistula with trapping technique

    Directory of Open Access Journals (Sweden)

    Benny Young

    2013-08-01

    Full Text Available Conventional endovascular treatment for carotid cavernous fistula (CCF involves a direct delivery of either coils, detachable balloon or both to the fistula with end point of CCF resolution and carotid artery preservation. But in few cases with severe laceration of carotid artery, the feasible endovascular technique applicable is by blocking the filling of fistula from cerebral circulation. This method known as trapping technique which implicates carotid artery occlusion, was performed in our present case with good result. (Med J Indones. 2013;22:178-82. doi: 10.13181/mji.v22i3.588Keywords: Carotid cavernous fistula (CCF, carotid occlusion, trapping technique

  4. The structural properties of barium cobalt hexaferrite powder prepared by a simple heat treatment method

    Energy Technology Data Exchange (ETDEWEB)

    Chauhan, Chetna, E-mail: chetna.chauhan@nirmauni.ac.in [Electrical Engineering Department, Institute of Technology, Nirma University, Ahmedabad-382 481. Gujarat. India (India); Jotania, Rajshree, E-mail: rbjotania@gmail.com [Department of Physics, University School of Sciences, Gujarat University, Ahmeabad – 380009. Gujarat. India (India)

    2016-05-06

    The W-type barium hexaferrite was prepared using a simple heat treatment method. The precursor was calcinated at 650°C for 3 hours and then slowly cooled to room temperature in order to obtain barium cobalt hexaferrite powder. The prepared powder was characterised by different experimental techniques like XRD, FTIR and SEM. The X-ray diffractogram of the sample shows W-and M phases. The particle size calculated by Debye Scherrer formula. The FTIR spectra of the sample was taken at room temperature by using KBr pallet method which confirms the formation of hexaferrite phase. The morphological study on the hexaferrite powder was carried out by SEM analysis.

  5. A new technique in the surgical treatment of Hangman's fractures: Neurospinal Academy (NSA) technique

    OpenAIRE

    Sedat Dalbayrak; Onur Yaman; Mesut Yilmaz

    2013-01-01

    Context: Treatment of Hangman′s fractures is still controversial. Hangman′s fractures Type II and IIA are usually treated with surgical procedures. Aim: This study aims at describing the Neurospinal Academy (NSA) technique as an attempt to achieve an approximation of the fracture line to the axis body, which may be used for Type II and IIA patients with severe displacement and angulation. Settings and Design: NSA technique both pars or pedicle screws are placed bicortically to ensure that ant...

  6. Treatment of petroleum-contaminated water resources: modern techniques

    Science.gov (United States)

    Pogharnitskaya, O. V.; Konovalov, V. V.; Dmitrieva, N. V.; Belozerova, D. S.; Strelnikova, A. B.

    2016-09-01

    The article deals with the issue of petroleum-contaminated water resources. The authors have analyzed the dynamics of oil spills, including the world's largest ones, and claimed the issue to be global. The modern methods of mitigating oil spill effects have been studied, as well as the modern techniques of water resource treatment. The particular attention is paid to peat sorbent production, which is considered a promising trend of petroleum- contaminated water treatment.

  7. Treatment of petroleum-contaminated water resources: modern techniques

    OpenAIRE

    Pozharnitskaya, Olga Vyacheslavovna; Konovalov, Vyacheslav Vasilievich; N. V. Dmitrieva; Belozerova, D. S.; Strelnikova, A. B.

    2016-01-01

    The article deals with the issue of petroleum-contaminated water resources. The authors have analyzed the dynamics of oil spills, including the world's largest ones, and claimed the issue to be global. The modern methods of mitigating oil spill effects have been studied, as well as the modern techniques of water resource treatment. The particular attention is paid to peat sorbent production, which is considered a promising trend of petroleum- contaminated water treatment.

  8. Numerical simulation of thermal disposition with induction heating used for oncological hyperthermic treatment.

    Science.gov (United States)

    Dughiero, F; Corazza, S

    2005-01-01

    Hyperthermia plays an important role in oncological therapies, most often being used in combination with radiotherapy, chemotherapy and immunotherapy. The success of this therapy is strongly dependent on the precision and control of thermal deposition. Hyperthermia based on induction heating, with thermally self-regulating thermoseeds inserted into the tumorous mass, is used for interstitial treatment. The technique was the subject of the numerical study presented in the paper. The analysis was carried out using coupled electromagnetic heating and thermo-fluid dynamic FEM simulations. During thermal deposition by induction heating of inserted seeds, the simulations estimated the thermal field inside and outside the tumour, as well as the sensitivity of the thermal field to variations regarding seed temperature, configuration and proximity to vessels. The method, for which accurate anatomical patient's information is essential, is suitable for providing useful qualitative and quantitative information about thermal transients and power density distribution for hyperthermic treatment. Several grid steps were analysed and compared. A 1 cm seed grid was resulted in good homogeneity and effectiveness of the thermal deposition. The cold spot effect caused by large vessels was demonstrated and quantified. Simulations of the heating of a tumorous mass in the liver showed that an indcutor generator operating at 200 kHz frequency and 500 A current, producing a pulsating magnetic field of H = 60 A cm(-1), was adequate for the treatment. The seeds that perform best among those tested (Nicu (28% Cu), PdNi (27.2% Ni), PdCo (6.15% Co) and ferrite core) were the PdNi (1 mm radius, 10 mm length), as they have a low Curie temperature (52 degrees C), which is the closest to the desired treatment temperature and thus reduces the risk of hot spots.

  9. Endotoxin inactivation via steam-heat treatment in dilute simethicone emulsions used in biopharmaceutical processes.

    Science.gov (United States)

    Britt, Keith A; Galvin, Jeffrey; Gammell, Patrick; Nti-Gyabaah, Joseph; Boras, George; Kolwyck, David; Ramirez, José G; Presente, Esther; Naugle, Gregory

    2014-01-01

    Simethicone emulsion is used to regulate foaming in cell culture operations in biopharmaceutical processes. It is also a potential source of endotoxin contamination. The inactivation of endotoxins in dilute simethicone emulsions was assessed as a function of time at different steam temperatures using a Limulus amebocyte lysate kinetic chromogenic technique. Endotoxin inactivation from steam-heat treatment was fit to a four-parameter double exponential decay model, which indicated that endotoxin inactivation was biphasic, consisting of fast and slow regimes. In the fast regime, temperature-related effects were dominant. Transitioning into the slow regime, the observed temperature dependence diminished, and concentration-related effects became increasingly significant. The change in the Gibbs free energy moving through the transition state indicated that a large energy barrier must be overcome for endotoxin inactivation to occur. The corresponding Arrhenius pre-exponential factor was >10(12) s(-1) suggesting that endotoxins in aqueous solution exist as aggregates. The disorder associated with the endotoxin inactivation reaction pathway was assessed via the change in entropy moving through the transition state. This quantity was positive indicating that endotoxin inactivation may result from hydrolysis of individual endotoxin molecules, which perturbs the conformation of endotoxin aggregates, thereby modulating the biological activity observed. Steam-heat treatment decreased endotoxin levels by 1-2 logarithm (log) reduction (LRV), which may be practically relevant depending on incoming raw material endotoxin levels. Antifoam efficiency and cell culture performance were negligibly impacted following steam-heat treatment. The results from this study show that steam-heat treatment is a viable endotoxin control strategy that can be implemented to support large-scale biopharmaceutical manufacturing.

  10. Analysis of post wet chemistry heat treatment effects on Nb SRF surface resistance

    CERN Document Server

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

    2013-01-01

    Most of the current research in superconducting radio frequency (SRF) cavities is focused on ways to reduce the construction and operating cost of SRF based accelerators as well as on the development of new or improved cavity processing techniques. The increase in quality factors is the result of the reduction of the surface resistance of the materials. A recent test on a 1.5 GHz single cell cavity made from ingot niobium of medium purity and heat treated at 1400 C in a ultra-high vacuum induction furnace resulted in a residual resistance of about 1nanoohm and a quality factor at 2.0 K increasing with field up to 5x10^10 at a peak magnetic field of 90 mT. In this contribution, we present some results on the investigation of the origin of the extended Q0-increase, obtained by multiple HF rinses, oxypolishing and heat treatment of all Nb cavities.

  11. Effect of fat type and heat treatment on the microstructure of meat emulsions

    DEFF Research Database (Denmark)

    Miklos, Rikke; Lametsch, René; Nielsen, Mikkel Schou

    2013-01-01

    In comminuted meat products the gel-forming abilities of the myofibrillar proteins are of major importance. In meat emulsions fat will be present in globules which are stabilized by a membrane coating made of salt-soluble proteins. These discontinuous fat particles act as fillers or co......-polymers and stabilize the protein network. Differences in the physicochemical properties of saturated and unsaturated lipids affect the distribution of fat and thereby the functionality and quality of the final product. The objectives were to study the effects of lipid type and heat treatment on changes...... in microstructure of meat emulsions by use of a novel quantitative application of absorption- and phase-contrast tomography. The non-invasive technique offered the possibility to study the same sample in both raw and cooked condition. The samples were raw and heat treated meat emulsions (10% protein, 25% fat, 60...

  12. Purification of Single-Wall carbon nanotubes by heat treatment and supercritical extraction

    Directory of Open Access Journals (Sweden)

    Mariana Bertoncini

    2011-09-01

    Full Text Available Arc discharge is the most practical method for the synthesis of single wall carbon nanotubes (SWCNT. However, the production of SWCNT by this technique has low selectivity and yield, requiring further purification steps. This work is a study of purification of SWCNT by heat treatment in an inert atmosphere followed by supercritical fluid extraction. The raw arc discharge material was first heat-treated at 1250 °C under argon. The nanotubes were further submitted to an extraction process using supercritical CO2 as solvent. A surfactant (tributylphosphate, TBP and a chelating agent (hexafluoroacetylacetone, HFA were used together to eliminate metallic impurities from the remaining arc discharge catalysts. Analysis of Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES showed an efficient removal of iron and cobalt (>80%. The purified nanotubes were further analyzed by TGA and Raman spectroscopy.

  13. Enhancement of heat transfer in Czochralski growth of silicon crystals with a chemical cooling technique

    Science.gov (United States)

    Ding, Junling; Liu, Lijun; Zhao, Wenhan

    2017-06-01

    The cost of producing single-crystalline silicon with the Czochralski method can be reduced by promoting the crystal size and/or crystal pulling rate. However, more latent heat of solidification needs to be released from the melt-crystal (m-c) interface during the crystal growth process. In this study, the C-CO2 chemical endothermic reaction is proposed as a novel and efficient cooling technique to solve this problem. Compared with the conventional gas cooling method, C-CO2 endothermic reaction method can significantly enhance the heat transfer in the crystal at the m-c interface. It was found that the heat transfer is more enhanced with a chemical reaction of smaller activation energy, and the m-c interface becomes flatter. The influence of the carbon concentration in the chemical reactive gas flow on the heat removal in the crystal at the m-c interface is also investigated. The cooling effect is significantly increased with the increase in the carbon concentration when it is small. However, when the carbon concentration in the reactive gas is high, the cooling effect just increases slightly. The research demonstrates that the proposed chemical endothermic reaction is a promising cooling technique to be applied in CZ-Si crystal growth with large size/high pulling rate.

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

    Science.gov (United States)

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

    2002-09-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  16. Controlled nucleation and growth of thin hydroxyapatite layers on titanium implants by using induction heating technique.

    Science.gov (United States)

    Gómez Morales, J; Rodríguez Clemente, R; Armas, B; Combescure, C; Berjoan, R; Cubo, J; Martínez, E; García Carmona, J; Garelik, S; Murtra, J; Muraviev, D N

    2004-06-22

    This paper reports the results obtained by the development of a new wet method of hydroxyapatite (HA) thin layer deposition. The method is based on the localized precipitation of HA on metallic substrates activated by induction heating. The technique developed has been shown to allow for the complete coating of substrates with micrometric thin films of HA within a low processing time. The method has been successfully applied to coat Ti plaques and Ti-6A1-4V cylinders.

  17. Moisture-heating Treatment and Processing Optimization of Parboiled Rice

    Institute of Scientific and Technical Information of China (English)

    Zhao Siming; Xiong Shanbai

    2001-01-01

    Effect of moisture-heating treatment on the quality of parboiled rice and processing optimization were studied. Results indicated that the riboflavine content of parboiled rice is higher, and the color is light, aroma is strong and the head yield ratio is higher by soaking with acid and ethanol, cooking at high-pressure and then drying with high temperature-high moisture. Optimal processing parameters are soaking paddy with citrate acid for 2h, then with 1.5% ethanol for 1.5h, high pressure cooking for 30min, and then drying under 55%RH, 90℃ for 30min, cooling slowly for 2.5h, and shelling and milling immediately. Head yield ratio and whole rice ratio was 67.3% and 87.0% respectively, the color of finished product is light, rice aroma is strong, and the content of riboflavine is 2.47mg/100g.

  18. Moisture-heating Treatment and Processing Optimization of Parboiled Rice

    Institute of Scientific and Technical Information of China (English)

    ZhaoSiming; XiongShanbai

    2001-01-01

    Abstract: Effect of moisture-heating treatment on the quality ofparboiled rice and processing optimization were studied. Resultsindicated that the riboflavine content of parboiled rice is higher, and thecolor is light, aroma is strong and the head yield ratio is higher bysoaking with acid and ethanol, cooking at high-pressure and thendrying with high temperature-high moisture. Optimal processingparameters are soaking paddy with citrate acid for 2h, then with 1.5%ethanol for 1.5h, high pressure cooking for 30min, and then dryingunder 55%RH, 90~C for 30min, cooling slowly for 2.5h, and shelling andmilling immediately. Head yield ratio and whole rice ratio was 67.3%and 87.0% respectively, the color of finished product is light, ricearoma is strong, and the content of riboflavine is 2.47mg/100g.

  19. Analysis of the building system of four mills and their suitability for heat treatment pest disinfestation

    Directory of Open Access Journals (Sweden)

    Loredana Strano

    2013-09-01

    Full Text Available The last century researchers at Kansas State University demonstrated the validity of the heat treatment as a method of pest control in more than 20 mills. However factors such as the high capital investment required to heat large buildings, inadequate control of high temperatures and the risk of damage to parts of the plants or the construction materials have prevented the large-scale adoption of this technique as a viable alternative to fumigants. Today the combination of the industrialization of the food industry, the technological and structural modernization of plants and developments in heat disinfection technologies have resulted in interesting results being obtained for the use of this system in primary and secondary production processing plants, both experimentally and in practice. However, the scientific literature highlights some of the factors that limit the efficiency of the treatment. This is related to aspects of the buildings and the plants and the environment of the buildings. The structure of the buildings appear to have an enormous impact on energy consumption, because this depends on the amount of heating time and the methods that have to be used when establishing a heat treatment regime. These factors are important if the fumigation temperatures are to be reached in the shortest possible time and can affect the choice of the technique used with current fumigants, especially when this is combined with the amount and cost of the energy consumed. The aim of this work is to analyse four Sicilians mills that intend to use the heat system for fumigation and pest control in order to identify those aspects of the buildings, plant and their environment which are “critical elements” and may discourage the use of this technology. Particular attention was paid to the type of construction materials and their thermal conductivity (roof, floors and walls, the number and volume of the buildings and the distance between them, the

  20. Treatment of 58 Cases of Tonsillitis by Pricking Technique

    Institute of Scientific and Technical Information of China (English)

    SUN Yu; ZHANG Zhi-gang; MIAO Hong; LI Wei; HUANG Guo-qi

    2003-01-01

    Ashi point (tonsil) in combination of the pricking and bleeding technique on Shaoshang (LU 11 )and Shangyang (LI 1) were used to treat 58 outpatients of acute tonsillitis. The results showed cure in 38 cases,remarkable effect in 17 cases and failure in 3 cases by one treatment, and the total effective rate in 95%.

  1. [Influence of cryogenic treatment and age-hardening heat treatment on the microhardness of palladium-silver dental alloys].

    Science.gov (United States)

    Zhao, Yao; Tong, Xu; Liu, Jiajun; Hao, Zhichao; Meng, Yukun

    2013-06-01

    The purpose of this study was to investigate the influence of cryogenic treatment and age-hardening heat treatment on the micro-Vicker's hardness of palladium-silver dental alloys. A low-gold content dental casting alloy composed of Ag-Pd-Cu-Au was prepared for this study. Experimental specimens according to standard requirements were prepared following a standard dental laboratory casting procedure, cast specimens were heated to 900 degrees C and quenched in ice water. The specimens were then divided into 4 groups. They were subsequently subjected to different treatments, including age-hardening heat treatment, cryogenic treatment, heat treatment combined with cryogenic treatment. The non-treated group was used as control. The micro-Vicker's hardness value was examined. The significance of correlation was analyzed. The micro-Vicker's hardness of specimens after age-hardening heat treatment, cryogenic treatment, heat treatment combined with cryogenic treatment increased by 129%, 13% and 141%, respectively, compared with that of the non-treated control group. Conclusion Age-hardening heat treatment and cryogenic treatment were effective in elevating the hardness of Ag-Pd-Cu-Au alloy.

  2. Microelectrode-guided Technique for Treatment of Parkinson's Diseases

    Institute of Scientific and Technical Information of China (English)

    陈坚; 杨正明; 郭东生; 牛洪泉

    2002-01-01

    From May, 2000 to June, 2001, 27 patients with Parkinson disease (PD), including 10cases of rigidity, 13 cases of tremor, 4 cases of rigidity and tremor, were treated by microelectrodeguided technique. Among them, phlebotomy was carried out in 17 cases and thalamotomy in 10 cases. All the targets of lesion were anatomically located by using MR and neurophysiological signals on microelectrode. Our results showed that the efficiency of microelectrode-guided technique for treatment of PD was 98 %. The postoperative unified parkinson disease rating scale were 12.3+ 9.1 and 13. 2± 8. 9 respectively, which significantly improved as compared with those before operation. It was concluded that by recognizing special electrical signals in neurons microelectrode-guided neuropsychological techniques can locate target at cellular level, which overcomes the individual difference in anatomy and function, and allow more accuracy, safety and efficiency of operation. This is especially true of PD patients who fail to respond to medical treatment.

  3. Vascular dynamics of a shape memory polymer foam aneurysm treatment technique.

    Science.gov (United States)

    Ortega, Jason; Maitland, Duncan; Wilson, Tom; Tsai, William; Savaş, Omer; Saloner, David

    2007-11-01

    The vascular dynamics of a shape memory polymer foam aneurysm treatment technique are assessed through the simulated treatment of a generic basilar aneurysm using coupled fluid dynamics and heat transfer calculations. The shape memory polymer foam, which expands to fill the aneurysm when heated, is modeled at three discrete stages of the treatment procedure. To estimate an upper bound for the maximum amount of thermal damage due to foam heating, a steady velocity is specified through the basilar artery, corresponding to a minimum physiological flow velocity over a cardiac cycle. During expansion, the foam alters the flow patterns within the aneurysm by shielding the aneurysm dome from a confined jet that issues from the basilar artery. The time scales for thermal damage to the artery walls and surrounding blood flow are computed from the temperature field. The flow through the post-treatment bifurcation is comprised of two counter-rotating vortex tubes that are located beneath the aneurysm neck and extend downstream into the outlet arteries. Beneath the aneurysm neck, a marked increase in the wall shear stress is observed due to the close proximity of the counter-rotating vortex tubes to the artery wall.

  4. Treatment of MSW fly ashes using the electrodialytic remediation technique

    DEFF Research Database (Denmark)

    Ferreira, Celia; Ribeiro, Alexandra B.; Ottosen, Lisbeth M.

    2004-01-01

    In the present work the electrodialytic remediation technique is applied for the treatment of fly ash, a hazardous by-product resulting from the incineration of municipal solid waste. Results are presented for an experiment conducted for 40 days at 38 mA, with a continuously stirred cell...... extraction tests and during the electrodialytic treatment. This substance was found to perform well for pH below 6 and above 9, although extractions are better in the acidic region. Other relevant observations include the retention of significant amounts of heavy metals on the cation-exchange membrane...... separating chambers III and IV and the dissolution of a large percentage of sample during the treatment. 39% of zinc, 14% of lead, 18% of copper and 60% of cadmium were removed from fly ash using the electrodialytic technique and these results are compared with previously reported experiments on similar...

  5. 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.

  6. Methods for microwave heat treatment of manufactured components

    Science.gov (United States)

    Ripley, Edward B.

    2010-08-03

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

  7. Apparatus for microwave heat treatment of manufactured components

    Science.gov (United States)

    Babcock & Wilcox Technical Services Y-12, LLC

    2008-04-15

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

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

    Directory of Open Access Journals (Sweden)

    Bojan Matijević

    2006-03-01

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

  9. Fluid dynamics and convective heat transfer in impinging jets through implementation of a high resolution liquid crystal technique

    Science.gov (United States)

    Kim, K.; Wiedner, B.; Camci, C.

    1993-01-01

    A combined convective heat transfer and fluid dynamics investigation in a turbulent round jet impinging on a flat surface is presented. The experimental study uses a high resolution liquid crystal technique for the determination of the convective heat transfer coefficients on the impingement plate. The heat transfer experiments are performed using a transient heat transfer method. The mean flow and the character of turbulent flow in the free jet is presented through five hole probe and hot wire measurements, respectively. The flow field character of the region near the impingement plate plays an important role in the amount of convective heat transfer. Detailed surveys obtained from five hole probe and hot wire measurements are provided. An extensive validation of the liquid crystal based heat transfer method against a conventional technique is also presented. After a complete documentation of the mean and turbulent flow field, the convective heat transfer coefficient distributions on the impingement plate are presented. The near wall of the impingement plate and the free jet region is treated separately. The current heat transfer distributions are compared to other studies available from the literature. The present paper contains complete sets of information on the three dimensional mean flow, turbulent velocity fluctuations, and convective heat transfer to the plate. The experiments also prove that the present nonintrusive heat transfer method is highly effective in obtaining high resolution heat transfer maps with a heat transfer coefficient uncertainty of 5.7 percent.

  10. Development of Layered Treatment Technique for Multiple Heavy Oil Reservoirs

    Institute of Scientific and Technical Information of China (English)

    Hu Zhimian; Wu Dehua

    1995-01-01

    @@ In order to solve the problems that there is steam absorbing inhomogeneity in various layers of well in heavy oil reservoirs during steam injection, and upperlayers and high permeability layers repeat steam absorption, as well as middle or low permeability layers absorb little steam or no steam, we have studied and developed seperate-layer treatment techniques for huff and puff wells in recent years. By test and application,these techniques have been proved successful in increasing steam stimulated effect and recovery efficiency in the period of cyclic steam stimulations of oil wells in multilayer heavy oil reservoirs.

  11. Simulation of the Effects of Cooling Techniques on Turbine Blade Heat Transfer

    Science.gov (United States)

    Shaw, Vince; Fatuzzo, Marco

    Increases in the performance demands of turbo machinery has stimulated the development many new technologies over the last half century. With applications that spread beyond marine, aviation, and power generation, improvements in gas turbine technologies provide a vast impact. High temperatures within the combustion chamber of the gas turbine engine are known to cause an increase in thermal efficiency and power produced by the engine. However, since operating temperatures of these engines reach above 1000 K within the turbine section, the need for advances in material science and cooling techniques to produce functioning engines under these high thermal and dynamic stresses is crucial. As with all research and development, costs related to the production of prototypes can be reduced through the use of computational simulations. By making use of Ansys Simulation Software, the effects of turbine cooling techniques were analyzed. Simulation of the Effects of Cooling Techniques on Turbine Blade Heat Transfer.

  12. Study on heating technique for high productivity, superior quality and lower consumption

    Institute of Scientific and Technical Information of China (English)

    CHENYong; ZHOUJiacong; MEIDongsheng

    2003-01-01

    The existing thermal characteristics of reheating fumace and heavy rail bloom heating technique was evaluated based on temperature measurement with thermal couples and energy balance. Then, the heating technique was optimized. The modified operation shows the annual production of steel for heavy rail is increased from 400 000 t to 500 000 t, the fluctuation of heating temperature is lowered from ±40℃ to ±20℃, while, temperature difference in bloom section is lessened from 65℃ to less than 45℃, specific fuel consumption is decreased from 2.147GJ/t to 2.014GJ/t of steel. Furthermore, metal loss due to oxidation is signifioantly reduced from 1.75 % to 0.72 % to 0.92 %, decarburization depth is lowered from 0.35—0.82 mm to 0.20—0.50 mm, and the rate of overbuming is decreased 45 %. The purpose for realizing high productivity, superior quality and lower consumption has been achieved.

  13. Modelling of Evaporator in Waste Heat Recovery System using Finite Volume Method and Fuzzy Technique

    Directory of Open Access Journals (Sweden)

    Jahedul Islam Chowdhury

    2015-12-01

    Full Text Available The evaporator is an important component in the Organic Rankine Cycle (ORC-based Waste Heat Recovery (WHR system since the effective heat transfer of this device reflects on the efficiency of the system. When the WHR system operates under supercritical conditions, the heat transfer mechanism in the evaporator is unpredictable due to the change of thermo-physical properties of the fluid with temperature. Although the conventional finite volume model can successfully capture those changes in the evaporator of the WHR process, the computation time for this method is high. To reduce the computation time, this paper develops a new fuzzy based evaporator model and compares its performance with the finite volume method. The results show that the fuzzy technique can be applied to predict the output of the supercritical evaporator in the waste heat recovery system and can significantly reduce the required computation time. The proposed model, therefore, has the potential to be used in real time control applications.

  14. 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.

  15. Persistent type I endoleak after endovascular treatment with Chimney technique

    Directory of Open Access Journals (Sweden)

    Ana Isabel Azevedo

    2016-09-01

    Full Text Available Thoracic endovascular aortic repair (TEVAR is increasingly used in the treatment of acute type B aortic dissection. Type Ia endoleaks are a common complication of the procedure, but its clinical significance as well as the best treatment strategy remain poorly defined. We present a case of a type Ia endoleak following TEVAR in the treatment of acute type B aortic dissection. Chimney technique approach was used in an attempt to seal the endoleak. Although technical success was suboptimal, the patient remained clinically stable and event free. Data regarding the natural course and management of type Ia endoleaks following TEVAR for aortic dissection are sparse. Future research is required to establish the clinical and technical determinants of the need to treat these endoleaks as well as the best treatment strategy.

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

    Energy Technology Data Exchange (ETDEWEB)

    Tollestrup, Alvin; /Fermilab

    2011-04-14

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

  17. Flow characteristics and micro-scale metallic particle formation in the laser supersonic heating technique

    Science.gov (United States)

    Lin, Shih-Lung; Lin, Jehnming

    2007-02-01

    The characteristics of the supersonic flow of the laser heating technique for producing micro-scale metallic particles were investigated in this study. A numerical model was established to predict the flow fields and particle trajectories leaving a spray nozzle with shock wave effects. The compressible flow of the shock waves and the trajectories of particles in diameters of 1-20 μm were simulated and compared with the flow visualization. In the experiment, a pulsed Nd-YAG laser was used as heat source on a carbon steel target within the nozzle, and the carbon steel particles were ejected by high-pressure air. The result shows that the shock wave structures were generated at various entrance pressures, and there is a significant increase in the amount of carbon steel particles and the spraying angles by increasing the entrance air pressure.

  18. [Non-fusion techniques for treatment of pediatric scoliosis].

    Science.gov (United States)

    Ridderbusch, K; Rupprecht, M; Kunkel, P; Stücker, R

    2013-12-01

    The primary goal of treatment in children with early onset scoliosis (EOS) is to control the deformity and to allow spinal and chest wall growth to continue and improve pulmonary function. In skeletally immature children spondylodesis leads to fusion of the instrumented segments with associated nonsymmetrical growth and pulmonary insufficiency. Non-fusion, techniques such as growing rods, vertical expandable prosthetic titanium rib® (VEPTR) and staples have evolved over the past years. Each technique has its different spectrum of indications which the surgeon has to follow accurately to prevent the patient from developing complications. A new trend started by using magnetically controlled growing rods to avoid the need for anesthesia and open surgery during adaptive growth. The intention of this article is to give the reader a synopsis about the three most important non-fusion techniques based on own experience and the current literature.

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

    Directory of Open Access Journals (Sweden)

    V. I. Тimoshpolsky

    2008-01-01

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

  20. Enhancement of native and phosphorylated TDP-43 immunoreactivity by proteinase K treatment following autoclave heating.

    Science.gov (United States)

    Mori, Fumiaki; Tanji, Kunikazu; Kakita, Akiyoshi; Takahashi, Hitoshi; Wakabayashi, Koichi

    2011-08-01

    TDP-43 is a major disease protein in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with TDP-43 (FTLD-TDP). To evaluate the effectiveness of proteinase K (PK) treatment in antigen retrieval for native and phosphorylated TDP-43 protein, we examined the temporal cortex and spinal cord from patients with sporadic ALS and FTLD-TDP and control subjects. PK treatment following heat retrieval enhanced the immunoreactivity for native TDP-43 in controls as well as for native and phosphorylated TDP-43 in ALS and FTLD-TDP. A significant number of TDP-43-positive neuropil threads were demonstrated in lesions, in which routine immunohistochemistry revealed that the predominant inclusions are cytoplasmic. This retrieval method is the best of immunohistochemical techniques for demonstrating TDP-43 pathology, especially in the neuropil. © 2010 Japanese Society of Neuropathology.

  1. Chronic Generalized Parodontitis. Part II. Modern Treatment and Prevention Techniques

    OpenAIRE

    Lukinykh L.M.; Kruglova N.V.

    2011-01-01

    To optimize a therapeutic process due to technological development in dentistry there have appeared new progressive technologies that allow improving life quality of patients with periodontal inflammatory diseases. Modern techniques of a complex etiopathogenic treatment of periodontal inflammatory diseases including conservative, orthopedic, orthodontic and surgical measures have been presented. There has been proved the use of preparations of systemic and local effect to treat chronic ge...

  2. Effects Of T6 Heat Treatment With Double Solution Treatment On Microstructure, Hardness And Corrosion Resistance Of Cast Al-Si-Cu Alloy

    Directory of Open Access Journals (Sweden)

    Wiengmoon A.

    2015-06-01

    Full Text Available Effects of T6 heat treatment with double solution treatment on microstructure, hardness and corrosion resistance of a cast A319 (Al-4.93wt%Si-3.47wt%Cu alloy were investigated. The T6 heat treatment comprised of the first solution treatment at 500±5°C for 8 h, the second solution treatment in the temperature range of 510 to 530±5°C for 2 h followed by water quenching (80°C, and artificial aging at 170°C for 24 h followed by water quenching (80°C. Microstructure of the alloy was studied by optical microscopy and electron microscopy, Rockwell hardness was measured, and corrosion resistance in 0.1 M NaCl aqueous solution was determined by a potentiodynamic technique. The results revealed that the T6 heat treatment with double solution treatment led to an improvement in corrosion resistance and comparable macrohardness as compared to those obtained from the case of single solution treatment. The second solution treatment at 520°C is the optimum leading to relatively low corrosion current density without substantial drawbacks on breakdown potential or the width of passive range.

  3. [Peripheral facial paralysis treated with the adapted acupuncture technique of heat-producing needling].

    Science.gov (United States)

    Zhang, Xi; Weli, Qing-Lin

    2011-09-01

    To improve the manipulations of traditional heat-producing needling, and observe its therapeutic effect on peripheral facial paralysis. Acupuncture was adopted for all the 50 patients with peripheral facial paralysis. Acupoints such as Dicang (ST 4), Jiache (ST 6), Qianzheng (Extra), Fengchi(GB 20), Yifeng (TE 17) of the affected side, Hegu (LI 4) of the healthy side, Shousanli (LI 10), Zusanli (ST 36) and Taichong (LR 3) of both sides were adopted. And an adapted heat-producing needling was applied. With the left thumb of the doctor press at the point, the needle was rotated slowly with the right thumb moving forward and index finger moving backward to maintain the needling sensation. Then, heavier pressure was given with the left thumb, and a 9-time lifting and thrusting manipulation with small amplitude, low and even frequency by the right thumb and the index finger. Heavy pressure was maintained by the left thumb, and the needle was inserted by the right thumb and index finger to promote the needling sensation. Thus, the tip of the needle was always kept at the level where the needling sensation appeared. Therefore, a heat sensation can be felt by the patient under the needle or at the distal area. The treatment should be given once a day. And therapeutic effect was observed after 15 times continue treatment. All the 50 patients were cured without any sequela. Adapted heat-producing needling can promote the recovery of the function of facial muscle, and the effect of treatment of peripheral facial paralysis with the manipulation is confirmed.

  4. Fabrication of TiO2 Crystalline Coatings by Combining Ti-6Al-4V Anodic Oxidation and Heat Treatments

    Directory of Open Access Journals (Sweden)

    María Laura Vera

    2015-01-01

    Full Text Available The bio- and hemocompatibility of titanium alloys are due to the formation of a TiO2 layer. This natural oxide may have fissures which are detrimental to its properties. Anodic oxidation is used to obtain thicker films. By means of this technique, at low voltages oxidation, amorphous and low roughness coatings are obtained, while, above a certain voltage, crystalline and porous coatings are obtained. According to the literature, the crystalline phases of TiO2, anatase, and rutile would present greater biocompatibility than the amorphous phase. On the other hand, for hemocompatible applications, smooth and homogeneous surfaces are required. One way to obtain crystalline and homogeneous coatings is by heat treatments after anodic oxidation. The aim of this study is to evaluate the influence of heat treatments on the thickness, morphology, and crystalline structure of the TiO2 anodic coatings. The characterization was performed by optical and scanning electron microscopy, X-ray diffraction, and X-ray reflectometry. Coatings with different colors of interference were obtained. There were no significant changes in the surface morphology and roughness after heat treatment of 500°C. Heat treated coatings have different proportions of the crystalline phases, depending on the voltage of anodic oxidation and the temperature of the heat treatment.

  5. Fabrication of TiO2 Crystalline Coatings by Combining Ti-6Al-4V Anodic Oxidation and Heat Treatments

    Science.gov (United States)

    Schvezov, Carlos Enrique; Ares, Alicia Esther

    2015-01-01

    The bio- and hemocompatibility of titanium alloys are due to the formation of a TiO2 layer. This natural oxide may have fissures which are detrimental to its properties. Anodic oxidation is used to obtain thicker films. By means of this technique, at low voltages oxidation, amorphous and low roughness coatings are obtained, while, above a certain voltage, crystalline and porous coatings are obtained. According to the literature, the crystalline phases of TiO2, anatase, and rutile would present greater biocompatibility than the amorphous phase. On the other hand, for hemocompatible applications, smooth and homogeneous surfaces are required. One way to obtain crystalline and homogeneous coatings is by heat treatments after anodic oxidation. The aim of this study is to evaluate the influence of heat treatments on the thickness, morphology, and crystalline structure of the TiO2 anodic coatings. The characterization was performed by optical and scanning electron microscopy, X-ray diffraction, and X-ray reflectometry. Coatings with different colors of interference were obtained. There were no significant changes in the surface morphology and roughness after heat treatment of 500°C. Heat treated coatings have different proportions of the crystalline phases, depending on the voltage of anodic oxidation and the temperature of the heat treatment. PMID:25784939

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

    Science.gov (United States)

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

    2017-03-01

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

  7. Modeling of Intercritical Heat Treatment of DP and TRIP Steels

    Institute of Scientific and Technical Information of China (English)

    REGER Mihaly; VERO Balazs; CSEPELI Zsolt; PAN Jiansheng

    2004-01-01

    The final microstructure of DP and TRIP assisted steels can evolve after hot working (hot rolling) or during post heat treatment process. In the formation of the final structure a number of different technological parameters have important roles, e.g. end temperature of rolling, cooling rates, temperature of intercritical annealing, etc. As a result of the individual factors and their combinations a lot of product technology routes are feasible. The effect of the different combinations of these technological parameters on the microstructure can be mapped by the special Jominy end-quench test (so called intercritical Jominy end-quench test) described in this paper. Unlike the traditional Jominy test, in this case there is a partial anstenizing between A1 and A3 temperatures which results in a given amount of ferrite in the microstructure before quenching. The method developed can be applied for mapping DP and TRIP assisted steels' microstructure in a wide range of technological parameters. The analysis of measured and calculated data can help us find the technological parameters optimal from the microstructural point of view.

  8. Modeling of Intercritical Heat Treatment of DP and TRIP Steels

    Institute of Scientific and Technical Information of China (English)

    REGERMihaly; VEROBalazs; CSEPELIZsolt; PANJiansheng

    2004-01-01

    The final microstructure of DP and TRIP assisted steels can evolve after hot working (hot rolling) or during post heat treatment process. In the formation of the final structure a number of different technological parameters have important roles, e.g. end temperature of rolling, cooling rates, temperature of intercritical annealing, etc. As a result of the individual factors and their combinations a lot of product technology routes are feasible. The effect of the different combinations of these technological parameters on the microstructure can be mapped by the special Jominy end-quench test (so called intercritical Jominy end-quench test) described in this paper. Unlike the traditional Jominy test, in this case there is a partial austenizing between A1 and A3 temperatures which results in a given amount of ferrite in the microstructure before quenching. The method developed can be applied for mapping DP and TRIP assisted steels' microstructure in a wide range of technological parameters. The analysis of measured and calculated data can help us find the technological parameters optimal from the microstructural point of view.

  9. Combined treatment of conventional techniques and acupressure in laryngectomized patients

    Directory of Open Access Journals (Sweden)

    Leonor Mora Yero

    2015-07-01

    Full Text Available Background: the use of traditional medicine techniques, specifically acupressure, along with established techniques, is widely used in developed countries for the rehabilitation of the laryngectomized patients.Objective: to describe the effectiveness of the combination of conventional techniques and those using acupressure in laryngectomized patients seen at the department of speech and phoniatrics of Ernesto Guevara Hospital from January, 2013 to December, 2014.Methods: a quasi-experimental study was carried out on a sample of 24 patients who had undergone laryngectomy and presented voluntarily or were referred for voice rehabilitation in the period and place herein mentioned. The sample was divided into two groups of 12 each. The first group was treated by the conventional method and the second group was treated with a combination of the traditional method and acupressure.Results: in the group of patients that received a conventional treatment a 50 % achieved rehabilitation. In the group where conventional techniques were combined with acupressure, rehabilitation of a 91,6 % was achieved. No adverse effects were manifested.Conclusions: the unit of the conventional technique with acupressure reduced the time for the rehabilitation of patients and increased the number of patients rehabilitated.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-11-01

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

  11. The effect of heat treatment on the corrosion behaviour of 319 aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Panagopoulos, C.N.; Georgiou, E.P.; Giannakopoulos, K.I. [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, Athens (Greece)

    2009-06-15

    The effect of various heat treatments on the corrosion behaviour of 319 T1 cast aluminium alloy was investigated. From this alloy, specimens were heat treated in T5, T6 and two steps solution heat treatment T6 conditions and afterwards were subjected to electrochemical corrosion in a 0.1 M NaCl solution (pH = 12). From the above treatments, T5 heat treatment did not improve the corrosion resistance of the as-received alloy in contrast to T6 heat treatment which improved the corrosion resistance of the same alloy. However, two steps solutionizing T6 treatment showed the best corrosion resistance of the aluminium alloy. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  12. Prediction of heat treatment in food processing machinery

    DEFF Research Database (Denmark)

    Karlson, Torben; Friis, Alan; Szabo, Peter

    1997-01-01

    The velocity and temperature fields of a shear thinning fluid in a co-rotating disc scraped surface heat exchanger (CDHE) are calculated using the finite element method. By tracking and timingparticles through the heat exchanger residence time and thermal time distributions are computed. The resi......The velocity and temperature fields of a shear thinning fluid in a co-rotating disc scraped surface heat exchanger (CDHE) are calculated using the finite element method. By tracking and timingparticles through the heat exchanger residence time and thermal time distributions are computed...

  13. A new technique in the surgical treatment of Hangman′s fractures: Neurospinal Academy (NSA technique

    Directory of Open Access Journals (Sweden)

    Sedat Dalbayrak

    2013-01-01

    Full Text Available Context: Treatment of Hangman′s fractures is still controversial. Hangman′s fractures Type II and IIA are usually treated with surgical procedures. Aim: This study aims at describing the Neurospinal Academy (NSA technique as an attempt to achieve an approximation of the fracture line to the axis body, which may be used for Type II and IIA patients with severe displacement and angulation. Settings and Design: NSA technique both pars or pedicle screws are placed bicortically to ensure that anterior surface of C2 vertebral body will be crossed 1-2 mm. A rod is prepared in suitable length and curve to connect the two screws. For placing the rod, sufficient amount of bone is resected from the C2 spinous process. C2 vertebral body is pulled back by means of the screws that crossed the anterior surface of C2 vertebral body. Materials and Methods: Hangman II and IIA patient are treated with NSA technique. Result: Angulated and tilted C2 vertebral body was pulled back and approximated to posterior elements. Conclusions: In Hangman′s fractures Type II and IIA with severe vertebral body and pedicle displacement, NSA technique is an effective and reliable treatment alternative for the approximation of posterior elements to the C2 vertebral body, which is tilted, angulated, and dislocated.

  14. Surgical technique for treatment of recalcitrant adductor longus tendinopathy.

    Science.gov (United States)

    Gill, Thomas J; Carroll, Kaitlin M; Makani, Amun; Wall, Andrew J; Dumont, Guillaume D; Cohn, Randy M

    2014-04-01

    Chronic groin pain in the athlete can be a difficult problem to manage. Adductor dysfunction is the most common cause of groin pain in athletes, with the adductor longus being the tendon most commonly involved. The most reproducible finding for adductor longus tendinopathy is tenderness along the tendon with passive abduction and resisted hip adduction in extension. Magnetic resonance imaging and injection of a corticosteroid and anesthetic into the proximal muscle-tendon junction are both helpful in confirming the diagnosis. Nonoperative treatment may consist of protected weight bearing, ice application, ultrasonography, electrical stimulation, and gentle stretching with progressive strengthening. However, nonoperative management is not always successful. In these instances, surgical treatment can be quite effective. We present the indications, surgical technique, and rehabilitation protocol of adductor tenotomy for chronic tendinopathy. This can prove a useful tool for the treatment of recalcitrant groin pain attributable to the adductor longus.

  15. 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.

  16. An Investigation of the Design Potential of Thermochromic Home Textiles Used with Electric Heating Techniques

    Directory of Open Access Journals (Sweden)

    Hung-Jen Chen

    2015-01-01

    Full Text Available Thermochromic colorants have been developed since before the 1900s. There are a large number of patents in different applications of thermochromic textiles, but many innovations leave the field of aesthetic and functional textile design unexplored in the area of smart materials. This study aims to develop thermochromic home textiles that change colors and patterns by integrating thermochromic pigments and electric conductive yarns into textile structures. Stainless steel conductive yarns were sewed on textile substrates to enable heat generation to increase fabric temperature. The heat generation and temperature rise could be controlled by monitoring the voltage applied. The experiments of this study focused on analyzing electric resistance and heating properties of the conductive yarns and observing color changing time and color changing effects of the thermochromic textiles. By using the technique in this research, an image of “tai chi” was designed and implemented in a backlighting thermochromic fabric. It illustrates a range of opportunities for thermochromic textiles in new design research directions of Chinese calligraphy and traditional Chinese painting.

  17. Investigating Morphological Stability of Faceted Interfaces with Axial Heat Processing (AHP) Technique

    Science.gov (United States)

    Abbaschian, Reza; Balikci, Ercan; Deal, Andrew; Gonik, Michael; Golyshev, Viladimir D.; Leonardi, Eddie; deVahlDavis, G.; Chen, P. Y. P.; Timchenko, V.

    2003-01-01

    Successful processing of homogeneous semiconductor single crystals from their melts depends strongly on precise control of thermal and fluid flow conditions near the solid/liquid interface. In this project, we utilize a novel crystal growth technique called Axial Heat Processing (AHP) that uses a baffle, positioned inside the melt near the interface, to supply and/or conduct heat axially to the interface. The baffle, which may or may not have a heater encased in it, can promote more stable and planar growth as well as reduce buoyancy driven convection. The latter is because the baffle reduces the aspect ratio of the melt as it separates the melt into three sections, above the baffle, in the feed gap between the baffle and the crucible wall, and below the baffle between the baffle base and the interface. AHP also enables a close monitoring and/or control of thermal boundaries near the solid/liquid interface during crystal growth by means of thermocouples placed in the baffle. The interface is kept planar when a heating element in the baffle is used. However, a proper choice of melt height is necessary to keep the interface planar when using the baffle without a heater. This study addresses the influence of melt height and growth velocity on the segregation profile of AHP-grown Sb doped Ge single crystals.

  18. New Sensor Concepts for Enhancing Heat Treatment Processes and Analysis

    Institute of Scientific and Technical Information of China (English)

    Jay I. Frankel

    2004-01-01

    The need for developing accurate quenching models requires an extensive experimental database that includes surface heat flux characterization. Quantification of the quenching process permits i) the development of high-quality heat treated products, ii) the evaluation of new quenchants and quenchant systems, and iii) the evaluation of quenchant quality over usage time. The surface heat transfer coefficient (or heat flux) is rarely measured, calculated or modeled in sufficient detail for real scientific use. Many single-thermocouple based probes are designed for the purpose of measuring the cooling power of a liquid quenchant or for monitoring quenchant quality. Lumped based probes are sufficient for these types of applications. However, the lack of sufficient distributed detail impedes the development of future high-quality heat-treated products. Frankel and his coworkers are developing a new family of transient thermal-rate sensors that will improve both diagnostic and real-time analyzes in heat transfer studies. Analyzes have been performed indicating that there exists a novel,thermal-rate sensor hierarchy that stabilizes predictions when used with analysis. This concept can be used for investigating both (i) direct surface heat transfer effects, and (ii) projective surface analysis based on embedded sensors. This new sensor family includes the ability to measure temperature, T; heat flux, q"; and their temporal derivatives, i.e., dT/dt, d2T/dt2 and dq"/dt.

  19. Interactions between goethite particles subjected to heat treatment

    DEFF Research Database (Denmark)

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

    2008-01-01

    We have studied the effect of heating on the magnetic properties of particles of nanocrystalline goethite by use of Mossbauer spectroscopy. Heating at 150 degrees C for 24 h leads to a change in the quadrupole shift in the low-temperature spectra, indicating a rotation of the sublattice magnetiza...

  20. Behavior of CuPb12Sn6 Alloys subjected to Heat Treatments

    Directory of Open Access Journals (Sweden)

    Cristian Achiței Dragoș

    2016-01-01

    Full Text Available The paper present the structural modifications induced by 3 heat treatments: homogenization, recrystallization and quenching, respecting the specific parameters of copper based alloys. The obtained modifications by heat treatments were highlighted by micro-hardness measurements, with Vickers method, and by electronic structural microscopy, at various magnitudes.

  1. 49 CFR 179.201-5 - Postweld heat treatment and corrosion resistance.

    Science.gov (United States)

    2010-10-01

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

  2. Comparison of heat treatment response of semisolid metal processed alloys A356 and F357

    CSIR Research Space (South Africa)

    Moller, H

    2010-01-01

    Full Text Available The heat treatment response of semisolid metal high pressure die cast Al-7Si-Mg alloys A356 and F357 was studied and compared. It was found that the heat treatment behaviour of alloy F357 is influenced markedly by the stability of the Mg containing...

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

    Science.gov (United States)

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

    2016-05-01

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

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

    CSIR Research Space (South Africa)

    Chauke, L

    2012-10-01

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

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

    CSIR Research Space (South Africa)

    Chauke, L

    2012-10-01

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

  6. Influence of heat treatment on magnesium alloys meant to automotive industry

    NARCIS (Netherlands)

    Popescu, G.; Moldovan, P.; Bojin, D.; Sillekens, W.H.

    2009-01-01

    The paper presents a study concerning the heat treatment realized on magnesium alloys, from AZ80 and ZK60 class. These alloys are destined to replace the conventional ferrous and aluminum alloys in automotive industry. It was realized the heat treatment, T5 - artificially aging, and it were

  7. The New Heat Treatment Technology of A356 Aluminium Alloy Prepared by Ptc

    Science.gov (United States)

    Zhang, Lianyong; Jiang, Yanhua; Ma, Zhuang; Wang, Wenkui

    Phase Transition Cooling (PTC), using the absorbed latent heat during the melting of phase transition cooling medium to cool and solidify alloys in the process of casting, is a new casting technology. Specimens of A356 casting aluminum alloy were prepared by this method in the paper. The new heat treatment process (cast and then aging directly without solid solution) of A356 alloy was performed. For comparison, the conventional T6 heat treatment (solution and then aging treatment) was performed too. The mechanical properties of A356 alloy with different heat treatments were measured by tensile strength testing methods and microstructures of the alloy with different heat treatment process were investigated by optical microscopy (OM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-rays diffraction (XRD) and transmission electron microscopy (TEM) too. The results show that ultimate tensile strength (UTS) of A356 alloy with the new heat treatment process is much higher than that with conventional heat treatment while the elongations with the two heat treatment processes are very close. This is due to the grain refinement obtained after PTC processing.

  8. Hippocampal sparing radiotherapy for pediatric medulloblastoma: impact of treatment margins and treatment technique

    DEFF Research Database (Denmark)

    Brodin, N. Patrik; af Rosenschold, Per Munck; Blomstrand, Malin

    2014-01-01

    BackgroundWe investigated how varying the treatment margin and applying hippocampal sparing and proton therapy impact the risk of neurocognitive impairment in pediatric medulloblastoma patients compared with current standard 3D conformal radiotherapy.MethodsWe included 17 pediatric medulloblastoma...... boost. Neurocognitive impairment risk was estimated based on dose-response models from pediatric CNS malignancy survivors and compared among different margins and treatment techniques.ResultsMean hippocampal dose and corresponding risk of cognitive impairment were decreased with decreasing treatment...

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

    Science.gov (United States)

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

    2017-03-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

  11. 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.

  12. Effect of heat treatment on mechanical dissipation in Ta$_2$O$_5$ coatings

    CERN Document Server

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

    2010-01-01

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

  13. Characterization of Machine Variability and Progressive Heat Treatment in Selective Laser Melting of Inconel 718

    Science.gov (United States)

    Prater, Tracie; Tilson, Will; Jones, Zack

    2015-01-01

    The absence of an economy of scale in spaceflight hardware makes additive manufacturing an immensely attractive option for propulsion components. As additive manufacturing techniques are increasingly adopted by government and industry to produce propulsion hardware in human-rated systems, significant development efforts are needed to establish these methods as reliable alternatives to conventional subtractive manufacturing. One of the critical challenges facing powder bed fusion techniques in this application is variability between machines used to perform builds. Even with implementation of robust process controls, it is possible for two machines operating at identical parameters with equivalent base materials to produce specimens with slightly different material properties. The machine variability study presented here evaluates 60 specimens of identical geometry built using the same parameters. 30 samples were produced on machine 1 (M1) and the other 30 samples were built on machine 2 (M2). Each of the 30-sample sets were further subdivided into three subsets (with 10 specimens in each subset) to assess the effect of progressive heat treatment on machine variability. The three categories for post-processing were: stress relief, stress relief followed by hot isostatic press (HIP), and stress relief followed by HIP followed by heat treatment per AMS 5664. Each specimen (a round, smooth tensile) was mechanically tested per ASTM E8. Two formal statistical techniques, hypothesis testing for equivalency of means and one-way analysis of variance (ANOVA), were applied to characterize the impact of machine variability and heat treatment on six material properties: tensile stress, yield stress, modulus of elasticity, fracture elongation, and reduction of area. This work represents the type of development effort that is critical as NASA, academia, and the industrial base work collaboratively to establish a path to certification for additively manufactured parts. For future

  14. Effects of heat treatment conditions on reactivity of chars in air

    Energy Technology Data Exchange (ETDEWEB)

    Ashu, J. T.; Walker, Jr., P. L.

    1977-09-01

    Reactivities of chars are maximized by keeping heat treatment temperatures as low as possible, minimizing soak time at maximum HTT and maximizing heating rates. It is feasible to use reactivity parameters as a tool for the study of thermal history of carbonaceous materials. Maximum HTT as well as the heating rate used for char preparation seem to be more important parameters in influencing char reactivity than the atmosphere used during preparation. Aging of chars in air following heat treatment at 800/sup 0/C has little or no effect on subsequent char reactivity. The most significant conclusion of this investigation is that rapid heating results in significant increase in char reactivity to air. Surface areas of rapidly heated samples are significantly higher than those prepared at the same temperature using slower heating rates.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-01-01

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

  16. Comparative study of novel endovascular treatment techniques for intracranial aneurysms

    Science.gov (United States)

    Cantón, Gádor; Lasheras, Juan C.; Levy, David I.; Sparks, Steven R.

    2002-11-01

    Intracranial aneurysms are life-threatening vascular lesions, which are potentially treatable to avoid the consequences of their rupture. Current treatments, either surgical or endovascular, are all guided to reduce the hemodynamic forces acting on the aneurysm wall in an effort to minimize the risk of rupture. Surgical clipping is still the most used technique to treat this type of aneurysm but there is a continued demand for less invasive approaches. This has led to the development of several endovascular techniques. We report here a comparative study of the reduction in the hemodynamic stresses and the modification of the flow in the parent vessel resulting from the use of three different techniques. The first one consists of endosaccular packing with platinum coils (GDC, Target Therapeutics), which is already widely used but its long-term efficacy has not yet been determined. The second one consists of the embolization of the aneurismal sac with Onyx, a polymer which hardens when in contact with the blood (being developed by Micro Therapeutics, Inc.). The third one involves the packing of the sac with hydrocoils, platinum wires coated with a gel which quickly hydrates when in contact with blood (developed by MicroVention). A Digital Particle Image Velocimetry (DPIV) system is used to measure in vitro the velocity field inside a model of an ACOM aneurysm (an aneurysm forming in the anterior communicating artery). Physiological accurate pulsatile flow conditions are input to the arterial model through a programmable pump. The measurements show that although all treatment techniques lead to a reduction in both normal and tangential shear stresses on the aneurismal sac, each one of them also leads to different modifications of the flow in the parent vessel which may have consequences related to potential for clotting. Comparison of the untreated aneurysm with the above three treated cases also showed that the characteristics of the wall shear stresses on the parent

  17. Bioactive titanate layers formed on titanium and its alloys by simple chemical and heat treatments.

    Science.gov (United States)

    Kokubo, Tadashi; Yamaguchi, Seiji

    2015-01-01

    To reveal general principles for obtaining bone-bonding bioactive metallic titanium, Ti metal was heat-treated after exposure to a solution with different pH. The material formed an apatite layer at its surface in simulated body fluid when heat-treated after exposure to a strong acid or alkali solution, because it formed a positively charged titanium oxide and negatively charged sodium titanate film on its surface, respectively. Such treated these Ti metals tightly bonded to living bone. Porous Ti metal heat-treated after exposure to an acidic solution exhibited not only osteoconductive, but also osteoinductive behavior. Porous Ti metal exposed to an alkaline solution also exhibits osteoconductivity as well as osteoinductivity, if it was subsequently subjected to acid and heat treatments. These acid and heat treatments were not effective for most Ti-based alloys. However, even those alloys exhibited apatite formation when they were subjected to acid and heat treatment after a NaOH treatment, since the alloying elements were removed from the surface by the latter. The NaOH and heat treatments were also not effective for Ti-Zr-Nb-Ta alloys. These alloys displayed apatite formation when subjected to CaCl2 treatment after NaOH treatment, forming Ca-deficient calcium titanate at their surfaces after subsequent heat and hot water treatments. The bioactive Ti metal subjected to NaOH and heat treatments has been clinically used as an artificial hip joint material in Japan since 2007. A porous Ti metal subjected to NaOH, HCl and heat treatments has successfully undergone clinical trials as a spinal fusion device.

  18. Endoscopic treatment of calcaneal spur syndrome: A comprehensive technique.

    Science.gov (United States)

    Blanco, C E; Leon, H O; Guthrie, T B

    2001-05-01

    We describe a comprehensive approach to the endoscopic treatment of calcaneal spur syndrome developed by the Arthroscopic Group of the Orthopedic Service of Hospital Hermanos Ameijeiras in Havana, Cuba. The surgical technique involves treatment of the heel spur and plantar fasciitis commonly found in calcaneal spur syndrome, but it also addresses adjacent calcaneal periostitis and allows decompression of the nerve to the abductor digiti quinti. Medial endoscopy and lateral instrumentation are used in a sequential approach with exposure and debridement of the posterior roof of the calcaneal arch, followed by removal of the calcaneal spur, lateral to medial release of the medial 75% of the plantar fascia, and if necessary, debridement of the calcaneal tuberosity periosteum. This technique was used in a prospective case series from June 1997 to May 1998 to treat a select group of 38 feet in 30 patients who reported unacceptable levels of pain despite 5 months of conservative treatment, which included an aggressive 8-week physical therapy program prescribed by the treating physician. Good to excellent results were obtained at 3 months postoperatively in all patients with regard to pain relief and return to normal activity, although 5 patients required a short course of physical therapy to resolve symptoms brought on by sports, trauma, or impact loading before 1-year follow-up, at which time all patients reported good to excellent results. Complications included 3 superficial wound infections cured by oral antibiotics and 2 transient lateral paresthesias that resolved with rest and nonsteroidal inflammatory medications. The described technique may provide a useful method for treating refractory heel spur syndrome and warrants further study.

  19. Effect of heat treatment on hydrogen trapping in alloy K-500

    Energy Technology Data Exchange (ETDEWEB)

    Pound, B.G. [SRI Int., Menlo Park, CA (United States). Materials Research Center

    1998-12-01

    The effect of heat treatment on irreversible hydrogen trapping was investigated for alloy K-500 (UNS N05500) with a goal of providing more detailed insight into factors governing the intrinsic susceptibility to hydrogen embrittlement (HE). A potentiostatic pulse technique was used to determine the irreversible trapping constants (k) and hydrogen entry fluxes for annealed, annealed and aged (AA), and 12-h and 16-h direct-aged (DA) specimens of cold-drawn alloy K-500 that had been used earlier to provide as-received (unannealed, cold-drawn) and 8-h Da specimens. the type of heat treatment produced marked differences in irreversible trapping. Intrinsic susceptibility to HE, as defined by k, was increased considerably by annealing. Aging had a negligible effect on the intrinsic susceptibility for the annealed alloy, but resulted in a sizable increase for the unannealed alloy if performed for extended times. Intrinsic susceptibilities for the AA and DA alloys were correlated with the observed resistances to HE, implying that the previously reported decrease in resistance to HE (based upon tensile strength) produced by annealing was caused to a large extent, if not entirely, by a change in the irreversible traps.

  20. 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.

  1. Effects of heat treatment on the properties of powder injection molded AIN ceramics

    Institute of Scientific and Technical Information of China (English)

    DU Xueli; QIN Mingli; Akhtar Farid; FENG Peizhong; QU Xuanhui

    2008-01-01

    The effects of two different heat-treatment atmospheres,nitrogen atmosphere and reducing nitrogen atmosphere with carbon,on the properties of Y2O3-doped aluminum nitride (AlN) ceramics were investigated.The AlN powder as a raw material was synthesized by self-propagating high-temperature synthesis (SHS) and compacts were fabricated by employing powder injection molding technique.The polymer-wax binder consisted of 60 wt.% paraffin wax (PW),35 wt.% polypropylene (PP),and 5 wt.% stearic acid (SA).After the removal of binder,specimens were sintered at 1850℃ in nitrogen atmosphere under atmospheric pressure.To improve the thermal conductivity,sintered samples were reheated.The result reveals that the heat-treatment atmosphere has significant effect on the properties and secondary phase of AlN ceramics.The thermal conductivity and density of AlN ceramics reheated in nitrogen gas are 180 W·m-1 K-1 and 3.28 g,cm-3 and the secondary phase is yttrium aluminate.For the sample reheated in reducing nitrogen atmosphere with carbon,the thermal conductivity and density are 173 W.m-1.K-1 and 3.23 g·cm-3,respectively,and the secondary phase is YN.

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

    Directory of Open Access Journals (Sweden)

    VAISHAKA R. RAO

    2013-11-01

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

  3. Anomalies of autogamy in Paramecium tetraurelia temperature sensitive mutant induced by heat treatment.

    Science.gov (United States)

    Prajer, M; Iftode, F

    2001-01-01

    The run of autogamy in temperature sensitive mutant ts401, carrying also the mutation of trichocysts nd3a, at permissive (26 degrees C) and non-permissive temperature (35 degrees C) was studied and compared with this process in wild d4-2 stock of Paramecium tetraurelia. The effect of heat treatment on programmed nuclear and cortical events was investigated using cytological silver impregnation Fernandez-Galiano method and immunofluorescence technique with the application of two anti-alpha-tubulin antibodies. The appearance of cells with some large macronuclear fragments and an excess number of micronuclei suggests that nuclear differentiation is inhibited at restrictive temperature and that macronuclear regeneration takes place in this thermosensitive mutant. In such cells impaired oral reorganization was observed. After slight refeeding at the late autogamy, cells stopped at first postautogamous division were induced by heat treatment. The most striking feature of these abnormal divisions was the lack of a basal body duplication wave, which suggests that production of gamma-tubulin, structural protein being the essential component of the microtubule organizing centres, is disturbed at high temperature.

  4. Spectroscopic Evaluation of Effects of Heat Treatments on the Structures and Emulsifying Properties of Caseins

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hao; WANG Peng-jie; LEI Xin-gen; YANG Hong-ju; ZHANG Lu-da; REN Fa-zheng; ZHENG Li-min

    2013-01-01

    The effects of heat treatment(heating temperature and pH) on the structures and emulsifying properties of caseins were systematically studied by spectroscopy.Heat treatment from 60 to 100 ℃ resulted in an increase in their fluorescence intensity,hydrodynamic diameter,turbidity and emulsifying activity index,but decreased the size polydispersity of caseins.In the pH range of 5.5 to 7.0,the fluorescence intensity,hydrodynamic diameter,turbidity and emulsifying properties decreased with increased heating pH,but the size polydispersity of caseins increased with increased pH.The relationship between the surface fluorescence intensity and emulsifying activity was also investigated,revealing a correlation coefficient of 0.90.These results suggested that heat treatment could be used to modify the structures and emulsifying properties of caseins by appropriately selecting heating conditions.

  5. Dual-wavelength photoacoustic technique for monitoring tissue status during thermal treatments

    Science.gov (United States)

    Hsiao, Yi-Sing; Wang, Xueding; Deng, Cheri X.

    2013-06-01

    Photoacoustic (PA) techniques have been exploited for monitoring thermal treatments. However, PA signals depend not only on tissue temperature but also on tissue optical properties which indicate tissue status (e.g., native or coagulated). The changes in temperature and tissue status often occur simultaneously during thermal treatments, so both effects cause changes to PA signals. A new dual-wavelength PA technique to monitor tissue status independent of temperature is performed. By dividing the PA signal intensities obtained at two wavelengths at the same temperature, a ratio, which only depends on tissue optical properties, is obtained. Experiments were performed with two experimental groups, one with untreated tissue samples and the other with high-intensity focused ultrasound treated tissue samples including thermal coagulated lesion, using ex vivo porcine myocardium specimens to test the technique. The ratio of PA signal intensities obtained at 700 and 800 nm was constant for both groups from 25 to 43°C, but with distinct values for the two groups. Tissue alteration during thermal treatment was then studied using water bath heating of tissue samples from 35 to 60°C. We found that the ratio stayed constant before it exhibited a marked increase at around 55°C, indicating tissue changes at this temperature.

  6. Grain refinement in a cast high Nb containing TiAl alloy by heat treatment

    Institute of Scientific and Technical Information of China (English)

    LIU Zicheng; LIN Junpin; WANG Yanli; LIN Zhi; SONG Xiping; CHEN Guoliang

    2004-01-01

    The grain refinement of an as-cast Ti-46Al-8.5Nb-0.2W (atom fraction in %) alloy by the cyclic heat treatments was studied. The heat treatment scheme included a tempering at 1250°C and cyclic tempering at 1000 and 1200°C three times after solution treatment at the temperature above o phase transus followed by immediate fan cooling. The fine and homogeneous near-γ microstructure can be obtained by this heat treatment, which causes the breakdown of as-cast microstructure and prevents the anomalous growing of original γ phase.

  7. Influence of Femtosecond Laser Irradiation and Heat Treatment on Precipitation of Silver Nanoparticles in Glass

    Institute of Scientific and Technical Information of China (English)

    曾惠丹; 邱建荣; 姜雄伟; 曲士良; 朱从善; 干福熹

    2003-01-01

    Silver nanoparticles were precipitated inside an Ag2 O-doped glass by femtosecond laser irradiation and successive heat treatment. The influence of heat treatment temperature on the precipitation of silver nanoparticles was investigated. Absorption spectra show that the femtosecond laser irradiation results in an apparent decrease of the treatment temperature for the precipitation of Ag nanoparticles. We demonstrate the control of precipitation,dissolution and growth of silver nanoparticles inside glass by changing the heat treatment temperature or using further femtosecond laser irradiation.

  8. A finite volume approach to the problem of heat transfer in axisymmetric annulus geometry with internal heating element using local analytical solution techniques

    Energy Technology Data Exchange (ETDEWEB)

    Salama, A. [Atomic Energy Authority (AEA), Cairo (Egypt). Nuclear Research Center

    2014-11-15

    In this paper we implement the local analytical solution technique to the problem of heat transfer in axisymmetric annulus geometry with internal heating element. This method has shown to be very accurate in estimating the temperature field for axisymmetric problems even for coarse mesh. It is shown that this method reduces to the analytical solution for unidirectional heat transfer in the radial direction in homogeneous media. The technique is based on finding an analytical expression for the temperature field in the radial direction within each grid cell. This means that the temperature field in each cell is allowed to change in a nonlinear fashion along the radial direction. We compare this technique with the traditional finite volume technique and show that; with only few cells in the radial direction, this technique arrives at the mesh-independent solution quite accurately whereas it required denser mesh to arrive closer to this solution using traditional techniques. This method is proposed to the 1D codes that are currently being used to simulate thermalhydraulic characteristics of reactor systems. Furthermore, we also implement the experimental temperature field algorithm in which the governing equations are approximated for each cell as it would without extra manipulation to the governing equations. This technique is very simple and separates the physics from the solving part.

  9. Surgical treatment of scoliosis: a review of techniques currently applied

    Directory of Open Access Journals (Sweden)

    Maruyama Toru

    2008-04-01

    Full Text Available Abstract In this review, basic knowledge and recent innovation of surgical treatment for scoliosis will be described. Surgical treatment for scoliosis is indicated, in general, for the curve exceeding 45 or 50 degrees by the Cobb's method on the ground that: 1 Curves larger than 50 degrees progress even after skeletal maturity. 2 Curves of greater magnitude cause loss of pulmonary function, and much larger curves cause respiratory failure. 3 Larger the curve progress, more difficult to treat with surgery. Posterior fusion with instrumentation has been a standard of the surgical treatment for scoliosis. In modern instrumentation systems, more anchors are used to connect the rod and the spine, resulting in better correction and less frequent implant failures. Segmental pedicle screw constructs or hybrid constructs using pedicle screws, hooks, and wires are the trend of today. Anterior instrumentation surgery had been a choice of treatment for the thoracolumbar and lumbar scoliosis because better correction can be obtained with shorter fusion levels. Recently, superiority of anterior surgery for the thoracolumbar and lumbar scoliosis has been lost. Initial enthusiasm for anterior instrumentation for the thoracic curve using video assisted thoracoscopic surgery technique has faded out. Various attempts are being made with use of fusionless surgery. To control growth, epiphysiodesis on the convex side of the deformity with or without instrumentation is a technique to provide gradual progressive correction and to arrest the deterioration of the curves. To avoid fusion for skeletally immature children with spinal cord injury or myelodysplasia, vertebral wedge ostetomies are performed for the treatment of progressive paralytic scoliosis. For right thoracic curve with idiopathic scoliosis, multiple vertebral wedge osteotomies without fusion are performed. To provide correction and maintain it during the growing years while allowing spinal growth for

  10. Carbonated aqueous media for quench heat treatment of steels

    Science.gov (United States)

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

    2016-09-01

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

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

    African Journals Online (AJOL)

    GREGO

    2006-12-18

    Dec 18, 2006 ... African Journal of Biotechnology Vol. ... Full Length Research Paper ... as the fruit advanced in storage at ambiant temperature, whereas, they are still higher in heat ... infections or injuries (Mayer and Harel, 1991; Gerhard,.

  12. An experimental investigation of heat transfer enhancement in minichannel: Combination of nanofluid and micro fin structure techniques

    DEFF Research Database (Denmark)

    Zhang, Ji; Diao, Yanhua; Zhao, Yaohua;

    2017-01-01

    This work experimentally studied the single-phase heat transfer and pressure drop characteristics by using two heat transfer enhancement techniques (micro fin structure and nanofluids) in multiport minichannel flat tube (MMFT). MMFT consisted of numerous parallel rectangular minichannels and is w......This work experimentally studied the single-phase heat transfer and pressure drop characteristics by using two heat transfer enhancement techniques (micro fin structure and nanofluids) in multiport minichannel flat tube (MMFT). MMFT consisted of numerous parallel rectangular minichannels...... with different micro fin numbers (N = 0, 1, 2, 3 and 4) and nanofluids with three volume concentrations (φ = 0.005%, 0.01% and 0.1%) were used as test sections and working fluids respectively. Secondly, the experiments using two combined enhancement technique were performed. By using conjunctively two...

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

    Directory of Open Access Journals (Sweden)

    Ramesh Gopalan

    2011-01-01

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

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

    Science.gov (United States)

    Ramesh, Gopalan; Prabhu, Narayan Kotekar

    2011-04-14

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

  15. Performance analysis of system heat pump - heat recuperator used for air treatment in process industry

    OpenAIRE

    Milovančević Uroš M.; Kosi Franc F.

    2016-01-01

    A detailed parametric analysis and performance optimization of system “heat pump - recuperator is given in this paper. Mathematical model used for analysis is formed according to the physical model of the system and practical experience. Different types of compressors, and various temperature ranges are treated. Special attention is paid to influence of condensing and evaporating temperatures on system performances, so as to different features of heat recup...

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

    Energy Technology Data Exchange (ETDEWEB)

    Çoban, Onur, E-mail: onur_coban@yahoo.com

    2014-10-30

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

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

    Science.gov (United States)

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

    2017-01-01

    Heat treatment of milk aims to inhibit the growth of microbes, extend the shelf-life of products and improve the quality of the products. Heat treatment also leads to denaturation of whey protein and the formation of whey protein-casein polymer, which has negative effects on milk product. Hence the milk heat treatment conditions should be controlled in milk processing. In this study, the denaturation degree of whey protein and the combination degree of whey protein and casein when undergoing heat treatment were also determined by using the Native-PAGE and SDS-PAGE analysis. The results showed that the denaturation degree of whey protein and the combination degree of whey protein with casein extended with the increase of the heat-treated temperature and time. The effects of the heat-treated temperature and heat-treated time on the denaturation degree of whey protein and on the combination degree of whey protein and casein were well described using the quadratic regression equation. The analysis strategy used in this study reveals an intuitive and effective measure of the denaturation degree of whey protein, and the changes of milk protein under different heat treatment conditions efficiently and accurately in the dairy industry. It can be of great significance for dairy product proteins following processing treatments applied for dairy product manufacturing. PMID:28316470

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

    Science.gov (United States)

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

    2013-06-01

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

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

    Science.gov (United States)

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

    1982-12-01

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

  20. The effects of heat treatment on some technological properties of Scots pine (Pinus sylvestris L.) wood.

    Science.gov (United States)

    Korkut, Süleyman; Akgül, Mehmet; Dündar, Turker

    2008-04-01

    Heat treatment is often applied to wood species to improve their dimensional stability. This study examined the effect of heat treatment on certain mechanical properties of Scots pine (Pinus sylvestris L.), which has industrially high usage potential and large plantations in Turkey. Wood specimens obtained from Bolu, Turkey, were subjected to heat treatment under atmospheric pressure at varying temperatures (120, 150 and 180 degrees C) for varying durations (2, 6 and 10h). The test results of heat-treated Scots pine and control samples showed that technological properties including compression strength, bending strength, modulus of elasticity in bending, janka-hardness, impact bending strength and tension strength perpendicular to grain suffered with heat treatment, and increase in temperature and duration further diminished technological strength values of the wood specimens.

  1. 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.

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

    Science.gov (United States)

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

    2017-03-01

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

  3. Susceptibility to Hot Cracking and Weldment Heat Treatment of Haynes 230 Superalloy

    Institute of Scientific and Technical Information of China (English)

    C.M.Cheng; C.P.Chou; I.K.Lee; I.C.Kuo

    2006-01-01

    This study investigates the susceptibility of hot cracking and weldment heat treatment of Haynes 230 superalloy.The Varestriant test was conducted to evaluate this susceptibility. Welding was performed by gas tungsten arc welding(GTAW)and plasma arc welding(PAW)with stress relief heat treatment and solid solution heat treatment. A tensile test is then performed to measure the changes in the mechanical properties of the heattreated material. The results indicate that the number of thermal cycles does not affect the susceptibility of Haynes 230 superalloy to hot cracking. However, it does increase the strain. In weldment of heat treatment,stress relief annealing increases the yield strength and tensile strength of the welded parts. The section of the tensile specimens shows fibrous fractures on the welded parts, regardless of whether they are heat-treated.

  4. Pulse mitigation and heat transfer enhancement techniques. Volume 4: Transient behavior of heat pipe with thermal energy storage under pulse heat loads

    Science.gov (United States)

    Chow, L. C.; Chang, M. J.

    1992-08-01

    A novel design of a high-temperature axially grooved heat pipe (HP), which utilizes thermal energy storage (TES) to mitigate pulse heat loads, was presented. Phase-change material (PCM) encapsulated in cylindrical containers was used for thermal energy storage. The transient responses of the HP/TES system under two types of pulse heat loads were studied numerically. The first type is pulse heat loads applied at the heat pipe evaporator; the second type is reversed-pulse heat loads applied at the condenser. The transient response of three different HP/TES configurations were compared: (1) a heat pipe with a large empty cylinder installed in the vapor core, (2) a heat pipe with a large PCM cylinder, and (3) a heat pipe with six small PCM cylinders. It was found that the PCM is very effective in mitigating the adverse effect of pulse heat loads. The six small PCM cylinders are more efficient than the large PCM cylinder in relaxing the heat pipe temperature increase under pulse heat loads.

  5. The Effect of Post-Heat Treatment on Microstructure of 316L Cold-Sprayed Coatings and Their Corrosion Performance

    Science.gov (United States)

    Dikici, B.; Yilmazer, H.; Ozdemir, I.; Isik, M.

    2016-04-01

    The combined effects of process gases and post-heat treatment temperature on the microstructure of 316L cold-sprayed coatings on Al5052 substrates have been investigated in this study. The stainless steel coatings were subjected to heat treatment at four different temperatures (250, 500, 750, and 1000 °C) to study the effect of heat treatment. In addition, the corrosion performances of the coatings at different process temperatures have been compared using the potentiodynamic scanning technique. Microstructural characterization of the coatings was carried out using scanning and transmission electron microscopy and x-ray diffraction. The results of present study showed that cold-sprayed stainless steel coatings processed with helium exhibited higher corrosion resistance than those of coatings sprayed with nitrogen process gas. This could partially be attributed to the reduction in porosity level (4.9%) and improvement of particle-particle bonding. In addition, evaluation of the mechanical and microstructural properties of the coatings demonstrated that subsequent heat treatment has major influence on the deposited layers sprayed with He process gas.

  6. Fabrication and heat treatment of high strength Al-Cu-Mg alloy processed using selective laser melting

    Science.gov (United States)

    Zhang, Hu; Zhu, Haihong; Nie, Xiaojia; Qi, Ting; Hu, Zhiheng; Zeng, Xiaoyan

    2016-04-01

    The proposed paper illustrates the fabrication and heat treatment of high strength Al-Cu-Mg alloy produced by selective laser melting (SLM) process. Al-Cu-Mg alloy is one of the heat treatable aluminum alloys regarded as difficult to fusion weld. SLM is an additive manufacturing technique through which components are built by selectively melting powder layers with a focused laser beam. The process is characterized by short laser-powder interaction times and localized high heat input, which leads to steep thermal gradients, rapid solidification and fast cooling. In this research, 3D Al-Cu-Mg parts with relative high density of 99.8% are produced by SLM from gas atomized powders. Room temperature tensile tests reveal a remarkable mechanical behavior: the samples show yield and tensile strengths of about 276 MPa and 402 MPa, respectively, along with fracture strain of 6%. The effect of solution treatment on microstructure and related tensile properties is examined and the results demonstrate that the mechanical behavior of the SLMed Al-Cu-Mg samples can be greatly enhanced through proper heat treatment. After T4 solution treatment at 540°C, under the effect of precipitation strengthening, the tensile strength and the yield strength increase to 532 MPa and 338 MPa, respectively, and the elongation increases to 13%.

  7. Electrochemical Techniques in Textile Processes and Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    Mireia Sala

    2012-01-01

    Full Text Available The textile industry uses the electrochemical techniques both in textile processes (such as manufacturing fibers, dyeing processes, and decolorizing fabrics and in wastewaters treatments (color removal. Electrochemical reduction reactions are mostly used in sulfur and vat dyeing, but in some cases, they are applied to effluents discoloration. However, the main applications of electrochemical treatments in the textile sector are based on oxidation reactions. Most of electrochemical oxidation processes involve indirect reactions which imply the generation of hypochlorite or hydroxyl radical in situ. These electrogenerated species are able to bleach indigo-dyed denim fabrics and to degrade dyes in wastewater in order to achieve the effluent color removal. The aim of this paper is to review the electrochemical techniques applied to textile industry. In particular, they are an efficient method to remove color of textile effluents. The reuse of the discolored effluent is possible, which implies an important saving of salt and water (i.e., by means of the “UVEC Cell”.

  8. [Orthotopic liver transplant in rats. Surgical technique, complications and treatment].

    Science.gov (United States)

    Lausada, Natalia R; Gondolesi, G E; Ortiz, E; Dreizzen, E; Raimondi, J C

    2002-01-01

    The orthotopic rat liver transplant model is a widely used technique in transplantation research. It has many advantages over other animal transplant models because of its availability and low cost. However, it must be emphasized that success with the rat model requires thorough training. The aim of this paper is to describe the microsurgical technique involved in 60 rat liver transplants and to discuss the complications and their treatments. Forty-nine liver transplants were performed at the Experimental Laboratory of the University Hospital, Ontario, Canada (ELUH) and 11 were performed at the Laboratorio de Trasplante de Organos de la Facultad de Ciencias Médicas de La Plata, Buenos Aires. Argentina (LTO). Among the transplants performed at the ELUH, the observed complications were haemorrhage (n = 4), pneumothorax (n = 1), anastomotic failure (n = 15), bile leak (n = 3), and bile duct necrosis (n = 9). The remaining 17 rats at the ELUH were healthy at day 7 after surgery. Animal survival immediately postop, at 24 hours postop and at 7 days postop was achieved with the 9th, 20th and 21st transplants respectively. At the LTO, 3 rats died as a result of anaesthetic complications. Seven-day animal survival was achieved with the 11th transplant. We beleive that the description of the orthotopic rat liver transplantation technique, as well as the discussion regarding complications and their management, can be useful for researchers interested in performing liver transplantation in rats.

  9. Effect of heat treatments on failure mechanism of SiCp/2124 Al composite

    Institute of Scientific and Technical Information of China (English)

    M.Murato(g)lu

    2005-01-01

    The mechanical response of a 17% (volume fraction) silicon carbide particles reinforced 2124 Al composite prepared by powder metallurgy techniques was studied by altering the matrix strength with different heat treatments. The fracture mechanisms and the deformation microstructure were examined by scanning electron microscopy. The results show that matrix strength appears to play an important role in influcing the behaviour of the composite under hardness and tensile loading conditions and also fracture mechanisms. The high matrix strength results in a larger decrease in yield strength due to the increasing damage probability. The tensile yield strength values decrease under peak aged and overaged condition whereas under the solutinized condition the opposite effect can be seen.

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

    Science.gov (United States)

    Dissanayake, M; Vasiljevic, T

    2009-04-01

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

  11. Development of nondestructive evaluation techniques for high-temperature ceramic heat exchanger components. Tenth quarterly report, January-March 1980

    Energy Technology Data Exchange (ETDEWEB)

    Kupperman, D.S.; Yuhas, D.; Caines, M.J.

    1980-04-01

    The effectiveness of several conventional and unconventional NDE techniques for specific high-temperature ceramic components was determined. Techniques under study at ANL include dye-enhanced radiography, acoustic microscopy, conventional ultrasonic testing, acoustic-emission detection, acoustic impact testing, holography, interferometry, infrared scanning, internal friction measurements, and overload proof testing. The current effort involves SiC heat-exchanger tubes; previous ceramic NDE efforts at ANL have involved silicon-nitride gas-turbine rotors. Recent results on inspection of SiC heat-exchanger tubing by means of ultrasonic acoustic microscopy techniques and efforts initiated and planned for NDE of ceramic joints are discussed.

  12. Synthesis and characterization of nano-sized cobalt ferrite prepared via polyol method using conventional and microwave heating techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Amal M., E-mail: amozarei@yahoo.co [Surface Chemistry and Catalysis Laboratory, Physical Chemistry Department, National Research Center, Al Buhouth St., Cairo (Egypt); El-Latif, M.M. Abd; Mahmoud, Morsi M. [Fabrication Technology Department, Advanced Technology and New Materials Research Institute, Mubarak City for Scientific Research and Technology Applications, Alexandria (Egypt)

    2010-09-10

    Nano-sized single-phase cobalt ferrite samples were prepared via polyol method using ethylene glycol as a high boiling point solvent as well as a reducing agent. These samples were prepared by two different heating techniques; conventional heating technique and microwave assisting technique using a 2.45 GHz multimode microwave synthesis unit. The crystallite size of the obtained samples was found to be in the range from 10 nm to 12 nm. The obtained samples were characterized using transmission electron microscope (TEM) and X-ray diffraction (XRD). Quantum design SQUID magnetometer was used to study the magnetic measurement.

  13. Finite-element technique applied to heat conduction in solids with temperature dependent thermal conductivity

    Science.gov (United States)

    Aguirre-Ramirez, G.; Oden, J. T.

    1969-01-01

    Finite element method applied to heat conduction in solids with temperature dependent thermal conductivity, using nonlinear constitutive equation for heat ABCDEFGHIABCDEFGHIABCDEFGHIABCDEFGHIABCDEFGHIABCDEFGHIABCDEFGHIABCDEFGHIABCDEFGHIABCDEFGHIABCDEFGHIABCDEFGH

  14. INFLUENCE OF HEAT TREATMENT ON THE DEFECTS OF DRYING Hovenia dulcis Thunb. WOOD

    Directory of Open Access Journals (Sweden)

    Magnos Alan Vivian

    2011-05-01

    Full Text Available This study aimed to evaluate the influence of heat treatments of heating and freezing in the drying defects of Hovenia dulcis Thunb. wood. For this, were used samples from such species of wood concerned with dimensions of 2 x 10 x 20 cm. The heat treatments of heating and freezing were conducted in tank heated to 85ºC and in a freezer at -18ºC, respectively, where the samples remained during 12 and 24 hours for both treatments. After those pre-treatment, the samples were dried an electric oven with forced air circulation at temperatures of 60 and 90°C until the final moisture content achieves set 0 to 2%. The heat treatments showed different effects in function of defects of drying, While heating and freezing treatments reduced the bending towards the samples which did not suffer any of those treatments, the IRT tended to increase it. For the temperatures of drying, the samples submitted to 60ºC showed less pronounced defects, indicating that drying mild drying temperatures decrease the incidence of defects.

  15. Heat and Ice in Sermilik Fjord: Novel Observational Techniques Using PIES

    Science.gov (United States)

    Andres, M.; Straneo, F.; Sutherland, D.

    2014-12-01

    A 1-year pilot experiment using pressure-sensor-equipped inverted echo sounders (PIES) was conducted in Sermilik Fjord in eastern Greenland to test non-traditional methods for measuring the time-varying
heat content in high-latitude seas, shelves, and fjords and for detecting the presence of ice. PIES, which are installed on the seafloor below the reach of destructive iceberg keels, present
a promising and inexpensive way to improve understanding of fjord dynamics and shelf-fjord interactions and will increase long-term monitoring capabilities in high latitudes where
remoteness and harsh conditions hamper traditional in situ observation techniques. The use
of PIES to characterize variability at high latitudes is a novel application of an existing
technology, but rests on the same principle as the traditional blue-water uses for PIES: due
to the dependence of sound speed on temperature, the surface-to-bottom round-trip acoustic-travel-time associated with reflections between the PIES and the air-sea interface is an excellent proxy
for heat content in the intervening water column. Furthermore, since reflections from seawater-ice interfaces are also detected when ice
is present, PIES provide a means to characterize the ice component in high-latitude systems. The PIES deployed in Sermilik Fjord (August 2011 - September 2012) resolved changes in heat content at scales ranging from hourly to seasonal. Furthermore, during winter, the PIES logged about 300 iceberg detections and recorded a 2-week period of land-fast ice cover in March. The deepest icebergs in the fjord were found to have keel depths reaching to ~350 m and iceberg speeds averaged about 0.2 m/s but were as high as 0.5 m/s.

  16. Solidification analysis of micro-scale metallic particles in the laser supersonic heating technique

    Science.gov (United States)

    Lin, Shih-Lung; Lin, Jehnming

    2004-04-01

    In this paper, the authors analysed the solidification phenomenon in the laser supersonic heating technique used for producing metallic particles. A mathematical model was established to predict the velocity, temperature and solidification situation of metallic particles leaving a spray nozzle. The numerical analysis method was used to simulate the flow field structure of shock waves and to proceed with related experiment. In the experiment, a pulsed Nd-YAG laser was used as the heat source on a carbon steel target within the nozzle, and carbon steel particles were ejected by high pressure air. The solidification problem of carbon steel particles with radii of 1-50 µm in the compressible flow field was calculated and compared with experimental results. The result shows that the shock wave flow fields are generated at different entrance pressures (3-7 bar), and there is no significant difference in the radii of carbon steel particles produced by a fixed laser energy; however, in the flow field without the shock wave effect, the cooling effect is less evident in the solidification process.

  17. Performance assessment techniques for groundwater recovery and treatment systems

    Energy Technology Data Exchange (ETDEWEB)

    Kirkpatrick, G.L. [Environmental Resources Management, Inc., Exton, PA (United States)

    1993-03-01

    Groundwater recovery and treatment (pump and treat systems) continue to be the most commonly selected remedial technology for groundwater restoration and protection programs at hazardous waste sites and RCRA facilities nationwide. Implementing a typical groundwater recovery and treatment system includes the initial assessment of groundwater quality, characterizing aquifer hydrodynamics, recovery system design, system installation, testing, permitting, and operation and maintenance. This paper focuses on methods used to assess the long-term efficiency of a pump and treat system. Regulatory agencies and industry alike are sensitive to the need for accurate assessment of the performance and success of groundwater recovery systems for contaminant plume abatement and aquifer restoration. Several assessment methods are available to measure the long-term performance of a groundwater recovery system. This paper presents six assessment techniques: degree of compliance with regulatory agency agreement (Consent Order of Record of Decision), hydraulic demonstration of system performance, contaminant mass recovery calculation, system design and performance comparison, statistical evaluation of groundwater quality and preferably, integration of the assessment methods. Applying specific recovery system assessment methods depends upon the type, amount, and quality of data available. Use of an integrated approach is encouraged to evaluate the success of a groundwater recovery and treatment system. The methods presented in this paper are for engineers and corporate management to use when discussing the effectiveness of groundwater remediation systems with their environmental consultant. In addition, an independent (third party) system evaluation is recommended to be sure that a recovery system operates efficiently and with minimum expense.

  18. Monitoring Therapeutic Treatments against Burkholderia Infections Using Imaging Techniques

    Directory of Open Access Journals (Sweden)

    Tiffany M. Mott

    2013-05-01

    Full Text Available Burkholderia mallei, the etiologic agent of glanders, are Category B select agents with biothreat potential, and yet effective therapeutic treatments are lacking. In this study, we showed that CpG administration increased survival, demonstrating protection in the murine glanders model. Bacterial recovery from infected lungs, liver and spleen was significantly reduced in CpG-treated animals as compared with non-treated mice. Reciprocally, lungs of CpG-treated infected animals were infiltrated with higher levels of neutrophils and inflammatory monocytes, as compared to control animals. Employing the B. mallei bioluminescent strain CSM001 and the Neutrophil-Specific Fluorescent Imaging Agent, bacterial dissemination and neutrophil trafficking were monitored in real-time using multimodal in vivo whole body imaging techniques. CpG-treatment increased recruitment of neutrophils to the lungs and reduced bioluminescent bacteria, correlating with decreased bacterial burden and increased protection against acute murine glanders. Our results indicate that protection of CpG-treated animals was associated with recruitment of neutrophils prior to infection and demonstrated, for the first time, simultaneous real time in vivo imaging of neutrophils and bacteria. This study provides experimental evidence supporting the importance of incorporating optimized in vivo imaging methods to monitor disease progression and to evaluate the efficacy of therapeutic treatment during bacterial infections.

  19. Realization of tin freezing point using a loop heat pipe-based hydraulic temperature control technique

    Science.gov (United States)

    Joung, Wukchul; Gam, Kee Sool; Kim, Yong-Gyoo

    2015-10-01

    In this work, the freezing point of tin (Sn FP) was realized by inside nucleation where the supercooling of tin and the reheating of the sample after the nucleation were achieved without extracting the cell from an isothermal apparatus. To this end, a novel hydraulic temperature control technique, which was based on the thermo-hydraulic characteristics of a pressure-controlled loop heat pipe (LHP), was employed to provide a slow cooling of the sample for deep supercooling and fast reheating after nucleation to minimize the amount of initial freeze of the sample. The required temperature controls were achieved by the active pressure control of a control gas inside the compensation chamber of the pressure-controlled LHP, and slow cooling at  -0.05 K min-1 for the deep supercooling of tin and fast heating at 2 K min-1 for reheating the sample after nucleation was attained. Based on this hydraulic temperature control technique, the nucleation of tin was realized at supercooling of around 19 K, and a satisfactorily fast reheating of the sample to the plateau-producing temperature (i.e. 0.5 K below the Sn FP) was achieved without any temperature overshoots of the isothermal region. The inside-nucleated Sn FP showed many desirable features compared to the Sn FP realized by the conventional outside nucleation method. The longer freezing plateaus and the better immersion characteristics of the Sn FP were obtained by inside nucleation, and the measured freezing temperature of the inside-nucleated Sn FP was as much as 0.37 mK higher than the outside-nucleated Sn FP with an expanded uncertainty of 0.19 mK. Details on the experiment are provided and explanations for the observed differences are discussed.

  20. Endoscopic treatment for vesicoureteral reflux: how important is technique?

    Science.gov (United States)

    Watters, Sean T; Sung, Jennifer; Skoog, Steven J

    2013-12-01

    Endoscopic dextranomer/hyaluronic acid (Dx/HA) injection by subureteric transurethral injection (STING) or hydrodistention implantation technique (HIT) for treatment of vesicoureteral reflux (VUR) has variable results with HIT reporting better outcomes. We determined outcomes with each technique comparing reflux resolution rates and evaluating predictors of treatment success and failure. Univariate and multivariate analysis compared 163 patients (246 ureters) who underwent a single endoscopic Dx/HA injection from December 2001 to April 2010. Data on pre, peri, and post-operative variables were prospectively collected. Resolution was defined as no reflux on voiding cystourethrogram (VCUG) at 3 month follow up. Calculated ellipsoid volume (CEV) of Dx/HA mounds was defined as (4/3π(height/2) × (length/2) × (width/2)) based on post-operative ultrasound dimensions. Ureter resolution was 79.75% and 80.84% for STING and HIT, respectively (p = 0.86). Patient resolution was 70.0% and 74.3% for STING and HIT, respectively (p = 0.57). Multivariate ureter analysis revealed lower pre-operative grade (p = 0.004) and injected Dx/HA volume 0.80-1.00 mL (p = 0.039) as predictors of success. CEV <0.20 mL (p = 0.002) and CEV/injected-volume <25% (p = 0.006) were predictors of failure. Volcano morphology (p = 0.004) and lower pre-op grade (p = 0.015) were predictors of success for STING and HIT, respectively. We found no differences in ureter or patient resolution between endoscopic Dx/HA injection techniques STING or HIT. Lower pre-operative grade and moderated Dx/HA volume were predictors of success regardless of technique. Copyright © 2013 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

  1. The application of arbitrary incidence laser beams heat treatment temperature field calculation formulas

    Institute of Scientific and Technical Information of China (English)

    Kun Ma; Junchang Li; Zebin Fan; Jinbin Gui; Yingxiong Qin; Qiguang Zheng

    2005-01-01

    @@ Based on the calculation formulas of heat treatment temperature field for an arbitrary incident laser intensity distribution, the transformation intensity distribution of CO2 laser beam passing an integrating mirror is studied theoretically and experimentally. The derived formulas are applied in laser heat treatment research which is transformed by optical system, and the theoretical calculation results are compared with experimental results. It is shown that the formulas can be used to calculate the laser heat treatment temperature field accurately, and the calculation speed is obviously faster than the numerical calculation methods with the same precision. The calculation software can be used to select proper experiment parameters.

  2. Effect of heat treatment on K3, K3XF and MTwo endodontic files

    Directory of Open Access Journals (Sweden)

    Fernandes F. M. Braz

    2015-01-01

    Full Text Available The purpose of this study was to evaluate the effect of heat treatment on the transformation temperatures of K3, K3XF and MTwo endodontic files. DSC was used to investigate the domains of transformation temperatures and how the transformation temperatures vary along the file. The files were analysed as received and subjected to heat treatment. X-ray diffraction analysis was also used to investigate the stress-induced martensite transformation on the files under flexion. The results show that heat treatment influences the transformation temperatures and that under flexion, the conditions and situations in which files present a stress-induced martensite transformation can be identified.

  3. Effect of Heat Treatment on the Microstructure and Corrosion Resistance of Cu-Zn Alloy

    Institute of Scientific and Technical Information of China (English)

    Xu Tao; Zhang Hailong; Xiao Nianxin; Zhao Xiangling

    2007-01-01

    The microstructure of Cu-Zn alloy with different heat treatment conditions in 3.5% NaCl + NH3 solution were observed, and the average corrosion rates and electrochemical data of Cu-Zn alloy were measured, as well as the effect of heat treatment on microstructure and corrosion resistance of Cu-Zn alloy was analyzed. The results show that the microstructure of Cu-Zn alloy has been changed due to the heat treatment. As a results, the better corrosion resistance can be obtained for the Cu-Zn alloy quenched from 900℃ for 0.5h followed by tempered at 100℃ for 2h.

  4. Influence and Analysis of Concentrate Degree of Plasma Arc for Heat Process of Hardening Treatment

    Institute of Scientific and Technical Information of China (English)

    WANG Shuo-gui; YAN Hong-ri

    2004-01-01

    According to the practicable model of the plasma arc surface quench, the influence law of the heat process、cooling course、 temperature field about surface quench treatment by plasma arc due to the concentrate degree of plasma arc heat source are discussed in this paper. It shows that the concentrate degree of plasma arc heat source can change the width of the hardening zone and can not change the maximum harden depth. With the increase of the concentrate degree, the area of the heat influence zone is decreased and its shape is narrowed after the heat source. Relative to cooling rate, the influence of the heat source concentrate degree for heat absorption is bigger. The correctness of the practical model are proved with experimental results for quench hardening of 45# steel by plasma arc.

  5. Influence and Analysis of Concentrate Degree of Plasma Arc for Heat Process of Hardening Treatment

    Institute of Scientific and Technical Information of China (English)

    WANGShuo-gui; YANHong-ri

    2004-01-01

    According to the practicable model of the plasma arc surtace quench, the influence law ot me heat process, cooling course, temperature field about surface quench treatment by plasma arc due to the concentrate degree of plasma arc heat source are discussed in this paper. It shows that the concentrate degree of plasma arc heat source can change the width of the hardening zone and can not change the maximum harden depth. With the increase of the concentrate degree, the area of the heat influence zone is decreased and its shape is narrowed after the heat source. Relative to cooling rate, the influence of the heat source concentrate degree for heat absorption is bigger. The correctness of the practical model are proved with experimental results for quench hardening of 45# steel by plasma arc.

  6. Performance analysis of system heat pump - heat recuperator used for air treatment in process industry

    Directory of Open Access Journals (Sweden)

    Milovančević Uroš M.

    2016-01-01

    Full Text Available A detailed parametric analysis and performance optimization of system “heat pump - recuperator is given in this paper. Mathematical model used for analysis is formed according to the physical model of the system and practical experience. Different types of compressors, and various temperature ranges are treated. Special attention is paid to influence of condensing and evaporating temperatures on system performances, so as to different features of heat recuperator. It is found out that in accordance to the working regimes and the compressor type, it is possible to determine optimal conditions in which the system will consume the minimum of electricity.

  7. A novel laboratory scale method for studying heat treatment of cake flour

    OpenAIRE

    Chesterton, A. K. S.; Wilson, D I; Sadd, P. I.; Moggridge, G. D.

    2014-01-01

    This is the accepted manuscript version. The final version is available from Elsevier at http://www.sciencedirect.com/science/article/pii/S0260877414003112. A lab-scale method for replicating the time–temperature history experienced by cake flours undergoing heat treatment was developed based on a packed bed configuration. The performance of heat-treated flours was compared with untreated and commercially heat-treated flour by test baking a high ratio cake formulation. Both cake volume and...

  8. VARNISH LAYER HARDNESS, SCRATCH RESISTANCE, AND GLOSSINESS OF VARIOUS WOOD SPECIES AS AFFECTED BY HEAT TREATMENT

    Directory of Open Access Journals (Sweden)

    Nevzat Çakıcıer

    2011-03-01

    Full Text Available The aim of the study was to determine the effects of different heat treatment and varnish application combinations on hardness, scratch resistance, and glossiness of wood materials sampled from limba (Terminalia superba, iroko (Chlorophora excelsa, ash (Fraxinus excelsior L., and Anatolian chestnut (Castenea sativa Mill. species. The heat treatment was applied at two levels (150 and 180 oC for both 3 and 6 hour periods. After the heat treatment, four types of varnish (cellulose lacquer, synthetic varnish, polyurethane varnish, and water based varnish were applied, and hardness, scratch resistance, and glossiness of varnish film layers of the treated woods were measured. The effects of heat treatment and varnish combination applications on above mentioned variables were analyzed according to the study design (factorial design with 4 (species x 2 (heat x 2(duration x 4 (varnish = 64 experimental units with 10 samples for each combination of parameters. Glossiness increased on wood samples for all of the four wood species treated with cellulose lacquer and synthetic varnish and across all heating treatments. However, glossiness values were decreased for all the wood species depending on heating temperature and time. Values of hardness and scratch resistance were also decreased for all the four wood species across all the treatment combinations. The results were obtained from the upper surface of the application process and are thought to contribute to the national economy.

  9. 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).

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

    Science.gov (United States)

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

    2014-01-30

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

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

    Science.gov (United States)

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

    2015-12-01

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

  12. Effects of the laser beam superficial heat treatment on the gas Tungsten arc Ti-6al-4v welded metal microstructure

    Science.gov (United States)

    Voiculescu, I.; Dontu, Octavian; Geanta, V.; Ganatsios, S.

    2008-03-01

    The microstructure of the weld and the extent to which it is different from the thermo-mechanically processed base material is strongly influenced by the thermal cycle of welding. The mechanical properties of composite weld structures in titanium alloys depend on structural characteristics of each region (weld, base material and heat affected area), influenced by the specific thermal cycle imposed during welding and the subsequent post-weld heat treatment. In order to improve the as-welded metal toughness and ductility, the welded metal was subjected to various post weld laser heat treatments, above and below beta transus temperature in a shielding atmosphere of pure argon. Standard micro-hardness measurements and tensile strength techniques showed higher mechanical properties of the heat treated samples in different conditions with respect to the base metal. Metallographic investigations attribute this to the formation of α'phases in heat treated material, especially in the weld metal.

  13. Recovery of palladium, cesium, and selenium from heavy metal alkali borosilicate glass by combination of heat treatment and leaching processes

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhanglian; Okada, Takashi, E-mail: t-okada@u-fukui.ac.jp; Nishimura, Fumihiro; Yonezawa, Susumu

    2017-06-05

    Highlights: • A separation technique of both noble and less noble metal from glass is studied. • Via reductive heat treatment, 80% of palladium is extracted in liquid bismuth. • Sodium–potassium-rich materials with cesium and selenium are phase separated. • From the materials, over 80% of cesium and selenium are extracted in water. - Abstract: Reductive heat-treatment and leaching process were applied to a simulated lead or bismuth soda-potash-borosilicate glass with palladium, cesium, and selenium to separate these elements. In the reductive heat treatment, palladium is extracted in liquid heavy metal phase generated by the reduction of the heavy metal oxides, whereas cesium and selenium are concentrated in phase separated Na–K-rich materials on the glass surface. From the materials, cesium and selenium can be extracted in water, and the selenium extraction was higher in the treatment of the bismuth containing glass. The chemical forms of palladium in the glass affected the extraction efficiencies of cesium and selenium. Among the examined conditions, in the bismuth glass treatment, the cesium and selenium extraction efficiencies in water were over 80%, and that of palladium in liquid bismuth was over 80%.

  14. Congenital vertical talus: Treatment by reverse ponseti technique

    Directory of Open Access Journals (Sweden)

    Bhaskar Atul

    2008-01-01

    Full Text Available Background: The surgery for idiopathic congenital vertical talus (CVT can lead to stiffness, wound complications and under or over correction. There are sporadic literature on costing with mixed results. We describe our early experience of reverse ponseti technique. Materials and methods: Four cases (four feet of idiopathic congenital vertical talus (CVT which presented one month after birth were treated by serial manipulation and casting, tendoachilles tenotomy and percutaneous pinning of talonavicular joint. An average of 5.2 (range - four to six plaster cast applications were required to correct the forefoot deformity. Once the talus and navicular were aligned based on the radiographic talus-first metatarsal axis, percutaneous fixation of the talo-navicular joint with a Kirschner wire, and percutaneous tendoachilles tenotomy under anesthesia was performed following which a cast was applied with the foot in slight dorsiflexion. Results: The mean follow-up period for the four cases was 8.5 months (6-12 months. At the end of the treatment all feet were supple and plantigrade but still using ankle foot orthosis (AFO. The mean talocalcaneal angle was 70 degrees before treatment and this reduced to 31 degrees after casting. The mean talar axis first metatasal base angle (TAMBA angle was 60° before casting and this improved to 10.5°. Conclusion: Although our follow-up period is small, we would recommend early casting for idiopathic CVT along the same lines as the Ponseti technique for clubfoot except that the forces applied are in reverse direction. This early casting method can prevent extensive surgery in the future, however, a close vigil is required to detect any early relapse.

  15. Dosimetric trade-offs in breast treatment with VMAT technique.

    Science.gov (United States)

    Fogliata, Antonella; Seppälä, Jan; Reggiori, Giacomo; Lobefalo, Francesca; Palumbo, Valentina; De Rose, Fiorenza; Franceschini, Davide; Scorsetti, Marta; Cozzi, Luca

    2017-02-01

    Breast planning with volumetric modulated arc therapy (VMAT) has been explored, especially for left-sided breast treatments, with the primary intent of lowering the heart dose and improving target dose homogeneity. As a trade-off, larger healthy tissue volumes would receive low dose levels, with the potential risk of increasing late toxicities and secondary cancer induction, although no clinical data are available today to confirm the risk level. The scope of this work is to explore the dosimetric trade-offs using two different VMAT plans. Two planning strategies for dual-partial-arc VMAT, RA_avoid and RA_full, with and without avoidance sectors, were explored in a cohort of 20 patients, for whole left breast irradiation for 40.05 Gy to the mean target dose in 15 fractions. Common dose objectives included a stringent dose homogeneity, mean dose to the heart <5 Gy, ipsilateral lung (Ilung) <8 Gy, contralateral lung (Clung) <2 Gy and contralateral breast (Cbreast) <3 Gy. RA_full showed a better dose conformity, lower high-dose spillage in the healthy tissue and lower skin dose. RA_avoid presented a reduction of the mean doses for all critical structures: 51% to the heart, 12% to the Ilung, 81% to the Clung and 73% to the Cbreast. All differences were significant with p < 0.0001. The adaptation of VMAT options to planning objectives reduced significantly the healthy tissue dose levels at the price of some high-dose spillage. Evaluation of the trade-offs for application to the different critical structures should drive in improving the usage of the VMAT technique for breast cancer treatment. Advances in knowledge: Different planning strategies in the same VMAT technique could give significant variations in dose distributions. The choice of the trade-offs would affect the possible future late toxicity and secondary cancer induction risk.

  16. Photocatalytic activity and reusability of ZnO layer synthesised by electrolysis, hydrogen peroxide and heat treatment.

    Science.gov (United States)

    Akhmal Saadon, Syaiful; Sathishkumar, Palanivel; Mohd Yusoff, Abdull Rahim; Hakim Wirzal, Mohd Dzul; Rahmalan, Muhammad Taufiq; Nur, Hadi

    2016-08-01

    In this study, the zinc oxide (ZnO) layer was synthesised on the surface of Zn plates by three different techniques, i.e. electrolysis, hydrogen peroxide and heat treatment. The synthesised ZnO layers were characterised using scanning electron microscopy, X-ray diffraction, UV-visible diffuse reflectance and photoluminescence spectroscopy. The photocatalytic activity of the ZnO layer was further assessed against methylene blue (MB) degradation under UV irradiation. The photocatalytic degradation of MB was achieved up to 84%, 79% and 65% within 1 h for ZnO layers synthesised by electrolysis, heat and hydrogen peroxide treatment, respectively. The reusability results show that electrolysis and heat-treated ZnO layers have considerable photocatalytic stability. Furthermore, the results confirmed that the photocatalytic efficiency of ZnO was directly associated with the thickness and enlarged surface area of the layer. Finally, this study proved that the ZnO layers synthesised by electrolysis and heat treatment had shown better operational stability and reusability.

  17. Study On The Effect Of Corrosion Behaviour Of Stainless Steel Before And After Carburizing Heat Treatment

    Science.gov (United States)

    Sulaiman, S. A.; Alias, S. K.; Ahmad, S.; Fauzi, M. H. Mohd; Ahmad, N. N.

    2016-11-01

    This study investigates the effect of corrosion behaviour of stainless steel before and after carburizing process. All samples were prepared based on the testing specification requirement and the chemical compositions of the stainless steel were obtained using spectrometer tester. Samples were then undergoing pack carburizing process by adding 50g of carbon powder as the carburizing agent. Then the samples were heated at 900 °C and 950 °C for 8 hours. To obtain corrosion rate, weight loss test was conducted and the samples were immersed in three different solutions which were distilled water, hydrochloric acid and sodium chloride. Hardness and density test were employed to measure the physical properties of the ASTM 304 stainless steel. The microstructures of all samples were observed using Olympus BX41M optical microscope. The resulting phases after each heat treatment were tested by x-ray diffraction (XRD) tester. The percentage of corrosion values, determined from this technique, showed fairly good agreement. Carburizing process produced a carburizing layer improved mechanical properties and corrosion resistance abilities

  18. Effects of heat treatment on diffusion of Cu atoms into CdTe single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Soo, Y. L. [Department of Physics, State University of New York at Buffalo, Amherst, New York 14260 (United States); Huang, S. [Department of Physics, State University of New York at Buffalo, Amherst, New York 14260 (United States); Kim, S. [Department of Physics, State University of New York at Buffalo, Amherst, New York 14260 (United States); Kioseoglou, G. [Department of Physics, State University of New York at Buffalo, Amherst, New York 14260 (United States); Kao, Y. H. [Department of Physics, State University of New York at Buffalo, Amherst, New York 14260 (United States); Compaan, A. D. [Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606 (United States); Grecu, D. [Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606 (United States); Albin, D. [National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401 (United States)

    2000-06-19

    Angular dependence of x-ray fluorescence and x-ray absorption fine structure techniques have been used to study the diffusion of Cu atoms into the photovoltaic material CdTe. Depth profile, effective valency, and local structure of Cu atoms in a Cu-doped single crystal of CdTe were investigated before and after a second heat treatment. Enhanced Cu diffusion into the CdTe single crystal was observed as a result of heating at a moderate temperature around 200 degree sign C, resulting in a redistribution of the Cu impurities through a broader depth profile. Some of the Cu atoms are believed either to form small complexes with Te or occupy interstitial sites in the host but accompanied by a large local lattice distortion while others substitute for Cd on the cation sites. The results thus demonstrate that these nondestructive x-ray characterization methods are useful for probing microstructural changes in CdTe photovoltaic materials/devices in which some Cu-containing compounds are used as back contacts. (c) 2000 American Institute of Physics.

  19. The heat-compression technique for the conversion of platelet-rich fibrin preparation to a barrier membrane with a reduced rate of biodegradation.

    Science.gov (United States)

    Kawase, Tomoyuki; Kamiya, Mana; Kobayashi, Mito; Tanaka, Takaaki; Okuda, Kazuhiro; Wolff, Larry F; Yoshie, Hiromasa

    2015-05-01

    Platelet-rich fibrin (PRF) was developed as an advanced form of platelet-rich plasma to eliminate xenofactors, such as bovine thrombin, and it is mainly used as a source of growth factor for tissue regeneration. Furthermore, although a minor application, PRF in a compressed membrane-like form has also been used as a substitute for commercially available barrier membranes in guided-tissue regeneration (GTR) treatment. However, the PRF membrane is resorbed within 2 weeks or less at implantation sites; therefore, it can barely maintain sufficient space for bone regeneration. In this study, we developed and optimized a heat-compression technique and tested the feasibility of the resulting PRF membrane. Freshly prepared human PRF was first compressed with dry gauze and subsequently with a hot iron. Biodegradability was microscopically examined in vitro by treatment with plasmin at 37°C or in vivo by subcutaneous implantation in nude mice. Compared with the control gauze-compressed PRF, the heat-compressed PRF appeared plasmin-resistant and remained stable for longer than 10 days in vitro. Additionally, in animal implantation studies, the heat-compressed PRF was observed at least for 3 weeks postimplantation in vivo whereas the control PRF was completely resorbed within 2 weeks. Therefore, these findings suggest that the heat-compression technique reduces the rate of biodegradation of the PRF membrane without sacrificing its biocompatibility and that the heat-compressed PRF membrane easily could be prepared at chair-side and applied as a barrier membrane in the GTR treatment.

  20. Optimized evaporation technique for leachate treatment: Small scale implementation.

    Science.gov (United States)

    Benyoucef, Fatima; Makan, Abdelhadi; El Ghmari, Abderrahman; Ouatmane, Aziz

    2016-04-01

    This paper introduces an optimized evaporation technique for leachate treatment. For this purpose and in order to study the feasibility and measure the effectiveness of the forced evaporation, three cuboidal steel tubs were designed and implemented. The first control-tub was installed at the ground level to monitor natural evaporation. Similarly, the second and the third tub, models under investigation, were installed respectively at the ground level (equipped-tub 1) and out of the ground level (equipped-tub 2), and provided with special equipment to accelerate the evaporation process. The obtained results showed that the evaporation rate at the equipped-tubs was much accelerated with respect to the control-tub. It was accelerated five times in the winter period, where the evaporation rate was increased from a value of 0.37 mm/day to reach a value of 1.50 mm/day. In the summer period, the evaporation rate was accelerated more than three times and it increased from a value of 3.06 mm/day to reach a value of 10.25 mm/day. Overall, the optimized evaporation technique can be applied effectively either under electric or solar energy supply, and will accelerate the evaporation rate from three to five times whatever the season temperature. Copyright © 2016. Published by Elsevier Ltd.

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

    NARCIS (Netherlands)

    Berg, H.E.

    1993-01-01

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

  2. High pressure versus heat treatments for pasteurisation and sterilisation of model emulsions

    NARCIS (Netherlands)

    Ven, van der C.; Courvoisier, C.; Matser, A.M.

    2007-01-01

    Heat treatments can have considerable influence on the droplet size distribution of oil-in-water emulsions. In the present study, high-pressure (HP) pasteurisation and sterilisation were evaluated as alternatives for heat preservation of emulsions. HP conditions used were 600 MPa, 5 min, room temper

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

    African Journals Online (AJOL)

    African Journal of Food, Agriculture, Nutrition and Development ... Increased CAT and POX activities in mango and banana during heat treatment ... Pre-cooling of mango at 8 ºC showed twofold decreased CAT activity in the pulp whereas heat ...

  4. Effect of multi-temperature aging on the characterization of aluminum based castings heat treated using fluidized bed technique

    Science.gov (United States)

    Ragab, Kh. A.; Samuel, A. M.; Al-Ahmari, A. M. A.; Samuel, F. H.; Doty, H. W.

    2013-07-01

    The current study investigates the influences of the fluidized bed heat treatment on the quality indices and microstructural characterization of A356.2 and B319.2 castings. Traditional heat treatment technology, employing circulating air convection furnaces (CF), was used to establish a relevant comparison with fluidized sand bed (FB) for the heat treatment of the alloys investigated, employing T6 continuous aging cycles or multi-temperature aging cycles. The results of alloys subjected to multi-temperature aging cycles reveal that the strength results obtained after the T6 continuous aging treatment of A356 alloys are not improved by means of multi-temperature aging cycles, indicating therefore that the optimum properties are obtained using a T6 aging treatment. The optimum strength properties of B319.2 alloys, however, is obtained by applying multi-temperature aging cycles such as, for example, 230 °C/2 h followed by 180 °C/8 h, rather than T6 aging treatment. In the case of multi-temperature aging cycles, the modification factor has the most significant role in improving the quality index values of 356 and 319 alloys. The FB heattreated alloys have the highest strength values for all heat treatment cycles compared to CF heat-treated alloys; however, the FB has no significant effect on the quality values of 319 alloys compared to the CF.

  5. A code-independent technique for computational verification of fluid mechanics and heat transfer problems

    Institute of Scientific and Technical Information of China (English)

    M. Garbey; C. Picard

    2008-01-01

    The goal of this paper is to present a versatile framework for solution verification of PDE's.We first generalize the Richardson Extrapolation technique to an optimized extrapolation solution procedure that constructs the best consistent solution from a set of two or three coarse grid solution in the discrete norm of choice. This technique generalizes the Least Square Extrapolation method introduced by one of the author and W. Shyy. We second establish the conditioning number of the problem in a reduced space that approximates the main feature of the numerical solution thanks to a sensitivity analysis. Overall our method produces an a posteriori error estimation in this reduced space of approximation. The key feature of our method is that our construction does not require an internal knowledge of the software neither the source code that produces the solution to be verified. It can be applied in principle as a postprocessing procedure to off the shelf commercial code. We demonstrate the robustness of our method with two steady problems that are separately an incompressible back step flow test case and a heat transfer problem for a battery. Our error estimate might be ultimately verified with a near by manufactured solution. While our procedure is systematic and requires numerous computation of residuals, one can take advantage of distributed computing to get quickly the error estimate.

  6. Heat Treatment Effect on Microstructure, Hardness and Wear Resistance of Cr26 White Cast Iron

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shaoping; SHEN Yehui; ZHANG Hao; CHEN Dequan

    2015-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2014-03-01

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

  9. Elastic characterization of platinum/rhodium alloy at high temperature by combined laser heating and laser ultrasonic techniques.

    Science.gov (United States)

    Burgess, K; Prakapenka, V; Hellebrand, E; Zinin, P V

    2014-04-01

    We demonstrate an innovative pump-probe technique combined with laser heating to determine the velocity of a surface Rayleigh wave at high temperature. Laser ultrasonics in a point-source-point-receiver configuration was combined with laser heating to evaluate the elastic properties of micron size specimens. The measurements of the velocity of the surface Rayleigh wave (SRW) were conducted at 1070K. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Effect of high-temperature heat treatment duration on the purity and microstructure of MWCNTs

    Indian Academy of Sciences (India)

    I Srikanth; N Padmavathi; P S R Prasad; P Ghosal; R K Jain; Ch Subrahmanyam

    2016-02-01

    The effect of high-temperature heat treatment on purity and structural changes of multiwalled carbon nanotubes (MWCNTs) were studied by subjecting the raw MWCNTs (pristine MWCNTs) to 2600°C for 60 and 120 min. Thermogravimetric analysis (TGA), X-ray diffraction, Raman spectroscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to study the effect of heat-treatment duration on the purity and structural changes of MWCNTs. Results show that high-temperature heat treatment can be used to purify MWCNTs with proper optimization of treatment time. It was observed that 60 min heat treatment of raw MWCNTs imparts high purity and structural perfection to MWCNTs, while 120 min heat treatment imparts structural degradation to MWCNTs with collapse of the innermost shells. The present study indicates that metal impurities act as moderators in controlling the degradation of MWCNTs up to certain duration, and once the metal impurities escape completely, further heat treatment degrades the structure of MWCNTs.

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

    Energy Technology Data Exchange (ETDEWEB)

    Beckermann, Christoph; Carlson, Kent

    2011-07-22

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

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

    Science.gov (United States)

    2016-09-01

    emitting diode LHA landing, helicopter, assault LRA L. Raymond & Associates min minute mm millimeter MPa mega pascal NAMLT nitric acid mass loss...electron microscope SSC ship to shore connector xvi STEM scanning transmission electron microscopy TEM transmission electron microscope UTS ultimate...reduce repair costs either by developing lower cost repair techniques, or preventing damage from occurring, or both. Current repair techniques involve

  13. Effect of Heat Treatment on High Temperature Stress Rupture Strength of Brazing Seam for Nickel-base Superalloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to enhance the high-temperature stress rupture strength of brazing seam by heat treatment, it was diffusion treated, then solution heat treated, and finally aging treated. The microstructure of brazing seam especially morphology of phase and boride was observed and the strength of brazing seam was measured in this process. The results show that heat treatment can enhance high-temperature stress rupture strength by improving the microstructure of brazing seam. The strength of brazing seam after solution heat treatment decreases in comparison with that only after diffusion treatment while aging treatment after solution heat treatment increases the strength of brazing seam.

  14. Cyclodialysis Cleft Treatment Using a Minimally Invasive Technique

    Directory of Open Access Journals (Sweden)

    João Pinheiro-Costa

    2015-02-01

    Full Text Available Purpose: To report a case of a cyclodialysis cleft that was successfully managed with gas endotamponade and cyclocryotherapy. Methods: A 37-year-old male victim of a severe blunt ocular trauma was referred to our service for evaluation and treatment of a left eye hypotony. Clinical examination revealed an intraocular pressure of 2 mm Hg, a cyclodialysis cleft extending from the 11 to 1 o'clock positions and a hypotonic maculopathy. Left eye best corrected visual acuity (BCVA was 3/10. The patient failed to respond to conservative treatment with atropine 1%, so a single bubble of 16% C2F6 was injected into the vitreous cavity, followed by superior quadrant transconjunctival cyclocryotherapy. Results: After gas absorption, the intraocular pressure increased to 11 mm Hg and became steady during the 24 months of follow-up. His hypotonic maculopathy resolved, and the BCVA improved to 9/10. Complete closure of the cyclodialysis cleft was documented with ultrasound biomicroscopy. Conclusion: Cryotherapy associated with gas endotamponade is a minimally invasive technique that could be considered for patients with cyclodialysis clefts that fail to respond to medical therapy.

  15. Employment of rapid heat treatment of rolled steel products for shipbuilding application

    Energy Technology Data Exchange (ETDEWEB)

    Teliovich, R.V.; Ivasishin, O.M.; Yakushechkin, Ye.I.; Nikonenko, D.I. [AN Ukrainskoj SSR, Kiev (Ukraine). Inst. Fiziki Metallov

    2000-07-01

    Development of new efficient methods aimed to improve resistance of structural steels against brittle fracture, especially of those that should guarantee a reliable operation of steel constructions at low temperatures still remains actual. One of the most appealing goals for steel producers is to provide a high level of toughness for rolled steel products to be employed in shipbuilding industry. Besides metallurgical approaches aimed at steel cleaning from dangerous impurities (P, S, As) or additional alloying of steels with nickel or manganese, refining of microstructure using different heat treatments or thermomechanical processings is a fundamental basis of modern technological schemes of steel production. Heat treatment of steel rolled products also may result in an improvement in the mechanical properties if novel methods of rapid heating (RH) are employed. Application of direct resistant RH for bulk heat treatment instead of slow heating in furnaces allows to solve concomitantly two problems: to reduce significantly the efficient grain size of both austenite and ferrite and, due to this improve the strength and toughness; to improve radically technical and cost efficiency, as well as ecological parameters of heat treatment processing. In a present work, an influence of rapid heat treatment (RHT) on the mechanical properties of hot-rolled steel products was studied. (orig.)

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

    Science.gov (United States)

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

    2010-08-01

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

  17. Insulation and Heat Treatment of Bi-2212 Wire for Wind-and-React Coils

    Energy Technology Data Exchange (ETDEWEB)

    Peter K. F. Hwang

    2007-10-22

    Higher Field Magnets demand higher field materials such as Bi-2212 round superconducting wire. The Bi-2212 wire manufacture process depends on the coil fabrication method and wire insulation material. Considering the wind-and-react method, the coil must unifirmly heated to the melt temperature and uniformly cooled to the solidification temperature. During heat treat cycle for tightly wound coils, the leakage melt from conductor can chemically react with insulation on the conductor and creat short turns in the coils. In this research project, conductor, insulation, and coils are made to systemically study the suitable insulation materials, coil fabrication method, and heat treatment cycles. In this phase I study, 800 meters Bi-2212 wire with 3 different insulation materials have been produced. Best insulation material has been identified after testing six small coils for insulation integrity and critical current at 4.2 K. Four larger coils (2" dia) have been also made with Bi-2212 wrapped with best insulation and with different heattreatment cycle. These coils were tested for Ic in a 6T background field and at 4.2 K. The test result shows that Ic from 4 coils are very close to short samples (1 meter) result. It demonstrates that HTS coils can be made with Bi-2212 wire with best insulation consistently. Better wire insulation, improving coil winding technique, and wire manufacture process can be used for a wide range of high field magnet application including acclerators such as Muon Collider, fusion energy research, NMR spectroscopy, MRI, and other industrial magnets.

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

    Science.gov (United States)

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

    2003-05-15

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

  19. Heat Treatment and Properties of Nitrogen Alloyed, Martensitic,Corrosion-resistant Steels

    Institute of Scientific and Technical Information of China (English)

    Reinhold Schneider; Klaus Sammt; Roland Rabitsch; Michael Haspel

    2004-01-01

    This paper gives a short introduction to the typical process route and material properties of these steels in comparison to standard martensitic corrosion-resistant steels. The typical response of these steels to various heat treatment parameters is shown and explained using the three grades M333, N360 and M340 (all made by Bohler Edelstahl GmbH) as examples, and the physical metallurgy of these steels and its consequences for practical heat treatment is explained. The correlation between tempering parameters and their effect on the toughness and corrosion properties is explained in particular detail, showing that these new steels not only offer far better property combinations under the usual heat treatment parameters than standard martensitic corrosion-resistant steels, but that they also open the door to extending heat treatment combinations and properties.

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

    Directory of Open Access Journals (Sweden)

    Khalid Lafdi

    2007-01-01

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

  1. Grain growth of Al-4Cu-Mg alloy during isothermal heat treatment

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The microstructure of an Al-4Cu-Mg alloy during isothermal heat treatment in the Strain Induced Melt Activation (SIMA)process was investigated and the kinetics of grain growth was analyzed. The grain growth during isothermal heat treatment of the Al4Cu-Mg alloy coincided with the Ostwald ripening theory. During isothermal heat treatment, both grain shape and the high volume fraction of solid phase have significant effects on grain growth. Therefore, a new grain growth model based on the Ostwald ripening theory was proposed taking into consideration the grain shape and the volume fraction of solid phase. By comparing the calculated results with the experimental results, it was confirmed that the present model could be applied to grain growth during isothermal heat treatment of the Al-4Cu-Mg alloy in the SIMA process.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-01

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

  3. Effect of Heat-treatment Temperature on HA-coated Titanium Materials

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Homogeneous HA coating materials were prepared on porous titanium by the low-temperature combustion synthesis. It was found that the mechanical properties of the specimen depend on the coating process and the heat treatment, and the bending strength would be reduced during the coating process but could be improved by heat treatment. The effects of the temperature during heat-treatment on the phase composition and microstructure of the as-prepared coating, and the bending strength of the specimen were investigated by XRD and SEM.The experimental results show that in the coating process, slight oxidation of the substrate may give rise to a drop in bending strength; however, it could be increased by the reaction of HA and TiO2, and the sintering of the coating during heat treatment. The HA particles in the coating, with very fine sized particles, were pretty active and would decompose at 800 ℃ .

  4. Effect of Heat Treatment on Structures and Properties of Polyurethane Blend Ultrafiltration Membranes

    Institute of Scientific and Technical Information of China (English)

    封严; 肖长发

    2004-01-01

    The polyurethane/polyacrylonitrile ( PU/PAN ) and polyurethane/cellulose acetate (PU/CA) blend ultra filtration membranes were prepared based on LoebSourirajan phase transition method. The change of the structures and properties of the PU/PAN and PU/CA membranes with the heat treatment process was studied.The results showed: the water flux decreased and retention increased with the increase of heat treatment temperature of PU/PAN blend membrane, but the water flux of PU/CA blend membrane got the maximum with heat treatment temperature of 60℃ and decreased rapidly with the heat treatment temperature of 100 ℃. The interfacial microvoid structure and its influence on the properties of PU/PAN and PU/CA blend membranes were studied.

  5. The influence of heating rate on superconducting characteristics of MgB2 obtained by spark plasma sintering technique

    Science.gov (United States)

    Aldica, G.; Burdusel, M.; Popa, S.; Enculescu, M.; Pasuk, I.; Badica, P.

    2015-12-01

    Superconducting bulks of MgB2 were obtained by the Spark Plasma Sintering (SPS) technique. Different heating rates of 20, 100, 235, 355, and 475 °C/min were used. Samples have high density, above 95%. The onset critical temperature Tc, is about 38.8 K. There is an optimum heating rate of ∼100 °C/min to maximize the critical current density Jc0, the irreversibility field Hirr, the product (Jc0 x μ0Hirr), and to partially avoid formation of undesirable flux jumps at low temperatures. Significant microstructure differences were revealed for samples processed with low and high heating rates in respect to grain boundaries.

  6. Economics of wastewater treatment in GTL plant using spray technique

    Directory of Open Access Journals (Sweden)

    G.C. Enyi, G.G. Nasr, M. Burby

    2013-01-01

    Full Text Available In a Gas-to-liquid (GTL plant, significant quantities of CO2 and reaction water are produced and various chemicals are used as intermediate treatment chemicals. The reaction water is contaminated by these chemicals which impair the pH and the related properties of the water. The pH has to be controlled in the effluent treatment unit before the water is re-used or released to the environment. The overall aim of this investigation is to create a novel technique to address the problem of waste water treatment in GTL plants which will assist in the reduction of greenhouse gas (CO2 emissions into the atmosphere. A laboratory-scale effluent neutralisation unit for pH control utilising gas injectors was designed and built. The unit used the CO2 produced as a by-product of GTL process as wastewater treatment chemical instead of the conventional Sulphuric acid. The quality of wastewater after treatment with CO2 met the standards set by the state regulatory agency. The economics of the new process shows a better payout period of 3.6 years for capital investment of $1,645 Million compared to 4.7 years for an existing plant layout with capital investment of $1,900 Million. The effects of increase in plant capacity showed a lower payback back of 2.8 years for plant capacity of 140,000 barrels/day (22258 m3/day, 3.6 years for 34,000 barrels/day and 6.0 years for 12,500 barrels/day (1987 m3/day plant capacity. The sensitivity analysis using crystal ball simulator with ‘Microsoft Excel’ shows that the annual revenue has the greatest effects on the NPV of the plant than the CAPEX and inflation rate. Apart from the environmental benefits the process generates by reducing CO2 emissions into the atmosphere, the study also concludes that the replacement of conventional Sulphuric acid (H2SO4 unit with CO2 improves the economics of the plant.

  7. Economics of wastewater treatment in GTL plant using spray technique

    Energy Technology Data Exchange (ETDEWEB)

    Enyi, G.C.; Nasr, G.G.; Burby, M. [University of Salford, Manchester, M5 4WT (United Kingdom)

    2013-07-01

    In a Gas-to-liquid (GTL) plant, significant quantities of CO2 and reaction water are produced and various chemicals are used as intermediate treatment chemicals. The reaction water is contaminated by these chemicals which impair the pH and the related properties of the water. The pH has to be controlled in the effluent treatment unit before the water is re-used or released to the environment. The overall aim of this investigation is to create a novel technique to address the problem of waste water treatment in GTL plants which will assist in the reduction of greenhouse gas (CO2) emissions into the atmosphere. A laboratory-scale effluent neutralisation unit for pH control utilising gas injectors was designed and built. The unit used the CO2 produced as a by-product of GTL process as wastewater treatment chemical instead of the conventional Sulphuric acid. The quality of wastewater after treatment with CO2 met the standards set by the state regulatory agency. The economics of the new process shows a better payout period of 3.6 years for capital investment of $1,645 Million compared to 4.7 years for an existing plant layout with capital investment of $1,900 Million. The effects of increase in plant capacity showed a lower payback back of 2.8 years for plant capacity of 140,000 barrels/day (22258 m3/day), 3.6 years for 34,000 barrels/day and 6.0 years for 12,500 barrels/day (1987 m3/day) plant capacity. The sensitivity analysis using crystal ball simulator with 'Microsoft Excel' shows that the annual revenue has the greatest effects on the NPV of the plant than the CAPEX and inflation rate. Apart from the environmental benefits the process generates by reducing CO2 emissions into the atmosphere, the study also concludes that the replacement of conventional Sulphuric acid (H2SO4) unit with CO2 improves the economics of the plant.

  8. Sediment remediation treatment techniques for the Venice industrial canals

    Energy Technology Data Exchange (ETDEWEB)

    Pippa, R.; Scanferla, P.; Cammarata, F.; Zampieri, L.; Carlon, C. [Consorzio Venezia Ricerche (Italy); Pavoni, B. [Ca' Foscari University of Venice (Italy). Dept. of Environmental Sciences; Pannocchia, G. [Venezia Technologie SpA, Venice (Italy); Hreglich, S. [Stazione Sperimentale del Vetro, Venice (Italy); Avezzu, F. [Depuracque Impianti srl, Venice (Italy)

    2003-07-01

    The main objective of SeRTech project (Sediment Remediation Technologies) is to develop an integrated cost-effective treatment system to address heterogeneous contamination and matrixes, such as those of Venice lagoon dredged materials. Seven treatment techniques, selected over a large array, have been tested: Thermal Desorption. A preliminary set of isothermal treatments at different temperatures was performed to evaluated the losses of organic and the most volatile metals (such as Pb and As). An almost full volatilisation of organic compounds was observed at temperatures ranging between 200 and 300 C. Chemical stabilization-solidification. Depuracque Impianti srl process uses innovative patented additives (polimers and superplasticizers) to immobilize heavy metals into cement pellets. Solvent extraction. Organic contaminants such as PAHs and PCBs were extracted from sediments by using ethyl acetate. The results showed that solvent extraction obtained high efficiency in removal of PAHs and other organic contaminants. Immobilization of heavy metals employing sulfate-reducing bacteria. High Gradient Magnetic Separation (HGMS). Sulfate reducing bacteria (SBR) produce an iron sulfide containing biomass with a high capability to adsorbe hevy metals and some organic compounds. This biomass can be separated through a high gradient magnetic field removing a substantial fraction of contaminants. Vitrification. Sediment was mixed with other inorganic wastes (glass cullet, feldsphatic tailings) and low amounts of row material to obtain an inert glass, which in turn can be recycled into other useful products, for example glass fibres, foam glass and glass ceramics. Phytoremediation. Phragmites australis (Cav.), Trin; Juncus Iacustrus, Arthrocnmemum fruticosum, Spartina maritima, Helianthus annuus L., Zea mais L., Brassica napus L., Brassica juncea L. have been selected to verify limit and efficiency of phytoextraction for heavy metals (Zn, Pb, Hg, Cd, As, Ni). Not only

  9. PENGARUH PROSES HEAT-MOISTURE TREATMENT (HMT TERHADAP KARAKTERISTIK FISIKOKIMIA PATI [Effect of Heat-Moisture Treatment (HMT Process on Physicochemical Characteristics of Starch]-- Komunikasi Singkat

    Directory of Open Access Journals (Sweden)

    Feri Kusnandar

    2012-06-01

    Full Text Available Heat-Moisture Treatment (HMT is a hydrothermal treatment that modifies the physicochemical properties of starch. Without destroying it’s granular structure. This treatment involves treatment of starch granules at low moisture levels (<35% moisture w/w for a certain period of time at temperatures above glass transition temperature (Tg but below the gelatinization temperatures. In this review, impact of starch conditions (sources, composition as well as HMT conditions (moisture content, time period and temperature on the morphological, crystalline, gelatinisation and pasting characteristics of starch will be discussed.

  10. Polymorphic Behavior of Syndiotactic Polypropylene Induced by Heat Treatment

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The polymorphic behavior of syndiotactic polypropylene (s-PP) crystallized from the melt under different conditions was investigated by means of WAXD and DSC. The isothermal melt crystallization of s-PP proceeded in form I at tc≥110 ℃ and in form Ⅱ at tc<110 ℃. S-PP crystallized nonisothermally from the melt was the mixture of forms Ⅰ and Ⅱ. With increasing the cooling rate(a), the content of form I increased, and the content of form Ⅱ decreased. On heating, at 10 K/min, of quenched s-PP, it crystallized in form Ⅱ at t<70 ℃, continuing heating resulted in form Ⅱ→form I transition, which was an endothermal process.

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

    OpenAIRE

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

    2015-01-01

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

  12. Effect of Heat Treatment during Pelleting on Metabolisable Energy Values of Chicken Diet

    Directory of Open Access Journals (Sweden)

    Jiri Zelenka

    2016-03-01

    Full Text Available Pelleting is the most prevalent heat treatment in the production of poultry feed. Metabolisable energy values of mash and steam pelleted complete maize-type broiler finisher diet was investigated in an experiment with 24 individually followed Ross hybrid male chickens. Altogether four balance periods were compared. Heat treatment significantly (P < 0.001 increased classical metabolisable energy and nitrogen-corrected metabolisable energy values by 3.00 % and 2.99 %, respectively.

  13. Heat treatment of solid wood:effects on absorption, strength and colour

    OpenAIRE

    Johansson, Dennis

    2008-01-01

    Wood is a useful construction material, but it has less desirable properties such as poor durability and poor dimensional stability. These problems can be reduced by using various chemical treatments. Increased environmental awareness has raised the demand for more environmentally friendly methods. Heat treatment is an alternative method for improving these properties with no use of chemical additives. When wood is heated, chemical changes start to take place inside the wood structure. These ...

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

    Science.gov (United States)

    Tarmizi, Azmil Haizam Ahmad; Lin, Siew Wai

    2008-01-01

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

  15. Conformal mapping technique for two-dimensional porous media and jet impingement heat transfer

    Science.gov (United States)

    Siegel, R.

    1974-01-01

    Transpiration cooling and liquid metals both provide highly effective heat transfer. Using Darcy's law in porous media and the inviscid approximation for liquid metals, the local fluid velocity in these flows equals the gradient of a potential. The energy equation and flow region are simplified when transformed into potential plane coordinates. In these coordinates, the present problems are reduced to heat conduction solutions which are mapped into the physical geometry. Results are obtained for a porous region with simultaneously prescribed surface temperature and heat flux, heat transfer in a two-dimensional porous bed, and heat transfer for two liquid metal slot jets impinging on a heated plate.

  16. Introduction of fractional elements for improvising the performance of PID controller for heating furnace using AMIGO tuning technique

    Directory of Open Access Journals (Sweden)

    Amlan Basu

    2016-09-01

    Full Text Available The paper demonstrates about melioration of integer order and fractional order model of heating furnace. Both models are being placed in closed loop along with the proportional integral derivative (PID controller and fractional order proportional integral derivative (FOPID controller so that the various time domain performance characteristics of the heating furnace can be meliorated. The tuning parameters (Kp, Ki and Kd of the controllers has been found using the Astrom-Hagglund tuning technique and the differ-integrals (λ and μ are found using the Nelder-Mead optimisation technique.

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

    Science.gov (United States)

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

    2012-09-01

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

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

    Science.gov (United States)

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

    2016-04-20

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

  19. 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.

  20. Heat Treatment of Cr- and Cr-V ledeburitic tool steels

    Directory of Open Access Journals (Sweden)

    Peter Jurči

    2014-11-01

    Full Text Available Cr- and Cr-V ledeburitic cold work tool steels belong to the most important tool materials for large series manufacturing. To enable high production stability, the tools must be heat treated before use. This overview paper brings a comprehensive study on the heat treatment of these materials, starting from the soft annealing and finishing with the tempering. Also, it describes the impact of any step of the heat treatment on the most important structural and mechanical characteristics, like the hardness, the toughness and the wear resistance. The widely used AIS D2- steel (conventionally manufactured and Vanadis 6 (PM are used as examples in most cases.

  1. Influence Of Heat Treatment On Duplex Stainless Steel To Study The Material Properties

    Directory of Open Access Journals (Sweden)

    Jithin M

    2015-02-01

    Full Text Available Abstract The various heat treatment processes are annealing normalizing hardening tempering spheroidising surface hardening flame and induction hardening nitriding cyaniding carbonitriding carburizing etc Heat treatment on duplex stainless steel is to improve ductility toughness strength hardness and to relieve internal stress developed in the material. Here basically the experiment of hardness test impact test wear test and compression is done to get idea about heat treated duplex stainless steel which has extensive uses in all industries and scientific research and development fields.

  2. 3D cleaning, a perfected technique: thermal profile assessment of heated NaOCl

    Directory of Open Access Journals (Sweden)

    Alfredo Iandolo

    2017-06-01

    Conclusions: The advantages of heated NaOCl are numerous. For example, increased antibacterial activity, higher ability to dissolve organic tissue and decrease viscosity. The current study showed that the intracanal heating technology was able to achieve better results.

  3. Effect of alkali and heat treatments for bioactivity of TiO{sub 2} nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seo young, E-mail: mast6269@nate.com [Dept. of Dental Biomaterials and Institute of Bio degradable material, Institute of Oral Bioscience and BK21 plus project, School of Dentistry, Chonbuk National University, Jeonju, 561-756 (Korea, Republic of); Kim, Yu kyoung, E-mail: yk0830@naver.com [Dept. of Dental Biomaterials and Institute of Bio degradable material, Institute of Oral Bioscience and BK21 plus project, School of Dentistry, Chonbuk National University, Jeonju, 561-756 (Korea, Republic of); Park, Il song, E-mail: ilsong@jbnu.ac.kr [Division of Advanced Materials Engineering, Research Center for Advanced Materials Development and Institute of Biodegradable Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Jin, Guang chun, E-mail: jingc88@126.com [Oral Medical College, Beihua University, Jilin City 132013 (China); Bae, Tae sung, E-mail: bts@jbnu.ac.kr [Dept. of Dental Biomaterials and Institute of Bio degradable material, Institute of Oral Bioscience and BK21 plus project, School of Dentistry, Chonbuk National University, Jeonju, 561-756 (Korea, Republic of); Lee, Min ho, E-mail: mh@jbnu.ac.kr [Dept. of Dental Biomaterials and Institute of Bio degradable material, Institute of Oral Bioscience and BK21 plus project, School of Dentistry, Chonbuk National University, Jeonju, 561-756 (Korea, Republic of)

    2014-12-01

    Highlights: • TiO{sub 2} nanotubes formed via anodization were treated by alkali and heat. • The surface roughness was increased after alkali treatment (p < 0.05). • After alkali and heat treatment, the wettability was better than before treatment. • Alkali treated TiO{sub 2} nanotubes were shown higher HAp formation in SBF. • Heat treatment affected on the attachment of cells for alkali treated nanotubes. - Abstract: In this study, for improving the bioactivity of titanium used as an implant material, alkali and heat treatments were carried out after formation of the nanotubes via anodization. Nanotubes with uniform length, diameter, and thickness were formed by anodization. The alkali and heat-treated TiO{sub 2} nanotubes were covered with the complex network structure, and the Na compound was generated on the surface of the specimens. In addition, after 5 and 10 days of immersion in the SBF, the crystallized OCP and HAp phase was significantly increased on the surface of the alkali-treated TiO{sub 2} nanotubes (PNA) and alkali and heat-treated TiO{sub 2} nanotubes (PNAH) groups. Cell proliferation was decreased due to the formation of amorphous sodium titanate (Na{sub 2}TiO{sub 3}) layer on the surface of the PNA group. However, anatase and crystalline sodium titanate were formed on the surface of the PNAH group after heat treatment at 550 °C, and cell proliferation was improved. Thus, PNA group had higher HAp forming ability in the simulated body fluid. Additional heat treatment affected on enhancement of the bioactivity and the attachment of osteoblasts for PNA group.

  4. Effect of friction stir welding and post-weld heat treatment on a nanostructured ferritic alloy

    Science.gov (United States)

    Mazumder, B.; Yu, X.; Edmondson, P. D.; Parish, C. M.; Miller, M. K.; Meyer, H. M.; Feng, Z.

    2016-02-01

    Nanostructured ferritic alloys (NFAs) are new generation materials for use in high temperature energy systems, such as nuclear fission or fusion reactors. However, joining these materials is a concern, as their unique microstructure is destroyed by traditional liquid-state welding methods. The microstructural evolution of a friction stir welded 14YWT NFA was investigated by atom probe tomography, before and after a post-weld heat treatment (PWHT) at 1123K. The particle size, number density, elemental composition, and morphology of the titanium-yttrium-oxygen-enriched nanoclusters (NCs) in the stir and thermally-affected zones were studied and compared with the base metal. No statistical difference in the size of the NCs was observed in any of these conditions. After the PWHT, increases in the number density and the oxygen enrichment in the NCs were observed. Therefore, these new results provide additional supporting evidence that friction stir welding appears to be a viable joining technique for NFAs, as the microstructural parameters of the NCs are not strongly affected, in contrast to traditional welding techniques.

  5. Heat Transfer Analysis of Flat Plate Subjected to Multi-Jet Air Impingement using Principal Component Analysis and Computational Technique

    Directory of Open Access Journals (Sweden)

    Palaniappan Chandramohan

    2017-01-01

    Full Text Available The aim of this work is to investigate experimentally the variation in temperature, heat transfer coefficient and Nusselt number of a hot plate subjected to multi-jet air impingement cooling to use the multi-objective optimization technique to arrive at optimum conditions. A flat plate of 15 cm x 10 cm is heated through a heating foil with a constant heat flux of 7667 W/m2. Air jets with and without swirling action are considered, fixing the distance of target surface from nozzle exit at 2D, 4D and 6D. Reynolds numbers 18000, 20000and 22000 and pipe diameters 8mm, 10mm and 12 mm have been considered for investigation. Experiments are designed and analyzed using Taguchi’s technique, coupled with principal component analysis for multi-variate optimization by calculating multi-response performance index (MRPI. Based on the observations made, it is concluded that lower H/D ratio and higher Reynolds number result in higher heat transfer coefficient, in accordance with the first principles. Heat transfer coefficient obtained for jets with swirl is compared with that of jet without swirling for the same Reynolds number and H/D ratio. Furthermore, it is concluded that introducing swirl results in increase of heat transfer coefficients for all the test conditions for 10mm and 12mm diameter jets. However for 8mm jet, introduction of swirl reduced the heat transfer rate for all the test conditions. From Analysis of Variance (ANOVA, it is found that significant contributions on outputs are due to the effect of H/D ratio and Reynolds number. Confirmation experiments with optimum condition result in improved heat transfer coefficient and Nusselt number. Numerical simulation has also been performed with the optimum condition. It is observed that the simulation results are in consistence with the experimental results.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    -treated flies. Several hsp70 probe sets were up-regulated 1.7–2-fold in the mildly stressed flies weeks after the last heat treatment (P heat shock protein, Hsp70, is reported to return to normal levels of expression shortly after heat stress. We......Heat-induced hormesis, i.e. the beneficial effect of mild heat-induced stress, increases the average lifespan of many organisms. This effect, which depends on the heat shock factor, decreases the log mortality rate weeks after the stress has ceased. To identify candidate genes that mediate...... conclude that the heat shock response, and Hsp70 in particular, may be central to the heat-induced increase in the average lifespan in flies that are exposed to mild heat stress early in life....

  7. Dynamic measurements of thermophysical properties of metals and alloys at high temperatures by subsecond pulse heating techniques

    Science.gov (United States)

    Cezairliyan, Ared

    1993-01-01

    Rapid (subsecond) heating techniques developed at the National Institute of Standards and Technology for the measurements of selected thermophysical and related properties of metals and alloys at high temperatures (above 1000 C) are described. The techniques are based on rapid resistive self-heating of the specimen from room temperature to the desired high temperature in short times and measuring the relevant experimental quantities, such as electrical current through the specimen, voltage across the specimen, specimen temperature, length, etc., with appropriate time resolution. The first technique, referred to as the millisecond-resolution technique, is for measurements on solid metals and alloys in the temperature range 1000 C to the melting temperature of the specimen. It utilizes a heavy battery bank for the energy source, and the total heating time of the specimen is typically in the range of 100-1000 ms. Data are recorded digitally every 0.5 ms with a full-scale resolution of about one part in 8000. The properties that can be measured with this system are as follows: specific heat, enthalpy, thermal expansion, electrical resistivity, normal spectral emissivity, hemispherical total emissivity, temperature and energy of solid-solid phase transformations, and melting temperature (solidus). The second technique, referred to as the microsecond-resolution technique, is for measurements on liquid metals and alloys in the temperature range 1200 to 6000 C. It utilizes a capacitor bank for the energy source, and the total heating time of the specimen is typically in the range 50-500 micro-s. Data are recorded digitally every 0.5 micro-s with a full-scale resolution of about one part in 4000. The properties that can be measured with this system are: melting temperature (solidus and liquidus), heat of fusion, specific heat, enthalpy, and electrical resistivity. The third technique is for measurements of the surface tension of liquid metals and alloys at their melting

  8. Effects of solution heat treatment on corrosion resistance of 5083F Al alloy

    Institute of Scientific and Technical Information of China (English)

    Seong-Jong KIM; Seok-Ki JANG

    2009-01-01

    Aluminum alloys are used as substitutes for fiber reinforced polymer(FRP) in ships and boats. However, ships constructed with 5000-series Al alloy suffer a little corrosion in the marine environment, when they run in high speed, and high flow rate, etc. Therefore, solution heat treatment was carried out to prevent corrosion. The optimal heat treatment involved heating specimens for 120 min at 420 ℃ and then cooling them in water. In addition, the optimal ageing condition involved ageing specimens for 240 min at 180 ℃. The slow strain rate test(SSRT) in a seawater revealed that heat treatment under optimal conditions produced improved elongation, time-to-fracture and amount of dimples compared with the as-received specimen.

  9. Optimizing the heat treatment of Ni-based superalloy turbine discs

    Science.gov (United States)

    Furrer, D. U.; Shankar, R.; White, C.

    2003-03-01

    The heat-treatment processes for nickel-based superalloys continue to change due to the development of new alloys, new requirements, and subsequent new manufacturing facilities. Nickel-based superalloys are continuing to evolve to meet emerging applications, while new alloys are also being introduced for advanced applications. These new materials are also being optimized for numerous mechanical and physical properties, making the selection of heat-treatment parameters increasingly challenging. New processing facilities and methods are also being implemented to allow tailoring of heat-treating parameters to meet these new challenges. For example, the Ladish SuperCooler technology allows engineering and control of all aspects of the heat-treatment process for nickel-based components, resulting in never-before possible disc properties.

  10. Nondestructive evaluation techniques for silicon carbide heat-exchanger tubes. Second annual report, October 1978-September 1979

    Energy Technology Data Exchange (ETDEWEB)

    Kupperman, D.S.; Yuhas, D.; Deininger, W.; Sciammarella, C.

    1979-11-01

    This report discusses the development of ultrasonic testing, acoustic microscopy, dye-enhanced radiography, holographic interferometry, and infrared scanning techniques for flaw detection in silicon carbide (SiC) heat-exchanger tubing. Both preservice and in-service testing requirements are discussed. An ultrasonic boreside probe and an acoustic microscope stage have been designed for continuous monitoring of SiC tubing. Preliminary results with these acoustic systems are presented. In addition, a novel technique for detecting small surface flaws using holographic interferometry is discussed. Fracture mechanics analysis suggests that detection of flaws on the order of 100 ..mu..m is necessary to assure good reliability of ceramic heat exchangers. The acoustic and holographic techniques have been shown to be capable of detecting flaws of this size. However, the sensitivity of ultrasonic flaw detection in SiC is affected by the microstructure of the component. The practical considerations involved in the use of these techniques are discussed.

  11. Effect of heat treatment operations on the Rm tensile strength of silumins

    Directory of Open Access Journals (Sweden)

    J. Pezda

    2010-10-01

    Full Text Available Owing to good technological properties, low weight and good corrosion resistance, aluminum-silicon alloys are widely used as a material for cast machinery components. State of macro- and microstructure of a castings manufactured from Al-Si alloys, which is determined by a shape and distribution of hardening phases, segregation of alloying constituents and impurities, as well as distribution of porosity, create conditions to obtainment of proper mechanical properties. These properties can be improved through modification of the alloy and performed heat treatment operations. The paper presents effect of modification and heat treatment process on the Rm tensile strength of a selected silumins (EN AB-AlSi9Cu3(Fe, EN AB-AlSi12CuNiMg, EN AB-AlSi17Cu1Ni1Mg. Investigated alloys were put to treatments of refining and modification, and next to heat treatment. Temperature range of the heat treatment operations was determined on base of curves from the ATD method. Obtained results illustrate registered curves of melting and solidification from the ATD method and strength tests. On base of performed initial tests one determined parameters of the heat treatment process (temperature and duration of solutionig and ageing treatments enabling obtainment of improved Rm tensile strength of the investigated alloys.

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

    Directory of Open Access Journals (Sweden)

    M. Gouma

    2015-01-01

    Full Text Available This investigation established the process criteria for using UV-C light and mild heat (UV-H treatment to inactivate 5-Log10 cycles (performance criterion of common foodborne pathogen populations, Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus, when inoculated in chicken broth. To define the target microorganism and the proper UV-H treatment conditions (including UV dose, treatment time, and temperature that would achieve the stated performance criterion, mathematical equations based on Geeraerd’s model were developed for each microorganism. For the sake of comparison, inactivation equations for heat treatments were also performed on the same chicken broth and for the same microorganisms. L. monocytogenes was the most UV-H resistant microorganism at all temperatures, requiring a UV dose between 6.10 J/mL (5.6 min and 2.26 J/mL (2.09 min to achieve 5-Log10 reductions. In comparison with UV treatments at room temperatures, the combination of UV and mild heat allowed both the UV dose and treatment time to be reduced by 30% and 63% at 55°C and 60°C, respectively. Compared to heat treatments, the UV-H process reduced the heating time for 5-Log10 reductions of all the investigated microorganisms in chicken broth from 20-fold to 2-fold when the operating temperature varied from 53 to 60°C.

  13. First order reversal curve analysis on NdFeB nanocomposite ribbons subjected to Joule heating treatments

    Energy Technology Data Exchange (ETDEWEB)

    Pampillo, L.G. [INTECIN-Instituto de Tecnologias y ciencias de la Ingenieria ' Hilario Fernandez Long' (UBA-CONICET), Facultad de Ingenieria, Paseo Colon 850 (C1063ACV), C. A. B. A. (Argentina); Saccone, F.D., E-mail: fsaccone@fi.uba.ar [INTECIN-Instituto de Tecnologias y ciencias de la Ingenieria ' Hilario Fernandez Long' (UBA-CONICET), Facultad de Ingenieria, Paseo Colon 850 (C1063ACV), C. A. B. A. (Argentina); Knobel, M. [Instituto de Fisica Gleb Wataghin-Departamento de Fisica de Materia Condensada-Universidade Estadual de Campinas, Cidade Universitaria Zeferino Vaz, Barao Geraldo 13083-970, Campinas, Sao Paulo (Brazil); Sirkin, H.R.M. [INTECIN-Instituto de Tecnologias y ciencias de la Ingenieria ' Hilario Fernandez Long' (UBA-CONICET), Facultad de Ingenieria, Paseo Colon 850 (C1063ACV), C. A. B. A. (Argentina)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer Nd-lean amorphous precursors subjected to Joule heating. Black-Right-Pointing-Pointer Exchange-spring magnets. Black-Right-Pointing-Pointer FORC diagrams of irreversible switching fields. Black-Right-Pointing-Pointer This last techniques helped us to verify the optimized treatments conditions. - Abstract: Amorphous precursors with composition Nd{sub 4.5}Fe{sub 72-x}Co{sub 3+x}Cr{sub 2}Al{sub 1}B{sub 17.5} (x = 0, 2, 7, 12) were thermally treated by the Joule heating technique with a linearly varying electrical current. The crystallization kinetics was followed by monitoring the resistance of the ribbons during the heating up to the final applied current. Crystallized nanostructured phases coexist with an amorphous matrix, as it was observed by means of Moessbauer Spectroscopy and X-ray diffraction. The irreversible magnetic response of the Joule heated ribbons was analyzed by the First Order Reversal Curves (FORC) diagram technique. For the optimal treatments, associated with the higher maximum energy products for each sample composition, it was found that the main interaction is of a strongly dipolar characteristic. Over annealed samples show a FORC diagram that gives into account of softening, due to grain growth, for those phases precipitated at the first crystallization stage. When it is measured at 20 K, the hardest magnetic sample (Fe = 72 at.%, Co = 3 at.%, I{sub final} = 0.5 A), exhibits a diagram with characteristics corresponding to dipolar interactions of soft phases. This fact is consistent with an enhancement of the exchange length due to the increase in the soft phase stiffness as it is expected at low temperatures.

  14. Impact of Heat-Shock Treatment on Yellowing of Pak Choy Leaves

    Institute of Scientific and Technical Information of China (English)

    WANG Xiang-yang; SHEN Lian-qing; YUAN Hai-na

    2004-01-01

    The physiological mechanism of maintaining the green colour of pak choy leaves (Brassica rapa var chinensis) with heat-shock treatment was studied. Chlorophyll in the outer leaves of pak choy degraded rapidly during storage at ambient temperature (20 ± 2℃), a slight yellow appeared. Heat-shock treatment (46- 50℃) had a mild effect on maintaining the green colour of outer leaves. Normal chlorophyll degradation was associated with a binding of chlorophyll with chlorophyll-binding-protein preceding chlorophyll breakdown.Heat-shock treatment was found to reduce the binding-capacity between chlorophyllbinding-protein and chlorophyll. In the chlorophyll degradation pathway, pheide dioxygenase was synthesized during leaf senescence which was considered to be a key enzyme in chlorophyll degradation. Activity of this enzyme was reduced following heat-shock treatment, which might explain the observed reduction in chlorophyll breakdown. Two groups of heat-shock proteins were detected in treated leaves, the first group containing proteins from 54KDa to 74 Kda, and the second group contained proteins from 15 KDa to 29KDa. Heat-shock treatment was also found to retard the decline of glucose and fructose (the main energy substrates) of outer leaves.

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

    Science.gov (United States)

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

    2015-08-01

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

  16. Effect of heat treatment on wettability and MOE of pine and spruce wood

    Directory of Open Access Journals (Sweden)

    Povilas Navickas

    2015-09-01

    Full Text Available This research was performed in order to determine how the heating process affects the wettability and mechanical properties of spruce (Picea abies and pine (Pinus silvestris wood. Studies were carried out using wood heated in laboratory. The measurements of specimens were 315x20x20mm. Specimens were divided into the following four groups: specimens of one group were not exposed to heating, whereas specimens of three other groups were subjected to heating at the temperature of 190○C for 1 to 3 hours respectively, in the air under atmospheric pressure. Both heated and unheated specimens were moistened and dried in a climatic chamber. Before and after treatment the mechanical properties of specimens were assessed using the original method of transverse vibrations and contact angle measurements were carried out using the water drop method. The results showed a significant increase in wood hydrophobicity after treatment. Spruce contact angle after treatment increased from 1.3 to 1.45, pine from 1.4 to 2 times. MOE of pine wood decreased, while MOE of spruce slighty increased after heat treatment. Wood equilibrium moisture content after treatment is redused and it is known, that the drier the wood  - the better its mechanical properties. This factor may have the biggest influence to such result.DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7304

  17. Surgical treatment of iliotibial band friction syndrome with the mesh technique.

    Science.gov (United States)

    Sangkaew, Chanchit

    2007-05-01

    Iliotibial band friction syndrome is an overuse injury caused by repetitive friction of the iliotibial band across the lateral femoral epicondyle. It has been reported to afflict long-distance runners, cyclists and military personnel. Initial treatments include rest, anti-inflammatory medication, modalities (ice or heat), stretching, physical therapy, and possibly a corticosteroid injection. If the conservative treatment is unsuccessful, surgery has been advocated. This report describes a new surgical technique to release the pressure on the lateral femoral epicondyle in a patient who failed the nonoperative efforts. The surgery was performed with the knee held in 30 degrees of flexion and consisted of multiple 2 mm long incisions across the fiber of the iliotibial band covering the lateral femoral epicondyle. There were six incisions, each of which was 4 mm apart. The incisions were spontaneously enlarged and changed to several punctured wounds (mesh appearance) by the tension of iliotibial band, resulted in relaxing the tight iliotibial band over the lateral femoral epicondyle. At the final follow-up 2 years after surgery the patient was pain free and could resume his previous occupational activities. The surgical result of the present technique is encouraging.

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

    Science.gov (United States)

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

    2015-03-01

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

  19. Progress of heat-hazard treatment in deep mines

    Institute of Scientific and Technical Information of China (English)

    Yang Xiaojie; Han Qiaoyun; Pang Jiewen; Shi Xiaowei; Hou Dinggui; Liu Chao

    2011-01-01

    Based on the urgency of thermal hazard control in deep coal mines, we studied the status of deep thermal damage and cooling technology both at home and abroad, summarized the causes of deep thermal hazard, analysed and compared the control technologies for deep thermal hazards. The results show that the causes of deep thermal damage can be attributed to three aspects, i.e., climate, geological and mining factors, of which the geological factors are deemed the major reasons for thermal hazards. As well, we compared a number of cooling technologies of domestic and overseas provenance, such as central air conditioning cooling technology, ice cooling technology and water cooling technology, with one other cooling technology, i.e., the HEMS cooling technology, which has a large and important effect with its unique "pure air" cooling technology, realizes the utilizing of heat resources from underground to the ground. This technology makes use of heat obtained underground; thus the technology can promote low-carbon environmental economic development in coal mines, in order to achieve lowcarbon coal production in China.

  20. The effects of heat treatment on physical and technological properties and surface roughness of Camiyani Black Pine (Pinus nigra Arn. subsp. pallasiana var. pallasiana) wood.

    Science.gov (United States)

    Gündüz, Gökhan; Korkut, Süleyman; Korkut, Derya Sevim

    2008-05-01

    Heat treatment is often used to improve the dimensional stability of wood. In this study, the effects of heat treatment on physical properties and surface roughness of Camiyani Black Pine (Pinus nigra Arn. subsp. pallasiana var. pallasiana) wood were examined. Samples obtained from Yenice-Zonguldak Forest Enterprises, Turkey, were subjected to heat treatment at varying temperatures and for varying durations. The physical properties of heat-treated and control samples were tested, and oven-dry density, air-dry density, and swelling properties were determined. The mechanical properties of heat-treated and control samples were tested, and compression strength, and Janka-hardness were determined. A stylus method was employed to evaluate the surface characteristics of the samples. Roughness measurements by the stylus method were made in the direction perpendicular to the fiber. Four main roughness parameters, mean arithmetic deviation of profile (Ra), mean peak-to-valley height (Rz), root mean square roughness (Rq), and maximum roughness (Ry) obtained from the surface of wood were used to evaluate the effect of heat treatment on the surface characteristics of the specimens. Significant difference was determined (p=0.05) between physical and technological properties, and surface roughness parameters (Ra, Rz, Ry, Rq) for three temperatures and three durations of heat treatment. Based on the findings in this study, the results showed that density, swelling, compression strength, Janka-hardness and surface roughness values decreased with increasing treatment temperature and treatment times. Increase in temperature and duration further diminished technological strength values of the wood specimens. Camiyani Black Pine wood could be utilized by using proper heat treatment techniques without any losses in strength values in areas where working, stability, and surface smoothness, such as in window frames, are important factors.

  1. Development of a technique for environmental treatment by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myun Joo; Jin, J. H.; Jung, Y. D. and others

    2000-04-01

    This study was carried out for the development of pilot plant which can produce industrial water from effluent of sewage treatment plant by irradiation. As a basic study, the characteristics on decomposition of organic compounds, decoloration and sterilization of bacteria were evaluated. An additive mainly composed by sponge type of TiO{sub 2} was developed for reduction of irradiation dose and enhancement of removal efficiency of organic compounds. The optimum pilot plant was composed of sysem with gamma irradiation/ozone/additive/ion exchange. The effluent with BOD 20 ppm, COD 25 ppm and color 25 ADMI could be treated to less than 5 ppm and 5 ADMI under the irradiation of 5 kGy. The disinfection of microorganism also could be done perfectively under the same irradiation. A small amount of heavy metal ions and inorganic ions, nitrogen, contained in effluent were removed by ion exchanger. From the operation of pilot plant it could be concluded that irradiation technique can be a good method for the produce of industrial water from effluent.

  2. New surface treatment techniques against ice formation and growth

    Energy Technology Data Exchange (ETDEWEB)

    Megateli, R. [TechnoCentre eolien Gaspesie-les Iles, Murdochville, PQ (Canada). Centre CORUS

    2007-07-01

    The average wind speed in Murdochville, Quebec is 9 m/s, making it one of Canada's richest wind resource regions. As such, it is the site of a natural laboratory for the CORUS Center to study the North American climate and wind energy extraction. This presentation outlined research initiatives at CORUS, with particular reference to innovative treatments against ice accretion on wind turbine blades. Ice changes the aerodynamic profile of turbine blades, overloads the structure, increases vibrations and causes component wear. This results in loss of energy production, frequent failures, reduced service life and increased operating and maintenance costs. CORUS has been working on reducing ice accretion on blade surfaces without affecting the manufacturing process using ion implantation and UV rays irradiation. The ions used in the process are hydrogen, fluorine and argon. The technique modifies the surface chemical properties at the nano-scale depth level. This presentation provided details of the ion implantation procedure and the UV rays exposure procedure. An evaluation of wetting and water contact angles on blade samples was provided. Preliminary results showed that the high hysteresis of the non-treated samples had favourable conditions to ice adhesion. Argon implantation reduced the water contact angles and particularly hysteresis. Hydrogen implantation slightly increased the water contact angles and reduced the hysteresis. The process was beneficial in terms of service life. UV irradiation increased the hysteresis. figs.

  3. Influence of pH and heat treatment on β-lactolobulin-oleic acid complex

    Directory of Open Access Journals (Sweden)

    Ana-Maria SIMION (CIUCIU

    2015-12-01

    Full Text Available One of the major concerns of food technologists is to produce healthier products with specific functionalities. The potential use of β-lactoglobulin as a supplement for new functional products is encouraging due to its nutritional and functional characteristics. The aim of this work was to obtain β-lactoglobulin-oleic acid complexes at different pH values (5.0, 6.0, and 7.0 and to test their stability at different temperatures (25-85°C such as to allow identifying their potential use in a variety of food products. The complexes were characterized through different fluorescence spectroscopy based techniques: phase diagram, intrinsic and extrinsic fluorescence, along with fluorescence quenching experiments. Results showed the presence of more than two structurally distinct species with intermediates as induced by thermal treatment. The heat treatment at temperatures higher than 70°C caused an increase in both intrinsic and ANS fluorescence intensity. Acrylamide quenching showed no significant differences between the values of Stern-Volmer constants as function of temperature for pH 5.0, suggesting that no significant changes occurred in the Trp microenvironments. Quenching experiments with KI lead to decreases in Stern-Volmer constants in the temperature range 25-70°C, suggesting protein folding, whereas at higher temperatures a small increase was observed suggesting unfolding and an increased accessibility of the fluorophore to the quencher for all pH values.

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

    Science.gov (United States)

    Kondjoyan, Alain; Oillic, Samuel; Portanguen, Stéphane; Gros, Jean-Bernard

    2013-10-01

    A heat transfer model was used to simulate the temperature in 3 dimensions inside the meat. This model was combined with a first-order kinetic models to predict cooking losses. Identification of the parameters of the kinetic models and first validations were performed in a water bath. Afterwards, the performance of the combined model was determined in a fan-assisted oven under different air/steam conditions. Accurate knowledge of the heat transfer coefficient values and consideration of the retraction of the meat pieces are needed for the prediction of meat temperature. This is important since the temperature at the center of the product is often used to determine the cooking time. The combined model was also able to predict cooking losses from meat pieces of different sizes and subjected to different air/steam conditions. It was found that under the studied conditions, most of the water loss comes from the juice expelled by protein denaturation and contraction and not from evaporation.

  5. Comparing ambient, air-convection, and fluid-convection heating techniques in treating hypothermic burn patients, a clinical RCT

    Directory of Open Access Journals (Sweden)

    Sjöberg Folke

    2011-07-01

    Full Text Available Abstract Background Hypothermia in burns is common and increases morbidity and mortality. Several methods are available to reach and maintain normal core body temperature, but have not yet been evaluated in critical care for burned patients. Our unit's ordinary technique for controlling body temperature (Bair Hugger®+ radiator ceiling + bed warmer + Hotline® has many drawbacks e.g.; slow and the working environment is hampered. The aim of this study was to compare our ordinary heating technique with newly-developed methods: the Allon™2001 Thermowrap (a temperature regulating water-mattress, and Warmcloud (a temperature regulating air-mattress. Methods Ten consecutive burned patients (> 20% total burned surface area and a core temperature t-tests were used to assess the significance of differences between the treatments within the patients. ANOVA was used to assess the differences in temperature from the first to the last measurement among all treatments. Three-way ANOVA with the Tukey HSD post hoc test and a repeated measures ANOVA was used in the same manner, but included information about patients and treatment/measuring-cycles to control for potential confounding. Data are presented as mean (SD and (range. Probabilities of less than 0.05 were accepted as significant. Results The mean increase, 1.4 (SD 0.6°C; range 0.6-2.6°C in core temperature/treatment/measuring-cycle highly significantly favoured the Allon™2001 Thermowrap in contrast to the conventional method 0.2 (0.6°C (range -1.2 to 1.5°C and the Warmcloud 0.3 (0.4°C (range -0.4 to 0.9°C. The procedures for using the Allon™2001 Thermowrap were experienced to be more comfortable and straightforward than the conventional method or the Warmcloud. Conclusions The Allon™2001 Thermowrap was more effective than the Warmcloud or the conventional method in controlling patients' temperatures.

  6. Heat and mass transfer in combustion - Fundamental concepts and analytical techniques

    Science.gov (United States)

    Law, C. K.

    1984-01-01

    Fundamental combustion phenomena and the associated flame structures in laminar gaseous flows are discussed on physical bases within the framework of the three nondimensional parameters of interest to heat and mass transfer in chemically-reacting flows, namely the Damkoehler number, the Lewis number, and the Arrhenius number which is the ratio of the reaction activation energy to the characteristic thermal energy. The model problems selected for illustration are droplet combustion, boundary layer combustion, and the propagation, flammability, and stability of premixed flames. Fundamental concepts discussed include the flame structures for large activation energy reactions, S-curve interpretation of the ignition and extinctin states, reaction-induced local-similarity and non-similarity in boundary layer flows, the origin and removal of the cold boundary difficulty in modeling flame propagation, and effects of flame stretch and preferential diffusion on flame extinction and stability. Analytical techniques introduced include the Shvab-Zeldovich formulation, the local Shvab-Zeldovich formulation, flame-sheet approximation and the associated jump formulation, and large activation energy matched asymptotic analysis. Potentially promising research areas are suggested.

  7. Enhancement of downward-facing saturated boiling heat transfer by the cold spray technique

    Energy Technology Data Exchange (ETDEWEB)

    Sohag, Frauk A.; Beck, Faith R.; Mohanta, Lokanath; Cheung, Fan Bill; Segall, Albert E.; Eden, Timothy J.; Potter, John K. [Pennsylvania State University, University Park (United States)

    2017-02-15

    In-vessel retention by passive external reactor vessel cooling under severe accident conditions is a viable approach for retention of radioactive core melt within the reactor vessel. In this study, a new and versatile coating technique known as 'cold spray' that can readily be applied to operating and advanced reactors was developed to form a microporous coating on the outer surface of a simulated reactor lower head. Quenching experiments were performed under simulated in-vessel retention by passive external reactor vessel cooling conditions using test vessels with and without cold spray coatings. Quantitative measurements show that for all angular locations on the vessel outer surface, the local critical heat flux (CHF) values for the coated vessel were consistently higher than the corresponding CHF values for the bare vessel. However, it was also observed for both coated and uncoated surfaces that the local rate of boiling and local CHF limit vary appreciably along the outer surface of the test vessel. Nonetheless, results of this intriguing study clearly show that the use of cold spray coatings could enhance the local CHF limit for downward-facing boiling by > 88%.

  8. Analysis of Heat Environment Indexes Using Integrated Remote Sensing and Site Measurement Techniques in a Community

    Institute of Scientific and Technical Information of China (English)

    Kun Li; Jian Kang; YeHao Song; Dong Jiang

    2014-01-01

    Remote sensing and on⁃site measurement are used to determine the heat environment within a community, and are compared the differences for heat analysis. The two methods perform differently for various underlying surfaces. The individual methods can detect different aspects of the heat environment, which used in combination are useful for heat island research. The differences in estimated air and surface temperatures are smaller in open space and more obvious for vegetated surfaces. Ventilation does not affect the difference between air and surface temperature in open areas, and the vegetation surface and shading moderates surface temperature more effectively than the water surface; The forest is a type of underlying surface with heat comfortable, in which the feeling of air temperature is much difference to the structure of heat environment that should be survey and detected separately. The two methods can be used to study different aspects of the heat environment, thus forming a comprehensive approach for planners in urban and rural spaces.

  9. Application of active powders at fluidised bed heat treatment technologies

    OpenAIRE

    Babul, T.; Kucharieva, N.

    2014-01-01

    The paper describes the principles and conditions of carrying out of a new type of fluidised bed thermochemical treatment in chemically active powders with different ways of fluidisation. These new fluidised bed thermochemical treatments in chemically active powders are primarily for the formation of surface diffusion layers on parts made of constructional and tool steel. This method can be used for sherardising, alitising, carbonitriding, nitrocarburising, carburising or boronising. Chara...

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

    Science.gov (United States)

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

    1997-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-06-01

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

  12. Microstructure and room temperature mechanical properties of mullite fibers after heat-treatment at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yi; Cheng, Haifeng, E-mail: chfcfc@163.com; Liu, Haitao; Wang, Jun

    2013-08-20

    The composition and microstructure of Nitivy ALF 2880D fibers after heat-treatment at elevated temperatures are investigated by XRD, FT-IR, SEM and TEM analyses. Tensile properties of as-received and heat-treated fiber bundles have been studied. The results show that as-received fibers consist of γ-Al{sub 2}O{sub 3}, amorphous silica, and a little boron oxide. During heat-treatment process, boron oxide firstly melts and flows, resulting in large amount of liquid ravines, and then volatilizes, leaving several holes on fiber surface. Reaction between γ-Al{sub 2}O{sub 3} and amorphous silica begins when heat-treated temperature is above 1100 °C, and completes at 1300 °C. As heat-treated temperature increases from 1100 °C to 1400 °C, grain growth of mullite starts and leads to the reduction of room temperature tensile strength of fibers. Tensile strength of fibers stays stable when heat-treated temperature is below 1200 °C, while the strength retention of fibers sharply decreased to 50% after heat-treatment at 1300 °C.

  13. Synthesis of CaTiO3 from calcium titanyl oxalate hexahydrate (CTO) as precursor employing microwave heating technique

    Indian Academy of Sciences (India)

    B M Patil; R S Srinivasa; S R Dharwadkar

    2007-06-01

    Calcium titanate, CaTiO3, an important microwave dielectric material and one of major phases in synroc (synthetic rock), a titanate ceramic with potential application for fixation of high level nuclear waste was synthesized from calcium titanyl oxalate [CaTiO (C2O4)2.6H2O] (CTO) by employing microwave heating technique. CTO heated in microwave heating system in air at 500°C for 1 h gave a perovskite, CaTiO3. The product obtained by heating of CTO in the same system at 700°C for the same duration was however, much more crystalline. CaTiO3 obtained by the present method was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and BET surface area measurement.

  14. Effect of intake on fasting heat production, respiratory quotient and plasma metabolites measured using the washed rumen technique

    Science.gov (United States)

    The objective was to investigate the effect of intake prior to fasting on concentrations of metabolites and hormones, respiratory quotient (RQ) and fasting heat production (HP) using the washed rumen technique and to compare these values with those from the fed state. Six Holstein steers (360 ± 22 k...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-03-01

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

  16. The influence of heating rate on superconducting characteristics of MgB{sub 2} obtained by spark plasma sintering technique

    Energy Technology Data Exchange (ETDEWEB)

    Aldica, G. [National Institute of Materials Physics, Atomistilor 105bis, 077125 Magurele (Romania); Burdusel, M. [National Institute of Materials Physics, Atomistilor 105bis, 077125 Magurele (Romania); Faculty of Materials Science and Engineering, University ’Politehnica’ of Bucharest, Splaiul Independentei 313, 060042 Bucharest (Romania); Popa, S.; Enculescu, M.; Pasuk, I. [National Institute of Materials Physics, Atomistilor 105bis, 077125 Magurele (Romania); Badica, P., E-mail: badica2003@yahoo.com [National Institute of Materials Physics, Atomistilor 105bis, 077125 Magurele (Romania)

    2015-12-15

    Highlights: • MgB{sub 2} was obtained by ex-situ spark plasma sintering for different heating rates. • Heating rates were 20–475 °C/min: the optimum heating rate is ∼100 °C/min. • For 100 °C/min, J{sub c0}, H{sub irr} and (J{sub c0} x μ{sub 0}H{sub irr}) have maximum values. • For 100 °C/min, macro flux jumps are partially suppressed at 5 K. • Grain boundaries are modified depending on the heating rate. - Abstract: Superconducting bulks of MgB{sub 2} were obtained by the Spark Plasma Sintering (SPS) technique. Different heating rates of 20, 100, 235, 355, and 475 °C/min were used. Samples have high density, above 95%. The onset critical temperature T{sub c}, is about 38.8 K. There is an optimum heating rate of ∼100 °C/min to maximize the critical current density J{sub c0}, the irreversibility field H{sub irr}, the product (J{sub c0} x μ{sub 0}H{sub irr}), and to partially avoid formation of undesirable flux jumps at low temperatures. Significant microstructure differences were revealed for samples processed with low and high heating rates in respect to grain boundaries.

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

    Science.gov (United States)

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

    2012-01-01

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

  18. CONTEMPORARY PRINCIPLES FOR CHOLECYSTITIS TREATMENT WITH LAPAROSCOPIC TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Slobodan Aranđelović

    2016-03-01

    Full Text Available The first laparoscopic cholecystectomy (LC was performed in France in 1987 by a French surgeon (P. Mouret, and it rapidly became accepted until the end of the nineties in Europe and America as a "gold standard" in the treatment of the gallbladder. "There are just a few examples in the history of surgery, where the advantage of some surgical techniques is so quickly imposed, as it is in the case of laparoscopic cholecystectomy" (Cusshieri. Assuming the present of a surgical skill and experience, welltrained team and the specific technical equipment, the main advantages of this surgical method are less operative trauma and postoperative pain, faster recovery and a shorter hospital stay. The percentage of conversion to open cholecystectomy is 2%-20% and it is caused by certain conditions, such as older age, morbid obesity, and expressed inflammation of gallbladder and biliary anatomical anomalies. Male gender, anatomical variations, previous abdominal operations and technical problems, were rarer causes of conversion. Non-compliance and non-recognition of these risk factors can lead to complications, most notably the common bile duct injuries. At the Surgical Clinic in Nis, in the period of 3 years (January 2010 to November 2013 1.389 patients with symptomatic cholelithiasis underwent surgery, 626 (45,1% using standard techniques of laparoscopic method. Most patients, 60,10%, were female and 39,90% were male. Chronic calculous cholecystitis was an indication of the 86,20%, 8,50% in the acute, gallbladder polyp 5,30%. Conversion was forced out in 28 patients (4.47%. There have been no lethal operative outcomes in observed period, intraoperative lesions of vascular structures were not notified, total specific morbidity was about 2,07%. The technical aspect is still dominant at laparoscopic cholecystectomy (LC. Outstanding results at our clinic and in the world, impose the need for further development of this method, education of surgeons and staff

  19. 76 FR 3077 - Notice of Decision To Revise a Heat Treatment Schedule for Emerald Ash Borer

    Science.gov (United States)

    2011-01-19

    ... Emerald Ash Borer AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION: Notice. SUMMARY: We are advising the public of our decision to revise a heat treatment schedule for the emerald ash borer... revised treatment schedule will be sufficient to treat emerald ash borer. DATES: Effective Date:...

  20. Effects of local heat and cold treatment on surface and articular temperature of arthritic knees

    NARCIS (Netherlands)

    Oosterveld, Frederikus G.J.; Rasker, Johannes J.

    1994-01-01

    Objective: To evaluate and compare the effects of locally applied heat and cold treatments on skin and intraarticular temperature in patients with arthritis. Methods. Thirty-nine patients with arthritis of the knee were divided at random into 4 treatment groups (ice chips, nitrogen cold air, ligno-

  1. EFFECT OF CRYOGENIC AND HEATING TREATMENT ON THE SOLUTION PROPERTIES OF NITROCELLULOSE

    Institute of Scientific and Technical Information of China (English)

    Li Li; Hu Yang; Rong-shi Cheng; Zhi-liu Wang

    2005-01-01

    The effect of cryogenic and heating treatment on the solution properties of rigid polymer nitrocellulose (NC) in dilute tetrahydrofuran solution were studied with a sealed viscometer and a size exclusion chromatograph (SEC),respectively. The experimental results show that the relative viscosity of NC solution decreases after repeated freezingthawing treatment. The decreased viscosity value of NC could not be restored but decreased further after the solution being re-heated. The experimental results of SEC are fully consistent with that of viscosity measurements. It is believed that the effect of two treatments on NC solution both causes the apparent hydrodynamic volume to decrease. But they are assumed to be ascribed to different mechanisms.

  2. Effect of heat treatment on microstructural and optical properties of CBD grown Al-doped ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chandramohan, R., E-mail: rathinam.chandramohan@gmail.com [Department of Physics, Sree Sevugan Annamalai College, College Road, Devakottai 630303 (India); Vijayan, T.A. [Department of Physics, Sree Sevugan Annamalai College, College Road, Devakottai 630303 (India); Arumugam, S.; Ramalingam, H.B. [Department of Physics, Government Arts College, Udumalpet 642126 (India); Dhanasekaran, V.; Sundaram, K.; Mahalingam, T. [Department of Physics, Alagappa University, Karaikudi 630003 (India)

    2011-02-15

    Research highlights: > Effect of annealing temperature on Al-doped ZnO thin films. > Microstructural properties of Al-doped ZnO thin films. > Optical constants are found to increase with increase of heat treatment. - Abstract: Investigations on the effect of annealing temperature on the structural, optical properties and morphology of Al-doped ZnO thin films deposited on glass substrate by chemical bath deposition have been carried out. X-ray diffraction studies revealed that deposited films are in polycrystalline nature with hexagonal structure along the (0 0 2) crystallographic plane. Microstructural properties of films such as crystallite size, texture coefficient, stacking fault probability and microstrain were calculated from predominant (0 0 2) diffraction lines. The UV-Vis-NIR spectroscopy studies revealed that all the films have high optical transmittance (>60%) in the visible range. The optical band gap values are found to be in the range of 3.25-3.31 eV. Optical constants have been estimated and the values of n and k are found to increase with increase of heat treatment. The films have increased transmittance with increase of heat treatment. Al-doped ZnO thin films fabricated by this simple and economic chemical bath deposition technique without using any carrier gas are found to be good in structural and optical properties which are desirable for photovoltaic applications. Scanning electron microscopic images revealed that the hexagonal shaped grains that occupy the entire surface of the film with its near stoichiometric composition.

  3. Mathematical Optimization Techniques for Multi-Phase Radiation Treatment Design

    OpenAIRE

    Sonderman, David

    1983-01-01

    A mathematical model for optimal external beam radiotherapy treatment design over multiple treatment phases is presented. The solution procedure is discussed and illustrated on a case of boost treatment for lung cancer. The models are integrated with current radiobiological software to produce an optimal design over both phases of treatment displayed by means of computer graphics.

  4. A heat treatment procedure to produce fine-grained lamellar microstructures in a P/M titanium aluminide alloy

    Science.gov (United States)

    Au, Peter

    A process for fabricating advanced aerospace titanium aluminide alloys starting from metal powders (the hot isostatically consolidated P/M process) is presented in this thesis. This process does not suffer the difficulties of chemical inhomogeneities and coarse grain structure of castings. In addition heat treatments which take advantage of the refined structure of HIP processed materials are developed to achieve microstructure control and subsequent mechanical property control. It is shown that a better "property balance" is possible after the heat treatment of HIP consolidated materials than it is with alternative processing. It is well understood that the standard microstructures (near-gamma, duplex, nearly lamellar, and fully lamellar) do not have the balanced mechanical properties (tensile, yield, creep and fatigue strength, ductility and fracture toughness) necessary for optimal performance in aero engine and automotive applications. In this work a fine-grained fully lamellar (FGFL) microstructure is developed for property control and in particular for achieving a much improved property balance. A heat treatment procedure for this purpose which consists of cyclic processing in the alpha transus temperature region to achieve an FGFL structure with grain sizes in the range of 50 mum to 150 mum is presented. Compared with conventional duplex structured materials, the minimum creep rate is an order of magnitude lower with only a 10% loss in tensile yield strength. Moreover, a three-fold increase in tensile elongation is possible by converting to an FGFL structure with only a 30% loss in minimum creep rate. These are attractive trade-offs when considering the use of these alloys for aerospace purposes. A thorough literature review of the mechanisms of formation of standard microstructures and their deformation under mechanical loading is contained in the thesis. In addition, conventional techniques to produce FGFL microstructures in wrought and cast materials are

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

    Science.gov (United States)

    Hmurcik, L.; Serway, R. A.

    1982-12-01

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

  6. Effect of Post Heat Treatment on Corrosion Resistance of Phytic Acid Conversion Coated Magnesium

    Institute of Scientific and Technical Information of China (English)

    R.K. Gupta; K. Mensah-Darkwa; D. Kumar

    2013-01-01

    An environment friendly chemical conversion coating for magnesium was obtained by using a phytic acid solution.The effect of post-coating 1heat treatment on the microstructures and corrosion properties of phytic acid conversion coated magnesium was investigated.It was observed that the microstructure and corrosion resistive properties were improved for the heat treated samples.The corrosion current density for bare magnesium,phytic acid conversion coated magnesium,and post-coating heat treated magnesium was calculated to be 2.48 × 10-5,1.18 × 10-6,and 9.27 × 10-7 A/cm2,respectively.The lowest corrosion current density for the heat treated sample indicated its highest corrosion resistive effect for the magnesium.The maximum corrosion protective nature of the heat treated sample was further confirmed by the largest value of impedance in electrochemical impedance spectroscopy studies.

  7. Temperature and heat flux measurement techniques for aeroengine fire test: a review

    Science.gov (United States)

    Mohammed, I.; Abu Talib, A. R.; Sultan, M. T. H.; Saadon, S.

    2016-10-01

    This review is made of studies whereby some types of fire test measuring instrument were compared based on their mode of operation, sensing ability, temperature resistance and their calibration mode used for aero-engine applications. The study discusses issues affecting temperature and heat flux measurement, methods of measurement, calibration and uncertainties that occur in the fire test. It is found that the temperature and heat flux measurements of the flame from the standard burner need to be corrected and taken into account for radiation heat loss. Methods for temperature and heat flux measurements, as well as uncertainties analysis, were also discussed.

  8. HEALING OF HYDROGEN ATTACK CRACK IN AUSTENITE STAINLESS STEEL UNDER HEAT TREATMENT

    Institute of Scientific and Technical Information of China (English)

    X.G. Li; C.F. Dong; H. Chen

    2002-01-01

    The specimens of 304 austenite stainless steel with the hydrogen attack bubbles orcracks were heat treated at 600℃ for 6h. The SEM and TEM observations on thespecimens before and after the heat treatment showed that the bubbles or cracks could behealed completely by heat treatment. The healing of hydrogen attack bubbles or cracksis closely related to heat diffusion of Fe and C atoms in austenite. The driving forceof crack healing results fram the plastic deforming energy Es induced by the growthof hydrogen attack bubbles or cracks. The critical condition of healing of bubbles orcracks is Es ≥ 2γ/r (where γγ is the surface tension, r is the radius of bubbles or halflength of crack). During healing of the hydrogen attack bubbles or cracks, the recovery,polygonization and recrystallization of the sub-grain also occured.

  9. 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.

  10. Effects of induction heat treatment on mechanical properties of TiAl-based alloy

    Institute of Scientific and Technical Information of China (English)

    彭超群; 黄伯云; 贺跃辉

    2002-01-01

    The effects of rapid heating cyclic heat treatment on mechanical properties of a TiAl-based alloy (Ti-33Al-3Cr) were studied by means of an induction heating machine. The results show that: 1) fine fully-lamellar microstructure with colony size of about 50 μm and lamellar spacing of about 0.12 μm can be obtained; 2) the compression mechanical properties can be improved to a large extent and the best comprehensive compression mechanical properties can reach the yield stress 745 MPa, the large flow stress 1 672 MPa and the compression ratio 19.4%; and 3) the compression fracture at room temperature after induction heat treatment and aging is still typical cleavage fracture.

  11. Study of the Al-Si-X system by different cooling rates and heat treatment

    Directory of Open Access Journals (Sweden)

    Miguel Angel Suarez

    2012-10-01

    Full Text Available The solidification behavior of the Al-12.6% Si (A1, the hypereutectic Al-20%Si (A2 and the Al-20%Si-1.5% Fe-0.5%Mn (A3 (in wt. (% alloys, at different cooling rates is reported and discussed. The cooling rates ranged between 0.93 °C/s and 190 °C/s when cast in sand and copper wedge-shaped molds, respectively. A spheroidization heat treatment was carried out to the alloys in the as-cast condition at 540 °C for 11 hours and quench in water with a subsequent heat treatment at 170 °C for 5 hours with the purpose of improving the mechanical properties. The samples were characterized by optical microscopy, scanning electron microscopy and mechanically by tensile test, in order to evaluate the response of the heat treatment on the different starting microstructures and mechanical properties. It was found that alloys cooled at rates greater than 10.8 °C/s had a smaller particle size and better distribution, also showed a greater response to spheroidization heat treatment of all silicon (Si phases. The spheroidization heat treatment caused an increase in the ultimate tensile stress (UTS and elongation when compared with the alloys in the as-cast condition. The highest UTS value of 174 MPa was obtained for the (A1 alloy.

  12. Effects of temperature and method of heat treatment on myofibrillar proteins of pork

    Directory of Open Access Journals (Sweden)

    Vujadinović Dragan

    2014-01-01

    Full Text Available During the tests in this paper, meat processing was carried out at different temperatures between the range of 51°C to 100°C. The meat was processed by dry heat (roasting and wet heat treatments (cooking in water at atmospheric pressure. After heat treatment, myofibrillar proteins were extracted from solutions at constant ionic strength. Quantitative and qualitative determinations of protein´s fractions were performed by capillary electrophoresis. Myofibrillar proteins were also analized for fresh pork meat sample. Results obtained in fresh meat were compared with those recorded after roasting and cooking. In the fresh and thermally processed pork the following proteins were identified: myosin, light chain 3; myosin, light chain 2; troponin - C; troponin - I; myosin, light chain 1; tropomyosin; troponin - T; actin; desmin; α - actinin; C - protein; M - protein (Mβ; M - protein (Mα; heavy meromyosin - HMM. For both methods of thermal processing, with increasing heat treatment temperature, concentration of soluble protein in the extract decreases rapidly after 51°C. Cooking treatment had a more intense effect on the proteins change and denaturation than roasting. [Projekat Ministartsva nauke Republike Srbije: Effect of heat treatment temperature on protein structure and properties of pork meat

  13. Heat treatment of the EN AC-AlSi9Cu3(Fe alloy

    Directory of Open Access Journals (Sweden)

    J. Pezda

    2010-04-01

    Full Text Available Silumins are widely used in automotive, aviation and shipbuilding industries; as having specific gravity nearly three times lower than specific gravity of cast iron the silumins can be characterized by high mechanical properties. Additionally, they feature good casting properties, good machinability and good thermal conductivity. i.e. properties as required for machinery components operating in high temperatures and at considerable loads. Mechanical properties of the silumins can be upgraded, implementing suitably selected heat treatment. In the paper is presented an effect of modification and heat treatment processes on mechanical properties of the EN AC-AlSi9Cu3(Fe alloy. Investigated alloy has undergone typical processes of modification and refining, and next heat treatment. Temperature range of the heat treatment operations was determined on base of curves from the ATD method. Obtained results concern registered melting and solidification curves from the ATD method and strength tests. On base of the performed tests one has determined range of the heat treatment parameters which would assure obtainment of the best possible mechanical properties of the EN AC-AlSi9Cu3(Fe alloy.

  14. Effects of Heat Treatment Temperature and Time on Structure and Static Magnetic Property of W-type Ferrite Hollow Microspheres

    Institute of Scientific and Technical Information of China (English)

    REN Ping; GUAN Jianguo; ZHANG Junxi

    2007-01-01

    Hollow spheres of hexagonal ferrite BaCo2Fe16O27 were fabricated through a spray pyrolysis technique using co-precipitation ferrite powder precursor as materials, followed by calcinations in an air atmosphere. The phase composition, micro-morphology, and static magnetic property of the particles were measured by XRD, SEM, and VSM. The results indicate that the method for preparation of ferrite hollow microspheres (FHM) results in a broad particles size distribution. The density of FHM decreased from 5.31 g/cm3 to 2.31 g/cm3. When the heating rate was 5 ℃/min, and temperature was 1 200 ℃ for 4 hours, pure W-type ferrites were formed. With the heat treatment temperature and time increasing, the crystal structure becomes perfect, the saturation magnetization is increased and the coercive force is decreased.

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

    Science.gov (United States)

    Pepe, Larissa S; Moraes, Jaqueline; Albano, Kivia M; Telis, Vânia R N; Franco, Célia M L

    2016-04-01

    The effect of heat-moisture treatment on structural, physicochemical, and rheological characteristics of arrowroot starch was investigated. Heat-moisture treatment was performed with starch samples conditioned to 28% moisture at 100 ℃ for 2, 4, 8, and 16 h. Structural and physicochemical characterization of native and modified starches, as well as rheological assays with gels of native and 4 h modified starches subjected to acid and sterilization stresses were performed. Arrowroot starch had 23.1% of amylose and a CA-type crystalline pattern that changed over the treatment time to A-type. Modified starches had higher pasting temperature and lower peak viscosity while breakdown viscosity practically disappeared, independently of the treatment time. Gelatinization temperature and crystallinity increased, while enthalpy, swelling power, and solubility decreased with the treatment. Gels from modified starches, independently of the stress conditions, were found to have more stable apparent viscosities and higher G' and G″ than gels from native starch. Heat-moisture treatment caused a reorganization of starch chains that increased molecular interactions. This increase resulted in higher paste stability and strengthened gels that showed higher resistance to shearing and heat, even after acid or sterilization conditions. A treatment time of 4 h was enough to deeply changing the physicochemical properties of starch.

  16. An Experimentally Validated Numerical Modeling Technique for Perforated Plate Heat Exchangers.

    Science.gov (United States)

    White, M J; Nellis, G F; Kelin, S A; Zhu, W; Gianchandani, Y

    2010-11-01

    Cryogenic and high-temperature systems often require compact heat exchangers with a high resistance to axial conduction in order to control the heat transfer induced by axial temperature differences. One attractive design for such applications is a perforated plate heat exchanger that utilizes high conductivity perforated plates to provide the stream-to-stream heat transfer and low conductivity spacers to prevent axial conduction between the perforated plates. This paper presents a numerical model of a perforated plate heat exchanger that accounts for axial conduction, external parasitic heat loads, variable fluid and material properties, and conduction to and from the ends of the heat exchanger. The numerical model is validated by experimentally testing several perforated plate heat exchangers that are fabricated using microelectromechanical systems based manufacturing methods. This type of heat exchanger was investigated for potential use in a cryosurgical probe. One of these heat exchangers included perforated plates with integrated platinum resistance thermometers. These plates provided in situ measurements of the internal temperature distribution in addition to the temperature, pressure, and flow rate measured at the inlet and exit ports of the device. The platinum wires were deposited between the fluid passages on the perforated plate and are used to measure the temperature at the interface between the wall material and the flowing fluid. The experimental testing demonstrates the ability of the numerical model to accurately predict both the overall performance and the internal temperature distribution of perforated plate heat exchangers over a range of geometry and operating conditions. The parameters that were varied include the axial length, temperature range, mass flow rate, and working fluid.

  17. Effects of Heat Treatment on Thermal Decomposition and Combustion Performance of Larix spp. Wood

    Directory of Open Access Journals (Sweden)

    Dong Xing

    2014-06-01

    Full Text Available Larix spp., a wood species of low dimensional stability, was heat-treated in nitrogen at 180 to 210 °C for 6 h. Changes in the thermal decomposition and combustion behaviors of the wood after heat treatment were investigated by TGA, SEM, FTIR, and cone calorimetry. TGA confirmed the loss of hemicellulose from heat-treated Larix spp. Small cracks in the cell wall and loss of resin from the vessels of heat-treated wood were observed by SEM. Hemicellulose degradation within the heat-treated samples was indicated by decreased intensities of typical O-H and C=O stretching vibration peaks in the FTIR spectra. The HRR and MLR curves of treated wood were much lower than those of the untreated ones, which is preferable for fire safety. However, the time to ignition of treated samples decreased from 22 to 13 s and the total smoke production increased by 4.76 and 43.3% for 180- and 210 °C-treated samples, respectively, a detrimental effect on fire safety. To determine the influence of heat treatment on the combustion behavior of Larix spp., the fire safety properties of heat-treated wood (such as wood structure building, furniture, and floors must be studied further.

  18. High strength microstructural forms developed in titanium alloys by rapid heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Ivasishin, O.M. [Institute of Metal Physics, Kiev (Ukraine)

    2001-09-01

    It is shown that rapid heat treatment of alpha+beta and beta titanium alloys, which includes rapid heating of alloys with initial equiaxed microstructure into single-phase beta field is able to produce microstructural forms in which high strength can be well balanced with other mechanical properties. Main advantage of rapid heating approach comes from the possibility to extend the level of ''useful'' strength. Desirably high strength is provided by intragranular morphology and microchemistry while beta-grain refinement permits a reliability of such high strength conditions. (orig.)

  19. Improving the crash behavior of structural components made of advanced high strength steel by local heat treatment

    Science.gov (United States)

    Conrads, L.; Daamen, M.; Hirt, G.; Bambach, M.

    2016-11-01

    High manganese TWIP steel belongs to the second generation of advanced high strength steels. During the production of strip material, the microstructure and hence the mechanical properties of TWIP steel can be adapted to the specific needs of crash relevant structures. Whereas typically the whole steel strip is heat-treated after cold rolling, a local heat treatment can be applied to tailor the properties accordingly. In this work, a method is presented to identify a suitable process window for the local laser heat treatment of TWIP steel. The material is strain hardened and afterwards heat-treated at various temperatures for a short time. The influence of the respective heat treatment on microstructure and mechanical properties is evaluated and the most appropriate heat treatment is then reproduced using laser heating. To verify the effect of a local laser heat treatment at a structural component, crash boxes with different heat treatment patterns were produced and tested. The dynamic crash tests show that the local heat treatment can be used to improve the crash behavior of structural components. In addition, their deformation path can be influenced by using adapted heat treatment patterns and the crash behavior can be controlled.

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

    Science.gov (United States)

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

    2016-05-15

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

  1. Dynamic model for predicting survival of mature larvae of Tribolium confusum during facility heat treatments.

    Science.gov (United States)

    Boina, Dhana Raj; Subramanyam, Bhadriraju; Alavi, Sajid

    2008-06-01

    Structural heat treatment, a viable alternative to methyl bromide fumigation, involves raising the ambient temperature of food-processing facilities between 50 and 60 degrees C by using gas, electric, or steam heaters, and holding these elevated temperatures for 24 h or longer to kill stored-product insects. A dynamic model was developed to predict survival of mature larvae, which is the most heat-tolerant stage of the confused flour beetle, Tribolium confusum (Jacquelin du Val), at elevated temperatures between 46 and 60 degrees C. The model is based on two nonlinear relationships: 1) logarithmic survival of T. confusum mature larvae as a function of time, and 2) logarithmic reduction in larval survival as a function of temperature. The dynamic model was validated with nine independent data sets collected during actual facility heat treatments conducted on two separate occasions at the Kansas State University pilot flour and feed mills. The rate of increase of temperature over time varied among the nine locations where mature larvae of T. confusum were exposed, and the approximate heating rates during the entire heat treatment ranged from 1.1 to 13.2 degrees C/h. The absolute deviation in the predicted number of larvae surviving the heat treatment was within 3-7% of the actual observed data. Comparison of the absolute deviation in the time taken for equivalent larval survival showed that the model predictions were within 2-6% of the observed data. The dynamic model can be used to predict survival of mature larvae of T. confusum during heat treatments of food-processing facilities based on time-dependent temperature profiles obtained at any given location.

  2. A New Graphical Technique for Energy Efficient Design of Heat Recovery System in Chemical/Refining Industries

    Directory of Open Access Journals (Sweden)

    Dina Ahmed Kamel

    2016-12-01

    Full Text Available Chemical processes are energy intensive industries; the majority of energy consumed in industrial processes is mainly used for heating and cooling requirements. This results in increasing the interest in obtaining the optimum design of the heat exchanger networks to reduce the energy consumption and face the growing energy crises. Most of the published literature over the last fifty years promotes the process integration technology as a main part of the process system engineering science. Graphical Pinch Analysis method normally includes two key steps, firstly obtaining the energy targets which include the minimum energy required for the HEN design, then designing the heat exchanger network (HEN. This paper introduces a new graphical approach for the design of new heat exchanger networks (HENs based on pinch analysis rules. The HEN is represented on a simple graph, where the cold stream temperatures are plotted on the X-axis while the driving forces for each exchanger are plotted on the Y-axis. This graphical technique can describe the energy analysis problems in term of temperature driving force inside the heat exchanger, which is an important factor in the design process as the differences in these driving forces are involved in calculating the area of heat exchangers, and consequently affecting the cost.

  3. CERN wide inventory of existing vacuum and heat treatment furnaces

    CERN Document Server

    Milani, Adrien

    2016-01-01

    L’utilisation des fours au CERN a plusieurs objectifs (Traitement thermique, brasage, séchage, polymérisation, ... ). Les fours sont donc répartis dans les différents départements, en fonction de l’utilisation de chacun. Cependant il n’existe pas à l’heure actuelle de référencement permettant de connaitre la présence de chaque four ainsi que leurs caractéristiques techniques. L’objectif de mon stage a donc été de créer un inventaire des fours de traitement thermique présents au CERN, afin de connaitre précisément leurs applications possibles. Cette base de données permettra entre autre aux différents départements de savoir quelle personne contacter en fonction de l’utilisation voulue.

  4. Evolution of eutectic structures in Al-Zn-Mg-Cu alloys during heat treatment

    Institute of Scientific and Technical Information of China (English)

    FAN Xi-gang; JIANG Da-ming; MENG Qing-chang; ZHANG Bao-you; WANG Tao

    2006-01-01

    The evolution of the eutectic structures in the alloys with different copper contents during heat treatment was studied by scanning electron microscopy(SEM), energy dispersive X-ray spectroscopy(EDS), and differential scanning calorimetry(DSC). The as cast microstructures involve α(Al), eutectic(α(Al) + Mg(Al, Cu, Zn)2) and Al7Cu2Fe. The Al2CuMg particles form during heat treatment. The volume of coarse phases decreases quickly in the initial 12 h during heat treatment. The volume of coarse phases change a little at 400 and 420 ℃. Copper content has a great influence on the evolution of the eutectic. The coarse phases dissolve slowly in alloy with higher copper content.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ganapati Myneni; H. Umezawa

    2003-06-01

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

  6. Enhancement of Structure, Tc and Irreversibility Line in High Tc Superconductors by Heat Treatments

    Directory of Open Access Journals (Sweden)

    Abdeljabar Aboulkassim

    2015-08-01

    Full Text Available AC susceptibility (ac= ’+ i‖ and X ray diffraction (XRD are very useful for characterizing high Tc superconductors. We report here on the preparation, X-ray diffraction with Rietveld refinement, resistivity , AC magnetic susceptibility measurements and effect of heat treatments in (Y1-xNdxSrBaCu3O6+z. Each sample was subject to two types of heat treatment: oxygen annealing [O] and argon annealing followed by oxygen annealing [AO]. For each x, the [AO] heat treatment increases the orthorhombicity ε = (b-a/(b+a (for 0≤x0.2, the distance d[Cu(1-(Sr/Ba] (for x0.25; increase in cationic and chain oxygen ordering; psh and in-phase purity for the [AO] samples may account for the observed data.

  7. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-10-01

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

  9. Heat stroke during long-term clozapine treatment: should we be concerned about hot weather?

    Directory of Open Access Journals (Sweden)

    Maurício Scopel Hoffmann

    2016-03-01

    Full Text Available Objective To describe the case of a patient with schizophrenia on clozapine treatment who had an episode of heat stroke. Case description During a heat wave in January and February 2014, a patient with schizophrenia who was on treatment with clozapine was initially referred for differential diagnose between systemic infection and neuroleptic malignant syndrome, but was finally diagnosed with heat stroke and treated with control of body temperature and hydration. Comments This report aims to alert clinicians take this condition into consideration among other differential diagnoses, especially nowadays with the rise in global temperatures, and to highlight the need for accurate diagnosis of clinical events during pharmacological intervention, in order to improve treatment decisions and outcomes.

  10. Microstructure - property characterization of some Zn-Al alloys: effects of heat treatment parameters

    Energy Technology Data Exchange (ETDEWEB)

    Kishore Prasad, B. [CSIR, Bhopal (India). Regional Res. Lab.; Kumar Patwardhan, A. [Roorkee Univ. (India). Dept. of Metallurgical Engineering; Halasyam Yegneswaran, A. [CSIR, Bhopal (India). Regional Res. Lab.

    1996-12-01

    An attempt has been made in this investigation to understand the response of some Zn-Al alloys at different temperatures and durations of holding during T6 heat treatment (solutionizing followed by artificial ageing). Aspects studied include microstructure, hardness, density and electrical resistivity. This study correlates these properties to the microstructure of Zn based alloys comprising Ni/Si and compares the same to alloys with no alloying elements. Various combinations of microstructure and properties in the alloys have been obtained by appropriately controlling the parameters (i.e. the temperature and duration) of the T6 heat treatment. Furthermore, the presence of thermally stable microconstituents resulting from the addition of Ni/Si improves the hardness of the alloys. Optimized heat treatment parameters are suggested for the alloys. (orig.)

  11. Raising the heat and wear resistances of hardened carbon steels by friction strengthening treatment

    Science.gov (United States)

    Makarov, A. V.; Korshunov, L. G.; Malygina, I. Yu.; Solodova, I. L.

    2007-03-01

    The effect of friction treatment by a hard-alloy indenter on the microhardness and resistance to the heat-induced softening upon tempering of hardened medium-and high-carbon steels at 100-600°C is studied. The x-ray and electron microscopy methods are used to determine the causes of the increase in the heat resistance of the friction-strained steel surfaces. A comparative analysis of the effect of the hardening treatment by a hard-alloy indenter and by abrasive particles on the friction-induced heat resistance is performed for the case of high-speed friction treatment of a high-carbon laser-hardened steel.

  12. Heat treatment of processing sludge of ornamental rocks: application as pozzolan in cement matrices

    Directory of Open Access Journals (Sweden)

    J.G. Uliana

    Full Text Available The sector of ornamental rocks produces significant volume of waste during the sawing of the blocks and demand to find ways to recycle, given its environmental impact. Considering the possibilities of use of industrial by-products as mineral admixtures, aiming at sustainable development in the construction industry, this paper aims to study the performance of the processing sludge of ornamental rocks and grinding after heat treatment, based on their potential application as partial substitute for cement. The residue was characterized, cast and milled to produce glassy material. Was analyzed the mechanical performance and pozzolanic activity with partial replacement of cement by waste in natural condition and after heat treatment in mortars for comparison. The results were promising, so it was possible to verify that after heat treatment, the treated waste is presented as a material with pozzolanic characteristics.

  13. Heuristic algorithm for planning and scheduling of forged pieces heat treatment

    Directory of Open Access Journals (Sweden)

    R. Lenort

    2012-04-01

    Full Text Available The paper presents a heuristic algorithm for planning and scheduling of forged pieces heat treatment which allows maximizing the capacity exploitation of the heat treatment process and the entire forging process. Five Focusing Steps continuous improvement process was selected as a methodological basis for the algorithm design. Its application was supported by simulation experiments performed on a dynamic computer model of the researched process. The experimental work has made it possible to elicit the general rules for planning and scheduling of the heat treatment process of forged pieces which reduce losses caused by equipment conversion and setup times, and which increase the throughput of this process. The HIPO diagram was used to design the algorithm.

  14. 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.

  15. The effect of heat treatment on the gouging abrasion resistance of alloy white cast irons

    Science.gov (United States)

    Are, I. R. S.; Arnold, B. K.

    1995-02-01

    A series of heat treatments was employed to vary the microstructure of four commercially important alloy white cast irons, the wear resistance of which was then assessed by the ASTM jaw-crusher gouging abrasion test. Compared with the as-cast condition, standard austenitizing treatments produced a substantial increase in hardness, a marked decrease in the retained aus-tenite content in the matrix, and, in general, a significant improvement in gouging abrasion resistance. The gouging abrasion resistance tended to decline with increasing austenitizing tem-perature, although the changes in hardness and retained austenite content varied, depending on alloy composition. Subcritical heat treatment at 500 ° following hardening reduced the retained austenite content to values less than 10 pct, and in three of the alloys it caused a significant fall in both hardness and gouging abrasion resistance. The net result of the heat treatments was the development of optimal gouging abrasion resistance at intermediate levels of retained aus-tenite. The differing responses of the alloys to both high-temperature austenitizing treatments and to subcritical heat treatments at 500 ° were related to the effects of the differing carbon and alloying-element concentrations on changes in the M s temperature and secondary carbide precipitation.

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Science.gov (United States)

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

    2014-08-06

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

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

    Science.gov (United States)

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

    2013-01-01

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

  19. 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.

  20. EFFECT OF HEAT TREATMENT ON THE GERMINATION OF SEEDS SOEL

    Directory of Open Access Journals (Sweden)

    Y. M’Sadak

    2015-01-01

    Full Text Available The object of this work was to study the effect of thermal treatments (in the oven and in the compost on the seed germination SOEL. The laboratory evaluation on the treatment in the oven berries at two temperatures (50°C and 60°C for three exposure time ( one day, two days and three days gave a germination rate zero for 60°C for an exposure time of one day. The spatio-temporal thermal monitoring of forestry compost windrow which was introduced to deal with berries SOEL showed a substantially homogeneous distribution of the temperature rising to 60°C and even longer swath stretching and used for a time period of 5 consecutive days. The germination rate was zero for all fruit seeds treated before the first reversal fact, regardless of the depth and location of the windrow considered that the berries were introduced. Thus, composting can be a solution to prevent the spread of SOEL by seed.

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

    Directory of Open Access Journals (Sweden)

    Caroline Lumi Miyazaki

    2009-09-01

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

  2. Casting Simulation Within the Framework of ICME: Coupling of Solidification, Heat Treatment, and Structural Analysis

    Science.gov (United States)

    Guo, Jianzheng; Scott, Sam; Cao, Weisheng; Köser, Ole

    2016-05-01

    Integrated computational materials engineering (ICME) is becoming a compulsory practice for developing advanced materials, re-thinking manufacturing processing, and engineering components to meet challenging design goals quickly and cost-effectively. As a key component of the ICME approach, a numerical approach is being developed for the prediction of casting microstructure, defects formation and mechanical properties from solidification to heat treatment. Because of the processing conditions and complexity of geometry, material properties of a cast part are not normally homogeneous. This variation and the potential weakening inherent in manufacturing are currently accommodated by incorporating large safety factors that counter design goals. The simulation of the different manufacturing process stages is integrated such that the resultant microstructure of the previous event is used as the initial condition of the following event, ensuring the tracking of the component history while maintaining a high level of accuracy across these manufacturing stages. This paper explains the significance of integrated analytical prediction to obtain more precise simulation results and sets out how available techniques may be applied accordingly.

  3. Grain-refining heat treatments to improve cryogenic toughness of high-strength steels

    Science.gov (United States)

    Rush, H. F.

    1984-01-01

    The development of two high Reynolds number wind tunnels at NASA Langley Research Center which operate at cryogenic temperatures with high dynamic pressures has imposed severe requirements on materials for model construction. Existing commercial high strength steels lack sufficient toughness to permit their safe use at temperatures approaching that of liquid nitrogen (-320 F). Therefore, a program to improve the cryogenic toughness of commercial high strength steels was conducted. Significant improvement in the cryogenic toughness of commercial high strength martensitic and maraging steels was demonstrated through the use of grain refining heat treatments. Charpy impact strength at -320 F was increased by 50 to 180 percent for the various alloys without significant loss in tensile strength. The grain sizes of the 9 percent Ni-Co alloys and 200 grade maraging steels were reduced to 1/10 of the original size or smaller, with the added benefit of improved machinability. This grain refining technique should permit these alloys with ultimate strengths of 220 to 270 ksi to receive consideration for cryogenic service.

  4. Conjugate Heat Transfer Analysis of an Ultrasonic Molten Metal Treatment System

    Institute of Scientific and Technical Information of China (English)

    ZHU Youli; BIAN Feilong; WANG Yanli; ZHAO Qian

    2014-01-01

    In piezoceramic ultrasonic devices, the piezoceramic stacks may fail permanently or function improperly if their working temperatures overstep the Curie temperature of the piezoceramic material. While the end of the horn usually serves near the melting point of the molten metal and is enclosed in an airtight chamber, so that it is difficult to experimentally measure the temperature of the transducer and its variation with time, which bring heavy difficulty to the design of the ultrasonic molten metal treatment system. To find a way out, conjugate heat transfer analysis of an ultrasonic molten metal treatment system is performed with coupled fluid and heat transfer finite element method. In modeling of the system, the RNG model and the SIMPLE algorithm are adopted for turbulence and nonlinear coupling between the momentum equation and the energy equation. Forced air cooling as well as natural air cooling is analyzed to compare the difference of temperature evolution. Numerical results show that, after about 350 s of working time, temperatures in the surface of the ceramic stacks in forced air cooling drop about 7 K compared with that in natural cooling. At 240 s, The molten metal surface emits heat radiation with a maximum rate of about 19 036 W/m2, while the heat insulation disc absorbs heat radiation at a maximum rate of about 7922 W/m2, which indicates the effectiveness of heat insulation of the asbestos pad. Transient heat transfer film coefficient and its distribution, which are difficult to be measured experimentally are also obtained through numerical simulation. At 240 s, the heat transfer film coefficient in the surface of the transducer ranges from -17.86 to 20.17 W/(m2•K). Compared with the trial and error method based on the test, the proposed research provides a more effective way in the design and analysis of the temperature control of the molten metal treatment system.

  5. 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.

  6. Vestibuloplasty by modified Kazanjian technique in treatment with dental implants.

    Science.gov (United States)

    Ponzoni, Daniela; Jardim, Ellen Cristina Gaetti; de Carvalho, Paulo Sérgio Perri

    2013-07-01

    Dentists are often faced with extensively resorbed mandibular ridges with shallow buccal vestibule and high insertion of the mentalis muscle in relation to the crest of the ridge, causing the displacement of the prosthesis. Vestibuloplasty techniques aim at eliminating the muscle insertions, reposition the mucosa, and increase the area chapeável, giving more stability to the prosthesis. Among the techniques to deepen the vestibule are submucosal vestibuloplasties by secondary epithelialization and with mucosal and skin grafts. We will discuss vestibuloplasty by secondary epithelialization with emphasis on the so-called modified Kazanjian technique. This technique provides an appropriate result and does not require hospitalization, additional surgery at the donor, or prolonged periods without the use of prosthesis.

  7. A heat mathematical model of polymer composite cylinder during microwave treatment

    Directory of Open Access Journals (Sweden)

    S. V. Reznik

    2014-01-01

    Full Text Available Traditional technologies of producing epoxy based polymer composite materials (PCM require a long-term and energy consuming thermal processing. Microwave heating could be used as an alternative technology for heating work pieces made of PCM; this would allow to reduce treatment time and energy consumption significantly. A mathematical model of temperature distribution inside a cylindrical composite system during microwave treatment was investigated in this paper. The model includes a hollow PCM cylinder made of an epoxy binder and carbon fibers and a solid cylindrical mandrel. Theoretical and experimental results on the temperature state of the system were analyzed and discussed.

  8. Development of materials database system for cae system of heat treatment based on data mining technology

    Institute of Scientific and Technical Information of China (English)

    GU Qiang; ZHONG Rui; JU Dong-ying

    2006-01-01

    Computer simulation for materials processing needs a huge database containing a great deal of various physical properties of materials. In order to employ the accumulated large data on materials heat treatment in the past years,it is significant to develop an intelligent database system. Based on the data mining technology for data analysis,an intelligent database web tool system of computer simulation for heat treatment process named as IndBASEweb-HT was built up. The architecture and the arithmetic of this system as well as its application were introduced.

  9. 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.

  10. Diode laser heat treatment of lithium manganese oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Proell, J., E-mail: johannes.proell@kit.edu [Karlsruhe Institute of Technology, Institute for Applied Materials, P.O. Box 3640, 76021 Karlsruhe (Germany); Kohler, R.; Mangang, A.; Ulrich, S.; Bruns, M.; Seifert, H.J. [Karlsruhe Institute of Technology, Institute for Applied Materials, P.O. Box 3640, 76021 Karlsruhe (Germany); Pfleging, W. [Karlsruhe Institute of Technology, Institute for Applied Materials, P.O. Box 3640, 76021 Karlsruhe (Germany); Karlsruhe Nano Micro Facility, H.-von-Helmholtz-Platz 1, 76344 Egg.-Leopoldshafen (Germany)

    2012-04-01

    The crystallization of lithium manganese oxide thin films prepared by radio frequency magnetron sputtering on stainless steel substrates under 10 Pa argon pressure is demonstrated by a laser annealing technique. Laser annealing processes were developed as a function of annealing time and temperature with the objective to form an electrochemically active lithium manganese oxide cathode. It is demonstrated, that laser annealing with 940 nm diode laser radiation and an annealing time of 2000 s at 600 Degree-Sign C delivers appropriate parameters for formation of a crystalline spinel-like phase. Characteristic features of this phase could be detected via Raman spectroscopy, showing the characteristic main Raman band at 627 cm{sup -1}. Within cyclic voltammetric measurements, the two characteristic redox pairs for spinel lithium manganese oxide in the 4 V region could be detected, indicating that the film was well-crystallized and de-/intercalation processes were reversible. Raman post-analysis of a cycled cathode showed that the spinel-like structure was preserved within the cycling process but mechanical degradation effects such as film cracking were observed via scanning electron microscopy. Typical features for the formation of an additional surface reaction layer could be detected using X-ray photoelectron spectroscopy.

  11. Effects of Nanosilver-Impregnation and Heat Treatment on Coating Pulloff Adhesion Strength on Solid Wood

    Directory of Open Access Journals (Sweden)

    Hamid Reza Taghiyari

    2016-01-01

    Full Text Available Effects of impregnation with a silver nano-suspension, as well as of heat-treatment, on pull-off adhesion strengths of the coating system on three commercial solid wood species were studied. The wood species included beech, poplar, and fi r. The size range of silver nanoparticles was 30 – 80 nm. The specimens were coated with an un-pigmented sealer and a clear fi nish on the basis of an organic solvent. The results showed that the highest and the lowest pull-off strengths were found in beech specimens heat-treated at 145 °C (5.7 MPa and in nanosilver-impregnated poplar specimens heat-treated at 185 °C (2.5 MPa, respectively. Impregnation with nanosilver decreased pull-off strength in the case of all species as a result of formation of micro checks in the cell walls caused by the impregnation under high pressure in vessel. Heat-treatment at the temperature lower than 145 °C increased pull-off strength as to the irreversible hydrogen bonding in the course of water movements within the pore system of the cell walls, resulting in extra bonds among cell wall components and higher mechanical properties. However, heat treatment at the temperature higher than 185 °C significantly decreased the strength as the degradation of hemicellulose and cell wall wood components caused signifi cant decrease in mechanical strength and cell wall thinning. High thermal conductivity coefficient of silver intensified the impact of heat-treatment by rapid absorption of heat on the surface of the specimens.

  12. A new on-board imaging treatment technique for palliative and emergency treatments in radiation oncology

    Energy Technology Data Exchange (ETDEWEB)

    Held, Mareike

    2016-03-23

    and reconstruction corrections. Consequently, multiple image value-to-density calibration curves are necessary for accurate dose calculation. UCSF has implemented the new technique clinically for emergency treatments on their patients who stand to benefit from the fast simulation to treatment time frame that is achieved through this on-board imaging workflow.

  13. Effect of heat treatment duration on tribological behavior of electroless Ni-(high)P coatings

    Science.gov (United States)

    Biswas, A.; Das, S. K.; Sahoo, P.

    2016-09-01

    Electroless nickel coating occurs through an autocatalytic chemical reaction and without the aid of electricity. From tribological perspective, it is recommended due to its high hardness, wear resistance, lubricity and corrosion resistance properties. In this paper electroless Ni-P coatings with high phosphorous weight percentages are developed on mild steel (AISI 1040) substrates. The coatings are subjected to heat treatment at 300°C and 500°C for time durations up to 4 hours. The effect of heat treatment duration on the hardness as well as tribological properties is discussed in detail. Hardness is measured in a micro hardness tester while the tribological tests are carried out on a pin-on-disc tribotester. Wear is reported in the form of wear rates of the sample subjected to the test. As expected, heat treatment of electroless Ni-P coating results in enhancement in its hardness which in turn increases its wear resistance. The present study also finds that duration of heat treatment has quite an effect on the properties of the coating. Increase in heat treatment time in general results in increase in the hardness of the coating. Coefficient of friction is also found to be lesser for the samples heat treated for longer durations (4 hour). However, in case of wear, similar trend is not observed. Instead samples heat treated for 2 to 3 hour display better wear resistance compared to the same heat treated for 4 hour duration. The microstructure of the coating is also carried out to ensure about its proper development. From scanning electron microscopy (SEM), the coating is found to possess the conventional nodular structure while energy dispersive X-ray analysis (EDX) shows that the phosphorous content in the coating to be greater than 9%. This means that the current coating belongs to the high phosphorous category. From X-ray diffraction analysis (XRD), it is found that coating is amorphous in as-deposited condition but transforms into a crystalline structure with

  14. Comparison of surgical techniques in the treatment of laryngeal polypoid degeneration.

    Science.gov (United States)

    Lumpkin, S M; Bishop, S G; Bennett, S

    1987-01-01

    Surgical excision has been the accepted treatment of laryngeal polypoid degeneration, or chronic polypoid corditis. We report on 29 women with polypoid degeneration who received one of three surgical treatments: vocal fold stripping, carbon dioxide laser obliteration, or the Hirano technique. The duration of postoperative dysphonia was longest with the laser removal and shortest with the Hirano technique. A combination of vocal hygiene management and the Hirano technique of removal provided the most efficacious treatment.

  15. Influence of austempering heat treatment on mechanical and corrosion properties of ductile iron samples

    Directory of Open Access Journals (Sweden)

    M. Janjić

    2016-07-01

    Full Text Available Mechanical properties and corrosion resistance of metals are closely related to the microstructure characteristics of the material. The paper compares the results of these two sets of properties after investigating samples of base ductile iron and heat-treated samples of the base austempered ductile iron (ADI. The basic material is perlite ferritic iron alloyed with copper and nickel. To test the corrosion rate of the base material (ductile iron and the heattreated samples (ADI, electrochemical techniques of potentiostatic polarization were used (the technique of Tafel curves extrapolation and the potentiodynamic polarization technique.

  16. Heat treatment of EN AC-AlSi13Cu2Fe silumin and its effect on change of hardness of the alloy

    Directory of Open Access Journals (Sweden)

    J. Pezda

    2010-01-01

    Full Text Available Wide application of aluminum casting alloys is connected with their very good physical and technical properties. Within such group of alloys, silumins play important role in automotive and aviation industry, as well as in another branches of technique, because the silumins enable casting of complicated shapes. The most important parameters which predetermine mechanical properties of a material in aspects of suitability for castings of machinery components are: tensile strength (Rm, elongation and hardness. Alloys based on equilibrium system of Al-Si comprise additional constituents (e.g.: Mg, Cu enabling, except modification, improvement of mechanical properties, obtained in result of heat treatment. In the paper are presented results of investigations concerning effect of the heat treatment on change of hardness (HB of the EN AC-AlSi12Cu2Fe alloy. Investigated alloy was melted in an electric resistance furnace. Run of the crystallization was presented with use of the thermal-derivative method (ATD. This method was also implemented to determination of heat treatments temperature range of the alloy. Performed heat treatment gave effect in change of the hardness. Performed investigations have enabled determination of heat treatment parameters range, which conditions suitable hardness of the investigated alloy.

  17. Numerical Study Of The Heat Transfer Phenomenon Of A Rectangular Plate Including Void, Notch Using Finite Difference Technique

    Science.gov (United States)

    Deb Nath, S. K.; Peyada, N. K.

    2015-12-01

    In the present study, we have developed a code using Matlab software for solving a rectangular aluminum plate having void, notch, at different boundary conditions discretizing a two dimensional (2D) heat conduction equation by the finite difference technique. We have solved a 2D mixed boundary heat conduction problem analytically using Fourier integrals (Deb Nath et al., 2006; 2007; 2007; Deb Nath and Ahmed, 2008; Deb Nath, 2008; Deb Nath and Afsar, 2009; Deb Nath and Ahmed, 2009; 2009; Deb Nath et al., 2010; Deb Nath, 2013) and the same problem is also solved using the present code developed by the finite difference technique (Ahmed et al., 2005; Deb Nath, 2002; Deb Nath et al., 2008; Ahmed and Deb Nath, 2009; Deb Nath et al., 2011; Mohiuddin et al., 2012). To verify the soundness of the present heat conduction code results using the finite difference method, the distribution of temperature at some sections of a 2D heated plate obtained by the analytical method is compared with those of the plate obtained by the present finite difference method. Interpolation technique is used as an example when the boundary of the plate does not pass through the discretized grid points of the plate. Sometimes hot and cold fluids are passed through rectangular channels in industries and many types of technical equipment. The distribution of temperature of plates including notches, slots with different temperature boundary conditions are studied. Transient heat transfer in several pure metallic plates is also studied to find out the required time to reach equilibrium temperature. So, this study will help find design parameters of such structures.

  18. Numerical Study Of The Heat Transfer Phenomenon Of A Rectangular Plate Including Void, Notch Using Finite Difference Technique

    Directory of Open Access Journals (Sweden)

    Deb Nath S.K.

    2015-12-01

    Full Text Available In the present study, we have developed a code using Matlab software for solving a rectangular aluminum plate having void, notch, at different boundary conditions discretizing a two dimensional (2D heat conduction equation by the finite difference technique. We have solved a 2D mixed boundary heat conduction problem analytically using Fourier integrals (Deb Nath et al., 2006; 2007; 2007; Deb Nath and Ahmed, 2008; Deb Nath, 2008; Deb Nath and Afsar, 2009; Deb Nath and Ahmed, 2009; 2009; Deb Nath et al., 2010; Deb Nath, 2013 and the same problem is also solved using the present code developed by the finite difference technique (Ahmed et al., 2005; Deb Nath, 2002; Deb Nath et al., 2008; Ahmed and Deb Nath, 2009; Deb Nath et al., 2011; Mohiuddin et al., 2012. To verify the soundness of the present heat conduction code results using the finite difference method, the distribution of temperature at some sections of a 2D heated plate obtained by the analytical method is compared with those of the plate obtained by the present finite difference method. Interpolation technique is used as an example when the boundary of the plate does not pass through the discretized grid points of the plate. Sometimes hot and cold fluids are passed through rectangular channels in industries and many types of technical equipment. The distribution of temperature of plates including notches, slots with different temperature boundary conditions are studied. Transient heat transfer in several pure metallic plates is also studied to find out the required time to reach equilibrium temperature. So, this study will help find design parameters of such structures.

  19. Effect of heat treatment on structure, surface composition, infrared emission and surface electrical properties of tourmaline

    Science.gov (United States)

    He, Dengliang; Liu, Shuxin

    2017-02-01

    Crystal structure, surface composition, infrared emission properties and surface electrical properties of tourmaline from Guangxi of China, when subjected to heat treatment in air atmosphere had been studied by some methods, including X-ray fluorescence spectrum (XRF), X-ray diffraction (XRD) meter, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), energy dispersion spectroscopy (EDS), scanning electron microscope (SEM) and Zeta potential analyzer, etc. Experimental results show that the unit cell of tourmaline would shrink during heat treatment because Fe2+ were oxidized. Moreover, the Fe3+/Fetotal inside tourmaline can be raised after treatment. Infrared normal total emissivity of tourmaline reaches 0.87, and infrared radiation energy density is 4.56 × 102W/m2. It can maintain excellent infrared emission properties at high temperature. Simultaneously, tourmaline presents negative Zeta potential in the aqueous solution, and its Zeta potential reaches ‑18.04 mV. Zeta potential of tourmaline was increased to ‑24.83 mV after heat treatment at 400∘C, and decrease to ‑11.78 mV after heat treatment at 600∘C. These findings may provide reference data for tourmaline’s application in the field of functional materials.

  20. Selection of heat treatment condition of the Mg-Al-Zn alloys

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2009-02-01

    Full Text Available Purpose: Main aim of this paper are results of the optimization of heat treatment conditions, which are temperature and heating time during solution heat treatment or ageing as well the cooling rate after solution treatment for MCMgAl12Zn1, MCMgAl9Zn1, MCMgAl6Zn1, MCMgAl3Zn1 cast magnesium alloys.Design/methodology/approach: The following results concern mechanical properties especially hardness.Findings: The different heat treatment kinds employed contributed to the improvement of mechanical properties of the alloy.Research limitations/implications: According to the alloys characteristic, the applied cooling rate and alloy additions seems to be a good compromise for mechanical properties, nevertheless further tests should be carried out in order to examine different cooling rates and parameters of solution treatment process and aging process.Practical implications: Generally magnesium alloys are applied in motor industry and machine building, but they find application in a helicopter production, planes, disc scanners, a mobile telephony, computers, bicycle elements, household and office equipment, radio engineering and an air - navigation, in chemical, power, textile and nuclear industrial, etc.Originality/value: Contemporary materials should possess high mechanical properties, physical and chemical, as well as technological ones, to ensure long and reliable use. The above mentioned requirements and expectations regarding the contemporary materials are met by the non-ferrous metals alloys used nowadays, including the magnesium alloys.

  1. Electrochemical Corrosion Behavior ofthe Laser Continuous Heat Treatment Welded Joints of 2205 Duplex Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    LIU Heping; JIN Xuejun

    2011-01-01

    The electrochemical corrosion behaviors of the welded joints of 2205 duplex stainless steel with the laser continuous heat treatment were investigated.The secondary austenite formation is the outcome of thermodynamic equilibrium breach of the alloy during heat treatment and the result of the continuous heat treatment which has the most important effect on the weld material.The partitioning behaviors of chromium and molybdenum as well as the volume fraction of ferrite and austenite have a remarkable influence on the composition of the individual phase.Mechanical examination of the laser trated weld demonstrates that the tensile strength and yield strength increase with increasing the amount of the secondary austenite.It is shown that the ultimate tensile strength of the 6 kW laser-treated weld is higher about 20 MPa than no heat treatment weld and the ductility can be further improved without compromising strength.The results indicate that the welding alters the corrosion behavior because of different post heat treatment power and the broad active peak is not identified which is attributed to the dissolution of the secondary austenitic in the ferrite phase.It is indicated that pitting resistance equivalent (PRE) values of base metal and 6 kW weld are higher than that of other welds; base metal is 33.7,6 kW weld 33.3,no treatment 32.4,4 kW weld 32.8,8 kW weld 32.5.The extent of corrosion resistance improvement after reheating treatment is mainly caused by the removal of nitrogen from ferritic regions,which occurred as a consequence of secondary austenite growth.

  2. The Strengthening of Weight Heavy Alloys During Heat Treatment

    Directory of Open Access Journals (Sweden)

    M. Kaczorowski

    2012-12-01

    Full Text Available The results of studies of W-Ni-Co-Fe experimental alloy, with chemical composition assuring a possibility of producing Ni-basedsupersaturated solid solution are presented. The alloy was prepared from tungsten, nickel, cobalt and iron powders which were first mixedthen melted in a ceramic crucible where they slowly solidified in hydrogen atmosphere. Next specimens were cut from the casting andheated at a temperature 950oC. After solution treatment the specimens were water quenched and then aged for 20 h at a temperature 300oC.The specimens were subjected to microhardness measurements and structure investigations. The latter included both conventionalmetallography and SEM observations. Moreover, for some specimens X-ray diffractometry studies and TEM investigations wereconducted. It was concluded that quenching lead to an increase of tungsten concentration in nickel matrix which was confirmed by Nilattice parameter increase. Aging of supersaturated solid solution caused strengthening of the Ni-based matrix, which was proved byhardness measurements. The TEM observation did not yield explicit proofs that the precipitation process could be responsible forstrengthening of the alloy.

  3. Microstructural Evolution of 6061 Alloy during Isothermal Heat Treatment

    Institute of Scientific and Technical Information of China (English)

    Na Wang; Zhimin Zhou; Guimin Lu

    2011-01-01

    The semi-solid billet of 6061 aluminum alloy was prepared by the near-liquidus semi-continuous casting (LSC) with rosette or near-spheroide grains. The pre-deformation processing was applied before partial remelting to further improve the microstructure and properties of the semi-solid alloy. The efiects of different processing parameters, such as holding temperature and holding time, on the semisolid microstructures during partial remelting have been investigated. It was found that the optimal partial remelting parameters should be 630℃ and 10-15 min for 6061 alloy cold rolled with 60% reduction in height of pre-deformation. The coarsening rates were anasysed by Lifshitz-Slyozov-Wagner (LSW) theory. The pre-deformed 6061 alloy exhibits lower coarsening rate constants than that of the as-cast one, and also lower than other alloys processed by different method found in previous literature. It is because the coarsening rate is associated with the initial microstructure and composition of the alloy. The secondary phases in the alloy inhibit the migration of the liquid film grain boundaries. The microstructure obtained by using the combination of near-liquidus semicontinuous casting and pre-deformation treatment is better than that without pre-deformation processing, which demonstrates that the used method is promising for fabricating high quality semi-solid alloys.

  4. 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.

  5. Influence of Heat Treatment on the Morphologies of Copper Nanoparticles Based Films by a Spin Coating Method

    Directory of Open Access Journals (Sweden)

    Wei Liu

    2017-01-01

    Full Text Available We have investigated the influence of heat treatment on the morphologies of copper nanoparticles based films on glass slides by a spin coating method. The experiments show that heat treatment can modify the sizes and morphologies of copper nanoparticles based films on glass slides. We suggest that through changing the parameters of heat treatment process may be helpful to vary the scattering and absorbing intensity of copper nanoparticles when used in energy harvesting/conversion and optical devices.

  6. Machinability of Austempered Ductile Iron (ADI) Produced by Integrated Green Technology of Continuous Casting-Heat Treatment Processes

    Science.gov (United States)

    Meena, A.; El Mansori, M.; Ghidossi, P.

    2011-01-01

    This study presents the novel processing technique known as continuous casting-heat treatment processes to produce Austempered Ductile Iron (ADI) which is a new class of ductile iron. ADI is characterized by improved mechanical properties but has low machinability as compared to other cast irons and steel of similar strength. The novel technique is developed by the integration of casting (in die casting) and heat treatment processes in foundry to save cost energy and time. Specimens just after casting were austenitized at 930° C for 90 min and then austempered in fluidized bed at 380° C for 90 and 120 min. Hence, the effect of austempering time on the morphology of retained austenite and mechanical properties of the material were examined and compared with conventionally produced ADI. Drilling tests were then carried out to evaluate the machinability of ADI in terms of cutting forces, chip micro-hardness, chip morphology and surface roughness. The mechanical properties of ADI austempered for 120 min have found to be better as compare to the ADI austempered for 90 min.

  7. Unsteady High Turbulence Effects on Turbine Blade Film Cooling Heat Transfer Performance Using a Transient Liquid Crystal Technique

    Science.gov (United States)

    Han, J. C.; Ekkad, S. V.; Du, H.; Teng, S.

    2000-01-01

    Unsteady wake effect, with and without trailing edge ejection, on detailed heat transfer coefficient and film cooling effectiveness distributions is presented for a downstream film-cooled gas turbine blade. Tests were performed on a five-blade linear cascade at an exit Reynolds number of 5.3 x 10(exp 5). Upstream unsteady wakes were simulated using a spoke-wheel type wake generator. Coolant blowing ratio was varied from 0.4 to 1.2; air and CO2 were used as coolants to simulate different density ratios. Surface heat transfer and film effectiveness distributions were obtained using a transient liquid crystal technique; coolant temperature profiles were determined with a cold wire technique. Results show that Nusselt numbers for a film cooled blade are much higher compared to a blade without film injection. Unsteady wake slightly enhances Nusselt numbers but significantly reduces film effectiveness versus no wake cases. Nusselt numbers increase only slic,htly but film cooling, effectiveness increases significantly with increasing, blowing ratio. Higher density coolant (CO2) provides higher effectiveness at higher blowing ratios (M = 1.2) whereas lower density coolant (Air) provides higher 0 effectiveness at lower blowing ratios (M = 0.8). Trailing edge ejection generally has more effect on film effectiveness than on the heat transfer, typically reducing film effectiveness and enhancing heat transfer. Similar data is also presented for a film cooled cylindrical leading edge model.

  8. Comparison of two different gingivectomy techniques for gingival cleft treatment.

    Science.gov (United States)

    Malkoc, Siddik; Buyukyilmaz, Tamer; Gelgor, Ibrahim; Gursel, Mihtikar

    2004-06-01

    Interdental clefts or invaginations contribute to orthodontic relapse and poor periodontal health in extraction cases. These clefts or invaginations can be removed both by electrosurgical or conventional surgical gingivectomy techniques. This study investigates and compares the efficacy of two different techniques to remove gingival clefts with respect to periodontal health and patient tolerance. Twenty-two patients (mean age, 15.7 years) with bilateral gingival clefts participated in this study. In each patient, the gingival invaginations were removed by gingivectomy using electrosurgery on one side and conventional surgery on the contralateral side. The length and depth of the invaginations, the gingival index of the adjacent teeth, and the changes in visual analogue scale scores were recorded before and after the operation for both groups. Mann-Whitney U-test and Wilcoxon tests were used to analyze the data statistically. The results showed significant improvement in invagination depth and length and gingival index scores for both techniques. There were no statistical differences between the two gingivectomy techniques with respect to gingival health and patient tolerance. Both techniques can be used to remove the gingival invaginations efficiently.

  9. Treatment of Pediatric Diseases by the Method of Evacuating the Bowels to Remove the Internal Heat

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Evacuating the bowels to remove internal heat is one of the major therapeutic principles in treating pediatric diseases. Since the children are incapable of controlling in take of milk or food, the accumulated foodstuffs in the body will impede the spleen and stomach in digestion and transportation. In addition, children are easy to be attacked by exopathogens, because their organs are tender and do not fully develop. Once an exopathogen gets into the interior, it will transform into heat. However, simple measures of eliminating the heat often fail in the treatment of some critical and emergent pediatric cases. We have treated such cases by the method of evacuating bowels to remove the internal heat with miracle effects and would like to share our experience with our colleagues. The following are some examples.

  10. Effects of Heat Treatment on Microstructure and Hardness of Laser Clad NiWCRE Alloy Layer

    Institute of Scientific and Technical Information of China (English)

    LIU Su-qin; HUANG Jin-liang; WANG Shun-xing; DONG Qi-ming

    2004-01-01

    The effects of heat treatment on microstructure and hardness of laser surface-clad Ni21+20%WC+0.5%CeO2 on the heat-resistant cast iron were investigated by means of X-ray diffraction(XRD), transmission electron microscope(TEM)and microhardness test. The experimental results showed that heat-treating at 500℃ has no effect on microstructure and hardness of the layers. Although the phase composition of the layers heat-treated at 700℃ and 800℃ remain unchanged,more Ni3B and Ni4B3 phases are precipitated on the matrix of the cladding layer, the metastable phase-M7C3 is transformed into steady phase-M23C6, and the precipitated phases coarsened.

  11. Effects of Heat Treatment on Microstructure and Hardness of Laser Clad NiWCRE Alloy Layer

    Institute of Scientific and Technical Information of China (English)

    LIUSu-qin; HUANGJin-liang; WANGShun-xing; DONGQi-ming

    2004-01-01

    The ettects of heat treatment on microstructure and hardness ot laser surface-clad Ni21+20%WC+0.5%CeO2 on the heat-resistant cast iron were investigated by means of X-ray diffraction(XRD), transmission electron microscope(TEM) and microhardness test. The experimental results showed that heat-treating at 500℃ has no effect on microstructure and hardness of the layers. Although the phase composition of the layers heat-treated at 700℃ and 800℃ remain unchanged, more Ni3B and Ni4B3 phases are precipitated on the matrix of the cladding layer, the metastable phase-M7C3 is transformed into steady phase-M23C6, and the precipitated phases coarsened.

  12. Investigation of laser heating effect of metallic nanoparticles on cancer treatment

    Science.gov (United States)

    Shan, G. S.; Liu, X. M.; Chen, H. J.; Yu, J. S.; Chen, X. D.; Yao, Y.; Qi, L. M.; Chen, Z. J.

    2016-07-01

    Metallic nanoparticles can be applied for hyperthermia therapy of cancer treatment to enhance the efficacy because of their high absorption rate. The absorption of laser energy by metallic nanoparticles is strongly dependent on the concentration, shape, material of nanoparticles and the wavelength of the laser. However, there is no systematic investigation on the heating effect involving different material, concentration and laser wavelength. In this paper, gold nanoparticles (AuNPs), sliver nanoparticles (AgNPs) and sliver nanowires (AgNWs) with different concentrations are heated by 450nm and 532nm wavelength laser to investigate the heating effect. The result shows that the temperature distribution of heated metallic nanoparticles is non-uniform.

  13. Analysis of Thermal Stresses and Strains Developing during the Heat Treatment of Windmill Shaft

    Directory of Open Access Journals (Sweden)

    Cebo-Rudnicka A.

    2017-06-01

    Full Text Available In the paper the results of evaluation of the temperature and stress fields during four cycles of the heat treatment process of the windmill shaft has been presented. The temperature field has been calculated from the solution to the heat conduction equation over the whole heat treatment cycles of the windmill shaft. To calculate the stress field an incremental method has been used. The relations between stresses and strains have been described by Prandtl-Reuss equation for the elastic-plastic body. In order to determine the changes in the temperature and stress fields during heat treatment of the windmill shaft self-developed software utilizing the Finite Element Method has been used. This software can also be used to calculate temperature changes and stress field in ingots and other axially symmetric products. In the mathematical model of heating and cooling of the shaft maximum values of the strains have been determined, which allowed to avoid the crack formation. The critical values of strains have been determined by using modified Rice and Tracy criterion.

  14. Use of fast heat-treatment for improving the structural strength of steels

    Energy Technology Data Exchange (ETDEWEB)

    Gridnev, V.N.; Oshkaderov, S.P.

    1988-05-01

    Comparisons are drawn between the traditional and high-speed methods for heat treatment from the viewpoint of the processes of phase transformation and structure formation as well as the resultant strength properties of steels. Differences in the kinetic parameters and the observability and controllability of these processes under the two methods of heat treatment are assessed. The formation of austenite under high-speed heating is discussed along with the possibilities of action on its granular structure and the use of incomplete homogenization for hardening steel afforded by rapid treatment. The effects of high-speed annealing on phase behavior, including carbide, martensite, and austenite, on impurity binding energy, and on other strengthening parameters were evaluated. Decomposition of supercooled austenite in accelerated heating is discussed. Reasons for the thermal stabilization of supercooled austenite during hardening of steel with the formation of martensite or bainite structures were investigated. Using fast heating it is possible to obtain carbon and economically alloyed steels with strength properties similar to those of complex-alloy steels hardened by traditional methods.

  15. The Effect of Heat Treatment and Mechanical Polishing on Nitinol Stent

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang Soo; Lee, Se Chol; Kim, Kyu Suk; Choi, Seong Hoon; Park, Chan Soo [Eulji University, Daejeon (Korea, Republic of); Yoon, Chang Jin; Kang, Sung Gwon [Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Park, Jae Hyung [Seoul National University Hospital, Seoul (Korea, Republic of)

    2009-09-15

    To understand the effect of heat treatment and mechanical polishing of a Nitinol wire on the chemical composition and physical morphology of the wire surface. Stents with a diameter of 1.0 cm, length of 8-10 cm, and composed of a Nitinol wire, were heat-treated at 500 .deg. C for 30 minutes, and mechanically polished with walnut shell granules. The wire surface morphology was studied with both an optical and a scanning electron microscope (SEM). In addition, an elemental analysis was performed by Energy Dispersive X-ray spectroscopy (EDX). Long microcracks along the wire direction and short microcracks across the wire were observed by SEM from the raw Nitinol wire. Upon heat treatment, the color of the wire turned blue, and Na, K, Cl, Si, Al atoms were seen from the EDX of the heat treated wire, which were absent in the original wire. The microcracks disappeared with the mechanical polishing, and the Na, K, Cl, Si, Al atoms all disappeared after the mechanical polishing. Mechanical polishing using walnut shell granules effectively removed the microcracks of a nitinol wire and impurities produced from the heat treatment.

  16. Structural Evolvement of Heating Treatment of Mg/Al-LDH and Preparation of Mineral Mesoporous Materials

    Institute of Scientific and Technical Information of China (English)

    CHEN Tianhu; XU Huifang; WANG Yifeng; QING Chengsong; FAN Mingde; CHEN Gang

    2006-01-01

    Although hydrotalcite, or layered double hydroxides (LDHs), is not a common mineral, it is an important material that can be easily synthesized in laboratory. In this study, structural evolvement and BET surface area changes of heat treated Mg/Al-LDH is evaluated by XRD, TEM and N2-BET analyses. The results indicate that the magnesium-aluminum LDH with carbonate as interlayer anion,periclase-like oxides was formed at temperatures of 400-800℃. Meanwhile, 2-3 nanometer mesoporous were formed during decomposition of LDH. However, the heat treated samples still preserve the morphology of the original LDH plates. Periclase-like formed from LDH heat treatment may re-hydrolyze and recover the structure of LDH. However, crystallinity of the recovered LDH is lower than that of the original LDH. This heat treatment will result in formation of (Mg, Al)-oxide nano-crystals and nanopores among the nano-crystals. When heating temperature exceeds 1000, the periclase-like (Mg, Al)-oxide is transformed into a composite with periclase (MgO) and spinel phases.The periclase can be re-hydrolyzed and dissolved in HCl solution. After acid treatment, the sample with a high surface area is composed of spinel nano-crystals and nanopores among them. Our results will provide a new and economic way to synthesize mesoporous materials through pathways of phase transformation of precursor materials with different composition.

  17. HEMS technique for heat-harm control and geo-thermal utilization in deep mines

    Institute of Scientific and Technical Information of China (English)

    Pingye Guo; Guolong Zhu; Manchao He

    2014-01-01

    With the increasing exploitation scope and intensity, the shallow resources would be exhausted in the future;and the deep mining will become an essential choice. In deep tunnel engineering, the heat-harm becomes one of the main barriers. Investigations on high temperature coal mine have been done in Northern China, with the constructing of three models of high temperature mines suffering heat-harm, at the Jiahe mine, Sanhejian mine and Zhangshuanglou mine. The domestic and abroad cooling technologies of the mine respectively are also summarized after comparatively analyzing the advantages and disadvantages of each technology. Finally, we find that the high temperature exchange machinery system (HEMS) technology that use mine discharge as the cold source, is excellent to heat-harm control in deep mines. Taking the Jiahe coal mine as an example, we systematically introduce this technology by disposing three main workstations. HEMS technology with its operations and functions in different exploitation levels are accomplished, including the extraction of refrigerating output, the transportation of chilled water by closed circulation line, the decompression of circulation lines and equipment by pressure transformation machine, and the heat exchange and cooling of workplace by heat exchange between wind stream and the chilled water. The exchanged heat source from the workplace is taken to ground heating by the circulating water which acts as a carrier. It shows that the HEMS-technology benefit in environment protection and emission reduction. Results of this project illustrate that it is efficient in heat-harm control with the temperature decrease of the workplace down to 26–29 ?C, and being 4–6 ?C lower than the original, and the relative humidity 5%–15%lower than before. It greatly improves the working environment of underground workplace suffering heat-harm of high tem-perature and high humidity. In addition, by the extracting of deep geothermal energy, ground

  18. Treatment of 320 Cases of Infantile Diarrhea by Needling Technique of Setting Fire on Mountains

    Institute of Scientific and Technical Information of China (English)

    BO Li-ya; ZHANG Hui-ling; WU Chun-sheng; HUANG Guo-qi

    2003-01-01

    In the treatment of 320 cases of infantile diarrhea by the needling technique of setting fire on mountains, with Zusanli (ST 36) and Changqiang (GV 1)as the main acupoints, all cases were cured after 1-3 treatments.

  19. Measurement of heat treatment induced residual stresses by using ESPI combined with hole-drilling method

    Institute of Scientific and Technical Information of China (English)

    Jie Cheng; Si-Young Kwak; Ho-Young Hwang

    2010-01-01

    In this study,residual stresses in heat treated specimen were measured by using ESPI(Electronic Speckle-Pattern Interferometry)combined with the hole-drilling method.The specimen,made of SUS 304austenitic stainless steel,was quenched and water cooled to room temperature.Numerical simulation using a hybrid FDM/FEM package was also carried out to simulate the heat treatment process.As a result,the thermal stress fields were obtained from both the experiment and the numerical simulation.By comparision of stress fields,results from the experimental method and numerical simulation well agreed to each other,therefore,it is proved that the presented experimental method is applicable and reliable for heat treatment induced residual stress measurement.

  20. Effect of T6 heat treatment on damping characteristics of Al/RHA composites

    Indian Academy of Sciences (India)

    D Siva Prasad; A Rama Krishna

    2012-11-01

    In the present work, effect of T6 heat treatment on the damping behaviour of aluminum/rice husk ash (RHA) composites fabricated by vortex method was studied using dynamic mechanical analyser (DMA) at frequencies ranging from 1 Hz to 25 Hz at room temperature under three-point bending test mode. The matrix material for the present work was A356.2 and reinforced with different weight % of 4, 6 and 8 rice husk ash particles. It was observed that composite exhibits high damping capacities than unreinforced alloy and increases with increase in weight % and the storage modulus increases with the addition of RHA particles but decreases with the increase in weight %. The heat treated composites exhibit higher damping capacity than the composites without heat treatment and increases with the increase in weight % of the reinforcement and loss in the storage modulus was observed and further decreases with the increase in the weight %of reinforcement. The related mechanisms were also discussed.

  1. Protocol for using protein solubility as an indicator of full-fat soybean heat treatment

    Directory of Open Access Journals (Sweden)

    Palić Dragan V.

    2009-01-01

    Full Text Available When the degree of full-fat soybean (FFSB processing is determined using protein solubility as an indicator of heat treatment extent, a problem represents the lack of a standard with known value of protein solubility, against which the protein solubility of heat treated FFSB would be determined. Also, a special practical problem imposes the fact that universal ranges of units for describing the degree of FFSB processing are used globally, without taking into consideration specific regional differences. In this paper, a protocol was proposed for establishing unit ranges for defining under-, adequately- and over-processed FFSB when protein solubility is used as an indicator of the extent of heat treatment.

  2. 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.

  3. Changes of crystallinity and spherulite morphology in isotactic polypropylene after rolling and heat treatment

    Institute of Scientific and Technical Information of China (English)

    Juan Jia; Weimin Mao; Dierk Raabe

    2008-01-01

    The spherulite morphology of the rolled and subsequent heat-treated isotaetic polypropylene (iPP) was observed by polarized microscopy, and the crystallinity evolution of materials was also measured by the wide angle X-ray scattering (WAXS). Rolling led to the oblate spherulites in the deformed iPP samples. The sheared crystalline lamellae broke apart into sets of crystalline blocks during rolling. As a result, the crystallinity of the iPP samples was greatly reduced during deformation, which induced the unclear spherulites and spherulite boundaries. Subsequent heat treatment resulted in the strong recrystallization of the rolled iPP samples. But the recrystallization in this work only meant the rearrangement of the macromolecule along the unbroken crystalline lamellae and the existing small crystalline blocks in the deformed spherulites. Heat treatment did not change the shape of the spherulites formed during deformation. The recrystallization also resulted in very clear spherulites and spherulite boundaries.

  4. Evaluation of heat treatment schedules for emerald ash borer (Coleoptera: Buprestidae).

    Science.gov (United States)

    Myers, Scott W; Fraser, Ivich; Mastro, Victor C

    2009-12-01

    The thermotolerance of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), was evaluated by subjecting larvae and prepupae to a number of time-temperature regimes. Three independent experiments were conducted during 2006 and 2007 by heating emerald ash borer infested firewood in laboratory ovens. Heat treatments were established based on the internal wood temperature. Treatments ranged from 45 to 65 degrees C for 30 and 60 min, and the ability of larvae to pupate and emerge as adults was used to evaluate the success of each treatment. A fourth experiment was conducted to examine heat treatments on exposed prepupae removed from logs and subjected to ambient temperatures of 50, 55, and 60 degrees C for 15, 30, 45, and 60 min. Results from the firewood experiments were consistent in the first experiment. Emergence data showed emerald ash borer larvae were capable of surviving a temperatures-time combination up to 60 degrees C for 30 min in wood. The 65 degrees C for 30 min treatment was, however, effective in preventing emerald ash borer emergence on both dates. Conversely, in the second experiment using saturated steam heat, complete mortality was achieved at 50 and 55 degrees C for both 30 and 60 min. Results from the prepupae experiment showed emerald ash borer survivorship in temperature-time combinations up to 55 degrees C for 30 min, and at 50 degrees C for 60 min; 60 degrees C for 15 min and longer was effective in preventing pupation in exposed prepupae. Overall results suggest that emerald ash borer survival is variable depending on heating conditions, and an internal wood temperature of 60 degrees C for 60 min should be considered the minimum for safe treatment for firewood.

  5. Advanced modeling techniques in application to plasma pulse treatment

    Science.gov (United States)

    Pashchenko, A. F.; Pashchenko, F. F.

    2016-06-01

    Different approaches considered for simulation of plasma pulse treatment process. The assumption of a significant non-linearity of processes in the treatment of oil wells has been confirmed. Method of functional transformations and fuzzy logic methods suggested for construction of a mathematical model. It is shown, that models, based on fuzzy logic are able to provide a satisfactory accuracy of simulation and prediction of non-linear processes observed.

  6. Successful Treatment of Cutaneous Botryomycosis with a Combination of Minocycline and Topical Heat Therapy

    Directory of Open Access Journals (Sweden)

    Masaya Ishibashi

    2012-05-01

    Full Text Available Cutaneous botryomycosis is a chronic focal infection characterized by a granulomatous inflammatory response to bacterial pathogens such as Staphylococcus aureus. Treatment requires antibiotic therapy and may also require surgical debridement. We employed topical heat therapy and oral minocycline. The lesions became flattened and pigmented after 1 month. We consider that this simple treatment can be an effective and harmless complementary therapy for cutaneous botryomycosis.

  7. Comparison of hybrid volumetric modulated arc therapy (VMAT technique and double arc VMAT technique in the treatment of prostate cancer

    Directory of Open Access Journals (Sweden)

    Amaloo Christopher

    2015-09-01

    Full Text Available Background. Volumetric modulated arc therapy (VMAT has quickly become accepted as standard of care for the treatment of prostate cancer based on studies showing it is able to provide faster delivery with adequate target coverage and reduced monitor units while maintaining organ at risk (OAR sparing. This study aims to demonstrate the potential to increase dose conformality with increased planner control and OAR sparing using a hybrid treatment technique compared to VMAT.

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

    DEFF Research Database (Denmark)

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

    2009-01-01

    The mechanical strength of thin, symmetric sandwich specimens consisting of a dense yttria-stabilized zirconia (YSZ) substrate coated with a porous NiO–YSZ layer at both major faces was investigated. Specimens were loaded in uniaxial tension to failure following heat treatments at various...

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

    DEFF Research Database (Denmark)

    Eldrup, Morten Mostgaard; Singh, B.N.

    1998-01-01

    The electrical conductivity of three different types of copper alloys, viz. CuNiBe, CuCrZr and Cu-Al(2)O(3) as well as of pure copper are reported. The alloys have undergone different pre-irradiation heat treatments and have been fission-neutron irradiated up to 0.3 dpa. In some cases post...

  10. Effect of thermal ammoniation and heat treatment on the faecal and ...

    African Journals Online (AJOL)

    and utilization of bird proof grain sorghum by pigs. I.S. Brand*, H.A. .... gains for the growth interval 30 - 90 kg live mass. The ... found with the heat treatment of whole oats grain that ..... (P :s; 0,01) less weight per day, and had significantly.

  11. Effect of heat treatments on precipitate microstructure and mechanical properties of CuCrZr alloy

    DEFF Research Database (Denmark)

    Singh, B.N; Edwards, D.J.; Tähtinen, S.

    2004-01-01

    A number of specimens of CuCrZr alloy was prime aged and then overaged at 600oC for 1, 2 and 4 hours and for 4 hours at 700 and 850oC. After different heat treatments, both the precipitate microstructure and mechanical properties were characterized.Mechanical properties were determined at 50...

  12. Effect of solution heat treatment time on a rheocast Al-Zn-Mg-Cu alloy

    CSIR Research Space (South Africa)

    Mazibuko, NE

    2011-06-01

    Full Text Available During rheo-high pressure die casting (R-HPDC) of Al-Zn-Mg-Cu alloys a coarse eutectic phase is formed. This eutectic phase is difficult to take into solution because of its size and it would require longer solution heat treatment times...

  13. Effect of Heat Moisture Treatment on Functional Properties and Microstuctural Profiles of Sweet Potato Flour

    Directory of Open Access Journals (Sweden)

    Widya Dwi Rukmi Putri

    2014-05-01

    Full Text Available Heat moisture treatment is the physical method of modification to give sweet potato flour desired physical properties for application in the manufacture of flour based products. Two varieties of sweet potato flour were characterized to understand the changes of physicochemical properties and micro-structural profile upon heat moisture treatment. Sweet potato flours were analyzed its pasting properties, crystallinity characteristics and starch granule structure by using Rapid Visco Analyzer, X-ray Diffraction and Scanning Electron Microscopy, respectively. The results indicated that the heat moisture treatment affected characteristics of all sweet potato flour were treated at, moderate and high temperature. There were a decreasing in peak viscosity and an increase in cold paste viscosity following heat-moisture treatment compare to native sweet potato. The changes differ between yellow sweet potato and purple sweet potato. This indicates that different starches may respond differently to physical modification. The diffractograph of flour samples showed the main peak mainly in 15°, 16°, 17°, 22° and 23°, that correspond to the spacing-d in 5, 8, 5, 3, 4, 9 and 3, 8 Å, respectively. This reflection indicates the presence of a A-type crystalline.

  14. Deposition, Heat Treatment And Characterization of Two Layer Bioactive Coatings on Cylindrical PEEK.

    Science.gov (United States)

    Durham, John W; Rabiei, Afsaneh

    2016-09-15

    Polyether ether ketone (PEEK) rods were coated via ion beam asssited deposition (IBAD) at room temperature. The coating consists of a two-layer design of yttria-stabilized zirconia (YSZ) as a heat-protection layer, and hydroxyapatite (HA) as a top layer to increase bioactivity. A rotating substrate holder was designed to deposit an even coating on the cylindrical surface of PEEK rods; the uniformity is verified by cross-sectional measurements using scanning electron microscopy (SEM). Deposition is followed by heat treatment of the coating using microwave annealing and autoclaving. Transmission electron microscopy (TEM) showed a dense, uniform columnar grain structure in the YSZ layer that is well bonded to the PEEK substrate, while the calcium phosphate layer was amorphous and pore-free in its as-deposited state. Subsequent heat treatment via microwave energy introduced HA crystallization in the calcium phosphate layer and additional autoclaving further expanded the crystallization of the HA layer. Chemical composition evaluation of the coating indicated the Ca/P ratios of the HA layer to be near that of stoichiometric HA, with minor variations through the HA layer thickness. The adhesion strength of as-deposited HA/YSZ coatings on smooth, polished PEEK surfaces was mostly unaffected by microwave heat treatment, but decreased with additional autoclave treatment. Increasing surface roughness showed improvement of bond strength.

  15. Effect of thermal ammoniation and heat treatment of high-tannin ...

    African Journals Online (AJOL)

    An experiment was conducted to (i) determine the effect of heat treatment and thermal ammoniation on dry-matter digestibility ... these stresses are severe. However, the ..... gains with chickens fed an untreated low-tannin sorghum diet and a ...

  16. Statement on a heat treatment to control Agrilus planipennis

    DEFF Research Database (Denmark)

    Baker, R.; Candresse, T.; Dormannsné Simon, E.

    2012-01-01

    In 2011, the EFSA Panel on Plant Health was asked by the European Commission to provide an opinion on a technical file submitted by the US Authorities to support a request to list a new heat treatment (60 °C/60 min) among the EU import requirements for wood of Agrilus planipennis host plants. Aft...

  17. Nuclear metallurgy lectures. Chapter 9, Fabrication and heat treatment of uranium

    Energy Technology Data Exchange (ETDEWEB)

    Riches, J.W.

    1955-05-12

    This chapter presents the highlights of the fabrication and heat treatment of uranium with emphasis on HAPO type core material. For pile use three properties of uranium are of prime interest; grain size, type and degree of preferred orientation, and the mechanical properties.

  18. The Integration of Vacuum Brazing into Heat Treatment - A Progressive Combined Process

    Institute of Scientific and Technical Information of China (English)

    Ingo Reinkensmeier; Henkjan Buursen

    2004-01-01

    The continuous constructive challenge to improve the functionality and efficiency of components always results in higher demands on production engineering, against the background of the generally increasing cost pressure. In many cases, you will just succeed in producing competitive and innovative products by combining and coupling of different procedures to an independent (hybrid) technology. The use of hybrid procedures for metal joining and heat treatment of metallic materials finds more and more industrial fields of application. Modern vacuum lines with integrated pressurized gas quenching are considered high-performance and flexible means of production for brazing and heat treatment tasks as well in the turbine industry as in the mould making and tool manufacturing industry. In doing so, the heat treatment is coupled with the brazing cycle in a combined process so that the brazing temperatures and soak times are adapted to the necessary temperatures and times for solution heat treatment and austeniting. This user-oriented article describes on the one hand examples of brazing of turbine components, but above all the practical experience from the plastics processing industry, where the requirement for a high-efficient cooling of injection moulding dies gains more and more importance.The combined procedure "Vacuum Brazing and Hardening" offers plenty of possibilities to produce mould inserts with an efficient tempering system in an economic way.

  19. Influence of Si content and heat treatment on microstructure of Al-Fe-Si alloys

    Institute of Scientific and Technical Information of China (English)

    Zhao Yuhua; Wang Xiubin; Liu Yulin; Wang Chao

    2014-01-01

    The effect of Si addition and heat treatment on the Al-5wt.%Fe al oy has been investigated by OM, SEM-EDS and XRD. The results show that the Si plays a significant role in refining the primary Al3Fe phase. It was found that the addition of 3.0wt.% Si made the al oy present the finest and wel -distributed primary Al3Fe phase, but the Al3Fe phase almost disappeared when 5wt.% Si was added. With further increase in the Si content, some Fe-rich phases appeared in the inter-grains and coarsened. In addition, the heat treatments exert a significant impact on the microstructural evolution of the Al-5wt.%Fe-5wt.%Si al oy. After heat treatment for 28 hours at 590 ºC, the coarse platelet or blocky Fe-rich phase in Al-5wt.%Fe-5wt.%Si al oys was granulated; the phase transformation from metastable platelet Al3FeSi and blocky Al8Fe2Si to stable Al5FeSi had occurred. With the extension of heat treatment, the Si phase coarsened gradual y.

  20. Statement on a heat treatment to control Agrilus planipennis

    DEFF Research Database (Denmark)

    Baker, R.; Candresse, T.; Dormannsné Simon, E.

    2012-01-01

    In 2011, the EFSA Panel on Plant Health was asked by the European Commission to provide an opinion on a technical file submitted by the US Authorities to support a request to list a new heat treatment (60 °C/60 min) among the EU import requirements for wood of Agrilus planipennis host plants. Aft...