WorldWideScience

Sample records for determining reheating temperature

  1. Quintessential inflation at low reheating temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Salo, Llibert Areste [Universitat Politecnica de Catalunya, Departament de Matematiques, Barcelona (Spain); Ludwig-Maximilians-Universitaet, Fakultaet fuer Physik, Munich (Germany); Haro, Jaume de [Universitat Politecnica de Catalunya, Departament de Matematiques, Terrassa (Spain)

    2017-11-15

    We have tested some simple quintessential inflation models, imposing the requirement that they match with the recent observational data provided by the BICEP and Planck team and leading to a reheating temperature, which is obtained via gravitational particle production after inflation, supporting the nucleosynthesis success. Moreover, for the models coming from supergravity one needs to demand low temperatures in order to avoid problems such as the gravitino overproduction or the gravitational production of moduli fields, which are obtained only when the reheating temperature is due to the production of massless particles with a coupling constant very close to its conformal value. (orig.)

  2. Low reheating temperatures in monomial and binomial inflationary models

    International Nuclear Information System (INIS)

    Rehagen, Thomas; Gelmini, Graciela B.

    2015-01-01

    We investigate the allowed range of reheating temperature values in light of the Planck 2015 results and the recent joint analysis of Cosmic Microwave Background (CMB) data from the BICEP2/Keck Array and Planck experiments, using monomial and binomial inflationary potentials. While the well studied ϕ 2 inflationary potential is no longer favored by current CMB data, as well as ϕ p with p>2, a ϕ 1 potential and canonical reheating (w re =0) provide a good fit to the CMB measurements. In this last case, we find that the Planck 2015 68% confidence limit upper bound on the spectral index, n s , implies an upper bound on the reheating temperature of T re ≲6×10 10 GeV, and excludes instantaneous reheating. The low reheating temperatures allowed by this model open the possibility that dark matter could be produced during the reheating period instead of when the Universe is radiation dominated, which could lead to very different predictions for the relic density and momentum distribution of WIMPs, sterile neutrinos, and axions. We also study binomial inflationary potentials and show the effects of a small departure from a ϕ 1 potential. We find that as a subdominant ϕ 2 term in the potential increases, first instantaneous reheating becomes allowed, and then the lowest possible reheating temperature of T re =4 MeV is excluded by the Planck 2015 68% confidence limit

  3. Standard test method for determination of "microwave safe for reheating" for ceramicware

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This test method determines the suitability of ceramicware for use in microwave re-heating applications. Microwave ovens are mainly used for reheating and defrosting frozen foods. Severe thermal conditions can occur while reheating foods. Typical reheating of foods requires one to five min. in the microwave at the highest power settings. Longer periods than five minutes are considered cooking. Cooking test methods and standards are not addressed in this test method. Most ceramicware is minimally absorbing of the microwave energy and will not heat up significantly. Unfortunately there are some products that absorb microwave energy to a greater extent and can become very hot in the microwave and pose a serious hazard. Additionally, the nature of microwave heating introduces radiation in a non-uniform manner producing temperature differentials in the food being cooked as well as the ceramic container holding it. The differential may become great enough to thermal shock the ware and create dangerous condition...

  4. Reheating temperature and gauge mediation models of supersymmetry breaking

    International Nuclear Information System (INIS)

    Olechowski, Marek; Pokorski, Stefan; Turzynski, Krzysztof; Wells, James D.

    2009-01-01

    For supersymmetric theories with gravitino dark matter, the maximal reheating temperature consistent with big bang nucleosynthesis bounds arises when the physical gaugino masses are degenerate. We consider the cases of a stau or sneutrino next-to-lightest superpartner, which have relatively less constraint from big bang nucleosynthesis. The resulting parameter space is consistent with leptogenesis requirements, and can be reached in generalized gauge mediation models. Such models illustrate a class of theories that overcome the well-known tension between big bang nucleosynthesis and leptogenesis.

  5. A review of temperature measurement in the steel reheat furnace

    International Nuclear Information System (INIS)

    Martocci, A.P.; Mihalow, F.A.

    1985-01-01

    The incentive for conducting research and development on reheat furnaces is substantial; the domestic steel industry spent approximately one billion dollars on fuel in reheat furnaces in 1981. Bethlehem Steel Corp. spent /145 million of that total, and neither figure includes fuel consumed in soaking pits or annealing furnaces. If the authors set a goal to save 10% of these annual fuel costs, that translates into /100 million for the domestic steel industry and /14.5 million for Bethlehem Steel. These large sums of money are significant incentives. The purpose of this paper is to review the historical heating practices and equipment at steel reheat furnaces along with current practices and instrumentation

  6. CMB constraints on the inflaton couplings and reheating temperature in α-attractor inflation

    Science.gov (United States)

    Drewes, Marco; Kang, Jin U.; Mun, Ui Ri

    2017-11-01

    We study reheating in α-attractor models of inflation in which the inflaton couples to other scalars or fermions. We show that the parameter space contains viable regions in which the inflaton couplings to radiation can be determined from the properties of CMB temperature fluctuations, in particular the spectral index. This may be the only way to measure these fundamental microphysical parameters, which shaped the universe by setting the initial temperature of the hot big bang and contain important information about the embedding of a given model of inflation into a more fundamental theory of physics. The method can be applied to other models of single field inflation.

  7. Probing the reheating temperature of the universe with a gravitational wave background

    International Nuclear Information System (INIS)

    Nakayama, Kazunori; Saito, Shun; Suwa, Yudai; Yokoyama, Jun'ichi

    2008-01-01

    The thermal history of the universe after big bang nucleosynthesis (BBN) is well understood both theoretically and observationally, and recent cosmological observations also begin to reveal the inflationary dynamics. However, the epoch between inflation and BBN is scarcely known. In this paper we show that the detection of the stochastic gravitational wave background around 1 Hz provides useful information about thermal history well before BBN. In particular, the reheating temperature of the universe may be determined by future space-based laser interferometer experiments such as DECIGO and/or BBO if it is around 10 6−9 GeV, depending on the tensor-to-scalar ratio r and dilution factor F

  8. Constraining curvatonic reheating

    Energy Technology Data Exchange (ETDEWEB)

    Hardwick, Robert J.; Vennin, Vincent; Koyama, Kazuya; Wands, David, E-mail: robert.hardwick@port.ac.uk, E-mail: vincent.vennin@port.ac.uk, E-mail: kazuya.koyama@port.ac.uk, E-mail: david.wands@port.ac.uk [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom)

    2016-08-01

    We derive the first systematic observational constraints on reheating in models of inflation where an additional light scalar field contributes to primordial density perturbations and affects the expansion history during reheating. This encompasses the original curvaton model but also covers a larger class of scenarios. We find that, compared to the single-field case, lower values of the energy density at the end of inflation and of the reheating temperature are preferred when an additional scalar field is introduced. For instance, if inflation is driven by a quartic potential, which is one of the most favoured models when a light scalar field is added, the upper bound T {sub reh} < 5 × 10{sup 4} GeV on the reheating temperature T {sub reh} is derived, and the implications of this value on post-inflationary physics are discussed. The information gained about reheating is also quantified and it is found that it remains modest in plateau inflation (though still larger than in the single-field version of the model) but can become substantial in quartic inflation. The role played by the vev of the additional scalar field at the end of inflation is highlighted, and opens interesting possibilities for exploring stochastic inflation effects that could determine its distribution.

  9. Steel billet reheat simulation with growth of oxide layer and investigation on zone temperature sensitivity

    International Nuclear Information System (INIS)

    Dubey, Satish Kumar; Srinivasan, P.

    2014-01-01

    This paper presents a three-dimensional heat conduction numerical model and simulation of steel billet reheating in a reheat furnace. The model considers the growth of oxide scale on the billet surfaces. Control-volume approach and implicit scheme of finite difference method are used to discretize the transient heat conduction equation. The model is validated with analytical results subject to limited conditions. Simulations are carried out for predictions of three-dimensional temperature filed in the billet and oxide scale growth on the billet surfaces. The model predictions are in agreement with expected trends. It was found that the effect of oxide scale on billet heating is considerable. In order to investigate the effect of zone temperatures on the responses, a parametric sensitivity subject to six responses of interest are carried out using analysis of mean approach. The simulation approach and parametric study presented will be useful and applicable to the steel industry.

  10. Effect of re-heating on the hot electron temperature

    International Nuclear Information System (INIS)

    Estabrook, K.; Rosen, M.

    1980-01-01

    Resonant absorption is the direct conversion of the transverse laser light to longitudinal electron plasma waves (epw) at the critical density [10 21 (1.06 μm/lambda 0 ) 2 cm -3 ]. The oscillating longitudinal electric field of the epw heats the electrons by accelerating them down the density gradient to a temperature of approximately 21T/sub e/ 0 25 ([I(W/cm 2 )/10 16 ](lambda 0 /1.06 μm) 2 ) 0 4 . This section extends the previous work by studying the effects of magnetic fields and collisions (albedo) which return the heated electrons for further heating. A magnetic field increases their temperature and collisions do not

  11. Magnetic reheating

    Science.gov (United States)

    Saga, Shohei; Tashiro, Hiroyuki; Yokoyama, Shuichiro

    2018-02-01

    We provide a new bound on the amplitude of primordial magnetic fields (PMFs) by using a novel mechanism, magnetic reheating. The damping of the magnetohydrodynamics fluid motions in a primordial plasma brings the dissipation of the PMFs. In the early Universe with z ≳ 2 × 106, cosmic microwave background (CMB) photons are quickly thermalized with the dissipated energy and shift to a different Planck distribution with a new temperature. In other words, the PMF dissipation changes the baryon-to-photon number ratio, and we name such a process magnetic reheating. From the current baryon-to-photon number ratio obtained from the big bang nucleosynthesis and CMB observations, we put the strongest constraint on the PMFs on small scales which CMB observations cannot access, B0 ≲ 1.0 μG at the scales 104 generation mechanisms of PMFs in the early Universe.

  12. CFD analysis of temperature imbalance in superheater/reheater region of tangentially coal-fired boiler

    Science.gov (United States)

    Zainudin, A. F.; Hasini, H.; Fadhil, S. S. A.

    2017-10-01

    This paper presents a CFD analysis of the flow, velocity and temperature distribution in a 700 MW tangentially coal-fired boiler operating in Malaysia. The main objective of the analysis is to gain insights on the occurrences in the boiler so as to understand the inherent steam temperature imbalance problem. The results show that the root cause of the problem comes from the residual swirl in the horizontal pass. The deflection of the residual swirl due to the sudden reduction and expansion of the flow cross-sectional area causes velocity deviation between the left and right side of the boiler. This consequently results in flue gas temperature imbalance which has often caused tube leaks in the superheater/reheater region. Therefore, eliminating the residual swirl or restraining it from being diverted might help to alleviate the problem.

  13. Reheating of the Universe as holographic thermalization

    Energy Technology Data Exchange (ETDEWEB)

    Kawai, Shinsuke, E-mail: shinsuke.kawai@gmail.com [Department of Physics, Sungkyunkwan University, Suwon 16419 (Korea, Republic of); Nakayama, Yu [California Institute of Technology, 452-48, Pasadena, CA 91125 (United States); Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, Kashiwa, Chiba 277-8583 (Japan)

    2016-08-10

    Assuming gauge/gravity correspondence we study reheating of the Universe using its holographic dual. Inflaton decay and thermalisation of the decay products correspond to collapse of a spherical shell and formation of a blackhole in the dual anti-de Sitter (AdS) spacetime. The reheating temperature is computed as the Hawking temperature of the developed blackhole probed by a dynamical boundary, and is determined by the inflaton energy density and the AdS radius, with corrections from the dynamics of the shell collapse. For given initial energy density of the inflaton field the holographic model typically gives lower reheating temperature than the instant reheating scenario, while it is shown to be safely within phenomenological bounds.

  14. Reheating of the Universe as holographic thermalization

    Directory of Open Access Journals (Sweden)

    Shinsuke Kawai

    2016-08-01

    Full Text Available Assuming gauge/gravity correspondence we study reheating of the Universe using its holographic dual. Inflaton decay and thermalisation of the decay products correspond to collapse of a spherical shell and formation of a blackhole in the dual anti-de Sitter (AdS spacetime. The reheating temperature is computed as the Hawking temperature of the developed blackhole probed by a dynamical boundary, and is determined by the inflaton energy density and the AdS radius, with corrections from the dynamics of the shell collapse. For given initial energy density of the inflaton field the holographic model typically gives lower reheating temperature than the instant reheating scenario, while it is shown to be safely within phenomenological bounds.

  15. Optimization of advanced high-temperature Brayton cycles with multiple reheat stages

    International Nuclear Information System (INIS)

    Haihua Zhao; Per F Peterson

    2005-01-01

    Full text of publication follows: This paper presents an overview and a few point designs for multiple-reheat Brayton cycle power conversion systems using high temperature molten salts (or liquid metals). All designs are derived from the General Atomics GT-MHR power conversion unit (PCU). The GT-MHR PCU is currently the only closed helium cycle system that has undergone detailed engineering design analysis, and that has turbomachinery which is sufficiently large to extrapolate to a >1000 MW(e) multiple reheat gas cycle power conversion system. Analysis shows that, with relatively small engineering modifications, multiple GT-MHR PCU's can be connected together to create a power conversion system in the >1000 MW(e) class. The resulting power conversion system is quite compact, and results in what is likely the minimum gas duct volume possible for a multiple-reheat system. To realize this, compact offset fin plate type liquid-to-gas heat exchangers (power densities from 10 to 120 MW/m 3 ) are needed. Both metal and non-metal heat exchangers are being investigated for high-temperature, gas-cooled reactors for temperatures to 1000 deg. C. Recent high temperature heat exchanger studies for nuclear hydrogen production has suggested that carbon-coated composite materials such as liquid silicon infiltrated chopped fiber carbon-carbon preformed material potentially could be used to fabricate plate fin heat exchangers with reasonable price. Different fluids such as helium, nitrogen and helium mixture, and supercritical CO 2 are compared for these multiple reheat Brayton cycles. Nitrogen and helium mixture cycle need about 40% more total PCU volume than helium cycle while keeping the same net cycle efficiency. Supercritical CO 2 needs very high pressure to optimize. Due to relatively detailed design for components such as heat exchangers, turbomachinery, and duct system, relatively accurate total pressure loss can be obtained, which results in more credible net efficiency

  16. Effect of inter-critically reheating temperature on microstructure and properties of simulated inter-critically reheated coarse grained heat affected zone in X70 steel

    International Nuclear Information System (INIS)

    Zhu, Zhixiong; Kuzmikova, Lenka; Li, Huijun; Barbaro, Frank

    2014-01-01

    This study investigated the influence of the inter-critical reheating temperature on the microstructure and mechanical properties of a coarse grained heat affected zone (CGHAZ) in an API 5L grade X70 pipeline steel seam weld. A Gleeble 3500 thermo-mechanical simulator was employed to duplicate particular weld thermal cycles in order to accurately assess specific regions of the weld HAZ. Detailed microstructural analysis, including investigation of the martensite–austenite (M–A) constituent, was performed using optical microscope (OM), scanning electron microscope (SEM) and selective etching techniques. It is shown that the fracture toughness of the CGHAZ is significantly reduced following exposure to a subsequent inter-critical thermal cycle. Fracture toughness gradually improves as the inter-critical temperature is increased, but does not return to the value of the original CGHAZ due to the presence of isolated large M–A particles and coarse microstructure. Significance of M–A particles to the HAZ fracture toughness is first related to the location of particles along prior austenite grain boundaries, followed by the size of individual M–A particles

  17. Curvaton reheating in a logamediate inflationary model

    International Nuclear Information System (INIS)

    Campo, Sergio del; Herrera, Ramon; Saavedra, Joel; Campuzano, Cuauhtemoc; Rojas, Efrain

    2009-01-01

    In a logamediate inflationary universe model we introduce the curvaton field in order to bring this inflationary model to an end. In this approach we determine the reheating temperature. We also outline some interesting constraints on the parameters that describe our models. Thus, we give the parameter space in this scenario.

  18. Assessment of uniform temperature assumption in zoning on the numerical simulation of a walking beam reheating furnace

    International Nuclear Information System (INIS)

    Morgado, Tiago; Coelho, Pedro J.; Talukdar, Prabal

    2015-01-01

    The numerical simulation of the heating process of steel slabs in a walking beam reheating furnace is reported using two different models. In one model, the turbulent reactive flow in the furnace is simulated together with the heat conduction in the slabs. The calculations are performed using a commercial code and a user-defined function is used to simulate the periodic movement of the slabs by the walking beams in the furnace. Unsteady calculations are performed until a periodic transient solution is achieved. In the second model, the furnace is divided into a small number of zones and the average temperature and chemical composition are prescribed in every zone based on the results of the first model. The unsteady heating process of the slabs is modeled using the same software and accounting for radiative transfer in the furnace and heat conduction in the slabs. The results of the first model are taken as a benchmark for the second one. It is shown that the first model predicts radiative heat fluxes and temperatures of the slabs that are consistent with previous work. The two models yield volume average temperatures of the slabs leaving the furnace that differ by less than 3%, provided that accurate values of the temperature of the gases and walls are used. The second model is computationally more economical, requiring only about 5% of the computational time of the first one. - Highlights: • The heating process of steel slabs in a reheating furnace is numerically simulated. • Unsteady calculations accounting for the periodic movement of the slabs are reported. • We compare two models differing on how the thermochemical composition is obtained. • The models predict mean slab temperatures at the exit that differ by less than 3%. • The computational time of the fastest model is only about 5% of the slowest one

  19. Reheating experiment in the 35-ton pile

    International Nuclear Information System (INIS)

    Cherot, J.; Girard, Y.

    1957-01-01

    When the 35-ton pile was started up it was necessary for us, in order to study certain effects (xenon for example), to know the anti reactivity value of the rods as a function of their dimensions. We have made use of the possibility, in the reheating experiment, of raising the temperature of the graphite-uranium block by simple heating, in order to determine the anti reactivity curves of the rods, and from that the overall temperature coefficient. For the latter we have considered two solutions: first, one in which the average temperature of the pile is defined as our arithmetical mean of the different values given by the 28 thermocouples distributed throughout the pile; a second in which the temperature in likened to a poisoning and is balanced by the square of the flux. The way in which the measurements have been made is indicated, and the different instruments used are described. The method of reheating does not permit the separation of the temperature coefficients of uranium and of graphite. The precision obtained is only moderate, and suffers from the changes of various parameters necessary to other manipulations carried out simultaneously (life time modulators for example), and finally it is a function of the comparatively restricted time allowed. It is evident of course that more careful stabilisation at the different plateaux chosen would have necessitated long periods of reheating. (author) [fr

  20. Root cause analysis of oxide scale forming and shedding in high temperature reheater of a 200MW super high pressure boiler

    Science.gov (United States)

    Bo, Jiang; Hao, Weidong; Hu, Zhihong; Liu, Fuguo

    2015-12-01

    In order to solve the problem of over temperature tube-burst caused by oxide scale shedding and blocking tubes of high temperature reheater of a 200MW super high pressure power plant boiler, this paper expounds the mechanism of scale forming and shedding, and analyzes the probable causes of the tube-burst failure. The results show that the root cause of scale forming is that greater steam extraction flow after reforming of the second extraction leads to less steam flow into reheater, which causes over temperature to some of the heated tubes; and the root cause of scale shedding is that long term operation in AGC-R mode brings about great fluctuations of unit load, steam temperature and pressure, accelerating scale shedding. In conclusion, preventive measures are drawn up considering the operation mode of the unit.

  1. Effect of Primary Recrystallized Microstructure and Nitriding on Secondary Recrystallization in Grain Oriented Silicon Steel by Low Temperature Slab Reheating

    Directory of Open Access Journals (Sweden)

    LIU Gong-tao

    2018-01-01

    Full Text Available Different primary recrystallized grain sizes were obtained by controlling decarburization process in grain oriented silicon steel produced by low temperature slab reheating technique. The effect of primary grain size on secondary recrystallization and magnetic properties was studied. The appropriate nitrogen content after nitriding was explored in case of very large primary grain size, and the effect of {411}〈148〉 primary recrystallized texture on the abnormal growth behavior was discussed. The results show that an increase in average primary grain size from 10μm to 15μm leads to an increase of secondary recrystallization temperature and a sharper Goss texture with higher magnetic permeability, in the condition of a very large average primary grain size of 28μm, the suitable amount of nitrogen increases to about 6×10-4. The {411}〈148〉 oriented grains in primary recrystallized microstructure can easily grow into larger sizes due to their size advantage, and thus hinder the abnormal growth of secondary grains, moreover, the hindering effect is more pronounced in the abnormal growth of Brass-oriented grains due to their misorientation with low migration rate other than Goss grains.

  2. Experimental thermal behavior of a power plant reheater

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, M. Manuela Prieto; Garcia, F. Javier Fernandez; Ramon, Ines Suarez [Departamento de Energia, Universidad de Oviedo, Campus de Viesques, 33204 Gijon, Asturias (Spain); Roces, Hilario Sanchez [Central Termica de Soto de Ribera, Soto de Ribera, Asturias (Spain)

    2006-04-15

    The process conditions of power plant components subjected to high pressures and temperatures are essential to determine their remaining life, availability and efficiency. It is, therefore, expedient to pay special attention to critical components, such as superheater and reheater heat exchangers, headers, and main and reheated steam lines. In this paper, on-line and off-line variables of a power plant reheater that has presented problems of thickness losses and repetitive tube fissures are studied. The fissures are associated with the effect of a thermal-mechanical mechanism. Off-line measurements were taken of the following variables: pressure, temperature, velocity and composition of the gases. On-line instrumentation was completed by the installation of specific thermocouples to ascertain the temperatures in the tubes outlet. Various angles for the fuel inlet of the burners and variations in the number and location of the working burners were also assayed. As a consequence of this analysis, it can be deduced that there are important differences in the outlet temperature of the reheater tubes that decrease for lower powers. Finally, it is pointed that a non-uniform distribution of the steam flow in the reheater might be the cause of the problem. (author)

  3. Effects of Re-heating Tissue Samples to Core Body Temperature on High-Velocity Ballistic Projectile-tissue Interactions.

    Science.gov (United States)

    Humphrey, Caitlin; Henneberg, Maciej; Wachsberger, Christian; Maiden, Nicholas; Kumaratilake, Jaliya

    2017-11-01

    Damage produced by high-speed projectiles on organic tissue will depend on the physical properties of the tissues. Conditioning organic tissue samples to human core body temperature (37°C) prior to conducting ballistic experiments enables their behavior to closely mimic that of living tissues. To minimize autolytic changes after death, the tissues are refrigerated soon after their removal from the body and re-heated to 37°C prior to testing. This research investigates whether heating 50-mm-cube samples of porcine liver, kidney, and heart to 37°C for varying durations (maximum 7 h) can affect the penetration response of a high-speed, steel sphere projectile. Longer conditioning times for heart and liver resulted in a slight loss of velocity/energy of the projectile, but the reverse effect occurred for the kidney. Possible reasons for these trends include autolytic changes causing softening (heart and liver) and dehydration causing an increase in density (kidney). © 2017 American Academy of Forensic Sciences.

  4. Reheating after inflation

    International Nuclear Information System (INIS)

    Kripfganz, Jochen; Karl-Marx-Universitaet, Leipzig; Ilgenfritz, E.M.

    1986-01-01

    A numerical analysis of reheating is performed for a classical scalar field with exponentially flat potential. An operational definition of the reheating time is given involving the gradient contribution to the inflation field energy. For the parameter range studied the product of reheating time and Hubble constant H is found to be of order one, being approximately independent of the value of H. (author)

  5. Reheating after inflation

    International Nuclear Information System (INIS)

    Kripfganz, J.; Ilgenfritz, E.M.

    1985-07-01

    A numerical analysis of reheating is performed for a classical scalar field with exponentially flat potential. An operational definition of the reheating time is given involving the gradient contribution to the inflation field energy. For the parameter range studied the product of reheating time and Hubble constant H is found to be of order one, being approximately independent of the value of H. (author)

  6. Correlation Between Microstructure and Low-Temperature Impact Toughness of Simulated Reheated Zones in the Multi-pass Weld Metal of High-Strength Steel

    Science.gov (United States)

    Kang, Yongjoon; Park, Gitae; Jeong, Seonghoon; Lee, Changhee

    2018-01-01

    A large fraction of reheated weld metal is formed during multi-pass welding, which significantly affects the mechanical properties (especially toughness) of welded structures. In this study, the low-temperature toughness of the simulated reheated zone in multi-pass weld metal was evaluated and compared to that of the as-deposited zone using microstructural analyses. Two kinds of high-strength steel welds with different hardenabilities were produced by single-pass, bead-in-groove welding, and both welds were thermally cycled to peak temperatures above Ac3 using a Gleeble simulator. When the weld metals were reheated, their toughness deteriorated in response to the increase in the fraction of detrimental microstructural components, i.e., grain boundary ferrite and coalesced bainite in the weld metals with low and high hardenabilities, respectively. In addition, toughness deterioration occurred in conjunction with an increase in the effective grain size, which was attributed to the decrease in nucleation probability of acicular ferrite; the main cause for this decrease changed depending on the hardenability of the weld metal.

  7. Gravitino or axino dark matter with reheat temperature as high as 10{sup 16} GeV

    Energy Technology Data Exchange (ETDEWEB)

    Co, Raymond T. [Berkeley Center for Theoretical Physics, Department of Physics, University of California,366 LeConte Hall MC 7300, Berkeley, CA 94720 (United States); Theoretical Physics Group, Lawrence Berkeley National Laboratory,1 Cyclotron Rd., Berkeley, CA 94720 (United States); D’Eramo, Francesco [Department of Physics, University of California Santa Cruz,1156 High Street, Santa Cruz, CA 95064 (United States); Santa Cruz Institute for Particle Physics,1156 High Street, Santa Cruz, CA 95064 (United States); Hall, Lawrence J. [Berkeley Center for Theoretical Physics, Department of Physics, University of California,366 LeConte Hall MC 7300, Berkeley, CA 94720 (United States); Theoretical Physics Group, Lawrence Berkeley National Laboratory,1 Cyclotron Rd., Berkeley, CA 94720 (United States)

    2017-03-01

    A new scheme for lightest supersymmetric particle (LSP) dark matter is introduced and studied in theories of TeV supersymmetry with a QCD axion, a, and a high reheat temperature after inflation, T{sub R}. A large overproduction of axinos (ã) and gravitinos (G̃) from scattering at T{sub R}, and from freeze-in at the TeV scale, is diluted by the late decay of a saxion condensate that arises from inflation. The two lightest superpartners are ã, with mass of order the TeV scale, and G̃ with mass m{sub 3/2} anywhere between the keV and TeV scales, depending on the mediation scale of supersymmetry breaking. Dark matter contains both warm and cold components: for G̃ LSP the warm component arises from ã→G̃a, while for ã LSP the warm component arises from G̃→ãa. The free-streaming scale for the warm component is predicted to be of order 1 Mpc (and independent of m{sub 3/2} in the case of G̃ LSP). T{sub R} can be as high as 10{sup 16} GeV, for any value of m{sub 3/2}, solving the gravitino problem. The PQ symmetry breaking scale V{sub PQ} depends on T{sub R} and m{sub 3/2} and can be anywhere in the range (10{sup 10}−10{sup 16}) GeV. Detailed predictions are made for the lifetime of the neutralino LOSP decaying to ã+h/Z and G̃+h/Z/γ, which is in the range of (10{sup −1}−10{sup 6})m over much of parameter space. For an axion misalignment angle of order unity, the axion contribution to dark matter is sub-dominant, except when V{sub PQ} approaches 10{sup 16} GeV.

  8. Advanced steel reheat furnace

    Energy Technology Data Exchange (ETDEWEB)

    Moyeda, D.; Sheldon, M.; Koppang, R. [Energy and Environmental Research Corp., Irvine, CA (United States); Lanyi, M.; Li, X.; Eleazer, B. [Air Products and Chemicals, Inc., Allentown, PA (United States)

    1997-10-01

    Energy and Environmental Research Corp. (EER) under a contract from the Department of Energy is pursuing the development and demonstration of an Advanced Steel Reheating Furnace. This paper reports the results of Phase 1, Research, which has evaluated an advanced furnace concept incorporating two proven and commercialized technologies previously applied to other high temperature combustion applications: EER`s gas reburn technology (GR) for post combustion NOx control; and Air Product`s oxy-fuel enrichment air (OEA) for improved flame heat transfer in the heating zones of the furnace. The combined technologies feature greater production throughput with associated furnace efficiency improvements; lowered NOx emissions; and better control over the furnace atmosphere, whether oxidizing or reducing, leading to better control over surface finish.

  9. IMPROVEMENT OF SLAB REHEATING PROCESS AT USIMINAS THROUGH MATHEMATICAL SIMULATION

    Directory of Open Access Journals (Sweden)

    Antônio Adel dos Santos

    2012-09-01

    Full Text Available Basic characteristics and application examples of the mathematical simulator for reheating process in walking-beam type furnaces, that has been developed and applied to Usiminas plate mill line at Ipatinga, are shown in this paper. This is a bi-dimensional mathematical model solved by the finite volume method, validated by temperature measurements inside the slab during heating and coded as a visual tool. Among these applications, the following can be highlighted: (i determination of suitable furnace zone temperatures and residence times for processing steels by accelerated cooling technology; (ii determination of slab average temperature at discharging as well as at each zone exit, supplying data to be fed to the automation system at the comissioning stage; (iii analyses of slab thermal distribution through the reheating process, enabling operational optimization

  10. Moisture separator reheaters for nuclear power plants

    International Nuclear Information System (INIS)

    Miyoshi, Michizo; Yonemura, Katsutoshi

    1974-01-01

    In the light water reactor plants using BWRS or PWRS, the pressure and temperature of steam at the inlet of turbines are low, and the steam is moist, as compared with the case of thermal power plants. Therefore, moisture separator/reheaters are used between high and low pressure turbines. The steam from a high pressure turbine enters a manifold, and goes zigzag through vertical plate separator elements, its moisture is removed from the steam. Then, after being reheated with the steam bled from the high pressure turbine and directly from a reactor, the steam is fed into a low pressure turbine. The development and test made on the components of a moisture separaotr/reheater and the overall model experiment are described together with the mechanism of moisture separation and reheating. (Mori, K.)

  11. The Higgs boson can delay reheating after inflation

    Science.gov (United States)

    Freese, Katherine; Sfakianakis, Evangelos I.; Stengel, Patrick; Visinelli, Luca

    2018-05-01

    The Standard Model Higgs boson, which has previously been shown to develop an effective vacuum expectation value during inflation, can give rise to large particle masses during inflation and reheating, leading to temporary blocking of the reheating process and a lower reheat temperature after inflation. We study the effects on the multiple stages of reheating: resonant particle production (preheating) as well as perturbative decays from coherent oscillations of the inflaton field. Specifically, we study both the cases of the inflaton coupling to Standard Model fermions through Yukawa interactions as well as to Abelian gauge fields through a Chern-Simons term. We find that, in the case of perturbative inflaton decay to SM fermions, reheating can be delayed due to Higgs blocking and the reheat temperature can decrease by up to an order of magnitude. In the case of gauge-reheating, Higgs-generated masses of the gauge fields can suppress preheating even for large inflaton-gauge couplings. In extreme cases, preheating can be shut down completely and must be substituted by perturbative decay as the dominant reheating channel. Finally, we discuss the distribution of reheat temperatures in different Hubble patches, arising from the stochastic nature of the Higgs VEV during inflation and its implications for the generation of both adiabatic and isocurvature fluctuations.

  12. Exergy analysis of a 1000 MW double reheat ultra-supercritical power plant

    International Nuclear Information System (INIS)

    Si, Ningning; Zhao, Zhigang; Su, Sheng; Han, Pengshuai; Sun, Zhijun; Xu, Jun; Cui, Xiaoning; Hu, Song; Wang, Yi; Jiang, Long; Zhou, Yingbiao; Chen, Gang; Xiang, Jun

    2017-01-01

    Highlights: • Set up a simple and effective method to analysis the performance of double reheat USC unit. • Exergy loss distribution of the double reheat USC unit was declared. • The sensitivity variations of the unit’s exergy efficiency has been revealed. • Provide the foundation for the operation optimization of double reheat USC unit. - Abstract: This study evaluates the performance of a 1000 MW double reheat ultra-supercritical power plant. An exergy analysis was performed to direct the energy loss distribution of this system. Based on the exergy balance equation, together with exergy efficiency, exergy loss coefficient, and exergy loss rate, the exergy distribution and efficiency of the unit were determined. Results show that the highest exergy loss in furnace is as high as 85%, which caused by the combustion of fuel and heat exchange of water wall. The VHP and the two LPs suffer the highest exergy losses, namely 1.86%, 2.04% and 2.13% respectively. The regenerative heating system has an exergy loss rate of 2.3%. The condenser suffers a heat loss of 999 MW, but its exergy is as low as 20.49 MW. The sensitivity variations of the unit’s exergy efficiency with load, feedwater temperature, main steam temperature and pressure, the twice reheat steam temperatures, and steam exhaust pressure were also analyzed, indicating that load, feedwater temperature, and steam exhaust pressure influence the exergy efficiency of this unit than other elements. The overall exergy efficiency decreases along with the gradual increase of steam exhaust pressure at any constant outlet boiler temperature, but it increases as the load, feedwater temperature, main steam temperature and pressure, and twice reheat steam temperatures increase at fixed steam exhaust pressure.

  13. Chilly dark sectors and asymmetric reheating

    International Nuclear Information System (INIS)

    Adshead, Peter; Cui, Yanou; Shelton, Jessie

    2016-01-01

    In a broad class of theories, the relic abundance of dark matter is determined by interactions internal to a thermalized dark sector, with no direct involvement of the Standard Model (SM). We point out that these theories raise an immediate cosmological question: how was the dark sector initially populated in the early universe? Motivated in part by the difficulty of accommodating large amounts of entropy carried in dark radiation with cosmic microwave background measurements of the effective number of relativistic species at recombination, N eff , we aim to establish which admissible cosmological histories can populate a thermal dark sector that never reaches thermal equilibrium with the SM. The minimal cosmological origin for such a dark sector is asymmetric reheating, when the same mechanism that populates the SM in the early universe also populates the dark sector at a lower temperature. Here we demonstrate that the resulting inevitable inflaton-mediated scattering between the dark sector and the SM can wash out a would-be temperature asymmetry, and establish the regions of parameter space where temperature asymmetries can be generated in minimal reheating scenarios. Thus obtaining a temperature asymmetry of a given size either restricts possible inflaton masses and couplings or necessitates a non-minimal cosmology for one or both sectors. As a side benefit, we develop techniques for evaluating collision terms in the relativistic Boltzmann equation when the full dependence on Bose-Einstein or Fermi-Dirac phase space distributions must be retained, and present several new results on relativistic thermal averages in an appendix.

  14. Chilly dark sectors and asymmetric reheating

    Energy Technology Data Exchange (ETDEWEB)

    Adshead, Peter [Department of Physics, University of Illinois at Urbana-Champaign,Urbana, IL 61801 (United States); Cui, Yanou [Perimeter Institute for Theoretical Physics,Waterloo, Ontario N2L 2Y5 (Canada); Maryland Center for Fundamental Physics, University of Maryland,College Park, MD 20742 (United States); Shelton, Jessie [Department of Physics, University of Illinois at Urbana-Champaign,Urbana, IL 61801 (United States)

    2016-06-06

    In a broad class of theories, the relic abundance of dark matter is determined by interactions internal to a thermalized dark sector, with no direct involvement of the Standard Model (SM). We point out that these theories raise an immediate cosmological question: how was the dark sector initially populated in the early universe? Motivated in part by the difficulty of accommodating large amounts of entropy carried in dark radiation with cosmic microwave background measurements of the effective number of relativistic species at recombination, N{sub eff}, we aim to establish which admissible cosmological histories can populate a thermal dark sector that never reaches thermal equilibrium with the SM. The minimal cosmological origin for such a dark sector is asymmetric reheating, when the same mechanism that populates the SM in the early universe also populates the dark sector at a lower temperature. Here we demonstrate that the resulting inevitable inflaton-mediated scattering between the dark sector and the SM can wash out a would-be temperature asymmetry, and establish the regions of parameter space where temperature asymmetries can be generated in minimal reheating scenarios. Thus obtaining a temperature asymmetry of a given size either restricts possible inflaton masses and couplings or necessitates a non-minimal cosmology for one or both sectors. As a side benefit, we develop techniques for evaluating collision terms in the relativistic Boltzmann equation when the full dependence on Bose-Einstein or Fermi-Dirac phase space distributions must be retained, and present several new results on relativistic thermal averages in an appendix.

  15. Chilly dark sectors and asymmetric reheating

    Science.gov (United States)

    Adshead, Peter; Cui, Yanou; Shelton, Jessie

    2016-06-01

    In a broad class of theories, the relic abundance of dark matter is determined by interactions internal to a thermalized dark sector, with no direct involvement of the Standard Model (SM). We point out that these theories raise an immediate cosmological question: how was the dark sector initially populated in the early universe? Motivated in part by the difficulty of accommodating large amounts of entropy carried in dark radiation with cosmic microwave background measurements of the effective number of relativistic species at recombination, N eff , we aim to establish which admissible cosmological histories can populate a thermal dark sector that never reaches thermal equilibrium with the SM. The minimal cosmological origin for such a dark sector is asymmetric reheating, when the same mechanism that populates the SM in the early universe also populates the dark sector at a lower temperature. Here we demonstrate that the resulting inevitable inflaton-mediated scattering between the dark sector and the SM can wash out a would-be temperature asymmetry, and establish the regions of parameter space where temperature asymmetries can be generated in minimal reheating scenarios. Thus obtaining a temperature asymmetry of a given size either restricts possible inflaton masses and couplings or necessitates a non-minimal cosmology for one or both sectors. As a side benefit, we develop techniques for evaluating collision terms in the relativistic Boltzmann equation when the full dependence on Bose-Einstein or Fermi-Dirac phase space distributions must be retained, and present several new results on relativistic thermal averages in an appendix.

  16. Reheating the D-brane universe via instant preheating

    International Nuclear Information System (INIS)

    Panda, Sudhakar; Sami, M.; Thongkool, I.

    2010-01-01

    We investigate a possibility of reheating in a scenario of D-brane inflation in a warped deformed conifold background which includes perturbative corrections to throat geometry sourced by a chiral operator of dimension 3/2 in the conformal field theory. The effective D-brane potential, in this case, belongs to the class of nonoscillatory models of inflation for which the conventional reheating mechanism does not work. We find that gravitational particle production is inefficient and leads to reheating temperature of the order of 10 8 GeV. We show that instant preheating is quite suitable to the present scenario and can easily reheat the universe to a temperature which is higher by about 3 orders of magnitude than its counterpart associated with gravitational particle production. The reheating temperature is shown to be insensitive to a particular choice of inflationary parameters suitable to observations.

  17. Parametric Amplification of Gravitational Fluctuations during Reheating

    International Nuclear Information System (INIS)

    Finelli, F.; Brandenberger, R.; Finelli, F.

    1999-01-01

    Cosmological perturbations can undergo amplification by parametric resonance during preheating even on scales larger than the Hubble radius, without violating causality. A unified description of gravitational and matter fluctuations is crucial to determine the strength of the instability. To extract specific signatures of the oscillating inflaton field during reheating, it is essential to focus on a variable describing metric fluctuations which is constant in the standard analyses of inflation. For a massive inflaton without self-coupling, we find no additional growth of superhorizon modes during reheating beyond the usual predictions. For a massless self-coupled inflaton, there is a sub-Hubble scale resonance. copyright 1999 The American Physical Society

  18. Method for operating a steam turbine of the nuclear type with electronic reheat control of a cycle steam reheater

    International Nuclear Information System (INIS)

    Luongo, M.C.

    1975-01-01

    An electronic system is provided for operating a nuclear electric power plant with electronic steam reheating control applied to the nuclear turbine system in response to low pressure turbine temperatures, and the control is adapted to operate in a plurality of different automatic control modes to control reheating steam flow and other steam conditions. Each of the modes of control permit turbine temperature variations within predetermined constraints and according to predetermined functions of time. (Official Gazette)

  19. Hemispherical power asymmetry from scale-dependent modulated reheating

    International Nuclear Information System (INIS)

    McDonald, John

    2013-01-01

    We propose a new model for the hemispherical power asymmetry of the CMB based on modulated reheating. Non-Gaussianity from modulated reheating can be small enough to satisfy the bound from Planck if the dominant modulation of the inflaton decay rate is linear in the modulating field σ. σ must then acquire a spatially-modulated power spectrum with a red scale-dependence. This can be achieved if the primordial perturbation of σ is generated via tachyonic growth of a complex scalar field. Modulated reheating due to σ then produces a spatially modulated and scale-dependent sub-dominant contribution to the adiabatic density perturbation. We show that it is possible to account for the observed asymmetry while remaining consistent with bounds from quasar number counts, non-Gaussianity and the CMB temperature quadupole. The model predicts that the adiabatic perturbation spectral index and its running will be modified by the modulated reheating component

  20. An investigation of reheat cracking in the weld heat affected zone of type 347 stainless steel

    Science.gov (United States)

    Phung-On, Isaratat

    2007-12-01

    microvoid corresponds to the size of precipitate that forms. In addition, there was intragranular cracking in some location indicating that another failure mechanism may also be possible. It was believed that failure may occur along a precipitate free zone. However, the distinct PFZ could not be detected. A SS-DTA technique was also implemented in order to determine precipitation temperatures of the material. The results showed the possible precipitation temperatures in the range of 850°C to 650°C. However, the results were not confidently reliable due to the small amount of carbide formed that affects the sensitivity of the SS-DTA. A simple grain boundary sliding model was generated proposing that the sliding is operated by the shear stress resulting from the formation of precipitate in the grain interior. Then, the sliding results in the microvoid formation and coalescence followed by cracking. In addition, a simple finite element model was generated to provide the illustration of the shear stress built up by the formation of precipitate. The model showed that shear stress can cause the grain boundary movement/sliding. Based on the results from this study, the recommendation for the selection of post weld heat treatment schedule as well as welding procedures can be determined for the prevention of the reheat cracking. A residual stress should be kept below the critical value during welding and post weld heat treating. The testing procedures used in this study can be applied as the guidelines to conduct the reheat cracking susceptibility test for material selection.

  1. Reheating for closed string inflation

    Energy Technology Data Exchange (ETDEWEB)

    Cicoli, Michele [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Mazumdar, Anupam [Lancaster Univ. (United Kingdom). Physics Dept.; Copenhagen Univ. (Denmark). Niels Bohr Institute

    2010-05-15

    We point out some of the outstanding challenges for embedding inflationary cosmology within string theory studying the process of reheating for models where the inflaton is a closed string mode parameterising the size of an internal cycle of the compactification manifold. A realistic model of inflation must explain the tiny perturbations in the cosmic microwave background radiation and also how to excite the ordinary matter degrees of freedom after inflation, required for the success of Big Bang Nucleosynthesis. We study these issues focusing on two promising inflationary models embedded in LARGE volume type IIB flux compactifications. We show that phenomenological requirements and consistency of the effective field theory treatment imply the presence at low energies of a hidden sector together with a visible sector, where the Minimal Supersymmetric Standard Model fields are residing. A detailed calculation of the inflaton coupling to the fields of the hidden sector, visible sector, and moduli sector, reveals that the inflaton fails to excite primarily the visible sector fields, instead hidden sector fields are excited copiously after the end of inflation. This sets severe constraints on hidden sector model building where the most promising scenario emerges as a pure N=1 SYM theory, forbidding the kinematical decay of the inflaton to the hidden sector. In this case it is possible to reheat the Universe with the visible degrees of freedom even though in some cases we discover a new tension between TeV scale SUSY and reheating on top of the well-known tension between TeV scale SUSY and inflation. (orig.)

  2. Reheating for closed string inflation

    International Nuclear Information System (INIS)

    Cicoli, Michele; Mazumdar, Anupam; Copenhagen Univ.

    2010-05-01

    We point out some of the outstanding challenges for embedding inflationary cosmology within string theory studying the process of reheating for models where the inflaton is a closed string mode parameterising the size of an internal cycle of the compactification manifold. A realistic model of inflation must explain the tiny perturbations in the cosmic microwave background radiation and also how to excite the ordinary matter degrees of freedom after inflation, required for the success of Big Bang Nucleosynthesis. We study these issues focusing on two promising inflationary models embedded in LARGE volume type IIB flux compactifications. We show that phenomenological requirements and consistency of the effective field theory treatment imply the presence at low energies of a hidden sector together with a visible sector, where the Minimal Supersymmetric Standard Model fields are residing. A detailed calculation of the inflaton coupling to the fields of the hidden sector, visible sector, and moduli sector, reveals that the inflaton fails to excite primarily the visible sector fields, instead hidden sector fields are excited copiously after the end of inflation. This sets severe constraints on hidden sector model building where the most promising scenario emerges as a pure N=1 SYM theory, forbidding the kinematical decay of the inflaton to the hidden sector. In this case it is possible to reheat the Universe with the visible degrees of freedom even though in some cases we discover a new tension between TeV scale SUSY and reheating on top of the well-known tension between TeV scale SUSY and inflation. (orig.)

  3. HTGR power plant hot reheat steam pressure control system

    International Nuclear Information System (INIS)

    Braytenbah, A.S.; Jaegtnes, K.O.

    1975-01-01

    A control system for a high temperature gas cooled reactor (HTGR) power plant is disclosed wherein such plant includes a plurality of steam generators. Dual turbine-generators are connected to the common steam headers, a high pressure element of each turbine receiving steam from the main steam header, and an intermediate-low pressure element of each turbine receiving steam from the hot reheat header. Associated with each high pressure element is a bypass line connected between the main steam header and a cold reheat header, which is commonly connected to the high pressure element exhausts. A control system governs the flow of steam through the first and second bypass lines to provide for a desired minimum steam flow through the steam generator reheater sections at times when the total steam flow through the turbines is less than such minimum, and to regulate the hot reheat header steam pressure to improve control of the auxiliary steam turbines and thereby improve control of the reactor coolant gas flow, particularly following a turbine trip. (U.S.)

  4. On ultraviolet freeze-in dark matter during reheating

    Science.gov (United States)

    Chen, Shao-Long; Kang, Zhaofeng

    2018-05-01

    The absence of any confirmative signals from extensive DM searching motivates us to go beyond the conventional WIMPs scenario. The feebly interacting massive particles (FIMPs) paradigm provides a good alternative which, despite of its feebly interaction with the thermal particles, still could correctly produce relic abundance without conventional DM signals. The Infrared-FIMP based on the renormalizable operators is usually suffering the very tiny coupling drawback, which can be overcome in the UltraViolet-FIMP scenario based on high dimensional effective operators. However, it is sensitive to the history of the very early Universe. The previous works terminates this sensitivity at the reheating temperature TRH. We, motivated by its UV-sensitivity, investigate the effects from the even earlier Universe, reheating era. We find that in the usual case with TRHgg mDM, the production rate during reheating is very small as long as the effective operators dimension d study the situation when TRH is even lower than mDM and DM can be directly produced during reheating if its mass does not exceed TMAX.

  5. Effect of Scale on Slab Heat Transfer in a Walking Beam Type Reheating Furnace

    OpenAIRE

    Man Young Kim

    2013-01-01

    In this work, the effects of scale on thermal behavior of the slab in a walking-beam type reheating furnace is studied by considering scale formation and growth in a furnace environment. Also, mathematical heat transfer model to predict the thermal radiation in a complex shaped reheating furnace with slab and skid buttons is developed with combined nongray WSGGM and blocked-off solution procedure. The model can attack the heat flux distribution within the furnace and the temperature distribut...

  6. Gravitational wave background from reheating after hybrid inflation

    International Nuclear Information System (INIS)

    Garcia-Bellido, Juan; Figueroa, Daniel G.; Sastre, Alfonso

    2008-01-01

    The reheating of the Universe after hybrid inflation proceeds through the nucleation and subsequent collision of large concentrations of energy density in the form of bubblelike structures moving at relativistic speeds. This generates a significant fraction of energy in the form of a stochastic background of gravitational waves, whose time evolution is determined by the successive stages of reheating: First, tachyonic preheating makes the amplitude of gravity waves grow exponentially fast. Second, bubble collisions add a new burst of gravitational radiation. Third, turbulent motions finally sets the end of gravitational waves production. From then on, these waves propagate unimpeded to us. We find that the fraction of energy density today in these primordial gravitational waves could be significant for grand unified theory (GUT)-scale models of inflation, although well beyond the frequency range sensitivity of gravitational wave observatories like LIGO, LISA, or BBO. However, low-scale models could still produce a detectable signal at frequencies accessible to BBO or DECIGO. For comparison, we have also computed the analogous gravitational wave background from some chaotic inflation models and obtained results similar to those found by other groups. The discovery of such a background would open a new observational window into the very early universe, where the details of the process of reheating, i.e. the big bang, could be explored. Moreover, it could also serve in the future as a new experimental tool for testing the inflationary paradigm

  7. Device and Container for Reheating and Sterilization

    Science.gov (United States)

    Sastry, Sudhir K.; Heskitt, Brian F.; Jun, Soojin; Marcy, Joseph E.; Mahna, Ritesh

    2012-01-01

    Long-duration space missions require the development of improved foods and novel packages that do not represent a significant disposal issue. In addition, it would also be desirable if rapid heating technologies could be used on Earth as well, to improve food quality during a sterilization process. For this purpose, a package equipped with electrodes was developed that will enable rapid reheating of contents via ohmic heating to serving temperature during space vehicle transit. Further, the package is designed with a resealing feature, which enables the package, once used, to contain and sterilize waste, including human waste for storage prior to jettison during a long-duration mission. Ohmic heating is a technology that has been investigated on and off for over a century. Literature indicates that foods processed by ohmic heating are of superior quality to their conventionally processed counterparts. This is due to the speed and uniformity of ohmic heating, which minimizes exposure of sensitive materials to high temperatures. In principle, the material may be heated rapidly to sterilization conditions, cooled rapidly, and stored. The ohmic heating device herein is incorporated within a package. While this by itself is not novel, a reusable feature also was developed with the intent that waste may be stored and re-sterilized within the packages. These would then serve a useful function after their use in food processing and storage. The enclosure should be designed to minimize mass (and for NASA's purposes, Equivalent System Mass, or ESM), while enabling the sterilization function. It should also be electrically insulating. For this reason, Ultem high-strength, machinable electrical insulator was used.

  8. Hypercharged dark matter and direct detection as a probe of reheating.

    Science.gov (United States)

    Feldstein, Brian; Ibe, Masahiro; Yanagida, Tsutomu T

    2014-03-14

    The lack of new physics at the LHC so far weakens the argument for TeV scale thermal dark matter. On the other hand, heavier, nonthermal dark matter is generally difficult to test experimentally. Here we consider the interesting and generic case of hypercharged dark matter, which can allow for heavy dark matter masses without spoiling testability. Planned direct detection experiments will be able to see a signal for masses up to an incredible 1010  GeV, and this can further serve to probe the reheating temperature up to about 109  GeV, as determined by the nonthermal dark matter relic abundance. The Z-mediated nature of the dark matter scattering may be determined in principle by comparing scattering rates on different detector nuclei, which in turn can reveal the dark matter mass. We will discuss the extent to which future experiments may be able to make such a determination.

  9. On finite density effects on cosmic reheating and moduli decay and implications for Dark Matter production

    International Nuclear Information System (INIS)

    Drewes, Marco

    2014-01-01

    We study the damping of an oscillating scalar field in a Friedmann-Robertson-Walker spacetime by perturbative processes, taking into account the back-reaction of the plasma of decay products on the damping rate. The scalar field may be identified with the inflaton, in which case this process resembles the reheating of the universe after inflation. It can also model a modulus that dominates the energy density of the universe at later times. We find that the finite density corrections to the damping rate can have a drastic effect on the thermal history and considerably increase both, the maximal temperature in the early universe and the reheating temperature at the onset of the radiation dominated era. As a result the abundance of some Dark Matter candidates may be considerably larger than previously estimated. We give improved analytic estimates for the maximal and the reheating temperatures and confirm them numerically in a simple model

  10. 3-D Transient Heat Transfer Analysis of Slab Heating Characteristics in a Reheating Furnace in Hot Strip Mills

    OpenAIRE

    J. Y. Jang; Y. W. Lee; C. N. Lin; C. H. Wang

    2015-01-01

    The reheating furnace is used to reheat the steel slabs before the hot-rolling process. The supported system includes the stationary/moving beams, and the skid buttons which block some thermal radiation transmitted to the bottom of the slabs. Therefore, it is important to analyze the steel slab temperature distribution during the heating period. A three-dimensional mathematical transient heat transfer model for the prediction of temperature distribution within the slab ha...

  11. Replacement of low pressure reheater and performance evaluation on domestic NPP moisture separator reheater

    International Nuclear Information System (INIS)

    Choi, Y. S.; Jeong, W. T.; Shon, S. Y.; Kim, M. H.

    2003-01-01

    Moisture Separator Reheater is one of the most important equipment for the integrity of low pressure turbine and the total efficiency of the nuclear power plant, It supplies the dry steam to low pressure turbine after separation of moisture and reheating the wet steam out of high pressure turbine. This equipment is always operated under severe conditions, therefore it should be carefully maintained for safe operation and operating confidence. After replacement low pressure reheater of moister separator reheater on domestic nuclear power plant, there was MSR performance degradation and vibration of condensate drain line. So I found out root cause and commented a solution, site people modified the equipment. Finally I concluded the performanc of MSR was good condition, after I inspected the equipment and evaluated the performance of MSR

  12. Numerical analysis method for reheater performance of moisture separator reheater for Nuclear Power Plants

    International Nuclear Information System (INIS)

    Oda, Tsuyoshi; Fujisawa, Kyosuke; Akamatsu, Hiroshi

    2014-01-01

    Nuclear power generation uses saturated steam of 6 MPa and 275degC level due to the restrictions imposed by the materials used in the nuclear reactor, and its efficiency, approximately 33-35%, is not high compared with fossil fuel power generation. Therefore, thermal engineers working on nuclear power generation have the important responsibility toward society of achieving the highest efficiency under the given restrictions. The use of a moisture separator reheater (MSR) is one of the measures we can take to achieve higher efficiency. Because the bottom of the MSR tube bundle making contact with the cycle steam at its lowest temperature is subcooled and inadequate drainage of the condensate inside the tubes causes cyclic flooding and temperature oscillations in some cases, it is necessary to have a minimum flow rate of excess heating steam slightly beyond the demand of/what is required for the heat transfer, and the consequent subcooling must be kept below a certain level. This report describes the numerical analysis method developed for the design of heat transfer performance and evaluation of the tube bundle integrity of MSRs. (author)

  13. What can the CMB tell about the microphysics of cosmic reheating?

    International Nuclear Information System (INIS)

    Drewes, Marco

    2016-01-01

    In inflationary cosmology, cosmic reheating after inflation sets the initial conditions for the hot big bang. We investigate how CMB data can be used to study the effective potential and couplings of the inflaton during reheating to constrain the underlying microphysics. If there is a phase of preheating that is driven by a parametric resonance or other instability, then the thermal history and expansion history during the reheating era depend on a large number of microphysical parameters in a complicated way. In this case the connection between CMB observables and microphysical parameters can only established with intense numerical studies. Such studies can help to improve CMB constraints on the effective inflaton potential in specific models, but parameter degeneracies usually make it impossible to extract meaningful best-fit values for individual microphysical parameters. If, on the other hand, reheating is driven by perturbative processes, then it can be possible to constrain the inflaton couplings and the reheating temperature from CMB data. This provides an indirect probe of fundamental microphysical parameters that most likely can never be measured directly in the laboratory, but have an immense impact on the evolution of the cosmos by setting the stage for the hot big bang

  14. Reheating mechanism of the curvaton with nonminimal derivative coupling to gravity

    International Nuclear Information System (INIS)

    Qiu, Taotao; Feng, Kaixi

    2017-01-01

    In this paper, we continue our study of the curvaton model with nonminimal derivative coupling (NDC) to Einstein gravity proposed in our previous work (Feng in Phys Lett B 729:99, 2014; Feng and Qiu in Phys Rev D 90(12):123508, 2014), focusing on the reheating mechanism. We found that according to whether the curvaton has or has not dominated the background after the end of inflation, it will have two different behaviors of evolution, which should be the general property of the curvaton with nonminimal couplings. This will cause two different parts of reheating, which goes on via the parametric resonance process. The reheating temperature is estimated for both cases in which reheating completes before and after curvaton domination, and the constraints are quite loose compared to that of overproduction of gravitinos. Finally we investigated the evolution of curvature perturbation during reheating. We have shown both analytically and numerically that the curvature perturbation will not blow up during the resonance process. (orig.)

  15. Reheating mechanism of the curvaton with nonminimal derivative coupling to gravity

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Taotao [Central China Normal University, Institute of Astrophysics, Wuhan (China); Central China Normal University, Key Laboratory of Quark and Lepton Physics (MOE) and College of Physical Science and Technology, Wuhan (China); Feng, Kaixi [Chinese Academy of Sciences, Institute of Theoretical Physics, Beijing (China)

    2017-10-15

    In this paper, we continue our study of the curvaton model with nonminimal derivative coupling (NDC) to Einstein gravity proposed in our previous work (Feng in Phys Lett B 729:99, 2014; Feng and Qiu in Phys Rev D 90(12):123508, 2014), focusing on the reheating mechanism. We found that according to whether the curvaton has or has not dominated the background after the end of inflation, it will have two different behaviors of evolution, which should be the general property of the curvaton with nonminimal couplings. This will cause two different parts of reheating, which goes on via the parametric resonance process. The reheating temperature is estimated for both cases in which reheating completes before and after curvaton domination, and the constraints are quite loose compared to that of overproduction of gravitinos. Finally we investigated the evolution of curvature perturbation during reheating. We have shown both analytically and numerically that the curvature perturbation will not blow up during the resonance process. (orig.)

  16. Energy conservation in reheating furnaces by reducing scrap and scale formation; Kuumamuokkauksen energiasaeaestoet romun maeaeraeae ja hilseilyae vaehentaemaellae

    Energy Technology Data Exchange (ETDEWEB)

    Kivivuori, S; Savolainen, P; Fredriksson, J; Paavola, J [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Materials Processing and Powder Metallurgy

    1997-12-31

    The main objective of the project `Energy Savings in Reheating Furnaces by Reducing Scrap and Scale Formation` is to reduce energy consumption and environmental harms in reheating and rolling of steel. This was done by analysing the different atmospheres in reheating furnaces of the steel companies participating in this project. These atmospheres were then simulated in a laboratory furnace. Scale formation tests with different steel grades were then carried out in these atmospheres. Scale removal tests were done to some steel grades too. The results showed that lower oxygen content - as expected - decreases oxidation despite the even higher carbondioxide content in the atmosphere. Lower oxygen content may cause difficulties in scale removal. This however is highly dependent on the steel grade. Heat treatment tests showed the effect of increased temperature and furnace time on decarburization. Some energy savings was obtained in fuel consumption by optimising the operation parameters and the atmosphere steadier in different reheating furnaces. (orig.)

  17. Energy conservation in reheating furnaces by reducing scrap and scale formation; Kuumamuokkauksen energiasaeaestoet romun maeaeraeae ja hilseilyae vaehentaemaellae

    Energy Technology Data Exchange (ETDEWEB)

    Kivivuori, S.; Savolainen, P.; Fredriksson, J.; Paavola, J. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Materials Processing and Powder Metallurgy

    1996-12-31

    The main objective of the project `Energy Savings in Reheating Furnaces by Reducing Scrap and Scale Formation` is to reduce energy consumption and environmental harms in reheating and rolling of steel. This was done by analysing the different atmospheres in reheating furnaces of the steel companies participating in this project. These atmospheres were then simulated in a laboratory furnace. Scale formation tests with different steel grades were then carried out in these atmospheres. Scale removal tests were done to some steel grades too. The results showed that lower oxygen content - as expected - decreases oxidation despite the even higher carbondioxide content in the atmosphere. Lower oxygen content may cause difficulties in scale removal. This however is highly dependent on the steel grade. Heat treatment tests showed the effect of increased temperature and furnace time on decarburization. Some energy savings was obtained in fuel consumption by optimising the operation parameters and the atmosphere steadier in different reheating furnaces. (orig.)

  18. Theoretical development of a thermal model for the reheater of a power plant boiler

    Energy Technology Data Exchange (ETDEWEB)

    Prieto, M.M. [Oviedo University, Energy Department, Campus de Viesques, 33204 GIJON. Asturias (Spain)]. E-mail: manuelap@uniovi.es; Suarez, I. [Oviedo University, Energy Department, Campus de Viesques, 33204 GIJON. Asturias (Spain); Fernandez, F.J. [Oviedo University, Energy Department, Campus de Viesques, 33204 GIJON. Asturias (Spain); Sanchez, H. [Central Termica de Soto de Ribera, Ribera de Arriba, Asturias (Spain); Mateos, M. [Central Termica de Soto de Ribera, Ribera de Arriba, Asturias (Spain)

    2007-02-15

    A three-dimensional numerical model for simulating flow and heat transfer in the reheater of a boiler is presented. The aim is to describe, as well as possible, the geometry of the reheater and to be able to perform different mass flows of steam along each of the tube serpentines. The model thus makes it possible to calculate the temperature of the tube surfaces along the reheater. The porosity concept is employed, along with empirical correlations for the convective heat transfer coefficient and the radiation heat transfer coefficients. The radiation equations consider most of the radiative effects of the gas: ash content, triatomic gases, type of fuel and temperatures, tube layout and distances and temperatures of other radiative surfaces. The model is proposed with a view to using the measured values of velocities, temperatures and gas composition in the reheater as boundary conditions. The equations are solved using a general purpose computational fluid dynamics (CFD) code in conjunction with specific calculations for the source terms.

  19. Reheating via Gravitational Particle Production in Simple Models of Quintessence or ΛCDM Inflation

    Directory of Open Access Journals (Sweden)

    Jaume de Haro

    2017-11-01

    Full Text Available We have tested some simple Λ CDM (the same test is also valid for quintessence inflation models, imposing that they match with the recent observational data provided by the BICEP and Planck’s team and leading to a reheating temperature, which is obtained via gravitational particle production after inflation, supporting the nucleosynthesis success.

  20. Observational status of Tachyon Natural Inflation and reheating

    Science.gov (United States)

    Rashidi, Narges; Nozari, Kourosh; Grøn, Øyvind

    2018-05-01

    We study observational viability of Natural Inflation with a tachyon field as inflaton. By obtaining the main perturbation parameters in this model, we perform a numerical analysis on the parameter space of the model and in confrontation with 68% and 95% CL regions of Planck2015 data. By adopting a warped background geometry, we find some new constraints on the width of the potential in terms of its height and the warp factor. We show that the Tachyon Natural Inflation in the large width limit recovers the tachyon model with a phi2 potential which is consistent with Planck2015 observational data. Then we focus on the reheating era after inflation by treating the number of e-folds, temperature and the effective equation of state parameter in this era. Since it is likely that the value of the effective equation of state parameter during the reheating era to be in the range 0Inflation model. In particular, we show that a prediction of this model is r<=8/3 δns, where δns is the scalar spectral tilt, δns=1‑ns. In this regard, given that from the Planck2015 data we have δns=0.032 (corresponding to ns=0.968), we get r<= 0.085.

  1. Early reheating and cosmic strings

    International Nuclear Information System (INIS)

    Stebbins, A.J. III.

    1987-01-01

    In the first chapter, possible thermal histories of the universe during the epoch z = 10 - 100 are studied. Expression for the fractional ionization and electron temperature are given in the case of homogeneous heating as a function of the parameters of arbitrary ionizing sources. It is shown that present and future limits on spectral distortions to the microwave background radiation do not provide very restrictive constraints on possible thermal histories of the universe. Heating by cosmic rays and very massive stars is discussed. In the second chapter, accretion of matter onto the wakes left behind by horizon-size pieces of cosmic string is studied. It was found that in a universe containing cold dissipationless matter (CDM), accretion onto wakes produce a network of sheet-like regions with a nonlinear density enhancement. In the third chapter, a formalism is developed for calculating the microwave ansisotropy produced by cosmic string loops in Minkowski space. The final formalism involves doing a one-dimensional integral along the string for each point on the sky. Exact solutions have only been found for a circular loop seen face-on. The equations are integrated for one particular loop configuration at nine points in its evolution

  2. Reheating experiment in the 35-ton pile; Experience de rechauffage sur la pile de 35 tonnes

    Energy Technology Data Exchange (ETDEWEB)

    Cherot, J; Girard, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    When the 35-ton pile was started up it was necessary for us, in order to study certain effects (xenon for example), to know the anti reactivity value of the rods as a function of their dimensions. We have made use of the possibility, in the reheating experiment, of raising the temperature of the graphite-uranium block by simple heating, in order to determine the anti reactivity curves of the rods, and from that the overall temperature coefficient. For the latter we have considered two solutions: first, one in which the average temperature of the pile is defined as our arithmetical mean of the different values given by the 28 thermocouples distributed throughout the pile; a second in which the temperature in likened to a poisoning and is balanced by the square of the flux. The way in which the measurements have been made is indicated, and the different instruments used are described. The method of reheating does not permit the separation of the temperature coefficients of uranium and of graphite. The precision obtained is only moderate, and suffers from the changes of various parameters necessary to other manipulations carried out simultaneously (life time modulators for example), and finally it is a function of the comparatively restricted time allowed. It is evident of course that more careful stabilisation at the different plateaux chosen would have necessitated long periods of reheating. (author) [French] Nous avions besoin lors de la montee en puissance de la pile de 35 tonnes, pour l'elude de divers effets (xenon par ex.) de la valeur de l'antireactivite des barres en fonction de leurs cotes. Nous avons profite dans l'experience rechauffage de la possibilite de monter en temperature, non nucleairement, le bloc graphite uranium, pour determiner les courbes d'antireactivite des barres et de la le coefficient global de temperature. Nous avons considere pour ce dernier deux solutions. Une premiere dans laquelle la temperature moyenne de la pile est definie comme

  3. Reheat cracking susceptibility of P23 (7CrWVMoNb9-6) steel welds made using matching and mis-matching filler metals

    Energy Technology Data Exchange (ETDEWEB)

    Nevasmaa, Pekka; Salonen, Jorma; Auerkari, Pertti; Rantala, Juhani; Holmstroem, Stefan [VTT Technical Research Centre of Finland, Espoo (Finland)

    2010-07-01

    Reheat cracking sensitivity of 7CrWVMoNb9-6 (P23) thick-section multipass welds has been investigated by Gleeble simulation, mechanical testing, fractography and metallography. The results demonstrate that the experimental weld metal made using a high-Nb-W-Ti-B type filler metal was sensitive to reheat cracking, with a reduction of area no more than 2-3% in the BWI reheat cracking (RC) test. Welds made using a high-W -low-Ti type filler metal with Nb content similar to the parent steel, as well as welds make using a Ni-Nb-Ti-free-(W-free) type filler metal with the chemical composition closer to P24 grade material, were more ductile and crack-resistant, though with reduced cross-weld creep strength. Fractography of RC test specimens showed evidence of pronounced localisation of damage at the prior austenite grain boundaries of the thermally reheated, experimental P23 weld metal. The reheat cracking susceptibility of the less ductile weld metal was apparently related both to the chemical composition (higher B, Nb and Ti content) and sub-structural features of the coarse-grained reheated weld metal microstructure. Appropriate single- and multi-cycle thermal Gleeble simulations to produce representative HAY and reheated weld metal microstructures (as function of peak temperature), in conjunction with the BWI RC test were successfully applied to characterise the reheat cracking sensitivity of the candidate weld metals and parent steel HAZ. (orig.)

  4. Leptogenesis and reheating in complex hybrid inflation

    International Nuclear Information System (INIS)

    Martinez-Prieto, Carlos; Delepine, David; Urena-Lopez, L. Arturo

    2010-01-01

    We study the transformation into a baryon asymmetry of a charge initially stored in a complex (waterfall) scalar field at the end of a hybrid inflation phase as described by Delepine, Martinez, and Urena-Lopez [Phys. Rev. Lett. 98, 161302 (2007)]. The waterfall field is coupled to right-handed neutrinos, and is also responsible for their Majorana masses. The charge is finally transferred to the leptons of the standard model through the decay of the right-handed neutrinos without introducing new CP violating interactions. Other needed processes, like the decay of the inflaton field and the reheating of the Universe, are also discussed in detail.

  5. MSW-resonant fermion mixing during reheating

    Science.gov (United States)

    Kanai, Tsuneto; Tsujikawa, Shinji

    2003-10-01

    We study the dynamics of reheating in which an inflaton field couples two flavor fermions through Yukawa-couplings. When two fermions have a mixing term with a constant coupling, we show that the Mikheyev-Smirnov-Wolfenstein (MSW)-type resonance emerges due to a time-dependent background in addition to the standard fermion creation via parametric resonance. This MSW resonance not only alters the number densities of fermions generated by a preheating process but also can lead to the larger energy transfer from the inflaton to fermions. Our mechanism can provide additional source terms for the creation of superheavy fermions which may be relevant for the leptogenesis scenario.

  6. MSW-resonant fermion mixing during reheating

    International Nuclear Information System (INIS)

    Kanai, Tsuneto; Tsujikawa, Shinji

    2003-01-01

    We study the dynamics of reheating in which an inflaton field couples two flavor fermions through Yukawa-couplings. When two fermions have a mixing term with a constant coupling, we show that the Mikheyev-Smirnov-Wolfenstein (MSW)-type resonance emerges due to a time-dependent background in addition to the standard fermion creation via parametric resonance. This MSW resonance not only alters the number densities of fermions generated by a preheating process but also can lead to the larger energy transfer from the inflaton to fermions. Our mechanism can provide additional source terms for the creation of superheavy fermions which may be relevant for the leptogenesis scenario

  7. Reheating effects in the matter power spectrum and implications for substructure

    International Nuclear Information System (INIS)

    Erickcek, Adrienne L.; Sigurdson, Kris

    2011-01-01

    The thermal and expansion history of the Universe before big bang nucleosynthesis is unknown. We investigate the evolution of cosmological perturbations through the transition from an early matter era to radiation domination. We treat reheating as the perturbative decay of an oscillating scalar field into relativistic plasma and cold dark matter. After reheating, we find that subhorizon perturbations in the decay-produced dark matter density are significantly enhanced, while subhorizon radiation perturbations are instead suppressed. If dark matter originates in the radiation bath after reheating, this suppression may be the primary cutoff in the matter power spectrum. Conversely, for dark matter produced nonthermally from scalar decay, enhanced perturbations can drive structure formation during the cosmic dark ages and dramatically increase the abundance of compact substructures. For low reheat temperatures, we find that as much as 50% of all dark matter is in microhalos with M > or approx. 0.1M + at z≅100, compared to a fraction of ∼10 -10 in the standard case. In this scenario, ultradense substructures may constitute a large fraction of dark matter in galaxies today.

  8. Thermodynamic Analysis of a Steam Power Plant with Double Reheat and Feed Water Heaters

    Directory of Open Access Journals (Sweden)

    M. M. Rashidi

    2014-03-01

    Full Text Available A steam cycle with double reheat and turbine extraction is presented. Six heaters are used, three of them at high pressure and the other three at low pressure with deaerator. The first and second law analysis for the cycle and optimization of the thermal and exergy efficiencies are investigated. An exergy analysis is performed to guide the thermodynamic improvement for this cycle. The exergy and irreversibility analyses of each component of the cycle are determined. Effects of turbine inlet pressure, boiler exit steam temperature, and condenser pressure on the first and second laws' efficiencies are investigated. Also the best turbine extraction pressure on the first law efficiency is obtained. The results show that the biggest exergy loss occurs in the boiler followed by the turbine. The results also show that the overall thermal efficiency and the second law efficiency decrease as the condenser pressure increases for any fixed outlet boiler temperature, however, they increase as the boiler temperature increases for any condenser pressure. Furthermore, the best values of extraction pressure from high, intermediate, and low pressure turbine which give the maximum first law efficiencies are obtained based on the required heat load corresponding to each exit boiler temperature.

  9. Brown Boveri moves to fourth generation MSRs [moisture separator reheaters

    International Nuclear Information System (INIS)

    Boeckh, P. von

    1987-01-01

    The fourth, space saving, generation of moisture separator reheaters from Brown Boveri and Cie (BBC) consists of two types of high velocity moisture separators, 'Mops' and 'Scrups', and the small size reheater, 'Road' . The design of the unit is described, together with operational experience. (author)

  10. Reheating, multifield inflation and the fate of the primordial observables

    International Nuclear Information System (INIS)

    Leung, Godfrey; Tarrant, Ewan R.M.; Copeland, Edmund J.; Byrnes, Christian T.

    2012-01-01

    We study the effects of perturbative reheating on the evolution of the curvature perturbation ζ, in two-field inflation models. We use numerical methods to explore the sensitivity of f NL , n ζ and r to the reheating process, and present simple qualitative arguments to explain our results. In general, if a large non-Gaussian signal exists at the start of reheating, it will remain non-zero at the end of reheating. Unless all isocurvature modes have completely decayed before the start of reheating, we find that the non-linearity parameter, f NL , can be sensitive to the reheating timescale, and that this dependence is most appreciable for 'runaway' inflationary potentials that only have a minimum in one direction. For potentials with a minimum in both directions, f NL can also be sensitive to reheating if a mild hierarchy exists between the decay rates of each field. Within the class of models studied, we find that the spectral index n ζ , is fairly insensitive to large changes in the field decay rates, indicating that n ζ is a more robust inflationary observable, unlike the non-linearity parameter f NL . Our results imply that the statistics of ζ, especially f NL , can only be reliably used to discriminate between models of two-field inflation if the physics of reheating are properly accounted for

  11. Design and stability limits of the HPLWR re-heater

    International Nuclear Information System (INIS)

    Herbell, H.; Class, A.; Starflinger, J.; Schulenberg, T.

    2010-01-01

    The High Performance Light Water Reactor (HPLWR) is a particular design study of a supercritical water cooled reactor. A heat exchanger design has been proposed for the re-heater as a shell-and-tube heat exchanger. Inside the tubes fluid undergoes pseudo-condensing, e.g. it changes its density from steam-like to liquid-like properties (from 80 kg/m 3 to 582 kg/m 3 ) at supercritical pressure, whereas the shell side superheats intermediate pressure steam. For sub-critical pressures an instability has been reported by Goodykoontz and Dorsch (19679. The experiment exhibits unstable steam condensation in case of downward flow inside a tube of 7.4 mm diameter and 2.42 m length in some specific cases. The counter-current condenser was cooled with water flowing in an annulus surrounding the condenser tube. This experiment motivates the current investigation of instabilities for supercritical pseudo-condensation. The study includes static instabilities, i.e. Ledingegg instability and flow maldistribution of the parallel tubes, as well as pressure drop oscillations. At the present stage, no instabilities are predicted for the specific operation conditions of the HPLWR. The commercial system code APROS is used to perform one dimensional transient simulations of the described experiment to understand the physical mechanism. These simulations show that choking flow initiates the pressure oscillations. These periodically change steam temperatures, and consequently the condensation rate. In turn, this modifies the sound speed which is responsible for choking. Condensate reverse flow at choked conditions triggers the pressure waves. APROS simulations and experimental results agree well both in pressure amplitude and frequency. APROS simulations at supercritical pressure conditions did not exhibit any instability as the fluid velocity is clearly sub-sonic in the entire HPLWR re-heater. (authors)

  12. Ionometric determination of fluorides at low temperatures

    International Nuclear Information System (INIS)

    Kostyukova, I.S.; Ennan, A.A.; Dzerzhko, E.K.; Leivikova, A.A.

    1995-01-01

    A method for determining fluoride ions in solution at low temperatures using a solid-contact fluorine-selective electrode (FSE) has been developed. The effect of temperature (60 to -15 degrees C) on the calibration slope, potential equilibrium time, and operational stability is studied; the effect of an organic additive (cryoprotector) on the calibration slope is also studied. The temperature relationships obtained for the solid-contact FSEs allow appropriate corrections to be applied to the operational algorithm of the open-quotes Ftoringclose quotes hand-held semiautomatic HF gas analyzer for the operational temperature range of -16 to 60 degrees C

  13. Toward an effective field theory approach to reheating

    Science.gov (United States)

    Özsoy, Ogan; Giblin, John T.; Nesbit, Eva; Şengör, Gizem; Watson, Scott

    2017-12-01

    We investigate whether effective field theory (EFT) approaches, which have been useful in examining inflation and dark energy, can also be used to establish a systematic approach to inflationary reheating. We consider two methods. First, we extend Weinberg's background EFT to the end of inflation and reheating. We establish when parametric resonance and decay of the inflaton occurs, but also find intrinsic theoretical limitations, which make it difficult to capture some reheating models. This motivates us to next consider Cheung et al.'s EFT approach, which instead focuses on perturbations and the symmetry breaking induced by the cosmological background. Adapting the latter approach to reheating implies some new and important differences compared to the EFT of inflation. In particular, there are new hierarchical scales, and we must account for inflaton oscillations during reheating, which lead to discrete symmetry breaking. Guided by the fundamental symmetries, we construct the EFT of reheating, and as an example of its usefulness we establish a new class of reheating models and the corresponding predictions for gravity wave observations. In this paper we primarily focus on the first stages of preheating. We conclude by discussing challenges for the approach and future directions. This paper builds on ideas first proposed in the paper [O. Ozsoy, G. Sengor, K. Sinha, and S. Watson, arXiv:1507.06651.].

  14. Effect of reheating on predictions following multiple-field inflation

    Science.gov (United States)

    Hotinli, Selim C.; Frazer, Jonathan; Jaffe, Andrew H.; Meyers, Joel; Price, Layne C.; Tarrant, Ewan R. M.

    2018-01-01

    We study the sensitivity of cosmological observables to the reheating phase following inflation driven by many scalar fields. We describe a method which allows semianalytic treatment of the impact of perturbative reheating on cosmological perturbations using the sudden decay approximation. Focusing on N -quadratic inflation, we show how the scalar spectral index and tensor-to-scalar ratio are affected by the rates at which the scalar fields decay into radiation. We find that for certain choices of decay rates, reheating following multiple-field inflation can have a significant impact on the prediction of cosmological observables.

  15. Finite Element Modeling of Reheat Stretch Blow Molding of PET

    Science.gov (United States)

    Krishnan, Dwarak; Dupaix, Rebecca B.

    2004-06-01

    Poly (ethylene terephthalate) or PET is a polymer used as a packaging material for consumer products such as beverages, food or other liquids, and in other applications including drawn fibers and stretched films. Key features that make it widely used are its transparency, dimensional stability, gas impermeability, impact resistance, and high stiffness and strength in certain preferential directions. These commercially useful properties arise from the fact that PET crystallizes upon deformation above the glass transition temperature. Additionally, this strain-induced crystallization causes the deformation behavior of PET to be highly sensitive to processing conditions. It is thus crucial for engineers to be able to predict its performance at various process temperatures, strain rates and strain states so as to optimize the manufacturing process. In addressing these issues; a finite element analysis of the reheat blow molding process with PET has been carried out using ABAQUS. The simulation employed a constitutive model for PET developed by Dupaix and Boyce et al.. The model includes the combined effects of molecular orientation and strain-induced crystallization on strain hardening when the material is deformed above the glass transition temperature. The simulated bottles were also compared with actual blow molded bottles to evaluate the validity of the simulation.

  16. Fireside corrosion of superheaters/reheaters in advanced power plants

    Energy Technology Data Exchange (ETDEWEB)

    Syed, A.U.; Simms, N.J.; Oakey, J.E. [Cranfield Univ. (United Kingdom). Energy Technology Centre

    2010-07-01

    The generation of increasing amounts of electricity while simultaneously reducing environmental emissions (CO{sub 2}, SO{sub 2}, NO{sub x} particles, etc) has become a goal for the power industry worldwide. Co-firing biomass and coal in new advanced pulverised fuel power plants is one route to address this issue, since biomass is regarded as a CO{sub 2} neutral fuel (i.e. CO{sub 2} uptake during its growth equals the CO{sub 2} emissions produced during its combustion) and such new advanced power plants operate at higher efficiencies than current plants as a result of using steam systems with high temperatures and pressures. However, co-firing has the potential to cause significant operational challenges for such power plants as amongst other issues, it will significantly change the chemistry of the deposits on the heat exchanger surfaces and the surrounding gas compositions. As a result these critical components can experience higher corrosion rates, and so shorter lives, causing increased operational costs, unless the most appropriate materials are selected for their construction. This paper reports the results of a series of 1000 hour laboratory corrosion tests that have been carried out in controlled atmosphere furnaces, to assess the effect of biomass/coal co-firing on the fireside corrosion of superheaters/reheaters. The materials used for the tests were one ferritic alloy (T92), two austenitic alloys (347HFG and HR3C) and one nickel based alloy (alloy 625). Temperatures of 600 and 650 C were used to represent the metal temperatures in advanced power plants. During these exposures, traditional mass change data were recorded as the samples were recoated with the simulated deposits. After these exposures, cross-sections through samples were prepared using standard metallographic techniques and then analysed using SEM/EDX. Pre-exposure micrometer and post-exposure image analyser measurements were used so that the metal wastage could be calculated. These data are

  17. Higgs inflation, reheating and gravitino production in no-scale Supersymmetric GUTs

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, John [Theoretical Particle Physics and Cosmology Group,Department of Physics, King’s College London,London WC2R 2LS (United Kingdom); Theoretical Physics Department, CERN,CH-1211 Geneva 23 (Switzerland); He, Hong-Jian [Institute of Modern Physics and Center for High Energy Physics, Tsinghua University,Beijing 100084 (China); Center for High Energy Physics, Peking University,Beijing 100871 (China); Xianyu, Zhong-Zhi [Center of Mathematical Sciences and Applications andDepartment of Physics, Harvard University,Massachusetts 02138 (United States)

    2016-08-30

    We extend our previous study of supersymmetric Higgs inflation in the context of no-scale supergravity and grand unification, to include models based on the flipped SU(5) and the Pati-Salam group. Like the previous SU(5) GUT model, these yield a class of inflation models whose inflation predictions interpolate between those of the quadratic chaotic inflation and Starobinsky-like inflation, while avoiding tension with proton decay limits. We further analyse the reheating process in these models, and derive the number of e-folds, which is independent of the reheating temperature. We derive the corresponding predictions for the scalar tilt and the tensor-to-scalar ratio in cosmic microwave background perturbations, as well as discussing the gravitino production following inflation.

  18. Higgs Inflation, Reheating and Gravitino Production in No-Scale Supersymmetric GUTs

    CERN Document Server

    Ellis, John; Xianyu, Zhong-Zhi

    2016-08-30

    We extend our previous study of supersymmetric Higgs inflation in the context of no-scale supergravity and grand unification, to include models based on the flipped SU(5) and the Pati-Salam group. Like the previous SU(5) GUT model, these yield a class of inflation models whose inflation predictions interpolate between those of the quadratic chaotic inflation and Starobinsky-like inflation, while also avoiding tension with proton decay limits. We further analyse the reheating process in these models, and derive the number of $e$-folds, which is independent of the reheating temperature. We derive the corresponding predictions for the scalar tilt and the tensor-to-scalar ratio in cosmic microwave background perturbations, and also discuss gravitino production following inflation.

  19. Reheat cracking in 1/2 CrMoV steel. Heat affected zones

    International Nuclear Information System (INIS)

    Batte, A.D.; Miller, R.C.; Murphy, M.C.

    1976-01-01

    Low alloy creep resisting steels are inherently susceptible to cracking during stress relief heat treatment (reheat cracking) though few welds give rise to problems in manufacture or service. Mechanical tests on simulated affected zone structures in CrMoV forgings have shown that cracking occurs when the high temperature ductility is inadequate to accommodate the residual welding strain. Differences in susceptibility result from differences in heat affected zone grain size if the purity level is sufficiently high; reheat cracking may then be avoided by ensuring complete grain refinement during welding. The susceptibility of a lower purity forging was insensitive to grain size; heat affected zone refinement is unlikely to eliminate cracking in such steel. (orig.) [de

  20. Calculations of Inflaton Decays and Reheating: with Applications to No-Scale Inflation Models

    CERN Document Server

    Ellis, John; Nanopoulos, Dimitri V; Olive, Keith A

    2015-01-01

    We discuss inflaton decays and reheating in no-scale Starobinsky-like models of inflation, calculating the effective equation-of-state parameter, $w$, during the epoch of inflaton decay, the reheating temperature, $T_{\\rm reh}$, and the number of inflationary e-folds, $N_*$, comparing analytical approximations with numerical calculations. We then illustrate these results with applications to models based on no-scale supergravity and motivated by generic string compactifications, including scenarios where the inflaton is identified as an untwisted-sector matter field with direct Yukawa couplings to MSSM fields, and where the inflaton decays via gravitational-strength interactions. Finally, we use our results to discuss the constraints on these models imposed by present measurements of the scalar spectral index $n_s$ and the tensor-to-scalar perturbation ratio $r$, converting them into constraints on $N_*$, the inflaton decay rate and other parameters of specific no-scale inflationary models.

  1. Thermodynamic and economic analysis of a partially-underground tower-type boiler design for advanced double reheat power plants

    International Nuclear Information System (INIS)

    Xu, Gang; Xu, Cheng; Yang, Yongping; Fang, Yaxiong; Zhou, Luyao; Yang, Zhiping

    2015-01-01

    An increasing number of tower-type boilers have been selected for advanced double reheat power plants, due to the uniform flue gas profile and the smooth steam temperature increase. The tall height and long steam pipelines lengths will however, result in dramatic increases in the difficulty of construction, as well as increased power plant investment cost. Given these factors, a novel partially-underground tower-type boiler design has been proposed in this study, which has nearly half of the boiler embedded underground, thereby significantly reducing the boiler height and steam pipeline lengths. Thermodynamic and economic analyses were quantitatively conducted on a 1000 MW advanced double reheat steam cycle. Results showed that compared to the reference power plant, the power plant with the proposed tower-type boiler design could reduce the net heat rate by 18.3 kJ/kWh and could reduce the cost of electricity (COE) by $0.60/MWh. The study also investigated the effects of price fluctuations on the cost-effectiveness of the reference power plant, for both the conventional and the proposed tower-type boilers designs, and found that the double reheat power plant with the proposed tower-type boiler design would be even more competitive and price-effective when the coal price and the investment costs increase. The research of this paper may provide a promising tower-type boiler design for advanced double reheat power plants with lower construction complexity and better cost-effectiveness. - Highlights: • A partially-underground tower-type boiler in double reheat power plants is proposed. for double reheat power plants is proposed. • Thermodynamic and economic analyses are quantitatively conducted. • Better energetic efficiency and greater economic benefits are achieved. • The impacts of price fluctuations on the economic feasibility are discussed

  2. Thermodynamic performance evaluation of combustion gas turbine cogeneration system with reheat

    International Nuclear Information System (INIS)

    Khaliq, A.; Kaushik, S.C.

    2004-01-01

    This communication presents thermodynamic methodology for the performance evaluation of combustion gas turbine cogeneration system with reheat. The energetic and exergetic efficiencies have been defined. The effects of process steam pressure and pinch point temperature used in the design of heat recovery steam generator, and reheat on energetic and exergetic efficiencies have been investigated. From the results obtained in graphs it is observed that the power to heat ratio increases with an increase in pinch point, but the first-law efficiency and second-law efficiency decreases with an increase in pinch point. The power to heat ratio and second-law efficiency increases significantly with increase in process steam pressure, but the first-law efficiency decreases with the same. Results also show that inclusion of reheat, provide significant improvement in electrical power output, process heat production, fuel-utilization (energetic) efficiency and second-law (exergetic) efficiency. This methodology may be quite useful in the selection and comparison of combined energy production systems from thermodynamic performance point of view

  3. Optimization of a slab heating pattern for minimum energy consumption in a walking-beam type reheating furnace

    International Nuclear Information System (INIS)

    Jang, Jiin-Yuh; Huang, Jun-Bo

    2015-01-01

    A two-dimensional mathematical heat transfer model for the prediction of the temperature history of steel slabs was performed in order to obtain the optimal heating pattern of these slabs with minimum energy consumption in a walking-beam type reheating furnace. An algorithm developed with a simplified conjugated-gradient method combined with a shooting method, was used as an optimizer to design the furnace temperature distribution, including the preheating zone, heating zone and soaking zone temperatures. Comparison with the in-situ experimental data indicated that the present heat transfer model works well for the prediction of the thermal behavior of a slab in the reheating furnace. The effect of the furnace temperature distribution on the design requirements, such as energy required for heating a slab, slab temperature uniformity at the furnace exit and slab discharging temperature, were investigated. The parametric study results indicated that energy consumption significantly decreases with reductions in the preheating zone temperature. The optimal design also resulted in lower energy consumption for heating a slab as compared to the original operational conditions in the steel plant. - Highlights: • The heating process of steel slabs in a reheating furnace is numerically simulated. • An algorithm is developed to search for the optimal heating pattern of a slab. • Energy consumption decreases with reductions in the preheating zone temperature

  4. Effect of Dynamic Reheating Controlled by the Weaving Width on the Microstructure of GTA Bead-On-Pipe Weld Metal of 25% Cr Super Duplex Stainless Steel

    Directory of Open Access Journals (Sweden)

    Hee-Joon Sung

    2018-05-01

    Full Text Available Gas tungsten arc welding (GTAW with three different heat inputs controlled by the weaving width was performed to understand their effects on the microstructural changes during bead-on-pipe welding of super duplex stainless steel. The microstructure of the weld metals was categorized into three different types of zones: non-reheated, reheated type, and reheating-free zone. Even though single-pass welding with different weaving widths was employed, a reheated microstructure was detected, which has been previously observed with multiple pass welding. This phenomenon was called “dynamic reheating”, because it was produced by the weaving operation during welding regardless of the weaving width. The categorized area fraction varied with the weaving width change. Electron backscatter diffraction (EBSD results at the edge (the area near the fusion line of the low-heat-input condition indicated a higher austenite volume fraction and a lower Cr2N fraction than that of the medium heat input condition. Thus, it described an inverse relationship, because higher heat input provided a lower austenite fraction. In addition, it was observed clearly that the austenite fraction at the medium heat input condition was dramatically increased by reheating, while the Cr2N fraction was reduced. Regardless of the weaving width, reheating contributed to the increase of the austenite fraction, further reducing the Cr2N quantity. The edge areas in the map showed an inverse relationship in the reheated area fraction between low heat input and medium heat input. For this reason, the austenite fraction on the weld metal was determined not only by the heat input, but also by the amount of reheating.

  5. Heating characteristics of billet in a walking hearth type reheating furnace

    International Nuclear Information System (INIS)

    Emadi, Ali; Saboonchi, Ahmad; Taheri, Mahdi; Hassanpour, Saeid

    2014-01-01

    The heating characteristics of billet in a walking hearth type reheating furnace were studied by developing a mathematical heat transfer model. Radiation calculations were conducted by means of zone method and considering all radiation exchange paths. The weighted-sum-of-gray-gas-model was used for better accuracy of gas radiation prediction. Convective heat flux was calculated by considering suitable value of convective heat transfer coefficient at any location of the furnace. The model was substantiated through its comparison to experimental data. A comparison was drawn to evaluate the effect of constant and variable convective coefficient on convective flux distribution and billet thermal behavior. The effect of furnace wall's emissivity of each zone and whole of the furnace on the billet thermal behavior was investigated. The obtained results revealed that by increasing furnace wall's emissivity for a determined residence time, billet's temperature in primary zones rises but it has no significant effect on its final temperature. However, by increasing wall's emissivity from 0.7 to 0.95, the residence time can be declined by about 5%. Moreover, emissivity increase in non-firing and preheating zones as compared to heating and soaking zones has greater impact on the billet thermal behavior. -- Highlights: • 3D radiation modeling by considering all possible paths of radiation exchange. • Using WSGG model for better prediction of gas radiation. • Using non-constant convection coefficient to consider variation of gas mass flow. • Investigation of effect of convection coefficient on billet temperature behavior. • Investigation of wall emissivity of furnace zones

  6. Rotational temperature determinations in molecular gas lasers

    International Nuclear Information System (INIS)

    Weaver, L.A.; Taylor, L.H.; Denes, L.J.

    1975-01-01

    The small-signal gain expressions for vibrational-rotational transitions are examined in detail to determine possible methods of extracting the rotational temperature from experimental gain measurements in molecular gas lasers. Approximate values of T/subr/ can be deduced from the rotational quantum numbers for which the P- and R-branch gains are maximum. Quite accurate values of T/subr/ and the population inversion density (n/subv//sub prime/-n/subv//sub double-prime/) can be determined by fitting data to suitably linearized gain relationships, or by performing least-squares fits of the P- and R-branch experimental data to the full gain expressions. Experimental gain measurements for 15 P-branch and 12 R-branch transitions in the 10.4-μm CO 2 band have been performed for pulsed uv-preionized laser discharges in CO 2 : N 2 : He=1 : 2 : 3 mixtures at 600 Torr. These data are subjected to the several gain analyses described herein, yielding a rotational temperature of 401plus-or-minus10 degreeK and an inversion density of (3.77plus-or-minus0.07) times10 17 cm -3 for conditions of maximum gain. These techniques provide accurate values of the gas temperature in molecular gas lasers with excellent temporal and spatial resolution, and should be useful in extending the conversion efficiency and arcing limits of high-energy electrically exc []ted lasers

  7. PFC Performance Improvement of Ultra-supercritical Secondary Reheat Unit

    Directory of Open Access Journals (Sweden)

    Li Jun

    2018-01-01

    Full Text Available Ultra-supercritical secondary reheat unit has been widely used in the world because of its advantages of large capacity, low consumption and high efficiency etc., but rapid load change ability of the turbines to be weakened which caused by its system organization, cannot meet the requirements of power grid frequency modulation. Based on the analysis of the control characteristics of ultra-supercritical once-through reheat unit, the primary frequency control based on feed-water flow overshoot compensation is proposed. The main steam pressure generated by the feed-water is changed to improve the primary frequency control capability. The relevant control strategy has been applied to the 1000MW secondary reheating unit. The results show that the technology is feasible and has high economical efficiency.

  8. Determination of irradiation temperature using SiC temperature monitors

    International Nuclear Information System (INIS)

    Maruyama, Tadashi; Onose, Shoji

    1999-01-01

    This paper describes a method for detecting the change in length of SiC temperature monitors and a discussion is made on the relationship between irradiation temperature and the recovery in length of SiC temperature monitors. The SiC specimens were irradiated in the experimental fast reactor JOYO' at the irradiation temperatures around 417 to 645degC (design temperature). The change in length of irradiated specimens was detected using a dilatometer with SiO 2 glass push rod in an infrared image furnace. The temperature at which recovery in macroscopic length begins was obtained from the annealing intersection temperature. The results of measurements indicated that a difference between annealing intersection temperature and the design temperature sometimes reached well over ±100degC. A calibration method to obtain accurate irradiation temperature was presented and compared with the design temperature. (author)

  9. Dark matter from gravitational particle production at reheating

    Energy Technology Data Exchange (ETDEWEB)

    Markkanen, Tommi [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom); Nurmi, Sami, E-mail: tommi.markkanen@kcl.ac.uk, E-mail: sami.t.nurmi@jyu.fi [Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 University of Jyväskylä (Finland)

    2017-02-01

    We show that curvature induced particle production at reheating generates adiabatic dark matter if there are non-minimally coupled spectator scalars weakly coupled to visible matter. The observed dark matter abundance implies an upper bound on spectator masses m and non-minimal coupling values ξ. For example, assuming quadratic inflation, instant reheating and a single spectator scalar with only gravitational couplings, the observed dark matter abundance is obtained for m ∼ 0.1 GeV and ξ ∼ 1. Larger mass and coupling values of the spectator are excluded as they would lead to overproduction of dark matter.

  10. Dark matter from gravitational particle production at reheating

    International Nuclear Information System (INIS)

    Markkanen, Tommi; Nurmi, Sami

    2017-01-01

    We show that curvature induced particle production at reheating generates adiabatic dark matter if there are non-minimally coupled spectator scalars weakly coupled to visible matter. The observed dark matter abundance implies an upper bound on spectator masses m and non-minimal coupling values ξ. For example, assuming quadratic inflation, instant reheating and a single spectator scalar with only gravitational couplings, the observed dark matter abundance is obtained for m ∼ 0.1 GeV and ξ ∼ 1. Larger mass and coupling values of the spectator are excluded as they would lead to overproduction of dark matter.

  11. Reheating via a generalized nonminimal coupling of curvature to matter

    International Nuclear Information System (INIS)

    Bertolami, Orfeu; Frazao, Pedro; Paramos, Jorge

    2011-01-01

    In this work, one shows that a generalized nonminimal coupling between geometry and matter is compatible with Starobinsky inflation and leads to a successful process of preheating, a reheating scenario based on the production of massive particles via parametric resonance. The model naturally extends the usual preheating mechanism, which resorts to an ad hoc scalar curvature-dependent mass term for a scalar field χ, and also encompasses a previously studied preheating channel based upon a nonstandard kinetic term.

  12. Dual turbine power plant and a reheat steam bypass flow control system for use therein

    International Nuclear Information System (INIS)

    Braytenbah, A.S.; Jaegtnes, K.O.

    1977-01-01

    An electric power plant having dual turbine-generators connected to a steam source that includes a high temperature gas cooled nuclear reactor is described. Each turbine comprises a high pressure portion operated by superheat steam and an intermediate-low pressure portion operated by reheat steam; a bypass line is connected across each turbine portion to permit a desired minimum flow of steam from the source at times when the combined flow of steam through the turbine is less than the minimum. Coolant gas is propelled through the reactor by a circulator which is driven by an auxiliary turbine which uses steam exhausted from the high pressure portions and their bypass lines. The pressure of the reheat steam is controlled by a single proportional-plus-integral controller which governs the steam flow through the bypass lines associated with the intermediate-low pressure portions. At times when the controller is not in use its output signal is limited to a value that permits an unbiased response when pressure control is resumed, as in event of a turbine trip. 25 claims, 2 figures

  13. Development of Next Generation Heating System for Scale Free Steel Reheating

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Arvind C. Thekdi

    2011-01-27

    The work carried out under this project includes development and design of components, controls, and economic modeling tools that would enable the steel industry to reduce energy intensity through reduction of scale formation during the steel reheating process. Application of scale free reheating offers savings in energy used for production of steel that is lost as scale, and increase in product yield for the global steel industry. The technology can be applied to a new furnace application as well as retrofit design for conversion of existing steel reheating furnaces. The development work has resulted in the knowledge base that will enable the steel industry and steel forging industry us to reheat steel with 75% to 95% reduction in scale formation and associated energy savings during the reheating process. Scale reduction also results in additional energy savings associated with higher yield from reheat furnaces. Energy used for steel production ranges from 9 MM Btu/ton to 16.6 MM Btu/ton or the industry average of approximately 13 MM Btu/ton. Hence, reduction in scale at reheating stage would represent a substantial energy reduction for the steel industry. Potential energy savings for the US steel industry could be in excess of 25 Trillion Btu/year when the technology is applied to all reheating processes. The development work has resulted in new design of reheating process and the required burners and control systems that would allow use of this technology for steel reheating in steel as well as steel forging industries.

  14. Temperature and emissivity determination of liquid steel S235

    International Nuclear Information System (INIS)

    Schöpp, H; Kozakov, R; Gött, G; Uhrlandt, D; Sperl, A; Wilhelm, G

    2012-01-01

    Temperature determination of liquid metals is difficult but a necessary tool for improving materials and processes such as arc welding in the metal-working industry. A method to determine the surface temperature of the weld pool is described. A TIG welding process and absolute calibrated optical emission spectroscopy are used. This method is combined with high-speed photography. 2D temperature profiles are obtained. The emissivity of the radiating surface has an important influence on the temperature determination. A temperature dependent emissivity for liquid steel is given for the spectral region between 650 and 850 nm. (paper)

  15. Temperature and emissivity determination of liquid steel S235

    Science.gov (United States)

    Schöpp, H.; Sperl, A.; Kozakov, R.; Gött, G.; Uhrlandt, D.; Wilhelm, G.

    2012-06-01

    Temperature determination of liquid metals is difficult but a necessary tool for improving materials and processes such as arc welding in the metal-working industry. A method to determine the surface temperature of the weld pool is described. A TIG welding process and absolute calibrated optical emission spectroscopy are used. This method is combined with high-speed photography. 2D temperature profiles are obtained. The emissivity of the radiating surface has an important influence on the temperature determination. A temperature dependent emissivity for liquid steel is given for the spectral region between 650 and 850 nm.

  16. Dielectric determination of the glass transition temperature (T sub g)

    Science.gov (United States)

    Ries, Heidi R.

    1990-01-01

    The objective is to determine the glass transition temperature of a polymer using a dielectric dissipation technique. A peak in the dissipation factor versus temperature curve is expected near the glass transition temperature T sub g. It should be noted that the glass transition is gradual rather than abrupt, so that the glass transition temperature T sub g is not clearly identifiable. In this case, the glass transition temperature is defined to be the temperature at the intersection point of the tangent lines to the dissipation factor versus temperature curve above and below the transition region, as illustrated.

  17. Furan formation during storage and reheating of sterilised vegetable purées.

    Science.gov (United States)

    Palmers, Stijn; Grauwet, Tara; Buvé, Carolien; Van de Vondel, Lore; Kebede, Biniam T; Hendrickx, Marc E; Van Loey, Ann

    2015-01-01

    To this day, research for furan mitigation has mostly targeted the levels of food production and handling of prepared foods by the consumer. However, part of the furan concentrations found in commercially available food products might originate from chemical deterioration reactions during storage. A range of individual vegetable purées was stored at two different temperatures to investigate the effects of storage on the furan concentrations of shelf-stable, vegetable-based foods. After 5 months of storage at 35°C (temperature-abuse conditions), a general increase in furan concentrations was observed. The furan formation during storage could be reduced by storing the vegetable purées at a refrigerated temperature of 4°C, at which the furan concentrations remained approximately constant for at least 5 months. Following storage, the vegetable purées were briefly reheated to 90°C to simulate the effect of the final preparation step before consumption. Contrary to storage, furan concentrations decreased as a result of evaporative losses. Both refrigerated storage and the reheating step prior to consumption showed the potential of mitigation measures for furan formation in vegetable-based foods (e.g. canned vegetables, ready-to-eat soups, sauces or baby foods). Next to furan, the vegetable purées were analysed for 2- and 3-methylfuran. Tomato was very susceptible to the formation of both alkylated derivatives of furan, as opposed to the other vegetables in this study. Methylfuran concentrations rapidly decreased during storage, which was contrary to the results observed for furan.

  18. Dynamics of cosmological perturbations and reheating in the anamorphic universe

    Energy Technology Data Exchange (ETDEWEB)

    Graef, L.L.; Ferreira, Elisa G.M.; Brandenberger, Robert [Physics Department, McGill University, Montreal, QC, H3A 2T8 (Canada); Hipólito-Ricaldi, W.S., E-mail: leilagraef@on.br, E-mail: wiliam.ricaldi@ufes.br, E-mail: elisa.ferreira@mail.mcgill.ca, E-mail: rhb@physics.mcgill.ca [Departamento de Ciências Naturais, Universidade Federal do Espírito Santo, Rodovia BR 101 Norte, km. 60, São Mateus, ES (Brazil)

    2017-04-01

    We discuss scalar-tensor realizations of the Anamorphic cosmological scenario recently proposed by Ijjas and Steinhardt [1]. Through an analysis of the dynamics of cosmological perturbations we obtain constraints on the parameters of the model. We also study gravitational Parker particle production in the contracting Anamorphic phase and we compute the fraction between the energy density of created particles at the end of the phase and the background energy density. We find that, as in the case of inflation, a new mechanism is required to reheat the universe.

  19. Particle creation and reheating in a braneworld inflationary scenario

    Science.gov (United States)

    Bilić, Neven; Domazet, Silvije; Djordjevic, Goran S.

    2017-10-01

    We study the cosmological particle creation in the tachyon inflation based on the D-brane dynamics in the Randall-Sundrum (RSII) model extended to include matter in the bulk. The presence of matter modifies the warp factor which results in two effects: a modification of the RSII cosmology and a modification of the tachyon potential. Besides, a string theory D-brane supports among other fields a U(1) gauge field reflecting open strings attached to the brane. We demonstrate how the interaction of the tachyon with the U(1) gauge field drives cosmological creation of massless particles and estimate the resulting reheating at the end of inflation.

  20. Inflation and reheating in induced-gravity models

    International Nuclear Information System (INIS)

    Barr, S.; Segre, G.

    1990-01-01

    The Planck mass is generated dynamically in induced-gravity models, typically being related to the vacuum expectation value of a scalar field φ, ε 1/2 left-angle φ right-angle=M Pl / √8π , where ε is a dimensionless parameter, typically smaller than one. We discuss in this paper the decay of the φ particle, which is mainly into gravitons, and the consequences this has for models in which the φ field is responsible for inflation. We show in particular that too much energy is stored in φ oscillations and adequate reheating does not occur

  1. Reheating of the Universe and evolution of the inflaton

    International Nuclear Information System (INIS)

    Mazzitelli, F.D.; Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina,); Paz, J.P.; Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad)

    1989-01-01

    The problem of the reheating of the Universe after inflation is considered. Our approach is based on the use, as ''first principles,'' of the renormalized version of (a) the evolution equation for the mean value of an interacting scalar field and (b) the semiclassical Einstein equations. We compute (for two different toy models) the characteristic time for the damping of the mean-value oscillations. We show that when the oscillations are damped the Universe becomes radiation dominated and inflation ends. The techniques used in this paper are those of quantum field theory in curved spacetime and can be generalized to more realistic models

  2. Moisture separators and reheaters for wet steam turbines

    International Nuclear Information System (INIS)

    Gibbins, J.

    1979-01-01

    Moisture separator reheater (M.S.R.) units are now a well established feature of the wet steam cycle as associated with the various types of water cooled reactor. This paper describes the development of M.S.Rs. as supplied by GEC for turbine generators of up to 1200 MW ratings covering the design procedures used and the features required to ensure efficient and reliable operation. In addition to details of the M.S.R. design, the desirable features of the steam supply, venting and drain control systems are also discussed. The recent developments, as provided on current projects, are described. (author)

  3. Reheat cracking in austenitic stainless steels; Fissuration en relaxation des aciers inoxydables austenitiques

    Energy Technology Data Exchange (ETDEWEB)

    Auzoux, Q.; Allais, L. [CEA Saclay, Dept. des Materiaux pour le Nucleaire, DMN, 91 - Gif sur Yvette (France); Pineau, A.; Gourgues, A.F. [Centre des Materiaux Pierre-Marie Fourt UMR CNRS 7633, 91 - Evry (France)

    2002-07-01

    Intergranular cracking can occur in heat-affected zones (HAZs) of austenitic stainless steel welded joints when reheated in the temperature range from 500 to 700 deg C. At this temperature, residual stresses due to welding relax by creep flow. HAZ may not sustain this small strain if its microstructure has been sufficiently altered during welding. In order to precise which particular microstructure alteration causes such an intergranular embrittlement, type 316L(N) HAZs were examined by transmission electron microscopy. A marked increase in the dislocation density, due to plastic strain during the welding process, was revealed, which caused an increase in Vickers hardness. Type 316L(N) HAZ were then simulated by the following thermal-mechanical process: annealing treatment and work hardening (pre-strain). Creep rupture tests on smooth specimens were also carried out at 600 deg C on both base metal and simulated HAZ. Pre-straining increased creep strength but reduced ductility. Slow strain rate tests on CT specimens confirmed this trend as well as did relaxation tests on CT specimens, which led to intergranular crack propagation in the pre-strained material only. Metallography and fractography showed no qualitative difference between base metal and HAZs in the creep cavitation around intergranular carbides. Although quantitative study of damage development is not achieved yet, experiments suggest that uniaxial creep strain smaller than one percent could lead to cavity nucleation when the material is pre-strained. Pre-strain as well as stress triaxiality reduce therefore creep ductility and enhance the reheat cracking risk. (authors)

  4. Reheat cracking susceptibility of new generation 2%CrMo(W)V P23 steel multipass welds made using matching and mis-matching filler metals

    Energy Technology Data Exchange (ETDEWEB)

    Nevasmaa, P.; Salonen, J.; Holmstroem, S. [VTT Technical Research Centre of Finland, Espoo (Finland)

    2007-06-15

    In comparison with conventional creep resisting grade T/P22, the modified 2%Cr steels T/P23 and T/P24 show nearly twice the creep strength at typical service temperatures of about 520-570 deg C. The possibility of welding thin-wall boiler tubes without preheating or PWHT has promoted the use of T23 and T24 in practical boiler service. For thick-wall applications and multipass welds, welding consumables still require further development to improve creep strength and ductility. Susceptibility to reheat cracking and hydrogen cracking increase with the wall-thickness and structural rigidity of the component. Consequently, thick-wall sections generally require the use of PWHT and sometimes preheating as well. This paper is concerned with weldability of P23 pipe steel, with particular emphasis on reheat cracking sensitivity of simulated HAZ microstructures and thick-section multipass welds made using closely matching and mis-matching filler metals. The results demonstrate that the weld metal is far more critical than the parent steel HAZ, both in terms of reheat cracking sensitivity and ductility and toughness. In the as-welded condition, the weld metal exhibited excessive hardness of {approx}380 HV and only diminutive Charpy toughness at room temperature. Adoption of the PWHT (760 deg C/2h) enhanced the weldment toughness; however, it also inevitably raises risk to reheat cracking in the weld metal that showed values of reduction of area (RA) no more than 2-3% in the BWI cracking test. The results imply that thick-section multipass welds made using filler metal with the chemical composition closer to P24 grade material are much less susceptible to reheat cracking than 'matching' P23 grade welds. (orig.)

  5. Condensation front modelling in a moisture separator reheater by application of SICLE numerical model

    International Nuclear Information System (INIS)

    Grange, J.L.; Caremoli, C.; Eddi, M.

    1988-01-01

    This paper presents improvements performed on SICLE numerical model in order to analyse the condensation front that occurs in the moisture separator reheaters (MSR) of nuclear power plants. Modifications of SICLE numerical model architecture and a fine modelling of reheater have allowed to correctly simulate the MSR thermohydraulic behaviour during a severe transient (plant islanding) [fr

  6. Reheating-volume measure for random-walk inflation

    International Nuclear Information System (INIS)

    Winitzki, Sergei

    2008-01-01

    The recently proposed 'reheating-volume' (RV) measure promises to solve the long-standing problem of extracting probabilistic predictions from cosmological multiverse scenarios involving eternal inflation. I give a detailed description of the new measure and its applications to generic models of eternal inflation of random-walk type. For those models I derive a general formula for RV-regulated probability distributions that is suitable for numerical computations. I show that the results of the RV cutoff in random-walk type models are always gauge invariant and independent of the initial conditions at the beginning of inflation. In a toy model where equal-time cutoffs lead to the 'youngness paradox', the RV cutoff yields unbiased results that are distinct from previously proposed measures.

  7. Gravitational wave signals and cosmological consequences of gravitational reheating

    Science.gov (United States)

    Artymowski, Michał; Czerwińska, Olga; Lalak, Zygmunt; Lewicki, Marek

    2018-04-01

    Reheating after inflation can proceed even if the inflaton couples to Standard Model (SM) particles only gravitationally. However, particle production during the transition between de-Sitter expansion and a decelerating Universe is rather inefficient and the necessity to recover the visible Universe leads to a non-standard cosmological evolution initially dominated by remnants of the inflaton field. We remain agnostic to the specific dynamics of the inflaton field and discuss a generic scenario in which its remnants behave as a perfect fluid with a general barotropic parameter w. Using CMB and BBN constraints we derive the allowed range of inflationary scales. We also show that this scenario results in a characteristic primordial Gravitational Wave (GW) spectrum which gives hope for observation in upcoming runs of LIGO as well as in other planned experiments.

  8. Analytical method for determining the channel-temperature distribution

    International Nuclear Information System (INIS)

    Kurbatov, I.M.

    1992-01-01

    The distribution of the predicted temperature over the volume or cross section of the active zone is important for thermal calculations of reactors taking into account random deviations. This requires a laborious calculation which includes the following steps: separation of the nominal temperature field, within the temperature range, into intervals, in each of which the temperature is set equal to its average value in the interval; determination of the number of channels whose temperature falls within each interval; construction of the channel-temperature distribution in each interval in accordance with the weighted error function; and summation of the number of channels with the same temperature over all intervals. This procedure can be greatly simplified with the help of methods which eliminate numerous variant calculations when the nominal temperature field is open-quotes refinedclose quotes up to the optimal field according to different criteria. In the present paper a universal analytical method is proposed for determining, by changing the coefficients in the channel-temperature distribution function, the form of this function that reflects all conditions of operation of the elements in the active zone. The problem is solved for the temperature of the coolant at the outlet from the reactor channels

  9. On the performance simulation of inter-stage turbine reheat

    International Nuclear Information System (INIS)

    Pellegrini, Alvise; Nikolaidis, Theoklis; Pachidis, Vassilios; Köhler, Stephan

    2017-01-01

    Highlights: • An innovative gas turbine performance simulation methodology is proposed. • It allows to perform DP and OD performance calculations for complex engines layouts. • It is essential for inter-turbine reheat (ITR) engine performance calculation. • A detailed description is provided for fast and flexible implementation. • The methodology is successfully verified against a commercial closed-source software. - Abstract: Several authors have suggested the implementation of reheat in high By-Pass Ratio (BPR) aero engines, to improve engine performance. In contrast to military afterburning, civil aero engines would aim at reducing Specific Fuel Consumption (SFC) by introducing ‘Inter-stage Turbine Reheat’ (ITR). To maximise benefits, the second combustor should be placed at an early stage of the expansion process, e.g. between the first and second High-Pressure Turbine (HPT) stages. The aforementioned cycle design requires the accurate simulation of two or more turbine stages on the same shaft. The Design Point (DP) performance can be easily evaluated by defining a Turbine Work Split (TWS) ratio between the turbine stages. However, the performance simulation of Off-Design (OD) operating points requires the calculation of the TWS parameter for every OD step, by taking into account the thermodynamic behaviour of each turbine stage, represented by their respective maps. No analytical solution of the aforementioned problem is currently available in the public domain. This paper presents an analytical methodology by which ITR can be simulated at DP and OD. Results show excellent agreement with a commercial, closed-source performance code; discrepancies range from 0% to 3.48%, and are ascribed to the different gas models implemented in the codes.

  10. 3-D Transient Heat Transfer Analysis of Slab Heating Characteristics in a Reheating Furnace in Hot Strip Mills

    Science.gov (United States)

    Jang, J. Y.; Lee, Y. W.; Lin, C. N.; Wang, C. H.

    2016-05-01

    A three-dimensional mathematical transient heat transfer model for the prediction of temperature distribution within the slab has been developed by considering the thermal radiation in the walking-beam-type reheating furnace chamber. The steel slabs are heated up through the non-firing, preheating, 1st-heating, 2nd-heating, and soaking zones in the furnace, respectively, where the furnace wall temperature is function of time. Comparison with the in-situ experimental data from Steel Company in Taiwan shows that the present heat transfer model works well for the prediction of thermal behavior of the slab in the reheating furnace. The effects of different skid button height (H=60mm, 90mm, and 120mm) and different gap distance between two slabs (S=50mm, 75mm, and 100mm) on the slab skid mark formation and temperature profiles are investigated. It is found that the skid mark severity decreases with an increase in the skid button height. The effect of gap distance is important only for the slab edge planes, while it is insignificant for the slab central planes.

  11. Operating Cell Temperature Determination in Flat-Plate Photovoltaic Modules

    International Nuclear Information System (INIS)

    Chenlo, F.

    2002-01-01

    Two procedures (simplified and complete) to determine me operating cell temperature in photovoltaic modules operating in real conditions assuming isothermal stationary modules are presented in this work. Some examples are included that show me dependence of this temperature on several environmental (sky, ground and ambient temperatures, solar irradiance, wind speed, etc.) and structural (module geometry and size, encapsulating materials, anti reflexive optical coatings, etc.) factors and also on electrical module performance. In a further step temperature profiles for non-isothermal modules are analysed besides transitory effects due to variable irradiance and wind gusts. (Author) 27 refs

  12. On effect of some thermodeformation parameters of welding cycle on tendency of pearlitic heat-resisting steels to fracture in reheating

    International Nuclear Information System (INIS)

    Prokhorov, N.N.; Bardokin, E.V.

    1979-01-01

    Studied is the inclination of the 12Kh1MF, 15Kh3M1F and N18K9M5T steels subject to thermodeformation cycle imitating a welding one, to fracture in reheating. A hot-rolled metal then subject to the same thermal treatment was used. The imitation of thermodeformation cycle of the welding permitted to vary maximum heating temperatures, the period during which the metal is kept at temperatures higher than 1100 deg C, and the cooling rate of ajacent zone metal. It is shown that the curve of the dependence of deformation ability and the tendency to fracture at the reheating of adjacent zone metal on the rate of its cooling at welding is U-shaped. Deformation ability has its maximum value at the cooling rate of 30 deg c/s in the range 1300 to 1000 deg C

  13. Determination of the yield locus by means of temperature measurement

    NARCIS (Netherlands)

    Banabic, D.; Huetink, Han

    2006-01-01

    The paper presents a theoretical background of the thermo-graphical method of determining the yield locus. The analytical expression of the temperature variation of the specimen deformed in the elastic state is determined starting from the first law of thermodynamics. The experimental method for

  14. Electron temperature determination in LTE and non-LTE plasmas

    International Nuclear Information System (INIS)

    Eddy, T.L.

    1983-01-01

    This article discusses how most experimental investigations assume a type of ''thermal equilibrium'' in which the excited levels are assumed to be populated according to the electron kinetic temperature, in the determination of electron temperature in LTE and non-LTE plasmas. This is justified on the basis that electron collisions dominate the equilibration of adjacent excited levels as shown by Byron, Stabler and Boartz. The comparison of temperature values calculated by various common methods as a check for local thermodynamic equilibrium (LTDE) or local thermal equilibrium (LTE) of the upper excited levels and the free electrons has been shown to indicate the excitation temperature in all cases utilized. Thomas shows that the source function of the first excited level may be dominated by non-local radiation, which would usually result in a different population than local collisional excitation would provide. Ionization from upper levels is by collisional means. The result may yield different valued excitation and electron temperatures

  15. Simultaneous Determination of Glass Transition Temperatures of Several Polymers.

    Science.gov (United States)

    He, Jiang; Liu, Wei; Huang, Yao-Xiong

    2016-01-01

    A simple and easy optical method is proposed for the determination of glass transition temperature (Tg) of polymers. Tg was determined using the technique of microsphere imaging to monitor the variation of the refractive index of polymer microsphere as a function of temperature. It was demonstrated that the method can eliminate most thermal lag and has sensitivity about six fold higher than the conventional method in Tg determination. So the determined Tg is more accurate and varies less with cooling/heating rate than that obtained by conventional methods. The most attractive character of the method is that it can simultaneously determine the Tg of several polymers in a single experiment, so it can greatly save experimental time and heating energy. The method is not only applicable for polymer microspheres, but also for the materials with arbitrary shapes. Therefore, it is expected to be broadly applied to different fundamental researches and practical applications of polymers.

  16. Engineered for the energy future. I. Moisture separator-reheaters: extreme reliability an imperative

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    A description is given of the design and development activities performed by Foster-Wheeler to insure operational reliability of sixteen moisture separator-reheaters being manufactured for eight twin-unit BWR power plants to be operated by TVA

  17. Thermodynamic performance simulation and concise formulas for triple-pressure reheat HRSG of gas–steam combined cycle under off-design condition

    International Nuclear Information System (INIS)

    Zhang, Guoqiang; Zheng, Jiongzhi; Yang, Yongping; Liu, Wenyi

    2016-01-01

    Highlights: • An off-design performance simulation of triple-pressure reheat HRSG is executed. • The bottoming cycle characteristics of energy transfer/conversion are analyzed. • Concise formulas for the off-design performance of bottoming cycle are proposed. • The accuracy of the formulas is verified under different load control strategies. • The errors of the formulas are generally within 1% at a load of 100–50%. - Abstract: Concise semi-theoretical, semi-empirical formulas are developed in this study to predict the off-design performance of the bottoming cycle of the gas–steam turbine combined cycle. The formulas merely refer to the key thermodynamic design parameters (full load parameters) of the bottoming cycle and off-design gas turbine exhaust temperature and flow, which are convenient in determining the overall performance of the bottoming cycle. First, a triple-pressure reheat heat recovery steam generator (HRSG) is modeled, and thermodynamic analysis is performed. Second, concise semi-theoretical, semi-empirical performance prediction formulas for the bottoming cycle are proposed through a comprehensive analysis of the heat transfer characteristics of the HRSG and the energy conversion characteristics of the steam turbine under the off-design condition. The concise formulas are found to be effective, i.e., fast, simple, and precise in obtaining the thermodynamic parameters for bottoming cycle efficiency, HRSG heat transfer capacity, HRSG efficiency, steam turbine power output, and steam turbine efficiency under the off-design condition. Accuracy is verified by comparing the concise formulas’ calculation results with the simulation results and practical operation data under different load control strategies. The calculation errors are within 1.5% (mainly less than 1% for both simulation and actual operation data) under combined cycle load (gas turbine load) ranging from 50% to 100%. However, accuracy declines sharply when the turbine

  18. DETERMINATION OF TEMPERATURE DISTRIBUTION FOR ANNULAR FINS WITH TEMPERATURE DEPENDENT THERMAL CONDUCTIVITY BY HPM

    Directory of Open Access Journals (Sweden)

    Davood Domairry Ganji

    2011-01-01

    Full Text Available In this paper, homotopy perturbation method has been used to evaluate the temperature distribution of annular fin with temperature-dependent thermal conductivity and to determine the temperature distribution within the fin. This method is useful and practical for solving the nonlinear heat transfer equation, which is associated with variable thermal conductivity condition. The homotopy perturbation method provides an approximate analytical solution in the form of an infinite power series. The annular fin heat transfer rate with temperature-dependent thermal conductivity has been obtained as a function of thermo-geometric fin parameter and the thermal conductivity parameter describing the variation of the thermal conductivity.

  19. Exergy Analysis of a Subcritical Reheat Steam Power Plant with Regression Modeling and Optimization

    Directory of Open Access Journals (Sweden)

    MUHIB ALI RAJPER

    2016-07-01

    Full Text Available In this paper, exergy analysis of a 210 MW SPP (Steam Power Plant is performed. Firstly, the plant is modeled and validated, followed by a parametric study to show the effects of various operating parameters on the performance parameters. The net power output, energy efficiency, and exergy efficiency are taken as the performance parameters, while the condenser pressure, main steam pressure, bled steam pressures, main steam temperature, and reheat steam temperature isnominated as the operating parameters. Moreover, multiple polynomial regression models are developed to correlate each performance parameter with the operating parameters. The performance is then optimizedby using Direct-searchmethod. According to the results, the net power output, energy efficiency, and exergy efficiency are calculated as 186.5 MW, 31.37 and 30.41%, respectively under normal operating conditions as a base case. The condenser is a major contributor towards the energy loss, followed by the boiler, whereas the highest irreversibilities occur in the boiler and turbine. According to the parametric study, variation in the operating parameters greatly influences the performance parameters. The regression models have appeared to be a good estimator of the performance parameters. The optimum net power output, energy efficiency and exergy efficiency are obtained as 227.6 MW, 37.4 and 36.4, respectively, which have been calculated along with optimal values of selected operating parameters.

  20. Optimal set values of zone modeling in the simulation of a walking beam type reheating furnace on the steady-state operating regime

    International Nuclear Information System (INIS)

    Yang, Zhi; Luo, Xiaochuan

    2016-01-01

    Highlights: • The adjoint equation is introduced to the PDE optimal control problem. • Lipschitz continuity for the gradient of the cost functional is derived. • The simulation time and iterations reduce by a large margin in the simulations. • The model validation and comparison are made to verify the proposed math model. - Abstract: In this paper, this study proposed a new method to solve the PDE optimal control problem by introducing the adjoint problem to the optimization model, which was used to get the reference values for the optimal furnace zone temperatures and the optimal temperature distribution of steel slabs in the reheating furnace on the steady-state operating regime. It was proved that the gradient of the cost functional could be written via the weak solution of this adjoint problem and then Lipschitz continuity of the gradient was derived. Model validation and comparison between the mathematics model and the experiment results indicated that the present heat transfer model worked well for the prediction of thermal behavior about a slab in the reheating furnace. Iterations and simulation time had shown a significant decline in the simulations of 20MnSi slab, and it was shown by numerical simulations for 0.4 m thick slabs that the proposed method was better applied in the medium and heavy plate plant, leading to better performance in terms of productivity, energy efficiency and other features of reheating furnaces.

  1. Reheating-volume measure in the string theory landscape

    International Nuclear Information System (INIS)

    Winitzki, Sergei

    2008-01-01

    I recently proposed the ''reheating-volume'' (RV) prescription as a possible solution to the measure problem in ''multiverse'' cosmology. The goal of this work is to extend the RV measure to scenarios involving bubble nucleation, such as the string theory landscape. In the spirit of the RV prescription, I propose to calculate the distribution of observable quantities in a landscape that is conditioned in probability to nucleate a finite total number of bubbles to the future of an initial bubble. A general formula for the relative number of bubbles of different types can be derived. I show that the RV measure is well defined and independent of the choice of the initial bubble type, as long as that type supports further bubble nucleation. Applying the RV measure to a generic landscape, I find that the abundance of Boltzmann brains is always negligibly small compared with the abundance of ordinary observers in the bubbles of the same type. As an illustration, I present explicit results for a toy landscape containing four vacuum states, and for landscapes with a single high-energy vacuum and a large number of low-energy vacua.

  2. Imprints of quantum gravity on large field inflation and reheating

    Energy Technology Data Exchange (ETDEWEB)

    Rompineve Sorbello, Fabrizio

    2017-04-18

    In this thesis we investigate the feasibility and phenomenology of transplanckian field displacements during Inflation as well as the production of very light fields during Reheating. We begin by focusing on realisations of axion inflation in the complex structure moduli sector of Type IIB String Theory (ST) flux compactifications. Firstly, we analyse the problem of backreaction of complex structure moduli on the inflationary trajectory in a concrete model of axion monodromy inflation. Secondly, we propose a realisation of natural inflation where the inflaton arises as a combination of two axions. In both cases we find sufficiently flat inflationary potentials over a limited, but transplanckian field range. However, our realisation of axion monodromy inflation requires a potentially large, though realisable, number of tunings to ensure that the inflationary shift symmetry is only weakly broken. The consequences of the Weak Gravity Conjecture (WGC) for axion monodromy inflation are then explored. We find that the conjecture provides a bound on the inflationary field range, but does not forbid transplanckian displacements. Moreover, we provide a strategy to generalise the WGC to general p-form gauge theories in ST. Finally, we focus on the physics of the early post-inflationary phase. We show that axion monodromy inflation can lead to a phase decomposition, followed by the radiation of potentially detectable gravitational waves. We also propose a strategy to evade the overproduction of Dark Radiation in the Large Volume Scenario of moduli stabilisation, by means of flavour branes wrapping the bulk cycle of the compactification manifold.

  3. Stress corrosion cracking in superheater and reheater austenitic tubing

    Energy Technology Data Exchange (ETDEWEB)

    Dooley, R. Barry [Structural Integrity Associates, Inc., Charlotte, NC (United States); Bursik, Albert [PowerPlant Chemistry GmbH, Neulussheim (Germany)

    2011-02-15

    University 101 courses are typically designed to help incoming first-year undergraduate students to adjust to the university, develop a better understanding of the college environment, and acquire essential academic success skills. Why are we offering a special Boiler and HRSG Tube Failures PPChem 101? The answer is simple, yet very conclusive: - There is a lack of knowledge on the identification of tube failure mechanisms and for the implementation of adequate counteractions in many power plants, particularly at industrial power and steam generators. - There is a lack of knowledge to prevent repeat tube failures. The vast majority of BTF/HTF have been, and continue to be, repeat failures. It is hoped that the information about the failure mechanisms of BTF supplied in this course will help to put plant engineers and chemists on the right track. The major goal of this course is the avoidance of repeat BTF. This eights lesson is focused on Stress Corrosion Cracking in Superheater and Reheater Austenitic Tubing. (orig.)

  4. Determining noncondensible gas fractions at elevated temperatures and pressures using wet and dry bulb temperature measurements

    International Nuclear Information System (INIS)

    Griffith, P.; Bowman, J.

    1987-01-01

    The work reported in this note was undertaken to provide a method of determining the noncondensible gas fractions in a steam-gas mixture such as might be found in large reactor safety experiment like LOFT. In essence, the method used involves measuring the wet and dry bulb temperatures and using an algorithm, in place of the psychometric chart, to determine the partial pressure of the noncondensible gas in the mixture. In accomplishing this, the authors did the following: (1) extended the use of wet and dry-bulb temperature readings to determine mixture composition up to a temperature of 589 K and a pressure of 4.13 x 10 6 Pa. (2) developed an algorithm to reduce the data (3) found which materials would survive those temperatures

  5. Gap-closing test structures for temperature budget determination

    NARCIS (Netherlands)

    Faber, Erik Jouwert; Wolters, Robertus A.M.; Schmitz, Jurriaan

    2011-01-01

    We present the extension of a method for determining the temperature budget of the process side of silicon substrates and chips, employing silicide formation reactions. In this work, silicon-on-insulator type substrates are used instead of bulk silicon wafers. By an appropriate choice of the layer

  6. Investigations for determining temperature, pressure and moisture distributions in concrete at high temperatures

    International Nuclear Information System (INIS)

    Weber, A.; Kamp, C.L.

    1987-01-01

    The paper gives a report on the test program. The main objective of the tests was the determination of the temperature and moisture fields decisive for the corrosion conditions, which are built up behind the liner in the range of the heated concrete. The determination of transport characteristics of the concrete are another objective. Small concrete specimens are used to determine the following data: Thermal conductivity, heat capacity, diffusion coefficient for liquid water, steam and air, steam sorption therms. The chemical shrinkage of the concrete as a function of moisture and temperature is being evaluated by means of tests and calculations. (orig./HP)

  7. The influence of heating rate on reheat-cracking in a commercial 2 1/4Cr1Mo steel

    International Nuclear Information System (INIS)

    Hippsley, C.A.

    1983-03-01

    The effects of elevated heating rate on stress-relief cracking in a commercial 2 1/4 Cr1Mo steel have been investigated. A SEN bend-specimen stress-relaxation test was used to assess reheat cracking susceptibility and fracture mechanisms for an initial post-weld heating rate of 1000 Kh - 1 . Two factors controlling the influence of heating rate on the final severity of cracking were identified, i.e. the rate of stress-relaxation with respect to temperature, and the time available for crack-growth. The factors were found to counteract each other, but in the case of commercial 2 1/4 Cr1Mo steel, the crack-growth factor outweighed the relaxation factor, resulting in a reduction in the propensity to stress-relief cracking at the elevated heating rate. However, by reference to the results of a separate investigation concerning A508/2 MnMoNiCr steel it was demonstrated that the balance between these two factors may be reversed in other alloy systems, with the consequence that reheat cracking is exacerbated by increasing the initial heating rate. A computer model was addressed to the stress-relaxation test conditions using data from the commercial 2 1/4 Cr1Mo steel. The model predictions exhibited reasonable agreement with experimental test results for both 100 Kh - 1 and 1000 Kh - 1 heating rates. (author)

  8. Device for determining the maximum temperature of an environment

    International Nuclear Information System (INIS)

    Cartier, Louis.

    1976-01-01

    This invention concerns a device for determining the maximum temperature of an environment. Its main characteristic is a central cylindrical rod on which can slide two identical tubes, the facing ends of which are placed end to end and the far ends are shaped to provide a sliding friction along the rod. The rod and tubes are fabricated in materials of which the linear expansion factors are different in value. The far ends are composed of tongs of which the fingers, fitted with claws, bear on the central rod. Because of this arrangement of the device the two tubes, placed end to end on being fitted, can expand under the effect of a rise in the temperature of the environment into which the device is introduced, with the result that there occurs an increase in the distance between the two far ends. This distance is maximal when the device is raised to its highest temperature. The far ends are shaped to allow the tubes to slide under the effect of expansion but to prevent sliding in the opposite direction when the device is taken back into the open air and the temperature drops to within ambient temperature. It follows that the tubes tend to return to their initial length and the ends that were placed end to end when fitted now have a gap between them. The measurement of this gap makes it possible to know the maximal temperature sought [fr

  9. Steam generator concept of a small HTR for reheating and for removal of the residual heat

    Energy Technology Data Exchange (ETDEWEB)

    Singh, J; Barnert, H; Hohn, H; Mondry, M [Institut fuer Reaktorenentwicklung, Kernforschungsanlage Juelich GmbH, Juelich (Germany)

    1988-07-01

    The steam generator of a small HTR is arranged above the core in an in line design of the primary loop, thereby helium flows upwards. Water flows downwards in the steam generator to realize cross flow. To achieve stable evaporation conditions during part load operation it is desired to realize upward evaporation in the steam generator. Moreover if the steam generator is also used as a heat sink for removal of residual heat, this desire of upwards evaporation becomes more imperative. It is possible to realize the design of steam generator with upwards evaporation by arranging a hot gas duct in its central region, so that hot helium can flow upwards through it. Therefore helium enters the steam generator from the top and flows downwards and water upwards. In the presented design, a heat exchanger is arranged in the central region of the steam generator instead of a hot gas duct. Hot helium of 750 deg. C flows upwards in this heat exchanger and thereby cools down to the temperature of about 700 deg. C before it enters the bundle of the steam generator at the top. Through an intermediate loop this heat is transferred outside the primary loop, where in an extra heat exchanger live steam is reheated to improve the thermal efficiency of the plant. This intermediate loop works on the basis of forced convection and transfer about 25 MW for reheating. During the shutdown operation of the reactor, this heat exchanger in the central region of the steam generator serves as a heat sink for removal of the residual heat through natural convection in the primary loop. At the same time it is further possible, that intermediate loop also works on the basis of natural convection, because during shutdown operation only a very small amount of heat has to be removed and moreover the outside heat exchanger can be arranged much higher above the central heat exchanger to get favourable conditions for the natural convection. Some of the highlights of the central heat exchanger are: coaxial

  10. Continuous Emission Spectrum Measurement for Electron Temperature Determination in Low-Temperature Collisional Plasmas

    International Nuclear Information System (INIS)

    Liu Qiuyan; Li Hong; Chen Zhipeng; Xie Jinlin; Liu Wandong

    2011-01-01

    Continuous emission spectrum measurement is applied for the inconvenient diagnostics of low-temperature collisional plasmas. According to the physical mechanism of continuous emission, a simplified model is presented to analyze the spectrum in low temperature plasma. The validity of this model is discussed in a wide range of discharge parameters, including electron temperature and ionization degree. Through the simplified model, the continuous emission spectrum in a collisional argon internal inductively coupled plasma is experimentally measured to determine the electron temperature distribution for different gas pressures and radio-frequency powers. The inverse Abel transform is also applied for a better spatially resoluted results. Meanwhile, the result of the continuous emission spectrum measurement is compared to that of the electrostatic double probes, which indicates the effectiveness of this method. (low temperature plasma)

  11. Determination of Cardinal Temperatures and Germination Respond to Different Temperature for Five Lawns Cultivars

    Directory of Open Access Journals (Sweden)

    hadi khavari

    2017-08-01

    Full Text Available Introduction: Germination of every plant species respond to temperature variation in particular way. Germination is critical stage in plant life cycle. Seed germination is a complex biological process that is influenced by various environmental and genetic factors. The effects of temperature on plant development are the basis for models used to predict the timing of germination. Estimation of the cardinal temperatures, including base, optimum, and maximum, is essential because rate of development increases between base and optimum, decreases between optimum and maximum, and ceases above the maximum and below the base temperatures. Usually, a linear increase in germination rate is associated with an increase in temperature from base temperature (Tb to an optimum. An increase of temperature from the optimum will reduce the germination rate to zero. To determine the best planting date for plants, it is necessary to find the base (Tb, optimum (To and maximum temperatures (Tc for seed germination. These are known as cardinal temperatures. Modelling of seed germination is considered an effective approach to determining cardinal temperatures for most plant species, although these methods have some limitations due to unpredictable biological changes. The results of fitting mechanical models are useful for evaluating seed quality, germination rate, germination percentage, germination uniformity and seed performance under different environmental stresses such as salinity, drought, and freezing. Regression models incorporating more parameters can produce more precise estimates. Cardinal temperature was determined using segmented and logistic models in millet varieties and seedling emergence of wheat. In the dent-like model at lower-than-optimum temperature, a linear relationship holds between temperature and germination rate. This relationship remains linear at higher-than-optimum temperatures, but with a reducing trend. With increasing temperature

  12. Spectrographical method for determining temperature variations of cosmic rays

    International Nuclear Information System (INIS)

    Dorman, L.I.; Krest'yannikov, Yu.Ya.; AN SSSR, Irkutsk. Sibirskij Inst. Zemnogo Magnetizma Ionosfery i Rasprostraneniya Radiovoln)

    1977-01-01

    A spectrographic method for determining [sigmaJsup(μ)/Jsup(μ)]sub(T) temperature variations in cosmic rays is proposed. The value of (sigmaJsup(μ)/Jsup(μ)]sub(T) is determined from three equations for neutron supermonitors and the equation for the muon component of cosmic rays. It is assumed that all the observation data include corrections for the barometric effect. No temperature effect is observed in the neutron component. To improve the reliability and accuracy of the results obtained the surface area of the existing devices and the number of spectrographic equations should be increased as compared with that of the unknown values. The value of [sigmaJsup(μ)/Jsup(μ)]sub(T) for time instants when the aerological probing was carried out, was determined from the data of observations of cosmic rays with the aid of a spectrographic complex of devices of Sib IZMIR. The r.m.s. dispersion of the difference is about 0.2%, which agrees with the expected dispersion. The agreement obtained can be regarded as an independent proof of the correctness of the theory of meteorological effects of cosmic rays. With the existing detection accuracy the spectrographic method can be used for determining the hourly values of temperature corrections for the muon component

  13. Determination of gas temperature in the plasmatron channel according to the known distribution of electronic temperature

    Directory of Open Access Journals (Sweden)

    Gerasimov Alexander V.

    2013-01-01

    Full Text Available An analytical method to calculate the temperature distribution of heavy particles in the channel of the plasma torch on the known distribution of the electronic temperature has been proposed. The results can be useful for a number of model calculations in determining the most effective conditions of gas blowing through the plasma torch with the purpose of heating the heavy component. This approach allows us to understand full details about the heating of cold gas, inpouring the plasma, and to estimate correctly the distribution of the gas temperature inside the channel.

  14. Effectiveness of oxygen barrier oven bags in low temperature cooking on reduction of warmed-over flavor in beef roasts.

    Science.gov (United States)

    Lepper-Blilie, A N; Berg, E P; Buchanan, D S; Keller, W L; Maddock-Carlin, K R; Berg, P T

    2014-03-01

    A 3×3×2 factorial was utilized to determine if roast size (small, medium, large), cooking method (open-pan, oven bag, vacuum bag), and heating process (fresh, reheated) prevented warmed-over flavor (WOF) in beef clod roasts. Fresh vacuum bag and reheated open-pan roasts had higher cardboardy flavor scores compared with fresh open-pan roast scores. Reheated roasts in oven and vacuum bags did not differ from fresh roasts for cardboardy flavor. Brothy and fat intensity were increased in reheated roasts in oven and vacuum bags compared with fresh roasts in oven and vacuum bags. Differences in TBARS were found in the interaction of heating process and roast size with the fresh and reheated large, and reheated medium roasts having the lowest values. Based on TBARS data, to prevent WOF in reheated beef roasts, a larger size roast in a cooking bag is the most effective method. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Quantative determination of surface temperatures using an infrared camera

    International Nuclear Information System (INIS)

    Hsieh, C.K.; Ellingson, W.A.

    1977-01-01

    A method is presented to determine the surface-temperature distribution at each point in an infrared picture. To handle the surface reflection problem, three cases are considered that include the use of black coatings, radiation shields, and band-pass filters. For uniform irradiation on the test surface, the irradiation can be measured by using a cooled, convex mirror. Equations are derived to show that this surrounding irradiation effect can be subtracted out from the scanned radiation; thus the net radiation is related to only emission from the surface. To provide for temperature measurements over a large field, the image-processing technique is used to digitize the infrared data. The paper spells out procedures that involve the use of a computer for making point-by-point temperature calculations. Finally, a sample case is given to illustrate applications of the method. 6 figures, 1 table

  16. Reheating, thermalization and non-thermal gravitino production in MSSM inflation

    Energy Technology Data Exchange (ETDEWEB)

    Ferrantelli, Andrea [Tallinn University of Technology, Faculty of Civil Engineering, Tallinn (Estonia)

    2017-10-15

    In the framework of MSSM inflation, matter and gravitino production are here investigated through the decay of the fields which are coupled to the udd inflaton, a gauge-invariant combination of squarks. After the end of inflation, the flat direction oscillates about the minimum of its potential, losing at each oscillation about 56% of its energy into bursts of gauge/gaugino and scalar quanta when crossing the origin. These particles then acquire a large inflaton VEV-induced mass and decay perturbatively into the MSSM quanta and gravitinos, transferring the inflaton energy very efficiently via instant preheating. Regarding thermalization, we show that the MSSM degrees of freedom thermalize very quickly, yet not immediately by virtue of the large vacuum expectation value of the inflaton, which breaks the SU(3){sub C} x U(1){sub Y} symmetry into a residual U(1). The energy transfer to the MSSM quanta is very efficient, since full thermalization is achieved after only O(40) complete oscillations. The udd inflaton thus provides an extremely efficient reheating of the Universe, with a temperature T{sub reh} = O(10{sup 8} GeV), which allows for instance several mechanisms of baryogenesis. We also compute the gravitino number density from the perturbative decay of the flat direction and of the SUSY multiplet. We find that the gravitinos are produced in negligible amount and satisfy cosmological bounds such as the Big Bang nucleosynthesis (BBN) and dark matter (DM) constraints. (orig.)

  17. Experimental Determination of Temperatures in a Liquid GAP

    International Nuclear Information System (INIS)

    Masson, Viviana; Ojeda, Andres; Fabian, Bonetto

    2003-01-01

    An experimental study of heat transfer in a gap of water at atmospheric pressure is presented under natural convection conditions.The objective of the work was to experimentally determine the expected maximum temperatures in the gap for a given heater power.The experimental set-up was a plane surface heated by resistances and facing a 1mm-liquid gap.Visualisation of phenomena by video and still picture was performed

  18. Cardinal Temperatures of Brassica sp. and How to Determine It

    Directory of Open Access Journals (Sweden)

    D. K. SUANDA SUANDA

    2013-08-01

    Full Text Available Cardinal temperatures consist of minimum, optimum and maximum of plant growth, and might beable to be determined by assessing effect of temperature on seed germination. An experiment ofseed germination was conducted in laboratory, using thermal gradient plate for ten days. To test hypothesisthat rapeseed genotypes vary in their response to temperatures. The design of this experiment was asplit plot with four replications. The main-treatments were 14 different temperatures: 0.4°C, 3.3°C,7.8°C, 11.6°C, 13.3°C, 15.0°C, 16.8°C, 18.3°C, 20.9°C, 21.1°C, 25.6°C, 29.0°C, 33.0°C and36.3°C. Sub-treatments were 6 brassica genotypes: Brassica napus genotypes (Tatyoon and Marnoo;B. campestris (Jumbuck and Chinoli B; B. juncea (No. 81797 and Zero Erusic Mustard (ZEM 2.Each treatment was using 50 seeds. Germinations were observed daily for ten days and data wereanalyzed with regression and correlation. Genotypes responded differently to temperatures with Jumbuckthe most sensitive to low temperature with minimum temperature (7.90°C, then respectively followedby Chinoli B (6.36°C, ZEM 2 (4.77°C, Tatyoon (4.63°C, No. 81797 (2.59°C, and Marnoo(1.00°C. For high temperature the most sensitive was No. 81797 with maximum temperature 38.61°C.and then respectively followed by Marnoo (39.76°C, Chinoli B (42.93°C, Tatyoon (43.79°C,Jumbuck (44.58°C and ZEM 2 (45.88°C. Optimum temperatures were for Jumbuck was 24.56°C,ZEM 2 (26.95°C, Tatyoon (27.12°C, No. 81797 (28.12°C, Chinoli B (29.74°C and Marnoo(30.48°C.

  19. Determining coronal electron temperatures from observations with UVCS/SOHO

    Science.gov (United States)

    Fineschi, S.; Esser, R.; Habbal, S. R.; Karovska, M.; Romoli, M.; Strachan, L.; Kohl, J. L.; Huber, M. C. E.

    1995-01-01

    The electron temperature is a fundamental physical parameter of the coronal plasma. Currently, there are no direct measurements of this quantity in the extended corona. Observations with the Ultraviolet Coronagraph Spectrometer (UVCS) aboard the upcoming Solar and Heliospheric Observatory (SOHO) mission can provide the most direct determination of the electron kinetic temperature (or, more precisely, the electron velocity distribution along the line of sight). This measurement is based on the observation of the Thomson-scattered Lyman alpha (Ly-alpha) profile. This observation is made particularly challenging by the fact that the integrated intensity of the electron-scattered Ly-alpha line is about 10(exp 3) times fainter than that of the resonantly-scattered Ly-alpha component. In addition, the former is distributed across 50 A (FWHM), unlike the latter that is concentrated in 1 A. These facts impose stringent requirements on the stray-light rejection properties of the coronagraph/spectrometer, and in particular on the requirements for the grating. We make use of laboratory measurements of the UVCS Ly-alpha grating stray-light, and of simulated electron-scattered Ly-alpha profiles to estimate the expected confidence levels of electron temperature determination. Models of different structures typical of the corona (e.g., streamers, coronal holes) are used for this parameter study.

  20. Neighborhood properties are important determinants of temperature sensitive mutations.

    Directory of Open Access Journals (Sweden)

    Svetlana Lockwood

    Full Text Available Temperature-sensitive (TS mutants are powerful tools to study gene function in vivo. These mutants exhibit wild-type activity at permissive temperatures and reduced activity at restrictive temperatures. Although random mutagenesis can be used to generate TS mutants, the procedure is laborious and unfeasible in multicellular organisms. Further, the underlying molecular mechanisms of the TS phenotype are poorly understood. To elucidate TS mechanisms, we used a machine learning method-logistic regression-to investigate a large number of sequence and structure features. We developed and tested 133 features, describing properties of either the mutation site or the mutation site neighborhood. We defined three types of neighborhood using sequence distance, Euclidean distance, and topological distance. We discovered that neighborhood features outperformed mutation site features in predicting TS mutations. The most predictive features suggest that TS mutations tend to occur at buried and rigid residues, and are located at conserved protein domains. The environment of a buried residue often determines the overall structural stability of a protein, thus may lead to reversible activity change upon temperature switch. We developed TS prediction models based on logistic regression and the Lasso regularized procedure. Through a ten-fold cross-validation, we obtained the area under the curve of 0.91 for the model using both sequence and structure features. Testing on independent datasets suggested that the model predicted TS mutations with a 50% precision. In summary, our study elucidated the molecular basis of TS mutants and suggested the importance of neighborhood properties in determining TS mutations. We further developed models to predict TS mutations derived from single amino acid substitutions. In this way, TS mutants can be efficiently obtained through experimentally introducing the predicted mutations.

  1. Determination of viability of preserved skin in low temperature

    International Nuclear Information System (INIS)

    Yang Hong Chang; Hao Zheng Ming; Zao Xiao Chun

    1999-01-01

    The skin from fresh human cadavers was stored in 4-18 degree C refrigerator. Before it was grafted for treatment of burn patients, it was quickly put into 40 degree C water and bring back to a former condition. The survival rate of skin was related with time and temperature of store. We used oxygen consumption to observe the change of viability of preserved skin. Oxygen consumption of skin was observed with apparatus made in the 304th Hospital of Peoples Liberation Army. The operating temperature was 5 - 45 degree C. Determination range was 0 - 199 mm Hg, resolving power of digital display was I mm Hg, instrumental error < 0.5 s'. Fresh human cadavers skin was made into 0.3 - 0.4 mm thick piece. Cleaned with NaCl 0.9% for three time. Then it was kept in neomycin solution for fifteen minutes. Then cut into 0.5 x 0.5 cm slices and stored in neomycin (2mg/ml). The skin was stored in 4 degree C refrigerator for five different periods (1, 2, 3, 5 and 7 days). Then the Oxygen consumption was determined immediately. The oxygen consumption was also determined before and after it was stored for 24 hours. After the skin was stored in 4 and -18 degree C for 24 hours the oxygen consumption was determined immediately. The prepared skin, which was stored in ordinary refrigerator, was useful and simple. The preserved skin was grafted onto the bum patient and survival rate was high and in short time. But the result showed the viability of preserved skin reduced with time. The result showed that the oxygen consumption of skin, which was stored at 4 degree C, on the fifth day was 62.23% and on day 7 was 30.5%. The study showed that the preserved skin which was stored at 4 degree C for five days was better while the vitality of skin evidently reduced after seven days and the survival rate was low. The oxygen consumption of preserved skin that was stored in -18 degree C refrigerator for 24 hours was 100%. But in 4 degree C refrigerator it was 89.1%. The result showed that the

  2. Prospects for determination of thermal history after inflation with future gravitational wave detectors

    International Nuclear Information System (INIS)

    Kuroyanagi, Sachiko; Nakayama, Kazunori; Saito, Shun

    2011-01-01

    Thermal history of the Universe between inflation and big-bang nucleosynthesis has not yet been revealed observationally. It will be probed by the detection of primordial gravitational waves generated during inflation, which contain information on the reheating temperature as well as the equation of state of the Universe after inflation. Based on the Fisher information formalism, we examine how accurately the tensor-to-scalar ratio and reheating temperature after inflation can be simultaneously determined with space-based gravitational wave detectors such as the DECI-hertz Interferometer Gravitational-wave Observatory and the Big-Bang Observer. We show that the reheating temperature is best determined if it is around 10 7 GeV for tensor-to-scalar ratio of around 0.1, and explore the detectable parameter space. We also find that equation of state of the early Universe can be also determined accurately enough to distinguish different equation-of-state parameters if the inflationary gravitational waves are successfully detected. Thus, future gravitational wave detectors provide a unique and promising opportunity to reveal the thermal history of the Universe around 10 7 GeV.

  3. Determination of temperature distributions in fast reactor core coolants

    International Nuclear Information System (INIS)

    Tillman, M.

    1975-04-01

    An analytical method of determination of a temperature distribution in the coolant medium in a fuel assembly of a liquid-metal-fast-breeder-reactor (LMFBR) is presented. The temperature field obtained is applied for a constant velocity (slug flow) fluid flowing, parallel to the fuel pins of a square and hexagonal array assembly. The coolant subchannels contain irregular boundaries. The geometry of the channel due to the rod adjacent to the wall (edge rod) differs from the geometry of the other channels. The governing energy equation is solved analytically, assuming series solutions for the Poisson and diffusion equations, and the total solution is superposed by the two. The boundary conditions are specified by symmetry considerations, assembly wall insulation and a continuity of the temperature field and heat fluxes. The initial condition is arbitrary. The method satisfies the boundary conditions on the irregular boundaries and the initial condition by a least squares technique. Computed results are presented for various geometrical forms, with ratio of rod pitch-to-diameter typical for LMFBR cores. These results are applicable for various fast-reactors, and thus the influence of the transient solution (which solves the diffusion equation) on the total depends on the core parameters. (author)

  4. Thermal Efficiency of Cogeneration Units with Multi-Stage Reheating for Russian Municipal Heating Systems

    Directory of Open Access Journals (Sweden)

    Evgeny Lisin

    2016-04-01

    Full Text Available This paper explores the layout of an optimum process for supplying heat to Russian municipal heating systems operating in a market environment. We analyze and compare the standard cogeneration unit design with two-stage reheating of service water coming from controlled extraction locations and layouts that employ three in-line reheaters with heat the supply controlled by a rotary diaphragm and qualitative/quantitative methods (so-called “uncontrolled extraction”. Cogeneration unit designs are benchmarked in terms of their thermal efficiency expressed as a fuel consumption rate. The specific fuel consumption rate on electricity production is viewed as a key parameter of thermal efficiency.

  5. Reheating signature in the gravitational wave spectrum from self-ordering scalar fields

    Energy Technology Data Exchange (ETDEWEB)

    Kuroyanagi, Sachiko [Asia Pacific Center for Theoretical Physics, Pohang, Gyeongbuk, 790-784 (Korea, Republic of); Hiramatsu, Takashi [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto, 606-8502 Japan (Japan); Yokoyama, Jun' ichi, E-mail: skuro@nagoya-u.jp, E-mail: hiramatz@yukawa.kyoto-u.ac.jp, E-mail: yokoyama@resceu.s.u-tokyo.ac.jp [Research Center for the Early Universe (RESCEU), School of Science, The University of Tokyo, Tokyo, 113-0033 Japan (Japan)

    2016-02-01

    We investigate the imprint of reheating on the gravitational wave spectrum produced by self-ordering of multi-component scalar fields after a global phase transition. The equation of state of the Universe during reheating, which usually has different behaviour from that of a radiation-dominated Universe, affects the evolution of gravitational waves through the Hubble expansion term in the equations of motion. This gives rise to a different power-law behavior of frequency in the gravitational wave spectrum. The reheating history is therefore imprinted in the shape of the spectrum. We perform 512{sup 3} lattice simulations to investigate how the ordering scalar field reacts to the change of the Hubble expansion and how the reheating effect arises in the spectrum. We also compare the result with inflation-produced gravitational waves, which has a similar spectral shape, and discuss whether it is possible to distinguish the origin between inflation and global phase transition by detecting the shape with future direct detection gravitational wave experiments such as DECIGO.

  6. High temperature metallic recuperator

    Science.gov (United States)

    Ward, M. E.; Solmon, N. G.; Smeltzer, C. E.

    1981-06-01

    An industrial 4.5 MM Btu/hr axial counterflow recuperator, fabricated to deliver 1600 F combustion air, was designed to handle rapid cyclic loading, a long life, acceptable costs, and a low maintenance requirement. A cost benefit anlysis of a high temperature waste heat recovery system utilizing the recurperator and components capable of 1600 F combustion air preheat shows that this system would have a payback period of less than two years. Fifteen companies and industrial associations were interviewed and expressed great interest in recuperation in large energy consuming industries. Determination of long term environmental effects on candidate recuperator tubing alloys was completed. Alloys found to be acceptable in the 2200 F flue gas environment of a steel billet reheat furnace, were identified.

  7. Determination of the glass transition temperature of cyclodextrin polymers.

    Science.gov (United States)

    Tabary, Nicolas; Garcia-Fernandez, Maria Jose; Danède, Florence; Descamps, Marc; Martel, Bernard; Willart, Jean-François

    2016-09-05

    The aim of this work was to determine the main physical characteristics of β-cyclodextrin polymers, well known for improving complexation capacities and providing enhanced and sustained release of a large panel of drugs. Two polymers were investigated: a polymer of β-cyclodextrin (polyβ-CD) and a polymer of partially methylated (DS=0.57) β-cyclodextrin (polyMe-β-CD). The physical characterizations were performed by powder X-ray diffraction and differential scanning calorimetry. The results indicate that these polymers are amorphous and that their glass transition is located above the thermal degradation point of the materials preventing their direct observation and thus their full characterization. We could however estimate the virtual glass transition temperatures by mixing the polymers with different plasticizers (trehalose and mannitol) which decreases Tg sufficiently to make the glass transition observable. Extrapolation to zero plasticizer concentration then yield the following Tg values: Tg (polyMe-β-CD)=317°C±5°C and Tg (polyβ-CD)=418°C±6°C. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Experimental determination of monoethanolamine protonation constant and its temperature dependency

    Directory of Open Access Journals (Sweden)

    Ma’mun Sholeh

    2017-01-01

    Full Text Available Carbon dioxide as one of the major contributors to the global warming problem is produced in large quantities by many important industries and its emission seems to rise from year to year. Aminebased absorption is one of the methods to capture CO2 from its sources. As a reactive system, mass transfer and chemical reaction take place simultaneously. In a vapor-liquid equilibrium model for the CO2-amine-water system, some parameters such as mass transfer coefficients and chemical equilibrium constants need to be known. However, some parameters could be determined experimentally and the rests could be regressed from the model. The protonation constant (pKa, as one of the model parameters, could then be measured experimentally. The purpose of this study is to measure the pKa of monoethanolamine (MEA at a range of temperatures from 303 to 330K by a potentiometric titration method. The experimental data obtained were in a good agreement with the literature data. The pKa data from this work together with those from the literature were then correlated in an empirical correlation to be used for future research.

  9. Determination of temperature and pressure in the calcium reduction process

    International Nuclear Information System (INIS)

    Arceri, Mariana E.

    1997-01-01

    The calcium reduction process consists in the reduction of uranium tetrafluoride (UF 4 ) with calcium in a refractory material crucible, in order to obtain metallic uranium. The crucible is in turn contained in a steel reactor, heated by means of an induction coil to bring the reagents from the environmental temperature to the temperature necessary for the reaction starting. For the design of the reactor, mathematical expressions that allow to estimate the temperature and pressure of the system have been developed

  10. Finite temperature susy GUT phase transitions determined by radiative corrections

    International Nuclear Information System (INIS)

    Kripfganz, J.; Perlt, H.

    1983-01-01

    Studying the 2-loop perturbative contribution to the free energy of supersymmetric grand unified theories, SU(3)xSU(2)xU(1) is found to be the prefered low temperature phase. The transition temperature is still within the weak coupling regime. (author)

  11. Finite temperature susy GUT phase transitions determined by radiative corrections

    International Nuclear Information System (INIS)

    Kripfganz, J.; Perlt, H.

    1983-02-01

    Studying the 2-loop perturbative contribution to the free energy of grand unified theories a sequence of phase transitions is found, with SU(3)xSU(2)xU(1) being the prefered low temperature phase. The transition temperatures are still within the weak coupling regime. (author)

  12. Experimental determination of neutron temperature distribution in reactor cell

    International Nuclear Information System (INIS)

    Bosevski, T.

    1965-12-01

    This paper describes theoretical preparation of the experiment for measuring neutron temperature distribution at the RB reactor by activation foils. Due to rather low neutron flux Cu and Lu foil were irradiated for 4 days. Special natural uranium fuel element was prepared to enable easy removal of foils after irradiation. Experimental device was placed in the reactor core at half height in order to measure directly the mean neutron density. Experimental data of neutron temperature distribution for square lattice pitch 16 cm are presented with mean values of neutron temperature in the moderator, in the fuel and on the fuel element surface

  13. Antilisterial properties of marinades during refrigerated storage and microwave oven reheating against post-cooking inoculated chicken breast meat.

    Science.gov (United States)

    Fouladkhah, Aliyar; Geornaras, Ifigenia; Nychas, George-John; Sofos, John N

    2013-02-01

    This study evaluated growth of Listeria monocytogenes inoculated on cooked chicken meat with different marinades and survival of the pathogen as affected by microwave oven reheating. During aerobic storage at 7 °C, on days 0, 1, 2, 4, and 7, samples were reheated by microwave oven (1100 W) for 45 or 90 s and analyzed microbiologically. L. monocytogenes counts on nonmarinated (control) samples increased (P 2.4 to 5.0 (90 s) log CFU/g. With similar trends across different marinates, the high levels of L. monocytogenes survivors found after microwave reheating, especially after storage for more than 2 d, indicate that length of storage and reheating time need to be considered for safe consumption of leftover cooked chicken. © 2013 Institute of Food Technologists®

  14. Curie temperature determination via thermogravimetric and continuous wavelet transformation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hasier, John; Nash, Philip [Thermal Processing Technology Center, IIT, Chicago, IL (United States); Riolo, Maria Annichia [University of Michigan, Center for the Study of Complex Systems, Ann Arbor, MI (United States)

    2017-12-15

    A cost effective method for conversion of a vertical tube thermogravimetric analysis system into a magnetic balance capable of measuring Curie Temperatures is presented. Reference and preliminary experimental data generated using this system is analyzed via a general-purpose wavelet based Curie point edge detection technique allowing for enhanced speed, ease and repeatability of magnetic balance data analysis. The Curie temperatures for a number of Heusler compounds are reported. (orig.)

  15. Optoacoustic temperature determination and automatic coagulation control in rabbits

    Science.gov (United States)

    Schlott, Kerstin; Koinzer, Stefan; Ptaszynski, Lars; Luft, Susanne; Baade, Alex; Bever, Marco; Roider, Johann; Birngruber, Reginald; Brinkmann, Ralf

    2011-03-01

    Retinal laser photocoagulation is an established treatment method for many retinal diseases like macula edema or diabetic retinopathy. The selection of the laser parameters is so far based on post treatment evaluation of the lesion size and strength. Due to local pigment variations in the fundus and individual transmission the same laser parameters often lead to an overtreatment. Optoacoustic allows a non invasive monitoring of the retinal temperature increase during retinal laser irradiation by measuring the temperature dependent pressure amplitudes, which are induced by short probe laser pulses. A 75 ns/ 523 nm Nd:YLF was used as a probe laser at a repetition rate of 1 kHz, and a cw / 532 nm treatment laser for heating. A contact lens was modified with a ring-shaped ultrasonic transducer to detect the pressure waves at the cornea. Temperatures were collected for irradiations leading to soft or invisible lesions. Based on this data the threshold for denaturation was found. By analyzing the initial temperature increase, the further temperature development during irradiation could be predicted. An algorithm was found to calculate the irradiation time, which is needed for a soft lesion formation, from the temperature curve. By this it was possible to provide a real-time dosimetry by automatically switching off the treatment laser after the calculated irradiation time. Automatically controlled coagulations appear softer and more uniformly.

  16. Simultaneously estimation for surface heat fluxes of steel slab in a reheating furnace based on DMC predictive control

    International Nuclear Information System (INIS)

    Li, Yanhao; Wang, Guangjun; Chen, Hong

    2015-01-01

    The predictive control theory is utilized for the research of a simultaneous estimation of heat fluxes through the upper, side and lower surface of a steel slab in a walking beam type rolling steel reheating furnace. An inverse algorithm based on dynamic matrix control (DMC) is established. That is, each surface heat flux of a slab is simultaneously estimated through rolling optimization on the basis of temperature measurements in selected points of its interior by utilizing step response function as predictive model of a slab's temperature. The reliability of the DMC results is enhanced without prior assuming specific functions of heat fluxes over a period of future time. The inverse algorithm proposed a respective regularization to effectively improve the stability of the estimated results by considering obvious strength differences between the upper as well as lower and side surface heat fluxes of the slab. - Highlights: • The predictive control theory is adopted. • An inversion scheme based on DMC is established. • Upper, side and lower surface heat fluxes of slab are estimated based DMC. • A respective regularization is proposed to improve the stability of results

  17. Noise temperature measurements for the determination of the thermodynamic temperature of the melting point of palladium

    Energy Technology Data Exchange (ETDEWEB)

    Edler, F.; Kuhne, M.; Tegeler, E. [Bundesanstalt Physikalisch-Technische, Berlin (Germany)

    2004-02-01

    The thermodynamic temperature of the melting point of palladium in air was measured by noise thermometric methods. The temperature measurement was based on noise comparison using a two-channel arrangement to eliminate parasitic noises of electronic components by cross correlation. Three miniature fixed points filled with pure palladium (purity: {approx}99.99%, mass: {approx}90 g) were used to realize the melts of the fixed point metal. The measured melting temperature of palladium in air amounted to 1552.95 deg C {+-} 0.21 K (k = 2). This temperature is 0.45 K lower than the temperature of the melting point of palladium measured by radiation thermometry. (authors)

  18. Realtime temperature determination during retinal photocoagulation on patients

    Science.gov (United States)

    Brinkmann, Ralf; Koinzer, Stefan; Schlott, Kerstin; Ptaszynski, Lars; Bever, Marco; Baade, Alex; Miura, Yoko; Birngruber, Reginald; Roider, Johann

    2011-03-01

    Retinal photocoagulation is a long time established treatment for a variety of retinal diseases, most commonly applied for diabetic macular edema and diabetic retinopathy. The damage extent of the induced thermal coagulations depend on the temperature increase and the time of irradiation. So far, the induced temperature rise is unknown due to intraocular variations in light transmission and scattering and RPE/choroidal pigmentation, which can vary inter- and intraindividually by more than a factor of four. Thus in clinical practice, often stronger and deeper coagulations are applied than therapeutically needed, which lead to extended retinal damage and strong pain perception. The final goal of this project focuses on a dosimetry control, which automatically generates a desired temperature profile and thus coagulation strength for every individual coagulation spot, ideally unburden the ophthalmologist from any laser settings. In this paper we present the first realtime temperature measurements achieved on patients during retinal photocoagulation by means of an optoacoustic method, making use of the temperature dependence of the thermal expansion coefficient of retinal tissue. Therefore, nanosecond probe laser pulses are repetitively and simultaneously applied with the treatment radiation in order to excite acoustic waves, which are detected at the cornea with an ultrasonic transducer embedded in the contact lens and then are processed by PC.

  19. Suppressing gravitino thermal production with a temperature-dependent messenger coupling

    International Nuclear Information System (INIS)

    Badziak, Marcin; Dalianis, Ioannis; Lalak, Zygmunt

    2016-01-01

    We show that the constraints on GMSB theories from the gravitino cosmology can be significantly relaxed if the messenger-spurion coupling is temperature dependent. We demonstrate this novel mechanism in a scenario in which this coupling depends on the VEV of an extra singlet field S that interacts with the thermalized plasma which can result in a significantly suppressed gravitino production rate. In such a scenario the relic gravitino abundance is determined by the thermal dynamics of the S field and it is easy to fit the observed dark matter abundance evading the stringent constraints on the reheating temperature, thus making gravitino dark matter consistent with thermal leptogenesis.

  20. Temperature determines toxicity: Bisphenol A reduces thermal tolerance in fish

    International Nuclear Information System (INIS)

    Little, Alexander G.; Seebacher, Frank

    2015-01-01

    Bisphenol A (BPA) is a ubiquitous pollutant around the globe, but whether environmental concentrations have toxic effects remains controversial. BPA interferes with a number of nuclear receptor pathways, including several that mediate animal responses to environmental input. Because thermal acclimation is regulated by these pathways in fish, we hypothesized that the toxicity of BPA would change with ambient temperature. We exposed zebrafish (Danio rerio) to ecologically relevant and artificially high concentrations of BPA at two acclimation temperatures, and tested physiological responses at two test temperatures that corresponded to acclimation temperatures. We found ecologically relevant concentrations of BPA (20 μg l −1 ) impair swimming performance, heart rate, muscle and cardiac SERCA activity and gene expression. We show many of these responses are temperature-specific and non-monotonic. Our results suggest that BPA pollution can compound the effects of climate change, and that its effects are more dynamic than toxicological assessments currently account for. - Highlights: • Whether environmental levels of BPA have toxic effects on local ecology remains controversial. • We show that ecological concentrations of BPA impair physiological performance in fish. • We also show that the toxic effects of BPA are temperature-specific and non-monotonic with dose. • BPA pollution will likely compound the effects of climate change, and vice-versa. • The toxic effects of BPA appear to be more dynamic than toxicological assessments account for. - BPA pollution is likely to compound the effects of climate change, and climate change may worsen the effects of BPA exposure. Its effects are likely to be more dynamic than toxicological assessments currently account for

  1. Methods of Temperature and Emission Measure Determination of Coronal Loops

    Science.gov (United States)

    Cirtain, J. W.; Schmelz, J. T.; Martens, P. C. H.

    2002-05-01

    Recent observational results from both SOHO-EIT and TRACE indicate that coronal loops are isothermal along their length (axially). These results are obtained from a narrowband filter ratio method that assumes that the plasma is isothermal along the line of sight (radially). However, these temperatures vary greatly from those derived from differential emission measure (DEM) curves produced from spectral lines recorded by SOHO-CDS. The DEM results indicate that the loops are neither axially nor radially isothermal. This discrepancy was investigated by Schmelz et al. (2001). They chose pairs of iron lines from the same CDS data set to mimic the EIT and TRACE loop results. Ratios of different lines gave different temperatures, indicating that the plasma was not radially isothermal. In addition the results indicated that the loop was axially isothermal, even though the DEM analysis of the same data showed this result to be false. Here we have analyzed the EIT data for the CDS loop published by Schmelz et al. (2001). We took the ratios of the 171-to-195 and 195-to-284 filter data, and made temperature maps of the loop. The results indicate that the loop is axially isothermal, but different temperatures were found for each pair of filters. Both ratio techniques force the resultant temperature to lie within the range where the response functions (for filters) or the emissivity functions (for lines) overlap; isothermal loops are therefore a byproduct of the analysis. This conclusion strengthens support for the idea that temperature and emission measure results from filter ratio methods may be misleading or even drastically wrong. This research was funded in part by the NASA/TRACE MODA grant for Montana State University. Solar physics research at the University of Memphis is supported by NASA grant NAG5-9783.

  2. Effect of Dynamic Reheating Induced by Weaving on the Microstructure of GTAW Weld Metal of 25% Cr Super Duplex Stainless Steel Weld Metal

    Directory of Open Access Journals (Sweden)

    Hee-Joon Sung

    2017-11-01

    Full Text Available The importance of the additional growth and/or transformation of the austenite phase that occurs in weld metals of super duplex stainless steel upon reheating is known. However, the effects have not been fully investigated, especially with respect to reheating induced by weaving during single-pass welding. In this work, bead-on-pipe gas tungsten arc welding (GTAW was conducted on super duplex stainless steel to understand the effect of weaving on the microstructure of weld metal. Microstructural analysis, electron backscatter diffraction (EBSD, and focused ion beam transmission electron microscopy (FIB-TEM were carried out to investigate the relationship between weaving and microstructural change. The weaving of GTAW produced a dynamic reheated area just before the weld bead during welding. It was revealed that extensive reheated weld existed even after one welding pass, and that the content of the austenite phase in the reheated area was higher than that in the non-reheated area, indicating the existence of a large quantity of intragranular austenite phase. In addition, the Cr2N content in the reheated area was lower than that in the non-reheated area. This reduction of Cr2N was closely related to the reheating resulting from weaving. TEM analysis revealed that Cr2N in the non-reheated area was dispersed following heating and transformed to secondary austenite.

  3. Determination of electron temperature and electron density in ...

    African Journals Online (AJOL)

    It is seen that the electron temperature increases from 5.8 × 102 oK to 7.83 × 104 oK as the pd is reduced from 130mm Hg × mm to 60 mm Hg × mm for argon. The electron densities increases from 2.8 × 1011/cm3 to 3.2 × 1011 /cm3 for the same variation of pds. For air the electron temperature increases from 3.6 × 104 oK to ...

  4. The approximate determination of the critical temperature of a liquid by measuring surface tension versus the temperature

    International Nuclear Information System (INIS)

    Maroto, J A; Nieves, F J de las; Quesada-Perez, M

    2004-01-01

    A classical experience in a physics student laboratory is to determine the surface tension of a liquid versus the temperature and to check the linear appearance of the obtained graph. In this work we show a simple method to estimate the critical temperature of three liquids by using experimental data of surface tension at different temperatures. By a logarithm fitting between surface tension and temperature, the critical temperature can be determined and compared with data from the literature. For two liquids (butanol and nitrobenzene) the comparison is acceptable but the differences are too high for the third liquid (water). By discussing the results it seems to be clear that the difference between the critical temperature of the liquid and the maximum temperature of the surface tension measurements is the determining factor in obtaining acceptable results. From this study it is possible to obtain more information on the liquid characteristics from surface tension measurements that are currently carried out in a student laboratory. Besides, in this paper it is shown how to select the most suitable liquids which provide both acceptable values for the critical temperature and measurements of the surface tension at moderate temperatures. The complementary use of numerical methods permits us to offer a complete experience for the students with a simple laboratory experiment which we recommend for physics students in advanced university courses

  5. Flare plasma density determination using observed temperature profiles

    International Nuclear Information System (INIS)

    Garcia, H.A.

    1986-01-01

    Observed electron temperature variations derived from flux intensity ratios of whole-disk continuum soft X-ray spectra recorded by GOES satellites are presently subjected to an analysis that is based on the nonequilibrium energy balance equation in order to obtain the physical properties of a large solar flare from onset through the gradual phase. A self-similar formalism which reduces the nonlinear, second-order PDE in length and time to a more tractable, nonlinear, first-order Ricatti equation is invoked. Plasma density is the principal unknown variable contained in the Ricatti equation, which also contains first-order time derivatives and first- and second-order spatial derivatives of temperature. This methodology is presently applied to the moderate size flare of January 28, 1982, for which a density profile is deduced under various parametric conditions. 37 references

  6. Determination of the temperature dependence of tungsten erosion

    International Nuclear Information System (INIS)

    Maier, H.; Greuner, H.; Toussaint, U. von; Balden, M.; Böswirth, B.; Elgeti, S.

    2015-01-01

    We present the results of erosion measurements on actively cooled tungsten samples at quasi-constant surface temperature conditions performed in the high heat flux facility GLADIS. The samples were exposed to a H beam at a central power density of 10 MW/m 2 up to a fluence of 10 26 m −2 . We observe a weak temperature dependence of the erosion yield. The data are compared with similar data obtained from loading with a H beam with He admixture. Both datasets are analysed in a probabilistic approach. We obtain activation energies of 0.04 eV and 0.06 eV for the cases with and without He, respectively

  7. Spectroscopic determination of temperatures in plasmas generated by arc torches

    Czech Academy of Sciences Publication Activity Database

    Mašláni, Alan; Sember, Viktor; Hrabovský, Milan

    2017-01-01

    Roč. 133, July (2017), s. 14-20 ISSN 0584-8547 R&D Projects: GA ČR(CZ) GA15-19444S Institutional support: RVO:61389021 Keywords : Arc plasma torch * Optical emission spectroscopy * Temperature * Boltzmann plot Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 3.241, year: 2016

  8. DETERMINATION OF THE TEMPERATURE DISTRIBUTION THE PERFORATED FINS UNDER

    Directory of Open Access Journals (Sweden)

    Aziz7 M. Mhamuad

    2015-02-01

    Full Text Available This work treats the problem of heat transfer for perforated fins under natural convection. The temperature distribution is examined for an array of rectangular fins (15 fins with uniform cross-sectional area (100x270 mm embedded with various vertical body perforations that extend through the fin thickness. The patterns of perforations include 18 circular perforations (holes. Experiments were carried out in an experimental facility that was specifically design and constructed for this purpose. The heat transfer rate and the coefficient of heat transfer increases with perforation diameter increased. 

  9. Determination of sulfonamides and trimethoprim using high temperature HPLC with simultaneous temperature and solvent gradient.

    Science.gov (United States)

    Giegold, Sascha; Teutenberg, Thorsten; Tuerk, Jochen; Kiffmeyer, Thekla; Wenclawiak, Bernd

    2008-10-01

    A fast HPLC method for the analysis of eight selected sulfonamides (SA) and trimethoprim has been developed with the use of high temperature HPLC. The separation could be achieved in less than 1.5 min on a 50 mm sub 2 microm column with simultaneous solvent and temperature gradient programming. Due to the lower viscosity of the mobile phase and the increased mass transfer at higher temperatures, the separation could be performed on a conventional HPLC system obtaining peak widths at half height between 0.6 and 1.3 s.

  10. Experimental determination of the temperature dependence of metallic work functions at low temperatures. Progress report

    International Nuclear Information System (INIS)

    Pipes, P.B.

    1977-01-01

    Progress made under ERDA Contract No. EY-76-S-02-2314.002 is described. Efforts to gain theoretical insight into the temperature dependence of the contact potential of Nb near the superconducting transition have only been qualitatively successful. Preliminary measurements of adsorbed 4 He gas on the temperature dependence of the contact potentials of metals were performed and compared with a previously developed theory

  11. Cotton fiber quality determined by fruit position, temperature and management

    OpenAIRE

    Wang, X.; Evers, J.B.; Zhang, L.; Mao, L.; Pan, X.; Li, Z.

    2013-01-01

    CottonXL is a tool to explore cotton fiber quality in relation to fruit position, to improve cotton quality by optimizing cotton plant structure, as well as to help farmers understand how the structure of the cotton plant determines crop growth and quality.

  12. Method for determining waveguide temperature for acoustic transceiver used in a gas turbine engine

    Science.gov (United States)

    DeSilva, Upul P.; Claussen, Heiko; Ragunathan, Karthik

    2018-04-17

    A method for determining waveguide temperature for at least one waveguide of a transceiver utilized for generating a temperature map. The transceiver generates an acoustic signal that travels through a measurement space in a hot gas flow path defined by a wall such as in a combustor. The method includes calculating a total time of flight for the acoustic signal and subtracting a waveguide travel time from the total time of flight to obtain a measurement space travel time. A temperature map is calculated based on the measurement space travel time. An estimated wall temperature is obtained from the temperature map. An estimated waveguide temperature is then calculated based on the estimated wall temperature wherein the estimated waveguide temperature is determined without the use of a temperature sensing device.

  13. Uncertainty in temperature-based determination of time of death

    Science.gov (United States)

    Weiser, Martin; Erdmann, Bodo; Schenkl, Sebastian; Muggenthaler, Holger; Hubig, Michael; Mall, Gita; Zachow, Stefan

    2018-03-01

    Temperature-based estimation of time of death (ToD) can be performed either with the help of simple phenomenological models of corpse cooling or with detailed mechanistic (thermodynamic) heat transfer models. The latter are much more complex, but allow a higher accuracy of ToD estimation as in principle all relevant cooling mechanisms can be taken into account. The potentially higher accuracy depends on the accuracy of tissue and environmental parameters as well as on the geometric resolution. We investigate the impact of parameter variations and geometry representation on the estimated ToD. For this, numerical simulation of analytic heat transport models is performed on a highly detailed 3D corpse model, that has been segmented and geometrically reconstructed from a computed tomography (CT) data set, differentiating various organs and tissue types. From that and prior information available on thermal parameters and their variability, we identify the most crucial parameters to measure or estimate, and obtain an a priori uncertainty quantification for the ToD.

  14. The determination of nuclear matter temperature and density

    International Nuclear Information System (INIS)

    Wolf, K.L.

    1981-01-01

    The purpose of this paper is to review some of the things we have learned about nuclear matter under extreme conditions during the past few years in relativistic heavy ion studies. High energy heavy-ion collisions provide a unique mechanism for exploring the dependence of the nuclear potential energy epsilon(rho,T) on the degree of compression and excitation, and may even show the existence of new phases of matter. Thus the determination of the nuclear equation of state remains the ultimate goal of many researchers in this field. (orig.)

  15. Design of large reheat steam turbines for U.K. and overseas markets

    International Nuclear Information System (INIS)

    Mitchell, J.M.

    1979-01-01

    Two prototype designs of large reheat steam turbines are described, together with the technical, economic and plant design aspects that have influenced their main features. Relevant service experience is outlined and details are given of the solutions adopted to overcome the relatively few problems that were encountered. The evolution of these designs to form the current range of adaptable, pre-engineered modular designs is presented and the main features of current machines are described. A brief account is given of likely future developments in large steam turbines. (author)

  16. Contamination prevention of superheaters and reheaters during initial startup and operation

    International Nuclear Information System (INIS)

    Gabrielli, F.; Sylvester, W.R.; Thimot, G.W.

    1976-01-01

    The general precautions that should be taken to minimize the potential for harmful contamination or oxygen corrosion of power plant superheaters and reheaters during the period from field storage through operation are discussed and summarized. Present boiler industry start-up and operating practices intended to minimize the introduction of solids to the superheater are, as proven by experience, adequate to avoid contamination-related problems. No basic changes to general industry practice are necessary. What is needed, however, is a continuing awareness of the potential for contamination-related problems so that in the specific application of these practices all likely sources of contamination will be considered

  17. Determination of surface temperatures in combustion environments using thermographic phosphors; Wandtemperaturmessungen in Verbrennungsumgebungen mithilfe thermographischer Phosphore

    Energy Technology Data Exchange (ETDEWEB)

    Bruebach, J.; Kissel, T. [TU Darmstadt (Germany). FG Energie- und Kraftwerkstechnik; Dreizler, A. [TU Darmstadt (Germany). FG Reaktive Stroemungen und Messtechnik

    2009-07-01

    A phosphor thermometry system was characterised with regard to all sources of systematic errors. Exemplary, the point measurement of a surface temperature and the determination of wall-normal temperature gradients within an optically accessible combustion chamber are outlined. Furthermore, the temporal temperature characteristic at the quartz ring of an optically accessible engine is presented. (orig.)

  18. Fast, Computer Supported Experimental Determination of Absolute Zero Temperature at School

    Science.gov (United States)

    Bogacz, Bogdan F.; Pedziwiatr, Antoni T.

    2014-01-01

    A simple and fast experimental method of determining absolute zero temperature is presented. Air gas thermometer coupled with pressure sensor and data acquisition system COACH is applied in a wide range of temperature. By constructing a pressure vs temperature plot for air under constant volume it is possible to obtain--by extrapolation to zero…

  19. Yolk-albumen testosterone in a lizard with temperature-dependent sex determination: relation with development.

    Science.gov (United States)

    Huang, Victoria; Bowden, Rachel M; Crews, David

    2013-06-01

    The leopard gecko (Eublepharis macularius) exhibits temperature-dependent sex determination as well as temperature-influenced polymorphisms. Research suggests that in oviparous reptiles with temperature-dependent sex determination, steroid hormones in the yolk might influence sex determination and sexual differentiation. From captive leopard geckos that were all from the same incubation temperature regime, we gathered freshly laid eggs, incubated them at one of two female-biased incubation temperatures (26 or 34°C), and measured testosterone content in the yolk-albumen at early or late development. No differences in the concentration of testosterone were detected in eggs from different incubation temperatures. We report testosterone concentrations in the yolk-albumen were higher in eggs of late development than early development at 26°C incubation temperatures, a finding opposite that reported in other TSD reptiles studied to date. Copyright © 2013. Published by Elsevier Inc.

  20. Method of determining coking temperature of coke. [Experimental method of determining final coking temperature using a small sample and calibration graph

    Energy Technology Data Exchange (ETDEWEB)

    Mel' nichuk, A.Yu.; Bondarenko, A.K.; Fialkov, B.S.; Khegay, L.U.; Khvan, L.A.; Muzyzhuk, V.D.; Zakharov, A.G.; Zelenskiy, V.P.

    1985-01-01

    The coking temperature of coke should be determined from the magnitude of the ionization current of the medium during heating (3/sup 0//min) of a coke sample (2 g, fraction < 0.2 mm) in an oxidation medium with air supply (1 1/min). The coking temperature is determined from the maximum magnitude of current using a graduated graph constructed during analysis of coke samples obtained with different final coking temperatures. The discrepancy between the established coking temperature and that defined from the proposed method is 8-19/sup 0/, and that defined from electrical resistance of coke is 26-43/sup 0/. In addition to high accuracy, this method reduces the time outlays for making the analysis.

  1. Temperature determines symbiont abundance in a multipartite bark beetle-fungus ectosymbiosis

    Science.gov (United States)

    D. L. Six; B. J. Bentz

    2007-01-01

    In this study, we report evidence that temperature plays a key role in determining the relative abundance of two mutualistic fungi associated with an economically and ecologically important bark beetle, Dendroctonus ponderosae. The symbiotic fungi possess different optimal temperature ranges. These differences determine which fungus is vectored by...

  2. Determination of Temperature Rise and Temperature Differentials of CEMII/B-V Cement for 20MPa Mass Concrete using Adiabatic Temperature Rise Data

    Science.gov (United States)

    Chee Siang, GO

    2017-07-01

    Experimental test was carried out to determine the temperature rise characteristics of Portland-Fly-Ash Cement (CEM II/B-V, 42.5N) of Blaine fineness 418.6m2/kg and 444.6m2/kg respectively for 20MPa mass concrete under adiabatic condition. The estimation on adiabatic temperature rise by way of CIRIA C660 method (Construction Industry Research & Information Information) was adopted to verify and validate the hot-box test results by simulating the heat generation curve of the concrete under semi-adiabatic condition. Test result found that Portland fly-ash cement has exhibited decrease in the peak value of temperature rise and maximum temperature rise rate. The result showed that the temperature development and distribution profile, which is directly contributed from the heat of hydration of cement with time, is affected by the insulation, initial placing temperature, geometry and size of concrete mass. The mock up data showing the measured temperature differential is significantly lower than the technical specifications 20°C temperature differential requirement and the 27.7°C limiting temperature differential for granite aggregate concrete as stipulated in BS8110-2: 1985. The concrete strength test result revealed that the 28 days cubes compressive strength was above the stipulated 20MPa characteristic strength at 90 days. The test demonstrated that with proper concrete mix design, the use of Portland flyash cement, combination of chilled water and flake ice, and good insulation is effective in reducing peak temperature rise, temperature differential, and lower adiabatic temperature rise for mass concrete pours. As far as the determined adiabatic temperature rise result was concern, the established result could be inferred for in-situ thermal properties of 20MPa mass concrete application, as the result could be repeatable on account of similar type of constituent materials and concrete mix design adopted for permanent works at project site.

  3. Determination of an instability temperature for alloys in the cooling gas of a high temperature reactor

    International Nuclear Information System (INIS)

    Grimmer, H.; Grman, D.; Krompholz, K.; Zimmermann, U.; Ullrich, G.

    1985-05-01

    High temperature alloys designed to be used for components in the primary circuit of a helium cooled high temperature nuclear reactor show massive CO production above a certain temperature, called the instability temperature T/sub i/, which increases with increasing partial pressure of CO in the cooling gas. At p/sub CO/ = 15 microbar, T/sub i/ lies between 900 and 950 degrees C for the four alloys under investigation: T/sub i/ is lowest for the iron base alloy Incoloy 800 H and increases for the nickel base alloys in the order Inconel 617, HDA 230 and Nimonic 86. Measurements of T/sub i/ made at 3 different laboratories were compared and shown to agree for p/sub CO/ 25 microbar, compatible with CO production by a reaction of Cr2O3 with carbides. Some measurements of T/sub i/ on HDA 230 and Nimonic 86 were performed in the course of simulated reactor disturbances. They showed that the oxide layer looses its protective properties above T/sub i/. A highlight of the examinations was the detection of eta-carbides (M6C) with unusual properties. M6C is the only type of carbide occuring in HDA 230. An eta-carbide with a lattice constant of 1088.8 pm had developed at the surface of Nimonic 86 during pre-oxidation before the disturbance simulation. Its composition is estimated at Ni3SiMo2C. Eta-carbides containing Si and especially eta-carbides with lattice constants as low as 1088.8 pm have been described only rarely until now. (author)

  4. Supersymmetric D-term inflation, reheating, and Affleck-Dine baryogenesis

    International Nuclear Information System (INIS)

    Kolda, C.; March-Russell, J.

    1999-01-01

    The phenomenology of supersymmetric models of inflation, where the inflationary vacuum energy is dominated by D terms of a U(1), is investigated. Particular attention is paid to the questions of how to arrange for sufficient e folds of inflation to occur, what kind of thermal history is expected after the end of inflation, and how to implement successful baryogenesis. Such models are argued to require a more restrictive symmetry structure than previously thought. In particular, it is nontrivial that the decays of the fields driving D inflation can reheat the Universe in such a way as to avoid the strong gravitino production constraints. We also show how the initial conditions for Affleck-Dine baryogenesis can arise in these models and that the simplest flat directions along which a baryon number is generated can often be ruled out by the constraints coming from a decoherence of the condensate in a hot environment. At the end, we find that successful reheating and baryogenesis can take place in a large subset of D-inflationary models. copyright 1999 The American Physical Society

  5. Stein industrie moisture separator reheaters in 900 MW and 1300 MW PWR units behaviour and feedback

    International Nuclear Information System (INIS)

    Guignard, S.; Gabrel, J.; Marceau, J.; Gauchet, J.P.

    1990-01-01

    Various metallurgical investigations were carried out with a view to making technological modifications to the Stein Industrie designed moisture separator reheaters of the 900 MW CP0/CP1 and 1300 MW P4/P'4 plant series. Dismantling and assessment of four reheater bundles from the CP0/CP1 plants revealed tube leaks at the bends and in the straight part of the bundle due chiefly to erosion-corrosion. In addition, thickness losses due to the same phenomenon were observed on the inner walls of the vessels and internal hardware in contact with wet steam. The assessments and inspections carried out in the field on the MSR bundles of the CP0 and CP1 plants confirmed the presence of erosion-corrosion, virtually stabilized to date, and revealed fouling of bends by sequestration of particles in the circuit with presence of some pitting. Fatigue cracking of the last support plate of certain MSRs of the CP0 series was also revealed. Adoption of finned tubes of 18% chrome ferritic stainless steel (Z 2 CT 18) for spare bundles and new MSRs, protection of vessels by austenitic and/or martensitic stainless steel internal hardware, modification of water conditioning in the steam-water circuit, and implementation of some technological modifications should guarantee the longterm resistance of the MSRs [fr

  6. Implementation of Fully Coupled Heat and Mass Transport Model to Determine Temperature and Moisture State at Elevated Temperatures

    DEFF Research Database (Denmark)

    Pecenko, R.; Hozjan, Tomaz; Svensson, Staffan

    2014-01-01

    The aim of this study is to present precise numerical formulation to determine temperature and moisture state of timber in the situation prior pyrolysis. The strong formulations needed for an accurate description of the physics are presented and discussed as well as their coupling terms. From...

  7. Determination of magnetic characteristics of nanoparticles by low-temperature calorimetry methods

    Energy Technology Data Exchange (ETDEWEB)

    Ugulava, A.; Toklikishvili, Z. [Department of Physics, I.Javakhishvili Tbilisi State University,I.Chavchavadze av. 3, 0179 Tbilisi, Georgia (United States); Chkhaidze, S., E-mail: simon.chkhaidze@tsu.ge [Department of Physics, I.Javakhishvili Tbilisi State University,I.Chavchavadze av. 3, 0179 Tbilisi, Georgia (United States); Kekutia, Sh. [V. Chavchanidze Institute of Cybernetics, at the Technical State University, S. Euli str. 5, 0186 Tbilisi, Georgia (United States)

    2017-05-15

    At low temperatures, the heat capacity of a superparamagnetic “ideal gas” determined by magnetic degrees of freedom can greatly exceed the lattice heat capacity. It is shown that in the presence of an external magnetic field, the temperature dependence of the magnetic part of the heat capacity has two maxima. The relations between the temperature at which these maxima are achieved, the magnetic moment of the nanoparticles and the magnetic anisotropy constant have been obtained. Measuring the heat capacity maxima temperatures by low-temperature calorimetry methods and using the obtained relations, we can obtain the numerical values both of the magnetic moment of nanoparticles and the magnetic anisotropy constants.

  8. Determination of the core temperature of a Li-ion cell during thermal runaway

    Science.gov (United States)

    Parhizi, M.; Ahmed, M. B.; Jain, A.

    2017-12-01

    Safety and performance of Li-ion cells is severely affected by thermal runaway where exothermic processes within the cell cause uncontrolled temperature rise, eventually leading to catastrophic failure. Most past experimental papers on thermal runaway only report surface temperature measurement, while the core temperature of the cell remains largely unknown. This paper presents an experimentally validated method based on thermal conduction analysis to determine the core temperature of a Li-ion cell during thermal runaway using surface temperature and chemical kinetics data. Experiments conducted on a thermal test cell show that core temperature computed using this method is in good agreement with independent thermocouple-based measurements in a wide range of experimental conditions. The validated method is used to predict core temperature as a function of time for several previously reported thermal runaway tests. In each case, the predicted peak core temperature is found to be several hundreds of degrees Celsius higher than the measured surface temperature. This shows that surface temperature alone is not sufficient for thermally characterizing the cell during thermal runaway. Besides providing key insights into the fundamental nature of thermal runaway, the ability to determine the core temperature shown here may lead to practical tools for characterizing and mitigating thermal runaway.

  9. Determining the field emitter temperature during laser irradiation in the pulsed laser atom probe

    International Nuclear Information System (INIS)

    Kellogg, G.L.

    1981-01-01

    Three methods are discussed for determining the field emitter temperature during laser irradiation in the recently developed Pulsed Laser Atom Probe. A procedure based on the reduction of the lattice evaporation field with increasing emitter temperature is found to be the most convenient and reliable method between 60 and 500 K. Calibration curves (plots of the evaporation field versus temperature) are presented for dc and pulsed field evaporation of W, Mo, and Rh. These results show directly the important influence of the evaporation rate on the temperature dependence of the evaporation field. The possibility of a temperature calibration based on the ionic charge state distribution of field evaporated lattice atoms is also discussed. The shift in the charge state distributions which occurs when the emitter temperature is increased and the applied field strength is decreased at a constant rate of evaporation is shown to be due to the changing field and not the changing temperature. Nevertheless, the emitter temperature can be deduced from the charge state distribution for a specified evaporation rate. Charge state distributions as a function of field strength and temperature are presented for the same three materials. Finally, a preliminary experiment is reported which shows that the emitter temperature can be determined from field ion microscope observations of single atom surface diffusion over low index crystal planes. This last calibration procedure is shown to be very useful at higher temperatures (>600 K) where the other two methods become unreliable

  10. Determination of plant growth rate and growth temperature range from measurement of physiological parameters

    Science.gov (United States)

    R. S. Criddle; B. N. Smith; L. D. Hansen; J. N. Church

    2001-01-01

    Many factors influence species range and diversity, but temperature and temperature variability are always major global determinants, irrespective of local constraints. On a global scale, the ranges of many taxa have been observed to increase and their diversity decrease with increasing latitude. On a local scale, gradients in species distribution are observable with...

  11. Temperature dependence of the cosphi conductance in Josephson tunnel junctions determined from plasma resonance experiments

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig; Sørensen, O. H.; Mygind, Jesper

    1978-01-01

    The microwave response at 9 GHz of Sn-O-Sn tunnel-junction current biased at zero dc voltage has been measured just below the critical temperature Tc of the Sn films. The temperature dependence of the cosφ conductance is determined from the resonant response at the junction plasma frequency fp...

  12. Twin solution calorimeter determines heats of formation of alloys at high temperatures

    Science.gov (United States)

    Darby, J. B., Jr.; Kleb, R.; Kleppa, O. J.

    1968-01-01

    Calvert-type, twin liquid metal solution calorimeter determines the heats of formation of transition metal alloys at high temperatures. The twin differential calorimeter measures the small heat effects generated over extended periods of time, has maximum operating temperature of 1073 degrees K and an automatic data recording system.

  13. Processes subject to integrated pollution control. Combustion processes: reheat and heat treatment furnaces 50 MW(th) and over

    International Nuclear Information System (INIS)

    1995-01-01

    This document, part of a series offering guidance on pollution control regulations issued by Her Majesty's Inspectorate of Pollution, focuses on combustion processes involved with reheat and heat treatment furnaces of 50 MW (th) and over. Techniques for controlling releases into air, water and to land are detailed as are the various pollution monitoring strategies. (UK)

  14. Temperature determination from a real plasma from line self-reversal

    International Nuclear Information System (INIS)

    Salakhov, M.K.; Fishman, I.S.

    1981-01-01

    The coefficient Z = M/sub infinity/Y/sub infinity/ is determined on the basis of the actual structure of a plasma (the M/sub infinity/ and Y/sub infinity/ coefficients in Bartels's theory). The absorption and emission spectra are utilized as recorded in a transverse section of the plasma, which are used in determining the actual course of the atomic concentration and the half-width of the thin-layer line. An iterative scheme is set up for determining the temperature. A mathematical experiment has been performed and the temperature distribution has been determined in the plasma of a low-voltage pulsed discharge

  15. Space-based gravitational-wave detectors can determine the thermal history of the early Universe

    International Nuclear Information System (INIS)

    Nakayama, Kazunori; Saito, Shun; Suwa, Yudai; Yokoyama, Jun'ichi

    2008-01-01

    It is shown that space-based gravitational-wave detectors such as DECIGO and/or the Big Bang Observer will provide us with invaluable information on the cosmic thermal history after inflation, and they will be able to determine the reheat temperature T R provided that it lies in the range preferred by the cosmological gravitino problem, T R ∼10 5-9 GeV. Therefore it is strongly desired that they will be put into practice as soon as possible

  16. Power and efficiency in a regenerative gas-turbine cycle with multiple reheating and intercooling stages

    Science.gov (United States)

    Calvo Hernández, A.; Roco, J. M. M.; Medina, A.

    1996-06-01

    Using an improved Brayton cycle as a model, a general analysis accounting for the efficiency and net power output of a gas-turbine power plant with multiple reheating and intercooling stages is presented. This analysis provides a general theoretical tool for the selection of the optimal operating conditions of the heat engine in terms of the compressor and turbine isentropic efficiencies and of the heat exchanger efficiency. Explicit results for the efficiency, net power output, optimized pressure ratios, maximum efficiency, maximum power, efficiency at maximum power, and power at maximum efficiency are given. Among others, the familiar results of the Brayton cycle (one compressor and one turbine) and of the corresponding Ericsson cycle (infinite compressors and infinite turbines) are obtained as particular cases.

  17. Flow-induced vibration and fretting-wear damage in a moisture separator reheater

    International Nuclear Information System (INIS)

    Pettigrew, M.J.; Taylor, C.E.; Fisher, N.J.

    1996-01-01

    Tube failures due to excessive flow-induced vibration were experienced in the tube bundles of moisture separator reheaters in a BWR nuclear station. This paper presents the results of a root cause analysis and covers recommendations for continued operation and for replacement tube bundles. The following tasks are discussed: tube failure analysis; flow velocity distribution calculations; flow-induced vibration analysis with particular emphasis on finned-tubes; fretting-wear testing of a tube and tube-support material combination under simulated operating conditions; field measurements of flow-induced vibration; and development of vibration specifications for replacement tube bundles. The effect of transient operating conditions and of other operational changes such as tube fouling were considered in the analysis. This paper outlines a typical field problem and illustrates the application of flow-induced vibration technology for the solution of a practical problem

  18. Reheating and dangerous relics in pre-big-bang string cosmology

    International Nuclear Information System (INIS)

    Buonanno, Alessandra; Lemoine, Martin; Olive, Keith A.

    2000-01-01

    We discuss the mechanism of reheating in pre-big-bang string cosmology and we calculate the amount of moduli and gravitinos produced gravitationally and in scattering processes of the thermal bath. We find that this abundance always exceeds the limits imposed by big-bang nucleosynthesis, and significant entropy production is required. The exact amount of entropy needed depends on the details of the high curvature phase between the dilaton-driven inflationary era and the radiation era. We show that the domination and decay of the zero-mode of a modulus field, which could well be the dilaton, or of axions, suffices to dilute moduli and gravitinos. In this context, baryogenesis can be accommodated in a simple way via the Affleck-Dine mechanism and in some cases the Affleck-Dine condensate could provide both the source of entropy and the baryon asymmetry

  19. Automatic Generation Control Study in Two Area Reheat Thermal Power System

    Science.gov (United States)

    Pritam, Anita; Sahu, Sibakanta; Rout, Sushil Dev; Ganthia, Sibani; Prasad Ganthia, Bibhu

    2017-08-01

    Due to industrial pollution our living environment destroyed. An electric grid system has may vital equipment like generator, motor, transformers and loads. There is always be an imbalance between sending end and receiving end system which cause system unstable. So this error and fault causing problem should be solved and corrected as soon as possible else it creates faults and system error and fall of efficiency of the whole power system. The main problem developed from this fault is deviation of frequency cause instability to the power system and may cause permanent damage to the system. Therefore this mechanism studied in this paper make the system stable and balance by regulating frequency at both sending and receiving end power system using automatic generation control using various controllers taking a two area reheat thermal power system into account.

  20. The creep life of superheater and reheater tubes under varying pressure conditions in operational boilers

    International Nuclear Information System (INIS)

    Mizen, D.C.; Plastow, B.

    1975-01-01

    The first of each manufacturer's 500 MW boilers supplied to the CEGB (Central Electricity Generating Board) have been subjected to an extensive programme of tests for performance optimization and safe operation. Around 250 thermocouples on superheater and reheater tubes have in each case been monitored as part of the exercise. The readings are corrected and used to compute creep rupture damage based on internationally agreed stress rupture data and a simple cumulative damage concept. Comparison of the design creep rupture life and the cumulative life consumed has in several applications been invaluable in influencing operating procedures and arranging tube modifications or replacements, so that loss of generation by creep rupture failure is minimized. (author)

  1. Observational signatures of the parametric amplification of gravitational waves during reheating after inflation

    Science.gov (United States)

    Kuroyanagi, Sachiko; Lin, Chunshan; Sasaki, Misao; Tsujikawa, Shinji

    2018-01-01

    We study the evolution of gravitational waves (GWs) during and after inflation as well as the resulting observational consequences in a Lorentz-violating massive gravity theory with one scalar (inflaton) and two tensor degrees of freedom. We consider two explicit examples of the tensor mass mg that depends either on the inflaton field ϕ or on its time derivative ϕ ˙, both of which lead to parametric excitations of GWs during reheating after inflation. The first example is Starobinsky's R2 inflation model with a ϕ -dependent mg, and the second is a low energy-scale inflation model with a ϕ ˙-dependent mg. We compute the energy density spectrum ΩGW(k ) today of the GW background. In the Starobinsky's model, we show that the GWs can be amplified up to the detectable ranges of both cosmic microwave background and DECi-hertz Interferometer Gravitational wave Observatory, but the bound from the big bang nucleosynthesis is quite tight to limit the growth. In low-scale inflation with a fast transition to the reheating stage driven by the potential V (ϕ )=M2ϕ2/2 around ϕ ≈Mpl (where Mpl is the reduced Planck mass), we find that the peak position of ΩGW(k ) induced by the parametric resonance can reach the sensitivity region of advanced LIGO for the Hubble parameter of order 1 GeV at the end of inflation. Thus, our massive gravity scenario offers exciting possibilities for probing the physics of primordial GWs at various different frequencies.

  2. Zone modelling of the thermal performances of a large-scale bloom reheating furnace

    International Nuclear Information System (INIS)

    Tan, Chee-Keong; Jenkins, Joana; Ward, John; Broughton, Jonathan; Heeley, Andy

    2013-01-01

    This paper describes the development and comparison of a two- (2D) and three-dimensional (3D) mathematical models, based on the zone method of radiation analysis, to simulate the thermal performances of a large bloom reheating furnace. The modelling approach adopted in the current paper differs from previous work since it takes into account the net radiation interchanges between the top and bottom firing sections of the furnace and also allows for enthalpy exchange due to the flows of combustion products between these sections. The models were initially validated at two different furnace throughput rates using experimental and plant's model data supplied by Tata Steel. The results to-date demonstrated that the model predictions are in good agreement with measured heating profiles of the blooms encountered in the actual furnace. It was also found no significant differences between the predictions from the 2D and 3D models. Following the validation, the 2D model was then used to assess the impact of the furnace responses to changing throughput rate. It was found that the potential furnace response to changing throughput rate influences the settling time of the furnace to the next steady state operation. Overall the current work demonstrates the feasibility and practicality of zone modelling and its potential for incorporation into a model based furnace control system. - Highlights: ► 2D and 3D zone models of large-scale bloom reheating furnace. ► The models were validated with experimental and plant model data. ► Examine the transient furnace response to changing the furnace throughput rates. ► No significant differences found between the predictions from the 2D and 3D models.

  3. Preparation of 147Pm metal and the determination of the melting point and phase transformation temperatures

    International Nuclear Information System (INIS)

    Angelini, P.; Adair, H.L.

    1976-07-01

    The promethium metal used in the determination of the melting point and phase transformation temperatures was prepared by reduction of promethium oxide with thorium metal at 1600 0 C and distilling the promethium metal into a quartz dome. The melting point and phase transformation temperatures of promethium metal were found to be 1042 +- 5 0 C and 890 +- 5 0 C, respectively. The ratio for the heat of the high-temperature transformation to the heat of fusion was determined to be 0.415

  4. Determining of electron temperature profile on the cross section of a Tokamak, using ECE technique

    Directory of Open Access Journals (Sweden)

    M. Hosseinpour

    2007-06-01

    Full Text Available  In this paper we have used plasma electron cyclotron emissions at the second harmonic frequency of extraordinary mode to determine the temperature profile of the plasma produced in IR-T1 Tokamak. The emissions obtained at different frequencies by a 5-channel heterodyne receiver, have been analyzed to determine the spatial variation of the electron temperature on the plasma cross section. The results have been also used to show the three-dimensional time evolution of the temperature profile during the period of confinement.

  5. The procedure for determining the residual life of high-temperature aggregates

    Science.gov (United States)

    Nikiforov, A. S.; Prihodko, E. V.; Kinzhibekova, A. K.; Karmanov, A. E.

    2018-01-01

    One of the main reasons for the withdrawal of high-temperature aggregates for repairs is the destruction of enclosing structures due to the occurrence of temperature stresses. A wide range of refractory materials used, a large number of product names, a difference in the operation of even the same aggregates makes it impossible to apply general principles for determining the residual resource of high-temperature aggregates, which is based, as a rule, on the determination of temperature stresses. In the article there is suggested a technique based on the method of simulation modeling, allowing to estimate the remaining resource and reliability of the operating equipment. There are given data on the calculation of these indicators for a 25-ton steel-casting ladle. The values obtained make it possible to evaluate the rationality of the further operation of the high-temperature unit by the condition of reliability of the enclosing structures.

  6. Determination of Material Properties Near the Glass Transition Temperature for an Isogrid Boom

    Science.gov (United States)

    Blandino, Joseph R.; Woods-Vedeler, Jessica A. (Technical Monitor)

    2002-01-01

    Experiments were performed and results obtained to determine the temperature dependence of the modulus of elasticity for a thermoplastic isogrid tube. The isogrid tube was subjected to axial tensile loads of 0-100 lbf and strain was measured at room and elevated temperatures of 100, 120, 140, 160, 180, 190, and 200 F. These were based on tube manufacturer specifying an incorrect glass transition temperature of 210 F. Two protocols were used. For the first protocol the tube was brought to temperature and a tensile test performed. The tube was allowed to cool between tests. For the second protocol the tube was ramped to the desired test temperature and held. A tensile test was performed and the tube temperature ramped to the next test temperature. The second protocol spanned the entire test range. The strain rate was constant at 0.008 in/min. Room temperature tests resulted in the determination of an average modulus of 2.34 x 106 Psi. The modulus decreased above 100 F. At 140 F the modulus had decreased by 7.26%. The two test protocols showed good agreement below 160 F. At this point the glass transition temperature had been exceeded. The two protocols were not repeated because the tube failed.

  7. Unified approach for determining the enthalpic fictive temperature of glasses with arbitrary thermal history

    DEFF Research Database (Denmark)

    Guo, Xiaoju; Potuzak, M.; Mauro, J. C.

    2011-01-01

    We propose a unified routine to determine the enthalpic fictive temperature of a glass with arbitrary thermal history under isobaric conditions. The technique is validated both experimentally and numerically using a novel approach for modeling of glass relaxation behavior. The technique is applic......We propose a unified routine to determine the enthalpic fictive temperature of a glass with arbitrary thermal history under isobaric conditions. The technique is validated both experimentally and numerically using a novel approach for modeling of glass relaxation behavior. The technique...... is applicable to glasses of any thermal history, as proved through a series of numerical simulations where the enthalpic fictive temperature is precisely known within the model. Also, we demonstrate that the enthalpic fictive temperature of a glass can be determined at any calorimetric scan rate in excellent...

  8. Investigation on the crystallography of the transformation products of reverted austenite in intercritically reheated coarse grained heat affected zone

    International Nuclear Information System (INIS)

    You, Yang; Shang, Chengjia; Chen, Liang; Subramanian, Sundaresa

    2013-01-01

    Highlights: ► Area of reverted austenite is traced out by crystallographic information. ► Bainite and martensite regions were confirmed within it. ► The martensite region is considered as the blocky MA particles. ► Martensite region has high deformation to initiate fracture. ► More uniform transformation of the reverted austenite is good for toughness. -- Abstract: In present study the intercritically reheated coarse grained heat affected zone (ICCGHAZ) showing the worst impact toughness in the heat affected zone of multi-pass welding was simulated by Gleeble-1500, and its microstructure was investigated in detail by means of scanning electron microscope (SEM) and electron backscattering diffraction (EBSD). With the crystallographic information from EBSD scanning the area of a single reverted austenite grain which formed during the thermal cycles of second pass simulation was traced out. Within it two regions with different characteristic both in morphology and crystallography were found out, showing an un-uniform transformation of the reverted austenite. The region I is a bainitic region containing larger bainitic ferrite grains, while the region II is made up of several clusters containing tiny grains. Based on the crystallographic information each cluster was determined as martensite island thereby should be considered as blocky Martensite/Austenite constituent (M/A), which is hard phase and harmful for toughness. Analysis on the level of deformation shows that the region II is much higher deformed than the region I, indicating there is high stress concentration within the region II. The possible influence of the region I and the region II on fracture is discussed under the early proposed M/A’s fracture-initiating mechanisms. It suggests that the main cause of the toughness reduction is the un-uniform transformation of the reverted austenite, and the toughness performance of the ICCGHAZ could be improved if the transformation of the reverted

  9. Temperature-dependent sex determination in the leopard gecko, Eublepharis macularius.

    Science.gov (United States)

    Viets, B E; Tousignant, A; Ewert, M A; Nelson, C E; Crews, D

    1993-05-01

    The leopard gecko, Eublepharis macularius, has temperature-dependent sex determination (TSD). Previous reports have shown that females are produced predominantly at cool incubation temperatures and males are produced predominantly at warm incubation temperatures (Pattern Ib). We report here that incubation at even higher temperatures (34 and 35 degrees C) produces mostly females (Pattern II). The lethal maximum constant incubation temperature for this species appears to be just above 35 degrees C. Although a previous study indicated that females from a warm incubation temperature (32 degrees C) failed to lay eggs, we found that 12 of 14 mature females incubated at 32.5 degrees C, and 5 of 6 mature females incubated at 34 degrees C produced fertile eggs and viable hatchlings.

  10. The effect of clear sky radiation on crop surface temperature determined by thermal thermometry

    International Nuclear Information System (INIS)

    Svendsen, H.; Jensen, H.E.; Jensen, S.E.; Mogensen, V.O.

    1990-01-01

    By numerical integration of Planck's radiation function, a relationship between emitted radiation from a black body in the wavelength band 8–14 μm and the corresponding surface temperature was obtained. Using this relationship, an equation was developed relating the temperature error at different temperatures to the crop surface emissivity and clear sky radiation. It is concluded that the temperature error to be expected from neglect of clear sky radiation in the wavelength band 8–14μm in radiometric crop surface temperature determination is < 0.2 and 0.1 °C for crops with an emissivity > 0.96 and 0.98, respectively, for a leaf temperature range from 0 to 30°C

  11. Molecular mechanisms of temperature-dependent sex determination in the context of ecological developmental biology.

    Science.gov (United States)

    Matsumoto, Yuiko; Crews, David

    2012-05-06

    Temperature-dependent sex determination (TSD) is a prime example of phenotypic plasticity in that gonadal sex is determined by the temperature of the incubating egg. In the red-eared slider turtle (Trachemys scripta), the effect of temperature can be overridden by exogenous ligands, i.e., sex steroid hormones and steroid metabolism enzyme inhibitors, during the temperature-sensitive period (TSP) of development. Precisely how the physical signal of temperature is transduced into a biological signal that ultimately results in sex determination remains unknown. In this review, we discuss the sex determining pathway underlying TSD by focusing on two candidate sex determining genes, Forkhead box protein L2 (FoxL2) and Doublesex mab3- related transcription factor 1 (Dmrt1). They appear to be involved in transducing the environmental temperature signal into a biological signal that subsequently determines gonadal sex. FoxL2 and Dmrt1 exhibit gonad-typical patterns of expression in response to temperature during the TSP in the red-eared slider turtle. Further, the biologically active ligands regulate the expression of FoxL2 and Dmrt1 during development to modify gonad trajectory. The precise regulatory mechanisms of expression of these genes by temperature or exogenous ligands are not clear. However, the environment often influences developmental gene expression by altering the epigenetic status in regulatory regions. Here, we will discuss if the regulation of FoxL2 and Dmrt1 expression by environment is mediated through epigenetic mechanisms during development in species with TSD. Published by Elsevier Ireland Ltd.

  12. Segregating variation for temperature-dependent sex determination in a lizard.

    Science.gov (United States)

    Rhen, T; Schroeder, A; Sakata, J T; Huang, V; Crews, D

    2011-04-01

    Temperature-dependent sex determination (TSD) was first reported in 1966 in an African lizard. It has since been shown that TSD occurs in some fish, several lizards, tuataras, numerous turtles and all crocodilians. Extreme temperatures can also cause sex reversal in several amphibians and lizards with genotypic sex determination. Research in TSD species indicates that estrogen signaling is important for ovary development and that orthologs of mammalian genes have a function in gonad differentiation. Nevertheless, the mechanism that actually transduces temperature into a biological signal for ovary versus testis development is not known in any species. Classical genetics could be used to identify the loci underlying TSD, but only if there is segregating variation for TSD. Here, we use the 'animal model' to analyze inheritance of sexual phenotype in a 13-generation pedigree of captive leopard geckos, Eublepharis macularius, a TSD reptile. We directly show genetic variance and genotype-by-temperature interactions for sex determination. Additive genetic variation was significant at a temperature that produces a female-biased sex ratio (30°C), but not at a temperature that produces a male-biased sex ratio (32.5°C). Conversely, dominance variance was significant at the male-biased temperature (32.5°C), but not at the female-biased temperature (30°C). Non-genetic maternal effects on sex determination were negligible in comparison with additive genetic variance, dominance variance and the primary effect of temperature. These data show for the first time that there is segregating variation for TSD in a reptile and consequently that a quantitative trait locus analysis would be practicable for identifying the genes underlying TSD.

  13. Determination of the bulk melting temperature of nickel using Monte Carlo simulations: Inaccuracy of extrapolation from cluster melting temperatures

    Science.gov (United States)

    Los, J. H.; Pellenq, R. J. M.

    2010-02-01

    We have determined the bulk melting temperature Tm of nickel according to a recent interatomic interaction model via Monte Carlo simulation by two methods: extrapolation from cluster melting temperatures based on the Pavlov model (a variant of the Gibbs-Thompson model) and by calculation of the liquid and solid Gibbs free energies via thermodynamic integration. The result of the latter, which is the most reliable method, gives Tm=2010±35K , to be compared to the experimental value of 1726 K. The cluster extrapolation method, however, gives a 325° higher value of Tm=2335K . This remarkable result is shown to be due to a barrier for melting, which is associated with a nonwetting behavior.

  14. A heat transfer model for the analysis of transient heating of the slab in a direct-fired walking beam type reheating furnace

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Man Young [School of Mechanical and Aerospace Systems Engineering, Research Center of Industrial Technology, Chonbuk National University, 664-14 Duckjin-Dong, Duckjin-Gu, Jeonju, Chonbuk 561-756 (Korea)

    2007-09-15

    A mathematical heat transfer model for the prediction of heat flux on the slab surface and temperature distribution in the slab has been developed by considering the thermal radiation in the furnace chamber and transient heat conduction governing equations in the slab, respectively. The furnace is modeled as radiating medium with spatially varying temperature and constant absorption coefficient. The steel slabs are moved on the next fixed beam by the walking beam after being heated up through the non-firing, charging, preheating, heating, and soaking zones in the furnace. Radiative heat flux calculated from the radiative heat exchange within the furnace modeled using the FVM by considering the effect of furnace wall, slab, and combustion gases is introduced as the boundary condition of the transient conduction equation of the slab. Heat transfer characteristics and temperature behavior of the slab is investigated by changing such parameters as absorption coefficient and emissivity of the slab. Comparison with the experimental work show that the present heat transfer model works well for the prediction of thermal behavior of the slab in the reheating furnace. (author)

  15. Determination of the glass transition temperature: methods correlation and structural heterogeneity

    OpenAIRE

    Hutchinson, John M.

    2009-01-01

    The definition of the glass transition temperature, Tg, is recalled and its experimental determination by various techniques is reviewed. The diversity of values of Tg obtained by the different methods is discussed, with particular attention being paid to Differential Scanning Calorimetry (DSC) and to dynamic techniques such as Dynamic Mechanical Thermal Analysis (DMTA) and Temperature Modulated DSC (TMDSC). This last technique, TMDSC, in particular, is considered in respect of ways in which ...

  16. Performance analysis of Arithmetic Mean method in determining peak junction temperature of semiconductor device

    Directory of Open Access Journals (Sweden)

    Mohana Sundaram Muthuvalu

    2015-12-01

    Full Text Available High reliability users of microelectronic devices have been derating junction temperature and other critical stress parameters to improve device reliability and extend operating life. The reliability of a semiconductor is determined by junction temperature. This paper gives a useful analysis on mathematical approach which can be implemented to predict temperature of a silicon die. The problem could be modeled as heat conduction equation. In this study, numerical approach based on implicit scheme and Arithmetic Mean (AM iterative method will be applied to solve the governing heat conduction equation. Numerical results are also included in order to assert the effectiveness of the proposed technique.

  17. FaceSheet Push-off Tests to Determine Composite Sandwich Toughness at Cryogenic Temperatures

    Science.gov (United States)

    Gates, Thomas S.; Herring, Helen M.

    2001-01-01

    A new novel test method, associated analysis, and experimental procedures are developed to investigate the toughness of the facesheet-to-core interface of a sandwich material at cryogenic temperatures. The test method is designed to simulate the failure mode associated with facesheet debonding from high levels of gas pressure in the sandwich core. The effects of specimen orientation are considered, and the results of toughness measurements are presented. Comparisons are made between room and liquid nitrogen (-196 C) test temperatures. It was determined that the test method is insensitive to specimen facesheet orientation and strain energy release rate increases with a decrease in the test temperature.

  18. The airglow layer emission altitude cannot be determined unambiguously from temperature comparison with lidars

    Science.gov (United States)

    Dunker, Tim

    2018-05-01

    I investigate the nightly mean emission height and width of the OH* (3-1) layer by comparing nightly mean temperatures measured by the ground-based spectrometer GRIPS 9 and the Na lidar at ALOMAR. The data set contains 42 coincident measurements taken between November 2010 and February 2014, when GRIPS 9 was in operation at the ALOMAR observatory (69.3° N, 16.0° E) in northern Norway. To closely resemble the mean temperature measured by GRIPS 9, I weight each nightly mean temperature profile measured by the lidar using Gaussian distributions with 40 different centre altitudes and 40 different full widths at half maximum. In principle, one can thus determine the altitude and width of an airglow layer by finding the minimum temperature difference between the two instruments. On most nights, several combinations of centre altitude and width yield a temperature difference of ±2 K. The generally assumed altitude of 87 km and width of 8 km is never an unambiguous, good solution for any of the measurements. Even for a fixed width of ˜ 8.4 km, one can sometimes find several centre altitudes that yield equally good temperature agreement. Weighted temperatures measured by lidar are not suitable to unambiguously determine the emission height and width of an airglow layer. However, when actual altitude and width data are lacking, a comparison with lidars can provide an estimate of how representative a measured rotational temperature is of an assumed altitude and width. I found the rotational temperature to represent the temperature at the commonly assumed altitude of 87.4 km and width of 8.4 km to within ±16 K, on average. This is not a measurement uncertainty.

  19. Method for analyzing passive silicon carbide thermometry with a continuous dilatometer to determine irradiation temperature

    Science.gov (United States)

    Campbell, Anne A.; Porter, Wallace D.; Katoh, Yutai; Snead, Lance L.

    2016-03-01

    Silicon carbide is used as a passive post-irradiation temperature monitor because the irradiation defects will anneal out above the irradiation temperature. The irradiation temperature is determined by measuring a property change after isochronal annealing, i.e., lattice spacing, dimensions, electrical resistivity, thermal diffusivity, or bulk density. However, such methods are time-consuming since the steps involved must be performed in a serial manner. This work presents the use of thermal expansion from continuous dilatometry to calculate the SiC irradiation temperature, which is an automated process requiring minimal setup time. Analysis software was written that performs the calculations to obtain the irradiation temperature and removes possible user-introduced error while standardizing the analysis. This method has been compared to an electrical resistivity and isochronal annealing investigation, and the results revealed agreement of the calculated temperatures. These results show that dilatometry is a reliable and less time-intensive process for determining irradiation temperature from passive SiC thermometry.

  20. Determination of the glass-transition temperature of proteins from a viscometric approach.

    Science.gov (United States)

    Monkos, Karol

    2015-03-01

    All fully hydrated proteins undergo a distinct change in their dynamical properties at glass-transition temperature Tg. To determine indirectly this temperature for dry albumins, the viscosity measurements of aqueous solutions of human, equine, ovine, porcine and rabbit serum albumin have been conducted at a wide range of concentrations and at temperatures ranging from 278 K to 318 K. Viscosity-temperature dependence of the solutions is discussed on the basis of the three parameters equation resulting from Avramov's model. One of the parameter in the Avramov's equation is the glass-transition temperature. For all studied albumins, Tg of a solution monotonically increases with increasing concentration. The glass-transition temperature of a solution depends both on Tg for a dissolved dry protein Tg,p and water Tg,w. To obtain Tg,p for each studied albumin the modified Gordon-Taylor equation was applied. This equation describes the dependence of Tg of a solution on concentration, and Tg,p and a parameter depending on the strength of the protein-solvent interaction are the fitting parameters. Thus determined the glass-transition temperature for the studied dry albumins is in the range (215.4-245.5)K. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. DETERMINING UNDISTURBED GROUND TEMPERATURE AS PART OF SHALLOW GEOTHERMAL RESOURCES ASSESSMENT

    Directory of Open Access Journals (Sweden)

    Tomislav Kurevija

    2010-12-01

    Full Text Available The undisturbed ground temperature is one of the key thermogeological parameters for the assessment and utilization of shallow geothermal resources. Geothermal energy is the type of energy which is stored in the ground where solar radiation has no effect. The depth at which the undisturbed ground temperature occurs, independent of seasonal changes in the surface air temperature, is functionally determined by climate parameters and thermogeological properties. In deeper layers, the increase of ground temperature depends solely on geothermal gradient. Determining accurate values of undisturbed ground temperature and depth of occurrence is crucial for the correct sizing of a borehole heat exchanger as part of the ground-source heat pump system, which is considered the most efficient technology for utilising shallow geothermal resources. The purpose of this paper is to define three specific temperature regions, based on the measured ground temperature data collected from the main meteorological stations in Croatia. The three regions are: Northern Croatia, Adriatic region, and the regions of Lika and Gorski Kotar.

  2. Towards an accurate and precise determination of the solid-solid transition temperature of enantiotropic systems

    Energy Technology Data Exchange (ETDEWEB)

    Herman, Christelle, E-mail: christelle.herman@ulb.ac.b [Universite Libre de Bruxelles, Transfers, Interfaces and Processes Department, Chemical Engineering Unit, 50 Avenue Franklin D-Roosevelt, CP 165/67, 1050 Bruxelles (Belgium); Leyssens, Tom [Universite Catholique de Louvain, Institute of Condensed Matter and Nanosciences, 1 Place Louis Pasteur, 1348 Louvain-La-Neuve (Belgium); Vermylen, Valerie [UCB Pharma, 60 Allee de la Recherche, 1070 Braine l' Alleud (Belgium); Halloin, Veronique; Haut, Benoit [Universite Libre de Bruxelles, Transfers, Interfaces and Processes Department, Chemical Engineering Unit, 50 Avenue Franklin D-Roosevelt, CP 165/67, 1050 Bruxelles (Belgium)

    2011-05-15

    Research highlights: We test two methods to obtain the solid-solid transition temperature of Etiracetam system, showing two enantiotropically related polymorphs. The first method, based on a thermodynamic development, is sensitive to the correctness of the data required. The second method is an experimental study of the stability thermal range of each morph. We identify the nature of crystals in suspension at equilibrium through Raman analysis. The solid-solid transition temperature is found equal to 303.65 K {+-} 0.5 K. - Abstract: This paper presents two distinct methods for the determination of the solid-solid transition temperature (T{sub tr}) separating the temperature ranges of stability of two crystallographic forms, hereafter called morphs, of a same substance. The first method, based on thermodynamic calculations, consists in determining T{sub tr} as the temperature at which the Gibbs free energies of the two morphs are equal to each other. For this purpose, some thermodynamic characteristics of both morphs are required, such as the specific heat capacities, the melting temperatures and the melting enthalpies. These are obtained using the Differential Scanning Calorimetry (DSC). In the second method, T{sub tr} is determined directly by an experimental study of the temperature ranges of stability of each morph. The three main originalities of the method developed are (i) to prepare samples composed by an isomassic mixture of crystals of both morphs, (ii) to set them in a thermostated and agitated suspension, and (iii) to use an in situ Raman spectroscopic probe for the determination of the crystallographic form of the crystals in suspension at equilibrium. Both methods are applied to determine the solid-solid transition temperature of the enantiotropic system of Etiracetam, and both of its two crystallographic forms so far identified, named morph I and morph II. The first method is shown to be very sensitive to the experimental data obtained by DSC while

  3. Towards an accurate and precise determination of the solid-solid transition temperature of enantiotropic systems

    International Nuclear Information System (INIS)

    Herman, Christelle; Leyssens, Tom; Vermylen, Valerie; Halloin, Veronique; Haut, Benoit

    2011-01-01

    Research highlights: → We test two methods to obtain the solid-solid transition temperature of Etiracetam system, showing two enantiotropically related polymorphs. → The first method, based on a thermodynamic development, is sensitive to the correctness of the data required. → The second method is an experimental study of the stability thermal range of each morph. → We identify the nature of crystals in suspension at equilibrium through Raman analysis. → The solid-solid transition temperature is found equal to 303.65 K ± 0.5 K. - Abstract: This paper presents two distinct methods for the determination of the solid-solid transition temperature (T tr ) separating the temperature ranges of stability of two crystallographic forms, hereafter called morphs, of a same substance. The first method, based on thermodynamic calculations, consists in determining T tr as the temperature at which the Gibbs free energies of the two morphs are equal to each other. For this purpose, some thermodynamic characteristics of both morphs are required, such as the specific heat capacities, the melting temperatures and the melting enthalpies. These are obtained using the Differential Scanning Calorimetry (DSC). In the second method, T tr is determined directly by an experimental study of the temperature ranges of stability of each morph. The three main originalities of the method developed are (i) to prepare samples composed by an isomassic mixture of crystals of both morphs, (ii) to set them in a thermostated and agitated suspension, and (iii) to use an in situ Raman spectroscopic probe for the determination of the crystallographic form of the crystals in suspension at equilibrium. Both methods are applied to determine the solid-solid transition temperature of the enantiotropic system of Etiracetam, and both of its two crystallographic forms so far identified, named morph I and morph II. The first method is shown to be very sensitive to the experimental data obtained by DSC

  4. Determination of the temperature coefficients and the kinetic parameters for the HTTR safety analysis

    International Nuclear Information System (INIS)

    Tokuhara, K.; Nakata, T.; Murata, I.; Yamashita, K.; Shindo, R.

    1991-01-01

    This report describes the calculational methods which were employed to determine the temperature coefficients and the kinetic parameters for the safety analysis in the HTTR (High Temperature Engineering Test Reactor). The temperature coefficients (doppler, moderator temperature) and the kinetic parameters (prompt neutron life time; l, effective delayed neutron fraction; β eff) are important for the point model core dynamic analysis and should be evaluated properly. The temperature coefficients were calculated by the whole core model. Doppler coefficient was evaluated under the conditions of all control rods withdrawn and the uniform change of fuel temperature. The minimum and the maximum value of the evaluated doppler coefficients in a burnup cycle are -4.6x10 -5 and -1.5x10 -5 ΔK/K/deg. C respectively. The moderator temperature coefficient was evaluated under the conditions of all control rods withdrawn and the uniform change of moderator temperature. The minimum and the maximum value of the evaluated moderator temperature coefficients in a burnup cycle are -17.1x10 -5 and 0.99x10 -5 ΔK/K/deg. C respectively. In spite of positive moderator temperature coefficient, the power coefficient is always negative. Therefore the HTTR possesses inherent power-suppressing feed back characteristic in all operating condition. We surveyed the effects of the Xe existence, the control rods existence, the fuel temperature and the region in which the temperature was changed on the moderator temperature coefficients. The kinetic parameters were calculated by the perturbation method with the whole core model. The minimum and the maximum value of the evaluated effective delayed neutron fraction (β eff) are 0.0047 and 0.0065 respectively. These of the evaluated prompt neutron life time (l) are 0.67 and 0.78 ms respectively. We have surveyed the effects of the fuel depletion and the core power level on these parameters, and considered these effects on the kinetic parameters. From

  5. Research on weld cracking of TP321H stainless steel pipeline under elevated temperature

    International Nuclear Information System (INIS)

    Pan, Jian-hua; Fan, Zhi-cao; Zong, Ning-sheng

    2016-01-01

    The failure of pipeline which adopted material type TP321H austenitic stainless steel and occurred cracking after servicing at elevated temperature for less than two years had been investigated. The cracks were appeared repeatedly although they had been repaired for several times. The pipeline stress analysis was conducted to determine stress levels of cracking positions by finite element analysis software ABAQUS. The mechanical properties of base metals and welds including tensile and charpy impact tests were carried out. The test results showed that ductility of welds cut from the serviced pipeline was very poor. The microstructure investigations suggested that it was intergranular crack located in the HAZ near fusion line. It could be determined that it was reheat cracking based on some other works such as metallographic inspection, SEM, X-ray diffraction, etc. Welds analysis results showed that the welding of pipeline had not been in accord with right qualification of welding procedure leading to poor welding quality. The cracking reasons and preventive measures were discussed. Several suggestions were proposed to help extend service lifetime of the stainless steel pipeline under elevated temperature condition. - Highlights: • The pipeline is calculated by finite element analysis software ABAQUS. • Various tests are made, such as mechanical property, SEM, EDS, X-ray diffraction. • It is reheat cracking or stress relief cracking for the pipeline failure. • The stress levels of pipeline should be as low as possible. • The lifetime of pipeline would be shorten obviously due to poor weld quality.

  6. The effect of airflow on thermographically determined temperature of the distal forelimb of the horse.

    Science.gov (United States)

    Westermann, S; Stanek, C; Schramel, J P; Ion, A; Buchner, H H F

    2013-09-01

    Current literature suggests that thermographic imaging of horses should be performed in a draught-free room. However, studies on the effect of airflow on determined temperature have not been published. To investigate effects of airflow on thermographically determined temperature of horses' forelimbs; to assess the relationship of wind velocity, rectal temperature, ambient temperature and humidity. Thermographic images were obtained for the forelimbs of 6 horses in a draught-free room. Three replicates (R) with defined wind velocities (R1, 0.5-1.0 m/s; R2, 1.3-2.6 m/s; and R3, 3.0-4.0 m/s) were conducted. Each replicate consisted of a baseline image, a 15 min phase with the wind on and a 15 min phase with the wind off. We exposed only the right leg to airflow and determined the temperature by thermography with the wind on and wind off. Temperature differences between baseline and wind on, between wind on and wind off and between different wind velocities were analysed by a general linear model, Student's paired t test and ANOVA. After the onset of wind, the temperature on the right forelimb decreased within 1-3 min (by approximately 0.6°C at R1, 1.5°C at R2 and 2.1°C at R3). With the wind off, the temperature increased within 3 min (by approximately 1.2°C at R1, 1.7°C at R2 and 2.1°C at R3). With increasing wind velocity, the temperature differences between baseline and wind on and between wind on and wind off increased significantly. Barely noticeable wind velocities caused a decrease in thermographically determined temperatures of the forelimbs of the horse. Further research is required to assess the influence of airflow on other parts of the body and at different ambient temperatures, as well as the effect on horses with inflammatory lesions, especially of the distal limbs. It is essential for practitioners to perform thermography on horses in a draught-free environment in order to avoid false-positive or -negative diagnoses. © 2012 EVJ Ltd.

  7. DETERMINATION ANALYSIS OF TEMPERATURE REGIMES, FUNCTIONAL CHARACTERISTICS AND SLIDING CURVES OF A HYDRODYNAMIC CLUTCH

    Directory of Open Access Journals (Sweden)

    Božidar V Krstić

    2010-01-01

    Full Text Available Analysis of output quality of power transmitters is possible in position when characteristics are determined earlier. This is the reason why we focused on determination of these characteristics for a concrete power hydro-transmitter. This means that the investigation task primarily consisted of determination of functional characteristics, defining of the sliding curves and temperature regimes of a concrete hydrodynamic clutch. Results of velocity and pressure field investigations in the working space of this clutch, obtained by use of the same test setup, are the basis for determination and analysis of the functional characteristics, sliding curves and temperature regimes. In this work we also analyzed function of the hydrodynamic transmitter in assembly with an internal combustion engine, as well as a process of acceleration and deceleration of a vehicle with this assembly in it.

  8. High-Temperature Shape Memory Polymers

    Science.gov (United States)

    Yoonessi, Mitra; Weiss, Robert A.

    2012-01-01

    physical conformation changes when exposed to an external stimulus, such as a change in temperature. Such materials have a permanent shape, but can be reshaped above a critical temperature and fixed into a temporary shape when cooled under stress to below the critical temperature. When reheated above the critical temperature (Tc, also sometimes called the triggering or switching temperature), the materials revert to the permanent shape. The current innovation involves a chemically treated (sulfonated, carboxylated, phosphonated, or other polar function group), high-temperature, semicrystalline thermoplastic poly(ether ether ketone) (Tg .140 C, Tm = 340 C) mix containing organometallic complexes (Zn++, Li+, or other metal, ammonium, or phosphonium salts), or high-temperature ionic liquids (e.g. hexafluorosilicate salt with 1-propyl-3- methyl imidazolium, Tm = 210 C) to form a network where dipolar or ionic interactions between the polymer and the low-molecular-weight or inorganic compound forms a complex that provides a physical crosslink. Hereafter, these compounds will be referred to as "additives". The polymer is semicrystalline, and the high-melt-point crystals provide a temporary crosslink that acts as a permanent crosslink just so long as the melting temperature is not exceeded. In this example case, the melting point is .340 C, and the shape memory critical temperature is between 150 and 250 C. PEEK is an engineering thermoplastic with a high Young fs modulus, nominally 3.6 GPa. An important aspect of the invention is the control of the PEEK functionalization (in this example, the sulfonation degree), and the thermal properties (i.e. melting point) of the additive, which determines the switching temperature. Because the compound is thermoplastic, it can be formed into the "permanent" shape by conventional plastics processing operations. In addition, the compound may be covalently cross - linked after forming the permanent shape by S-PEEK by applying ionizing

  9. Surface temperature and surface heat flux determination of the inverse heat conduction problem for a slab

    International Nuclear Information System (INIS)

    Kuroyanagi, Toshiyuki

    1983-07-01

    Based on an idea that surface conditions should be a reflection of interior temperature and interior heat flux variation as inverse as interior conditions has been determined completely by the surface temperature and/on surface heat flux as boundary conditions, a method is presented for determining the surface temperature and the surface heat flux of a solid when the temperature and heat flux at an interior point are a prescribed function of time. The method is developed by the integration of Duhumels' integral which has unknown temperature or unknown heat flux in its integrand. Specific forms of surface condition determination are developed for a sample inverse problem: slab. Ducussing the effect of a degree of avairable informations at an interior point due to damped system and the effect of variation of surface conditions on those formulations, it is shown that those formulations are capable of representing the unknown surface conditions except for small time interval followed by discontinuous change of surface conditions. The small un-resolved time interval is demonstrated by a numerical example. An evaluation method of heat flux at an interior point, which is requested by those formulations, is discussed. (author)

  10. A new method for determining the Curie temperature using a dilatometer

    International Nuclear Information System (INIS)

    Verma, A; Sundararaman, M; Singh, J B; Nalawade, S A

    2010-01-01

    Dilatometry is a tool used for the study of dimensional changes in materials as a function of temperature and also to identify phase transformations including magnetic transformations. In this paper, we describe two new methods that can be employed in an inductively heated dilatometer to determine the Curie temperature in metallic ferromagnetic materials. These methods are based on the fundamental magnetic properties of materials such as hysteresis loss and anomalous thermal conductivity changes near the Curie point. These methods have been used to determine the Curie point in nickel, iron and Co–5 at% Ni alloy. The values obtained match well with those reported in the literature. The effects of the geometry of the specimen and of the push-rod material on the measurement sensitivity of the transition temperature have been discussed

  11. Determination of ice content in hardened concrete by low-temperature calorimetry

    DEFF Research Database (Denmark)

    Wu, Min; Johannesson, Björn; Geiker, Mette Rica

    2014-01-01

    Low-temperature calorimetry has been used to determine the ice content in concrete at different temperatures when exposed to low-temperature environments. However, the analysis of the ice content from the measured data of heat flow is not straightforward. In this study, two important factors...... influencing the ice content calculation are discussed. The importance of the baseline determination for the calculation of the ice content is realized. Two different methods of generating the baseline are discussed. First, the ‘J-baseline’ is discussed which is a recently proposed extrapolation method based...... the ‘J-baseline’ method and the ‘C-baseline’ method can be used to calculate the approximate baseline. The heat of fusion of the water confined in small pores is another important parameter to be considered in ice content calculation. This property must be carefully analyzed in order to accurately...

  12. THE MAXIMUM EFFECT OF DEEP LAKES ON TEMPERATURE PROFILES – DETERMINATION OF THE GEOTHERMAL GRADIENT

    Directory of Open Access Journals (Sweden)

    Eppelbaum L. V.

    2009-07-01

    Full Text Available Understanding the climate change processes on the basis of geothermal observations in boreholes is an important and at the same time high-intricate problem. Many non-climatic effects could cause changes in ground surface temperatures. In this study we investigate the effects of deep lakes on the borehole temperature profilesobserved within or in the vicinity of the lakes. We propose a method based on utilization of Laplace equation with nonuniform boundary conditions. The proposed method makes possible to estimate the maximum effect of deep lakes (here the term "deep lake" means that long term mean annual temperature of bottom sediments can beconsidered as a constant value on the borehole temperature profiles. This method also allows one to estimate an accuracy of the determination of the geothermal gradient.

  13. A role of neutral hydrogen in CHS plasmas with reheat and collapse and comparison with JIPP T-IIU tokamak plasmas

    International Nuclear Information System (INIS)

    Morita, S.; Yamada, H.; Iguchi, H.

    1992-09-01

    Results are described on NBI plasmas of the Compact Helical System (CHS). An increase in the stored energy, which is called plasma 'reheat', is observed with density peaking when gas puffing is turned off in the high density region. A plasma collapse with large increase in radiation loss occurs even in discharges whose Z eff values (typically, less than 2-3) do not show any increase when the gas puffing is continued. Both phenomena are basically explained by the edge electron temperature due to the difference in the amount of edge hydrogen neutrals. After turning off the gas puffing, the central electron density n e0 shows an increase of 80% and the density peaking factor (n e0 /n-bar e ) changes from 1.0 to 2.0, in typical cases, and a high inward velocity of the impurities appears (v = 20 m/s). The accumulation is studied in relation to the poloidal rotation and the edge temperature. These results are compared with results from plasmas with IOC- and H-modes in the JIPPT-IIU tokamak. (author)

  14. Structure determination of an integral membrane protein at room temperature from crystals in situ

    International Nuclear Information System (INIS)

    Axford, Danny; Foadi, James; Hu, Nien-Jen; Choudhury, Hassanul Ghani; Iwata, So; Beis, Konstantinos; Evans, Gwyndaf; Alguel, Yilmaz

    2015-01-01

    The X-ray structure determination of an integral membrane protein using synchrotron diffraction data measured in situ at room temperature is demonstrated. The structure determination of an integral membrane protein using synchrotron X-ray diffraction data collected at room temperature directly in vapour-diffusion crystallization plates (in situ) is demonstrated. Exposing the crystals in situ eliminates manual sample handling and, since it is performed at room temperature, removes the complication of cryoprotection and potential structural anomalies induced by sample cryocooling. Essential to the method is the ability to limit radiation damage by recording a small amount of data per sample from many samples and subsequently assembling the resulting data sets using specialized software. The validity of this procedure is established by the structure determination of Haemophilus influenza TehA at 2.3 Å resolution. The method presented offers an effective protocol for the fast and efficient determination of membrane-protein structures at room temperature using third-generation synchrotron beamlines

  15. A thermogravimetric method for accurate determination of thermodynamic quantities at high temperatures

    NARCIS (Netherlands)

    Verdonk, A.H.; Nedermeijer, J.; Laverman, J.W.

    1975-01-01

    A method for the determination of the change in enthalpy, entropy, and specific heat capacity for monovariant heterogenous equilibria is presented. These quantities are obtained indirectly by measuring the temperature dependence of equilibrium pressures. At a given pressure of the relevant gas the

  16. Climate risk assessment in museums : degradation risks determined from temperature and relative humidity data

    NARCIS (Netherlands)

    Martens, M.H.J.

    2012-01-01

    The main subject of this thesis is the determination of climate risks to objects in museums on the basis of measured and/or simulated temperature and relative humidity data. The focus is on the quantification of climate related risks for the preservation quality of indoor climate in Dutch museums.

  17. Structure determination of an integral membrane protein at room temperature from crystals in situ

    Energy Technology Data Exchange (ETDEWEB)

    Axford, Danny [Diamond Light Source, Harwell Science and Innovation Campus, Oxfordshire OX11 0DE (United Kingdom); Foadi, James [Diamond Light Source, Harwell Science and Innovation Campus, Oxfordshire OX11 0DE (United Kingdom); Imperial College London, London SW7 2AZ (United Kingdom); Hu, Nien-Jen; Choudhury, Hassanul Ghani [Diamond Light Source, Harwell Science and Innovation Campus, Oxfordshire OX11 0DE (United Kingdom); Imperial College London, London SW7 2AZ (United Kingdom); Rutherford Appleton Laboratory, Oxfordshire OX11 0FA (United Kingdom); Iwata, So [Diamond Light Source, Harwell Science and Innovation Campus, Oxfordshire OX11 0DE (United Kingdom); Diamond Light Source, Harwell Science and Innovation Campus, Oxfordshire OX11 0DE (United Kingdom); Imperial College London, London SW7 2AZ (United Kingdom); Rutherford Appleton Laboratory, Oxfordshire OX11 0FA (United Kingdom); Kyoto University, Kyoto 606-8501 (Japan); Beis, Konstantinos [Diamond Light Source, Harwell Science and Innovation Campus, Oxfordshire OX11 0DE (United Kingdom); Imperial College London, London SW7 2AZ (United Kingdom); Rutherford Appleton Laboratory, Oxfordshire OX11 0FA (United Kingdom); Evans, Gwyndaf, E-mail: gwyndaf.evans@diamond.ac.uk [Diamond Light Source, Harwell Science and Innovation Campus, Oxfordshire OX11 0DE (United Kingdom); Alguel, Yilmaz, E-mail: gwyndaf.evans@diamond.ac.uk [Diamond Light Source, Harwell Science and Innovation Campus, Oxfordshire OX11 0DE (United Kingdom); Imperial College London, London SW7 2AZ (United Kingdom); Rutherford Appleton Laboratory, Oxfordshire OX11 0FA (United Kingdom)

    2015-05-14

    The X-ray structure determination of an integral membrane protein using synchrotron diffraction data measured in situ at room temperature is demonstrated. The structure determination of an integral membrane protein using synchrotron X-ray diffraction data collected at room temperature directly in vapour-diffusion crystallization plates (in situ) is demonstrated. Exposing the crystals in situ eliminates manual sample handling and, since it is performed at room temperature, removes the complication of cryoprotection and potential structural anomalies induced by sample cryocooling. Essential to the method is the ability to limit radiation damage by recording a small amount of data per sample from many samples and subsequently assembling the resulting data sets using specialized software. The validity of this procedure is established by the structure determination of Haemophilus influenza TehA at 2.3 Å resolution. The method presented offers an effective protocol for the fast and efficient determination of membrane-protein structures at room temperature using third-generation synchrotron beamlines.

  18. Embryonic origin of mate choice in a lizard with temperature-dependent sex determination.

    Science.gov (United States)

    Putz, Oliver; Crews, David

    2006-01-01

    Individual differences in the adult sexual behavior of vertebrates are rooted in the fetal environment. In the leopard gecko (Eublepharis macularius), a species with temperature-dependent sex determination (TSD), hatchling sex ratios differ between incubation temperatures, as does sexuality in same-sex animals. This variation can primarily be ascribed to the temperature having direct organizing actions on the brain. Here we demonstrate that embryonic temperature can affect adult mate choice in the leopard gecko. Given the simultaneous choice between two females from different incubation temperatures (30.0 and 34.0 degrees C), males from one incubation temperature (30.0 degrees C) preferred the female from 34.0 degrees C, while males from another incubation temperature (32.5 degrees C) preferred the female from 30.0 degrees C. We suggest that this difference in mate choice is due to an environmental influence on brain development leading to differential perception of opposite-sex individuals. This previously unrecognized modulator of adult mate choice lends further support to the view that mate choice is best understood in the context of an individual's entire life-history. Thus, sexual selection results from a combination of the female's as well as the male's life history. Female attractiveness and male choice therefore are complementary. Copyright 2005 Wiley Periodicals, Inc.

  19. Temperature dependence of the cosphi conductance in Josephson tunnel junctions determined from plasma resonance experiments

    International Nuclear Information System (INIS)

    Pedersen, N.F.; Soerensen, O.H.; Mygind, J.

    1978-01-01

    The microwave response at 9 GHz of Sn-O-Sn tunnel-junction current biased at zero dc voltage has been measured just below the critical temperature T/sub c/ of the Sn films. The temperature dependence of the cosphi conductance is determined from the resonant response at the junction plasma frequency f/sub p/ as the temperature is decreased from T/sub c/. We used three different schemes for observation of the plasma oscillations: (a) second-harmonic generation (excitation at approx. 4.5 GHz, f/sub p/ approx. 4.5 GHz); (b) mixing (excitations at approx. 9 and approx. 18 GHz, f/sub p/ approx. 9 GHz); (c) parametric half-harmonic oscillation (excitation at approx. 18 GHz, f/sub p/ approx. 9 GHz). Measurements were possible in two temperature intervals; 0.994 or = T/T/sub c/ > or = 0.930, with the result that as the temperature was decreased the cosphi amplitude first increased from about zero to positive values and then at lower temperatures decreased approaching -1 at the lowest temperatures of the experiment

  20. Novel determination of surface temperature of lithium hydride hydrolysis using DRIFT spectroscopy

    International Nuclear Information System (INIS)

    Awbery, Roy P.; Tsang, S.C.

    2008-01-01

    Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy has been used to show how increasing temperature causes the hydroxyl band of LiOH to shift linearly and reversibly towards lower wavenumbers. The band shift with temperature was used to determine the surface temperature of LiH when exposed to water vapour at 158, 317, 793 and >1900 Pa (5%, 10%, 25% and >60% relative humidity), the exothermic hydrolysis reaction resulting in surface temperature increases of up to 50 deg. C. The rate of surface heating was found to increase slightly with increasing water vapour exposures up to 793 Pa, demonstrating that the LiH hydrolysis reaction rate was dependent upon the partial pressure of water vapour. The growth of surface LiOH appeared to significantly slow down further reaction until the water vapour exposure was increased beyond 1900 Pa, when formation of hydrated LiOH occurred. The effect of temperature on detectors was also investigated showing that baselines shifted towards higher intensities with increasing temperature when measured with a DTGS detector and towards lower intensities with an MCT detector, over the temperature range 25-450 deg. C

  1. Indirect Determination of the Thermodynamic Temperature of a Gold Fixed-Point Cell

    Science.gov (United States)

    Battuello, M.; Girard, F.; Florio, M.

    2010-09-01

    Since the value T 90(Au) was fixed on the ITS-90, some determinations of the thermodynamic temperature of the gold point have been performed which form, with other renormalized results of previous measurements by radiation thermometry, the basis for the current best estimates of ( T - T 90)Au = 39.9 mK as elaborated by the CCT-WG4. Such a value, even if consistent with the behavior of T - T 90 differences at lower temperatures, is quite influenced by the low values of T Au as determined with few radiometric measurements. At INRIM, an independent indirect determination of the thermodynamic temperature of gold was performed by means of a radiation thermometry approach. A fixed-point technique was used to realize approximated thermodynamic scales from the Zn point up to the Cu point. A Si-based standard radiation thermometer working at 900 nm and 950 nm was used. The low uncertainty presently associated to the thermodynamic temperature of fixed points and the accuracy of INRIM realizations, allowed scales with an uncertainty lower than 0.03 K in terms of the thermodynamic temperature to be realized. A fixed-point cell filled with gold, 99.999 % in purity, was measured, and its freezing temperature was determined by both interpolation and extrapolation. An average T Au = 1337.395 K was found with a combined standard uncertainty of 23 mK. Such a value is 25 mK higher than the presently available value as derived by the CCT-WG4 value of ( T - T 90)Au = 39.9 mK.

  2. A Novel Candidate Gene for Temperature-Dependent Sex Determination in the Common Snapping Turtle

    Science.gov (United States)

    Schroeder, Anthony L.; Metzger, Kelsey J.; Miller, Alexandra; Rhen, Turk

    2016-01-01

    Temperature-dependent sex determination (TSD) was described nearly 50 years ago. Researchers have since identified many genes that display differential expression at male- vs. female-producing temperatures. Yet, it is unclear whether these genes (1) are involved in sex determination per se, (2) are downstream effectors involved in differentiation of ovaries and testes, or (3) are thermo-sensitive but unrelated to gonad development. Here we present multiple lines of evidence linking CIRBP to sex determination in the snapping turtle, Chelydra serpentina. We demonstrate significant associations between a single nucleotide polymorphism (SNP) (c63A > C) in CIRBP, transcript levels in embryonic gonads during specification of gonad fate, and sex in hatchlings from a thermal regime that produces mixed sex ratios. The A allele was induced in embryos exposed to a female-producing temperature, while expression of the C allele did not differ between female- and male-producing temperatures. In accord with this pattern of temperature-dependent, allele-specific expression, AA homozygotes were more likely to develop ovaries than AC heterozygotes, which, in turn, were more likely to develop ovaries than CC homozygotes. Multiple regression using SNPs in CIRBP and adjacent loci suggests that c63A > C may be the causal variant or closely linked to it. Differences in CIRBP allele frequencies among turtles from northern Minnesota, southern Minnesota, and Texas reflect small and large-scale latitudinal differences in TSD pattern. Finally, analysis of CIRBP protein localization reveals that CIRBP is in a position to mediate temperature effects on the developing gonads. Together, these studies strongly suggest that CIRBP is involved in determining the fate of the bipotential gonad. PMID:26936926

  3. Two-Layer Linear MPC Approach Aimed at Walking Beam Billets Reheating Furnace Optimization

    Directory of Open Access Journals (Sweden)

    Silvia Maria Zanoli

    2017-01-01

    Full Text Available In this paper, the problem of the control and optimization of a walking beam billets reheating furnace located in an Italian steel plant is analyzed. An ad hoc Advanced Process Control framework has been developed, based on a two-layer linear Model Predictive Control architecture. This control block optimizes the steady and transient states of the considered process. Two main problems have been addressed. First, in order to manage all process conditions, a tailored module defines the process variables set to be included in the control problem. In particular, a unified approach for the selection on the control inputs to be used for control objectives related to the process outputs is guaranteed. The impact of the proposed method on the controller formulation is also detailed. Second, an innovative mathematical approach for stoichiometric ratios constraints handling has been proposed, together with their introduction in the controller optimization problems. The designed control system has been installed on a real plant, replacing operators’ mental model in the conduction of local PID controllers. After two years from the first startup, a strong energy efficiency improvement has been observed.

  4. Significance of reheat cracks to the integrity of pressure vessels for light-water reactors

    International Nuclear Information System (INIS)

    Canonico, D.A.

    1977-01-01

    Reheat cracks usually manifest themselves as macroscopic defects, which are centimeters long and deep, and are detectable by the usual nondestructive examination (NDE) procedures or as microscopic grain boundary decohesions (GBD) that are beyond the limit of detection by commercial NDE procedures. This report has concentrated on the significance of the microscopic cracks that may go undetected. The probability that GBD exist in the heat-affected zones (HAZ) of weldments of pressure vessel steels is high; particularly in SA 508 Class 2 weldments. A sample of the HAZ from the prolongation-weldment from the Heavy Section Steel Technology program Intermediate Test Vessel (ITV) No. 4 was examined by the Staatliche Materialprufungsanstalt (MPA). They reported GBD 5 mm (0.2 in.) long. This prompted an examination of the HAZ from the ITV vessel that had been tested to failure at 24 0 C (75 0 F). During testing, the region of the weld which contained the flaw that initiated the failure was strained up to 0.5%. A metallographic examination of this region of the weldment revealed GBD, but none of the size reported by the MPA. Further, there was no evidence that the GBD had extended as a consequence of the tests. Fracture toughness tests were made of the HAZ of welds from ITV-4. The electron-beam welding procedure, which permits more accurate siting of the crack, was used. Fracture toughness values in excess of 220 MPa root m (200 ksi root in.) were obtained at -18 0 C

  5. 13%Cr internal hardware cracks of 1300 MW moisture separator reheater

    International Nuclear Information System (INIS)

    Gauchet, J.P.; Chatelain, M.; Marceau, J.; Guignard, S.; Charbonnel, A.; Vandershaeghe, A.; Roguet, D.

    1994-01-01

    Degradations have been observed on fixing bearing pads of 13% Cr steel plates which protect against erosion-corrosion the inner part of vessels of 1300 MW moisture separator reheaters. These cracks are located between the parent metal sheet and the HAZ of the welds between 13% Cr steel plate and the 18/10 austenitic support washer which assure the fixation on the vessel. They were like an intergranular network and corresponded to a stress intergranular corrosion phenomenon under stream-water. This phenomenon is possible with a very local dechromisation of some 13% Cr grain boundaries which are sometimes enriched with aluminium coming from the parent metal of the steel plate. Two studies have been undertaken: - a mechanical analysis of the behaviour and loading stresses of fixing bearing pads in order to reduce the stress levels which reveal the cracks; - welding tests with different filler metals in order to remove the dechromised and aluminium enriched ares which ar potential corrosion zones. Another solutions for ''in service'' and future devices have been tested and are described. (authors). 9 figs

  6. Practical Considerations for Determination of Glass Transition Temperature of a Maximally Freeze Concentrated Solution.

    Science.gov (United States)

    Pansare, Swapnil K; Patel, Sajal Manubhai

    2016-08-01

    Glass transition temperature is a unique thermal characteristic of amorphous systems and is associated with changes in physical properties such as heat capacity, viscosity, electrical resistance, and molecular mobility. Glass transition temperature for amorphous solids is referred as (T g), whereas for maximally freeze concentrated solution, the notation is (T g'). This article is focused on the factors affecting determination of T g' for application to lyophilization process design and frozen storage stability. Also, this review provides a perspective on use of various types of solutes in protein formulation and their effect on T g'. Although various analytical techniques are used for determination of T g' based on the changes in physical properties associated with glass transition, the differential scanning calorimetry (DSC) is the most commonly used technique. In this article, an overview of DSC technique is provided along with brief discussion on the alternate analytical techniques for T g' determination. Additionally, challenges associated with T g' determination, using DSC for protein formulations, are discussed. The purpose of this review is to provide a practical industry perspective on determination of T g' for protein formulations as it relates to design and development of lyophilization process and/or for frozen storage; however, a comprehensive review of glass transition temperature (T g, T g'), in general, is outside the scope of this work.

  7. Short-Wave Near-Infrared Spectrometer for Alcohol Determination and Temperature Correction

    Directory of Open Access Journals (Sweden)

    Qingbo Fu

    2012-01-01

    Full Text Available A multichannel short-wave near-infrared (SW-NIR spectrometer module based on charge-coupled device (CCD detection was designed. The design relied on a tungsten lamp enhanced by light emitting diodes, a fixed grating monochromator and a linear CCD array. The main advantages were high optical resolution and an optimized signal-to-noise ratio (0.24 nm and 500, resp. in the whole wavelength range of 650 to 1100 nm. An application to alcohol determination using partial least squares calibration and the temperature correction was presented. It was found that the direct transfer method had significant systematic prediction errors due to temperature effect. Generalized least squares weighting (GLSW method was utilized for temperature correction. After recalibration, the RMSEP found for the 25°C model was 0.53% v/v and errors of the same order of magnitude were obtained at other temperatures (15, 35 and 40°C. And an 2 better than 0.99 was achieved for each validation set. The possibility and accuracy of using the miniature SW-NIR spectrometer and GLSW transfer calibration method for alcohol determination at different temperatures were proven. And the analysis procedure was simple and fast, allowing a strict control of alcohol content in the wine industry.

  8. A Simple Experiment to Determine the Characteristics of an NTC Thermistor for Low-Temperature Measurement Applications

    Science.gov (United States)

    Mawire, A.

    2012-01-01

    A simple low-cost experiment for undergraduate students to determine the characteristics of a negative temperature coefficient of resistance thermistor is presented. The experiment measures the resistance-temperature and voltage-temperature characteristics of the thermistor. Results of the resistance-temperature experiment are used to determine…

  9. A unique approach to demonstrating that apical bud temperature specifically determines leaf initiation rate in the dicot Cucumis sativus

    NARCIS (Netherlands)

    Savvides, Andreas; Dieleman, Anja; Ieperen, van Wim; Marcelis, Leo F.M.

    2016-01-01

    Main conclusion: Leaf initiation rate is largely determined by the apical bud temperature even when apical bud temperature largely deviates from the temperature of other plant organs.We have long known that the rate of leaf initiation (LIR) is highly sensitive to temperature, but previous studies

  10. Determination of the PO2 temperature blood factor from oxygen dissociation curves.

    Science.gov (United States)

    Hérigault, R A; Soulard, C D; Teisseire, B P; Laurent, D N

    1983-01-01

    The variation with saturation of the temperature coefficient of PO2 in human blood (delta log PO2/delta T) was determined by continuous recording of the oxygen dissociation curve (ODC), at 37 degrees C and 25 degrees C, on the same blood samples. PCO2 and pH were held constant through an ODC run, and PCO2 was reduced at 25 degrees C to the value measured by anaerobic cooling of the same sample. delta log PO2/delta T was calculated from isosaturation points on the 37 and 25 degrees C curves. The temperature coefficient was also computed as an independent check on this method by determination of the effects of temperature (25, 30, 37 and 40 degrees C) on hemoglobin ligand interaction: fixed acid Bohr effect (delta log PO2/delta pH), carbamino-formation (delta log PO2/delta log PCO2) and hemoglobin oxygen affinity. The values of delta log PO2/delta T ratio obtained from the two different approaches were found to be in good agreement. The coefficient decreased when [H+] concentration was increased. A linear relationship between the Bohr factor and the temperature was found: delta log PO2/delta pH = 0.00267 T-0.520 (r = 0.85; n = 40) At 25 degrees C, the carbamino-formation was one order of magnitude lower than at 37 degrees C. Acid-base state and saturation value appeared to be major determinant factors for the temperature correction coefficient to be applied to blood PO2 values measured at standard (37 degrees C) temperature.

  11. Spectroscopic determination of ionization constants of quinoline and 3-aminoquinoline at different temperature

    International Nuclear Information System (INIS)

    Indhar, H.A.B.

    2000-01-01

    Quinoline and its derivative are chemically and biologically important heterocylic compounds. Its ionization constant (pK/sub a/ values have been previously determined only at 18 or 20 deg. C. We have enhanced this work at different temperatures from 20-50 deg. C at the interval of 5 deg. C. The dissociation constants (pk/sub a/s), and Gibb's free energies of quinoline and 3-aminoquinoline have been determined by UV-Spectrophotometer (lambda 2) equipped with a temperature control of - + 0.1 deg. C at temperatures ranging from 20-50 deg. C in water. The experimental data have been used for the determination of thermodynamic ionization constants (pk /sub a //sup t/) sub t/, concentration ionization constants (pK/sub a//sup M/) and Gibbs's free energy values of pK/sub a/sup M/. The ionization constant values decrease with increase of temperature. The significance of relative magnitudes of the values is discussed and some useful generalization are obtained. The curves are parabolic. A computer program in GW-BASIC calculates the values of dissociation constants. From the pK/sub a/ values, Gibb's free energies are compared and discussed. (author)

  12. Exploration of a new method in determining the glass transition temperature of BMGs by electrical resistivity

    Science.gov (United States)

    Guo, Jing; Zu, Fangqiu; Chen, Zhihao; Zheng, Shubin; Yuan, Yuan

    2005-07-01

    Based on a brief retrospect of the method in establishing Tg of the bulk metallic glasses (BMGs), some perplexities concerning this are pointed out. With the experimental results of Zr-Al-Ni-Cu-X (Nb,Ti) BMGs, a electrical resistivity method is proposed to determine the glass transition temperature of BMGs. With the method, we define two kinds of characteristic temperature related to the glass transition, Tg-dep and Tg-int, respectively. By comparing Tg-dep and Tg-int with Tg determined by the DSC method, we have found that, for the same alloy at the same heating rate, Tg-dep is very close to Tg-onset while Tg-int is approximate to Tg-mid. As a method to determine the glass transition temperature, the electrical resistivity method has proved to be more convenient and practical in comparison with the DSC method, especially when the DSC curve cannot show the glass transition character of BMGs. In addition, we would emphasize that when we refer to Tg, it is necessary to expatiate on the way of denoting the glass transition temperature, such as Tg-dep or Tg-int ( Tg-onset or Tg-mid), and on the heating rate, in order to avoid ambiguity.

  13. Stream hydraulics and temperature determine the metabolism of geothermal Icelandic streams

    Directory of Open Access Journals (Sweden)

    Demars B. O.L.

    2011-07-01

    Full Text Available Stream ecosystem metabolism plays a critical role in planetary biogeochemical cycling. Stream benthic habitat complexity and the available surface area for microbes relative to the free-flowing water volume are thought to be important determinants of ecosystem metabolism. Unfortunately, the engineered deepening and straightening of streams for drainage purposes could compromise stream natural services. Stream channel complexity may be quantitatively expressed with hydraulic parameters such as water transient storage, storage residence time, and water spiralling length. The temperature dependence of whole stream ecosystem respiration (ER, gross primary productivity (GPP and net ecosystem production (NEP = GPP − ER has recently been evaluated with a “natural experiment” in Icelandic geothermal streams along a 5–25 °C temperature gradient. There remained, however, a substantial amount of unexplained variability in the statistical models, which may be explained by hydraulic parameters found to be unrelated to temperature. We also specifically tested the additional and predicted synergistic effects of water transient storage and temperature on ER, using novel, more accurate, methods. Both ER and GPP were highly related to water transient storage (or water spiralling length but not to the storage residence time. While there was an additional effect of water transient storage and temperature on ER (r2 = 0.57; P = 0.015, GPP was more related to water transient storage than temperature. The predicted synergistic effect could not be confirmed, most likely due to data limitation. Our interpretation, based on causal statistical modelling, is that the metabolic balance of streams (NEP was primarily determined by the temperature dependence of respiration. Further field and experimental work is required to test the predicted synergistic effect on ER. Meanwhile, since higher metabolic activities allow for higher pollutant degradation or uptake

  14. High-speed three-dimensional plasma temperature determination of axially symmetric free-burning arcs

    International Nuclear Information System (INIS)

    Bachmann, B; Ekkert, K; Bachmann, J-P; Marques, J-L; Schein, J; Kozakov, R; Gött, G; Schöpp, H; Uhrlandt, D

    2013-01-01

    In this paper we introduce an experimental technique that allows for high-speed, three-dimensional determination of electron density and temperature in axially symmetric free-burning arcs. Optical filters with narrow spectral bands of 487.5–488.5 nm and 689–699 nm are utilized to gain two-dimensional spectral information of a free-burning argon tungsten inert gas arc. A setup of mirrors allows one to image identical arc sections of the two spectral bands onto a single camera chip. Two-different Abel inversion algorithms have been developed to reconstruct the original radial distribution of emission coefficients detected with each spectral window and to confirm the results. With the assumption of local thermodynamic equilibrium we calculate emission coefficients as a function of temperature by application of the Saha equation, the ideal gas law, the quasineutral gas condition and the NIST compilation of spectral lines. Ratios of calculated emission coefficients are compared with measured ones yielding local plasma temperatures. In the case of axial symmetry the three-dimensional plasma temperature distributions have been determined at dc currents of 100, 125, 150 and 200 A yielding temperatures up to 20000 K in the hot cathode region. These measurements have been validated by four different techniques utilizing a high-resolution spectrometer at different positions in the plasma. Plasma temperatures show good agreement throughout the different methods. Additionally spatially resolved transient plasma temperatures have been measured of a dc pulsed process employing a high-speed frame rate of 33000 frames per second showing the modulation of the arc isothermals with time and providing information about the sensitivity of the experimental approach. (paper)

  15. Upgrading the SPP-500-1 moisture separators-steam reheaters used in the Leningrad NPP turbine units

    Science.gov (United States)

    Legkostupova, V. V.; Sudakov, A. V.

    2015-03-01

    The specific features of existing designs of moisture separators-steam reheaters (MSRs) and experience gained with using them at nuclear power plants are considered. Main factors causing damage to and failures of MSRs are described: nonuniform distribution of wet steam flow among the separation modules, breakthrough of moisture through the separator (and sometimes also through the steam reheater), which may lead to the occurrence of additional thermal stresses and, hence, to thermal-fatigue damage to or stress corrosion cracking of metal. MSR failure results in a less efficient operation of the turbine unit as a whole and have an adverse effect on the reliability of the low-pressure cylinder's last-stage blades. By the time the design service life of the SPP-500-1 MSRs had been exhausted in power units equipped with RBMK-1000 reactors, the number of damages inflicted to both the separation part and to the pipework and heating surface tubes was so large, that a considerable drop of MSR effectiveness and turbine unit efficiency as a whole occurred. The design of the upgraded separation part used in the SPP-500-1 MSR at the Leningrad NPP is described and its effectiveness is shown, which was confirmed by tests. First, efforts taken to achieve more uniform distribution of moisture content over the perimeter and height of steam space downstream of the separation modules and to bring it to values close to the design ones were met with success. Second, no noticeable effect of the individual specific features of separation modules on the moisture content was revealed. Recommendations on elaborating advanced designs of moisture separators-steam reheaters are given: an MSR arrangement in which the separator is placed under or on the side from the steam reheater; axial admission of wet steam for ensuring its uniform distribution among the separation modules; inlet chambers with an extended preliminary separation system and devices for uniformly distributing steam flows in the

  16. Hydroxyl (6−2 airglow emission intensity ratios for rotational temperature determination

    Directory of Open Access Journals (Sweden)

    R. P. Lowe

    Full Text Available OH(6–2 Q1/P1 and R1/P1 airglow emission intensity ratios, for rotational states up to j' = 4.5, are measured to be lower than implied by transition probabilities published by various authors including Mies, Langhoff et al. and Turnbull and Lowe. Experimentally determined relative values of j' transitions yield OH(6–2 rotational temperatures 2 K lower than Langhoff et al., 7 K lower than Mies and 13 K lower than Turnbull and Lowe.Key words: Atmospheric composition and structure (airglow and aurora; pressure, density and temperature

  17. Temperature Field Prediction for Determining the Residual Stresses Under Heat Treatment of Aluminum Alloys

    Directory of Open Access Journals (Sweden)

    A. V. Livshits

    2014-01-01

    Full Text Available The article is devoted to non-stationary temperature field blanks from aluminum alloys during heat treatment. It consists of the introduction and two smaller paragraphs. In the introduction the author concerns the influence of residual stresses arising in the manufacturing process of details, on the strength of the whole aircraft construction and, consequently, on their technical and economic parameters, such as weight, reliability, efficiency, and cost. He also notes that the residual stresses appeared during the production of parts change their location, size and direction under the influence of the elastic deformations that occur during the exploitation of aircraft. Redistributed residual stresses may have a chaotic distribution that may cause overlap of these stresses on the stresses caused by the impact of workload of constructions and destruction or damage of aircraft components.The first paragraph is devoted to the existing methods and techniques for determining the residual stresses. The presented methods and techniques are analyzed to show the advantages and disadvantages of each of them. The conclusion is drawn that the method to determine the residual stresses is necessary, its cost is less than those of existing ones, and an error does not exceed 10%.In the second section, the author divides the problem of determining the residual stresses into two parts, and describes the solution methods of the first one. The first problem is to define the temperature field of the work piece. The author uses a Fourier equation with the definition of initial and boundary conditions to describe a mathematical model of the heat cycle of work piece cooling. He draws special attention here to the fact that it is complicated to determine the heat transfer coefficient, which characterizes the process of cooling the work piece during hardening because of its dependence on a number of factors, such as changing temperature-dependent material properties of

  18. Temperature measurement by thermal strain imaging with diagnostic power ultrasound, with potential for thermal index determination.

    Science.gov (United States)

    Liang, Hai-Dong; Zhou, Li-Xia; Wells, Peter N T; Halliwell, Michael

    2009-05-01

    ) temperature measurement for the determination of TI.

  19. Determination of hydrogen diffusivity and permeability in W near room temperature applying a tritium tracer technique

    International Nuclear Information System (INIS)

    Ikeda, T.; Otsuka, T.; Tanabe, T.

    2011-01-01

    Tungsten is a primary candidate of plasma facing material in ITER and beyond, owing to its good thermal property and low erosion. But hydrogen solubility and diffusivity near ITER operation temperatures (below 500 K) have scarcely studied. Mainly because its low hydrogen solubility and diffusivity at lower temperatures make the detection of hydrogen quite difficult. We have tried to observe hydrogen plasma driven permeation (PDP) through nickel and tungsten near room temperatures applying a tritium tracer technique, which is extremely sensible to detect tritium diluted in hydrogen. The apparent diffusion coefficients for PDP were determined by permeation lag times at first time, and those for nickel and tungsten were similar or a few times larger than those for gas driven permeation (GDP). The permeation rates for PDP in nickel and tungsten were larger than those for GDP normalized to the same gas pressure about 20 and 5 times larger, respectively.

  20. Testing program for determining the mechanical properties of concrete to temperatures of 6210C

    International Nuclear Information System (INIS)

    Oland, C.B.; Naus, D.J.; Robinson, G.C.

    1980-01-01

    Concrete temperatures in a Liquid Metal Fast Breeder Reactor (LMFBR) in excess of normal code limits can result from postulated large sodium spills in equipment cells. Elevated temperature concrete property data which may have application for providing a basis for the design and evaluation of such postulated accident conditions is limited. Data thus needed to be developed commensurate with LMFBR plant applications for critical physical and mechanical concrete properties under prototypic thermal accident conditions. A test program was conducted to define the variations in physical and mechanical properties of a limestone aggregate concrete and a lightweight insulating concrete exposed to elevated temperatures. Five test series were conducted: unconfined compression, shear, rebar bond, sustained loading (creep), and thermal properties. Testing procedures for determining the mechanical properties of concrete from ambient to 621 0 C (1150 0 F) are described. Ther thermal properties tests are discussed in a separate paper which is also being presented at this conference

  1. Algorithm to determine electrical submersible pump performance considering temperature changes for viscous crude oils

    Energy Technology Data Exchange (ETDEWEB)

    Valderrama, A. [Petroleos de Venezuela, S.A., Distrito Socialista Tecnologico (Venezuela); Valencia, F. [Petroleos de Venezuela, S.A., Instituto de Tecnologia Venezolana para el Petroleo (Venezuela)

    2011-07-01

    In the heavy oil industry, electrical submersible pumps (ESPs) are used to transfer energy to fluids through stages made up of one impeller and one diffuser. Since liquid temperature increases through the different stages, viscosity might change between the inlet and outlet of the pump, thus affecting performance. The aim of this research was to create an algorithm to determine ESPs' performance curves considering temperature changes through the stages. A computational algorithm was developed and then compared with data collected in a laboratory with a CG2900 ESP. Results confirmed that when the fluid's viscosity is affected by the temperature changes, the stages of multistage pump systems do not have the same performance. Thus the developed algorithm could help production engineers to take viscosity changes into account and optimize the ESP design. This study developed an algorithm to take into account the fluid viscosity changes through pump stages.

  2. Determination of the temperature of bremsstrahlung photon generated by ultraintense laser using various thickness attenuators

    International Nuclear Information System (INIS)

    Hasegawa, Shuichi; Takashima, Ryuta; Todoriki, Masaru; Kikkawa, Satoshi; Soda, Keita; Takano, Kei; Oishi, Yuji; Nayuki, Takuya; Fujii, Takashi; Nemoto, Koshichi

    2011-01-01

    We evaluate the simplified method using the Lambert-Beer law to measure the temperature of bremsstrahlung photon generated by an ultraintense laser. Analytical values are compared to the results of the Monte Carlo calculation of GEANT4 and they agreed very well on the condition of the appropriate distance between the attenuator and the detector. We performed the experiment to measure the temperature of bremsstrahlung x-ray emitted from a metal target irradiated by a Ti:sapphire laser with 76 mJ, 72 fs, 2.2 x 10 18 W/cm 2 . For a Cu target of 30 μm thick, the photon temperature was reasonably determined to be 0.18 MeV, which is in good agreement with previous studies.

  3. Proposal for determining changes in entropy of semi ideal gas using mean values of temperature functions

    Directory of Open Access Journals (Sweden)

    Pejović Branko B.

    2014-01-01

    Full Text Available In a semi-ideal gas, entropy changes cannot be determined through the medium specific heat capacity in a manner as determined by the change of internal energy and enthalpy, i.e. the amount of heat exchanged. Taking this into account, the authors conducted two models through which it is possible to determine the change in the specific entropy of a semi-ideal gas for arbitrary temperature interval using the spread sheet method, using the mean values of the appropriate functions. The idea is to replace integration, which occurs here in evitably, with mean values of the previous functions. The models are derived based on the functional dependence of the actual specific heat capacity on the temperature. The theorem used is that of the mean value of a function as well as the mathematical properties of the definite integral. The mean value of a fractional function is determined via its integrand while the logarithmic functions were performed by applying a suitable transformation of the differential calculus. The relations derived relation, using the computer program, have enabled the design of appropriate thermodynamic tables through which it is possible to determine the change in entropy of arbitrary state changes in an efficient and rational manner, without the use of calculus or finished forms. In this way, the change in the entropy of a semi-ideal gas is determined for an arbitrary temperature interval using the method which is analogous to that applied in determining the change of internal energy and enthalpy or the amount of heat exchanged, which was the goal of the work. Verification of the proposed method for both the above functions was performed for a a few characteristic semi-ideal gases where change c(T is significant, for the three adopted temperature intervals, for the characteristic change of state. This was compared to the results of the classical integral and the proposed method through the prepared tables. In certain or special cases

  4. New strategies invonving upconverting nanoparticles for determining moderate temperatures by luminescence thermometry

    Energy Technology Data Exchange (ETDEWEB)

    Savchuk, Ol.A. [Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA) and EMaS, Universitat Rovira i Virgili (URV), c/Marcellí Domingo s/n E-43007, Tarragona (Spain); Carvajal, J.J., E-mail: joanjosep.carvajal@urv.cat [Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA) and EMaS, Universitat Rovira i Virgili (URV), c/Marcellí Domingo s/n E-43007, Tarragona (Spain); Pujol, M.C.; Massons, J. [Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA) and EMaS, Universitat Rovira i Virgili (URV), c/Marcellí Domingo s/n E-43007, Tarragona (Spain); Haro-González, P. [Fluorescence Imaging Group, Departamento de Física de Materiales, Facultad de Ciencias, Universidad Autónoma de Madrid, C/Francisco Tomás y Valiente 7, E-28049 Madrid (Spain); Martínez, O.; Jiménez, J. [GdS-Optronlab, Departamento Física Materia Condensada, Universidad de Valladolid, Edificio I+D, Paseo de Belén 11, 47011 Valladolid (Spain); Aguiló, M.; Díaz, F. [Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA) and EMaS, Universitat Rovira i Virgili (URV), c/Marcellí Domingo s/n E-43007, Tarragona (Spain)

    2016-01-15

    Here we analyze alternative luminescence thermometry techniques to FIR, such as intensity ratio luminescence thermometry between the emission arising from two electronic levels that are not necessarily thermally coupled, but that show different evolutions with temperature, and lifetime luminescence nanothermometry in (Ho,Tm,Yb):KLu(WO{sub 4}){sub 2} and (Er,Yb):NaY{sub 2}F{sub 5}O nanoparticles. (Ho,Tm,Yb):KLu(WO{sub 4}){sub 2} nanoparticles exhibited a maximum relative sensitivity of 0.61% K{sup −1}, similar to that achievable in Er-doped systems, which are the upconverting systems presenting the highest sensitivity. From another side, (Er,Yb):NaY{sub 2}F{sub 5}O nanocrystals show great potentiality as thermal sensors at the nanoscale for moderate temperatures due to the incorporation of additional non-radiative relaxation mechanisms that shorten the emission lifetime generated by the oxygen present in the structure when compared to (Er,Yb):NaYF{sub 4} nanoparticles exhibiting the highest upconversion efficiency. We used those nanoparticles for ex-vivo temperature determination by laser induced heating in chicken breast using lifetime-based thermometry. The results obtained indicate that these techniques might constitute alternatives to FIR with potential applications for the determination of moderate temperatures, with sensitivities comparable to those that can be achieved by FIR or even higher. - Highlights: • Other nanothermometry techniques than FIR proposed with upconversion nanoparticles. • Energy transfer between different lanthanide ions can be used for thermometry. • Lifetime measurements can constitute also a tool for temperature determination.

  5. Sex determination and differentiation in Aurelia sp.1: the absence of temperature dependence

    Science.gov (United States)

    Liu, Chunsheng; Gu, Zhifeng; Xing, Mengxin; Sun, Yun; Chen, Siqing; Chen, Zhaoting

    2018-03-01

    Cnidarians, being regarded as `basal' metazoan animals, are considered to have relatively high plasticity in terms of sex reversal. In this study we used an experimental approach to demonstrate sexual differentiation and plasticity in benthic polyps and pelagic medusae of Aurelia sp.1 maintained at different temperatures. Results indicated that in Aurelia sp.1, sex differentiation has been determined at the polyp stage and that all medusae originating from a given polyp are, phenotypically, of the same sex. In addition, the sex of polyps budding from the same clone (either male or female) at different temperatures appears to be the same as that of the parent. The sex of medusae that had originated from a known-sex polyp was observed to remain the same as that of the parent, irrespective of differences in strobilation or rearing temperatures. These results indicate that the mechanism of sex determination of Aurelia sp.1. is not influenced by prevailing temperature regimes. A comparison of variability in terms of sexual plasticity of Aurelia sp.1 with that of Hydrozoa and Anthozoa suggests that species characterized by a free-swimming medusa life stage have a high dispersal potential, which probably results in a lower rate of sex reversal.

  6. A new method to determine oxidative stability of vegetable fats and oils at simulated frying temperature

    Directory of Open Access Journals (Sweden)

    Gertz Christian

    2001-01-01

    Full Text Available A new procedure at simulated frying conditions in our laboratory was developed to monitor frying stability of fats and oils. Water-conditioned silica was prepared and added to the fresh vegetable oil, which was heated for two hours at 170°C. The oil stability at frying temperature was then evaluated by determining the amount of formed dimeric triglycerides The results obtained showed that the stability of the vegetable oils at frying temperature could not be explained by the fatty acid composition alone. Corn oil was observed to be more stable than soybean oil, and rapeseed oil was better than olive oil. It was also observed that crude, non-refined oils were found to have a better heat stability than refin-ed oils. To estimate the effectiveness of synthetic and naturally occurring antioxidants, namely various tocopherols, tocopherol acetate and phytosterol fractions, phenolic compounds like quercetin, oryzanol, ferulic acid, gallates, BHT, BHA and other compounds like ascorbic acid 6-palmitate and squalene were added to refined sunflower and rape seed oil, and their oxidative stability at elevated temperature (OSET values determined. Both linoleic and oleic rich oils gave comparable results for the activity of the various compounds. alpha-tocopherol, tocopherol esters and BHA had low effects on oil stability at frying temperature, while ascorbyl palmitate and some phytosterol fractions were found to have the most stabilizing activity under frying conditions.

  7. Interstellar Gas Flow Vector and Temperature Determination over 5 Years of IBEX Observations

    International Nuclear Information System (INIS)

    Möbius, E; Heirtzler, D; Kucharek, H; Lee, M A; Leonard, T; Schwadron, N; Bzowski, M; Kubiak, M A; Sokół, J M; Fuselier, S A; McComas, D J; Wurz, P

    2015-01-01

    The Interstellar Boundary Explorer (IBEX) observes the interstellar neutral gas flow trajectories at their perihelion in Earth's orbit every year from December through early April, when the Earth's orbital motion is into the oncoming flow. These observations have defined a narrow region of possible, but very tightly coupled interstellar neutral flow parameters, with inflow speed, latitude, and temperature as well-defined functions of inflow longitude. The best- fit flow vector is different by ≈ 3° and lower by ≈ 3 km/s than obtained previously with Ulysses GAS, but the temperature is comparable. The possible coupled parameter space reaches to the previous flow vector, but only for a substantially higher temperature (by ≈ 2000 K). Along with recent pickup ion observations and including historical observations of the interstellar gas, these findings have led to a discussion, whether the interstellar gas flow into the solar system has been stable or variable over time. These intriguing possibilities call for more detailed analysis and a longer database. IBEX has accumulated observations over six interstellar flow seasons. We review key observations and refinements in the analysis, in particular, towards narrowing the uncertainties in the temperature determination. We also address ongoing attempts to optimize the flow vector determination through varying the IBEX spacecraft pointing and discuss related implications for the local interstellar cloud and its interaction with the heliosphere

  8. Drosophila mitotypes determine developmental time in a diet and temperature dependent manner.

    Science.gov (United States)

    Towarnicki, Samuel G; Ballard, J William O

    2017-07-01

    It is well known that specific mitochondrial (mt) DNA mutations can reduce organismal fitness and influence mitochondrial-nuclear interactions. However, determining specific mtDNA mutations that are beneficial has been elusive. In this study, we vary the diet and environmental temperature to study larval development time of two Drosophila melanogaster mitotypes (Alstonville and Dahomey), in two nuclear genetic backgrounds, and investigate developmental differences through weight, feeding rate, and movement. To manipulate the diet, we utilize the nutritional geometric framework to manipulate isocaloric diets of differing macronutrient ratios (1:2 and 1:16 protein: carbohydrate (P:C) ratios) and raise flies at three temperatures (19°C, 23°C and 27°C). Larvae with Dahomey mtDNA develop more slowly than Alstonville when fed the 1:2 P:C diet at all temperatures and developed more quickly when fed the 1:16 P:C diet at 23°C and 27°C. We determined that Dahomey larvae eat more, move less, and weigh more than Alstonville larvae when raised on the 1:16 P:C diet and that these physiological responses are modified by temperature. We suggest that 1 (or more) of 4 mtDNA changes is likely responsible for the observed effects and posit the mtDNA changes moderate a physiological trade-off between consumption and foraging. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Determination of ion temperatures from Zeeman broadened spectral lines in the edge of Tore Supra

    Energy Technology Data Exchange (ETDEWEB)

    Klepper, C.C.; Isler, R.C.; Tobin, S.J.; Hogan, J.T. [Oak Ridge National Lab., TN (United States). Fusion Energy Div.; Hess, W.R. [Association EURATOM-CEA sur la Fusion Controlee, St-Paul-lez-Durance (France). Centre d`Etudes de Cadarache

    1994-09-01

    The authors have examined a {sup 3}P {yields} {sup 3}S multiplet of C III in Tore Supra in order to assess the possibility of determining the ion temperatures from transitions where the Zeeman effect cannot be neglected compared to the Doppler broadening. The preliminary studies lead them to believe that with good quality data the temperatures can be determined within about 20% in the 20--30 eV range and within about 50% in the neighborhood of 5 eV by fitting the entire multiplet rather than a semi-isolated feature, even though certain parameters important for the analysis, such as polarization effects of the optics, are not well characterized. In order to quantify these conclusions more precisely, future work will concentrate on developing numerical fitting routines and on examining the validity of the assumption that the distribution function for low ionization stages is Maxwellian.

  10. Determination of ion temperatures from Zeeman broadened spectral lines in the edge of Tore Supra

    International Nuclear Information System (INIS)

    Klepper, C.C.; Isler, R.C.; Tobin, S.J.; Hogan, J.T.; Hess, W.R.

    1994-01-01

    The authors have examined a 3 P → 3 S multiplet of C III in Tore Supra in order to assess the possibility of determining the ion temperatures from transitions where the Zeeman effect cannot be neglected compared to the Doppler broadening. The preliminary studies lead them to believe that with good quality data the temperatures can be determined within about 20% in the 20--30 eV range and within about 50% in the neighborhood of 5 eV by fitting the entire multiplet rather than a semi-isolated feature, even though certain parameters important for the analysis, such as polarization effects of the optics, are not well characterized. In order to quantify these conclusions more precisely, future work will concentrate on developing numerical fitting routines and on examining the validity of the assumption that the distribution function for low ionization stages is Maxwellian

  11. Room Temperature Magnetic Determination of the Current Center Line for the ITER TF Coils

    CERN Document Server

    Lerch, Philippe; Buzio, Marco; Negrazus, Marco; Baynham, Elwyn; Sanfilippo, Stephane; Foussat, Arnaud

    2014-01-01

    The ITER tokamak includes 18 superconducting D-shaped toroidal field (IT) coils. Unavoidable shape deformations as well as assembly errors will lead to field errors, which can be modeled with the knowledge of the current center line (CCL). Accurate survey during the entire manufacturing and assembly process, including transfer of survey points, is complex. In order to increase the level of confidence, a room temperature magnetic measurement of the CCL on assembled and closed winding packs is foreseen, prior to insertion into their cold case. In this contribution, we discuss the principle of the CCL determination and present a low frequency ac measurement system under development at PSI, within an ITER framework contract. The largest current allowed to flow in the TF coil at room temperature and the precision requirements for the determination of the CCL loci of the coil are hard boundaries. Eddy currents in the radial plates, the winding pack enclosures, and possibly from iron in the reinforced concrete floor...

  12. Embrittlement of Intercritically Reheated Coarse Grain Heat-Affected Zone of ASTM4130 Steel

    Science.gov (United States)

    Li, Liying; Han, Tao; Han, Bin

    2018-04-01

    In this investigation, a thermal welding simulation technique was used to investigate the microstructures and mechanical properties of the intercritically reheated coarse grain heat-affected zone (IR CGHAZ) of ASTM4130 steel. The effect of post weld heat treatment (PWHT) on the toughness of IR CGHAZ was also analyzed. The toughness of IR CGHAZ was measured by means of Charpy impact, and it is found that IR CGHAZ has the lowest toughness which is much lower than that of the base metal regardless of whether PWHT is applied or not. The as-welded IR CGHAZ is mainly composed of ferrite, martensite, and many blocky M-A constituents distributing along grain boundaries and subgrain boundaries in a near-connected network. Also, the prior austenite grains are still as coarse as those in the coarse grain heat-affected zone (CGHAZ). The presence of the blocky M-A constituents and the coarsened austenite grains result in the toughness deterioration of the as-welded IR CGHAZ. Most of the blocky M-A constituents are decomposed to granular bainite due to the effect of the PWHT. However, PWHT cannot refine the prior austenite grains. Thus, the low toughness of IR CGHAZ after PWHT can be attributed to two factors, i.e., the coarsened austenite grains, and the presence of the remaining M-A constituents and granular bainite, which are located at grain boundaries and subgrain boundaries in a near-connected network. The absorbed energy of the IR CGHAZ was increased by about 3.75 times, which means that the PWHT can effectively improve the toughness but it cannot be recovered to the level of base metal.

  13. A calculation strategy for the determination of the temperature distribution in radioactive waste repositories

    International Nuclear Information System (INIS)

    Hahne, K.; Biurrun, E.

    1989-01-01

    In the past many calculation tools have been developed for the determination of instationary temperature distributions in radioactive waste repositories (single source model/large scale model/unit cell model using analytical or numerical methods; overall model using analytical or numerical methods). This paper discusses how, in practice, all these calculation tools have to be associated sensibly in a special calculation strategy making use of their actual advantages

  14. An analytical method for determining the temperature dependent moisture diffusivities of pumpkin seeds during drying process

    Energy Technology Data Exchange (ETDEWEB)

    Can, Ahmet [Department of Mechanical Engineering, University of Trakya, 22030 Edirne (Turkey)

    2007-02-15

    This paper presents an analytical method, which determines the moisture diffusion coefficients for the natural and forced convection hot air drying of pumpkin seeds and their temperature dependence. In order to obtain scientific data, the pumpkin seed drying process was investigated under both natural and forced hot air convection regimes. This paper presents the experimental results in which the drying air was heated by solar energy. (author)

  15. Comparison of signaling interactions determining annual and perennial plant growth in response to low temperature

    Directory of Open Access Journals (Sweden)

    Astrid eWingler

    2015-01-01

    Full Text Available Low temperature inhibits plant growth despite the fact that considerable rates of photosynthetic activity can be maintained. Instead of lower rates of photosynthesis, active inhibition of cell division and expansion is primarily responsible for reduced growth. This results in sink limitation and enables plants to accumulate carbohydrates that act as compatible solutes or are stored throughout the winter to enable re-growth in spring. Regulation of growth in response to temperature therefore requires coordination with carbon metabolism, e.g. via the signaling metabolite trehalose-6-phosphate. The phytohormones gibberellins (GA and jasmonate (JA play an important role in regulating growth in response to temperature. Growth restriction at low temperature is mainly mediated by DELLA proteins, whose degradation is promoted by GA. For annual plants, it has been shown that the GA/DELLA pathway interacts with JA signaling and C-repeat binding factor (CBF dependent cold acclimation, but these interactions have not been explored in detail for perennials. Growth regulation in response to seasonal factors is, however, particularly important in perennials, especially at high latitudes. In autumn, growth cessation in trees is caused by shortening of the daylength in interaction with phytohormone signaling. In perennial grasses seasonal differences in the sensitivity to GA may enable enhanced growth in spring. This review provides an overview of the signaling interactions that determine plant growth at low temperature and highlights gaps in our knowledge, especially concerning the seasonality of signaling responses in perennial plants.

  16. Experimental program to determine maximum temperatures for dry storage of spent fuel

    International Nuclear Information System (INIS)

    Knox, C.A.; Gilbert, E.R.; White, G.D.

    1985-02-01

    Although air is used as a cover gas in some dry storage facilities, other facilities use inert cover gases which must be monitored to assure inertness of the atmosphere. Thus qualifying air as a cover gas is attractive for the dry storage of spent fuels. At sufficiently high temperatures, air can react with spent fuel (UO 2 ) at the site of cladding breaches that formed during reactor irradiation or during dry storage. The reaction rate is temperature dependent; hence the rates can be maintained at acceptable levels if temperatures are low. Tests with spent fuel are being conducted at Pacific Northwest Laboratory (PNL) to determine the allowable temperatures for storage of spent fuel in air. Tests performed with nonirradiated UO 2 pellets indicated that moisture, surface condition, gamma radiation, gadolinia content of the fuel pellet, and temperature are important variables. Tests were then initiated on spent fuel to develop design data under simulated dry storage conditions. Tests have been conducted at 200 and 230 0 C on spent fuel in air and 275 0 C in moist nitrogen. The results for nonirradiated UO 2 and published data for irradiated fuel indicate that above 230 0 C, oxidation rates are unacceptably high for extended storage in air. The tests with spent fuel will be continued for approximately three years to enable reliable extrapolations to be made for extended storage in air and inert gases with oxidizing constituents. 6 refs., 6 figs., 3 tabs

  17. Temperature, precipitation and biotic interactions as determinants of tree seedling recruitment across the tree line ecotone.

    Science.gov (United States)

    Tingstad, Lise; Olsen, Siri Lie; Klanderud, Kari; Vandvik, Vigdis; Ohlson, Mikael

    2015-10-01

    Seedling recruitment is a critical life history stage for trees, and successful recruitment is tightly linked to both abiotic factors and biotic interactions. In order to better understand how tree species' distributions may change in response to anticipated climate change, more knowledge of the effects of complex climate and biotic interactions is needed. We conducted a seed-sowing experiment to investigate how temperature, precipitation and biotic interactions impact recruitment of Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) seedlings in southern Norway. Seeds were sown into intact vegetation and experimentally created gaps. To study the combined effects of temperature and precipitation, the experiment was replicated across 12 sites, spanning a natural climate gradient from boreal to alpine and from sub-continental to oceanic. Seedling emergence and survival were assessed 12 and 16 months after sowing, respectively, and above-ground biomass and height were determined at the end of the experiment. Interestingly, very few seedlings were detected in the boreal sites, and the highest number of seedlings emerged and established in the alpine sites, indicating that low temperature did not limit seedling recruitment. Site precipitation had an overall positive effect on seedling recruitment, especially at intermediate precipitation levels. Seedling emergence, establishment and biomass were higher in gap plots compared to intact vegetation at all temperature levels. These results suggest that biotic interactions in the form of competition may be more important than temperature as a limiting factor for tree seedling recruitment in the sub- and low-alpine zone of southern Norway.

  18. Temperature distribution determination of JPSR power reactor fuel element and cladding

    International Nuclear Information System (INIS)

    Sudarmono

    1996-01-01

    In order to utilize of fuel rod efficiency, a concept of JAERI passive Safety Reactor (JPSR) has been developed in Japan Atomic Energy Research Institute. In the JPSR design, UO 2 . are adopted as a fuel rod. The temperature distribution in the fuel rod and cladding in the hottest channel is a potential limiting design constraint of the JPSR. In the present determination, temperature distribution of the fuel rod and cladding for JPSR were PET:formed using COBRA-IV-I to evaluate the safety margin of the present JPSR design. In this method, the whole core was represented by the 1/4 sector and divided into 50 subchannels and 40 axial nodes. The temperature become maximum at the elevation of 1.922 and 2.196 m in the typical cell under operating condition. The maximum temperature in the center of the fuel rod surface of the fuel rod and cladding were 1620,4 o C, 722,8 o C, and 348,6 o C. The maximum results of temperature in the center of the fuel rod and cladding; were 2015,28 o C and 550 o C which were observed at 3.1 second in the typical cell

  19. Temperature dependence of the calibration factor of radon and radium determination in water samples by SSNTD

    CERN Document Server

    Hunyadi, I; Hakl, J; Baradacs, E; Dezso, Z

    1999-01-01

    The sensitivity of a sup 2 sup 2 sup 6 Ra determination method of water samples by SSNTD was measured as a function of storage temperature during exposure. The method is based on an etched track type radon monitor, which is closed into a gas permeable foil and is immersed in the water sample. The sample is sealed in a glass vessel and stored for an exposure time of 10-30 days. The sensitivity increased more than a factor of two when the storage temperature was raised from 2 deg. C to 30 deg. C. Temperature dependence of the partition coefficient of radon between water and air provides explanation for this dependence. For practical radio- analytical application the temperature dependence of the calibration factor is given by fitting the sensitivity data obtained by measuring sup 2 sup 2 sup 6 Ra standard solutions (in the activity concentration range of 0.1-48.5 kBq m sup - sup 3) at different storage temperatures.

  20. A study on different thermodynamic cycle schemes coupled with a high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Qu, Xinhe; Yang, Xiaoyong; Wang, Jie

    2017-01-01

    Highlights: • The features of three different power generation schemes, including closed Brayton cycle, non-reheating combined cycle and reheating combined cycle, coupled with high temperature gas-cooled reactor (HTGR) were investigated and compared. • The effects and mechanism of reactor core outlet temperature, compression ratio and other key parameters over cycle characteristics were analyzed by the thermodynamic models.. • It is found that reheated combined cycle has the highest efficiency. Reactor outlet temperature and main steam parameters are key factors to improve the cycle’s performance. - Abstract: With gradual increase in reactor outlet temperature, the efficient power conversion technology has become one of developing trends of (very) high temperature gas-cooled reactors (HTGRs). In this paper, different cycle power generation schemes for HTGRs were systematically studied. Physical and mathematical models were established for these three cycle schemes: closed Brayton cycle, simple combined cycle, and reheated combined cycle. The effects and mechanism of key parameters such as reactor core outlet temperature, reactor core inlet temperature and compression ratio on the features of these cycles were analyzed. Then, optimization results were given with engineering restrictive conditions, including pinch point temperature differences. Results revealed that within the temperature range of HTGRs (700–900 °C), the reheated combined cycle had the highest efficiency, while the simple combined cycle had the lowest efficiency (900 °C). The efficiencies of the closed Brayton cycle, simple combined cycle and reheated combined cycle are 49.5%, 46.6% and 50.1%, respectively. These results provide insights on the different schemes of these cycles, and reveal the effects of key parameters on performance of these cycles. It could be helpful to understand and develop a combined cycle coupled with a high temperature reactor in the future.

  1. Standard test method for determining liquidus temperature of immobilized waste glasses and simulated waste glasses

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 These practices cover procedures for determining the liquidus temperature (TL) of nuclear waste, mixed nuclear waste, simulated nuclear waste, or hazardous waste glass in the temperature range from 600°C to 1600°C. This method differs from Practice C829 in that it employs additional methods to determine TL. TL is useful in waste glass plant operation, glass formulation, and melter design to determine the minimum temperature that must be maintained in a waste glass melt to make sure that crystallization does not occur or is below a particular constraint, for example, 1 volume % crystallinity or T1%. As of now, many institutions studying waste and simulated waste vitrification are not in agreement regarding this constraint (1). 1.2 Three methods are included, differing in (1) the type of equipment available to the analyst (that is, type of furnace and characterization equipment), (2) the quantity of glass available to the analyst, (3) the precision and accuracy desired for the measurement, and (4) candi...

  2. Determination of trapping parameters of the high temperature thermoluminescence peak in equilibrated ordinary chondrites

    International Nuclear Information System (INIS)

    Akridge, Jannette M.C.; Benoit, Paul H.; Sears, Derek W.G.

    2001-01-01

    Most meteorites exhibit thermoluminescence (TL) that can be used to constrain their recent thermal and irradiation history, but quantitative conclusions require a knowledge of the detailed TL peak structure of the TL glow curve. We have determined TL peak parameters for the high temperature portion of the glow curve for six ordinary chondrites: Chicora (LL6); Innisfree (L5); Lost City (H5); Paragould (LL6); Pribram (H5); and Tilden (L6). The saturation dose for all these meteorites is approximately 3600 Gy. Published procedures were used to determine the number and temperatures of peaks in the high temperature (>570 K) portion of the glow curve and peak fitting was used to estimate TL trap parameters for each peak. These data were then tested and adjusted, if necessary, by comparing calculated decay results with TL glow curves for samples heated at ∼420 K for various times. We find evidence for four TL peaks in the high temperature portion of the glow curve, where trapping parameters vary slightly from meteorite to meteorite. For the Lost City meteorite, the TL peak temperatures (K), activation energies (E, eV), and Arrhenius factors (s, x 10 -9 s -1 ) are: 325, 1.26, 4.8; 360, 1.33, 3.88; 401, 1.44, 5.8; and 455, 1.5, 2.25, respectively. These data could be used to estimate dose rates for meteorites; however, the albedo values required for the calculation are not yet sufficiently known. However, terrestrial ages, or surface exposure ages, for meteorite finds from hot deserts like those in Australia or North Africa, can be estimated from these data

  3. Determination of trapping parameters of the high temperature thermoluminescence peak in equilibrated ordinary chondrites

    Energy Technology Data Exchange (ETDEWEB)

    Akridge, Jannette M.C.; Benoit, Paul H. E-mail: pbenoit@comp.uark.edu; Sears, Derek W.G

    2001-02-01

    Most meteorites exhibit thermoluminescence (TL) that can be used to constrain their recent thermal and irradiation history, but quantitative conclusions require a knowledge of the detailed TL peak structure of the TL glow curve. We have determined TL peak parameters for the high temperature portion of the glow curve for six ordinary chondrites: Chicora (LL6); Innisfree (L5); Lost City (H5); Paragould (LL6); Pribram (H5); and Tilden (L6). The saturation dose for all these meteorites is approximately 3600 Gy. Published procedures were used to determine the number and temperatures of peaks in the high temperature (>570 K) portion of the glow curve and peak fitting was used to estimate TL trap parameters for each peak. These data were then tested and adjusted, if necessary, by comparing calculated decay results with TL glow curves for samples heated at {approx}420 K for various times. We find evidence for four TL peaks in the high temperature portion of the glow curve, where trapping parameters vary slightly from meteorite to meteorite. For the Lost City meteorite, the TL peak temperatures (K), activation energies (E, eV), and Arrhenius factors (s, x 10{sup -9} s{sup -1}) are: 325, 1.26, 4.8; 360, 1.33, 3.88; 401, 1.44, 5.8; and 455, 1.5, 2.25, respectively. These data could be used to estimate dose rates for meteorites; however, the albedo values required for the calculation are not yet sufficiently known. However, terrestrial ages, or surface exposure ages, for meteorite finds from hot deserts like those in Australia or North Africa, can be estimated from these data.

  4. SOLUBILITY PREDICTION OF SULFONAMIDES AT VARIOUS TEMPERATURES USING A SINGLE DETERMINATION

    Directory of Open Access Journals (Sweden)

    JALAL HANAEE

    2005-04-01

    Full Text Available Solubility of sulphamethoxazole, sulphisoxazole and sulphasalazine in six solvents namely water,methanol, ethanol, 1-propanol, acetone and chloroform were determined at 15, 25, 37 and 45 °C. Two models derived from the Hildebrand solubility approach are proposed for solubility prediction at different temperatures using a single determination. The experimental data of the present work as well as data gathered from the literature have been employed to investigate the accuracy and prediction capability of the proposed models. The overall percent deviations between the predicted and experimental values were 10.78 and 14.63% which were comparable to those of the classical two and three parameter models. The proposed models were much superior to the two pure predictive models i.e., the ones which do not require experimental solubility determination, as the overall percent deviations produced by the latter models were 150.09 and 161.00%.

  5. The effects of temperature and diet on age grading and population age structure determination in Drosophila.

    Science.gov (United States)

    Aw, Wen C; Ballard, J William O

    2013-10-01

    The age structure of natural population is of interest in physiological, life history and ecological studies but it is often difficult to determine. One methodological problem is that samples may need to be invasively sampled preventing subsequent taxonomic curation. A second problem is that it can be very expensive to accurately determine the age structure of given population because large sample sizes are often necessary. In this study, we test the effects of temperature (17 °C, 23 °C and 26 °C) and diet (standard cornmeal and low calorie diet) on the accuracy of the non-invasive, inexpensive and high throughput near-infrared spectroscopy (NIRS) technique to determine the age of Drosophila flies. Composite and simplified calibration models were developed for each sex. Independent sets for each temperature and diet treatments with flies not involved in calibration model were then used to validate the accuracy of the calibration models. The composite NIRS calibration model was generated by including flies reared under all temperatures and diets. This approach permits rapid age measurement and age structure determination in large population of flies as less than or equal to 9 days, or more than 9 days old with 85-97% and 64-99% accuracy, respectively. The simplified calibration models were generated by including flies reared at 23 °C on standard diet. Low accuracy rates were observed when simplified calibration models were used to identify (a) Drosophila reared at 17 °C and 26 °C and (b) 23 °C with low calorie diet. These results strongly suggest that appropriate calibration models need to be developed in the laboratory before this technique can be reliably used in field. These calibration models should include the major environmental variables that change across space and time in the particular natural population to be studied. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Electron cyclotron emission measurements on JET: Michelson interferometer, new absolute calibration, and determination of electron temperature.

    Science.gov (United States)

    Schmuck, S; Fessey, J; Gerbaud, T; Alper, B; Beurskens, M N A; de la Luna, E; Sirinelli, A; Zerbini, M

    2012-12-01

    At the fusion experiment JET, a Michelson interferometer is used to measure the spectrum of the electron cyclotron emission in the spectral range 70-500 GHz. The interferometer is absolutely calibrated using the hot/cold technique and, in consequence, the spatial profile of the plasma electron temperature is determined from the measurements. The current state of the interferometer hardware, the calibration setup, and the analysis technique for calibration and plasma operation are described. A new, full-system, absolute calibration employing continuous data acquisition has been performed recently and the calibration method and results are presented. The noise level in the measurement is very low and as a result the electron cyclotron emission spectrum and thus the spatial profile of the electron temperature are determined to within ±5% and in the most relevant region to within ±2%. The new calibration shows that the absolute response of the system has decreased by about 15% compared to that measured previously and possible reasons for this change are presented. Temperature profiles measured with the Michelson interferometer are compared with profiles measured independently using Thomson scattering diagnostics, which have also been recently refurbished and recalibrated, and agreement within experimental uncertainties is obtained.

  7. Method for the determination of technical specifications limiting temperature in EBR-II operation

    International Nuclear Information System (INIS)

    Chang, L.K.; Hill, D.J.; Ku, J.Y.

    1994-01-01

    The methodology and analysis procedure to qualify the Mark-V and Mark-VA fuels for the Experimental Breeder Reactor II are summarized in this paper. Fuel performance data and design safety criteria are essential for thermal-hydraulic analysis and safety evaluations. Normal and off-normal operation duty cycles and transient classifications are required for the safety assessment of the fuels. The temperature limits of subassemblies were first determined by a steady-state thermal-structural and fuel damage analysis, in which a trial-and-error approach was used to predict the maximum allowable fuel pin temperature that satisfies the design criteria for steady-state normal operation. The steady-state temperature limits were used as the basis of the off-normal transient analysis to assess the safety performance of the fuel for anticipated, unlikely and extremely unlikely events. If the design criteria for the off-normal events are not satisfied, then the subassembly temperature limit is reduced and an iterative procedure is employed until all design criteria are met

  8. Method and apparatus for determination of temperature, neutron absorption cross section and neutron moderating power

    Science.gov (United States)

    Vagelatos, Nicholas; Steinman, Donald K.; John, Joseph; Young, Jack C.

    1981-01-01

    A nuclear method and apparatus determines the temperature of a medium by injecting fast neutrons into the medium and detecting returning slow neutrons in three first energy ranges by producing three respective detection signals. The detection signals are combined to produce three derived indicia each systematically related to the population of slow neutrons returning from the medium in a respective one of three second energy ranges, specifically exclusively epithermal neutrons, exclusively substantially all thermal neutrons and exclusively a portion of the thermal neutron spectrum. The derived indicia are compared with calibration indicia similarly systematically related to the population of slow neutrons in the same three second energy ranges returning from similarly irradiated calibration media for which the relationships temperature, neutron absorption cross section and neutron moderating power to such calibration indicia are known. The comparison indicates the temperature at which the calibration indicia correspond to the derived indicia and consequently the temperature of the medium. The neutron absorption cross section and moderating power of the medium can be identified at the same time.

  9. Quantitative determination of acid oils in low-temperature coal tar by means of fractional distillation

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, A

    1950-01-01

    The aromatic hydroxy compounds in low-temperature tar were separated, and 75 compounds in the boiling range 180/sup 0/ to 320/sup 0/ isolated by means of fractional distillation in packed columns of at least 45 theoretical plates. Mixtures not separable by fractionation were separated by means of other physicochemical or chemical methods. Hydroxy compounds with boiling point up to 230/sup 0/C were detemined quantitatively, as were the phenols present in low-temperature carbonization liquors. With the Krupp-Lurgi process of low-temperature carbonization, 1.8% phenol, 1.8% o-cresol, and 3.6% m-p-cresols were formed. The tar contained up to 1.3% 1:3:5-xylenol and up to 0.9% 1:2:4-xylenol. Of the 12.1% v/v of phenol, cresols, and xylenols present in tar, 11.2% were determined quantitatively, and 9 hydroxy compounds were identified in the remaining 0.9%. On the basis of these investigations, a technical plant that permitted the recovery of pure low-temperature tar phenols and the preparation of a number of different phenol resins from the mixtures was erected.

  10. Determining the temperature and density distribution from a Z-pinch radiation source

    International Nuclear Information System (INIS)

    Matuska, W.; Lee, H.

    1997-01-01

    High temperature radiation sources exceeding one hundred eV can be produced via z-pinches using currently available pulsed power. The usual approach to compare the z-pinch simulation and experimental data is to convert the radiation output at the source, whose temperature and density distributions are computed from the 2-D MHD code, into simulated data such as a spectrometer reading. This conversion process involves a radiation transfer calculation through the axially symmetric source, assuming local thermodynamic equilibrium (LTE), and folding the radiation that reaches the detector with the frequency-dependent response function. In this paper the authors propose a different approach by which they can determine the temperature and density distributions of the radiation source directly from the spatially resolved spectral data. This unfolding process is reliable and unambiguous for the ideal case where LTE holds and the source is axially symmetric. In reality, imperfect LTE and axial symmetry will introduce inaccuracies into the unfolded distributions. The authors use a parameter optimization routine to find the temperature and density distributions that best fit the data. They know from their past experience that the radiation source resulting from the implosion of a thin foil does not exhibit good axial symmetry. However, recent experiments carried out at Sandia National Laboratory using multiple wire arrays were very promising to achieve reasonably good symmetry. For these experiments the method will provide a valuable diagnostic tool

  11. Array-type sensor to determine corrosive conditions in high temperature water under gamma rays irradiation

    International Nuclear Information System (INIS)

    Satoh, T.; Tsukada, T.; Uchida, S.; Katoh, C.

    2010-01-01

    One of the problems to determine electrochemical corrosion potential (ECP) in high temperature water under irradiation is to apply long-lived and reliable reference electrodes. In order to avoid troubles due to the reference electrode, a new concept to determine ECP without the reference electrode has been proposed. Several metal plates are applied as working electrodes and at the same time as the reference electrodes. Potential of the metal plates with stable oxide films on their surfaces show stable values in high temperature water. As a result of the combination of their potential values, ECP of each metal can be determined without any specific reference electrode. Array-type sensors consisting of several metal plates, e.g., Fe, Ni, Cr, Zr, Pt, Pd, Re, Ir, with well developed oxide films on their surface were prepared for ECP measurement in high temperature water under neutron/gamma ray irradiations. In order to confirm the feasibility of this concept, responses of the redox potentials of the pure metals to changes in the simulated BWR reactor water conditions were measured and the ECP was determined by the differences in potentials between a couple of metal plates. Major conclusions of the study are as follows: 1) The redox potentials of the Fe, Pt, Zr, Ir, Pd, and Re electrodes showed the different dependences on the changes in O 2 and H 2 O 2 concentrations. The redox potentials of the electrodes increased as the oxidant concentrations increased except for Zr electrode. The potential of the Zr electrode was kept the very low potential at the wide range of O 2 and H 2 O 2 concentrations differed form the other electrodes. 2) It was estimated that the redox potential of highly soluble metal may be increased, while that of low soluble metal may be decreased by an oxide film. The stable oxide film would cause the stable potential response of the electrode with oxide film. 3) The relationship between the oxidant concentrations and the redox potentials of the

  12. Application of the orthogonal collocation method to determination of temperature distribution in cylindrical conductors

    International Nuclear Information System (INIS)

    Fortini, Maria A.; Stamoulis, Michel N.; Ferreira, Angela F.M.; Pereira, Claubia; Costa, Antonella L.; Silva, Clarysson A.M.

    2008-01-01

    In this work, an analytical model for the determination of the temperature distribution in cylindrical heater components with characteristics of nuclear fuel rods, is presented. The heat conductor is characterized by an arbitrary number of solid walls and different types of materials, whose thermal properties are taken as function of temperature. The heat conduction fundamental equation is solved numerically with the method of weighted residuals (MWR) using a technique of orthogonal collocation. The results obtained with the proposed method are compared with the experimental data from tests performed in the TRIGA IPR-R1 research reactor localized at the CDTN/CNEN (Centro de Desenvolvimento da Tecnologia Nuclear/Comissao Nacional de Energia Nuclear) at Belo Horizonte in Brazil

  13. Steroid signaling system responds differently to temperature and hormone manipulation in the red-eared slider turtle (Trachemys scripta elegans), a reptile with temperature-dependent sex determination.

    Science.gov (United States)

    Ramsey, M; Crews, D

    2007-01-01

    Many reptiles, including the red-eared slider turtle (Trachemys scripta elegans), exhibit temperature-dependent sex determination (TSD). Temperature determines gonadal sex during the middle of embryogenesis, or the temperature-sensitive period (TSP), when gonadal sex is labile to both temperature and hormones--particularly estrogen. The biological actions of steroid hormones are mediated by their receptors as defined here as the classic transcriptional regulation of target genes. To elucidate estrogen action during sex determination, we examined estrogen receptor alpha (Esr1, hereafter referred to as ERalpha), estrogen receptor beta (Esr2, hereafter referred to as ERbeta), and androgen receptor (Ar, hereafter referred to as AR) expression in slider turtle gonads before, during and after the TSP, as well as following sex reversal via temperature or steroid hormone manipulation. ERalpha and AR levels spike at the female-producing temperature while ovarian sex is determined, but none of the receptors exhibited sexually dimorphic localization within the gonad prior to morphological differentiation. All three receptors respond differentially to sex-reversing treatments. When shifted to female-producing temperatures, embryos maintain ERalpha and AR expression while ERbeta is reduced. When shifted to male-producing temperatures, medullary expression of all three receptors is reduced. Feminization via estradiol (E(2)) treatment at a male-producing temperature profoundly changed the expression patterns for all three receptors. ERalpha and ERbeta redirected to the cortex in E(2)-created ovaries, while AR medullary expression was transiently reduced. Although warmer incubation temperature and estrogen result in the same endpoint (ovarian development), our results indicate different steroid signaling patterns between temperature- and estrogen-induced feminization. 2007 S. Karger AG, Basel

  14. A Histological Analysis of Visceral Organs to Evaluate the Effect of Duration of Heating From Refrigeration to Core Body Temperature for Ballistics Investigations.

    Science.gov (United States)

    Humphrey, Caitlin; Kumaratilake, Jaliya

    2017-12-01

    Animal organs have been used in ballistics research to investigate the effects on human organs. Such organs are refrigerated until the investigation to minimize autolytic degradation and at times have been reheated to the human core body temperature to simulate the in situ environment. The aim of this investigation was to study the microstructural changes that may occur in fresh chilled visceral organs of the thorax and abdomen (ie, heart, lung, liver, and kidney) during the period of reheating to 37°C. Fifty-millimeter cubes of porcine heart, lung, liver, and kidney were taken rapidly after slaughter, chilled overnight, and the next morning were reheated to core body temperature (37°C). Histological changes occurring in the tissues during the reheating phase were investigated. The findings indicated that no cytoplasmic or nuclear changes occurred in any of the tissues during the period of reheating. Therefore, reheating of animal organs to the human core body temperature is not necessary, if the organs are refrigerated.

  15. Determination of thicknesses and temperatures of crystalline silicon wafers from optical measurements in the far infrared region

    Science.gov (United States)

    Franta, Daniel; Franta, Pavel; Vohánka, Jiří; Čermák, Martin; Ohlídal, Ivan

    2018-05-01

    Optical measurements of transmittance in the far infrared region performed on crystalline silicon wafers exhibit partially coherent interference effects appropriate for the determination of thicknesses of the wafers. The knowledge of accurate spectral and temperature dependencies of the optical constants of crystalline silicon in this spectral region is crucial for the determination of its thickness and vice versa. The recently published temperature dependent dispersion model of crystalline silicon is suitable for this purpose. Because the linear thermal expansion of crystalline silicon is known, the temperatures of the wafers can be determined with high precision from the evolution of the interference patterns at elevated temperatures.

  16. Water temperature, not fish morph, determines parasite infections of sympatric Icelandic threespine sticklebacks (Gasterosteus aculeatus).

    Science.gov (United States)

    Karvonen, Anssi; Kristjánsson, Bjarni K; Skúlason, Skúli; Lanki, Maiju; Rellstab, Christian; Jokela, Jukka

    2013-06-01

    Parasite communities of fishes are known to respond directly to the abiotic environment of the host, for example, to water quality and water temperature. Biotic factors are also important as they affect the exposure profile through heterogeneities in parasite distribution in the environment. Parasites in a particular environment may pose a strong selection on fish. For example, ecological differences in selection by parasites have been hypothesized to facilitate evolutionary differentiation of freshwater fish morphs specializing on different food types. However, as parasites may also respond directly to abiotic environment the parasite risk does not depend only on biotic features of the host environment. It is possible that different morphs experience specific selection gradients by parasites but it is not clear how consistent the selection is when abiotic factors change. We examined parasite pressure in sympatric morphs of threespine stickleback (Gasterosteus aculeatus) across a temperature gradient in two large Icelandic lakes, Myvatn and Thingvallavatn. Habitat-specific temperature gradients in these lakes are opposite. Myvatn lava rock morph lives in a warm environment, while the mud morph lives in the cold. In Thingvallavatn, the lava rock morph lives in a cold environment and the mud morph in a warm habitat. We found more parasites in fish living in higher temperature in both lakes, independent of the fish morph, and this pattern was similar for the two dominating parasite taxa, trematodes and cestodes. However, at the same time, we also found higher parasite abundance in a third morph living in deep cold-water habitat in Thingvallavatn compared to the cold-water lava morph, indicating strong effect of habitat-specific biotic factors. Our results suggest complex interactions between water temperature and biotic factors in determining the parasite community structure, a pattern that may have implications for differentiation of stickleback morphs.

  17. Method for the determination of technical specifications limiting temperature in EBR-II operation

    International Nuclear Information System (INIS)

    Chang, L.K.; Hill, D.J.; Ku, J.Y.

    2004-01-01

    The methodology and analysis procedure to qualify the Mark-V and Mark-VA fuels for the Experimental Breeder Reactor II are summarized in this paper. Fuel performance data and design safety criteria are essential for thermal-hydraulic analyses and safety evaluations. Normal and off-normal operation duty cycles and transient classifications are required for the safety assessment of the fuels. Design safety criteria for steady-state normal and transient off-normal operations were developed to ensure structural integrity of the fuel pin. The maximum allowable coolant outlet temperatures and powers of subassemblies for steady-state normal operation conditions were first determined in a row-by-row basis by a thermal-hydraulic and fuel damage analysis, in which a trial-and-error approach was used to predict the maximum subassembly coolant outlet temperatures and powers that satisfy the design safety criteria for steady-state normal operation conditions. The limiting steady-state temperature and power were then used as the initial subassembly thermal conditions for the off-normal transient analysis to assess the safety performance of the fuel pin for anticipated, unlikely and extremely unlikely events. If the design safety criteria for the off-normal events are not satisfied, then the initial steady-state subassembly temperatures and/or powers are reduced and an iterative procedure is employed until the design safety criteria for off-normal conditions are satisfied, and the initial subassembly outlet coolant temperature and power are the technical specification limits for reactor operation. (author)

  18. Use of Single-Tow Ceramic Matrix Minicomposites to Determine Fundamental Room and Elevated Temperature Properties

    Science.gov (United States)

    Almansour, Amjad S.

    The room and high temperature mechanical properties of continuous ceramic fiber reinforced matrix composites makes them attractive for implementation in aerospace and nuclear applications. However, the effect of fiber content has not been addressed in previous work. Therefore, single tow composites with fiber content ranging from 3 to 47 % was studied. Single fiber tow minicomposite is the basic architectural feature of woven and laminate ceramic matrix composites (CMCs). An in depth understanding of the initiation and evolution of damage in various ceramic fiber reinforced minicomposites with different fiber volume fractions and interphases was investigated employing several non-destructive evaluation techniques. A new technique is used to determine matrix crack content based on a damage parameter derived from speed of sound measurements which is compared with the established method using cumulative energy of Acoustic Emission (AE) events. Also, a modified theoretical model was implemented to obtain matrix stress at the onset of matrix cracking. Room temperature tensile, high temperature creep rupture and high temperature oxidation degradation loading conditions were all considered and composites' constituents were characterized. Moreover, fibers/matrix load sharing was modeled in creep and fiber volume fraction effect on load transfer was investigated using derived theoretical models. Fibers and matrix creep parameters, load transfer model results and numerical model methodology were used to construct minicomposites' creep strain model to predict creep damage of the different fiber type and content minicomposites. Furthermore, different fiber volume fractions ceramic matrix minicomposites' electrical resistivity temperature dependence isn't well understood. Therefore, the influence of fiber content, heat treatment cycles and creep on electrical resistivity measurements of SiC/SiC minicomposites were also studied here. Next, minicomposites' testing and

  19. Design of capacitance measurement module for determining critical cold temperature of tea leaves

    Directory of Open Access Journals (Sweden)

    Yongzong Lu

    2016-12-01

    Full Text Available Critical cold temperature is one of the most crucial control factors for crop frost protection. Tea leaf's capacitance has a significant response to cold injury and appears as a peak response to a typical low temperature which is the critical temperature. However, the testing system is complex and inconvenient. In view of these, a tea leaf's critical temperature detector based on capacitance measurement module was designed and developed to measure accurately and conveniently the capacitance. Software was also designed to measure parameters, record data, query data as well as data deletion module. The detector utilized the MSP430F149 MCU as the control core and ILI9320TFT as the display module, and its software was compiled by IAR5.3. Capacitance measurement module was the crucial part in the overall design which was based on the principle of oscillator. Based on hardware debugging and stability analysis of capacitance measurement module, it was found that the output voltage of the capacitance measurement circuit is stable with 0.36% average deviation. The relationship between capacitance and 1/Uc2 was found to be linear distribution with the determination coefficient above 0.99. The result indicated that the output voltage of capacitance measurement module well corresponded to the change in value of the capacitance. The measurement error of the circuit was also within the required range of 0 to 100 pF which meets the requirement of tea leaf's capacitance. Keywords: Tea leaves, Critical cold temperature, Capacitance peak response, Frost protection, Detector

  20. Numerical and experimental determination of surface temperature and moisture evolution in a field soil

    Science.gov (United States)

    Akinyemi, Olukayode D.; Mendes, Nathan

    2007-03-01

    Knowledge about the dynamics of soil moisture and heat, especially at the surface, provides important insights into the physical processes governing their interactions with the atmosphere, thereby improving the understanding of patterns of climate dynamics. In this context the paper presents the numerical and field experimental results of temperature and moisture evolution, which were measured on the surface of a sandy soil at Abeokuta, south-western Nigeria. An unconditionally stable numerical method was used, which linearizes the vapour concentration driving-potential term giving the moisture exchanged at the boundaries in terms of temperature and moisture content, and simultaneously solves the governing equations for each time step. The model avoids stability problems and limitations to low moisture contents and the usual assumption of constant thermal conductivity. Instantaneous temperature measurements were made at the surface using a thermocouple, while the gravimetric method was employed to determine the volumetric water contents at some specific hours of the experimental period. The observed experimental data compared fairly well with the predicted values, with both having correlation coefficients greater than 0.9 and consequently following a common diurnal trend. The sensitivity of the model was very high to the choice of simulation parameters, especially grid size refinement and time step. While the model underestimated the soil moisture content at 6 a.m. and 10 p.m., the measured temperatures were however overestimated. When compared to moisture content, average errors for temperature were low resulting in a minimal absolute difference in amplitude of 0.81 °C.

  1. Temperature Dependence of Arn+ Cluster Backscattering from Polymer Surfaces: a New Method to Determine the Surface Glass Transition Temperature.

    Science.gov (United States)

    Poleunis, Claude; Cristaudo, Vanina; Delcorte, Arnaud

    2018-01-01

    In this work, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to study the intensity variations of the backscattered Ar n + clusters as a function of temperature for several amorphous polymer surfaces (polyolefins, polystyrene, and polymethyl methacrylate). For all these investigated polymers, our results show a transition of the ratio Ar 2 + /(Ar 2 + + Ar 3 + ) when the temperature is scanned from -120 °C to +125 °C (the exact limits depend on the studied polymer). This transition generally spans over a few tens of degrees and the temperature of the inflection point of each curve is always lower than the bulk glass transition temperature (T g ) reported for the considered polymer. Due to the surface sensitivity of the cluster backscattering process (several nanometers), the presented analysis could provide a new method to specifically evaluate a surface transition temperature of polymers, with the same lateral resolution as the gas cluster beam. Graphical abstract ᅟ.

  2. Gonadal expression of Sf1 and aromatase during sex determination in the red-eared slider turtle (Trachemys scripta), a reptile with temperature-dependent sex determination.

    Science.gov (United States)

    Ramsey, Mary; Shoemaker, Christina; Crews, David

    2007-12-01

    Many egg-laying reptiles have temperature-dependent sex determination (TSD), where the offspring sex is determined by incubation temperature during a temperature-sensitive period (TSP) in the middle third of development. The underlying mechanism transducing a temperature cue into an ovary or testis is unknown, but it is known that steroid hormones play an important role. During the TSP, exogenous application of estrogen can override a temperature cue and produce females, while blocking the activity of aromatase (Cyp19a1), the enzyme that converts testosterone to estradiol, produces males from a female-biased temperature. The production of estrogen is a key step in ovarian differentiation for many vertebrates, including TSD reptiles, and temperature-based differences in aromatase expression during the TSP may be a critical step in ovarian determination. Steroidogenic factor-1 (Sf1) is a key gene in vertebrate sex determination and regulates many steroidogenic enzymes, including aromatase. We find that Sf1 and aromatase are differentially expressed during sex determination in the red-eared slider turtle, Trachemys scripta elegans. Sf1 is expressed at higher levels during testis development while aromatase expression increases during ovary determination. We also assayed Sf1 and aromatase response to sex-reversing treatments via temperature or the modulation of estrogen availability. Sf1 expression was redirected to low-level female-specific patterns with feminizing temperature shift or exogenous estradiol application and redirected to more intense male-specific patterns with male-producing temperature shift or inhibition of aromatase activity. Conversely, aromatase expression was redirected to more intense female-specific patterns with female-producing treatment and redirected toward diffuse low-level male-specific patterns with masculinizing sex reversal. Our data do not lend support to a role for Sf1 in the regulation of aromatase expression during slider turtle sex

  3. Determination of total carbonates in soil archaeometry using a new pressure method with temperature compensation

    Science.gov (United States)

    Barouchas, Pantelis; Koulos, Vasilios; Melfos, Vasilios

    2017-04-01

    For the determination of total carbonates in soil archaeometry a new technique was applied using a multi-sensor philosophy, which combines simultaneous measurement of pressure and temperature. This technology is innovative and complies with EN ISO 10693:2013, ASTM D4373-02(2007) and Soil Science Society of America standard test methods for calcium carbonate content in soils and sediments. The total carbonates analysis is based on a pressure method that utilizes the FOGII Digital Soil CalcimeterTM, which is a portable apparatus. The total carbonate content determined by treating a 1.000 g (+/- 0.001 g) dried sample specimens with 6N hydrochloric acid (HCL) reagent grade, in an enclosed reaction vessel. Carbon dioxide gas evolved during the reaction between the acid and carbonate fraction of the specimen, was measured by the resulting pressure generated, taking in account the temperature conditions during the reaction. Prior to analysis the procedure was validated with Sand/Soil mixtures from BIPEA proficiency testing program with soils of different origins. For applying this new method in archaeometry a total number of ten samples were used from various rocks which are related with cultural constructions and implements in Greece. They represent a large range of periods since the Neolithic times, and were selected because there was an uncertainty about their accurate mineralogical composition especially regarding the presence of carbonate minerals. The results were compared to the results from ELTRA CS580 inorganic carbon analyzer using an infrared cell. The determination of total carbonates for 10 samples from different ancient sites indicated a very good correlation (R2 >0.97) between the pressure method with temperature compensation and the infrared method. The proposed method is quickly and accurate in archaeometry and can replace easily other techniques for total carbonates testing. The FOGII Digital Soil CalcimeterTM is portable and easily can be carried for

  4. Operating Cell Temperature Determination in Flat-Plate Photovoltaic Modules; Calculo de la Temperature de Operacion de Celulas Solares en un Panel Fotovoltaico Plano

    Energy Technology Data Exchange (ETDEWEB)

    Chenlo, F.

    2002-07-01

    Two procedures (simplified and complete) to determine the operating cell temperature in photovoltaic modules operating in real conditions assuming isothermal stationary modules are presented in this work. Some examples are included that show the dependence of this temperature on several environment (sky, ground and ambient temperatures, solar irradiance, wind speed, etc.) and structural (module geometry and size, encapsulating materials, antirreflexive optical coatings, etc) factors and also on electrical module performance. In a further step temperature profiles for non-isothermal modules are analysed besides transitory effects due to variable irradiance and wind gusts. (Author)

  5. Current status on techniques for determining paleo-temperature using geothermometer

    International Nuclear Information System (INIS)

    Kanazawa, Sunao; Oikawa, Teruki; Umeda, Koji; Tomiyama, Shingo

    2005-01-01

    Development of the research technologies for geotectonic events has been carried out to evaluate the long-term stability of geological environment. In terms of the effects of geothermal activity, it is necessary to estimate the geothermal regime and thermal history on any given site. This paper describes the current status on techniques for determining paleo-temperature using geothermometer, and presents a concept of the systematic research techniques. The application of geothermometer, especially thermochronology, has been effective in the studies on the cooling history of geological body and the paleo-geothermal structure at depth. (author)

  6. Determination of Ground Heat Exchangers Temperature Field in Geothermal Heat Pumps

    Science.gov (United States)

    Zhurmilova, I.; Shtym, A.

    2017-11-01

    For the heating and cooling supply of buildings and constructions geothermal heat pumps using low-potential ground energy are applied by means of ground exchangers. The process of heat transfer in a system of ground exchangers is a phenomenon of complex heat transfer. The paper presents a mathematical modeling of heat exchange processes, the temperature fields are built which are necessary for the determination of the ground array that ensures an adequate supply of low potential energy excluding the freezing of soil around the pipes in the ground heat exchangers and guaranteeing a reliable operation of geothermal heat pumps.

  7. Determination of hydration numbers of electrolytes from temperature dependence of PMR chemical shifts

    International Nuclear Information System (INIS)

    Subramanian, N.

    1979-01-01

    The method proposed by Malinowski et al. for the determination of effective hydration numbers (h) of electrolytes leads to a consistent incrrease in the observed values of 'h' with increase in solution concentration. An attempt is made to rationalize the experimental results by cosidering the simultaneous effects of temperature and concentration on the proton chemical shift. It is suggested that Malinowski's technique might yeld 'h' values very close to the true value for those ions for which there is a fortuitous cancellation of structure-making and structure-breaking properties. (Author) [pt

  8. Is the thermal-spike model consistent with experimentally determined electron temperature?

    International Nuclear Information System (INIS)

    Ajryan, Eh.A.; Fedorov, A.V.; Kostenko, B.F.

    2000-01-01

    Carbon K-Auger electron spectra from amorphous carbon foils induced by fast heavy ions are theoretically investigated. The high-energy tail of the Auger structure showing a clear projectile charge dependence is analyzed within the thermal-spike model framework as well as in the frame of another model taking into account some kinetic features of the process. A poor comparison results between theoretically and experimentally determined temperatures are suggested to be due to an improper account of double electron excitations or due to shake-up processes which leave the system in a more energetic initial state than a statically screened core hole

  9. Determination of the liquidus temperature of tin using the heat pulse-based melting and comparison with traditional methods

    Science.gov (United States)

    Joung, Wukchul; Park, Jihye; Pearce, Jonathan V.

    2018-06-01

    In this work, the liquidus temperature of tin was determined by melting the sample using the pressure-controlled loop heat pipe. Square wave-type pressure steps generated periodic 0.7 °C temperature steps in the isothermal region in the vicinity of the tin sample, and the tin was melted with controllable heat pulses from the generated temperature changes. The melting temperatures at specific melted fractions were measured, and they were extrapolated to the melted fraction of unity to determine the liquidus temperature of tin. To investigate the influence of the impurity distribution on the melting behavior, a molten tin sample was solidified by an outward slow freezing or by quenching to segregate the impurities inside the sample with concentrations increasing outwards or to spread the impurities uniformly, respectively. The measured melting temperatures followed the local solidus temperature variations well in the case of the segregated sample and stayed near the solidus temperature in the quenched sample due to the microscopic melting behavior. The extrapolated melting temperatures of the segregated and quenched samples were 0.95 mK and 0.49 mK higher than the outside-nucleated freezing temperature of tin (with uncertainties of 0.15 mK and 0.16 mK, at approximately 95% level of confidence), respectively. The extrapolated melting temperature of the segregated sample was supposed to be a closer approximation to the liquidus temperature of tin, whereas the quenched sample yielded the possibility of a misleading extrapolation to the solidus temperature. Therefore, the determination of the liquidus temperature could result in different extrapolated melting temperatures depending on the way the impurities were distributed within the sample, which has implications for the contemporary methodology for realizing temperature fixed points of the International Temperature Scale of 1990 (ITS-90).

  10. Experimental determination of neutron temperature distribution in reactor cell; Eksperimentalno odredjivanje raspodele neutronske temperature u celiji reaktorske resetke

    Energy Technology Data Exchange (ETDEWEB)

    Bosevski, T [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1965-12-15

    This paper describes theoretical preparation of the experiment for measuring neutron temperature distribution at the RB reactor by activation foils. Due to rather low neutron flux Cu and Lu foil were irradiated for 4 days. Special natural uranium fuel element was prepared to enable easy removal of foils after irradiation. Experimental device was placed in the reactor core at half height in order to measure directly the mean neutron density. Experimental data of neutron temperature distribution for square lattice pitch 16 cm are presented with mean values of neutron temperature in the moderator, in the fuel and on the fuel element surface.

  11. A probabilistic method for determining effluent temperature limits for flow instability for SRS reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, B.J.; White, A.M.

    1990-06-01

    This manual describes the uncertainty analysis used to determine the effluent temperature limits for a Mark 22 charge in the Savannah River Site production reactors. The postulated accident scenario is a DEGB/LOCA resulting from a coolant pipe break at the plenum inlet accompanied by the safety rod failure described in the previous chapter. The analysis described in this manual is used to calculate the limits for the flow instability phase of the accident. For this phase of the accident, the limits criterion is that the Stanton number does not exceed 0.00455 [1]. The limits are determined for a specified 84% probability that the Stanton number will not exceed 0.00455 in any assembly in the core.

  12. On determination of enthalpies of complex formation reactions by means of temperature coefficient of complexing degree

    International Nuclear Information System (INIS)

    Povar, I.G.

    1995-01-01

    Equations describing the relation between temperature coefficient of ∂lnα/∂T complexing degree and the sum of changes in the enthalpy of complex formation of the composition M m L n δH mn multiplied by the weight coefficients k mm , are presented. A method to determine changes in the enthalpy of certain ΔH mm reactions from ∂lnα/∂T derivatives has been suggested. The best approximating equation from lnα/(T) dependence has been found. Errors of thus determined δH mm values are estimated and the results of calculation experiment for the system In 3+ -F - are provided. 10 refs., 2 figs., 3 tabs

  13. A probabilistic method for determining effluent temperature limits for flow instability for SRS reactors

    International Nuclear Information System (INIS)

    Hardy, B.J.; White, A.M.

    1990-06-01

    This manual describes the uncertainty analysis used to determine the effluent temperature limits for a Mark 22 charge in the Savannah River Site production reactors. The postulated accident scenario is a DEGB/LOCA resulting from a coolant pipe break at the plenum inlet accompanied by the safety rod failure described in the previous chapter. The analysis described in this manual is used to calculate the limits for the flow instability phase of the accident. For this phase of the accident, the limits criterion is that the Stanton number does not exceed 0.00455 [1]. The limits are determined for a specified 84% probability that the Stanton number will not exceed 0.00455 in any assembly in the core

  14. Determination of Cardinal Temperatures for Cool Season Turfgrass and Two Common Weed Species

    Directory of Open Access Journals (Sweden)

    Marjan Diayanat

    2018-02-01

    Full Text Available Introduction The presence of broadleaf weeds not only reduces the aesthetic quality of the turfgrass, but more importantly they compete with desired turfgrass for water, nutrients, and light. Weed management after seeding is an important component to successfully establishing a healthy stand of cool season turfgrass. Weed seed germination is a key process because determines both the number of weeds that could potentially emerge and the timing of their appearance in the turfgrass. Temperature is of the most important factor regulating germination of non-dormant seeds in irrigated, annual agroecosystems at the beginning of the growth season where light, nutrients, and moisture are typically not growth limiting. Also prostrate knotweed (Polygonum aviculare L. and annual sowthistle (Sonchus oleraceus L. are two annual common broad leaf weeds in cool season turfgrass. Prostrate knotweed is very competitive in infertile and compacted soils and often invades turfgrasses along driveways, sidewalks, and beaten paths across lawns. Annual sowthistle is found in open habitats that include waste areas, turf, and roadsides. The aim of this study was to evaluate different nonlinear regression models to describe response of germination rate to different temperatures in perennial ryegrass (Lolium perenne L., fescue (Festuca rubra L., prostrate knotweed and annual sowthistle. Materials and Methods This experiment was based on completely randomized design with 4 replications at Islamic Azad University in the laboratory of Science Research Branch in 2015. The seeds were treated with different temperatures (2, 5, 10, 15, 20, 25, 30, 35, 40 and 45oC Twenty five seeds were placed in each petri dish for each species in per replication. Ten milliliters of distilled water were added to each petri dish and the filter papers were regularly moistened to ensure saturation throughout the germination tests. Petri dishes were placed in germinator with 16 hour day, 8 hour night

  15. A system to control low pressure turbine temperatures

    International Nuclear Information System (INIS)

    1980-01-01

    An improved system to control low pressure turbine cycle steam and metal temperatures by governing the heat transfer operation in a moisture separator-reheater is described. The use of the present invention in a pressurized water reactor or a boiling water reactor steam turbine system is demonstrated. (UK)

  16. Exergy based parametric analysis of a combined reheat regenerative thermal power plant and water–LiBr vapor absorption refrigeration system

    International Nuclear Information System (INIS)

    Gogoi, T.K.; Talukdar, K.

    2014-01-01

    Highlights: • Exergy analysis of a combined power–absorption cooling system is provided. • Exergetic efficiency of the power cycle and absorption cooling system are calculated. • Irreversibility in each component and total system irreversibility are calculated. • Effect of operating parameters on exergetic performance and irreversibility is analyzed. • Optimum operating parameters are identified based on energy and exergy based results. - Abstract: In this paper, exergy analysis of a combined reheat regenerative steam turbine (ST) based power cycle and water–LiBr vapor absorption refrigeration system (VARS) is presented. Exergetic efficiency of the power cycle and VARS, energy utilization factor (EUF) of the combined system (CS) and irreversibility in each system component are calculated. The effect of fuel flow rate, boiler pressure, cooling capacity and VARS components’ temperature on performance, component and total system irreversibility is analyzed. The second law based results indicate optimum performance at 150 bar boiler pressure and VARS generator, condenser, evaporator and absorber temperature of 80 °C, 37.5 °C, 15 °C and 35 °C respectively. The present exergy based results conform well to the first law based results obtained in a previous analysis done on the same combined system. Irreversibility distribution among various power cycle components shows the highest irreversibility in the cooling tower. Irreversibility of the exhaust flue gas leaving the boiler and the boiler are the next major contributors. Among the VARS components, exergy destruction in the generator is the highest followed by irreversibility contribution of the absorber, condenser and the evaporator

  17. A new method for the determination of vaporization enthalpies of ionic liquids at low temperatures.

    Science.gov (United States)

    Verevkin, Sergey P; Zaitsau, Dzmitry H; Emelyanenko, Vladimir N; Heintz, Andreas

    2011-11-10

    A new method for the determination of vaporization enthalpies of extremely low volatile ILs has been developed using a newly constructed quartz crystal microbalance (QCM) vacuum setup. Because of the very high sensitivity of the QCM it has been possible to reduce the average temperature of the vaporization studies by approximately 100 K in comparison to other conventional techniques. The physical basis of the evaluation procedure has been developed and test measurements have been performed with the common ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [C(2)mim][NTf(2)] extending the range of measuring vaporization enthalpies down to 363 K. The results obtained for [C(2)mim][NTf(2)] have been tested for thermodynamic consistency by comparison with data already available at higher temperatures. Comparison of the temperature-dependent vaporization enthalpy data taken from the literature show only acceptable agreement with the heat capacity difference of -40 J K(-1) mol(-1). The method developed in this work opens also a new way to obtain reliable values of vaporization enthalpies of thermally unstable ionic liquids.

  18. Determination of Proper Austenitization Temperatures for Hot Stamping of AISI 4140 Steel

    Science.gov (United States)

    Samadian, Pedram; Parsa, Mohammad Habibi; Shakeri, Amid

    2014-04-01

    High strength steels are desirable materials for use in automobile bodies in order to reduce vehicle weight and increase the safety of car passengers, but steel grades with high strength commonly show poor formability. Recently, steels with controlled microstructures and compositions are used to gain adequate strength after hot stamping while maintaining good formability during processing. In this study, microstructure evolutions and changes in mechanical properties of AISI 4140 steel sheets resulting from the hot stamping process at different austenitization temperatures were investigated. To determine the proper austenitization temperatures, the results were compared with those of the cold-worked and cold-worked plus quench-tempered specimens. Comparisons showed that the austenitization temperatures of 1000 and 1100 °C are proper for hot stamping of 3-mm-thick AISI 4140 steel sheets due to the resultant martensitic microstructure which led to the yield and ultimate tensile strength of 1.3 and 2.1 GPa, respectively. Such conditions resulted in more favorable simultaneous strength and elongation than those of hot-stamped conventional boron steels.

  19. Tekken testing to determine the preheating temperature on ASTM A514 GR B steel

    International Nuclear Information System (INIS)

    Asta, Eduardo; Zalazar, Monica; Quesada, Hector

    2003-01-01

    The cold cracking test methods are used to determine the preheating temperature in order to avoid cracking in steel welding.In this work Tekken tests on high strength quenching and tempering (ASTM A514 GrB) structural steel with a thickness of 25 mm have been made.The welds were done using a FCAW process with gas shielding and basic low hydrogen cored wire E 110T5-K4.The welding parameters and joint design applied in this work are similar to the ones used on site production.The base metal, HAZ and weld metal microstructure have been evaluated by optical and SEM microscopy.Thermal cycles records of each welding have been made to relate preheat temperature with the cooling time on the range of 800-500 degC (t8/5) or 800-100degC (t8/1) and the evidence of crack or no crack condition.Finally, a preheat temperature of 150degC and the cooling time larger than 17 s improve a welding integrity without cracks

  20. Electron temperature determination from the HeI 3889 angstroem and 5016 angstroem line intensities

    International Nuclear Information System (INIS)

    Brenning, N.

    1979-03-01

    The possibility of determining electron temperature by helium spectro scopy in low-density (n(sub e) 2 m - ) plasmas is discussed. It is concluded that most lines can only be used at very low densities (n(sub e) 1 m - ) because the line intensities are highly influenced by secondary processes, such as electron impact induced transitions between excited levels or excitations from metastable levels. The density range where measurements are possible can extended if the influence of these secondary processes on the line intensities can be determined. For most helium I lines this is impossible for lack of atomic data. However, there are two exceptions, the 3889 angstroem (3 3 P yields 2 3 S) and the 5016 angstroem (3 1 yields 2 1 S) lines. The influence from secondary processes on these lines is calculated, and methods are developed which can be used for measurement of electron temperatures T(sub e 1 m - . The use of the methods is illustrated by a experiment where they have been successfully applied. (author)

  1. Effective temperatures and scattering cross sections in water mixtures determined by Deep Inelastic Neutron Scattering

    International Nuclear Information System (INIS)

    Dawidowski, J.; Rodríguez Palomino, L.A.; Márquez Damián, J.I.; Blostein, J.J.; Cuello, G.J.

    2016-01-01

    Highlights: • Effective temperatures of atoms can be determined by the DINS technique. • This is the first time that such application of this experimental technique is made. • This technique is able to measure the known cross sections of the atoms. • No anomalous cross section was found, at variance with Dreissmann’s et al. claims. - Abstract: The present work shows a series of results of Deep Inelastic Neutron Scattering (DINS) experiments on light and heavy water mixtures performed at the spectrometer VESUVIO (Rutherford Appleton Laboratory, UK) employing an analysis method based on the information provided by individual detectors in forward and backward scattering positions. We investigated the effective temperatures of the different atoms composing the samples, a magnitude of considerable interest for Nuclear Engineering. The peak intensities and their relation with the bound-atom cross sections is analyzed, showing a good agreement with tabulated values which supports the use of this technique as non-destructive mass spectrometry. Previous results in the determination of scattering cross sections by this technique (known in the literature) that were at variance with the present findings are commented.

  2. The accuracy of liquid-liquid phase transition temperatures determined from semiautomated light scattering measurements

    Science.gov (United States)

    Dean, Kevin M.; Babayco, Christopher B.; Sluss, Daniel R. B.; Williamson, J. Charles

    2010-08-01

    The synthetic-method determination of liquid-liquid coexistence curves using semiautomated light scattering instrumentation and stirred samples is based on identifying the coexistence curve transition temperatures (Tcx) from sudden changes in turbidity associated with droplet formation. Here we use a thorough set of such measurements to evaluate the accuracy of several different analysis methods reported in the literature for assigning Tcx. More than 20 samples each of weakly opalescent isobutyric acid+water and strongly opalescent aniline+hexane were tested with our instrumentation. Transmitted light and scattering intensities at 2°, 24°, and 90° were collected simultaneously as a function of temperature for each stirred sample, and the data were compared with visual observations and light scattering theory. We find that assigning Tcx to the onset of decreased transmitted light or increased 2° scattering has a potential accuracy of 0.01 K or better for many samples. However, the turbidity due to critical opalescence obscures the identification of Tcx from the light scattering data of near-critical stirred samples, and no simple rule of interpretation can be applied regardless of collection geometry. At best, when 90° scattering is collected along with transmitted or 2° data, the accuracy of Tcx is limited to 0.05 K for near-critical samples. Visual determination of Tcx remains the more accurate approach in this case.

  3. Tekken tests in a steel 'ASTM A 514 GR B' to determine the preheating temperature

    International Nuclear Information System (INIS)

    Quesada, Hector Juan; Zalazar, Monica; Asta, Eduardo Pablo

    2004-01-01

    Cold fissure tests are used to determine the proper preheating temperature in order to prevent fissures during the steel welding process. Tekken tests were carried out on a quenched and tempered high resistance 25.4 mm thick steel (ASTM A514 Gr.B) used in structural applications. The welding was carried out using a FCAW semiautomatic process with gas protection and low hydrogen tubular electrode E110T5-K4. Similar parameters and splicing design were later applied in production. The microstructures of the base material and the welding were determined by optic and electron microscopy. The thermal cycles of the welding were recorded in order to relate the preheating temperature with the cooling time from 800 o C - 500 o C (t 8/5 ) and from 800 o C - 100 o C (tg/1) and the presence or not of fissures. Preheating at 150 o C and t 8/5 greater than 17 s was found to guarantee fissure free welding (CW)

  4. Temperature-dependent sex determination modulates cardiovascular maturation in embryonic snapping turtles Chelydra serpentina.

    Science.gov (United States)

    Alvine, Travis; Rhen, Turk; Crossley, Dane A

    2013-03-01

    We investigated sex differences in cardiovascular maturation in embryos of the snapping turtle Chelydra serpentina, a species with temperature-dependent sex determination. One group of eggs was incubated at 26.5°C to produce males. Another group of eggs was incubated at 26.5°C until embryos reached stage 17; eggs were then shifted to 31°C for 6 days to produce females, and returned to 26.5°C for the rest of embryogenesis. Thus, males and females were at the same temperature when autonomic tone was determined and for most of development. Cholinergic blockade increased resting blood pressure (P(m)) and heart rate (f(H)) in both sexes at 75% and 90% of incubation. However, the magnitude of the f(H) response was enhanced in males compared with females at 90% of incubation. β-adrenergic blockade increased P(m) at 75% of incubation in both sexes but had no effect at 90% of incubation. β-adrenergic blockade reduced f(H) at both time points but produced a stronger response at 90% versus 75% of incubation. We found that α-adrenergic blockade decreased P(m) in both sexes at 75% and 90% of incubation and decreased f(H) at 75% of incubation in both sexes. At 90% of incubation, f(H) decreased in females but not males. Although these data clearly demonstrate sexual dimorphism in the autonomic regulation of cardiovascular physiology in embryos, further studies are needed to test whether differences are caused by endocrine signals from gonads or by a hormone-independent temperature effect.

  5. Bringing VY Canis Majoris Down to Size: An Improved Determination of Its Effective Temperature

    Science.gov (United States)

    Massey, Philip; Levesque, Emily M.; Plez, Bertrand

    2006-08-01

    The star VY CMa is a late-type M supergiant with many peculiarities, mostly related to the intense circumstellar environment due to the star's high mass-loss rate. Claims have been made that would imply that this star is considerably more luminous (L~5×105 Lsolar) and larger (R~2800 Rsolar) than other Galactic red supergiants (RSGs). Indeed, such a location in the H-R diagram would be well within the ``Hayashi forbidden zone,'' where stars cannot be in hydrostatic equilibrium. These extraordinary properties, however, rest on an assumed effective temperature of 2800-3000 K, far cooler than recent work has shown RSGs to be. To obtain a better estimate, we fit newly obtained spectrophotometry in the optical and NIR with the same MARCS models used for our recent determination of the physical properties of other RSGs; we also use V-K and V-J from the literature to derive an effective temperature. We find that the star likely has a temperature of 3650 K, a luminosity L~6×104 Lsolar, and a radius of ~600 Rsolar. These values are consistent with VY CMa being an ordinary, evolved 15 Msolar RSG and agree well with the Geneva evolutionary tracks. We find that the circumstellar dust region has a temperature of 760 K, and an effective radius of ~130 AU, if spherical geometry is assumed for the latter. What causes this star to have such a high mass loss and large variations in brightness (but with little change in color) remains a mystery at present, although we speculate that perhaps this star and NML Cyg are simply normal RSGs caught during an unusually unstable time.

  6. Determination of the mobility ratio in InSb at the temperature of the conductivity type conversion

    Energy Technology Data Exchange (ETDEWEB)

    Somogyi, K. [Research Institute for Technical Physics and Materials Science, HAS, 1525 Budapest, P.O. Box 49 (Hungary)

    2005-05-01

    The temperature dependence of magneto-transport in bulk p-type InSb was investigated, and a special approach was applied for the precise determination of the temperature dependence. Such measurements also allow the determination of the mobility ratio (b) which is known to be large in InSb. Although this type of investigation is standard, in this work an improved method of carrying out temperature-dependent Hall measurements is reported and improved calculations for the determination of large b values in InSb are presented. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Determination of equilibrium humidities using temperature and humidity controlled X-ray diffraction (RH-XRD)

    International Nuclear Information System (INIS)

    Linnow, Kirsten; Steiger, Michael

    2007-01-01

    Confined growth of crystals in porous building materials is generally considered to be a major cause of damage. We report on the use of X-ray diffraction under controlled conditions of temperature and relative humidity (RH-XRD) for the investigation of potentially deleterious phase transition reactions. An improved procedure based on rate measurements is used for the accurate and reproducible determination of equilibrium humidities of deliquescence and hydration reactions. The deliquescence humidities of NaCl (75.4 ± 0.5% RH) and Ca(NO 3 ) 2 .4H 2 O (50.8 ± 0.7% RH) at 25 deg. C determined with this improved RH-XRD technique are in excellent agreement with available literature data. Measurement of the hydration of anhydrous Ca(NO 3 ) 2 to form Ca(NO 3 ) 2 .2H 2 O revealed an equilibrium humidity of 10.2 ± 0.3%, which is also in reasonable agreement with available data. In conclusion, dynamic X-ray diffraction measurements are an appropriate method for the accurate and precise determination of equilibrium humidities with a number of interesting future applications

  8. Determining the potential independent critical pitting temperature (CPT) by a potentiostatic method using the Avesta Cell

    International Nuclear Information System (INIS)

    Arnvig, P.E.; Bisgard, A.D.

    1996-01-01

    The development of a potentiostatic method for determining the potential independent Critical Pitting Temperature (CPT) using the Avesta Cell is presented. The new potentiostatic method has been used to determine the CPT for austenitic stainless steels. The precision of the potentiostatic method of approximately ±2 C is close to that of the traditional potentiodynamic method. The time required to determine a CPT is much shorter than when using the potentiodynamic method. A CPT is obtained within 1.5 to 3 hours for each specimen. The influence of various experimental parameters such as electrochemical potential, evaluation criteria for the CPT, test area, stabilization time prior to polarization and inert gas purging is described. The lack of sensitivity towards many of these parameters as well as the high reproducibility obtained is associated with fundamentals of the pitting process. It is argued that the potential independent CPT characterizes the stable propagating pitting event as opposed to the potential dependent CPT or pitting potentials, which to a larger extent are affected by the nucleation part of the pitting process

  9. Determination of surface coverage of catalysts : temperature programmed experiments on platinum and iridium sponge catalysts after low temperature ammonia oxidation

    NARCIS (Netherlands)

    van den Broek, A.C.M.; Grondelle, van J.; Santen, van R.A.

    1999-01-01

    The activity of iridium and platinum sponge catalysts was studied in the low temperature gas phase oxidation of ammonia with oxygen. Under the reaction conditions used, iridium was found to be more active and more selective to nitrogen than platinum. Furthermore it was established from activity

  10. Comparison of elastic and inelastic seismic response of high temperature piping systems

    International Nuclear Information System (INIS)

    Thomas, F.M.; McCabe, S.L.; Liu, Y.

    1994-01-01

    A study of high temperature power piping systems is presented. The response of the piping systems is determined when subjected to seismic disturbances. Two piping systems are presented, a main steam line, and a cold reheat line. Each of the piping systems are modeled using the ANSYS computer program and two analyses are performed on each piping system. First, each piping system is subjected to a seismic disturbance and the pipe material is assumed to remain linear and elastic. Next the analysis is repeated for each piping system when the pipe material is modeled as having elastic-plastic behavior. The results of the linear elastic analysis and elastic-plastic analysis are compared for each of the two pipe models. The pipe stresses, strains, and displacements, are compared. These comparisons are made so that the effect of the material yielding can be determined and to access what error is made when a linear analysis is performed on a system that yields

  11. Incubation temperature and gonadal sex affect growth and physiology in the leopard gecko (Eublepharis macularius), a lizard with temperature-dependent sex determination.

    Science.gov (United States)

    Tousignant, A; Crews, D

    1995-05-01

    Temperature-dependent sex determination (TSD), in which the temperature at which an egg incubates determines the sex of the individual, occurs in egg-laying reptiles of three separate orders. Previous studies have shown that the embryonic environment can have effects lasting beyond the period of sex determination. We investigated the relative roles of incubation temperature, exogenous estradiol, and gonadal sex (testis vs. ovary) in the differentiation of adult morphological and physiological traits of the leopard gecko, Eublepharis macularius. The results indicate that incubation temperature, steroid hormones, and gonads interact in the development of morphological and physiological characters with incubation temperature resulting in the greatest differences in adult phenotype. Incubation temperature did not affect reproductive success directly, but may influence offspring survival in natural situations through effects on adult female body size. Postnatal hormones seem to be more influential in the formation of adult phenotypes than prenatal hormones. These results demonstrate that TSD species can be used to investigate the effects of the physical environment on development in individuals without a predetermined genetic sex and thus provide further insight into the roles of gonadal sex and the embryonic environment in sexual differentiation.

  12. Determining water use of sorghum from two-source energy balance and radiometric temperatures

    Directory of Open Access Journals (Sweden)

    J. M. Sánchez

    2011-10-01

    Full Text Available Estimates of surface actual evapotranspiration (ET can assist in predicting crop water requirements. An alternative to the traditional crop-coefficient methods are the energy balance models. The objective of this research was to show how surface temperature observations can be used, together with a two-source energy balance model, to determine crop water use throughout the different phenological stages of a crop grown. Radiometric temperatures were collected in a sorghum (Sorghum bicolor field as part of an experimental campaign carried out in Barrax, Spain, during the 2010 summer growing season. Performance of the Simplified Two-Source Energy Balance (STSEB model was evaluated by comparison of estimated ET with values measured on a weighing lysimeter. Errors of ±0.14 mm h−1 and ±1.0 mm d−1 were obtained at hourly and daily scales, respectively. Total accumulated crop water use during the campaign was underestimated by 5%. It is then shown that thermal radiometry can provide precise crop water necessities and is a promising tool for irrigation management.

  13. ELECTRON TEMPERATURES OF PLANETARY NEBULAE DETERMINED FROM THE He I DISCONTINUITIES

    International Nuclear Information System (INIS)

    Zhang, Y.; Nakashima, J.; Kwok, S.; Yuan, H.-B.; Liu, X.-W.; Hua, C.-T.

    2009-01-01

    We have used the He I discontinuities at 3421 A to determine the electron temperatures, designated T e (He I), for a sample of five Galactic planetary nebulae (PNe). We compared T e (He I) with the electron temperatures derived from the hydrogen Balmer jump at 3646 A, designated T e (H I), and found that T e (He I) are generally lower than T e (H I). There are two possible interpretations, (1) the presence of substantial He 2+ zone, or (2) the presence of hydrogen-deficient cold clumps within diffuse nebulae. A series of photoionization models were constructed to test the two scenarios. We found that the observed T e (He I)/T e (H I) discrepancies are beyond the predictions of chemically homogeneous models. Our modeling shows that the presence of a small amount of hydrogen-deficient inclusions seems to be able to reproduce the observed intensities of He I discontinuities. We stress the value of He I discontinuities in investigating nebular physical conditions. Albeit with some observational and technical limitations, He I discontinuities should be considered in future modeling work.

  14. Mechanisms Controlling Global Mean Sea Surface Temperature Determined From a State Estimate

    Science.gov (United States)

    Ponte, R. M.; Piecuch, C. G.

    2018-04-01

    Global mean sea surface temperature (T¯) is a variable of primary interest in studies of climate variability and change. The temporal evolution of T¯ can be influenced by surface heat fluxes (F¯) and by diffusion (D¯) and advection (A¯) processes internal to the ocean, but quantifying the contribution of these different factors from data alone is prone to substantial uncertainties. Here we derive a closed T¯ budget for the period 1993-2015 based on a global ocean state estimate, which is an exact solution of a general circulation model constrained to most extant ocean observations through advanced optimization methods. The estimated average temperature of the top (10-m thick) level in the model, taken to represent T¯, shows relatively small variability at most time scales compared to F¯, D¯, or A¯, reflecting the tendency for largely balancing effects from all the latter terms. The seasonal cycle in T¯ is mostly determined by small imbalances between F¯ and D¯, with negligible contributions from A¯. While D¯ seems to simply damp F¯ at the annual period, a different dynamical role for D¯ at semiannual period is suggested by it being larger than F¯. At periods longer than annual, A¯ contributes importantly to T¯ variability, pointing to the direct influence of the variable ocean circulation on T¯ and mean surface climate.

  15. Prediction and experimental determination of the solubility of exotic scales at high temperatures - Zinc sulfide

    DEFF Research Database (Denmark)

    Carolina Figueroa Murcia, Diana; Fosbøl, Philip Loldrup; Thomsen, Kaj

    2016-01-01

    The presence of "exotic" scale such as Zinc Sulfide (ZnS), Lead Sulfide (PbS) and Iron Sulfide (FeS) in HP/HT reservoirs has been identified. "Exotic" scale materials come as a new challenge in HP/HT reservoirs. This has led to the development of more advanced tools to predict their behavior...... at extreme conditions. The aim of this work is to include ZnS into the group of scale materials that can be modeled with the Extended UNIQUAC model. Solubility data for ZnS are scarce in the open literature. In order to improve the available data, we study the experimental behavior of ZnS solubility at high...... temperatures. The determination of the solubility of ZnS is carried out at temperatures up to 250°C. Zinc sulfide (99.99%) and ultra-pure water are placed in a vial in a reduced oxygen atmosphere. The sample is placed in a controlled bath and stirred until equilibrium is attained. The suspension is filtered...

  16. Determination of Intracellular Vitrification Temperatures for Unicellular Micro Organisms under Conditions Relevant for Cryopreservation.

    Science.gov (United States)

    Fonseca, Fernanda; Meneghel, Julie; Cenard, Stéphanie; Passot, Stéphanie; Morris, G John

    2016-01-01

    During cryopreservation ice nucleation and crystal growth may occur within cells or the intracellular compartment may vitrify. Whilst previous literature describes intracellular vitrification in a qualitative manner, here we measure the intracellular vitrification temperature of bacteria and yeasts under conditions relevant to cryopreservation, including the addition of high levels of permeating and nonpermeating additives and the application of rapid rates of cooling. The effects of growth conditions that are known to modify cellular freezing resistance on the intracellular vitrification temperature are also examined. For bacteria a plot of the activity on thawing against intracellular glass transition of the maximally freeze-concentrated matrix (Tg') shows that cells with the lowest value of intracellular Tg' survive the freezing process better than cells with a higher intracellular Tg'. This paper demonstrates the role of the physical state of the intracellular environment in determining the response of microbial cells to preservation and could be a powerful tool to be manipulated to allow the optimization of methods for the preservation of microorganisms.

  17. Standard test method for determination of reference temperature, to, for ferritic steels in the transition range

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This test method covers the determination of a reference temperature, To, which characterizes the fracture toughness of ferritic steels that experience onset of cleavage cracking at elastic, or elastic-plastic KJc instabilities, or both. The specific types of ferritic steels (3.2.1) covered are those with yield strengths ranging from 275 to 825 MPa (40 to 120 ksi) and weld metals, after stress-relief annealing, that have 10 % or less strength mismatch relative to that of the base metal. 1.2 The specimens covered are fatigue precracked single-edge notched bend bars, SE(B), and standard or disk-shaped compact tension specimens, C(T) or DC(T). A range of specimen sizes with proportional dimensions is recommended. The dimension on which the proportionality is based is specimen thickness. 1.3 Median KJc values tend to vary with the specimen type at a given test temperature, presumably due to constraint differences among the allowable test specimens in 1.2. The degree of KJc variability among specimen types i...

  18. A hybrid computation method for determining fluctuations of temperature in branched structures

    International Nuclear Information System (INIS)

    Czomber, L.

    1982-01-01

    A hybrid computation method for determining temperature fluctuations at discrete points of slab like geometries is developed on the basis of a new formulation of the finite difference method. For this purpose, a new finite difference method is combined with an exact solution of the heat equation within the range of values of the Laplace transformation. Whereas the exact solution can be applied to arbitraryly large ranges, the finite difference formulation is given for structural ranges which need finer discretization. The boundary conditions of the exact solution are substituted by finite difference terms for the boundary residual flow or an internal heat source, depending on the problem. The resulting system of conditional equations contains only the node parameters of the finite difference method. (orig.) [de

  19. Influence of Fixed Temperature of Chilled Water Outlet Setting toward Performance of Chiller Absorbtion with Two Level Heating Cycle Method

    Directory of Open Access Journals (Sweden)

    I Gusti Agung Bagus Wirajati

    2012-11-01

    Full Text Available The study investigated the performance of re-heat two stage cycle. This paper presents the working principle and theexperimental results of the reheat two stage adsorption cycle. The performance of the cycle was evaluated under differentheat source temperature and mass recovery time. Coefficient of performance (COP and cooling capacity have beencalculated to analyze the influences of experimental conditions. The experimental results shown in both COP and coolingcapacity increased along with heat source temperature increased, and mass recovery time is very effective to improve theperformance without increasing heat source temperature.

  20. Experimental determination of the temperature-dependent penetration depth in V3Si

    International Nuclear Information System (INIS)

    Christen, D.K.; Kerchner, H.R.; Sekula, S.T.; Chang, Y.K.

    1984-03-01

    Small angle neutron diffraction from the flux-line lattice (FLL) in a high quality, single crystal of superconducting V 3 Si has been used to deduce the low-field penetration depth lambda (T). An absolute determination is possible because the FLL form factor F/sub hk/ is essentially single-valued in the scattering vector magnitude absolute value of K/sub hk/, as well as nearly London-like at low field. We obtain lambda (0) = 102 +- 1 nm, 20% to 30% larger than previous determinations of the London penetration depth lambda/sub L/ (0). The temperature dependence of lambda (T) is found to deviate from that of the BCS theory. An assessment of the data indicates the most prominent source of the discrepancy is due to strong electron-phonon coupling, and we find 2Δ(0)/k/sub B/T/sub c/ = 3.88 +- 0.07, in reasonable agreement with values found in the literature

  1. Determination of the physical properties of room temperature ionic liquids using a Love wave device.

    Science.gov (United States)

    Ouali, F Fouzia; Doy, Nicola; McHale, Glen; Hardacre, Christopher; Ge, Rile; Allen, Ray W K; MacInnes, Jordan M; Newton, Michael I

    2011-09-01

    In this work, we have shown that a 100 MHz Love wave device can be used to determine whether room temperature ionic liquids (RTILs) are Newtonian fluids and have developed a technique that allows the determination of the density-viscosity product, ρη, of a Newtonian RTIL. In addition, a test for a Newtonian response was established by relating the phase change to insertion loss change. Five concentrations of a water-miscible RTIL and seven pure RTILs were measured. The changes in phase and insertion loss were found to vary linearly with the square root of the density-viscosity product for values up to (ρη)(1/2) ~ 10 kg m(-2) s(-1/2). The square root of the density-viscosity product was deduced from the changes in either phase or insertion loss using glycerol as a calibration liquid. In both cases, the deduced values of ρη agree well with those measured using viscosity and density meters. Miniaturization of the device, beyond that achievable with the lower-frequency quartz crystal microbalance approach, to measure smaller volumes is possible. The ability to fabricate Love wave and other surface acoustic wave sensors using planar metallization technologies gives potential for future integration into lab-on-a-chip analytical systems for characterizing ionic liquids.

  2. Determination of temperature dependence of full matrix material constants of PZT-8 piezoceramics using only one sample.

    Science.gov (United States)

    Zhang, Yang; Tang, Liguo; Tian, Hua; Wang, Jiyang; Cao, Wenwu; Zhang, Zhongwu

    2017-08-15

    Resonant ultrasound spectroscopy (RUS) was used to determine the temperature dependence of full matrix material constants of PZT-8 piezoceramics from room temperature to 100 °C. Property variations from sample to samples can be eliminated by using only one sample, so that data self-consistency can be guaranteed. The RUS measurement system error was estimated to be lower than 2.35%. The obtained full matrix material constants at different temperatures all have excellent self-consistency, which can help accurately predict device performance at high temperatures using finite element simulations.

  3. Experimental determination of the effect of temperature and humidity on the development of colour in Pinus radiata

    Directory of Open Access Journals (Sweden)

    M. McCurdy

    2005-06-01

    Full Text Available Experiments were undertaken to determine the effects of drying conditions (temperature and humidity on the development of kiln brown stain in radiata pine during drying. Eight schedules were tested with temperatures ranging from 50°C to 120°C and relative humidity from 14% to 67%. The variables measured were moisture content, color expressed using the CIELab color space, and nitrogen content. The experiments have shown that the kiln brown stain is influenced by drying temperature and drying time. The recommendation is therefore that low-temperature and low-humidity schedules be developed for controlling color development.

  4. Thermal models of buildings. Determination of temperatures, heating and cooling loads. Theories, models and computer programs

    Energy Technology Data Exchange (ETDEWEB)

    Kaellblad, K

    1998-05-01

    The need to estimate indoor temperatures, heating or cooling load and energy requirements for buildings arises in many stages of a buildings life cycle, e.g. at the early layout stage, during the design of a building and for energy retrofitting planning. Other purposes are to meet the authorities requirements given in building codes. All these situations require good calculation methods. The main purpose of this report is to present the authors work with problems related to thermal models and calculation methods for determination of temperatures and heating or cooling loads in buildings. Thus the major part of the report deals with treatment of solar radiation in glazing systems, shading of solar and sky radiation and the computer program JULOTTA used to simulate the thermal behavior of rooms and buildings. Other parts of thermal models of buildings are more briefly discussed and included in order to give an overview of existing problems and available solutions. A brief presentation of how thermal models can be built up is also given and it is a hope that the report can be useful as an introduction to this part of building physics as well as during development of calculation methods and computer programs. The report may also serve as a help for the users of energy related programs. Independent of which method or program a user choose to work with it is his or her own responsibility to understand the limits of the tool, else wrong conclusions may be drawn from the results 52 refs, 22 figs, 4 tabs

  5. Determination of excitation temperature and vibrational temperature of the N2(C 3Πu, ν') state in Ne-N2 RF discharges

    International Nuclear Information System (INIS)

    Rehman, N U; Naveed, M A; Zakaullah, M; Khan, F U

    2008-01-01

    Optical emission spectroscopy is used to investigate the effect of neon mixing on the excitation and vibrational temperatures of the second positive system in nitrogen plasma generated by a 13.56 MHz RF generator. The excitation temperature is determined from Ne I line intensities, using Boltzmann's plot. The overpopulation of the levels of the N 2 (C 3 Π u , ν') states with neon mixing are monitored by measuring the emission intensities of the second positive system of nitrogen molecules. The vibrational temperature is calculated for the sequence Δν = -2, with the assumption that it follows Boltzmann's distribution. But due to overpopulation of levels, e.g. 1, 4, a linearization process was employed for such distributions allowing us to calculate the vibrational temperature of the N 2 (C 3 Π u , ν') state. It is found that the excitation temperature as well as the vibrational temperature of the second positive system can be raised significantly by mixing neon with nitrogen plasma. It is also found that the vibrational temperature increases with power and pressure up to 0.5 mbar.

  6. Determining rotational temperatures from the OH(8-3 band, and a comparison with OH(6-2 rotational temperatures at Davis, Antarctica

    Directory of Open Access Journals (Sweden)

    F. Phillips

    2004-04-01

    Full Text Available Rotational temperatures derived from the OH(8–3 band may vary by ~18K depending on the choice of transition probabilities. This is of concern when absolute temperatures or trends determined in combination with measurements of other hydroxyl bands are important. In this paper, measurements of the OH(8–3 temperature-insensitive Q/P and R/P line intensity ratios are used to select the most appropriate transition probabilities for use with this band. Aurora, airglow and solar and telluric absorption in the OH(8–3 band are also investigated. Water vapour absorption of P1(4, airglow or auroral contamination of P1(2 and solar absorption in the vicinity of P1(5 are concerns to be considered when deriving rotational temperatures from this band.

    A comparison is made of temperatures derived from OH(6–2 and OH(8–3 spectra collected alternately at Davis (69° S, 78° E in 1990. An average difference of ~4K is found, with OH(8–3 temperatures being warmer, but a difference of this magnitude is within the two sigma uncertainty limit of the measurements.

    Key words. Atmospheric composition and structure airglow and aurora; pressure, density, and temperature

  7. Constraints on temperature-dependent sex determination in the leopard gecko (Eublepharis macularius): response to Kratochvil et al.

    Science.gov (United States)

    Huang, Victoria; Sakata, Jon T; Rhen, Turk; Coomber, Patricia; Simmonds, Sarah; Crews, David

    2008-12-01

    Kratochvil et al. (Naturwissenschaften 95:209-215, 2008) reported recently that in the leopard gecko (Eublepharis macularius) of the family Eublepharidae with temperature-dependent sex determination (TSD), clutches in which eggs were incubated at the same temperature produce only same-sex siblings. Interpreting this result in light of studies of sex steroid hormone involvement in sex determination, they suggested that maternally derived yolk steroid hormones could constrain sex-determining mechanisms in TSD reptiles. We have worked extensively with this species and have routinely incubated clutches at constant temperatures. To test the consistency of high frequency same-sex clutches across different incubation temperatures, we examined our records of clutches at the University of Texas at Austin from 1992 to 2001. We observed that clutches in which eggs were incubated at the same incubation temperature produced mixed-sex clutches as well as same-sex clutches. Furthermore, cases in which eggs within a clutch were separated and incubated at different temperatures produced the expected number of mixed-sex clutches. These results suggest that maternal influences on sex determination are secondary relative to incubation temperature effects.

  8. Experimental Determination of Temperature During Rotary Friction Welding of AA1050 Aluminum with AISI 304 Stainless Steel

    Directory of Open Access Journals (Sweden)

    Eder Paduan Alves

    2012-03-01

    Full Text Available The purpose of this study was the temperature monitoring at bonding interface during the rotary friction welding process of dissimilar materials: AA1050 aluminum with AISI 304 stainless steel. As it is directly related to the mechanical strenght of the junction, its experimental determination in real time is of fundamental importance for understanding and characterizing the main process steps, and the definition and optimization of parameters. The temperature gradients were obtained using a system called Thermocouple Data-Logger, which allowed monitoring and recording data in real-time operation. In the graph temperature versus time obtained, the heating rates, cooling were analyzed, and the maximum temperature was determined that occurred during welding, and characterized every phases of the process. The efficiency of this system demonstrated by experimental tests and the knowledge of the temperature at the bonding interface open new lines of research to understand the process of friction welding.

  9. Evaluation of methods for characterizing the melting curves of a high temperature cobalt-carbon fixed point to define and determine its melting temperature

    Science.gov (United States)

    Lowe, David; Machin, Graham

    2012-06-01

    The future mise en pratique for the realization of the kelvin will be founded on the melting temperatures of particular metal-carbon eutectic alloys as thermodynamic temperature references. However, at the moment there is no consensus on what should be taken as the melting temperature. An ideal melting or freezing curve should be a completely flat plateau at a specific temperature. Any departure from the ideal is due to shortcomings in the realization and should be accommodated within the uncertainty budget. However, for the proposed alloy-based fixed points, melting takes place over typically some hundreds of millikelvins. Including the entire melting range within the uncertainties would lead to an unnecessarily pessimistic view of the utility of these as reference standards. Therefore, detailed analysis of the shape of the melting curve is needed to give a value associated with some identifiable aspect of the phase transition. A range of approaches are or could be used; some purely practical, determining the point of inflection (POI) of the melting curve, some attempting to extrapolate to the liquidus temperature just at the end of melting, and a method that claims to give the liquidus temperature and an impurity correction based on the analytical Scheil model of solidification that has not previously been applied to eutectic melting. The different methods have been applied to cobalt-carbon melting curves that were obtained under conditions for which the Scheil model might be valid. In the light of the findings of this study it is recommended that the POI continue to be used as a pragmatic measure of temperature but where required a specified limits approach should be used to define and determine the melting temperature.

  10. Melting temperatures of MgO under high pressure determined by micro-texture observation

    Science.gov (United States)

    Kimura, T.; Ohfuji, H.; Nishi, M.; Irifune, T.

    2016-12-01

    Periclase (MgO) is the second abundant mineral after bridgmanite in the Earth's lower mantle, and its melting temperature (Tm) under pressure is important to constrain the chemical composition of ultra-deep magma formed near the mantle-core boundary. However, the melting behavior is highly controversial among previous studies: a laser-heated diamond anvil cell (LHDAC) study reported a melting curve with a dTm/dP of 30 K/GPa at zero pressure [1], while several theoretical computations gave substantially higher dTm/dP of 90 100 K/GPa [2,3]. We performed a series of LHDAC experiments for measurements of Tm of MgO under high pressure, using single crystal MgO as the starting material. The melting was detected by using micro-texture observations of the quenched samples. We found that the laser-heated area of the sample quenched from the Tm in previous LHDAC experiments [1] showed randomly aggregated granular crystals, which was not caused by melting, but by plastic deformation of the sample. This suggests that the Tms of their study were substantially underestimated. On the other hand, the sample recovered from the temperature higher by 1500-1700 K than the Tms in previous LHDAC experiments showed a characteristic internal texture comparable to the solidification texture typically shown in metal casting. We determined the Tms based on the observation of this texture up to 32 GPa. Fitting our Tms to the Simon equation yields dTm/dP of 82 K/GPa at zero pressure, which is consistent with those of the theoretical predictions (90 100 K/GPa) [2,3]. Extrapolation of the present melting curve of MgO to the pressure of the CMB (135 GPa) gives a melting temperature of 8900 K. The present steep melting slope offers the eutectic composition close to peridotite (in terms of Mg/Si ratio) throughout the lower mantle conditions. According to the model for sink/float relationship between the solid mantle and the magma [4], a considerable amount of iron (Fe/(Mg+Fe) > 0.24) is expected

  11. A new method to determine the energy saving night temperature for vegetative growth of Phalaenopsis

    NARCIS (Netherlands)

    Pollet, B.; Kromwijk, J.A.M.; Vanhaecke, L.; Dambre, P.; Labeke, M.C.; Marcelis, L.F.M.; Steppe, K.

    2011-01-01

    Knowledge of the energy saving night temperature (i.e. a relatively cool night temperature without affecting photosynthetic activity and physiology) and a better understanding of low night temperature effects on the photosynthetic physiology of Phalaenopsis would improve their production in terms of

  12. The mean and variance of environmental temperature interact to determine physiological tolerance and fitness.

    Science.gov (United States)

    Bozinovic, Francisco; Bastías, Daniel A; Boher, Francisca; Clavijo-Baquet, Sabrina; Estay, Sergio A; Angilletta, Michael J

    2011-01-01

    Global climate change poses one of the greatest threats to biodiversity. Most analyses of the potential biological impacts have focused on changes in mean temperature, but changes in thermal variance will also impact organisms and populations. We assessed the combined effects of the mean and variance of temperature on thermal tolerances, organismal survival, and population growth in Drosophila melanogaster. Because the performance of ectotherms relates nonlinearly to temperature, we predicted that responses to thermal variation (±0° or ±5°C) would depend on the mean temperature (17° or 24°C). Consistent with our prediction, thermal variation enhanced the rate of population growth (r(max)) at a low mean temperature but depressed this rate at a high mean temperature. The interactive effect on fitness occurred despite the fact that flies improved their heat and cold tolerances through acclimation to thermal conditions. Flies exposed to a high mean and a high variance of temperature recovered from heat coma faster and survived heat exposure better than did flies that developed at other conditions. Relatively high survival following heat exposure was associated with low survival following cold exposure. Recovery from chill coma was affected primarily by the mean temperature; flies acclimated to a low mean temperature recovered much faster than did flies acclimated to a high mean temperature. To develop more realistic predictions about the biological impacts of climate change, one must consider the interactions between the mean environmental temperature and the variance of environmental temperature.

  13. Local-scale and watershed-scale determinants of summertime urban stream temperatures

    Science.gov (United States)

    Derek B. Booth; Kristin A. Kraseski; C. Rhett. Jackson

    2014-01-01

    The influence of urbanization on the temperature of small streams is widely recognized, but these effects are confounded by the great natural variety of their contributing watersheds. To evaluate the relative importance of local-scale and watershed-scale factors on summer temperatures in urban streams, hundreds of near-instantaneous temperature measurements throughout...

  14. Ammonia and temperature determine potential clustering in the anaerobic digestion microbiome.

    Science.gov (United States)

    De Vrieze, Jo; Saunders, Aaron Marc; He, Ying; Fang, Jing; Nielsen, Per Halkjaer; Verstraete, Willy; Boon, Nico

    2015-05-15

    Anaerobic digestion is regarded as a key environmental technology in the present and future bio-based economy. The microbial community completing the anaerobic digestion process is considered complex, and several attempts already have been carried out to determine the key microbial populations. However, the key differences in the anaerobic digestion microbiomes, and the environmental/process parameters that drive these differences, remain poorly understood. In this research, we hypothesized that differences in operational parameters lead to a particular composition and organization of microbial communities in full-scale installations. A total of 38 samples were collected from 29 different full-scale anaerobic digestion installations, showing constant biogas production in function of time. Microbial community analysis was carried out by means of amplicon sequencing and real-time PCR. The bacterial community in all samples was dominated by representatives of the Firmicutes, Bacteroidetes and Proteobacteria, covering 86.1 ± 10.7% of the total bacterial community. Acetoclastic methanogenesis was dominated by Methanosaetaceae, yet, only the hydrogenotrophic Methanobacteriales correlated with biogas production, confirming their importance in high-rate anaerobic digestion systems. In-depth analysis of operational and environmental parameters and bacterial community structure indicated the presence of three potential clusters in anaerobic digestion. These clusters were determined by total ammonia concentration, free ammonia concentration and temperature, and characterized by an increased relative abundance of Bacteroidales, Clostridiales and Lactobacillales, respectively. None of the methanogenic populations, however, could be significantly attributed to any of the three clusters. Nonetheless, further experimental research will be required to validate the existence of these different clusters, and to which extent the presence of these clusters relates to stable or sub

  15. Empirical temperature-dependent intermolecular potentials determined by data mining from crystal data

    Science.gov (United States)

    Hofmann, D. W. M.; Kuleshova, L. N.

    2018-05-01

    Modern force fields are accurate enough to describe thermal effects in molecular crystals. Here, we have extended our earlier approach to discrete force fields for various temperatures to a force field with a continuous function. For the parametrisation of the force field, we used data mining on experimental structures with the temperature as an additional descriptor. The obtained force field can be used to minimise energy at a finite temperature and for molecular dynamics with zero-K potentials. The applicability of the method has been demonstrated for the prediction of crystal density, temperature density gradients and transition temperature.

  16. Low-temperature transitions in cod and tuna determined by differential scanning calorimetry

    DEFF Research Database (Denmark)

    Jensen, Kristina Nedenskov; Jørgensen, Bo; Nielsen, Jette

    2003-01-01

    Differential scanning calorimetry measurements have revealed different thermal transitions in cod and tuna samples. Transition temperatures detected Lit -11degreesC, -15degreesC and -21degreesC were highly dependent on the annealing temperature. In tuna muscle an additional transition was observed...... at -72degreesC. This transition appeared differently than the thermal events observed at higher temperatures, as it spanned a broad temperature interval of 25degreesC. The transition was comparable to low-temperature glass transitions reported in protein-rich systems. No transition at this low...... temperature was detected in cod samples. The transitions observed at higher temperatures (-11degreesC to -21degreesC) may possibly stein from a glassy matrix containing muscle proteins. However, the presence of a glass transition at - 11degreesC was in disagreement with the low storage stability at -18degrees...

  17. Determination of temperature variation during the individual steps of the production of hospital diets of modified consistency.

    Science.gov (United States)

    Monteiro, T H; De Souza Santos, R; Cremonezi Japur, C; Neves Campanelli Marçal Vieira, M

    2011-01-01

    Many disease outbreaks of food origin are caused by foods prepared in Food Service and Nutrition Units of hospitals, affecting hospitalized patients who, in most cases, are immunocompromised and therefore at a higher risk of severe worsening of their clinical status. The aim of this study was to determine the variations in temperature and the time-temperature factor of hospital diets. The time and temperature for the preparation of 4 diets of modified consistency were determined on 5 nonconsecutive days in a hospital Diet and Nutrition Unit at the end of preparation and during the maintenance period, portioning and distribution at 3 sites, i.e., the first, the middle and the last to receive the diets. All foods reached an adequate temperature at the end of cooking, but temperature varied significantly from the maintenance period to the final distribution, characterizing critical periods for microorganism proliferation. During holding, temperatures that presented a risk were reached by 16.7% of the meats and 59% of the salads of the general diet, by 16.7% of the garnishes in the bland diet and by 20% of the meats and garnishes in the viscous diet. The same occurred at the end of distribution for 100% of the hot samples and of the salads and for 61% of the desserts. None of the preparations remained at risk temperature for a time exceeding that established by law. The exposure to inadequate temperature did not last long enough to pose risks to the patient.

  18. Room temperature phosphorimetric determination of cyanide based on triplet state energy transfer

    International Nuclear Information System (INIS)

    Fernandez-Argueelles, Maria Teresa; Costa-Fernandez, Jose M.; Pereiro, Rosario; Sanz-Medel, Alfredo

    2003-01-01

    The determination of cyanide ions in water samples by room temperature phosphorescence (RTP) detection is described. The method is based on the measurement of the RTP emission of α-bromonaphthalene (BrN). The principle of the RTP cyanide determination involves the energy transfer (ET) from the BrN phosphor molecule insensitive to the presence of cyanide (acting as a donor) to a cyanide-sensitive dye (acceptor). The RTP emission spectrum of BrN overlaps significantly with the absorption spectrum of the complex formed between copper and Cadion 2B, giving rise to a non-radiative ET from the phosphor molecules to the metal complex. The sensing of cyanide ions is based on the displacement by cyanide of the copper ions from its complex with Cadion 2B (the free chelating molecule presents a low absorbance in the region of maximum emission of the BrN phosphor). An increase in the concentration of cyanide causes a decrease on the concentration of the Cadion 2B-copper complex (acceptor) with the subsequent decrease of the absorbance in the overlapping region with the RTP spectra, resulting in higher RTP emission signals measured. Both, RTP intensities and triplet lifetimes of the BrN increased with the increase of the cyanide concentration. The calibration graphs were linear up to a concentration of 500 mg l -1 cyanide and a precision of ±2 and ±0.5% for five replicates of 50 μg l -1 of cyanide has been obtained when measuring intensities and triplet lifetimes values, respectively. A detection limit of 3 μg l -1 of cyanide was achieved under optimal reaction conditions and pH 11. The use of phosphorescence measurements (low background noise signals) resulted in an important improvement on the sensitivity of the cyanide detection higher than eight times as compared to the molecular absorption spectrophotometric method for cyanide detection based on the use of Cadion 2B-copper as cyanide-indicator. Interference studies were performed with cations and anions present in

  19. Determination of Henry’s law constant of light hydrocarbon gases at low temperatures

    International Nuclear Information System (INIS)

    Mohebbi, V.; Naderifar, A.; Behbahani, R.M.; Moshfeghian, M.

    2012-01-01

    Highlights: ► Henry’s constants of light hydrocarbon gases are reported at low temperatures. ► Solubility of iso-butane in water at low temperatures (275 K to 293 K) was measured. ► An expression of Krichevsky–Kasarnovsky equation is reported. - Abstract: The solubility of i-butane in water at the low temperatures was measured (274 K to 293 K). Additionally, Henry’s law constants of light hydrocarbons (methane, ethane, propane, i-butane, and n-butane) in water at the low temperatures are reported. A modified equation based on Krichevsky–Kasarnovsky equation is proposed to consider the effect of pressure and temperature on the equation parameters. Results show that Henry’s law constant of the selected components depends on temperature. It is deduced that pressure has a considerable effect on Henry’s law constant for methane, ethane, and propane, whereas this dependency for butanes is negligible.

  20. Determining the baking isotherm temperature of Söderberg electrodes and associated structural changes

    OpenAIRE

    Shoko, L.; Beukes, J.P.; Strydom, C.A.

    2013-01-01

    One of the most commonly employed electrode systems in industrial metal smelting applications is continuous self-baking electrodes, i.e. the Söderberg electrode system. In this system, the temperature at which transition from a liquid/soft paste to a solid carbonaceous electrode takes place is termed the baking isotherm temperature. This temperature is extremely important within the context of electrode management. In this paper, thermo mechanical analysis (TMA) was used to measure the dimens...

  1. Simulations of the broad line region of NGC 5548 with CLOUDY code: Temperature determination

    Directory of Open Access Journals (Sweden)

    Ilić D.

    2007-01-01

    Full Text Available In this paper an analysis of the physical properties of the Broad Line Region (BLR of the active galaxy NGC 5548 is presented. Using the photoionization code CLOUDY and the measurements of Peterson et al. (2002, the physical conditions of the BLR are simulated and the BLR temperature is obtained. This temperature was compared to the temperature estimated with the Boltzmann-Plot (BP method (Popović et al. 2007. It was shown that the measured variability in the BLR temperature could be due to the change in the hydrogen density.

  2. Simultaneous determination of reference free-stream temperature and convective heat transfer coefficients

    International Nuclear Information System (INIS)

    Jeong, Gi Ho; Song, Ki Bum; Kim, Kui Soon

    2001-01-01

    This paper deals with the development of a new method that can obtain heat transfer coefficient and reference free stream temperature simultaneously. The method is based on transient heat transfer experiments using two narrow-band TLCs. The method is validated through error analysis in terms of the random uncertainties in the measured temperatures. It is shown how the uncertainties in heat transfer coefficient and free stream temperature can be reduced. The general method described in this paper is applicable to many heat transfer models with unknown free stream temperature

  3. A spectral measurement method for determining white OLED average junction temperatures

    Science.gov (United States)

    Zhu, Yiting; Narendran, Nadarajah

    2016-09-01

    The objective of this study was to investigate an indirect method of measuring the average junction temperature of a white organic light-emitting diode (OLED) based on temperature sensitivity differences in the radiant power emitted by individual emitter materials (i.e., "blue," "green," and "red"). The measured spectral power distributions (SPDs) of the white OLED as a function of temperature showed amplitude decrease as a function of temperature in the different spectral bands, red, green, and blue. Analyzed data showed a good linear correlation between the integrated radiance for each spectral band and the OLED panel temperature, measured at a reference point on the back surface of the panel. The integrated radiance ratio of the spectral band green compared to red, (G/R), correlates linearly with panel temperature. Assuming that the panel reference point temperature is proportional to the average junction temperature of the OLED panel, the G/R ratio can be used for estimating the average junction temperature of an OLED panel.

  4. Air temperature determination inside residual heat removal pump room of Angra-1 nuclear power plant after a design basic accident

    International Nuclear Information System (INIS)

    Siniscalchi, Marcio Rezende

    2005-01-01

    This work develops heat transfer theoretical models for determination of air temperature inside the Residual Heat Removal Pump Room of Angra 1 Nuclear Power Plant after a Design Basis Accident without forced ventilation. Two models had been developed. The differential equations are solved by analytical methods. A software in FORTRAN language are developed for simulations of temperature inside rooms for different geometries and materials. (author)

  5. Experimental Determination of Temperature During Rotary Friction Welding of AA1050 Aluminum with AISI 304 Stainless Steel

    OpenAIRE

    Alves, Eder Paduan; Piorino Neto, Francisco; An, Chen Ying; Silva, Euclides Castorino da

    2012-01-01

    Abstract: The purpose of this study was the temperature monitoring at bonding interface during the rotary friction welding process of dissimilar materiais: AA1050 aluminum with AISI 304 stainless steel. As it is directly related to the mechanical strenght of the junction, its experimental determination in real time is of fundamental importance for understanding and characterizing the main process steps, and the definition and optimization of parameters. The temperature gradients were obtained...

  6. EIS pitting temperature determination of A182 nickel based alloy in simulated BWR environment containing dilute seawater

    International Nuclear Information System (INIS)

    Lavigne, Olivier; Shoji, Tetsuo; Takeda, Yoichi

    2014-01-01

    Graphical abstract: - Highlights: • Stable pitting events in function of the temperature are monitored by electrochemical impedance spectroscopy. • The pitting temperature for the nickel based alloy A182 in solution containing 450 ppm Cl − is defined as above 160 °C. • The presented method can be applied for others passive alloys as stainless steel in solution containing aggressive anions. - Abstract: A method based on electrochemical impedance spectroscopy (EIS) measurements to monitor the pitting temperature of passive alloys in a given media is developed in this communication. The pitting corrosion behavior of the nickel based alloy 182 in water containing 450 ppm by weight of chloride is presented in this study. The analysis of the EIS fit parameters from the proposed equivalent electrical circuit allows to determine the temperature from which stable pitting event occurs at open circuit potential. For the A182 sample this temperature is measured above 160 °C

  7. Rapid and sensitive determination of carbohydrates in foods using high temperature liquid chromatography with evaporative light scattering detection.

    Science.gov (United States)

    Terol, Amanda; Paredes, Eduardo; Maestre, Salvador E; Prats, Soledad; Todolí, José L

    2012-04-01

    In the present work, an evaporative light scattering detector was used as a high-temperature liquid chromatography detector for the determination of carbohydrates. The compounds studied were glucose, fructose, galactose, sucrose, maltose, and lactose. The effect of column temperature on the retention times and detectability of these compounds was investigated. Column heating temperatures ranged from 25 to 175°C. The optimum temperature in terms of peak resolution and detectability with pure water as mobile phase and a liquid flow rate of 1 mL/min was 150°C as it allowed the separation of glucose and the three disaccharides here considered in less than 3 min. These conditions were employed for lactose determination in milk samples. Limits of quantification were between 2 and 4.7 mg/L. On the other hand, a temperature gradient was developed for the simultaneous determination of glucose, fructose, and sucrose in orange juices, due to coelution of monosaccharides at temperatures higher than 70°C, being limits of quantifications between 8.5 and 12 mg/L. The proposed hyphenation was successfully applied to different types of milk and different varieties of oranges and mandarins. Recoveries for spiked samples were close to 100% for all the studied analytes. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. A spectroscopic method to determine the electron temperature of an argon surface wave sustained plasmas using a collision radiative model

    Energy Technology Data Exchange (ETDEWEB)

    Vries, N de; Iordanova, E; Hartgers, A; Veldhuizen, E M van; Donker, M J van der; Mullen, J J A M van der [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands)

    2006-10-07

    A method is presented to determine the electron temperature in a low pressure argon plasma using emission spectroscopic measurements and a collisional radiative (CR) model. Absolute line intensity measurements are made in order to construct the atomic state distribution function. In addition to the excited states, the ground state density is also taken into account. Because of this, the excitation temperature can be determined with high precision. A CR-model has been used to determine the degree of equilibrium departure and to obtain the relationship between the excitation temperature and the electron temperature. This method is applied to a microwave plasma which has been generated inside a quartz tube using a surfatron device. The densities of argon levels close to the continuum are used to get an estimated value of the electron density. These values are used as input data for the CR-model. For an argon pressure of 6 mbar, the 4p level densities vary between 8 x 10{sup 14} and 6 x 10{sup 15} m{sup -3}. Using the estimated values for the electron density, between 2 x 10{sup 19} and 3 x 10{sup 19} m{sup -3}, the electron temperature was found to range between 1.15 and 1.20 eV. An extensive error analysis showed that the relative error in the electron temperature is less than 6%.

  9. A spectroscopic method to determine the electron temperature of an argon surface wave sustained plasmas using a collision radiative model

    International Nuclear Information System (INIS)

    Vries, N de; Iordanova, E; Hartgers, A; Veldhuizen, E M van; Donker, M J van der; Mullen, J J A M van der

    2006-01-01

    A method is presented to determine the electron temperature in a low pressure argon plasma using emission spectroscopic measurements and a collisional radiative (CR) model. Absolute line intensity measurements are made in order to construct the atomic state distribution function. In addition to the excited states, the ground state density is also taken into account. Because of this, the excitation temperature can be determined with high precision. A CR-model has been used to determine the degree of equilibrium departure and to obtain the relationship between the excitation temperature and the electron temperature. This method is applied to a microwave plasma which has been generated inside a quartz tube using a surfatron device. The densities of argon levels close to the continuum are used to get an estimated value of the electron density. These values are used as input data for the CR-model. For an argon pressure of 6 mbar, the 4p level densities vary between 8 x 10 14 and 6 x 10 15 m -3 . Using the estimated values for the electron density, between 2 x 10 19 and 3 x 10 19 m -3 , the electron temperature was found to range between 1.15 and 1.20 eV. An extensive error analysis showed that the relative error in the electron temperature is less than 6%

  10. A System And Method To Determine Thermophysical Properties Of A Multi-Component Gas At Arbitrary Temperature And Pressure

    Science.gov (United States)

    Morrow, Thomas E.; Behring, II, Kendricks A.

    2004-03-09

    A method to determine thermodynamic properties of a natural gas hydrocarbon, when the speed of sound in the gas is known at an arbitrary temperature and pressure. Thus, the known parameters are the sound speed, temperature, pressure, and concentrations of any dilute components of the gas. The method uses a set of reference gases and their calculated density and speed of sound values to estimate the density of the subject gas. Additional calculations can be made to estimate the molecular weight of the subject gas, which can then be used as the basis for mass flow calculations, to determine the speed of sound at standard pressure and temperature, and to determine various thermophysical characteristics of the gas.

  11. Use of basic principle of nucleation in determining temperature-threshold neutron energy relationship in superheated emulsions

    CERN Document Server

    Das, M; Chatterjee, B K; Roy, S C

    2003-01-01

    Detection of neutrons through use of superheated emulsions has been known for about two decades. The minimum neutron energy (threshold) required to nucleate drops of a given liquid has a dependence on the temperature of the liquid. The basic principle of nucleation has been utilized to find the relationship between the operating temperature and threshold neutron energy for superheated emulsions made of R-114 liquid. The threshold energy thus determined for different temperatures has been compared with accurate experimental results obtained using monoenergetic neutron sources. The agreement is found to be satisfactory and confirms the applicability of the present simple method to other liquids.

  12. Determining Role of the Chain Mechanism in the Temperature Dependence of the Gas-Phase Rate of Combustion Reactions

    Science.gov (United States)

    Azatyan, V. V.; Bolod'yan, I. A.; Kopylov, N. P.; Kopylov, S. N.; Prokopenko, V. M.; Shebeko, Yu. N.

    2018-05-01

    It is shown that the strong dependence of the rate of gas-phase combustion reactions on temperature is determined by the high values of the reaction rate constants of free atoms and radicals. It is established that with a branched chain mechanism, a special role in the reaction rate temperature dependence is played by positive feedback between the concentrations of active intermediate species and the rate of their change. The role of the chemical mechanism in the temperature dependence of the process rate with and without inhibitors is considered.

  13. Determination of the temperature causing a nociceptive response in the tail of albino BALB/c mice.

    Science.gov (United States)

    Aguirre Siancas, E E; Lam Figueroa, N M; Delgado Rios, J C; Ruiz Ramirez, E; Portilla Flores, O S; Crispín Huamaní, L J; Alarcón Velásquez, L

    2018-06-08

    Designs for determining nociceptive response in rodents are of great use in neurology and experimental neuroscience. Immersing mice's tails in warm water is one of the most widely used procedures to evaluate this response; however, a wide range of temperatures are used in different studies. Knowing the temperature that produces a powerful nociceptive response in the tail of BALB/c mice is extremely useful. Eight 2-month-old male BALB/c mice were used. A 14-cm high beaker was filled with water up to 13 cm. The animals' tails were immersed in the container with a starting temperature of 36°C. The water temperature was raised in 1°C increments until we identified the temperatures that produced nociceptive responses. That response was determined by counting the time taken before the mouse shook its tail to remove it from the water. Six of the 8 mice began shaking their tails at the temperature of 51°C. All animals removed their tails from the water at the temperatures of 54°C, 55°C, and 56°C, taking a mean time of 8.54, 7.99, and 5.33seconds, respectively. ANOVA applied to the response times for each of the 3 temperatures indicated revealed a value of F=2.8 (P=.123). The response time was statistically similar for the temperatures of 54°C, 55°C, and 56°C; however, the data were less dispersed for the latter temperature. Copyright © 2018 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  14. Experimental determination of the bulk temperature values in a nonisothermal flow of the chemically reacting nitrogen tetroxide

    International Nuclear Information System (INIS)

    Devojno, A.N.; Kolykhan, L.I.; Stepanenko, V.N.; Tverkovkin, B.E.; Uyutov, G.I.

    1975-01-01

    The technique and results of an experimental determination of mean mass temperatures of a cooled chemically active nitrogen tetroxide flowing in a circular tube under turbulent flow conditions are considered. The parameters range as follows: pressure-from 8.10 5 to 16.10 5 H/m 2 , flow temperature-from 140 deg to 550 deg C, Reynolds number-from 3,1.1g 5 , flow velocity-from 3.5 to 45 m/s. The gas temperature along the length of the test tube is measured with movable probe with a mixer and thermocouple in a stainless steel capillary 2mm in dia and the wall 0,2 mm thick. The mean-square deviations of measured temperature values from the predicted ones are about -0.9 and +1.8%. The obtained data show the predicted temperature values to be somewhat lower than the measured ones, the difference increasing with the distance to the test tube outlet. It may be explained by both unaccounted systematic experimental errors and errors in calculating the mean mass flow temperatures. The investigation described confirms the possibility of an experimental determination of the mean gas temperature along the cooled channel length by mean mass of a movable mixer with a single thermocouple

  15. Method for determining the outlet temperature of fuel assemblies unsupplied with thermometer in WWER-440 reactors

    International Nuclear Information System (INIS)

    Miko, S.; Kalya, Z.; Hamvas, I.

    1987-09-01

    The paper outlines a method for the evaluation of the outlet temperatures of fuel assemblies unsupplied with thermometer in WWER-440 reactors. The process is based on interpolation of directly measured assembly temperatures. A quantitative comparison of the errors of described algorithm to those of standard plant-computer interpolation rutine is also presented. (author)

  16. Determination of Factors Related to Students' Understandings of Heat, Temperature and Internal Energy Concepts

    Science.gov (United States)

    Gurcay, Deniz; Gulbas, Etna

    2018-01-01

    The purpose of this research is to investigate the relationships between high school students' learning approaches and logical thinking abilities and their understandings of heat, temperature and internal energy concepts. Learning Approach Questionnaire, Test of Logical Thinking and Three-Tier Heat, Temperature and Internal Energy Test were used…

  17. The role of riparian vegetation density, channel orientation and water velocity in determining river temperature dynamics

    Science.gov (United States)

    Garner, Grace; Malcolm, Iain A.; Sadler, Jonathan P.; Hannah, David M.

    2017-10-01

    A simulation experiment was used to understand the importance of riparian vegetation density, channel orientation and flow velocity for stream energy budgets and river temperature dynamics. Water temperature and meteorological observations were obtained in addition to hemispherical photographs along a ∼1 km reach of the Girnock Burn, a tributary of the Aberdeenshire Dee, Scotland. Data from nine hemispherical images (representing different uniform canopy density scenarios) were used to parameterise a deterministic net radiation model and simulate radiative fluxes. For each vegetation scenario, the effects of eight channel orientations were investigated by changing the position of north at 45° intervals in each hemispheric image. Simulated radiative fluxes and observed turbulent fluxes drove a high-resolution water temperature model of the reach. Simulations were performed under low and high water velocity scenarios. Both velocity scenarios yielded decreases in mean (≥1.6 °C) and maximum (≥3.0 °C) temperature as canopy density increased. Slow-flowing water resided longer within the reach, which enhanced heat accumulation and dissipation, and drove higher maximum and lower minimum temperatures. Intermediate levels of shade produced highly variable energy flux and water temperature dynamics depending on the channel orientation and thus the time of day when the channel was shaded. We demonstrate that in many reaches relatively sparse but strategically located vegetation could produce substantial reductions in maximum temperature and suggest that these criteria are used to inform future river management.

  18. Determining Ms temperature on a AISI D2 cold work tool steel using magnetic Barkhausen noise

    Energy Technology Data Exchange (ETDEWEB)

    Huallpa, Edgar Apaza, E-mail: gared1@gmail.com [Escola Politécnica da Universidade de São Paulo, Av. Prof. Mello Moraes 2463, 05508-030 SP (Brazil); Sánchez, J. Capó, E-mail: jcapo@usp.br [Departamento de Física, Facultad de Ciencias Naturales, Universidad de Oriente, Av. Patricio Lumumba s/n 90500, Santiago de Cuba (Cuba); Padovese, L.R., E-mail: lrpadove@usp.br [Escola Politécnica da Universidade de São Paulo, Av. Prof. Mello Moraes 2463, 05508-030 SP (Brazil); Goldenstein, Hélio, E-mail: hgoldens@usp.br [Escola Politécnica da Universidade de São Paulo, Av. Prof. Mello Moraes 2463, 05508-030 SP (Brazil)

    2013-11-15

    Highlights: ► MBN was used to follow the martensite transformation in a tool steel. ► The results were compared with resistivity experiments. ► The Ms was estimated with Andrews equation coupled to ThermoCalc calculations. The experimental results showed good agreement. -- Abstract: The use of Magnetic Barkhausen Noise (MBN) as a experimental method for measuring the martensite start (Ms) temperature was explored, using as model system a cold-work tool steel (AISI D2) austenitized at a very high temperature (1473 K), so as to transform in sub-zero temperatures. The progress of the transformation was also followed with electrical resistance measurements, optical microscopy and scanning electron microscopy. Both MBN and resistivity measurements showed a change near 230 K during cooling, corresponding to the Ms temperature, as compared with 245 K, estimated with Andrews empirical equation applied to the austenite composition calculated using ThermoCalc.

  19. Experimental determination of fuel surface temperature in the Dalat Nuclear Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Khang, Ngo Phu; Huy, Ngo Quang; An, Tran Khac; Lam, Pham Van [Nuclear Research Inst., Da Lat (Viet Nam)

    1994-10-01

    Measured fuel surface temperatures, obtained at various locations of the core of the Dalat Nuclear Research Reactor under normal operating conditions, are presented, and some thermal characteristics of the reactor are discussed. (author). 2 refs., 11 figs., 2 tabs.

  20. Fiber optic distributed temperature sensing for the determination of the nocturnal atmospheric boundary layer height

    Directory of Open Access Journals (Sweden)

    C. A. Keller

    2011-02-01

    Full Text Available A new method for measuring air temperature profiles in the atmospheric boundary layer at high spatial and temporal resolution is presented. The measurements are based on Raman scattering distributed temperature sensing (DTS with a fiber optic cable attached to a tethered balloon. These data were used to estimate the height of the stable nocturnal boundary layer. The experiment was successfully deployed during a two-day campaign in September 2009, providing evidence that DTS is well suited for this atmospheric application. Observed stable temperature profiles exhibit an exponential shape confirming similarity concepts of the temperature inversion close to the surface. The atmospheric mixing height (MH was estimated to vary between 5 m and 50 m as a result of the nocturnal boundary layer evolution. This value is in good agreement with the MH derived from concurrent Radon-222 (222Rn measurements and in previous studies.

  1. Determination of temperature measurements uncertainties of the heat transport primary system of Embalse nuclear power plant

    International Nuclear Information System (INIS)

    Pomerantz, Marcelo E.; Coutsiers, Eduardo E.; Moreno, Carlos A.

    1999-01-01

    In this work, the systematic errors in temperature measurements in inlet and outlet headers of HTPS coolant channels of Embalse nuclear power plant are evaluated. These uncertainties are necessary for a later evaluation of the channel power maps transferred to the coolant. The power maps calculated in this way are used to compare power distributions using neutronic codes. Therefore, a methodology to correct systematic errors of temperature in outlet feeders and inlet headers is developed in this work. (author)

  2. Determination of transient temperature distribution inside a wellbore considering drill string assembly and casing program

    International Nuclear Information System (INIS)

    Yang, Mou; Zhao, Xiangyang; Meng, Yingfeng; Li, Gao; Zhang, Lin; Xu, Haiming; Tang, Daqian

    2017-01-01

    Highlights: • The different wellbore conditions of heat transfer models were developed. • Drill string assembly and casing programs impact on down-hole temperatures. • The thermal performance in circulation and shut-in stages were deeply investigated. • Full-scale model coincided with the measured field data preferably. - Abstract: Heat exchange efficiency between each region of the wellbore and formation systems is influenced by the high thermal conductivity of the drill string and casing, which further affects temperature distribution of the wellbore. Based on the energy conservation principle, the Modified Raymond, Simplified and Full-scale models were developed, which were solved by the fully implicit finite difference method. The results indicated that wellbore and formation temperatures were significantly influenced at the connection points between the drill collar and drill pipe, as well as the casing shoe. Apart from the near surface, little change was observed in temperature distribution in the cement section. In the open-hole section, the temperature rapidly decreased in the circulation stage and gradually increased in the shut-in stage. Most important, the simulated result from the full-scale model coincided with the measured field data better than the other numerical models. These findings not only confirm the effect of the drill string assembly and casing programs on the wellbore and formation temperature distribution, but also contribute to resource exploration, drilling safety and reduced drilling costs.

  3. Effect of Time and Temperature on Thickened Infant Formula.

    Science.gov (United States)

    Gosa, Memorie M; Dodrill, Pamela

    2017-04-01

    Unlike adult populations, who primarily depend on liquids for hydration alone, infants rely on liquids to provide them with hydration and nutrition. Speech-language pathologists working within pediatric medical settings often identify dysphagia in patients and subsequently recommend thickened liquids to reduce aspiration risk. Caregivers frequently report difficulty attempting to prepare infant formula to the prescribed thickness. This study was designed to determine (1) the relationship between consistencies in modified barium swallow studies and thickened infant formulas and (2) the effects of time and temperature on the resulting thickness of infant formula. Prepackaged barium consistencies and 1 standard infant formula that was thickened with rice cereal and with 2 commercially available thickening agents were studied. Thickness was determined via a line spread test after various time and temperature conditions were met. There were significant differences between the thickened formula and barium test consistencies. Formula thickened with rice cereal separated over time into thin liquid and solid residue. Formula thickened with a starch-based thickening agent was thicker than the desired consistency immediately after mixing, and it continued to thicken over time. The data from this project suggest that nectar-thick and honey-thick infant formulas undergo significant changes in flow rates within 30 minutes of preparation or if refrigerated and then reheated after 3 hours. Additional empirical evidence is warranted to determine the most reliable methods and safest products for thickening infant formula when necessary for effective dysphagia management.

  4. Microstructural characteristics and gastro-small intestinal digestion in vitro of potato starch: Effects of refrigerated storage and reheating in microwave.

    Science.gov (United States)

    Colussi, Rosana; Singh, Jaspreet; Kaur, Lovedeep; Zavareze, Elessandra da Rosa; Dias, Alvaro Renato Guerra; Stewart, Robert B; Singh, Harjinder

    2017-07-01

    The objective of our study was to evaluate paste clarity, retrogradation (syneresis %), thermal characteristics and kinetics of glucose release during in vitro gastro-small intestinal digestion of freshly cooked and refrigerated potato starch. Freshly cooked starch pastes had a paste clarity of 71%, which decreased to 35.4% whereas syneresis (%) increased after 7days of refrigerated storage. The X-ray and thermal characteristics of native, retrograded and microwave reheated starch samples differed significantly from each other. For the freshly cooked starch pastes, ∼88% starch hydrolysis was observed at the end (150min) of digestion under simulated gastro-small intestinal conditions that decreased to ∼70% for the 7day stored pastes. The hydrolysis (%) of refrigerated pastes increased to 86% and 92% after one and two cycles of microwave reheating, respectively. These results contribute to the understanding of starch retrogradation in relation to starch digestion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Determination of thermal diffusivity of dental enamel and dentin as a function of temperature, using infrared thermography

    International Nuclear Information System (INIS)

    Pereira, Thiago Martini

    2009-01-01

    In this work it was developed a software that calculates automatically, the thermal diffusivity value as a function of temperature in materials. The infrared thermography technique was used for data acquisition of temperature distribution as a function of time. These data were used to adjust a temperature function obtained from the homogeneous heat equation with specific boundary conditions. For that, an infrared camera (detecting from 8 μm to 9 μm) was calibrated to detect temperature ranging from 185 degree C up to 1300 degree C at an acquisition rate of 300 Hz. It was used, 10 samples of dental enamel and 10 samples of dentin, with 4 mm x 4 mm x 2 mm, which were obtained from bovine lower incisor teeth. These samples were irradiated with an Er:Cr:YSGG pulsed laser (λ = 2,78 μm). The resulting temperature was recorded 2 s prior, 10 s during irradiation and continuing for 2 more seconds after it. After each irradiation, all obtained thermal images were processed in the software, creating a file with the data of thermal diffusivity as a function of temperature. Another file with the thermal diffusivity values was also calculated after each laser pulse. The mean result of thermal diffusivity obtained for dental enamel was 0,0084 ± 0,001 cm2/s for the temperature interval of 220-550 degree C. The mean value for thermal diffusivity obtained for dentin was 0,0015 0,0004 cm2/s in temperatures up to 360 degree C; however, this value increases for higher temperatures. According to these results, it was possible to conclude that the use of infrared thermography, associated with the software developed in this work, is an efficient method to determine the thermal diffusivity values as a function of temperature in different materials. (author)

  6. Transcriptomic responses to environmental temperature by turtles with temperature-dependent and genotypic sex determination assessed by RNAseq inform the genetic architecture of embryonic gonadal development.

    Science.gov (United States)

    Radhakrishnan, Srihari; Literman, Robert; Neuwald, Jennifer; Severin, Andrew; Valenzuela, Nicole

    2017-01-01

    Vertebrate sexual fate is decided primarily by the individual's genotype (GSD), by the environmental temperature during development (TSD), or both. Turtles exhibit TSD and GSD, making them ideal to study the evolution of sex determination. Here we analyze temperature-specific gonadal transcriptomes (RNA-sequencing validated by qPCR) of painted turtles (Chrysemys picta TSD) before and during the thermosensitive period, and at equivalent stages in soft-shell turtles (Apalone spinifera-GSD), to test whether TSD's and GSD's transcriptional circuitry is identical but deployed differently between mechanisms. Our data show that most elements of the mammalian urogenital network are active during turtle gonadogenesis, but their transcription is generally more thermoresponsive in TSD than GSD, and concordant with their sex-specific function in mammals [e.g., upregulation of Amh, Ar, Esr1, Fog2, Gata4, Igf1r, Insr, and Lhx9 at male-producing temperature, and of β-catenin, Foxl2, Aromatase (Cyp19a1), Fst, Nf-kb, Crabp2 at female-producing temperature in Chrysemys]. Notably, antagonistic elements in gonadogenesis (e.g., β-catenin and Insr) were thermosensitive only in TSD early-embryos. Cirbp showed warm-temperature upregulation in both turtles disputing its purported key TSD role. Genes that may convert thermal inputs into sex-specific development (e.g., signaling and hormonal pathways, RNA-binding and heat-shock) were differentially regulated. Jak-Stat, Nf-κB, retinoic-acid, Wnt, and Mapk-signaling (not Akt and Ras-signaling) potentially mediate TSD thermosensitivity. Numerous species-specific ncRNAs (including Xist) were differentially-expressed, mostly upregulated at colder temperatures, as were unannotated loci that constitute novel TSD candidates. Cirbp showed warm-temperature upregulation in both turtles. Consistent transcription between turtles and alligator revealed putatively-critical reptilian TSD elements for male (Sf1, Amh, Amhr2) and female (Crabp2 and Hspb1

  7. Transcriptomic responses to environmental temperature by turtles with temperature-dependent and genotypic sex determination assessed by RNAseq inform the genetic architecture of embryonic gonadal development.

    Directory of Open Access Journals (Sweden)

    Srihari Radhakrishnan

    Full Text Available Vertebrate sexual fate is decided primarily by the individual's genotype (GSD, by the environmental temperature during development (TSD, or both. Turtles exhibit TSD and GSD, making them ideal to study the evolution of sex determination. Here we analyze temperature-specific gonadal transcriptomes (RNA-sequencing validated by qPCR of painted turtles (Chrysemys picta TSD before and during the thermosensitive period, and at equivalent stages in soft-shell turtles (Apalone spinifera-GSD, to test whether TSD's and GSD's transcriptional circuitry is identical but deployed differently between mechanisms. Our data show that most elements of the mammalian urogenital network are active during turtle gonadogenesis, but their transcription is generally more thermoresponsive in TSD than GSD, and concordant with their sex-specific function in mammals [e.g., upregulation of Amh, Ar, Esr1, Fog2, Gata4, Igf1r, Insr, and Lhx9 at male-producing temperature, and of β-catenin, Foxl2, Aromatase (Cyp19a1, Fst, Nf-kb, Crabp2 at female-producing temperature in Chrysemys]. Notably, antagonistic elements in gonadogenesis (e.g., β-catenin and Insr were thermosensitive only in TSD early-embryos. Cirbp showed warm-temperature upregulation in both turtles disputing its purported key TSD role. Genes that may convert thermal inputs into sex-specific development (e.g., signaling and hormonal pathways, RNA-binding and heat-shock were differentially regulated. Jak-Stat, Nf-κB, retinoic-acid, Wnt, and Mapk-signaling (not Akt and Ras-signaling potentially mediate TSD thermosensitivity. Numerous species-specific ncRNAs (including Xist were differentially-expressed, mostly upregulated at colder temperatures, as were unannotated loci that constitute novel TSD candidates. Cirbp showed warm-temperature upregulation in both turtles. Consistent transcription between turtles and alligator revealed putatively-critical reptilian TSD elements for male (Sf1, Amh, Amhr2 and female (Crabp2 and

  8. New calibration methodology for calorimetric determination of isobaric thermal expansivity of liquids as a function of temperature and pressure

    Energy Technology Data Exchange (ETDEWEB)

    Navia, Paloma; Troncoso, Jacobo [Departamento de Fisica Aplicada, Facultad de Ciencias de Ourense, Campus As Lagoas, 32004 Ourense (Spain); Romani, Luis [Departamento de Fisica Aplicada, Facultad de Ciencias de Ourense, Campus As Lagoas, 32004 Ourense (Spain)], E-mail: romani@uvigo.es

    2008-11-15

    A new method for determining isobaric thermal expansivity of liquids as a function of temperature and pressure through calorimetric measurements against pressure is described. It is based on a previously reported measurement technique, but due to the different kind of calorimeter and experimental set up, a new calibration procedure was developed. Two isobaric thermal expansivity standards are needed; in this work, with a view on the quality of the available literature data, hexane and water are chosen. The measurements were carried out in the temperature and pressure intervals (278.15 to 348.15) K and (0.5 to 55) MPa for a set of liquids, and experimental values are compared with the available literature data in order to evaluate the precision of the experimental procedure. The analysis of the results reveals that the proposed methodology is highly accurate for isobaric thermal expansivity determination, and it allows obtaining a precise characterisation of the temperature and pressure dependence of this thermodynamic coefficient.

  9. New calibration methodology for calorimetric determination of isobaric thermal expansivity of liquids as a function of temperature and pressure

    International Nuclear Information System (INIS)

    Navia, Paloma; Troncoso, Jacobo; Romani, Luis

    2008-01-01

    A new method for determining isobaric thermal expansivity of liquids as a function of temperature and pressure through calorimetric measurements against pressure is described. It is based on a previously reported measurement technique, but due to the different kind of calorimeter and experimental set up, a new calibration procedure was developed. Two isobaric thermal expansivity standards are needed; in this work, with a view on the quality of the available literature data, hexane and water are chosen. The measurements were carried out in the temperature and pressure intervals (278.15 to 348.15) K and (0.5 to 55) MPa for a set of liquids, and experimental values are compared with the available literature data in order to evaluate the precision of the experimental procedure. The analysis of the results reveals that the proposed methodology is highly accurate for isobaric thermal expansivity determination, and it allows obtaining a precise characterisation of the temperature and pressure dependence of this thermodynamic coefficient

  10. DETERMINING THE COMPOSITION OF HIGH TEMPERATURE COMBUSTION PRODUCTS OF FOSSIL FUEL BASED ON VARIATIONAL PRINCIPLES AND GEOMETRIC PROGRAMMING

    Directory of Open Access Journals (Sweden)

    Velibor V Vujović

    2011-01-01

    Full Text Available This paper presents the algorithm and results of a computer program for calculation of complex equilibrium composition for the high temperature fossil fuel combustion products. The method of determining the composition of high temperatures combustion products at the temperatures appearing in the open cycle MHD power generation is given. The determination of combustion product composition is based on minimization of the Gibbs free energy. The number of equations to be solved is reduced by using variational principles and a method of geometric programming and is equal to the sum of the numbers of elements and phases. A short description of the computer program for the calculation of the composition and an example of the results are also given.

  11. Determination of maximum water temperature within the spent fuel pool of Angra Nuclear Power Plant - Unit 3

    Energy Technology Data Exchange (ETDEWEB)

    Werner, F.L., E-mail: fernanda.werner@poli.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Departamento de Engenharia Nuclear; Alves, A.S.M., E-mail: asergi@eletronuclear.gov.br [Eletrobras Termonuclear (Eletronuclear), Rio de Janeiro, RJ (Brazil); Frutuoso e Melo, P.F., E-mail: frutuoso@nuclear.ufrj.br [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    In this paper, a mathematical model for the determination of the maximum water temperature within the spent fuel pool of Angra Nuclear Power Plant – Unit 3 was developed. The model was obtained from the boundary layer analysis and the application of Navier-Stokes equation to a vertical flat plate immersed in a water flow under free convection regime. Both types of pressure loss coefficients through the flow channel were considers in the modeling, the form coefficient for fuel assemblies (FAs) and the loss due to rod friction. The resulting equations enabled the determination of a mixed water temperature below the storage racks (High Density Storage Racks) as well as the estimation of a temperature gradient through the racks. The model was applied to the authorized operation of the plant (power operation, plant outage and upset condition) and faulted conditions (loss of coolant accidents and external events). The results obtained are in agreement with Brazilian and international standards. (author)

  12. Determination of maximum water temperature within the spent fuel pool of Angra Nuclear Power Plant - Unit 3

    International Nuclear Information System (INIS)

    Werner, F.L.; Frutuoso e Melo, P.F.

    2017-01-01

    In this paper, a mathematical model for the determination of the maximum water temperature within the spent fuel pool of Angra Nuclear Power Plant – Unit 3 was developed. The model was obtained from the boundary layer analysis and the application of Navier-Stokes equation to a vertical flat plate immersed in a water flow under free convection regime. Both types of pressure loss coefficients through the flow channel were considers in the modeling, the form coefficient for fuel assemblies (FAs) and the loss due to rod friction. The resulting equations enabled the determination of a mixed water temperature below the storage racks (High Density Storage Racks) as well as the estimation of a temperature gradient through the racks. The model was applied to the authorized operation of the plant (power operation, plant outage and upset condition) and faulted conditions (loss of coolant accidents and external events). The results obtained are in agreement with Brazilian and international standards. (author)

  13. Experimental determination of temperature fields in sodium-cooled rod bundles with hexagonal rod arrangement and grid spacers

    International Nuclear Information System (INIS)

    Moeller, R.; Tschoeke, H.; Kolodziej, M.

    1977-01-01

    Three-dimensional temperature fields in the claddings of sodium cooled rods were determined experimentally under representative nominal operating conditions for a SNR typical 19-rod bundle model provided with spark-eroded spacers. These experiments are required to verify thermohydraulic computer programs which will provide the output data for strength calculations of the high loaded cladding tubes. In this work the essentials are reported of the measured circumferential distributions of wall temperatures of peripheral rods. In addition the sub-channel temperatures measured over the bundle cross section are indicated, they are required to sustain codes for the global thermohydraulic design of core elements. The most important results are: 1) The whole fuel element is located within the thermal entrance length. 2) High azimuthal temperature differences were measured in the claddings of peripheral rods, which are strongly influenced by the distance between the rod and the shroud, especially for the corner rod. 3) With decreasing Pe-number ( [de

  14. Determination of electron temperature of the envelopes for the A2 Ia supergiants α Cyg and ν Cep

    International Nuclear Information System (INIS)

    Glushneva, I.N.

    1984-01-01

    On the basis of the analysis of the energy distribution data in the spectra of two bright A2 Ia supergiants, α Cyg and ω Cep, the electron temperature of the envelope and the contributions of the star and of the mantle in the continuum formation are determined. It is shown that the temperature obtained on the basis of the observations in the ultraviolet range lambda lambda 3200-3600 A is slightly higher that the effective temperature (Tsub(e) approximately 8500 K), being 12500 K in the case of α Cyg and 11000 K for ν Cep. The analysis of the α Cyg infrared excess shows that the regions with T approximately 10 4 K as well as with higher temperatures (about 2x10 4 K) exist in the envelope

  15. Temporal variation in temperature determines disease spread and maintenance in Paramecium microcosm populations

    Science.gov (United States)

    Duncan, Alison B.; Fellous, Simon; Kaltz, Oliver

    2011-01-01

    The environment is rarely constant and organisms are exposed to temporal and spatial variations that impact their life histories and inter-species interactions. It is important to understand how such variations affect epidemiological dynamics in host–parasite systems. We explored effects of temporal variation in temperature on experimental microcosm populations of the ciliate Paramecium caudatum and its bacterial parasite Holospora undulata. Infected and uninfected populations of two P. caudatum genotypes were created and four constant temperature treatments (26°C, 28°C, 30°C and 32°C) compared with four variable treatments with the same mean temperatures. Variable temperature treatments were achieved by alternating populations between permissive (23°C) and restrictive (35°C) conditions daily over 30 days. Variable conditions and high temperatures caused greater declines in Paramecium populations, greater fluctuations in population size and higher incidence of extinction. The additional effect of parasite infection was additive and enhanced the negative effects of the variable environment and higher temperatures by up to 50 per cent. The variable environment and high temperatures also caused a decrease in parasite prevalence (up to 40%) and an increase in extinction (absence of detection) (up to 30%). The host genotypes responded similarly to the different environmental stresses and their effect on parasite traits were generally in the same direction. This work provides, to our knowledge, the first experimental demonstration that epidemiological dynamics are influenced by environmental variation. We also emphasize the need to consider environmental variance, as well as means, when trying to understand, or predict population dynamics or range. PMID:21450730

  16. Determining pH at elevated pressure and temperature using in situ ¹³C NMR.

    Science.gov (United States)

    Surface, J Andrew; Wang, Fei; Zhu, Yanzhe; Hayes, Sophia E; Giammar, Daniel E; Conradi, Mark S

    2015-02-03

    We have developed an approach for determining pH at elevated pressures and temperatures by using (13)C NMR measurements of inorganic carbon species together with a geochemical equilibrium model. The approach can determine in situ pH with precision better than 0.1 pH units at pressures, temperatures, and ionic strengths typical of geologic carbon sequestration systems. A custom-built high pressure NMR probe was used to collect (13)C NMR spectra of (13)C-labeled CO2 reactions with NaOH solutions and Mg(OH)2 suspensions at pressures up to 107 bar and temperatures of 80 °C. The quantitative nature of NMR spectroscopy allows the concentration ratio [CO2]/[HCO3(-)] to be experimentally determined. This ratio is then used with equilibrium constants calculated for the specific pressure and temperature conditions and appropriate activity coefficients for the solutes to calculate the in situ pH. The experimentally determined [CO2]/[HCO3(-)] ratios agree well with the predicted values for experiments performed with three different concentrations of NaOH and equilibration with multiple pressures of CO2. The approach was then applied to experiments with Mg(OH)2 slurries in which the change in pH could track the dissolution of CO2 into solution, rapid initial Mg(OH)2 dissolution, and onset of magnesium carbonate precipitation.

  17. Determination of rotational temperature of AlO from the B2Σ+–X2Σ+ ...

    Indian Academy of Sciences (India)

    pp. 597–600. Determination of rotational temperature of AlO from the B2Σ+–X2Σ+ system. M M CHAUDHARI1, C T LONDHE2 and S H BEHERE2. 1Maharashtra Mahavidyalaya, Nilanga 413 521, Dist. Latur, India. 2Department of Physics, Dr Babasaheb Ambedkar Marathwada University,. Aurangabad 431 004, India.

  18. Method of determination of temperature and heat resistance of the points on the integrated circuit crystal surface

    Directory of Open Access Journals (Sweden)

    Popov V. M.

    2011-12-01

    Full Text Available Method for visualization of integrated circuit (IC surface temperature by means of the liquid crystal film deposited from solution on its surface is proposed. The boundaries of local regions represent isotherms with corresponding phase transitions. On the base of isotherms positions and consumed by IC power thermal resistances between crystal and environment are determined.

  19. 40 CFR 86.129-94 - Road load power, test weight, inertia weight class determination, and fuel temperature profile.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Road load power, test weight, inertia... Procedures § 86.129-94 Road load power, test weight, inertia weight class determination, and fuel temperature... duty trucks 1,2,3 Test weightbasis 4,5 Test equivalent test weight(pounds) Inertia weight class(pounds...

  20. The Stark-crossing method for the simultaneous determination of the electron temperature and density in plasmas

    International Nuclear Information System (INIS)

    Torres, J; Carabano, O; Fernandez, M; Rubio, S; Alvarez, R; Rodero, A; Lao, C; Quintero, M C; Gamero, A; Sola, A

    2006-01-01

    The use of the Stark broadening of Balmer lines spontaneously emitted by atmospheric-pressure plasmas as a method to determine both the electron density and temperature in high-pressure plasmas is discussed in this paper. This method is applied to argon and helium plasmas produced in microwave discharges. Especially for Ar plasmas, valuable and reliable results are obtained

  1. Acoustic travel time gauges for in-situ determination of pressure and temperature in multi-anvil apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xuebing; Chen, Ting; Qi, Xintong [Department of Geosciences, Stony Brook University, Stony Brook, New York 11794 (United States); Zou, Yongtao; Liebermann, Robert C.; Li, Baosheng [Mineral Physics Institute, Stony Brook University, Stony Brook, New York 11794 (United States); Kung, Jennifer [Department of Earth Sciences, National Cheng Kung University, Tainan 70101, Taiwan (China); Yu, Tony; Wang, Yanbin [GeoSoilEnviroCARS, Center for Advanced Radiation Sources, The University of Chicago, 5640 S. Ellis Avenue, Chicago, Illinois 60637 (United States)

    2015-08-14

    In this study, we developed a new method for in-situ pressure determination in multi-anvil, high-pressure apparatus using an acoustic travel time approach within the framework of acoustoelasticity. The ultrasonic travel times of polycrystalline Al{sub 2}O{sub 3} were calibrated against NaCl pressure scale up to 15 GPa and 900 °C in a Kawai-type double-stage multi-anvil apparatus in conjunction with synchrotron X-radiation, thereby providing a convenient and reliable gauge for pressure determination at ambient and high temperatures. The pressures derived from this new travel time method are in excellent agreement with those from the fixed-point methods. Application of this new pressure gauge in an offline experiment revealed a remarkable agreement of the densities of coesite with those from the previous single crystal compression studies under hydrostatic conditions, thus providing strong validation for the current travel time pressure scale. The travel time approach not only can be used for continuous in-situ pressure determination at room temperature, high temperatures, during compression and decompression, but also bears a unique capability that none of the previous scales can deliver, i.e., simultaneous pressure and temperature determination with a high accuracy (±0.16 GPa in pressure and ±17 °C in temperature). Therefore, the new in-situ Al{sub 2}O{sub 3} pressure gauge is expected to enable new and expanded opportunities for offline laboratory studies of solid and liquid materials under high pressure and high temperature in multi-anvil apparatus.

  2. Acoustic travel time gauges for in-situ determination of pressure and temperature in multi-anvil apparatus

    International Nuclear Information System (INIS)

    Wang, Xuebing; Chen, Ting; Qi, Xintong; Zou, Yongtao; Liebermann, Robert C.; Li, Baosheng; Kung, Jennifer; Yu, Tony; Wang, Yanbin

    2015-01-01

    In this study, we developed a new method for in-situ pressure determination in multi-anvil, high-pressure apparatus using an acoustic travel time approach within the framework of acoustoelasticity. The ultrasonic travel times of polycrystalline Al 2 O 3 were calibrated against NaCl pressure scale up to 15 GPa and 900 °C in a Kawai-type double-stage multi-anvil apparatus in conjunction with synchrotron X-radiation, thereby providing a convenient and reliable gauge for pressure determination at ambient and high temperatures. The pressures derived from this new travel time method are in excellent agreement with those from the fixed-point methods. Application of this new pressure gauge in an offline experiment revealed a remarkable agreement of the densities of coesite with those from the previous single crystal compression studies under hydrostatic conditions, thus providing strong validation for the current travel time pressure scale. The travel time approach not only can be used for continuous in-situ pressure determination at room temperature, high temperatures, during compression and decompression, but also bears a unique capability that none of the previous scales can deliver, i.e., simultaneous pressure and temperature determination with a high accuracy (±0.16 GPa in pressure and ±17 °C in temperature). Therefore, the new in-situ Al 2 O 3 pressure gauge is expected to enable new and expanded opportunities for offline laboratory studies of solid and liquid materials under high pressure and high temperature in multi-anvil apparatus

  3. A new procedure for the determination of distillation temperature distribution of high-boiling petroleum products and fractions.

    Science.gov (United States)

    Boczkaj, Grzegorz; Przyjazny, Andrzej; Kamiński, Marian

    2011-03-01

    The distribution of distillation temperatures of liquid and semi-fluid products, including petroleum fractions and products, is an important process and practical parameter. It provides information on properties of crude oil and content of particular fractions, classified on the basis of their boiling points, as well as the optimum conditions of atmospheric or vacuum distillation. At present, the distribution of distillation temperatures is often investigated by simulated distillation (SIMDIS) using capillary gas chromatography (CGC) with a short capillary column with polydimethylsiloxane as the stationary phase. This paper presents the results of investigations on the possibility of replacing currently used CGC columns for SIMDIS with a deactivated fused silica capillary tube without any stationary phase. The SIMDIS technique making use of such an empty fused silica column allows a considerable lowering of elution temperature of the analytes, which results in a decrease of the final oven temperature while ensuring a complete separation of the mixture. This eliminates the possibility of decomposition of less thermally stable mixture components and bleeding of the stationary phase which would result in an increase of the detector signal. It also improves the stability of the baseline, which is especially important in the determination of the end point of elution, which is the basis for finding the final temperature of distillation. This is the key parameter for the safety process of hydrocracking, where an excessively high final temperature of distillation of a batch can result in serious damage to an expensive catalyst bed. This paper compares the distribution of distillation temperatures of the fraction from vacuum distillation of petroleum obtained using SIMDIS with that obtained by the proposed procedure. A good agreement between the two procedures was observed. In addition, typical values of elution temperatures of n-paraffin standards obtained by the two

  4. Determination of Scattering and Absorption Coefficients for Plasma-Sprayed Yttria-Stabilized Zirconia Thermal Barrier Coatings at Elevated Temperatures

    Science.gov (United States)

    Eldridge, Jeffrey I.; Spuckler, Charles M.; Markham, James R.

    2009-01-01

    The temperature dependence of the scattering and absorption coefficients for a set of freestanding plasma-sprayed 8 wt% yttria-stabilized zirconia (8YSZ) thermal barrier coatings (TBCs) was determined at temperatures up to 1360 C in a wavelength range from 1.2 micrometers up to the 8YSZ absorption edge. The scattering and absorption coefficients were determined by fitting the directional-hemispherical reflectance and transmittance values calculated by a four-flux Kubelka Munk method to the experimentally measured hemispherical-directional reflectance and transmittance values obtained for five 8YSZ thicknesses. The scattering coefficient exhibited a continuous decrease with increasing wavelength and showed no significant temperature dependence. The scattering is primarily attributed to the relatively temperature-insensitive refractive index mismatch between the 8YSZ and its internal voids. The absorption coefficient was very low (less than 1 per centimeter) at wavelengths between 2 micrometers and the absorption edge and showed a definite temperature dependence that consisted of a shift of the absorption edge to shorter wavelengths and an increase in the weak absorption below the absorption edge with increasing temperature. The shift in the absorption edge with temperature is attributed to strongly temperature-dependent multiphonon absorption. While TBC hemispherical transmittance beyond the absorption edge can be predicted by a simple exponential decrease with thickness, below the absorption edge, typical TBC thicknesses are well below the thickness range where a simple exponential decrease in hemispherical transmittance with TBC thickness is expected. [Correction added after online publication August 11, 2009: "edge to a shorter wavelengths" has been updated as edge to shorter wavelengths."

  5. Thermometric determination of cartilage matrix temperatures during thermal chondroplasty: comparison of bipolar and monopolar radiofrequency devices.

    Science.gov (United States)

    Edwards, Ryland B; Lu, Yan; Rodriguez, Edwin; Markel, Mark D

    2002-04-01

    To compare cartilage matrix temperatures between monopolar radiofrequency energy (mRFE) and bipolar RFE (bRFE) at 3 depths under the articular surface during thermal chondroplasty. We hypothesized that cartilage temperatures would be higher at all cartilage depths for the bRFE device than for the mRFE device. Randomized trial using bovine cartilage. Sixty osteochondral sections from the femoropatellar joint of 15 adult cattle were used for this study. Using a custom jig, fluoroptic thermometry probes were placed at one of the following depths under the articular surface: 200 microm, 500 microm, or 2,000 microm. RF treatment was performed either with fluid flow (F) (120 mL/min) or without fluid flow (NF) (n = 5/depth/RFE device/flow; total specimens, 60). Irrigation fluid temperature was room temperature (22 degrees C). Thermometry data were acquired at 4 Hz for 5 seconds with the RF probe off, for 20 seconds with the RF probe on, and then for 15 seconds with the RF probe off. During RF treatment, a 0.79-cm2 area (1.0-cm diameter) of the articular surface centered over the thermometry probe was treated in a paintbrush manner in noncontact (bRFE) or light contact (mRFE). Thermal chondroplasty with bRFE resulted in higher cartilage matrix temperatures compared with mRFE for all depths and regardless of fluid flow. Bipolar RFE resulted in temperatures of 95 degrees C to 100 degrees C at 200 microm and 500 microm under the surface, with temperatures of 75 degrees C to 78 degrees C at 2,000 microm. Fluid flow during bRFE application had no effect at 200 microm. Monopolar RFE resulted in temperatures of 61 degrees C to 68 degrees C at 200 microm, 54 degrees C to 70 degrees C at 500 microm under the surface, and 28 degrees C to 30 degrees C at 2,000 microm below the surface. A significant effect of fluid flow during mRFE application occurred at 200 microm (NF, 61 degrees C; F, 63 degrees C) and 500 microm (NF, 53 degrees C; F, 68 degrees C). In this study, we found

  6. Determination of heat conductivity and thermal diffusivity of waste glass melter feed: Extension to high temperatures

    International Nuclear Information System (INIS)

    Rice, Jarrett A.; Pokorny, Richard; Schweiger, Michael J.; Hrma, Pavel R.

    2014-01-01

    The heat conductivity (λ) and the thermal diffusivity (a) of reacting glass batch, or melter feed, control the heat flux into and within the cold cap, a layer of reacting material floating on the pool of molten glass in an all-electric continuous waste glass melter. After previously estimating λ of melter feed at temperatures up to 680 deg C, we focus in this work on the λ(T) function at T > 680 deg C, at which the feed material becomes foamy. We used a customized experimental setup consisting of a large cylindrical crucible with an assembly of thermocouples, which monitored the evolution of the temperature field while the crucible with feed was heated at a constant rate from room temperature up to 1100°C. Approximating measured temperature profiles by polynomial functions, we used the heat transfer equation to estimate the λ(T) approximation function, which we subsequently optimized using the finite-volume method combined with least-squares analysis. The heat conductivity increased as the temperature increased until the feed began to expand into foam, at which point the conductivity dropped. It began to increase again as the foam turned into a bubble-free glass melt. We discuss the implications of this behavior for the mathematical modeling of the cold cap

  7. Effect of pre-strain on creep of three AISI 316 austenitic stainless steels in relation to reheat cracking of weld-affected zones

    Science.gov (United States)

    Auzoux, Q.; Allais, L.; Caës, C.; Monnet, I.; Gourgues, A. F.; Pineau, A.

    2010-05-01

    Microstructural modifications induced by welding of 316 stainless steels and their effect on creep properties and relaxation crack propagation were examined. Cumulative strain due to multi-pass welding hardens the materials by increasing the dislocation density. Creep tests were conducted on three plates from different grades of 316 steel at 600 °C, with various carbon and nitrogen contents. These plates were tested both in the annealed condition and after warm rolling, which introduced pre-strain. It was found that the creep strain rate and ductility after warm rolling was reduced compared with the annealed condition. Moreover, all steels exhibited intergranular crack propagation during relaxation tests on Compact Tension specimens in the pre-strained state, but not in the annealed state. These results confirmed that the reheat cracking risk increases with both residual stress triaxiality and pre-strain. On the contrary, high solute content and strain-induced carbide precipitation, which are thought to increase reheat cracking risk of stabilised austenitic stainless steels did not appear as key parameters in reheat cracking of 316 stainless steels.

  8. Effect of pre-strain on creep of three AISI 316 austenitic stainless steels in relation to reheat cracking of weld-affected zones

    International Nuclear Information System (INIS)

    Auzoux, Q.; Allais, L.; Caes, C.; Monnet, I.; Gourgues, A.F.; Pineau, A.

    2010-01-01

    Microstructural modifications induced by welding of 316 stainless steels and their effect on creep properties and relaxation crack propagation were examined. Cumulative strain due to multi-pass welding hardens the materials by increasing the dislocation density. Creep tests were conducted on three plates from different grades of 316 steel at 600 deg. C, with various carbon and nitrogen contents. These plates were tested both in the annealed condition and after warm rolling, which introduced pre-strain. It was found that the creep strain rate and ductility after warm rolling was reduced compared with the annealed condition. Moreover, all steels exhibited intergranular crack propagation during relaxation tests on Compact Tension specimens in the pre-strained state, but not in the annealed state. These results confirmed that the reheat cracking risk increases with both residual stress triaxiality and pre-strain. On the contrary, high solute content and strain-induced carbide precipitation, which are thought to increase reheat cracking risk of stabilised austenitic stainless steels did not appear as key parameters in reheat cracking of 316 stainless steels.

  9. Irradiation temperature memorization by retention of krypton-85. Application to the temperature determination for the internal cladding surface of fuel elements in PWR

    International Nuclear Information System (INIS)

    Fremiot, Claude

    1977-01-01

    The temperature of the inner surface of the cladding fuel elements, which can not be measured directly, can be determined after irradiation. During its stage within the reactor, the cladding is bombarded by krypton-85 fission product, which is trapped in the metallic lattice defects. The experience shows that the krypton release during postirradiation heating takes place at the irradiation temperature. This method was applied for PWR fuel element. A very simple model for retention and release of the krypton is proposed. The krypton trap-energy in zircaloy partakes in this model. This technique can be ordered amongst the Hot'Lab' control methods and expert appraisements. It is pointed out that the principal interest in that method is the fact that it does not need any fuel element instrumentation. At the present, this method is being used by CEA for routine-control. [fr

  10. Determination of new time-temperature-transformation diagrams for lead-calcium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, F.; Lambertin, M. [Arts et Metiers Paristech, LaBoMaP, ENSAM, Rue porte de Paris, 71250 Cluny (France); Delfaut-Durut, L. [CEA, centre de Valduc [SEMP, LECM], 21120 Is-sur-Tille (France); Maitre, A. [SPCTS, UFR Sciences et techniques, 87060 Limoges (France); Vilasi, M. [LCSM, Universite Nancy I, 54506 Vandoeuvre les Nancy (France)

    2008-12-01

    The Pb-Ca is an age hardening alloy that allows for an increase in the hardness compared to pure lead. The hardening is obtained after different successive ageing transformations. In addition, this hardening is followed by an overageing which induces a softening. The ageing and overageing transformation mechanisms are now well identified in lead-calcium alloys. In this paper, we propose to represent the domain of stability of each transformation via time-temperature-transformation diagrams for a calcium concentration from 600 to 1280 ppm and in a range of temperatures from -20 to 180 C. These diagrams are constructed with the data obtained by in situ ageing with metallographic observations, hardness and electrical resistance measurements. The specificities of lead-calcium such as its fast ageing at ambient temperature and its overageing over time required the design of specific devices to be able to identify the characteristics of these alloys. (author)

  11. Determination of composition and physical properties of partially ionized plasmas in the function of temperature

    International Nuclear Information System (INIS)

    Zaporowski, B.

    1992-01-01

    The investigations of various kinds of partially ionized plasma were conducted for the pressure of 0.1 MPa and in the range of temperature of 298.15 K to 24000 K. The physical properties of various kinds of partially ionized plasma depend mainly of their composition and temperature. The composition of particular kinds of partially ionized plasmas varies also in the function of temperature. Simultaneous going on of physical and chemical processes in plasma is the reason of difficulties in the calculations of plasma's physical properties. The use of the laws of macroscopic thermodynamics for the calculations of physical properties of partially ionized plasma is impossible. There are enough exact methods for measuring of physical properties of partially ionized plasma. For these reasons the theoretical method using the base of statistic physics was used to calculate the composition and physical properties of various kinds of partially ionized plasma. (author) 2 refs., 2 figs

  12. Determination of the Temperature Dependence of Heat Capacity for Some Molecular Crystals of Nitro Compounds

    Science.gov (United States)

    Kovalev, Yu. M.; Kuropatenko, V. F.

    2018-05-01

    An analysis of the existing approximations used for describing the dependence of heat capacity at a constant volume on the temperature of a molecular crystal has been carried out. It is shown that the considered Debye and Einstein approximations do not enable one to adequately describe the dependence of heat capacity at a constant volume on the temperature of the molecular crystals of nitro compounds. This inference requires the development of special approximations that would describe both low-frequency and high-frequency parts of the vibrational spectra of molecular crystals. This work presents a universal dependence allowing one to describe the dependence of heat capacity at a constant volume on temperature for a number of molecular crystals of nitro compounds.

  13. THE MAXIMUM EFFECT OF DEEP LAKES ON TEMPERATURE PROFILES – DETERMINATION OF THE GEOTHERMAL GRADIENT

    OpenAIRE

    Eppelbaum L. V.; Kutasov I. M.; Balobaev V. T.

    2009-01-01

    Understanding the climate change processes on the basis of geothermal observations in boreholes is an important and at the same time high-intricate problem. Many non-climatic effects could cause changes in ground surface temperatures. In this study we investigate the effects of deep lakes on the borehole temperature profilesobserved within or in the vicinity of the lakes. We propose a method based on utilization of Laplace equation with nonuniform boundary conditions. The proposed method make...

  14. The determination of temperature stability of silver nanotubes by the molecular dynamics simulation

    Science.gov (United States)

    Filatov, O.; Soldatenko, S.; Soldatenko, O.

    2018-04-01

    Molecular dynamics simulation using the embedded-atom method is applied to study thermal stability of silver nanotubes and its coefficient of linear thermal expansion. The correspondence of face centered cubic structure potential for this task is tested. Three types of nanotubes are modelled: scrolled from graphene-like plane, scrolled from plane with cubic structure and cut from cylinder. It is established that only the last two of them are stable. The last one describes in details. There is critical temperature when free ends of the nanotube close but the interior surface retains. At higher temperatures, the interior surface collapses and the nanotube is unstable.

  15. Determination of temperature dependency of material parameters for lead-free alkali niobate piezoceramics by the inverse method

    Directory of Open Access Journals (Sweden)

    K. Ogo

    2016-06-01

    Full Text Available Sodium potassium niobate (NKN piezoceramics have been paid much attention as lead-free piezoelectric materials in high temperature devices because of their high Curie temperature. The temperature dependency of their material parameters, however, has not been determined in detail up to now. For this purpose, we exploit the so-called Inverse Method denoting a simulation-based characterization approach. Compared with other characterization methods, the Inverse Method requires only one sample shape of the piezoceramic material and has further decisive advantages. The identification of material parameters showed that NKN is mechanically softer in shear direction compared with lead zirconate titanate (PZT at room temperature. The temperature dependency of the material parameters of NKN was evaluated in the temperature range from 30 °C to 150 °C. As a result, we figured out that dielectric constants and piezoelectric constants show a monotonous and isotropic increment with increasing temperature. On the other hand, elastic stiffness constant c 44 E of NKN significantly decreased in contrast to other elastic stiffness constants. It could be revealed that the decrement of c 44 E is associated with an orthorhombic-tetragonal phase transition. Furthermore, ratio of elastic compliance constants s 44 E / s 33 E exhibited similar temperature dependent behavior to the ratio of piezoelectric constants d15/d33. It is suspected that mechanical softness in shear direction is one origin of the large piezoelectric shear mode of NKN. Our results show that NKN are suitable for high temperature devices, and that the Inverse Method should be a helpful approach to characterize material parameters under their practical operating conditions for NKN.

  16. Comparing daily temperature averaging methods: the role of surface and atmosphere variables in determining spatial and seasonal variability

    Science.gov (United States)

    Bernhardt, Jase; Carleton, Andrew M.

    2018-05-01

    The two main methods for determining the average daily near-surface air temperature, twice-daily averaging (i.e., [Tmax+Tmin]/2) and hourly averaging (i.e., the average of 24 hourly temperature measurements), typically show differences associated with the asymmetry of the daily temperature curve. To quantify the relative influence of several land surface and atmosphere variables on the two temperature averaging methods, we correlate data for 215 weather stations across the Contiguous United States (CONUS) for the period 1981-2010 with the differences between the two temperature-averaging methods. The variables are land use-land cover (LULC) type, soil moisture, snow cover, cloud cover, atmospheric moisture (i.e., specific humidity, dew point temperature), and precipitation. Multiple linear regression models explain the spatial and monthly variations in the difference between the two temperature-averaging methods. We find statistically significant correlations between both the land surface and atmosphere variables studied with the difference between temperature-averaging methods, especially for the extreme (i.e., summer, winter) seasons (adjusted R2 > 0.50). Models considering stations with certain LULC types, particularly forest and developed land, have adjusted R2 values > 0.70, indicating that both surface and atmosphere variables control the daily temperature curve and its asymmetry. This study improves our understanding of the role of surface and near-surface conditions in modifying thermal climates of the CONUS for a wide range of environments, and their likely importance as anthropogenic forcings—notably LULC changes and greenhouse gas emissions—continues.

  17. Determination of the amplitude and phase relationships between oscillations in skin temperature and photoplethysmography-measured blood flow in fingertips

    International Nuclear Information System (INIS)

    Sagaidachnyi, A A; Skripal, A V; Fomin, A V; Usanov, D A

    2014-01-01

    It is well established that skin temperature oscillations in fingertips coexist with blood flow oscillations and there is a certain correlation between them. At the same time, the reasons for differences in waveform and the delay between the blood flow and temperature oscillations are far from being fully understood. In this study we determine the relationships between spectral components of the blood flow and temperature oscillations in fingertips, and we ascertain the frequency dependences of amplitude attenuation and delay time for the temperature oscillations. The blood flow oscillations were considered as a source of thermal waves propagating from micro-vessels towards the skin surface and manifesting as temperature oscillations. The finger temperature was measured by infrared thermography and blood flow was assessed by photoplethysmography for ten healthy subjects. The time–frequency analysis of oscillations was based on the Morlet wavelet transform. The frequency dependences of delay time and amplitude attenuation in temperature compared with blood flow oscillations have been determined in endothelial (0.005–0.02 Hz) and neurogenic (0.02–0.05 Hz) frequency bands using the wavelet spectra. We approximated the experimental frequency dependences by equations describing thermal wave propagation through the medium and taking into account the thermal properties and thickness of a tissue. Results of analysis show that with the increase of frequency f the delay time of temperature oscillations decreases inversely proportional to f 1/2 , and the attenuation of the amplitude increases directly proportional to exp f 1/2 . Using these relationships allows us to increase correlation between the processed temperature oscillations and blood flow oscillations from 0.2 to 0.7 within the frequency interval 0.005–0.05 Hz. The established experimental and theoretical relationships clarify an understanding of interrelation between the dynamics of blood flow and skin

  18. Plasma Temperature Determination of Hydrogen Containing High-Frequency Electrode less Lamps by Intensity Distribution Measurements of Hydrogen Molecular Band

    International Nuclear Information System (INIS)

    Gavare, Z.; Revalde, G.; Skudra, A.

    2011-01-01

    The goal of the present work was the investigation of the possibility to use intensity distribution of the Q-branch lines of the hydrogen Fulcher-a diagonal band (d3η u- a3Σg + electronic transition; Q-branch with ν=ν=2) to determine the temperature of hydrogen containing high-frequency electrode less lamps (HFEDLs). The values of the rotational temperatures have been obtained from the relative intensity distributions for hydrogen-helium and hydrogen-argon HFEDLs depending on the applied current. The results have been compared with the method of temperature derivation from Doppler profiles of He 667.8 nm and Ar 772.4 nm lines. The results of both methods are in good agreement, showing that the method of gas temperature determination from the intensity distribution in the hydrogen Fulcher-a (2-2)Q band can be used for the hydrogen containing HFEDLs. It was observed that the admixture of 10% hydrogen in the argon HFEDLs significantly reduces the gas temperature

  19. Channel Temperature Determination for AlGaN/GaN HEMTs on SiC and Sapphire

    Science.gov (United States)

    Freeman, Jon C.; Mueller, Wolfgang

    2008-01-01

    Numerical simulation results (with emphasis on channel temperature) for a single gate AlGaN/GaN High Electron Mobility Transistor (HEMT) with either a sapphire or SiC substrate are presented. The static I-V characteristics, with concomitant channel temperatures (T(sub ch)) are calculated using the software package ATLAS, from Silvaco, Inc. An in-depth study of analytical (and previous numerical) methods for the determination of T(sub ch) in both single and multiple gate devices is also included. We develop a method for calculating T(sub ch) for the single gate device with the temperature dependence of the thermal conductivity of all material layers included. We also present a new method for determining the temperature on each gate in a multi-gate array. These models are compared with experimental results, and show good agreement. We demonstrate that one may obtain the channel temperature within an accuracy of +/-10 C in some cases. Comparisons between different approaches are given to show the limits, sensitivities, and needed approximations, for reasonable agreement with measurements.

  20. Determination of Coherency and Rigidity Temperatures in Al-Cu Alloys Using In Situ Neutron Diffraction During Casting

    Science.gov (United States)

    Drezet, Jean-Marie; Mireux, Bastien; Szaraz, Zoltan; Pirling, Thilo

    2014-08-01

    The rigidity temperature of a solidifying alloy is the temperature at which the solid phase is sufficiently coalesced to transmit tensile stress. It is a major input parameter in numerical modeling of solidification processes as it defines the point at which thermally induced deformations start to generate internal stresses in a casting. This temperature has been determined for an Al-13 wt.% Cu alloy using in situ neutron diffraction during casting in a dog-bone-shaped mold. This setup allows the sample to build up internal stress naturally as its contraction is not possible. The cooling on both sides of the mold induces a hot spot at the middle of the sample that is irradiated by neutrons. Diffraction patterns are recorded every 11 s using a large detector, and the very first change of diffraction angles allows for the determination of the rigidity temperature. We measured rigidity temperatures equal to 557°C and 548°C depending on the cooling rate for grain refined Al-13 wt.% Cu alloys. At a high cooling rate, rigidity is reached during the formation of the eutectic phase. In this case, the solid phase is not sufficiently coalesced to sustain tensile load and thus cannot avoid hot tear formation.

  1. On a non-linear problem posed by the temperature determination in an electrically heated plate

    International Nuclear Information System (INIS)

    Gerber, R.

    1958-01-01

    Let us consider a flat plate, electrically heated, with one face thermally insulated and the other face isothermal. It is shown that a two-dimensional perturbation of the insulated face has no influence on the temperature of this face. (author) [fr

  2. An inverse radiation model for optical determination of temperature and species concentration: Development and validation

    DEFF Research Database (Denmark)

    Ren, Tao; Modest, Michael F.; Fateev, Alexander

    2015-01-01

    2010 (Rothman et al. (2010) [1]), which contains line-by-line (LBL) information for several combustion gas species, such as CO2 and H2O, was used to predict gas spectral transmissivities. The model was validated by retrieving temperatures and species concentrations from experimental CO2 and H2O...

  3. Temperature response of an acoustically forced turbulent lean premixed flame: A quantitative experimental determination

    KAUST Repository

    Chrystie, Robin; Burns, Iain Stewart; Kaminski, Clemens Friedrich

    2013-01-01

    Temperature measurements have been taken on an acoustically forced lean premixed turbulent bluff-body stabilized flame. The burner used in this study is a test-bed to investigate thermoacoustic instability in gas-turbine engines at the University of Cambridge. Numerous experiments have been performed on the burner, one of which used two-line OH planar laser induced fluorescence to measure temperature. Here, we employ vibrational coherent anti-Stokes Raman scattering (CARS) of nitrogen as an alternative to measure temperature, circumventing the limitations of the former method. The use of nitrogen CARS avoids the problem of probing regions of the flame with low OH concentrations that resulted in erroneous temperature. Such an application of CARS showed that the results from previous efforts were systematically biased up to 47% close to the bluff-body. We also critically review the limitations of CARS used in our experiments, pertaining to spatial resolution and associated biasing further downstream from the bluff-body. Using the more accurate results from this work, more up-to-date computational fluid dynamical (CFD) models of the burner can be validated, with the aim of improved understanding and prediction of thermoacoustic instability in gas turbines. © 2013 Copyright Taylor and Francis Group, LLC.

  4. Experimental determination of a critical temperature for maximum anaerobic digester biogas production

    CSIR Research Space (South Africa)

    Sichilalu, S

    2017-08-01

    Full Text Available fission of methanogenic bacteria. The temperature was varied over time over several days and the biogas production is recorded every after 24 hours(1 day) . Based on the experiment setup, the results show a higher biogas production proportional to the rise...

  5. Determination of the potentiostatic stability of PEMFC electro catalysts at elevated temperatures

    NARCIS (Netherlands)

    Dam, V.A.T.; Jayasayee, K.; Bruijn, de F.A.

    2009-01-01

    The electrochemical stability of platinum on carbon catalyst (Hispec TM 4000, Johnson Matthey) has been investigated predominantly at constant potentials ranging from 0.95 to 1.25 V at elevated temperatures. By combining a quartz crystal microbalance (QCM) with electrochemical techniques, dynamic

  6. Temperature response of an acoustically forced turbulent lean premixed flame: A quantitative experimental determination

    KAUST Repository

    Chrystie, Robin

    2013-01-02

    Temperature measurements have been taken on an acoustically forced lean premixed turbulent bluff-body stabilized flame. The burner used in this study is a test-bed to investigate thermoacoustic instability in gas-turbine engines at the University of Cambridge. Numerous experiments have been performed on the burner, one of which used two-line OH planar laser induced fluorescence to measure temperature. Here, we employ vibrational coherent anti-Stokes Raman scattering (CARS) of nitrogen as an alternative to measure temperature, circumventing the limitations of the former method. The use of nitrogen CARS avoids the problem of probing regions of the flame with low OH concentrations that resulted in erroneous temperature. Such an application of CARS showed that the results from previous efforts were systematically biased up to 47% close to the bluff-body. We also critically review the limitations of CARS used in our experiments, pertaining to spatial resolution and associated biasing further downstream from the bluff-body. Using the more accurate results from this work, more up-to-date computational fluid dynamical (CFD) models of the burner can be validated, with the aim of improved understanding and prediction of thermoacoustic instability in gas turbines. © 2013 Copyright Taylor and Francis Group, LLC.

  7. Temperature and composition dependence of birefringence of lithium-tantalate crystals determined by holographic scattering

    International Nuclear Information System (INIS)

    Bastwoeste, K.; Schwalenberg, S.; Baeumer, Ch.; Kraetzig, E.

    2003-01-01

    Iron-doped lithium-tantalate samples with different compositions ranging from the congruently melting to the stoichiometric one are analyzed by anisotropic holographic scattering. The temperature dependence of the birefringence yields information on the composition of the crystals. (copyright 2003 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Temperature and composition dependence of birefringence of lithium-tantalate crystals determined by holographic scattering

    Energy Technology Data Exchange (ETDEWEB)

    Bastwoeste, K.; Schwalenberg, S.; Baeumer, Ch.; Kraetzig, E. [Fachbereich Physik, Universitaet Osnabrueck, D-49069 Osnabrueck (Germany)

    2003-09-01

    Iron-doped lithium-tantalate samples with different compositions ranging from the congruently melting to the stoichiometric one are analyzed by anisotropic holographic scattering. The temperature dependence of the birefringence yields information on the composition of the crystals. (copyright 2003 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Determining Role of Temperature Chart while Evaluating Specific Expenses of Organic Fuel

    Directory of Open Access Journals (Sweden)

    A. P. Nesenchouk

    2009-01-01

    Full Text Available The paper considers designing principles of operational space continuous heating and heat-treating furnaces at mechanical engineering, automotive and tractor enterprises in theRepublicofBelarus. A role of temperature chart on heating metallic charge while evaluating specific expenses of organic fuel in heating and heat-treating furnaces of mechanical engineering, automotive and tractor industries. 

  10. Electron density and temperature determination in a Tokamak plasma using light scattering

    International Nuclear Information System (INIS)

    Perez-Navarro Gomez, A.; Zurro Hernandez, B.

    1976-01-01

    A theoretical foundation review for light scattering by plasmas is presented. Furthemore, a review of the experimental methods for electron density and temperature measurements, with spatial and time resolution, is included in a Tokamak plasma using spectral analysis of the scattered radiation. (author) [es

  11. Electron density and temperature determination in a Tokamak plasma using light scattering

    International Nuclear Information System (INIS)

    Perez-Navarro Gomerz, A.; Zurro Hernandez, B.

    1976-01-01

    A theoretical foundation review for light scattering by plasmas is presented. Furthermore, we have included a review of the experimental methods for electron density and temperature measurements, with spatial and time resolution, in a Tokamak plasma using spectral analysis of the scattered radiation. (Author) 13 refs

  12. Length determination on industrial polymer parts from measurement performed under transient temperature conditions

    DEFF Research Database (Denmark)

    Dalla Costa, Giuseppe; Madruga, Daniel González; De Chiffre, Leonardo

    2016-01-01

    A way to reduce the cost of metrology in manufacturing is to perform dimensional verification directly in the production environment, avoiding a long and expensive acclimatization phase. In this work the effect of a transient temperature state, typical of the production environment, was investiga...

  13. Determining the influence of temperature on various types of standard resistors

    CSIR Research Space (South Africa)

    Marais, EL

    2006-10-01

    Full Text Available Types of Standard Resistors Speaker / Author: E.L. Marais CSIR National Metrology Laboratory PO Box 395, Pretoria, 0001, South Africa Email: elmarais@csir.co.za Phone: 012 841 3013 Fax: 012 841 2131 Abstract The temperature coefficient...

  14. Plasma Temperature Determination of Hydrogen Containing High-Frequency Electrodeless Lamps by Intensity Distribution Measurements of Hydrogen Molecular Band

    OpenAIRE

    Gavare, Zanda; Revalde, Gita; Skudra, Atis

    2010-01-01

    The goal of the present work was the investigation of the possibility to use intensity distribution of the Q-branch lines of the hydrogen Fulcher-α diagonal band (d3Πu−→a3∑g+ electronic transition; Q-branch with v=v′=2) to determine the temperature of hydrogen containing high-frequency electrodeless lamps (HFEDLs). The values of the rotational temperatures have been obtained from the relative intensity distributions for hydrogen-helium and hydrogen-argon HFEDLs depending on the applied curren...

  15. Note: A dual temperature closed loop batch reactor for determining the partitioning of trace gases within CO2-water systems.

    Science.gov (United States)

    Warr, Oliver; Rochelle, Christopher A; Masters, Andrew J; Ballentine, Christopher J

    2016-01-01

    An experimental approach is presented which can be used to determine partitioning of trace gases within CO2-water systems. The key advantages of this system are (1) The system can be isolated with no external exchange, making it ideal for experiments with conservative tracers. (2) Both phases can be sampled concurrently to give an accurate composition at each phase at any given time. (3) Use of a lower temperature flow loop outside of the reactor removes contamination and facilitates sampling. (4) Rapid equilibration at given pressure/temperature conditions is significantly aided by stirring and circulating the water phase using a magnetic stirrer and high-pressure liquid chromatography pump, respectively.

  16. Experimental determination of the temperature range of AlO molecular emission in laser-induced aluminum plasma in air

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Xueshi; Motto-Ros, Vincent [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon Villeurbanne (France); Lei, Wenqi [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon Villeurbanne (France); State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China); Zheng, Lijuan [State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China); Yu, Jin, E-mail: jin.yu@univ-lyon1.fr [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon Villeurbanne (France); Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astrophysics, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2014-09-01

    Measurements with laser-induced breakdown spectroscopy (LIBS) usually take place in the atmospheric air. For quantitative analysis of metallic elements, oxidation may represent an important issue which can significantly modify the stoichiometry of the plasma. Molecule formation in plasma should be therefore studied and taken into account in the LIBS practice. In this work, we experimentally investigated the temporal evolution and transformation of the plasma induced on an aluminum target by a nanosecond infrared (1064 nm) laser in the atmospheric air, in terms of its temperatures over a large interval of time from hundreds of nanoseconds to tens of microseconds. Such evolution was then correlated to the temporal evolution of the emission intensity from AlO molecules in the ablation plume. In particular, for a given ablation laser pulse energy, the appearance of the molecular emission while the plume cools down allows determining a minimal delay, τ{sub min}, which corresponds to a maximal value of the temperature, T{sub max}, below which the molecular emission begins to be clearly observed and to grow as a function of the delay. Such delay or such temperature indicates the longest delay or the lowest temperature for laser-induced plasma to be suitable for a correct analysis of metallic elements without significant influence of the alternation of the stoichiometry by oxidation. In our experiment, the values of τ{sub min} and T{sub max} have been determined for a range of ablation laser pulse energies from 5 mJ to 50 mJ. These values lie respectively in the range of 3 to 15 μs for τ{sub min}, and 4500 K to 6600 K in terms of the molecule temperature for T{sub max}. Beyond the practical interest for LIBS, our results provide also insights to the kinetics of the AlO molecule formation in laser-induced plasma. - Highlights: • Determination of the temperatures in laser-induced plasma up to tens of microseconds • Determination of the molecule temperature by fitting

  17. Adaptation to environmental temperature is a major determinant of molecular evolutionary rates in archaea.

    Science.gov (United States)

    Groussin, Mathieu; Gouy, Manolo

    2011-09-01

    Methods to infer the ancestral conditions of life are commonly based on geological and paleontological analyses. Recently, several studies used genome sequences to gain information about past ecological conditions taking advantage of the property that the G+C and amino acid contents of bacterial and archaeal ribosomal DNA genes and proteins, respectively, are strongly influenced by the environmental temperature. The adaptation to optimal growth temperature (OGT) since the Last Universal Common Ancestor (LUCA) over the universal tree of life was examined, and it was concluded that LUCA was likely to have been a mesophilic organism and that a parallel adaptation to high temperature occurred independently along the two lineages leading to the ancestors of Bacteria on one side and of Archaea and Eukarya on the other side. Here, we focus on Archaea to gain a precise view of the adaptation to OGT over time in this domain. It has been often proposed on the basis of indirect evidence that the last archaeal common ancestor was a hyperthermophilic organism. Moreover, many results showed the influence of environmental temperature on the evolutionary dynamics of archaeal genomes: Thermophilic organisms generally display lower evolutionary rates than mesophiles. However, to our knowledge, no study tried to explain the differences of evolutionary rates for the entire archaeal domain and to investigate the evolution of substitution rates over time. A comprehensive archaeal phylogeny and a non homogeneous model of the molecular evolutionary process allowed us to estimate ancestral base and amino acid compositions and OGTs at each internal node of the archaeal phylogenetic tree. The last archaeal common ancestor is predicted to have been hyperthermophilic and adaptations to cooler environments can be observed for extant mesophilic species. Furthermore, mesophilic species present both long branches and high variation of nucleotide and amino acid compositions since the last archaeal

  18. Determination of the electronic temperature in the torsatron TJ-I Upgrade by the two filters

    Energy Technology Data Exchange (ETDEWEB)

    Medina, F.; Ochando, M.

    1994-07-01

    A Te monitor for the TJ-IU torsatron, based on the two-filters method, has been designed. It will consist of two surface-barrier silicon detectors looking at the same plasma region through berylium filters of different thickness. Plasma electron temperature is deduced from the ratio of the soft-x-ray fluxes transmitted through the two filters. The flexibility in magnetic configuration of TJ-IU plasmas has been taken into account in the mechanical design of this diagnostic. It will be attached to an upper 1 port of the vacuum vessel and the whole system will be movable both, to change the spatial resolution when needed and to enable the scan of the full plasma cross-section to obtain the radial profile of electron temperature in a shot-to-shot basis. (Author) 7 refs.

  19. Determination of the electronic temperature in the torsatron TJ-I Upgrade by the two filters

    International Nuclear Information System (INIS)

    Medina, F.; Ochando, M.

    1994-01-01

    A Te monitor for the TJ-IU torsatron, based on the two-filters method, has been designed. It will consist of two surface-barrier silicon detectors looking at the same plasma region through berylium filters of different thickness. Plasma electron temperature is deduced from the ratio of the soft-x-ray fluxes transmitted through the two filters. The flexibility in magnetic configuration of TJ-IU plasmas has been taken into account in the mechanical design of this diagnostic. It will be attached to an upper 1 port of the vacuum vessel and the whole system will be movable both, to change the spatial resolution when needed and to enable the scan of the full plasma cross-section to obtain the radial profile of electron temperature in a shot-to-shot basis. (Author) 7 refs

  20. Determination of primary flow by correlation of temperatures of the coolant

    International Nuclear Information System (INIS)

    Villanueva, Jose

    2003-01-01

    Correlation techniques are often used to assess primary coolant flow in nuclear reactors. Observable fluctuations of some physical or chemical coolant properties are suitable for this purpose. This work describes a development carried out at the National Atomic Energy Commission of Argentina (CNEA) to apply this technique to correlate temperature fluctuations. A laboratory test was performed. Two thermocouples were installed on a hydraulic loop. A stationary flow of water circulated by the mentioned loop, where a mechanical turbine type flowmeter was installed. Transit times given by the correlation flowmeter, for different flow values measured with the mechanical flowmeter, were registered and a calibration between them was done. A very good linear behavior was obtained in all the measured range. It was necessary to increase the fluctuation level by adding water at different temperatures at the measuring system input. (author)

  1. Determination of the electronic temperature in the torsatron TJ-I Upgrade by the two filters

    International Nuclear Information System (INIS)

    Medina, F.; Ochando, M.

    1994-01-01

    A Te monitor for the TJ-IU torsatron, based on the two-filters method, has been designed. It will consist of two surface-barrier silicon detectors looking at the same plasma region through berilium filters of different thickness. Plasma electron temperature is deduced from the ratio of the soft-x-ray fluxes transmitted through the two filters. The flexibility in magnetic configuration of TJ-IU plasmas has been taken into account in the mechanical design of this diagnostic. It will be attached to an upper port of the vacuum vessel and the whole system will be movable both, to change the spatial resolution when needed and to enable the scan of the full plasma cross-section to obtain the radial profile of electron temperature in a shot-to-shot basis. (Author)

  2. Heavy atom enhanced room-temperature phosphorimetry for ultratrace determination of harmane

    Directory of Open Access Journals (Sweden)

    Flávia F. de Carvalho Marques

    2008-01-01

    Full Text Available Harmane has been proposed for the treatment of epilepsy, AIDS and leshmaniosis. Its room-temperature phosphorescence was induced using either AgNO3 or TlNO3, enabling absolute limits of detection of 0.12 and 2.4 ng respectively, with linear dynamic ranges extending up to 456 ng (AgNO3 and 911 ng (TlNO3. Relative standard deviations around 3% were observed for substrates containing 46 ng of harmane. Such sensitivity and precision are needed because harmane intake must be strictly controlled to achieve proper therapeutic response. Interference studies were performed using thalidomide, reserpine and yohimbine. Recovery of 104±6% was achieved using solid surface room-temperature phosphorimetry. The result was comparable to the one obtained by micellar electrokinetic chromatography.

  3. Determination of the gelatinization temperature of starch presented in maize flours

    Energy Technology Data Exchange (ETDEWEB)

    Coral, D F; Pineda-Gomez, P; Rosales-Rivera, A [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Manizales, Caldas (Colombia); Rodriguez-Garcia, M E, E-mail: dfcoralc@unal.edu.c [Departamento de Nanotecnologia, Centro de Fisica Aplicada y Tecnologia Avanzada, UNAM, Queretaro, Qro. (Mexico)

    2009-05-01

    A study of the influence of the moisture and the grain size on the gelatinization temperature (Tp1) of starch from four industrial maize flours as well as an unprocessed maize sample is presented. The gelatinization is a phase transition that can be observed using Differential Scanning Calorimetry (DSC), and it is manifest as an endothermic peak in the DSC thermogram. Results show that for 60, 65, 70 and 75% of moisture, the endothermic peak temperature increases from 70 to 75 deg. C when the moisture increases, and decrease when the grain size increases from 250 to 420mum. A study of the gelatinization enthalpy (DELTAHp) is also presented, this is related with the gelatinized starch present in the sample. The enthalpy decrease when the moisture increases and it decrease when grain size is increased.

  4. Temperature Compensation in Determining of Remazol Black B Concentrations Using Plastic Optical Fiber Based Sensor

    Science.gov (United States)

    Chong, Su Sin; Aziz, A.R. Abdul; Harun, Sulaiman W.; Arof, Hamzah

    2014-01-01

    In this study, the construction and test of tapered plastic optical fiber (POF) sensors, based on an intensity modulation approach are described. Tapered fiber sensors with different diameters of 0.65 mm, 0.45 mm, and 0.35 mm, were used to measure various concentrations of Remazol black B (RBB) dye aqueous solutions at room temperature. The concentrations of the RBB solutions were varied from 0 ppm to 70 ppm. In addition, the effect of varying the temperature of the RBB solution was also investigated. In this case, the output of the sensor was measured at four different temperatures of 27 °C, 30 °C, 35 °C, and 40 °C, while its concentration was fixed at 50 ppm and 100 ppm. The experimental results show that the tapered POF with d = 0.45 mm achieves the best performance with a reasonably good sensitivity of 61 × 10−4 and a linearity of more than 99%. It also maintains a sufficient and stable signal when heat was applied to the solution with a linearity of more than 97%. Since the transmitted intensity is dependent on both the concentration and temperature of the analyte, multiple linear regression analysis was performed to combine the two independent variables into a single equation. The resulting equation was then validated experimentally and the best agreement between the calculated and experimental results was achieved by the sensor with d = 0.45 mm, where the minimum discrepancy is less than 5%. The authors conclude that POF-based sensors are suitable for RBB dye concentration sensing and, with refinement in fabrication, better results could be achieved. Their low fabrication cost, simple configuration, accuracy, and high sensitivity would attract many potential applications in chemical and biological sensing. PMID:25166498

  5. Experimental determination of the Koo fuel temperature coefficient for an HTGR lattice

    Energy Technology Data Exchange (ETDEWEB)

    Agostini, P.; Benedetti, F.; Brighenti, G.; Chiodi, P. L.; Dell' Oro, P.; Giuliani, C.; Tassan, S.

    1974-10-15

    This paper describes temperature-dependent k-infinity measurements conducted using an assembly of loose HTGR coated particles in the BR-2 reactor by means of null reactivity oscillating method comparing the effect of poisoned and unpoisoned lattices like tests performed in the Physical Constants Test Reactor (PCTR) at Hanford. The RB-2 reactor was the property of the Italian firm AGIP NUCLEARE and operated at the Montecuccolino Center in Bologna.

  6. Temperature Compensation in Determining of Remazol Black B Concentrations Using Plastic Optical Fiber Based Sensor

    Directory of Open Access Journals (Sweden)

    Su Sin Chong

    2014-08-01

    Full Text Available In this study, the construction and test of tapered plastic optical fiber (POF sensors, based on an intensity modulation approach are described. Tapered fiber sensors with different diameters of 0.65 mm, 0.45 mm, and 0.35 mm, were used to measure various concentrations of Remazol black B (RBB dye aqueous solutions at room temperature. The concentrations of the RBB solutions were varied from 0 ppm to 70 ppm. In addition, the effect of varying the temperature of the RBB solution was also investigated. In this case, the output of the sensor was measured at four different temperatures of 27 °C, 30 °C, 35 °C, and 40 °C, while its concentration was fixed at 50 ppm and 100 ppm. The experimental results show that the tapered POF with d = 0.45 mm achieves the best performance with a reasonably good sensitivity of 61 × 10−4 and a linearity of more than 99%. It also maintains a sufficient and stable signal when heat was applied to the solution with a linearity of more than 97%. Since the transmitted intensity is dependent on both the concentration and temperature of the analyte, multiple linear regression analysis was performed to combine the two independent variables into a single equation. The resulting equation was then validated experimentally and the best agreement between the calculated and experimental results was achieved by the sensor with d = 0.45 mm, where the minimum discrepancy is less than 5%. The authors conclude that POF-based sensors are suitable for RBB dye concentration sensing and, with refinement in fabrication, better results could be achieved. Their low fabrication cost, simple configuration, accuracy, and high sensitivity would attract many potential applications in chemical and biological sensing.

  7. Determination of a constitutive law for salt at elevated temperature and pressure

    International Nuclear Information System (INIS)

    Senseny, P.E.

    1985-01-01

    A constitutive law for natural rock salt is given that describes the relationship among strain rate, stress rate, stress, temperature, and time. Tests required to evaluate the constitutive parameters are identified, and procedures for performing these tests are described. Results are presented from a series of tests performed on bedded salt from the Palo Duro basin. These results are used to evaluate the constitutive law suitable for predicting stresses and deformations in a nuclear waste repository or other engineered structure in salt

  8. Experimental determination of the Curie temperature for Ga(Mn)As

    Czech Academy of Sciences Publication Activity Database

    Vašek, Petr; Svoboda, Pavel; Novák, Vít; Výborný, Zdeněk; Jurka, Vlastimil; Smrčka, Ludvík

    2011-01-01

    Roč. 24, 1-2 (2011), s. 805-808 ISSN 1557-1939 R&D Projects: GA MŠk MEB020928; GA AV ČR KAN400100652 Institutional research plan: CEZ:AV0Z10100521 Keywords : Ga(Mn)As * Hall effect * magnetoresistance * Curie temperature Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.650, year: 2011

  9. Iterative Boltzmann plot method for temperature and pressure determination in a xenon high pressure discharge lamp

    Energy Technology Data Exchange (ETDEWEB)

    Zalach, J.; Franke, St. [INP Greifswald, Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany)

    2013-01-28

    The Boltzmann plot method allows to calculate plasma temperatures and pressures if absolutely calibrated emission coefficients of spectral lines are available. However, xenon arcs are not very well suited to be analyzed this way, as there are only a limited number of lines with atomic data available. These lines have high excitation energies in a small interval between 9.8 and 11.5 eV. Uncertainties in the experimental method and in the atomic data further limit the accuracy of the evaluation procedure. This may result in implausible values of temperature and pressure with inadmissible uncertainty. To omit these shortcomings, an iterative scheme is proposed that is making use of additional information about the xenon fill pressure. This method is proved to be robust against noisy data and significantly reduces the uncertainties. Intentionally distorted synthetic data are used to illustrate the performance of the method, and measurements performed on a laboratory xenon high pressure discharge lamp are analyzed resulting in reasonable temperatures and pressures with significantly reduced uncertainties.

  10. DETERMINATION OF THE OPTIMAL TEMPERING TEMPERATURE IN HARD FACING OF THE FORGING DIES

    Directory of Open Access Journals (Sweden)

    Milan Mutavdžić

    2012-06-01

    Full Text Available Here is analyzed selection of the optimal technology for heat treatment during the reparation of the damaged forging dies. Those tools are manufactured from alloyed tool steels for operation at elevated temperatures. Those steels are prone to self-hardening, so in reparatory hard-facing they must be preheated, additionally heated and tempered. During the tempering, in temperature interval 500-600°C, a secondary increase of hardness and decrease of impact toughness occurs, the so-called reversible tempering brittleness. Here is shown that it can be avoided by application of metallurgical and technological measures. Metallurgical measures assume adequate selection of steels. Since the considered steels are per se prone to tempering brittleness, we conducted experimental investigations to define the technological measures to avoid it. Tests on models were conducted: tempering from different temperatures, slow heating and cooling in still air. Hardness measurements showed that at 520°C, the secondary increase of hardness occurs, with drop of the impact toughness. Additional hard-facing tests included samples tempered at various regimes. Samples were prepared for mechanical and metallographic investigations. Results presented illustrate influence of additional heat treatment on structure, hardness and mechanical properties of the hard-faced layers. This enabled establishing the possibility of avoiding the tempering brittleness through technological measures.

  11. Determination of the optimal tempering temperature in hard facing of the forging dies

    Directory of Open Access Journals (Sweden)

    Milan Mutavdžić

    2012-05-01

    Full Text Available Here is analyzed selection of the optimal technology for heat treatment during the reparation of the damaged forging dies. Those tools are manufactured from alloyed tool steels for operation at elevated temperatures. Those steels are prone to self-hardening, so in reparatory hard-facing they must be preheated, additionally heated and tempered. During the tempering, in temperature interval 500-600°C, a secondary increase of hardness and decrease of impact toughness occurs, the so-called reversible tempering brittleness. Here is shown that it can be avoided by application of metallurgical and technological measures. Metallurgical measures assume adequate selection of steels. Since the considered steels are per se prone to tempering brittleness, we conducted experimental investigations to define the technological measures to avoid it. Tests on models were conducted: tempering from different temperatures, slow heating and cooling in still air. Hardness measurements showed that at 520°C, the secondary increase of hardness occurs, with drop of the impact toughness. Additional hard-facing tests included samples tempered at various regimes. Samples were prepared for mechanical and metallographic investigations. Results presented illustrate influence of additional heat treatment on structure, hardness and mechanical properties of the hard-faced layers. This enabled establishing the possibility of avoiding the tempering brittleness through technological measures. 

  12. Determination of Optimum Viewing Angles for the Angular Normalization of Land Surface Temperature over Vegetated Surface

    Directory of Open Access Journals (Sweden)

    Huazhong Ren

    2015-03-01

    Full Text Available Multi-angular observation of land surface thermal radiation is considered to be a promising method of performing the angular normalization of land surface temperature (LST retrieved from remote sensing data. This paper focuses on an investigation of the minimum requirements of viewing angles to perform such normalizations on LST. The normally kernel-driven bi-directional reflectance distribution function (BRDF is first extended to the thermal infrared (TIR domain as TIR-BRDF model, and its uncertainty is shown to be less than 0.3 K when used to fit the hemispheric directional thermal radiation. A local optimum three-angle combination is found and verified using the TIR-BRDF model based on two patterns: the single-point pattern and the linear-array pattern. The TIR-BRDF is applied to an airborne multi-angular dataset to retrieve LST at nadir (Te-nadir from different viewing directions, and the results show that this model can obtain reliable Te-nadir from 3 to 4 directional observations with large angle intervals, thus corresponding to large temperature angular variations. The Te-nadir is generally larger than temperature of the slant direction, with a difference of approximately 0.5~2.0 K for vegetated pixels and up to several Kelvins for non-vegetated pixels. The findings of this paper will facilitate the future development of multi-angular thermal infrared sensors.

  13. Simultaneous determination of nitric acid and uranium concentrations in aqueous solution from measurements of electrical conductivity, density, and temperature

    International Nuclear Information System (INIS)

    Spencer, B.B.

    1991-01-01

    Nuclear fuel reprocessing plants handle aqueous solutions of nitric acid and uranium in large quantities. Automatic control of process operations requires reliable measurements of these solutes concentration, but this is difficult to directly measure. Physical properties such as solution density and electrical conductivity vary with solute concentration and temperature. Conductivity, density and temperature can be measured accurately with relatively simple and inexpensive devices. These properties can be used to determine solute concentrations will good correlations. This paper provides the appropriate correlations for solutions containing 2 to 6 Molar (M) nitric acid and 0 to 300 g/L uranium metal at temperatures from 25--90 degrees C. The equations are most accurate below 5 M nitric acid, due to a broad maximum in the conductivity curve at 6 M. 12 refs., 9 figs., 6 tabs

  14. Application of the modulated temperature differential scanning calorimetry technique for the determination of the specific heat of copper nanofluids

    International Nuclear Information System (INIS)

    De Robertis, E.; Cosme, E.H.H.; Neves, R.S.; Kuznetsov, A.Yu.; Campos, A.P.C.; Landi, S.M.; Achete, C.A.

    2012-01-01

    The purpose of this work is to investigate the applicability of the modulated temperature differential scanning calorimetry technique to measure specific heat of copper nanofluids by using the ASTM E2719 standard procedure, which is generally applied to thermally stable solids and liquids. The one-step method of preparation of copper nanofluid samples is described. The synthesized nanoparticles were separated from the base fluid and examined by X-ray diffraction and transmission electron microscopy in order to evaluate their structure, morphology and chemical nature. The presence of copper nanoparticles in the base fluid alters the characteristics of crystallization and melting processes and reduces the specific heat values of nanofluids in the whole studied temperature range. - Highlights: ► Copper nanofluids prepared by one-step method. ► Methodology of synthesis improved nanofluid stability. ► Specific heat determinations using modulated temperature differential scanning calorimetry. ► Good agreement between theoretical and experimental values.

  15. Paleomagnetism in the Determination of the Emplacement Temperature of Cerro Colorado Tuff Cone, El Pinacate Volcanic Field, Sonora, Mexico.

    Science.gov (United States)

    Rodriguez Trejo, A.; Alva-Valdivia, L. M.; Vidal Solano, J. R.; Garcia Amador, B.; Gonzalez-Rangel, J. A.

    2014-12-01

    Cerro Colorado Maar is located at the World Heritage Site, biosphere reserve El Pinacate and Gran Desierto del Altar, at the NNW region of Sonora, Mexico (in El Pinacate Volcanic Field). It is a tuff cone, about 1 km diameter, result of several phreatomagmatic episodes during the late Quaternary. We report paleomagnetic and rock magnetic properties from fusiform volcanic bombs obtained from the borders of Cerro Colorado. This study is based in the thermoremanent magnetization TRM normally acquired by volcanic rocks, which can be used to estimate the emplacement temperature range. We performed the experiments on 20 lithic fragments (10 cm to 20 cm approximately), taking 6-8 paleomagnetic cores from each. Rock magnetic experiments (magnetic susceptibility vs. temperature (k-T), hysteresis curves and FORC analysis, shows that the main magnetic mineral carriers of magnetization are titanomagnetite and titanohematite in different levels of intergrowth. The k-T curves suggest in many cases, only one magnetic phase, but also in other cases a second magnetic phase. Thermal demagnetization was used to demagnetize the specimens in detailed short steps and make a well-defined emplacement temperature determination ranges. We found that temperature emplacement determination range for these two magnetic phases is between 350-450 °C, and 550-580 °C, respectively. These results are consistent with those expected in an eruption of Surtsey type, showing a distinct volcanic activity compared to the other craters from El Pinacate volcanic field.

  16. Determination of enthalpy, temperature, surface tension and geometry of the material transfer in PGMAW for the system argon–iron

    International Nuclear Information System (INIS)

    Siewert, E; Schein, J; Forster, G

    2013-01-01

    The metal transfer is a fundamental process in gas metal arc welding, which substantially determines the shape of the weld seam and strongly influences arc formation and stability. In this investigation the material transfer from the wire electrode (anode) to the workpiece (cathode) is analysed experimentally with high accuracy using various innovative diagnostic techniques for a pulsed gas metal arc welding (PGMAW) process. A high-speed two-colour pyrometer, a calorimeter, thermocouples, a stereo optical setup and a droplet oscillation technique are used to analyse a precisely defined PGMAW process. Thus, results obtained are verified by different measurement techniques and enable a comprehensive description of the material transfer procedure. The surface temperature of both electrodes as well as the droplet temperature, enthalpy and surface tension were determined. Furthermore, the geometry of the arc, wire, droplets and weld pool were extracted in three dimensions in order to describe the interaction between the material transfer and the formation of the weld seam. The experiments are performed using argon as shielding gas and pure iron as filler and base material to reduce complex chemical processes. It turned out that the wire feed rate has the biggest influence on droplet temperature and detachment. A correlation between weld pool formation and weld pool surface temperature gradient was observed, which is mainly a function of welding speed and wire feed rate. The experimental results obtained provide a detailed data pool for use in modelling. (paper)

  17. Reexamination of a novel determination of density, temperature, and symmetry energy based on a modified Fisher model

    Science.gov (United States)

    Liu, X.; Zheng, H.; Lin, W.; Huang, M.; Yang, Y. Y.; Wang, J. S.; Wada, R.; Bonasera, A.; Natowitz, J. B.

    2018-01-01

    In this article, a mistake in the formulation of the modified Fisher model (MFM) derived in the pioneering works of the Purdue group is addressed and corrected by reversing the sign of the mixing entropy term in the original formulation. The errors in the results of the previous MFM-related studies, such as isotopic yield distribution, isobaric yield ratios, isoscaling, m scaling, self-consistent determination of density, symmetry energy, and temperature, and density and temperature determination related to the intermediate mass fragment (IMF) freezeout, are quantitatively analyzed. It is found that the errors originating from the mistake in sign of the mixing entropy term are generally small and even have no effect in some cases.

  18. The ecology and evolution of temperature-dependent reaction norms for sex determination in reptiles: a mechanistic conceptual model.

    Science.gov (United States)

    Pezaro, Nadav; Doody, J Sean; Thompson, Michael B

    2017-08-01

    Sex-determining mechanisms are broadly categorised as being based on either genetic or environmental factors. Vertebrate sex determination exhibits remarkable diversity but displays distinct phylogenetic patterns. While all eutherian mammals possess XY male heterogamety and female heterogamety (ZW) is ubiquitous in birds, poikilothermic vertebrates (fish, amphibians and reptiles) exhibit multiple genetic sex-determination (GSD) systems as well as environmental sex determination (ESD). Temperature is the factor controlling ESD in reptiles and temperature-dependent sex determination (TSD) in reptiles has become a focal point in the study of this phenomenon. Current patterns of climate change may cause detrimental skews in the population sex ratios of reptiles exhibiting TSD. Understanding the patterns of variation, both within and among populations and linking such patterns with the selection processes they are associated with, is the central challenge of research aimed at predicting the capacity of populations to adapt to novel conditions. Here we present a conceptual model that innovates by defining an individual reaction norm for sex determination as a range of incubation temperatures. By deconstructing individual reaction norms for TSD and revealing their underlying interacting elements, we offer a conceptual solution that explains how variation among individual reaction norms can be inferred from the pattern of population reaction norms. The model also links environmental variation with the different patterns of TSD and describes the processes from which they may arise. Specific climate scenarios are singled out as eco-evolutionary traps that may lead to demographic extinction or a transition to either male or female heterogametic GSD. We describe how the conceptual principles can be applied to interpret TSD data and to explain the adaptive capacity of TSD to climate change as well as its limits and the potential applications for conservation and management

  19. Timescales for determining temperature and dissolved oxygen trends in the Long Island Sound (LIS) estuary

    Science.gov (United States)

    Staniec, Allison; Vlahos, Penny

    2017-12-01

    Long-term time series represent a critical part of the oceanographic community's efforts to discern natural and anthropogenically forced variations in the environment. They provide regular measurements of climate relevant indicators including temperature, oxygen concentrations, and salinity. When evaluating time series, it is essential to isolate long-term trends from autocorrelation in data and noise due to natural variability. Herein we apply a statistical approach, well-established in atmospheric time series, to key parameters in the U.S. east coast's Long Island Sound estuary (LIS). Analysis shows that the LIS time series (established in the early 1990s) is sufficiently long to detect significant trends in physical-chemical parameters including temperature (T) and dissolved oxygen (DO). Over the last two decades, overall (combined surface and deep) LIS T has increased at an average rate of 0.08 ± 0.03 °C yr-1 while overall DO has dropped at an average rate of 0.03 ± 0.01 mg L-1yr-1 since 1994 at the 95% confidence level. This trend is notably faster than the global open ocean T trend (0.01 °C yr-1), as might be expected for a shallower estuarine system. T and DO trends were always significant for the existing time series using four month data increments. Rates of change of DO and T in LIS are strongly correlated and the rate of decrease of DO concentrations is consistent with the expected reduced solubility of DO at these higher temperatures. Thus, changes in T alone, across decadal timescales can account for between 33 and 100% of the observed decrease in DO. This has significant implications for other dissolved gases and the long-term management of LIS hypoxia.

  20. Determination of time constants of reactor pressure and temperature sensors: the dynamic data system method

    International Nuclear Information System (INIS)

    Wu, S.M.; Hsu, M.C.; Chow, M.C.

    1979-01-01

    A new modeling technique is introduced for on-line sensor time constant identification, both for the resistance temperature detector (RTD) and for the pressure sensor using power plant operational data. The sensor's time constant is estimated from a real characteristic root of the fitted autoregressive moving average model. The RTD's time constant values were identified to be 8.4 s, with a standard deviation of 1.2 s. The pressure sensor time constant was identified to be 28.6 ms, with a standard deviation of 3.5 ms

  1. Heavy atom enhanced room-temperature phosphorimetry for ultratrace determination of harmane

    OpenAIRE

    Flávia F. de Carvalho Marques; Flávia da Silva Figueiredo; Ricardo Queiroz Aucelio

    2008-01-01

    Harmane has been proposed for the treatment of epilepsy, AIDS and leshmaniosis. Its room-temperature phosphorescence was induced using either AgNO3 or TlNO3, enabling absolute limits of detection of 0.12 and 2.4 ng respectively, with linear dynamic ranges extending up to 456 ng (AgNO3) and 911 ng (TlNO3). Relative standard deviations around 3% were observed for substrates containing 46 ng of harmane. Such sensitivity and precision are needed because harmane intake must be strictly controlled ...

  2. Venting temperature determines surface chemistry of magnetron sputtered TiN films

    Energy Technology Data Exchange (ETDEWEB)

    Greczynski, G. [Thin Film Physics Division, Department of Physics (IFM), Linköping University, SE-581 83 Linköping (Sweden); Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, D-52074 Aachen (Germany); Mráz, S.; Schneider, J. M. [Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, D-52074 Aachen (Germany); Hultman, L. [Thin Film Physics Division, Department of Physics (IFM), Linköping University, SE-581 83 Linköping (Sweden)

    2016-01-25

    Surface properties of refractory ceramic transition metal nitride thin films grown by magnetron sputtering are essential for resistance towards oxidation necessary in all modern applications. Here, typically neglected factors, including exposure to residual process gases following the growth and the venting temperature T{sub v}, each affecting the surface chemistry, are addressed. It is demonstrated for the TiN model materials system that T{sub v} has a substantial effect on the composition and thickness-evolution of the reacted surface layer and should therefore be reported. The phenomena are also shown to have impact on the reliable surface characterization by x-ray photoelectron spectroscopy.

  3. Experimental determination of the high-temperature rate constant for the reaction of OH with sec-butanol.

    Science.gov (United States)

    Pang, Genny A; Hanson, Ronald K; Golden, David M; Bowman, Craig T

    2012-10-04

    The overall rate constant for the reaction of OH with sec-butanol [CH(3)CH(OH)CH(2)CH(3)] was determined from measurements of the near-first-order OH decay in shock-heated mixtures of tert-butylhydroperoxide (as a fast source of OH) with sec-butanol in excess. Three kinetic mechanisms from the literature describing sec-butanol combustion were used to examine the sensitivity of the rate constant determination to secondary kinetics. The overall rate constant determined can be described by the Arrhenius expression 6.97 × 10(-11) exp(-1550/T[K]) cm(3) molecule(-1) s(-1), valid over the temperature range of 888-1178 K. Uncertainty bounds of ±30% were found to adequately account for the uncertainty in secondary kinetics. To our knowledge, the current data represent the first efforts toward an experimentally determined rate constant for the overall reaction of OH with sec-butanol at combustion-relevant temperatures. A rate constant predicted using a structure-activity relationship from the literature was compared to the current data and previous rate constant measurements for the title reaction at atmospheric-relevant temperatures. The structure-activity relationship was found to be unable to correctly predict the measured rate constant at all temperatures where experimental data exist. We found that the three-parameter fit of 4.95 × 10(-20)T(2.66) exp(+1123/T[K]) cm(3) molecule(-1) s(-1) better describes the overall rate constant for the reaction of OH with sec-butanol from 263 to 1178 K.

  4. An easy way to determine simultaneously the electron density and temperature in high-pressure plasmas by using Stark broadening

    International Nuclear Information System (INIS)

    Torres, J; Jonkers, J; Sande, M J van de; Mullen, J J A M van der; Gamero, A; Sola, A

    2003-01-01

    This paper discusses the possibility of determining, at the same time, both the electron density and temperature in a discharge produced at atmospheric pressure using the Stark broadening of lines spontaneously emitted by a plasma. This direct method allows us to obtain experimental results that are in good agreement with others previously obtained for the same type of discharge. Its advantages and disadvantages compared to other direct methods of diagnostics, namely Thomson scattering, are also discussed. (rapid communication)

  5. A high-temperature high-pressure calorimeter for determining heats of solution up to 623 K.

    Science.gov (United States)

    Djamali, Essmaiil; Turner, Peter J; Murray, Richard C; Cobble, James W

    2010-07-01

    A high-temperature high-pressure isoperibol calorimeter for determining the heats of solution and reaction of very dilute substances in water (10(-4) m) at temperatures up to 623 K is described. The energies of vaporization of water at steam saturation pressure were measured as a function of temperature and the results agree with the corresponding values from steam tables to better than 0.08+/-0.18%. The novelties of the present instrument relative to flow type heat capacity calorimeters are that measurements can be made at orders of magnitude lower concentrations and that measurement of heat of reaction involving solids or gases or in the presence of high concentrations of supporting electrolytes, acids, and bases is possible. Furthermore, the advantage of using enthalpy data over heat capacity data for calculations of the standard state Gibbs free energies of electrolytes is that the experimental heat data of this research need only be integrated once to derive higher temperature free energy data from lower temperatures. The derived heat capacities can be used mathematically to obtain free energies by double integration. However, the resulting errors are much smaller than if experimental aqueous heat capacities were used for the integrations.

  6. Determination of channel temperature for AlGaN/GaN HEMTs by high spectral resolution micro-Raman spectroscopy

    International Nuclear Information System (INIS)

    Zhang Guangchen; Feng Shiwei; Li Jingwan; Guo Chunsheng; Zhao Yan

    2012-01-01

    Channel temperature determinations of AlGaN/GaN high electron mobility transistors (HEMTs) by high spectral resolution micro-Raman spectroscopy are proposed. The temperature dependence of the E2 phonon frequency of GaN material is calibrated by using a JYT-64000 micro-Raman system. By using the Lorentz fitting method, the measurement uncertainty for the Raman phonon frequency of ±0.035 cm −1 is achieved, corresponding to a temperature accuracy of ±3.2 °C for GaN material, which is the highest temperature resolution in the published works. The thermal resistance of the tested AlGaN/GaN HEMT sample is 22.8 °C/W, which is in reasonably good agreement with a three dimensional heat conduction simulation. The difference among the channel temperatures obtained by micro-Raman spectroscopy, the pulsed electrical method and the infrared image method are also investigated quantificationally. (semiconductor devices)

  7. Determining solid-fluid interface temperature distribution during phase change of cryogenic propellants using transient thermal modeling

    Science.gov (United States)

    Bellur, K.; Médici, E. F.; Hermanson, J. C.; Choi, C. K.; Allen, J. S.

    2018-04-01

    Control of boil-off of cryogenic propellants is a continuing technical challenge for long duration space missions. Predicting phase change rates of cryogenic liquids requires an accurate estimation of solid-fluid interface temperature distributions in regions where a contact line or a thin liquid film exists. This paper described a methodology to predict inner wall temperature gradients with and without evaporation using discrete temperature measurements on the outer wall of a container. Phase change experiments with liquid hydrogen and methane in cylindrical test cells of various materials and sizes were conducted at the Neutron Imaging Facility at the National Institute of Standards and Technology. Two types of tests were conducted. The first type of testing involved thermal cycling of an evacuated cell (dry) and the second involved controlled phase change with cryogenic liquids (wet). During both types of tests, temperatures were measured using Si-diode sensors mounted on the exterior surface of the test cells. Heat is transferred to the test cell by conduction through a helium exchange gas and through the cryostat sample holder. Thermal conduction through the sample holder is shown to be the dominant mode with the rate of heat transfer limited by six independent contact resistances. An iterative methodology is employed to determine contact resistances between the various components of the cryostat stick insert, test cell and lid using the dry test data. After the contact resistances are established, inner wall temperature distributions during wet tests are calculated.

  8. Determination of Optimal Temperature for Biosorption of Heavy Metal Mixture from Aqueous Solution by Pretreated Biomass of Aspergillus niger

    Directory of Open Access Journals (Sweden)

    Javad Yousefi

    2012-01-01

    Full Text Available Biosorption is a novel technology that uses dead and inactive biomass for removal of heavy metals from aqueous solution. Some parameters such as temperature, contact time, solution pH, initial metal concentration, biosorbent dose and also agitating speed of solution and biosorbent mixing can affect the amount of metal sorption by biosorbent. The aim of this study was to investigate the effects of different treatments of temperatures (25, 35, 45 and 55oC on biosorption of metals mixture in order to determine optimal temperature for more metals removal from aqueous solution. This study uses dead and pretreated biomass of Aspergillus niger with 0.5N NaOH for removal of Zn(II, Co(II and Cd(II. In all temperature treatments and in the case of all of heavy metals, maximum amount of metal sorption and concentration decrease was occurred in first 5 minutes and achieved to equilibrium after 20 minute. The percent of metals sorption show growth trend with temperature increase. Between 4 experimental treatments, 55oC treatment was shown maximum sorption and 25oC was shown minimum sorption amount. The percent of Cr(II sorption was increase from 28.5% in 25oC to 44.7% in 55oC. Also, this increase was from 40% to 58% for Cd(II and from 37.7% to 65.6% for Zn(II. About 60% of increase in sorption by A. niger was due to increase in temperature. Therefore the amount of metals sorption can be increase, only with temperature increase and without any biomass addition.

  9. Food Safety: Recommendations for Determining Doneness in Consumer Egg Dish Recipes and Measurement of Endpoint Temperatures When Recipes Are Followed

    Directory of Open Access Journals (Sweden)

    Sandria Godwin

    2016-06-01

    Full Text Available Many consumers do not follow recommended food safety practices for cooking egg dishes, such as pies, quiches, and casseroles, potentially leading to foodborne illnesses such as Salmonellosis. The United States Department of Agriculture (USDA recommends cooking egg mixtures until the center reaches 71 °C (160 °F. The objectives of this study were to determine what endpoint temperature information consumers receive from egg dish recipes, and if recipes would lead to safe temperatures when followed. Egg dish recipes (n = 226 from 65 websites, 50 cookbooks, and nine magazine titles (multiple issues of each were analyzed. Time was the most frequently used indicator, given in 92% of the recipes, with 15% using only time. Other indicators included: set (89, browned (76, clean toothpick/knife (60, puffed (27, and jiggled (13. Only two recipes indicated final endpoint temperatures. Three recipes (a pie, a quiche, and an egg casserole were chosen and prepared in triplicate to see if they would reach recommended temperatures. The pie and quiche were still liquid at 71 °C, and were well over the recommended temperature when cooked according to instructions, but the egg casserole was not consistently above 71 °C, when the recipe instructions indicated it was done and the center was light brown and “jiggled” This research indicates that consumers are not receiving information on endpoint temperatures in egg recipes, but the likelihood of foodborne illness is low since most dishes probably be cooked past the recommended temperature before the consumer considers them done unless there are many inclusions that may absorb liquid and reduce the appearance of liquid in the dish.

  10. Food Safety: Recommendations for Determining Doneness in Consumer Egg Dish Recipes and Measurement of Endpoint Temperatures When Recipes Are Followed

    Science.gov (United States)

    Godwin, Sandria; Maughan, Curtis; Chambers, Edgar

    2016-01-01

    Many consumers do not follow recommended food safety practices for cooking egg dishes, such as pies, quiches, and casseroles, potentially leading to foodborne illnesses such as Salmonellosis. The United States Department of Agriculture (USDA) recommends cooking egg mixtures until the center reaches 71 °C (160 °F). The objectives of this study were to determine what endpoint temperature information consumers receive from egg dish recipes, and if recipes would lead to safe temperatures when followed. Egg dish recipes (n = 226) from 65 websites, 50 cookbooks, and nine magazine titles (multiple issues of each) were analyzed. Time was the most frequently used indicator, given in 92% of the recipes, with 15% using only time. Other indicators included: set (89), browned (76), clean toothpick/knife (60), puffed (27), and jiggled (13). Only two recipes indicated final endpoint temperatures. Three recipes (a pie, a quiche, and an egg casserole) were chosen and prepared in triplicate to see if they would reach recommended temperatures. The pie and quiche were still liquid at 71 °C, and were well over the recommended temperature when cooked according to instructions, but the egg casserole was not consistently above 71 °C, when the recipe instructions indicated it was done and the center was light brown and “jiggled” This research indicates that consumers are not receiving information on endpoint temperatures in egg recipes, but the likelihood of foodborne illness is low since most dishes probably be cooked past the recommended temperature before the consumer considers them done unless there are many inclusions that may absorb liquid and reduce the appearance of liquid in the dish. PMID:28231140

  11. Food Safety: Recommendations for Determining Doneness in Consumer Egg Dish Recipes and Measurement of Endpoint Temperatures When Recipes Are Followed.

    Science.gov (United States)

    Godwin, Sandria; Maughan, Curtis; Chambers, Edgar

    2016-06-23

    Many consumers do not follow recommended food safety practices for cooking egg dishes, such as pies, quiches, and casseroles, potentially leading to foodborne illnesses such as Salmonellosis. The United States Department of Agriculture (USDA) recommends cooking egg mixtures until the center reaches 71 °C (160 °F). The objectives of this study were to determine what endpoint temperature information consumers receive from egg dish recipes, and if recipes would lead to safe temperatures when followed. Egg dish recipes ( n = 226) from 65 websites, 50 cookbooks, and nine magazine titles (multiple issues of each) were analyzed. Time was the most frequently used indicator, given in 92% of the recipes, with 15% using only time. Other indicators included: set (89), browned (76), clean toothpick/knife (60), puffed (27), and jiggled (13). Only two recipes indicated final endpoint temperatures. Three recipes (a pie, a quiche, and an egg casserole) were chosen and prepared in triplicate to see if they would reach recommended temperatures. The pie and quiche were still liquid at 71 °C, and were well over the recommended temperature when cooked according to instructions, but the egg casserole was not consistently above 71 °C, when the recipe instructions indicated it was done and the center was light brown and "jiggled" This research indicates that consumers are not receiving information on endpoint temperatures in egg recipes, but the likelihood of foodborne illness is low since most dishes probably be cooked past the recommended temperature before the consumer considers them done unless there are many inclusions that may absorb liquid and reduce the appearance of liquid in the dish.

  12. Mechanical and chemical cleaning of the tubes bundles of the moisture separator reheaters (GSS) of Nuclear power plants

    International Nuclear Information System (INIS)

    Guerra, Patrice; Ruiz, Jose T.; Ureta, Roman; Carreres, Cristina; Virginie, Le-Guerroue

    2012-09-01

    The cleaning operation concerns the 'GSS' system (GSS stands for moisture separator reheaters, MSR) which are classified as 'watch quality guarantee', not classified as safety facility and subjected to Pressure Equipment regulations. The follow-up of the operational GSS (steel carbon) of EDF nuclear power plants CP0 group reveals a clog rate due to a relevant magnetite deposits that could result in equipment damage, loss of availability and loss of plant productivity. The pressure drop between inlet and outlet of the heating steam is close to maximum design criterion. The service consisted in designing, developing, qualifying and carrying out a process which removes clog from the inside of GSS U-tubes bundle located in the vapor circuit and which respects the equipment integrity and ensures the process harmlessness. This cleaning has to enable the complete removal of deposits and oxides (magnetite) in order to recover a passage diameter and a surface finish equivalent to the origin, thus avoiding the replacement of the GSS and obtaining a considerable reduction of costs. To do so, LAINSA and SOLARCA designed, developed, qualified and operated on 14 GSS bundles, by carrying out the following operations: - Cartography of the GSS tubes bundles clogging state; - Pre-Mechanical cleaning to un-block the sealed tubes and release the inside tubes passing; - Isolation of the bundle and check of leaks of the system; - Chemical cleaning with the efficiency and harmlessness parameters follow-up: - Acid Phase by means of weak organic acids to eliminate all the deposits; - Passivation phase; - Final Rinsing respecting the customer criteria; - Drying; - Waste management and waste treatment. The implementation of this operation enables the elimination of the whole deposits (magnetite) and oxides located inside the GSS tube bundle and thus to recover a passage diameter inside the tubes, and a pressure drop close to a new system and therefore to enables the

  13. Dependence of cosmological energy-density irregularities on the shape of the scalar-field potential during inflation and ''reheating''

    International Nuclear Information System (INIS)

    Ratra, B.

    1991-01-01

    Estimates for the baryon-dominated epoch form of the large-scale adiabatic energy-density irregularities generated during an early scalar-field-dominated inflation epoch, in simple inflation-modified hot-big-bang models, are compared to the widely used approximate general expression, which is proportional to the large-scale, gauge-invariant part of H 2 left-angle φφ * right-angle/(Φ b ) 2 evaluated at the first Hubble radius crossing (here Φ b and φ are the spatially homogeneous and inhomogeneous parts of the scalar field, H is the Hubble parameter, and an overdot represents a derivative with respect to time). In the de Sitter inflation limit, if the inflation-epoch background scalar-field solution is an ''attractor,'' or if there is sufficient inflation before the scale of interest leaves the Hubble radius, the approximate general expression identically reproduces what we have found. It is also less than an order of magnitude away from our expression in a large fraction of the parameter space of the inflation model we study and is within 2 orders of magnitude of our result in almost all of parameter space. We also show that the more accurate general expression (which the above formula is an approximation of) identically reproduces our results in the simple models studied, provided the inflation-epoch background scalar-field solution is an ''attractor'' or if there is sufficient inflation. The approximate general formula is used to restudy energy-density inhomogeneities in the quartic-potential scalar-field de Sitter inflation model; the difference between the standard result in this model and our result in related models is traced to a difference in the form of the part of the potential used to model ''reheating'' and the end of inflation

  14. Evaluation of the DSC technique in the determination of the terminal temperature solubility of hydrogen in Zircaloy 4

    International Nuclear Information System (INIS)

    Vizcaino, Pablo; Banchik, Abraham D.

    1999-01-01

    The determination of the terminal temperature solubility of hydrogen in the zirconium alloys is a matter of our interest, since the hydride precipitation in these materials make them susceptible to the delay hydrogen cracking (DHC). Nowadays efforts are directed to the determination of this parameter on irradiated materials. In this frame we have begun a program to determine these curves on irradiated zirconium alloys like Zircaloys, Zr 2.5% Nb, Zr 1% Nb, zirconium sponge and high oxygen zirconium with different microstructures using the differential scanning calorimeter technique. The earlier task that we have imposed to us is the evaluation the reproducibility of this technique and the influence of the heating and cooling rates on the results. With these objectives we have initiated this work measuring the terminal temperature solubility (TTS) in unirradiated recrystallized and cold worked Zircaloy-4. We have found that the reproducibility of the technique is good; the average values (TSSD) and (TSSP) agree within the experimental error and the dispersions are low. Variance analysis indicates that the values of TSSD and TSSP do not depend on the heating and cooling rates. Within the rank analyzed the differences in the measurements are only possible to be attributed to statistical and/or experimental errors. The obtained curves of solubility show to a good agreement with the values obtained by others authors until 200 ppm (weight) of hydrogen. Similar comparisons between precipitation curves have not been made in regard to which these values depend on the maximum temperature reached in the experience. (author)

  15. Inheritance of nesting behaviour across natural environmental variation in a turtle with temperature-dependent sex determination.

    Science.gov (United States)

    McGaugh, Suzanne E; Schwanz, Lisa E; Bowden, Rachel M; Gonzalez, Julie E; Janzen, Fredric J

    2010-04-22

    Nesting behaviour is critical for reproductive success in oviparous organisms with no parental care. In organisms where sex is determined by incubation temperature, nesting behaviour may be a prime target of selection in response to unbalanced sex ratios. To produce an evolutionary change in response to sex-ratio selection, components of nesting behaviour must be heritable. We estimated the field heritability of two key components of nesting behaviour in a population of painted turtles (Chrysemys picta) with temperature-dependent sex determination by applying the 'animal model' to a pedigree reconstructed from genotype data. We obtained estimates of low to non-detectable heritability using repeated records across all environments. We then determined environment-specific heritability by grouping records with similar temperatures for the winter preceding the nesting season, a variable known to be highly associated with our two traits of interest, nest vegetation cover and Julian date of nesting. The heritability estimates of nest vegetation cover and Julian date of nesting were qualitatively highest and significant, or nearly so, after hot winters. Additive genetic variance for these traits was not detectable after cold winters. Our analysis suggests that the potential for evolutionary change of nesting behaviour may be dependent on the thermal conditions of the preceding winter, a season that is predicted to be especially subject to climate change.

  16. DIRECTLY DETERMINED LINEAR RADII AND EFFECTIVE TEMPERATURES OF EXOPLANET HOST STARS

    International Nuclear Information System (INIS)

    Van Belle, Gerard T.; Von Braun, Kaspar

    2009-01-01

    We present interferometric angular sizes for 12 stars with known planetary companions, for comparison with 28 additional main-sequence stars not known to host planets. For all objects we estimate bolometric fluxes and reddenings through spectral-energy distribution (SED) fits, and in conjunction with the angular sizes, measurements of effective temperature. The angular sizes of these stars are sufficiently small that the fundamental resolution limits of our primary instrument, the Palomar Testbed Interferometer, are investigated at the sub-milliarcsecond level and empirically established based upon known performance limits. We demonstrate that the effective temperature scale as a function of dereddened (V - K) 0 color is statistically identical for stars with and without planets. A useful byproduct of this investigation is a direct calibration of the T EFF scale for solarlike stars, as a function of both spectral type and (V - K) 0 color. Additionally, in an Appendix we provide SED fits for the 166 stars with known planets which have sufficient photometry available in the literature for such fits; this derived 'XO-Rad' database includes homogeneous estimates of bolometric flux, reddening, and angular size.

  17. Isotopic dependence of the fragments' internal temperatures determined from multifragment emission

    Science.gov (United States)

    Souza, S. R.; Donangelo, R.

    2018-05-01

    The internal temperatures of fragments produced by an excited nuclear source are investigated by using the microcanonical version of the statistical multifragmentation model, with discrete energy. We focus on the fragments' properties at the breakup stage, before they have time to deexcite by particle emission. Since the adopted model provides the excitation energy distribution of these primordial fragments, it allows one to calculate the temperatures of different isotope families and to make inferences about the sensitivity to their isospin composition. It is found that, due to the functional form of the nuclear density of states and the excitation energy distribution of the fragments, proton-rich isotopes are hotter than neutron-rich isotopes. This property has been taken to be an indication of earlier emission of the former from a source that cools down as it expands and emits fragments. Although this scenario is incompatible with the prompt breakup of a thermally equilibrated source, our results reveal that the latter framework also provides the same qualitative features just mentioned. Therefore they suggest that this property cannot be taken as evidence for nonequilibrium emission. We also found that this sensitivity to the isotopic composition of the fragments depends on the isospin composition of the source, and that it is weakened as the excitation energy of the source increases.

  18. Laboratory determined suction potential of Topopah Spring tuff at high temperatures

    International Nuclear Information System (INIS)

    Daily, W.; Lin, Wunan.

    1991-01-01

    The purpose of this work is to experimentally determine the capillary suction potential of Topopah Spring tuff from Yucca Mountain, Nye County, Nevada. This data can be used to help characterize the unsaturated hydraulic properties of the densely welded tuff at this site. 7 refs., 4 figs., 1 tab

  19. Electromagnetic losses in a three-phase high temperature superconducting cable determined by calorimetric measurements

    DEFF Research Database (Denmark)

    Traeholt, C.; Veje, E.; Tønnesen, Ole

    2002-01-01

    conventional phases (600 mm2 Cu) could be moved in the plane. It was possible to vary the inter-phase distance (centre to centre distance) from 9 to 48 cm. The HTS cable conductor was placed in a stainless steel cryostat and cooled with flowing liquid nitrogen (LN2). The losses were determined using...

  20. Shear strain determination of the polymer polydimethysiloxane (PMDS) using digital image correlation in different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    De Oliveira, G N [Pos-graduacao em Engenharia Mecanica, TEM/PGMEC, Universidade Federal Fluminense, Rua Passo da Patria, 156, Niteroi, R.J., Brazil, Cep.: 24.210-240 (Brazil); Nunes, L C S [Laboratorio de Mecanica Teorica e Aplicada, Departamento de Engenharia Mecanica, Universidade Federal Fluminense, Rua Passo da Patria, 156, Niteroi, R.J., Brazil, Cep.: 24.210-240 (Brazil); Dos Santos, P A M, E-mail: pams@if.uff.br [Instituto de Fisica, Laboratorio de Optica Nao-linear e Aplicada, Universidade Federal Fluminense, Av. Gal. Nilton Tavares de Souza, s/n, Gragoata, Niteroi, R.J., Brazil, Cep.:24.210-346 (Brazil)

    2011-01-01

    In the present work a digital image correlation (DIC) method is used in order to analyze the adhesive shear modulus of poly-dimethylsiloxane (PDMS) submitted to different loads and temperatures. This is an optical-numerical full-field surface displacement measurement method. It is based on a comparison between two images of a specimen coated by a random speckled pattern in the undeformed and in the deformed states. A single lap joint testing is performed. This is a standard test specimen for characterizing adhesive properties and it is considered the simplest form of adhesive joints. For the single lap joint specimen, steel adherends are bonded using a flexible rubber elastic polymer (PDMS), which is a commercially available silicone elastic rubber.

  1. High-temperature thermodynamic activities of zirconium in platinum alloys determined by nitrogen-nitride equilibria

    International Nuclear Information System (INIS)

    Goodman, D.A.

    1980-05-01

    A high-temperature nitrogen-nitride equilibrium apparatus is constructed for the study of alloy thermodynamics to 2300 0 C. Zirconium-platinum alloys are studied by means of the reaction 9ZrN + 11Pt → Zr 9 Pt 11 + 9/2 N 2 . Carful attention is paid to the problems of diffusion-limited reaction and ternary phase formation. The results of this study are and a/sub Zr//sup 1985 0 C/ = 2.4 x 10 -4 in Zr 9 Pt 11 ΔG/sub f 1985 0 C/ 0 Zr 9 Pt 11 less than or equal to -16.6 kcal/g atom. These results are in full accord with the valence bond theory developed by Engel and Brewer; this confirms their prediction of an unusual interaction of these alloys

  2. Evaluating the Coda Phase Delay Method for Determining Temperature Ratios in Windy Environments

    Energy Technology Data Exchange (ETDEWEB)

    Albert, Sarah [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bowman, Daniel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rodgers, Arthur [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Seastrand, Douglas [National Security Technologies, LLC. (NSTec), Las Vegas, NV (United States)

    2017-07-01

    We evaluate the acoustic coda phase delay method for estimating changes in atmospheric phenomena in realistic environments. Previous studies verifying the method took place in an environment with negligible wind. The equation for effective sound speed, which the method is based upon, shows that the influence of wind is equal to the square of temperature. Under normal conditions, wind is significant and therefore cannot be ignored. Results from this study con rm the previous statement. The acoustic coda phase delay method breaks down in non-ideal environments, namely those where wind speed and direction varies across small distances. We suggest that future studies make use of gradiometry to better understand the effect of wind on the acoustic coda and subsequent phase delays.

  3. Determination of transient temperature and heat flux on the surface of a reactor control rod based on temperature measurements at the interior points

    International Nuclear Information System (INIS)

    Cebula, Artur; Taler, Jan

    2014-01-01

    The paper presents heat transfer calculation results concerning a control rod of nuclear power plant. Apart from numerical calculation results, experimental heat transfer measurements of the control rod model are also presented. The control rod that is the object of interest is surrounded by a mixing region of hot and cold streams and, as a consequence, is subjected to thermal fluctuations. The paper describes a method based on the solution of the inverse heat conduction problem (IHCP) for determining heat flux on the outer surface of the rod. Numerical tests were conducted to validate the method by comparison of the results with the time changes of surface temperature and heat flux which were obtained from the computational fluid dynamics (CFD) simulation of the mixing process. A measuring instrument was designed to measure the heat flux at the outer surface of the control rod model. In addition, the principle of operation and construction of heat flux meter is presented in detail. -- Highlights: • Temperature and heat flux estimation during cooling of control rod are presented. • The inverse technique is based on the space marching method. • The instrument for surface heat flux measurement was manufactured and tested. • CFD simulations were used to validate the developed inverse technique. • Actual data were used to demonstrate practical applicability of the method

  4. Determinants of attenuation and temperature sensitivity in the type 1 poliovirus Sabin vaccine.

    OpenAIRE

    Bouchard, M J; Lam, D H; Racaniello, V R

    1995-01-01

    To identify determinants of attenuation in the poliovirus type 1 Sabin vaccine strain, a series of recombinant viruses were constructed by using infectious cDNA clones of the virulent type 1 poliovirus P1/Mahoney and the attenuated type 1 vaccine strain P1/Sabin. Intracerebral inoculation of these viruses into transgenic mice which express the human receptor for poliovirus identified regions of the genome that conferred reduced neurovirulence. Exchange of smaller restriction fragments and sit...

  5. Microcontroller based Stator Winding Resistance Determination of Induction Motor Drive on Temperature Variations

    OpenAIRE

    Siraj Ahmed T; Sukhdeo Sao; K.S.R Anjaneyulu

    2014-01-01

    In this paper an experiment has been conducted to determine the online stator winding resistance of an induction motor, in industries as well as domestic purpose induction motors is largely utilized, as it has both applications of variable and constant torque operation nature. The major requirement of an electric drive system is its independent control of torque and speed; this is achieved in DC motor Drive but has more disadvantages. With the help of fast acting switching devices it is possi...

  6. Standard test method for conducting drop-weight test to determine nil-ductility transition temperature of ferritic steels

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This test method covers the determination of the nil-ductility transition (NDT) temperature of ferritic steels, 5/8 in. (15.9 mm) and thicker. 1.2 This test method may be used whenever the inquiry, contract, order, or specification states that the steels are subject to fracture toughness requirements as determined by the drop-weight test. 1.3 The values stated in inch-pound units are to be regarded as the standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  7. Diffraction and single-crystal elastic constants of Inconel 625 at room and elevated temperatures determined by neutron diffraction

    International Nuclear Information System (INIS)

    Wang, Zhuqing; Stoica, Alexandru D.; Ma, Dong; Beese, Allison M.

    2016-01-01

    In this work, diffraction and single-crystal elastic constants of Inconel 625 have been determined by means of in situ loading at room and elevated temperatures using time-of-flight neutron diffraction. Theoretical models proposed by Voigt, Reuss, and Kroner were used to determine single-crystal elastic constants from measured diffraction elastic constants, with the Kroner model having the best ability to capture experimental data. The magnitude of single-crystal elastic moduli, computed from single-crystal elastic constants, decreases and the single crystal anisotropy increases as temperature increases, indicating the importance of texture in affecting macroscopic stress at elevated temperatures. The experimental data reported here are of great importance in understanding additive manufacturing of metallic components as: diffraction elastic constants are required for computing residual stresses from residual lattice strains measured using neutron diffraction, which can be used to validate thermomechanical models of additive manufacturing, while single-crystal elastic constants can be used in crystal plasticity modeling, for example, to understand mechanical deformation behavior of additively manufactured components.

  8. Diffraction and single-crystal elastic constants of Inconel 625 at room and elevated temperatures determined by neutron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhuqing [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Stoica, Alexandru D. [Chemical and Engineering Materials Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Ma, Dong, E-mail: dongma@ornl.gov [Chemical and Engineering Materials Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Beese, Allison M., E-mail: amb961@psu.edu [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States)

    2016-09-30

    In this work, diffraction and single-crystal elastic constants of Inconel 625 have been determined by means of in situ loading at room and elevated temperatures using time-of-flight neutron diffraction. Theoretical models proposed by Voigt, Reuss, and Kroner were used to determine single-crystal elastic constants from measured diffraction elastic constants, with the Kroner model having the best ability to capture experimental data. The magnitude of single-crystal elastic moduli, computed from single-crystal elastic constants, decreases and the single crystal anisotropy increases as temperature increases, indicating the importance of texture in affecting macroscopic stress at elevated temperatures. The experimental data reported here are of great importance in understanding additive manufacturing of metallic components as: diffraction elastic constants are required for computing residual stresses from residual lattice strains measured using neutron diffraction, which can be used to validate thermomechanical models of additive manufacturing, while single-crystal elastic constants can be used in crystal plasticity modeling, for example, to understand mechanical deformation behavior of additively manufactured components.

  9. Welding stainless steels for structures operating at liquid helium temperature

    Energy Technology Data Exchange (ETDEWEB)

    Witherell, C.E.

    1980-04-18

    Superconducting magnets for fusion energy reactors require massive monolithic stainless steel weldments which must operate at extremely low temperatures under stresses approaching 100 ksi (700 MPa). A three-year study was conducted to determine the feasibility of producing heavy-section welds having usable levels of strength and toughness at 4.2/sup 0/K for fabrication of these structures in Type 304LN plate. Seven welding processes were evaluated. Test weldments in full-thickness plate were made under severe restraint to simulate that of actual structures. Type 316L filler metal was used for most welds. Welds deposited under some conditions and which solidify as primary austenite have exhibited intergranular embrittlement at 4.2/sup 0/K. This is believed to be associated with grain boundary metal carbides or carbonitrides precipitated during reheating of already deposited beads by subsequent passes. Weld deposits which solidify as primary delta ferrite appear immune. Through use of fully austenitic filler metals of low nitrogen content under controlled shielded metal arc welding conditions, and through use of filler metals solidifying as primary delta ferrite where only minimum residuals remain to room temperature, welds of Type 316L composition have been made with 4.2K yield strength matching that of Type 304LN plate and acceptable levels of soundness, ductility and toughness.

  10. Welding stainless steels for structures operating at liquid helium temperature

    International Nuclear Information System (INIS)

    Witherell, C.E.

    1980-01-01

    Superconducting magnets for fusion energy reactors require massive monolithic stainless steel weldments which must operate at extremely low temperatures under stresses approaching 100 ksi (700 MPa). A three-year study was conducted to determine the feasibility of producing heavy-section welds having usable levels of strength and toughness at 4.2 0 K for fabrication of these structures in Type 304LN plate. Seven welding processes were evaluated. Test weldments in full-thickness plate were made under severe restraint to simulate that of actual structures. Type 316L filler metal was used for most welds. Welds deposited under some conditions and which solidify as primary austenite have exhibited intergranular embrittlement at 4.2 0 K. This is believed to be associated with grain boundary metal carbides or carbonitrides precipitated during reheating of already deposited beads by subsequent passes. Weld deposits which solidify as primary delta ferrite appear immune. Through use of fully austenitic filler metals of low nitrogen content under controlled shielded metal arc welding conditions, and through use of filler metals solidifying as primary delta ferrite where only minimum residuals remain to room temperature, welds of Type 316L composition have been made with 4.2K yield strength matching that of Type 304LN plate and acceptable levels of soundness, ductility and toughness

  11. Electrochemical determination of the glass transition temperature of thin polyelectrolyte brushes at solid-liquid interfaces by impedance spectroscopy.

    Science.gov (United States)

    Alonso-García, Teodoro; Rodríguez-Presa, María José; Gervasi, Claudio; Moya, Sergio; Azzaroni, Omar

    2013-07-16

    Devising strategies to assess the glass transition temperature (Tg) of polyelectrolyte assemblies at solid-electrolyte interfaces is very important to understand and rationalize the temperature-dependent behavior of polyelectrolyte films in a wide range of settings. Despite the evolving perception of the importance of measuring Tg under aqueous conditions in thin film configurations, its straightforward measurement poses a challenging situation that still remains elusive in polymer and materials science. Here, we describe a new method based on electrochemical impedance spectroscopy (EIS) to estimate the glass transition temperature of planar polyelectrolyte brushes at solid-liquid interfaces. To measure Tg, the charge transfer resistance (Rct) of a redox probe diffusing through the polyelectrolyte brush was measured, and the temperature corresponding to the discontinuous change in Rct was identified as Tg. Furthermore, we demonstrate that impedance measurements not only facilitate the estimation of Tg but also enable a reliable evaluation of the transport properties of the polymeric interface, i.e., determination of diffusion coefficients, close to the thermal transition. We consider that this approach bridges the gap between electrochemistry and the traditional tools used in polymer science and offers new opportunities to characterize the thermal behavior of complex polymeric interfaces and macromolecular assemblies.

  12. Room-temperature susceptometry predicts biopsy-determined hepatic iron in patients with elevated serum ferritin.

    Science.gov (United States)

    Maliken, Bryan D; Avrin, William F; Nelson, James E; Mooney, Jody; Kumar, Sankaran; Kowdley, Kris V

    2012-01-01

    There is an ongoing clinical need for novel methods to measure hepatic iron content (HIC) noninvasively. Both magnetic resonance imaging (MRI) and superconducting quantum interference device (SQUID) methods have previously shown promise for estimation of HIC, but these methods can be expensive and are not widely available. Room-temperature susceptometry (RTS) represents an inexpensive alternative and was previously found to be strongly correlated with HIC estimated by SQUID measurements among patients with transfusional iron overload related to thalassemia. The goal of the current study was to examine the relationship between RTS and biochemical HIC measured in liver biopsy specimens in a more varied patient cohort. Susceptometry was performed in a diverse group of patients with hyperferritinemia due to hereditary hemochromatosis (HHC) (n = 2), secondary iron overload (n = 3), nonalcoholic fatty liver disease (NAFLD) (n = 2), and chronic viral hepatitis (n = 3) within one month of liver biopsy in the absence of iron depletion therapy. The correlation coefficient between HIC estimated by susceptometry and by biochemical iron measurement in liver tissue was 0.71 (p = 0.022). Variance between liver iron measurement and susceptometry measurement was primarily related to reliance on the patient's body-mass index (BMI) to estimate the magnetic susceptibility of tissue overlying the liver. We believe RTS holds promise for noninvasive measurement of HIC. Improved measurement techniques, including more accurate overlayer correction, may further improve the accuracy of liver susceptometry in patients with liver disease.

  13. Determination of temperature dependant viscosity values of lubricants via simultaneous measurements of refractive index

    International Nuclear Information System (INIS)

    Yaltkaya, S.

    2005-01-01

    Viscosity is one of the most important parameter in rheological and tribological properties of fluids. The objective of this study is to obtain the viscosity values from the simultaneous refractive-index measurements of lubricants, simply by dipping the fiber-optic probe into the oil to be measured. Due to the fact that these parameters are temperature dependent, within the interval under consideration, oil heated up steadily while measuring the viscosity and refractive index at the same time. The refractive index sensor, the digital viscometer and the thermometer were connected to a PC via an analog to digital converter and the values were acquired at the same time. The fiber optic refractive index sensor has been designed in our laboratory. By utilising Fresnel's fundamental reflection law, the intensity of reflected light from boundary surface (optic fiber core-motor oil) was measured at 660 nm wavelength and then refractive index of the oil was calculated. The derived refractive index values were converted viscosity values that acquired by using the calibration equation. The viscometer, used during the study, was the rotational Brookfield type

  14. Experimental determination of cesium saturated vapor pressure in the 483/642 deg K temperature

    Energy Technology Data Exchange (ETDEWEB)

    Gushchin, G I; Subbotin, V A; Khachaturov, Eh Kh [Gosudarstvennyj Komitet po Ispol' zovaniyu Atomnoj Ehnergii SSSR, Obninsk. Fiziko-Ehnergeticheskij Inst.

    1975-07-01

    Test results of saturated cesium vapour pressure in the temperature range of 483.13-642 deg K and pressure range of 15.77-1.389 N/m/sup 2/ by direct static method are presented. The testing system comprises a differential bellows-type pressure sensor, a thermostatic unit and a gas system with V-shaped oil manometer used for argon-assisted sensor calibration. The static sensor characteristic approaches linearity in the pressure range of 10-600 N/m/sup 2/. The greatest non-linearity is observed at low pressures (10-40 N/m/sup 2/) and does not exceed 3-4%. Sensor sensitivity is 0.39 mV/N/m/sup 2/ in this pressure range. The characteristic hysteresis is 0.5% and below. With pressures greater than 600 N/m/sup 2/, the sensor sensitivity gradually decreases by 12% while the characteristic hysteresis increases to 2-3%. A brief description of the experimental procedure is offered. The present results are compared with other authors' data.

  15. New method for the exact determination of phenols in low-temperature tar and tar oils

    Energy Technology Data Exchange (ETDEWEB)

    Lambris, G; Haferkorn, H

    1949-01-01

    A 3-gram sample of water-free tar or tar oil containing approximately 50% phenols is dissolved in a mixture of benzene and xylene and a known excess of a 20% KOH solution of known normality saturated with benzene and xylene is added. Weight of the KOH is determined by difference. This mixture is shaken repeatedly in a 300-milliliter separatory funnel. After standing for 0.5 h, the dark or almost black phenolate solution containing the major portion is separated and weighed. Care must be taken to prevent the induction of solids. The phenolate in the residue is extracted with hot water and titrated with 0.2N HCl and 1 ml. Congo red (1:100). If water is present in the tar or tar oil, 100 ml of xylene is added immediately after weighing and the water separated by distillation the weight of which must be determined. Any phenols carried over are dissolved in the small quantity of xylene in the distillate. This quantity is added to the bulk of the xylene. After any remaining phenols are extracted from the tar residue with boiling benzene, the benzene-xylene mixture is treated with KOH as above. The accuracy of the method is estimated to be +-1% as shown by experiments with phenol; o-, m-, and p-cresol; cresol mixture; and pyrocatechol. The weight of the dissolved phenols X is determined by X = c - a + cd/(ab - d) where a = weight of KOH, b = HCl used per gram of KOH, C = weight of major portion of phenolate solution, which is formed by shaking the phenol solution with KOH, d = HCl used for titration of phenolate residue.

  16. Determination of an optimum reactor coolant system average temperature within the licensed operating window

    International Nuclear Information System (INIS)

    Thaulez, F.; Basic, I.; Vrbanic, I.

    2003-01-01

    The Krsko modernization power uprate analyses have been performed in such a way as to cover plant operation in a range of average reactor coolant temperatures (Tavg) of 301.7 deg C to 307.4 deg C, with steam generator tube plugging levels of up to 5%. The upper bound is temporarily restricted to 305.7 deg C, as long as Zirc-4 fuel is present in the core. (It is, however,acceptable to operate at 307.4 deg C with a few Zirc-4 assemblies, if meeting certain conditionsand subjected to a corrosion and rod internal pressure evaluation in the frame of the cyclespecificnuclear core design.) The Tavg optimization method takes into account two effects, that are opposed to each other: the impact of steam pressure on the electrical power output versus the impact of Tavg on the cost of reactor fuel. The positive economical impact of a Tavg increase through the increase in MWe output is around 6 to 8 times higher than the corresponding negative impact on the fuel cost. From this perspective, it is desirable to have Tavg as high as possible. This statement is not affected by a change in the relationship between steam pressure and Tavg level. However, there are also other considerations intervening in the definition of the optimum. This paper discusses the procedure for selection of optimal Tavg for the forthcoming cycle in relation to the impacts of change in Tavg level and/or variations of the steam pressure versus Tavg relationship. (author)

  17. DATING: A computer code for determining allowable temperatures for dry storage of spent fuel in inert and nitrogen gases

    International Nuclear Information System (INIS)

    Simonen, E.P.; Gilbert, E.R.

    1988-12-01

    The DATING (Determining Allowable Temperatures in Inert and Nitrogen Gases) code can be used to calculate allowable initial temperatures for dry storage of light-water-reactor spent fuel. The calculations are based on the life fraction rule using both measured data and mechanistic equations as reported by Chin et al. (1986). The code is written in FORTRAN and utilizes an efficient numerical integration method for rapid calculations on IBM-compatible personal computers. This report documents the technical basis for the DATING calculations, describes the computational method and code statements, and includes a user's guide with examples. The software for the DATING code is available through the National Energy Software Center operated by Argonne National Laboratory, Argonne, Illinois 60439. 5 refs., 8 figs., 5 tabs

  18. Fuel assembly outlet temperature profile influence on core by-pass flow and power distribution determination in WWER -440 reactors

    International Nuclear Information System (INIS)

    Petenyi, V.; Klucarova, K.; Remis, J.

    2003-01-01

    The in core instrumentation of the WWER-440 reactors consists of the thermocouple system and the system of self powered detectors (SPD). The thermocouple systems are positioned about 50 cm above the fuel bundle upper flow-mixing grid. The usual assumption is that, the coolant is well mixed in the Tc location, i.e. the temperature is constant through the flow cross-section area. The present evaluations by using the FLUENT 5.5.14 code reveal that, this assumption is not fulfilled. There exists a temperature profile that depends on fuel assembly geometry and on inner power profile of the fuel assembly. The paper presents the estimation of this effect and its influence on the core power distribution and the core by-pass flow determination. Comparison with measurements in Mochovce NPP will also be a part of this presentation (Authors)

  19. Determination of the electron energy distribution function of a low temperature plasma from optical emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dodt, Dirk Hilar

    2009-01-05

    The experimental determination of the electron energy distribution of a low pressure glow discharge in neon from emission spectroscopic data has been demonstrated. The spectral data were obtained with a simple overview spectrometer and analyzed using a strict probabilistic, Bayesian data analysis. It is this Integrated Data Analysis (IDA) approach, which allows the significant extraction of non-thermal properties of the electron energy distribution function (EEDF). The results bear potential as a non-invasive alternative to probe measurements. This allows the investigation of spatially inhomogeneous plasmas (gradient length smaller than typical probe sheath dimensions) and plasmas with reactive constituents. The diagnostic of reactive plasmas is an important practical application, needed e.g. for the monitoring and control of process plasmas. Moreover, the experimental validation of probe theories for magnetized plasmas as a long-standing topic in plasma diagnostics could be addressed by the spectroscopic method. (orig.)

  20. Determination of the electron energy distribution function of a low temperature plasma from optical emission spectroscopy

    International Nuclear Information System (INIS)

    Dodt, Dirk Hilar

    2009-01-01

    The experimental determination of the electron energy distribution of a low pressure glow discharge in neon from emission spectroscopic data has been demonstrated. The spectral data were obtained with a simple overview spectrometer and analyzed using a strict probabilistic, Bayesian data analysis. It is this Integrated Data Analysis (IDA) approach, which allows the significant extraction of non-thermal properties of the electron energy distribution function (EEDF). The results bear potential as a non-invasive alternative to probe measurements. This allows the investigation of spatially inhomogeneous plasmas (gradient length smaller than typical probe sheath dimensions) and plasmas with reactive constituents. The diagnostic of reactive plasmas is an important practical application, needed e.g. for the monitoring and control of process plasmas. Moreover, the experimental validation of probe theories for magnetized plasmas as a long-standing topic in plasma diagnostics could be addressed by the spectroscopic method. (orig.)