Sample records for rapidly heat thin

  1. A molecular dynamics study on thin film liquid boiling characteristics under rapid linear boundary heating: Effect of liquid film thickness (United States)

    Rabbi, Kazi Fazle; Tamim, Saiful Islam; Faisal, A. H. M.; Mukut, K. M.; Hasan, Mohammad Nasim


    This study is a molecular dynamics investigation of phase change phenomena i.e. boiling of thin liquid films subjected to rapid linear heating at the boundary. The purpose of this study is to understand the phase change heat transfer phenomena at nano scale level. In the simulation, a thin film of liquid argon over a platinum surface has been considered. The simulation domain herein is a three-phase system consisting of liquid and vapor argon atoms placed over a platinum wall. Initially the whole system is brought to an equilibrium state at 90 K and then the temperature of the bottom wall is increased to a higher temperature (250K) within a finite time interval. Four different liquid argon film thicknesses have been considered (3 nm, 4 nm, 5 nm and 6 nm) in this study. The boundary heating rate (40×109 K/s) is kept constant in all these cases. Variation in system temperature, pressure, net evaporation number, spatial number density of the argon region with time for different film thickness have been demonstrated and analyzed. The present study indicates that the pattern of phase transition may be significantly different (i.e. evaporation or explosive boiling) depending on the liquid film thickness. Among the four cases considered in the present study, explosive boiling has been observed only for the liquid films of 5nm and 6nm thickness, while for the other cases, evaporation take place.

  2. Improved Thin, Flexible Heat Pipes (United States)

    Rosenfeld, John H.; Gernert, Nelson J.; Sarraf, David B.; Wollen, Peter J.; Surina, Frank C.; Fale, John E.


    Flexible heat pipes of an improved type are fabricated as layers of different materials laminated together into vacuum- tight sheets or tapes. In comparison with prior flexible heat pipes, these flexible heat pipes are less susceptible to leakage. Other advantages of these flexible heat pipes, relative to prior flexible heat pipes, include high reliability and greater ease and lower cost of fabrication. Because these heat pipes are very thin, they are highly flexible. When coated on outside surfaces with adhesives, these flexible heat pipes can be applied, like common adhesive tapes, to the surfaces of heat sinks and objects to be cooled, even if those surfaces are curved.

  3. Poly(4-vinylphenol gate insulator with cross-linking using a rapid low-power microwave induction heating scheme for organic thin-film-transistors

    Directory of Open Access Journals (Sweden)

    Ching-Lin Fan


    Full Text Available A Microwave-Induction Heating (MIH scheme is proposed for the poly(4-vinylphenol (PVP gate insulator cross-linking process to replace the traditional oven heating cross-linking process. The cross-linking time is significantly decreased from 1 h to 5 min by heating the metal below the PVP layer using microwave irradiation. The necessary microwave power was substantially reduced to about 50 W by decreasing the chamber pressure. The MIH scheme is a good candidate to replace traditional thermal heating for cross-linking of PVP as the gate insulator for organic thin-film-transistors.

  4. Poly(4-vinylphenol) gate insulator with cross-linking using a rapid low-power microwave induction heating scheme for organic thin-film-transistors (United States)

    Fan, Ching-Lin; Shang, Ming-Chi; Hsia, Mao-Yuan; Wang, Shea-Jue; Huang, Bohr-Ran; Lee, Win-Der


    A Microwave-Induction Heating (MIH) scheme is proposed for the poly(4-vinylphenol) (PVP) gate insulator cross-linking process to replace the traditional oven heating cross-linking process. The cross-linking time is significantly decreased from 1 h to 5 min by heating the metal below the PVP layer using microwave irradiation. The necessary microwave power was substantially reduced to about 50 W by decreasing the chamber pressure. The MIH scheme is a good candidate to replace traditional thermal heating for cross-linking of PVP as the gate insulator for organic thin-film-transistors.

  5. Investigation of Rapid Low-Power Microwave-Induction Heating Scheme on the Cross-Linking Process of the Poly(4-vinylphenol) for the Gate Insulator of Pentacene-Based Thin-Film Transistors. (United States)

    Fan, Ching-Lin; Shang, Ming-Chi; Wang, Shea-Jue; Hsia, Mao-Yuan; Lee, Win-Der; Huang, Bohr-Ran


    In this study, a proposed Microwave-Induction Heating (MIH) scheme has been systematically studied to acquire suitable MIH parameters including chamber pressure, microwave power and heating time. The proposed MIH means that the thin indium tin oxide (ITO) metal below the Poly(4-vinylphenol) (PVP) film is heated rapidly by microwave irradiation and the heated ITO metal gate can heat the PVP gate insulator, resulting in PVP cross-linking. It is found that the attenuation of the microwave energy decreases with the decreasing chamber pressure. The optimal conditions are a power of 50 W, a heating time of 5 min, and a chamber pressure of 20 mTorr. When suitable MIH parameters were used, the effect of PVP cross-linking and the device performance were similar to those obtained using traditional oven heating, even though the cross-linking time was significantly decreased from 1 h to 5 min. Besides the gate leakage current, the interface trap state density (Nit) was also calculated to describe the interface status between the gate insulator and the active layer. The lowest interface trap state density can be found in the device with the PVP gate insulator cross-linked by using the optimal MIH condition. Therefore, it is believed that the MIH scheme is a good candidate to cross-link the PVP gate insulator for organic thin-film transistor applications as a result of its features of rapid heating (5 min) and low-power microwave-irradiation (50 W).

  6. Investigation of Rapid Low-Power Microwave-Induction Heating Scheme on the Cross-Linking Process of the Poly(4-vinylphenol for the Gate Insulator of Pentacene-Based Thin-Film Transistors

    Directory of Open Access Journals (Sweden)

    Ching-Lin Fan


    Full Text Available In this study, a proposed Microwave-Induction Heating (MIH scheme has been systematically studied to acquire suitable MIH parameters including chamber pressure, microwave power and heating time. The proposed MIH means that the thin indium tin oxide (ITO metal below the Poly(4-vinylphenol (PVP film is heated rapidly by microwave irradiation and the heated ITO metal gate can heat the PVP gate insulator, resulting in PVP cross-linking. It is found that the attenuation of the microwave energy decreases with the decreasing chamber pressure. The optimal conditions are a power of 50 W, a heating time of 5 min, and a chamber pressure of 20 mTorr. When suitable MIH parameters were used, the effect of PVP cross-linking and the device performance were similar to those obtained using traditional oven heating, even though the cross-linking time was significantly decreased from 1 h to 5 min. Besides the gate leakage current, the interface trap state density (Nit was also calculated to describe the interface status between the gate insulator and the active layer. The lowest interface trap state density can be found in the device with the PVP gate insulator cross-linked by using the optimal MIH condition. Therefore, it is believed that the MIH scheme is a good candidate to cross-link the PVP gate insulator for organic thin-film transistor applications as a result of its features of rapid heating (5 min and low-power microwave-irradiation (50 W.

  7. Poly(4-vinylphenol) gate insulator with cross-linking using a rapid low-power microwave induction heating scheme for organic thin-film-transistors


    Ching-Lin Fan; Ming-Chi Shang; Mao-Yuan Hsia; Shea-Jue Wang; Bohr-Ran Huang; Win-Der Lee


    A Microwave-Induction Heating (MIH) scheme is proposed for the poly(4-vinylphenol) (PVP) gate insulator cross-linking process to replace the traditional oven heating cross-linking process. The cross-linking time is significantly decreased from 1 h to 5 min by heating the metal below the PVP layer using microwave irradiation. The necessary microwave power was substantially reduced to about 50 W by decreasing the chamber pressure. The MIH scheme is a good candidate to replace traditional therma...

  8. Rapid heating of matter using high power lasers

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Woosuk [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    This slide presentation describes motivation (uniform and rapid heating of a target, opportunity to study warm dense matter, study of nuclear fusion reactions), rapid heating of matter with intense laser-driven ion beams, visualization of the expanding warm dense gold and diamond, and nuclear fusion experiments using high power lasers (direct heating of deuterium spheres (radius ~ 10nm) with an intense laser pulse.

  9. Thin Film Heat Flux Sensors: Design and Methodology (United States)

    Fralick, Gustave C.; Wrbanek, John D.


    Thin Film Heat Flux Sensors: Design and Methodology: (1) Heat flux is one of a number of parameters, together with pressure, temperature, flow, etc. of interest to engine designers and fluid dynamists, (2) The measurement of heat flux is of interest in directly determining the cooling requirements of hot section blades and vanes, and (3)In addition, if the surface and gas temperatures are known, the measurement of heat flux provides a value for the convective heat transfer coefficient that can be compared with the value provided by CFD codes.

  10. Rapid DNA amplification using a battery-powered thin-film resistive thermocycler. (United States)

    Herold, Keith E; Sergeev, Nikolay; Matviyenko, Andriy; Rasooly, Avraham


    A prototype handheld, compact, rapid thermocycler was developed for multiplex analysis of nucleic acids in an inexpensive, portable configuration. Instead of the commonly used Peltier heating/cooling element, electric thin-film resistive heater and a miniature fan enable rapid heating and cooling of glass capillaries leading to a simple, low-cost Thin-Film Resistive Thermocycler (TFRT). Computer-based pulse width modulation control yields heating rates of 6-7 K/s and cooling rates of 5 K/s. The four capillaries are closely coupled to the heater, resulting in low power consumption. The energy required by a nominal PCR cycle (20 s at each temperature) was found to be 57+/-2 J yielding an average power of approximately 1.0 W (not including the computer and the control system). Thus the device can be powered by a standard 9 V alkaline battery (or other 9 V power supply). The prototype TFRT was demonstrated (in a benchtop configuration) for detection of three important food pathogens (E. coli ETEC, Shigella dysenteriae, and Salmonella enterica). PCR amplicons were analyzed by gel electrophoresis. The 35 cycle PCR protocol using a single channel was completed in less then 18 min. Simple and efficient heating/cooling, low cost, rapid amplification, and low power consumption make the device suitable for portable DNA amplification applications including clinical point of care diagnostics and field use.

  11. Stochastic heating in laser interaction with ultra-thin foils (United States)

    Luis Martins, Joana; Siminos, Evangelos; Fulop, Tunde


    Stochastic heating of electrons in multiple counter-propagating electromagnetic waves has been investigated theoretically and numerically in numerous works since the 80s (e.g. Ref.). Stochastic heating has been invoked as a possible mechanism responsible for electron heating in scenarios such as laser interaction with thin foils for ion acceleration and electron heating in beat-wave injection. However, a clear experimental verification of this heating process has not been done, to our knowledge. In this work, we examine electron heating during the interaction of multiple laser pulses with ultra-thin foils (a few atomic layers wide) through numerical particle-in-cell and particle-particle simulations. Such targets could prevent the development of instabilities/processes which could hinder the interpretation of observations. We include realistic temporally and spatially finite laser pulses and targets and explore in detail possible setups for an experimental observation of stochastic heating, analyzing signatures in the electron energy spectra, angular distribution, and radiation emission.

  12. Estimating local heat transfer coefficients from thin wall temperature measurements (United States)

    Gazizov, I. M.; Davletshin, I. A.; Paereliy, A. A.


    An approach to experimental estimation of local heat transfer coefficient on a plane wall has been described. The approach is based on measurements of heat-transfer fluid and wall temperatures during some certain time of wall cooling. The wall was a thin plate, a printed circuit board, made of composite epoxy material covered with a copper layer. The temperature field can be considered uniform across the plate thickness when heat transfer is moderate and thermal resistance of the plate in transversal direction is low. This significantly simplifies the heat balance written for the wall sections that is used to estimate the heat transfer coefficient. The copper layer on the plate etched to form a single strip acted as resistance thermometers that measured the local temperature of the wall.

  13. Heat Treatment Development for a Rapidly Solidified Heat Resistant Cast Al-Si Alloy (United States)

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


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

  14. Rapid densification of sol–gel derived yttria-stabilized zirconia thin films

    Energy Technology Data Exchange (ETDEWEB)

    Veldhuis, Sjoerd A.; Brinks, Peter; Elshof, Johan E. ten, E-mail:


    A method based on X-ray reflectivity was used to study the densification behavior of 8 mol% yttria-stabilized zirconia for use in solid oxide fuel cells. Sol–gel derived thin electrolyte films were prepared via spin coating. Subsequent microwave-assisted rapid thermal annealing at 650–1000 °C resulted in crack-free 70 nm thin films. A maximum density of approximately 95% was achieved within 5 min at 1000 °C. X-ray photoelectron spectroscopy depth analysis on the thin films showed that the shorter annealing times, as opposed to conventional heating, resulted in lower Si concentrations at the top surface and at the substrate interface. - Highlights: • Parameter-free method based on XRR to study densification 8YSZ • Microwave-assisted thermal annealing resulted in crack-free 70 nm thin films. • Density up to 95% was achieved within 5 min at 1000 °C. • XPS analysis showed that short annealing times resulted in lower Si concentrations.

  15. Thermodynamic properties of pulverized coal during rapid heating devolatilization processes

    Energy Technology Data Exchange (ETDEWEB)

    Proscia, W.M.; Freihaut, J.D. [United Technologies Research Center, E. Hartford, CT (United States); Rastogi, S.; Klinzing, G.E. [Univ. of Pittsburg, PA (United States)


    The thermodynamic properties of coal under conditions of rapid heating have been determined using a combination of UTRC facilities including a proprietary rapid heating rate differential thermal analyzer (RHR-DTA), a microbomb calorimeter (MBC), an entrained flow reactor (EFR), an elemental analyzer (EA), and a FT-IR. The total heat of devolatilization, was measured for a HVA bituminous coal (PSOC 1451D, Pittsburgh No. 8) and a LV bituminous coal (PSOC 1516D, Lower Kittaning). For the HVA coal, the contributions of each of the following components to the overall heat of devolatilization were measured: the specific heat of coal/char during devolatilization, the heat of thermal decomposition of the coal, the specific heat capacity of tars, and the heat of vaporization of tars. Morphological characterization of coal and char samples was performed at the University of Pittsburgh using a PC-based image analysis system, BET apparatus, helium pcynometer, and mercury porosimeter. The bulk density, true density, CO{sub 2} surface area, pore volume distribution, and particle size distribution as a function of extent of reaction are reported for both the HVA and LV coal. Analyses of the data were performed to obtain the fractal dimension of the particles as well as estimates for the external surface area. The morphological data together with the thermodynamic data obtained in this investigation provides a complete database for a set of common, well characterized coal and char samples. This database can be used to improve the prediction of particle temperatures in coal devolatilization models. Such models are used both to obtain kinetic rates from fundamental studies and in predicting furnace performance with comprehensive coal combustion codes. Recommendations for heat capacity functions and heats of devolatilization for the HVA and LV coals are given. Results of sample particle temperature calculations using the recommended thermodynamic properties are provided.

  16. Rapid Nanoparticle Synthesis by Magnetic and Microwave Heating

    Directory of Open Access Journals (Sweden)

    Viktor Chikan


    Full Text Available Traditional hot-injection (HI syntheses of colloidal nanoparticles (NPs allows good separation of the nucleation and growth stages of the reaction, a key limitation in obtaining monodisperse NPs, but with limited scalability. Here, two methods are presented for obtaining NPs via rapid heating: magnetic and microwave-assisted. Both of these techniques provide improved engineering control over the separation of nucleation and growth stages of nanomaterial synthesis when the reaction is initiated from room temperature. The advantages of these techniques with preliminary data are presented in this prospective article. It is shown here that microwave assisted heating could possibly provide some selectivity in activating the nanomaterial precursor materials, while magnetic heating can produce very tiny particles in a very short time (even on the millisecond timescale, which is important for scalability. The fast magnetic heating also allows for synthesizing larger particles with improved size distribution, therefore impacting, not only the quantity, but the quality of the nanomaterials.

  17. Structural and compositional properties of CZTS thin films formed by rapid thermal annealing of electrodeposited layers (United States)

    Lehner, J.; Ganchev, M.; Loorits, M.; Revathi, N.; Raadik, T.; Raudoja, J.; Grossberg, M.; Mellikov, E.; Volobujeva, O.


    In this work Cu2ZnSnS4 (CZTS) thin films were formed by rapid thermal annealing (RTA) of sequentially electrodeposited Cu-Zn and Sn films in 5% H2S containing atmosphere. Six different thermal profiles were used in the experiments. In three of these, the temperature ramping up was varied, while the variable in the other three profiles was the cooling down rate. The optimising parameters for RTA of electrodeposited films were found and annealed films were characterised by X-ray diffraction (XRD), micro-Raman spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM+EDS). The material parameters such as lattice strain and crystallite size were also determined and the influence of annealing temperature and heating rate on these parameters was discussed.The pathway of MoS2 formation was investigated.

  18. Heat transfer in thin, compact heat exchangers with circular, rectangular, or pin-fin flow passages (United States)

    Olson, D. A.


    Heat transfer and pressure drop have been measured of three thin, compact heat exchangers in helium gas at 3.5 MPa and higher, with Reynolds numbers of 450 to 36,000. The flow geometries for the three heat exchanger specimens were: circular tube, rectangular channel, and staggered pin fin with tapered pins. The specimens were heated radiatively at heat fluxes up to 77 W/sq cm. Correlations were developed for the isothermal friction factor as a function of Reynolds number, and for the Nusselt number as a function of Reynolds number and the ratio of wall temperature to fluid temperature. The specimen with the pin fin internal geometry had significantly better heat transfer than the other specimens, but it also had higher pressure drop. For certain conditions of helium flow and heating, the temperature more than doubled from the inlet to the outlet of the specimens, producing large changes in gas velocity, density, viscosity, and thermal conductivity. These changes in properties did not affect the correlations for friction factor and Nusselt number in turbulent flow.

  19. Synthesis of CVD-graphene on rapidly heated copper foils. (United States)

    Kim, Sang-Min; Kim, Jae-Hyun; Kim, Kwang-Seop; Hwangbo, Yun; Yoon, Jong-Hyuk; Lee, Eun-Kyu; Ryu, Jaechul; Lee, Hak-Joo; Cho, Seungmin; Lee, Seung-Mo


    Most chemical vapor deposition (CVD) systems used for graphene growth mainly employ convection and radiation heat transfer between the heating source and the metal catalyst in order to reach the activation temperature of the reaction, which in general leads to a long synthesis time and poor energy efficiency. Here, we report a highly time- and energy-efficient CVD setup, in which the metal catalyst (Cu) is designed to be physically contacted with a heating source to give quick heat transfer by conduction. The induced conduction heating enabled the usual effects of the pretreatment and annealing of Cu (i.e., annihilation of surface defects, impurities and contaminants) to be achieved in a significantly shorter time compared to conventional CVD. Notably, the rapid heating was observed to lead to larger grains of Cu with high uniformity as compared to the Cu annealed by conventional CVD, which are believed to be beneficial for the growth of high quality graphene. Through this CVD setup, bundles of high quality (∼252 Ω per square) and large area (over 16 inch) graphenes were able to be readily synthesized in 40 min in a significantly efficient way. When considering ease of scalability, high energy effectiveness and considerable productivity, our method is expected to be welcomed by industrialists.

  20. Rapid Heat Treatment of Aluminum High-Pressure Diecastings (United States)

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


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

  1. Heat transfer mechanism with thin filaments including ceramic high temperature heat exchanger (United States)

    Im, Kwan H.; Ahluwalia, Rajesh K.


    A radiative heat transfer mechanism in a furnace having burners through which pulverized coal and air are burned producing combustion gases and contaminants. A plurality of elongated conduits are positioned inside the furnace proximate to the burners generally parallel to the flow of combustion gases in the furnace. A plurality of thin filaments are inside each of the elongated hollow conduits, the filaments having diameters in the range of from about 1 micrometer to about 1,000 micrometers and having an infrared radiation cross-section sufficient to cause the filaments to heat upon exposure to infrared radiation. Blower mechanism is associated with the elongated conduits for limiting the amount of soot and ash which deposit on the conduits to preserve the radiative and convective transfer of heat energy from the combustion gases to the conduits.

  2. Advances in rapid cooling treatment for heat stroke

    Directory of Open Access Journals (Sweden)

    Jia-jia ZHAO


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

  3. Direct synthesis and characterization of optically transparent conformal zinc oxide nanocrystalline thin films by rapid thermal plasma CVD


    Pedersen, Joachim D; Esposito, Heather J; Teh, Kwok Siong


    We report a rapid, self-catalyzed, solid precursor-based thermal plasma chemical vapor deposition process for depositing a conformal, nonporous, and optically transparent nanocrystalline ZnO thin film at 130 Torr (0.17 atm). Pure solid zinc is inductively heated and melted, followed by ionization by thermal induction argon/oxygen plasma to produce conformal, nonporous nanocrystalline ZnO films at a growth rate of up to 50 nm/min on amorphous and crystalline substrates including Si (100), fuse...

  4. Isotropic Heating of Galaxy Cluster Cores via Rapidly Reorienting Active Galactic Nucleus Jets (United States)

    Babul, Arif; Sharma, Prateek; Reynolds, Christopher S.


    Active galactic nucleus (AGN) jets carry more than sufficient energy to stave off catastrophic cooling of the intracluster medium (ICM) in the cores of cool-core clusters. However, in order to prevent catastrophic cooling, the ICM must be heated in a near-isotropic fashion and narrow bipolar jets with P jet = 1044 - 45 erg s-1, typical of radio AGNs at cluster centers, are inefficient in heating the gas in the transverse direction to the jets. We argue that due to existent conditions in cluster cores, the supermassive black holes (SMBHs) will, in addition to accreting gas via radiatively inefficient flows, experience short stochastic episodes of enhanced accretion via thin disks. In general, the orientation of these accretion disks will be misaligned with the spin axis of the black holes (BHs) and the ensuing torques will cause the BH's spin axis (and therefore the jet axis) to slew and rapidly change direction. This model not only explains recent observations showing successive generations of jet-lobes-bubbles in individual cool-core clusters that are offset from each other in the angular direction with respect to the cluster center, but also shows that AGN jets can heat the cluster core nearly isotropically on the gas cooling timescale. Our model does require that the SMBHs at the centers of cool-core clusters be spinning relatively slowly. Torques from individual misaligned disks are ineffective at tilting rapidly spinning BHs by more than a few degrees. Additionally, since SMBHs that host thin accretion disks will manifest as quasars, we predict that roughly 1-2 rich clusters within z < 0.5 should have quasars at their centers.

  5. Thin Film Heat Flux Sensor Development for Ceramic Matrix Composite (CMC) Systems (United States)

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


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

  6. Rapid dynamic thinning on Upernavik Icestream, West Greenland

    DEFF Research Database (Denmark)

    Khan, Shfaqat Abbas; Kjær, Kurt H.; Korsgaard, Niels Jákup


    , and Jakobshavn Isbræ (JI) in West Greenland) as a result of significant accelerations in flow speed. The situation across Greenland continues to evolve. Evidence from GRACE (Velicogna, 2009), GPS (Khan, 2010) and ICESat (Pritchard, 2009) suggest that there is an ongoing northward migration of increasing ice loss......) laser altimetry data supplemented with altimeter surveys from NASA’s Airborne Topographic Mapper (ATM). To assess thinning prior to 2003, we analyze 1985 aerial photos and derived a 2x2 m grid digital elevation model (DEM)....

  7. Rapid precision casting for complex thin-walled aluminum alloy parts

    Directory of Open Access Journals (Sweden)

    Xuanpu DONG


    Full Text Available Based on Vacuum Differential Pressure Casting (VDPC precision forming technology and the Selective Laser Sintering (SLS Rapid Prototyping (RP technology, a rapid manufacturing method called Rapid Precision Casting (RPC process from computer three-dimensional solid models to metallic parts was investigated. The experimental results showed that the main advantage of RPC was not only its ability to cast higher internal quality and more accurate complex thin-walled aluminum alloy parts, but also the greatly-reduced lead time cycle from Selective Laser Sintering(SLS plastic prototyping to metallic parts. The key forming technology of RPC for complex thin-walled metallic parts has been developed for new casting production and Rapid Tooling (RT, and it is possible to rapidly manufacture high-quality and accurate metallic parts by means of RP in foundry industry.

  8. Versatile and Rapid Plasma Heating Device for Steel and Aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, G.S.


    The main objective of the research was to enhance steel and aluminum manufacturing with the development of a new plasma RPD device. During the project (1) plasma devices were manufactured (2) testing for the two metals were carried out and (3) market development strategies were explored. Bayzi Corporation has invented a Rapid Plasma Device (RPD) which produces plasma, comprising of a mixture of ionized gas and free electrons. The ions, when they hit a conducting surface, deposit heat in addition to the convective heat. Two generic models called the RPD-Al and RPD-S have been developed for the aluminum market and the steel market. Aluminum melting rates increased to as high as 12.7 g/s compared to 3 g/s of the current industrial practice. The RPD melting furnace operated at higher energy efficiency of 65% unlike most industrial processes operating in the range of 13 to 50%. The RPD aluminum melting furnace produced environment friendly cleaner melts with less than 1% dross. Dross is the residue in the furnace after the melt is poured out. Cast ingots were extremely clean and shining. Current practices produce dross in the range of 3 to 12%. The RPD furnace uses very low power ~0.2 kWh/Lb to melt aluminum. RPDs operate in one atmosphere using ambient air to produce plasma while the conventional systems use expensive gases like argon, or helium in air-tight chambers. RPDs are easy to operate and do not need intensive capital investment. Narrow beam, as well as wide area plasma have been developed for different applications. An RPD was developed for thermal treatments of steels. Two different applications have been pursued. Industrial air hardening steel knife edges were subjected to plasma beam hardening. Hardness, as measured, indicated uniform distribution without any distortion. The biggest advantage with this method is that the whole part need not be heated in a furnace which will lead to oxidation and distortion. No conventional process will offer localized

  9. Rapid densification of sol–gel derived yttria-stabilized zirconia thin films

    NARCIS (Netherlands)

    Veldhuis, Sjoerd; Brinks, Peter; ten Elshof, Johan E.


    A method based on X-ray reflectivity was used to study the densification behavior of 8 mol% yttria-stabilized zirconia for use in solid oxide fuel cells. Sol–gel derived thin electrolyte films were prepared via spin coating. Subsequent microwave-assisted rapid thermal annealing at 650–1000 °C

  10. Rapid contrasting of ultrathin sections using microwave irradiation with heat dissipation. (United States)

    Hernández-Chavarría, F; Vargas-Montero, M


    The use of microwave irradiation (MWI) to accelerate fixation, dehydration and contrasting (staining) for electron microscopy has been applied to the development of rapid methods to process biological samples in electron microscopy. A simple explanation is that the reduced time in those procedures is due to heating. In this paper we propose a contrasting method for thin sections that avoids the thermal effects of MWI. Grids with thin sections of mouse kidney, the dinoflagellate Alexandrium monilatum, spermatophores of the fly Archicepsis diversiformis, the bacteria Acinetobacter calcoaceticum and Enterobacter cloacae were placed into Beem capsules and stained with uranyl acetate and lead citrate, while immersed in an ice-water bath, and irradiated for periods ranging from 30 s to 2 min. After each contrasting procedure, the Beem capsule was filled with distilled water to wash the grids under MWI with the same irradiation time as used to contrast. Good results were obtained on irradiating for 1 min and the temperature of the Beem capsule was maintained around 5 degrees C.

  11. Thinning and rupture of a thin liquid film on a heated surface

    Energy Technology Data Exchange (ETDEWEB)

    Bankoff, S.G.; Davis, S.H.


    Results on the dynamics and stability of thin films are summarized on the following topics: forced dryout, film instabilities on a horizontal plane and on inclined planes, instrumentation, coating flows, and droplet spreading. (DLC)

  12. Rapid heating effects on grain-size, texture and magnetic properties ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 34; Issue 7. Rapid heating effects on ... The rapid heating effects on the microstructure, texture and magnetic properties of 3% Si nonoriented electrical steel has been investigated through optical microscopy, X-ray diffraction and Epstein frame. The results show that ...

  13. Implantable polymer/metal thin film structures for the localized treatment of cancer by Joule heating (United States)

    Kan-Dapaah, Kwabena; Rahbar, Nima; Theriault, Christian; Soboyejo, Wole


    This paper presents an implantable polymer/metal alloy thin film structure for localized post-operative treatment of breast cancer. A combination of experiments and models is used to study the temperature changes due to Joule heating by patterned metallic thin films embedded in poly-dimethylsiloxane. The heat conduction within the device and the surrounding normal/cancerous breast tissue is modeled with three-dimensional finite element method (FEM). The FEM simulations are used to explore the potential effects of device geometry and Joule heating on the temperature distribution and lesion (thermal dose). The FEM model is validated using a gel model that mimics biological media. The predictions are also compared to prior results from in vitro studies and relevant in vivo studies in the literature. The implications of the results are discussed for the potential application of polymer/metal thin film structures in hyperthermic treatment of cancer.

  14. Homotopy Perturbation Method for Thin Film Flow and Heat Transfer over an Unsteady Stretching Sheet with Internal Heating and Variable Heat Flux

    Directory of Open Access Journals (Sweden)

    I-Chung Liu


    Full Text Available We have analyzed the effects of variable heat flux and internal heat generation on the flow and heat transfer in a thin film on a horizontal sheet in the presence of thermal radiation. Similarity transformations are used to transform the governing equations to a set of coupled nonlinear ordinary differential equations. The obtained differential equations are solved approximately by the homotopy perturbation method (HPM. The effects of various parameters governing the flow and heat transfer in this study are discussed and presented graphically. Comparison of numerical results is made with the earlier published results under limiting cases.

  15. Rapid preparation of solution-processed InGaZnO thin films by microwave annealing and photoirradiation

    Directory of Open Access Journals (Sweden)

    Heajeong Cheong


    Full Text Available We fabricated solution-processed indium–gallium–zinc oxide (IGZO thin-film transistors (TFTs by microwave (MW annealing an IGZO precursor film followed by irradiating with vacuum ultraviolet (VUV light. MW annealing allows more rapid heating of the precursor film than conventional annealing processes using a hot plate or electric oven and promotes the crystallization of IGZO. VUV irradiation was used to reduce the duration and temperature of the post-annealing step. Consequently, the IGZO TFTs fabricated through MW annealing for 5 min and VUV irradiation for 1 min exhibited an on/off current ratio of 108 and a field-effect mobility of 0.3 cm2 V−1 s−1. These results indicate that MW annealing and photoirradiation is an effective combination for annealing solution processed IGZO precursor films to prepare the semiconductor layers of TFTs.

  16. Rapid fabrication of hierarchically structured supramolecular nanocomposite thin films in one minute (United States)

    Xu, Ting; Kao, Joseph


    Functional nanocomposites containing nanoparticles of different chemical compositions may exhibit new properties to meet demands for advanced technology. It is imperative to simultaneously achieve hierarchical structural control and to develop rapid, scalable fabrication to minimize degradation of nanoparticle properties and for compatibility with nanomanufacturing. The assembly kinetics of supramolecular nanocomposite in thin films is governed by the energetic cost arising from defects, the chain mobility, and the activation energy for inter-domain diffusion. By optimizing only one parameter, the solvent fraction in the film, the assembly kinetics can be precisely tailored to produce hierarchically structured thin films of supramolecular nanocomposites in approximately one minute. Moreover, the strong wavelength dependent optical anisotropy in the nanocomposite highlights their potential applications for light manipulation and information transmission. The present invention opens a new avenue in designing manufacture-friendly continuous processing for the fabrication of functional nanocomposite thin films.

  17. Beam Interaction with Thin Materials: Heat Deposition, Cooling Phenomena and Damage Limits

    CERN Document Server

    Sapinski, M


    Thin targets, inserted into particle beams can serve various purposes, starting from beam emittance measurements like in wire scanner or scintillating screens up to beam content modifications like in case of stripper foils. The mechanisms of energy deposition in a thin target for various beam types are discussed, together with properties of particles produced in this kind of interaction. The cooldown processes, from heat transfer up to cooling by sublimation, and their efficiencies are presented. Finally, damage conditions are discussed and conclusions about typical damage limits are drawn. The experiments performed with the wire scanners at CERN accelerators and a mathematical model of heating and cooling of a wire are presented.

  18. Choosing optimal rapid manufacturing process for thin-walled products using expert algorithm

    Directory of Open Access Journals (Sweden)

    Filip Gorski


    Full Text Available Choosing right Rapid Prototyping technology is not easy, especially for companies inexperienced with that group of manufacturing techniques. Paper summarizes research focused on creating an algorithm for expert system, helping to choose optimal process and determine its parameters for thin-walled products rapid manufacturing. Research was based upon trial manufacturing of different thin-walled items using various RP technologies. Products were categorized, each category was defined by a set of requirements. Basing on research outcome, main algorithm has been created. Next step was developing detailed algorithms for optimizing particular methods. Implementation of these algorithms brings huge benefit for recipients, including cost reduction, supply time decrease and improvements in information flow.

  19. Modification of microstructure and micromagnetic properties in Gd-Fe thin films by rapid thermal processing


    Talapatraa, A.; Chelvane, J. Arout; Satpati, B.; Kumar, S.; Mohanty, J.


    Impact of rapid thermal processing (RTP) on microstructure and magnetic properties of Gd-Fe thin films have been investigated with a special emphasis to magnetic microstructure. 100 nm thick amorphous Gd-Fe film shows elongated stripe domains with characteristic feature size of 122 nm, which signifies the development of perpendicular magnetic anisotropy (PMA) in this system. RTP at 550^oC for different time intervals viz. 5, 10, 15, 20 minutes induces the crystallization of Fe over the amorph...

  20. Moisture removal characteristics of thin layer rough rice under sequenced infrared radiation heating and cooling (United States)

    Rice drying with infrared (IR) radiation has been investigated during recent years and showed promising potential with improved quality and energy efficiency. The objective of this study was to further investigate the moisture removal characteristics of thin layer rough rice heated by IR and cooled ...

  1. Controllability and stability of 3D heat conduction equation in a submicroscale thin film

    NARCIS (Netherlands)

    Heidari, H.; Zwart, Heiko J.; Malek, Alaeddin

    We obtain a closed form analytic solution for the Dual Phase Lagging equation. This equation is a linear, time-independent partial differential equation modeling the heat distribution in a thin film. The spatial domain is of micrometer and nanometer geometries. We show that the solution is described

  2. Rapid heating of solid density material by a petawatt laser (United States)

    Evans, R. G.; Clark, E. L.; Eagleton, R. T.; Dunne, A. M.; Edwards, R. D.; Garbett, W. J.; Goldsack, T. J.; James, S.; Smith, C. C.; Thomas, B. R.; Clarke, R.; Neely, D. J.; Rose, S. J.


    Time-resolved x-ray spectra from solid targets irradiated by the VULCAN Petawatt laser focused to 1020Wcm-2 show that material at solid density is heated to temperatures above 500 eV to a depth of about 15 μm and for a duration of more than 30 ps. Modeling with the implicit hybrid plasma code LSP shows that the heating is sensitive to the laser prepulse through resistive inhibition of the laser accelerated electrons in the blow off layer.

  3. Diamond thin film temperature and heat-flux sensors (United States)

    Aslam, M.; Yang, G. S.; Masood, A.; Fredricks, R.


    Diamond film temperature and heat-flux sensors are developed using a technology compatible with silicon integrated circuit processing. The technology involves diamond nucleation, patterning, doping, and metallization. Multi-sensor test chips were designed and fabricated to study the thermistor behavior. The minimum feature size (device width) for 1st and 2nd generation chips are 160 and 5 micron, respectively. The p-type diamond thermistors on the 1st generation test chip show temperature and response time ranges of 80-1270 K and 0.29-25 microseconds, respectively. An array of diamond thermistors, acting as heat flux sensors, was successfully fabricated on an oxidized Si rod with a diameter of 1 cm. Some problems were encountered in the patterning of the Pt/Ti ohmic contacts on the rod, due mainly to the surface roughness of the diamond film. The use of thermistors with a minimum width of 5 micron (to improve the spatial resolution of measurement) resulted in lithographic problems related to surface roughness of diamond films. We improved the mean surface roughness from 124 nm to 30 nm by using an ultra high nucleation density of 10(exp 11)/sq cm. To deposit thermistors with such small dimensions on a curved surface, a new 3-D diamond patterning technique is currently under development. This involves writing a diamond seed pattern directly on the curved surface by a computer-controlled nozzle.

  4. Evolution of the properties of ZnO thin films subjected to heating treatments

    Energy Technology Data Exchange (ETDEWEB)

    Prepelita, Petronela; Stefan, N.; Luculescu, C.; Garoi, F., E-mail:; Birjega, R.


    Structural and optical properties of ZnO thin films (200 nm thickness) deposited using magnetron sputtering technique are influenced by structural defects. Therefore, we applied various heating treatments in order to control and improve the crystallinity of the samples. These treatments were realized in air at temperatures of 350 Degree-Sign C, 550 Degree-Sign C and 700 Degree-Sign C respectively, each for a duration of 1 h. The properties of the samples were investigated both before and after the heating treatment. Modern methods like X-ray Diffraction, Atomic Force Microscopy and Scanning Electron Microscopy were used to analyze the structure and morphology of the heated ZnO thin films. These heating treatments may be held responsible for rearrangements in the morphology of the thin films. Thus, it was observed that an increase of porosity and agglomeration of the crystallites is followed by an increase in the size of the crystallites. Inter-crystalline borders will migrate determining a coalescence of several crystallites during the heating process, as well. As a consequence, an increase of the band gap width from 3.26 eV to 3.30 eV (at 350 Degree-Sign C) and 3.32 eV (at 550 Degree-Sign C) respectively, occurred.

  5. Near-field radiative heat transfer between metamaterials coated with silicon carbide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Basu, Soumyadipta, E-mail:; Yang, Yue; Wang, Liping, E-mail: [School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, Arizona 85287 (United States)


    In this letter, we study the near-field radiative heat transfer between two metamaterial substrates coated with silicon carbide (SiC) thin films. It is known that metamaterials can enhance the near-field heat transfer over ordinary materials due to excitation of magnetic plasmons associated with s polarization, while strong surface phonon polariton exists for SiC. By careful tuning of the optical properties of metamaterial, it is possible to excite electrical and magnetic resonances for the metamaterial and surface phonon polaritons for SiC at different spectral regions, resulting in the enhanced heat transfer. The effect of the SiC film thickness at different vacuum gaps is investigated. Results obtained from this study will be beneficial for application of thin film coatings for energy harvesting.

  6. Direct synthesis and characterization of optically transparent conformal zinc oxide nanocrystalline thin films by rapid thermal plasma CVD

    National Research Council Canada - National Science Library

    Pedersen, Joachim D; Esposito, Heather J; Teh, Kwok Siong


    We report a rapid, self-catalyzed, solid precursor-based thermal plasma chemical vapor deposition process for depositing a conformal, nonporous, and optically transparent nanocrystalline ZnO thin film at 130 Torr (0.17 atm...

  7. Rapid IV Versus Oral Rehydration: Responses to Subsequent Exercise Heat Stress

    National Research Council Canada - National Science Library

    Kenefick, Robert W; O'Moore, Kathleen M; Mahood, Nicholas V; Castellani, John W


    This study sought to determine the effect of rapid intravenous (IV) versus oral (ORAL) rehydration immediately after dehydration, on cardiovascular, thermoregulatory, and perceptual responses during subsequent exercise in the heat.

  8. Rapid shift in thermal resistance between generations through maternal heat exposure

    NARCIS (Netherlands)

    Zizzari, Z.V.; Ellers, J.


    Given the current rapid climate change, understanding the mechanisms underlying heat tolerance and its plasticity is an important goal of global change biology. Soil fauna communities are especially vulnerable because of their limited dispersal ability. It is generally recognized that

  9. Optical heating and rapid transformation of functionalized fullerenes. (United States)

    Krishna, Vijay; Stevens, Nathanael; Koopman, Ben; Moudgil, Brij


    Irradiating single-walled carbon nanotubes can lead to heat generation or ignition. These processes could be used in medical and industrial applications, but the poor solvent compatibility and high aspect ratios of nanotubes have led to concerns about safety. Here, we show that certain functionalized fullerenes, including polyhydroxy fullerenes (which are known to be environmentally safe and to have therapeutic properties) are heated or ignited by exposure to low-intensity (fullerenes and other functionalized fullerenes can be transformed into single-walled nanotubes, multiwalled nanotubes and carbon onions without the presence of a catalyst by exposure to low-intensity laser irradiation in an oxygen-free environment. To demonstrate the potential usefulness of these processes in applications, we disrupted animal cells dosed with polyhydroxy fullerenes by exposing them to a near-infrared laser for a few seconds, and also ignited an explosive charge in contact with a particle of carboxy fullerenes.

  10. Transient Response to Rapid Cooling of a Stainless Steel Sodium Heat Pipe (United States)

    Mireles, Omar R.; Houts, Michael G.


    Compact fission power systems are under consideration for use in long duration space exploration missions. Power demands on the order of 500 W, to 5 kW, will be required for up to 15 years of continuous service. One such small reactor design consists of a fast spectrum reactor cooled with an array of in-core alkali metal heat pipes coupled to thermoelectric or Stirling power conversion systems. Heat pipes advantageous attributes include a simplistic design, lack of moving parts, and well understood behavior. Concerns over reactor transients induced by heat pipe instability as a function of extreme thermal transients require experimental investigations. One particular concern is rapid cooling of the heat pipe condenser that would propagate to cool the evaporator. Rapid cooling of the reactor core beyond acceptable design limits could possibly induce unintended reactor control issues. This paper discusses a series of experimental demonstrations where a heat pipe operating at near prototypic conditions experienced rapid cooling of the condenser. The condenser section of a stainless steel sodium heat pipe was enclosed within a heat exchanger. The heat pipe - heat exchanger assembly was housed within a vacuum chamber held at a pressure of 50 Torr of helium. The heat pipe was brought to steady state operating conditions using graphite resistance heaters then cooled by a high flow of gaseous nitrogen through the heat exchanger. Subsequent thermal transient behavior was characterized by performing an energy balance using temperature, pressure and flow rate data obtained throughout the tests. Results indicate the degree of temperature change that results from a rapid cooling scenario will not significantly influence thermal stability of an operating heat pipe, even under extreme condenser cooling conditions.

  11. Rapid thinning and collapse of lake calving Yakutat Glacier, Southeast Alaska (United States)

    Trussel, Barbara Lea

    Glaciers around the globe are experiencing a notable retreat and thinning, triggered by atmospheric warming. Tidewater glaciers in particular have received much attention, because they have been recognized to contribute substantially to global sea level rise. However, lake calving glaciers in Alaska show increasingly high thinning and retreat rates and are therefore contributors to sea level rise. The number of such lake calving systems is increasing worldwide as land-terminating glaciers retreat into overdeepened basins and form proglacial lakes. Yakutat Glacier in Southeast Alaska is a low elevation lake calving glacier with an accumulation to total area ratio of 0.03. It experienced rapid thinning of 4.43 +/- 0.06 m w.e. yr-1 between 2000-2010 and terminus retreat of over 15 km since the beginning of the 20th century. Simultaneously, adjacent Yakutat Icefield land-terminating glaciers thinned at lower but still substantial rates (3.54 +/- 0.06 m w.e. yr -1 for the same time period), indicating lake calving dynamics help drive increased mass loss. Yakutat Glacier sustained a ˜3 km long floating tongue for over a decade, which started to disintegrate into large tabular icebergs in 2010. Such floating tongues are rarely seen on temperate tidewater glaciers. The floating ice was weakened by surface ablation, which then allowed rifts to form and intersect. Ice velocity from GPS measurements showed that the ice on the floating tongue was moving substantially faster than grounded ice, which was attributed to rift opening between the floating and grounded ice. Temporal variations of rift opening were determined from time-lapse imagery, and correlated well with variations in ice speeds. Larger rift opening rates occurred during and after precipitation or increased melt episodes. Both of these events increased subglacial discharge and could potentially increase the subaqueous currents towards the open lake and thus increase drag on the ice underside. Simultaneously

  12. Self-consistent viscous heating of rapidly compressed turbulence (United States)

    Campos, Alejandro; Morgan, Brandon; Olson, Britton; Greenough, Jeffrey


    Given turbulence subjected to infinitely rapid deformations, linear terms representing interactions between the mean flow and the turbulence dictate the flow evolution, whereas non-linear terms corresponding to turbulence-turbulence interactions are safely ignored. For rapidly deformed flows where the turbulence Reynolds number is not sufficiently large, viscous effects can't be neglected and tend to play a prominent role, as shown in Davidovits & Fisch (2016). For such a case, the rapid increase of viscosity in a plasma-as compared to the weaker scaling of viscosity in a fluid-leads to the sudden viscous dissipation of turbulent kinetic energy. As described in Davidovits & Fisch, increases in temperature caused by the direct compression of the plasma drive sufficiently large values of viscosity. We report on numerical simulations of turbulence where the increase in temperature is the result of both the direct compression (an inviscid mechanism) and the self-consistent viscous transfer of energy from the turbulent scales towards the thermal energy. A comparison between implicit large-eddy simulations against well-resolved direct numerical simulations is included to asses the effect of the numerical and subgrid-scale dissipation on the self-consistent viscous energy transfer. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  13. Chemically synthesized PbS Nano particulate thin films for a rapid NO2 gas sensor

    Directory of Open Access Journals (Sweden)

    Burungale Vishal V.


    Full Text Available Rapid NO2 gas sensor has been developed based on PbS nanoparticulate thin films synthesized by Successive Ionic Layer Adsorption and Reaction (SILAR method at different precursor concentrations. The structural and morphological properties were investigated by means of X-ray diffraction and field emission scanning electron microscope. NO2 gas sensing properties of PbS thin films deposited at different concentrations were tested. PbS film with 0.25 M precursor concentration showed the highest sensitivity. In order to optimize the operating temperature, the sensitivity of the sensor to 50 ppm NO2 gas was measured at different operating temperatures, from 50 to 200 °C. The gas sensitivity increased with an increase in operating temperature and achieved the maximum value at 150 °C, followed by a decrease in sensitivity with further increase of the operating temperature. The sensitivity was about 35 % for 50 ppm NO2 at 150 °C with rapid response time of 6 s. T90 and T10 recovery time was 97 s at this gas concentration.

  14. Firearm suppressor having enhanced thermal management for rapid heat dissipation (United States)

    Moss, William C.; Anderson, Andrew T.


    A suppressor is disclosed for use with a weapon having a barrel through which a bullet is fired. The suppressor has an inner portion having a bore extending coaxially therethrough. The inner portion is adapted to be secured to a distal end of the barrel. A plurality of axial flow segments project radially from the inner portion and form axial flow paths through which expanding propellant gasses discharged from the barrel flow through. The axial flow segments have radially extending wall portions that define sections which may be filled with thermally conductive material, which in one example is a thermally conductive foam. The conductive foam helps to dissipate heat deposited within the suppressor during firing of the weapon.

  15. Observations of steady anomalous magnetic heating in thin current sheets. [of solar corona (United States)

    Martens, P. C. H.; Van Den Oord, G. H. J.; Hoyng, P.


    The Hard X-ray Imaging Spectrometer of the Solar Maximum Mission has yielded observations of a faint, steadily emitting loop-like structure, which have allowed the thermal evolution of this loop over a period of about 15 hr to be followed. Only 0.1 percent of the volume of the loop appears to be steadily heated, at the large rate of 0.6 erg/cu cm sec; this suggests that the heating represents the dissipation of magnetic fields in thin current sheets. Ion-kinetic tearing, as proposed by Galeev et al. (1981), is noted to be especially consonant with these observations. The source of the present X-ray emission is identified with the H-alpha filament in the same region. The present findings are held to constitute the first direct evidence for the steady dissipation of coronal magnetic fields via enhanced thin current sheet resistivity.

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

    Energy Technology Data Exchange (ETDEWEB)

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


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

  17. Phonon and electron temperature and non-Fourier heat transport in thin layers

    Energy Technology Data Exchange (ETDEWEB)

    Carlomagno, I.; Cimmelli, V.A. [Department of Mathematics, Computer Science and Economics, University of Basilicata, Campus Macchia Romana, Viale dell' Ateneo Lucano 10, 85100 Potenza (Italy); Sellitto, A. [Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (Italy)


    We present a thermodynamic model of heat conductor which allows for different temperatures of phonons and electrons. This model is applied to calculate the steady-state radial temperature profile in a circular thin layer. The compatibility of the obtained temperature profiles with the second law of thermodynamics is investigated in view of the requirement of positive entropy production and of a nonlocal constitutive equation for the entropy flux.

  18. Phonons spreading from laser-heated gold nanoparticle array accelerate diffusion of excitons in an underlying polythiophene thin film. (United States)

    Rais, David; Menšík, Miroslav; Paruzel, Bartosz; Kurunthu, Dharmalingam; Pfleger, Jiří


    Localized surface plasmon (LSP) photophysical phenomena occurring in metal nanostructures are often presented as a method to effectively couple light into photovoltaic devices of sub-wavelength-scale thickness. However, the excitation of LSP is also associated with rapid energy dissipation leading to local heating, which affects the excitation energy pathway. We studied a system consisting of a planar gold nanoparticle (AuNP) array deposited at the surface of a semiconducting polymer thin film (P3HT). We observed heat transfer from laser pulse excited AuNPs into the P3HT, which was evidenced as a long-living thermochromic effect on transient optical absorption. By modeling of the ultrafast kinetics of exciton population evolution, we determined that their decay was caused by their mutual annihilation. The decay rate was controlled by a phonon-assisted one-dimensional diffusion mechanism with a diffusion constant of 2.2 nm2 ps-1. The transferred heat resulted in an increase of the diffusion constant by a factor of almost 2, compared to the control system of P3HT without AuNPs. These results are of practical use for the design of plasmon-enhanced optoelectronic devices.

  19. Subsampling phase retrieval for rapid thermal measurements of heated microstructures. (United States)

    Taylor, Lucas N; Talghader, Joseph J


    A subsampling technique for real-time phase retrieval of high-speed thermal signals is demonstrated with heated metal lines such as those found in microelectronic interconnects. The thermal signals were produced by applying a current through aluminum resistors deposited on soda-lime-silica glass, and the resulting refractive index changes were measured using a Mach-Zehnder interferometer with a microscope objective and high-speed camera. The temperatures of the resistors were measured both by the phase-retrieval method and by monitoring the resistance of the aluminum lines. The method used to analyze the phase is at least 60× faster than the state of the art but it maintains a small spatial phase noise of 16 nm, remaining comparable to the state of the art. For slowly varying signals, the system is able to perform absolute phase measurements over time, distinguishing temperature changes as small as 2 K. With angular scanning or structured illumination improvements, the system could also perform fast thermal tomography.

  20. Nanoscale Structural and Mechanical Analysis of Bacillus anthracis Spores Inactivated with Rapid Dry Heating (United States)

    Felker, Daniel L.; Burggraf, Larry W.


    Effective killing of Bacillus anthracis spores is of paramount importance to antibioterrorism, food safety, environmental protection, and the medical device industry. Thus, a deeper understanding of the mechanisms of spore resistance and inactivation is highly desired for developing new strategies or improving the known methods for spore destruction. Previous studies have shown that spore inactivation mechanisms differ considerably depending upon the killing agents, such as heat (wet heat, dry heat), UV, ionizing radiation, and chemicals. It is believed that wet heat kills spores by inactivating critical enzymes, while dry heat kills spores by damaging their DNA. Many studies have focused on the biochemical aspects of spore inactivation by dry heat; few have investigated structural damages and changes in spore mechanical properties. In this study, we have inactivated Bacillus anthracis spores with rapid dry heating and performed nanoscale topographical and mechanical analysis of inactivated spores using atomic force microscopy (AFM). Our results revealed significant changes in spore morphology and nanomechanical properties after heat inactivation. In addition, we also found that these changes were different under different heating conditions that produced similar inactivation probabilities (high temperature for short exposure time versus low temperature for long exposure time). We attributed the differences to the differential thermal and mechanical stresses in the spore. The buildup of internal thermal and mechanical stresses may become prominent only in ultrafast, high-temperature heat inactivation when the experimental timescale is too short for heat-generated vapor to efficiently escape from the spore. Our results thus provide direct, visual evidences of the importance of thermal stresses and heat and mass transfer to spore inactivation by very rapid dry heating. PMID:24375142

  1. Fabrication and Testing of a Thin-Film Heat Flux Sensor for a Stirling Convertor (United States)

    Wilson, Scott D.; Fralick, Gustave; Wrbanek, John; Sayir, Ali


    The NASA Glenn Research Center (GRC) has been testing high efficiency free-piston Stirling convertors for potential use in radioisotope power systems since 1999. Stirling convertors are being operated for many years to demonstrate a radioisotope power system capable of providing reliable power for potential multi-year missions. Techniques used to monitor the convertors for change in performance include measurements of temperature, pressure, energy addition, and energy rejection. Micro-porous bulk insulation is used in the Stirling convertor test set up to minimize the loss of thermal energy from the electric heat source to the environment. The insulation is characterized before extended operation, enabling correlation of the net thermal energy addition to the convertor. Aging microporous bulk insulation changes insulation efficiency, introducing errors in the correlation for net thermal energy addition. A thin-mm heat flux sensor was designed and fabricated to directly measure the net thermal energy addition to the Stirling convertor. The fabrication techniques include slip casting and using Physical Vapor Deposition (PVD). One micron thick noble metal thermocouples measure temperature on the surface of an Alumina ceramic disc and heat flux is calculated. Fabrication, integration, and test results of a thin film heat flux sensor are presented.

  2. Investigation of char strength and expansion properties of an intumescent coating exposed to rapid heating rates

    DEFF Research Database (Denmark)

    Nørgaard, Kristian Petersen; Dam-Johansen, Kim; Català, Pere


    , char properties, measured at room temperature, were dependent on the preceding storage conditions (in air or in a desiccator). The char was found to have the highest mechanical strength against compression in the outer crust facing the heat source. For thin (147μm) free coating films, a tendency...... with respect to the mechanical resistance against compression, degree of expansion, and residual mass fraction. Experimental results show that when using this type of shock heating, the mechanical resistance of the char against compression cannot meaningfully be correlated to the expansion factor. In addition...

  3. Condensation on Highly Superheated Surfaces: Unstable Thin Films in a Wickless Heat Pipe. (United States)

    Kundan, Akshay; Nguyen, Thao T T; Plawsky, Joel L; Wayner, Peter C; Chao, David F; Sicker, Ronald J


    A wickless heat pipe was operated on the International Space Station to provide a better understanding of how the microgravity environment might alter the physical and interfacial forces driving evaporation and condensation. Traditional heat pipes are divided into three zones: evaporation at the heated end, condensation at the cooled end, and intermediate or adiabatic in between. The microgravity experiments reported herein show that the situation may be dramatically more complicated. Beyond a threshold heat input, there was a transition from evaporation at the heated end to large-scale condensation, even as surface temperatures exceeded the boiling point by 160 K. The hotter the surface, the more vapor was condensed onto it. The condensation process at the heated end is initiated by thickness and temperature disturbances in the thin liquid film that wet the solid surface. Those disturbances effectively leave the vapor "superheated" in that region. Condensation is amplified and sustained by the high Marangoni stresses that exist near the heater and that drive liquid to cooler regions of the device.

  4. Standard Test Method for Measuring Heat Transfer Rate Using a Thin-Skin Calorimeter

    CERN Document Server

    American Society for Testing and Materials. Philadelphia


    1.1 This test method covers the design and use of a thin metallic calorimeter for measuring heat transfer rate (also called heat flux). Thermocouples are attached to the unexposed surface of the calorimeter. A one-dimensional heat flow analysis is used for calculating the heat transfer rate from the temperature measurements. Applications include aerodynamic heating, laser and radiation power measurements, and fire safety testing. 1.2 Advantages 1.2.1 Simplicity of ConstructionThe calorimeter may be constructed from a number of materials. The size and shape can often be made to match the actual application. Thermocouples may be attached to the metal by spot, electron beam, or laser welding. 1.2.2 Heat transfer rate distributions may be obtained if metals with low thermal conductivity, such as some stainless steels, are used. 1.2.3 The calorimeters can be fabricated with smooth surfaces, without insulators or plugs and the attendant temperature discontinuities, to provide more realistic flow conditions for ...

  5. Characterization of a high performance ultra-thin heat pipe cooling module for mobile hand held electronic devices (United States)

    Ahamed, Mohammad Shahed; Saito, Yuji; Mashiko, Koichi; Mochizuki, Masataka


    In recent years, heat pipes have been widely used in various hand held mobile electronic devices such as smart phones, tablet PCs, digital cameras. With the development of technology these devices have different user friendly features and applications; which require very high clock speeds of the processor. In general, a high clock speed generates a lot of heat, which needs to be spreaded or removed to eliminate the hot spot on the processor surface. However, it is a challenging task to achieve proper cooling of such electronic devices mentioned above because of their confined spaces and concentrated heat sources. Regarding this challenge, we introduced an ultra-thin heat pipe; this heat pipe consists of a special fiber wick structure named as "Center Fiber Wick" which can provide sufficient vapor space on the both sides of the wick structure. We also developed a cooling module that uses this kind of ultra-thin heat pipe to eliminate the hot spot issue. This cooling module consists of an ultra-thin heat pipe and a metal plate. By changing the width, the flattened thickness and the effective length of the ultra-thin heat pipe, several experiments have been conducted to characterize the thermal properties of the developed cooling module. In addition, other experiments were also conducted to determine the effects of changes in the number of heat pipes in a single module. Characterization and comparison of the module have also been conducted both experimentally and theoretically.

  6. Characterization of a high performance ultra-thin heat pipe cooling module for mobile hand held electronic devices (United States)

    Ahamed, Mohammad Shahed; Saito, Yuji; Mashiko, Koichi; Mochizuki, Masataka


    In recent years, heat pipes have been widely used in various hand held mobile electronic devices such as smart phones, tablet PCs, digital cameras. With the development of technology these devices have different user friendly features and applications; which require very high clock speeds of the processor. In general, a high clock speed generates a lot of heat, which needs to be spreaded or removed to eliminate the hot spot on the processor surface. However, it is a challenging task to achieve proper cooling of such electronic devices mentioned above because of their confined spaces and concentrated heat sources. Regarding this challenge, we introduced an ultra-thin heat pipe; this heat pipe consists of a special fiber wick structure named as "Center Fiber Wick" which can provide sufficient vapor space on the both sides of the wick structure. We also developed a cooling module that uses this kind of ultra-thin heat pipe to eliminate the hot spot issue. This cooling module consists of an ultra-thin heat pipe and a metal plate. By changing the width, the flattened thickness and the effective length of the ultra-thin heat pipe, several experiments have been conducted to characterize the thermal properties of the developed cooling module. In addition, other experiments were also conducted to determine the effects of changes in the number of heat pipes in a single module. Characterization and comparison of the module have also been conducted both experimentally and theoretically.

  7. Enhancement of Heat and Mass Transfer in Mechanically Contstrained Ultra Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Drost; Jim Liburdy; Brian Paul; Richard Peterson


    Oregon State University (OSU) and the Pacific Northwest National Laboratory (PNNL) were funded by the U.S. Department of Energy to conduct research focused on resolving the key technical issues that limited the deployment of efficient and extremely compact microtechnology based heat actuated absorption heat pumps and gas absorbers. Success in demonstrating these technologies will reduce the main barriers to the deployment of a technology that can significantly reduce energy consumption in the building, automotive and industrial sectors while providing a technology that can improve our ability to sequester CO{sub 2}. The proposed research cost $939,477. $539,477 of the proposed amount funded research conducted at OSU while the balance ($400,000) was used at PNNL. The project lasted 42 months and started in April 2001. Recent developments at the Pacific Northwest National Laboratory and Oregon State University suggest that the performance of absorption and desorption systems can be significantly enhanced by the use of an ultra-thin film gas/liquid contactor. This device employs microtechnology-based structures to mechanically constrain the gas/liquid interface. This technology can be used to form very thin liquid films with a film thickness less then 100 microns while still allowing gas/liquid contact. When the resistance to mass transfer in gas desorption and absorption is dominated by diffusion in the liquid phase the use of extremely thin films (<100 microns) for desorption and absorption can radically reduce the size of a gas desorber or absorber. The development of compact absorbers and desorbers enables the deployment of small heat-actuated absorption heat pumps for distributed space heating and cooling applications, heat-actuated automotive air conditioning, manportable cooling, gas absorption units for the chemical process industry and the development of high capacity CO{sub 2} absorption devices for CO{sub 2} collection and sequestration. The energy

  8. The influence of aging and diabetes on heat transfer characteristics of the skin to a rapidly applied heat source. (United States)

    Petrofsky, Jerrold; Lee, Haneul; Trivedi, Moxi; Hudlikar, Akshay N; Yang, Chia-hao; Goraksh, Neha; Alshammari, Faris; Mohanan, Mitali; Soni, Janhavi; Agilan, Brindha; Pai, Nikhila; Chindam, Tirupathi; Murugesan, Vengatesh; Yim, Jong Eun; Katrak, Vahishta


    Numerous studies have examined the blood flow of the skin at rest and in response to sustained heat and shown that, in older people and people with diabetes, the skin blood flow response to heat is diminished compared to younger people. It is not sustained heat, however, that usually causes burns; it is a more rapid application of heat. Ten younger subjects, 10 older subjects, and 10 subjects with diabetes were examined before and after applying a water-filled thermode to the skin above the quadriceps muscle to observe the changes in skin temperature and skin blood flow and the ability of the skin to absorb heat after a 2-min heat exposure with water at 44°C. Skin temperature rose from 31.2°C at rest to 38.3°C after 2 min of heat application in all subjects (P > 0.05 between groups). The calories required in the younger group of subjects was 2.26 times the calories required in the older group of subjects for the same change in skin temperature and 13.8 times the calories needed to increase skin temperature in the subjects with diabetes. Furthermore, the blood flow at rest was lower in people with diabetes than older subjects and both groups less than that seen in younger subjects. The blood flow response to heat was slower in the subjects with diabetes compared to the older subjects and much slower than that seen in the younger subjects. Reduced skin blood flow of older and subjects with diabetes, decreased thickness of the dermal layer, and increased subcutaneous fat, as well as damage to transient receptor potential vanilloid 1 receptors, may account for some of the differences between the groups.

  9. Failure analysis on unexpected wall thinning of heat-exchange tubes in ammonia evaporators

    Directory of Open Access Journals (Sweden)

    Shi-Meng Hu


    Full Text Available A failure incident of heat-exchange tubes in ammonia evaporators, which suffered from unexpected wall thinning after only one-year service with respect to their original design lifetime of fifteen years, was reported and carefully analyzed. After overall inspection, many tube walls in the evaporators were found to experience severe degradations at both sides with distinct corroded defects and general cracking of corrosion layers. Thus, comprehensive investigations including external appearance, microscopic morphology and chemical composition were carried out by using a series of characterization methods. The analysis results demonstrated that the unexpected wall thinning of tubes was primarily ascribed to multiple corrosion factors including uniform corrosion, pitting and interaction behavior between them. Relative failure mechanisms were discussed in detail and prevention measures were also proposed for ammonia evaporators under similar operating condition.

  10. Enhancement and Tunability of Near-Field Radiative Heat Transfer Mediated by Surface Plasmon Polaritons in Thin Plasmonic Films

    Directory of Open Access Journals (Sweden)

    Svetlana V. Boriskina


    Full Text Available The properties of thermal radiation exchange between hot and cold objects can be strongly modified if they interact in the near field where electromagnetic coupling occurs across gaps narrower than the dominant wavelength of thermal radiation. Using a rigorous fluctuational electrodynamics approach, we predict that ultra-thin films of plasmonic materials can be used to dramatically enhance near-field heat transfer. The total spectrally integrated film-to-film heat transfer is over an order of magnitude larger than between the same materials in bulk form and also exceeds the levels achievable with polar dielectrics such as SiC. We attribute this enhancement to the significant spectral broadening of radiative heat transfer due to coupling between surface plasmon polaritons (SPPs on both sides of each thin film. We show that the radiative heat flux spectrum can be further shaped by the choice of the substrate onto which the thin film is deposited. In particular, substrates supporting surface phonon polaritons (SPhP strongly modify the heat flux spectrum owing to the interactions between SPPs on thin films and SPhPs of the substrate. The use of thin film phase change materials on polar dielectric substrates allows for dynamic switching of the heat flux spectrum between SPP-mediated and SPhP-mediated peaks.

  11. A laser ion source with a thin ohmic-heating ionizer for the TIARA-ISOL

    CERN Document Server

    Koizumi, M; Oshima, M; Sekine, T; Wakui, T; Jin, W G; Katsuragawa, H; Miyatake, H; Ishida, Y


    An ohmic-heating laser ion source with a thin ionizer of thickness of 30 mu m has been developed for the TIARA-ISOL. It can form an electric field of 4-5 V/cm inside the ionizer. The properties of the laser ion source were tested on- and off-line with aluminum isotopes. The FWHM of the time distribution of the bunched photoions from the ion source was about 4 mu s for sup 2 sup 7 Al. In on-line experiment, a photoionization efficiency of about 0.1% for sup 2 sup 5 Al was obtained.

  12. Development of a new laser heating system for thin film growth by chemical vapor deposition (United States)

    Fujimoto, Eiji; Sumiya, Masatomo; Ohnishi, Tsuyoshi; Lippmaa, Mikk; Takeguchi, Masaki; Koinuma, Hideomi; Matsumoto, Yuji


    We have developed a new laser heating system for thin film growth by chemical vapor deposition (CVD). A collimated beam from a high-power continuous-wave 808 nm semiconductor laser was directly introduced into a CVD growth chamber without an optical fiber. The light path of the heating laser inside the chamber was isolated mechanically from the growth area by bellows to protect the optics from film coating. Three types of heat absorbers, (10 × 10 × 2 mm3) consisting of SiC, Ni/NiOx, or pyrolytic graphite covered with pyrolytic BN (PG/PBN), located at the backside of the substrate, were tested for heating performance. It was confirmed that the substrate temperature could reach higher than 1500 °C in vacuum when a PG/PBN absorber was used. A wide-range temperature response between 400 °C and 1000 °C was achieved at high heating and cooling rates. Although the thermal energy loss increased in a H2 gas ambient due to the higher thermal conductivity, temperatures up to 1000°C were achieved even in 200 Torr H2. We have demonstrated the capabilities of this laser heating system by growing ZnO films by metalorganic chemical vapor deposition. The growth mode of ZnO films was changed from columnar to lateral growth by repeated temperature modulation in this laser heating system, and consequently atomically smooth epitaxial ZnO films were successfully grown on an a-plane sapphire substrate.

  13. Enhancement and tunability of near-field radiative heat transfer mediated by surface plasmon polaritons in thin plasmonic films

    CERN Document Server

    Boriskina, Svetlana V; Huang, Yi; Zhou, Jiawei; Chiloyan, Vazrik; Chen, Gang


    The properties of thermal radiation exchange between hot and cold objects can be strongly modified if they interact in the near field where electromagnetic coupling occurs across gaps narrower than the dominant wavelength of thermal radiation. Using a rigorous fluctuational electrodynamics approach, we predict that ultra-thin films of plasmonic materials can be used to dramatically enhance near-field heat transfer. The total spectrally integrated film-to-film heat transfer is over an order of magnitude larger than between the same materials in bulk form and also exceeds the levels achievable with polar dielectrics such as SiC. We attribute this enhancement to the significant spectral broadening of radiative heat transfer due to coupling between surface plasmon polaritons (SPPs) on both sides of each thin film. We show that the radiative heat flux spectrum can be further shaped by the choice of the substrate onto which the thin film is deposited. In particular, substrates supporting surface phonon polaritons (...

  14. Laser thinning for monolayer graphene formation: heat sink and interference effect. (United States)

    Han, Gang Hee; Chae, Seung Jin; Kim, Eun Sung; Güneş, Fethullah; Lee, Il Ha; Lee, Sang Won; Lee, Si Young; Lim, Seong Chu; Jeong, Hae Kyung; Jeong, Mun Seok; Lee, Young Hee


    Despite the availability of large-area graphene synthesized by chemical vapor deposition (CVD), the control of a uniform monolayer graphene remained challenging. Here, we report a method of acquiring monolayer graphene by laser irradiation. The accumulation of heat on graphene by absorbing light, followed by oxidative burning of upper graphene layers, which strongly relies on the wavelength of light and optical parameters of the substrate, was in situ measured by the G-band shift in Raman spectroscopy. The substrate plays a crucial role as a heat sink for the bottom monolayer graphene, resulting in no burning or etching. Oscillatory thinning behavior dependent on the substrate oxide thickness was evaluated by adopting a simple Fresnel's equation. This paves the way for future research in utilizing monolayer graphene for high-speed electronic devices.

  15. X-ray reflectivity measurement of interdiffusion in metallic multilayers during rapid heating (United States)

    Liu, J. P.; Kirchhoff, J.; Zhou, L.; Zhao, M.; Grapes, M. D.; Dale, D. S.; Tate, M. D.; Philipp, H. T.; Gruner, S. M.; Weihs, T. P.; Hufnagel, T. C.


    A technique for measuring interdiffusion in multilayer materials during rapid heating using X-ray reflectivity is described. In this technique the sample is bent to achieve a range of incident angles simultaneously, and the scattered intensity is recorded on a fast high-dynamic-range mixed-mode pixel array detector. Heating of the multilayer is achieved by electrical resistive heating of the silicon substrate, monitored by an infrared pyrometer. As an example, reflectivity data from Al/Ni heated at rates up to 200 K s−1 are presented. At short times the interdiffusion coefficient can be determined from the rate of decay of the reflectivity peaks, and it is shown that the activation energy for interdiffusion is consistent with a grain boundary diffusion mechanism. At longer times the simple analysis no longer applies because the evolution of the reflectivity pattern is complicated by other processes, such as nucleation and growth of intermetallic phases. PMID:28664887

  16. X-ray reflectivity measurement of interdiffusion in metallic multilayers during rapid heating. (United States)

    Liu, J P; Kirchhoff, J; Zhou, L; Zhao, M; Grapes, M D; Dale, D S; Tate, M D; Philipp, H T; Gruner, S M; Weihs, T P; Hufnagel, T C


    A technique for measuring interdiffusion in multilayer materials during rapid heating using X-ray reflectivity is described. In this technique the sample is bent to achieve a range of incident angles simultaneously, and the scattered intensity is recorded on a fast high-dynamic-range mixed-mode pixel array detector. Heating of the multilayer is achieved by electrical resistive heating of the silicon substrate, monitored by an infrared pyrometer. As an example, reflectivity data from Al/Ni heated at rates up to 200 K s-1 are presented. At short times the interdiffusion coefficient can be determined from the rate of decay of the reflectivity peaks, and it is shown that the activation energy for interdiffusion is consistent with a grain boundary diffusion mechanism. At longer times the simple analysis no longer applies because the evolution of the reflectivity pattern is complicated by other processes, such as nucleation and growth of intermetallic phases.

  17. Modeling and Analysis of Entropy Generation in Light Heating of Nanoscaled Silicon and Germanium Thin Films

    Directory of Open Access Journals (Sweden)

    José Ernesto Nájera-Carpio


    Full Text Available In this work, the irreversible processes in light heating of Silicon (Si and Germanium (Ge thin films are examined. Each film is exposed to light irradiation with radiative and convective boundary conditions. Heat, electron and hole transport and generation-recombination processes of electron-hole pairs are studied in terms of a phenomenological model obtained from basic principles of irreversible thermodynamics. We present an analysis of the contributions to the entropy production in the stationary state due to the dissipative effects associated with electron and hole transport, generation-recombination of electron-hole pairs as well as heat transport. The most significant contribution to the entropy production comes from the interaction of light with the medium in both Si and Ge. This interaction includes two processes, namely, the generation of electron-hole pairs and the transferring of energy from the absorbed light to the lattice. In Si the following contribution in magnitude comes from the heat transport. In Ge all the remaining contributions to entropy production have nearly the same order of magnitude. The results are compared and explained addressing the differences in the magnitude of the thermodynamic forces, Onsager’s coefficients and transport properties of Si and Ge.

  18. Thin layer modeling of tom yum herbs in vacuum heat pump dryer. (United States)

    Artnaseaw, A; Theerakulpisut, S; Benjapiyaporn, C


    Thin layer vacuum heat pump drying experiments were conducted to determine drying models for Tom Yum herbs (chili, lemon grass, kaffir lime leaf and galangal slice). The drying experiments were conducted in a vacuum heat pump dryer at a constant drying pressure of 0.2 bars and drying temperatures ranging from 50 °C to 65 °C. The experimental results were fitted to a number of well-known thin layer drying models and it was found, for the range of drying temperature tested, that the Midilli model is the best model for all Tom Yum herbs. To account for the influence of drying temperature, the constants and coefficients of model were formulated as functions of the drying temperature. Statistical tests of agreement between the model and experimental results were performed by determining the coefficient of determination (R²) , reduced chi-square (χ²) and root mean square error (RMSE). It was found that the model is in very good agreement with the experimental results.

  19. Thermal and mechanical effect during rapid heating of astroloy for improving structural integrity

    Energy Technology Data Exchange (ETDEWEB)

    Popoolaa, A.P.I., E-mail: [Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Pretoria (South Africa); Oluwasegun, K.M. [Department of Materials Science and Engineering, Obafemi Awolowo University (Nigeria); Olorunniwo, O.E., E-mail: [Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Pretoria (South Africa); Department of Materials Science and Engineering, Obafemi Awolowo University (Nigeria); Atanda, P.O. [Department of Materials Science and Engineering, Obafemi Awolowo University (Nigeria); Aigbodion, V.S. [Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Pretoria (South Africa); Department of Metallurgical and Materials Engineering, University of Nigeria, Nsukka (Nigeria)


    The behaviour of γ′ phase to thermal and mechanical effects during rapid heating of Astroloy(Turbine Disc alloy) a Powder metallurgy (PM) nickel base superalloy has been investigated. The thermo-mechanical affected zone (TMAZ) and heat affected zone (HAZ) microstructure of an inertia friction welded Astroloy were simulated using a Gleeble thermo-mechanical simulation system. Detailed microstructural examination of the simulated TMAZ and HAZ and those present in actual inertial friction welded specimens showed that γ′ particles persisted during rapid heating up to a temperature where the formation of liquid is thermodynamically favoured, and subsequently re-solidified eutectically. The result obtained showed that forging during the thermo-mechanical simulation significantly enhanced resistance to weld liquation cracking of the alloy. This is attributable to strain-induced rapid isothermal dissolution of the constitutional liquation products within 150 μm from the centre of the forged sample. This was not observed in purely thermally simulated samples. The microstructure within the TMAZ of the as-welded alloy is similar to the microstructure in the forged Gleeble specimens. - Highlights: • The behaviour of γ′ phase to thermal and mechanical effects during rapid heating of Astrology • The thermo-mechanical affected zone (TMAZ) and heat affected zone (HAZ). • significantly enhanced resistance to weld liquation cracking of the alloy. • This was not observed in purely thermally simulated samples. • The microstructure within the TMAZ of the as-welded alloy is similar to the microstructure in the forged Gleeble specimens.

  20. Direct synthesis and characterization of optically transparent conformal zinc oxide nanocrystalline thin films by rapid thermal plasma CVD (United States)

    Pedersen, Joachim D.; Esposito, Heather J.; Teh, Kwok Siong


    We report a rapid, self-catalyzed, solid precursor-based thermal plasma chemical vapor deposition process for depositing a conformal, nonporous, and optically transparent nanocrystalline ZnO thin film at 130 Torr (0.17 atm). Pure solid zinc is inductively heated and melted, followed by ionization by thermal induction argon/oxygen plasma to produce conformal, nonporous nanocrystalline ZnO films at a growth rate of up to 50 nm/min on amorphous and crystalline substrates including Si (100), fused quartz, glass, muscovite, c- and a-plane sapphire (Al2O3), gold, titanium, and polyimide. X-ray diffraction indicates the grains of as-deposited ZnO to be highly textured, with the fastest growth occurring along the c-axis. The individual grains are observed to be faceted by (103) planes which are the slowest growth planes. ZnO nanocrystalline films of nominal thicknesses of 200 nm are deposited at substrate temperatures of 330°C and 160°C on metal/ceramic substrates and polymer substrates, respectively. In addition, 20-nm- and 200-nm-thick films are also deposited on quartz substrates for optical characterization. At optical spectra above 375 nm, the measured optical transmittance of a 200-nm-thick ZnO film is greater than 80%, while that of a 20-nm-thick film is close to 100%. For a 200-nm-thick ZnO film with an average grain size of 100 nm, a four-point probe measurement shows electrical conductivity of up to 910 S/m. Annealing of 200-nm-thick ZnO films in 300 sccm pure argon at temperatures ranging from 750°C to 950°C (at homologous temperatures between 0.46 and 0.54) alters the textures and morphologies of the thin film. Based on scanning electron microscope images, higher annealing temperatures appear to restructure the ZnO nanocrystalline films to form nanorods of ZnO due to a combination of grain boundary diffusion and bulk diffusion. PACS: films and coatings, 81.15.-z; nanocrystalline materials, 81.07.Bc; II-VI semiconductors, 81.05.Dz.

  1. Effect of aging heat time and annealing temperature on the properties of nanocrystalline tin dioxide thin films (United States)

    Kadhim, Imad H.; Abu Hassan, H.


    Nanocrystalline tin dioxide (SnO2) thin films have been successfully prepared by sol-gel spin-coating technique on p-type Si (100) substrates. A stable solution was prepared by mixing tin(II) chloride dihydrate, pure ethanol, and glycerin. Temperature affects the properties of SnO2 thin films, particularly the crystallite size where the crystallization of SnO2 with tetragonal rutile structure is achieved when thin films that prepared under different aging heat times are annealed at 400∘C. By increasing aging heat time in the presence of annealing temperatures the FESEM images indicated that the thickness of the fabricated film was directly proportional to solution viscosity, increasing from approximately 380 nm to 744 nm, as well as the crystallization of the thin films improved and reduced defects.

  2. On the effect of laterally varying boundary heat flux on rapidly rotating spherical shell convection (United States)

    Sahoo, Swarandeep; Sreenivasan, Binod


    The onset of convection in a rotating spherical shell subject to laterally varying heat flux at the outer boundary is considered in this paper. The focus is on the geophysically relevant regime of rapid rotation (low Ekman number) where the natural length scale of convection is significantly smaller than the length scale imposed by the boundary heat flux pattern. Contrary to earlier studies at a higher Ekman number, we find a substantial reduction in the onset Rayleigh number Rac with increasing lateral variation. The decrease in Rac is shown to be closely correlated to the equatorial heat flux surplus in the steady, basic state solution. The consistency of such a correlation makes the estimation of Rac possible without solving the full stability problem. The steady baroclinic flow has a strong cyclone-anticyclone asymmetry in the kinetic helicity only for equatorially symmetric lateral variations, with possible implications for dynamo action. Equatorially antisymmetric variations, on the other hand, break the symmetry of the mean flow, in turn negating its helicity. Analysis of the perturbation solution reveals strongly localized clusters through which convection rolls drift in and out at a frequency higher than that for the reference case with homogeneous boundary heat flux. Large lateral variations produce a marked decrease in the azimuthal length scale of columns, which indicates that small-scale motions are essential to the transport of heat in rapidly rotating, localized convection. With an equatorially antisymmetric heat flux pattern, convection in individual clusters goes through an asynchronous wax-wane cycle whose frequency is much lower than the drift rate of the columns. These continual variations in convection intensity may in turn result in fluctuations in the magnetic field intensity, an effect that needs to be considered in dynamo models. Finally, there is a notable analogy between the role of a laterally varying boundary heat flux and the role of a

  3. A very light and thin liquid hydrogen/deuterium heat pipe target for COSY experiments (United States)

    Abdel-Bary, M.; Abdel-Samad, S.; Kilian, K.


    A liquid hydrogen/deuterium heat pipe (HP) target is used at the COSY external experiments TOF, GEM and MOMO. The target liquid is produced at a cooled condenser and guided through a central tube assisted by gravitation into the target cell. An aluminum condenser is used instead of copper, which requires less material, improves conductivities and provides shorter cooling down time. Residual condenser temperature fluctuations in the order of ≈0.4 K are reduced by using thermal resistances between the cooling machine and the condenser of the heat pipe combined with a controlled heating power. A new design with only a 7-mm-diameter HP has been developed. The diameter of the condenser part remains at 16 mm to provide enough condensation area. The small amount of material ensures short cooling down times. A cold gas deuterium HP target has been designed and developed which allows protons with energy ⩽1 MeV to be measured. A 7-mm-diameter HP is used to fill a cooling jacket around the D 2 gas cell with LH 2. The D 2 gas is stabilized at 200 mbar to allow for thin windows. Its density is increased by factor 15 compared to room temperature.

  4. Microwave assisted radiant heating effect on the crystallization of SnO2 thin films prepared by spin-coating (United States)

    Gome, Anil; Reddy, V. Raghavendra; Ganesan, V.; Gupta, Ajay


    Crystallization study of SnO2 thin films prepared by spin-coating method are reported when subjected to microwave assisted radiant heating (MARH). The as-prepared and annealed films are studied using atomic force microscopy, grazing incidence x-ray diffraction and conversion electron Mossbauer spectroscopy measurements. Sn4+ state in all films is confirmed from 119Sn Mossbauer spectroscopy measurements. The results indicate that one can employ microwave heating to prepare SnO2 thin films with controlled surface morphology which might be useful for various practical applications.

  5. Electrowetting-based microfluidic operations on rapid-manufactured devices for heat pipe applications (United States)

    Hale, Renee S.; Bahadur, Vaibhav


    The heat transport capacity of traditional heat pipes is limited by the capillary pressure generated in the internal wick that pumps condensate to the evaporator. Recently, the authors conceptualized a novel heat pipe architecture, wherein wick-based pumping is replaced by electrowetting (EW)-based pumping of microliter droplets in the adiabatic section. An electrowetting heat pipe (EHP) can overcome the capillary limit to heat transport capacity and enable compact, planar, gravity-insensitive, and ultralow power consumption heat pipes that transport kiloWatt heat loads over extended distances. This work develops a novel technique for rapid, scalable fabrication of EW-based devices and studies critical microfluidic operations underlying the EHP, with the objective of predicting the key performance parameters of the EHP. Devices are fabricated on a printed circuit board (PCB) substrate with mechanically-milled electrodes, and a removable polyimide dielectric film. The first set of experiments uncovers the maximum channel gap (1 mm) for reliable EW-based pumping; this parameter determines the heat transport capacity of the EHP, which scales linearly with the channel gap. The second set of experiments uncovers the maximum channel gap (375 microns) at which EW voltages can successfully split droplets. This is an important consideration which ensures EHP operability in the event of unintentional droplet merging. The third set of experiments demonstrate and study EW-induced droplet generation from an open-to-air reservoir, which mimics the interface between the condenser and adiabatic sections of the EHP. The experimental findings predict that planar, water-based EHPs with a (10 cm by 4 mm) cross section can transport 1.6 kW over extended distances (>1 m), with a thermal resistance of 0.01 K W-1.

  6. Weight restoration therapy rapidly reverses cortical thinning in anorexia nervosa: A longitudinal study. (United States)

    Bernardoni, Fabio; King, Joseph A; Geisler, Daniel; Stein, Elisa; Jaite, Charlotte; Nätsch, Dagmar; Tam, Friederike I; Boehm, Ilka; Seidel, Maria; Roessner, Veit; Ehrlich, Stefan


    Structural magnetic resonance imaging studies have documented reduced gray matter in acutely ill patients with anorexia nervosa to be at least partially reversible following weight restoration. However, few longitudinal studies exist and the underlying mechanisms of these structural changes are elusive. In particular, the relative speed and completeness of brain structure normalization during realimentation remain unknown. Here we report from a structural neuroimaging study including a sample of adolescent/young adult female patients with acute anorexia nervosa (n=47), long-term recovered patients (n=34), and healthy controls (n=75). The majority of acutely ill patients were scanned longitudinally (n=35): at the beginning of standardized weight restoration therapy and again after partial weight normalization (>10% body mass index increase). High-resolution structural images were processed and analyzed with the longitudinal stream of FreeSurfer software to test for changes in cortical thickness and volumes of select subcortical regions of interest. We found globally reduced cortical thickness in acutely ill patients to increase rapidly (0.06 mm/month) during brief weight restoration therapy (≈3 months). This significant increase was predicted by weight restoration alone and could not be ascribed to potentially mediating factors such as duration of illness, hydration status, or symptom improvements. By comparing cortical thickness in partially weight-restored patients with that measured in healthy controls, we confirmed that cortical thickness had normalized already at follow-up. This pattern of thinning in illness and rapid normalization during weight rehabilitation was largely mirrored in subcortical volumes. Together, our findings indicate that structural brain insults inflicted by starvation in anorexia nervosa may be reversed at a rate much faster than previously thought if interventions are successful before the disorder becomes chronic. This provides

  7. Heat transfer in YBaCuO thin film/sapphire substrate system

    Energy Technology Data Exchange (ETDEWEB)

    Sergeev, A.; Semenov, A.; Trifonov, V.; Karasik, B.; Gol' tsman, G.; Gershenzon, E. (Moscow State Pedagogical Univ. (Russian Federation))


    The thermal boundary resistance at the YBaCuO thin film/Al[sub 2]O[sub 3] substrate interface was investigated. The transparency for thermal phonons incident on the interface as well as for phonons moving from the substrate was determined. We have measured a transient voltage response of current-biased films to continuously modulated radiation. The observed knee in the modulation frequency dependence of the response reflects the crossover from the diffusion regime to the contact resistance regime of the heat transfer across the interface. The values of transparency were independently deduced both from the phonon escape time and from the time of phonon return to the film which were identified with peculiarities in the frequency dependence. The results are much more consistent with the acoustic mismatch theory than the diffuse mismatch model. 11 refs., 2 figs.

  8. Rapid thermal processing for production of chalcopyrite thin films for solar cells: Design, analysis, and experimental implementation (United States)

    Lovelett, Robert J.

    The direct conversion of solar energy to electricity, or photovoltaic energy conversion, has a number of environmental, social, and economic advantages over conventional electricity generation from fossil fuels. Currently, the most commonly-used material for photovoltaics is crystalline silicon, which is now produced at large scale and silicon-based devices have achieved power conversion efficiencies over 25% However, alternative materials, such as inorganic thin films, offer a number of advantages including the potential for lower manufacturing costs, higher theoretical efficiencies, and better performance in the field. One of these materials is the chalcopyrite Cu(InGa)(SeS) 2, which has demonstrated module efficiencies over 17% and cell efficiencies over 22%. Cu(InGa)(SeS)2 is now in the early stages of commercialization using a precursor reaction process referred to as a "selenization/sulfization" reaction. The precursor reaction process is promising because it has demonstrated high efficiency along with the large area (approximately 1 m2) uniformity that is required for modules. However, some challenges remain that limit the growth of the chalcopyrite solar cell industry including: slow reactions that limit process throughput, a limited understanding of complex reaction kinetics and transport phenomena that affect the through-film composition, and the use of highly toxic H2Se in the reaction process. In this work, I approach each of these challenges. First, to improve process throughput, I designed and implemented a rapid thermal processing (RTP) reactor, whereby the samples are heated by a 1000 W quartz-halogen lamp that is capable of fast temperature ramps and high temperature dwells. With the reactor in place, however, achieving effective temperature control in the thin film material system is complicated by two intrinsic process characteristics: (i) the temperature of the Cu(InGa)(SeS)2 film cannot be measured directly, which leaves the system without

  9. Rapid amplification/detection of nucleic acid targets utilizing a HDA/thin film biosensor. (United States)

    Jenison, Robert; Jaeckel, Heidi; Klonoski, Joshua; Latorra, David; Wiens, Jacinta


    Thin film biosensors exploit a flat, optically coated silicon-based surface whereupon formation of nucleic acid hybrids are enzymatically transduced in a molecular thin film that can be detected by the unaided human eye under white light. While the limit of sensitivity for detection of nucleic acid targets is at sub-attomole levels (60 000 copies) many clinical specimens containing bacterial pathogens have much lower levels of analyte present. Herein, we describe a platform, termed HDA/thin film biosensor, which performs helicase-dependant nucleic acid amplification on a thin film biosensor surface to improve the limit of sensitivity to 10 copies of the mecA gene present in methicillin-resistant strains of Staphylococcus. As double-stranded DNA is unwound by helicase it was either bound by solution-phase DNA primers to be copied by DNA polymerase or hybridized to surface immobilized probe on the thin film biosensor surface to be detected. Herein, we show that amplification reactions on the thin film biosensor are equivalent to in standard thin wall tubes, with detection at the limit of sensitivity of the assay occurring after 30 minutes of incubation time. Further we validate the approach by detecting the presence of the mecA gene in methicillin-resistant Staphylococcus aureus (MRSA) from positive blood culture aliquots with high specificity (signal/noise ratio of 105).

  10. Numerical study of heat and mass transfer during evaporation of a thin liquid film

    Directory of Open Access Journals (Sweden)

    Oubella M’hand


    Full Text Available A numerical study of mixed convection heat and mass transfer with film evaporation in a vertical channel is developed. The emphasis is focused on the effects of vaporization of three different liquid films having widely different properties, along the isothermal and wetted walls on the heat and mass transfer rates in the channel. The induced laminar downward flow is a mixture of blowing dry air and vapour of water, methanol or acetone, assumed as ideal gases. A two-dimensional steady state and elliptical flow model, connected with variable thermo-physical properties, is used and the phase change problem is based on thin liquid film assumptions. The governing equations of the model are solved by a finite volume method and the velocity-pressure fields are linked by SIMPLE algorithm. The numerical results, including the velocity, temperature and concentration profiles, as well as axial variations of Nusselt numbers, Sherwood number and dimensionless film evaporation rate are presented for two values of inlet temperature and Reynolds number. It was found that lower the inlet temperature and Re, the higher the induced flows cooling with respect of most volatile film. The better mass transfer rates related with film evaporation are found for a system with low mass diffusion coefficient.

  11. Rapid systemic up-regulation of genes after heat-wounding and electrical stimulation (United States)

    Davies, E.; Vian, A.; Vian, C.; Stankovic, B.


    When one leaf of a tomato plant is electrically-stimulated or heat-wounded, proteinase inhibitor genes are rapidly up-regulated in distant leaves. The identity of the systemic wound signal(s) is not yet known, but major candidates include hormones transmitted via the phloem or the xylem, the electrically-stimulated self-propagating electrical signal in the phloem (the action potential, AP), or the heat-wound-induced surge in hydraulic pressure in the xylem evoking a local change in membrane potential in adjacent living cells (the variation potential, VP). In order to discriminate between these signals we have adopted two approaches. The first approach involves applying stimuli that evoke known signals and determining whether these signals have similar effects on the "model" transcripts for proteinase inhibitors (pin) and calmodulin (cal). Here we show that a heat wound almost invariably evokes a VP, while an electrical stimulation occasionally evokes an AP, and both of these signals induce accumulation of transcripts encoding proteinase inhibitors. The second approach involves identifying the array of genes turned on by heat-wounding. To this end, we have constructed a subtractive library for heat-wounded tissue, isolated over 800 putatively up-regulated clones, and shown that all but two of the fifty that we have analyzed by Northern hybridization are, indeed, up-regulated. Here we show the early kinetics of up-regulation of three of these transcripts in the terminal (4th) leaf in response to heat-wounding the 3rd leaf, about 5 cm away. Even though these transcripts show somewhat different time courses of induction, with one peaking at 30 min, another at 15 min, and another at 5 min after flaming of a distant leaf, they all exhibit a similar pattern, i.e., a transient period of transcript accumulation preceding a period of transcript decrease, followed by a second period of transcript accumulation.

  12. Adherent and Conformal Zn(S,O,OH) Thin Films by Rapid Chemical Bath Deposition with Hexamethylenetetramine Additive. (United States)

    Opasanont, Borirak; Van, Khoa T; Kuba, Austin G; Choudhury, Kaushik Roy; Baxter, Jason B


    ZnS is a wide band gap semiconductor whose many applications, such as photovoltaic buffer layers, require uniform and continuous films down to several nanometers thick. Chemical bath deposition (CBD) is a simple, low-cost, and scalable technique to deposit such inorganic films. However, previous attempts at CBD of ZnS have often resulted in nodular noncontinuous films, slow growth rates at low pH, and high ratio of oxygen impurities at high pH. In this work, ZnS thin films were grown by adding hexamethylenetetramine (HMTA) to a conventional recipe that uses zinc sulfate, nitrilotriacetic acid trisodium salt, and thioacetamide. Dynamic bath characterization showed that HMTA helps the bath to maintain near-neutral pH and also acts as a catalyst, which leads to fast nucleation and deposition rates, continuous films, and less oxygen impurities in the films. Films deposited on glass from HMTA-containing bath were uniform, continuous, and 90 nm thick after 1 h, as opposed to films grown without HMTA that were ∼3 times thinner and more nodular. On Cu2(Zn,Sn)Se4, films grown with HMTA were continuous within 10 min. The films have comparatively few oxygen impurities, with S/(S+O) atomic ratio of 88%, and high optical transmission of 98% at 360 nm. The Zn(S,O,OH) films exhibit excellent adhesion to glass and high resistivity, which make them ideal nucleation layers for other metal sulfides. Their promise as a nucleation layer was demonstrated with the deposition of thin, continuous Sb2S3 overlayers. This novel HMTA chemistry enables rapid deposition of Zn(S,O,OH) thin films to serve as a nucleation layer, a photovoltaic buffer layer, or an extremely thin continuous coating for thin film applications. HMTA may also be applied in a similar manner for solution deposition of other metal chalcogenide and oxide thin films with superior properties.

  13. Rapid fabrication of mesoporous TiO2 thin films by pulsed fibre laser for dye sensitized solar cells (United States)

    Hadi, Aseel; Alhabradi, Mansour; Chen, Qian; Liu, Hong; Guo, Wei; Curioni, Michele; Cernik, Robert; Liu, Zhu


    In this paper we demonstrate for the first time that a fibre laser with a wavelength of 1070 nm and a pulse width of milliseconds can be applied to generate mesoporous nanocrystalline (nc) TiO2 thin films on ITO coated glass in ambient atmosphere, by complete vaporisation of organic binder and inter-connection of TiO2 nanoparticles, without thermally damaging the ITO layer and the glass substrate. The fabrication of the mesoporous TiO2 thin films was achieved by stationary laser beam irradiation of 1 min. The dye sensitized solar cell (DSSC) with the laser-sintered TiO2 photoanode reached higher power conversion efficiency (PCE) of 3.20% for the TiO2 film thickness of 6 μm compared with 2.99% for the furnace-sintered. Electrochemical impedance spectroscopy studies revealed that the laser sintering under the optimised condition effectively decreased charge transfer resistance and increased electron lifetime of the TiO2 thin films. The use of the fibre laser with over 40% wall-plug efficiency offers an economically-feasible, industrial viable solution to the major challenge of rapid fabrication of large scale, mass production of mesoporous metal oxide thin film based solar energy systems, potentially for perovskite and monolithic tandem solar cells, in the future.

  14. 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: [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)


    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.

  15. Impact of thermodynamic properties and heat loss on ignition of transportation fuels in rapid compression machines

    KAUST Repository

    Ahmed, Ahfaz


    Rapid compression machines (RCM) are extensively used to study autoignition of a wide variety of fuels at engine relevant conditions. Fuels ranging from pure species to full boiling range gasoline and diesel can be studied in an RCM to develop a better understanding of autoignition kinetics in low to intermediate temperature ranges. In an RCM, autoignition is achieved by compressing a fuel/oxidizer mixture to higher pressure and temperature, thereby initiating chemical reactions promoting ignition. During these experiments, the pressure is continuously monitored and is used to deduce significant events such as the end of compression and the onset of ignition. The pressure profile is also used to assess the temperature evolution of the gas mixture with time using the adiabatic core hypothesis and the heat capacity ratio of the gas mixture. In such RCM studies, real transportation fuels containing many components are often represented by simpler surrogate fuels. While simpler surrogates such as primary reference fuels (PRFs) and ternary primary reference fuel (TPRFs) can match research and motor octane number of transportation fuels, they may not accurately replicate thermodynamic properties (including heat capacity ratio). This non-conformity could exhibit significant discrepancies in the end of compression temperature, thereby affecting ignition delay (τign) measurements. Another aspect of RCMs that can affect τign measurement is post compression heat loss, which depends on various RCM parameters including geometry, extent of insulation, pre-heating temperature etc. To, better understand the effects of these non-chemical kinetic parameters on τign, thermodynamic properties of a number of FACE G gasoline surrogates were calculated and simulated in a multi-zone RCM model. The problem was further investigated using a variance based analysis and individual sensitivities were calculated. This study highlights the effects on τign due to thermodynamic properties of

  16. Evaluation of Specific Heat, Sound Velocity and Lattice Thermal Conductivity of Strained Nanocrystalline Bismuth Antimony Telluride Thin Films (United States)

    Zheng, D.; Tanaka, S.; Miyazaki, K.; Takashiri, M.


    To investigate the effect of strain on specific heat, sound velocity and lattice thermal conductivity of nanocrystalline bismuth antimony telluride thin films, we performed both experimental study and modeling. The nanocrystalline thin films had mostly preferred crystal orientation along c-axis, and strains in the both directions of c-axis and a- b-axis. It was found that the thermal conductivity of nanocrystalline thin films decreased greatly as compared with that of bulk alloys. To gain insight into the thermal transport in the strained nanocrystalline thin films, we estimated the lattice thermal conductivity based on the phonon transport model of full distribution of mean free paths accounting for the effects of grain size and strain which was influenced to both the sound velocity and the specific heat. As a result, the lattice thermal conductivity was increased when the strain was shifted from compressive to tensile direction. We also confirmed that the strain was influenced by the lattice thermal conductivity but the reduction of the lattice thermal conductivity of thin films can be mainly attributed to the nano-size effect rather than the strain effect. Finally, it was found that the measured lattice thermal conductivities were in good agreement with modeling.

  17. Surge in the heating market. Renewable energies rapidly gaining market share; Wende im Waermemarkt. Erneuerbare Energien gewinnen rasant an Marktanteilen

    Energy Technology Data Exchange (ETDEWEB)

    Briese, Dirk; Hein, Thomas; Gatena, Jens [trend:research GmbH Institut fuer Trend- und Marktforschung, Bremen (Germany)


    The proportion of heat produced from renewable energies is rapidly growing in Germany. The main reasons for this dynamic development are governmental funds for heating technologies based on renewable energy, the growing importance attached by large parts of the population to environmentally responsible energy production and the rising costs of fossil fuels. Biomass plants, solar thermal installations and heat pumps will be widely used in upcoming refurbishment and new building projects, as a recent study shows.

  18. Molecular dynamics study on the effect of boundary heating rate on the phase change characteristics of thin film liquid

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Mohammad Nasim, E-mail:; Morshed, A. K. M. Monjur, E-mail:; Rabbi, Kazi Fazle, E-mail:; Haque, Mominul, E-mail: [Department of Mechanical Engineering, Bangladesh University of Engineering and Technology (BUET) Dhaka-1000 (Bangladesh)


    In this study, theoretical investigation of thin film liquid phase change phenomena under different boundary heating rates has been conducted with the help of molecular dynamics simulation. To do this, the case of argon boiling over a platinum surface has been considered. The study has been conducted to get a better understanding of the nano-scale physics of evaporation/boiling for a three phase system with particular emphasis on the effect of boundary heating rate. The simulation domain consisted of liquid and vapor argon atoms placed over a platinum wall. Initially the whole system was brought to an equilibrium state at 90 K with the help of equilibrium molecular dynamics and then the temperature of the bottom wall was increased to a higher temperature (250 K/130 K) over a finite heating period. Depending on the heating period, the boundary heating rate has been varied in the range of 1600×10{sup 9} K/s to 8×10{sup 9} K/s. The variations of argon region temperature, pressure, net evaporation number with respect to time under different boundary heating rates have been determined and discussed. The heat fluxes normal to platinum wall for different cases were also calculated and compared with theoretical upper limit of maximum possible heat transfer to elucidate the effect of boundary heating rate.

  19. High temperature setup for measurements of Seebeck coefficient and electrical resistivity of thin films using inductive heating (United States)

    Adnane, L.; Williams, N.; Silva, H.; Gokirmak, A.


    We have developed an automated setup for simultaneous measurement of Seebeck coefficient S(T) and electrical resistivity ρ(T) of thin film samples from room temperature to ˜650 °C. S and ρ are extracted from current-voltage (I-V) measurements obtained using a semiconductor parameter analyzer and temperature measurements obtained using commercial thermocouples. The slope and the x-axis intercept of the I-V characteristics represent the sample conductance G and the Seebeck voltage, respectively. The measured G(T) can be scaled to ρ(T) by the geometry factor obtained from the room temperature resistivity measurement of the film. The setup uses resistive or inductive heating to control the temperature and temperature gradient on the sample. Inductive heating is achieved with steel plates that surround the test area and a water cooled copper pipe coil underneath that generates an AC magnetic field. The measurements can be performed using resistive heating only or inductive heating only, or a combination of both depending on the desired heating ranges. Inductive heating provides a more uniform heating of the test area, does not require contacts to the sample holder, can be used up to the Curie temperature of the particular magnetic material, and the temperature gradients can be adjusted by the relative positions of the coil and sample. Example results obtained for low doped single-crystal silicon with inductive heating only and with resistive heating only are presented.

  20. Rapid heat treatment for anatase conversion of titania nanotube orthopedic surfaces (United States)

    Bhosle, Sachin M.; Friedrich, Craig R.


    The amorphous to anatase transformation of anodized nanotubular titania surfaces has been studied by x-ray diffraction and transmission electron microscopy (TEM). A more rapid heat treatment for conversion of amorphous to crystalline anatase favorable for orthopedic implant applications was demonstrated. Nanotube titania surfaces were fabricated by electrochemical anodization of Ti6Al4V in an electrolyte containing 0.2 wt% NH4F, 60% ethylene glycol and 40% deionized water. The resulting surfaces were systematically heat treated in air with isochronal and isothermal experiments to study the temperature and time dependent transformation respectively. Energy dispersive spectroscopy shows that the anatase phase transformation of TiO2 in the as-anodized amorphous nanotube layer can be achieved in as little as 5 min at 350 °C in contrast to reports of higher temperature and much longer time. Crystallinity analysis at different temperatures and times yield transformation rate coefficients and activation energy for crystalline anatase coalescence. TEM confirms the (101) TiO2 presence within the nanotubes. These results confirm that for applications where amorphous titania nanotube surfaces are converted to crystalline anatase, a 5 min production flow-through heating process could be used instead of a 3 h batch process, reducing time, cost, and complexity.

  1. Rapid Embedded Wire Heating via Resistive Guiding of Laser-Generated Fast Electrons as a Hydrodynamic Driver

    CERN Document Server

    Robinson, A P L; Pasley, J


    Resistively guiding laser-generated fast electron beams in targets consisting of a resistive wire embedded in lower $Z$ material should allow one to rapidly heat the wire to over 100eV over a substantial distance without strongly heating the surrounding material. On the multi-ps timescale this can drive hydrodynamic motion in the surrounding material. Thus ultra-intense laser solid interactions have the potential as a controlled driver of radiation hydrodynamics in solid density material. In this paper we assess the laser and target parameters needed to achieve such rapid and controlled heating of the embedded wire.

  2. Effects of Cross-Sectional Shape, Solidity, and Distribution of Heat-Transfer Coefficient on the Torsional Stiffness of Thin Wings Subjected to Aerodynamic Heating (United States)

    Thomson, Robert G.


    A study has been made of the effects of varying the shape, solidity, and heat-transfer coefficient of thin wings with regard to their influence on the torsional-stiffness reduction induced by aerodynamic heating. The variations in airfoil shape include blunting, flattening, and combined blunting and flattening of a solid wing of symmetrical double-wedge cross section. Hollow double-wedge wings of constant skin thickness with and without internal webs also are considered. The effects of heat-transfer coefficients appropriate for laminar and turbulent flow are investigated in addition to a step transition along the chord from a lower to a higher constant value of heat-transfer coefficient. From the results given it is concluded that the flattening of a solid double wedge decreases the reduction in torsional stiffness while slight degrees of blunting increase the loss. The influence of chordwise variations in heat-transfer coefficient due to turbulent and laminar boundary-layer flow on the torsional stiffness of solid wings is negligible. The effect of a step transition in heat-transfer coefficient along the chord of a solid wing can, however, become appreciable. The torsional-stiffness reduction of multiweb and hollow double-wedge wings is substantially less than that calculated for a solid wing subjected to the same heating conditions.

  3. Effects of heat treatments on the transport properties of Cu/sub x/S thin films

    Energy Technology Data Exchange (ETDEWEB)

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


    We have studied the effects of heat treatments on three Cu/sub x/S thin films (1.995< or =x< or =2). Our results suggest that initial heat treatments cause copper in grain boundaries to diffuse irreversibly into the Cu/sub x/S crystallites. Subsequent heating in hydrogen causes a reduction in surface oxides while the reverse process occurs in an oxygen atmosphere. At a given elevated temperature, the resistivity rho and charge density P vary with time according to the expressions P = P/sub 0/e/sup( plus-or-minust//tau)/sup 1/2/ and rho = rho/sub 0/e/sup( minus-or-plust//tau)/sup 1/2/ . On the other hand, the mobility is found to be approximately constant at a given temperature during heat treatment.

  4. A Comprehensive Study of a Micro-Channel Heat Sink Using Integrated Thin-Film Temperature Sensors. (United States)

    Wang, Tao; Wang, Jiejun; He, Jian; Wu, Chuangui; Luo, Wenbo; Shuai, Yao; Zhang, Wanli; Chen, Xiancai; Zhang, Jian; Lin, Jia


    A micro-channel heat sink is a promising cooling method for high power integrated circuits (IC). However, the understanding of such a micro-channel device is not sufficient, because the tools for studying it are very limited. The details inside the micro-channels are not readily available. In this letter, a micro-channel heat sink is comprehensively studied using the integrated temperature sensors. The highly sensitive thin film temperature sensors can accurately monitor the temperature change in the micro-channel in real time. The outstanding heat dissipation performance of the micro-channel heat sink is proven in terms of maximum temperature, cooling speed and heat resistance. The temperature profile along the micro-channel is extracted, and even small temperature perturbations can be detected. The heat source formed temperature peak shifts towards the flow direction with the increasing flow rate. However, the temperature non-uniformity is independent of flow rate, but solely dependent on the heating power. Specific designs for minimizing the temperature non-uniformity are necessary. In addition, the experimental results from the integrated temperature sensors match the simulation results well. This can be used to directly verify the modeling results, helping to build a convincing simulation model. The integrated sensor could be a powerful tool for studying the micro-channel based heat sink.

  5. Functional Design of Dielectric-Metal-Dielectric-Based Thin-Film Encapsulation with Heat Transfer and Flexibility for Flexible Displays. (United States)

    Kwon, Jeong Hyun; Choi, Seungyeop; Jeon, Yongmin; Kim, Hyuncheol; Chang, Ki Soo; Choi, Kyung Cheol


    In this study, a new and efficient dielectric-metal-dielectric-based thin-film encapsulation (DMD-TFE) with an inserted Ag thin film is proposed to guarantee the reliability of flexible displays by improving the barrier properties, mechanical flexibility, and heat dissipation, which are considered to be essential requirements for organic light-emitting diode (OLED) encapsulation. The DMD-TFE, which is composed of Al 2 O 3 , Ag, and a silica nanoparticle-embedded sol-gel hybrid nanocomposite, shows a water vapor transmission rate of 8.70 × 10 -6 g/m 2 /day and good mechanical reliability at a bending radius of 30 mm, corresponding to 0.41% strain for 1000 bending cycles. The electrical performance of a thin-film encapsulated phosphorescent organic light-emitting diode (PHOLED) was identical to that of a glass-lid encapsulated PHOLED. The operational lifetimes of the thin-film encapsulated and glass-lid encapsulated PHOLEDs are 832 and 754 h, respectively. After 80 days, the thin-film encapsulated PHOLED did not show performance degradation or dark spots on the cell image in a shelf-lifetime test. Finally, the difference in lifetime of the OLED devices in relation to the presence and thickness of a Ag film was analyzed by applying various TFE structures to fluorescent organic light-emitting diodes (FOLEDs) that could generate high amounts of heat. To demonstrate the difference in heat dissipation effect among the TFE structures, the saturated temperatures of the encapsulated FOLEDs were measured from the back side surface of the glass substrate, and were found to be 67.78, 65.12, 60.44, and 39.67 °C after all encapsulated FOLEDs were operated at an initial luminance of 10 000 cd/m 2 for sufficient heat generation. Furthermore, the operational lifetime tests of the encapsulated FOLED devices showed results that were consistent with the measurements of real-time temperature profiles taken with an infrared camera. A multifunctional hybrid thin-film encapsulation

  6. Frequency-domain Harman technique for rapid characterization of bulk and thin film thermoelectric materials (United States)

    Moran, Samuel

    Nanostructured thermoelectrics, often in the form of thin films, may potentially improve the generally poor efficiency of bulk thermoelectric power generators and coolers. In order to characterize the efficiency of these new materials it is necessary to measure their thermoelectric figure of merit, ZT. The only direct measurement of ZT is based on the Harman technique and relies on measuring the voltage drop across a sample subjected to a passing continuous current. Application of this technique to thin films is currently carried out as a time-domain measurement of the voltage as the thermal component decays after switching off an applied voltage. This work develops a technique for direct simultaneous measurement of figure of merit and Seebeck coefficient from the harmonic response of a thermoelectric material under alternating current excitation. A thermocouple mounted on the top surface measures voltage across the device as the frequency of the applied voltage is varied. A thermal model allows the sample thermal conductivity to also be determined and shows good agreement with measurements. This technique provides improved signal-to-noise ratio and accuracy compared to time-domain ZT measurements for comparable conditions while simultaneously measuring Seebeck coefficient. The technique is applied to both bulk and thin film thermoelectric samples.

  7. Investigations of rapid thermal annealing induced structural evolution of ZnO: Ge nanocomposite thin films via GISAXS

    Energy Technology Data Exchange (ETDEWEB)

    Ceylan, Abdullah, E-mail: [Department of Physics Eng., Hacettepe University, Beytepe, 06800 Ankara (Turkey); Ozcan, Yusuf [Department of Electricity and Energy, Pamukkale University, Denizli (Turkey); Orujalipoor, Ilghar [Department of Nanotechnology and Nanomedicine, Hacettepe University, Beytepe, 06800 Ankara (Turkey); Huang, Yen-Chih; Jeng, U-Ser [National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu Science Park, Hsinchu, Taiwan (China); Ide, Semra [Department of Physics Eng., Hacettepe University, Beytepe, 06800 Ankara (Turkey); Department of Nanotechnology and Nanomedicine, Hacettepe University, Beytepe, 06800 Ankara (Turkey)


    In this work, we present in depth structural investigations of nanocomposite ZnO: Ge thin films by utilizing a state of the art grazing incidence small angle x-ray spectroscopy (GISAXS) technique. The samples have been deposited by sequential r.f. and d.c. sputtering of ZnO and Ge thin film layers, respectively, on single crystal Si(100) substrates. Transformation of Ge layers into Ge nanoparticles (Ge-np) has been initiated by ex-situ rapid thermal annealing of asprepared thin film samples at 600 °C for 30, 60, and 90 s under forming gas atmosphere. A special attention has been paid on the effects of reactive and nonreactive growth of ZnO layers on the structural evolution of Ge-np. GISAXS analyses have been performed via cylindrical and spherical form factor calculations for different nanostructure types. Variations of the size, shape, and distributions of both ZnO and Ge nanostructures have been determined. It has been realized that GISAXS results are not only remarkably consistent with the electron microscopy observations but also provide additional information on the large scale size and shape distribution of the nanostructured components.

  8. Development and Demonstration of a High Efficiency, Rapid Heating, Low NOx Alternative to Conventional Heating of Round Steel Shapes, Steel Substrate (Strip) and Coil Box Transfer Bars

    Energy Technology Data Exchange (ETDEWEB)

    Kurek, Harry; Wagner, John


    Direct Flame Impingement involves the use of an array of very high-velocity flame jets impinging on a work piece to rapidly heat the work piece. The predominant mode of heat transfer is convection. Because of the locally high rate of heat transfer at the surface of the work piece, the refractory walls and exhaust gases of a DFI furnace are significantly cooler than in conventional radiant heating furnaces, resulting in high thermal efficiency and low NOx emissions. A DFI furnace is composed of a successive arrangement of heating modules through or by which the work piece is conveyed, and can be configured for square, round, flat, and curved metal shapes (e.g., billets, tubes, flat bars, and coiled bars) in single- or multi-stranded applications.

  9. Blast-Wave Generation and Propagation in Rapidly Heated Laser-Irradiated Targets (United States)

    Ivancic, S. T.; Stillman, C. R.; Nilson, P. M.; Solodov, A. A.; Froula, D. H.


    Time-resolved extreme ultraviolet (XUV) spectroscopy was used to study the creation and propagation of a >100-Mbar blast wave in a target irradiated by an intense (>1018WWcm2 cm2) laser pulse. Blast waves provide a platform to generate immense pressures in the laboratory. A temporal double flash of XUV radiation was observed when viewing the rear side of the target, which is attributed to the emergence of a blast wave following rapid heating by a fast-electron beam generated from the laser pulse. The time-history of XUV emission in the photon energy range of 50 to 200 eV was recorded with an x-ray streak camera with 7-ps temporal resolution. The heating and expansion of the target was simulated with an electron transport code coupled to 1-D radiation-hydrodynamics simulations. The temporal delay between the two flashes measured in a systematic study of target thickness and composition was found to evolve in good agreement with a Sedov-Taylor blast-wave solution. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944 and Department of Energy Office of Science Award Number DE-SC-0012317.

  10. Bounds on Heat Transport in Rapidly Rotating Rayleigh-B\\'{e}nard Convection

    CERN Document Server

    Grooms, Ian


    The heat transport in rotating Rayleigh-B\\'enard convection is considered in the limit of rapid rotation (small Ekman number $E$) and strong thermal forcing (large Rayleigh number $Ra$). The analysis proceeds from a set of asymptotically reduced equations appropriate for rotationally constrained dynamics; the conjectured range of validity for these equations is $Ra \\lesssim E^{-8/5}$. A rigorous bound on heat transport of $Nu \\le 20.56Ra^3E^4$ is derived in the limit of infinite Prandtl number using the background method. We demonstrate that the exponent in this bound cannot be improved on using a piece-wise monotonic background temperature profile like the one used here. This is true for finite Prandtl numbers as well, i.e. $Nu \\lesssim Ra^3$ is the best upper bound for this particular setup of the background method. The feature that obstructs the availability of a better bound in this case is the appearance of small-scale thermal plumes emanating from (or entering) the thermal boundary layer.

  11. Incremental heating of Bishop Tuff sanidine reveals preeruptive radiogenic Ar and rapid remobilization from cold storage (United States)

    Andersen, Nathan L.; Jicha, Brian R.; Singer, Brad S.; Hildreth, Wes


    Accurate and precise ages of large silicic eruptions are critical to calibrating the geologic timescale and gauging the tempo of changes in climate, biologic evolution, and magmatic processes throughout Earth history. The conventional approach to dating these eruptive products using the 40Ar/39Ar method is to fuse dozens of individual feldspar crystals. However, dispersion of fusion dates is common and interpretation is complicated by increasingly precise data obtained via multicollector mass spectrometry. Incremental heating of 49 individual Bishop Tuff (BT) sanidine crystals produces 40Ar/39Ar dates with reduced dispersion, yet we find a 16-ky range of plateau dates that is not attributable to excess Ar. We interpret this dispersion to reflect cooling of the magma reservoir margins below ˜475 °C, accumulation of radiogenic Ar, and rapid preeruption remobilization. Accordingly, these data elucidate the recycling of subsolidus material into voluminous rhyolite magma reservoirs and the effect of preeruptive magmatic processes on the 40Ar/39Ar system. The youngest sanidine dates, likely the most representative of the BT eruption age, yield a weighted mean of 764.8 ± 0.3/0.6 ka (2σ analytical/full uncertainty) indicating eruption only ˜7 ky following the Matuyama‑Brunhes magnetic polarity reversal. Single-crystal incremental heating provides leverage with which to interpret complex populations of 40Ar/39Ar sanidine and U-Pb zircon dates and a substantially improved capability to resolve the timing and causal relationship of events in the geologic record.

  12. Aligned carbon nanotube, graphene and graphite oxide thin films via substrate-directed rapid interfacial deposition. (United States)

    D'Arcy, Julio M; Tran, Henry D; Stieg, Adam Z; Gimzewski, James K; Kaner, Richard B


    A procedure for depositing thin films of carbon nanostructures is described that overcomes the limitations typically associated with solution based methods. Transparent and conductively continuous carbon coatings can be grown on virtually any type of substrate within seconds. Interfacial surface tension gradients result in directional fluid flow and film spreading at the water/oil interface. Transparent films of carbon nanostructures are produced including aligned ropes of single-walled carbon nanotubes and assemblies of single sheets of chemically converted graphene and graphite oxide. Process scale-up, layer-by-layer deposition, and a simple method for coating non-activated hydrophobic surfaces are demonstrated.

  13. A hybrid surface modification method on copper wire braids for enhancing thermal performance of ultra-thin heat pipes (United States)

    Sheng, W. K.; Lin, H. T.; Wu, C. H.; Kuo, L. S.; Chen, P. H.


    Copper is the most widely used material in heat pipe manufacturing. Since the capability of wick structures inside a heat pipe will dominate its thermal performance, in this study, we introduce a hybrid surface modification method on the copper wire braids being inserted as wick structure into an ultra-thin heat pipe. The hybrid method is the combination of a chemical-oxidation-based method and a sol-gel method with nanoparticles being dip-coated onto the braid. The experimental data show that braids under hybrid treatment perform higher water rising speed than the oxidized braids while owning higher water net weight than those braids being only dip-coated with nanoparticle.

  14. Influence of substrate heating and annealing on the properties and photoresponse of manganese doped zinc oxide thin films (United States)

    Sugumar, Ravishankar; Angappane, S.


    The structural and optical properties of manganese doped zinc oxide thin films deposited at different substrate temperatures and annealing conditions have been studied. Further, the UV light sensing properties of the fabricated thin film devices have been carried out. The 3% Mn doped ZnO (MZO) films were deposited by RF magnetron sputtering. The as-prepared film, deposited without substrate heating, shows the polycrystalline nature with under-developed grains, which develops well-defined crystal boundaries after annealing. On the other hand, the films deposited at 700 °C and annealed at 700 °C show single crystalline c-axis orientated growth. Notably, there are changes observed in the band gap and photoluminescence of the films subject to different deposition and annealing conditions. The photoresponse of the MZO thin film devices shows responsivity varying from 2.5 × 10-2 to 7.9 A/W, detectivity from 1.6 × 1010 to 37.8 × 1010 Jones and sensitivity from 4.7 to 15.4% under the UV light. Markedly, the films show the response times varying from ∼0.1 to ∼28 s and the recovery times varying between ∼0.1 and ∼120 s. These findings demonstrate the influence of structural and optical properties brought out by the substrate heating and annealing of 3% Mn doped ZnO films on the photoresponse of devices.

  15. Structural and Optical Properties of CuInS2 Thin Films Prepared by Magnetron Sputtering and Sulfurization Heat Treatment

    Directory of Open Access Journals (Sweden)

    Rongfeng Guan


    Full Text Available CuInS2 thin films were prepared by sulfurization of Cu-In precursor films through magnetron sputtering and the resulting films characterized using X-ray diffraction, Raman spectrometry, and UV-Vis spectrophotometry. The results demonstrate that a sputtering power of 80–120 W is more suitable for sputtered Cu-In precursor films and can be used to obtain CuInS2 films with good crystallinity through vulcanization heat treatment. The sputtering gas pressure and sulfurization temperature were shown to impact on the film quality due to improper processes during the CuInS2 phase. Some of the CuIn11S17 and CuS2 impurities were observed in the composition of the prepared CuInS2 thin films. Optimization of process parameters obtained from the experimental data was determined as a sputtering power of 80~120 W, a sputtering gas pressure of 0.6–0.8 Pa, a heat treatment temperature of 450~470°C, and a holding time of 2~3 hours. The optical band gap obtained for CuInS2 thin films is between 1.48 and 1.5 eV.

  16. KMCThinFilm: A C++ Framework for the Rapid Development of Lattice Kinetic Monte Carlo (kMC) Simulations of Thin Film Growth (United States)


    196–201. 44. Kratzer P. Monte Carlo and kinetic Monte Carlo methods–a tutorial. In: Grotendorst J, Attig N, Blügel S, Marx D, editors. Multiscale...Monte Carlo (kMC) Simulations of Thin Film Growth by James J Ramsey Approved for public release; distribution is...Research Laboratory KMCThinFilm: A C++ Framework for the Rapid Development of Lattice Kinetic Monte Carlo (kMC) Simulations of Thin Film Growth by

  17. Heterogeneous glacial lake changes and links of lake expansions to the rapid thinning of adjacent glacier termini in the Himalayas (United States)

    Song, Chunqiao; Sheng, Yongwei; Wang, Jida; Ke, Linghong; Madson, Austin; Nie, Yong


    Glacier mass loss in the Himalayas has far-reaching implications for the alteration of regional hydrologic regimes, an increased risk of glacial lake outburst, downstream water resource abundance, and contributions to sea level rise. However, the mass losses of Himalayan glaciers are not well understood towing to the scarcity of observations and the heterogeneous responses of Himalayan glaciers to climate change and local factors (e.g., glacier surge, interacting with proglacial lakes). In particular, there is a lack of understanding on the unique interactions between moraine-dammed glacial lakes and their effects on debris cover on valley glacier termini. In this study, we examined the temporal evolution of 151 large glacial lakes across the Himalayas and then classified these glacial lakes into three categories: proglacial lakes in contact with full or partial debris-covered glaciers (debris-contact lakes), ice cliff-contact lakes, and non-glacier-contact lakes. The results show that debris-contact lakes experienced a dramatic areal increase of 36.5% over the years 2000 to 2014, while the latter two categories of lakes remained generally stable. The majority of lake expansions occurred at the glacier front without marked lake level rises. This suggests that the rapid expansion of these debris-contact lakes can be largely attributed to the thinning of debris-covered ice as caused by the melting of glacial fronts and the subsequent glacial retreat. We reconstructed the height variations of glacier fronts in contact with 57 different proglacial lakes during the years 2000 to 2014. These reconstructed surface elevation changes of debris-covered, lake-contact glacier fronts reveal significant thinning trends with considerable lowering rates that range from 1.0 to 9.7 m/y. Our study reveals that a substantial average ice thinning of 3.9 m/y occurred at the glacier fronts that are in contact with glacial lakes.

  18. Tailoring the mechanical behavior of nanocrystalline thin films with alloying and heat treatments (United States)

    Dasgupta, Suman

    Metals and alloys with grain sizes below a hundred nanometers exhibit very different mechanical and physical properties compared to their coarse grained counterparts. Unique nanoscale deformation mechanisms are triggered by the ubiquitous nature of grain boundaries in nanocrystalline (NC) materials. Microstructural instabilities can develop in NC materials during deformation due to stress-coupled grain boundary migration and global stress-driven grain growth. The presence or absence of these mechanisms can dramatically affect the attendant mechanical response of the material. The ability to control these grain boundary instabilities with impurity doping might make it possible to engineer nanostructured materials with desired properties. Motivated by this prospect, a collaborative effort was launched with scientists from The University of Pennsylvania, The University of Sydney and The Johns Hopkins University. This dissertation, in particular, describes efforts to tailor mechanical behavior of NC alloy systems by controlling global stress-driven grain growth through alloying and annealing treatments. NC aluminum and nickel, which have been shown to exhibit stress-assisted grain growth, were chosen as the parent materials for this study. NC aluminum was doped with oxygen, and NC nickel with phosphorus, to assess the role of grain boundary solutes in stabilizing grains against stress-assisted grain growth. Confocal co-sputtering techniques were employed to fabricate alloy thin films with precise control over chemistry and microstructure. Tensile properties were measured through microtensile testing and microstructural evolution associated with deformation was characterized using ex-situ and in-situ precession-assisted crystal orientation mapping in TEM. The critical global solute concentrations required to stabilize grain boundaries against applied stresses were identified. Local grain boundary pinning imparted mechanical stability to the microstructure and resulted

  19. Rapid prototyping of all-solution-processed multi-lengthscale electrodes using polymer-induced thin film wrinkling. (United States)

    Gabardo, Christine M; Adams-McGavin, Robert C; Fung, Barnabas C; Mahoney, Eric J; Fang, Qiyin; Soleymani, Leyla


    Three-dimensional electrodes that are controllable over multiple lengthscales are very important for use in bioanalytical systems that integrate solid-phase devices with solution-phase samples. Here we present a fabrication method based on all-solution-processing and thin film wrinkling using smart polymers that is ideal for rapid prototyping of tunable three-dimensional electrodes and is extendable to large volume manufacturing. Although all-solution-processing is an attractive alternative to vapor-based techniques for low-cost manufacturing of electrodes, it often results in films suffering from low conductivity and poor substrate adhesion. These limitations are addressed here by using a smart polymer to create a conformal layer of overlapping wrinkles on the substrate to shorten the current path and embed the conductor onto the polymer layer. The structural evolution of these wrinkled electrodes, deposited by electroless deposition onto a nanoparticle seed layer, is studied at varying deposition times to understand its effects on structural parameters such as porosity, wrinkle wavelength and height. Furthermore, the effect of structural parameters on functional properties such as electro-active surface area and surface-enhanced Raman scattering is investigated. It is found that wrinkling of electroless-deposited thin films can be used to reduce sheet resistance, increase surface area, and enhance the surface-enhanced Raman scattering signal.

  20. Rapid prototyping of all-solution-processed multi-lengthscale electrodes using polymer-induced thin film wrinkling (United States)

    Gabardo, Christine M.; Adams-McGavin, Robert C.; Fung, Barnabas C.; Mahoney, Eric J.; Fang, Qiyin; Soleymani, Leyla


    Three-dimensional electrodes that are controllable over multiple lengthscales are very important for use in bioanalytical systems that integrate solid-phase devices with solution-phase samples. Here we present a fabrication method based on all-solution-processing and thin film wrinkling using smart polymers that is ideal for rapid prototyping of tunable three-dimensional electrodes and is extendable to large volume manufacturing. Although all-solution-processing is an attractive alternative to vapor-based techniques for low-cost manufacturing of electrodes, it often results in films suffering from low conductivity and poor substrate adhesion. These limitations are addressed here by using a smart polymer to create a conformal layer of overlapping wrinkles on the substrate to shorten the current path and embed the conductor onto the polymer layer. The structural evolution of these wrinkled electrodes, deposited by electroless deposition onto a nanoparticle seed layer, is studied at varying deposition times to understand its effects on structural parameters such as porosity, wrinkle wavelength and height. Furthermore, the effect of structural parameters on functional properties such as electro-active surface area and surface-enhanced Raman scattering is investigated. It is found that wrinkling of electroless-deposited thin films can be used to reduce sheet resistance, increase surface area, and enhance the surface-enhanced Raman scattering signal.

  1. Rapid differentiation of Listeria monocytogenes epidemic clones III and IV and their intact compared with heat-killed populations using Fourier transform infrared spectroscopy and chemometrics. (United States)

    Nyarko, Esmond B; Puzey, Kenneth A; Donnelly, Catherine W


    The objectives of this study were to determine if Fourier transform infrared (FT-IR) spectroscopy and multivariate statistical analysis (chemometrics) could be used to rapidly differentiate epidemic clones (ECs) of Listeria monocytogenes, as well as their intact compared with heat-killed populations. FT-IR spectra were collected from dried thin smears on infrared slides prepared from aliquots of 10 μL of each L. monocytogenes ECs (ECIII: J1-101 and R2-499; ECIV: J1-129 and J1-220), and also from intact and heat-killed cell populations of each EC strain using 250 scans at a resolution of 4 cm(-1) in the mid-infrared region in a reflectance mode. Chemometric analysis of spectra involved the application of the multivariate discriminant method for canonical variate analysis (CVA) and linear discriminant analysis (LDA). CVA of the spectra in the wavelength region 4000 to 600 cm(-1) separated the EC strains while LDA resulted in a 100% accurate classification of all spectra in the data set. Further, CVA separated intact and heat-killed cells of each EC strain and there was 100% accuracy in the classification of all spectra when LDA was applied. FT-IR spectral wavenumbers 1650 to 1390 cm(-1) were used to separate heat-killed and intact populations of L. monocytogenes. The FT-IR spectroscopy method allowed discrimination between strains that belong to the same EC. FT-IR is a highly discriminatory and reproducible method that can be used for the rapid subtyping of L. monocytogenes, as well as for the detection of live compared with dead populations of the organism. Fourier transform infrared (FT-IR) spectroscopy and multivariate statistical analysis can be used for L. monocytogenes source tracking and for clinical case isolate comparison during epidemiological investigations since the method is capable of differentiating epidemic clones and it uses a library of well-characterized strains. The FT-IR method is potentially less expensive and more rapid compared to genetic

  2. Heat-treatment controlled structural and optical properties of sol-gel fabricated Eu:ZnO thin films (United States)

    Ghosh, Subhabrata; Uma Mahendra Kumar, K.; Bhaktha, B. N. Shivakiran


    We report on the fabrication of sol-gel derived Eu-doped ZnO films and the effects of heat-treatment on their structural and optical properties. X-ray diffraction data analysis confirms the decrease in strain in the thin films with increasing heat-treatment temperatures, and the compressive stress of the samples is found to become tensile for heat-treatments between 650 °C and 800 °C. X-ray-absorption fine-structure spectra performed at the Eu L3-edge confirm the absence of clustering of Eu-ions. The photoluminescence (PL) spectra of undoped and doped films consist of near-band edge emissions along with the defect state emissions of ZnO. Intense red emission (612 nm) is observed under UV excitation attributed to the 5D0 →7F2 energy level transition of Eu3+ ions in the doped films. The elemental composition and the existence of Eu2+ as well as Eu3+ has been discussed with the help of X-ray photoelectron spectroscopy. ZnO → Eu3+ energy transfer has also been confirmed with the help of PL excitation spectra in these transparent ZnO thin films for applications in integrated optic devices operating in the UV-visible region.

  3. Validation of ANSYS CFX for gas and liquid metal flows with conjugate heat transfer within the European project THINS

    Energy Technology Data Exchange (ETDEWEB)

    Papukchiev, A., E-mail:; Buchholz, S.


    Highlights: • ANSYS CFX is validated for gas and liquid metal flows. • L-STAR and TALL-3D experiments are simulated. • Complex flow and heat transfer phenomena are modelled. • Conjugate heat transfer has to be considered in CFD analyses. - Abstract: Within the FP7 European project THINS (Thermal Hydraulics of Innovative Nuclear Systems), numerical tools for the simulation of the thermal-hydraulics of next generation rector systems were developed, applied and validated for innovative coolants. The Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) gGmbH participated in THINS with activities related to the development and validation of computational fluid dynamics (CFD) and coupled System Thermal Hydraulics (STH) – CFD codes. High quality measurements from the L-STAR and TALL-3D experiments were used to assess the numerical results. Two-equation eddy viscosity and scale resolving turbulence models were used in the validation process of ANSYS CFX for gas and liquid metal flows with conjugate heat transfer. This paper provides a brief overview on the main results achieved at GRS within the project.

  4. Rapid determination of the radiochemical purity of 99mTc-antimony trisulfide colloid prepared by standard and alternative heating methods. (United States)

    Smyth, Douglas R


    The purpose of this study was to validate a rapid quality control method for the lymphoscintigraphic tracer 99mTc-antimony trisulfide colloid (99mTc-ATC). ATC was labeled with 99mTc according to the manufacturer's instructions as well as by alternative heating conditions designed to provide a range of percentages of radiochemical purity (RCP): the tracer was prepared in a dry block heater with heating cavities of different sizes, the temperature of the heating block was varied from 70 degrees C to 115 degrees C, or the duration of heating was varied from 15 to 35 min. Anion-exchange minicolumns were trialled to separate any 99mTc-pertechnetate impurity from 99mTc-ATC with physiologic saline as the eluent. Quality control results were compared with the results from the manufacturer's recommended method, which uses an instant thin-layer chromatography (ITLC) strip with saline as the migrating solution. The quality control results obtained with a cartridge method in 2-3 min compared favorably with those obtained with the ITLC method with saline when the tracer was prepared by heating at 115 degrees C in a dry block heater for 35 min (RCPs, 99.4%+/-0.3% [mean+/-SD] and 99.2%+/-0.3%, respectively; n=25). The cartridge and ITLC quality control results also were in excellent agreement (correlation coefficient, 0.99) over a range of RCPs (80%-100%). An alternative anion-exchange cartridge that was tested in this study was not suitable for assaying the RCP of 99mTc-ATC because of the complete retention of 99mTc-pertechnetate on the sorbent. Compared with the established ITLC method, the cartridge quality control method tested in this study is rapid and provides a reliable assessment of the RCP of 99mTc-ATC. For the preparation of 99mTc-ATC, a dry block heater can be successfully substituted for a boiling water bath and is recommended for heating at high altitudes.

  5. Rapid thermal annealing of FePt and FePt/Cu thin films

    Energy Technology Data Exchange (ETDEWEB)

    Brombacher, Christoph


    Chemically ordered FePt is one of the most promising materials to reach the ultimate limitations in storage density of future magnetic recording devices due to its high uniaxial magnetocrystalline anisotropy and a corrosion resistance superior to rare-earth based magnets. In this study, FePt and FePt/Cu bilayers have been sputter deposited at room temperature onto thermally oxidized silicon wafers, glass substrates and self-assembled arrays of spherical SiO{sub 2} particles with diameters down to 10 nm. Millisecond flash lamp annealing, as well as conventional rapid thermal annealing was employed to induce the phase transformation from the chemically disordered A1 phase into the chemically ordered L1{sub 0} phase. The influence of the annealing temperature, annealing time and the film thickness on the ordering transformation and (001) texture evolution of FePt films with near equiatomic composition was studied. Whereas flash lamp annealed FePt films exhibit a polycrystalline morphology with high chemical L1{sub 0} order, rapid thermal annealing can lead to the formation of chemically ordered FePt films with (001) texture on amorphous SiO{sub 2}/Si substrates. The resultant high perpendicular magnetic anisotropy and large coercivities up to 40 kOe are demonstrated. Simultaneously to the ordering transformation, rapid thermal annealing to temperatures exceeding 600 C leads to a break up of the continuous FePt film into separated islands. This dewetting behavior was utilized to create regular arrays of FePt nanostructures on SiO{sub 2} particle templates with periods down to 50 nm. The addition of Cu improves the (001) texture formation and chemical ordering for annealing temperatures T{sub a} {<=}600 C. In addition, the magnetic anisotropy and the coercivity of the ternary FePtCu alloy can be effectively tailored by adjusting the Cu content. The prospects of FePtCu based exchange spring media, as well as the magnetic properties of FePtCu nanostructures fabricated

  6. Heat flow increase following the rise of mantle isotherms and crustal thinning (United States)

    Mareschal, J. C.; Bergantz, G.


    Heat flow measurements in the western United States define a zone of high heat flow which coincides with the Basin and Range Province where extension has taken place recently. In this region, the average reduced heat flow is approx 30 mW sq. meters higher than in stable continental provinces; locally (e.g., Battle Mountain High), the heat flow anomaly can be more than 100 mW/sq meters above average. Estimates of the amount of extension range between 30% and 100% for the past 30 Ma. In the Colorado Plateau, which has been uplifted without major tectonic deformation, the heat flow is only slightly above average. Analytical calculations show that an abrupt change in heat flow at the base of the lithosphere 30 Ma ago would not affect the surface significantly. Uplift would proceed at a slow rate. A thermal perturbation at the base of a 40 km thick crust, however, would reach the surface faster and, after 30 Ma, the increase in surface heat flow would be about 75% of the amplitude of the heat flow anomaly. The number of volcanic rocks in the Basin and Range suggests that magma intrusions may provide an effective heat transfer mechanism. It can be show that if the source of the intrusions is at the base of the lithosphere, the response time will be much longer than 30 Ma, and most ot the heat transferred from the asthenosphere will be absorbed in the lithosphere.

  7. Influence of Heating Conditions for Formation of a Thin Apatite Film on Zirconia Using a Molecular Precursor Method

    Directory of Open Access Journals (Sweden)

    Masatsugu Hirota


    Full Text Available The influence of heating conditions, heating temperature, and heating time on the formation of a thin carbonate-containing hydroxyapatite (CA film onto partially stabilized zirconia using a molecular precursor method was evaluated. The molecular precursor solution was prepared from a mixture of calcium-ethylenediaminetetraacetic acid complex and phosphate compounds at Ca/P ratio of 1.67. After the application of molecular precursor solution onto zirconia, four different heating conditions—namely, 600 °C-2 h, 800 °C-2 h, 1000 °C-2 h, and 600 °C-4 h—were applied. No distinct difference of surface appearance of CA coating was observed between 600 and 800 °C-2 h. Fusion of apatite crystals was observed at 1000 °C-2 h. Surface roughness of CA film at 1000 °C-2 h was significantly higher than those under other heating conditions. Heating at 800 °C produced a significantly more hydrophilic surface and higher degree of crystallization. No significant differences were recognized in the critical load at the first crack in the coating among the four samples by scratch tests. After 30 days’ immersion in phosphate buffered saline, the four different CA coating films were still present. Simulated body fluid immersion experiments were performed as in vitro biocompatibility tests. After 48 h immersion, the CA film at 800 °C-2 h showed a greater amount of spherical crystal precipitation. It was suggested that properties of CA coating on partially stabilized zirconia using a molecular precursor method were influenced by the heating temperature and time.

  8. Steady heat conduction-based thermal conductivity measurement of single walled carbon nanotubes thin film using a micropipette thermal sensor. (United States)

    Shrestha, R; Lee, K M; Chang, W S; Kim, D S; Rhee, G H; Choi, T Y


    In this paper, we describe the thermal conductivity measurement of single-walled carbon nanotubes thin film using a laser point source-based steady state heat conduction method. A high precision micropipette thermal sensor fabricated with a sensing tip size varying from 2 μm to 5 μm and capable of measuring thermal fluctuation with resolution of ±0.01 K was used to measure the temperature gradient across the suspended carbon nanotubes (CNT) film with a thickness of 100 nm. We used a steady heat conduction model to correlate the temperature gradient to the thermal conductivity of the film. We measured the average thermal conductivity of CNT film as 74.3 ± 7.9 W m(-1) K(-1) at room temperature.

  9. Heat-Induced Agglomeration of Amorphous Silicon Nanoparticles Toward the Formation of Silicon Thin Film. (United States)

    Jang, Bo Yun; Kim, Ja Young; Seo, Gyeongju; Shin, Chae-Ho; Ko, Chang Hyun


    The thermal behavior of silicon nanoparticles (Si NPs) was investigated for the preparation of silicon thin film using a solution process. TEM analysis of Si NPs, synthesized by inductively coupled plasma, revealed that the micro-structure of the Si NPs was amorphous and that the Si NPs had melted and merged at a comparatively low temperature (~750 °C) considering bulk melting temperature of silicon (1414 °C). A silicon ink solution was prepared by dispersing amorphous Si NPs in propylene glycol (PG). It was then coated onto a silicon wafer and a quartz plate to form a thin film. These films were annealed in a vacuum or in an N₂ environment to increase their film density. N2 annealing at 800 °C and 1000 °C induced the crystallization of the amorphous thin film. An elemental analysis by the SIMS depth profile showed that N₂annealing at 1000 °C for 180 min drastically reduced the concentrations of carbon and oxygen inside the silicon thin film. These results indicate that silicon ink prepared using amorphous Si NPs in PG can serve as a proper means of preparing silicon thin film via solution process.

  10. Half-Space Temperature Field with a Movable Thermally Thin-Coated Boundary Under External Heat Flux

    Directory of Open Access Journals (Sweden)

    P. A. Vlasov


    Full Text Available In engineering practice analytical methods of the mathematical theory of heat conduction hold a special place. This is due to many reasons, in particular, because of the fact that the solutions of the relevant problems represented in analytically closed form, can be used not only for a parametric analysis of the studied temperature field and to explore the specific features of its formation, but also to test the developed computational algorithms, which are aimed at solving real-world application heat and mass transfer problems. Difficulties arising when using the analytical mathematical theory methods of heat conduction in practice are well known. Also they are significantly exacerbated if the boundaries of the system under study are movable, even in the simplest case, when the law of motion is known.The main goal of the conducted research is to have an analytically closed-form problem solution for finding the orthotropic half-space temperature field, a boundary of which has thermally thin coating exposed to extremely concentrated stationary external heat flux and uniformly moves parallel to itself.The assumption that the covering of the boundary is thermally thin, allowed to realize the idea of \\concentrated capacity", that is to accept the hypothesis that the mean-thickness coating temperature is equal to the temperature of its boundaries. This assumption allowed us to reduce the problem under consideration to a mixed problem for a parabolic equation with a specific boundary condition.The Hankel integral transform of zero order with respect to the radial variable and the Laplace transform with respect to the temporal variable were used to solve the reduced problem. These techniques have allowed us to submit the required solution as an iterated integral.

  11. Rapid Thermal Annealing for Solution Synthesis of Transparent Conducting Aluminum Zinc Oxide Thin Films (United States)

    Ullah, Sana; De Matteis, Fabio; Davoli, Ivan


    Transparent conducting oxide films with optimized dopant molar ratio have been prepared with limited pre- and postdeposition annealing duration of 10 min. Multiple aluminum zinc oxide (AZO) layers were spin-coated on ordinary glass substrates. The predeposition consolidation temperature and dopant molar ratio were optimized for electrical conductivity and optical transparency. Next, a group of films were deposited on Corning glass substrates from precursor solutions with the optimized dopant ratio, followed by postdeposition rapid thermal annealing (RTA) at different temperatures and in controlled environments. The lowest resistivity of 10.1 × 10-3 Ω cm was obtained for films receiving RTA at 600°C for 10 min each in vacuum then in N2-5%H2 environment, while resistivity of 20.3 × 10-3 Ω cm was obtained for films subjected to RTA directly in N2-5%H2. Optical measurements revealed average total transmittance of about 85% in the visible region. A direct allowed transition bandgap was determined based on the absorption edge with a value slightly above 3.0 eV, within the typical range for semiconductors. RTA resulted in desorption of oxygen with enhanced carrier concentration and crystallinity, which increased the carrier mobility with decreased bulk resistivity while maintaining the required optical transparency.

  12. Rapid thermal chemical vapor deposition growth of nanometer-thin SiC on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Steckl, A.J.; Li, J.P. (Univ. of Cincinnati, OH (United States))


    Rapid thermal chemical vapor deposition growth of [beta]-SiC ultrathin films on Si (100) was achieved using the carbonization reaction of the silicon substrate with C[sub 3]H[sub 8] gas. Growth rates of 0.5-2 nm s[sup -1] have been achieved at 1100-1300degC using C[sub 3]H[sub 8] flow rates of 7-9 standard cm[sup 3] min[sup -1]. X-ray and electron diffraction indicate single-crystal growth. Therefore nanometer-scale SiC films can be grown by controlling the reaction time to a few seconds. The activation energy at atmospheric pressure is 3.12 eV. The growth rate was found to decrease significantly at higher C[sub 3]H[sub 8] flow rates, leading to films of constant thickness beyond a certain critical reaction time. Using this regime of self-limiting growth, SiC films of 3-5 nm have been grown with relatively little sensitivity to the growth time. (orig.).

  13. Ultra rapid direct heating synthesis of ZnO nanorods with improved light trapping from stacked photoanodes for high efficiency photocatalytic water splitting (United States)

    Cheat Lee, Wei; Fang, Yuanxing; Commandeur, Daniel; Qian, Rong; Al-Abdullah, Zainab T. Y.; Chen, Qiao


    An ultra rapid growth method for vertically aligned ZnO nanorod (NR) thin films on metal meshes was developed using a direct heating synthesis technique. A typical NR growth rate of 10 μm h-1 was achieved. The effects of the applied heating power and growth duration on the morphologies of ZnO nanostructures were examined. High density surface defects were formed on the ZnO NRs, which is responsible for slow charge recombination and high efficiency in the photoelectrochemical (PEC) water splitting process. The light absorption for a photoanode was significantly improved by light trapping using a 3D stacked metal mesh photoanode structure. With the internal reflection between the stacked photoanodes, the final light leakage is minimised. The light absorption in the stacked photoanode is improved without restricting the charge transportation. In comparison with a single mesh photoanode and a chemical bath deposition grown flat photoanode, the PEC water splitting efficiency from the stacked photoanode was increased by a factor of 2.6 and 6.1 respectively.

  14. Thin-layer agar (TL7H11 for rapid isolation of Mycobacterium tuberculosis in sputum specimens

    Directory of Open Access Journals (Sweden)

    Habiba Binte Alam


    Full Text Available Background: Tuberculosis (TB remains one of the major causes of death from a single infectious agent worldwide. The early detection of new cases of pulmonary tuberculosis is an important goal in tuberculosis control program.Objective: 1n this study, thin layer agar (TLA culture was compared with Lowenstein-Jensen (LJ culture for rapid detection of pulmonary tuberculosis. Methods: It was a cross sectional study conducted in National Tuberculosis Reference Labora­tory (NTRL of National Institute of Disease of Chest and Hospital (NIDCH, Dhaka, from July 2010 to June 2011. A total of 100 sputum smear positive for acid fast bacilli (AFB by Z-N staining, pulmonary tuberculosis patients were included in this study. Samples were processed by modified Petroff method and then cultured on thin layer 7H11(TL7H11 plates and L-J tubes. TL7H11 plates were observed microscopically for rnicrocolony growth once a week for 6 weeks, and L-J tubes were observed once a week for 8 weeks. Results: The recovery rates of mycobacteria on only TLA, only LJ and on both media were 90%, 97% and 88% respectively. Overall positivity was 99% in both L-J and TLA media. Mean time for detection of mycobacteria on TLA was 9.04±1.66 days compared to 21.78±6.19 days on L-J media. The rate of contamination was higher (6% in L-J media than in TLA media (4%. Conclusion: The TL7H11 media can be used as an alternative to the Lowenstein-Jensen medium for early isolation of mycobacteria in resource constrained settings.

  15. Sinterable Ceramic Powders from Laser Heated Gas Phase Reactions and Rapidly Solidified Ceramic Materials. (United States)


    Gattuso, T. R., Meunier, M., Adler, D., and Haggerty, J. S., "IR Laser- Induced Deposition of Silicon Thin Films ", to be published in the Proceedings of...and Thin Films by Laser Induced Gas Phase Reactions", presented at the Nineteenth University Conference on Ceramic Science, Emergent Process Methods... Silicon Carbonitrides from Monomeric Organosilicon Precursors". To be presented at the 1983 Annual Meeting of the American Ceramic Society, April 1983

  16. Mechanical, structural and dissolution properties of heat treated thin-film phosphate based glasses


    Stuart, Bryan W.; Gimeno-Fabra, Miquel; Segal, Joel; Ahmed, Ifty; Grant, David M.


    Here we show the deposition of 2.7 μm thick phosphate based glass films produced by magnetron sputtering, followed by post heat treatments at 500 °C. Variations in degradation properties pre and post heat treatment were attributed to the formation of Hematite crystals within a glass matrix, iron oxidation and the depletion of hydrophilic P-O-P bonds within the surface layer. As deposited and heat treated coatings showed interfacial tensile adhesion in excess of 73.6 MPa; which surpassed ISO a...

  17. Physics of microstructures enhancement of thin film evaporation heat transfer in microchannels flow boiling (United States)

    Bigham, Sajjad; Fazeli, Abdolreza; Moghaddam, Saeed


    Performance enhancement of the two-phase flow boiling heat transfer process in microchannels through implementation of surface micro- and nanostructures has gained substantial interest in recent years. However, the reported results range widely from a decline to improvements in performance depending on the test conditions and fluid properties, without a consensus on the physical mechanisms responsible for the observed behavior. This gap in knowledge stems from a lack of understanding of the physics of surface structures interactions with microscale heat and mass transfer events involved in the microchannel flow boiling process. Here, using a novel measurement technique, the heat and mass transfer process is analyzed within surface structures with unprecedented detail. The local heat flux and dryout time scale are measured as the liquid wicks through surface structures and evaporates. The physics governing heat transfer enhancement on textured surfaces is explained by a deterministic model that involves three key parameters: the drying time scale of the liquid film wicking into the surface structures (τd), the heating length scale of the liquid film (δH) and the area fraction of the evaporating liquid film (Ar). It is shown that the model accurately predicts the optimum spacing between surface structures (i.e. pillars fabricated on the microchannel wall) in boiling of two fluids FC-72 and water with fundamentally different wicking characteristics.

  18. Mechanical, structural and dissolution properties of heat treated thin-film phosphate based glasses (United States)

    Stuart, Bryan W.; Gimeno-Fabra, Miquel; Segal, Joel; Ahmed, Ifty; Grant, David M.


    Here we show the deposition of 2.7 μm thick phosphate based glass films produced by magnetron sputtering, followed by post heat treatments at 500 °C. Variations in degradation properties pre and post heat treatment were attributed to the formation of Hematite crystals within a glass matrix, iron oxidation and the depletion of hydrophilic P-O-P bonds within the surface layer. As deposited and heat treated coatings showed interfacial tensile adhesion in excess of 73.6 MPa; which surpassed ISO and FDA requirements for HA coatings. Scratch testing of coatings on polished substrates revealed brittle failure mechanisms, amplified due to heat treatment and interfacial failure occurring from 2.3 to 5.0 N. Coatings that were deposited onto sandblasted substrates to mimic commercial implant surfaces, did not suffer from tensile cracking or trackside delamination showing substantial interfacial improvements to between 8.6 and 11.3 N. An exponential dissolution rate was observed from 0 to 2 h for as deposited coatings, which was eliminated via heat treatment. From 2 to 24 h ion release rates ordered P > Na > Mg > Ca > Fe whilst all coatings exhibited linear degradation rates, which reduced by factors of 2.4-3.0 following heat treatments.

  19. Rapid and ultrasensitive flexible palladium nano-thin film biosensing electrode development for cancer antigen HER2 detection (United States)

    Huang, Yun-Tzu; Chang, Chia-Yu; Chen, Wei; Su, Chien-Hao; Hsu, Guo-Cheng; Chang, Chia-Ching

    HER2 (human epidermal growth factor receptor 2) is one of the significant surface antigens of breast cancer Trace amount of HER2 protein in human serum is highly correlated to the tumor progression in breast cancers especially in the cases of recurrence. Therefore, HER2 detection of human serum is significant for early detection of cancer recurrence. Conventional HER2 detection approaches may not be sensitive enough or contain highly false positive rate or time consuming for accurate detection. Therefore, a rapid, highly sensitive and specific sensing is highly desired. By using HER2 specific binding peptide functionalized palladium thin film electrochemical electrode the HER2 protein concentration can be determined at sub-nanogram level by electrochemical impedance spectroscopy (EIS) within 10 mins. The Pd nano-film is sputtered on the flexible plastics substrate and reduces the cost of this electrode. Due to the low cost of the electrode, it is designed as a disposable biosensing probe which may reduce the concern of human sample contamination. The self-management after breast cancer operation may be feasible in the near future. Keywords: Electrochemical impedance spectroscopy(EIS), breast cancer, biosensor Corresponding author:; Cheeshin Technology Co. Collaboration.

  20. Rapid thermal annealing of sputter-deposited ZnO:Al films for microcrystalline Si thin-film solar cells

    Directory of Open Access Journals (Sweden)

    Hanajiri T.


    Full Text Available Rapid thermal annealing of sputter-deposited ZnO and Al-doped ZnO (AZO films with and without an amorphous silicon (a-Si capping layer was investigated using a radio-frequency (rf argon thermal plasma jet of argon at atmospheric pressure. The resistivity of bare ZnO films on glass decreased from 108 to 104–105 Ω cm at maximum surface temperatures Tmaxs above 650 °C, whereas the resistivity increased from 10-4 to 10-3–10-2Ω cm for bare AZO films. On the other hand, the resistivity of AZO films with a 30-nm-thick a-Si capping layer remained below 10-4Ω cm, even after TPJ annealing at a Tmax of 825 °C. The film crystallization of both AZO and a-Si layers was promoted without the formation of an intermixing layer. Additionally, the crystallization of phosphorous- and boron-doped a-Si layers at the sample surface was promoted, compared to that of intrinsic a-Si under the identical plasma annealing conditions. The TPJ annealing of n+-a-Si/textured AZO was applied for single junction n-i-p microcrystalline Si thin-film solar cells.

  1. Retinal nerve fiber layer thinning: a window into rapid eye movement sleep behavior disorders in Parkinson's disease. (United States)

    Yang, Zi-Jiao; Wei, Jing; Mao, Cheng-Jie; Zhang, Jin-Ru; Chen, Jing; Ji, Xiao-Yan; Liu, Jun-Yi; Shen, Yun; Xiong, Kang-Ping; Huang, Jun-Ying; Yang, Ya-Ping; Liu, Chun-Feng


    Retinal nerve fiber layer (RNFL) thinning occurs in Parkinson's disease (PD) and other neurodegenerative diseases. Idiopathic RBD (iRBD) is a well-established prodromal hallmark of synucleinopathies and occurs secondary to many neurodegenerative diseases, including PD. The aim of this study is to determine whether or not retinal structures are altered with the onset of rapid eye movement (REM) sleep behavior disorders (RBD). In all, a total of 63 patients with PD, 14 patients with idiopathic RBD, and 26 sex- and age-matched healthy controls were enrolled and underwent optical coherence tomography measurements (HD-OCT (Zeiss) ) for the average and every quadrant of RNFL thickness. The REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ) was used to classify PD patients with clinically probable RBD (PD + pRBD) or without probable RBD (PD - pRBD). Patients with iRBD were identified by polysomnography. For patients with RBD (idiopathic or secondary to PD), we found a significant decrease in RNFL thickness compared with groups without RBD (PD - pRBD and healthy controls) (all p treatment. Multiple linear regression analysis showed that RBDSQ score was negatively associated with average and inferior RNFL variation in PD (all p < 0.005). The findings show that RNFL was slightly but significantly thinner in idiopathic RBD. In PD, RNFL thickness may vary depending on the presence of RBD.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hmurcik, L.; Serway, R.A.


    The effects of hydrogen heat treatments are reported on CdS/Cu/sub x/S polycrystalline thin-film solar cells. The short-circuit current I/sub sc/ of the cells changes in an exponential manner such that I/sub sc/ = I/sub sc/ (t = 0)e/sup( t//tau)/sup 1/2/. The principle physical mechanism responsible for this change appears to be copper diffusion through the Cu/sub x/S layer as copper oxides at the surface are reduced or formed. We were able to maximize the cell efficiency with an error of 5% or less by monitoring changes in cell parameters during heat treatments. Changes in Cu/sub x/S stoichiometry were correlated with the sheet resistance of the Cu/sub x/S layer in completed cells. Results indicate that heat treatment in a hydrogen atmosphere causes an increase in resistivity (corresponding to an increase in stoichiometry) while oxygen causes the reverse.

  3. Stagnation point flow and heat transfer on a thin porous sheet: Applications to flow dynamics of the circulatory system (United States)

    Misra, J. C.; Sinha, A.; Mallick, B.


    The paper is concerned with the modeling and analysis of stagnation point flow and heat transfer on a thin porous sheet under the action of an induced magnetic field. The fluid is considered to be incompressible viscous and electrically conducting. The study is motivated towards exploring some interesting phenomena in the micro-circulatory system. Heat transfer is considered to be governed by the heat equation. In order to take care of the induced magnetism that affects the flow process, the flow equations are coupled with magnetic field variables. The analysis has been performed under the purview of the boundary layer theory, together with the use of similarity transformation. The transformed equations are solved by developing an appropriate numerical method. Numerical results have been computed for a typical situation of the fluid in motion. The results are displayed graphically/in tabular form, which depict the distribution of velocity and temperature under the action of the induced magnetic field and permeability of the porous sheet. The study shows that the flow of the fluid reduces, as the strength of the induced magnetic field increases. However, the reduction in velocity is accompanied by an enhancement of the temperature field.

  4. Thermal Management of Rapid Fire Gun Breeches: The Case for Heat Pipes (United States)


    at a Depth of 1 Inch ........................................... 23 10. The Effect of the Presence of an Embedded Heat Pipe: Temperature vs. Tim e...desired, the lower the boiling point of the liquid chosen has to be. Exercising the gun barrel heat transfer algorithm of Polk (1980), the effect of the presence of an

  5. Discovery of Rapid and Reversible Water Insertion in Rare Earth Sulfates: A New Process for Thermochemical Heat Storage. (United States)

    Hatada, Naoyuki; Shizume, Kunihiko; Uda, Tetsuya


    Thermal energy storage based on chemical reactions is a prospective technology for the reduction of fossil-fuel consumption by storing and using waste heat. For widespread application, a critical challenge is to identify appropriate reversible reactions that occur below 250 °C, where abundant low-grade waste heat and solar energy might be available. Here, it is shown that lanthanum sulfate monohydrate La 2 (SO 4 ) 3 ⋅H 2 O undergoes rapid and reversible dehydration/hydration reactions in the temperature range from 50 to 250 °C upon heating/cooling with remarkably small thermal hysteresis (dehydration/hydration behavior. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. The asymptotic equivalence of fixed heat flux and fixed temperature thermal boundary conditions for rapidly rotating convection

    CERN Document Server

    Calkins, Michael A; Julien, Keith; Nieves, David; Driggs, Derek; Marti, Philippe


    The influence of fixed temperature and fixed heat flux thermal boundary conditions on rapidly rotating convection in the plane layer geometry is investigated for the case of stress-free mechanical boundary conditions. It is shown that whereas the leading order system satisfies fixed temperature boundary conditions implicitly, a double boundary layer structure is necessary to satisfy the fixed heat flux thermal boundary conditions. The boundary layers consist of a classical Ekman layer adjacent to the solid boundaries that adjust viscous stresses to zero, and a layer in thermal wind balance just outside the Ekman layers adjusts the temperature such that the fixed heat flux thermal boundary conditions are satisfied. The influence of these boundary layers on the interior geostrophically balanced convection is shown to be asymptotically weak, however. Upon defining a simple rescaling of the thermal variables, the leading order reduced system of governing equations are therefore equivalent for both boundary condit...

  7. Heat Capacity, Crystallization, and Nucleation in Poly(vinyl alcohol) Thin Films (United States)

    Thomas, David; Wurm, Andreas; Zhuravlev, Evgeny; Schick, Christoph; Cebe, Peggy

    Polyvinyl alcohol (PVA) is hydrophilic, biodegradable, semi-crystalline polymer with a wide array of applications ranging from textiles and packaging to medicine. Despite possessing favorable properties, PVA thermally degrades at temperatures just in excess of 200 °C which occurs slightly below the observed peak endothermic melting peak at 203 °C. Utilizing fast scanning calorimetry it is possible to minimize sample degradation allowing measurements of the liquid phase heat capacity as well as study nucleation and crystallization from the amorphous melt state. Samples cut from parent films 2-3 μm thick were placed on UFSC1 sensors and brought between -80 and 270 °C at rates of 2000 °C/s under a nitrogen atmosphere. After five complete cycles samples did not show any signs of degradation. By fitting the symmetry corrected glassy phase heat capacity with literature values for the specific heat capacity from the ATHAS databank sample masses were determined to vary between 15-50 ng. Homogeneous nucleation was observed for all samples cooled from the melt with peak temperature 123 °C. Fitting linear heat capacity baselines in the melt and glassy states it was possible to obtain an experimental measurement of the heat capacity increment 44.5 J/mol K at the glass transition 85 °C. NSF DMR-1206010.

  8. Improved identification and quantitation of mature endogenous peptides in the rodent hypothalamus using a rapid conductive sample heating system. (United States)

    Yang, Ning; Anapindi, Krishna D B; Romanova, Elena V; Rubakhin, Stanislav S; Sweedler, Jonathan V


    Measurement, identification, and quantitation of endogenous peptides in tissue samples by mass spectrometry (MS) contribute to our understanding of the complex molecular mechanisms of numerous biological phenomena. For accurate results, it is essential to arrest the postmortem degradation of ubiquitous proteins in samples prior to performing peptidomic measurements. Doing so ensures that the detection of endogenous peptides, typically present at relatively low levels of abundance, is not overwhelmed by protein degradation products. Heat stabilization has been shown to inactivate the enzymes in tissue samples and minimize the presence of protein degradation products in the subsequent peptide extracts. However, the efficacy of different heat treatments to preserve the integrity of full-length endogenous peptides has not been well documented; prior peptidomic studies of heat stabilization methods have not distinguished between the full-length (mature) and numerous truncated (possible artifacts of sampling) forms of endogenous peptides. We show that thermal sample treatment via rapid conductive heat transfer is effective for detection of mature endogenous peptides in fresh and frozen rodent brain tissues. Freshly isolated tissue processing with the commercial Stabilizor T1 heat stabilization system resulted in the confident identification of 65% more full-length mature neuropeptides compared to widely used sample treatment in a hot water bath. This finding was validated by a follow-up quantitative multiple reaction monitoring MS analysis of select neuropeptides. The rapid conductive heating in partial vacuum provided by the Stabilizor T1 effectively reduces protein degradation and decreases the chemical complexity of the sample, as assessed by determining total protein content. This system enabled the detection, identification, and quantitation of neuropeptides related to 22 prohormones expressed in individual rat hypothalami and suprachiasmatic nuclei.

  9. Rapid laser annealing of Cu(In,Ga)Se2 thin films by using a continuous wave Nd:YAG laser (λ0= 532 nm) (United States)

    Kim, Nam-Hoon; Ko, Pil Ju; Cho, Geum-Bae; Park, Chan Il


    Rapid laser annealing of a Cu(In,Ga)Se2 (CIGS) thin film absorber was proposed and demonstrated using a continuous 532-nm Nd:YAG laser, following sputtering with Cu0.9In0.7Ga0.3Se2 target, because the conventional annealing temperature for improving the crystallinity of CIGS thin films is higher than the decomposition temperature of a typical flexible polymer substrate. When the laser optical power was incrementally increased over the range from 2.00 to 3.00 W, for 200 s, XRD patterns showed the formation of CIGS chalcopyrite (112), (220/204), and (312/116) phases in the laser-annealed CIGS thin films, at laser optical powers of 2.75 and 3.00 W. The band gaps of these laser-annealed CIGS thin films varied from 1.45 to 1.83 eV and depended on the laser optical power. The relative mean absorbance of the laser-annealed CIGS thin films was 1.806, suggesting that approximately 98.44% of the incident photons were observed by the 600-nm-thick film in the visible spectral region. Conductivity type varied with changes in the laser optical power. The resistivities of the laser-annealed CIGS thin films were of order of 10-3 - 101 Ω-cm.

  10. Rapid nanocrystallization of soft-magnetic amorphous alloys using microwave induction heating

    Energy Technology Data Exchange (ETDEWEB)

    Nicula, R. [Swiss Federal Laboratories for Materials Testing and Research - Empa, Feuerwerkerstr. 39, CH-3602 Thun (Switzerland)], E-mail:; Stir, M.; Ishizaki, K. [Swiss Federal Laboratories for Materials Testing and Research - Empa, Feuerwerkerstr. 39, CH-3602 Thun (Switzerland); Catala-Civera, J.-M. [Polytechnical University of Valencia, School of Telecommunication, Camino de Vera s/n, E-46022 Valencia (Spain); Vaucher, S. [Swiss Federal Laboratories for Materials Testing and Research - Empa, Feuerwerkerstr. 39, CH-3602 Thun (Switzerland)


    The crystallization of Fe{sub 73}Nb{sub 3}Cu{sub 1}Si{sub 16}B{sub 7} alloy during microwave heating was investigated in situ using synchrotron radiation powder diffraction. The phase transformation comprises a primary nanocrystallization stage and a final microcrystallization step. We provide evidence for a strong enhancement of the transformation kinetics. Microwave heating occurs as a result of both ohmic and magnetic losses induced by eddy currents, which defines a volumetric microwave induction heating process. Nanocrystallization is completed within 5 s, while full crystallization is achieved in less than 10 s.

  11. Magnetohydrodynamic thin film and heat transfer of power law fluids over an unsteady stretching sheet with variable thermal conductivity

    Directory of Open Access Journals (Sweden)

    Lin Yanhai


    Full Text Available This paper presents an investigation on the MHD thin film flow and heat transfer of a power law fluid over an unsteady stretching sheet. The effects of power law viscosity on a temperature field are taken into account with a modified Fourier’s law Proposed by Zheng by assuming that the temperature field is similar to the velocity field. The governing equations are reduced to a system of nonlinear ordinary differential equations. The numerical solutions are obtained by using the shooting method coupled with the Runge-Kutta method. The influence of the Hartmann number, the power law exponent, the unsteadiness parameter, the thickness parameter and the generalized Prandtl number on the velocity and temperature fields are presented graphically and analyzed. Moreover, the critical formula for parameters are derived which indicated that the magnetic field has no effect on the critical value.

  12. Effect of heat treatments in vacuum on CdS thin films prepared by the spray deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Escosura, L.; Garcia-Camarero, E.; Arjona, F.; Rueda, F.


    The effects of short heat treatments in vacuum (10 min at 200-400/sup 0/C) on the electrical, structural and optical properties of hexagonal polycrystalline CdS thin films prepared by the spray deposition technique were studied. It was found that the electrical and structural properties change remarkably under these treatments. However, the optical properties do not vary significantly. The resistivity, in particular, decreased from about 500 ..cap omega.. cm to less then 1 ..cap omega.. for a 300/sup 0/C annealing while the electron mobility increased by two orders of magnitude, a result similar to that reported by Martinuzzi and coworkers. A hexagonal phase was obtained regardless of deposition temperature. The preferential orientation changed when samples were subjected to vacuum annealing at 300/sup 0/C or more, indicating that a recrystallization had taken place in the films.

  13. Parametric investigation on transient boiling heat transfer of metal rod cooled rapidly in water pool

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chi Young [Department of Fire Protection Engineering, Pukyong National University, 45, Yongso-ro, Nam-gu, Busan 48513 (Korea, Republic of); Kim, Sunwoo, E-mail: [Mechanical Engineering Department, University of Alaska Fairbanks, P. O. Box 755905, Fairbanks, AK 99775-5905 (United States)


    Highlights: • Effects of liquid subcooling, surface coating, material property, and surface oxidation are examined. • Liquid subcooling affects remarkably the quenching phenomena. • Cr-coated surfaces for ATF might extend the quenching duration. • Solids with low heat capacity shorten the quenching duration. • Surface oxidation can affect strongly the film boiling heat transfer and MFB point. - Abstract: In this work, the effects of liquid subcooling, surface coating, material property, and surface oxidation on transient pool boiling heat transfer were investigated experimentally using the vertical metal rod and quenching method. The change in rod temperature was measured with time during quenching, and the visualization of boiling around the test specimen was performed using the high-speed video camera. As the test materials, the zircaloy (Zry), stainless steel (SS), niobium (Nb), and copper (Cu) were tested. In addition, the chromium-coated niobium (Cr-Nb) and chromium-coated stainless steel (Cr-SS) were prepared for accident tolerant fuel (ATF) application. Low liquid subcooling and Cr-coating shifted the quenching curve to the right, which indicates a prolongation of quenching duration. On the other hand, the material with small heat capacity and surface oxidation caused the quenching curve to move to the left. To examine the influence of the material property and surface oxidation on the film boiling heat transfer performance and minimum film boiling (MFB) point in more detail, the wall temperature and heat flux were calculated from the present transient temperature profile using the inverse heat transfer analysis, and then the curves of wall temperature and heat flux in the film boiling regime were obtained. In the present experimental conditions, the effect of material property on the film boiling heat transfer performance and MFB point seemed to be minor. On the other hand, based on the experimental results of the Cu test specimen, the surface

  14. Development of Rapid Pipe Moulding Process for Carbon Fiber Reinforced Thermoplastics by Direct Resistance Heating (United States)

    Tanaka, Kazuto; Harada, Ryuki; Uemura, Toshiki; Katayama, Tsutao; Kuwahara, Hideyuki

    To deal with environmental issues, the gasoline mileage of passenger cars can be improved by reduction of the car weight. The use of car components made of Carbon Fiber Reinforced Plastics (CFRP) is increasing because of its superior mechanical properties and relatively low density. Many vehicle structural parts are pipe-shaped, such as suspension arms, torsion beams, door guard bars and impact beams. A reduction of the car weight is expected by using CFRP for these parts. Especially, when considering the recyclability and ease of production, Carbon Fiber Reinforced Thermoplastics are a prime candidate. On the other hand, the moulding process of CFRTP pipes for mass production has not been well established yet. For this pipe moulding process an induction heating method has been investigated already, however, this method requires a complicated coil system. To reduce the production cost, another system without such complicated equipment is to be developed. In this study, the pipe moulding process of CFRTP using direct resistance heating was developed. This heating method heats up the mould by Joule heating using skin effect of high-frequency current. The direct resistance heating method is desirable from a cost perspective, because this method can heat the mould directly without using any coils. Formerly developed Non-woven Stitched Multi-axial Cloth (NSMC) was used as semi-product material. NSMC is very suitable for the lamination process due to the fact that non-crimp stitched carbon fiber of [0°/+45°/90°/-45°] and polyamide 6 non-woven fabric are stitched to one sheet, resulting in a short production cycle time. The use of the pipe moulding process with the direct resistance heating method in combination with the NSMC, has resulted in the successful moulding of a CFRTP pipe of 300 mm in length, 40 mm in diameter and 2 mm in thickness.

  15. Studying the Dynamics of Breakdown of Thin Horizontal Liquid Layers with Local Heating

    Directory of Open Access Journals (Sweden)

    Spesivtsev Serafim


    Full Text Available Experimental study of liquid layers breakdown when heated locally from the substrate side was made. Water and ethanol were used as working liquids with a layer thickness of 300 μm. Basic steps of the breakdown process were found and mean velocities of the dry spot formation were determined; the values are 0.06 mm/sec for ethanol and 5.15 mm/sec for water. The formation of residual layer over the hot-spot before the breakdown has been found for both liquids. The creation of a droplet cluster near the heating region is observed when using water as a working fluid. It was shown that evaporation is one of the general factors influencing the process of layer breakdown and dry spot formation as well as thermocapillary effect.

  16. Heat transfer enhancement on thin wires in superfluid helium forced flows

    CERN Document Server

    Duri, Davide; Moro, Jean-Paul; Roche, Philippe-Emmanuel; Diribarne, Pantxo


    In this paper, we report the first evidence of an enhancement of the heat transfer from a heated wire by an external turbulent flow of superfluid helium. We used a standard Pt-Rh hot-wire anemometer and overheat it up to 21 K in a pressurized liquid helium turbulent round jet at temperatures between 1.9 K and 2.12 K. The null-velocity response of the sensor can be satisfactorily modeled by the counter flow mechanism while the extra cooling produced by the forced convection is found to scale similarly as the corresponding extra cooling in classical fluids. We propose a preliminary analysis of the response of the sensor and show that -contrary to a common assumption- such sensor can be used to probe local velocity in turbulent superfluid helium.

  17. Analysis of Heat-and-Mass Transfer Conjugated Problem Solution while Forming Thin-Wall Castings

    Directory of Open Access Journals (Sweden)

    R. I. Еsman


    Full Text Available The paper contains an analysis of heat-and-mass transfer conjugated problem in case of moving of liquid melts in channels of metallic forms (moulds, dies, crystallizers etc.. Investigations of velocity profiles at various flow sections, current lines in the calculated area, pressure and viscosity fields in non-stationary state have been carried out in the paper.The paper reveals that current is of parabolic shape in the annular channel at rather large distance from a projection up and down the flow and pressure along channel section is practically unchangeable.The executed investigations of heat-and-mass transfer in the moving melt make it possible to create a data base of control parameters for development of prospective technologies  of special casting methods. 

  18. Casting/mold thermal contact heat transfer during solidification of Al-Cu-Si alloy (LM 21) plates in thick and thin molds (United States)

    Prabhu, K. Narayan; Chowdary, Bheemappa; Venkataraman, N.


    Heat flow at the casting/mold interface was assessed and studied during solidification of Al-Cu-Si (LM 21) alloy in preheated cast iron molds of two different thicknesses, coated with graphite and alumina based dressings. The casting and the mold were instrumented with thermocouples connected to a computer controlled temperature data acquisition system. The thermal history at nodal locations in the mold and casting obtained during experimentation was used to estimate the heat flux by solving the one-dimensional inverse heat conduction problem. The cooling rate and solidification time were measured using the computer-aided cooling curve analysis data. The estimated heat flux transients showed a peak due to the formation of a stable solid shell, which has a higher thermal conductivity compared with the liquid metal in contact with the mold wall prior to the occurrence of the peak. The high values of heat flux transients obtained with thin molds were attributed to mold distortion due to thermal stresses. For thin molds, assumption of Newtonian heating yielded reliable interfacial heat transfer coefficients as compared with one-dimensional inverse modeling. The time of occurrence of peak heat flux increased with a decrease in the mold wall thickness and increase in the casting thickness.

  19. Low heat flow from young oceanic lithosphere at the Middle America Trench off Mexico [rapid communication (United States)

    Minshull, Timothy A.; Bartolomé, Rafael; Byrne, Siobhán; Dañobeitia, Juanjo


    Seismic reflection profiles across the Middle America Trench at 20°N show a high amplitude bottom simulating reflector interpreted as marking a phase transition between methane hydrate and free gas in the pore space of both accreted and trench sediments. We determine the depth of the hydrate-gas phase boundary in order to estimate the geothermal gradient and hence the heat flow beneath the trench and the frontal part of the accretionary wedge which overlies the downgoing plate. After correction for sedimentation, heat flow values in the trench and through the accretionary wedge are only about half of the values predicted by plate cooling models for the 10 Ma subducting lithosphere. There is no systematic correlation between heat flow in the accretionary wedge and distance from the trench. A comparison with heat flow predicted by a simple analytical model suggests that there is little shear heating from within or beneath the wedge, despite the high basal friction suggested by the large taper angle of the wedge. The geothermal gradient varies systematically along the margin and is negatively correlated with the frontal slope of the wedge. Some local peaks may be attributed to channelised fluid expulsion.

  20. Peculiar features of boron distribution in high temperature fracture area of rapidly quenched heat-resistant nickel alloy

    Energy Technology Data Exchange (ETDEWEB)

    Shulga, A. V., E-mail: [National Research Nuclear University MEPhI (Russian Federation)


    This article comprises the results of comprehensive study of the structure and distribution in the high temperature fracture area of rapidly quenched heat-resistant superalloy of grade EP741NP after tensile tests. The structure and boron distribution in the fracture area are studied in detail by means of direct track autoradiography in combination with metallography of macro- and microstructure. A rather extensive region of microcracks generation and intensive boron redistribution is detected in the high temperature fracture area of rapidly quenched nickel superalloy of grade EP741NP. A significant decrease in boron content in the fracture area and formation of elliptically arranged boride precipitates are revealed. The mechanism of intense boron migration and stability violation of the structural and phase state in the fracture area of rapidly quenched heat-resistant nickel superalloy of grade EP741NP is proposed on the basis of accounting for deformation occurring in the fracture area and analysis of the stressed state near a crack.

  1. Critical heat flux for free convection boiling in thin rectangular channels (United States)

    Cheng, Lap Y.; Tichler, P. R.

    A review of the experimental data on free convection boiling critical heat flux (CHF) in vertical rectangular channels reveals three mechanisms of burnout. They are the pool boiling limit, the circulation limit, and the flooding limit associated with a transition in flow regime from churn to annular flow. The dominance of a particular mechanism depends on the dimensions of the channel. Analytical models were developed for each free convection boiling limit. Limited agreement with data is observed. A CHF correlation, which is valid for a wide range of gap sizes, was constructed from the CHF's calculated according to the three mechanisms of burnout.

  2. Technical Design of Flexible Thin-Film Solar Heating Clothes with Switchable Output Power

    Directory of Open Access Journals (Sweden)

    Zhao Yu Xiao


    Full Text Available This research focuses on the research and development of thermal clothes through technical design, by adopting unique removable electronic equipment and applying carbon fiber material to thermal clothes against cold, so as to meet the requirements of active heating and passive warmth retention. Firstly, the specification of power supply system was determined in accordance with the requirements of power system, and the specification of charging system was determined according to the specification of power system. Then circuit system was designed and tested. Fianlly, the electronic device was configured on the clothes appropriately, so that it should be conforms to ergonomic principles, convenient and fast.

  3. Rapid killing of bed bugs (Cimex lectularius L.) on surfaces using heat: application to luggage. (United States)

    Loudon, Catherine


    The resistance of bed bugs (Cimex lectularius L.) to chemical insecticides has motivated the development of non-chemical control methods such as heat treatment. However, because bed bugs tend to hide in cracks or crevices, their behavior incidentally generates a thermally insulated microenvironment for themselves. Bed bugs located on the outer surface of luggage are less insulated and potentially more vulnerable to brief heat treatment. Soft-sided suitcases with adult male bed bugs on the outside were exposed to an air temperature of 70-75 °C. It took 6 min to kill all of the bed bugs, even those that had concealed themselves under zipper flaps or decorative piping. During heating, only one bed bug (out of 250 in total) moved into the luggage (through a closed zipper). Over long periods of time (24 h) at room temperature, adult male bed bugs on the exterior of luggage only infrequently moved inside; only 3% (5/170) had moved inside during 24 h. Brief exterior heat treatment of luggage is a promising way to reduce the spread of bed bugs being transported on the outer surface of luggage. This treatment will not kill bed bugs inside the luggage, but could be a component of integrated management for this pest. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  4. Transformation Heat Treatment of Rapidly Quenched Nb3A1 Precursor Monitored in situ by High Energy Synchrotron Diffraction

    CERN Document Server

    Scheuerlein, C; Di Michiel, M; Jin, X; Takeuchi, T; Kikuchi, A; Tsuchiya, K; Nakagawa, K; Nakamoto, T


    Nb3Al superconductors are studied for use in high field magnets. Fine grained Nb3Al with nearly stoichiometric Al content is obtained by a Rapid Heating Quenching and Transformation (RHQT) process. We describe a non destructive in situ study of the transformation process step of a RHQ Nb3Al precursor wire with ramp rates of either 120 °C/h or 800 °C/h. High energy synchrotron x-ray diffraction measurements show the transformation from a Nb(Al)SS supersaturated solid solution into Nb3Al. When heating with a ramp rate of 120 °C/h a strong reduction of the Nb(Al)SS (110) diffraction peak component is observed when the temperature exceeds 660 °C. Additional diffraction peaks are detectable in the approximate temperature interval 610 °C - 750 °C and significant Nb3Al growth is observed above 730 °C.

  5. Evaluation of Ti(3)Si Phase Stability from Heat-Treated, Rapidly Solidified Ti-Si Alloys


    COSTA, Alex Matos da Silva; de Lima, Gisele Ferreira; Rodrigues,Geovani; NUNES, Carlos Angelo; Coelho,Gilberto Carvalho; Suzuki, Paulo Atsushi


    Ti-base alloys containing significant amounts of silicon have been considered for high temperature structural applications. Thus, information concerning phase stability on the Ti-Si system is fundamental and there are not many investigations covering the phase stability of the Ti(3)Si phase, specially its dependence on oxygen/nitrogen contamination. In this work the stability of this phase has been evaluated through heat-treatment of rapidly solidified Ti-rich Ti-Si alloys at 700 A degrees C ...

  6. Development of a Thin Film Primary Surface Heat Exchanger for Advanced Power Cycles

    Energy Technology Data Exchange (ETDEWEB)

    Allison, Tim [Southwest Research Inst., San Antonio, TX (United States); Beck, Griffin [Southwest Research Inst., San Antonio, TX (United States); Bennett, Jeffrey [Southwest Research Inst., San Antonio, TX (United States); Hoopes, Kevin [Southwest Research Inst., San Antonio, TX (United States); Miller, Larry [Southwest Research Inst., San Antonio, TX (United States)


    This project objective is to develop a high-temperature design upgrade for an existing primary surface heat exchanger so that the redesigned hardware is capable of operation in CO2 at temperatures up to 1,510°F (821°C) and pressure differentials up to 130 psi (9 bar). The heat exchanger is proposed for use as a recuperator in an advanced low-pressure oxy-fuel Brayton cycle that is predicted to achieve over 50% thermodynamic efficiency, although the heat exchanger could also be used in other high-temperature, low-differential pressure cycles. This report describes the progress to date, which includes continuing work performed to select and test new candidate materials for the recuperator redesign, final mechanical and thermal performance analysis results of various redesign concepts, and the preliminary design of a test loop for the redesigned recuperator including a budgetary estimate for detailed test loop design, procurement, and test operation. A materials search was performed in order to investigate high-temperature properties of many candidate materials, including high-temperature strength and nickel content. These properties were used to rank the candidate materials, resulting in a reduced list of nine materials for corrosion testing. Multiple test rigs were considered and analyzed for short-term corrosion testing and Thermal Gravimetric Analysis (TGA) was selected as the most cost-effective option for evaluating corrosion resistance of the candidate materials. In addition, tantalum, niobium, and chromium coatings were identified as potential options for increased corrosion resistance. The test results show that many materials exhibit relatively low weight gain rates, and that niobium and tantalum coatings may improve corrosion resistance for many materials, while chromium coatings appear to oxidize and debond quickly. Metallurgical analysis of alloys was also performed, showing evidence of intergranular attack in 282 that may cause long

  7. Quantitative effects of rapid heating on soot-particle sizing through analysis of two-pulse LII

    KAUST Repository

    Cenker, Emre


    During the rapid laser pulse heating and consecutive cooling in laser-induced incandescence (LII), soot particles may undergo thermal annealing and sublimation processes which lead to a permanent change in its optical properties and its primary particle size, respectively. Overall, effects of these two processes on soot and LII model-based particle sizing are investigated by measuring the two-color time-resolved (2C-TiRe) LII signal decay from in-flame soot after two consecutive laser pulses at 1064-nm wavelength. Experiments are carried out on a non-premixed laminar ethylene/air flame from a Santoro burner with both low and moderate laser fluences suitable for particle sizing. The probe volume is set to a radial position close to the flame axis where the soot particles are known to be immature or less graphitic. With the first pulse, soot is pre-heated, and the LII signal after the consecutive second pulse is used for analysis. The two-color incandescence emission technique is used for the pyrometric determination of the LII-heated peak soot temperature at the second pulse. A new LII simulation tool is developed which accounts for particle heating via absorption and annealing, and cooling via sublimation, conduction, and radiation with various existing sub-models from the literature. The same approach of using two laser pulses is implemented in the simulations. Measurements indicate that thermal annealing and associated absorption enhancement becomes important at laser fluences above 0.17 J/cm2 for the immature in-flame soot. After a heating pulse at 0.33 J/cm2, the increase of the soot absorption function is calculated as 35% using the temperature measured at the second pulse and an absorption model based on the Rayleigh approximation. Present annealing model, on the other hand, predicts graphitization of soot even in the absence of laser heating at typical flame temperatures. Recorded experimental LII signal decays and LII-heated peak soot temperature

  8. Impact of ink synthesis on processing of inkjet-printed silicon nanoparticle thin films: A comparison of Rapid Thermal Annealing and photonic sintering

    Energy Technology Data Exchange (ETDEWEB)

    Drahi, E.; Blayac, S. [Centre Microélectronique de Provence/Ecole Nationale Supérieure des Mines de Saint Etienne, 880, avenue de Mimet Gardanne, 13541 (France); Borbely, A. [Science des Matériaux et des Structures/Ecole Nationale Supérieure des Mines de Saint Etienne, 158, cours Fauriel Saint Etienne Cedex 2, 42023 (France); Benaben, P. [Centre Microélectronique de Provence/Ecole Nationale Supérieure des Mines de Saint Etienne, 880, avenue de Mimet Gardanne, 13541 (France)


    Inkjet printing has a high potential for cost reduction in solar cell and thermoelectric industry. This study demonstrates that silicon thin films can be produced by inkjet-printing of silicon nanoparticles followed by subsequent drying and annealing steps. Ink formulation is crucial for the sintering of the silicon nanoparticles and control of the microstructure at low temperature. Upon heating, the microstructure is modified from porous layer made of juxtaposed silicon nanoparticles to denser layer with coarser grains. This evolution is monitored by scanning electron microscopy and by micro-Raman spectroscopy, which offer a fast and precise characterization of the microstructure and chemical composition of thin films. Above a threshold temperature of 800 °C cracks appear within thin film and substrate because of the stress induced by the oxidation of the surface. An innovative sintering method, photonic annealing, is studied in order to reduce both oxidation and stress in the thin films as well as reducing processing time. Evolution of the thermal conductivity is performed by micro-Raman spectroscopy and can be tailored in a large range between ~ 1 and ~ 100 W·m{sup −1}·K{sup −1} depending on the sintering method and atmosphere. Therefore control of the microstructure evolution with applied annealing process allows tailoring of both microstructure and thermal conductivity of the silicon thin films. - Highlights: • Impact of ink synthesis on sintering (Si nanoparticle surface chemistry) • Photonic annealing of inkjet printed Si nanoparticles • Micro-Raman spectroscopy and X-Ray Diffraction for thin film characterization.

  9. Micro Injection Molding of Thin Walled Geometries with Induction Heating System

    DEFF Research Database (Denmark)

    Menotti, Stefano; Hansen, Hans Nørgaard; Bissacco, Giuliano


    To eliminate defects and improve the quality of molded parts, increasing the mold temperature is one of the applicable solutions. A high mold temperature can increase the path flow of the polymer inside the cavity allowing reduction of the number of injection points, reduction of part thickness...... and moulding of smaller and more complex geometries. The last two aspects are very important in micro injection molding. In this paper a new embedded induction heating system is proposed and validated. An experimental investigation was performed based on a test geometry integrating different aspect ratios...... of small structures. ABS was used as material and different combinations of injection velocity, pressure and mold temperature were tested. The replicated test objects were measured by means of an optical CMM machine. On the basis of the experimental investigation the efficacy of the embedded induction...

  10. Incubation behavior of silicon nanowire growth investigated by laser-assisted rapid heating

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Sang-gil; Kim, Eunpa; Grigoropoulos, Costas P., E-mail: [Department of Mechanical Engineering, University of California, Berkeley, California 94720-1740 (United States); Allen, Frances I.; Minor, Andrew M. [Department of Materials Science and Engineering, University of California, Berkeley, California 94720-1740 (United States); National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Hwang, David J. [Department of Mechanical Engineering, Stony Brook University, Stony Brook, New York 11794 (United States)


    We investigate the early stage of silicon nanowire growth by the vapor-liquid-solid mechanism using laser-localized heating combined with ex-situ chemical mapping analysis by energy-filtered transmission electron microscopy. By achieving fast heating and cooling times, we can precisely determine the nucleation times for nanowire growth. We find that the silicon nanowire nucleation process occurs on a time scale of ∼10 ms, i.e., orders of magnitude faster than the times reported in investigations using furnace processes. The rate-limiting step for silicon nanowire growth at temperatures in the vicinity of the eutectic temperature is found to be the gas reaction and/or the silicon crystal growth process, whereas at higher temperatures it is the rate of silicon diffusion through the molten catalyst that dictates the nucleation kinetics.

  11. Temperature and humidity based projections of a rapid rise in global heat stress exposure during the 21st century (United States)

    Coffel, Ethan D.; Horton, Radley M.; de Sherbinin, Alex


    As a result of global increases in both temperature and specific humidity, heat stress is projected to intensify throughout the 21st century. Some of the regions most susceptible to dangerous heat and humidity combinations are also among the most densely populated. Consequently, there is the potential for widespread exposure to wet bulb temperatures that approach and in some cases exceed postulated theoretical limits of human tolerance by mid- to late-century. We project that by 2080 the relative frequency of present-day extreme wet bulb temperature events could rise by a factor of 100–250 (approximately double the frequency change projected for temperature alone) in the tropics and parts of the mid-latitudes, areas which are projected to contain approximately half the world’s population. In addition, population exposure to wet bulb temperatures that exceed recent deadly heat waves may increase by a factor of five to ten, with 150–750 million person-days of exposure to wet bulb temperatures above those seen in today’s most severe heat waves by 2070–2080. Under RCP 8.5, exposure to wet bulb temperatures above 35 °C—the theoretical limit for human tolerance—could exceed a million person-days per year by 2080. Limiting emissions to follow RCP 4.5 entirely eliminates exposure to that extreme threshold. Some of the most affected regions, especially Northeast India and coastal West Africa, currently have scarce cooling infrastructure, relatively low adaptive capacity, and rapidly growing populations. In the coming decades heat stress may prove to be one of the most widely experienced and directly dangerous aspects of climate change, posing a severe threat to human health, energy infrastructure, and outdoor activities ranging from agricultural production to military training.

  12. Thermophoresis and thermal radiation with heat and mass transfer in a magnetohydrodynamic thin-film second-grade fluid of variable properties past a stretching sheet (United States)

    Khan, Noor Saeed; Gul, Taza; Islam, Saeed; Khan, Waris


    The influences of thermophoresis and thermal radiation of a magnetohydrodynamic two-dimensional thin-film second-grade fluid with heat and mass transfer flow in the presence of viscous dissipation past a stretching sheet are analyzed. The main focus of the study is to discuss the significant roll of the fluid variable properties like thermal conductivity and viscosity under the variation of the thin film. The thermal conductivity varies directly as a linear function of temperature showing the property that expresses the ability of a material to transfer heat, and the viscosity is assumed to vary inversely as a linear function of temperature showing that viscous forces become weak at increasing temperature. Thermophoresis occurs to discuss the mass deposition at the surface of the stretching sheet while thermal radiation occurs, especially, at high temperature. The basic governing equations for the velocity, temperature and concentration of the fluid flow have been transformed to high nonlinear coupled differential equations with physical conditions by invoking suitable similarity transformations. The solution of the problem has been obtained by using HAM (Homotopy Analysis Method). The heat and mass transfer flow behaviors are affected significantly by the thin film. The physical influences of thin film parameter and all other parameters have been studied graphically and illustrated. The residual graphs and residual error table elucidate the authentication of the present work.

  13. Reduction in anisotropy of mechanical properties of coilable (α+β)-type titanium alloy thin sheet through simple heat treatment for use in next-generation aircraft applications

    Energy Technology Data Exchange (ETDEWEB)

    Nakai, Masaaki, E-mail: [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Niinomi, Mitsuo; Hieda, Junko; Cho, Ken [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Nagasawa, Yuya [Graduate School of Engineering, Tohoku University, Sendai 980-8579 (Japan); Konno, Takashi [Titanium Research and Development Section, Kobe Steel, Ltd., Takasago 676-8670 (Japan); Ito, Yoshinori [Materials Research Laboratory, Kobe Steel, Ltd., Kobe 651-2271 (Japan); Itsumi, Yoshio; Oyama, Hideto [Titanium Research and Development Section, Kobe Steel, Ltd., Takasago 676-8670 (Japan)


    In order to reduce the anisotropy of mechanical properties of a coilable thin sheet of (α+β)-type titanium alloy, Ti–4.5Al–2Mo–1.6V–0.5Fe–0.3Si–0.03C (Ti9), for use in aircraft applications, duplex heat treatments were examined. In each duplex heat treatment, the first heat treatment controls the volume fraction of the primary α phase and orientation of the acicular α phase in (α+β) two-phase area between the primary α grains, whereas the second heat treatment stabilizes the α and β phases. The microstructure of the Ti9 sheet after the duplex heat treatment was analyzed by optical microscopy, pole-figure measurement through X-ray diffraction, and electron backscatter diffraction. The mechanical properties of the duplex heat-treated Ti9 sheet were evaluated by tensile tests. The Ti9 sheet was heat treated to obtain two different types of microstructures. A microstructure consisting of acicular α phase in the β grains was obtained by a first heat treatment above the β transus (1273 K) followed by water quenching and a second heat treatment at 973 K. A microstructure consisting of equiaxed primary α grains and an (acicular α+β) two-phase area between the primary α grains was obtained by heating below the β transus (1123–1223 K) followed by water quenching and a second heat treatment at 973 K. The volume fraction of the primary α grains decreased and the volume fraction of the acicular α phase with 12 variants increased instead of increasing first heat-treatment temperature, suppressing the alignment of the c axis of the α lattice parallel to the transverse direction within the rolling plane (T-texture formation) as a result. Anisotropy of the tensile properties can be decreased by increasing the first heat-treatment temperature because the T texture was decreased.

  14. Ion-beam mixed ultra-thin cobalt suicide (CoSi2) films by cobalt sputtering and rapid thermal annealing (United States)

    Kal, S.; Kasko, I.; Ryssel, H.


    The influence of ion-beam mixing on ultra-thin cobalt silicide (CoSi2) formation was investigated by characterizing the ion-beam mixed and unmixed CoSi2 films. A Ge+ ion-implantation through the Co film prior to silicidation causes an interface mixing of the cobalt film with the silicon substrate and results in improved silicide-to-silicon interface roughness. Rapid thermal annealing was used to form Ge+ ion mixed and unmixed thin CoSi2 layer from 10 nm sputter deposited Co film. The silicide films were characterized by secondary neutral mass spectroscopy, x-ray diffraction, tunneling electron microscopy (TEM), Rutherford backscattering, and sheet resistance measurements. The experi-mental results indicate that the final rapid thermal annealing temperature should not exceed 800°C for thin (films reveals that Ge+ ion mixing (45 keV, 1 × 1015 cm-2) produces homogeneous silicide with smooth silicide-to-silicon interface.

  15. Rapid presumptive identification of the Mycobacterium tuberculosis-bovis complex by radiometric determination of heat stable urease

    Energy Technology Data Exchange (ETDEWEB)

    Gandy, J.H.; Pruden, E.L.; Cox, F.R.


    Simple and rapid Bactec methodologies for the determination of neat (unaltered) and heat stable urease activity of mycobacteria are presented. Clinical isolates (63) and stock cultures (32)--consisting of: M. tuberculosis (19), M. bovis (5), M. kansasii (15), M. marinum (4), M. simiae (3), M. scrofulaceum (16), M. gordonae (6), M. szulgai (6), M. flavescens (1), M. gastri (1), M. intracellulare (6), M. fortuitum-chelonei complex (12), and M. smegmatis (1)--were tested for neat urease activity by Bactec radiometry. Mycobacterial isolates (50-100 mg wet weight) were incubated at 35 degrees C for 30 minutes with microCi14C-urea. Urease-positive mycobacteria gave Bactec growth index (GI) values greater than 100 units, whereas urease-negative species gave values less than 10 GI units. Eighty-three isolates possessing neat urease activity were heated at 80 degrees C for 30 minutes followed by incubation at 35 degrees C for 30 minutes with 1 microCi14C-urea. Mycobacterium tuberculosis-bovis complex demonstrated heat-stable urease activity (GI more than 130 units) and could be distinguished from mycobacteria other than tuberculosis (MOTT), which gave GI values equal to or less than 40 units.

  16. Simplified and rapid method for extraction of ergosterol from natural samples and detection with quantitative and semi-quantitative methods using thin-layer chromatography


    Larsen, Cand.scient Thomas; Ravn, Senior scientist Helle; Axelsen, Senior Scientist Jørgen


    A new and simplified method for extraction of ergosterol (ergoste-5,7,22-trien-3-beta-ol) from fungi in soil and litter was developed using pre-soaking extraction and paraffin oil for recovery. Recoveries of ergosterol were in the range of 94 - 100% depending on the solvent to oil ratio. Extraction efficiencies equal to heat-assisted extraction treatments were obtained with pre-soaked extraction. Ergosterol was detected with thin-layer chromatography (TLC) using fluorodensitometry with a quan...

  17. Thinning and rupture of a thin liquid film on a heated surface. Annual technical progress report, November 1, 1991--October 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Bankoff, S.G.; Davis, S.H.


    Results on the dynamics and stability of thin films are summarized on the following topics: forced dryout, film instabilities on a horizontal plane and on inclined planes, instrumentation, coating flows, and droplet spreading. (DLC)

  18. Structural stability of hydrogenated amorphous carbon overcoats used in heat-assisted magnetic recording investigated by rapid thermal annealing

    KAUST Repository

    Wang, N.


    Ultrathin amorphous carbon (a-C) films are extensively used as protective overcoats of magnetic recording media. Increasing demands for even higher storage densities have necessitated the development of new storage technologies, such as heat-assisted magnetic recording (HAMR), which uses laser-assisted heating to record data on high-stability media that can store single bits in extremely small areas (∼1 Tbit/in.2). Because HAMR relies on locally changing the coercivity of the magnetic medium by raising the temperature above the Curie temperature for data to be stored by the magnetic write field, it raises a concern about the structural stability of the ultrathin a-C film. In this study, rapid thermal annealing (RTA) experiments were performed to examine the thermal stability of ultrathin hydrogenated amorphous carbon (a-C:H) films deposited by plasma-enhanced chemical vapor deposition. Structural changes in the a-C:H films caused by RTA were investigated by x-ray photoelectron spectroscopy, Raman spectroscopy, x-ray reflectivity, and conductive atomic force microscopy. The results show that the films exhibit thermal stability up to a maximum temperature in the range of 400-450 °C. Heating above this critical temperature leads to hydrogen depletion and sp 2 clustering. The critical temperature determined by the results of this study represents an upper bound of the temperature rise due to laser heating in HAMR hard-disk drives and the Curie temperature of magnetic materials used in HAMR hard disks. © 2013 American Institute of Physics.

  19. Mechanical Testing of PMCs under Simulated Rapid Heat-Up Propulsion Environments. II; In-Plane Compressive Behavior (United States)

    Stokes, Eric H.; Shin, E. Eugene; Sutter, James K.


    Carbon fiber thermoset polymer matrix composites (PMC) with high temperature polyimide based in-situ polymerized monomer reactant (PMR) resin has been used for some time in applications which can see temperatures up to 550 F. Currently, graphite fiber PMR based composites are used in several aircraft engine components including the outer bypass duct for the GE F-404, exit flaps for the P&W F-100-229, and the core cowl for the GE/Snecma CF6-80A3. Newer formulations, including PMR-II-50 are being investigated as potential weight reduction replacements of various metallic components in next generation high performance propulsion rocket engines that can see temperatures which exceed 550 F. Extensive FEM thermal modeling indicates that these components are exposed to rapid heat-up rates (up to -200 F/sec) and to a maximum temperature of around 600 F. Even though the predicted maximum part temperatures were within the capability of PW-II-50, the rapid heat-up causes significant through-thickness thermal gradients in the composite part and even more unstable states when combined with moisture. Designing composite parts for such extreme service environments will require accurate measurement of intrinsic and transient mechanical properties and the hygrothermal performance of these materials under more realistic use conditions. The mechanical properties of polymers degrade when exposed to elevated temperatures even in the absence of gaseous oxygen. Accurate mechanical characterization of the material is necessary in order to reduce system weight while providing sufficient factors of safety. Historically, the testing of PMCs at elevated temperatures has been plagued by the antagonism between two factors. First, moisture has been shown to profoundly affect the mechanical response of these materials at temperatures above their glass transition temperature while concurrently lowering the material's Tg. Moisture phenomena is due to one or a combination of three effects, i

  20. Rapid automated materials synthesis instrument: exploring the composition and heat-treatment of nanoprecursors toward low temperature red phosphors. (United States)

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


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

  1. Rapid crystallization of WS{sub 2} films assisted by a thin nickel layer: An in situ energy-dispersive X-ray diffraction study

    Energy Technology Data Exchange (ETDEWEB)

    Ellmer, K.; Seeger, S. [Hahn-Meitner-Institut Berlin, Dept. Solare Energetik, Glienicker Str. 100, 14109 Berlin (Germany); Mientus, R. [Opto-Transmitter-Umweltschutz-Technologie e.V., Koepenicker Str. 325b, 12555 Berlin (Germany)


    By rapid thermal crystallization of an amorphous WS{sub 3+x} film, deposited by reactive magnetron sputtering at temperatures below 150 C, layer-type semiconducting tungsten disulfide films (WS{sub 2}) were grown. The rapid crystallization was monitored in real-time by in situ energy-dispersive X-ray diffraction. The films crystallize very fast (>40 nm/s), provided that a thin nickel film acts as nucleation seeds. Experiments on different substrates and the onset of the crystallization only at a temperature between 600 and 700 C points to the decisive role of seeds for the textured growth of WS{sub 2}, most probably liquid NiS{sub x} drops. The rapidly crystallized WS{sub 2} films exhibit a pronounced (001) texture with the van der Waals planes oriented parallel to the surface, leading to photoactive layers with a high hole mobility of about 80 cm{sup 2}/Vs making such films suitable as absorbers for thin film solar cells. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. A simplified method for rapid quantification of intracellular nucleoside triphosphates by one-dimensional thin-layer chromatography

    DEFF Research Database (Denmark)

    Jendresen, Christian Bille; Kilstrup, Mogens; Martinussen, Jan


    -pyrophosphate (PRPP), and inorganic pyrophosphate (PPi) in cell extracts. The method uses one-dimensional thin-layer chromatography (TLC) and radiolabeled biological samples. Nucleotides are resolved at the level of ionic charge in an optimized acidic ammonium formate and chloride solvent, permitting...

  3. In-situ X-Ray Analysis of Rapid Thermal Processing for Thin-Film Solar Cells: Closing the Gap between Production and Laboratory Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Toney, Michael F. [SLAC National Accelerator Lab., Menlo Park, CA (United States); van Hest, Maikel F. A. M. [National Renewable Energy Lab. (NREL), Golden, CO (United States)


    For materials synthesis, it is well known that the material final state may not reach equilibrium and depends on the synthetic process. In particular, processes that quickly remove the available energy from the material may leave it in a metastable state and the metastability may actually impart desirable functional properties. By its very nature, Rapid thermal processing (RTP) is ideally suited to produce such metastable materials. However, metastability and the dynamics of reaching a metastable state are poorly understood, since this is best accomplished through in situ monitoring. In this regard, RTP is particularly challenging as the processing time are very short (seconds to minutes). As a result, there is only poor understanding, and hence use, of RTP in industry. This is potentially a cost-increasing limitation, because RTP can decrease cost by decreasing processing time, and as such, increase throughput and decrease the total thermal budget of processing - a significant cost. RTP is already being used for key processing steps in PV technologies. With silicon wafer PV, it is used for establishing electrical contact between the Ag metal grid and the silicon (known as firing). In this process, a silicon wafer with deposited metal/frit in a grid pattern is heated rapidly to temperatures between 750 and 800 ºC. The processing time when the temperature is held above 600ºC is short (<5 seconds). This process has historically been optimized empirically and it is unclear how the thermal processing affects formation of the final contact between the metal and the silicon. In the case of thin-film PV, RTP has been demonstrated in the process of making absorber layers, i.e. CIGS and CZTS. Use of RTP can reduce the processing time from 10s of minutes to seconds, reducing the thermal budget and increasing the throughput significantly. The conversion from precursor material to final PV material is not well understood, and most of the process optimization is done

  4. Metallic Thin-Film Bonding and Alloy Generation (United States)

    Fryer, Jack Merrill (Inventor); Campbell, Geoff (Inventor); Peotter, Brian S. (Inventor); Droppers, Lloyd (Inventor)


    Diffusion bonding a stack of aluminum thin films is particularly challenging due to a stable aluminum oxide coating that rapidly forms on the aluminum thin films when they are exposed to atmosphere and the relatively low meting temperature of aluminum. By plating the individual aluminum thin films with a metal that does not rapidly form a stable oxide coating, the individual aluminum thin films may be readily diffusion bonded together using heat and pressure. The resulting diffusion bonded structure can be an alloy of choice through the use of a carefully selected base and plating metals. The aluminum thin films may also be etched with distinct patterns that form a microfluidic fluid flow path through the stack of aluminum thin films when diffusion bonded together.

  5. Rapid thermal annealing effect on the spatial resistivity distribution of AZO thin films deposited by pulsed-direct-current sputtering for solar cells applications

    Energy Technology Data Exchange (ETDEWEB)

    Ayachi, Boubakeur, E-mail: [Institute of Electronics, Microelectronics and Nanotechnology, Lille 1 University, Avenue Poincaré, UMR 8520, CS 60069, Villeneuve d’Ascq 59652 (France); Aviles, Thomas [CROSSLUX, Avenue Georges Vacher, ZI Rousset Peynier, Immeuble CCE, Rousset 13106 (France); Vilcot, Jean-Pierre [Institute of Electronics, Microelectronics and Nanotechnology, Lille 1 University, Avenue Poincaré, UMR 8520, CS 60069, Villeneuve d’Ascq 59652 (France); Sion, Cathy [Institute of Electronics, Microelectronics and Nanotechnology, Lille 1 University, Avenue Poincaré, UMR 8520, CS 60069, Villeneuve d’Ascq 59652 (France); Ecole Centrale Lille, Cité Scientifique – CS20048, Villeneuve d’Ascq 59651 (France)


    Graphical abstract: - Highlights: • High quality pulsed-DC sputtered AZO thin films were obtained after RTA treatment. • RTA for 30 s was sufficient to achieve uniform spatial resistivity distribution. • RTA for longer than 1 min showed a small increase in resistivity value. • Such improvement was attributed to grain boundaries passivation and doping activation. • In the framework of low cost solar cells development, RTA process would be helpful. - Abstract: Room temperature deposited aluminium-doped zinc oxide thin films on glass substrate, using pulsed-DC magnetron sputtering, have shown high optical transmittance and low electrical resistivity with high uniformity of its spatial distribution after they were exposed to a rapid thermal annealing process at 400 °C under N{sub 2}H{sub 2} atmosphere. It is particularly interesting to note that such an annealing process of AZO thin films for only 30 s was sufficient, on one hand to improve their optical transmittance from 73% to 86%, on the other hand to both decrease their resistivity from 1.7 × 10{sup −3} Ω cm to 5.1 × 10{sup −4} Ω cm and achieve the highest uniformity spatial distribution. To understand the mechanisms behind such improvements of the optoelectronic properties, electrical, optical, structural and morphological changes as a function of annealing time have been investigated by using hall measurement, UV–visible spectrometry, X-ray diffraction and scanning electron microscope imaging, respectively.

  6. Heat waves imposed during early pod development in soybean (Glycine max) cause significant yield loss despite a rapid recovery from oxidative stress. (United States)

    Siebers, Matthew H; Yendrek, Craig R; Drag, David; Locke, Anna M; Rios Acosta, Lorena; Leakey, Andrew D B; Ainsworth, Elizabeth A; Bernacchi, Carl J; Ort, Donald R


    Heat waves already have a large impact on crops and are predicted to become more intense and more frequent in the future. In this study, heat waves were imposed on soybean using infrared heating technology in a fully open-air field experiment. Five separate heat waves were applied to field-grown soybean (Glycine max) in central Illinois, three in 2010 and two in 2011. Thirty years of historical weather data from Illinois were analyzed to determine the length and intensity of a regionally realistic heat wave resulting in experimental heat wave treatments during which day and night canopy temperatures were elevated 6 °C above ambient for 3 days. Heat waves were applied during early or late reproductive stages to determine whether and when heat waves had an impact on carbon metabolism and seed yield. By the third day of each heat wave, net photosynthesis (A), specific leaf weight (SLW), and leaf total nonstructural carbohydrate concentration (TNC) were decreased, while leaf oxidative stress was increased. However, A, SLW, TNC, and measures of oxidative stress were no different than the control ca. 12 h after the heat waves ended, indicating rapid physiological recovery from the high-temperature stress. That end of season seed yield was reduced (~10%) only when heat waves were applied during early pod developmental stages indicates the yield loss had more to do with direct impacts of the heat waves on reproductive process than on photosynthesis. Soybean was unable to mitigate yield loss after heat waves given during late reproductive stages. This study shows that short high-temperature stress events that reduce photosynthesis and increase oxidative stress resulted in significant losses to soybean production in the Midwest, U.S. The study also suggests that to mitigate heat wave-induced yield loss, soybean needs improved reproductive and photosynthetic tolerance to high but increasingly common temperatures. Published 2015. This article is a U.S. Government work and is

  7. Heat

    CERN Document Server

    Lawrence, Ellen


    Is it possible to make heat by rubbing your hands together? Why does an ice cube melt when you hold it? In this title, students will conduct experiments to help them understand what heat is. Kids will also investigate concepts such as which materials are good at conducting heat and which are the best insulators. Using everyday items that can easily be found around the house, students will transform into scientists as they carry out step-by-step experiments to answer interesting questions. Along the way, children will pick up important scientific skills. Heat includes seven experiments with detailed, age-appropriate instructions, surprising facts and background information, a "conclusions" section to pull all the concepts in the book together, and a glossary of science words. Colorful, dynamic designs and images truly put the FUN into FUN-damental Experiments.

  8. Rapid acclimation of juvenile corals to CO2 -mediated acidification by upregulation of heat shock protein and Bcl-2 genes. (United States)

    Moya, A; Huisman, L; Forêt, S; Gattuso, J-P; Hayward, D C; Ball, E E; Miller, D J


    Corals play a key role in ocean ecosystems and carbonate balance, but their molecular response to ocean acidification remains unclear. The only previous whole-transcriptome study (Moya et al. Molecular Ecology, 2012; 21, 2440) documented extensive disruption of gene expression, particularly of genes encoding skeletal organic matrix proteins, in juvenile corals (Acropora millepora) after short-term (3 d) exposure to elevated pCO2 . In this study, whole-transcriptome analysis was used to compare the effects of such 'acute' (3 d) exposure to elevated pCO2 with a longer ('prolonged'; 9 d) period of exposure beginning immediately post-fertilization. Far fewer genes were differentially expressed under the 9-d treatment, and although the transcriptome data implied wholesale disruption of metabolism and calcification genes in the acute treatment experiment, expression of most genes was at control levels after prolonged treatment. There was little overlap between the genes responding to the acute and prolonged treatments, but heat shock proteins (HSPs) and heat shock factors (HSFs) were over-represented amongst the genes responding to both treatments. Amongst these was an HSP70 gene previously shown to be involved in acclimation to thermal stress in a field population of another acroporid coral. The most obvious feature of the molecular response in the 9-d treatment experiment was the upregulation of five distinct Bcl-2 family members, the majority predicted to be anti-apoptotic. This suggests that an important component of the longer term response to elevated CO2 is suppression of apoptosis. It therefore appears that juvenile A. millepora have the capacity to rapidly acclimate to elevated pCO2 , a process mediated by upregulation of specific HSPs and a suite of Bcl-2 family members. © 2014 John Wiley & Sons Ltd.

  9. Characterization of Mycobacterium paratuberculosis by gas-liquid and thin-layer chromatography and rapid demonstration of mycobactin dependence using radiometric methods

    Energy Technology Data Exchange (ETDEWEB)

    Damato, J.J.; Knisley, C.; Collins, M.T.


    Thirty-six Mycobacterium paratuberculosis isolates of bovine, caprine, and ovine origins were evaluated by using gas-liquid chromatography (GLC), thin-layer chromatography (TLC), and BACTEC 7H12 Middlebrook TB medium in an effort to more rapidly differentiate this group of organisms from other mycobacteria. Bacterial suspensions (0.1 ml) were inoculated by syringe into 7H12 broth containing 2 micrograms of mycobactin P per ml and control broth without mycobactin P. Cultures were incubated at 37/sup 0/C and read daily with a BACTEC Model 301. After 8 days of incubation, the growth index readings for the test broths containing mycobactin P were twice those of the control broths without mycobactin P. Sixty-five isolates of mycobacteria other than M. paratuberculosis were also examined. No difference was noted between the growth index readings of control and mycobactin-containing broths. Except for Mycobacterium avium-Mycobacterium intracellulare, TLC studies differentiated M. paratuberculosis from the other mycobacterial species tested. The GLC data reveal that all M. paratuberculosis isolates had a distinctive peak (14A) which was not found among M. avium-M. intracellulare complex organisms. These data indicate that 7H12 radiometric broth was able to rapidly demonstrate the mycobactin dependence of M. paratuberculosis and GLC and TLC procedures were capable of rapidly differentiating this organism from the other mycobacteria studied.

  10. Temperature of Heating and Cooling of Massive, Thin, and Wedge-Shaped Plates from Hard-to-Machine Steels During Their Grinding (United States)

    Dement‧ev, V. B.; Ivanova, T. N.; Dolginov, A. M.


    Grinding of flat parts occurs by solid abrasive particles due to the physicomechanical process of deformation and to the action of a process liquid at high temperatures in a zone small in volume and difficult for observation. The rate of heating and cooling depends on the change in the intensity of the heat flux and in the velocity and time of action of the heat source. A study has been made of the regularities of the influence of each of these parameters on the depth and character of structural transformations during the grinding of flat parts from hard-to-machine steels. A procedure to calculate temperature in grinding massive, thin, and wedge-shaped parts has been developed with account taken of the geometric and thermophysical parameters of the tool and the treated part, and also of cutting regimes. The procedure can be used as a constituent part in developing a system for automatic design of the technological process of grinding of flat surfaces. A relationship between the temperature in the grinding zone and the regimes of treatment has been established which makes it possible to control the quality of the surface layer of massive, thin, and wedge-shaped plates from hard-to-machine steels. The rational boundaries of shift of cutting regimes have been determined.

  11. Development of a model system for rapid assessment of insect mortality in heated controlled atmosphere quarantine treatments. (United States)

    Neven, Lisa G


    The development of postharvest quarantine treatments can be both expensive and time-consuming. It is necessary to determine the species and stage of the pest most tolerant to the treatment, if more than one species is the target of the treatment. Initial laboratory studies often include infesting the commodity with various egg and larval stages of the pest and performing treatments and evaluations of the fruit. In collaboration with others, I have previously developed combination high temperature under controlled atmosphere treatments against two quarantine pests in apples (Malus spp.) and peaches and nectarines (both Prunus spp.). I decided to develop an artificial system that can be used for these initial tests without the need for infesting large quantities of the fruit. I tested the system on the immature stages of the pests under regular air and controlled atmospheres by using the controlled atmosphere water bath system. This system can be used for rapid assessment of the most tolerant stage and species of a pest to a combination heat and controlled atmosphere treatment without the expense of infesting, treating, and evaluating the commodity.

  12. Fabrication of a Cu(InGaSe2 Thin Film Photovoltaic Absorber by Rapid Thermal Annealing of CuGa/In Precursors Coated with a Se Layer

    Directory of Open Access Journals (Sweden)

    Chun-Yao Hsu


    Full Text Available Cu(InGaSe2 (CIGS thin film absorbers are prepared using sputtering and selenization processes. The CuGa/In precursors are selenized during rapid thermal annealing (RTA, by the deposition of a Se layer on them. This work investigates the effect of the Cu content in precursors on the structural and electrical properties of the absorber. Using X-ray diffraction, field emission scanning electron microscopy, Raman spectroscopy, and Hall effect measurement, it is found that the CIGS thin films produced exhibit facetted grains and a single chalcopyrite phase with a preferred orientation along the (1 1 2 plane. A Cu-poor precursor with a Cu/( ratio of 0.75 demonstrates a higher resistance, due to an increase in the grain boundary scattering and a reduced carrier lifetime. A Cu-rich precursor with a Cu/( ratio of 1.15 exhibits an inappropriate second phase ( in the absorber. However, the precursor with a Cu/( ratio of 0.95 exhibits larger grains and lower resistance, which is suitable for its application to solar cells. The deposition of this precursor on Mo-coated soda lime glass substrate and further RTA causes the formation of a MoSe2 layer at the interface of the Mo and CIGS.

  13. Rapid identification of siderophores by combined thin-layer chromatography/matrix-assisted laser desorption/ionization mass spectrometry. (United States)

    Hayen, Heiko; Volmer, Dietrich A


    The investigation of a combined thin-layer chromatography/matrix-assisted laser desorption/ionization mass spectrometry (TLC/MALDI-MS) method for the analysis of siderophores from microbial samples is described. The investigated siderophores were enterobactin, ferrioxamine B, ferrichrome, ferrirhodin, rhodotorulic acid and coprogen. Solid-phase extraction was employed to recover the siderophores from the microbial samples. After visualization of the spots via spraying with ferric chloride or chrome azurol sulfonate assay solution, the MALDI matrix was applied to the gel surface. Several TLC/MALDI experimental parameters were optimized, such as type and concentration of MALDI matrix, as well as the type and composition of solvent to facilitate analyte transport from the inside of the TLC gel to the surface. The impact of these parameters on sensitivity, precision and ion formation of the various siderophores was studied. The detection limits for the investigated siderophores were in the range 1-4 pmol. These values were about 4-24 times higher than the detection limits obtained directly from stainless steel MALDI targets. The differences were most likely due to incomplete transport of the 'trapped' analyte molecules from the deeper layers of the TLC gel to the surface and into the matrix layer. In addition, chromatographic band broadening spread the analyte further in TLC as compared with the steel plates, resulting in less analyte per surface area. The identification of the siderophores was aided by concurrently applying a Ga(III) nitrate solution to the TLC plate during the visualization step. The resulting formation of Ga(III) complexes lead to distinctive (69)Ga/(71)Ga isotope patterns in the mass spectra. The versatility of the TLC/MALDI-MS assay was demonstrated by using it to analyze siderophores in a Pseudomonas aeruginosa sample. An iron-binding compound was identified in the sample, namely pyochelin (2-(2-o-hydroxyphenyl-2-thiazolin-4-yl)-3

  14. Effects of Rapid Thermal Annealing on the Structural, Electrical, and Optical Properties of Zr-Doped ZnO Thin Films Grown by Atomic Layer Deposition

    Directory of Open Access Journals (Sweden)

    Jingjin Wu


    Full Text Available The 4 at. % zirconium-doped zinc oxide (ZnO:Zr films grown by atomic layer deposition (ALD were annealed at various temperatures ranging from 350 to 950 °C. The structural, electrical, and optical properties of rapid thermal annealing (RTA treated ZnO:Zr films have been evaluated to find out the stability limit. It was found that the grain size increased at 350 °C and decreased between 350 and 850 °C, while creeping up again at 850 °C. UV–vis characterization shows that the optical band gap shifts towards larger wavelengths. The Hall measurement shows that the resistivity almost keeps constant at low annealing temperatures, and increases rapidly after treatment at 750 °C due to the effect of both the carrier concentration and the Hall mobility. The best annealing temperature is found in the range of 350–550 °C. The ZnO:Zr film-coated glass substrates show good optical and electrical performance up to 550 °C during superstrate thin film solar cell deposition.

  15. Low-Cost and Rapid Fabrication of Metallic Nanostructures for Sensitive Biosensors Using Hot-Embossing and Dielectric-Heating Nanoimprint Methods

    Directory of Open Access Journals (Sweden)

    Kuang-Li Lee


    Full Text Available We propose two approaches—hot-embossing and dielectric-heating nanoimprinting methods—for low-cost and rapid fabrication of periodic nanostructures. Each nanofabrication process for the imprinted plastic nanostructures is completed within several seconds without the use of release agents and epoxy. Low-cost, large-area, and highly sensitive aluminum nanostructures on A4 size plastic films are fabricated by evaporating aluminum film on hot-embossing nanostructures. The narrowest bandwidth of the Fano resonance is only 2.7 nm in the visible light region. The periodic aluminum nanostructure achieves a figure of merit of 150, and an intensity sensitivity of 29,345%/RIU (refractive index unit. The rapid fabrication is also achieved by using radio-frequency (RF sensitive plastic films and a commercial RF welding machine. The dielectric-heating, using RF power, takes advantage of the rapid heating/cooling process and lower electric power consumption. The fabricated capped aluminum nanoslit array has a 5 nm Fano linewidth and 490.46 nm/RIU wavelength sensitivity. The biosensing capabilities of the metallic nanostructures are further verified by measuring antigen–antibody interactions using bovine serum albumin (BSA and anti-BSA. These rapid and high-throughput fabrication methods can benefit low-cost, highly sensitive biosensors and other sensing applications.

  16. Current-Induced Joule Heating and Electrical Field Effects in Low Temperature Measurements on TIPS Pentacene Thin Film Transistors

    NARCIS (Netherlands)

    Nikiforov, G.O.; Venkateshvaran, D.; Mooser, S.; Meneau, A.; Strobel, T.; Kronemeijer, A.; Jiang, L.; Lee, M.J.; Sirringhaus, H.


    The channel temperature (Tch) of solution-processed 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS pentacene) thin film transistors (TFTs) is closely monitored in real time during current–voltage (I–V) measurements carried out in a He exchange gas cryostat at various base temperatures (Tb)

  17. The pulsations of boundary conditions – factor of the rapid wear on heat exchange surfaces in heterogeneous dispersed flows (United States)

    Khodunkov, V. P.


    The results of experimental studies of industrial furnace with a fluidized bed reactor. The data on the values of the coefficient of heat transfer, the quality of fluidization and mixing efficiency. In theory shows that there are significant variables of temperature gradients on the walls of the heat exchange elements are qualitative arguments about the causes of increased wear of heat exchange surfaces in a fluidized bed.

  18. Rapid, non-destructive and non-contact inspection of solid foods by means of photothermal radiometry; thermal effusivity and initial heating coefficient (United States)

    Gijsbertsen, A.; Bicanic, D.; Gielen, J. L. W.; Chirtoc, M.


    CO 2-laser photothermal radiometry (PTR) was demonstrated to be suitable for the non-destructive and non-contact characterization (both optical and thermal) of solid phase agricultural commodities (fresh vegetables, fruits) and confectionery products (candy). Proper interpretation of PTR signals enable one to calculate two parameters, i.e. the well known thermal effusivity e ( e= λρc p, where λ and ρcp are the thermal conductivity and the volume specific heat, respectively) and a newly introduced physical quantity termed 'initial heating coefficient' chi ( χ= β/( ρcp), β is the absorption coefficient). Obtained values for e are in a good agreement with data reported in the literature. PTR enables one to rapidly determine e via a single measurement. As opposed to this, the knowledge of two out of three thermophysical parameters (thermal diffusivity, thermal conductivity and volume specific heat) is a condition sine qua non for determining effusivity in the conventional manner.

  19. Initial verification of an induction heating set-up for injection molding

    DEFF Research Database (Denmark)

    Menotti, Stefano; Hansen, Hans Nørgaard; Bissacco, Giuliano


    Molding of thin and long parts by injection molding leads to special requirements for the mold in order to ensure proper filling and acceptable cycle time. This paper investigates the applicability of embedded induction heating for the improvement of the filling of thin long parts. The object...... selected for the investigation is a thin spiral. For the complete molding of the component, elevated mold temperatures are required. For this propose a new injection molding set-up was developed, which allows rapid heating of the cavity wall by an induction heating system. The temperature was measured...

  20. Effect of Heat Treatment Under Nitrogen Atmosphere on Sprayed Fluorine Doped In2O3 Thin Films (United States)

    Beji, Nasreddine; Ajili, Mejda; Turki, Najoua Kamoun


    Fluorine-doped indium oxide thin films (In2O3:F) were prepared at 500°C for different fluorine concentrations (0 at.%, 2 at.%, 6 at.% and 10 at.%) using the chemical spray pyrolysis technique. Structure and surface morphology of these films were characterized by x-ray diffraction (XRD) and atomic force microscopy (AFM). XRD analysis revealed that fluorine doped In2O3 thin films exhibit a centered cubic structure with the (400) preferential orientation. The change of the preferential reflection plane from (222) to (400) was found after doping. The doping optimum concentration of thin film crystal structure is obtained witha fluorine ratio equal to 2 at.%. The crystallinity improvement of In2O3:F (2 at.%) film is detected after annealing at 200°C, 300°C, and 400°C in nitrogen gas for 45 min. Transmission and reflection spectra measurements were performed over the wavelength range of 250-2500 nm. The band gap energy increase from 3.10 eV to 3.45 eV was detected after treatment at 400°C. In parallel, the electrical resistivity, deduced from Hall effect measurements, decreases from 428.90 × 10-4 Ω cm to 6.58 × 10-4 Ω cm.

  1. Simultaneous specific heat, thermal conductivity and imaging evaluations in thin samples of 8CB liquid crystal dispersed with microemulsion of DDAB/water micelles (United States)

    Paoloni, S.; Mercuri, F.; Zammit, U.


    In this work we use a photopyroelectric calorimetric set up to analyze the transformations occurring in thin samples of liquid crystal-microemulsion system by combining the results of the simultaneously performed high temperature resolution polarization microscopy observations and the temperature dependence of the specific heat, and of the thermal conductivity. This enabled an accurate direct correlation of the observations concerning the different measured quantities for a most comprehensive interpretation of the obtained results. It is found that the I-N conversion progresses in the entire nematic range because of the micelles expelled from the nucleating nematic volumes remaining confined in the residual isotropic material. A hysteretic behavior is observed in the nematic range between cooling and heating run because of the different micelle content in the material during the cooling and heating runs. A moderate hysteresys also over the N-A transition indicated an additional material refinement from micelles during the transition. Finally in samples with different micelle concentration the same maximum micelle content is retained in the nematic and smectic phases.

  2. Rapid cooling and exhumation as a consequence of extension and crustal thinning: Inferences from the Late Miocene to Pliocene Palu Metamorphic Complex, Sulawesi, Indonesia (United States)

    Hennig, Juliane; Hall, Robert; Forster, Margaret A.; Kohn, Barry P.; Lister, Gordon S.


    Metamorphic complexes forming high mountains of 1.5-2 km in Western Sulawesi were previously considered to be Mesozoic or older basement of Gondwana crust. However, many of the metamorphic rocks are much younger than previously thought. Some have Eocene sedimentary protoliths. New geothermobarometric and geochronological data from metamorphic rocks of the Palu Metamorphic Complex (PMC) and associated granitoids provide information on the timing and mechanisms of Neogene metamorphism and contemporaneous rapid exhumation. The metamorphic rocks are strongly deformed and some were partially melted to form migmatites. Schists contain relict andalusite, cordierite, staurolite and Mn-rich garnet which are wrapped by a pervasive fabric. 40Ar/39Ar dating of biotite, white mica and amphibole from strongly deformed, mylonitic schists and recrystallised amphibolites reveals cooling occurred in the Early Pliocene (c. 5.3-4.8 Ma) in the northern part and during the Late Pliocene (c. 3.1-2.7 Ma) in the southern part of the PMC. U-Pb, 40Ar/39Ar and (U-Th)/He analyses of various minerals from PMC metamorphic and S-type magmatic rocks give very similar mid to Late Pliocene ages, indicating very fast cooling and rapid exhumation, and show the high speed at which tectonic processes, including magmatism, exhumation, and reworking into a sediment, must have occurred. The high rates could be unique to this area but we suggest they record the true speed of metamorphic complex exhumation in a very young orogenic belt. Rates in older orogens appear lower because they are averages measured over longer periods of time. Contemporaneous magmatism and deformation are interpreted as a consequence of decompressional melting due to extension and thinning of the crust, promoted by possible detachment faults and normal faulting at the major NW-trending Palu-Koro and Tambarana Faults. In contrast, I-type magmatic rocks, separated from the PMC by the Palu-Koro Fault, were exhumed from upper crustal

  3. Non-Fourier Heat Transfer with Phonons and Electrons in a Circular Thin Layer Surrounding a Hot Nanodevice

    Directory of Open Access Journals (Sweden)

    Vito Antonio Cimmelli


    Full Text Available A nonlocal model for heat transfer with phonons and electrons is applied to infer the steady-state radial temperature profile in a circular layer surrounding an inner hot component. Such a profile, following by the numerical solution of the heat equation, predicts that the temperature behaves in an anomalous way, since for radial distances from the heat source smaller than the mean-free path of phonons and electrons, it increases for increasing distances. The compatibility of this temperature behavior with the second law of thermodynamics is investigated by calculating numerically the local entropy production as a function of the radial distance. It turns out that such a production is positive and strictly decreasing with the radial distance.

  4. UV-pretreatment- and near-infrared rapid thermal annealing-enhanced dehydrogenation for a-Si:H thin films at 400 °C

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Sanghyun [AP Systems Corp., 15-5 Dongtansandan 8-gil, Dongtanmyeon, Hwaseongsi, Gyeonggido 445-811 (Korea, Republic of); Dept. of Chem. and Biomol. Engng., Sogang Univ., 35 Baekbeomro, Mapogu, Seoul 121-742 (Korea, Republic of); Hwang, Chi-Sun [ETRI, 138 Gajeongro, Yuseonggu, Daejeon 305-350 (Korea, Republic of); Jeong, Pilseong; Lee, Sungyong [AP Systems Corp., 15-5 Dongtansandan 8-gil, Dongtanmyeon, Hwaseongsi, Gyeonggido 445-811 (Korea, Republic of); Lee, Kwang Soon, E-mail: [Dept. of Chem. and Biomol. Engng., Sogang Univ., 35 Baekbeomro, Mapogu, Seoul 121-742 (Korea, Republic of)


    A new dehydrogenation processing method was developed for the low-temperature polysilicon process. This method can reduce both the process temperature and time through the combination of an ultraviolet pretreatment (UVP) process with near-infrared rapid thermal annealing (NIR-RTA). NIR-RTA using tungsten-halogen lamps was observed to reduce the dehydrogenation time by approximately two thirds and the temperature by approximately 20 °C compared to conventional furnace processing. The UVP process was able to lower the dehydrogenation temperature by a further 20 °C. Thus, the new dehydrogenation process, consisting of UVP followed by NIR-RTA, could achieve a hydrogen concentration of 1.97 at.% in 20 min at 360 °C. - Highlights: • An enhanced dehydrogenation process for flexible substrates as well as glass substrates is proposed.. • UV pretreatment and NIR-RTA are used.. • Temperature of the LTPS process for a-Si:H thin films could be reduced by 40 °C.. • Dehydrogenation time of the LTPS process could be reduced by 20 min..

  5. Joule heating effect on a continuously moving thin needle in MHD Sakiadis flow with thermophoresis and Brownian moment (United States)

    Sulochana, C.; Ashwinkumar, G. P.; Sandeep, N.


    In the current study, we investigated the impact of thermophoresis and Brownian moment on the boundary layer 2D forced convection flow of a magnetohydrodynamic nanofluid along a persistently moving horizontal needle with frictional heating effect. The various pertinent parameters are taken into account in the present analysis, namely, the thermophoresis and Brownian moment, uneven heat source/sink, Joule heating and frictional heating effects. To check the variation in the boundary layer behavior, we considered two distinct nanoparticles namely Al50Cu50 (alloy with 50% alumina and 50% copper) and Cu with water as base liquid. Numerical solutions are derived for the reduced system of governing PDEs by employing the shooting process. Computational results of the flow, energy and mass transport are interpreted with the support of tables and graphical illustrations. The obtained results indicate that the increase in the needle size significantly reduces the flow and thermal fields. In particular, the velocity field of the Cu-water nanofluid is highly affected when compared with the Al50Cu50 -water nanofluid. Also, we showed that the thermophoresis and Brownian moment parameters are capable of enhancing the thermal conductivity to a great extent.

  6. The effects of heat treatment on optical, structural, electrochromic and bonding properties of Nb{sub 2}O{sub 5} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Coşkun, Özlem Duyar, E-mail: [Hacettepe University, Department of Physics Engineering, Thin Film Preparation and Characterization Laboratory, Ankara (Turkey); Demirel, Selen, E-mail: [Hacettepe University, Department of Physics Engineering, Thin Film Preparation and Characterization Laboratory, Ankara (Turkey); Hacettepe University, Nanotechnology and Nanomedicine Department, Ankara (Turkey); Atak, Gamze, E-mail: [Hacettepe University, Department of Physics Engineering, Thin Film Preparation and Characterization Laboratory, Ankara (Turkey)


    Nb{sub 2}O{sub 5} thin films were deposited onto heated glass substrates by RF magnetron sputtering using a Nb{sub 2}O{sub 5} target. The films were annealed in air at temperatures between 400 and 700 °C for 6 h. Effects of the crystalline structure on optical, structural, electrochromic and bonding properties of the Nb{sub 2}O{sub 5} thin films were investigated by X-ray diffraction, atomic force microscopy, X-ray photoelectron spectroscopy, optical spectrophotometry and electrochemical measurements. The film refractive index varied between 2.09 and 2.22 at the wavelength of 550 nm depending on the annealing temperature. The decrease of the optical band gap revealed for the films with increasing annealing temperature is attributed to oxygen-ion vacancies in the film structure. The orthorhombic structure of Nb{sub 2}O{sub 5} films resulted in good electrochromic properties with high colouration efficiencies of 19.56 cm{sup 2}/C and 53.24 cm{sup 2}/C at 550 nm and 1000 nm, respectively. The optical, structural and electrochromic properties of the different crystalline polymorphic forms of the Nb{sub 2}O{sub 5} films make them attractive for optical applications. - Highlights: • Stoichiometric Nb{sub 2}O{sub 5} films prepared using RF magnetron sputtering technique. • The different crystalline forms of Nb{sub 2}O{sub 5} thin films obtained by annealing. • The optical, structural and electrochromic properties of the films were investigated. • The optical band gap decreased with increasing annealing temperature. • The orthorhombic T-Nb{sub 2}O{sub 5} films exhibited a higher colouration efficiency.

  7. In situ X-ray diffraction study of crystallization process of GeSbTe thin films during heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Naohiko [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan)]. E-mail:; Konomi, Ichiro [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan); Seno, Yoshiki [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan); Motohiro, Tomoyoshi [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan)


    The crystallization processes of the Ge{sub 2}Sb{sub 2}Te{sub 5} thin film used for PD and DVD-RAM were studied in its realistic optical disk film configurations for the first time by X-ray diffraction using an intense X-ray beam of a synchrotron orbital radiation facility (SPring-8) and in situ quick detection with a Position-Sensitive-Proportional-Counter. The dependence of the amorphous-to-fcc phase-change temperature T{sub 1} on the rate of temperature elevation R{sub et} gave an activation energy E{sub a}: 0.93 eV much less than previously reported 2.2 eV obtained from a model sample 25-45 times thicker than in the real optical disks. The similar measurement on the Ge{sub 4}Sb{sub 1}Te{sub 5} film whose large reflectance change attains the readability by CD-ROM drives gave E{sub a}: 1.13 eV with larger T{sub 1} than Ge{sub 2}Sb{sub 2}Te{sub 5} thin films at any R{sub et} implying a lower sensitivity in erasing as well as a better data stability of the phase-change disk.

  8. Rapid bonding and easy debonding of orthodontic appliances with 4-META/MMA-TBB resin using thermal heating. (United States)

    Kameda, Takashi; Ohkuma, Kazuo; Terada, Kazuto


    4-Methacryloyloxyethyl trimellitate anhydride/methyl methacrylate-tri-n-butylborane (4-META/MMA-TBB) resin is widely used as a direct bonding adhesive for orthodontic appliances because of its strong bonding ability. However, its clinical disadvantages include long setting times and difficult debonding with subsequent residual adhesive left on the enamel surface. To resolve these problems, thermal heating was applied to orthodontic appliances. The setting time was dramatically reduced by thermal heating (160°C for 5 s), with the shear bond strength remaining the same as that stated in the manufacturer's instructions. Debonding of appliances following thermal heating (160°C for 20 s) could be easily performed, decreasing the amount of adhesive left on enamel. These conditions were not accompanied by an increase in the heat pain threshold of pulpal dentin. These results suggest that the use of thermal heating in the bonding/debonding of 4-META/MMA-TBB resin may resolve its clinical weaknesses, making its ease of use similar to light-cured resin.

  9. White-Light-Induced Collective Heating of Gold Nanocomposite/Bombyx mori Silk Thin Films with Ultrahigh Broadband Absorbance. (United States)

    Tsao, Shao Hsuan; Wan, Dehui; Lai, Yu-Sheng; Chang, Ho-Ming; Yu, Chen-Chieh; Lin, Keng-Te; Chen, Hsuen-Li


    This paper describes a systematic investigation of the phenomenon of white-light-induced heating in silk fibroin films embedded with gold nanoparticles (Au NPs). The Au NPs functioned to develop an ultrahigh broadband absorber, allowing white light to be used as a source for photothermal generation. With an increase of the Au content in the composite films, the absorbance was enhanced significantly around the localized surface plasmon resonance (LSPR) wavelength, while non-LSPR wavelengths were also increased dramatically. The greater amount of absorbed light increased the rate of photoheating. The optimized composite film exhibited ultrahigh absorbances of approximately 95% over the spectral range from 350 to 750 nm, with moderate absorbances (>60%) at longer wavelengths (750-1000 nm). As a result, the composite film absorbed almost all of the incident light and, accordingly, converted this optical energy to local heat. Therefore, significant temperature increases (ca. 100 °C) were readily obtained when we irradiated the composite film under a light-emitting diode or halogen lamp. Moreover, such composite films displayed linear light-to-heat responses with respect to the light intensity, as well as great photothermal stability. A broadband absorptive film coated on a simple Al/Si Schottky diode displayed a linear, significant, stable photo-thermo-electronic effect in response to varying the light intensity.

  10. Effect of Homogenizing Heat Treatment of Liquid Aluminum-Copper Alloys on the Structure of Rapidly Crystallized Specimens (United States)

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


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

  11. Heat transfer analysis of MHD thin film flow of an unsteady second grade fluid past a vertical oscillating belt. (United States)

    Gul, Taza; Islam, Saeed; Shah, Rehan Ali; Khan, Ilyas; Khalid, Asma; Shafie, Sharidan


    This article aims to study the thin film layer flowing on a vertical oscillating belt. The flow is considered to satisfy the constitutive equation of unsteady second grade fluid. The governing equation for velocity and temperature fields with subjected initial and boundary conditions are solved by two analytical techniques namely Adomian Decomposition Method (ADM) and Optimal Homotopy Asymptotic Method (OHAM). The comparisons of ADM and OHAM solutions for velocity and temperature fields are shown numerically and graphically for both the lift and drainage problems. It is found that both these solutions are identical. In order to understand the physical behavior of the embedded parameters such as Stock number, frequency parameter, magnetic parameter, Brinkman number and Prandtl number, the analytical results are plotted graphically and discussed.

  12. Heat transfer analysis of MHD thin film flow of an unsteady second grade fluid past a vertical oscillating belt.

    Directory of Open Access Journals (Sweden)

    Taza Gul

    Full Text Available This article aims to study the thin film layer flowing on a vertical oscillating belt. The flow is considered to satisfy the constitutive equation of unsteady second grade fluid. The governing equation for velocity and temperature fields with subjected initial and boundary conditions are solved by two analytical techniques namely Adomian Decomposition Method (ADM and Optimal Homotopy Asymptotic Method (OHAM. The comparisons of ADM and OHAM solutions for velocity and temperature fields are shown numerically and graphically for both the lift and drainage problems. It is found that both these solutions are identical. In order to understand the physical behavior of the embedded parameters such as Stock number, frequency parameter, magnetic parameter, Brinkman number and Prandtl number, the analytical results are plotted graphically and discussed.

  13. Heat treatment and thickness-dependent electrical study of Se{sub 50}Te{sub 20}S{sub 30} thin film

    Energy Technology Data Exchange (ETDEWEB)

    Abd-Elrahman, M.I.; Hafiz, M.M.; Qasem, Ammar; Abdel-Rahim, M.A. [Assiut University, Physics Department, Faculty of Science, Assiut (Egypt)


    Chalcogenide Se{sub 50}Te{sub 20}S{sub 30} thin film of different thickness was deposited using thermal evaporation technique. The thermogram of the chalcogenide bulk Se{sub 50}Te{sub 20}S{sub 30} was obtained using a differential scanning calorimetry (DSC) with heating rate of 7.5 K/min. The glass transition temperature T{sub g}, crystallization temperature T{sub c} and peak crystallization temperature T{sub p} were identified. The X-ray diffraction (XRD) examination indicates the amorphous nature of the as-deposited film and polycrystalline structure of the thermal annealed ones. The dark electrical resistivity (ρ) measurements were taken in temperature range (300-500 K) and thickness range (200-450 nm). Analysis of the electrical resistivity results revealed two types of conduction mechanisms: conduction due to extended states in the temperature range (T > T{sub c}) and variable range hopping in the temperature range (T < T{sub c}). The effect of the heat treatment and thickness on the density of localized states at the Fermi level N(E{sub F}) and hopping parameters were studied. (orig.)

  14. Theoretical development of a new surface heat flux calibration method for thin-film resistive temperature gauges and co-axial thermocouples (United States)

    Frankel, J. I.; Keyhani, M.


    This paper presents a theoretically developed and computationally demonstrated surface heat flux calibration method applicable to thin-film resistive temperature gauges and co-axial thermocouples. For this study, the physical situation of interest involves hypersonic shock-tunnel studies. For experiments instrumented with these gauges, constant thermophysical properties are assumed since small temperature variations normally occur in the short-duration run times. Extraction of the net surface heat flux is acquired by resolving a newly formulated first-kind Volterra integral equation that contains calibration data. The proposed calibration method is based on an inverse approach which contrasts system identification methods. Several key advantages to this approach are discussed and demonstrated in the context of these gauges. Advantages of the proposed approach include (a) only one unknown "regularization" parameter is required; (b) estimation of the optimal regularization parameter is systematically and theoretically developed and demonstrated through the energy residuals, (c) computational coding is minimal and computer run times are short, and (d) results indicate robustness, stability and accuracy in the methodology. This calibration formulation and its subsequent regularized numerical method do not explicitly require the thermal effusivity, sqrt{ρ C k} owing to its input-output based derivation.

  15. Role of heat treatment on structural and optical properties of thermally evaporated Ga{sub 10}Se{sub 81}Pb{sub 9} chalcogenide thin films

    Energy Technology Data Exchange (ETDEWEB)

    El-Sebaii, A.A., E-mail: [Department of Physics, Faculty of Science, King Abdulaziz University, 80203 Jeddah 21589 (Saudi Arabia); Khan, Shamshad A. [Department of Physics, St. Andrews College, Gorakhpur 273001 (India); Al-Marzouki, F.M.; Faidah, A.S.; Al-Ghamdi, A.A. [Department of Physics, Faculty of Science, King Abdulaziz University, 80203 Jeddah 21589 (Saudi Arabia)


    Amorphous chalcogenides, based on Se, have become materials of commercial importance and were widely used for optical storage media. The present work deals with the structural and optical properties of Ga{sub 10}Se{sub 81}Pb{sub 9} ternary chalcogenide glass prepared by melt quenching technique. The glass transition, crystallization and melting temperatures of the synthesized glass were measured by non-isothermal DSC measurements at a constant heating rate of 30 K/min. Thin films of thickness 4000 A were prepared by thermal evaporation techniques on glass/Si (1 0 0) wafer substrate. These thin films were thermally annealed for two hours at three different annealing temperatures of 345, 360 and 375 K, which were in between the glass transition and crystallization temperatures of the Ga{sub 10}Se{sub 81}Pb{sub 9} glass. The structural, morphological and optical properties of as-prepared and annealed thin films were studied. Analysis of the optical absorption data showed that the rules of the non-direct transitions predominate. It was also found that the optical band gap decreases while the absorption coefficient, refractive index and extinction coefficient increase with increasing the annealing temperature. Due to the higher values of absorption coefficient and annealing dependence of the optical band gap and optical constants, the investigated material could be used for optical storage. - Highlights: Black-Right-Pointing-Pointer Annealing effect on structure and optical band gap has been investigated. Black-Right-Pointing-Pointer The amorphous nature has been verified by x-ray diffraction and DSC measurements. Black-Right-Pointing-Pointer Thermal annealing causes a decrease in optical band gap in Ga{sub 10}Se{sub 81}Pb{sub 9} thin films. Black-Right-Pointing-Pointer The decrease in optical band gap can be interpreted on the basis of amorphous-crystalline phase transformation. Black-Right-Pointing-Pointer Optical absorption data showed that the rules of the non

  16. In Situ Synchrotron X-Ray Diffraction and Small Angle X-Ray Scattering Studies on Rapidly Heated and Cooled Ti-Al and Al-Cu-Mg Alloys Using Laser-Based Heating (United States)

    Kenel, C.; Schloth, P.; Van Petegem, S.; Fife, J. L.; Grolimund, D.; Menzel, A.; Van Swygenhoven, H.; Leinenbach, C.


    Beam-based additive manufacturing (AM) typically involves high cooling rates in a range of 103-104 K/s. Therefore, new techniques are required to understand the non-equilibrium evolution of materials at appropriate time scales. Most technical alloys have not been optimized for such rapid solidification, and microstructural, phase, and elemental solubility behavior can be very different. In this work, the combination of complementary in situ synchrotron micro-x-ray diffraction (microXRD) and small angle x-ray scattering (SAXS) studies with laser-based heating and rapid cooling is presented as an approach to study alloy behavior under processing conditions similar to AM techniques. In rapidly solidified Ti-48Al, the full solidification and phase transformation sequences are observed using microXRD with high temporal resolution. The high cooling rates are achieved by fast heat extraction. Further, the temperature- and cooling rate-dependent precipitation of sub-nanometer clusters in an Al-Cu-Mg alloy can be studied by SAXS. The sensitivity of SAXS on the length scales of the newly formed phases allows their size and fraction to be determined. These techniques are unique tools to help provide a deeper understanding of underlying alloy behavior and its influence on resulting microstructures and properties after AM. Their availability to materials scientists is crucial for both in-depth investigations of novel alloys and also future production of high-quality parts using AM.

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

    Directory of Open Access Journals (Sweden)

    M. Sobhani


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

  18. Ultrafast heating effect on transient magnetic properties of L1{sub 0}-FePt thin films with perpendicular anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Jiaqi; Cui Boyin [Key Lab for Advanced Photonic Materials and Devices, and Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); Zhang Zongzhi, E-mail: [Key Lab for Advanced Photonic Materials and Devices, and Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); Ma, B. [Key Lab for Advanced Photonic Materials and Devices, and Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); Jin, Q.Y. [Key Lab for Advanced Photonic Materials and Devices, and Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); Laboratory of Advanced Materials, Fudan University, Shanghai 200433 (China)


    Laser-induced ultrafast magnetization dynamics and transient coercivity behavior in perpendicular magnetized L1{sub 0}-FePt films are investigated using the time-resolved polar magneto-optical Kerr technique. The magnetization after photo-excitation shows a dramatic reduction on the picosecond time scale. In contrast, the coercivity shows a weak decrease, accompanied by a skewed Kerr loop shape for low and intermediate fluences. The results can be interpreted by the laser-induced non-uniform demagnetization due to the weakened coupling between FePt grains of different size and/or components. The remaining coercivity vanishes when the film is fully demagnetized at higher fluence. We claim that the remaining coercivity can be manipulated by employing appropriate laser energy and film thickness, which may be helpful for application in heat-assisted magnetic recording.

  19. Rapid alkali catalyzed transesterification of microalgae lipids to biodiesel using simultaneous cooling and microwave heating and its optimization. (United States)

    Chee Loong, Teo; Idris, Ani


    Biodiesel with improved yield was produced from microalgae biomass under simultaneous cooling and microwave heating (SCMH). Nannochloropsis sp. and Tetraselmis sp. which were known to contain higher lipid species were used. The yield obtained using this novel technique was compared with the conventional heating (CH) and microwave heating (MWH) as the control method. The results revealed that the yields obtained using the novel SCMH were higher; Nannochloropsis sp. (83.33%) and Tetraselmis sp. (77.14%) than the control methods. Maximum yields were obtained using SCMH when the microwave was set at 50°C, 800W, 16h of reaction with simultaneous cooling at 15°C; and water content and lipid to methanol ratio in reaction mixture was kept to 0 and 1:12 respectively. GC analysis depicted that the biodiesel produced from this technique has lower carbon components (<19 C) and has both reasonable CN and IV reflecting good ignition and lubricating properties. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Indoor Light Enhanced Photocatalytic Ultra-Thin Films on Flexible Non-Heat Resistant Substrates Reducing Bacterial Infection Risks

    Directory of Open Access Journals (Sweden)

    Sami Rtimi


    Full Text Available Photocatalytic antibacterial sol-gel coated substrates have been reported to kill bacteria under light or in the dark. These coatings showed non-uniform distribution, poor adhesion to the substrate and short effective lifetime as antibacterial surfaces. These serious limitations to the performance/stability retard the potential application of antibacterial films on a wide range of surfaces in hospital facilities and public places. Here, the preparation, testing and performance of flexible ultra-thin films prepared by direct current magnetron sputtering (DCMS at different energies are reviewed. This review reports the recent advancements in the preparation of highly adhesive photocatalytic coatings prepared by up to date sputtering technology: High Power Impulse Magnetron Sputtering (HIPIMS. These latter films demonstrated an accelerated antibacterial capability compared to thicker films prepared by DCMS leading to materials saving. Nanoparticulates of Ti and Cu have been shown during the last decades to possess high oxidative redox potentials leading to bacterial inactivation kinetics in the minute range. In the case of TiO2CuOx films, the kinetics of abatement of Escherichia coli (E. coli and methicillin resistant Staphylococcus aureus (MRSA were enhanced under indoor visible light and were perceived to occur within few minutes. Oligodynamic effect was seen to be responsible for bacterial inactivation by the small amount of released material in the dark and/or under light as detected by inductively-coupled plasma mass spectrometry (ICP-MS. The spectral absorbance (detected by Diffuse Reflectance Spectroscopy (DRS was also seen to slightly shift to the visible region based on the preparation method.

  1. Properties and Developments of Combustion and Gasification of Coal and Char in a CO2-Rich and Recycled Flue Gases Atmosphere by Rapid Heating

    Directory of Open Access Journals (Sweden)

    Zhigang Li


    Full Text Available Combustion and gasification properties of pulverized coal and char have been investigated experimentally under the conditions of high temperature gradient of order 200°C·s−1 by a CO2 gas laser beam and CO2-rich atmospheres with 5% and 10% O2. The laser heating makes a more ideal experimental condition compared with previous studies with a TG-DTA, because it is able to minimize effects of coal oxidation and combustion by rapid heating process like radiative heat transfer condition. The experimental results indicated that coal weight reduction ratio to gases followed the Arrhenius equation with increasing coal temperature; further which were increased around 5% with adding H2O in CO2-rich atmosphere. In addition, coal-water mixtures with different water/coal mass ratio were used in order to investigate roles of water vapor in the process of coal gasification and combustion. Furthermore, char-water mixtures with different water/char mass ratio were also measured in order to discuss the generation ratio of CO/CO2, and specified that the source of Hydrocarbons is volatile matter from coal. Moreover, it was confirmed that generations of CO and Hydrocarbons gases are mainly dependent on coal temperature and O2 concentration, and they are stimulated at temperature over 1000°C in the CO2-rich atmosphere.

  2. Improvement of Self-Heating of Indium Gallium Zinc Aluminum Oxide Thin-Film Transistors Using Al2O3 Barrier Layer (United States)

    Jian, Li-Yi; Lee, Hsin-Ying; Lin, Yung-Hao; Lee, Ching-Ting


    To study the self-heating effect, aluminum oxide (Al2O3) barrier layers of various thicknesses have been inserted between the channel layer and insulator layer in bottom-gate-type indium gallium zinc aluminum oxide (IGZAO) thin-film transistors (TFTs). Each IGZAO channel layer was deposited on indium tin oxide (ITO)-coated glass substrate by using a magnetron radiofrequency cosputtering system with dual targets composed of indium gallium zinc oxide (IGZO) and Al. The 3 s orbital of Al cation provided an extra transport pathway and widened the conduction-band bottom, thus increasing the electron mobility of the IGZAO films. The Al-O bonds were able to sustain the oxygen stability of the IGZAO films. The self-heating behavior of the resulting IGZAO TFTs was studied by Hall measurements on the IGZAO films as well as the electrical performance of the IGZAO TFTs with Al2O3 barrier layers of various thicknesses at different temperatures. IGZAO TFTs with 50-nm-thick Al2O3 barrier layer were stressed by positive gate bias stress (PGBS, at gate-source voltage V GS = 5 V and drain-source voltage V DS = 0 V); at V GS = 5 V and V DS = 10 V, the threshold voltage shifts were 0.04 V and 0.2 V, respectively, much smaller than for the other IGZAO TFTs without Al2O3 barrier layer, which shifted by 0.2 V and 1.0 V when stressed under the same conditions.

  3. Ultra-high thermally conductive and rapid heat responsive poly(benzobisoxazole) nanocomposites with self-aligned graphene. (United States)

    Zhao, Weifeng; Kong, Jie; Liu, Hu; Zhuang, Qiang; Gu, Junwei; Guo, Zhanhu


    Self-alignment of thermally reduced graphene sheets (TRG) that enable highly efficient heat transfer paths in their poly(p-phenylene benzobisoxazole) (PBO)-based nanocomposite films along the in-plane direction was achieved for the first time without any assistance of an external magnetic or an electric field. In the in-plane direction, the nanocomposite films possess an ultra-high thermal diffusivity (900-1000 mm(2) s(-1)) and a thermal conductivity (50 W m(-1) K(-1)) with a TRG concentration graphene filler loading. The arranged TRG was also found to display a high efficiency for PBO reinforcement. A 64% increase in the Young's modulus was achieved by the addition of only 0.35 vol% of TRG, corresponding to a reinforcement value as high as 747 ± 38 GPa, due to effective load transfer between the PBO matrix and TRG sheets via strong interfacial interactions. Moreover, the highly ordered graphene in PBO could provide good candidates for effective heat shielding barriers, and thus the prepared PBO composites exhibit a thermal stability remarkably higher than that of neat PBO resin.

  4. Can cognitive dissonance methods developed in the West for combatting the ‘thin ideal’ help slow the rapidly increasing prevalence of eating disorders in non-Western cultures? (United States)

    Witcomb, Gemma L.; Arcelus, Jon; Chen, Jue


    Summary Eating disorders are common, life-threatening conditions in Western countries, but until relatively recently they were regarded as uncommon in non-Western cultures. However, the prevalence of eating disorders in many of the more affluent non-Western countries is rising rapidly as community members, particularly young women, internalize the ‘thin ideal’ that has been widely promoted by the international media. This review discusses the factors involved in the development of eating disorders in non-Western settings with a particular emphasis on the influences of urbanization, modernization, Westernization, and the resulting changes in women's roles. The cognitive dissonance programs developed in Western countries that have proven successful in countering the negative effects of the thin idea are described and their potential application to East Asia and other non-Western countries are discussed. PMID:24991176

  5. Towards the geophysical regime in numerical dynamo models: studies of rapidly-rotating convection driven dynamos with low Pm and constant heat flux boundary conditions

    DEFF Research Database (Denmark)

    Sheyko, A.A.; Finlay, Chris; Marti, P.

    We present a set of numerical dynamo models with the convection strength varied by a factor of 30 and the ratio of magnetic to viscous diffusivities by a factor of 20 at rapid rotation rates (E =nu/(2 Omega d^2 ) = 10-6 and 10-7 ) using a heat flux outer BC. This regime has been little explored...... on the structure of the dynamos and how this changes in relation to the selection of control parameters, a comparison with the proposed rotating convection and dynamo scaling laws, energy spectra of steady solutions and inner core rotation rates. Magnetic field on the CMB. E=2.959*10-7, Ra=6591.0, Pm=0.05, Pr=1....

  6. The Effect of a Rapid Heating Rate, Mechanical Vibration and Surfactant Chemistry on the Structure–Property Relationships of Epoxy/Clay Nanocomposites

    Directory of Open Access Journals (Sweden)

    Kevin Magniez


    Full Text Available The role of processing conditions and intercalant chemistry in montmorillonite clays on the dispersion, morphology and mechanical properties of two epoxy/clay nanocomposite systems was investigated in this paper. This work highlights the importance of employing complementary techniques (X-ray diffraction, small angle X-ray scattering, optical microscopy and transmission electron microscopy to correlate nanomorphology to macroscale properties. Materials were prepared using an out of autoclave manufacturing process equipped to generate rapid heating rates and mechanical vibration. The results suggested that the quaternary ammonium surfactant on C30B clay reacted with the epoxy during cure, while the primary ammonium surfactant (I.30E catalysed the polymerisation reaction. These effects led to important differences in nanocomposite clay morphologies. The use of mechanical vibration at 4 Hz prior to matrix gelation was found to facilitate clay dispersion and to reduce the area fraction of I.30E clay agglomerates in addition to increasing flexural strength by over 40%.

  7. Development of Amorphous/Microcrystalline Silicon Tandem Thin-Film Solar Modules with Low Output Voltage, High Energy Yield, Low Light-Induced Degradation, and High Damp-Heat Reliability


    Chin-Yi Tsai; Chin-Yao Tsai


    In this work, tandem amorphous/microcrystalline silicon thin-film solar modules with low output voltage, high energy yield, low light-induced degradation, and high damp-heat reliability were successfully designed and developed. Several key technologies of passivation, transparent-conducting-oxide films, and cell and segment laser scribing were researched, developed, and introduced into the production line to enhance the performance of these low-voltage modules. A 900 kWp photovoltaic system w...

  8. A One-Step Rapid Assembly of Thin Film Coating Using Green Coordination Complexes for Enhanced Removal of Trace Organic Contaminants by Membranes. (United States)

    Guo, Hao; Yao, Zhikan; Yang, Zhe; Ma, Xiaohua; Wang, Jianqiang; Tang, Chuyang Y


    We report a fast, simple, and green coating method using the coordination complex of tannic acid (TA) and ferric ion (Fe3+) to enhance the removal of trace organic contaminants (TrOCs) by polyamide membranes. The entire coating process can be completed in less than 2 min; quartz crystal microbalance characterization revealed that a TA-Fe thin film formed in merely 10-20 s. Coating this TA-Fe thin film on a commercial nanofiltration membrane (NF270) reduced its effective pore size from 0.44 to 0.40 nm. The TA-Fe-coated NF270 showed significantly increased rejection of both NaCl and trace organic contaminants. In comparison with the more-time-consuming polydopamine coating (e.g., 0.5 h), the TA-Fe coating presented greater resistance to TrOC permeation (i.e., lower permeability of TrOCs). The advantages of the fast coating process, greatly improved rejection performance, and use of green accessible materials make TA-Fe a highly promising coating material for large-scale applications.

  9. Multi-step cure kinetic model of ultra-thin glass fiber epoxy prepreg exhibiting both autocatalytic and diffusion-controlled regimes under isothermal and dynamic-heating conditions (United States)

    Kim, Ye Chan; Min, Hyunsung; Hong, Sungyong; Wang, Mei; Sun, Hanna; Park, In-Kyung; Choi, Hyouk Ryeol; Koo, Ja Choon; Moon, Hyungpil; Kim, Kwang J.; Suhr, Jonghwan; Nam, Jae-Do


    As packaging technologies are demanded that reduce the assembly area of substrate, thin composite laminate substrates require the utmost high performance in such material properties as the coefficient of thermal expansion (CTE), and stiffness. Accordingly, thermosetting resin systems, which consist of multiple fillers, monomers and/or catalysts in thermoset-based glass fiber prepregs, are extremely complicated and closely associated with rheological properties, which depend on the temperature cycles for cure. For the process control of these complex systems, it is usually required to obtain a reliable kinetic model that could be used for the complex thermal cycles, which usually includes both the isothermal and dynamic-heating segments. In this study, an ultra-thin prepreg with highly loaded silica beads and glass fibers in the epoxy/amine resin system was investigated as a model system by isothermal/dynamic heating experiments. The maximum degree of cure was obtained as a function of temperature. The curing kinetics of the model prepreg system exhibited a multi-step reaction and a limited conversion as a function of isothermal curing temperatures, which are often observed in epoxy cure system because of the rate-determining diffusion of polymer chain growth. The modified kinetic equation accurately described the isothermal behavior and the beginning of the dynamic-heating behavior by integrating the obtained maximum degree of cure into the kinetic model development.

  10. Heat Flux Instrumentation Laboratory (HFIL) (United States)

    Federal Laboratory Consortium — Description: The Heat Flux Instrumentation Laboratory is used to develop advanced, flexible, thin film gauge instrumentation for the Air Force Research Laboratory....

  11. Heat waves imposed during early pod development in soybean (Glycine max) cause significant yield loss despite a rapid recovery from oxidative stress (United States)

    This study is the first field based experiment that uses IR heaters to study the effects of a regionally defined heat wave on soybean physiology and productivity. The heating technology was successful and all of the heat waves were maintained at the target temperature for the three day duration of t...

  12. Comparative evaluation of bivalent malaria rapid diagnostic tests versus traditional methods in field with special reference to heat stability testing in Central India.

    Directory of Open Access Journals (Sweden)

    Neeru Singh

    Full Text Available BACKGROUND: Malaria presents a diagnostic challenge in areas where both Plasmodium falciparum and P.vivax are co-endemic. Bivalent Rapid Diagnostic tests (RDTs showed promise as diagnostic tools for P.falciparum and P.vivax. To assist national malaria control programme in the selection of RDTs, commercially available seven malaria RDTs were evaluated in terms of their performance with special reference to heat stability. METHODOLOGY/PRINCIPAL FINDINGS: This study was undertaken in four forested districts of central India (July, 2011- March, 2012. All RDTs were tested simultaneously in field along with microscopy as gold standard. These RDTs were stored in their original packing at 25°C before transport to the field or they were stored at 35°C and 45°C upto 100 days for testing the performance of RDTs at high temperature. In all 2841 patients with fever were screened for malaria of which 26% were positive for P.falciparum, and 17% for P.vivax. The highest sensitivity of any RDT for P.falciparum was 98% (95% CI; 95.9-98.8 and lowest sensitivity was 76% (95% CI; 71.7-79.6. For P.vivax highest and lowest sensitivity for any RDT was 80% (95% CI; 94.9 - 83.9 and 20% (95% CI; 15.6-24.5 respectively. Heat stability experiments showed that most RDTs for P.falciparum showed high sensitivity at 45°C upto 90 days. While for P.vivax only two RDTs maintained good sensitivity upto day 90 when compared with RDTs kept at room temperature. Agreement between observers was excellent for positive and negative readings for both P.falciparum and P.vivax (Kappa >0.6-0.9. CONCLUSION: This is first field evaluation of RDTs regarding their temperature stability. Although RDTs are useful as diagnostic tool for P.falciparum and P.vivax even at high temperature, the quality of RDTs should be regulated and monitored more closely.

  13. Oscillating heat pipes

    CERN Document Server

    Ma, Hongbin


    This book presents the fundamental fluid flow and heat transfer principles occurring in oscillating heat pipes and also provides updated developments and recent innovations in research and applications of heat pipes. Starting with fundamental presentation of heat pipes, the focus is on oscillating motions and its heat transfer enhancement in a two-phase heat transfer system. The book covers thermodynamic analysis, interfacial phenomenon, thin film evaporation,  theoretical models of oscillating motion and heat transfer of single phase and two-phase flows, primary  factors affecting oscillating motions and heat transfer,  neutron imaging study of oscillating motions in an oscillating heat pipes, and nanofluid’s effect on the heat transfer performance in oscillating heat pipes.  The importance of thermally-excited oscillating motion combined with phase change heat transfer to a wide variety of applications is emphasized. This book is an essential resource and learning tool for senior undergraduate, gradua...

  14. Effect of residual stress relaxation by means of local rapid induction heating on stress corrosion cracking behavior and electrochemical characterization of welded Ti-6Al-4V alloy under slow strain rate test (United States)

    Liu, Yan; Tang, Shawei; Liu, Guangyi; Sun, Yue; Hu, Jin


    In this study, a welded Ti-6Al-4V alloy was treated by means of local rapid induction heating in order to relax the residual stress existed in the weldment. The welded samples were heat treated at the different temperatures. The stress corrosion cracking behavior and electrochemical characterization of the as-welded samples before and after the post weld heat treatment as a function of residual stress were investigated. Electrochemical impedance spectroscopy measurements of the samples under slow strain rate test were performed in a LiCl-methanol solution. The results demonstrated that the residual stress in the as-welded sample was dramatically reduced after the post weld heat treatment, and the residual stress decreased with the increase in the heat treatment temperature. The stress corrosion cracking susceptibility and electrochemical activity of the as-welded sample were significantly reduced after the heat treatment due to the relaxation of the residual stress, which gradually decreased with the decreasing value of the residual stress distributed in the heat treated samples.

  15. Investigation of ultrafast lattice heating in thin (semi-)metal films using time-resolved electron diffraction; Untersuchung der schnellen Gitteraufheizung in duennen (Halb-)Metallfilmen mit Hilfe zeitaufgeloester Elektronenbeugung

    Energy Technology Data Exchange (ETDEWEB)

    Ligges, Manuel


    In the framework of the present thesis the fast lattice heating in thin metal and bismuth layers after optical short-pulse excitation was studied. By irradiation of ultrathin solid films with ultrashort (femtosecond) laser pulses for sort times an extreme nonequilibrium state occurs: The electronic system is strongly excited, while the lattice system remains cold. An energetic exchange between both systems follows, which is based on the electron-phonon interaction and leads to heating of the lattice system. This lattice heating can be observed by means of the Debye-Waller effect in the electron diffraction image. By means of the excitation-interrogation scheme by a series of moment records this lattice heating can be observed time-resolvedly. The experimentally determind time scales for this process permit conclusions on the electron-phonon coupling in the studied materials. In this thesis a time-resolving transmissi9on-electron diffraction experiment with sub-picosecond time resolution was constructed and optimized. By means of this experiment the fast lattice heating in thin gold, silver, copper, and bismuth films was studied. The observed heating behaviour of the metal films shows agreement with theoretical predictions of different model calculations. The results of the measurements on bismuth films show a hitherto not observed coupling behaviour. [German] Im Rahmen der vorliegenden Arbeit wurde die schnelle Gitteraufheizung in duennen Metall- und Wismutschichten nach optischer Kurzimpulsanregung untersucht. Durch Bestrahlung duenner Festkoerperfilme mit ultrakurzen (Femtosekunden-) Laserimpulsen entsteht fuer kurze Zeiten ein extremer Nichtgleichgewichtszustand: Das elektronische System wird stark angeregt, waehrend das Gittersystem kalt bleibt. Es folgt ein energetischer Austausch zwischen beiden Systemen, der auf der Elektron-Phonon-Wechselwirkung beruht und zur Aufheizung des Gittersystems fuehrt. Diese Gitteraufheizung kann anhand des Debye

  16. In{sub 6}Se{sub 7} thin films by heating thermally evaporated indium and chemical bath deposited selenium multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Ornelas, R.E.; Avellaneda, D. [Universidad Autonoma de Nuevo Leon, Facultad de Ingenieria Mecanica y Electrica, San Nicolas de los Garza, Nuevo Leon-66450 (Mexico); Shaji, S. [Universidad Autonoma de Nuevo Leon, Facultad de Ingenieria Mecanica y Electrica, San Nicolas de los Garza, Nuevo Leon-66450 (Mexico); Universidad Autonoma de Nuevo Leon-CIIDIT, Apodaca, N.L (Mexico); Castillo, G.A.; Roy, T.K. Das [Universidad Autonoma de Nuevo Leon, Facultad de Ingenieria Mecanica y Electrica, San Nicolas de los Garza, Nuevo Leon-66450 (Mexico); Krishnan, B., E-mail: [Universidad Autonoma de Nuevo Leon, Facultad de Ingenieria Mecanica y Electrica, San Nicolas de los Garza, Nuevo Leon-66450 (Mexico); Universidad Autonoma de Nuevo Leon-CIIDIT, Apodaca, N.L (Mexico)


    Indium selenide (In{sub 6}Se{sub 7}) thin films were prepared via selenization of thermally evaporated indium thin films by dipping in sodium selenosulphate solution followed by annealing in nitrogen atmosphere. First, indium was thermally evaporated on glass substrate. Then, the indium coated glass substrates were dipped in a solution containing 80 ml 0.125 M sodium selenosulphate and 1.5 ml dilute acetic acid (25%) for 5 min. Glass/In-Se layers were annealed at 200-400 Degree-Sign C in nitrogen atmosphere (0.1 Torr) for 30 min. X-ray diffraction studies showed the formation of monoclinic In{sub 6}Se{sub 7}. Morphology of the thin films formed at different conditions was analyzed using Scanning electron microscopy. The elemental analysis was done using Energy dispersive X-ray detection. Electrical conductivity under dark and illumination conditions was evaluated. Optical band gap was computed using transmittance and reflectance spectra. The band gap value was in the range 1.8-2.6 eV corresponding to a direct allowed transition. We studied the effect of indium layer thickness and selenium deposition time on the structure, electrical and optical properties of In{sub 6}Se{sub 7} thin films.

  17. Furnace for rapid thermal processing

    NARCIS (Netherlands)

    Roozeboom, F.; Duine, P.A.; Sluis, P. van der


    A Method (1) for Rapid Thermal Processing of a wafer (7), wherein the wafer (7) is heated by lamps (9), and the heat radiation is reflected by an optical switching device (15,17) which is in the reflecting state during the heating stage. During the cooling stage of the wafer (7), the heat is

  18. Large area photonic flash soldering of thin chips on flex foils for flexible electronic systems: In situ temperature measurements and thermal modelling

    NARCIS (Netherlands)

    Ende, D.A. van den; Hendriks, R.; Cauchois, R.; Groen, W.A.


    In this work photonic energy from a high power xenon flash lamp is used for soldering thin chips on polyimide and polyester foil substrates using standard Sn-Ag-Cu lead free alloys. The absorption of the xenon light pulse leads to rapid heating of components and tracks up to temperatures above the

  19. Chemical heat pump (United States)

    Greiner, Leonard


    A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer. The heat pump part of the system heats or cools a house or other structure through a combination of evaporation and absorption or, conversely, condensation and desorption, in a pair of containers. A set of automatic controls change the system for operation during winter and summer months and for daytime and nighttime operation to satisfactorily heat and cool a house during an entire year. The absorber chamber is subjected to solar heating during regeneration cycles and is covered by one or more layers of glass or other transparent material. Daytime home air used for heating the home is passed at appropriate flow rates between the absorber container and the first transparent cover layer in heat transfer relationship in a manner that greatly reduce eddies and resultant heat loss from the absorbant surface to ambient atmosphere.

  20. Rapid insight into heating-induced phase transformations in the solid state of the calcium salt of atorvastatin using multivariate data analysis

    DEFF Research Database (Denmark)

    Christensen, Niels Peter Aae; Van Eerdenbrugh, Bernard; Kwok, Kaho


    To investigate the heating-induced dehydration and melting behavior of the trihydrate phase of the calcium salt of atorvastatin.......To investigate the heating-induced dehydration and melting behavior of the trihydrate phase of the calcium salt of atorvastatin....

  1. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... stage of heat illness) include flushed, hot, dry skin; fainting; a rapid, weak pulse; rapid, shallow breathing; vomiting; and increased body temperature of more than 104 degrees. People with these ...

  2. Electrical Behavior of Cd0.3Zn1.1x S0.7 Thin Films for Non-Heat Light Emitting Diodes

    Directory of Open Access Journals (Sweden)

    Cliff Orori Mosiori


    Full Text Available In developing countries like Kenya, solution processing technique is the cheapest and simplest technique to grow inorganic composites thin films. This method was used to grow thin films of Cd0.3Zn1.1xS0.7 on ordinary microscope Perspex substrate slides from aqueous solutions of Zinc chloride and cadmium chloride in ammonia solution. A solution of triethanalomine was used as a complexing agent while thiourea was used as source of sulphide ions. Electrical properties as a function of their thicknesses were obtained by varying deposition time while all other parameters were maintained constant. Using a resistance measurement device and a Gauss meter, resistivity and the conductivity of the films were found to be thickness dependent with semiconductor nature.

  3. Analytical Solutions of Heat Transfer and Film Thickness with Slip Condition Effect in Thin-Film Evaporation for Two-Phase Flow in Microchannel

    Directory of Open Access Journals (Sweden)

    Ahmed Jassim Shkarah


    Full Text Available Physical and mathematical model has been developed to predict the two-phase flow and heat transfer in a microchannel with evaporative heat transfer. Sample solutions to the model were obtained for both analytical analysis and numerical analysis. It is assumed that the capillary pressure is neglected (Morris, 2003. Results are provided for liquid film thickness, total heat flux, and evaporating heat flux distribution. In addition to the sample calculations that were used to illustrate the transport characteristics, computations based on the current model were performed to generate results for comparisons with the analytical results of Wang et al. (2008 and Wayner Jr. et al. (1976. The calculated results from the current model match closely with those of analytical results of Wang et al. (2008 and Wayner Jr. et al. (1976. This work will lead to a better understanding of heat transfer and fluid flow occurring in the evaporating film region and develop an analytical equation for evaporating liquid film thickness.

  4. Thin film ceramic thermocouples (United States)

    Gregory, Otto (Inventor); Fralick, Gustave (Inventor); Wrbanek, John (Inventor); You, Tao (Inventor)


    A thin film ceramic thermocouple (10) having two ceramic thermocouple (12, 14) that are in contact with each other in at least on point to form a junction, and wherein each element was prepared in a different oxygen/nitrogen/argon plasma. Since each element is prepared under different plasma conditions, they have different electrical conductivity and different charge carrier concentration. The thin film thermocouple (10) can be transparent. A versatile ceramic sensor system having an RTD heat flux sensor can be combined with a thermocouple and a strain sensor to yield a multifunctional ceramic sensor array. The transparent ceramic temperature sensor that could ultimately be used for calibration of optical sensors.

  5. On thin ice/in hot water: Rapid drawdown of Wordie Ice Shelf glaciers in the decades after collapse in response to a changing ocean (United States)

    Walker, C. C.; Gardner, A. S.


    Over the past 50 years, several Antarctic Peninsula ice shelves have retreated or collapsed completely. One such collapse was the Wordie Ice Shelf (WIS), located in Marguerite Bay, which began to disintegrate around 1989. We use several observational datasets to show that the glaciers that used to maintain WIS have experienced a surprising acceleration in flow ( 500m/yr) that began 2008, nearly 20 years after the onset of WIS collapse. During the same period, airborne altimetry from NASA Operation IceBridge shows the glaciers experienced a drawdown at their calving fronts between 4 and 9 m/yr, a near-doubling in rate of elevation change from the 1990's and early-2000's. The time lag between WIS collapse and rapid glacier drawdown suggests that these recent changes are unrelated to loss of buttressing. We identify possible links to changes in ocean conditions using in-situ Palmer Station Long-Term Ecological Research (PAL LTER) ocean CTD-gridded observations (Martinson et al., 2008) taken along the continental shelf on the west Antarctic Peninsula (WAP) since 1993. We use ECCO2 simulations and atmospheric reanalysis data to characterize changes in atmospheric forcing. We also measure changes in ice shelf area using historic archives and Landsat imagery for 50 glacier systems along the WAP from 1945 to present. Surface structural changes in the WIS system, e.g., melt ponds, sea/fast ice presence, and crevasse density/orientation, are also examined. We conclude that recent changes in WIS tributaries likely resulted from a significant increase in upwelling of warm, salty Upper Circumpolar Deep Water (UCDW) due to enhanced wind forcing following coincident global atmospheric oscillation events, namely a positive Southern Annular Mode and a moderate La Nina event. This enabled enhanced incursions of UCDW into Marguerite Bay between 2008-2014, in part due to the deep Marguerite Trough that connects the bay to the continental shelf break, along which the southern boundary

  6. Infrared heating (United States)

    IR heating was first industrially used in the 1930s for automotive curing applications and rapidly became a widely applied technology in the manufacturing industry. Contrarily, a slower pace in the development of IR technologies for processing foods and agricultural products was observed, due to lim...

  7. High-Temperature Liquid Metal Transport Physics of Capillary Pumping Heat Transport System (CPHTS) Research: Experimental and Theoretical Studies of Evaporating Liquid Metal Thin Film (United States)


    Gagliardo, D. L. Jacobson, D. S. Hussey and M. Arif, "Use of neutron imaging for proton exchange membrane fuel cell (PEMFC) performance analysis...Borgmeyer, C. Wilson, R. A. Winholtz, H. B. Ma, D. Jacobson, D. Hussey , 2010, “Heat Transport Capability and Fluid Flow Neutron Radiography of Three

  8. Electrocaloric devices based on thini-film heat switches

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, Richard I [Los Alamos National Laboratory; Malloy, Kevin J [UNM


    We describe a new approach to refrigeration and electrical generation that exploits the attractive properties of thin films of electrocaloric materials. Layers of electrocaloric material coupled with thin-film heat switches can work as either refrigerators or electrical generators, depending on the phasing of the applied voltages and heat switching. With heat switches based on thin layers of liquid crystals, the efficiency of these thin-film heat engines can be at least as high as that of current thermoelectric devices. Advanced heat switches would enable thin-film heat engines to outperform conventional vaporcompression devices.

  9. Development of Amorphous/Microcrystalline Silicon Tandem Thin-Film Solar Modules with Low Output Voltage, High Energy Yield, Low Light-Induced Degradation, and High Damp-Heat Reliability

    Directory of Open Access Journals (Sweden)

    Chin-Yi Tsai


    Full Text Available In this work, tandem amorphous/microcrystalline silicon thin-film solar modules with low output voltage, high energy yield, low light-induced degradation, and high damp-heat reliability were successfully designed and developed. Several key technologies of passivation, transparent-conducting-oxide films, and cell and segment laser scribing were researched, developed, and introduced into the production line to enhance the performance of these low-voltage modules. A 900 kWp photovoltaic system with these low-voltage panels was installed and its performance ratio has been simulated and projected to be 92.1%, which is 20% more than the crystalline silicon and CdTe counterparts.

  10. Enhanced Thermochromic Properties and Solar-Heat Shielding Ability of W(x)V(1-x)O2 Thin Films with Ag Nanowires Capping Layers. (United States)

    Zhao, Li Li; Miao, Lei; Liu, Cheng Yan; Wang, Hai Long; Tanemura, Sakae; Sun, Li Xian; Gao, Xiang; Zhou, Jian Hua


    Considerable efforts have been made to shift the phase transition temperature of metal-doped vanadium dioxide (VO2) films nearer the ambient temperature while maintain the excellent thermochromic properties simultaneously. Here, we describe a facile and economic solution-based method to fabricate W-doped VO2 (V(1-x)W(x)O2) thin films with excellent thermochromic properties for the application of smart windows. The substitutional doping of tungsten atoms notably reduces the phase transition temperature to the ambient temperature and retains the excellent thermochromic property. Furthermore, Ag nanowires (NWs) are employed as capping layers to effectively decrease the thermal emissivity from 0.833 to 0.603, while the original near infrared region (NIR) modulation ability is not severely affected. Besides, the Ag NWs layers further depress the phase transition temperature as well as the hysteresis loop width, which is important to the fenestration application. These solution-grown Ag NWs/V(1-x)W(x)O2 thin films exhibit excellent solar modulation ability, narrowed hysteresis loop width as well as low thermal emissivity, which provide a promising perspective into the practical application of VO2-based smart windows.

  11. Heat Pipe Technology (United States)


    The heat pipe, a sealed chamber whose walls are lined with a "wick," a thin capillary network containing a working fluid in liquid form was developed for a heat distribution system for non-rotating satellites. Use of the heat pipe provides a continuous heat transfer mechanism. "Heat tubes" that improve temperature control in plastics manufacturing equipment incorporated the heat pipe technology. James M. Stewart, an independent consultant, patented the heat tubes he developed and granted a license to Kona Corporation. The Kona Nozzle for heaterless injection molding gets heat for its operation from an external source and has no internal heating bands, reducing machine maintenance and also eliminating electrical hazards associated with heater bands. The nozzles are used by Eastman Kodak, Bic Pen Corporation, Polaroid, Tupperware, Ford Motor Company, RCA, and Western Electric in the molding of their products.

  12. Effect of heat treatments and window layer processing on the characteristics of CuInGaSe{sub 2} thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ramanathan, K.; Contreras, M.A.; Tuttle, J.R. [National Renewable Energy Lab., Golden, CO (United States)] [and others


    Interaction between chemical bath deposited CdS and ZnO window layers are a focus of this paper. Low temperature anneals were used to follow the changes at the interface. Optical absorption spectra show that CdS and ZnO intermix upon annealing. When applied to ZnO/CdS/CuInGaSe{sub 2} thin film solar cells, changes in the short and long wavelength response were observed. The latter is attributed to an increase in the energy gap of the absorber by diffusion of S. The interdiffusion is shown to increase the short wavelength collection, and hence the current density of the devices. Photoluminescence data provides some indication of the quality of the interface.

  13. Synthesis of renewable diesel through hydrodeoxygenation reaction from nyamplung oil (Calophyllum Inophyllum oil) using NiMo/Z and NiMo/C catalysts with rapid heating and cooling method (United States)

    Susanto, B. H.; Prakasa, M. B.; Shahab, M. H.


    The synthesis of metal nanocrystal was conducted by modification preparation from simple heating method which heating and cooling process run rapidly. The result of NiMo/Z 575 °C characterizations are 33.73 m2/gram surface area and 31.80 nm crystal size. By used NiMo/C 700 °C catalyst for 30 minutes which had surface area of 263.21 m2/gram, had 31.77 nm crystal size, and good morphology, obtained catalyst with high activity, selectivity, and stability. After catalyst activated, synthesis of renewable diesel performed in hydrogenation reactor at 375 °C, 12 bar, and 800 rpm. The result of conversion was 81.99%, yield was 68.08%, and selectivity was 84.54%.

  14. Rapid ordering of block copolymer thin films. (United States)

    Majewski, Pawel W; Yager, Kevin G


    Block-copolymers self-assemble into diverse morphologies, where nanoscale order can be finely tuned via block architecture and processing conditions. However, the ultimate usage of these materials in real-world applications may be hampered by the extremely long thermal annealing times-hours or days-required to achieve good order. Here, we provide an overview of the fundamentals of block-copolymer self-assembly kinetics, and review the techniques that have been demonstrated to influence, and enhance, these ordering kinetics. We discuss the inherent tradeoffs between oven annealing, solvent annealing, microwave annealing, zone annealing, and other directed self-assembly methods; including an assessment of spatial and temporal characteristics. We also review both real-space and reciprocal-space analysis techniques for quantifying order in these systems.

  15. White Paper for U.S. Army Rapid Equipping Force: Waste Heat Recovery with Thermoelectric and Lithium-Ion Hybrid Power System

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J C


    By harvesting waste heat from engine exhaust and storing it in light-weight high-capacity modules, it is believed that the need for energy transport by convoys can be lowered significantly. By storing this power during operation, substantial electrical power can be provided during long periods of silent operation, while the engines are not operating. It is proposed to investigate the potential of installing efficient thermoelectric generators on the exhaust systems of trucks and other vehicles to generate electrical power from the waste heat contained in the exhaust and to store that power in advanced power packs comprised of polymer-gel lithium ion batteries. Efficient inexpensive methods for production of the thermoelectric generator are also proposed. The technology that exists at LLNL, as well as that which exists at industrial partners, all have high technology readiness level (TRL). Work is needed for integration and deployment.

  16. Prefabricated modular district heating station is available rapidly. Welded transfer station DSP Midi; Vorgefertigte, modulare Fernwaermestation ist schnell verfuegbar. Geschweisste Uebergabestation DSP Midi

    Energy Technology Data Exchange (ETDEWEB)

    Simon, Joern [Danfoss GmbH, Hamburg (Germany). District Energy Div.


    Danfoss GmbH (Hamburg, Federal Republic of Germany) has developed a modular, standardized approach for welded district heating stations. The prefabricated transfer stations with a capacity up to 250 kW can be supplied in a compact frame. These stations have short delivery times and are extremely flexible: DSP MIDI systems have a modular design and adapters. Thus, DSP MIDI systems cover about 90 % of the technical connection requirements in Germany.

  17. Rapid assessment of bovine spongiform encephalopathy prion inactivation by heat treatment in yellow grease produced in the industrial manufacturing process of meat and bone meals


    YOSHIOKA, Miyako; Matsuura, Yuichi; Okada, Hiroyuki; Shimozaki, Noriko; Yamamura, Tomoaki; Murayama, Yuichi; Yokoyama, Takashi; Mohri, Shirou


    Background Prions, infectious agents associated with transmissible spongiform encephalopathy, are primarily composed of the misfolded and pathogenic form (PrPSc) of the host-encoded prion protein. Because PrPSc retains infectivity after undergoing routine sterilizing processes, the cause of bovine spongiform encephalopathy (BSE) outbreaks are suspected to be feeding cattle meat and bone meals (MBMs) contaminated with the prion. To assess the validity of prion inactivation by heat treatment in...

  18. Analytical strategy for rapid identification and quantification of lubricant additives in mineral oil by high-performance thin-layer chromatography with UV absorption and fluorescence detection combined with mass spectrometry and infrared spectroscopy. (United States)

    Dytkiewitz, Elisabeth; Morlock, Gertrud E


    A simple strategy for identification and quantification of lubricant additives in mineral oil was demonstrated by high-performance thin-layer chromatography with UV absorption and fluorescence detection using various coupling options, e.g., with attenuated total reflectance infrared (ATR-IR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, electrospray ionization mass spectrometry (ESI-MS), and direct analysis in real-time mass spectrometry (DART-MS). For the additives zinc bis(O,O'-diisobutyl dithiophosphate), zinc bis(O,O'-didodecyl dithiophosphate), and Anglamol 99, 2 chromatographic systems were developed, i.e., a reversed-phase (RP) system on RP2 plates using an acetonitrile-based mobile phase and a normal-phase system on silica gel 60 plates using a toluene-based gradient. Densitometry was performed by absorption measurement at 220 nm. Repeatabilities (relative standard deviation, n = 6) between 2.2 and 5.5% and correlation coefficients >0.9973 were highly satisfactory for the analysis of these additives in the mineral oil. Primuline reagent was used to improve the detection limit of the lipophilic additives by a factor of 2, followed by fluorescence measurement at UV 366/>400 nm. For rapid identification by ATR-IR and FTIR, the respective additive zones on the plate were online extracted by an interface called ChromeXtract, concentrated, and directly applied for measurements in the wave number range of 4000-400 cm(-1). Identification was confirmed by online ESI-MS within a minute using ChromeXtract and by DART-MS within seconds.

  19. Heat and Mass Transfer in a Thin Liquid Film over an Unsteady Stretching Surface in the Presence of Thermosolutal Capillarity and Variable Magnetic Field

    Directory of Open Access Journals (Sweden)

    Yan Zhang


    Full Text Available The heat and mass transfer characteristics of a liquid film which contain thermosolutal capillarity and a variable magnetic field over an unsteady stretching sheet have been investigated. The governing equations for momentum, energy, and concentration are established and transformed to a set of coupled ordinary equations with the aid of similarity transformation. The analytical solutions are obtained using the double-parameter transformation perturbation expansion method. The effects of various relevant parameters such as unsteady parameter, Prandtl number, Schmidt number, thermocapillary number, and solutal capillary number on the velocity, temperature, and concentration fields are discussed and presented graphically. Results show that increasing values of thermocapillary number and solutal capillary number both lead to a decrease in the temperature and concentration fields. Furthermore, the influences of thermocapillary number on various fields are more remarkable in comparison to the solutal capillary number.

  20. Dummy-surface molecularly imprinted polymers on magnetic graphene oxide for rapid and selective quantification of acrylamide in heat-processed (including fried) foods. (United States)

    Ning, Fangjian; Qiu, Tingting; Wang, Qi; Peng, Hailong; Li, Yanbin; Wu, Xiaqing; Zhang, Zhong; Chen, Linxin; Xiong, Hua


    Novel nano-sized dummy-surface molecularly imprinted polymers (DSMIPs) on a magnetic graphene oxide (GO-Fe3O4) surface were developed as substrates, using propionamide as a dummy template molecule for the selective recognition and rapid pre-concentration and removal of acrylamide (AM) from food samples. These products showed rapid kinetics, high binding capacity (adsorption at 3.68mg·g-1), and selectivity (imprinting factor α 2.83); the adsorption processes followed the Langmuir-Freundlich isotherm and pseudo-second-order kinetic models. Excellent recognition selectivity toward acrylamide was achieved compared to structural analogs, such as propionic and acrylic acids (selectivity factor β 2.33, and 2.20, respectively). Moreover, DSMIPs-GO-Fe3O4 was used to quantify acrylamide in food samples, yielding satisfactory recovery (86.7-94.3%) and low relative standard deviation (acrylamide from food samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Rapid assessment of bovine spongiform encephalopathy prion inactivation by heat treatment in yellow grease produced in the industrial manufacturing process of meat and bone meals. (United States)

    Yoshioka, Miyako; Matsuura, Yuichi; Okada, Hiroyuki; Shimozaki, Noriko; Yamamura, Tomoaki; Murayama, Yuichi; Yokoyama, Takashi; Mohri, Shirou


    Prions, infectious agents associated with transmissible spongiform encephalopathy, are primarily composed of the misfolded and pathogenic form (PrPSc) of the host-encoded prion protein. Because PrPSc retains infectivity after undergoing routine sterilizing processes, the cause of bovine spongiform encephalopathy (BSE) outbreaks are suspected to be feeding cattle meat and bone meals (MBMs) contaminated with the prion. To assess the validity of prion inactivation by heat treatment in yellow grease, which is produced in the industrial manufacturing process of MBMs, we pooled, homogenized, and heat treated the spinal cords of BSE-infected cows under various experimental conditions. Prion inactivation was analyzed quantitatively in terms of the infectivity and PrPSc of the treated samples. Following treatment at 140°C for 1 h, infectivity was reduced to 1/35 of that of the untreated samples. Treatment at 180°C for 3 h was required to reduce infectivity. However, PrPSc was detected in all heat-treated samples by using the protein misfolding cyclic amplification (PMCA) technique, which amplifies PrPScin vitro. Quantitative analysis of the inactivation efficiency of BSE PrPSc was possible with the introduction of the PMCA50, which is the dilution ratio of 10% homogenate needed to yield 50% positivity for PrPSc in amplified samples. Log PMCA50 exhibited a strong linear correlation with the transmission rate in the bioassay; infectivity was no longer detected when the log PMCA50 of the inoculated sample was reduced to 1.75. The quantitative PMCA assay may be useful for safety evaluation for recycling and effective utilization of MBMs as an organic resource.

  2. SiC Nanowires Synthesized by Rapidly Heating a Mixture of SiO and Arc-Discharge Plasma Pretreated Carbon Black

    Directory of Open Access Journals (Sweden)

    Wang Feng-Lei


    Full Text Available Abstract SiC nanowires have been synthesized at 1,600 °C by using a simple and low-cost method in a high-frequency induction furnace. The commercial SiO powder and the arc-discharge plasma pretreated carbon black were mixed and used as the source materials. The heating-up and reaction time is less than half an hour. It was found that most of the nanowires have core-shell SiC/SiO2nanostructures. The nucleation, precipitation, and growth processes were discussed in terms of the oxide-assisted cluster-solid mechanism.

  3. SiC Nanowires Synthesized by Rapidly Heating a Mixture of SiO and Arc-Discharge Plasma Pretreated Carbon Black


    Wang Feng-Lei; Zhang Li-Ying; Zhang Ya-Fei


    Abstract SiC nanowires have been synthesized at 1,600 °C by using a simple and low-cost method in a high-frequency induction furnace. The commercial SiO powder and the arc-discharge plasma pretreated carbon black were mixed and used as the source materials. The heating-up and reaction time is less than half an hour. It was found that most of the nanowires have core-shell SiC/SiO2nanostructures. The nucleation, precipitation, and growth processes were discussed in terms of the oxide-assis...

  4. Grain Growth in Nanocrystalline Mg-Al Thin Films (United States)

    Kruska, Karen; Rohatgi, Aashish; Vemuri, Rama S.; Kovarik, Libor; Moser, Trevor H.; Evans, James E.; Browning, Nigel D.


    An improved understanding of grain growth kinetics in nanocrystalline materials, and in metals and alloys in general, is of continuing interest to the scientific community. In this study, Mg-Al thin films containing 10 wt pct Al and with 14.5 nm average grain size were produced by magnetron sputtering and subjected to heat treatments. The grain growth evolution in the early stages of heat treatment at 423 K, 473 K, and 573 K (150 °C, 200 °C, and 300 °C) was observed with transmission electron microscopy and analyzed based upon the classical equation developed by Burke and Turnbull. The grain growth exponent was found to be 7 ± 2 and the activation energy for grain growth was 31.1 ± 13.4 kJ/mol, the latter being significantly lower than in bulk Mg-Al alloys. The observed grain growth kinetics are explained by the Al supersaturation in the matrix and the pinning effects of the rapidly forming beta precipitates and possibly shallow grain boundary grooves. The low activation energy is attributed to the rapid surface diffusion which is dominant in thin film systems.

  5. Grain Growth in Nanocrystalline Mg-Al Thin Films (United States)

    Kruska, Karen; Rohatgi, Aashish; Vemuri, Rama S.; Kovarik, Libor; Moser, Trevor H.; Evans, James E.; Browning, Nigel D.


    An improved understanding of grain growth kinetics in nanocrystalline materials, and in metals and alloys in general, is of continuing interest to the scientific community. In this study, Mg-Al thin films containing 10 wt pct Al and with 14.5 nm average grain size were produced by magnetron sputtering and subjected to heat treatments. The grain growth evolution in the early stages of heat treatment at 423 K, 473 K, and 573 K (150 °C, 200 °C, and 300 °C) was observed with transmission electron microscopy and analyzed based upon the classical equation developed by Burke and Turnbull. The grain growth exponent was found to be 7 ± 2 and the activation energy for grain growth was 31.1 ± 13.4 kJ/mol, the latter being significantly lower than in bulk Mg-Al alloys. The observed grain growth kinetics are explained by the Al supersaturation in the matrix and the pinning effects of the rapidly forming beta precipitates and possibly shallow grain boundary grooves. The low activation energy is attributed to the rapid surface diffusion which is dominant in thin film systems.

  6. Grain Growth in Nanocrystalline Mg-Al Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Kruska, Karen; Rohatgi, Aashish; Vemuri, Rama S.; Kovarik, Libor; Moser, Trevor H.; Evans, James E.; Browning, Nigel D.


    An improved understanding of grain growth kinetics in nanocrystalline materials, and in metals and alloys in general, is of continuing interest to the scientific community. In this study, Mg - Al thin films containing ~10 wt.% Al and with 14.5 nm average grain size were produced by magnetron-sputtering and subjected to heat-treatments. The grain growth evolution in the early stages of heat treatment at 423 K (150 °C), 473 K (200 °C) and 573K (300 °C) was observed with transmission electron microscopy and analyzed based upon the classical equation developed by Burke and Turnbull. The grain growth exponent was found to be 7±2 and the activation energy for grain growth was 31.1±13.4 kJ/mol, the latter being significantly lower than in bulk Mg-Al alloys. The observed grain growth kinetics are explained by the Al supersaturation in the matrix and the pinning effects of the rapidly forming beta precipitates and possibly shallow grain boundary grooves. The low activation energy is attributed to the rapid surface diffusion which is dominant in thin film systems.

  7. Growth and characterization of PNZST thin films

    Energy Technology Data Exchange (ETDEWEB)

    Zhai Jiwei; Li, X.; Yao, Y.; Chen, Haydn


    We have grown and compared microstructures and dielectric properties of PNZST thin films prepared on two different substrates by sol-gel methods. To ensure a complete single-phase perovskite PNZST thin film, a capping layer of PbO must be added to the top surface of the thin film before final heat treatment. Microstructure characterization was examined with X-ray diffraction, scanning and transmission electron microscopy. Dielectric and antiferroelectric properties were investigated as a function of temperature.

  8. The rapid formation of tin oxide pillared laponite by microwave heating: Characterisation by tin-119 Mössbauer spectroscopy, X-ray photoelectron spectroscopy and nuclear magnetic resonance (United States)

    Berry, Frank J.; Ashcroft, R. Claire; Beevers, Martin S.; Bond, Stephen P.; Gelders, Andrew; Lawrence, Monique A. M.; McWhinnie, William R.


    The intercalation of organotin-compounds into laponite and the formation of tin(IV) oxide pillars is rapidly achieved when performed in a microwave oven.119Sn Mössbauer- and x-ray- photoelectron-spectroscopy suggest that Ph3SnCl and Ph2SnCl2 undergo hydrolysis on the surface once sorbed. The treatment of Ph3SnCl/laponite with microwave radiation also induces the formation of a metallic phase which contains both tin and magnesium.

  9. High heating rate decomposition dynamics of copper oxide by nanocalorimetry-coupled time-of-flight mass spectrometry (United States)

    Yi, Feng; DeLisio, Jeffery B.; Nguyen, Nam; Zachariah, Michael R.; LaVan, David A.


    The thermodynamics and evolved gases were measured during the rapid decomposition of copper oxide (CuO) thin film at rates exceeding 100,000 K/s. CuO decomposes to release oxygen when heated and serves as an oxidizer in reactive composites and chemical looping combustion. Other instruments have shown either one or two decomposition steps during heating. We have confirmed that CuO decomposes by two steps at both slower and higher heating rates. The decomposition path influences the reaction course in reactive Al/CuO/Al composites, and full understanding is important in designing reactive mixtures and other new reactive materials.

  10. Interaction between fast ions and ion cyclotron heating in a tokamak plasma; Interaction des ions rapides avec les ondes a la frequence cyclotronique ionique dans un plasma de tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Bergeaud, V


    In an ignited fusion reactor, the plasma temperature is sustained by the fusion reactions. However, before this regime is reached, it is necessary to bring an additional power to the plasma. One of the methods that enables the coupling of power is the use of an electromagnetic wave in the ion cyclotron range of frequencies (ICRF). This thesis deals with the interaction between ICRF heating and the fast ions. The thesis contains a theoretical study of the influence of ICRF heating on the ion distribution function. A particular emphasis is put on the importance of the toroidal spectrum of the modes of propagation of the wave in the tokamak. It is necessary to take into account all these modes in order to correctly assess the strength of the wave particle interaction, especially for high energy particles (of the order of hundreds of keV). The classical treatment of the wave particle interaction is based on the hypothesis that the cyclotron phase of the particle and the wave phase are de-correlated between successive resonant interactions. One is therefore led to consider ICRF heating as a diffusive process. This hypothesis is reconsidered in this thesis and it is shown that strong correlations exist in a large part of the velocity space. For this study, a numerical code that computes the full trajectory of particles interacting with a complete electromagnetic field has been developed. The thesis also deals with the problem of fast ion losses due to the breaking of the toroidal symmetry of the confinement magnetic field (called the ripple modulation). Between two toroidal coils, local magnetic wells exist, and particles can be trapped there. When trapped they undergo a vertical drift that makes them quit the plasma rapidly. The ripple modulation also causes an enhancement of the radial diffusion, thereby increasing the losses. A Monte Carlo model describing these mechanisms is presented. This model is validated thanks to a comparison with an experimental database from

  11. Frequency-dependent heat capacity

    DEFF Research Database (Denmark)

    Behrens, Claus Flensted

    The frequency–dependent heat capacity of super-cooled glycerol near the glass transition is measured using the 3w detection technique. An electrical conducting thin film with a temperature–dependent electrical resistance is deposited on a substrate. The thin film is used simultaneously as a heater...

  12. A Solution Processable High-Performance Thermoelectric Copper Selenide Thin Film. (United States)

    Lin, Zhaoyang; Hollar, Courtney; Kang, Joon Sang; Yin, Anxiang; Wang, Yiliu; Shiu, Hui-Ying; Huang, Yu; Hu, Yongjie; Zhang, Yanliang; Duan, Xiangfeng


    A solid-state thermoelectric device is attractive for diverse technological areas such as cooling, power generation and waste heat recovery with unique advantages of quiet operation, zero hazardous emissions, and long lifetime. With the rapid growth of flexible electronics and miniature sensors, the low-cost flexible thermoelectric energy harvester is highly desired as a potential power supply. Herein, a flexible thermoelectric copper selenide (Cu2 Se) thin film, consisting of earth-abundant elements, is reported. The thin film is fabricated by a low-cost and scalable spin coating process using ink solution with a truly soluble precursor. The Cu2 Se thin film exhibits a power factor of 0.62 mW/(m K2 ) at 684 K on rigid Al2 O3 substrate and 0.46 mW/(m K2 ) at 664 K on flexible polyimide substrate, which is much higher than the values obtained from other solution processed Cu2 Se thin films (films to date (≈0.5 mW/(m K2 )). Additionally, the fabricated thin film shows great promise to be integrated with the flexible electronic devices, with negligible performance change after 1000 bending cycles. Together, the study demonstrates a low-cost and scalable pathway to high-performance flexible thin film thermoelectric devices from relatively earth-abundant elements. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Baking process of thin plate carbonaceous compact

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Yoshio; Shimada, Toyokazu


    As a production process of a thin plate carbonaceous compact for separator of phosphoric acid fuel cell, there is a process to knead carbonaceous powder and thermosetting resin solution, to form and harden the kneaded material and then to bake, carbonize and graphitize it. However in this baking and carbonization treatment, many thin plate compacts are set in a compiled manner within a heating furnace and receive a heat treatment from their circumference. Since the above compacts to be heated tend generally to be heated from their peripheries, their baked conditions are not homogeneous easily causing the formation of cracks, etc.. As a process to heat and bake homogeneously by removing the above problematical points, this invention offers a process to set in a heating furnace a laminate consisting of the lamination of thin plate carbonaceous compacts and the heat resistant soaking plates which hold the upper and lower ends of the above lamination, to fill the upper and under peripheries of the laminate above with high heat conductive packing material and its side periphery with low heat conductive packing material respectively and to heat and sinter it. In addition, the invention specifies the high and low heat conductive packing materials respectively. (1 fig, 2 tabs)

  14. Potential polymer concrete heat exchanger tubes for corrosive environments

    Energy Technology Data Exchange (ETDEWEB)

    Fontana, J.J.; Reams, W.; Cheng, H.C.


    It has long been known that carbon steel exposed to some geothermal brines is aggressively attacked, and large corrosion allowances must be made in the design of piping used in such environments. In addition, scaling of the pipes reduces the flow through within a short period of time. Several high temperature polymer concretes have been developed which can be used as non-corrosive liner materials. In addition, polymer concretes with high thermal conductivities have been developed which may be used as heat exchanger tubes for geothermal brines. Studies have indicated that polymer concretes will not scale as rapidly as carbon steel does, thus making them attractive alternatives for heat exchanger tubes. Thin walled, thermally conductive polymer concrete tubes have been made that can withstand pressures >4.1 MPa at 150/sup 0/C without leaking. Continuing studies are being made to characterize these materials and evaluate them for heat exchanger applications.

  15. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... weak pulse; rapid, shallow breathing; vomiting; and increased body temperature of more than 104 degrees. People with ... nausea, loss of consciousness, vomiting or a high body temperature. For late stage heat stroke symptoms, cool ...

  16. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... pulse; rapid, shallow breathing; vomiting; and increased body temperature of more than 104 degrees. People with these ... loss of consciousness, vomiting or a high body temperature. For late stage heat stroke symptoms, cool the ...

  17. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... skin; headache; dizziness; weakness; feeling exhausted; heavy sweating; nausea; and giddiness. Symptoms of heat stroke (late stage ... skin, rapid pulse, elevated or lowered blood pressure, nausea, loss of consciousness, vomiting or a high body ...

  18. Rapid freeze-drying cycle optimization using computer programs developed based on heat and mass transfer models and facilitated by tunable diode laser absorption spectroscopy (TDLAS). (United States)

    Kuu, Wei Y; Nail, Steven L


    Computer programs in FORTRAN were developed to rapidly determine the optimal shelf temperature, T(f), and chamber pressure, P(c), to achieve the shortest primary drying time. The constraint for the optimization is to ensure that the product temperature profile, T(b), is below the target temperature, T(target). Five percent mannitol was chosen as the model formulation. After obtaining the optimal sets of T(f) and P(c), each cycle was assigned with a cycle rank number in terms of the length of drying time. Further optimization was achieved by dividing the drying time into a series of ramping steps for T(f), in a cascading manner (termed the cascading T(f) cycle), to further shorten the cycle time. For the purpose of demonstrating the validity of the optimized T(f) and P(c), four cycles with different predicted lengths of drying time, along with the cascading T(f) cycle, were chosen for experimental cycle runs. Tunable diode laser absorption spectroscopy (TDLAS) was used to continuously measure the sublimation rate. As predicted, maximum product temperatures were controlled slightly below the target temperature of -25 degrees C, and the cascading T(f)-ramping cycle is the most efficient cycle design. In addition, the experimental cycle rank order closely matches with that determined by modeling.

  19. Rapid Sintering of Silica Xerogel Ceramic Derived from Sago Waste Ash Using Sub-millimeter Wave Heating with a 300 GHz CW Gyrotron (United States)

    Aripin, Haji; Mitsudo, Seitaro; Sudiana, I. Nyoman; Tani, Shinji; Sako, Katsuhide; Fujii, Yutaka; Saito, Teruo; Idehara, Toshitaka; Sabchevski, Sliven


    In this paper, we present and discuss experimental results from a microwave sintering of a silica-glass ceramic, produced from a silica xerogel extracted from a sago waste ash. As a radiation source for the microwave heating a sub-millimeter wave gyrotron (Gyrotron FU CW I) with an output frequency of 300 GHz has been used. The powders of silica xerogel have been dry pressed and then sintered at temperatures ranging from 300°C to 1500°C. The influence of the sintering temperature on the technological properties such as porosity and bulk density was studied in detail. Furthermore, X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) spectroscopy have been used in order to study the structure of the produced silica glass-ceramics. It has been found that the silica xerogel crystallizes at a temperature of 800°C, which is about 200°C lower than the one observed in the conventional process. The silica xerogel samples sintered by their irradiation with a sub-millimeter wave at 900°C for 18 minutes are fully crystallized into a silica glass-ceramic with a density of about 2.2 g/cm3 and cristobalite as a major crystalline phase. The results obtained in this study allow one to conclude that the microwave sintering with sub-millimeter waves is an appropriate technological process for production of silica glass-ceramics from a silica xerogel and is characterized with such advantages as shorter times of the thermal cycle, lower sintering temperatures and higher quality of the final product.

  20. Rapid total sulphur reduction in coal samples using various dilute alkaline leaching reagents under microwave heating: preventing sulphur emissions during coal processing. (United States)

    Mketo, Nomvano; Nomngongo, Philiswa Nosizo; Ngila, Jane Catherine


    Currently in South Africa, online flue gas desulphurisation (FGD) is being utilized as one of the most effective methods for total sulphur reduction in coal samples during the combustion process. However, the main disadvantage associated with FGD is the formation of its by-products (FGD gypsum). The latter is mostly formed in low grade quality, thereby bringing secondary pollution problems and extra disposal costs. Therefore, the current study describes the development of total sulphur extraction in coal under microwave heating using different dilute alkaline solutions such as NaOH, NaOH-H2O2, NH4OH, and NH4OH-H2O2. The experimental conditions were as follows: 150 °C, 5 min and 10% (m/v or v/v) for temperature, extraction time and reagent concentration, respectively. The most effective alkaline reagent for coal desulphurisation was observed to be NaOH-H2O2 with total sulphur reduction of 55% (from the inductively coupled plasma-optical emission spectrometry (ICP-OES) results). The NaOH-H2O2 reagent also showed significant morphological changes in coal as observed from the SEM images and effective demineralisation as revealed by the powder X-ray diffractometer (P-XRD) results. Additionally, desulphurisation results obtained from the developed microwave-assisted dilute alkaline extraction (MW-ADAE) method were quite comparable with the published work. The proposed total sulphur reduction method is advantageous as compared to some of the literature reported coal desulphurisation methods as it requires a short period (5 min) of time to reach its completion. Additionally, the proposed method shows excellent reproducibility (% RSD from 0.5 to 1); therefore, it can be utilized for routine analysis. Graphical abstract ᅟ.

  1. "E" Heating Head (United States)

    Fox, Robert L.; Swaim, Robert J.; Johnson, Samuel D.; Coultrip, Robert H.; Phillips, W. Morris; Copeland, Carl E.


    Two separate areas heated inductively for adhesive bonding in single operation. "E" heating head developed to satisfy need for fast-acting and reliable induction heating device. Used in attaching "high-hat" stiffeners to aircraft panels. Incorporates principles and circuitry of toroid joining gun. Width and length configured to provide variously sized heat zones, depending on bonding requirements. Lightweight, portable and provides rapid, reliable heating of dual areas in any environment. Well suited for flight-line and depot maintenance, and battlefield repair. Also useful in automotive assembly lines to strengthen automobile panels.

  2. Rapid determination of vial heat transfer parameters using tunable diode laser absorption spectroscopy (TDLAS) in response to step-changes in pressure set-point during freeze-drying. (United States)

    Kuu, Wei Y; Nail, Steven L; Sacha, Gregory


    The purpose of this study was to perform a rapid determination of vial heat transfer parameters, that is, the contact parameter K(cs) and the separation distance l(v), using the sublimation rate profiles measured by tunable diode laser absorption spectroscopy (TDLAS). In this study, each size of vial was filled with pure water followed by a freeze-drying cycle using a LyoStar II dryer (FTS Systems) with step-changes of the chamber pressure set-point at to 25, 50, 100, 200, 300, and 400 mTorr. K(cs) was independently determined by nonlinear parameter estimation using the sublimation rates measured at the pressure set-point of 25 mTorr. After obtaining K(cs), the l(v) value for each vial size was determined by nonlinear parameter estimation using the pooled sublimation rate profiles obtained at 25 to 400 mTorr. The vial heat transfer coefficient K(v), as a function of the chamber pressure, was readily calculated, using the obtained K(cs) and l(v) values. It is interesting to note the significant difference in K(v) of two similar types of 10 mL Schott tubing vials, primary due to the geometry of the vial-bottom, as demonstrated by the images of the contact areas of the vial-bottom. (c) 2008 Wiley-Liss, Inc. and the American Pharmacists Association

  3. Thin book

    DEFF Research Database (Denmark)

    En lille bog om teater og organisationer, med bidrag fra 19 teoretikere og praktikere, der deltog i en "Thin Book Summit" i Danmark i 2005. Bogen bidrager med en state-of-the-art antologi om forskellige former for samarbejde imellem teater og organisationer. Bogen fokuserer både på muligheder og...

  4. Evaluation of capillary and myofiber density in the pectoralis major muscles of rapidly growing, high-yield broiler chickens during increased heat stress. (United States)

    Joiner, K S; Hamlin, G A; Lien, A R J; Bilgili, S F


    Skeletal muscle development proceeds from early embryogenesis through marketing age in broiler chickens. While myofiber formation is essentially complete at hatching, myofiber hypertrophy can increase after hatch by assimilation of satellite cell nuclei into myofibers. As the diameter of the myofibers increases, capillary density peripheral to the myofiber is marginalized, limiting oxygen supply and subsequent diffusion into the myofiber, inducing microischemia. The superficial and deep pectoralis muscles constitute 25% of the total body weight in a market-age bird; thus compromise of those muscle groups can have profound economic impact on broiler production. We hypothesized that marginal capillary support relative to the hypertrophic myofibers increases the incidence of microischemia, especially in contemporary high-yield broilers under stressing conditions such as high environmental temperatures. We evaluated the following parameters in four different broiler strains at 39 and 53 days of age when reared under thermoneutral (20 to 25 C) versus hot (30 to 35 C) environmental conditions: capillary density, myofiber density and diameter, and degree of myodegeneration. Our data demonstrate that myofiber diameter significantly increased with age (P > or = 0.0001), while the absolute numbers of capillaries, blood vessels, and myofibers visible in five 400 x microscopic fields decreased (P > or = 0.0001). This is concomitant with marginalization of vascular support in rapidly growing myofibers. The myofiber diameter was significantly lower with hot environmental temperatures (P > or = 0.001); therefore, the absolute number of myofibers visible in five 400X microscopic fields was significantly higher. The incidence and subjective degree of myodegeneration characterized by loss of cross-striations, myocyte hyperrefractility, sarcoplasmic vacuolation, and nuclear pyknosis or loss also increased in hot conditions. Differences among strains were not observed.

  5. Microwave-assisted synthesis of TiO2 nanoparticles: photocatalytic activity of powders and thin films (United States)

    Falk, G. S.; Borlaf, M.; López-Muñoz, M. J.; Fariñas, J. C.; Rodrigues Neto, J. B.; Moreno, R.


    A simple, rapid, and effective synthesis methodology for the preparation of high-performance TiO2 nanoparticles and thin films by combining colloidal sol-gel and microwave-assisted hydrothermal synthesis was developed. The obtained results indicate that the heating with microwaves at 180 °C for 20 min was enough to synthesize crystalline TiO2 nanoparticles, presenting anatase as a major phase with a crystal size of 7 nm and a specific surface area of 220 m2 g-1. A secondary thermal treatment improved the crystallinity and induced the anatase-to-rutile transformation. The highest photocatalytic activity was found for the as-synthesized powder without any additional thermal treatment. Thin films were also prepared by dip-coating and its high photocatalytic activity showed a kinetic curve comparable to that of a thin film of commercial TiO2 powder prepared under similar conditions.

  6. Asymmetric gold nanoparticle reduction into polydimethylsiloxane thin films (United States)

    Dunklin, Jeremy R.; Forcherio, Gregory T.; Berry, Keith R.; Roper, D. Keith


    Polymer thin films embedded with plasmonic gold nanoparticles (AuNPs) are of significant interest in biomedicine, optics, photovoltaic, and nanoelectromechanical systems. Thin polydimethylsiloxane (PDMS) films containing 3-7 micron layers of AuNPs that were fabricated with a novel diffusive-reduction synthesis technique attenuated up to 85% of incoming laser light at the plasmon resonance. Rapid diffusive reduction of AuNPs into asymmetric PDMS thin films provided superior optothermal capabilities relative to thicker films in which AuNPs were reduced throughout. A photonto- heat conversion of up to 3000°C/watt was demonstrated, which represents a 3-230-fold increase over previous AuNPfunctionalized systems. Optical attenuation and thermal response increased in proportion to order of magnitude increases in tetrachloroaurate (TCA) solution concentration. Optical and thermoplasmonic responses were observed with and without an adjacent mesh support, which increased attenuation but decreased thermal response. Morphological, optical, and thermoplasmonic properties of asymmetric AuNP-PDMS films varied significantly with diffusive TCA concentration. Gold nanoparticles, networks, and conglomerates were formed via reduction as the amount of dissolved TCA increased across a log10-scale. Increasing TCA concentrations caused polymer surface cratering, leading to a larger effective surface area. This method, utilizing the diffusion of TCA into a single exposed partially cured PDMS interface, could be used to replace expensive lithographic or solution synthesis of plasmon-functionalized systems.

  7. Polycrystalline-thin-film thermophotovoltaic cells (United States)

    Dhere, Neelkanth G.


    Thermophotovoltaic (TPV) cells convert thermal energy to electricity. Modularity, portability, silent operation, absence of moving parts, reduced air pollution, rapid start-up, high power densities, potentially high conversion efficiencies, choice of a wide range of heat sources employing fossil fuels, biomass, and even solar radiation are key advantages of TPV cells in comparison with fuel cells, thermionic and thermoelectric convertors, and heat engines. The potential applications of TPV systems include: remote electricity supplies, transportation, co-generation, electric-grid independent appliances, and space, aerospace, and military power applications. The range of bandgaps for achieving high conversion efficiencies using low temperature (1000-2000 K) black-body or selective radiators is in the 0.5-0.75 eV range. Present high efficiency convertors are based on single crystalline materials such as In1-xGaxAs, GaSb, and Ga1-xInxSb. Several polycrystalline thin films such as Hg1-xCdxTe, Sn1-xCd2xTe2, and Pb1-xCdxTe, etc., have great potential for economic large-scale applications. A small fraction of the high concentration of charge carriers generated at high fluences effectively saturates the large density of defects in polycrystalline thin films. Photovoltaic conversion efficiencies of polycrystalline thin films and PV solar cells are comparable to single crystalline Si solar cells, e.g., 17.1% for CuIn1-xGaxSe2 and 15.8% for CdTe. The best recombination-state density Nt is in the range of 10-15-10-16 cm-3 acceptable for TPV applications. Higher efficiencies may be achieved because of the higher fluences, possibility of bandgap tailoring, and use of selective emitters such as rare earth oxides (erbia, holmia, yttria) and rare earth-yttrium aluminium garnets. As compared to higher bandgap semiconductors such as CdTe, it is easier to dope the lower bandgap semiconductors. TPV cell development can benefit from the more mature PV solar cell and opto

  8. Apparatus for the rapid electrolytic preparation of thin metal foils for transmission electron microscopy; Dispositif de polissage electrolytique pour la preparation d'echantillons pour la microscopie electronique par transmission

    Energy Technology Data Exchange (ETDEWEB)

    Le Coadic, Y.; Bourret, A. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires


    By thinning and perforating electrolytically 3 mm discs (the usual diameter of electron microscope holders) 100 {mu} to 200 {mu} thick, we prepare foils of iron and nickel of acceptable quality, i.e. containing enough thin areas to permit transmission electron microscope observations. Previous theories of electrolytic polishing are presented. We then study an electrolytic jet thinning technique in which two jets of electrolyte impinge onto the specimen, the entire system being immersed in a bath of the same electrolyte (electrolyte jet - in - electrolyte). A brief description is given of the construction and use of the apparatus. The basic technique can be modified for specialized applications, namely thicker and other materials (alloys, stainless steels, uranium carbide, copper,...) and low temperature electrolytic thinning. (authors) [French] Partant de pastilles de fer ou de nickel de 3 mm de diametre (diametre usuel des porte-echantillons de microscope electronique) et d'epaisseur comprise entre 100 et 200 {mu} nous obtenons par polissage et percage electrolytique des aires d'epaisseur convenable quant a leur utilisation en microscopie electronique. Apres un rappel des mecanismes du polissage electrolytique, nous etudions le polissage electrolytique par jets d'electrolyte dans l'electrolyte lui-meme, dans lequel 2 jets d'electrolyte aboutissent normalement aux 2 faces de la pastille, l'ensemble etant immerge dans un bain du meme electrolyte. La realisation et l'experimentation sont ensuite decrites de facon succincte. Nous concluons en evoquant les possibilites d'extension du champ des applications du dispositif a des materiaux autres (alliages, aciers, carbure d'uranium, cuivre,...) et d'epaisseur plus importante et au domaine des basses temperatures. (auteurs)

  9. Heat transfer of a non-Newtonian fluid (Carbopol aqueous solution) in transitional pipe flow

    Energy Technology Data Exchange (ETDEWEB)

    Peixinho, J.; Desaubry, C.; Lebouche, M. [LEMTA - Laboratoire d' Energetique et de Mecanique Theorique et Appliquee, 2 Avenue de la foret de Haye, BP 160, 54 504 Vandoeuvre-les-Nancy (France)


    An experimental study of the forced convection heat transfer for non-Newtonian fluid flow in a pipe is presented. We focus particularly on the transitional regime. A wall boundary heating condition of heat flux is imposed. The non-Newtonian fluid used is Carbopol (polyacrylic acid) aqueous solutions. Detailed rheology as well as the variation of the rheological parameters with temperature are reported. Newtonian and shear thinning fluids are also tested for comparative purposes. The characterization of the flow and the thermal convection is made via the pressure drop and the wall temperature measurements over a range of Reynolds number from laminar to turbulent regime. Our measurements show that the non-Newtonian character stabilizes the flow, i.e., the critical Reynolds number to transitional flow increases with shear thinning and yield stress. The heat transfer coefficients are given and compared with heat transfer laws for different regime flows. Details when the heat transfer coefficient loses rapidly its local dependence on the Reynolds number are analyzed. (author)

  10. Rapid Thawing and Heating of Foods (United States)


    Agriculture ATTN: Dr. Sam R. Hoover Washington, D.C. 20250 Dr. I.A. Wolff, Director Eastern Marketing & Nutrition Research Division Agricultural Research...Service U.S. Department of Agriculture Wyndmoor, Pennsylvania 19118 Dr. C. H. Harry Neufeld, Director Southeastern Marketing & Nutrition ...20230 3 - Exchange & Gift Division Library of Congress Washington, D.C. 205^0 1 - Subsistence & Culinary Arts Department U.S. Army QM School Ft

  11. Heat Islands (United States)

    EPA's Heat Island Effect Site provides information on heat islands, their impacts, mitigation strategies, related research, a directory of heat island reduction initiatives in U.S. communities, and EPA's Heat Island Reduction Program.

  12. Heat Waves (United States)

    Heat Waves Dangers we face during periods of very high temperatures include: Heat cramps: These are muscular pains and ... having trouble with the heat. If a heat wave is predicted or happening… - Slow down. Avoid strenuous ...

  13. Rapidly curable electrically conductive clear coatings

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, Mark P.; Anderson, Lawrence G.; Post, Gordon L.


    Rapidly curable electrically conductive clear coatings are applied to substrates. The electrically conductive clear coating includes to clear layer having a resinous binder with ultrafine non-stoichiometric tungsten oxide particles dispersed therein. The clear coating may be rapidly cured by subjecting the coating to infrared radiation that heats the tungsten oxide particles and surrounding resinous binder. Localized heating increases the temperature of the coating to thereby thermally cure the coating, while avoiding unwanted heating of the underlying substrate.

  14. Thin-Layer Solutions of the Helmholtz and Related Equations

    KAUST Repository

    Ockendon, J. R.


    This paper concerns a certain class of two-dimensional solutions to four generic partial differential equations-the Helmholtz, modified Helmholtz, and convection-diffusion equations, and the heat conduction equation in the frequency domain-and the connections between these equations for this particular class of solutions.S pecifically, we consider thin-layer solutions, valid in narrow regions across which there is rapid variation, in the singularly perturbed limit as the coefficient of the Laplacian tends to zero.F or the wellstudied Helmholtz equation, this is the high-frequency limit and the solutions in question underpin the conventional ray theory/WKB approach in that they provide descriptions valid in some of the regions where these classical techniques fail.E xamples are caustics, shadow boundaries, whispering gallery, and creeping waves and focusing and bouncing ball modes.It transpires that virtually all such thin-layer models reduce to a class of generalized parabolic wave equations, of which the heat conduction equation is a special case. Moreover, in most situations, we will find that the appropriate parabolic wave equation solutions can be derived as limits of exact solutions of the Helmholtz equation.W e also show how reasonably well-understood thin-layer phenomena associated with any one of the four generic equations may translate into less well-known effects associated with the others.In addition, our considerations also shed some light on the relationship between the methods of matched asymptotic, WKB, and multiple-scales expansions. © 2012 Society for Industrial and Applied Mathematics.


    Directory of Open Access Journals (Sweden)

    Afshin Kheidari Monfared


    Full Text Available Welding is a crucial manufacturing process and widely used for manufacturing various products including ships, automobiles, trains and bridges. Welding distortions often occur in welded structures of thin plates due to relatively low stiffness and result in their warpage during assembly process and high manufacturing cost. Therefore, prediction and reduction of welding distortions are important in order to improve quality of welded structures. Welding distortion during the assembly process is caused not only by local shrinkage due to rapid heating and cooling. 3-D thermo-elastic-plastic finite element method (FEM has been used to simulate single-bead-on-plate welding with 1 mm thickness. Experiments have been carried out to prove the simulated results. Comparison of the experimental results and FEM simulation results has confirmed that the proposed method efficiently  predicts level of  welding distortions while making single-bead-on-plate welding with 1 mm thickness.

  16. Laser thermoreflectance for semiconductor thin films metrology (United States)

    Gailly, P.; Hastanin, J.; Duterte, C.; Hernandez, Y.; Lecourt, J.-B.; Kupisiewicz, A.; Martin, P.-E.; Fleury-Frenette, K.


    We present a thermoreflectance-based metrology concept applied to compound semiconductor thin films off-line characterization in the solar cells scribing process. The presented thermoreflectance setup has been used to evaluate the thermal diffusivity of thin CdTe films and to measure eventual changes in the thermal properties of 5 μm CdTe films ablated by nano and picosecond laser pulses. The temperature response of the CdTe thin film to the nanosecond heating pulse has been numerically investigated using the finite-difference time-domain (FDTD) method. The computational and experimental results have been compared.

  17. Calcium bromide hydration for heat storage systems


    Ai Niwa; Noriyuki Kobayashi


    A chemical reaction is a common and simple way to produce heat for a heat storage system. The reaction produces heat energy without the use of electricity or fuel. The goal of this study was to develop a heat storage system for use in automobiles, which is able to provide heat rapidly via a hydration reaction. A heat storage system without an evaporator stores high-density heat and has a high heat output rate since the solid–liquid product that is formed is transferred as a heat medium to the...

  18. Getting the Heat Out (United States)


    to 20g  Nanostructured wick for enhanced heat transfer and fluid transport  Structural, flexible, thin, & light-weight materials that match the TEC ...Flexible, TEC -matched Casing Nanostructured WickVapor Cavity Approved For Public Release, Distribution Unlimited TJunction A New Thermal Opportunity chip...complements the Thermal Ground Plane (TGP) program. Microtechnologies for Air Cooled Exchangers (MACE) Nano -textured fins to enhance convection surface

  19. Evaluation of the Biofire FilmArray BioThreat-E Test (v2.5) for Rapid Identification of Ebola Virus Disease in Heat-Treated Blood Samples Obtained in Sierra Leone and the United Kingdom. (United States)

    Weller, Simon A; Bailey, Daniel; Matthews, Steven; Lumley, Sarah; Sweed, Angela; Ready, Derren; Eltringham, Gary; Richards, Jade; Vipond, Richard; Lukaszewski, Roman; Payne, Phillippa M; Aarons, Emma; Simpson, Andrew J; Hutley, Emma J; Brooks, Tim


    Rapid Ebola virus (EBOV) detection is crucial for appropriate patient management and care. The performance of the FilmArray BioThreat-E test (v2.5) using whole-blood samples was evaluated in Sierra Leone and the United Kingdom and was compared with results generated by a real-time Ebola Zaire PCR reference method. Samples were tested in diagnostic laboratories upon availability, included successive samples from individual patients, and were heat treated to facilitate EBOV inactivation prior to PCR. The BioThreat-E test had a sensitivity of 84% (confidence interval [CI], 64% to 95%) and a specificity of 89% (CI, 73% to 97%) in Sierra Leone (n = 60; 44 patients) and a sensitivity of 75% (CI, 19% to 99%) and a specificity of 100% (CI, 97% to 100%) in the United Kingdom (n = 108; 70 patients) compared to the reference real-time PCR. Statistical analysis (Fisher's exact test) indicated there was no significant difference between the methods at the 99% confidence level in either country. In 9 discrepant results (5 real-time PCR positives and BioThreat-E test negatives and 4 real-time PCR negatives and BioThreat-E test positives), the majority (n = 8) were obtained from samples with an observed or probable low viral load. The FilmArray BioThreat-E test (v2.5) therefore provides an attractive option for laboratories (either in austere field settings or in countries with an advanced technological infrastructure) which do not routinely offer an EBOV diagnostic capability. © Crown copyright 2015.

  20. Numerical Modelling of Indution Heating - Fundamentals

    DEFF Research Database (Denmark)

    Zhang, Wenqi

    Induction heating is extensively used for brazing and heat treatment of materials to produce consumer and industrial products; structural assemblies; electrical and electronic products; mining, machine, and hand tools; ordnance equipment; and aerospace assemblies. It is often applied when rapid...

  1. Microscale and nanoscale heat transfer fundamentals and engineering applications

    CERN Document Server

    Sobhan, CB


    Preface Introduction to Microscale Heat Transfer Microscale Heat Transfer: A Recent Avenue in Energy Transport State of the Art: Some Introductory Remarks Overview of Microscale Transport Phenomena Discussions on Size-Effect Behavior Fundamental Approach for Microscale Heat Transfer Introduction to Engineering Applications of Microscale Heat Transfer Microscale Heat Conduction Review of Conduction Heat Transfer Conduction at the Microscale Space and Timescales Fundamental Approach Thermal Conductivity Boltzmann Equation and Phonon Transport Conduction in Thin Films

  2. Phase and texture evolution in solution deposited lead zirconate titanate thin films: Formation and role of the Pt3Pb intermetallic phase (United States)

    Nittala, Krishna; Mhin, Sungwook; Dunnigan, Katherine M.; Robinson, Douglas S.; Ihlefeld, Jon F.; Kotula, Paul G.; Brennecka, Geoff L.; Jones, Jacob L.


    Solution deposition is widely used for the fabrication of lead zirconate titanate (PZT) thin films on platinized silicon substrates. However, phase and texture evolution during the crystallization process is not well understood, particularly due to the difficulty in tracking changes in the thin films in situ during heating. In this work, we characterized phase and texture evolution in situ during heating and crystallization of PZT thin films using high-energy X-ray diffraction. Films were pyrolyzed at either 300 °C or 400 °C and heated at various rates between 0.5 °C/s and ˜150 °C/s. For films that were pyrolyzed at 300 °C, the most rapid heating rates first induced strong intensities from a transient Pt3Pb phase. The Pt3Pb phase inherited the texture of the pre-existing platinum layer. Combined with other observations, the results suggest the conversion of the platinum to the intermetallic phase near the interface due to the interdiffusion of lead. In all experimental variations, the pyrochlore phase was observed to form concurrently with the disappearance of the Pt3Pb phase after which the perovskite phase ultimately crystallized. For films that were pyrolyzed at 400 °C, the Pt3Pb phase was not observed at any of the heating rates; instead, the pyrochlore phase was first observed, followed by the perovskite phase. Independent of the pyrolysis temperature or observation of Pt3Pb, a 111-dominant crystallographic texture formed in the perovskite phase when crystallized using fast heating rates. These results demonstrate that 111 textures in solution-derived PZT thin films are not correlated with the observation of Pt3Pb or other intermetallic or transient phases.

  3. [Clothing and heat disorder]. (United States)

    Satsumoto, Yayoi


    The influence of the clothing material properties(like water absorbency and rapid dryness, water vapor absorption, water vapor permeability and air permeability) and the design factor of the clothing(like opening condition and fitting of clothing), which contributed to prevent heat disorder, was outlined. WBGT(wet-bulb globe temperature) is used to show a guideline for environmental limitation of activities to prevent heat disorder. As the safety function is more important than thermal comfort for some sportswear and protective clothing with high cover area, clothing itself increases the risk of heat disorder. WBGT is corrected by CAF (clothing adjustment factor) in wearing such kind of protective clothing.

  4. Heat Stress (United States)

    ... Publications and Products Programs Contact NIOSH NIOSH HEAT STRESS Recommend on Facebook Tweet Share Compartir NEW OSHA- ... hot environments may be at risk of heat stress. Exposure to extreme heat can result in occupational ...

  5. Implementation of 350-2500 nm diffuse reflectance spectroscopy and High-Performance Thin-Layer Chromatography to rapidly assess manufacturing consistency and quality of cotrimoxazole tablets in Tanzania. (United States)

    Kaale, Eliangiringa; Hope, Samuel M; Jenkins, David; Layloff, Thomas


    To assess the quality of cotrimoxazole tablets produced by a Tanzanian manufacturer by a newly instituted quality assurance programme. Tablets underwent a diffuse reflectance spectroscopy procedure with periodic quality assessment confirmation by assay and dissolution testing using validated HPTLC techniques (including weight variation and disintegration evaluations). Based on results from the primary test methods, the first group of product was 99% compliance. This approach provides a model for rapidly assuring product quality of future procurements of other products that is more cost-effective than traditional pharmaceutical testing techniques. © 2015 John Wiley & Sons Ltd.

  6. Formation of an interface layer between Al{sub 1-x}Si{sub x}O{sub y} thin films and the Si substrate during rapid thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Michalowski, Pawel Piotr; Beyer, Volkhard; Czernohorsky, Malte; Kuecher, Peter; Teichert, Steffen [Fraunhofer-Center for Nanoelectronic Technologies, Koenigsbruecker Strasse 180, 01099 Dresden (Germany); Jaschke, Gert [Qimonda Dresden GmbH and Co. OHG, Koenigsbruecker Strasse 180, 01099 Dresden (Germany); Moeller, Wolfhard [Institute of Ion Beam Physics and Materials, Research Forschungszentrum Dresden-Rossendorf, PO Box 51 01 19, 01314 Dresden (Germany)


    Silicon diffusion from the substrate through Al{sub 1-x}Si{sub x}O{sub y} thin films was investigated by ToF-SIMS depth profiling. Two types of substrate stacks were analyzed: Si wafer with either native oxide or with additional silicon nitride layer. The amount of diffused silicon depends strongly on the type of the substrate. The activation energy for pure alumina was found to be 2.27 {+-} 0.02 eV and 3.73 {+-} 0.02 eV for SiO{sub 2}/Si and Si{sub 3}N{sub 4}/SiO{sub 2}/Si samples, respectively. Furthermore it was proved that the activation energy increases with higher concentration of Si for SiO{sub 2}/Si samples whereas it decreases for Si{sub 3}N{sub 4}/SiO{sub 2}/Si. Detailed analysis of SIMS depth profiles provide satisfactory explanation of this phenomenon: SiO{sub 2} has much stronger tendency to react with Al{sub 1-x}Si{sub x}O{sub y} material forming an interface layer that restrain further diffusion of Si from the substrate (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Crystallization and activation of silicon by microwave rapid annealing (United States)

    Kimura, Shunsuke; Ota, Kosuke; Hasumi, Masahiko; Suzuki, Ayuta; Ushijima, Mitsuru; Sameshima, Toshiyuki


    A combination of the carbon-powder absorber with microwave irradiation is proposed as a rapid heat method. 2-μm-diameter carbon powders with a packing density of 0.08 effectively absorbed 2.45 GHz 1000-W-microwave and heated themselves to 1163 °C for 26 s. The present heat treatment recrystallized n-type crystalline silicon surfaces implanted with 1.0 × 10^{15}hbox {-cm}^{-2}-boron and phosphorus atoms with crystalline volume ratios of 0.99 and 0.93, respectively, by microwave irradiation at 1000 W for 20 s. Activation and carrier generation were simultaneously achieved with a sheet resistivity of 62 Ω / hbox {sq}. A high photo-induced-carrier effective lifetime of 1.0 × 10^{-4} s was also achieved. Typical electrical current-rectified characteristic and solar cell characteristic with an efficiency of 12.1 % under 100-mW/cm2-air-mass-1.5 illumination were obtained. Moreover, heat treatment with microwave irradiation at 1000 W for 22 s successfully crystallized silicon thin films with thicknesses ranging from 2.4 to 50 nm formed on quartz substrates. Nano-crystalline cluster structure with a high volume ratio of 50 % was formed in the 1.8-nm (initial 2.4-nm)-thick silicon films. Photoluminescence around 1.77 eV was observed for the 1.8-nm-thick silicon films annealed at 260 °C in 1.3 × 106-Pa-H2O-vapor for 3 h after the microwave heating.

  8. Microplasma deposition of challenging thin films at atmospheric pressure (United States)

    Hopwood, Jeffrey; Thejaswini, H. C.; Plasma Engineering Laboratory Team


    Non-equilibrium microplasmas produce fluxes of ions and excited species to a surface while maintaining the surface near room temperature. At atmospheric pressure, however, it is very difficult to accelerate the highly collisional ions. While many applications do not benefit from energetic interactions between plasma and surface, conventional plasma deposition of thin films often requires either ion bombardment or substrate heating. For example, diamondlike carbon (DLC) is known to require ~ 100 eV ion bombardment and transparent conducting oxides (TCO) typically require substrate temperatures on the order of 400-500 K. A microwave-induced microplasma is used to dissociate dilute precursor molecules within flowing helium. The precursor and plasma species result in rapid deposition of thin films (>1 μm/min). This plasma produces a steady-state ion flux of 6×1017 cm-2s-1, which is more than two orders of magnitude greater than a low pressure capacitively coupled plasma. Likewise, the metastable density is roughly two orders greater. These and other microplasma diagnostics are correlated with the measured film properties of microplasma-deposited DLC and TCO. This study shows that high ion flux, even at low energy (~ 1 eV), can provide the needed surface interactions to produce these materials at room temperature.

  9. Heat pumps

    CERN Document Server

    Macmichael, DBA


    A fully revised and extended account of the design, manufacture and use of heat pumps in both industrial and domestic applications. Topics covered include a detailed description of the various heat pump cycles, the components of a heat pump system - drive, compressor, heat exchangers etc., and the more practical considerations to be taken into account in their selection.

  10. Scraped surface heat exchangers. (United States)

    Rao, Chetan S; Hartel, Richard W


    Scraped surface heat exchangers (SSHEs) are commonly used in the food, chemical, and pharmaceutical industries for heat transfer, crystallization, and other continuous processes. They are ideally suited for products that are viscous, sticky, that contain particulate matter, or that need some degree of crystallization. Since these characteristics describe a vast majority of processed foods, SSHEs are especially suited for pumpable food products. During operation, the product is brought in contact with a heat transfer surface that is rapidly and continuously scraped, thereby exposing the surface to the passage of untreated product. In addition to maintaining high and uniform heat exchange, the scraper blades also provide simultaneous mixing and agitation. Heat exchange for sticky and viscous foods such as heavy salad dressings, margarine, chocolate, peanut butter, fondant, ice cream, and shortenings is possible only by using SSHEs. High heat transfer coefficients are achieved because the boundary layer is continuously replaced by fresh material. Moreover, the product is in contact with the heating surface for only a few seconds and high temperature gradients can be used without the danger of causing undesirable reactions. SSHEs are versatile in the use of heat transfer medium and the various unit operations that can be carried out simultaneously. This article critically reviews the current understanding of the operations and applications of SSHEs.

  11. Electronic modules easily separated from heat sink (United States)


    Metal heat sink and electronic modules bonded to a thermal bridge can be easily cleaved for removal of the modules for replacement or repair. A thin film of grease between a fluorocarbon polymer film on the metal heat sink and an adhesive film on the modules acts as the cleavage plane.

  12. Pre-staining thin layer chromatography method for amino acid ...

    African Journals Online (AJOL)

    The modified thin layer chromatography can be used for the analysis of amino acids. When compared to the classical thin layer chromatography, the improved method was more rapid and inexpensive and the results obtained were clean and reproducible. However, it is suitable for the high throughput screening of amino ...

  13. Rapid Prototyping (United States)


    Javelin, a Lone Peak Engineering Inc. Company has introduced the SteamRoller(TM) System as a commercial product. The system was designed by Javelin during a Phase II NASA funded small commercial product. The purpose of the invention was to allow automated-feed of flexible ceramic tapes to the Laminated Object Manufacturing rapid prototyping equipment. The ceramic material that Javelin was working with during the Phase II project is silicon nitride. This engineered ceramic material is of interest for space-based component.

  14. Determination of crystal growth rates during rapid solidification of polycrystalline aluminum by nano-scale spatio-temporal resolution in situ transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zweiacker, K., E-mail:; Liu, C.; Wiezorek, J. M. K. [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, 648 Benedum Hall, 3700 OHara Street, Pittsburgh, Pennsylvania 15261 (United States); McKeown, J. T.; LaGrange, T.; Reed, B. W.; Campbell, G. H. [Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551 (United States)


    In situ investigations of rapid solidification in polycrystalline Al thin films were conducted using nano-scale spatio-temporal resolution dynamic transmission electron microscopy. Differences in crystal growth rates and asymmetries in melt pool development were observed as the heat extraction geometry was varied by controlling the proximity of the laser-pulse irradiation and the associated induced melt pools to the edge of the transmission electron microscopy support grid, which acts as a large heat sink. Experimental parameters have been established to maximize the reproducibility of the material response to the laser-pulse-related heating and to ensure that observations of the dynamical behavior of the metal are free from artifacts, leading to accurate interpretations and quantifiable measurements with improved precision. Interface migration rate measurements revealed solidification velocities that increased consistently from ∼1.3 m s{sup −1} to ∼2.5 m s{sup −1} during the rapid solidification process of the Al thin films. Under the influence of an additional large heat sink, increased crystal growth rates as high as 3.3 m s{sup −1} have been measured. The in situ experiments also provided evidence for development of a partially melted, two-phase region prior to the onset of rapid solidification facilitated crystal growth. Using the experimental observations and associated measurements as benchmarks, finite-element modeling based calculations of the melt pool evolution after pulsed laser irradiation have been performed to obtain estimates of the temperature evolution in the thin films.

  15. Heat flow study of the Emeishan large igneous province region: Implications for the geodynamics of the Emeishan mantle plume (United States)

    Jiang, Qiang; Qiu, Nansheng; Zhu, Chuanqing


    The Emeishan large igneous province (ELIP) is widely considered to be a consequence of a mantle plume. The supporting evidence includes rapid emplacement, voluminous flood basalt eruptions, and high mantle potential temperature estimates. Several studies have suggested that there was surface uplift prior to the eruption of the Emeishan flood basalts. Additionally, the plume's lateral extent is hard to constrain and has been variously estimated to be 800-1400 km in diameter. In this study, we analyzed present-day heat flow data and reconstructed the Permian paleo-heat flow using vitrinite reflectance and zircon (U-Th)/He thermochronology data in the ELIP region and discussed implications for the geodynamics of the Emeishan mantle plume. The present-day heat flow is higher in the inner and intermediate zones than in the outer zone, with a decrease of average heat flow from 76 mW/m2 to 51 mW/m2. Thermal history modeling results show that an abnormal high paleo-heat flow of 90-110 mW/m2 was caused by the Emeishan mantle plume activity. Based on the present-day heat flow data, we can calculate that there is lithospheric thinning in the central ELIP region, which may be due to the destruction of the lithosphere by mantle plume upwelling and magmatic underplating. The Permian paleo-heat flow anomaly implies that there was a temperature anomaly in the mantle. The ascending high-temperature mantle plume and the thinned lithosphere may have induced the large-scale uplift in the ELIP region. According to the range of the surface heat flow anomaly, it can be estimated that the diameter of the flattened head of the Emeishan mantle plume could have reached 1600-1800 km. Our research provides new insights into the geodynamics of the Emeishan mantle plume through study of heat flow.

  16. Heat pumps

    CERN Document Server

    Brodowicz, Kazimierz; Wyszynski, M L; Wyszynski


    Heat pumps and related technology are in widespread use in industrial processes and installations. This book presents a unified, comprehensive and systematic treatment of the design and operation of both compression and sorption heat pumps. Heat pump thermodynamics, the choice of working fluid and the characteristics of low temperature heat sources and their application to heat pumps are covered in detail.Economic aspects are discussed and the extensive use of the exergy concept in evaluating performance of heat pumps is a unique feature of the book. The thermodynamic and chemical properties o

  17. Effects of rapid thermal annealing on structural, chemical, and electrical characteristics of atomic-layer deposited lanthanum doped zirconium dioxide thin film on 4H-SiC substrate

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Way Foong, E-mail: [Institute of Nano Optoelectronics Research and Technology, School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Centre for Research Initiatives (CRI) Natural Sciences, Universiti Sains Malaysia, 11800 Penang (Malaysia); Quah, Hock Jin, E-mail: [Institute of Nano Optoelectronics Research and Technology, School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Centre for Research Initiatives (CRI) Natural Sciences, Universiti Sains Malaysia, 11800 Penang (Malaysia); Lu, Qifeng, E-mail: [Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ (United Kingdom); Mu, Yifei, E-mail: [Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ (United Kingdom); Ismail, Wan Azli Wan, E-mail: [Advance Analytical Services Lab, MIMOS Wafer Fab, MIMOS Berhad, Technology Park Malaysia, 57000 Kuala Lumpur (Malaysia); Rahim, Bazura Abdul, E-mail: [Advance Analytical Services Lab, MIMOS Wafer Fab, MIMOS Berhad, Technology Park Malaysia, 57000 Kuala Lumpur (Malaysia); Esa, Siti Rahmah, E-mail: [Advance Analytical Services Lab, MIMOS Wafer Fab, MIMOS Berhad, Technology Park Malaysia, 57000 Kuala Lumpur (Malaysia); Kee, Yeh Yee, E-mail: [Advance Analytical Services Lab, MIMOS Wafer Fab, MIMOS Berhad, Technology Park Malaysia, 57000 Kuala Lumpur (Malaysia); Zhao, Ce Zhou, E-mail: [Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ (United Kingdom); Department of Electrical and Electronic Engineering, Xi’an Jiaotong-Liverpool University, Suzhou, Jiangsu 215123 (China); and others


    Graphical abstract: - Highlights: • Studies of RTA temperatures on La doped ZrO2 atomic layer deposited on 4HSiC. • Oxygen vacancies improved insulating and catalytic properties of La doped ZrO2. • 700 °C annealed sample showed the highest EB, k value, and sensitivity on O2. • La doped ZrO2 was proposed as a potential metal reactive oxide on 4H-SiC. - Abstract: Effects of rapid thermal annealing at different temperatures (700–900 °C) on structural, chemical, and electrical characteristics of lanthanum (La) doped zirconium oxide (ZrO{sub 2}) atomic layer deposited on 4H-SiC substrates have been investigated. Chemical composition depth profiling analysis using X-ray photoelectron spectroscopy (XPS) and cross-sectional studies using high resolution transmission electron microscopy equipped with energy dispersive X-ray spectroscopy line scan analysis were insufficient to justify the presence of La in the investigated samples. The minute amount of La present in the bulk oxide was confirmed by chemical depth profiles of time-of-flight secondary ion mass spectrometry. The presence of La in the ZrO{sub 2} lattice led to the formation of oxygen vacancies, which was revealed through binding energy shift for XPS O 1s core level spectra of Zr−O. The highest amount of oxygen vacancies in the sample annealed at 700 °C has yielded the acquisition of the highest electric breakdown field (∼ 6.3 MV/cm) and dielectric constant value (k = 23) as well as the highest current–time (I–t) sensor response towards oxygen gas. The attainment of both the insulating and catalytic properties in the La doped ZrO{sub 2} signified the potential of the doped ZrO{sub 2} as a metal reactive oxide on 4H-SiC substrate.

  18. Boiling heat transfer of refrigerant R-21 in upward flow in plate-fin heat exchanger (United States)

    Kuznetsov, V. V.; Shamirzaev, A. S.


    The article presents the results of experimental investigation of boiling heat transfer of refrigerant R-21 in upward flow in a vertical plate-fin heat exchanger with transverse size of the channels that is smaller than the capillary constant. The heat transfer coefficients obtained in ranges of small mass velocities and low heat fluxes, which are typical of the industry, have been poorly studied yet. The characteristic patterns of the upward liquid-vapor flow in the heat exchanger channels and the regions of their existence are detected. The obtained data show a weak dependence of heat transfer coefficient on equilibrium vapor quality, mass flow rate, and heat flux density and do not correspond to calculations by the known heat transfer models. A possible reason for this behavior is a decisive influence of evaporation of thin liquid films on the heat transfer at low heat flux.

  19. Feasibility Study of Thin Film Thermocouple Piles (United States)

    Sisk, R. C.


    Historically, thermopile detectors, generators, and refrigerators based on bulk materials have been used to measure temperature, generate power for spacecraft, and cool sensors for scientific investigations. New potential uses of small, low-power, thin film thermopiles are in the area of microelectromechanical systems since power requirements decrease as electrical and mechanical machines shrink in size. In this research activity, thin film thermopile devices are fabricated utilizing radio frequency sputter coating and photoresist lift-off techniques. Electrical characterizations are performed on two designs in order to investigate the feasibility of generating small amounts of power, utilizing any available waste heat as the energy source.

  20. Pyrolyzed thin film carbon (United States)

    Tai, Yu-Chong (Inventor); Liger, Matthieu (Inventor); Harder, Theodore (Inventor); Konishi, Satoshi (Inventor); Miserendino, Scott (Inventor)


    A method of making carbon thin films comprises depositing a catalyst on a substrate, depositing a hydrocarbon in contact with the catalyst and pyrolyzing the hydrocarbon. A method of controlling a carbon thin film density comprises etching a cavity into a substrate, depositing a hydrocarbon into the cavity, and pyrolyzing the hydrocarbon while in the cavity to form a carbon thin film. Controlling a carbon thin film density is achieved by changing the volume of the cavity. Methods of making carbon containing patterned structures are also provided. Carbon thin films and carbon containing patterned structures can be used in NEMS, MEMS, liquid chromatography, and sensor devices.

  1. Thin film processes II

    CERN Document Server

    Kern, Werner


    This sequel to the 1978 classic, Thin Film Processes, gives a clear, practical exposition of important thin film deposition and etching processes that have not yet been adequately reviewed. It discusses selected processes in tutorial overviews with implementation guide lines and an introduction to the literature. Though edited to stand alone, when taken together, Thin Film Processes II and its predecessor present a thorough grounding in modern thin film techniques.Key Features* Provides an all-new sequel to the 1978 classic, Thin Film Processes* Introduces new topics, and sever

  2. Rapid starting methanol reactor system (United States)

    Chludzinski, Paul J.; Dantowitz, Philip; McElroy, James F.


    The invention relates to a methanol-to-hydrogen cracking reactor for use with a fuel cell vehicular power plant. The system is particularly designed for rapid start-up of the catalytic methanol cracking reactor after an extended shut-down period, i.e., after the vehicular fuel cell power plant has been inoperative overnight. Rapid system start-up is accomplished by a combination of direct and indirect heating of the cracking catalyst. Initially, liquid methanol is burned with a stoichiometric or slightly lean air mixture in the combustion chamber of the reactor assembly. The hot combustion gas travels down a flue gas chamber in heat exchange relationship with the catalytic cracking chamber transferring heat across the catalyst chamber wall to heat the catalyst indirectly. The combustion gas is then diverted back through the catalyst bed to heat the catalyst pellets directly. When the cracking reactor temperature reaches operating temperature, methanol combustion is stopped and a hot gas valve is switched to route the flue gas overboard, with methanol being fed directly to the catalytic cracking reactor. Thereafter, the burner operates on excess hydrogen from the fuel cells.


    Directory of Open Access Journals (Sweden)

    S. L. Rovin


    Full Text Available Heat recovery is an effective method of shortening specific energy consumption. new constructions of recuperators for heating and cupola furnaces have been designed and successfully introduced. two-stage recuperator with computer control providing blast heating up to 600 °C and reducing fuel consumption by 30% is of special interest.

  4. Reliability improvement of a flexible FD-SOI MOSFET via heat management (United States)

    Bong, Jae Hoon; Kim, Seung-Yoon; Jeong, Chan Bae; Chang, Ki Soo; Hwang, Wan Sik; Cho, Byung Jin


    Ultra-thin single-crystalline Si membrane transistors on a polymer substrate have drawn attention for flexible electronics applications. However, these devices accompany a reliability issue stemming from severe self-heating because of the inherent poor thermal conductivity of the polymer substrate. In the present study, under an operational condition of VG = 3 V and VD = 8 V, the temperature of the Si membrane transistor on the polymer substrate soared to about 64 °C immediately and remained consistently high. The excess heat generated from the active channel significantly degraded the device performance. However, the implementation of a silver heat spreading layer (HSL) between the active channel and the polymer substrate significantly alleviated the self-heating effect as the silver film rapidly spread the generated heat. The efficient heat spreading, monitored via a high resolution infrared thermal microscope, correlated well with the charge transfer characteristics of the device. These results may be helpful to realize high performance flexible devices using a silicon membrane.

  5. Study of the heat flux generated by accelerated electrons on the components near the plasma; Etude du flux de chaleur dissipe par les electrons rapides sur les composants proches du plasma

    Energy Technology Data Exchange (ETDEWEB)

    Laugier, J. [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee


    Experimental data have shown that a heat flux appears on components situated near the wave guide of the lower hybrid antenna of Tore-Supra. This heat flux is due to the energy release during collisions that occur between the component surface and the electrons accelerated by the high frequency field generated by the antenna. Simulations show that the electrons may reach an energy of 2-3 keV and that the heat flux generated in the shield may reach 10 MW/m{sup 2}. In this work a correlation has been established between the local heat flux due to electron impact and the mean electrical field near the antenna: {phi} (W/m{sup 2}) = 4.10{sup -4} x E{sup -6} (10{sup 5} V/m). It is also shown that the ratio of electrons that reach the shield is roughly not dependent on the value of the mean electrical field. In the hypothesis of a Gaussian distribution of electron initial velocities this ratio is 10%. (A.C.)

  6. Calcium bromide hydration for heat storage systems

    Directory of Open Access Journals (Sweden)

    Ai Niwa


    Full Text Available A chemical reaction is a common and simple way to produce heat for a heat storage system. The reaction produces heat energy without the use of electricity or fuel. The goal of this study was to develop a heat storage system for use in automobiles, which is able to provide heat rapidly via a hydration reaction. A heat storage system without an evaporator stores high-density heat and has a high heat output rate since the solid–liquid product that is formed is transferred as a heat medium to the object that requires heat. The exothermic heat produced from the solid–liquid reaction was measured, and the relationship between the equivalence ratio and the reaction heat was evaluated. The heat output and heat recovered by the heat storage system, which comprised a reaction vessel and a heat exchanger, were measured. We selected solid CaBr2 because it was the best metal halide for a hydration reaction and had a high heat yield from the dissolution reaction. With this system, we were able to achieve a heat recovery rate of 582 kJ/L-H2O. We found no degradation in the chemical composition of CaBr2 after it being recycled 100 times.

  7. Cohenite in Chondrites: Further Support for a Shock-Heating Origin (United States)

    Likkel, L.; Ruzicka, A. M.; Hutson, M.; Schepker, K.; Yeager, T.


    In thin sections of two chondrites, cohenite was found with optical microscopy to be preferentially near shock melt or in heat affected host. This is consistent with cohenite formation due to contact metamorphism from heating by nearby shock melt.

  8. Vibration welding system with thin film sensor (United States)

    Cai, Wayne W; Abell, Jeffrey A; Li, Xiaochun; Choi, Hongseok; Zhao, Jingzhou


    A vibration welding system includes an anvil, a welding horn, a thin film sensor, and a process controller. The anvil and horn include working surfaces that contact a work piece during the welding process. The sensor measures a control value at the working surface. The measured control value is transmitted to the controller, which controls the system in part using the measured control value. The thin film sensor may include a plurality of thermopiles and thermocouples which collectively measure temperature and heat flux at the working surface. A method includes providing a welder device with a slot adjacent to a working surface of the welder device, inserting the thin film sensor into the slot, and using the sensor to measure a control value at the working surface. A process controller then controls the vibration welding system in part using the measured control value.

  9. Crystallization behavior of Nd-doped SrBi{sub 2}Ta{sub 2}O{sub 9} thin films prepared by magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Li Yibin [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Zhang, Sam [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)], E-mail:; Fei Weidong [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, 150001 (China); Wang Huili [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)


    Nd-doped SrBi{sub 2}Ta{sub 2}O{sub 9} thin films are magnetron-sputtered on Pt/Ta/SiO{sub 2}/Si substrates. The effect of heating rate on crystallization behavior is investigated with conventional furnace annealing (CFA) and rapid thermal annealing (RTA). Grazing incidence X-ray diffraction and field emission scanning electron microscopy reveal that the crystallization goes through three stages (phases): amorphous, fluorite and finally Aurivillius. Under RTA, the fluorite-to-Aurivillius transformation starts around 100 {sup o}C lower than that under CFA. The reasons behind the transformation temperature drop are also discussed.

  10. Shunts in thin-film photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Malek, Stephanie; Riedel, Ingo; Parisi, Juergen [Energy and Semiconductor Research Laboratory, Department of Physics, University of Oldenburg, 26111 Oldenburg (Germany); Wischnath, Uli F. [aleo solar Deutschland GmbH, 26122 Oldenburg (Germany); Rechid, Juan [CIS Solartechnik GmbH and Co. KG, 20539 Hamburg (Germany)


    Shunts can lead to severe performance reduction in thin film solar cells. This work reports on a microscopic approach to locate and characterize the details of shunts in order to reveal their origin. Localization of hot spots and film disruptions is commonly addressed by lock-in infrared thermography (LIT) through visualization of the Joule heating. The resolution of this method is restricted to the {mu}m-range. We use different methods of LIT for the fast localization of local-lateral peculiarities in order to identify positions of interest. For a more detailed analysis of these features we use high resolution microscopy like Scanning Electron Microscopy (SEM) and AFM-based methods. These small-scale investigations can for example reveal whether areas of high heat dissipation are rather related to the inner structure of the involved thin films or to accidentally incorporated imperfections.

  11. Thin Film Processes

    CERN Document Server

    Vossen, John L.


    This sequel to the 1978 classic, Thin Film Processes, gives a clear, practical exposition of important thin film deposition and etching processes that have not yet been adequately reviewed. It discusses selected processes in tutorial overviews with implementation guide lines and an introduction to the literature. Though edited to stand alone, when taken together, Thin Film Processes II and its predecessor present a thorough grounding in modern thin film techniques. Key Features * Provides an all-new sequel to the 1978 classic, Thin Film Processes * Introduces new topics, and several key topics presented in the original volume are updated * Emphasizes practical applications of major thin film deposition and etching processes * Helps readers find the appropriate technology for a particular application

  12. Novel ultra-rapid freezing particle engineering process for enhancement of dissolution rates of poorly water-soluble drugs. (United States)

    Overhoff, Kirk A; Engstrom, Josh D; Chen, Bo; Scherzer, Brian D; Milner, Thomas E; Johnston, Keith P; Williams, Robert O


    An ultra-rapid freezing (URF) technology has been developed to produce high surface area powders composed of solid solutions of an active pharmaceutical ingredient (API) and a polymer stabilizer. A solution of API and polymer excipient(s) is spread on a cold solid surface to form a thin film that freezes in 50 ms to 1s. This study provides an understanding of how the solvent's physical properties and the thin film geometry influence the freezing rate and consequently the final physico-chemical properties of URF-processed powders. Theoretical calculations of heat transfer rates are shown to be in agreement with infrared images with 10ms resolution. Danazol (DAN)/polyvinylpyrrolidone (PVP) powders, produced from both acetonitrile (ACN) and tert-butanol (T-BUT) as the solvent, were amorphous with high surface areas (approximately 28-30 m2/g) and enhanced dissolution rates. However, differences in surface morphology were observed and attributed to the cooling rate (film thickness) as predicted by the model. Relative to spray-freezing processes that use liquid nitrogen, URF also offers fast heat transfer rates as a result of the intimate contact between the solution and cold solid surface, but without the complexity of cryogen evaporation (Leidenfrost effect). The ability to produce amorphous high surface area powders with submicron primary particles with a simple ultra-rapid freezing process is of practical interest in particle engineering to increase dissolution rates, and ultimately bioavailability.

  13. Heated Goggles (United States)


    The electrically heated ski goggles shown incorporate technology similar to that once used in Apollo astronauts' helmet visors, and for the same reason-providing fogfree sight in an activity that demands total vision. Defogging is accomplished by applying heat to prevent moisture condensation. Electric heat is supplied by a small battery built into the h goggles' headband. Heat is spread across the lenses by means of an invisible coating of electrically conductive metallic film. The goggles were introduced to the market last fall. They were designed by Sierracin Corporation, Sylmar, California, specialists in the field of heated transparent materials. The company produces heated windshields for military planes and for such civil aircraft as the Boeing 747, McDonnell Douglas DC-10 and Lockheed L-1011 TriStar.

  14. Honeycomb-Fin Heat Sink (United States)

    Rippel, Wally E.


    Improved finned heat sink for electronic components more lightweight, inexpensive, and efficient. Designed for use with forced air, easily scaled up to dissipate power up to few hundred watts. Fins are internal walls of aluminum honeycomb structure. Cell structure gives strength to thin aluminum foil. Length of channels chosen for thermodynamic efficency; columns of cells combined in any reasonable number because flowing air distributed to all. Heat sink cools nearly as effectively at ends as near its center, no matter how many columns of cells combined.

  15. Interdiffusion and growth of chromium silicide at the interface of Cr/Si(As) system during rapid thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Benkherbache, H. [Universite de M' Sila, (28000) M' Sila (Algeria); Merabet, A., E-mail: merabet_abdelali@yahoo.f [Laboratoire Physique et Mecanique des Materiaux Metalliques, Departement d' O.M.P., Faculte des Sciences de l' Ingenieur, Universite de Setif, (19000) Setif (Algeria)


    In this work, the solid-state reaction between a thin film of chromium and silicon has been studied using Rutherford backscattering spectroscopy, X-ray diffraction and the sheet resistance measurements. The thickness of 100 nm chromium layer has been deposited by electronic bombardment on Si (100) substrates, part of them had previously been implanted with arsenic ions of 10{sup 15} at/cm{sup 2} doses and an energy of 100 keV. The samples were heat treated under rapid thermal annealing at 500 {sup o}C for time intervals ranging from 15 to 60 s. The rapid thermal annealing leads to a reaction at the interface Cr/Si inducing the formation and the growth of the unique silicide CrSi{sub 2}, but no other phase can be detected. For samples implanted with arsenic, the saturation value of the sheet resistance is approximately 1.5 times higher than for the non-implanted case.

  16. Rapid dynamic thinning on Upernavik Icestream, West Greenland

    DEFF Research Database (Denmark)

    Khan, Shfaqat Abbas; Kjær, Kurt H.; Korsgaard, Niels Jákup

    The main outlet glaciers in Greenland have more than doubled their contribution to global sea level rise over the last decade. Several studies have shown increase in ice discharge from the main outlet glaciers (notably Kangerdlugssuaq (KG) and Helheim glaciers (HG) in Southeast Greenland, and Jak...

  17. Prediction of heat treatment in food processing machinery

    DEFF Research Database (Denmark)

    Karlson, Torben; Friis, Alan; Szabo, Peter


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

  18. Installation Effects on Heat Transfer Measurements for a Turbine Vane

    National Research Council Canada - National Science Library

    Polanka, Marc


    ...). This turbine vane was instrumented with two types of heat flux gauges. The first was a thin film Upilex gauge design wrapped over the full airfoil surface, while the second consisted of Pyrex insert type gauges...

  19. Thin film absorber for a solar collector (United States)

    Wilhelm, William G.


    This invention pertains to energy absorbers for solar collectors, and more particularly to high performance thin film absorbers. The solar collectors comprising the absorber of this invention overcome several problems seen in current systems, such as excessive hardware, high cost and unreliability. In the preferred form, the apparatus features a substantially rigid planar frame with a thin film window bonded to one planar side of the frame. An absorber in accordance with the present invention is comprised of two thin film layers that are sealed perimetrically. In a preferred embodiment, thin film layers are formed from a metal/plastic laminate. The layers define a fluid-tight planar envelope of large surface area to volume through which a heat transfer fluid flows. The absorber is bonded to the other planar side of the frame. The thin film construction of the absorber assures substantially full envelope wetting and thus good efficiency. The window and absorber films stress the frame adding to the overall strength of the collector.

  20. Synchronized Molecular-Dynamics Simulation via Macroscopic Heat and Momentum Transfer: An Application to Polymer Lubrication

    Directory of Open Access Journals (Sweden)

    Shugo Yasuda


    Full Text Available A synchronized molecular-dynamics simulation via macroscopic heat and momentum transfer is proposed to model the nonisothermal flow behaviors of complex fluids. In this method, the molecular-dynamics simulations are assigned to small fluid elements to calculate the local stresses and temperatures and are synchronized at certain time intervals to satisfy the macroscopic heat- and momentum-transport equations. This method is applied to the lubrication of a polymeric liquid composed of short chains of ten beads between parallel plates. The rheological properties and conformation of the polymer chains coupled with local viscous heating are investigated with a nondimensional parameter, the Nahme-Griffith number, which is defined as the ratio of the viscous heating to the thermal conduction at the characteristic temperature required to sufficiently change the viscosity. The present simulation demonstrates that strong shear thinning and a transitional behavior of the conformation of the polymer chains are exhibited with a rapid temperature rise when the Nahme-Griffith number exceeds unity. The results also clarify that the reentrant transition of the linear stress-optical relation occurs for large shear stresses due to the coupling of the conformation of polymer chains with heat generation under shear flows.

  1. Heat Stroke

    DEFF Research Database (Denmark)

    Mørch, Sofie Søndergaard; Andersen, Johnny Dohn Holmgren; Bestle, Morten Heiberg


    Heat stroke is an acute, life-threatening emergency characterized clinically by elevated body temperature and central nervous system dysfunction. Early recognition and treatment including aggressive cooling and management of life-threatening systemic complications are essential to reduce morbidity...... and mortality. This case report describes two Danish patients diagnosed with heat stroke syndrome during a heat wave in the summer of 2014. Both patients were morbidly obese and had several predisposing illnesses. However since heat stroke is a rare condition in areas with temperate climate, they were...... not diagnosed until several days after admittance; hence treatment with cooling was delayed. Both patients were admitted to the intensive care unit, where they were treated with an external cooling device and received treatment for complications. Both cases ended fatally. As global warming continues, more heat...

  2. Modeling with FCA-Based Model of Microstructure Evolution of MgCa08 Alloy During Drawing of Thin Wire in Heated Die / Modelowanie Za Pomocą FCA Rozwoju Mikrostruktury Stopu MgCa08 Podczas Ciągnienia Cienkiego Drutu W Podgrzewanym Ciagadle

    Directory of Open Access Journals (Sweden)

    Svyetlichnyy D. S.


    Full Text Available The paper deals with a modeling of manufacturing process of thin wire of MgCa08 alloy used as biocompatible soluble threads for medical application. Some difficulties in material deformation subjected with its hexagonal structure can be solved with accurate establishment of the deformation conditions, especially temperature history of the whole process. In drawing process with heated die, wire is preheated in furnace and then deformed. The only narrow temperature range allows for multi-pass drawing without wire breaking. Diameter below 0.1 mm required for the final product makes very important the consideration of microstructure evolution because grain size is comparable with the wire dimensions. For this reason the problem is considered in the micro scale by using the frontal cellular automata (FCA-based model. The goals of present work are the development and validation of FCA-base model of microstructure evolution of MgCa0.8 magnesium alloy. To reach this objective, plastometric and relaxation tests of MgCA08 alloy were done on physical simulator GLEEBLE 3800. Results of the experimental studies were used for parameters identification of the hardening-softening model of the material. Then, initial microstructure and its evolution during the drawing passes were simulated with FCA-based model. FCA consider dislocation density and flow stress, hardening and softening including recovery and recrystallization, grain refinement and grain rotation, as well as grain growth. It allows one to obtain structures close to real ones. Two variants of the drawing process with different temperature history were considered. The deformation scheme was the same. Simulation results with following short discussion confirm usefulness of FCA-based model for explanation and selection of rational technological condition of thin wire drawing of MgCa08 alloy.

  3. Ion acceleration and plasma jet formation in ultra-thin foils undergoing expansion and relativistic transparency

    Energy Technology Data Exchange (ETDEWEB)

    King, M.; Gray, R.J.; Powell, H.W.; MacLellan, D.A.; Gonzalez-Izquierdo, B. [SUPA Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Stockhausen, L.C. [Centro de Laseres Pulsados (CLPU), Parque Cientifico, Calle del Adaja, s/n. 37185 Villamayor, Salamanca (Spain); Hicks, G.S.; Dover, N.P. [The John Adams Institute for Accelerator Science, Blackett Laboratory, Imperial College London, London SW7 2BZ (United Kingdom); Rusby, D.R. [SUPA Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire OX11 0QX (United Kingdom); Carroll, D.C. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire OX11 0QX (United Kingdom); Padda, H. [SUPA Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Torres, R. [Centro de Laseres Pulsados (CLPU), Parque Cientifico, Calle del Adaja, s/n. 37185 Villamayor, Salamanca (Spain); Kar, S. [Centre for Plasma Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Clarke, R.J.; Musgrave, I.O. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire OX11 0QX (United Kingdom); Najmudin, Z. [The John Adams Institute for Accelerator Science, Blackett Laboratory, Imperial College London, London SW7 2BZ (United Kingdom); Borghesi, M. [Centre for Plasma Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Neely, D. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire OX11 0QX (United Kingdom); McKenna, P., E-mail: [SUPA Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom)


    At sufficiently high laser intensities, the rapid heating to relativistic velocities and resulting decompression of plasma electrons in an ultra-thin target foil can result in the target becoming relativistically transparent to the laser light during the interaction. Ion acceleration in this regime is strongly affected by the transition from an opaque to a relativistically transparent plasma. By spatially resolving the laser-accelerated proton beam at near-normal laser incidence and at an incidence angle of 30°, we identify characteristic features both experimentally and in particle-in-cell simulations which are consistent with the onset of three distinct ion acceleration mechanisms: sheath acceleration; radiation pressure acceleration; and transparency-enhanced acceleration. The latter mechanism occurs late in the interaction and is mediated by the formation of a plasma jet extending into the expanding ion population. The effect of laser incident angle on the plasma jet is explored.

  4. Optical thin film devices (United States)

    Mao, Shuzheng


    Thin film devices are applied to almost all modern scientific instruments, and these devices, especially optical thin film devices, play an essential role in the performances of the instruments, therefore, they are attracting more and more attention. Now there are numerous kinds of thin film devices and their applications are very diversified. The 300-page book, 'Thin Film Device and Applications,' by Prof. K. L. Chopra gives some general ideas, and my paper also outlines the designs, fabrication, and applications of some optical thin film devices made in my laboratory. Optical thin film devices have been greatly developed in the recent decades. Prof. A. Thelan has given a number of papers on the theory and techniques, Prof. H. A. Macleod's book, 'Thin Film Optical Filters,' has concisely concluded the important concepts of optical thin film devices, and Prof. J. A. Dobrowobski has proposed many successful designs for optical thin film devices. Recently, fully-automatic plants make it easier to produce thin film devices with various spectrum requirements, and some companies, such as Balzers, Leybold AG, Satis Vacuum AG, etc., have manufactured such kinds of coating plants for research or mass-production, and the successful example is the production of multilayer antireflection coatings with high stability and reproducibility. Therefore, it could be said that the design of optical thin film devices and coating plants is quite mature. However, we cannot expect that every problem has been solved, the R&D work still continues, the competition still continues, and new design concepts, new techniques, and new film materials are continually developed. Meanwhile, the high-price of fully-automatic coating plants makes unpopular, and automatic design of coating stacks is only the technique for optimizing the manual design according to the physical concepts and experience, in addition, not only the optical system, but also working environment should be taken into account when

  5. Heat-pipe planets (United States)

    Moore, William B.; Simon, Justin I.; Webb, A. Alexander G.


    Observations of the surfaces of all terrestrial bodies other than Earth reveal remarkable but unexplained similarities: endogenic resurfacing is dominated by plains-forming volcanism with few identifiable centers, magma compositions are highly magnesian (mafic to ultra-mafic), tectonic structures are dominantly contractional, and ancient topographic and gravity anomalies are preserved to the present. Here we show that cooling via volcanic heat pipes may explain these observations and provide a universal model of the way terrestrial bodies transition from a magma-ocean state into subsequent single-plate, stagnant-lid convection or plate tectonic phases. In the heat-pipe cooling mode, magma moves from a high melt-fraction asthenosphere through the lithosphere to erupt and cool at the surface via narrow channels. Despite high surface heat flow, the rapid volcanic resurfacing produces a thick, cold, and strong lithosphere which undergoes contractional strain forced by downward advection of the surface toward smaller radii. We hypothesize that heat-pipe cooling is the last significant endogenic resurfacing process experienced by most terrestrial bodies in the solar system, because subsequent stagnant-lid convection produces only weak tectonic deformation. Terrestrial exoplanets appreciably larger than Earth may remain in heat-pipe mode for much of the lifespan of a Sun-like star.

  6. Microwave heating causes rapid degradation of antioxidants in polypropylene packaging, leading to greatly increased specific migration to food simulants as shown by ESI-MS and GC-MS. (United States)

    Alin, Jonas; Hakkarainen, Minna


    Microwave heating of commercial microwavable polypropylene packaging in contact with fatty food simulants caused significant antioxidant degradation and increased specific migration as shown by electrospray ionization-mass spectrometry (ESI-MS) and gas chromatography-mass spectrometry (GC-MS). Degradation of the antioxidants Irgafos 168 and Irganox 1010 was not detected during conventional heating of polypropylene packaging at the same temperature. The migration into aqueous food simulants was primarily restricted by the water solubility of the migrants. Using isooctane as fatty food simulant caused significant swelling and greatly enhanced overall migration values compared to the other fatty food simulant, 99.9% ethanol, or the aqueous food simulants 10% ethanol, 3% acetic acid, or water. ESI-MS spectra clearly reflected the overall migration values, and the number and amount of compounds detected decreased as the hydrophilicity of the food simulant increased. ESI-MS was shown to be an excellent tool for the analysis of semivolatile migrants and a good complement to GC-MS analysis of volatile migrants.

  7. The Conditions of use of traditional heating vs fast heating readers of thermoluminescent dosemeters, a comparison. Les conditions d'utilisation d'un lecteur de dosimetres TL a chauffage traditionnel et d'un lecteur automatique a chauffage rapide. Leur comparaison

    Energy Technology Data Exchange (ETDEWEB)

    Marinello, G.; Pollack, J. (Hopital Henri Mondor, 94 - Creteil (FR)); Blanchard, P.; Barthe, J. (CEA Centre d' Etudes Nucleaires de Fontenay-aux-Roses, 92 (FR). Dept. de Protection Technique)


    The dosimetric properties of lithium borate activated with manganese or copper have been compared according to the heating procedures, i.e. with either a traditional heating reader or a new fast heating device associated with an automatic reader. When the adjustments of preheating and main heating are made optimal, fading becomes independent of the reader used and the reproducibility of the measurements is very good. The response curve of the TL material vs the dose is also found to be independent of the reader, provided it is normalized to 1 for the same reference dose. On the other hand the variation of the response vs energy (photon or electron beams) depends upon the heating procedures. Finally a particular characteristic of Li{sub 2}B{sub 4}O{sub 7}: Cu has been demonstrated: the response corresponding to a given dose is not proportional to the mass of the TL material used for the reading. As an interesting consequence it is possible to avoid weighing each reading sample and therefore to save time.

  8. Design and Testing of Metal and Silicon Heat Spreaders with Embedded Micromachined Heat Pipes

    Energy Technology Data Exchange (ETDEWEB)

    Benson, D.A.; Robino, C.V.


    The authors have developed a new type of heat spreader based on the integration of heat pipes directly within a thin planar structure suitable for use as a heat spreader or as the base layer in a substrate. The process uses micromachining methods to produce micron scale patterns that act as a wick in these small scale heat pipes. By using silicon or a low expansion metal as the wall material of these spreaders, they achieve a good match to the thermal coefficient of expansion of the die. The match allows the use of a thin high performance die attachment even on large size die. The embedded heat pipes result in high effective thermal conductivity for the new spreader technology.

  9. Heat pipes

    CERN Document Server

    Dunn, Peter D


    It is approximately 10 years since the Third Edition of Heat Pipes was published and the text is now established as the standard work on the subject. This new edition has been extensively updated, with revisions to most chapters. The introduction of new working fluids and extended life test data have been taken into account in chapter 3. A number of new types of heat pipes have become popular, and others have proved less effective. This is reflected in the contents of chapter 5. Heat pipes are employed in a wide range of applications, including electronics cooling, diecasting and injection mo

  10. Thin Film & Deposition Systems (Windows) (United States)

    Federal Laboratory Consortium — Coating Lab: Contains chambers for growing thin film window coatings. Plasma Applications Coating Lab: Contains chambers for growing thin film window coatings. Solar...

  11. An experimental study of heat pipe thermal management system with wet cooling method for lithium ion batteries (United States)

    Zhao, Rui; Gu, Junjie; Liu, Jie


    An effective battery thermal management (BTM) system is required for lithium-ion batteries to ensure a desirable operating temperature range with minimal temperature gradient, and thus to guarantee their high efficiency, long lifetime and great safety. In this paper, a heat pipe and wet cooling combined BTM system is developed to handle the thermal surge of lithium-ion batteries during high rate operations. The proposed BTM system relies on ultra-thin heat pipes which can efficiently transfer the heat from the battery sides to the cooling ends where the water evaporation process can rapidly dissipate the heat. Two sized battery packs, 3 Ah and 8 Ah, with different lengths of cooling ends are used and tested through a series high-intensity discharges in this study to examine the cooling effects of the combined BTM system, and its performance is compared with other four types of heat pipe involved BTM systems and natural convection cooling method. A combination of natural convection, fan cooling and wet cooling methods is also introduced to the heat pipe BTM system, which is able to control the temperature of battery pack in an appropriate temperature range with the minimum cost of energy and water spray.

  12. Effects Of Heat Sinks On VPPA Welds (United States)

    Nunes, Arthur C.; Steranka, Paul O., Jr.


    Report describes theoretical and experimental study of absorption of heat by metal blocks in contact with metal plate while plate subjected to variable-polarity plasma-arc (VPPA) welding. Purpose of study to contribute to development of comprehensive mathematical model of temperature in weld region. Also relevant to welding of thin sheets of metal to thick blocks of metal, heat treatment of metals, and hotspots in engines.

  13. Hot Topics! Heat Pumps and Geothermal Energy (United States)

    Roman, Harry T.


    The recent rapid rises in the cost of energy has significantly increased interest in alternative energy sources. The author discusses the underlying principles of heat pumps and geothermal energy. Related activities for technology education students are included.

  14. Heat pipe nuclear reactor for space power (United States)

    Koening, D. R.


    A heat-pipe-cooled nuclear reactor has been designed to provide 3.2 MWth to an out-of-core thermionic conversion system. The reactor is a fast reactor designed to operate at a nominal heat-pipe temperature of 1675 K. Each reactor fuel element consists of a hexagonal molybdenum block which is bonded along its axis to one end of a molybdenum/lithium-vapor heat pipe. The block is perforated with an array of longitudinal holes which are loaded with UO2 pellets. The heat pipe transfers heat directly to a string of six thermionic converters which are bonded along the other end of the heat pipe. An assembly of 90 such fuel elements forms a hexagonal core. The core is surrounded by a thermal radiation shield, a thin thermal neutron absorber, and a BeO reflector containing boron-loaded control drums.

  15. Improvement of the decay heat removal characteristics of the generation IV gas-cooled fast reactor; Amelioration des caracteristiques de la dissipation de la chaleur de decroissance pour les reacteurs a neutrons rapides de quatrieme generation refroidi au gaz

    Energy Technology Data Exchange (ETDEWEB)

    Epiney, A.S.


    The main drawback of the GFR is the difficulty to evacuate decay heat following a loss-of-coolant accident (LOCA) due to the low thermal inertia of the core, as well as to the low coolant density. The present doctoral research focuses on the improvement of decay heat removal (DHR) for the Generation-IV GFR. The reference GFR system design considered in the thesis is the 2006 CEA concept, with a power of 2400 MWth. The CEA 2006 DHR strategy foresees, in all accidental cases (independent of the system pressure), that the reactor is shut down. For high pressure events, dedicated DHR loops with blowers and heat exchangers are designed to operate when the power conversion system cannot be used to provide acceptable core temperatures under natural convection conditions. For de-pressurized events, the strategy relies on a dedicated small containment (called the guard containment) providing an intermediate back-up pressure. The DHR blowers, designed to work under these pressure conditions, need to be powered either by the power grid or by batteries for at least 24 hours. The specific contributions of the present research - aimed at achieving enhanced passivity of the DHR system for the GFR - are design and analysis related to (1) the injection of heavy gas into the primary circuit after a LOCA, to enable natural convection cooling at an intermediate-pressure level, and (2) an autonomous Brayton loop to evacuate decay heat at low primary pressure in case of a loss of the guard containment pressure. Both these developments reduce the dependence on blower power availability considerably. First, the thermal-hydraulic codes used in the study - TRACE and CATHARE - are validated for gas cooling. The validation includes benchmark comparisons between the codes, serving to identify the sensitivity of the results to the different modeling assumptions. The parameters found to be the most sensitive in this analysis, such as heat transfer and friction models, are then validated via a

  16. Magnetostriction of sputtered Sm-Fe thin films

    Energy Technology Data Exchange (ETDEWEB)

    Honda, T. (Tokin Corp., Sendai (Japan). Sendai Research Lab.); Hayashi, Y.; Arai, K.I.; Ishiyama, K.; Yamaguchi, M. (Tohoku Univ., Sendai (Japan). Research Institute of Electrical Communication)


    The magnetostriction and the magnetic properties of amorphous Sm[sub x]Fe[sub 100[minus]x] thin films prepared by sputtering were investigated at room temperature. The magnetostriction, -[lambda], of these films increased rapidly in low fields (<1kOe) and reached the maximum values of 300--400[times]10[sup [minus]6] at 16kOe for x = 30--40. These results suggest that Sm-Fe thin films could be used for micro-actuators. lie magnetic properties of Sm-Fe thin films did not show clear dependence on the sputtering conditions such as input power, Ar gas pressure, and substrate temperature.

  17. Thin film device applications

    CERN Document Server

    Kaur, Inderjeet


    Two-dimensional materials created ab initio by the process of condensation of atoms, molecules, or ions, called thin films, have unique properties significantly different from the corresponding bulk materials as a result of their physical dimensions, geometry, nonequilibrium microstructure, and metallurgy. Further, these characteristic features of thin films can be drasti­ cally modified and tailored to obtain the desired and required physical characteristics. These features form the basis of development of a host of extraordinary active and passive thin film device applications in the last two decades. On the one extreme, these applications are in the submicron dimensions in such areas as very large scale integration (VLSI), Josephson junction quantum interference devices, magnetic bubbles, and integrated optics. On the other extreme, large-area thin films are being used as selective coatings for solar thermal conversion, solar cells for photovoltaic conver­ sion, and protection and passivating layers. Ind...

  18. Ceramic Composite Thin Films (United States)

    Ruoff, Rodney S. (Inventor); Stankovich, Sasha (Inventor); Dikin, Dmitriy A. (Inventor); Nguyen, SonBinh T. (Inventor)


    A ceramic composite thin film or layer includes individual graphene oxide and/or electrically conductive graphene sheets dispersed in a ceramic (e.g. silica) matrix. The thin film or layer can be electrically conductive film or layer depending the amount of graphene sheets present. The composite films or layers are transparent, chemically inert and compatible with both glass and hydrophilic SiOx/silicon substrates. The composite film or layer can be produced by making a suspension of graphene oxide sheet fragments, introducing a silica-precursor or silica to the suspension to form a sol, depositing the sol on a substrate as thin film or layer, at least partially reducing the graphene oxide sheets to conductive graphene sheets, and thermally consolidating the thin film or layer to form a silica matrix in which the graphene oxide and/or graphene sheets are dispersed.

  19. Thin Solid Oxide Cell

    DEFF Research Database (Denmark)


    The present invention relates to a thin and in principle unsupported solid oxide cell, comprising at least a porous anode layer, an electrolyte layer and a porous cathode layer, wherein the anode layer and the cathode layer comprise an electrolyte material, at least one metal and a catalyst...... material, and wherein the overall thickness of the thin reversible cell is about 150 [mu]m or less, and to a method for producing same. The present invention also relates to a thin and in principle unsupported solid oxide cell, comprising at least a porous anode layer, an electrolyte layer and a porous...... cathode layer, wherein the anode layer and the cathode layer comprise an electrolyte material and a catalyst material, wherein the electrolyte material is doper zirconia, and wherein the overall thickness of the thin reversible cell is about 150 [mu]m or less, and to a method for producing same...

  20. Scanning and transmission electron microscopy investigation of multiwall carbon nanotube/nickel oxide nanocomposite thin films

    CSIR Research Space (South Africa)

    Roro, Kittessa T


    Full Text Available Owing to their unique electronic and optical properties, nanocomposite thin films are widely used for converting solar radiation therapy into other conventional energy forms, such as heat and electricity. Carbon nanotube-based composites which can...

  1. Sinterização de filmes finos de LiNbO3 em forno microondas: estudo da influência da direção do fluxo de calor Sintering of LiNbO3 thin films in microwave furnace: study of the influence of the heat flow direction

    Directory of Open Access Journals (Sweden)

    N. S. L. S. Vasconcelos


    Full Text Available Filmes finos de LiNbO3 foram preparados pelo método dos precursores poliméricos e depositados por "spin coating" sobre substratos de safira (0001. Os filmes foram tratados em forno microondas doméstico a 400 ºC por 15 e 20 min. Um material com alta perda dielétrica (susceptor de SiC foi usado para absorver energia das microondas e transformá-la em calor. Este calor foi transferido para o filme a fim de promover a sua cristalização. O susceptor foi posicionado acima do filme ou embaixo do substrato. Desta forma, a influência da direção do fluxo de calor na cristalização das amostras foi verificada. Os filmes foram caracterizados por difração de raios X, microscopia de força atômica e espectrofotometria (transmitância na região UV-visível e o índice de refração foi determinado por elipsometria. O crescimento epitaxial foi observado para o filme com susceptor posicionado embaixo do substrato. Verificou-se que os grãos apresentaram crescimento aleatório quando o susceptor foi posicionado acima do filme. Os filmes apresentaram-se relativamente densos, homogêneos e lisos, com boas propriedades ópticas.LiNbO3 thin films were prepared using a polymeric precursor solution deposited by spin coating on (0001 sapphire substrate. Heat treatment of the films was carried out in a microwave oven at 400 ºC for 15 and 20 min. A SiC susceptor (material with high dielectric loss was used to absorb microwave energy and transfer the heat to the film in order to promote crystallization. The susceptor was placed above the film or below the substrate. Thus, the influence of the heat flux direction on the sample crystallization was verified. The films were characterized by X-ray diffraction, atomic force microscopy and spectrophotometry (transmittance in the UV-Visible region and the refractive index was determined with an ellipsometer. The epitaxial growth was observed for the film with the susceptor placed below the substrate. Random growth

  2. Modular Heat Exchanger With Integral Heat Pipe (United States)

    Schreiber, Jeffrey G.


    Modular heat exchanger with integral heat pipe transports heat from source to Stirling engine. Alternative to heat exchangers depending on integrities of thousands of brazed joints, contains only 40 brazed tubes.

  3. Multifunctional thin film surface (United States)

    Brozik, Susan M.; Harper, Jason C.; Polsky, Ronen; Wheeler, David R.; Arango, Dulce C.; Dirk, Shawn M.


    A thin film with multiple binding functionality can be prepared on an electrode surface via consecutive electroreduction of two or more aryl-onium salts with different functional groups. This versatile and simple method for forming multifunctional surfaces provides an effective means for immobilization of diverse molecules at close proximities. The multifunctional thin film has applications in bioelectronics, molecular electronics, clinical diagnostics, and chemical and biological sensing.

  4. Sputtered Thin Film Research (United States)


    and Idonllly hy block numbor) Reactive Sputtering, Heteroepitaxy, Thin Films Single Crystal Zinc Oxide, Titanium Dioxide, Aluminum Nitride, Gallium...Conditions were determined for the deposition of amorphous neodymium ultra- phosphate films. This material holds the potential for the fabrication...reaching the substrate at any time during sputtering. A 17.2 cm diameter quartz plate was covered with a thin coating of zinc sulflde and placed on

  5. Rapid Polymer Sequencer (United States)

    Stolc, Viktor (Inventor); Brock, Matthew W (Inventor)


    Method and system for rapid and accurate determination of each of a sequence of unknown polymer components, such as nucleic acid components. A self-assembling monolayer of a selected substance is optionally provided on an interior surface of a pipette tip, and the interior surface is immersed in a selected liquid. A selected electrical field is impressed in a longitudinal direction, or in a transverse direction, in the tip region, a polymer sequence is passed through the tip region, and a change in an electrical current signal is measured as each polymer component passes through the tip region. Each of the measured changes in electrical current signals is compared with a database of reference electrical change signals, with each reference signal corresponding to an identified polymer component, to identify the unknown polymer component with a reference polymer component. The nanopore preferably has a pore inner diameter of no more than about 40 nm and is prepared by heating and pulling a very small section of a glass tubing.

  6. Thinning 'Elstar' apple with benzyladenine

    NARCIS (Netherlands)

    Maas, F.M.


    ‘Elstar’, the main apple cultivar grown in the Netherlands, requires adequate thinning to reach marketable fruit sizes and to achieve regular yields by preventing alternate bearing. At the moment, chemical thinning of ‘Elstar’ is the only economically feasible way of thinning. Thinning by hand is

  7. Characteristics of deposition process of thin films by ion-beam evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Kitayama, Shinji; Endo, Fumito; Suzuki, Tsuneo; Suematsu, Hisayuki; Jiang, Weihua; Yatsui, Kiyoshi [Nagoya Univ. of Technology, Extreme Energy-Density Research Inst., Nagaoka, Niigata (Japan)


    Intense pulsed ion-beam evaporation (IBE) has been proposed as one of the new techniques for the preparation of thin films. To understand the basic process of thin film deposition, the energy deposition on the substrate surface by ablation plasma was measured by using calorimetric technique. The characteristics of prepared thin films were studied with deposition energy. In addition, the substrate temperature was calculated, based on the experimental results, by using one-dimensional simulations only considering heat conduction. (author)

  8. In-situ investigation of thermal instabilities and solid state dewetting in polycrystalline platinum thin films via confocal laser microscopy (United States)

    Jahangir, S.; Cheng, Xuan; Huang, H. H.; Ihlefeld, J.; Nagarajan, V.


    Solid state dewetting and the subsequent morphological changes for platinum thin films grown on zinc oxide (ZnO) buffered (001) silicon substrates (Pt/ZnO/SiO2/(001)Si system) is investigated under vacuum conditions via a custom-designed confocal laser microscope coupled with a laser heating system. Live imaging of thin film dewetting under a range of heating and quenching vacuum ambients reveals events including hillock formation, hole formation, and hole growth that lead to formation of a network of Pt ligaments, break up of Pt ligaments to individual islands and subsequent Pt islands shape reformation, in chronological fashion. These findings are corroborated by ex-situ materials characterization and quantitative electron microscopy analysis. A secondary hole formation via blistering before film rupture is revealed to be the critical stage, after which a rapid dewetting catastrophe occurs. This process is instantaneous and cannot be captured by ex-situ methods. Finally, an intermetallic phase forms at 900 °C and alters the morphology of Pt islands, suggesting a practical limit to the thermal environments that may be used for these platinized silicon wafers in vacuum conditions.

  9. In-situ investigation of thermal instabilities and solid state dewetting in polycrystalline platinum thin films via confocal laser microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Jahangir, S.; Cheng, Xuan; Huang, H. H.; Nagarajan, V. [School of Materials Science and Engineering, University of New South Wales, Sydney 2052 (Australia); Ihlefeld, J. [Electronic, Optical, and Nanomaterials Department, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)


    Solid state dewetting and the subsequent morphological changes for platinum thin films grown on zinc oxide (ZnO) buffered (001) silicon substrates (Pt/ZnO/SiO{sub 2}/(001)Si system) is investigated under vacuum conditions via a custom-designed confocal laser microscope coupled with a laser heating system. Live imaging of thin film dewetting under a range of heating and quenching vacuum ambients reveals events including hillock formation, hole formation, and hole growth that lead to formation of a network of Pt ligaments, break up of Pt ligaments to individual islands and subsequent Pt islands shape reformation, in chronological fashion. These findings are corroborated by ex-situ materials characterization and quantitative electron microscopy analysis. A secondary hole formation via blistering before film rupture is revealed to be the critical stage, after which a rapid dewetting catastrophe occurs. This process is instantaneous and cannot be captured by ex-situ methods. Finally, an intermetallic phase forms at 900 °C and alters the morphology of Pt islands, suggesting a practical limit to the thermal environments that may be used for these platinized silicon wafers in vacuum conditions.

  10. Indium oxide thin film based ammonia gas and ethanol vapour sensor

    Indian Academy of Sciences (India)


    perature corning glass substrate by flash evaporation method. Gold was deposited on the film using thermal .... Two thin film gold electrodes were also depo-. Table 1. Parameters for fabrication of indium oxide thin .... periodic heating mode of operation, both response and recovery times are long (8–10%) (Patel et al 1994).

  11. Rugged microelectronic module package supports circuitry on heat sink (United States)

    Johnson, A. L.


    Rugged module package for thin film hybrid microcircuits incorporated a rigid, thermally conductive support structure, which serves as a heat sink, and a lead wire block in which T-shaped electrical connectors are potted. It protects the circuitry from shock and vibration loads, dissipates internal heat, and simplifies electrical connections between adjacent modules.

  12. Orifice Blocks Heat Pipe in Reverse Mode (United States)

    Alario, J. P.


    High forward-mode conductance is combined with rapid reverse-mode shutoff in a heat pipe originally developed to cool spacecraft payloads. A narrow orifice within the pipe "chokes off" the evaporator if heat sink becomes warmer than source. During normal operation, with source warmer than sink, orifice has little effect. Design is simpler and more compact than other thermal-diode heat pipes and requires no special materials, forgings, or unusual construction techniques.

  13. Thinning 'Elstar' apple with benzyladenine


    Maas, F.M.


    ‘Elstar’, the main apple cultivar grown in the Netherlands, requires adequate thinning to reach marketable fruit sizes and to achieve regular yields by preventing alternate bearing. At the moment, chemical thinning of ‘Elstar’ is the only economically feasible way of thinning. Thinning by hand is labour intensive and thus too expensive. Furthermore, hand thinning is usually carried out after June-drop, by which time only increases in fruit size are achieved and no reduction in alternate beari...

  14. Study of the thermal and hydraulic phenomena occurring during power excursion on a heated test section; Etude des phenomenes thermiques et hydrauliques accompagnant une excursion rapide de puissance sur un canal chauffant

    Energy Technology Data Exchange (ETDEWEB)

    Nyer, M. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires


    The thermal and hydrodynamic phenomena occurring during a power excursion were studied in an out-of-pile loop with a water cooled channel at low pressure (1 to 4 atm. abs. ). Circular and rectangular test sections with electrically heated walls of two different thermal diffusivity materials(aluminium and stainless steel) were used. The rectangular test sections were 600 mm long, 35 mm wide and had a 2, 9 mm gap; they simulate two half plates of the M.T.R. fuel element. Natural or forced convection are possible in the test section; the water height above it can be varied from 2.8 to 8 meters and the maximum allowed pressure at its outlet is 4 atm. abs.The heating source is a series of lead batteries which is able to generate, for short periods of time, 85 volts and 25000 amperes; linear, square or exponential power rise versus time can be realized. A 14 channels tape recorder (0-10 000 Hz bandwidth; is used for the measurements of temperature (8/100 mm diameter thermocouple), pressure ('Statham' pressure transducers) and void fraction (X rays). More than 500 tests have been carried out. The influence of the initial water temperature, flow rate, pressure, water height on the water ejections, pressure variations and void fraction in the test section were studied. Tests with energies up to 3000 W/cm in 50 milliseconds were attempted. The energy above which the instabilities appear was determined. An interpretation of the observed phenomena and a simplified theoretical model are presented. [French] Les phenomenes thermiques et hydrodynamiques qui apparaissent au cours d'une excursion de puissance ont ete etudies sur un canal refroidi par de l'eau a basse pression situe sur une installation hors pile. On a utilise des sections d'essais de geometrie cylindrique ou parallipedique dont les parois chauffees par effet Joule sont constituees de materiaux de diffusivite calorifique differente (aluminium et acier inoxydable). La section d

  15. Heat convection

    Energy Technology Data Exchange (ETDEWEB)

    Jiji, L.M. [City Univ. of New York, NY (United States). Dept. of Mechanical Engineering


    Professor Jiji's broad teaching experience lead him to select the topics for this book to provide a firm foundation for convection heat transfer with emphasis on fundamentals, physical phenomena, and mathematical modelling of a wide range of engineering applications. Reflecting recent developments, this textbook is the first to include an introduction to the challenging topic of microchannels. The strong pedagogic potential of Heat Convection is enhanced by the following ancillary materials: (1) Power Point lectures, (2) Problem Solutions, (3) Homework Facilitator, and, (4) Summary of Sections and Chapters. (orig.)

  16. Thin-film antifuses for pellistor type gas sensors

    NARCIS (Netherlands)

    Kovalgin, Alexeij Y.; Holleman, J.; van den Berg, Albert; Wallinga, Hans


    This work extends our previously reported idea of using the nano-scale conductive link (antifuse) as a combined heating /detecting element in a Pellistor-type gas sensor. Our new thin-film antifuse is designed in such a way that the oxide, for minimising the bulk influence on surface temperature,

  17. Efficient Solar-Thermal Energy Harvest Driven by Interfacial Plasmonic Heating-Assisted Evaporation. (United States)

    Chang, Chao; Yang, Chao; Liu, Yanming; Tao, Peng; Song, Chengyi; Shang, Wen; Wu, Jianbo; Deng, Tao


    The plasmonic heating effect of noble nanoparticles has recently received tremendous attention for various important applications. Herein, we report the utilization of interfacial plasmonic heating-assisted evaporation for efficient and facile solar-thermal energy harvest. An airlaid paper-supported gold nanoparticle thin film was placed at the thermal energy conversion region within a sealed chamber to convert solar energy into thermal energy. The generated thermal energy instantly vaporizes the water underneath into hot vapors that quickly diffuse to the thermal energy release region of the chamber to condense into liquids and release the collected thermal energy. The condensed water automatically flows back to the thermal energy conversion region under the capillary force from the hydrophilic copper mesh. Such an approach simultaneously realizes efficient solar-to-thermal energy conversion and rapid transportation of converted thermal energy to target application terminals. Compared to conventional external photothermal conversion design, the solar-thermal harvesting device driven by the internal plasmonic heating effect has reduced the overall thermal resistance by more than 50% and has demonstrated more than 25% improvement of solar water heating efficiency.

  18. Causes and consequences of mid–21st-century rapid ice loss events simulated by the Rossby centre regional atmosphere-ocean model

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Paquin


    Full Text Available Recent observations and modelling studies suggest that the Arctic climate is undergoing important transition. One manifestation of this change is seen in the rapid sea-ice cover decrease as experienced in 2007 and 2012. Although most numerical climate models cannot adequately reproduce the recent changes, some models produce similar Rapid Ice Loss Events (RILEs during the mid–21st-century. This study presents an analysis of four specific RILEs clustered around 2040 in three transient climate projections performed with the coupled Rossby Centre regional Atmosphere-Ocean model (RCAO. The analysis shows that long-term thinning causes increased vulnerability of the Arctic Ocean sea-ice cover. In the Atlantic sector, pre-conditioning (thinning of sea ice combined with anomalous atmospheric and oceanic heat transport causes large ice loss, while in the Pacific sector of the Arctic Ocean sea-ice albedo feedback appears important, particularly along the retreating sea-ice margin. Although maximum sea-ice loss occurs in the autumn, response in surface air temperature occurs in early winter, caused by strong increase in ocean-atmosphere surface energy fluxes, mainly the turbulent fluxes. Synchronicity of the events around 2040 in the projections is caused by a strong large-scale atmospheric circulation anomaly at the Atlantic lateral boundary of the regional model. The limited impact on land is caused by vertical propagation of the surface heat anomaly rather than horizontal, caused by the absence of low-level temperature inversion over the ocean.

  19. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... for signs of heat stroke or exhaustion. Heat Stroke and Exhaustion Symptoms of early heat exhaustion symptoms ... heavy sweating; nausea; and giddiness. Symptoms of heat stroke (late stage of heat illness) include flushed, hot, ...

  20. Renewable Heating and Cooling (United States)

    Renewable heating and cooling is a set of alternative resources and technologies that can be used in place of conventional heating and cooling technologies for common applications such as water heating, space heating, space cooling and process heat.

  1. Geometry of Thin Nematic Elastomer Sheets (United States)

    Aharoni, Hillel; Sharon, Eran; Kupferman, Raz


    A thin sheet of nematic elastomer attains 3D configurations depending on the nematic director field upon heating. In this Letter, we describe the intrinsic geometry of such a sheet and derive an expression for the metric induced by general nematic director fields. Furthermore, we investigate the reverse problem of constructing a director field that induces a specified 2D geometry. We provide an explicit recipe for how to construct any surface of revolution using this method. Finally, we show that by inscribing a director field gradient across the sheet's thickness, one can obtain a nontrivial hyperbolic reference curvature tensor, which together with the prescription of a reference metric allows dictation of actual configurations for a thin sheet of nematic elastomer.

  2. Neat monolayer tiling of molecularly thin two-dimensional materials in 1 min. (United States)

    Matsuba, Kazuaki; Wang, Chengxiang; Saruwatari, Kazuko; Uesusuki, Yusuke; Akatsuka, Kosho; Osada, Minoru; Ebina, Yasuo; Ma, Renzhi; Sasaki, Takayoshi


    Controlled arrangement of molecularly thin two-dimensional (2D) materials on a substrate, particularly into precisely organized mono- and multilayer structures, is a key to design a nanodevice using their unique and enhanced physical properties. Several techniques such as mechanical transfer process and Langmuir-Blodgett deposition have been applied for this purpose, but they have severe restrictions for large-scale practical applications, for example, limited processable area and long fabrication time, requiring skilled multistep operations. We report a facile one-pot spin-coating method to realize dense monolayer tiling of various 2D materials, such as graphene and metal oxide nanosheets, within 1 min over a wide area (for example, a 30-mmφ substrate). Centrifugal force drives the nanosheets in a thin fluid layer to the substrate edge where they are packed edge to edge all the way to the central region, without forming overlaps. We investigated the relationship between precursor concentration, rotation speed, and ultraviolet-visible absorbance and developed an effective method to optimize the parameters for neat monolayer films. The multilayer buildup is feasible by repeating the spin-coating process combined with a heat treatment at moderate temperature. This versatile solution-based technique will provide both fundamental and practical advancements in the rapid large-scale production of artificial lattice-like films and nanodevices based on 2D materials.

  3. High-quality crystalline rubrene thin film on electron-irradiated PS

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyeok Moo; Kim, Yong Nam; Kim, Jae Joon; Cho, Sung Oh [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)


    From much of recent works, it was found that charge carrier transport in organic thin film transistors (OTFTs) is strongly affected by the first several semiconductor monolayers next to the semiconductor insulator interface. Among the interfacial factors, insulator surface roughness, surface energy, surface polarity and dielectric constant of dielectrics are considered as important parameters to affect performance of the OTFT. Thus, recently, a lot of efforts to optimize the conditions of surface of dielectrics using various treatment techniques have been performed. Among these techniques, surface modification using polymeric materials is very simple and qualities of polymer surface are hardly affected by preparation conditions. However, surface chain segmental motions near the glass transition temperature disrupts the growth of large-grain morphologies leading low carrier mobility. Thus, there is limitation in temperature to fabricate the organic semiconductor active layer. Here we present a strategy to fabricate high-quality crystalline rubrene thin film using combination of abrupt heating technique and electron irradiation of common homopolymer dielectrics of polystyrene (PS). Electron irradiation induces crosslinking of hydrocarbon chains of PS that restricts chain segmental motion even at the high temperature of 170 .deg. C. Through this method, high quality crystalline rubrene film can be remarkably rapidly produced on PS/SiO{sub 2} bilayer dielectrics in just 1 min

  4. Rapid magnetic hardening by rapid thermal annealing in NdFeB-based nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Chu, K.-T.; Jin, Z Q; Chakka, Vamsi M; Liu, J P [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States)


    A systematic study of heat treatments and magnetic hardening of NdFeB-based melt-spun nanocomposite ribbons have been carried out. Comparison was made between samples treated by rapid thermal annealing and by conventional furnace annealing. Heating rates up to 200 K s{sup -1} were adopted in the rapid thermal processing. It was observed that magnetic hardening can be realized in an annealing time as short as 1 s. Coercivity of 10.2 kOe in the nanocomposites has been obtained by rapid thermal annealing for 1 s, and prolonged annealing did not give any increase in coercivity. Detailed results on the effects of annealing time, temperature and heating rate have been obtained. The dependence of magnetic properties on the annealing parameters has been investigated. Structural characterization revealed that there is a close correlation between magnetic hardening and nanostructured morphology. The coercivity mechanism was also studied by analysing the magnetization minor loops.

  5. Modeling microscale heat transfer using Calore.

    Energy Technology Data Exchange (ETDEWEB)

    Gallis, Michail A.; Rader, Daniel John; Wong, Chung-Nin Channy; Bainbridge, Bruce L.; Torczynski, John Robert; Piekos, Edward Stanley


    Modeling microscale heat transfer with the computational-heat-transfer code Calore is discussed. Microscale heat transfer problems differ from their macroscopic counterparts in that conductive heat transfer in both solid and gaseous materials may have important noncontinuum effects. In a solid material, three noncontinuum effects are considered: ballistic transport of phonons across a thin film, scattering of phonons from surface roughness at a gas-solid interface, and scattering of phonons from grain boundaries within the solid material. These processes are modeled for polycrystalline silicon, and the thermal-conductivity values predicted by these models are compared to experimental data. In a gaseous material, two noncontinuum effects are considered: ballistic transport of gas molecules across a thin gap and accommodation of gas molecules to solid conditions when reflecting from a solid surface. These processes are modeled for arbitrary gases by allowing the gas and solid temperatures across a gas-solid interface to differ: a finite heat transfer coefficient (contact conductance) is imposed at the gas-solid interface so that the temperature difference is proportional to the normal heat flux. In this approach, the behavior of gas in the bulk is not changed from behavior observed under macroscopic conditions. These models are implemented in Calore as user subroutines. The user subroutines reside within Sandia's Source Forge server, where they undergo version control and regression testing and are available to analysts needing these capabilities. A Calore simulation is presented that exercises these models for a heated microbeam separated from an ambient-temperature substrate by a thin gas-filled gap. Failure to use the noncontinuum heat transfer models for the solid and the gas causes the maximum temperature of the microbeam to be significantly underpredicted.

  6. Note: Anodic bonding with cooling of heat-sensitive areas

    DEFF Research Database (Denmark)

    Vesborg, Peter Christian Kjærgaard; Olsen, Jakob Lind; Henriksen, Toke Riishøj


    Anodic bonding of silicon to glass always involves heating the glass and device to high temperatures so that cations become mobile in the electric field. We present a simple way of bonding thin silicon samples to borosilicate glass by means of heating from the glass side while locally cooling heat......-sensitive areas from the silicon side. Despite the high thermal conductivity of silicon, this method allows a strong anodic bond to form just millimeters away from areas essentially at room temperature....

  7. Thin film photovoltaic device (United States)

    Catalano, A.W.; Bhushan, M.


    A thin film photovoltaic solar cell which utilizes a zinc phosphide semiconductor is of the homojunction type comprising an n-type conductivity region forming an electrical junction with a p-type region, both regions consisting essentially of the same semiconductor material. The n-type region is formed by treating zinc phosphide with an extrinsic dopant such as magnesium. The semiconductor is formed on a multilayer substrate which acts as an opaque contact. Various transparent contacts may be used, including a thin metal film of the same chemical composition as the n-type dopant or conductive oxides or metal grids. 5 figs.

  8. Shear Thinning in Xenon (United States)

    Bergm Robert F.; Moldover, Michael R.; Yao, Minwu; Zimmerli, Gregory A.


    We measured shear thinning, a viscosity decrease ordinarily associated with complex liquids such as molten plastics or ketchup, near the critical point of xenon. The data span a wide range of dimensionless shear rate: the product of the shear rate and the relaxation time of critical fluctuations was greater than 0.001 and was less than 700. As predicted by theory, shear thinning occurred when this product was greater than 1. The measurements were conducted aboard the Space Shuttle Columbia to avoid the density stratification caused by Earth's gravity.

  9. Thin Film Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Zweibel, K.


    The motivation to develop thin film technologies dates back to the inception of photovoltaics. It is an idea based on achieving truly low-cost photovoltaics appropriate for mass production and energy significant markets. The key to the idea is the use of pennies worth of active materials. Since sunlight carries relatively little energy in comparison with combustion-based energy sources, photovoltaic (PV) modules must be cheap to produce energy that can be competitive. Thin films are presumed to be the answer to that low-cost requirement. But how cheap do they have to be? The following is an oversimplified analysis that allows some insight into this question.

  10. Compact interior heat exchangers for CO{sub 2} mobile heat pumping systems

    Energy Technology Data Exchange (ETDEWEB)

    Hafner, Armin


    The natural refrigerant carbon dioxide (CO{sub 2}) offers new possibilities for design of flexible, efficient and environmentally safe mobile heat pumping systems. As high-efficient car engines with less waste heat are developed, extra heating of the passenger compartment is needed in the cold season. A reversible transcritical CO{sub 2} system with gliding temperature heat rejection can give high air delivery temperature which results in rapid heating of the passenger compartment and rapid defogging or defrosting of windows. When operated in cooling mode, the efficiency of transcritical CO{sub 2} systems is higher compared to common (HFC) air conditioning systems, at most dominant operating conditions. Several issues were identified for the design of compact interior heat exchangers for automotive reversible CO{sub 2} heat pumping systems. Among theses issues are: (1) Refrigerant flow distribution, (2) Heat exchanger fluid flow circuiting, (3) Air temperature uniformity downstream of the heat exchanger, (4) Minimization of temperature approach, (5) Windshield flash fogging due to retained water inside the heat exchanger, (6) Internal beat conduction in heating mode operation, and (7) Refrigerant side pressure drop In order to provide a basis for understanding these issues, the author developed a calculation model and set up a test facility and investigated different prototype heat exchangers experimentally.

  11. Ultra Thin Quantum Well Materials

    Energy Technology Data Exchange (ETDEWEB)

    Dr Saeid Ghamaty


    This project has enabled Hi-Z technology Inc. (Hi-Z) to understand how to improve the thermoelectric properties of Si/SiGe Quantum Well Thermoelectric Materials. The research that was completed under this project has enabled Hi-Z Technology, Inc. (Hi-Z) to satisfy the project goal to understand how to improve thermoelectric conversion efficiency and reduce costs by fabricating ultra thin Si/SiGe quantum well (QW) materials and measuring their properties. In addition, Hi-Z gained critical new understanding on how thin film fabrication increases the silicon substrate's electrical conductivity, which is important new knowledge to develop critical material fabrication parameters. QW materials are constructed with alternate layers of an electrical conductor, SiGe and an electrical insulator, Si. Film thicknesses were varied, ranging from 2nm to 10nm where 10 nm was the original film thickness prior to this work. The optimum performance was determined at a Si and SiGe thickness of 4nm for an electrical current and heat flow parallel to the films, which was an important conclusion of this work. Essential new information was obtained on how the Si substrate electrical conductivity increases by up to an order of magnitude upon deposition of QW films. Test measurements and calculations are accurate and include both the quantum well and the substrate. The large increase in substrate electrical conductivity means that a larger portion of the electrical current passes through the substrate. The silicon substrate's increased electrical conductivity is due to inherent impurities and thermal donors which are activated during both molecular beam epitaxy and sputtering deposition of QW materials. Hi-Z's forward looking cost estimations based on future high performance QW modules, in which the best Seebeck coefficient and electrical resistivity are taken from separate samples predict that the electricity cost produced with a QW module could be achieved at <$0.35/W

  12. Thinning stagnated ponderosa and Jeffrey pine stands in northeastern California: 30-year effects (United States)

    Robert J. Lilieholm; Dennis E. Teeguarden; Donald T. Gordon


    Response to precommercial thinning in stagnated 55-year-old ponderosa (Pinus ponderosa Dougl. ex Laws.) and Jeffrey pine (P. jeffreyi Grev. and Balf.) stands in northeastern alifornia was rapid and long-lasting. During the first 5 years after thinning, average annual diameter at breast height (d.b.h.) and height growth of trees on...

  13. Heat pump


    Klíma, Martin


    Bakalářská práce popisuje a charakterizuje tepelné čerpadlo. Obsahuje souhrn jednotlivých druhů tepelných čerpadel z hlediska získávání energie, princip jejich funkce a popis odlišností mezi jednotlivými druhy kompresorů, použití pracovní látky a její vývin do budoucna. Závěrem je zde uveden můj vlastní názor na tepelné čerpadlo, které bych preferoval. Bachelor thesis describes and characterizes the heat pump. Summarizes the various types of heat pumps in terms of energy production, princi...

  14. Heat Exchange


    Bottomley, Stephen


    Heat Exchange’ is an international touring exhibition of enamel metalwork curated by Turrell.E (UK), Gegenwart (Germany/UK) and Cameron (Australia). Bottomley was one of twenty-three international artists invited to join a transcontinental on-line blog and forum that recorded individual contemporary approaches to working with vitreous enamel the year prior to the 2012 exhibition that coincided with the SNAG (Society of North American Goldsmiths) National Conference in Phoenix Arizona USA.Vitr...

  15. Thin-film calorimetry. In-situ characterization of materials for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Omelcenko, Alexander; Wulfmeier, Hendrik; Albrecht, Daniel; Fritze, Holger [Clausthal Univ. of Technology, Goslar (Germany). Inst. of Energy Research and Physical Technologies; El Mofid, Wassima; Ivanov, Svetlozar; Bund, Andreas [Ilmenau Univ. of Technology (Germany). Dept. of Electrochemistry


    Thin-film calorimetry allows for qualitative and quantitative in-situ analysis of thermodynamic properties of thin films and thin-film systems from room temperature up to 1000 C. It is based on highly sensitive piezoelectric langasite resonators which serve simultaneously as planar temperature sensors and substrates for the films of interest. Generation or consumption of heat during phase transformations of the films cause deviations from the regular course of the resonance frequency. Thermodynamic data such as phase transformation temperatures and enthalpies are extracted from these deviations. Thin-film calorimetry on Sn and Al thin films is performed to prove the concept. The results demonstrate high reproducibility of the measurement approach and are in agreement with literature data obtained by established calorimetric techniques. The calibration of the system is done in different atmospheres by application of defined heat pulses via heating structures. The latter replace the films of interest and simulate phase transformations to provide detailed analysis of the heat transfer mechanisms occurring in the measurement system. Based on this analysis, a data evaluation concept is developed. Application-relevant studies are performed on thin films of the lithium-ion battery materials NMC(A), NCA, LMO, and MoS{sub 2}. Their phase transformation temperatures and enthalpies are evaluated in oxidizing and reducing atmospheres. Furthermore, their thermodynamic stability ranges are presented. Finally, measurements on all-solid-state thin-film batteries during electrochemical cycling are performed. They demonstrate the suitability of the system for in-situ investigations.

  16. Methods and compositions for rapid thermal cycling (United States)

    Beer, Neil Reginald; Benett, William J.; Frank, James M.; Deotte, Joshua R.; Spadaccini, Christopher


    The rapid thermal cycling of a material is targeted. A microfluidic heat exchanger with an internal porous medium is coupled to tanks containing cold fluid and hot fluid. Fluid flows alternately from the cold tank and the hot tank into the porous medium, cooling and heating samples contained in the microfluidic heat exchanger's sample wells. A valve may be coupled to the tanks and a pump, and switching the position of the valve may switch the source and direction of fluid flowing through the porous medium. A controller may control the switching of valve positions based on the temperature of the samples and determined temperature thresholds. A sample tray for containing samples to be thermally cycled may be used in conjunction with the thermal cycling system. A surface or internal electrical heater may aid in heating the samples, or may replace the necessity for the hot tank.

  17. Avoid heat transfer equipment vibration

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, V.


    Tube bundles in heat exchangers, boilers, superheaters and heaters are often subject to vibration and noise problems. Vibration can lead to tube thinning and wear, resulting in tube failures. Excessive noise can be a problem to plant operating personnel. Large gas pressure drop across the equipment is also a side effect, which results in large operating costs. With the design checks presented in this paper, one can predict during design if problems associated with noise and vibration are likely to occur in petroleum refineries.

  18. Thin Wall Iron Castings

    Energy Technology Data Exchange (ETDEWEB)

    J.F. Cuttino; D.M. Stefanescu; T.S. Piwonka


    Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.

  19. Epitaxial thin films (United States)

    Hunt, Andrew Tye; Deshpande, Girish; Lin, Wen-Yi; Jan, Tzyy-Jiuan


    Epitatial thin films for use as buffer layers for high temperature superconductors, electrolytes in solid oxide fuel cells (SOFC), gas separation membranes or dielectric material in electronic devices, are disclosed. By using CCVD, CACVD or any other suitable deposition process, epitaxial films having pore-free, ideal grain boundaries, and dense structure can be formed. Several different types of materials are disclosed for use as buffer layers in high temperature superconductors. In addition, the use of epitaxial thin films for electrolytes and electrode formation in SOFCs results in densification for pore-free and ideal gain boundary/interface microstructure. Gas separation membranes for the production of oxygen and hydrogen are also disclosed. These semipermeable membranes are formed by high-quality, dense, gas-tight, pinhole free sub-micro scale layers of mixed-conducting oxides on porous ceramic substrates. Epitaxial thin films as dielectric material in capacitors are also taught herein. Capacitors are utilized according to their capacitance values which are dependent on their physical structure and dielectric permittivity. The epitaxial thin films of the current invention form low-loss dielectric layers with extremely high permittivity. This high permittivity allows for the formation of capacitors that can have their capacitance adjusted by applying a DC bias between their electrodes.

  20. Thermal deformation in a thin circular plate due to a partially ...

    Indian Academy of Sciences (India)

    Keywords. Transient problem; thermal deformation; heat conduction problem. Abstract. In this paper, we develop an integral transform to determine temperature distribution in a thin circular plate, subjected to a partially distributed and axisymmetric heat supply on the curved surface, and study the thermal deformation.

  1. Heat pump system (United States)

    Swenson, Paul F.; Moore, Paul B.


    An air heating and cooling system for a building includes an expansion-type refrigeration circuit and a heat engine. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The heat engine includes a heat rejection circuit having a source of rejected heat and a primary heat exchanger connected to the source of rejected heat. The heat rejection circuit also includes an evaporator in heat exchange relation with the primary heat exchanger, a heat engine indoor heat exchanger, and a heat engine outdoor heat exchanger. The indoor heat exchangers are disposed in series air flow relationship, with the heat engine indoor heat exchanger being disposed downstream from the refrigeration circuit indoor heat exchanger. The outdoor heat exchangers are also disposed in series air flow relationship, with the heat engine outdoor heat exchanger disposed downstream from the refrigeration circuit outdoor heat exchanger. A common fluid is used in both of the indoor heat exchangers and in both of the outdoor heat exchangers. In a first embodiment, the heat engine is a Rankine cycle engine. In a second embodiment, the heat engine is a non-Rankine cycle engine.

  2. Thin film metal-oxides

    CERN Document Server

    Ramanathan, Shriram


    Presents an account of the fundamental structure-property relations in oxide thin films. This title discusses the functional properties of thin film oxides in the context of applications in the electronics and renewable energy technologies.

  3. Turbulent energy losses during orchard heating

    Energy Technology Data Exchange (ETDEWEB)

    Bland, W.L.


    Two rapid-response drag anemometers and low time constant thermocouples, all at 4 m above a heated orchard floor, sampled wind component in the vertical direction and temperature at 30 Hz. The turbulent heat flux calculated revealed not more than 10% of the heat lost from the orchard was via turbulent transort. The observations failed to support previous estimates that at least a third of the energy applied was lost through turbulent transport. Underestimation of heat loss due to mean flow and a newly revealed flux due to spatial variations in the mean flow may explain the unaccounted for loss.

  4. Heat-Exchanger/Heat-Pipe Interface (United States)

    Snyder, H. J.; Van Hagan, T. H.


    Monolithic assembly reliable and light in weight. Heat exchanger and evaporator ends of heat pipes integrated in monolithic halves welded together. Interface assembly connects heat exchanger of furnace, reactor, or other power source with heat pipes carrying heat to radiator or power-consuming system. One of several concepts proposed for nuclear power supplies aboard spacecraft, interface useful on Earth in solar thermal power systems, heat engines, and lightweight cooling systems.

  5. An On-Line Method for Thermal Diffusivity Detection of Thin Films Using Infrared Video

    Directory of Open Access Journals (Sweden)

    Dong Huilong


    Full Text Available A novel method for thermal diffusivity evolution of thin-film materials with pulsed Gaussian beam and infrared video is reported. Compared with common pulse methods performed in specialized labs, the proposed method implements a rapid on-line measurement without producing the off-centre detection error. Through mathematical deduction of the original heat conduction model, it is discovered that the area s, which is encircled by the maximum temperature curve rTMAX(θ, increases linearly over elapsed time. The thermal diffusivity is acquired from the growth rate of the area s. In this study, the off-centre detection error is avoided by performing the distance regularized level set evolution formulation. The area s was extracted from the binary images of temperature variation rate, without inducing errors from determination of the heat source centre. Thermal diffusivities of three materials, 304 stainless steel, titanium, and zirconium have been measured with the established on-line detection system, and the measurement errors are: −2.26%, −1.07%, and 1.61% respectively.

  6. Ultrasonic-Assisted Incremental Microforming of Thin Shell Pyramids of Metallic Foil

    Directory of Open Access Journals (Sweden)

    Toshiyuki Obikawa


    Full Text Available Single point incremental forming is used for rapid prototyping of sheet metal parts. This forming technology was applied to the fabrication of thin shell micropyramids of aluminum, stainless steel, and titanium foils. A single point tool used had a tip radius of 0.1 mm or 0.01 mm. An ultrasonic spindle with axial vibration was implemented for improving the shape accuracy of micropyramids formed on 5–12 micrometers-thick aluminum, stainless steel, and titanium foils. The formability was also investigated by comparing the forming limits of micropyramids of aluminum foil formed with and without ultrasonic vibration. The shapes of pyramids incrementally formed were truncated pyramids, twisted pyramids, stepwise pyramids, and star pyramids about 1 mm in size. A much smaller truncated pyramid was formed only for titanium foil for qualitative investigation of the size reduction on forming accuracy. It was found that the ultrasonic vibration improved the shape accuracy of the formed pyramids. In addition, laser heating increased the forming limit of aluminum foil and it is more effective when both the ultrasonic vibration and laser heating are applied.

  7. Ultra-thin multilayer capacitors.

    Energy Technology Data Exchange (ETDEWEB)

    Renk, Timothy Jerome; Monson, Todd C.


    The fabrication of ultra-thin lanthanum-doped lead zirconium titanate (PLZT) multilayer ceramic capacitors (MLCCs) using a high-power pulsed ion beam was studied. The deposition experiments were conducted on the RHEPP-1 facility at Sandia National Laboratories. The goal of this work was to increase the energy density of ceramic capacitors through the formation of a multilayer device with excellent materials properties, dielectric constant, and standoff voltage. For successful device construction, there are a number of challenging requirements including achieving correct stoichiometric and crystallographic composition of the deposited PLZT, as well as the creation of a defect free homogenous film. This report details some success in satisfying these requirements, although 900 C temperatures were necessary for PLZT perovskite phase formation. These temperatures were applied to a previously deposited multi-layer film which was then post-annealed to this temperature. The film exhibited mechanical distress attributable to differences in the coefficient of thermal expansion (CTE) of the various layers. This caused significant defects in the deposited films that led to shorts across devices. A follow-on single layer deposition without post-anneal produced smooth layers with good interface behavior, but without the perovskite phase formation. These issues will need to be addressed in order for ion beam deposited MLCCs to become a viable technology. It is possible that future in-situ heating during deposition may address both the CTE issue, and result in lowered processing temperatures, which in turn could raise the probability of successful MLCC formation.

  8. Thermally evaporated conformal thin films on non-traditional/non-planar substrates (United States)

    Pulsifer, Drew Patrick

    female's elytra. As rearing EAB and then deploying dead females as decoys is both arduous and inconvenient, the development of an artificial decoy would be of great interest to entomologists and foresters. A dead female EAB was used to make a negative die of nickel and a positive die of epoxy. The process of fabricating the paired dies utilized thermally evaporated conformal thin films in several critical steps. In order to conformally coat the EAB with nickel, the substrate stage holding the female EAB was periodically rocked and rotated during the deposition. This process was designed to result in a uniform thin film of ˜ 500-nm thickness with dense morphology. The nickel film was then reinforced through an electroforming process and mounted in a fixture which allowed it to be heated electrically. The corresponding positive die was replicated from the negative die through a series of successive castings. The final EAB positive die was fabricated from a hard epoxy material and attached to a fixture which allowed it to be heated while being pressed into the negative die. Decoys were then made by first depositing a quarter-wave-stack Bragg reflector on a polymer sheet and then stamping it with the pair of matched negative and positive dies to take the shape of the upper surface of an EAB female. As nearly 100 decoys were fabricated from just one EAB female, this bioreplication process is industrially scalable. Preliminary results from field trapping tests are indicative of success. For the second setting, a method of developing latent fingermarks with thermally evaporated conformal thin films was developed. Fingermarks have long been used to identify the individual who left them behind when he/she touched an object with the friction ridges of his/her hands. In many cases the fingermark which is left behind consists of sebaceous secretions which are not clearly visible under normal conditions. In order to make the fingermarks visible and identifiable, they are

  9. Effect of the rate of temperature increase on water quality during heating in electromagnetic- and gas-heated pans. (United States)

    Hiratsuka, Hiroshi; Sasaki, Ken


    More rapid increases in the pH value and hardness during electromagnetic heating of a pan of water were observed than when the pan was heated by LNG or LPG. The water quality changed universally in several tap water samples across Japan. This quality change was closely correlated with the rate of temperature increase, irrespective of heating by electromagnetic induction, LNG or LPG.

  10. Ultra thin films for sensing and heating of microprobes

    NARCIS (Netherlands)

    Gaitas, A.


    This dissertation aims to advance the current state of cantilevers with integrated metal thermal and deflection sensing elements. Metallic sensing elements enable the use of alternative substrate materials (such as polymers), that tend to exhibit higher compliance properties and are more robust

  11. Thin Films Protect Electronics from Heat and Radiation (United States)


    While Anne St. Clair worked on high performance polyimides at Langley Research Center, she noticed that some of the films were nearly colorless. The polyimides became known as LaRC-CP1 and LaRC-CP2, and were licensed by NeXolve Corporation, based in Huntsville, Alabama. Today, NeXolve provides polyimide film products to commercial customers for spacecraft, telescopes, and circuit boards.

  12. Rare Earth Oxide Thin Films

    CERN Document Server

    Fanciulli, Marco


    Thin rare earth (RE) oxide films are emerging materials for microelectronic, nanoelectronic, and spintronic applications. The state-of-the-art of thin film deposition techniques as well as the structural, physical, chemical, and electrical properties of thin RE oxide films and of their interface with semiconducting substrates are discussed. The aim is to identify proper methodologies for the development of RE oxides thin films and to evaluate their effectiveness as innovative materials in different applications.

  13. Heating systems for heating subsurface formations

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Scott Vinh [Houston, TX; Vinegar, Harold J [Bellaire, TX


    Methods and systems for heating a subsurface formation are described herein. A heating system for a subsurface formation includes a sealed conduit positioned in an opening in the formation and a heat source. The sealed conduit includes a heat transfer fluid. The heat source provides heat to a portion of the sealed conduit to change phase of the heat transfer fluid from a liquid to a vapor. The vapor in the sealed conduit rises in the sealed conduit, condenses to transfer heat to the formation and returns to the conduit portion as a liquid.

  14. Hydride heat pump with heat regenerator (United States)

    Jones, Jack A. (Inventor)


    A regenerative hydride heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system. A series of at least four canisters containing a lower temperature performing hydride and a series of at least four canisters containing a higher temperature performing hydride is provided. Each canister contains a heat conductive passageway through which a heat transfer fluid is circulated so that sensible heat is regenerated. The process and system are useful for air conditioning rooms, providing room heat in the winter or for hot water heating throughout the year, and, in general, for pumping heat from a lower temperature to a higher temperature.

  15. Thin film metallic sensors in an alternating magnetic field for magnetic nanoparticle hyperthermia cancer therapy (United States)

    Hussein, Z. A.; Boekelheide, Z.

    In magnetic nanoparticle hyperthermia in an alternating magnetic field for cancer therapy, it is important to monitor the temperature in situ. This can be done optically or electrically, but electronic measurements can be problematic because conducting parts heat up in a changing magnetic field. Microfabricated thin film sensors may be advantageous because eddy current heating is a function of size, and are promising for further miniaturization of sensors and fabrication of arrays of sensors. Thin films could also be used for in situ magnetic field sensors or for strain sensors. For a proof of concept, we fabricated a metallic thin film resistive thermometer by photolithographically patterning a 500Å Au/100Å Cr thin film on a glass substrate. Measurements were taken in a solenoidal coil supplying 0.04 T (rms) at 235 kHz with the sensor parallel and perpendicular to the magnetic field. In the parallel orientation, the resistive thermometer mirrored the background heating from the coil, while in the perpendicular orientation self-heating was observed due to eddy current heating of the conducting elements by Faraday's law. This suggests that metallic thin film sensors can be used in an alternating magnetic field, parallel to the field, with no significant self-heating.

  16. Sputtered Thin Film Research (United States)


    influences substrate heating and uniformity of the deposition Th. ing .50 L/sec in the milxitorr range. Use of the turbomolecular pump in place...evaluation of the films eposited. Prior to film deposition the wafers were degreased, boiled in nitric acid rinsed in high resitivity deionized...the shutters were opened and film depositxon was initiated. After film deposition, heat treatments in nitrogen, hydrogen and oxygen were investigated

  17. Using a Microscale Approach to Rapidly Separate and Characterize Three Photosynthetic Pigment Species from Fern (United States)

    Ayudhya, Theppawut Israsena Na; Posey, Frederick T.; Tyus, Jessica C.; Dingra, Nin N.


    A rapid separation of three photosynthetic pigments (chlorophyll "a" and "b" and xanthophyll) from fern ("Polystichum acrostichoides") is described using microscale solvent extraction and traditional thin layer chromatography that minimizes use of harmful chemicals and lengthy procedures. The experiment introduces…

  18. Modeling of thinning process of structures in temperature analysis and its verification

    Energy Technology Data Exchange (ETDEWEB)

    Tsukimori, K.; Furuhashi, I. [Japan Nuclear Cycle Development Institute, JNC, Ibaraki-ken (Japan)


    It is important to consider the thinning process in analyzing the behavior of structures including the change of their strength when thinning of structures is significant due to corrosion, melting, etc. The thinning process in the stress or strain analysis can be expressed by using artificial creep and reduction of elastic modulus for example. If the thinning process goes with temperature change, temperature analysis has to be needed. If the structures are relatively thin like thin plates or thin shells, the effect of thinning process may be neglected in the temperature analysis. However, in the cases of thick structures or the structures of which temperature gradient in the thickness is expected to be large due to thermal boundary conditions, the thinning process should be considered in the temperature analyses as well as stress or strain analyses. In this study the modeling of thinning process in the temperature analysis has been developed. The detailed formulation is described and the function of this modeling is verified by simple one dimensional problem. As an applied example, a problem of thinning heat tube is analyzed. (authors)

  19. In Situ Tuning of Focused-Ion-Beam Defined Nanomechanical Resonators Using Joule Heating

    DEFF Research Database (Denmark)

    Homann, Lasse Vinther; Booth, Tim; Lei, Anders


    Nanomechanical resonators have a huge potential for a variety of applications, including high-resolution mass sensing. In this paper, we demonstrate a novel rapid prototyping method for fabricating nanoelectromechanical systems using focused-ion-beam milling as well as in situ electromechanical...... characterization using a transmission electron microscope. Nanomechanical resonators were cut out of thin membrane chips, which have been prefabricated using standard cleanroom processing. We have demonstrated the fabrication of double-clamped beams with feature sizes down to 200 nm using a fabrication time of 30...... min per device. Afterwards, the dynamic and structural properties of a double-clamped beam were measured after subsequent Joule heating events in order to ascertain the dependence of the internal structure on the Q-factor and resonant frequency of the device. It was observed that a change from...

  20. Heat pipes

    CERN Document Server

    Dunn, Peter D


    A comprehensive, up-to-date coverage of the theory, design and manufacture of heat pipes and their applications. This latest edition has been thoroughly revised, up-dated and expanded to give an in-depth coverage of the new developments in the field. Significant new material has been added to all the chapters and the applications section has been totally rewritten to ensure that topical and important applications are appropriately emphasised. The bibliography has been considerably enlarged to incorporate much valuable new information. Thus readers of the previous edition, which has established

  1. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... Emergencies A-Z Share this! Home » Emergency 101 Heat-Related Illnesses Dr. Glenn Mitchell , Emergency physician at ... about heat cramps and heat stroke and exhaustion. Heat Cramps Symptoms include muscle spasms, usually in the ...

  2. Low temperature nuclear heat

    Energy Technology Data Exchange (ETDEWEB)

    Kotakorpi, J.; Tarjanne, R. (comps.)


    The meeting was concerned with the use of low grade nuclear heat for district heating, desalination, process heat, and agriculture and aquaculture. The sessions covered applications and demand, heat sources, and economics.

  3. Regenerative Hydride Heat Pump (United States)

    Jones, Jack A.


    Hydride heat pump features regenerative heating and single circulation loop. Counterflow heat exchangers accommodate different temperatures of FeTi and LaNi4.7Al0.3 subloops. Heating scheme increases efficiency.

  4. Failure analysis of thin film solar modules using lock-in thermography


    Siegloch, Max


    Lock-in thermography (LIT) is an imaging method that depicts radiated heat and its diffusion in manifold samples. LIT offers versatile possibilities for the characterization of solar cells and modules since the radiated heat is proportional to the dissipation of electrical power. Up to now, the quantitative correlation of detected heat and dissi-pated electrical power has been known for silicon solar cells only. For many other types of solar cells and modules – especially thin film solar cell...

  5. Synthesis of thin films by the pyrosol process

    Directory of Open Access Journals (Sweden)

    Tucić Aleksandar


    Full Text Available Among many aerosol routes, the Pyrosol process, due to its simplicity, low cost and quality of obtained films, represents a promising technique for the synthesis of thin films. The pyrosol process is based on the transport and pyrolysls of an aerosol of processor solution, generated in an ultrasonic atomizer, on a heated substrate. The theoretical principles of the pyrosol process are presented in this paper, as well as the influence of some synthesis parameters on the deposition of SnO2 thin films.

  6. Biomimetic thin film deposition

    Energy Technology Data Exchange (ETDEWEB)

    Rieke, P.R.; Graff, G.E.; Campbell, A.A.; Bunker, B.C.; Baskaran, S.; Song, L.; Tarasevich, B.J.; Fryxell, G.E.


    Biological mineral deposition for the formation of bone, mollusk shell and other hard tissues provides materials scientists with illustrative materials processing strategies. This presentation will review the key features of biomineralization and how these features can be of technical importance. We have adapted existing knowledge of biomineralization to develop a unique method of depositing inorganic thin films and coating. Our approach to thin film deposition is to modify substrate surfaces to imitate the proteins found in nature that are responsible for controlling mineral deposition. These biomimetic surfaces control the nucleation and growth of the mineral from a supersaturated aqueous solution. This has many processing advantages including simple processing equipment, environmentally benign reagents, uniform coating of highly complex shapes, and enhanced adherence of coating. Many different types of metal oxide, hydroxide, sulfide and phosphate materials with useful mechanical, optical, electronic and biomedical properties can be deposited.

  7. Thin film processes

    CERN Document Server

    Vossen, John L


    Remarkable advances have been made in recent years in the science and technology of thin film processes for deposition and etching. It is the purpose of this book to bring together tutorial reviews of selected filmdeposition and etching processes from a process viewpoint. Emphasis is placed on the practical use of the processes to provide working guidelines for their implementation, a guide to the literature, and an overview of each process.

  8. Thin film superconductor magnetic bearings (United States)

    Weinberger, Bernard R.


    A superconductor magnetic bearing includes a shaft (10) that is subject to a load (L) and rotatable around an axis of rotation, a magnet (12) mounted to the shaft, and a stator (14) in proximity to the shaft. The stator (14) has a superconductor thin film assembly (16) positioned to interact with the magnet (12) to produce a levitation force on the shaft (10) that supports the load (L). The thin film assembly (16) includes at least two superconductor thin films (18) and at least one substrate (20). Each thin film (18) is positioned on a substrate (20) and all the thin films are positioned such that an applied magnetic field from the magnet (12) passes through all the thin films. A similar bearing in which the thin film assembly (16) is mounted on the shaft (10) and the magnet (12) is part of the stator (14) also can be constructed.

  9. Isomerization and optical bistability of DR1 doped organic-inorganic sol-gel thin film (United States)

    Gao, Tianxi; Que, Wenxiu; Shao, Jinyou


    To investigate the isomerization process of the disperse red 1 (DR1) doped TiO2/ormosil thin film, both the photo-isomerization and the thermal isomerization of the thin films were observed as a change of the absorption spectrum. Under a real-time heat treatment, the change of the linear refractive index shows a thermal stable working temperature range below Tg. The optical bistability (OB) effect of the DR1 doped thin films based on different matrices was studied and measured at a wavelength of 532 nm. Results indicate that the TiO2/ormosils based thin film presents a better OB-gain than that of the poly (methyl methacrylate) (PMMA) based thin film due to its more rigid network structure. Moreover, it is also noted that higher titanium content is helpful for enhancing the OB-gain of the as-prepared hybrid thin films.

  10. Heating of protostellar accretion disks (United States)

    de Campos, R. R.; Jatenco-Pereira, V.


    The magneto-rotational instability (MRI) is believed to be the mechanism responsible for a magneto-hydrodynamic turbulence that could lead to the accretion observed in protoplanetary disks. The need of a minimum amount of ionization in protostellar accretion disks is necessary for the MRI to take place. There are in the literature several studies that include the damping of Alfvén waves as an additional heating source besides the viscous heating mechanism in a geometrically thin and optically thick disk. The damping of the waves transfers energy to the disk increasing the temperature and consequently its ionization fraction, making possible the presence of the MRI in a large part of the disk. We analyzed the contribution of non-ideal effects such as Ohmic and ambipolar diffusion for the disk heating and compare these heating rates with those obtained by damping of Alfvén waves. In order to study these non-ideal effects, we have estimated the radiation emission of each effect through the energy conservation equation, and associated each emission with a black body radiation, which enabled us to assign a temperature contribution of each effect. Using the ATHENA code we were able to simulate the disk at different radial distances, and estimate the electric current density needed to calculate the radiation emission associated with each effect. Once we have those data, we were able to compare the results with other heating sources, like viscosity and Alfvén waves damping, and we concluded that the Ohmic and ambipolar diffusions do not heat the disk in any significant way.

  11. Segmented heat exchanger (United States)

    Baldwin, Darryl Dean; Willi, Martin Leo; Fiveland, Scott Byron; Timmons, Kristine Ann


    A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

  12. Dual source heat pump (United States)

    Ecker, Amir L.; Pietsch, Joseph A.


    What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid provides energy for defrosting the second heat exchanger when operating in the air source mode and also provides a alternate source of heat.

  13. Turbulent resistive heating of solar coronal arches (United States)

    Benford, G.


    The possibility that coronal heating occurs by means of anomalous Joule heating by electrostatic ion cyclotron waves is examined, with consideration given to currents running from foot of a loop to the other. It is assumed that self-fields generated by the currents are absent and currents follow the direction of the magnetic field, allowing the plasma cylinder to expand radially. Ion and electron heating rates are defined within the cylinder, together with longitudinal conduction and convection, radiation and cross-field transport, all in terms of Coulomb and turbulent effects. The dominant force is identified as electrostatic ion cyclotron instability, while ion acoustic modes remain stable. Rapid heating from an initial temperature of 10 eV to 100-1000 eV levels is calculated, with plasma reaching and maintaining a temperature in the 100 eV range. Strong heating is also possible according to the turbulent Ohm's law and by resistive heating.

  14. Forced convective heat transfer in curved diffusers (United States)

    Rojas, J.; Whitelaw, J. H.; Yianneskis, M.


    Measurements of the velocity characteristics of the flows in two curved diffusers of rectangular cross section with C and S-shaped centerlines are presented and related to measurements of wall heat transfer coefficients along the heated flat walls of the ducts. The velocity results were obtained by laser-Doppler anemometry in a water tunnel and the heat transfer results by liquid crystal thermography in a wind tunnel. The thermographic technique allowed the rapid and inexpensive measurement of wall heat transfer coefficients along flat walls of arbitrary boundary shapes with an accuracy of about 5 percent. The results show that an increase in secondary flow velocities near the heated wall causes an increase in the local wall heat transfer coefficient, and quantify the variation for maximum secondary-flow velocities in a range from 1.5 to 17 percent of the bulk flow velocity.

  15. Rapid and Complete Enzyme Hydrolysis of Lignocellulosic Nanofibrils (United States)

    Raquel Martin-Sampedro; Ilari Filpponen; Ingrid C. Hoeger; J.Y. Zhu; Janne Laine; Orlando J. Rojas


    Rapid enzymatic saccharification of lignocellulosic nanofibrils (LCNF) was investigated by monitoring nanoscale changes in mass via quartz crystal microgravimetry and also by measuring reducing sugar yields. In only a few minutes LCNF thin films were completely hydrolyzed upon incubation in multicomponent enzyme systems. Conversion to sugars and oligosaccharides of...

  16. Status of Joining Thin Sheet and Thin Wall Tubes of 14YWT

    Energy Technology Data Exchange (ETDEWEB)

    Hoelzer, David T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Unocic, Kinga A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Tang, Wei [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Feng, Zhili [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)


    Beginning this fiscal year, the FCRD research project initiated an investigation on joining thin sections of the advanced ODS 14YWT ferritic alloy. Friction stir welding (FSW) was investigated as a method to join thin plate and tubing of 14YWT since it is a solid state joining method that has been shown in past studies to be a promising method for joining plates of ODS alloys, such as 14YWT. However, this study will attempt to be the first to demonstrate if FSW can successfully join thin plates and thin wall tubing of 14YWT. In the first FSW attempt, a 1.06 cm thick plate of 14YWT (SM13 heat) was successfully rolled at 1000ºC to the target thickness of 0.1 cm with no edge cracking. This achievement is a highlight since previous attempts to roll 14YWT plates have resulted in extensive cracking. For the FSW run, a pin tool being developed by the ORNL FSW Process Development effort was used. The first FSW run successfully produced a bead-on-plate weld in the 0.1 cm thick plate. The quality of the weld zone appears very good with no evidence of large defects such as cavities. The microstructural characterization study of the bead-on-plate weld zone has been initiated to compare the results of the microstructure analysis with those obtained in the reference microstructural analysis of the 14YWT (SM13 heat) that showed ultra-fine grain size of 0.43 μm and a high number density of ~2-5 nm sizes oxygen-enriched nanoclusters.

  17. Electromagnetic Heating Methods for Heavy Oil Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Sahni, A.; Kumar, M.; Knapp, R.B.


    The most widely used method of thermal oil recovery is by injecting steam into the reservoir. A well-designed steam injection project is very efficient in recovering oil, however its applicability is limited in many situations. Simulation studies and field experience has shown that for low injectivity reservoirs, small thickness of the oil-bearing zone, and reservoir heterogeneity limits the performance of steam injection. This paper discusses alternative methods of transferring heat to heavy oil reservoirs, based on electromagnetic energy. They present a detailed analysis of low frequency electric resistive (ohmic) heating and higher frequency electromagnetic heating (radio and microwave frequency). They show the applicability of electromagnetic heating in two example reservoirs. The first reservoir model has thin sand zones separated by impermeable shale layers, and very viscous oil. They model preheating the reservoir with low frequency current using two horizontal electrodes, before injecting steam. The second reservoir model has very low permeability and moderately viscous oil. In this case they use a high frequency microwave antenna located near the producing well as the heat source. Simulation results presented in this paper show that in some cases, electromagnetic heating may be a good alternative to steam injection or maybe used in combination with steam to improve heavy oil production. They identify the parameters which are critical in electromagnetic heating. They also discuss past field applications of electromagnetic heating including technical challenges and limitations.

  18. Enhancement of Aluminum Alloy Forgings through Rapid Billet Heating

    Energy Technology Data Exchange (ETDEWEB)

    Kervick, R.; Blue, C. A.; Kadolkar, P. B.; Ando, T.; Lu, H.; Nakazawa, K.; Mayer, H.; Mochnal, G.


    Forging is a manufacturing process in which metal is pressed, pounded or squeezed under great pressure and, often, under high strain rates into high-strength parts known as forgings. The process is typically performed hot by preheating the metal to a desired temperature before it is worked. The forging process can create parts that are stronger than those manufactured by any other metal working process. Forgings are almost always used where reliability and human safety are critical. Forgings are normally component parts contained inside assembled items such airplanes, automobiles, tractors, ships, oil drilling equipment, engines missiles, and all kinds of capital equipment Forgings are stronger than castings and surpass them in predictable strength properties, producing superior strength that is assured, part to part.

  19. The Effective Fracture Toughness of Aluminum at Rapid Heating Rates. (United States)


    Load (lb) y Load at Yield (lb) 1 Plate thickness N Number of Fatigue Cucles n Ramberg - Osgood exponent for true plastic tensile strain S P Laser power on...l Etftl tun-i ( [I ___nlhfu t _(_t )__l] C10) n + l y toa t I t u t E t where n - the Ramberg - Osgood exponent for true plastic tensile v strain...n htpuatu (at n+l E tf tl ,tu, n uhu n+l [ (-) hf u -0tu tut t where n - the Ramberg - Osgood exponent for true plastic tensile strain atpu - true

  20. Rapid Nanoparticle Synthesis by Magnetic and Microwave Heating

    National Research Council Canada - National Science Library

    Viktor Chikan; Emily J McLaurin


      Traditional hot-injection (HI) syntheses of colloidal nanoparticles (NPs) allows good separation of the nucleation and growth stages of the reaction, a key limitation in obtaining monodisperse NPs, but with limited scalability...

  1. Thermal Inactivation of Bacillus anthracis Spores Using Rapid Resistive Heating (United States)


    I have to extend my gratitude and thanks to one of my previous active duty Air Force units. The AFRL Battlespace Acoustics Branch (RHCB) within...coating (CARC)-painted steel (non-smooth steel surface), polycarbonate, and vinyl tile (Lewandowski et al., 2010; Edmonds et al., 2009). The highest

  2. Rapid Solidification of Magnetic Oxides (United States)

    Kalonji, G.; Deguire, M. R.


    The enhanced control over microstructural evolution inherent in rapid solidification processing techniques are exploited to create novel ceramic magnetic materials. The great sensitivity of magnetic properties to local structure provides a powerful probe both for the study of structure and of microscopic solidification mechanisms. The first system studied is the SrO-Fe2O3 binary, which contains the commercially important hard magnetic compound strontium hexaferrite. The products were analyzed by transmission electron microscopy, Mossbauer spectroscopy, magnetic measurements, and differential thermal analysis. As-quenched ribbons contain high concentrations of super-paramagnetic particles, 80 to 250 Angstroms in diameter, in a glassy matrix. This suggests the possibility of crystallizing monodomain strontium hexaferrite during subsequent heat treatment, with a resulting increase in coercivity over conventionally processed ferrite magnets. That magnetic properties can be controlled in solidification processing by varying the quench rate is demonstrated.

  3. Instantaneous heat flux flowing into ceramic combustion chamber wall surface of low heat rejection engine; Shanetsu engine no ceramic nenshoshitsu hekimen eno shunji netsuryusoku

    Energy Technology Data Exchange (ETDEWEB)

    Enomoto, Y.; Hagihara, Y. [Musashi Institute of Technology, Tokyo (Japan); Kimura, S. [Nissan Motor Co. Ltd., Tokyo (Japan); Adachi, K. [Daido Hoxan Inc., Sapporo (Japan); Nagano, H. [Riso Kagaku Corp., Tokyo (Japan); Ishii, A. [Mitani Sangyo Co. Ltd., Tokyo (Japan)


    To evaluate the effectiveness of low heat rejection engine under heat loss condition, instantaneous heat fluxes flowing into ceramic piston surface and aluminum alloy (Loex) piston surface using thin film thermocouple were measured, and both were compared. As a result, in the working stroke, the instantaneous heat flux flowing into ceramic piston surface was larger than the instantaneous heat flux flowing into Loex piston surface. Accordingly, it became clear that reduction of heat loss was not effected when ceramics that thermal conductivity is small was used for combustion chamber wall. 21 refs., 14 figs.

  4. Application of Ultra Thin Titanium-based Thermal Ground Plane (TiTGP) Thermal Solution for DoD Applications (United States)


    thinner TGP, thin- wall cylindrical heat pipes were flattened, and bonded between two aluminum facesheets. Although these TGPs were thinner (~4 mm...tolerant to internal temporal working fluid pressure variations caused by temperature. The thin- wall flattened heat pipes tended toward their...2.6 ppm/°C, respectively) resulting in delamination of components and cracking The Titanium Based Approach Titanium has superior mechanical

  5. Thermal stability of gallium-doped zinc oxide thin film on glass substrates by an RF sputtering process. (United States)

    Kang, Jong-Ho; Lee, Myung-Hyun; Lim, Young Soo; Choi, Hyoung-Seuk; Seo, Won-Seon; Bang, Jung-Sik; Jang, Hyun-Woo; Choi, Heon-Jin


    The effects of a heat treatment on the structural and electrical properties of GZO thin films grown by RF magnetron sputtering were investigated. The heat treatment involved temperatures in the range from 200 degrees C to 500 degrees C under air. As the temperature was increased, the electrical properties of GZO thin films increased exponentially and the surface morphology was drastically altered. The effect of temperature is discussed based on electrical and structural characterization of the materials.

  6. Rapid Prototyping Laboratory (United States)

    Federal Laboratory Consortium — The ARDEC Rapid Prototyping (RP) Laboratory was established in December 1992 to provide low cost RP capabilities to the ARDEC engineering community. The Stratasys,...

  7. Heat transfer to the adsorbent in solar adsorption cooling device (United States)

    Pilat, Peter; Patsch, Marek; Papucik, Stefan; Vantuch, Martin


    The article deals with design and construction of solar adsorption cooling device and with heat transfer problem in adsorber. The most important part of adsorption cooling system is adsorber/desorber containing adsorbent. Zeolith (adsorbent) type was chosen for its high adsorption capacity, like a coolant was used water. In adsorber/desorber occur, at heating of adsorbent, to heat transfer from heat change medium to the adsorbent. The time required for heating of adsorber filling is very important, because on it depend flexibility of cooling system. Zeolith has a large thermal resistance, therefore it had to be adapted the design and construction of adsorber. As the best shows the tube type of adsorber with double coat construction. By this construction is ensured thin layer of adsorbent and heating is quick in all volume of adsorbent. The process of heat transfer was experimentally measured, but for comparison simulated in ANSYS, too.

  8. Thin Thermoelectric Generator System for Body Energy Harvesting (United States)

    Settaluri, Krishna T.; Lo, Hsinyi; Ram, Rajeev J.


    Wearable thermoelectric generators (TEGs) harvest thermal energy generated by the body to generate useful electricity. The performance of these systems is limited by (1) the small working temperature differential between the body and ambient, (2) the desire to use natural air convection cooling on the cold side of the generator, and (3) the requirement for thin, lightweight systems that are comfortable for long-term use. Our work has focused on the design of the heat transfer system as part of the overall thermoelectric (TE) system. In particular, the small heat transfer coefficient for natural air convection results in a module thermal impedance that is smaller than that of the heat sink. In this heat-sink-limited regime, the thermal resistance of the generator should be optimized to match that of the heat sink to achieve the best performance. In addition, we have designed flat (1 mm thickness) copper heat spreaders to realize performance surpassing splayed pin heat sinks. Two-dimensional (2-D) heat spreading exploits the large surface area available in a wristband and allows patterned copper to efficiently cool the TE. A direct current (DC)/DC converter is integrated on the wristband. The system generates up to 28.5 μW/cm2 before the converter and 8.6 μW/cm2 after the converter, with 30% efficiency. It generates output of 4.15 V with overall thickness under 5 mm.

  9. Nonazeotropic Heat Pump (United States)

    Ealker, David H.; Deming, Glenn


    Heat pump collects heat from water circulating in heat-rejection loop, raises temperature of collected heat, and transfers collected heat to water in separate pipe. Includes sealed motor/compressor with cooling coils, evaporator, and condenser, all mounted in outer housing. Gradients of temperature in evaporator and condenser increase heat-transfer efficiency of vapor-compression cycle. Intended to recover relatively-low-temperature waste heat and use it to make hot water.

  10. Rapid thermal processing science and technology

    CERN Document Server

    Fair, Richard B


    This is the first definitive book on rapid thermal processing (RTP), an essential namufacturing technology for single-wafer processing in highly controlled environments. Written and edited by nine experts in the field, this book covers a range of topics for academics and engineers alike, moving from basic theory to advanced technology for wafer manufacturing. The book also provides new information on the suitability or RTP for thin film deposition, junction formation, silicides, epitaxy, and in situ processing. Complete discussions on equipment designs and comparisons between RTP and other

  11. High heat flux single phase heat exchanger (United States)

    Valenzuela, Javier A.; Izenson, Michael G.


    This paper presents the results obtained to date in a program to develop a high heat flux, single-phase heat exchanger for spacecraft thermal management. The intended application is a net generation interface heat exchanger to couple the crew module water thermal bus to the two-phase ammonia main thermal bus in the Space Station Freedom. The large size of the interface heat exchanger is dictated by the relatively poor water-side heat transfer characteristics. The objective of this program is to develop a single-phase heat transfer approach which can achieve heat fluxes and heat transfer coefficients comparable to those of the evaporation ammonia side. A new heat exchanger concept has been developed to meet these objecties. The main feature of this heat exchanger is that it can achieve very high heat fluxes with a pressure drop one to two orders of magnitude lower than those of previous microchannel or jet impingement high heat flux heat exchangers. This paper describes proof-of-concept experiments performed in air and water and presents analytical model of the heat exchanger.

  12. Testing techniques for mechanical characterization of rapidly solidified materials (United States)

    Koch, C. C.


    Mechanical property testing techniques are reviewed for rapidly solidified materials. Mechanical testing of rapidly solidified materials is complicated by the fact that in most cases at least one dimension of the material is very small (less than 100 microns). For some geometries, i.e., powder or thin surface layers, microhardness is the only feasible mechanical test. The ribbon geometry which is obtained by the melt-spinning method, however, has been used for a variety of mechanical property measurements including elastic properties, tensile properties, fracture toughness, creep, and fatigue. These techniques are described with emphasis placed on the precautions required by the restricted geometry of rapidly solidified specimens.

  13. Influência da energia de soldagem em uniões de lâminas finas através de laser pulsado de Nd:YAG Effect of the heat input on pulsed Nd:YAG laser welding of thin foil

    Directory of Open Access Journals (Sweden)

    Vicente A. Ventrella


    as an important manufacturing process. It can be performed using either pulsed or continuous lasers. A pulsed laser can be used to create weld seams in thin foils by means of overlapping pulses. Typical problems in lap joint welding of thin foils for sealing components in corrosive environment applications include excessive distortion, absence of intimate contact between couple, melt drop through and high level of residual stress. Pulsed laser processing is expected to be the method of choice because it allows more precise heat control compared with continuous laser processing. Experimental investigations were carried out using a pulsed neodymium: yttrium aluminum garnet laser welding to examine the influence of the pulse energy in the characteristics of the weld fillet. The pulse energy was varied from 1.0 to 2.25 J at an increment of 0.25 J and 4 ms pulse duration. The base material used for this study was the AISI 316L stainless steel foil with 100µm thickness. The welds were analyzed by optical microscopy, tensile shear tests and micro hardness. The results indicated that pulse energy control is of considerable importance for thin foil weld quality since it can generate good mechanical properties and discontinuities free weld joints. The ultimate tensile strength of the welded joints increased at first and then decreased with the pulse energy increasing. The process showed very sensitive to the gap between couple.

  14. Analysis and characterization of differential gene expression during rapid trophoblastic elongation in the pig using suppression subtractive hybridization

    Directory of Open Access Journals (Sweden)

    Malayer Jerry R


    Full Text Available Abstract During late peri-implantation development, porcine conceptuses undergo a rapid (2–3 hrs morphological transformation from a 10 mm sphere to a thin filamentous form greater than 150 mm in length. Elongation of the conceptus is important for establishing adequate placental surface area needed for embryo and fetal survival throughout gestation. Genes involved with triggering this unique transition in conceptus development are not well defined. Objective of the present study was to utilize suppression subtractive hybridization (SSH to characterize the change in gene expression during conceptus transformation from spherical (8–9 mm to tubular (15–40 mm to early filamentous (>150 mm morphology. Spherical, tubular, and filamentous conceptuses were collected from pregnant gilts and subjected to SSH. Forward and reverse subtractions were performed to identify candidate genes differentially expressed during spherical to tubular and tubular to filamentous transition. A total of 384 transcripts were differentially screened to ensure unique expression. Of the transcripts screened, sequences were obtained for 142 that were confirmed to be differentially expressed among the various morphologies. Gene expression profiles during rapid trophoblastic elongation were generated for selected mRNAs using quantitative real-time PCR. During the transition from tubular to early filamentous conceptuses, s-adenosylhomocysteine hydrolase and heat shock cognate 70 kDa expression were significantly enhanced. A novel unknown gene was isolated and shown to be significantly up-regulated at the onset of rapid trophoblastic elongation and further enhanced in filamentous conceptuses.

  15. Heat Illness: A Handbook for Medical Officers (United States)


    gastrointestinal bleeding. jaundice due to hepatic Injury, aspiratioai prneumoinla, noncardiogenic pulmonar ~y edema and myocardial Infarction...cerebral edema . 25) 4. Recovery and Profiling Patients with heat exhaustion experience rapid clinical recovery. However, they all need at least heat stroke induced cereb~ral edema is not) kntoVVn. Ncurologic d(et eriorat ion after initial recover i- Judy rep~resent Iinn-;r8 (11 iili

  16. Thin Glass Coatings for the Corrosion Protection of Metals

    DEFF Research Database (Denmark)

    Lampert, Felix

    This dissertation presents the research work aimed at developing functional submicrometer thick SiOx barrier coatings for the corrosion protection of stainless steel substrates in chloride containing media, which may enable the use of stainless steels as plate material for marine heat exchangers...... with localized corrosion and do not impact the heat transfer or the component performance. The herein presented approach focuses primarily on the formation of SiOx-like thin films from Hydrogen Silsesquioxane (HSQ) –based “spin-on-glass” (SOG) precursor. The technology is well known for the deposition...... in corrosion sensitive applications. Since the deposition of SiOx thin films is a well-established technology, the SOG technology was directly benchmarked to PVD-based SiO2 coatings. The coating adhesion was assessed by cross cut testing and increasing load scratch testing and the efficiency of the sub...

  17. Phase separation in Fe2CrSi thin films (United States)

    Meinert, Markus; Hübner, Torsten; Schmalhorst, Jan; Reiss, Günter; Arenholz, Elke


    Thin films of a nominal Fe2CrSi alloy have been deposited by magnetron co-sputtering with various heat treatments on MgO and MgAl2O4 substrates. After heat treatment, the films were found to decompose into a nearly epitaxial Fe3Si film with the D03 structure and Cr3Si precipitates with the A15 structure. We explain the experimental results on the basis of ab initio calculations, which reveal that this decomposition is energetically highly favorable.

  18. HIFU treatment time reduction through heating approach optimisation. (United States)

    Coon, Joshua; Todd, Nick; Roemer, Robert


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

  19. Multiple source heat pump (United States)

    Ecker, Amir L.


    A heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating a fluid in heat exchange relationship with a refrigerant fluid, at least three refrigerant heat exchangers, one for effecting heat exchange with the fluid, a second for effecting heat exchange with a heat exchange fluid, and a third for effecting heat exchange with ambient air; a compressor for compressing the refrigerant; at least one throttling valve connected at the inlet side of a heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circuit and pump for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and directional flow of refrigerant therethrough for selecting a particular mode of operation. Also disclosed are a variety of embodiments, modes of operation, and schematics therefor.

  20. Cryogenic heat transfer

    CERN Document Server

    Barron, Randall F


    Cryogenic Heat Transfer, Second Edition continues to address specific heat transfer problems that occur in the cryogenic temperature range where there are distinct differences from conventional heat transfer problems. This updated version examines the use of computer-aided design in cryogenic engineering and emphasizes commonly used computer programs to address modern cryogenic heat transfer problems. It introduces additional topics in cryogenic heat transfer that include latent heat expressions; lumped-capacity transient heat transfer; thermal stresses; Laplace transform solutions; oscillating flow heat transfer, and computer-aided heat exchanger design. It also includes new examples and homework problems throughout the book, and provides ample references for further study.

  1. Heat pump technology

    CERN Document Server

    Von Cube, Hans Ludwig; Goodall, E G A


    Heat Pump Technology discusses the history, underlying concepts, usage, and advancements in the use of heat pumps. The book covers topics such as the applications and types of heat pumps; thermodynamic principles involved in heat pumps such as internal energy, enthalpy, and exergy; and natural heat sources and energy storage. Also discussed are topics such as the importance of the heat pump in the energy industry; heat pump designs and systems; the development of heat pumps over time; and examples of practical everyday uses of heat pumps. The text is recommended for those who would like to kno

  2. Investigation of the correlation between dielectric function, thickness and morphology of nano-granular ZnO very thin films

    Energy Technology Data Exchange (ETDEWEB)

    Gilliot, Mickaël, E-mail: [Laboratoire d' Ingénierie et Sciences des Matériaux, Université de Reims Champagne-Ardenne (France); Hadjadj, Aomar [Laboratoire d' Ingénierie et Sciences des Matériaux, Université de Reims Champagne-Ardenne (France); Martin, Jérôme [Laboratoire de Nanotechnologie et d' Instrumentation Optique, Université de Technologie de Troyes (France)


    Thin nano-granular ZnO layers were prepared using a sol–gel synthesis and spin-coating deposition process with a thickness ranging between 20 and 120 nm. The complex dielectric function (ϵ) of the ZnO film was determined from spectroscopic ellipsometry measurements. Up to a critical thickness close to 60 nm, the magnitude of both the real and the imaginary parts of ϵ rapidly increases and then slowly tends to values closer to the bulk ZnO material. This trend suggests a drastic change in the film porosity at both sides of this critical thickness, due to the pre-heating and post-crystallization processes, as confirmed by additional characterization of the structure and the morphology of the ZnO films. - Highlights: • c-Axis oriented ZnO thin films were grown with different morphological states. • The morphology and structures are controlled by controlling the thickness. • The optical properties are correlated to morphological evolution. • Two growth behaviors and property evolutions are identified around a critical thickness.

  3. Furnace for rapid thermal processing with optical switching film disposed between heater and reflector

    NARCIS (Netherlands)

    Roozeboom, F.; Duine, P.A.; Sluis, P. van der


    A furnace (1) for Rapid Thermal Processing of a wafer (7), characterized in that the wafer (7) is heated by lamps (9), and the heat radiation is reflected by an optical switching device (15,17) which is in the reflecting state during the heating stage. During the cooling stage of the wafer (7), the

  4. Carbonyl Compounds Produced by Vaporizing Cannabis Oil Thinning Agents. (United States)

    Troutt, William D; DiDonato, Matthew D


    Cannabis use has increased in the United States, particularly the use of vaporized cannabis oil, which is often mixed with thinning agents for use in vaporizing devices. E-cigarette research shows that heated thinning agents produce potentially harmful carbonyls; however, similar studies have not been conducted (1) with agents that are commonly used in the cannabis industry and (2) at temperatures that are appropriate for cannabis oil vaporization. The goal of this study was to determine whether thinning agents used in the cannabis industry produce potentially harmful carbonyls when heated to a temperature that is appropriate for cannabis oil vaporization. Four thinning agents (propylene glycol [PG], vegetable glycerin [VG], polyethylene glycol 400 [PEG 400], and medium chain triglycerides [MCT]) were heated to 230°C and the resulting vapors were tested for acetaldehyde, acrolein, and formaldehyde. Each agent was tested three times. Testing was conducted in a smoking laboratory. Carbonyl levels were measured in micrograms per puff block. Analyses showed that PEG 400 produced significantly higher levels of acetaldehyde and formaldehyde than PG, MCT, and VG. Formaldehyde production was also significantly greater in PG compared with MCT and VG. Acrolein production did not differ significantly across the agents. PG and PEG 400 produced high levels of acetaldehyde and formaldehyde when heated to 230°C. Formaldehyde production from PEG 400 isolate was particularly high, with one inhalation accounting for 1.12% of the daily exposure limit, nearly the same exposure as smoking one cigarette. Because PG and PEG 400 are often mixed with cannabis oil, individuals who vaporize cannabis oil products may risk exposure to harmful formaldehyde levels. Although more research is needed, consumers and policy makers should consider these potential health effects before use and when drafting cannabis-related legislation.

  5. Handbook of thin film technology

    CERN Document Server

    Frey, Hartmut


    “Handbook of Thin Film Technology” covers all aspects of coatings preparation, characterization and applications. Different deposition techniques based on vacuum and plasma processes are presented. Methods of surface and thin film analysis including coating thickness, structural, optical, electrical, mechanical and magnetic properties of films are detailed described. The several applications of thin coatings and a special chapter focusing on nanoparticle-based films can be found in this handbook. A complete reference for students and professionals interested in the science and technology of thin films.

  6. Rapid quenching effects in PVC films (United States)

    Lee, H. D.; Mandell, J. F.; Mcgarry, F. J.


    Using a specially constructed microbalance for hydrostatic weighing, density changes in PVC thin films (with no additives, 30-100 micrometers thick), due to rapid quenching (approximately 300 C/sec) through the glass transition temperature, have been observed. The more severe the quench, the greater is the free volume content. Isobaric volume recovery of PVC has also been studied by volume dilatometry. Both show aging of relaxing molecular rearrangements takes place as a linear function of logarithmic aging time at room temperature. Distribution of retardation times and Primak's distributed activation energy spectra have been applied to the volume recovery data. The concomitant changes in mechanical properties of PVC after quenching have been monitored by tensile creep and stress-strain to failure. All reflect the presence of excess free volume content, due to rapid quenching.

  7. Interfacial heat transfer behavior at metal/die in finger-plated casting during high pressure die casting process

    Directory of Open Access Journals (Sweden)

    Wen-bo Yu


    Full Text Available Heat transfer at the metal-die interface has a great influence on the solidification process and casting structure. As thin-wall components are extensively produced by high pressure die casting process (HPDC, the B390 alloy finger-plate casting was cast against an H13 steel die on a cold-chamber HPDC machine. The interfacial heat transfer behavior at different positions of the die was carefully studied using an inverse approach based on the temperature measurements inside the die. Furthermore, the filling process and the solidification rate in different finger-plates were also given to explain the distribution of interfacial heat flux (q and interfacial heat transfer coefficient (h. Measurement results at the side of sprue indicates that qmax and hmax could reach 9.2 MW昺-2 and 64.3 kW昺-2昁-1, respectively. The simulation of melt flow in the die reveals that the thinnest (T1 finger plate could accelerate the melt flow from 50 m晄-1 to 110 m晄-1. Due to this high velocity, the interfacial heat flux at the end of T1 could firstly reach a highest value 7.92 MW昺-2 among the ends of Tn (n=2,3,4,5. In addition, the qmax and hmax values of T2, T4 and T5 finger-plates increase with the increasing thickness of the finger plate. Finally, at the rapid decreasing stage of interfacial heat transfer coefficient (h, the decreasing rate of h has an exponential relationship with the increasing rate of solid fraction (f.

  8. Heat Related Illnesses

    National Research Council Canada - National Science Library

    Carter, R; Cheuvront, S. N; Sawka, M. N


    .... The risk of serious heat illness can be markedly reduced by implementing a variety of countermeasures, including becoming acclimated to the heat, managing heat stress exposure, and maintaining hydration...

  9. Heat Roadmap Europe 1

    DEFF Research Database (Denmark)

    Connolly, David; Mathiesen, Brian Vad; Østergaard, Poul Alberg


    Heat Roadmap Europe (Pre-study 1) investigates the role of district heating in the EU27 energy system by mapping local conditions across Europe, identifying the potential for district heating expansion, and subsequently simulating the potential resource in an hourly model of the EU27 energy system....... In 2010, approximately 12% of the space heating demand in Europe is met by district heating, but in this study four alternative scenarios are considered for the EU27 energy system: 1. 2010 with 30% district heating 2. 2010 with 50% district heating 3. 2030 with 30% district heating 4. 2050 with 50......% district heating These scenarios are investigated in two steps. Firstly, district heating replaces individual boilers by converting condensing power plants to combined heat and power plants (CHP) to illustrate how district heating improves the overall efficiency of the energy system. In the second step...

  10. Multidimensional Heat Conduction

    DEFF Research Database (Denmark)

    Rode, Carsten


    Analytical theory of multidimensional heat conduction. General heat conduction equation in three dimensions. Steay state, analytical solutions. The Laplace equation. Method of separation of variables. Principle of superposition. Shape factors. Transient, multidimensional heat conduction....

  11. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... sweating; nausea; and giddiness. Symptoms of heat stroke (late stage of heat illness) include flushed, hot, dry ... consciousness, vomiting or a high body temperature. For late stage heat stroke symptoms, cool the person further ...

  12. Absorption heat pump system (United States)

    Grossman, Gershon


    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  13. Rapid Airplane Parametric Input Design (RAPID) (United States)

    Smith, Robert E.


    RAPID is a methodology and software system to define a class of airplane configurations and directly evaluate surface grids, volume grids, and grid sensitivity on and about the configurations. A distinguishing characteristic which separates RAPID from other airplane surface modellers is that the output grids and grid sensitivity are directly applicable in CFD analysis. A small set of design parameters and grid control parameters govern the process which is incorporated into interactive software for 'real time' visual analysis and into batch software for the application of optimization technology. The computed surface grids and volume grids are suitable for a wide range of Computational Fluid Dynamics (CFD) simulation. The general airplane configuration has wing, fuselage, horizontal tail, and vertical tail components. The double-delta wing and tail components are manifested by solving a fourth order partial differential equation (PDE) subject to Dirichlet and Neumann boundary conditions. The design parameters are incorporated into the boundary conditions and therefore govern the shapes of the surfaces. The PDE solution yields a smooth transition between boundaries. Surface grids suitable for CFD calculation are created by establishing an H-type topology about the configuration and incorporating grid spacing functions in the PDE equation for the lifting components and the fuselage definition equations. User specified grid parameters govern the location and degree of grid concentration. A two-block volume grid about a configuration is calculated using the Control Point Form (CPF) technique. The interactive software, which runs on Silicon Graphics IRIS workstations, allows design parameters to be continuously varied and the resulting surface grid to be observed in real time. The batch software computes both the surface and volume grids and also computes the sensitivity of the output grid with respect to the input design parameters by applying the precompiler tool

  14. Heat diffusion in magnetic superlattices on glass substrates (United States)

    Hoveyda, F.; Adnani, M.; Smadici, S.


    Pump-probe experiments and polarizing microscopy are applied to examine temperature and heat flow in metallic magnetic superlattices on glass substrates. A model of heat diffusion in thin layers for cylindrical symmetry, equivalent to the Green's function method, gives a good description of the results. The frequency dependence of temperature modulation shows that a glass layer should be added to the sample structure. The demagnetization patterns are reproduced with a Green's function that includes an interface conductance.

  15. Peculiarities of determining the effective thermal conductivity of multilayer nanostructures under unsteady heating (United States)

    Khvesyuk, V. I.; Chirkov, A. Yu


    Some features of pulse heating method are considered to study the main regularities of changes in the temperature of thin films in application to flash method. Heat exchange with the surrounding space is taken into account. The characteristic parameters of laser heating system are specified. The mathematical model of the heating process is based on the heat equation with effective heat conductivity. Such an analysis allows to estimate effective thermal diffusivity and thermal conductance including Kapitza conductance. For multi-layer nano-films Kapitza conductance can be estimated as its contribution to effective conductance is significant.

  16. MultiLayer solid electrolyte for lithium thin film batteries (United States)

    Lee, Se -Hee; Tracy, C. Edwin; Pitts, John Roland; Liu, Ping


    A lithium metal thin-film battery composite structure is provided that includes a combination of a thin, stable, solid electrolyte layer [18] such as Lipon, designed in use to be in contact with a lithium metal anode layer; and a rapid-deposit solid electrolyte layer [16] such as LiAlF.sub.4 in contact with the thin, stable, solid electrolyte layer [18]. Batteries made up of or containing these structures are more efficient to produce than other lithium metal batteries that use only a single solid electrolyte. They are also more resistant to stress and strain than batteries made using layers of only the stable, solid electrolyte materials. Furthermore, lithium anode batteries as disclosed herein are useful as rechargeable batteries.

  17. Fabrication of organic semiconducting materials and high-performance organic thin-film transistors based on electron-irradiated polystyrene

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyeok Moo


    It was discovered that non-luminescent polystyrene (PS) can be converted to luminescent materials whose color can be changed in a wide visible range by electron irradiation. After the analyses of electron-irradiated PS, it was found that polycyclic aromatic hydrocarbons are produced by the irradiation and these PAHs are the origin of the luminescence from the electron-irradiated polymer. Based on the finding, a straightforward approach to produce desired light-emitting nanoarchitectures and nanopatterns only by irradiating an electron beam to the polymer was presented. In particular, the top-down irradiation approach provides a powerful tool to fabricate a variety of interesting nanoarchitectures when combined with bottom-up approaches; PS nanostructures prepared by self-assembling techniques can be directly transformed to luminescent nanostructures by electron irradiation while keeping their pristine morphologies. Light-emitting materials are widely used for optical, photonic, chemical and biomedical devices and a rapid progress in the devices requires well-defined luminescent nanoarchitectures. The approach presented here will be useful for a wide range of research fields including optics, photonics, chemistry, and biologics. On the other hand, a very simple but effective approach to produce high-performance rubrene organic thin-film transistors (OTFTs) with characteristics better than amorphous silicon TFTs was presented. Only by an abrupt heating process, high-quality crystalline rubrene semiconductor thin films that have almost ideal structures for OTFTs are created. The produced crystalline thin films consist of highly ordered, uniaxially oriented single-crystalline grains with large average sizes and the grains are interconnected with one another to form continuous films over the whole dielectric surfaces. Such high-quality crystalline rubrene thin films are remarkably rapidly produced in just 30 sec through this approach. Moreover, the increase of carrier

  18. Thin-film absorber for a solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Wilhelm, W.G.


    This invention pertains to energy absorbers for solar collectors, and more particularly to high performance thin film absorbers. The solar collectors comprising the absorber of this invention overcome several problems seen in current systems, such as excessive hardware, high cost and unreliability. In the preferred form, the apparatus features a substantially rigid planar frame with a thin film window bonded to one planar side of the frame. An absorber in accordance with the present invention is comprised of two thin film layers that are sealed perimetrically. In a preferred embodiment, thin film layers are formed from a metal/plastic laminate. The layers define a fluid-tight planar envelope of large surface area to volume through which a heat transfer fluid flows. The absorber is bonded to the other planar side of the frame. The thin film construction of the absorber assures substantially full envelope wetting and thus good efficiency. The window and absorber films stress the frame adding to the overall strength of the collector.

  19. Regenerative adsorbent heat pump (United States)

    Jones, Jack A. (Inventor)


    A regenerative adsorbent heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system and at least a portion of the heat of adsorption. A series of at least four compressors containing an adsorbent is provided. A large amount of heat is transferred from compressor to compressor so that heat is regenerated. The process and system are useful for air conditioning rooms, providing room heat in the winter or for hot water heating throughout the year, and, in general, for pumping heat from a lower temperature to a higher temperature.

  20. Rapid shallow breathing (United States)

    ... the smallest air passages of the lungs in children ( bronchiolitis ) Pneumonia or other lung infection Transient tachypnea of the newborn Anxiety and panic Other serious lung disease Home Care Rapid, shallow breathing should not be treated at home. It is ...

  1. Rapid Strep Test (United States)

    ... worse than normal. Your first thoughts turn to strep throat. A rapid strep test in your doctor’s office ... your suspicions.Viruses cause most sore throats. However, strep throat is an infection caused by the Group A ...

  2. Thin-film solar cell

    NARCIS (Netherlands)

    Metselaar, J.W.; Kuznetsov, V.I.


    The invention relates to a thin-film solar cell provided with at least one p-i-n junction comprising at least one p-i junction which is at an angle alpha with that surface of the thin-film solar cell which collects light during operation and at least one i-n junction which is at an angle beta with

  3. Dewetting of Thin Polymer Films (United States)

    Dixit, P. S.; Sorensen, J. L.; Kent, M.; Jeon, H. S.


    DEWETTING OF THIN POLYMER FILMS P. S. Dixit,(1) J. L. Sorensen,(2) M. Kent,(2) H. S. Jeon*(1) (1) Department of Petroleum and Chemical Engineering, New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM 87801, (2) Department 1832, Sandia National Laboratories, Albuquerque, NM. Dewetting of thin polymer films is of technological importance for a variety of applications such as protective coatings, dielectric layers, and adhesives. Stable and smooth films are required for the above applications. Above the glass transition temperature (Tg) the instability of polymer thin films on a nonwettable substrate can be occurred. The dewetting mechanism and structure of polypropylene (Tg = -20 ^circC) and polystyrene (Tg = 100 ^circC) thin films is investigated as a function of film thickness (25 Åh < 250 Åand quenching temperature. Contact angle measurements are used in conjunction with optical microscope to check the surface homogeneity of the films. Uniform thin films are prepared by spin casting the polymer solutions onto silicon substrates with different contact angles. We found that the stable and unstable regions of the thin films as a function of the film thickness and quenching temperature, and then constructed a stability diagram for the dewetting of thin polymer films. We also found that the dewetting patterns of the thin films are affected substantially by the changes of film thickness and quenching temperature.

  4. Chemical thinning of 'Conference' pears

    NARCIS (Netherlands)

    Maas, F.M.; Kanne, H.J.; Steeg, van der P.A.H.


    The increasing difference in the market value of small and larger sized ‘Conference’ pears (>65 mm) and the high labour costs for hand thinning, makes it interesting for growers to find a cheaper and reliable method for thinning pear trees. In 2007, 2008 and 2009 trials were carried out to test

  5. Thin lenses of asymmetric power

    Directory of Open Access Journals (Sweden)

    W. F. Harris


    Full Text Available It is generally supposed that thin systems, including refracting surfaces and thin lenses, have powers that are necessarily symmetric.  In other words they have powers which can be represented assymmetric dioptric power matrices and in the familar spherocylindrical form used in optometry and ophthalmology.  This paper shows that this is not correct and that it is indeed possible for a thin system to have a power that is not symmetric and which cannot be expressed in spherocylindrical form.  Thin systems of asymmetric power are illustratedby means of a thin lens that is modelled with small prisms and is chosen to have a dioptric power ma-trix that is antisymmetric.  Similar models can be devised for a thin system whose dioptric power matrix is any  2 2 ×  matrix.  Thus any power, symmetric, asymmetric or antisymmetric, is possible for a thin system.  In this sense our understanding of the power of thin systems is now complete.

  6. Center for Thin Film Studies (United States)


    12 (3.22) To understand (3.22) requires a basic knowledge of differential geometry (Do Carmo , 1976). The determinant and trace of M1dj are the...A.G. Dirks and H.J. Leamy, "Columnar Microstructure in Vapour Deposited Thin Films," Thin Solid Films 47 219-233 (1977). M.P. Do Carmo , Differential

  7. Thin films: Past, present, future

    Energy Technology Data Exchange (ETDEWEB)

    Zweibel, K


    This report describes the characteristics of the thin film photovoltaic modules necessary for an acceptable rate of return for rural areas and underdeveloped countries. The topics of the paper include a development of goals of cost and performance for an acceptable PV system, a review of current technologies for meeting these goals, issues and opportunities in thin film technologies.

  8. Polyimide Aerogel Thin Films (United States)

    Meador, Mary Ann; Guo, Haiquan


    Polyimide aerogels have been crosslinked through multifunctional amines. This invention builds on "Polyimide Aerogels With Three-Dimensional Cross-Linked Structure," and may be considered as a continuation of that invention, which results in a polyimide aerogel with a flexible, formable form. Gels formed from polyamic acid solutions, end-capped with anhydrides, and cross-linked with the multifunctional amines, are chemically imidized and dried using supercritical CO2 extraction to give aerogels having density around 0.1 to 0.3 g/cubic cm. The aerogels are 80 to 95% porous, and have high surface areas (200 to 600 sq m/g) and low thermal conductivity (as low as 14 mW/m-K at room temperature). Notably, the cross-linked polyimide aerogels have higher modulus than polymer-reinforced silica aerogels of similar density, and can be fabricated as both monoliths and thin films.

  9. Thin film hydrogen sensor (United States)

    Lauf, R.J.; Hoffheins, B.S.; Fleming, P.H.


    A hydrogen sensor element comprises an essentially inert, electrically-insulating substrate having a thin-film metallization deposited thereon which forms at least two resistors on the substrate. The metallization comprises a layer of Pd or a Pd alloy for sensing hydrogen and an underlying intermediate metal layer for providing enhanced adhesion of the metallization to the substrate. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors, and at least one of the resistors is left uncovered. The difference in electrical resistances of the covered resistor and the uncovered resistor is related to hydrogen concentration in a gas to which the sensor element is exposed. 6 figs.

  10. Modelling the tribology of thin film interfaces

    CERN Document Server

    Zugic, R


    substrate). Within each group of simulations, three lubricant film thicknesses are studied to examine the effect of varying lubricant thickness. Statistical data are collected from each simulation and presented in this work. Via these data, together with the evolution, of atomic and molecular configurations, a very detailed picture of the properties of this thin film interface is presented. In particular, we conclude that perfluoropolyether lubricant forms distinct molecular layers when confined between two substrates, the rate of heat generation under shearing conditions typical of those in a head-disk interface is insufficient for thermal mechanisms to result directly in lubricant degradation, and mechanical stresses attained in the head-disk interface are unlikely to result in any significant degree of lubricant degradation. This thesis examines the tribology of a head-disk interface in an operating hard disk drive via non-equilibrium molecular dynamics computer simulations. The aim of this work is to deri...

  11. RAPID3? Aptly named! (United States)

    Berthelot, J-M


    The RAPID3 score is the sum of three 0-10 patient self-report scores: pain, functional impairment on MDHAQ, and patient global estimate. It requires 5 seconds for scoring and can be used in all rheumatologic conditions, although it has mostly been used in rheumatoid arthritis where cutoffs for low disease activity (12/30) have been set. A RAPID3 score of ≤ 3/30 with 1 or 0 swollen joints (RAPID3 ≤ 3 + ≤ SJ1) provides remission criteria comparable to Boolean, SDAI, CDAI, and DAS28 remission criteria, in far less time than a formal joint count. RAPID3 performs as well as the DAS28 in separating active drugs from placebos in clinical trials. RAPID3 also predicts subsequent structural disease progression. RAPID3 can be determined at short intervals at home, allowing the determination of the area under the curve of disease activity between two visits and flare detection. However, RAPID3 should not be seen as a substitute for DAS28 and face to face visits in routine care. Monitoring patient status with only self-report information without a rheumatologist's advice (including joints and physical examination, and consideration of imaging and laboratory tests) may indeed be as undesirable for most patients than joint examination without a patient questionnaire. Conversely, combining the RAPID3 and the DAS28 may consist in faster or more sensitive confirmation that a medication is effective. Similarly, better enquiring of most important concerns of patients (pain, functional status and overall opinion on their disorder) should reinforces patients' confidence in their rheumatologist and treatments.

  12. Nonlinear optical thin films (United States)

    Leslie, Thomas M.


    A focused approach to development and evaluation of organic polymer films for use in optoelectronics is presented. The issues and challenges that are addressed include: (1) material synthesis, purification, and the tailoring of the material properties; (2) deposition of uniform thin films by a variety of methods; (3) characterization of material physical properties (thermal, electrical, optical, and electro-optical); and (4) device fabrication and testing. Photonic materials, devices, and systems were identified as critical technology areas by the Department of Commerce and the Department of Defense. This approach offers strong integration of basic material issues through engineering applications by the development of materials that can be exploited as the active unit in a variety of polymeric thin film devices. Improved materials were developed with unprecedented purity and stability. The absorptive properties can be tailored and controlled to provide significant improvement in propagation losses and nonlinear performance. Furthermore, the materials were incorporated into polymers that are highly compatible with fabrication and patterning processes for integrated optical devices and circuits. By simultaneously addressing the issues of materials development and characterization, keeping device design and fabrication in mind, many obstacles were overcome for implementation of these polymeric materials and devices into systems. We intend to considerably improve the upper use temperature, poling stability, and compatibility with silicon based devices. The principal device application that was targeted is a linear electro-optic modulation etalon. Organic polymers need to be properly designed and coupled with existing integrated circuit technology to create new photonic devices for optical communication, image processing, other laser applications such as harmonic generation, and eventually optical computing. The progression from microscopic sample to a suitable film

  13. The religion of thinness

    Directory of Open Access Journals (Sweden)

    Michelle Lelwica


    Full Text Available This paper examines the almost religious-like devotion of especially women in pursuing the goal of a thinner body. The quest for a slender body is analysed as a ‘cultural religion’, which the author calls the ‘Religion of Thinness’. The analysis revolves around four observations. The first is that for many women in the US today, the quest for a slender body serves what has historically been a ‘religious’ function: providing a sense of purpose that orients and gives meaning to their lives, especially in times of suffering and uncertainty. Second, this quest has many features in common with traditional religions, including beliefs, myths, rituals, moral codes, and sacred images—all of which encourage women to find ‘salvation’ (i.e., happiness and well-being through the pursuit of a ‘better’ (i.e., thinner body.Third, this secular faith draws so many adherents in large part because it appeals to and addresses what might be referred to as spiritual needs—including the need for a sense of purpose, inspiration, security, virtue, love, and well-being—even though it shortchanges these needs, and, in the long run, fails to deliver the salvation it promises. Fourth, a number of traditional religious ideas, paradigms and motifs tacit­ly inform and support the Religion of Thinness. More specifically, its soteri­ology resurrects and recycles the misogynist, anti-body, other-worldly, and exclusivist aspects of patriarchal religion. Ultimately, the analysis is not only critical of the Religion of Thinness; it also raises suspicions about any clear-cut divisions between ‘religion’, ‘culture’, and ‘the body’. In fact, examining the functions, features, and ideologies embedded in this secular devotion gives us insight into the constitutive role of the body in the production and apprehension of religious and cultural meanings.

  14. Thin films of copper antimony sulfide: A photovoltaic absorber material

    Energy Technology Data Exchange (ETDEWEB)

    Ornelas-Acosta, R.E. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66450 (Mexico); Shaji, S. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66450 (Mexico); Universidad Autónoma de Nuevo León-CIIDIT, Apodaca, Nuevo León (Mexico); Avellaneda, D.; Castillo, G.A.; Das Roy, T.K. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66450 (Mexico); Krishnan, B., E-mail: [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66450 (Mexico); Universidad Autónoma de Nuevo León-CIIDIT, Apodaca, Nuevo León (Mexico)


    Highlights: • CuSbS{sub 2} thin films were prepared by heating Sb{sub 2}S{sub 3}/Cu layers. • Analyzed the structure, composition, optical, and electrical properties. • PV structures: glass/SnO{sub 2}:F/n-CdS/p-CuSbS{sub 2}/C/Ag were formed at different conditions. • The PV parameters (J{sub sc}, V{sub oc}, and FF) were evaluated from the J–V characteristics. • J{sub sc}: 0.52–3.20 mA/cm{sup 2}, V{sub oc}:187–323 mV, FF: 0.27–0.48 were obtained. - Abstract: In this work, we report preparation and characterization of CuSbS{sub 2} thin films by heating glass/Sb{sub 2}S{sub 3}/Cu layers and their use as absorber material in photovoltaic structures: glass/SnO{sub 2}:F/n-CdS/p-CuSbS{sub 2}/C/Ag. The Sb{sub 2}S{sub 3} thin films of 600 nm were prepared by chemical bath deposition on which copper thin films of 50 nm were thermally evaporated, and the glass/Sb{sub 2}S{sub 3}/Cu multilayers were heated in vacuum at different temperatures. X-ray diffraction analysis showed the formation of orthorhombic CuSbS{sub 2} after heating the precursor layers. Studies on identification and chemical state of the elements were done using X-ray photoelectron spectroscopy. The optical band gap of the CuSbS{sub 2} thin films was 1.55 eV and the thin films were photoconductive. The photovoltaic parameters of the devices using CuSbS{sub 2} as absorber and CdS as window layer were evaluated from the J–V curves, yielding J{sub sc}, V{sub oc}, and FF values in the range of 0.52–3.20 mA/cm{sup 2}, 187–323 mV, and 0.27–0.48, respectively, under illumination of AM1.5 radiation.

  15. Molecular dynamics simulation of Cu/Au thin films under temperature gradient

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qibin, E-mail: [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030 (China); Chongqing Key Laboratory of Heterogeneous Material Mechanics, Chongqing University, Chongqing 400030 (China); Peng, Xianghe [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030 (China); Peng, Tiefeng, E-mail: [State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030 (China); Tang, Qizhong [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); Zhang, Xiaomin [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); Chongqing Key Laboratory of Heterogeneous Material Mechanics, Chongqing University, Chongqing 400030 (China); Huang, Cheng [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China)


    Graphical abstract: Heat transportation in the thin films. - Highlights: • The coherent lattice interface is found at thin films after annealing. • The vacancies are observed clearly in the deposit thin films. • The defect and component will influence the energy transportation in the coatings. • The vacancies and lattice mismatch can enlarge the mobility of atoms. • The phonon transportation in thin films has no apparent rule. - Abstract: Three modulation period thin films, 1.8 nm Cu/3.6 nm Au, 2.7 nm Cu/2.7 nm Au and 3.6 nm Cu/1.8 nm Au, are obtained from deposition method and ideal modeling based on lattice constant, to examine their structures and thermophysical characteristics under temperature gradient. The coherent lattice interface is found both at deposit and ideal thin films after annealing. Also, the vacancies are observed clearly in the deposit thin films. The defect and component of thin films will influence the energy transportation in the coatings. The vacancies and lattice mismatch can enlarge the mobility of atoms and result in the failure of coating under the thermal stress. The power spectrum of atoms’ movement has no apparent rule for phonon transportation in thin films. The results are helpful to reveal the micro-mechanism and provide reasonable basis for the failure of metallic coatings.

  16. Substrate bias effect on crystallinity of polycrystalline silicon thin films prepared by pulsed ion-beam evaporation method

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Fazlat; Gunji, Michiharu; Yang, Sung-Chae; Suzuki, Tsuneo; Suematsu, Hisayuki; Jiang, Weihua; Yatsui, Kiyoshi [Nagaoka Univ. of Technology, Extreme Energy-Density Research Inst., Nagaoka, Niigata (Japan)


    The deposition of polycrystalline silicon thin films has been tried by a pulsed ion-beam evaporation method, where high crystallinity and deposition rate have been achieved without heating the substrate. The crystallinity and the deposition rate were improved by applying bias voltage to the substrate, where instantaneous substrate heating might have occurred by ion-bombardment. (author)

  17. Heat pumps in district heating networks

    DEFF Research Database (Denmark)

    Ommen, Torben Schmidt; Markussen, Wiebke Brix; Elmegaard, Brian

    constraints limit the power plants. Efficient heat pumps can be used to decouple the constraints of electricity and heat production, while maintaining the high energy efficiency needed to match the politically agreed carbon emission goals. The requirements in terms of COP, location, capacity and economy...... are calculated using an energy system model which includes power plants, heat pumps and district heating consumption profiles. The model is developed with focus on accurate representation of the performance of the units in different locations and operating modes. The model can assist in investment decisions...... and strategic planning in the energy sector. The paper presents a case study of optimal implementation of heat pumps in the present energy system of the Copenhagen area. By introduction of the correct capacity of heat pumps, a 1,6 % reduction in fuel consumption for electricity and heat production can...

  18. Physical mechanism of refractive index inhomogeneity of hafnium oxide thin film prepared by ion beam sputtering technique (United States)

    Liu, Huasong; Wang, Lishuan; Li, Shida; Jiang, Yugang; Liu, Dandan; Yang, Xiao; Ji, Yiqin; Zhang, Feng; Chen, Deying


    The HfO2 thin films prepared by ion beam sputtering are thinned after heat treatment. The optical constants of the thin films were obtained by inversion of the ellipsometric parameters. The crystal structure of the films was characterized by X-ray diffractometer. The results show that the correlation coefficient between the refractive index and the grain size is more than 90%. The refractive index increases with the increase of the grain size. The physical mechanism of the refractive index inhomogeneity in the film thickness direction is crystallization of thin films.

  19. Mathematical model of temperature field distribution in thin plates during polishing with a free abrasive

    Directory of Open Access Journals (Sweden)

    Avilov Alex


    Full Text Available The purpose of this paper is to estimate the dynamic characteristics of the heating process of thin plates during polishing with a free abrasive. A mathematical model of the temperature field distribution in space and time according to the plate thickness is based on Lagrange equation of the second kind in the thermodynamics of irreversible processes (variation principle Bio. The research results of thermo elasticity of thin plates (membranes will allow to correct the modes of polishing with a free abrasive to receive the exact reflecting surfaces of satellites reflector, to increase temperature stability and the ability of radio signal reflection, satellite precision guidance. Calculations of temperature fields in thin plates of different thicknesses (membranes is held in the Excel, a graphical characteristics of temperature fields in thin plates (membranes show non-linearity of temperature distribution according to the thickness of thin plates (membranes.

  20. [Application of the vapor test for the detection and immunologic determination of Escherichia coli heat labile enterotoxin]. (United States)

    Germani, Y; Bégaud, E; Brethes, B; Guesdon, J L


    The principle of this thin-layer immunoassay (vapour condensation technique or TVAP) is based on the ability of antibodies to absorb firmly to polystyrene surfaces and to retain their reactivity. A condensation pattern consisting of large confluent water drops is noticable when an antibody-antigen reaction takes place. We used this technique to detect and assay the Escherichia coli heat-labile enterotoxin (ETEC LT+) and compared the results of 53 strains (40 positives and 13 negatives) with single radial immune haemolysis, Gm1-ELISA and Vero cell culture tests. With the reagents used, this reaction was specific for a toxin dilution up to 1/14. As little as 0.025 micrograms/ml of cholera toxin could be detected. The TVAP-test is simple, rapid and cost-effective. It is thus quite suitable for use in diarrhoeal endemic areas.