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Sample records for differential thermal analysis

  1. Differential-thermal analysis of irradiated lignite

    International Nuclear Information System (INIS)

    Chichek, F.; Eyubova, N.

    2006-01-01

    Full text: In this theme our purpose is to explain thermo-differential analysis of lignites irradiated. During experiment Caraman Ermenek (washed), Caraman Ermenek (crude), Nevshehir (crude), Slopi (crude), Trakya Harman (washed) lignite coals were used. Five of five kinds of coal samples with 3mm and 1gr of each sample were obtained. Then they were filled into the Tubes after having dried total 25 samples with 1 gr at 1000 degrees temperature for one hour. Air in the tubes was pumped out and closed. Coal samples in vacuum medium were irradiated by gamma rays of Co60 at 5.5 kGy, 19.2 kGy, 65.7 kGy, 169.6 kGy, 411.2 kGy doses to the normal conditions. Then differential thermal analysis was carried out both in original and the samples irradiated. Argon gas was used to make inert medium in the camera. T=200-8500 degrees temperature was selected. At the experiment done from 1000-1300 degrees temperatures too great endothermic reaction pick was begun to form by being observed thermal changings. At 3000-4200 degrees temperature exothermic reaction picks and at 7000 degrees parallel exothermic reaction picks were observed. Initial endothermic and exothermic reaction picks in five lignite samples were observed like a sharp curve. At the end coal irradiated samples were compared with original coal samples. At the result of experiment it was revealed that in comparison with original coal samples coal samples irradiated form exothermic and endothermic curves at very reaction pick and temperature intervals of these pick were large. Besides loss of weight was observed to begin at low temperatures in samples irradiated and especially momentary weight loss at some heats in the rang of known temperatures was observed in the coal Slopi contain in bitumen. Because of heat the weigh loss in the non irradiated samples forms parabolic curve and because of heat the weight loss in the samples irradiated forms stepped curves. It has shown that the coal irradiated can be easily departed by

  2. Differential-thermal analysis of irradiated lignite

    International Nuclear Information System (INIS)

    Chichek, F; Eyubova, N.

    2006-01-01

    Full text: In this theme our purpose is to explain thermo-differential analysis of lignite's irradiated. During experiment Caraman Ermenek (washed), Caraman Ermenek (crude), Nevshehir (crude), Slopi (crude), Trakya Harman (washed) lignite coals were used. Five of five kinds of coal samples with 3mm and 1 gr of each sample were obtained. Then they were filled into the Tubes after having dried total 25 samples with 1 gr at 1000C temperature for one hour. Air in the tubes was pumped out and closed. Coal samples in vacuum medium were irradiated by gamma rays of Co-60 at 5.5 kGy, 19.2 kGy, 65.7 kGy, 169.6 kGy, 411.2 kGy, doses to the normal conditions. At the end coal irradiated samples were compared with original coal samples. At the result of experiment it was revealed that in comparison with original coal samples coal samples irradiated from exothermic and endothermic curves at very reaction pick and temperature intervals of these pick were large. Besides loss of weight was observed to begin at low temperatures in samples irradiated and especially momentary weight loss at some heats in the rang of known temperatures was observed in the coal Slopi contain in bitumen. Because of heat the weight loss in the non irradiated samples forms parabolic curve and because of heat the weight loss in the samples irradiated forms stepped curves. It was shown that the coal irradiated can be easily departed by heat because of the chemical structure in comparison the original one.

  3. Thermogravimetric and differential thermal analysis of potassium bicarbonate contaminated cellulose

    Science.gov (United States)

    A. Broido

    1966-01-01

    When samples undergo a complicated set of simultaneous and sequential reactions, as cellulose does on heating, results of thermogravimetric and differential thermal analyses are difficult to interpret. Nevertheless, careful comparison of pure and contaminated samples, pyrolyzed under identical conditions, can yield useful information. In these experiments TGA and DTA...

  4. Analysis of the sensitivity and sample-furnace thermal-lag of a differential thermal analyzer

    International Nuclear Information System (INIS)

    Roura, P.; Farjas, J.

    2005-01-01

    The heat exchange between the horizontal furnace of a differential thermal analyzer (DTA) and the sample is analyzed with the aim of understanding the parameters governing the thermal signal. The resistance due to radiation and conduction through the gas has been calculated and compared to the experimental values of the thermal-lag between the sample and furnace and apparatus sensitivity. The overall evolution of these parameters with the temperature and their relative values are well understood by considering the temperature differences that arise between the sample and holder. Two RC thermal models are used for describing the apparatus performance at different temperature ranges. Finally, the possibility of improving the signal quality through the control of the leak resistances is stressed

  5. Analysis of Siderite Thermal Decomposition by Differential Scanning Calorimetry

    Science.gov (United States)

    Bell, M. S.; Lin, I.-C.; McKay, D. S.

    2000-01-01

    Characterization of carbonate devolitilization has important implications for atmospheric interactions and climatic effects related to large meteorite impacts in platform sediments. On a smaller scale, meteorites contain carbonates which have witnessed shock metamorphic events and may record pressure/temperature histories of impact(s). ALH84001 meteorite contains zoned Ca-Mg-Fe-carbonates which formed on Mars. Magnetite crystals are found in the rims and cores of these carbonates and some are associated with void spaces leading to the suggestion by Brearley et al. that the crystals were produced by thermal decomposition of the carbonate at high temperature, possibly by incipient shock melting or devolitilization. Golden et al. recently synthesized spherical Mg-Fe-Ca-carbonates from solution under mild hydrothermal conditions that have similar carbonate compositional zoning to those of ALH84001. They have shown experimental evidence that the carbonate-sulfide-magnetite assemblage in ALH84001 can result from a multistep inorganic process involving heating possibly due to shock events. Experimental shock studies on calcium carbonate prove its stability to approx. 60 GPa, well in excess of the approx. 45 GPa peak pressures indicated by other shock features in ALH84001. In addition, Raman spectroscopy of carbonate globules in ALH84001 indicates no presence of CaO and MgO. Such oxide phases should be found associated with the magnetites in voids if these magnetites are high temperature shock products, the voids resulting from devolitilization of CO2 from calcium or magnesium carbonate. However, if the starting material was siderite (FeCO3), thermal breakdown of the ALH84001 carbonate at 470 C would produce iron oxide + CO2. As no documentation of shock effects in siderite exists, we have begun shock experiments to determine whether or not magnetite is produced by the decomposition of siderite within the < 45GPa pressure window and by the resultant thermal pulse to approx

  6. Thermal Analysis of Pure Uranium Metal, UMo and UMoSi Alloys Using a Differential Thermal Analyzer

    International Nuclear Information System (INIS)

    Yanlinastuti; Sutri Indaryati; Rahmiati

    2010-01-01

    Thermal analysis of pure uranium metal, U-7%Mo and U-7%Mo-1%Si alloys have been done using a Differential Thermal Analyzer (DTA). The experiments are conducted in order to measure the thermal stability, thermochemical properties of elevated temperature and enthalpy of the specimens. From the analysis results it is showed that uranium metal will transform from α to β phases at temperature of 667.16°C and enthalpy of 2.3034 cal/g and from β to γ phases at temperature of 773.05 °C and enthalpy of 2.8725 cal/g and start melting at temperature of 1125.26 °C and enthalpy of 2.1316 cal/g. The U-7%Mo shows its thermal stability up to temperature of 650 °C and its thermal changes at temperature of 673.75 °C indicated by the formation of an endothermic peak and enthalpy of 0.0257 cal/g. The U-7%Mo-1%Si alloys shows its thermal stability up to temperature of 550 °C and its thermal changes at temperature of 574.18 °C indicated by the formation of an endothermic peak and enthalpy of 0.613 cal/g. From the three specimens it is showed that they have a good thermal stability at temperature up to 550 °C. (author)

  7. Thermo Gravimetric and Differential Thermal Analysis of Clay of Western Rajasthan (india)

    Science.gov (United States)

    Shekhawat, M. S.

    The paper presents the study of thermo gravimetric and differential thermal analysis of blended clay. Western part of Rajasthan (India) is rich resource of Ball clays and it is mainly used by porcelain, sanitary ware, and tile industry. The quality and grade of clay available in the region vary from one deposit to other. To upgrade the fired colour and strength properties, different variety of clays may be blended together. The paper compares the results of thermal analysis one of blended clay B2 with reference clay of Ukraine which is imported by industries owners. The result revealed that the blended clay is having mineral kaolinite while the Ukrainian clay is Halloysite.

  8. Investigation of Thermal Behavior for Natural Fibres Reinforced Epoxy using Thermogravimetric and Differential Scanning Calorimetric Analysis

    Directory of Open Access Journals (Sweden)

    Fauzi F.A.

    2016-01-01

    Full Text Available This paper presented the research works on the investigation of the thermal behavior of the natural fibres; i.e. pineapple leaf fibre, kenaf fibre and mengkuang fibres reinforced epoxy. The thermogravimetric analysis and differential scanning calorimetric analysis were used to measure the thermal behavior of the treated and untreated pineapple, kenaf and mengkuang fibres reinforced epoxy. The samples for both analysis were subjected to maximum temperature 600°C at the heating rate of 10°C/min. The results showed that the treated fibres show higher maximum peak temperature as compared to the untreated fibres. Additionally, the glass transition temperature showed a lower value for all treated fibre. It can be concluded that investigation of thermal properties of these natural fibres could improve the utilization of natural fibre composites in various applications i.e. sports applications.

  9. Thermal treatment investigation of natural lizardite at the atmospheric pressure, based on XRD and differential thermal analysis/thermal gravimetric analysis methods

    International Nuclear Information System (INIS)

    Dabiri, R.; Karimi Shahraki, B.; Mollaei, H.; Ghaffari, M.

    2009-01-01

    Determination of stability limits, mineralogical changes and thermal reaction of serpentine minerals are very important for the investigation of magmatism, mechanism and depth of plates of subduction. During the subduction process, serpentine (Lizardite) minerals will release their water due to thermal reactions. This dehydration can play an important role in volcanism processes related to the subduction, In this study, serpentine minerals (Lizardite) collected from the Neyriz Ophiolite Complex were dehydrated under the constant atmospheric pressure. These mineralogical changes were determined by X-Ray diffraction and differential thermal analysis-thermal gravimetric analyses methods. This study shows natural lizardites that heated for about one hour is stable up to 550 d eg C . Dehydration reactions on lizardite started at approximately between 100 to 150 d eg C and dehydroxylation reactions started at approximately 550-690 d eg C . As a result of thermal reaction, the decomposition of lizardite will take place and then changes in to olivine (forsterite). Crystallization of olivine (forsterite) will start at 600 d eg C . This mineral is stable up to 700 d eg C and then crystallization of enstatite will start at 700 d eg C . During this dehydration and crystallization reaction, amorphous processes will start at 600 d eg C and some amount water and silica will release.

  10. Studies of the thermal properties of horn keratin by dielectric spectroscopy, thermogravimetric analysis and differential thermal analysis

    International Nuclear Information System (INIS)

    Marzec, E.; Piskunowicz, P.; Jaroszyk, F.

    2002-01-01

    The dielectric and thermal properties of horn keratin have been studied bu dielectric spectroscopy in the frequency range 10 1 -10 5 Hz, thermogravimetric analysis (TG) and different thermal analysis (DTA). Measurement of non-irradiated and g amma - irradiated keratin with doses 5, 50 kGy were performed at temperature from 22 to 260 o C. The results revealed the occurrence of phase transitions related to release of loosely bound water and bound water up to 200 o Cand the denaturation of the crystalline structure above this temperature. The influence of γ-irradiation on the thermal behaviour of keratin is significant only in the temperature range of denaturation. The decrease in the temperature of denaturation would suggest that γ-irradiation initiates main-chain degradation. (authors)

  11. Differential Thermal Analysis and Dielectric Studies on 2-Methyl-2-Nitro-Propane under High Pressure

    Science.gov (United States)

    Büsing, D.; Jenau, M.; Reuter, J.; Würflinger, A.; Tamarit, J. Li.

    1995-05-01

    Differential thermal analysis and dielectric studies under pressures up to 300 MPa and temperatures of about 200 to 350 K have been performed on 2-methyl-2-nitro-propane (TBN). TBN displays an orientationally disordered phase (ODIC), solid I, and two non-plastic phases, solids II and III. The coexistence region of the plastic phase I increases with increasing pressure, whereas the low-temperature phase II apparently vanishes at a triple point I, II, III, above 300 MPa. The static permittivity increases on freezing, characterizing the solid I as an ODIC phase. In the frame of the Kirkwood-Onsager-Fröhlich theory the g-factor is about unity, discounting specific dielectric correlations. The dielectric behaviour of TBN is similar to previously studied related compounds, such as 2-chloro-2-methyl-propane or 2-brome- 2-methyl-propane

  12. Analysis of Zr++++ dan ZrO++ cations through their Hydroxide precipitate with thermal differential analysis method

    International Nuclear Information System (INIS)

    Simbolon, Sahat; Ratmi-Herlani

    1996-01-01

    Hydroxide of zirconyl and zirconium, made by reacting zirconium and zirconyl solution with NH 4 OH 25 % solution, were analysed by thermal differential analysis (TDA). It was also done TDA method for hydroxide of zirconyl and zirconium, made by reacting zirconyl chloride and zirconium chloride solid with NH 4 OH 25 % solution directly. It was found that TDA of hydroxide precipitate made through solution had a clear TDA counter, meanwhile TDA thermogram of hydroxide precipitate made by direct adding NH 4 OH 25 % solution to zirconyl and zirconium hydroxide had no clear TDA thermogram. Precipitate Zr O(OH) 2 and Zr(OH) 4 found through solution could be differentiated each other based on their TDA thermograms

  13. A real time analysis of the self-assembly process using thermal analysis inside the differential scanning calorimeter instrument.

    Science.gov (United States)

    Roy, Debmalya; Shastri, Babita; Mukhopadhyay, K

    2012-07-12

    The supramolecular assembly of the regioregular poly-3-hexylthiophene (rr-P3HT) in solution has been investigated thoroughly in the past. In the current study, our focus is on the enthalpy of nanofiber formation using thermal analysis techniques by performing the self-assembly process inside the differential scanning calorimetry (DSC) instrument. Thermogravimetric analysis (TGA) was carried out to check the concentration of the solvent during the self-assembly process of P3HT in p-xylene. Ultraviolet visible (UV-vis) spectophotometric technique, small-angle X-ray scattering (SAXS) experiment, atomic force microscopic (AFM), and scanning electron microscopic (SEM) images were used to characterize the different experimental yields generated by cooling the reaction mixture at desired temperatures. Comparison of the morphologies of self-assembled products at different fiber formation temperatures gives us an idea about the possible crystallization parameters which could affect the P3HT nanofiber morphology.

  14. Design of glass-ceramic complex microstructure with using onset point of crystallization in differential thermal analysis

    International Nuclear Information System (INIS)

    Hwang, Seongjin; Kim, Jinho; Shin, Hyo-Soon; Kim, Jong-Hee; Kim, Hyungsun

    2008-01-01

    Two types of frits with different compositions were used to develop a high strength substrate in electronic packaging using a low temperature co-fired ceramic process. In order to reveal the crystallization stage during heating to approximately 900 deg. C, a glass-ceramic consisting of the two types of frits, which had been crystallized to diopside and anorthite after firing, was tested at different mixing ratios of the frits. The exothermal peaks deconvoluted by a Gauss function in the differential thermal analysis curves were used to determine the onset point of crystallization of diopside or anorthite. The onset points of crystallization were affected by the mixing ratio of the frits, and the microstructure of the glass-ceramic depended on the onset point of crystallization. It was found that when multicrystalline phases appear in the microstructure, the resulting complex microstructure could be predicted from the onset point of crystallization obtained by differential thermal analysis

  15. Thermal Properties and Thermal Analysis:

    Science.gov (United States)

    Kasap, Safa; Tonchev, Dan

    The chapter provides a summary of the fundamental concepts that are needed to understand the heat capacity C P, thermal conductivity κ, and thermal expansion coefficient α L of materials. The C P, κ, and α of various classes of materials, namely, semiconductors, polymers, and glasses, are reviewed, and various typical characteristics are summarized. A key concept in crystalline solids is the Debye theory of the heat capacity, which has been widely used for many decades for calculating the C P of crystals. The thermal properties are interrelated through Grüneisen's theorem. Various useful empirical rules for calculating C P and κ have been used, some of which are summarized. Conventional differential scanning calorimetry (DSC) is a powerful and convenient thermal analysis technique that allows various important physical and chemical transformations, such as the glass transition, crystallization, oxidation, melting etc. to be studied. DSC can also be used to obtain information on the kinetics of the transformations, and some of these thermal analysis techniques are summarized. Temperature-modulated DSC, TMDSC, is a relatively recent innovation in which the sample temperature is ramped slowly and, at the same time, sinusoidally modulated. TMDSC has a number of distinct advantages compared with the conventional DSC since it measures the complex heat capacity. For example, the glass-transition temperature T g measured by TMDSC has almost no dependence on the thermal history, and corresponds to an almost step life change in C P. The new Tzero DSC has an additional thermocouple to calibrate better for thermal lags inherent in the DSC measurement, and allows more accurate thermal analysis.

  16. The tetragonal-monoclinic transformations of zirconia studied by small angle neutron scattering and differential thermal analysis

    International Nuclear Information System (INIS)

    Li, Z.; Epperson, J.E.; Fang, Y.; Chan, S.K.

    1992-08-01

    The tetragonal-monoclinic transformations of zirconia have been studied on pristine single crystals and on their cycled crystallites. Two complementary techniques have been used. Small angle neutron scattering experiments were carried out to monitor the degree of completion of a transformation under equilibrium conditions for collections of 20--30 large crystals using the total internal and external surface area as an indicator. Differential thermal analysis experiments were carried out on smaller single-domain crystals of different sizes individually during heating and cooling to measure the rates of latent heat absorption and emission. The investigation establishes the upper limit of stability of the monoclinic phase, the lower limit of stability of the tetragonal phase, and the coexistence temperature between the two phases. The characteristics of the transformations are also inferred from these experiments

  17. Micro-differential thermal analysis detection of adsorbed explosive molecules using microfabricated bridges

    DEFF Research Database (Denmark)

    Senesac, Larry R.; Yi, Dechang; Greve, Anders

    2009-01-01

    Although micromechanical sensors enable chemical vapor sensing with unprecedented sensitivity using variations in mass and stress, obtaining chemical selectivity using the micromechanical response still remains as a crucial challenge. Chemoselectivity in vapor detection using immobilized selective...... layers that rely on weak chemical interactions provides only partial selectivity. Here we show that the very low thermal mass of micromechanical sensors can be used to produce unique responses that can be used for achieving chemical selectivity without losing sensitivity or reversibility. We demonstrate...

  18. Thermal/hydraulic bowing stability analysis of grid-supported multi-pin bundles with differential swelling and irradiation creep

    International Nuclear Information System (INIS)

    McAreavey, G.

    1977-01-01

    Azimuthal variations of clad temperature in fuel pin bundles leads to pin bowing by differential thermal expansion. During irradiation in a fast flux further possibly more severe bowing is caused by differential neutron induced voidage swelling, which, being temperature sensitive, will also vary azimuthally. The problem of pin bowing in a fuel element cluster involves consideration of the thermal/hydraulic behaviour, allowing for both inherent and induced clad temperature non-uniformities, coupled with the restrained bowing behaviour, including differential thermal expansion, differential swelling, and irradiation creep. All pins must be considered simultaneously. In the temperature and stress ranges of interest thermal creep may be neglected. An existing computer code, IAMBIC solves the zero time thermal bowing problem for a cluster of up to 61 pins on hexagonal pitch, with up to 21 supports at arbitrary axial spacing. The present paper describes the basis of TRIAMBIC, a time dependent code which analyses the irradiation induced effects in fuel pin bunbles due to fast neutrons. (Auth.)

  19. Differential thermal analysis of the glassy system AsSe-AsTe

    International Nuclear Information System (INIS)

    El Den, M.B.; El Mously, M.K.

    1986-11-01

    Thermal induced phase transformation for the system AsSe-AsTe has been studied using DTA. The dependence of the characteristic temperature Tg, Tc and Tm on the ratio of Se/Tc has been determined. The increase of Te content leads to the decrease of both Tg and Tc, i.e. tellurium enhances the crystallization process in these glasses exactly as in the case of AsSe 3/2-x Te x and AsSe 5/2-x Te x . The kinetic calculations have also been tried. Reasonable results have been obtained for two compositions only AsSe 0.5 Te 0.5 and AsSe 0.1 Te 0.9 with E cryst equal to 31.0 kcal/mole for the first and 45 and 65 kcal/mole for the second. The other compositions either do not crystallize completely or have complicated and overlapped peaks. (author)

  20. Studies on Rapidly Frozen Suspensions of Yeast Cells by Differential Thermal Analysis and Conductometry

    Science.gov (United States)

    Mazur, Peter

    1963-01-01

    Few, if any, yeast cells survived rapid cooling to -196°C and subsequent slow warming. After rapid freezing, the suspensions absorbed latent heat of fusion between -15° and 0°C during warming, and the relation between the amount of heat absorbed and the concentration of cells was the same as that in equivalent KCl solutions, indicating that frozen suspensions behave thermally like frozen solutions. The amount of heat absorbed was such that more than 80 per cent of the intracellular solution had to be frozen. The conductometric behavior of frozen suspensions showed that cell solutes were still inside the cells and surrounded by an intact cell membrane at the time heat was being absorbed. Two models are consistent with these findings. The first assumes that intracellular freezing has taken place; the second that all freezable water has left the cells and frozen externally. The latter model is ruled out because rapidly cooled cells do not shrink by an amount equal to the volume of water that would have to be withdrawn to prevent internal freezing. PMID:13934216

  1. Transcriptome analysis and identification of significantly differentially expressed genes in Holstein calves subjected to severe thermal stress

    Science.gov (United States)

    Srikanth, Krishnamoorthy; Lee, Eunjin; Kwan, Anam; Lim, Youngjo; Lee, Junyep; Jang, Gulwon; Chung, Hoyoung

    2017-11-01

    RNA-Seq analysis was used to characterize transcriptome response of Holstein calves to thermal stress. A total of eight animals aged between 2 and 3 months were randomly selected and subjected to thermal stress corresponding to a temperature humidity index of 95 in an environmentally controlled house for 12 h consecutively for 3 days. A set of 15,787 unigenes were found to be expressed and after a threshold of threefold change, and a Q value physiological and metabolic processes to survive. Many of the genes identified in this study have not been previously reported to be involved in thermal stress response. The results of this study extend our understanding of the animal's response to thermal stress and some of the identified genes may prove useful in the efforts to breed Holstein cattle with superior thermotolerance, which might help in minimizing production loss due to thermal stress.

  2. An apparatus for differential thermal analysis (1961); Realisation d'un appareil d'analyse thermique differentielle (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Rappeneau, J; Quetier, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    An apparatus for differential thermal analysis has been developed for the study of the energy stored in irradiated graphite. It makes possible the measurement of variations in the differential enthalpy d H / d{theta} of irradiated graphite between room temperature and 800 deg. C. The integration of the results gives values for the total energy H({theta}). The temperature measurements are made with an accuracy of 0,1 deg. C and are reproducible to {+-} 0,2 deg. C. The characteristics of the apparatus are such that it is possible to study, as a function of irradiation conditions (doses, temperatures), the evolution of the energy spectrum of the graphite as well as the modifications of this spectrum brought about by annealing and successive irradiations, by slow annealing, or by annealing under irradiation. The apparatus developed can also be used for the study of metals and alloys (transition temperatures and heats of transformation), in particular uranium and uranium alloys. (authors) [French] Un appareil d'analyse thermique differentielle a ete realise pour etudier l'energie emmagasinee par le graphite irradie. Il permet de determiner la variation de l'enthalpie differentielle dH / d{theta} du graphite irradie entre la temperature ambiante et 800 deg. C. L'integration des resultats obtenus fournit les valeurs de l'energie totale H({theta}). Les mesures de temperature sont effectuees avec une sensibilite de 0,1 deg. C et la reproductibilite des mesures est assuree a {+-} 0,2 deg. C. Les caracteristiques de cet appareil sont suffisantes pour permettre d'etudier en fonction des conditions d'irradiation (doses, temperatures) l'evolution du spectre d'energie du graphite ainsi que les modifications de ce spectre par des recuits et des irradiations successives, par des recuits lents, ou par des recuits sous rayonnement. Par ailleurs, l'appareil mis au point peut etre utilise pour etudier les metaux et alliages (temperatures de transition et chaleurs de transformation), en

  3. Electroperturbation of human stratum corneum fine structure by high voltage pulses: a freeze-fracture electron microscopy and differential thermal analysis study.

    Science.gov (United States)

    Jadoul, A; Tanojo, H; Préat, V; Bouwstra, J A; Spies, F; Boddé, H E

    1998-08-01

    Application of high voltage pulses (HVP) to the skin has been shown to promote the transdermal drug delivery by a mechanism involving skin electroporation. The aim of this study was to detect potential changes in lipid phase and ultrastructure induced in human stratum corneum by various HVP protocols, using differential thermal analysis and freeze-fracture electron microscopy. Due to the time involved between the moment the electric field is switched off and the analysis, only "secondary" phenomena rather than primary events could be observed. A decrease in enthalpies for the phase transitions observed at 70 degrees C and 85 degrees C was detected by differential thermal analysis after HVP treatment. No changes in transition temperature could be seen. The freeze-fracture electron microscopy study revealed a dramatic perturbation of the lamellar ordering of the intercellular lipid after application of HVP. Most of the planes displayed rough surfaces. The lipid lamellae exhibited rounded off steps or a vanished stepwise order. There was no evidence for perturbation of the corneocytes content. In conclusion, the freeze-fracture electron microscopy and differential thermal analysis studies suggest that HVP application induces a general perturbation of the stratum corneum lipid ultrastructure.

  4. Thermal analysis studies of ammonium uranyl carbonate

    International Nuclear Information System (INIS)

    Cao Xinsheng; Ma Xuezhong; Wang Fapin; Liu Naixin; Ji Changhong

    1988-01-01

    The simultaneous thermogravimetry and differential thermal analysis of the ammonium uranyl carbonate powder were performed with heat balance in the following atmosphers: Air, Ar and Ar-8%H 2 . The thermogravimetry and differential thermal analysis curves of the ammonium uranyl carbonate powder obtained from different source were reported and discussed

  5. ESTIMATION OF THERMAL PARAMETERS OF POWER BIPOLAR TRANSISTORS BY THE METHOD OF THERMAL RELAXATION DIFFERENTIAL SPECTROMETRY

    Directory of Open Access Journals (Sweden)

    V. S. Niss

    2015-01-01

    Full Text Available Thermal performance of electronic devices determines the stability and reliability of the equipment. This leads to the need for a detailed thermal analysis of semiconductor devices. The goal of the work is evaluation of thermal parameters of high-power bipolar transistors in plastic packages TO-252 and TO-126 by a method of thermal relaxation differential spectrometry. Thermal constants of device elements and distribution structure of thermal resistance defined as discrete and continuous spectra using previously developed relaxation impedance spectrometer. Continuous spectrum, based on higher-order derivatives of the dynamic thermal impedance, follows the model of Foster, and discrete to model of Cauer. The structure of sample thermal resistance is presented in the form of siх-chain electro-thermal RC model. Analysis of the heat flow spreading in the studied structures is carried out on the basis of the concept of thermal diffusivity. For transistor structures the area and distribution of the heat flow cross-section are determined. On the basis of the measurements the thermal parameters of high-power bipolar transistors is evaluated, in particular, the structure of their thermal resistance. For all of the measured samples is obtained that the thermal resistance of the layer planting crystal makes a defining contribution to the internal thermal resistance of transistors. In the transition layer at the border of semiconductor-solder the thermal resistance increases due to changes in the mechanism of heat transfer. Defects in this area in the form of delamination of solder, voids and cracks lead to additional growth of thermal resistance caused by the reduction of the active square of the transition layer. Method of thermal relaxation differential spectrometry allows effectively control the distribution of heat flow in high-power semiconductor devices, which is important for improving the design, improve the quality of landing crystals of power

  6. The degree of hydration assessment of blended cement pastes by differential thermal and thermogravimetric analysis. Morphological evolution of the solid phases

    International Nuclear Information System (INIS)

    Monteagudo, S.M.; Moragues, A.; Gálvez, J.C.; Casati, M.J.; Reyes, E.

    2014-01-01

    Highlights: • A proposal of hydration degree calculation for blended cement pastes is presented. • The method is based both on the contributions of various authors and on DTA–TG results. • Paste and mortar specimens with BFS, FA and SF mineral admixtures were used. • The evaluation of CH gives information on hydration and pozzolanic reactions. • The assessment of α provides an insight into future strength evolution. - Abstract: The degree of hydration assessment of cement paste from differential thermal and thermogravimetric analysis data has been performed by several authors that have offered a number of proposals for technical application to blended cements. In this paper, two calculation methods are studied in detail. Then, a proposal of the degree of hydration calculation for blended cements, based on the analysis of experimental results of DTA–TG, is presented. The proposed method combines the contributions of the authors and allows straightforward calculation of the degree of hydration from the experimental results. Validation of the methodology was performed by macroscopic and microstructural tests through paste and mortar specimens with blast furnace slag, flying ash and silica fume mineral admixtures bei(g)ng used. Tests of scanning electron microscopy with an energy dispersive analyser on paste specimens, and of mechanical strength on mortar specimens with the same percentages of substitution, were performed. They showed good agreement with the information derived from the differential thermal and thermogravimetric analysis data

  7. Characterization of thermal reaction of aluminum/copper (II) oxide/poly(tetrafluoroethene) nanocomposite by thermogravimetric analysis, differential scanning calorimetry, mass spectrometry and X-ray diffraction

    International Nuclear Information System (INIS)

    Li, Xiangyu; Yang, Hongtao; Li, Yan-chun

    2015-01-01

    Highlights: • The thermal reaction properties of the Al/CuO/PTFE nanocomposite were investigated. • The Al/PTFE and CuO/PTFE nanocomposites were prepared and tested for comparison. • TG/DSC–MS and XRD analysis were performed. • PTFE is oxidizing Al and reducing CuO during the thermal decomposition. - Abstract: The application of fluoropolymers as reactive agent in energetic materials have attracted significant interest recently. In this study, the thermal reaction properties of the aluminum nanoparticles/copper (II) oxide nanoparticles/poly(tetrafluoroethene) (Al-NPs/CuO-NPs/PTFE) nanocomposite (mass ratio of Al-NPs/CuO-NPs/PTFE = 20/60/20) were investigated by means of thermogravimetry/differential scanning calorimetry–mass spectrometry (TG/DSC–MS) and X-ray diffraction (XRD) analyses. The Al-NPs/PTFE (mass ratio of Al-NPs/PTFE = 50/50) and CuO-NPs/PTFE (mass ratio of CuO-NPs/PTFE = 75/25) nanocomposites were also prepared and tested for comparison. It is observed that PTFE is acting as both oxidizer and reducer during the thermal decomposition process of Al-NPs/CuO-NPs/PTFE nanocomposites. Before 615 °C, PTFE is oxidized by CuO-NPs and oxidizing Al-NPs, resulting mass reduction. After 615 °C, the excessive aluminum and copper (I)/copper (II) oxide will proceed the exothermic condensed phase reaction.

  8. Pyrolysis characteristics and kinetic parameters determination of biomass fuel powders by differential thermal gravimetric analysis (TGA/DTG)

    International Nuclear Information System (INIS)

    El-Sayed, Saad A.; Mostafa, M.E.

    2014-01-01

    Highlights: • The sugarcane bagasse powder has better energy value compared to the cotton stalks. • Bagasse moisture is entrained in its cell walls and its evaporation needs more energy. • The cotton stalks is more reactive and readily combustible than the bagasse powders. • A lower E and A 0 has been found for bagasse compared with cotton stalks powders. • Calculated E of bagasse and cotton stalks by direct and integral methods are different. - Abstract: The kinetics of the thermal decomposition of the two biomass materials (sugarcane bagasse and cotton stalks powders) were evaluated using a differential thermo-gravimetric analyzer under a non-isothermal condition. Two distinct reaction zones were observed for the two biomasses. The direct Arrhenius plot method and the integral method were applied for determination of kinetic parameters: activation energy, pre-exponential factor, and order of reaction. The weight loss curve showed that pyrolysis of sugarcane bagasse and cotton stalks took place mainly in the range of 200–500 °C. The activation energy of the sugarcane bagasse powder obtained by the direct Arrhenius plot method ranged between 43 and 53.5 kJ/mol. On the other side, the integral method shows larger values of activation energy (77–87.7 kJ/mol). The activation energy of the cotton stalks powder obtained by the direct Arrhenius plot method was ranged between 98.5 and 100.2 kJ/mol, but the integral method shows larger values of activation energy (72.5–127.8 kJ/mol)

  9. A comprehensive physicochemical, thermal, and spectroscopic characterization of zinc (II) chloride using X-ray diffraction, particle size distribution, differential scanning calorimetry, thermogravimetric analysis/differential thermogravimetric analysis, ultraviolet-visible, and Fourier transform-infrared spectroscopy.

    Science.gov (United States)

    Trivedi, Mahendra Kumar; Sethi, Kalyan Kumar; Panda, Parthasarathi; Jana, Snehasis

    2017-01-01

    Zinc chloride is an important inorganic compound used as a source of zinc and has other numerous industrial applications. Unfortunately, it lacks reliable and accurate physicochemical, thermal, and spectral characterization information altogether. Hence, the authors tried to explore in-depth characterization of zinc chloride using the modern analytical technique. The analysis of zinc chloride was performed using powder X-ray diffraction (PXRD), particle size distribution, differential scanning calorimetry (DSC), thermogravimetric analysis/differential thermogravimetric analysis (TGA/DTG), ultraviolet-visible spectroscopy (UV-vis), and Fourier transform-infrared (FT-IR) analytical techniques. The PXRD patterns showed well-defined, narrow, sharp, and the significant peaks. The crystallite size was found in the range of 14.70-55.40 nm and showed average crystallite size of 41.34 nm. The average particle size was found to be of 1.123 ( d 10 ), 3.025 ( d 50 ), and 6.712 ( d 90 ) μm and average surface area of 2.71 m 2 /g. The span and relative span values were 5.849 μm and 1.93, respectively. The DSC thermogram showed a small endothermic inflation at 308.10°C with the latent heat (ΔH) of fusion 28.52 J/g. An exothermic reaction was observed at 449.32°C with the ΔH of decomposition 66.10 J/g. The TGA revealed two steps of the thermal degradation and lost 8.207 and 89.72% of weight in the first and second step of degradation, respectively. Similarly, the DTG analysis disclosed T max at 508.21°C. The UV-vis spectrum showed absorbance maxima at 197.60 nm (λ max ), and FT-IR spectrum showed a peak at 511/cm might be due to the Zn-Cl stretching. These in-depth, comprehensive data would be very much useful in all stages of nutraceuticals/pharmaceuticals formulation research and development and other industrial applications.

  10. Construction of a differential thermal analysis installation; Realisation d'une installation d'analyse thermique differentielle

    Energy Technology Data Exchange (ETDEWEB)

    Branche, G; Chantret, F [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    The authors are indicating the characteristics of a D.T.A. installation they built. Experimental rooms, ovens, thermal regulation, recording methods are thoroughly described, with outlining of the requirements to obtain a high sensitivity. Numerous D.T.A. curves relating to argillaceous substances, bituminous shales, and uraniferous compounds are given. (author) [French] Les auteurs donnent les caracteristiques de l'installation d'Analyse Thermique Differentielle qu'ils ont construits. Ils decrivent en detail les chambres d'experiences, les fours, la regulation thermique, l'enregistrement, en insistant sur les conditions necessaires pour obtenir une sensibilite elevee. Ils donnent de nombreuses courbes differentielles relatives des produits argileux, des schistes bitumineux et des composes uraniferes. (auteur)

  11. Molecular thermal transistor: Dimension analysis and mechanism

    Science.gov (United States)

    Behnia, S.; Panahinia, R.

    2018-04-01

    Recently, large challenge has been spent to realize high efficient thermal transistors. Outstanding properties of DNA make it as an excellent nano material in future technologies. In this paper, we introduced a high efficient DNA based thermal transistor. The thermal transistor operates when the system shows an increase in the thermal flux despite of decreasing temperature gradient. This is what called as negative differential thermal resistance (NDTR). Based on multifractal analysis, we could distinguish regions with NDTR state from non-NDTR state. Moreover, Based on dimension spectrum of the system, it is detected that NDTR state is accompanied by ballistic transport regime. The generalized correlation sum (analogous to specific heat) shows that an irregular decrease in the specific heat induces an increase in the mean free path (mfp) of phonons. This leads to the occurrence of NDTR.

  12. Thermal analysis methods in the characterization of photocatalytic titania precursors

    Czech Academy of Sciences Publication Activity Database

    Pulišová, Petra; Večerníková, Eva; Maříková, Monika; Balek, V.; Boháček, Jaroslav; Šubrt, Jan

    2012-01-01

    Roč. 108, č. 2 (2012), s. 489-492 ISSN 1388-6150 R&D Projects: GA MŠk 1M0577 Institutional research plan: CEZ:AV0Z40320502 Keywords : differential thermal analysis * thermogravimetry * emanation thermal analysis * titanium dioxide * photocatalyst Subject RIV: CA - Inorganic Chemistry Impact factor: 1.982, year: 2012

  13. An Integrated Approach to Thermal Analysis of Pharmaceutical Solids

    Science.gov (United States)

    Riley, Shelley R. Rabel

    2015-01-01

    A three-tiered experiment for undergraduate Instrumental Analysis students is presented in which students characterize the solid-state thermal behavior of an active pharmaceutical ingredient (acetaminophen) and excipient (a-lactose hydrate) using differential scanning calorimetry, thermogravimetric analysis, and thermal microscopy. Students are…

  14. LOFT differential pressure uncertainty analysis

    International Nuclear Information System (INIS)

    Evans, R.P.; Biladeau, G.L.; Quinn, P.A.

    1977-03-01

    A performance analysis of the LOFT differential pressure (ΔP) measurement is presented. Along with completed descriptions of test programs and theoretical studies that have been conducted on the ΔP, specific sources of measurement uncertainty are identified, quantified, and combined to provide an assessment of the ability of this measurement to satisfy the SDD 1.4.1C (June 1975) requirement of measurement of differential pressure

  15. Existence of negative differential thermal conductance in one-dimensional diffusive thermal transport

    Science.gov (United States)

    Hu, Jiuning; Chen, Yong P.

    2013-06-01

    We show that in a finite one-dimensional (1D) system with diffusive thermal transport described by the Fourier's law, negative differential thermal conductance (NDTC) cannot occur when the temperature at one end is fixed and there are no abrupt junctions. We demonstrate that NDTC in this case requires the presence of junction(s) with temperature-dependent thermal contact resistance (TCR). We derive a necessary and sufficient condition for the existence of NDTC in terms of the properties of the TCR for systems with a single junction. We show that under certain circumstances we even could have infinite (negative or positive) differential thermal conductance in the presence of the TCR. Our predictions provide theoretical basis for constructing NDTC-based devices, such as thermal amplifiers, oscillators, and logic devices.

  16. Thermal rectification and negative differential thermal conductance in harmonic chains with nonlinear system-bath coupling

    Science.gov (United States)

    Ming, Yi; Li, Hui-Min; Ding, Ze-Jun

    2016-03-01

    Thermal rectification and negative differential thermal conductance were realized in harmonic chains in this work. We used the generalized Caldeira-Leggett model to study the heat flow. In contrast to most previous studies considering only the linear system-bath coupling, we considered the nonlinear system-bath coupling based on recent experiment [Eichler et al., Nat. Nanotech. 6, 339 (2011), 10.1038/nnano.2011.71]. When the linear coupling constant is weak, the multiphonon processes induced by the nonlinear coupling allow more phonons transport across the system-bath interface and hence the heat current is enhanced. Consequently, thermal rectification and negative differential thermal conductance are achieved when the nonlinear couplings are asymmetric. However, when the linear coupling constant is strong, the umklapp processes dominate the multiphonon processes. Nonlinear coupling suppresses the heat current. Thermal rectification is also achieved. But the direction of rectification is reversed compared to the results of weak linear coupling constant.

  17. Thermal analysis with expendable cartridge

    International Nuclear Information System (INIS)

    Susaki, K.; Landgraf, F.J.G.

    1981-01-01

    The pratical method of thermal analysis with expendable cartridge and some aspects of its use are presented. The results of the method applied to the system Nb-Mn are presented together with data from microprobe. (Author) [pt

  18. Thermal Analysis of Solar Panels

    Science.gov (United States)

    Barth, Nicolas; de Correia, João Pedro Magalhães; Ahzi, Saïd; Khaleel, Mohammad Ahmed

    In this work, we propose to analyze the thermal behavior of PV panels using finite element simulations (FEM). We applied this analysis to compute the temperature distribution in a PV panel BP 350 subjected to different atmospheric conditions. This analysis takes into account existing formulations in the literature and, based on NOCT conditions, meteorological data was used to validate our approach for different wind speed and solar irradiance. The electrical performance of the PV panel was also studied. The proposed 2D FEM analysis is applied to different region's climates and was also used to consider the role of thermal inertia on the optimization of the PV device efficiency.

  19. Mantle differentiation and thermal evolution of Mars, Mercury, and Venus

    International Nuclear Information System (INIS)

    Spohn, T.

    1991-01-01

    In the present models for the thermal evolution of Mercury, Venus, and Mars encompass core and mantle chemical differentiation, lithospheric growth, and volcanic heat-transfer processes. Calculation results indicate that crust and lithosphere thicknesses are primarily dependent on planet size as well as the bulk concentration of planetary radiogenic elements and the lithosphere's thermal conductivity. The evidence for Martian volcanism for at least 3.5 Gyr, and in Mercury for up to 1 Gyr, in conjunction with the presence of a magnetic field on Mercury and its absence on Mars, suggest the dominance of a lithospheric conduction heat-transfer mechanism in these planets for most of their thermal history; by contrast, volcanic heat piping may have been an important heat-transfer mechanism on Venus. 50 refs

  20. Thermal analysis applied to irradiated propolis

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Andrea Harumi; Machado, Luci Brocardo; Mastro, N.L. del E-mail: nelida@usp.br

    2002-03-01

    Propolis is a resinous hive product, collected by bees. Raw propolis requires a decontamination procedure and irradiation appears as a promising technique for this purpose. The valuable properties of propolis for food and pharmaceutical industries have led to increasing interest in its technological behavior. Thermal analysis is a chemical analysis that gives information about changes on heating of great importance for technological applications. Ground propolis samples were {sup 60}Co gamma irradiated with 0 and 10 kGy. Thermogravimetry curves shown a similar multi-stage decomposition pattern for both irradiated and unirradiated samples up to 600 deg. C. Similarly, through differential scanning calorimetry , a coincidence of melting point of irradiated and unirradiated samples was found. The results suggest that the irradiation process do not interfere on the thermal properties of propolis when irradiated up to 10 kGy.

  1. Multidimensional real analysis I differentiation

    CERN Document Server

    Duistermaat, J J; van Braam Houckgeest, J P

    2004-01-01

    Part one of the authors' comprehensive and innovative work on multidimensional real analysis. This book is based on extensive teaching experience at Utrecht University and gives a thorough account of differential analysis in multidimensional Euclidean space. It is an ideal preparation for students who wish to go on to more advanced study. The notation is carefully organized and all proofs are clean, complete and rigorous. The authors have taken care to pay proper attention to all aspects of the theory. In many respects this book presents an original treatment of the subject and it contains man

  2. Applied analysis and differential equations

    CERN Document Server

    Cârj, Ovidiu

    2007-01-01

    This volume contains refereed research articles written by experts in the field of applied analysis, differential equations and related topics. Well-known leading mathematicians worldwide and prominent young scientists cover a diverse range of topics, including the most exciting recent developments. A broad range of topics of recent interest are treated: existence, uniqueness, viability, asymptotic stability, viscosity solutions, controllability and numerical analysis for ODE, PDE and stochastic equations. The scope of the book is wide, ranging from pure mathematics to various applied fields such as classical mechanics, biomedicine, and population dynamics.

  3. The (CuGaSe{sub 2}){sub 1-x}(MgSe){sub x} alloy system (0{<=}x{<=}0.5): X-ray diffraction, energy dispersive spectrometry and differential thermal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Grima Gallardo, P.; Munoz, M.; Ruiz, J. [Centro de Estudios en Semiconductores (C.E.S.), Dpto. Fisica, Fac. Ciencias, La Hechicera, Merida (Venezuela); Delgado, G.E. [Laboratorio de Cristalografia, Dpto. Quimica, Fac. Ciencias, Universidad de Los Andes, Merida 5101 (Venezuela); Briceno, J.M. [Laboratorio de Analisis Quimico y Estructural (LAQUEM), Dpto. Fisica, Fac. Ciencias, La Hechicera, Merida (Venezuela)

    2004-07-01

    The (CuGaSe{sub 2}){sub 1-x}(MgSe){sub x} alloy system (0differential thermal analysis. The solubility of MgSe in CuGaSe{sub 2} was found to be nearly complete for all the compositions studied, although traces of MgSe appear as a secondary phase at x{>=}0.15. All the alloys showed the chalcopyrite structure and the lattice parameters of the unit cell do not follow a linear behavior but showed a soft local maximum at x {proportional_to} 0.15. In the single-phase field, the increasing behavior of the lattice parameters can be reproduced using an extension for quaternary alloys of Jaffe and Zunger's model for chalcopyrites. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. Thermal mapping of mountain slopes on Mars by application of a Differential Apparent Thermal Inertia technique

    Science.gov (United States)

    Kubiak, Marta; Mège, Daniel; Gurgurewicz, Joanna; Ciazela, Jakub

    2015-04-01

    Thermal inertia (P) is an important property of geologic surfaces that essentially describes the resistance to temperature (T) change as heat is added. Most remote sensing data describe the surface only. P is a volume property that is sensitive to the composition of the subsurface, down to a depth reached by the diurnal heating wave. As direct measurement of P is not possible on Mars, thermal inertia models (Fergason et al., 2006) and deductive methods (the Apparent Thermal Inertia: ATI and Differential Apparent Thermal Inertia: DATI) are used to estimate it. ATI is computed as (1 - A) / (Tday - Tnight), where A is albedo. Due to the lack of the thermal daytime images with maximum land surface temperature (LST) and nighttime images with minimum LST in Valles Marineris region, the ATI method is difficult to apply. Instead, we have explored the DATI technique (Sabol et al., 2006). DATI is calculated based on shorter time (t) intervals with a high |ΔT/Δt| gradient (in the morning or in the afternoon) and is proportional to the day/night temperature difference (ATI), and hence P. Mars, which exhibits exceptionally high |ΔT/Δt| gradients due to the lack of vegetation and thin atmosphere, is especially suitable for the DATI approach. Here we present a new deductive method for high-resolution differential apparent thermal inertia (DATI) mapping for areas of highly contrasted relief (e.g., Valles Marineris). Contrary to the thermal inertia models, our method takes local relief characteristics (slopes and aspects) into account. This is crucial as topography highly influences A and ΔT measurements. In spite of the different approach, DATI values in the flat areas are in the same range as the values obtained by Fergason et al. (2006). They provide, however, more accurate information for geological interpretations of hilly or mountainous terrains. Sabol, D. E., Gillespie, A. R., McDonald, E., and Danilina, I., 2006. Differential Thermal Inertia of Geological Surfaces. In

  5. The (AgInSe2)1-x(VSe)x system (0≤x≤0.5): X-ray diffraction and differential thermal analysis measurements

    International Nuclear Information System (INIS)

    Duran, S.; Grima, P.; Quintero, M.; Ruiz, J.; Munoz, M.; Ceballos, L.; Briceno, J.M.; Romero, H.

    2005-01-01

    Polycrystalline samples of the (AgInSe 2 ) 1-x (VSe) x system were prepared by the melt and anneal method. The anneal temperature was 900 K and the anneal time one month. The step composition was 0.1 and the weight of each sample approximately 1 g. Additionally, the composition x=1/3 was also prepared, since these alloys have been reported as electronic, i.e. definite compounds exist in the diagram at precise values of composition, one of them x=1/3. The stoichiometric relation of the samples was investigated by SEM technique. The experimental values, in average, are very close to the nominal values, all of them lying inside the interval of the experimental error (±5%). X-Ray Diffraction (XRD) and Differential Thermal Analysis (DTA) techniques were used for characterization of the alloy samples. Guinier photographs were obtained for all the samples and unit cell parameters were calculated using the available software for indexation. The diffraction patterns show sharp lines indicating good thermal equilibrium of the samples. Transition temperatures obtained from DTA measurements were manually obtained from the T vs. T graph with the criteria that the transition occurs at the intersection of the base line with the slope of the thermal transition peak, as usually. From the analysis of the experimental results it was observed that the solid solubility of VSe in AgInSe 2 is approximately 20%, i.e. the single-phase region exists in the composition range 0≤x 0.2 at least two phases coexist. A schematic T-x phase diagram is proposed. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. The (AgInSe{sub 2}){sub 1-x}(VSe){sub x} system (0{<=}x{<=}0.5): X-ray diffraction and differential thermal analysis measurements

    Energy Technology Data Exchange (ETDEWEB)

    Duran, S.; Grima, P.; Quintero, M.; Ruiz, J. [Centro de Estudio en Semiconductores (C.E.S.), Dpto. Fisica, Fac. Ciencias, Universidad de Los Andes, Merida (Venezuela); Munoz, M. [Centro de Estudio en Semiconductores (C.E.S.), Dpto. Fisica, Fac. Ciencias, Universidad de Los Andes, Merida (Venezuela); Ceballos, L. [Laboratorio de Cristalografia, Dpto. Quimica, Fac. Ciencias, Universidad de Los Andes, Merida (Venezuela); Briceno, J.M. [Laboratorio de Analisis Quimico y Estructural (LAQUEM), Dpto. Fisica, Fac. Ciencias, Universidad de Los Andes, Merida (Venezuela); Romero, H. [Laboratorio de Magnetismo de Solidos, Dpto. Fisica, Fac. Ciencias, Universidad de Los Andes, Merida (Venezuela)

    2005-08-01

    Polycrystalline samples of the (AgInSe{sub 2}){sub 1-x}(VSe){sub x} system were prepared by the melt and anneal method. The anneal temperature was 900 K and the anneal time one month. The step composition was 0.1 and the weight of each sample approximately 1 g. Additionally, the composition x=1/3 was also prepared, since these alloys have been reported as electronic, i.e. definite compounds exist in the diagram at precise values of composition, one of them x=1/3. The stoichiometric relation of the samples was investigated by SEM technique. The experimental values, in average, are very close to the nominal values, all of them lying inside the interval of the experimental error ({+-}5%). X-Ray Diffraction (XRD) and Differential Thermal Analysis (DTA) techniques were used for characterization of the alloy samples. Guinier photographs were obtained for all the samples and unit cell parameters were calculated using the available software for indexation. The diffraction patterns show sharp lines indicating good thermal equilibrium of the samples. Transition temperatures obtained from DTA measurements were manually obtained from the T vs. T graph with the criteria that the transition occurs at the intersection of the base line with the slope of the thermal transition peak, as usually. From the analysis of the experimental results it was observed that the solid solubility of VSe in AgInSe{sub 2} is approximately 20%, i.e. the single-phase region exists in the composition range 0{<=}x<0.2, whereas for x>0.2 at least two phases coexist. A schematic T-x phase diagram is proposed. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Differential Fault Analysis on CLEFIA

    Science.gov (United States)

    Chen, Hua; Wu, Wenling; Feng, Dengguo

    CLEFIA is a new 128-bit block cipher proposed by SONY corporation recently. The fundamental structure of CLEFIA is a generalized Feistel structure consisting of 4 data lines. In this paper, the strength of CLEFIA against the differential fault attack is explored. Our attack adopts the byte-oriented model of random faults. Through inducing randomly one byte fault in one round, four bytes of faults can be simultaneously obtained in the next round, which can efficiently reduce the total induce times in the attack. After attacking the last several rounds' encryptions, the original secret key can be recovered based on some analysis of the key schedule. The data complexity analysis and experiments show that only about 18 faulty ciphertexts are needed to recover the entire 128-bit secret key and about 54 faulty ciphertexts for 192/256-bit keys.

  8. Automatic differentiation algorithms in model analysis

    NARCIS (Netherlands)

    Huiskes, M.J.

    2002-01-01

    Title: Automatic differentiation algorithms in model analysis
    Author: M.J. Huiskes
    Date: 19 March, 2002

    In this thesis automatic differentiation algorithms and derivative-based methods

  9. Equipment for dekryptonation thermal analysis

    International Nuclear Information System (INIS)

    Lukac, P.; Pruzinec, J.

    Emanation thermal analysis is used for studying changes in the dynamic temperature conditions during kinetics studies of some reactions in solids. A kryptonated sample is placed in a furnace with a programmable temperature controller. 85 Kr released from the sample is entrapped by the carrier gas in a through-flow Geiger-Mueller detector. The detector signal is processed into an integral form and recorded. Examples are given of the study of modification transformations in NH 4 NO 3 , pearlite and PVC. (M.D.)

  10. THERMAL CONDUCTIVITY ANALYSIS OF GASES

    Science.gov (United States)

    Clark, W.J.

    1949-06-01

    This patent describes apparatus for the quantitative analysis of a gaseous mixture at subatmospheric pressure by measurement of its thermal conductivity. A heated wire forms one leg of a bridge circuit, while the gas under test is passed about the wire at a constant rate. The bridge unbalance will be a measure of the change in composition of the gas, if compensation is made for the effect due to gas pressure change. The apparatus provides a voltage varying with fluctuations of pressure in series with the indicating device placed across the bridge, to counterbalance the voltage change caused by fluctuations in the pressure of the gaseous mixture.

  11. Thermal Power Plant Performance Analysis

    CERN Document Server

    2012-01-01

    The analysis of the reliability and availability of power plants is frequently based on simple indexes that do not take into account the criticality of some failures used for availability analysis. This criticality should be evaluated based on concepts of reliability which consider the effect of a component failure on the performance of the entire plant. System reliability analysis tools provide a root-cause analysis leading to the improvement of the plant maintenance plan.   Taking in view that the power plant performance can be evaluated not only based on  thermodynamic related indexes, such as heat-rate, Thermal Power Plant Performance Analysis focuses on the presentation of reliability-based tools used to define performance of complex systems and introduces the basic concepts of reliability, maintainability and risk analysis aiming at their application as tools for power plant performance improvement, including: ·         selection of critical equipment and components, ·         defini...

  12. The micro thermal analysis of polymers

    International Nuclear Information System (INIS)

    Grandy, David Brian

    2002-01-01

    This study is concerned with the development of micro-thermal analysis as a technique for characterising heterogeneous polymers. It is divided into two main parts. In the first part, the use of miniature Wollaston wire near-field thermal probes mounted in an atomic force microscope (AFM) to carry out highly localised thermal analysis (L-TA) of amorphous and semi-crystalline polymers is investigated. Here, the temperature of the probe sensor or tip is scanned over a pre-selected temperature range while in contact with the surface of a sample. It is thereby used to heat a volume of material of the order of several cubic micrometres. The effect of the glass transition, cold crystallisation, melting and degree of crystallinity on L-TA measurements is investigated. The materials used are poly(ethylene terephthalate), polystyrene and fluorocarbon-coated poly(butylene terephthalate). The primary measurements are the micro- or localised analogues of thermomechanical analysis (L-TMA) and differential thermal analysis (L-DTA). The effect of applying a sinusoidal modulation to the temperature of the probe is also investigated. In the second part, conventional ultra-sharp inert AFM probes are used, in conjunction with a variable-temperature microscope stage, to conduct variable-temperature mechanical property-based imaging of phase-separated polymer blends and copolymers. Here, the temperature of the whole sample is varied and the temperature of the probe tip remains essentially the same as that of the sample. The primary AFM imaging mode is pulsed force mode (PFM-AFM). This is an intermittent contact (IC) method in which a mechanical modulation is applied to the probe cantilever. The methodology is demonstrated on a model 50:50 blend of polystyrene and poly(methyl methacrylate) (PS-PMMA) and three segmented polyurethane (SPU) elastomers containing different chain extenders. In doing so, it is shown that PFM-AFM imaging can be carried out successfully over a temperature range

  13. Response of Turkey Muscle Satellite Cells to Thermal Challenge. II. Transcriptome Effects in Differentiating Cells

    Directory of Open Access Journals (Sweden)

    Kent M. Reed

    2017-11-01

    Full Text Available Background: Exposure of poultry to extreme temperatures during the critical period of post-hatch growth can seriously affect muscle development and thus compromise subsequent meat quality. This study was designed to characterize transcriptional changes induced in turkey muscle satellite cells by thermal challenge during differentiation. Our goal is to better define how thermal stress alters breast muscle ultrastructure and subsequent development.Results: Skeletal muscle satellite cells previously isolated from the Pectoralis major muscle of 7-wk-old male turkeys (Meleagris gallopavo from two breeding lines: the F-line (16 wk body weight-selected and RBC2 (randombred control line were used in this study. Cultured cells were induced to differentiate at 38°C (control or thermal challenge temperatures of 33 or 43°C. After 48 h of differentiation, cells were harvested and total RNA was isolated for RNAseq analysis. Analysis of 39.9 Gb of sequence found 89% mapped to the turkey genome (UMD5.0, annotation 101 with average expression of 18,917 genes per library. In the cultured satellite cells, slow/cardiac muscle isoforms are generally present in greater abundance than fast skeletal isoforms. Statistically significant differences in gene expression were observed among treatments and between turkey lines, with a greater number of genes affected in the F-line cells following cold treatment whereas more differentially expressed (DE genes were observed in the RBC2 cells following heat treatment. Many of the most significant pathways involved signaling, consistent with ongoing cellular differentiation. Regulation of Ca2+ homeostasis appears to be significantly affected by temperature treatment, particularly cold treatment.Conclusions: Satellite cell differentiation is directly influenced by temperature at the level of gene transcription with greater effects attributed to selection for fast growth. At lower temperature, muscle-associated genes in the

  14. HRB-22 preirradiation thermal analysis

    International Nuclear Information System (INIS)

    Acharya, R.; Sawa, K.

    1995-05-01

    This report describes the preirradiation thermal analysis of the HRB-22 capsule designed for irradiation in the removable beryllium (RB) position of the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL). CACA-2 a heavy isotope and fission product concentration calculational code for experimental irradiation capsules was used to determine time dependent fission power for the fuel compacts. The Heat Engineering and Transfer in Nine Geometries (HEATING) computer code, version 7.2, was used to solve the steady-state heat conduction problem. The diameters of the graphite fuel body that contains the compacts and the primary pressure vessel were selected such that the requirements of running the compacts at an average temperature of < 1,250 C and not exceeding a maximum fuel temperature of 1,350 C was met throughout the four cycles of irradiation

  15. HANARO thermal hydraulic accident analysis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chul; Kim, Heon Il; Lee, Bo Yook; Lee, Sang Yong [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-06-01

    For the safety assessment of HANARO, accident analyses for the anticipated operational transients, accident scenarios and limiting accident scenarios were conducted. To do this, the commercial nuclear reactor system code. RELAP5/MOD2 was modified to RELAP5/KMRR; the thermal hydraulic correlations and the heat exchanger model was changed to incorporate HANARO characteristics. This report summarizes the RELAP/KMRR calculation results and the subchannel analyses results based on the RELAP/KMRR results. During the calculation, major concern was placed on the integrity of the fuel. For all the scenarios, the important accident analysis parameters, i.e., fuel centerline temperatures and the minimum critical heat flux ratio(MCHFR), satisfied safe design limits. It was verified, therefore, that the HANARO was safely designed. 21 tabs., 89 figs., 39 refs. (Author) .new.

  16. Differential thermal analysis microsystem for explosive detection

    DEFF Research Database (Denmark)

    Olsen, Jesper Kenneth; Greve, Anders; Senesac, L.

    2011-01-01

    as a small silicon nitride membrane incorporating heater elements and a temperature measurement resistor. In this manuscript the DTA system is described and tested by measuring calorimetric response of 3 different kinds of explosives (TNT, RDX and PETN). This project is carried out under the framework...

  17. Differential analysis of matrix convex functions II

    DEFF Research Database (Denmark)

    Hansen, Frank; Tomiyama, Jun

    2009-01-01

    We continue the analysis in [F. Hansen, and J. Tomiyama, Differential analysis of matrix convex functions. Linear Algebra Appl., 420:102--116, 2007] of matrix convex functions of a fixed order defined in a real interval by differential methods as opposed to the characterization in terms of divided...

  18. Selected papers on analysis and differential equations

    CERN Document Server

    Society, American Mathematical

    2010-01-01

    This volume contains translations of papers that originally appeared in the Japanese journal Sūgaku. These papers range over a variety of topics in ordinary and partial differential equations, and in analysis. Many of them are survey papers presenting new results obtained in the last few years. This volume is suitable for graduate students and research mathematicians interested in analysis and differential equations.

  19. Product differentiation during continuous-flow thermal gradient PCR.

    Science.gov (United States)

    Crews, Niel; Wittwer, Carl; Palais, Robert; Gale, Bruce

    2008-06-01

    A continuous-flow PCR microfluidic device was developed in which the target DNA product can be detected and identified during its amplification. This in situ characterization potentially eliminates the requirement for further post-PCR analysis. Multiple small targets have been amplified from human genomic DNA, having sizes of 108, 122, and 134 bp. With a DNA dye in the PCR mixture, the amplification and unique melting behavior of each sample is observed from a single fluorescent image. The melting behavior of the amplifying DNA, which depends on its molecular composition, occurs spatially in the thermal gradient PCR device, and can be observed with an optical resolution of 0.1 degrees C pixel(-1). Since many PCR cycles are within the field of view of the CCD camera, melting analysis can be performed at any cycle that contains a significant quantity of amplicon, thereby eliminating the cycle-selection challenges typically associated with continuous-flow PCR microfluidics.

  20. Investigation of magnetocaloric effect in La{sub 0.45}Pr{sub 0.25}Ca{sub 0.3}MnO{sub 3} by magnetic, differential scanning calorimetry and thermal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Aparnadevi, M; Barik, S K [Department of Physics, 2 Science Drive 3, National University of Singapore, Lower Kent Ridge Road, Singapore-117 452 (Singapore); Mahendiran, R [Department of Physics, 2 Science Drive 3, National University of Singapore, Lower Kent Ridge Road, Singapore-117 452 (Singapore)

    2012-10-15

    We investigated magnetocaloric effect in La{sub 0.45}Pr{sub 0.25}Ca{sub 0.3}MnO{sub 3} by direct methods (changes in temperature and latent heat) and indirect method (magnetization isotherms). This compound undergoes a first-order paramagnetic to ferromagnetic transition with T{sub C}=200 K upon cooling. The paramagnetic phase becomes unstable and it transforms into a ferromagnetic phase under the application of magnetic field, which results in a field-induced metamagnetic transition (FIMMT). The FIMMT is accompanied by release of latent heat and temperature of the sample as evidenced from differential scanning calorimetry and thermal analysis experiments. A large magnetic entropy change of {Delta}S{sub m}=-7.2 J kg{sup -1} K{sup -1} at T=212.5 K and refrigeration capacity of 228 J kg{sup -1} are found for a field change of {Delta}H=5 T. It is suggested that destruction of magnetic polarons and growth of ferromagnetic phase accompanied by a lattice volume change with increasing magnetic field is responsible for the large magnetocaloric effect in this compound. - Highlights: Black-Right-Pointing-Pointer We report magnetic entropy change measured by indirect and direct methods in La{sub 0.45}Pr{sub 0.25}Ca{sub 0.3}MnO{sub 3.} Black-Right-Pointing-Pointer Anomalous field-induced induced metamagnetic transition is found in the paramagnetic state. Black-Right-Pointing-Pointer A large reversible magnetic entropy change ({Delta}S{sub m}=7.2 J kg{sup -1} K{sup -1} for {Delta}H=5 T). Black-Right-Pointing-Pointer A large refrigeration capacity (RC=228 J kg{sup -1}). Black-Right-Pointing-Pointer Collapse of magnetic polarons is suggested as possible origin of the large MCE.

  1. Investigation of magnetocaloric effect in La0.45Pr0.25Ca0.3MnO3 by magnetic, differential scanning calorimetry and thermal analysis

    International Nuclear Information System (INIS)

    Aparnadevi, M.; Barik, S.K.; Mahendiran, R.

    2012-01-01

    We investigated magnetocaloric effect in La 0.45 Pr 0.25 Ca 0.3 MnO 3 by direct methods (changes in temperature and latent heat) and indirect method (magnetization isotherms). This compound undergoes a first-order paramagnetic to ferromagnetic transition with T C =200 K upon cooling. The paramagnetic phase becomes unstable and it transforms into a ferromagnetic phase under the application of magnetic field, which results in a field-induced metamagnetic transition (FIMMT). The FIMMT is accompanied by release of latent heat and temperature of the sample as evidenced from differential scanning calorimetry and thermal analysis experiments. A large magnetic entropy change of ΔS m =−7.2 J kg −1 K −1 at T=212.5 K and refrigeration capacity of 228 J kg −1 are found for a field change of ΔH=5 T. It is suggested that destruction of magnetic polarons and growth of ferromagnetic phase accompanied by a lattice volume change with increasing magnetic field is responsible for the large magnetocaloric effect in this compound. - Highlights: ► We report magnetic entropy change measured by indirect and direct methods in La 0.45 Pr 0.25 Ca 0.3 MnO 3. ► Anomalous field-induced induced metamagnetic transition is found in the paramagnetic state. ► A large reversible magnetic entropy change (ΔS m =7.2 J kg −1 K −1 for ΔH=5 T). ► A large refrigeration capacity (RC=228 J kg −1 ). ► Collapse of magnetic polarons is suggested as possible origin of the large MCE.

  2. Analysis of thermal process of pozzolan production

    Directory of Open Access Journals (Sweden)

    Mejía De Gutiérrez, R.

    2004-06-01

    Full Text Available The objective of this study was evaluated the effect of heat treatment parameters on the pozzolanic activity of natural kaolin clays. The experimental design included three factors: kaolin type, temperature and time. Five types of Colombian kaolin clays were thermally treated from 400 to 1000 °C by 1, 2, and 3 hours. The raw materials and the products obtained were characterized by X-Ray Diffraction (XRD, Fourier Transform Infrared Spectroscopy (FTIR and Differential Thermal / Thermo gravimetric Analysis (DTAJ TGA. The pozzolanic activity of thermally treated samples according to chemical and mechanical tests was investigated.

    El objetivo de este estudio fue caracterizar las variables de producción de un metacaolín de alta reactividad puzolánica. El diseño experimental utilizó un modelo factorial que consideró tres factores: tipo de caolín (C, temperatura y tiempo. A partir del conocimiento de las fuentes de caolín y el contacto con proveedores y distribuidores del producto a nivel nacional, se seleccionaron cinco muestras representativas de arcillas caoliníticas, las cuales se sometieron a un tratamiento térmico entre 400 y 1.000 ºC (seis niveles de temperatura y tres tiempos de exposición, 1, 2 y 3 horas. Los caolines de origen y los productos obtenidos de cada proceso térmico fueron evaluados mediante técnicas de tipo físico y químico, difracción de rayos X, infrarrojo FTIR, y análisis térmico diferencial (OTA, TGA. Complementariamente se evalúa la actividad puzolánica, tanto química como mecánica, del producto obtenido a diferentes temperaturas de estudio.

  3. The Peltier driven frequency domain approach in thermal analysis.

    Science.gov (United States)

    De Marchi, Andrea; Giaretto, Valter

    2014-10-01

    The merits of Frequency Domain analysis as a tool for thermal system characterization are discussed, and the complex thermal impedance approach is illustrated. Pure AC thermal flux generation with negligible DC component is possible with a Peltier device, differently from other existing methods in which a significant DC component is intrinsically attached to the generated AC flux. Such technique is named here Peltier Driven Frequency Domain (PDFD). As a necessary prerequisite, a novel one-dimensional analytical model for an asymmetrically loaded Peltier device is developed, which is general enough to be useful in most practical situations as a design tool for measurement systems and as a key for the interpretation of experimental results. Impedance analysis is possible with Peltier devices by the inbuilt Seebeck effect differential thermometer, and is used in the paper for an experimental validation of the analytical model. Suggestions are then given for possible applications of PDFD, including the determination of thermal properties of materials.

  4. Transient thermal analysis of Vega launcher structures

    Energy Technology Data Exchange (ETDEWEB)

    Gori, F. [University of Rome ' Tor Vergata' , Rome (Italy); De Stefanis, M. [Thales Alenia Space Italia, Rome (Italy); Worek, W.M. [University of Illinois at Chicago, Chicago (United States)], E-mail: wworek@uic.edu; Minkowycz, W.J. [University of Illinois at Chicago, Chicago (United States)

    2008-12-15

    A transient thermal analysis is carried out to verify the base cover thermal protection system of Vega 2nd stage Solid Rocket Motor (SRM) and the flange coupling of the inter-stage 2/3. The analysis is performed with a finite element code. The work has developed suitable numerical Fortran subroutines to assign radiation and convection boundary conditions. The thermal behaviour of the structures is presented.

  5. Metallography and thermal analysis of ceramic nuclear fuels

    International Nuclear Information System (INIS)

    Tebaldi, V.

    1988-01-01

    The book contains two parts: the ceramography laboratory and the thermal treatment laboratory. After general remarks on sintering the first part includes sample preparation for ceramography (grinding, polishing, etching), microscopic examination and quantitative image analysis. The second part deals with temperature measurement, oxide/metal ratio determination, thermogravimetry, differential thermal analysis (DTA), melting point determination and constitution of phase diagrams. Installation of a Pu laboratory, sample decontamination, and research with a microprobe are described. 188 photomicrographs present the microstructure of ceramics based on U, Pu and higher actinides

  6. Introduction of Differential Scanning Calorimetry in a General Chemistry Laboratory Course: Determination of Thermal Properties of Organic Hydrocarbons

    Science.gov (United States)

    D'Amelia, Ronald; Franks, Thomas; Nirode, William F.

    2007-01-01

    In first-year general chemistry undergraduate courses, thermodynamics and thermal properties such as melting points and changes in enthalpy ([Delta]H) and entropy ([Delta]S) of phase changes are frequently discussed. Typically, classical calorimetric methods of analysis are used to determine [Delta]H of reactions. Differential scanning calorimetry…

  7. Temperature Modulated Nanomechanical Thermal Analysis

    DEFF Research Database (Denmark)

    Alves, Gustavo Marcati A.; Bose-Goswami, Sanjukta; Mansano, Ronaldo D.

    2018-01-01

    The response of microcantilever deflection to complex heating profiles was used to study thermal events like glass transition and enthalpy relaxation on nanograms of the biopolymer Poly(lactic-co-glycolic acid) (PLGA). The use of two heating rates enables the separation of effects on the deflection...... response that depends on previous thermal history (non-reversing signal) and effects that depends only on the heating rate variation (reversing signal). As these effects may appear superposed in the total response, temperature modulation can increase the measurement sensitivity to some thermal events when...

  8. The competition between thermal contraction and differentiation in the stress history of the moon

    Science.gov (United States)

    Kirk, Randolph L.; Stevenson, David J.

    1989-01-01

    The stress history of the moon is discussed, taking into consideration the effects of thermal contraction and differentiation. The amount of expansion caused by extracting basalt from undifferentiated lunar material is estimated taking account of the uncertainty in the knowledge of the appropriate compositions, and the resulting estimate of the expansion is used to compare the relative importance of the thermal and differentiation effects in the moon's volumetric history. The results of calculations show that differentiation is likely to be of major importance and, thus, thermal expansion is not the sole possible contributor to evolutionary changes in the lunar radius.

  9. Numerical Analysis of Partial Differential Equations

    CERN Document Server

    Lui, S H

    2011-01-01

    A balanced guide to the essential techniques for solving elliptic partial differential equations Numerical Analysis of Partial Differential Equations provides a comprehensive, self-contained treatment of the quantitative methods used to solve elliptic partial differential equations (PDEs), with a focus on the efficiency as well as the error of the presented methods. The author utilizes coverage of theoretical PDEs, along with the nu merical solution of linear systems and various examples and exercises, to supply readers with an introduction to the essential concepts in the numerical analysis

  10. Analysis of Anther Cell Differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Hong [Pennsylvania State Univ., University Park, PA (United States)

    2015-01-19

    This grant supports research on genes that regulate Arabidopsis anther development. The proposed research largely concerns that functions of two key regulatory genes: SPL and DYT1, which encode two putative transcription factors, as well as genes that interact with these genes. Last year, we reported progress in preparation for ChIP analysis with SPL and DYT1, in dyt1 and ams microarray experiments and initial data analysis, in functional analysis of one of the DYT1 target gene, MYB35.

  11. Thermal energy systems design and analysis

    CERN Document Server

    Penoncello, Steven G

    2015-01-01

    IntroductionThermal Energy Systems Design and AnalysisSoftwareThermal Energy System TopicsUnits and Unit SystemsThermophysical PropertiesEngineering DesignEngineering EconomicsIntroductionCommon Engineering Economics NomenclatureEconomic Analysis Tool: The Cash Flow DiagramTime Value of MoneyTime Value of Money ExamplesUsing Software to Calculate Interest FactorsEconomic Decision MakingDepreciation and TaxesProblemsAnalysis of Thermal Energy SystemsIntroductionNomenclatureThermophysical Properties of SubstancesSuggested Thermal Energy Systems Analysis ProcedureConserved and Balanced QuantitiesConservation of MassConservation of Energy (The First Law of Thermodynamics)Entropy Balance (The Second Law of Thermodynamics)Exergy Balance: The Combined LawEnergy and Exergy Analysis of Thermal Energy CyclesDetailed Analysis of Thermal Energy CyclesProblemsFluid Transport in Thermal Energy SystemsIntroductionPiping and Tubing StandardsFluid Flow FundamentalsValves and FittingsDesign and Analysis of Pipe NetworksEconomi...

  12. Multivariate analysis of microarray data: differential expression and differential connection.

    Science.gov (United States)

    Kiiveri, Harri T

    2011-02-01

    Typical analysis of microarray data ignores the correlation between gene expression values. In this paper we present a model for microarray data which specifically allows for correlation between genes. As a result we combine gene network ideas with linear models and differential expression. We use sparse inverse covariance matrices and their associated graphical representation to capture the notion of gene networks. An important issue in using these models is the identification of the pattern of zeroes in the inverse covariance matrix. The limitations of existing methods for doing this are discussed and we provide a workable solution for determining the zero pattern. We then consider a method for estimating the parameters in the inverse covariance matrix which is suitable for very high dimensional matrices. We also show how to construct multivariate tests of hypotheses. These overall multivariate tests can be broken down into two components, the first one being similar to tests for differential expression and the second involving the connections between genes. The methods in this paper enable the extraction of a wealth of information concerning the relationships between genes which can be conveniently represented in graphical form. Differentially expressed genes can be placed in the context of the gene network and places in the gene network where unusual or interesting patterns have emerged can be identified, leading to the formulation of hypotheses for future experimentation.

  13. Multivariate analysis of microarray data: differential expression and differential connection

    Directory of Open Access Journals (Sweden)

    Kiiveri Harri T

    2011-02-01

    Full Text Available Abstract Background Typical analysis of microarray data ignores the correlation between gene expression values. In this paper we present a model for microarray data which specifically allows for correlation between genes. As a result we combine gene network ideas with linear models and differential expression. Results We use sparse inverse covariance matrices and their associated graphical representation to capture the notion of gene networks. An important issue in using these models is the identification of the pattern of zeroes in the inverse covariance matrix. The limitations of existing methods for doing this are discussed and we provide a workable solution for determining the zero pattern. We then consider a method for estimating the parameters in the inverse covariance matrix which is suitable for very high dimensional matrices. We also show how to construct multivariate tests of hypotheses. These overall multivariate tests can be broken down into two components, the first one being similar to tests for differential expression and the second involving the connections between genes. Conclusion The methods in this paper enable the extraction of a wealth of information concerning the relationships between genes which can be conveniently represented in graphical form. Differentially expressed genes can be placed in the context of the gene network and places in the gene network where unusual or interesting patterns have emerged can be identified, leading to the formulation of hypotheses for future experimentation.

  14. Thermal analysis of iron hydroxide microspheres

    International Nuclear Information System (INIS)

    Turcanu, C.N.; Cornescu, M.

    1979-03-01

    The thermal treatment is an important step in the preparative technology of the iron oxids microspheres with well established mechanical, physical and chemical characteristics. The first indications on the heating procedure have been obtained from the thermal analysis on iron hydroxide microspheres prepared by the support precipitation and internal gelification methods. (author)

  15. Phenotypic and genetic differentiation among yellow monkeyflower populations from thermal and non-thermal soils in Yellowstone National Park.

    Science.gov (United States)

    Lekberg, Ylva; Roskilly, Beth; Hendrick, Margaret F; Zabinski, Catherine A; Barr, Camille M; Fishman, Lila

    2012-09-01

    In flowering plants, soil heterogeneity can generate divergent natural selection over fine spatial scales, and thus promote local adaptation in the absence of geographic barriers to gene flow. Here, we investigate phenotypic and genetic differentiation in one of the few flowering plants that thrives in both geothermal and non-thermal soils in Yellowstone National Park (YNP). Yellow monkeyflowers (Mimulus guttatus) growing at two geothermal ("thermal") sites in YNP were distinct in growth form and phenology from paired populations growing nearby ( 0.34), which were only weakly differentiated from each other (all F (ST) geothermal gradient in Yellowstone.

  16. Thermal Isolation and Differential Cooling of Heterogeneously Integrated Devices

    Science.gov (United States)

    2016-07-01

    negligible and only the interaction of the via, substrate, and film material play a role in keff,z. Figure 12: Evolution of keff,z of a TXV...integrated system considered in this work the CMOS power dissipation is negligible when compared to the dissipation of the power amplifier chiplets. As...Conf., pp. 111-121, 1994. [35] A. Bar-Cohen, Ed., Encyclopedia of Thermal Packaging. Set 1: Thermal Packaging Techniques. Singapore : World

  17. Quick Spacecraft Thermal Analysis Tool, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — For spacecraft design and development teams concerned with cost and schedule, the Quick Spacecraft Thermal Analysis Tool (QuickSTAT) is an innovative software suite...

  18. Probing the heat sources during thermal runaway process by thermal analysis of different battery chemistries

    Science.gov (United States)

    Zheng, Siqi; Wang, Li; Feng, Xuning; He, Xiangming

    2018-02-01

    Safety issue is very important for the lithium ion battery used in electric vehicle or other applications. This paper probes the heat sources in the thermal runaway processes of lithium ion batteries composed of different chemistries using accelerating rate calorimetry (ARC) and differential scanning calorimetry (DSC). The adiabatic thermal runaway features for the 4 types of commercial lithium ion batteries are tested using ARC, whereas the reaction characteristics of the component materials, including the cathode, the anode and the separator, inside the 4 types of batteries are measured using DSC. The peaks and valleys of the critical component reactions measured by DSC can match the fluctuations in the temperature rise rate measured by ARC, therefore the relevance between the DSC curves and the ARC curves is utilized to probe the heat source in the thermal runaway process and reveal the thermal runaway mechanisms. The results and analysis indicate that internal short circuit is not the only way to thermal runaway, but can lead to extra electrical heat, which is comparable with the heat released by chemical reactions. The analytical approach of the thermal runaway mechanisms in this paper can guide the safety design of commercial lithium ion batteries.

  19. Phylogenetic conservatism of thermal traits explains dispersal limitation and genomic differentiation of Streptomyces sister-taxa.

    Science.gov (United States)

    Choudoir, Mallory J; Buckley, Daniel H

    2018-06-07

    The latitudinal diversity gradient is a pattern of biogeography observed broadly in plants and animals but largely undocumented in terrestrial microbial systems. Although patterns of microbial biogeography across broad taxonomic scales have been described in a range of contexts, the mechanisms that generate biogeographic patterns between closely related taxa remain incompletely characterized. Adaptive processes are a major driver of microbial biogeography, but there is less understanding of how microbial biogeography and diversification are shaped by dispersal limitation and drift. We recently described a latitudinal diversity gradient of species richness and intraspecific genetic diversity in Streptomyces by using a geographically explicit culture collection. Within this geographically explicit culture collection, we have identified Streptomyces sister-taxa whose geographic distribution is delimited by latitude. These sister-taxa differ in geographic distribution, genomic diversity, and ecological traits despite having nearly identical SSU rRNA gene sequences. Comparative genomic analysis reveals genomic differentiation of these sister-taxa consistent with restricted gene flow across latitude. Furthermore, we show phylogenetic conservatism of thermal traits between the sister-taxa suggesting that thermal trait adaptation limits dispersal and gene flow across climate regimes as defined by latitude. Such phylogenetic conservatism of thermal traits is commonly associated with latitudinal diversity gradients for plants and animals. These data provide further support for the hypothesis that the Streptomyces latitudinal diversity gradient was formed as a result of historical demographic processes defined by dispersal limitation and driven by paleoclimate dynamics.

  20. Thermal analysis of rare earth gallates and aluminates

    International Nuclear Information System (INIS)

    O'Bryan, H.M.; Gallagher, P.K.; Berkstresser, G.W.; Brandle, C.D.

    1990-01-01

    Dilatometry, high-temperature x-ray diffraction, differential thermal analysis, and differential scanning calorimetry have been performed on LaGaO 3 , NdGaO 3 , PrGaO 3 , SmAlO 3 , and LaAlO 3 single crystals grown by the Czochralski technique. First order phase transitions have been located at 145 degree C for LaGaO 3 and 785 degree C for SmAlO 3 , and ΔH has been measured for the LaGaO 3 transition. Second order transitions have been identified for LaGaO 3 , PrGaO 3 , NdGaO 3 , and LaAlO 3 . The usefulness of these compounds as substrates for high temperature superconducting films is discussed in terms of thermal expansion matching

  1. Thermal Analysis of TRIO-CINEMA Mission

    Directory of Open Access Journals (Sweden)

    Jaegun Yoo

    2012-03-01

    Full Text Available Thermal analysis and control design are prerequisite essential to design the satellite. In the space environment, it makes satellite survive from extreme hot and cold conditions. In recent years CubeSat mission is developed for many kinds of purpose. Triplet Ionospheric Observatory (TRIO–CubeSat for Ion, Neutral, Electron, MAgnetic fields (CINEMA is required to weigh less than 3 kg and operate on minimal 3 W power. In this paper we describe the thermal analysis and control design for TRIO-CINEMA mission. For this thermal analysis, we made a thermal model of the CubeSat with finite element method and NX6.0 TMG software is used to simulate this analysis model. Based on this result, passive thermal control method has been applied to thermal design of CINEMA. In order to get the better conduction between solar panel and chassis, we choose aluminum 6061-T6 for the material property of standoff. We can increase the average temperature of top and bottom solar panels from -70°C to -40°C and decrease the average temperature of the magnetometer from +93°C to -4°C using black paint on the surface of the chassis, inside of top & bottom solar panels, and magnetometer.

  2. Estudo termoanalítico de comprimidos revestidos contendo captopril através de termogravimetria (TG e calorimetria exploratória diferencial (DSC Thermal analysis study of captopril coated tablets by thermogravimetry (TG and differential scanning calorimetry (DSC

    Directory of Open Access Journals (Sweden)

    Giovana Carolina Bazzo

    2005-09-01

    Full Text Available No presente trabalho foram desenvolvidos comprimidos de captopril revestidos com hidroxipropilmetilcelulose (HPMC, Opadry®, polivinilpirrolidona (PVP, Eudragit® E e goma laca. Foi realizado estudo termoanalítico do fármaco e das formulações através de termogravimetria (TG e calorimetria exploratória diferencial (DSC. Através da análise das curvas DSC verificou-se que não houve a ocorrência de interação entre o fármaco e os excipientes lactose, celulose microcristalina, croscarmelose sódica, Aerosil® e talco, utilizados na formulação do comprimido. Através desta técnica detectou-se a possibilidade de interação entre captopril e estearato de magnésio. De acordo com os resultados obtidos através de DSC não foram observadas alterações na cristalinidade do fármaco decorrentes dos processos de compressão e revestimento. A termogravimetria foi utilizada para o estudo da cinética de degradação do captopril e dos comprimidos. Os parâmetros cinéticos foram determinados através do método de Ozawa. Os resultados demonstraram que não houve alteração da estabilidade térmica do captopril na forma de comprimido. A formulação revestida com HPMC foi a que apresentou maior estabilidade térmica, quando comparada às demais formulações de revestimento.In the present study, captopril coated tablets with hydroxypropylmethylcellulose (HPMC, Opadry®, polyvinylpirrolidone (PVP, Eudragit® and shellac were produced. Differential scanning calorimetry (DSC and thermogravimetry (TG were used to evaluate the thermal properties of the drug and the formulations. On the basis of DSC results, captopril was found to be compatible with lactose, microcrystalline cellulose, sodium croscarmellose, Aerosil® and talc. Some possibility of interaction between drug-excipient was observed with magnesium stearate. However, additional techniques to confirm the results obtained are needed. There was no influence of mechanical treatment (tableting

  3. Bidirectional negative differential thermal resistance in three-segment Frenkel–Kontorova lattices

    International Nuclear Information System (INIS)

    Ou, Ya-li; Lu, Shi-cai; Hu, Cai-tian; Ai, Bao-quan

    2016-01-01

    By coupling three nonlinear 1D lattice segments, we demonstrate a thermal insulator model, where the system acts like an insulator for large temperature bias and a conductor for very small temperature bias. We numerically investigate the parameter range of the thermal insulator and find that the nonlinear response (the role of on-site potential), the weakly coupling interaction between each segment, and the small system size collectively contribute to the appearance of bidirectional negative differential thermal resistance (BNDTR). The corresponding exhibition of BNDTR can be explained in terms of effective phonon-band shifts. Our results can provide a new perspective for understanding the microscopic mechanism of negative differential thermal resistance and also would be conducive to further developments in designing and fabricating thermal devices and functional materials. (paper)

  4. Thermodynamical analysis of human thermal comfort

    International Nuclear Information System (INIS)

    Prek, Matjaz

    2006-01-01

    Traditional methods of human thermal comfort analysis are based on the first law of thermodynamics. These methods use an energy balance of the human body to determine heat transfer between the body and its environment. By contrast, the second law of thermodynamics introduces the useful concept of exergy. It enables the determination of the exergy consumption within the human body dependent on human and environmental factors. Human body exergy consumption varies with the combination of environmental (room) conditions. This process is related to human thermal comfort in connection with temperature, heat, and mass transfer. In this paper a thermodynamic analysis of human heat and mass transfer based on the 2nd law of thermodynamics in presented. It is shown that the human body's exergy consumption in relation to selected human parameters exhibits a minimal value at certain combinations of environmental parameters. The expected thermal sensation also shows that there is a correlation between exergy consumption and thermal sensation. Thus, our analysis represents an improvement in human thermal modelling and gives more information about the environmental impact on expected human thermal sensation

  5. Root cause analysis of thermal sleeve separation

    Energy Technology Data Exchange (ETDEWEB)

    Jo, J. C.; Jhung, M. J.; Yu, S. O.; Kim, H. J.; Yune, Y. K.; Park, J. Y

    2006-01-15

    Thermal sleeves in the shape of thin wall cylinder seated inside the nozzle part of each Safety Injection (SI) line at Pressurized Water Reactors (PWRs) have such functions as prevention and relief of potential excessive transient thermal stress in the wall of SI line nozzle part which is initially heated up with hot water flowing in the primary coolant piping system when cold water is injected into the system through the SI nozzles during the SI operation mode. Recently, mechanical failures that the sleeves were separated from the SI branch pipe and fell into the connected cold leg main pipe occurred in sequence at some typical PWR plants in Korea. To find out the root cause of thermal sleeve breakaway failures, the flow situation in the junction of primary coolant main pipe and SI branch pipe, and the vibration modal characteristics of the thermal sleeve are investigated in detail by using both Computational Fluid Dynamic (CFD) code and structure analysis finite element code. As the results, the transient response in fluid force exerting on the local part of thermal sleeve wall surface to the primary coolant flow through the pipe junction area during the normal reactor operation mode shows oscillatory characteristics with frequencies ranging from 17 to 18, which coincide with one of the lower mode natural frequencies of thermal sleeve having a pinned support condition on the circumferential prominence on the outer surface of thermal sleeve which is put into the circumferential groove on the inner surface of SI nozzle at the mid-height of the thermal sleeve. In addition, the variation of force on the thermal sleeve surface yields alternating torques in the directions of two rectangular axes which are perpendicular to the longitudinal axis of cylindrical thermal sleeve, which cause rolling, pitching and rotating motions of the thermal sleeve. Consequently, it is seen that this flow situation surrounding the thermal sleeve during the normal reactor operation can

  6. Plutonium storage thermal analysis (U)

    International Nuclear Information System (INIS)

    Hensel, S.J.; Lee, S.Y.; Schaade, J.B.

    1997-01-01

    Thermal modeling of plutonium metal ingots stored in food pack cans provides information useful for performing stored material safety evaluations. Four storage can geometries were modeled, and several conclusions can be made from the 14 cases analyzed. The ingot temperature increased from 7 degrees F to 12 degrees F (depending on can configuration) per additional watt of power. Including internal convection lowers computed ingot temperatures by 70 degrees F. Accounting for the heat flow through the bottom of the cans to the storage rack lowered computed ingot temperatures by an additional 70 degrees F to 80 degrees F. In the rimmed can systems storing ingots with a power of 10.35 watts, the ingot temperature varies from 190 degrees F to 213 degrees F. Including a plastic bag between the inner and outer can increases the ingot temperature by 15 degrees F. Adding a label to the outer can side reduces the outer can side temperature by 13 degrees F. Changes in ambient temperature affect the outer can temperatures more than the ingot temperature by a factor of 3. Similarly, a 5 degrees F drop in outer can temperature due to increased convection lowered the ingot temperature by only 2 degrees F

  7. Study of Selected Composites Copper Concentrate-Plastic Waste Using Thermal Analysis

    Science.gov (United States)

    Szyszka, Danuta

    2017-12-01

    The paper presents thermal analysis of selected composites (copper concentrate, plastic waste) in two stages. The first stage consisted in thermogravimetric analysis and differential thermal analysis on the applied plastic waste and copper concentrate, and subsequently, a comparative study has been carried out on products obtained, constituting composites of those materials. As a result of analyses, it was found that up to ca. 400 °C composites show high thermal stability, whereas above that temperature, a thermal decomposition of the composite occurs, resulting in emissions of organic compounds, i.e. hydrocarbon compounds and organic oxygenate derivatives.

  8. Thermal Analysis of Filler Reinforced Polymeric Composites

    Science.gov (United States)

    Ghadge, Mahesh Devidas

    compared with that predicted by mean field theories. At low volume fractions the FEM and mean field theory results are matching. However, at high volume fractions, the results obtained by the two methods are not in agreement. This is due to the fact that mean field theory do not consider the particle interactions happening at higher volume fractions. The present analysis can be used to tailor the thermal properties of ESBR for required thermal conductivity for a wide range of applications such as racing tires, electronic gadgets or aeronautical components. In addition, the proposed FEM models can be used to design and optimize the properties of new composite materials providing more insight into the thermal conductivity of composite polymers and aid in understanding heat transfer mechanism of reinforced polymers.

  9. Differentially expressed genes associated with adaptation to different thermal environments in three sympatric Cuban Anolis lizards.

    Science.gov (United States)

    Akashi, Hiroshi D; Cádiz Díaz, Antonio; Shigenobu, Shuji; Makino, Takashi; Kawata, Masakado

    2016-05-01

    How animals achieve evolutionary adaptation to different thermal environments is an important issue for evolutionary biology as well as for biodiversity conservation in the context of recent global warming. In Cuba, three sympatric species of Anolis lizards (Anolis allogus, A. homolechis and A. sagrei) inhabit different thermal microhabitats, thereby providing an excellent opportunity to examine how they have adapted to different environmental temperatures. Here, we performed RNA-seq on the brain, liver and skin tissues from these three species to analyse their transcriptional responses at two different temperatures. In total, we identified 400, 816 and 781 differentially expressed genes (DEGs) between the two temperatures in A. allogus, A. homolechis and A. sagrei, respectively. Only 62 of these DEGs were shared across the three species, indicating that global transcriptional responses have diverged among these species. Gene ontology (GO) analysis showed that large numbers of ribosomal protein genes were DEGs in the warm-adapted A. homolechis, suggesting that the upregulation of protein synthesis is an important physiological mechanism in the adaptation of this species to hotter environments. GO analysis also showed that GO terms associated with circadian regulation were enriched in all three species. A gene associated with circadian regulation, Nr1d1, was detected as a DEG with opposite expression patterns between the cool-adapted A. allogus and the hot-adapted A. sagrei. Because the environmental temperature fluctuates more widely in open habitats than in forests throughout the day, the circadian thermoregulation could also be important for adaptation to distinct thermal habitats. © 2016 John Wiley & Sons Ltd.

  10. Analysis of uncertainties of thermal hydraulic calculations

    International Nuclear Information System (INIS)

    Macek, J.; Vavrin, J.

    2002-12-01

    In 1993-1997 it was proposed, within OECD projects, that a common program should be set up for uncertainty analysis by a probabilistic method based on a non-parametric statistical approach for system computer codes such as RELAP, ATHLET and CATHARE and that a method should be developed for statistical analysis of experimental databases for the preparation of the input deck and statistical analysis of the output calculation results. Software for such statistical analyses would then have to be processed as individual tools independent of the computer codes used for the thermal hydraulic analysis and programs for uncertainty analysis. In this context, a method for estimation of a thermal hydraulic calculation is outlined and selected methods of statistical analysis of uncertainties are described, including methods for prediction accuracy assessment based on the discrete Fourier transformation principle. (author)

  11. Thermal analysis of kieselguhr sludge

    Directory of Open Access Journals (Sweden)

    S. T. Antipov

    2013-01-01

    Full Text Available It’s currently necessary to clarify the mechanisms of thermodynamic and mass transfer processes in capillary porous media. In this paper we obtain the thermogravimetric curves of evaporation drying kieselguhr sludge. It is also an analysis of the curves, allowing to choose the optimum conditions of drying.

  12. Thermal analysis of spices decontaminated by irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Varsanyi, I; Farkas, J [Koezponti Elelmiszeripari Kutato Intezet, Budapest (Hungary); Liptay, G; Petrik-Brandt, E [Budapesti Mueszaki Egyetem (Hungary)

    1979-01-01

    The cell-count-reducing effect of ionizing radiations is well known. To reduce microbiological contamination in the most frequently used spices, ground paprika, black pepper and a mixture of seven spices, a radiation dose of 1.5 Mrad (15 kGy) was applied. The aim of the investigation was to find out whether this dose caused significant changes in the spices which could be detected by thermal analysis. The results unambiguously show that the applied dose does not cause significant changes detectable by thermal analysis. This finding supports earlier experiences according to which no structural changes, disadvantageously influencing utilization of radiation treated spices, are caused by similar or smaller doses.

  13. Role of thermal analysis in uranium oxide fuel fabrication process

    International Nuclear Information System (INIS)

    Balaji Rao, Y.; Yadav, R.B.

    2006-01-01

    The present paper discusses the application of thermal analysis, particularly, differential thermal analysis (Dta) at various stages of fuel fabrication process. The useful role of Dta in knowing the decomposition pattern and calcination temperature of Adu along with de-nitration temperature is explained. The decomposition pattern depends upon the type of drying process adopted for wet ADU cake (ADU C). Also, the paper highlights the utility of DTA in determining the APS and SSA of UO 2+x and U 3 O 8 powders as an alternate technique. Further, the temperature difference (ΔT max ) between the two exothermic peaks obtained in UO 2+x powder oxidation is related to sintered density of UO 2 pellets. (author)

  14. Vanadium Dioxide as a Natural Disordered Metamaterial: Perfect Thermal Emission and Large Broadband Negative Differential Thermal Emittance

    Directory of Open Access Journals (Sweden)

    Mikhail A. Kats

    2013-10-01

    Full Text Available We experimentally demonstrate that a thin (approximately 150-nm film of vanadium dioxide (VO_{2} deposited on sapphire has an anomalous thermal emittance profile when heated, which arises because of the optical interaction between the film and the substrate when the VO_{2} is at an intermediate state of its insulator-metal transition (IMT. Within the IMT region, the VO_{2} film comprises nanoscale islands of the metal and dielectric phases and can thus be viewed as a natural, disordered metamaterial. This structure displays “perfect” blackbodylike thermal emissivity over a narrow wavelength range (approximately 40  cm^{-1}, surpassing the emissivity of our black-soot reference. We observe large broadband negative differential thermal emittance over a >10 °C range: Upon heating, the VO_{2}-sapphire structure emits less thermal radiation and appears colder on an infrared camera. Our experimental approach allows for a direct measurement and extraction of wavelength- and temperature-dependent thermal emittance. We anticipate that emissivity engineering with thin-film geometries comprising VO_{2} and other thermochromic materials will find applications in infrared camouflage, thermal regulation, and infrared tagging and labeling.

  15. Thermal behavior and phase identification of Valsartan by standard and temperature-modulated differential scanning calorimetry.

    Science.gov (United States)

    Skotnicki, Marcin; Gaweł, Agnieszka; Cebe, Peggy; Pyda, Marek

    2013-10-01

    Thermal behavior of angiotensin II type 1 (AT1) receptor antagonist, Valsartan (VAL), was examined employing thermogravimetric analysis (TGA), standard differential scanning calorimetry (DSC) and temperature-modulated differential scanning calorimetry (TMDSC). The stability of VAL was measured by TGA from 25 to 600°C. Decomposition of Valsartan starts around 160°C. The DSC curve shows two endotherms, occurring around 80°C and 100°C, related to evaporation of water and enthalpy relaxation, respectively. Valsartan was identified by DSC as an amorphous material and it was confirmed by X-ray powder diffraction. The glass transition of fresh Valsartan appears around 76°C (fictive temperature). TMDSC allows separation of the total heat flow rate into reversing and nonreversing parts. The nonreversing curve corresponds to the enthalpy relaxation and the reversing curve shows changes of heat capacity around 94°C. In the second run, TMDSC curve shows the glass transition process occurring at around 74°C. Results from standard DSC and TMDSC of Valsartan were compared over the whole range of temperature.

  16. Micro-thermal analysis of polyester coatings

    NARCIS (Netherlands)

    Fischer, H.R.

    2010-01-01

    The application and suitability of micro-thermal analysis to detect changes in the chemical and physical properties of coating due to ageing and especially photo-degradation is demonstrated using a model polyester coating based on neopentyl glycol isophthalic acid. The changes in chemical structure

  17. Use of labelled atoms in thermal analysis

    International Nuclear Information System (INIS)

    Balek, V.; Beckman, I.N.

    1985-01-01

    The article informs of the preparation of labelled samples for which the most frequently used radionuclides are 14 C, 3 H or 2 H, 32 P, 35 S and others as well as radioactive gases such as 85 Kr, 133 Xe or 220 Rn and 222 Rn. The equipment is described for the application of labelled atoms in thermal analysis consisting of a detector for measuring radioactivity and a system for measuring thermal analysis parameters. Examples are given of the use of labelled atoms in the study of chemical reactions of solids, in autoradiography or in Moessbauer spectroscopy. The greatest attention is devoted to the use of labelled atoms in emanation thermal analysis. By this technique it is possible to study chemical reactions and phase transformations, to continuously monitor changes in the surface and morphology of dispersion substances, to characterize the mobility of defects in the structure of solids and the active state of the structure of solids and to ascertain mechanical, radiation and chemical effects on solids. Attention is also devoted to the technological applications of emanation thermal analysis (the solidification of cement paste, calcination and the firing of the mixture of oxides for the manufacture of ferrites). (E.S.)

  18. Thermal effects in concrete containment analysis

    International Nuclear Information System (INIS)

    Pfeiffer, P.A.; Kennedy, J.M.; Marchertas, A.H.

    1988-01-01

    Analyses of the thermo-mechanical response of the 1:6-scale reinforced concrete containment are presented. Three temperature- pressure scenarios are analyzed to complete loss of the pressure integrity. These results are compared to the analysis of pressure alone, to assess the importance of thermal effects. 19 refs., 9 figs., 8 tabs

  19. Thermal analysis of the SSC beam scraper

    International Nuclear Information System (INIS)

    Tran, N.; Dao, B.

    1993-04-01

    When a particle beam impacts a beam scraper, heat is generated resulting in a rise in the temperature of the material. The maximum temperature rise should be kept to a minimum in order to maintain scraper efficiency and performance. In this paper the results of a thermal analysis of a scraper are presented

  20. Evaluation of the differential energy distribution of systems of non-thermally activated molecules

    International Nuclear Information System (INIS)

    Rogers, E.B.

    1986-01-01

    A non-thermally activated molecule may undergo pressure dependent deactivation or energy dependent decomposition. It should be possible to use the pressure dependent stabilization/decomposition yields to determine the energy distribution in non-thermal systems. The numerical technique of regularization has been applied to this chemical problem to evaluate this distribution. The resulting method has been tested with a number of simulated distributions and kinetic models. Application was then made to several real chemical systems to determine the energy distribution resulting from the primary excitation process. Testing showed the method to be quite effective in reproducing input distributions from simulated data in all test cases. The effect of experimental error proved to be negligible when the error-filled data were first smoothed with a parabolic spline. This method has been applied to three different hot atom activated systems. Application to 18 F-for-F substituted CH 3 CF 3 generated a broad distribution extending from 62 to 318 kcal/mol, with a median energy of 138 kcal/mol. The shape of this distribution (and those from the other applications) indicated the involvement of two mechanisms in the excitation process. Analysis of the T-for-H substituted CH 3 CH 2 F system showed a more narrow distribution (56-218 kcal/mol) with a median energy of 79.8 kcal/mol. The distribution of the T-for-H substituted CH 3 CH 2 Cl system, extending from 54.5 to 199 kcal/mol was seen to be quite similar. It was concluded that this method is a valid approach to evaluating differential energy distributions in non-thermal systems, specifically those activated by hot atom substitution

  1. Thermal analysis of a gas centrifuge

    International Nuclear Information System (INIS)

    Andrade, D.A.; Bastos, J.L.F.; Maiorino, J.R.

    1996-01-01

    The centrifuge separation efficiency is the result of the composition of the centrifuge field to the secondary flow in the axial direction near to the rotor wall. For a given machine, the centrifuge field can not be altered and the effort to augment the separation efficiency should be concentrated on the secondary flow. The secondary flow has a mechanical and a thermal component. The mechanical component is due to the deceleration of the gas at the scoop region. The thermal component is due to the temperature differences at the rotor. This paper presents a thermal model of a centrifuge in order to understand the main heat transfer mechanisms and to establish the boundary conditions for a fluid flow computer code. The heat transfer analysis takes into account conduction at the structure parts of the rotor and shell, radiation with multi-reflections between the rotor and the shell, and convection to the ambient. (author)

  2. Urban thermal landscape characterization and analysis

    International Nuclear Information System (INIS)

    Xue, Y; Fung, T; Tsou, J

    2014-01-01

    Urban warming is sensitive to the nature (thermal properties, including albedo, water content, heat capacity and thermal conductivity) and the placement (surface geometry or urban topography) of urban surface. In this research, the pattern and variation of urban surface temperature is regarded as one kind of landscape, urban thermal landscape, which is assumed as the presentation of local surface heating process upon urban landscape. The goal of this research is to develop a research framework incorporating geospatial statistics, thermal infrared remote sensing and landscape ecology to study the urban effect on local surface thermal landscape regarding both the pattern and process. This research chose Hong Kong as the case study. Within the study area, urban and rural area coexists upon a hilly topography. In order to probe the possibility of local surface warming mechanism discrepancy between urban and rural area, the sample points are grouped into urban and rural categories in according with the land use map taken into a linear regression model separately to examine the possible difference in local warming mechanism. Global regression analysis confirmed the relationship between environmental factors and surface temperature and the urban-rural distinctive mechanism of dominating diurnal surface warming is uncovered

  3. Bimodal Nuclear Thermal Rocket Analysis Developments

    Science.gov (United States)

    Belair, Michael; Lavelle, Thomas; Saimento, Charles; Juhasz, Albert; Stewart, Mark

    2014-01-01

    Nuclear thermal propulsion has long been considered an enabling technology for human missions to Mars and beyond. One concept of operations for these missions utilizes the nuclear reactor to generate electrical power during coast phases, known as bimodal operation. This presentation focuses on the systems modeling and analysis efforts for a NERVA derived concept. The NERVA bimodal operation derives the thermal energy from the core tie tube elements. Recent analysis has shown potential temperature distributions in the tie tube elements that may limit the thermodynamic efficiency of the closed Brayton cycle used to generate electricity with the current design. The results of this analysis are discussed as well as the potential implications to a bimodal NERVA type reactor.

  4. Stability, rheology and thermal analysis of functionalized alumina- thermal oil-based nanofluids for advanced cooling systems

    International Nuclear Information System (INIS)

    Ilyas, Suhaib Umer; Pendyala, Rajashekhar; Narahari, Marneni; Susin, Lim

    2017-01-01

    Highlights: • Alumina nanoparticles are functionalized with oleic acid. • Functionalization of alumina nanoparticles gives better dispersion in thermal oil. • Thermophysical properties of nanofluids are experimentally measured. • TGA confirms the improvement in life of nanofluids. - Abstract: Thermal oils are widely used as cooling media in heat transfer processes. However, their potential has not been utilised exquisitely in many applications due to low thermal properties. Thermal oil-based nanofluids are prepared by dispersing functionalized alumina with varying concentrations of 0.5–3 wt.% to enhance thermal properties of oil for advanced cooling systems. The oleic acid coated alumina is prepared and then dispersed in the oil to overcome the aggregation of nanoparticles in base fluid. The surface characterizations of functionalized nanoparticles are performed using different analysis such as XRD, EDS, SEM, TEM and FTIR. Dispersion behaviour and agglomeration studies are conducted at natural and functionalized conditions using different analysis to ensure long-term stability of nanofluids. In addition, rheological behaviour of non-Newtonian nanofluids is studied at high shear rates (100–2000 s"−"1). Effective densities and enhancement in thermal conductivities are measured for different nanofluids concentrations. Specific heat capacity is measured using Differential Scanning Calorimetry. The correlations are developed for thermophysical properties of nanofluids. Thermogravimetric analysis is performed with respect to temperature and time to exploit the effect of the addition of nanoparticles on the degradation of nanofluids. Significant improvement in the thermal properties of oil is observed using highly stable functionalized alumina nano-additives.

  5. Thermal analysis of spices decontaminated by irradiation

    International Nuclear Information System (INIS)

    Varsanyi, I.; Farkas, J.; Liptay, G.; Petrik-Brandt, E.

    1979-01-01

    The cell-count-reducing effect of ionizing radiations is well known. To reduce microbiological contamination in the most frequently used spices, ground paprika, black pepper and a mixture of seven spices, a radiation dose of 1.5 Mrad (15 kGy) was applied. The aim of the investigation was to find out whether this dose caused significant changes in the spices which could be detected by thermal analysis. The results unambiguously show that the applied dose does not cause significant changes detectable by thermal analysis. This finding supports earlier experiences according to which no structural changes, disadvantageously influencing utilization of radiation treated spices, are caused by similar or smaller doses. (author)

  6. Biomass pyrolysis and combustion integral and differential reaction heats with temperatures using thermogravimetric analysis/differential scanning calorimetry.

    Science.gov (United States)

    Shen, Jiacheng; Igathinathane, C; Yu, Manlu; Pothula, Anand Kumar

    2015-06-01

    Integral reaction heats of switchgrass, big bluestem, and corn stalks were determined using thermogravimetric analysis/differential scanning calorimetry (TGA/DSC). Iso-conversion differential reaction heats using TGA/DSC pyrolysis and combustion of biomass were not available, despite reports available on heats required and released. A concept of iso-conversion differential reaction heats was used to determine the differential reaction heats of each thermal characteristics segment of these materials. Results showed that the integral reaction heats were endothermic from 30 to 700°C for pyrolysis of switchgrass and big bluestem, but they were exothermic for corn stalks prior to 587°C. However, the integral reaction heats for combustion of the materials followed an endothermic to exothermic transition. The differential reaction heats of switchgrass pyrolysis were predominantly endothermic in the fraction of mass loss (0.0536-0.975), and were exothermic for corn stalks (0.0885-0.850) and big bluestem (0.736-0.919). Study results provided better insight into biomass thermal mechanism. Published by Elsevier Ltd.

  7. Application of Thermal Network Model to Transient Thermal Analysis of Power Electronic Package Substrate

    Directory of Open Access Journals (Sweden)

    Masaru Ishizuka

    2011-01-01

    Full Text Available In recent years, there is a growing demand to have smaller and lighter electronic circuits which have greater complexity, multifunctionality, and reliability. High-density multichip packaging technology has been used in order to meet these requirements. The higher the density scale is, the larger the power dissipation per unit area becomes. Therefore, in the designing process, it has become very important to carry out the thermal analysis. However, the heat transport model in multichip modules is very complex, and its treatment is tedious and time consuming. This paper describes an application of the thermal network method to the transient thermal analysis of multichip modules and proposes a simple model for the thermal analysis of multichip modules as a preliminary thermal design tool. On the basis of the result of transient thermal analysis, the validity of the thermal network method and the simple thermal analysis model is confirmed.

  8. The Effect of Thermal Cycling on Crystal-Liquid Separation During Lunar Magma Ocean Differentiation

    Science.gov (United States)

    Mills, Ryan D.

    2013-01-01

    Differentiation of magma oceans likely involves a mixture of fractional and equilibrium crystallization [1]. The existence of: 1) large volumes of anorthosite in the lunar highlands and 2) the incompatible- rich (KREEP) reservoir suggests that fractional crystallization may have dominated during differentiation of the Moon. For this to have occurred, crystal fractionation must have been remarkably efficient. Several authors [e.g. 2, 3] have hypothesized that equilibrium crystallization would have dominated early in differentiation of magma oceans because of crystal entrainment during turbulent convection. However, recent numerical modeling [4] suggests that crystal settling could have occurred throughout the entire solidification history of the lunar magma ocean if crystals were large and crystal fraction was low. These results indicate that the crystal size distribution could have played an important role in differentiation of the lunar magma ocean. Here, I suggest that thermal cycling from tidal heating during lunar magma ocean crystallization caused crystals to coarsen, leading to efficient crystal-liquid separation.

  9. Parameter Uncertainty for Repository Thermal Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hardin, Ernest [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hadgu, Teklu [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Greenberg, Harris [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dupont, Mark [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-01

    This report is one follow-on to a study of reference geologic disposal design concepts (Hardin et al. 2011a). Based on an analysis of maximum temperatures, that study concluded that certain disposal concepts would require extended decay storage prior to emplacement, or the use of small waste packages, or both. The study used nominal values for thermal properties of host geologic media and engineered materials, demonstrating the need for uncertainty analysis to support the conclusions. This report is a first step that identifies the input parameters of the maximum temperature calculation, surveys published data on measured values, uses an analytical approach to determine which parameters are most important, and performs an example sensitivity analysis. Using results from this first step, temperature calculations planned for FY12 can focus on only the important parameters, and can use the uncertainty ranges reported here. The survey of published information on thermal properties of geologic media and engineered materials, is intended to be sufficient for use in generic calculations to evaluate the feasibility of reference disposal concepts. A full compendium of literature data is beyond the scope of this report. The term “uncertainty” is used here to represent both measurement uncertainty and spatial variability, or variability across host geologic units. For the most important parameters (e.g., buffer thermal conductivity) the extent of literature data surveyed samples these different forms of uncertainty and variability. Finally, this report is intended to be one chapter or section of a larger FY12 deliverable summarizing all the work on design concepts and thermal load management for geologic disposal (M3FT-12SN0804032, due 15Aug2012).

  10. Development of disruption thermal analysis code DREAM

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, Seiichiro; Kobayahsi, Takeshi [Kawasaki Heavy Industries Ltd., Kobe (Japan); Seki, Masahiro

    1989-07-01

    When a plasma disruption takes place in a tokamak type fusion reactor, plasma facing componenets such as first wall and divertor/limiter are subjected to a intensse heat load in a short duration. At the surface of the wall, temperature rapidly rises, and melting and evaporation occurs. It causes reduction of wall thickness and crack initiation/propagation. As lifetime of the components is significantly affected by them, the transient analysis in consideration of phase changes and radiation heat loss in required in the design of these components. This paper describes the computer code DREAM, developed to perform the disruption thermal analysis, taking phase changes and radiation into account. (author).

  11. Development of disruption thermal analysis code DREAM

    International Nuclear Information System (INIS)

    Yamazaki, Seiichiro; Kobayahsi, Takeshi; Seki, Masahiro.

    1989-01-01

    When a plasma disruption takes place in a tokamak type fusion reactor, plasma facing componenets such as first wall and divertor/limiter are subjected to a intensse heat load in a short duration. At the surface of the wall, temperature rapidly rises, and melting and evaporation occurs. It causes reduction of wall thickness and crack initiation/propagation. As lifetime of the components is significantly affected by them, the transient analysis in consideration of phase changes and radiation heat loss in required in the design of these components. This paper describes the computer code DREAM, developed to perform the disruption thermal analysis, taking phase changes and radiation into account. (author)

  12. Availability Performance Analysis of Thermal Power Plants

    Science.gov (United States)

    Bhangu, Navneet Singh; Singh, Rupinder; Pahuja, G. L.

    2018-03-01

    This case study presents the availability evaluation method of thermal power plants for conducting performance analysis in Indian environment. A generic availability model has been proposed for a maintained system (thermal plants) using reliability block diagrams and fault tree analysis. The availability indices have been evaluated under realistic working environment using inclusion exclusion principle. Four year failure database has been used to compute availability for different combinatory of plant capacity, that is, full working state, reduced capacity or failure state. Availability is found to be very less even at full rated capacity (440 MW) which is not acceptable especially in prevailing energy scenario. One of the probable reason for this may be the difference in the age/health of existing thermal power plants which requires special attention of each unit from case to case basis. The maintenance techniques being used are conventional (50 years old) and improper in context of the modern equipment, which further aggravate the problem of low availability. This study highlights procedure for finding critical plants/units/subsystems and helps in deciding preventive maintenance program.

  13. Current lead thermal analysis code 'CURRENT'

    International Nuclear Information System (INIS)

    Yamaguchi, Masahito; Tada, Eisuke; Shimamoto, Susumu; Hata, Kenichiro.

    1985-08-01

    Large gas-cooled current lead with the capacity more than 30 kA and 22 kV is required for superconducting toroidal and poloidal coils for fusion application. The current lead is used to carry electrical current from the power supply system at room temperature to the superconducting coil at 4 K. Accordingly, the thermal performance of the current lead is significantly important to determine the heat load requirements of the coil system at 4 K. Japan Atomic Energy Research Institute (JAERI) has being developed the large gas-cooled current leads with the optimum condition in which the heat load is around 1 W per 1 kA at 4 K. In order to design the current lead with the optimum thermal performances, JAERI developed thermal analysis code named as ''CURRENT'' which can theoretically calculate the optimum geometric shape and cooling conditions of the current lead. The basic equations and the instruction manual of the analysis code are described in this report. (author)

  14. Thermal transient analysis applied to horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

    Duong, A.N. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[ConocoPhillips Canada Resources Corp., Calgary, AB (Canada)

    2008-10-15

    Steam assisted gravity drainage (SAGD) is a thermal recovery process used to recover bitumen and heavy oil. This paper presented a newly developed model to estimate cooling time and formation thermal diffusivity by using a thermal transient analysis along the horizontal wellbore under a steam heating process. This radial conduction heating model provides information on the heat influx distribution along a horizontal wellbore or elongated steam chamber, and is therefore important for determining the effectiveness of the heating process in the start-up phase in SAGD. Net heat flux estimation in the target formation during start-up can be difficult to measure because of uncertainties regarding heat loss in the vertical section; steam quality along the horizontal segment; distribution of steam along the wellbore; operational conditions; and additional effects of convection heating. The newly presented model can be considered analogous to pressure transient analysis of a buildup after a constant pressure drawdown. The model is based on an assumption of an infinite-acting system. This paper also proposed a new concept of a heating ring to measure the heat storage in the heated bitumen at the time of testing. Field observations were used to demonstrate how the model can be used to save heat energy, conserve steam and enhance bitumen recovery. 18 refs., 14 figs., 2 appendices.

  15. Tracking degradation in lithium iron phosphate batteries using differential thermal voltammetry

    Science.gov (United States)

    Shibagaki, Toshio; Merla, Yu; Offer, Gregory J.

    2018-01-01

    Diagnosing the state-of-health of lithium ion batteries in-operando is becoming increasingly important for multiple applications. We report the application of differential thermal voltammetry (DTV) to lithium iron phosphate (LFP) cells for the first time, and demonstrate that the technique is capable of diagnosing degradation in a similar way to incremental capacity analysis (ICA). DTV has the advantage of not requiring current and works for multiple cells in parallel, and is less sensitive to temperature introducing errors. Cells were aged by holding at 100% SOC or cycling at 1C charge, 6D discharge, both at an elevated temperature of 45 °C under forced air convection. Cells were periodically characterised, measuring capacity fade, resistance increase (power fade), and DTV fingerprints. The DTV results for both cells correlated well with both capacity and power, suggesting they could be used to diagnose SOH in-operando for both charge and discharge. The DTV peak-to-peak capacity correlated well with total capacity fade for the cycled cell, suggesting that it should be possible to estimate SOC and SOH from DTV for incomplete cycles within the voltage hysteresis region of an LFP cell.

  16. Numerical analysis of systems of ordinary and stochastic differential equations

    CERN Document Server

    Artemiev, S S

    1997-01-01

    This text deals with numerical analysis of systems of both ordinary and stochastic differential equations. It covers numerical solution problems of the Cauchy problem for stiff ordinary differential equations (ODE) systems by Rosenbrock-type methods (RTMs).

  17. Thermal Analysis On The Kinetics Of Magnesium-Aluminum Layered Double Hydroxides In Different Heating Rates

    Directory of Open Access Journals (Sweden)

    Hongbo Y.

    2015-06-01

    Full Text Available The thermal decomposition of magnesium-aluminum layered double hydroxides (LDHs was investigated by thermogravimetry analysis and differential scanning calorimetry (DSC methods in argon environment. The influence of heating rates (including 2.5, 5, 10, 15 and 20K/min on the thermal behavior of LDHs was revealed. By the methods of Kissinger and Flynn-Wall-Ozawa, the thermal kinetic parameters of activation energy and pre-exponential factor for the exothermic processes under non-isothermal conditions were calculated using the analysis of corresponding DSC curves.

  18. The role of non-thermal atmospheric pressure biocompatible plasma in the differentiation of osteoblastic precursor cells, MC3T3-E1.

    Science.gov (United States)

    Han, Ihn; Choi, Eun Ha

    2017-05-30

    Non-thermal atmospheric pressure plasma is ionized matter, composed of highly reactive species that include positive ions, negative ions, free radicals, neutral atoms, and molecules. Recent reports have suggested that non-thermal biocompatible plasma (NBP) can selectively kill a variety of cancer cells, and promote stem cell differentiation. However as of yet, the regulation of proliferation and differentiation potential of NBP has been poorly understood.Here, we investigated the effects of NBP on the osteogenic differentiation of precursor cell lines of osteoblasts, MC3T3 E1 and SaOS-2. For in vitro osteogenic differentiation, precursor cell lines were treated with NBP, and cultured with osteogenic induction medium. After 10 days of treatment, the NBP was shown to be effective in osteogenic differentiation in MC3T3 E1 cells by von Kossa and Alizarin Red S staining assay. Real-time PCR was then performed to investigate the expression of osteogenic specific genes, Runx2, OCN, COL1, ALP and osterix in MC3T3 E1 cells after treatment with NBP for 4 days. Furthermore, analysis of the protein expression showed that NBP treatment significantly reduced PI3K/AKT signaling and MAPK family signaling. However, p38 controlled phosphorylation of transcription factor forkhead box O1 (FoxO1) that related to cell differentiation with increased phosphorylated p38. These results suggest that non-thermal atmospheric pressure plasma can induce osteogenic differentiation, and enhance bone formation.

  19. Remote Thermal Analysis Through the Internet

    Science.gov (United States)

    Malroy, Eric T.

    2002-07-01

    The Heater of the Hypersonic Tunnel Facility (HTF) was modeled using SINDA/FLUINT thermal software. A description of the model is given. The project presented the opportunity of interfacing the thermal model with the Internet and was a demonstration that complex analysis is possible through the Internet. Some of the issues that need to be addressed related to interfacing software with the Internet are the following: justification for using the Internet, selection of the web server, choice of the CGI language, security of the system, communication among the parties, maintenance of state between web pages, and simultaneous users on the Internet system. The opportunities available for using the Internet for analysis are many and can present a significant jump in technology. This paper presents a vision how interfacing with the Internet could develop in the future. Using a separate Optical Internet (OI) for analysis, coupled with virtual reality analysis rooms (VRAR), could provide a synergistic environment to couple together engineering analysis within industry, academia, and government. The process of analysis could be broken down into sub-components so that specialization could occur resulting in superior quality, minimized cost and reduced time for engineering analysis and manufacturing. Some possible subcomponents of the system are solver routines, databases, Graphical User Interfaces, engineering design software, VRARs, computer processing, CAD systems, manufacturing, and a plethora of other options only limited by ones imagination. On a larger scope, the specialization of companies on the optical network would allow companies to rapidly construct and reconstruct their infrastructure based on changing economic conditions. This could transform business.

  20. Differential gene expression during thermal stress and bleaching in the Caribbean coral Montastraea faveolata.

    Science.gov (United States)

    DeSalvo, M K; Voolstra, C R; Sunagawa, S; Schwarz, J A; Stillman, J H; Coffroth, M A; Szmant, A M; Medina, M

    2008-09-01

    The declining health of coral reefs worldwide is likely to intensify in response to continued anthropogenic disturbance from coastal development, pollution, and climate change. In response to these stresses, reef-building corals may exhibit bleaching, which marks the breakdown in symbiosis between coral and zooxanthellae. Mass coral bleaching due to elevated water temperature can devastate coral reefs on a large geographical scale. In order to understand the molecular and cellular basis of bleaching in corals, we have measured gene expression changes associated with thermal stress and bleaching using a complementary DNA microarray containing 1310 genes of the Caribbean coral Montastraea faveolata. In a first experiment, we identified differentially expressed genes by comparing experimentally bleached M. faveolata fragments to control non-heat-stressed fragments. In a second experiment, we identified differentially expressed genes during a time course experiment with four time points across 9 days. Results suggest that thermal stress and bleaching in M. faveolata affect the following processes: oxidative stress, Ca(2+) homeostasis, cytoskeletal organization, cell death, calcification, metabolism, protein synthesis, heat shock protein activity, and transposon activity. These results represent the first medium-scale transcriptomic study focused on revealing the cellular foundation of thermal stress-induced coral bleaching. We postulate that oxidative stress in thermal-stressed corals causes a disruption of Ca(2+) homeostasis, which in turn leads to cytoskeletal and cell adhesion changes, decreased calcification, and the initiation of cell death via apoptosis and necrosis.

  1. Foundation heat transfer analysis for buildings with thermal piles

    International Nuclear Information System (INIS)

    Almanza Huerta, Luis Enrique; Krarti, Moncef

    2015-01-01

    Highlights: • A numerical transient thermal model for thermo-active foundations is developed. • Thermal interactions between thermal piles and building foundations are evaluated. • A simplified analysis method of thermal interactions between thermal piles and building foundations is developed. - Abstract: Thermal piles or thermo-active foundations utilize heat exchangers embedded within foundation footings to heat and/or cool buildings. In this paper, the impact of thermal piles on building foundation heat transfer is investigated. In particular, a simplified analysis method is developed to estimate the annual ground-coupled foundation heat transfer when buildings are equipped with thermal piles. First, a numerical analysis of the thermal performance of thermo-active building foundations is developed and used to assess the interactions between thermal piles and slab-on-grade building foundations. The impact of various design parameters and operating conditions is evaluated including foundation pile depth, building slab width, foundation insulation configuration, and soil thermal properties. Based on the results of a series of parametric analyses, a simplified analysis method is presented to assess the impact of the thermal piles on the annual heat fluxes toward or from the building foundations. A comparative evaluation of the predictions of the simplified analysis method and those obtained from the detailed numerical analysis indicated good agreement with prediction accuracy lower than 5%. Moreover, it is found that thermal piles can affect annual building foundation heat loss/gain by up to 30% depending on foundation size and insulation level

  2. SBWR core thermal hydraulic analysis during startup

    International Nuclear Information System (INIS)

    Lin, J.H.; Huang, R.L.; Sawyer, C.D.

    1993-01-01

    This paper reports on a thermal hydraulic analysis of the SIMPLIFIED BOILING WATER REACTOR (SBWR) during startup. The potential instability during a SBWR startup has drawn the attention of designers, researchers, and engineers. It has not been a concern for a Boiling Water Reactor (BWR) with forced recirculation; however, for SBWR with natural circulation the concern exists. The concern is about the possibility of a geysering mode oscillation during SBWR startup from a cold temperature and a low system pressure with a low natural circulation flow rate. A thermal hydraulic analysis of the SBWR is performed in simulation of the startup using the TRACG computer code. The temperature, pressure, and reactor power profiles of SBWR during the startup are presented. The results are compared with the data of a natural circulation boiling water reactor, the DODEWAARD plant, in which no instabilities have been observed during many startups. It is shown that a SBWR startup which follows proper procedures, geysering and other modes of oscillations can be avoided

  3. THERMAL CHARACTERISTICS AND THE DIFFERENTIAL EMISSION MEASURE DISTRIBUTION DURING A B8.3 FLARE ON 2009 JULY 4

    Energy Technology Data Exchange (ETDEWEB)

    Awasthi, Arun Kumar [Astronomical Institute, University of Wroclaw, Wroclaw (Poland); Sylwester, Barbara; Sylwester, Janusz [Solar Physics Division, Space Research Centre, Polish Academy of Sciences, Wroclaw (Poland); Jain, Rajmal, E-mail: arun.awasthi.87@gmail.com, E-mail: awasthi@astro.uni.wroc.pl [Kadi Sarva Vishwavidyalaya, Gandhinagar, Gujarat (India)

    2016-06-01

    We investigate the evolution of the differential emission measure distribution (DEM[ T ]) in various phases of a B8.3 flare which occurred on 2009 July 04. We analyze the soft X-ray (SXR) emission in the 1.6–8.0 keV range, recorded collectively by the Solar Photometer in X-rays (SphinX; Polish) and the Solar X-ray Spectrometer (Indian) instruments. We conduct a comparative investigation of the best-fit DEM[ T ] distributions derived by employing various inversion schemes, namely, single Gaussian, power-law functions and a Withbroe–Sylwester (W–S) maximum likelihood algorithm. In addition, the SXR spectrum in three different energy bands, that is, 1.6–5.0 keV (low), 5.0–8.0 keV (high), and 1.6–8.0 keV (combined), is analyzed to determine the dependence of the best-fit DEM[ T ] distribution on the selection of the energy interval. The evolution of the DEM[ T ] distribution, derived using a W–S algorithm, reveals multi-thermal plasma during the rise to the maximum phase of the flare, and isothermal plasma in the post-maximum phase of the flare. The thermal energy content is estimated by considering the flare plasma to be (1) isothermal and (2) multi-thermal in nature. We find that the energy content during the flare, estimated using the multi-thermal approach, is in good agreement with that derived using the isothermal assumption, except during the flare maximum. Furthermore, the (multi-) thermal energy estimated while employing the low-energy band of the SXR spectrum results in higher values than that derived from the combined energy band. On the contrary, the analysis of the high-energy band of the SXR spectrum leads to lower thermal energy than that estimated from the combined energy band.

  4. Thermal-Signature-Based Sleep Analysis Sensor

    Directory of Open Access Journals (Sweden)

    Ali Seba

    2017-10-01

    Full Text Available This paper addresses the development of a new technique in the sleep analysis domain. Sleep is defined as a periodic physiological state during which vigilance is suspended and reactivity to external stimulations diminished. We sleep on average between six and nine hours per night and our sleep is composed of four to six cycles of about 90 min each. Each of these cycles is composed of a succession of several stages of sleep that vary in depth. Analysis of sleep is usually done via polysomnography. This examination consists of recording, among other things, electrical cerebral activity by electroencephalography (EEG, ocular movements by electrooculography (EOG, and chin muscle tone by electromyography (EMG. Recordings are made mostly in a hospital, more specifically in a service for monitoring the pathologies related to sleep. The readings are then interpreted manually by an expert to generate a hypnogram, a curve showing the succession of sleep stages during the night in 30s epochs. The proposed method is based on the follow-up of the thermal signature that makes it possible to classify the activity into three classes: “awakening,” “calm sleep,” and “restless sleep”. The contribution of this non-invasive method is part of the screening of sleep disorders, to be validated by a more complete analysis of the sleep. The measure provided by this new system, based on temperature monitoring (patient and ambient, aims to be integrated into the tele-medicine platform developed within the framework of the Smart-EEG project by the SYEL–SYstèmes ELectroniques team. Analysis of the data collected during the first surveys carried out with this method showed a correlation between thermal signature and activity during sleep. The advantage of this method lies in its simplicity and the possibility of carrying out measurements of activity during sleep and without direct contact with the patient at home or hospitals.

  5. Applying homotopy analysis method for solving differential-difference equation

    International Nuclear Information System (INIS)

    Wang Zhen; Zou Li; Zhang Hongqing

    2007-01-01

    In this Letter, we apply the homotopy analysis method to solving the differential-difference equations. A simple but typical example is applied to illustrate the validity and the great potential of the generalized homotopy analysis method in solving differential-difference equation. Comparisons are made between the results of the proposed method and exact solutions. The results show that the homotopy analysis method is an attractive method in solving the differential-difference equations

  6. Theory and practice of near-field thermal probes for microscopy and thermal analysis

    International Nuclear Information System (INIS)

    Hodges, C.S.

    1999-03-01

    Bacterial mats called biofilms that form on the surfaces of industrial steel pipes can cause corrosion of the pipe. Examining the steel surface of the corroded pipe usually involves removal of the biofilm using acid. This acid can also cause corrosion of the pipe so that the observed corrosion cracks and pits are the result of both the acid and the biofilm. It was thought that non-invasive examination of the corrosion caused by the biofilm may be obtained by using a thin wire bent into a loop that acts as both a heat source a nd a detector of heat, measuring the changes in heat flow out of the wire as the wire passes over the steel with the biofilm still present. This technique of using a heated probe to scan samples on a microscopic scale is called Scanning Thermal Microscopy (SThM) and uses an alternating current to produce a.c. thermal waves that emanate from the probe tip into the sample. The alternating current allows better signal-to-noise ratios and also selective depth imaging of the sample since the thermal wave penetrates into the sample a distance inversely proportional to the applied current frequency. Reversal in the contrast of SThM images on biofilms and subsequently all samples was observed as either the frequency or the amplitude of the temperature waves was altered. Whilst changing the time constant of the feedback circuit attached to the SThM probe did go some way to explain this effect, a full explanation is still wanting. Despite many efforts to image the biofilm/steel interface with the biofilm still present, often the biofilm was either too thick or too complicated to do this. A simpler thermal test sample is required to calibrate the thermal probe. In addition to SThM, one may select a point on a sample surface and ramp the temperature of the probe to obtain a Localised Thermal Analysis (LTA) temperature scan looking for melts, recrystallisations, glass transitions of the part of the sample in contact with the probe. This technique is a

  7. Microgeographic differentiation in thermal performance curves between rural and urban populations of an aquatic insect.

    Science.gov (United States)

    Tüzün, Nedim; Op de Beeck, Lin; Brans, Kristien I; Janssens, Lizanne; Stoks, Robby

    2017-12-01

    The rapidly increasing rate of urbanization has a major impact on the ecology and evolution of species. While increased temperatures are a key aspect of urbanization ("urban heat islands"), we have very limited knowledge whether this generates differentiation in thermal responses between rural and urban populations. In a common garden experiment, we compared the thermal performance curves (TPCs) for growth rate and mortality in larvae of the damselfly Coenagrion puella from three urban and three rural populations. TPCs for growth rate shifted vertically, consistent with the faster-slower theoretical model whereby the cold-adapted rural larvae grew faster than the warm-adapted urban larvae across temperatures. In line with costs of rapid growth, rural larvae showed lower survival than urban larvae across temperatures. The relatively lower temperatures hence expected shorter growing seasons in rural populations compared to the populations in the urban heat islands likely impose stronger time constraints to reach a certain developmental stage before winter, thereby selecting for faster growth rates. In addition, higher predation rates at higher temperature may have contributed to the growth rate differences between urban and rural ponds. A faster-slower differentiation in TPCs may be a widespread pattern along the urbanization gradient. The observed microgeographic differentiation in TPCs supports the view that urbanization may drive life-history evolution. Moreover, because of the urban heat island effect, urban environments have the potential to aid in developing predictions on the impact of climate change on rural populations.

  8. Mathematical Modeling and Numerical Analysis of Thermal Distribution in Arch Dams considering Solar Radiation Effect

    Science.gov (United States)

    Mirzabozorg, H.; Hariri-Ardebili, M. A.; Shirkhan, M.; Seyed-Kolbadi, S. M.

    2014-01-01

    The effect of solar radiation on thermal distribution in thin high arch dams is investigated. The differential equation governing thermal behavior of mass concrete in three-dimensional space is solved applying appropriate boundary conditions. Solar radiation is implemented considering the dam face direction relative to the sun, the slop relative to horizon, the region cloud cover, and the surrounding topography. It has been observed that solar radiation changes the surface temperature drastically and leads to nonuniform temperature distribution. Solar radiation effects should be considered in thermal transient analysis of thin arch dams. PMID:24695817

  9. Mathematical modeling and numerical analysis of thermal distribution in arch dams considering solar radiation effect.

    Science.gov (United States)

    Mirzabozorg, H; Hariri-Ardebili, M A; Shirkhan, M; Seyed-Kolbadi, S M

    2014-01-01

    The effect of solar radiation on thermal distribution in thin high arch dams is investigated. The differential equation governing thermal behavior of mass concrete in three-dimensional space is solved applying appropriate boundary conditions. Solar radiation is implemented considering the dam face direction relative to the sun, the slop relative to horizon, the region cloud cover, and the surrounding topography. It has been observed that solar radiation changes the surface temperature drastically and leads to nonuniform temperature distribution. Solar radiation effects should be considered in thermal transient analysis of thin arch dams.

  10. Thermal analysis on motorcycle disc brake geometry

    Science.gov (United States)

    W. M. Zurin W., S.; Talib, R. J.; Ismail, N. I.

    2017-08-01

    Braking is a phase of slowing and stop the movement of motorcycle. During braking, the frictional heat was generated and the energy was ideally should be faster dissipated to surrounding to prevent the built up of the excessive temperature which may lead to brake fluid vaporization, thermoelastic deformation at the contact surface, material degradation and failure. In this paper, solid and ventilated type of motorcycle disc brake are being analyse using Computational Fluid Dynamic (CFD) software. The main focus of the analysis is the thermal behaviour during braking for solid and ventilated disc brake. A comparison between both geometries is being discussed to determine the better braking performance in term of temperature distribution. It is found that ventilated disc brake is having better braking performance in terms of heat transfer compare to solid disc.

  11. Stability analysis of impulsive functional differential equations

    CERN Document Server

    Stamova, Ivanka

    2009-01-01

    This book is devoted to impulsive functional differential equations which are a natural generalization of impulsive ordinary differential equations (without delay) and of functional differential equations (without impulses). At the present time the qualitative theory of such equationsis under rapid development. After a presentation of the fundamental theory of existence, uniqueness and continuability of solutions, a systematic development of stability theory for that class of problems is given which makes the book unique. It addresses to a wide audience such as mathematicians, applied research

  12. A study of poly(vinyl alcohol thermal degradation by thermogravimetry and differential thermogravimetry

    Directory of Open Access Journals (Sweden)

    Julián Esteban Barrera

    2007-05-01

    Full Text Available The thermal degradation of poly(vinyl alcohol (PVA having different degrees of hydrolysis and molecular weights was studied by thermogravimetry (TGA and differential thermogravimetry (DTGA. Four degradation events were identified whose intensity was related to the degree of hydrolysis. It was verified that the solid-state degradation mechanism for high hydrolysis degrees corresponded to eliminating water-forming side groups in stoichiometric amounts. The presence of acetate groups and lower melting points delayed the polymer’s thermal decomposition at lower hydrolysis degrees. There was no direct correlation in these samples between weight-loss during the first degradation event and the stoichiometric quantities which would be produced by eliminating the side groups. Reaction order and energy activation value qualitative coincidence was found by evaluating experimental data by using Freeman-Carroll and Friedman kinetic models.

  13. Selected papers on analysis and differential equations

    CERN Document Server

    Nomizu, Katsumi

    2003-01-01

    This volume contains translations of papers that originally appeared in the Japanese journal, Sugaku. The papers range over a variety of topics, including nonlinear partial differential equations, C^*-algebras, and Schrödinger operators.

  14. Spin wave differential circuit for realization of thermally stable magnonic sensors

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Taichi, E-mail: goto@ee.tut.ac.jp; Kanazawa, Naoki; Buyandalai, Altansargai; Takagi, Hiroyuki; Nakamura, Yuichi; Inoue, Mitsuteru [Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibari-Ga-Oka, Tempaku, Toyohashi, Aichi 441-8580 (Japan); Okajima, Shingo; Hasegawa, Takashi [Murata Manufacturing Co., Ltd., Kyoto 617-8555 (Japan); Granovsky, Alexander B. [Faculty of Physics, Moscow State University, Leninskie Gory, Moscow 119992 (Russian Federation); Sekiguchi, Koji [Department of Physics, Keio University, Yokohama 223-8522 (Japan); JST-PRESTO, Kawaguchi, Saitama 332-0012 (Japan); Ross, Caroline A. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States)

    2015-03-30

    A magnetic-field sensor with a high sensitivity of 38 pT/Hz was demonstrated. By utilizing a spin-wave differential circuit (SWDC) using two yttrium iron garnet (YIG) films, the temperature sensitivity was suppressed, and the thermal stability of the phase of the spin waves was −0.0095° K{sup −1}, which is three orders of magnitude better than a simple YIG-based sensor, ∼20° K{sup −1}. The SWDC architecture opens the way to design YIG-based magnonic devices.

  15. Spin wave differential circuit for realization of thermally stable magnonic sensors

    International Nuclear Information System (INIS)

    Goto, Taichi; Kanazawa, Naoki; Buyandalai, Altansargai; Takagi, Hiroyuki; Nakamura, Yuichi; Inoue, Mitsuteru; Okajima, Shingo; Hasegawa, Takashi; Granovsky, Alexander B.; Sekiguchi, Koji; Ross, Caroline A.

    2015-01-01

    A magnetic-field sensor with a high sensitivity of 38 pT/Hz was demonstrated. By utilizing a spin-wave differential circuit (SWDC) using two yttrium iron garnet (YIG) films, the temperature sensitivity was suppressed, and the thermal stability of the phase of the spin waves was −0.0095° K −1 , which is three orders of magnitude better than a simple YIG-based sensor, ∼20° K −1 . The SWDC architecture opens the way to design YIG-based magnonic devices

  16. Pressure Measurement in Supersonic Air Flow by Differential Absorptive Laser-Induced Thermal Acoustics

    Science.gov (United States)

    Hart, Roger C.; Herring, Gregory C.; Balla, Robert J.

    2007-01-01

    Nonintrusive, off-body flow barometry in Mach-2 airflow has been demonstrated in a large-scale supersonic wind tunnel using seedless laser-induced thermal acoustics (LITA). The static pressure of the gas flow is determined with a novel differential absorption measurement of the ultrasonic sound produced by the LITA pump process. Simultaneously, stream-wise velocity and static gas temperature of the same spatially-resolved sample volume were measured with this nonresonant time-averaged LITA technique. Mach number, temperature and pressure have 0.2%, 0.4%, and 4% rms agreement, respectively, in comparison with known free-stream conditions.

  17. Thermal analysis of transportation packaging for nuclear spent fuel

    International Nuclear Information System (INIS)

    Akamatsu, Hiroshi; Taniuchi, Hiroaki

    1989-01-01

    Safety analysis of transportation packaging for nuclear spent fuel comprises structural, thermal, containment, shielding and criticality factors, and the safety of a packaging is verified by these analyses. In thermal analysis, the temperature of each part of the packaging is calculated under normal and accident test conditions. As an example of thermal analysis, the temperature distribution of a packaging being subjected to a normal test was calculated by the TRUMP code and compared with measured data. (author)

  18. Sensitivity analysis and design optimization through automatic differentiation

    International Nuclear Information System (INIS)

    Hovland, Paul D; Norris, Boyana; Strout, Michelle Mills; Bhowmick, Sanjukta; Utke, Jean

    2005-01-01

    Automatic differentiation is a technique for transforming a program or subprogram that computes a function, including arbitrarily complex simulation codes, into one that computes the derivatives of that function. We describe the implementation and application of automatic differentiation tools. We highlight recent advances in the combinatorial algorithms and compiler technology that underlie successful implementation of automatic differentiation tools. We discuss applications of automatic differentiation in design optimization and sensitivity analysis. We also describe ongoing research in the design of language-independent source transformation infrastructures for automatic differentiation algorithms

  19. Thermal analysis and safety information for metal nanopowders by DSC

    Energy Technology Data Exchange (ETDEWEB)

    Tseng, J.M.; Huang, S.T. [Institute of Safety and Disaster Prevention Technology, Central Taiwan University of Science and Technology, 666, Buzih Road, Beitun District, Taichung 40601, Taiwan, ROC (China); Duh, Y.S.; Hsieh, T.Y.; Sun, Y.Y. [Department of Safety Health and Environmental Engineering, National United University, Miaoli, Taiwan, ROC (China); Lin, J.Z. [Institute of Safety and Disaster Prevention Technology, Central Taiwan University of Science and Technology, 666, Buzih Road, Beitun District, Taichung 40601, Taiwan, ROC (China); Wu, H.C. [Institute of Occupational Safety and Health, Council of Labor Affairs, Taipei, Taiwan, ROC (China); Kao, C.S., E-mail: jcsk@nuu.edu.tw [Department of Safety Health and Environmental Engineering, National United University, Miaoli, Taiwan, ROC (China)

    2013-08-20

    Highlights: • Metal nanopowders are common and frequently employed in industry. • Nano iron powder experimental results of T{sub o} were 140–150 °C. • Safety information can benefit relevant metal powders industries. - Abstract: Metal nanopowders are common and frequently employed in industry. Iron is mostly applied in high-performance magnetic materials and pollutants treatment for groundwater. Zinc is widely used in brass, bronze, die casting metal, alloys, rubber, and paints, etc. Nonetheless, some disasters induced by metal powders are due to the lack of related safety information. In this study, we applied differential scanning calorimetry (DSC) and used thermal analysis software to evaluate the related thermal safety information, such as exothermic onset temperature (T{sub o}), peak of temperature (T{sub p}), and heat of reaction (ΔH). The nano iron powder experimental results of T{sub o} were 140–150 °C, 148–158 °C, and 141–149 °C for 15 nm, 35 nm, and 65 nm, respectively. The ΔH was larger than 3900 J/g, 5000 J/g, and 3900 J/g for 15 nm, 35 nm, and 65 nm, respectively. Safety information can benefit the relevant metal powders industries for preventing accidents from occurring.

  20. Ninth Thermal and Fluids Analysis Workshop Proceedings

    Science.gov (United States)

    Sakowski, Barbara (Compiler)

    1999-01-01

    The Ninth Thermal and Fluids Analysis Workshop (TFAWS 98) was held at the Ohio Aerospace Institute in Cleveland, Ohio from August 31 to September 4, 1998. The theme for the hands-on training workshop and conference was "Integrating Computational Fluid Dynamics and Heat Transfer into the Design Process." Highlights of the workshop (in addition to the papers published herein) included an address by the NASA Chief Engineer, Dr. Daniel Mulville; a CFD short course by Dr. John D. Anderson of the University of Maryland; and a short course by Dr. Robert Cochran of Sandia National Laboratories. In addition, lectures and hands-on training were offered in the use of several cutting-edge engineering design and analysis-oriented CFD and Heat Transfer tools. The workshop resulted in international participation of over 125 persons representing aerospace and automotive industries, academia, software providers, government agencies, and private corporations. The papers published herein address issues and solutions related to the integration of computational fluid dynamics and heat transfer into the engineering design process. Although the primary focus is aerospace, the topics and ideas presented are applicable to many other areas where these and other disciplines are interdependent.

  1. Asymptotic analysis for functional stochastic differential equations

    CERN Document Server

    Bao, Jianhai; Yuan, Chenggui

    2016-01-01

    This brief treats dynamical systems that involve delays and random disturbances. The study is motivated by a wide variety of systems in real life in which random noise has to be taken into consideration and the effect of delays cannot be ignored. Concentrating on such systems that are described by functional stochastic differential equations, this work focuses on the study of large time behavior, in particular, ergodicity. This brief is written for probabilists, applied mathematicians, engineers, and scientists who need to use delay systems and functional stochastic differential equations in their work. Selected topics from the brief can also be used in a graduate level topics course in probability and stochastic processes.

  2. Decomposition analysis of differential dose volume histograms

    International Nuclear Information System (INIS)

    Heuvel, Frank van den

    2006-01-01

    Dose volume histograms are a common tool to assess the value of a treatment plan for various forms of radiation therapy treatment. The purpose of this work is to introduce, validate, and apply a set of tools to analyze differential dose volume histograms by decomposing them into physically and clinically meaningful normal distributions. A weighted sum of the decomposed normal distributions (e.g., weighted dose) is proposed as a new measure of target dose, rather than the more unstable point dose. The method and its theory are presented and validated using simulated distributions. Additional validation is performed by analyzing simple four field box techniques encompassing a predefined target, using different treatment energies inside a water phantom. Furthermore, two clinical situations are analyzed using this methodology to illustrate practical usefulness. A comparison of a treatment plan for a breast patient using a tangential field setup with wedges is compared to a comparable geometry using dose compensators. Finally, a normal tissue complication probability (NTCP) calculation is refined using this decomposition. The NTCP calculation is performed on a liver as organ at risk in a treatment of a mesothelioma patient with involvement of the right lung. The comparison of the wedged breast treatment versus the compensator technique yields comparable classical dose parameters (e.g., conformity index ≅1 and equal dose at the ICRU dose point). The methodology proposed here shows a 4% difference in weighted dose outlining the difference in treatment using a single parameter instead of at least two in a classical analysis (e.g., mean dose, and maximal dose, or total dose variance). NTCP-calculations for the mesothelioma case are generated automatically and show a 3% decrease with respect to the classical calculation. The decrease is slightly dependant on the fractionation and on the α/β-value utilized. In conclusion, this method is able to distinguish clinically

  3. Analysis of thermal power calibration method

    International Nuclear Information System (INIS)

    Zagar, T.; Ravnik, M.; Persic, A.

    2000-01-01

    The methods for determining fuel element burnup have recently become interesting because of activities related to the shipment of highly enriched fuel elements back to the United States for final disposal before 2009. The most common and practical method for determining fuel element burnup in research reactors is reactor calculation. Experience has shown that burnup calculations become complicated and biased with uncertainties if a long period of reactor operation must be reproduced. Besides this, accuracy of calculated burnup is always limited with accuracy of reactor power calibration, since burnup calculation is based on calculated power density distribution, which is usually expressed in terms of power released per fuel element and normalised to the reactor power It is obvious that reactor thermal power calibration is very important for precise fuel element burnup calculation. Calculated fuel element burnup is linearly dependent on the thermal reactor power. The reactor power level may be determined from measured absolute thermal flux distribution across the core in the horizontal and vertical planes. Flux distributions are measured with activation of cadmium covered and bare foils irradiated by the steady reactor power. But it should be realised that this method is time consuming and not accurate. This method is practical only for zero power reactors and is in practice very seldom performed for other reactors (e.g. for TRIGA reactor in Ljubljana absolute thermal flux distribution was not performed since reactor reconstruction in 1991). In case of power reactors and research reactors in which a temperature rise across the core is produced and measured than a heat balance method is the most common and accurate method of determining the power output of the core. The purpose of this paper is to analyse the accuracy of calorimetric reactor power calibration method and to analyse the influence of control rod position on nuclear detector reading for TRIGA reactors

  4. Continuous nowhere differentiable functions the monsters of analysis

    CERN Document Server

    Jarnicki, Marek

    2015-01-01

    This book covers the construction, analysis, and theory of continuous nowhere differentiable functions, comprehensively and accessibly. After illuminating the significance of the subject through an overview of its history, the reader is introduced to the sophisticated toolkit of ideas and tricks used to study the explicit continuous nowhere differentiable functions of Weierstrass, Takagi–van der Waerden, Bolzano, and others. Modern tools of functional analysis, measure theory, and Fourier analysis are applied to examine the generic nature of continuous nowhere differentiable functions, as well as linear structures within the (nonlinear) space of continuous nowhere differentiable functions. To round out the presentation, advanced techniques from several areas of mathematics are brought together to give a state-of-the-art analysis of Riemann’s continuous, and purportedly nowhere differentiable, function. For the reader’s benefit, claims requiring elaboration, and open problems, are clearly indicated. An a...

  5. Tensor analysis and elementary differential geometry for physicists and engineers

    CERN Document Server

    Nguyen-Schäfer, Hung

    2017-01-01

    This book comprehensively presents topics, such as Dirac notation, tensor analysis, elementary differential geometry of moving surfaces, and k-differential forms. Additionally, two new chapters of Cartan differential forms and Dirac and tensor notations in quantum mechanics are added to this second edition. The reader is provided with hands-on calculations and worked-out examples at which he will learn how to handle the bra-ket notation, tensors, differential geometry, and differential forms; and to apply them to the physical and engineering world. Many methods and applications are given in CFD, continuum mechanics, electrodynamics in special relativity, cosmology in the Minkowski four-dimensional spacetime, and relativistic and non-relativistic quantum mechanics. Tensors, differential geometry, differential forms, and Dirac notation are very useful advanced mathematical tools in many fields of modern physics and computational engineering. They are involved in special and general relativity physics, quantum m...

  6. Differential analysis of matrix convex functions

    DEFF Research Database (Denmark)

    Hansen, Frank; Tomiyama, Jun

    2007-01-01

    We analyze matrix convex functions of a fixed order defined in a real interval by differential methods as opposed to the characterization in terms of divided differences given by Kraus [F. Kraus, Über konvekse Matrixfunktionen, Math. Z. 41 (1936) 18-42]. We obtain for each order conditions for ma...

  7. Analysis of Non-contact Acousto Thermal Signature Data (Postprint)

    Science.gov (United States)

    2016-02-01

    AFRL-RX-WP-JA-2016-0321 ANALYSIS OF NON-CONTACT ACOUSTO-THERMAL SIGNATURE DATA (POSTPRINT) Amanda K. Criner AFRL/RX...October 2014 – 16 September 2015 4. TITLE AND SUBTITLE ANALYSIS OF NON-CONTACT ACOUSTO-THERMAL SIGNATURE DATA (POSTPRINT) 5a. CONTRACT NUMBER...words) The non-contact acousto-thermal signature (NCATS) is a nondestructive evaluation technique with potential to detect fatigue in materials such as

  8. Measuring the temperature dependent thermal diffusivity of geomaterials using high-speed differential scanning calorimetry

    Science.gov (United States)

    von Aulock, Felix W.; Wadsworth, Fabian B.; Vasseur, Jeremie; Lavallée, Yan

    2016-04-01

    Heat diffusion in the Earth's crust is critical to fundamental geological processes, such as the cooling of magma, heat dissipation during and following transient heating events (e.g. during frictional heating along faults), and to the timescales of contact metamorphosis. The complex composition and multiphase nature of geomaterials prohibits the accurate modeling of thermal diffusivities and measurements over a range of temperatures are sparse due to the specialized nature of the equipment and lack of instrument availability. We present a novel method to measure the thermal diffusivity of geomaterials such as minerals and rocks with high precision and accuracy using a commercially available differential scanning calorimeter (DSC). A DSC 404 F1 Pegasus® equipped with a Netzsch high-speed furnace was used to apply a step-heating program to corundum single crystal standards of varying thicknesses. The standards were cylindrical discs of 0.25-1 mm thickness with 5.2-6 mm diameter. Heating between each 50 °C temperature interval was conducted at a rate of 100 °C/min over the temperature range 150-1050 °C. Such large heating rates induces temperature disequilibrium in the samples used. However, isothermal segments of 2 minutes were used during which the temperature variably equilibrated with the furnace between the heating segments and thus the directly-measured heat-flow relaxed to a constant value before the next heating step was applied. A finite-difference 2D conductive heat transfer model was used in cylindrical geometry for which the measured furnace temperature was directly applied as the boundary condition on the sample-cylinder surfaces. The model temperature was averaged over the sample volume per unit time and converted to heat-flow using the well constrained thermal properties for corundum single crystals. By adjusting the thermal diffusivity in the model solution and comparing the resultant heat-flow with the measured values, we obtain a model

  9. Quantitative analysis of thermal insulation coatings

    DEFF Research Database (Denmark)

    Kiil, Søren

    2014-01-01

    This work concerns the development of simulation tools for mapping of insulation properties of thermal insulation coatings based on selected functional filler materials. A mathematical model, which includes the underlying physics (i.e. thermal conductivity of a heterogeneous two-component coating...

  10. Micro-thermal analysis of polyester coatings

    Science.gov (United States)

    Fischer, Hartmut R.

    2010-04-01

    The application and suitability of micro-thermal analysis to detect changes in the chemical and physical properties of coating due to ageing and especially photo-degradation is demonstrated using a model polyester coating based on neopentyl glycol isophthalic acid. The changes in chemical structure like chain scission and cross-linking are manifested by a shift of the LTA detectable Tg and by a change of the slope of the part of the LTA graph responsible for the penetration of the hot sensor into the material after passing the glass transition temperature. As such LTA is a valuable tool to have a quick look into coating surfaces and especially their ageing. The photo-degradation of polyester in air leads to the formation of a cross-linked network at a surface layer of about 3-4 μm coupled with an increase in hardness and of the glass transition temperature by ˜90 K, the effect is less drastic for a photo-degradation in a nitrogen environment. Moreover, the presence of a non-equilibrium dense surface layer with a higher Tg formed during the drying of the coating formulation and the film solidification can be shown.

  11. Pharmaceutical applications of dynamic mechanical thermal analysis.

    Science.gov (United States)

    Jones, David S; Tian, Yiwei; Abu-Diak, Osama; Andrews, Gavin P

    2012-04-01

    The successful development of polymeric drug delivery and biomedical devices requires a comprehensive understanding of the viscoleastic properties of polymers as these have been shown to directly affect clinical efficacy. Dynamic mechanical thermal analysis (DMTA) is an accessible and versatile analytical technique in which an oscillating stress or strain is applied to a sample as a function of oscillatory frequency and temperature. Through cyclic application of a non-destructive stress or strain, a comprehensive understanding of the viscoelastic properties of polymers may be obtained. In this review, we provide a concise overview of the theory of DMTA and the basic instrumental/operating principles. Moreover, the application of DMTA for the characterization of solid pharmaceutical and biomedical systems has been discussed in detail. In particular we have described the potential of DMTA to measure and understand relaxation transitions and miscibility in binary and higher-order systems and describe the more recent applications of the technique for this purpose. © 2011 Elsevier B.V. All rights reserved.

  12. THERMAL HYDRAULIC ANALYSIS OF FIRE DIVERTOR

    International Nuclear Information System (INIS)

    C.B. bAXI; M.A. ULRICKSON; D.E. DRIMEYER; P. HEITZENROEDER

    2000-01-01

    The Fusion Ignition Research Experiment (FIRE) is being designed as a next step in the US magnetic fusion program. The FIRE tokamak has a major radius of 2 m, a minor radius of 0.525 m, and liquid nitrogen cooled copper coils. The aim is to produce a pulse length of 20 s with a plasma current of 6.6 MA and with alpha dominated heating. The outer divertor and baffle of FIRE are water cooled. The worst thermal condition for the outer divertor and baffle is the baseline D-T operating mode (10 T, 6.6 MA, 20 s) with a plasma exhaust power of 67 MW and a peak heat flux of 20 MW/m 2 . A swirl tape (ST) heat transfer enhancement method is used in the outer divertor cooling channels to increase the heat transfer coefficient and the critical heat flux (CHF). The plasma-facing surface consists of tungsten brush. The finite element (FE) analysis shows that for an inlet water temperature of 30 C, inlet pressure of 1.5 MPa and a flow velocity of 10 m/s, the incident critical heat flux is greater than 30 MW/m 2 . The peak copper temperature is 490 C, peak tungsten temperature is 1560 C, and the pressure drop is less than 0.5 MPa. All these results fulfill the design requirements

  13. Compatibility analysis of DUPIC fuel(4) - thermal hydraulic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jee Won; Chae, Kyung Myung; Choi, Hang Bok

    2000-07-01

    Thermal-hydraulic compatibility of the DUPIC fuel bundle in the CANDU reactor has been studied. The critical channel power, the critical power ratio, the channel exit quality and the channel flow are calculated for the DUPIC and the standard fuels by using the NUCIRC code. The physical models and associated parametric values for the NUCIRC analysis of the fuels are also presented. Based upon the slave channel analysis, the critical channel power and the critical power ratios have been found to be very similar for the two fuel types. The same dryout model is used in this study for the standard and the DUPIC fuel bundles. To assess the dryout characteristics of the DUPIC fuel bundle, the ASSERT-PV code has been used for the subchannel analysis. Based upon the results of the subchannel analysis, it is found that the dryout location and the power for the two fuel types are indeed very similar. This study shows that thermal performance of the DUPIC fuel is not significantly different from that of the standard fuel.

  14. Novel Therapeutic Effects of Non-thermal atmospheric pressure plasma for Muscle Regeneration and Differentiation

    Science.gov (United States)

    Choi, Jae Won; Kang, Sung Un; Kim, Yang Eun; Park, Ju Kyeong; Yang, Sang Sik; Kim, Yeon Soo; Lee, Yun Sang; Lee, Yuijina; Kim, Chul-Ho

    2016-01-01

    Skeletal muscle can repair muscle tissue damage, but significant loss of muscle tissue or its long-lasting chronic degeneration makes injured skeletal muscle tissue difficult to restore. It has been demonstrated that non-thermal atmospheric pressure plasma (NTP) can be used in many biological areas including regenerative medicine. Therefore, we determined whether NTP, as a non-contact biological external stimulator that generates biological catalyzers, can induce regeneration of injured muscle without biomaterials. Treatment with NTP in the defected muscle of a Sprague Dawley (SD) rat increased the number of proliferating muscle cells 7 days after plasma treatment (dapt) and rapidly induced formation of muscle tissue and muscle cell differentiation at 14 dapt. In addition, in vitro experiments also showed that NTP could induce muscle cell proliferation and differentiation of human muscle cells. Taken together, our results demonstrated that NTP promotes restoration of muscle defects through control of cell proliferation and differentiation without biological or structural supporters, suggesting that NTP has the potential for use in muscle tissue engineering and regenerative therapies. PMID:27349181

  15. Performance testing of thermal analysis codes for nuclear fuel casks

    International Nuclear Information System (INIS)

    Sanchez, L.C.

    1987-01-01

    In 1982 Sandia National Laboratories held the First Industry/Government Joint Thermal and Structural Codes Information Exchange and presented the initial stages of an investigation of thermal analysis computer codes for use in the design of nuclear fuel shipping casks. The objective of the investigation was to (1) document publicly available computer codes, (2) assess code capabilities as determined from their user's manuals, and (3) assess code performance on cask-like model problems. Computer codes are required to handle the thermal phenomena of conduction, convection and radiation. Several of the available thermal computer codes were tested on a set of model problems to assess performance on cask-like problems. Solutions obtained with the computer codes for steady-state thermal analysis were in good agreement and the solutions for transient thermal analysis differed slightly among the computer codes due to modeling differences

  16. Differential die-away analysis system response modeling and detector design

    International Nuclear Information System (INIS)

    Jordan, K.A.; Gozani, T.; Vujic, J.

    2008-01-01

    Differential die-away-analysis (DDAA) is a sensitive technique to detect presence of fissile materials such as 235 U and 239 Pu. DDAA uses a high-energy (14 MeV) pulsed neutron generator to interrogate a shipping container. The signature is a fast neutron signal hundreds of microseconds after the cessation of the neutron pulse. This fast neutron signal has decay time identical to the thermal neutron diffusion decay time of the inspected cargo. The theoretical aspects of a cargo inspection system based on the differential die-away technique are explored. A detailed mathematical model of the system is developed, and experimental results validating this model are presented

  17. Thermal and Alignment Analysis of the Instrument-Level ATLAS Thermal Vacuum Test

    Science.gov (United States)

    Bradshaw, Heather

    2012-01-01

    This paper describes the thermal analysis and test design performed in preparation for the ATLAS thermal vacuum test. NASA's Advanced Topographic Laser Altimeter System (ATLAS) will be flown as the sole instrument aboard the Ice, Cloud, and land Elevation Satellite-2 (ICESat-2). It will be used to take measurements of topography and ice thickness for Arctic and Antarctic regions, providing crucial data used to predict future changes in worldwide sea levels. Due to the precise measurements ATLAS is taking, the laser altimeter has very tight pointing requirements. Therefore, the instrument is very sensitive to temperature-induced thermal distortions. For this reason, it is necessary to perform a Structural, Thermal, Optical Performance (STOP) analysis not only for flight, but also to ensure performance requirements can be operationally met during instrument-level thermal vacuum testing. This paper describes the thermal model created for the chamber setup, which was used to generate inputs for the environmental STOP analysis. This paper also presents the results of the STOP analysis, which indicate that the test predictions adequately replicate the thermal distortions predicted for flight. This is a new application of an existing process, as STOP analyses are generally performed to predict flight behavior only. Another novel aspect of this test is that it presents the opportunity to verify pointing results of a STOP model, which is not generally done. It is possible in this case, however, because the actual pointing will be measured using flight hardware during thermal vacuum testing and can be compared to STOP predictions.

  18. Thermal Analysis of Sintered Silver Nanoparticles Film

    Directory of Open Access Journals (Sweden)

    M. Keikhaie

    2014-07-01

    Full Text Available Thin bonded films have many applications in antireflection and reflection coating, insulating and conducting films and semiconductor industries. Thermal conductivity is one of the most important parameter for power packaging since the thermal resistance of the interconnections is directly related to the heat removal capability and thermal management of the power package. The defects in materials play very important role on the effective thermal conductivity. In this paper, finite element method (FEM was utilized to simulate the effect of pores on the effective thermal conductivity of sintered silver nanoparticles film. The simulation results indicate that the effective thermal conductivity of film is different at different directions and would be enhanced when the pore angle is 90. The simulation results will help us to further understand the heat transfer process across highly porous structures and will provide us a powerful guide to design coating with high thermal insulation or conductor property. Because of there is no similar experimental data for this simulation results, this paper is a comparative work among three different models.

  19. Thermal and Structural Analysis of FIMS Grating

    Directory of Open Access Journals (Sweden)

    K.-I. Seon

    2001-06-01

    Full Text Available Far ultraviolet IMaging Spectrograph (FIMS should be designed to maintain its structural stability and to minimize optical performance degradation in launch and in operation enviroments. The structural and thermal analyzes of grating and grating mount system, which are directly related to FIMS optical performance, was performed using finite element method. The grating mount was made to keep the grating stress down, while keeping the natural frequency of the grating mount higher than 100 Hz. Transient and static thermal analyzes were also performed and the results shows that the thermal stress on the grating can be attenuated sufficiently The optical performance variation due to temperature variation was within the allowed range.

  20. Thermal analysis and design of passive solar buildings

    CERN Document Server

    Athienitis, AK

    2013-01-01

    Passive solar design techniques are becoming increasingly important in building design. This design reference book takes the building engineer or physicist step-by-step through the thermal analysis and design of passive solar buildings. In particular it emphasises two important topics: the maximum utilization of available solar energy and thermal storage, and the sizing of an appropriate auxiliary heating/cooling system in conjunction with good thermal control.Thermal Analysis and Design of Passive Solar Buildings is an important contribution towards the optimization of buildings as systems th

  1. Thermal mechanical analysis of applications with internal heat generation

    Science.gov (United States)

    Govindarajan, Srisharan Garg

    establish operational safety of the BORAL control blades used at the Missouri University Research Reactor (MURR) to support their relicensing efforts with the Nuclear Regulatory Commission (NRC). The common theme in both these sections is the nuclear heat source, high heat flux, non-uniform heating, composite structures and differential thermal expansion. The goal is to establish the target and component operational safety, and also provide documented analysis that can be referred to in the future.

  2. Thermal creep force: analysis and application

    OpenAIRE

    Wolfe, David M.

    2016-01-01

    Approved for public release; distribution is unlimited The existence of two motive forces on a Crookes radiometer has complicated the investigation of either force independently. The thermal creep shear force, in particular, has been subject to differing interpretations of the direction in which it acts and its order of magnitude. A horizontal vane radiometer design is provided, which isolates the thermal creep shear force. The horizontal vane radiometer is explored through experiment, kin...

  3. Differential equation analysis in biomedical science and engineering ordinary differential equation applications with R

    CERN Document Server

    Schiesser, William E

    2014-01-01

    Features a solid foundation of mathematical and computational tools to formulate and solve real-world ODE problems across various fields With a step-by-step approach to solving ordinary differential equations (ODEs), Differential Equation Analysis in Biomedical Science and Engineering: Ordinary Differential Equation Applications with R successfully applies computational techniques for solving real-worldODE problems that are found in a variety of fields, including chemistry, physics, biology,and physiology. The book provides readers with the necessary knowledge to reproduce andextend the comp

  4. Differential equation analysis in biomedical science and engineering partial differential equation applications with R

    CERN Document Server

    Schiesser, William E

    2014-01-01

    Features a solid foundation of mathematical and computational tools to formulate and solve real-world PDE problems across various fields With a step-by-step approach to solving partial differential equations (PDEs), Differential Equation Analysis in Biomedical Science and Engineering: Partial Differential Equation Applications with R successfully applies computational techniques for solving real-world PDE problems that are found in a variety of fields, including chemistry, physics, biology, and physiology. The book provides readers with the necessary knowledge to reproduce and extend the com

  5. Transcriptomic Analysis of Flower Bud Differentiation in Magnolia sinostellata

    Directory of Open Access Journals (Sweden)

    Lijie Fan

    2018-04-01

    Full Text Available Magnolias are widely cultivated for their beautiful flowers, but despite their popularity, the molecular mechanisms regulating flower bud differentiation have not been elucidated. Here, we used paraffin sections and RNA-seq to study the process of flower bud differentiation in Magnolia sinostellata. Flower bud development occurred between 28 April and 30 May 2017 and was divided into five stages: undifferentiated, early flower bud differentiation, petal primordium differentiation, stamen primordium differentiation, and pistil primordium differentiation. A total of 52,441 expressed genes were identified, of which 11,592 were significantly differentially expressed in the five bud development stages. Of these, 82 genes were involved in the flowering. In addition, MADS-box and AP2 family genes play critical roles in the formation of flower organs and 20 differentially expressed genes associated with flower bud differentiation were identified in M. sinostellata. A qRT-PCR analysis verified that the MADS-box and AP2 family genes were expressed at high levels during flower bud differentiation. Consequently, this study provides a theoretical basis for the genetic regulation of flowering in M. sinostellata, which lays a foundation for further research into flowering genes and may facilitate the development of new cultivars.

  6. Noise Analysis of Single-Ended Input Differential Amplifier using Stochastic Differential Equation

    OpenAIRE

    Tarun Kumar Rawat; Abhirup Lahiri; Ashish Gupta

    2008-01-01

    In this paper, we analyze the effect of noise in a single- ended input differential amplifier working at high frequencies. Both extrinsic and intrinsic noise are analyzed using time domain method employing techniques from stochastic calculus. Stochastic differential equations are used to obtain autocorrelation functions of the output noise voltage and other solution statistics like mean and variance. The analysis leads to important design implications and suggests changes in the device parame...

  7. Acoustic Emission Analysis of Damage Progression in Thermal Barrier Coatings Under Thermal Cyclic Conditions

    Science.gov (United States)

    Appleby, Matthew; Zhu, Dongming; Morscher, Gregory

    2015-01-01

    Damage evolution of electron beam-physical vapor deposited (EBVD-PVD) ZrO2-7 wt.% Y2O3 thermal barrier coatings (TBCs) under thermal cyclic conditions was monitored using an acoustic emission (AE) technique. The coatings were heated using a laser heat flux technique that yields a high reproducibility in thermal loading. Along with AE, real-time thermal conductivity measurements were also taken using infrared thermography. Tests were performed on samples with induced stress concentrations, as well as calcium-magnesium-alumino-silicate (CMAS) exposure, for comparison of damage mechanisms and AE response to the baseline (as-produced) coating. Analysis of acoustic waveforms was used to investigate damage development by comparing when events occurred, AE event frequency, energy content and location. The test results have shown that AE accumulation correlates well with thermal conductivity changes and that AE waveform analysis could be a valuable tool for monitoring coating degradation and provide insight on specific damage mechanisms.

  8. Thermal analysis of annular fins with temperature-dependent thermal properties

    Institute of Scientific and Technical Information of China (English)

    I. G. AKSOY

    2013-01-01

    The thermal analysis of the annular rectangular profile fins with variable thermal properties is investigated by using the homotopy analysis method (HAM). The thermal conductivity and heat transfer coefficient are assumed to vary with a linear and power-law function of temperature, respectively. The effects of the thermal-geometric fin parameter and the thermal conductivity parameter variations on the temperature distribution and fin efficiency are investigated for different heat transfer modes. Results from the HAM are compared with numerical results of the finite difference method (FDM). It can be seen that the variation of dimensionless parameters has a significant effect on the temperature distribution and fin efficiency.

  9. Long SAGE analysis of genes differentially expressed in the midgut ...

    African Journals Online (AJOL)

    Long SAGE analysis of genes differentially expressed in the midgut and silk gland between the sexes of the silkwormBombyx mori. Liping Gan, Ying Wang, Jian Xi, Yanshan Niu, Hongyou Qin, Yanghu Sima, Shiqing Xu ...

  10. PC analysis of stochastic differential equations driven by Wiener noise

    KAUST Repository

    Le Maitre, Olivier; Knio, Omar

    2015-01-01

    A polynomial chaos (PC) analysis with stochastic expansion coefficients is proposed for stochastic differential equations driven by additive or multiplicative Wiener noise. It is shown that for this setting, a Galerkin formalism naturally leads

  11. International conference Fourier Analysis and Pseudo-Differential Operators

    CERN Document Server

    Turunen, Ville; Fourier Analysis : Pseudo-differential Operators, Time-Frequency Analysis and Partial Differential Equations

    2014-01-01

    This book is devoted to the broad field of Fourier analysis and its applications to several areas of mathematics, including problems in the theory of pseudo-differential operators, partial differential equations, and time-frequency analysis. This collection of 20 refereed articles is based on selected talks given at the international conference “Fourier Analysis and Pseudo-Differential Operators,” June 25–30, 2012, at Aalto University, Finland, and presents the latest advances in the field. The conference was a satellite meeting of the 6th European Congress of Mathematics, which took place in Krakow in July 2012; it was also the 6th meeting in the series “Fourier Analysis and Partial Differential Equations.”

  12. Differential thermal, Thermogravimetric and X-ray diffraction investigation of hydration phases in cementitious waste form

    International Nuclear Information System (INIS)

    Khalil, M.Y.; Nagy, M.E.; El-Sourougy, M.R.; Zaki, A.A.

    1996-01-01

    Hydration phases of cement determine the final properties of the product. Adding other components to the cement paste may alter the final phases formed and affect properties of the hardened products. In this work ordinary portland cement and/or blast furnace slag cement were hardened with low-or intermediate-level radioactive liquid wastes and different additives. Hydration phases were investigated using differential thermal, thermogravimetric, and X-ray diffraction techniques. Low-and intermediate-level liquid wastes were found not to affect the hydration phases of cement. The addition of inorganic exchangers and latex were found to affect the hydration properties of the cement waste system. This resulted in a reduction of compressive strength. On the contrary, addition of epoxy also affected the hydration causing increase in compressive strength. 10 figs., 2 tabs

  13. On the thermal stability of a radiating gas under general differential approximation

    International Nuclear Information System (INIS)

    Bestman, A.R.

    1988-02-01

    The thermal stability of a radiating gas in a semi-infinite space is studied under a general differential approximation. The fluid is bounded on the axis z'=0 by a horizontal infinite wall maintained at a temperature T 0 which is high enough for radiative heat transfer to be significant. At z'=∞, the fluid is at uniform temperature T ∞ such that T 0 >T ∞ . The equations of motion under small perturbation theory reduce to a set of linear homogeneous equations with a variable coefficient subject to homogeneous boundary conditions when the unperturbed temperature is adopted as the independent variable. The solution is effected via a finite difference scheme and the Rayleigh number is determined by Newton's iterative method. (author). 8 refs

  14. Thermal analysis on organic phase change materials for heat storage applications

    Science.gov (United States)

    Lager, Daniel

    2016-07-01

    In this paper, methodologies based on thermal analysis to evaluate specific heat capacity, phase transition enthalpies, thermal cycling stability and thermal conductivity of organic phase change materials (PCMs) are discussed. Calibration routines for a disc type heat flow differential scanning calorimetry (hf-DSC) are compared and the applied heating rates are adapted due to the low thermal conductivity of the organic PCMs. An assessment of thermal conductivity measurements based on "Laser Flash Analysis" (LFA) and the "Transient Hot Bridge" method (THB) in solid and liquid state has been performed. It could be shown that a disc type hf-DSC is a useful method for measuring specific heat capacity, melting enthalpies and cycling stability of organic PCM if temperature and sensitivity calibration are adapted to the material and quantity to be measured. The LFA method shows repeatable and reproducible thermal diffusivity results in solid state and a high effort for sample preparation in comparison to THB in liquid state. Thermal conductivity results of the two applied methods show large deviations in liquid phase and have to be validated by further experiments.

  15. Effect of irradiation on differential thermal properties and crystallization behavior of some lithium borate glasses

    International Nuclear Information System (INIS)

    El-Alaily, N.A.; Mohamed, R.M.

    2001-01-01

    Differential thermal properties and the crystallization behavior of binary system Li 2 O-B 2 O 3 glasses were investigated. The effects of the presence of oxides of aluminum, lead or one of the transition metals TiO 2 or V 2 O 5 or Fe 2 O 3 in the parent glass were also studied. The effects of three different heat treatments on the crystalline structure of all the studied glasses were also investigated. The results showed that all glass samples were amorphous before the heat treatment, with the most common formed phase being tetraborate Li 2 B 8 O 13 (Li 2 O-4B 2 O 3 ). The exposure of the glass samples to either gamma rays or fast neutrons resulted in considerable changes in their thermal behavior. The results also showed that T g increases for all studied glasses when subjected to irradiation either by fast neutron or gamma rays, while T c decreased only at higher doses

  16. Phase relations in the system NaCl-KCl-H2O: IV. Differential thermal analysis of the sylvite liquidus in the KCl-H2O binary, the liquidus in the NaCl-KCl-H2O ternary, and the solidus in the NaCl-KCl binary to 2 kb pressure, and a summary of experimental data for thermodynamic-PTX analysis of solid-liquid equilibria at elevated P-T conditions

    Science.gov (United States)

    Chou, I.-Ming; Sterner, S.M.; Pitzer, Kenneth S.

    1992-01-01

    The sylvite liquidus in the binary system KCl-H2O and the liquidus in the ternary system NaCl-KCl-H2O were determined by using isobaric differential thermal analysis (DTA) cooling scans at pressures up to 2 kbars. Sylvite solubilities along the three-phase curve in the binary system KCl-H2O were obtained by the intersection of sylvite-liquidus isopleths with the three-phase curve in a P-T plot. These solubility data can be represented by the equation Wt.% KCl (??0.2) = 12.19 + 0.1557T - 5.4071 ?? 10-5 T2, where 400 ??? T ??? 770??C. These data are consistent with previous experimental observations. The solidus in the binary system NaCl-KCl was determined by using isobaric DTA heating scans at pressures up to 2 kbars. Using these liquidus and solidus data and other published information, a thermodynamic-PTX analysis of solid-liquid equilibria at high pressures and temperatures for the ternary system has been performed and is presented in an accompanying paper (Part V of this series). However, all experimental liquidus, solidus, and solvus data used in this analysis are summarized in this report (Part IV) and they are compared with the calculated values based on the analysis. ?? 1992.

  17. SLAC divertor channel entrance thermal stress analysis

    International Nuclear Information System (INIS)

    Johnson, G.L.; Stein, W.; Lu, S.C.; Riddle, R.A.

    1985-01-01

    X-ray beams emerging from the new SLAC electron-positron storage ring (PEP) impinge on the entrance to tangential divertor channels causing highly localized heating in the channel structure. Analyses were completed to determine the temperatures and thermally-induced stresses due to this heating. These parts are cooled with water flowing axially over them at 30 0 C. The current design and operating conditions should result in the entrance to the new divertor channel operating at a peak temperature of 123 0 C with a peak thermal stress at 91% of yield. Any micro-cracks that form due to thermally-induced stresses should not propagate to the coolant wall nor form a path for the coolant to leak into the storage ring vacuum. 34 figs., 4 tabs

  18. Thermal analysis of a glass bending process

    International Nuclear Information System (INIS)

    Buonanno, G.; Dell'Isola, M.; Frattolillo, A.; Giovinco, G.

    2005-01-01

    The paper presents the thermal simulation of naturally ventilated ovens used in glass sheets hot forming for windscreen production. The determination of thermal and flow conditions in the oven and, consequently, the windshield temperature distribution is necessary both for the productive process optimisation and to assure beforehand, without any iterative tuning process, the required characteristics of the product considered. To this purpose, the authors carried out a 3D numerical simulation of the thermal interaction between the glass and the oven internal surfaces during the whole heating process inside the oven. In particular, a finite volumes method was used to take into account both the convective, conductive and radiative heat transfer in the oven. The numerical temperature distribution in the glass was validated through the comparison with the data obtained from an experimental apparatus designed and built for the purpose

  19. DIFFERENTIAL BLOOD COUNT OF TENCH Tinca tinca (Linnaeus, 1758 IN CONDITIONS OF THERMAL STRESS

    Directory of Open Access Journals (Sweden)

    Edhem Hasković

    2014-03-01

    Full Text Available Defining the physiological feature provides an understanding of functional adaptation of species to its ecological niche as well as the various forms of stress factors. This paper gives an overview of changes in certain forms of leukocytes (WBC differential under the influence of thermal stress (increased temperature. In our experiment, we used 46 specimens of tench (Tinca tinca fished in the Jablanica Lake reservoir. Specimens had previously been adapted in specially prepared tanks for 20 days.  The control group of animals (16 was exposed to constant water temperature of 10 0C, while in the treated groups (30, the water temperature was gradually risen to 28 0C and, as such, held for 30 minutes. All specimens were aged 2+ and 3+.It was found that the thermal regime change causes adaptive response of tench specimens by increasing the number of neutrophils and pseudoeosinophils but reduction in the number of lymphocytes. Observed were statistically significant differences in the number of segmented granulocytes, pseudoeosinophils and lymphocytes between the control and the experimental group. However, a significantly higher number of segmented granulocytes and pseudoeosinophils was at the experimental group, while in the control group a number of lymphocytes was significantly higher compared with the experimental group. Neither form of leukocytes showed any significant difference between males and females of the experimental group. It is interesting to note that among individuals from both the control and experimental group, eosinophils and monocytes were rarely noticed, while basophils were not found at all. Key words: thermal stress, tench, Tinca tinca, pseudoeosinophils

  20. Small thermal oscillation analysis of the MOTA

    International Nuclear Information System (INIS)

    Guthrie, G.L.

    1978-09-01

    The MOTA (Materials Open Test Assembly) was designed to achieve a degree of thermal regulation compatible with the generation of useful materials property data obtained by irradiation of candidate reactor structural materials in the FFTF. Attaining a high degree of regulation is limited by the necessity to avoid undamped thermal oscillations. The report documents some of the analyses used to select usable configurations and determine effects of parameter choices, and investigates limitations on allowable gains of the sensor-control-valve assembly. The main purpose of the document is to make the methods available to others, rather than to give a tabulation of specific numerical results

  1. Dynamic data analysis modeling data with differential equations

    CERN Document Server

    Ramsay, James

    2017-01-01

    This text focuses on the use of smoothing methods for developing and estimating differential equations following recent developments in functional data analysis and building on techniques described in Ramsay and Silverman (2005) Functional Data Analysis. The central concept of a dynamical system as a buffer that translates sudden changes in input into smooth controlled output responses has led to applications of previously analyzed data, opening up entirely new opportunities for dynamical systems. The technical level has been kept low so that those with little or no exposure to differential equations as modeling objects can be brought into this data analysis landscape. There are already many texts on the mathematical properties of ordinary differential equations, or dynamic models, and there is a large literature distributed over many fields on models for real world processes consisting of differential equations. However, a researcher interested in fitting such a model to data, or a statistician interested in...

  2. Thermal analysis of cold vacuum drying of spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Piepho, M.G.

    1998-07-20

    The thermal analysis examined transient thermal and chemical behavior of the Multi canister Overpack (MCO) container for a broad range of cases that represent the Cold Vacuum Drying (CVD) processes. The cases were defined to consider both normal and off-normal operations at the CVD Facility for an MCO with Mark IV N, Reactor spent fuel in four fuel baskets and one scrap basket. This analysis provides the basis for the MCO thermal behavior at the CVD Facility for its Phase 2 Safety Analysis Report (revision 4).

  3. Inverse thermal analysis method to study solidification in cast iron

    DEFF Research Database (Denmark)

    Dioszegi, Atilla; Hattel, Jesper

    2004-01-01

    Solidification modelling of cast metals is widely used to predict final properties in cast components. Accurate models necessitate good knowledge of the solidification behaviour. The present study includes a re-examination of the Fourier thermal analysis method. This involves an inverse numerical...... solution of a 1-dimensional heat transfer problem connected to solidification of cast alloys. In the analysis, the relation between the thermal state and the fraction solid of the metal is evaluated by a numerical method. This method contains an iteration algorithm controlled by an under relaxation term...... inverse thermal analysis was tested on both experimental and simulated data....

  4. Thermal analysis of the IDENT 1578 fuel pin shipping container

    International Nuclear Information System (INIS)

    Ingham, J.G.

    1980-01-01

    The IDENT 1578 container, which is a 110-in. long 5.5-in. OD tube, is designed for shipping FFTF fuel elements in T-3 casks between HEDL, HFEF, and other laboratories. The thermal analysis was conducted to evaluate whether or not the container satisfies its thermal design criteria

  5. Thermal analysis elements of liquefied gas storage tanks

    Science.gov (United States)

    Yanvarev, I. A.; Krupnikov, A. V.

    2017-08-01

    Tasks of solving energy and resource efficient usage problems, both for oil producing companies and for companies extracting and transporting natural gas, are associated with liquefied petroleum gas technology development. Improving the operation efficiency of liquefied products storages provides for conducting structural, functional, and appropriate thermal analysis of tank parks in the general case as complex dynamic thermal systems.

  6. Lumped thermal capacitance analysis of transient heat conduction ...

    African Journals Online (AJOL)

    Lumped thermal capacitance analysis has been undertaken to investigate the transient temperature variations, associated induced thermal stress distributions, and the structural integrity of Ghana Research Reactor-1 (GHAR R-1) vessel after 15 years of operation. The beltline configuration of the cylindrical vessel of the ...

  7. Statistical analysis of thermal conductivity of nanofluid containing ...

    Indian Academy of Sciences (India)

    Thermal conductivity measurements of nanofluids were analysed via two-factor completely randomized design and comparison of data means is carried out with Duncan's multiple-range test. Statistical analysis of experimental data show that temperature and weight fraction have a reasonable impact on the thermal ...

  8. Study of the aging processes in polyurethane adhesives using thermal treatment and differential calorimetric, dielectric, and mechanical techniques ; 1, identifying the aging processes ; 2, quantifying the aging effect

    CERN Document Server

    Althouse, L P

    1979-01-01

    Study of the aging processes in polyurethane adhesives using thermal treatment and differential calorimetric, dielectric, and mechanical techniques ; 1, identifying the aging processes ; 2, quantifying the aging effect

  9. Thermal behavior and kinetics assessment of ethanol/gasoline blends during combustion by thermogravimetric analysis

    International Nuclear Information System (INIS)

    3, CEP 12.516-410 Guaratinguetá, SP (Brazil); U.T.P. – Universidad Tecnológica de Pereira, Faculty of Mechanical Engineering, Pereira, Risaralda (Colombia))" data-affiliation=" (UNESP – Univ Estadual Paulista, Campus of Guaratinguetá, Department of Energy, Laboratory of Combustion and Carbon Capture LC3, CEP 12.516-410 Guaratinguetá, SP (Brazil); U.T.P. – Universidad Tecnológica de Pereira, Faculty of Mechanical Engineering, Pereira, Risaralda (Colombia))" >Rios Quiroga, Luis Carlos; 3, CEP 12.516-410 Guaratinguetá, SP (Brazil))" data-affiliation=" (UNESP – Univ Estadual Paulista, Campus of Guaratinguetá, Department of Energy, Laboratory of Combustion and Carbon Capture LC3, CEP 12.516-410 Guaratinguetá, SP (Brazil))" >Balestieri, José 3, CEP 12.516-410 Guaratinguetá, SP (Brazil))" data-affiliation=" (UNESP – Univ Estadual Paulista, Campus of Guaratinguetá, Department of Energy, Laboratory of Combustion and Carbon Capture LC3, CEP 12.516-410 Guaratinguetá, SP (Brazil))" >Antonio Perrella; 3, CEP 12.516-410 Guaratinguetá, SP (Brazil))" data-affiliation=" (UNESP – Univ Estadual Paulista, Campus of Guaratinguetá, Department of Energy, Laboratory of Combustion and Carbon Capture LC3, CEP 12.516-410 Guaratinguetá, SP (Brazil))" >Ávila, Ivonete

    2017-01-01

    Highlights: • Kinetic parameters of thermal decomposition events were obtained. • Thermal analysis was used as a tool for understanding combustion processes. • Blends would be classified using thermogravimetric analysis technics. • Synergistic effect of ethanol mixed with gasoline was studied and defined. • Relative error and activation energy values were used to analyze the synergy. - Abstract: The use of ethanol as a fuel or as an additive blended with gasoline is very important for most countries, which aim to reduce the heavy dependence on fossil fuels and mitigate greenhouse gases emission. An increased use of ethanol-gasoline blends has placed great relevance on acquiring knowledge about their physical and chemical properties. Thus, knowledge of such properties favors a better understanding of the effect of the percentage of ethanol/gasoline blends on engine performance. Thence, the present study has established a correlation between activation energy and synergetic effects, obtained by a thermal analysis, and ethanol content in gasoline for different blends in order to use this technique as a tool to classify these blends in the process in order to obtain useful energy in spark ignition engines. For such a purpose, a kinetic study has been conducted through a simultaneous thermal analysis system – TGA (thermogravimetry analysis) and DTA (differential thermal analysis) by following the methodology of non-isothermal tests. Thermogravimetric tests were performed and fuel activation energies for gasoline, ethanol, and percentages of 5, 10, 15, 20, 25, 30, 50, and 75% (%v) ethanol mixed with gasoline, which was achieved by the model free kinetics. The analysis results suggest that the theoretical curves characteristics of the thermal decomposition of ethanol-gasoline blends are rather different due to their ethanol content. Furthermore, it was observed significant interactions and synergistic effects, especially regarding those with low ethanol

  10. Thermal-buckling analysis of an LMFBR overflow vessel

    International Nuclear Information System (INIS)

    Severud, L.K.

    1983-01-01

    During a reactor scram, cold sodium flows into the hot overflow vessel. The effect on the vessel is a compressive thermal stress in a zone just above the sodium level. This condition must be sufficiently controlled to preclude thermal buckling. Also, under repeated scrams, the vessel should not suffer thermal stress low cycle fatigue. To evaluate the closeness to buckling and satisfaction of ASMA Code limits, a combination of simple approximations, detailed elastic shell buckling analyses, and correlations to results of thermal buckling tests were employed. This paper describes the analysis methods, special considerations, and evaluations accomplished for this FFTF vessel to assure satisfaction of ASME buckling design criteria, rules, and limits

  11. Thermodynamic analysis of pumped thermal electricity storage

    International Nuclear Information System (INIS)

    White, Alexander; Parks, Geoff; Markides, Christos N.

    2013-01-01

    The increasing use of renewable energy technologies for electricity generation, many of which have an unpredictably intermittent nature, will inevitably lead to a greater need for electricity storage. Although there are many existing and emerging storage technologies, most have limitations in terms of geographical constraints, high capital cost or low cycle life, and few are of sufficient scale (in terms of both power and storage capacity) for integration at the transmission and distribution levels. This paper is concerned with a relatively new concept which will be referred to here as Pumped Thermal Electricity Storage (PTES), and which may be able to make a significant contribution towards future storage needs. During charge, PTES makes use of a high temperature ratio heat pump to convert electrical energy into thermal energy which is stored as ‘sensible heat’ in two thermal reservoirs, one hot and one cold. When required, the thermal energy is then converted back to electricity by effectively running the heat pump backwards as a heat engine. The paper focuses on thermodynamic aspects of PTES, including energy and power density, and the various sources of irreversibility and their impact on round-trip efficiency. It is shown that, for given compression and expansion efficiencies, the cycle performance is controlled chiefly by the ratio between the highest and lowest temperatures in each reservoir rather than by the cycle pressure ratio. The sensitivity of round-trip efficiency to various loss parameters has been analysed and indicates particular susceptibility to compression and expansion irreversibility

  12. Experimental analysis of current conduction through thermally ...

    Indian Academy of Sciences (India)

    Electrical properties of SiO2 grown on the Si-face of the epitaxial 4H-SiC ... Thermal oxide reliability is one of the most critical concerns in the realization of ... material for high temperature, high power, high frequency, and nonvolatile .... conduction mechanism in MOSiC system with varying oxide thicknesses has been.

  13. Thermal CFD Analysis of Tubular Light Guides

    Directory of Open Access Journals (Sweden)

    Ondřej Šikula

    2013-12-01

    Full Text Available Tubular light guides are applicable for daylighting of windowless areas in buildings. Despite their many positive indoor climate aspects they can also present some problems with heat losses and condensation. A computer CFD model focused on the evaluation of temperature distribution and air flow inside tubular light guides of different dimensions was studied. The physical model of the tested light guides of lengths more than 0.60 m proves shows that Rayleigh numbers are adequate for a turbulent air flow. The turbulent model was applied despite the small heat flux differences between the turbulent and laminar model. The CFD simulations resulted into conclusions that the growing ratio of length/diameter increases the heat transmission loss/linear transmittance as much as by 50 percent. Tubular light guides of smaller diameters have lower heat transmission losses compared to the wider ones of the same lengths with the same outdoor temperature being taken into account. The simulation results confirmed the thermal bridge effect of the tubular light guide tube inside the insulated flat roof details. The thermal transmittance of the studied light guides in the whole roof area was substituted with the point thermal bridges. This substitution gives possibility for simple thermal evaluation of the tubular light pipes in roof constructions.

  14. Construction of a fast differential thermal analysis apparatus

    International Nuclear Information System (INIS)

    Vernois, G.

    1964-10-01

    The author analyzes the various possibilities of DTA as well as conventional installation set-ups. He shows that by varying simultaneously the heating rate and the size of the samples it is possible to obtain very similar thermo-grams. He shows the advantages of using fast heating rates and proposes a type of oven and types of crucible which allow heating rates of over 1 deg. per second, rapid manipulation, a controlled atmosphere (from a vacuum up to high pressures) and forced cooling. He gives details of research carried with this type of installation showing the quantitative nature of the analyses and, as an example, studies the influence of a grinding on the qualitative and quantitative results. (author) [fr

  15. CRYSTALLIZATION KINETICS OF GLASS-CERAMICS BY DIFFERENTIAL THERMAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    A. NOZAD

    2011-06-01

    Full Text Available The crystallization behavior of fluorphlogopite, a glass-ceramic in the MgO–SiO2–Al2O3–K2O–B2O3–F system, was studied by substitution of Li2O for K2O in the glass composition. DTA, XRD and SEM were used for the study of crystallization behavior, formed phases and microstructure of the resulting glass-ceramics. Crystallization kinetics of the glass was investigated under non-isothermal conditions, using the formal theory of transformations for heterogeneous nucleation. The crystallization results were analyzed, and both the activation energy of crystallization process as well as the crystallization mechanism were characterized. Calculated kinetic parameters indicated that the appropriate crystallization mechanism was bulk crystallization for base glass and the sample with addition of Li2O. Non-isothermal DTA experiments showed that the crystallization activation energies of base glasses was in the range of 234-246 KJ/mol and in the samples with addition of Li2O was changed to the range of 317-322 KJ/mol.

  16. Contact Thermal Analysis and Wear Simulation of a Brake Block

    Directory of Open Access Journals (Sweden)

    Nándor Békési

    2013-01-01

    Full Text Available The present paper describes an experimental test and a coupled contact-thermal-wear analysis of a railway wheel/brake block system through the braking process. During the test, the friction, the generated heat, and the wear were evaluated. It was found that the contact between the brake block and the wheel occurs in relatively small and slowly moving hot spots, caused by the wear and the thermal effects. A coupled simulation method was developed including numerical frictional contact, transient thermal and incremental wear calculations. In the 3D simulation, the effects of the friction, the thermal expansion, the wear, and the temperature-dependent material properties were also considered. A good agreement was found between the results of the test and the calculations, both for the thermal and wear results. The proposed method is suitable for modelling the slowly oscillating wear caused by the thermal expansions in the contact area.

  17. Evaluation of Thermal Margin Analysis Models for SMART

    International Nuclear Information System (INIS)

    Seo, Kyong Won; Kwon, Hyuk; Hwang, Dae Hyun

    2011-01-01

    Thermal margin of SMART would be analyzed by three different methods. The first method is subchannel analysis by MATRA-S code and it would be a reference data for the other two methods. The second method is an on-line few channel analysis by FAST code that would be integrated into SCOPS/SCOMS. The last one is a single channel module analysis by safety analysis. Several thermal margin analysis models for SMART reactor core by subchannel analysis were setup and tested. We adopted a strategy of single stage analysis for thermal analysis of SMART reactor core. The model should represent characteristics of the SMART reactor core including hot channel. The model should be simple as possible to be evaluated within reasonable time and cost

  18. New methodology developed for the differential scanning calorimetry analysis of polymeric matrixes incorporating phase change materials

    International Nuclear Information System (INIS)

    Barreneche, Camila; Solé, Aran; Miró, Laia; Martorell, Ingrid; Cabeza, Luisa F; Fernández, A Inés

    2012-01-01

    Nowadays, thermal comfort needs in buildings have led to an increase in energy consumption of the residential and service sectors. For this reason, thermal energy storage is shown as an alternative to achieve reduction of this high consumption. Phase change materials (PCM) have been studied to store energy due to their high storage capacity. A polymeric material capable of macroencapsulating PCM was developed by the authors of this paper. However, difficulties were found while measuring the thermal properties of these materials by differential scanning calorimetry (DSC). The polymeric matrix interferes in the detection of PCM properties by DSC. To remove this interfering effect, a new methodology which replaces the conventional empty crucible used as a reference in the DSC analysis by crucibles composed of the polymeric matrix was developed. Thus, a clear signal from the PCM is obtained by subtracting the new full crucible signal from the sample signal. (paper)

  19. Neutron importance calculation in an equivalent cell using the age approximation and differential thermalization models. Determination of the cross section sensitivity to the parameters of a differential model in the thermal range

    International Nuclear Information System (INIS)

    Sidorenko, V.D.

    1978-01-01

    The equations are discussed for calculating the importance of neutron function in heterogeneous media obtained with the integral transport theory method. The thermalization effect in the thermal range is described using the differential model. The account of neutron slowing-down in the epithermal range is accomplished in the age approximation. The fast range is described in the 3-group approximation. On the basis of the equations derived the share of delayed neutrons and lifetimes of prompt neutrons are calculated and compared with available experimental data. In the thermal range the sensitivity of cross sections to some parameters of the differential model is analyzed for reactor cells typical for WWER type reactor cores. The models and approximations used are found to be adequate for the calculations

  20. Performance analysis of a lunar based solar thermal power system with regolith thermal storage

    International Nuclear Information System (INIS)

    Lu, Xiaochen; Ma, Rong; Wang, Chao; Yao, Wei

    2016-01-01

    The manned deep-space exploration is a hot topic of the current space activities. The continuous supply of thermal and electrical energy for the scientific equipment and human beings is a crucial issue for the lunar outposts. Since the night lasts for periods of about 350 h at most locations on the lunar surface, massive energy storage is required for continuous energy supply during the lengthy lunar night and the in-situ resource utilization is demanded. A lunar based solar thermal power system with regolith thermal storage is presented in this paper. The performance analysis is carried out by the finite-time thermodynamics to take into account major irreversible losses. The influences of some key design parameters are analyzed for system optimization. The analytical results shows that the lunar based solar thermal power system with regolith thermal storage can meet the requirement of the continuous energy supply for lunar outposts. - Highlights: • A lunar based solar thermal power system with regolith thermal storage is presented. • The performance analysis is carried out by the finite-time thermodynamics. • The influences of some key design parameters are analyzed.

  1. Thermal protection system gap analysis using a loosely coupled fluid-structural thermal numerical method

    Science.gov (United States)

    Huang, Jie; Li, Piao; Yao, Weixing

    2018-05-01

    A loosely coupled fluid-structural thermal numerical method is introduced for the thermal protection system (TPS) gap thermal control analysis in this paper. The aerodynamic heating and structural thermal are analyzed by computational fluid dynamics (CFD) and numerical heat transfer (NHT) methods respectively. An interpolation algorithm based on the control surface is adopted for the data exchanges on the coupled surface. In order to verify the analysis precision of the loosely coupled method, a circular tube example was analyzed, and the wall temperature agrees well with the test result. TPS gap thermal control performance was studied by the loosely coupled method successfully. The gap heat flux is mainly distributed in the small region at the top of the gap which is the high temperature region. Besides, TPS gap temperature and the power of the active cooling system (CCS) calculated by the traditional uncoupled method are higher than that calculated by the coupled method obviously. The reason is that the uncoupled method doesn't consider the coupled effect between the aerodynamic heating and structural thermal, however the coupled method considers it, so TPS gap thermal control performance can be analyzed more accurately by the coupled method.

  2. Dynamic thermal analysis of machines in running state

    CERN Document Server

    Wang, Lihui

    2014-01-01

    With the increasing complexity and dynamism in today’s machine design and development, more precise, robust and practical approaches and systems are needed to support machine design. Existing design methods treat the targeted machine as stationery. Analysis and simulation are mostly performed at the component level. Although there are some computer-aided engineering tools capable of motion analysis and vibration simulation etc., the machine itself is in the dry-run state. For effective machine design, understanding its thermal behaviours is crucial in achieving the desired performance in real situation. Dynamic Thermal Analysis of Machines in Running State presents a set of innovative solutions to dynamic thermal analysis of machines when they are put under actual working conditions. The objective is to better understand the thermal behaviours of a machine in real situation while at the design stage. The book has two major sections, with the first section presenting a broad-based review of the key areas of ...

  3. Finite element analysis of thermal stress distribution in different ...

    African Journals Online (AJOL)

    Nigerian Journal of Clinical Practice • Jan-Feb 2016 • Vol 19 • Issue 1. Abstract ... Key words: Amalgam, finite element method, glass ionomer cement, resin composite, thermal stress ... applications for force analysis and assessment of different.

  4. Shuttle TPS thermal performance and analysis methodology

    Science.gov (United States)

    Neuenschwander, W. E.; Mcbride, D. U.; Armour, G. A.

    1983-01-01

    Thermal performance of the thermal protection system was approximately as predicted. The only extensive anomalies were filler bar scorching and over-predictions in the high Delta p gap heating regions of the orbiter. A technique to predict filler bar scorching has been developed that can aid in defining a solution. Improvement in high Delta p gap heating methodology is still under study. Minor anomalies were also examined for improvements in modeling techniques and prediction capabilities. These include improved definition of low Delta p gap heating, an analytical model for inner mode line convection heat transfer, better modeling of structure, and inclusion of sneak heating. The limited number of problems related to penetration items that presented themselves during orbital flight tests were resolved expeditiously, and designs were changed and proved successful within the time frame of that program.

  5. Thermal-hydraulic analysis of nuclear reactors

    CERN Document Server

    Zohuri, Bahman

    2015-01-01

    This text covers the fundamentals of thermodynamics required to understand electrical power generation systems and the application of these principles to nuclear reactor power plant systems. It is not a traditional general thermodynamics text, per se, but a practical thermodynamics volume intended to explain the fundamentals and apply them to the challenges facing actual nuclear power plants systems, where thermal hydraulics comes to play.  Written in a lucid, straight-forward style while retaining scientific rigor, the content is accessible to upper division undergraduate students and aimed at practicing engineers in nuclear power facilities and engineering scientists and technicians in industry, academic research groups, and national laboratories. The book is also a valuable resource for students and faculty in various engineering programs concerned with nuclear reactors. This book also: Provides extensive coverage of thermal hydraulics with thermodynamics in nuclear reactors, beginning with fundamental ...

  6. LOFT blowdown loop piping thermal analysis Class I review

    International Nuclear Information System (INIS)

    Kinnaman, T.L.

    1978-01-01

    In accordance with ASME Code, Section III requirements, all analyses of Class I components must be independently reviewed. Since the LOFT blowdown loop piping up through the blowdown valve is a Class I piping system, the thermal analyses are reviewed. The Thermal Analysis Branch comments to this review are also included. It is the opinion of the Thermal Analysis Branch that these comments satisfy all of the reviewers questions and that the analyses should stand as is, without additional considerations in meeting the ASME Code requirements and ANC Specification 60139

  7. An analysis of transient thermal properties for high power GaN-based laser diodes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Min; Kim, Seungtaek; Kang, Sung Bok; Kim, Young Jin; Jeong, Hoon; Lee, Kyeongkyun; Kim, Jongseok [Korea Institute of Industrial Technology, 35-3 Hongcheon-Ri, Ipjang-Myeon, Cheonan, Chungnam 331-825 (Korea); Lee, Sangdon; Suh, Dongsik [QSI Co., Ltd., 315-9 Cheonheung-Ri, Sungger-Eup, Cheonan, Chungnam 330-836 (Korea); Yi, Jeong Hoon; Choi, Yoonho; Jung, Seok Gu; Noh, Minsoo [LG Electronics Advanced Research Institute, 16 Woomyeon-Dong, Seocho-Gu, Seoul 137-724 (Korea)

    2010-07-15

    Thermal properties of 405 nm GaN-based laser diodes were investigated by employing a transient heating response method based on the temperature dependence of diode forward voltage. Thermal resistances of materials consisting of packaged laser diodes were differentiated in transient thermal response curves at a current below threshold current. With a current above threshold current, no significant change in thermal resistances and difference between junction-up and junction-down laser diodes was observed at pulses shorter than 3 sec. From an analysis with long current injections, thermal resistance of a packaged laser diode with a junction-up bonding was {proportional_to}45 C/W which was higher than that of a junction-down bonded laser diode by {proportional_to}10 C/W. Further analyses based on parameters obtained from voltage recovery curves indicated that the time constant for cooling is directly related to the thermal resistance and thermal capacitance of a laser diode package. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Transient analysis of the double pass photovoltaic thermal solar collector

    International Nuclear Information System (INIS)

    Alfegi, Ebrahim M.; Sopian, Kamaruzzaman; Abakr, Yousif A.

    2006-01-01

    A mathematical model of a double pass photovoltaic thermal (PV/T) solar collector is reported in this work. It is composed of five couple unsteady nonlinear partial differential equations which are solved by using Gear implicit numerical scheme. That model was validated against experimental data and was found to accurately predict the temperature of the circulated air as well as the temperature distribution of every static elements in a two-pass PV/T solar collector.(Author)

  9. Window design : visual and thermal consequences : analysis of the thermal and daylighting performance of windows

    NARCIS (Netherlands)

    Bergem-Jansen, P.M. van; Soeleman, R.S.

    1979-01-01

    Selected results of an analysis for the thermal and lighting requirements associated with windows in utility buildings are presented. This analysis concerns the effects of r¡indow size and shape, orientation and of different ways of supplementing the daylight by artifieial light for a typical office

  10. The analysis of thermally stimulated processes

    CERN Document Server

    Chen, R; Pamplin, Brian

    1981-01-01

    Thermally stimulated processes include a number of phenomena - either physical or chemical in nature - in which a certain property of a substance is measured during controlled heating from a 'low' temperature. Workers and graduate students in a wide spectrum of fields require an introduction to methods of extracting information from such measurements. This book gives an interdisciplinary approach to various methods which may be applied to analytical chemistry including radiation dosimetry and determination of archaeological and geological ages. In addition, recent advances are included, such

  11. Viscoelastic Analysis of Thermally Stiffening Polymer Nanocomposites

    Science.gov (United States)

    Ehlers, Andrew; Rende, Deniz; Senses, Erkan; Akcora, Pinar; Ozisik, Rahmi

    Poly(ethylene oxide), PEO, filled with silica nanoparticles coated with poly(methyl methacrylate), PMMA, was shown to present thermally stiffening behavior above the glass transition temperature of both PEO and PMMA. In the current study, the viscoelastic beahvior of this nanocomposite system is investigated via nanoindenation experiments to complement on going rheological studies. Results were compared to neat polymers, PEO and PMMA, to understand the effect of coated nanoparticles. This material is based upon work supported by the National Science Foundation under Grant No. CMMI-1538730.

  12. Thermal stress analysis of space shuttle orbiter wing skin panel and thermal protection system

    Science.gov (United States)

    Ko, William L.; Jenkins, Jerald M.

    1987-01-01

    Preflight thermal stress analysis of the space shuttle orbiter wing skin panel and the thermal protection system (TPS) was performed. The heated skin panel analyzed was rectangular in shape and contained a small square cool region at its center. The wing skin immediately outside the cool region was found to be close to the state of elastic instability in the chordwise direction based on the conservative temperature distribution. The wing skin was found to be quite stable in the spanwise direction. The potential wing skin thermal instability was not severe enough to tear apart the strain isolation pad (SIP) layer. Also, the preflight thermal stress analysis was performed on the TPS tile under the most severe temperature gradient during the simulated reentry heating. The tensile thermal stress induced in the TPS tile was found to be much lower than the tensile strength of the TPS material. The thermal bending of the TPS tile was not severe enough to cause tearing of the SIP layer.

  13. Thermal conductivity analysis and applications of nanocellulose materials

    Science.gov (United States)

    Uetani, Kojiro; Hatori, Kimihito

    2017-01-01

    Abstract In this review, we summarize the recent progress in thermal conductivity analysis of nanocellulose materials called cellulose nanopapers, and compare them with polymeric materials, including neat polymers, composites, and traditional paper. It is important to individually measure the in-plane and through-plane heat-conducting properties of two-dimensional planar materials, so steady-state and non-equilibrium methods, in particular the laser spot periodic heating radiation thermometry method, are reviewed. The structural dependency of cellulose nanopaper on thermal conduction is described in terms of the crystallite size effect, fibre orientation, and interfacial thermal resistance between fibres and small pores. The novel applications of cellulose as thermally conductive transparent materials and thermal-guiding materials are also discussed. PMID:29152020

  14. Thermal Analysis of Braille Formed by Using Screen Printing and Inks with Thermo Powder

    Directory of Open Access Journals (Sweden)

    Svіtlana HAVENKO

    2015-03-01

    Full Text Available In order to improve the integration of blind people into society, suitable conditions should be provided for them. The expansion of Braille (BR use could serve the purpose. Depending on the materials used for Braille, it can be formed or printed in different ways: embossing, screen printing, thermoforming, digital printing. The aim of this research is to determine the effect of thermal properties of screen printing inks and inks with thermo-powder on the qualitative parameters of Braille. Screen printing inks and inks with thermo-powder were chosen for the research. Carrying out the qualitative analysis of printouts with Braille, the thermal stability was evaluated by analyzing the thermograms obtained with derivatograph Q-1500. This paper presents the findings of the thermogravimetric (TG, differential thermogravimetric (DTG and differential thermal analysis (DTA of printouts printed on paperboard Plike and using traditional screen printing inks and screen printing inks with thermo-powder. Based on the testing findings it is determined that thermal stability of printouts printed with thermo-powder ink is higher than printed with screen printing inks. It is determined that the appropriate temperature range of screen printing inks with thermo-powder drying is 98 ºC – 198 ºC because in this case better relief of Braille dots is obtained.DOI: http://dx.doi.org/10.5755/j01.ms.21.1.5702

  15. Thermal Analysis Of 3013/9975 Configuration

    International Nuclear Information System (INIS)

    Gupta, N.

    2009-01-01

    The 3013 containers are designed in accordance with the DOE-STD-3013-2004 and are qualified to store plutonium (Pu) bearing materials for 50 years. The U.S. Department of Energy (DOE) certified Model 9975 shipping package is used to transport the 3013 containers to the K-Area Material Storage (KAMS) facility at the Savannah River Site (SRS) and to store the containers until the plutonium can be properly dispositioned. Detailed thermal analyses to support the storage in the KAMS facility are given in References 2, 3, and 4. The analyses in this paper serve to provide non-accident condition, non-bounding, specific 3013 container temperatures for use in the surveillance activities. This paper presents a methodology where critical component temperatures are estimated using numerical methods over a range of package and storage parameters. The analyses include factors such as ambient storage temperature and the content weight, density, heat generation rate, and fill height, that may impact the thermal response of the packages. Statistical methods are used to develop algebraic equations for ease of computations to cover the factor space. All computations were performed in BTU-FT-Hr- o F units.

  16. Proteomic analysis of osteogenic differentiation of dental follicle precursor cells

    DEFF Research Database (Denmark)

    Morsczeck, Christian; Petersen, Jørgen; Völlner, Florian

    2009-01-01

    of differentiation. In the present study we applied 2-DE combined with capillary-LC-MS/MS analysis to profile differentially regulated proteins upon differentiation of dental follicle precursor cells (DFPCs). Out of 115 differentially regulated proteins, glutamine synthetase, lysosomal proteinase cathepsin B....... The bioinformatic analyses suggest that proteins associated with cell cycle progression and protein metabolism were down-regulated and proteins involved in catabolism, cell motility and biological quality were up-regulated. These results display the general physiological state of DFPCs before and after osteogenic...... proteins, plastin 3 T-isoform, beta-actin, superoxide dismutases, and transgelin were found to be highly up-regulated, whereas cofilin-1, pro-alpha 1 collagen, destrin, prolyl 4-hydrolase and dihydrolipoamide dehydrogenase were found to be highly down-regulated. The group of up-regulated proteins...

  17. Tensor and vector analysis with applications to differential geometry

    CERN Document Server

    Springer, C E

    2012-01-01

    Concise and user-friendly, this college-level text assumes only a knowledge of basic calculus in its elementary and gradual development of tensor theory. The introductory approach bridges the gap between mere manipulation and a genuine understanding of an important aspect of both pure and applied mathematics.Beginning with a consideration of coordinate transformations and mappings, the treatment examines loci in three-space, transformation of coordinates in space and differentiation, tensor algebra and analysis, and vector analysis and algebra. Additional topics include differentiation of vect

  18. Melting temperature and enthalpy variations of phase change materials (PCMs): a differential scanning calorimetry (DSC) analysis

    Science.gov (United States)

    Sun, Xiaoqin; Lee, Kyoung Ok; Medina, Mario A.; Chu, Youhong; Li, Chuanchang

    2018-06-01

    Differential scanning calorimetry (DSC) analysis is a standard thermal analysis technique used to determine the phase transition temperature, enthalpy, heat of fusion, specific heat and activation energy of phase change materials (PCMs). To determine the appropriate heating rate and sample mass, various DSC measurements were carried out using two kinds of PCMs, namely N-octadecane paraffin and calcium chloride hexahydrate. The variations in phase transition temperature, enthalpy, heat of fusion, specific heat and activation energy were observed within applicable heating rates and sample masses. It was found that the phase transition temperature range increased with increasing heating rate and sample mass; while the heat of fusion varied without any established pattern. The specific heat decreased with the increase of heating rate and sample mass. For accuracy purpose, it is recommended that for PCMs with high thermal conductivity (e.g. hydrated salt) the focus will be on heating rate rather than sample mass.

  19. Product differentiation by analysis of DNA melting curves during the polymerase chain reaction.

    Science.gov (United States)

    Ririe, K M; Rasmussen, R P; Wittwer, C T

    1997-02-15

    A microvolume fluorometer integrated with a thermal cycler was used to acquire DNA melting curves during polymerase chain reaction by fluorescence monitoring of the double-stranded DNA specific dye SYBR Green I. Plotting fluorescence as a function of temperature as the thermal cycler heats through the dissociation temperature of the product gives a DNA melting curve. The shape and position of this DNA melting curve are functions of the GC/AT ratio, length, and sequence and can be used to differentiate amplification products separated by less than 2 degrees C in melting temperature. Desired products can be distinguished from undesirable products, in many cases eliminating the need for gel electrophoresis. Analysis of melting curves can extend the dynamic range of initial template quantification when amplification is monitored with double-stranded DNA specific dyes. Complete amplification and analysis of products can be performed in less than 15 min.

  20. Thermal dehydration of cobalt and zinc formate dihydrates by controlled-rate thermogravimetry (CRTG) and simultaneous X-ray diffractometry-differential scanning calorimetry (XRD-DSC)

    International Nuclear Information System (INIS)

    Arii, T.; Kishi, A.

    1999-01-01

    The thermal dehydration study of the similar hydrated salts, cobalt and zinc formate dihydrates, have been carried out successfully by means of X-ray diffractometry-differential scanning calorimetry (XRD-DSC) and controlled-rate thermogravimetry (CRTG). X-ray diffraction analysis recorded simultaneously indicates that the resulting anhydrous product, Zn(HCO 2 ) 2 , was crystalline, while Co(HCO 2 ) 2 was amorphous.The XRD-DSC data are proven to be invaluable in verifying the interpretation of overlapping processes in thermal events. In addition, these differences in the resulting anhydrous products can be explained from kinetic analysis results based on the CRTG data. The kinetic mechanism governing the dehydration of zinc formate dihydrate is a nucleation and growth process, while in the case of cobalt formate dihydrate a phase boundary controlled reaction is the governing mechanism. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  1. Pressurized Thermal Shock Analysis for OPR1000 Pressure Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Bhowmik, P. K.; Shamim, J. A.; Gairola, A.; Suh, Kune Y. [Seoul National Univ., Seoul (Korea, Republic of)

    2014-10-15

    The study provides a brief understanding of the analysis procedure and techniques using ANSYS, such as the acceptance criteria, selection and categorization of events, thermal analysis, structural analysis including fracture mechanics assessment, crack propagation and evaluation of material properties. PTS may result from instrumentation and control malfunction, inadvertent steam dump, and postulated accidents such as smallbreak (SB) LOCA, large-break (LB) LOCA, main steam line break (MSLB), feedwater line breaks and steam generator overfill. In this study our main focus is to consider only the LB LOCA due to a cold leg break of the Optimized Power Reactor 1000 MWe (OPR1000). Consideration is given as well to the emergency core cooling system (ECCS) specific sequence with the operating parameters like pressure, temperature and time sequences. The static structural and thermal analysis to investigate the effects of PTS on RPV is the main motivation of this study. Specific surface crack effects and its propagation is also considered to measure the integrity of the RPV. This study describes the procedure for pressurized thermal shock analysis due to a loss of coolant accidental condition and emergency core cooling system operation for reactor pressure vessel.. Different accidental events that cause pressurized thermal shock to nuclear RPV that can also be analyzed in the same way. Considering the limitations of low speed computer only the static analysis is conducted. The modified LBLOCA phases and simplified geometry can is utilized to analyze the effect of PTS on RPV for general understanding not for specific specialized purpose. However, by integrating the disciplines of thermal and structural analysis, and fracture mechanics analysis a clearer understanding of the total aspect of the PTS problem has resulted. By adopting the CFD, thermal hydraulics, uncertainties and risk analysis for different type of accidental conditions, events and sequences with proper

  2. Differentiation of the molecular structure of nitro compounds as the basis for simulation of their thermal destruction processes

    Energy Technology Data Exchange (ETDEWEB)

    Korolev, V L; Pivina, Tatyana S; Sheremetev, Aleksei B [N.D.Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow (Russian Federation); Porollo, A A [University of Cincinnati, Cincinnati (United States); Petukhova, T V; Ivshin, Viktor P [Mari State University, Yoshkar-Ola (Russian Federation)

    2009-10-31

    Data on the experimental and theoretical studies of thermal decomposition of C- and N-nitro compounds of aliphatic, alicyclic, aromatic and heteroaromatic compounds, which formed the grounds for the development of ab initio approach to the prediction of the mechanisms of thermolysis of energetic compounds, are described systematically. The relationships between the structures and thermolysis mechanisms of compounds based on differentiation of the structural fragments depending on the functional surrounding of nitro groups are identified. Using the RRN (Recombination Reaction Network) strategy and original CASB (Computer Assisted Structure Building) software, full reaction mechanisms for the thermal destruction of nitro compounds at different thermal decomposition levels (including extensive ones) are simulated. The full set of possible mechanisms of thermal decomposition of 38 chemically different nitro compounds is presented

  3. Analysis of Thermal Comfort in an Intelligent Building

    Science.gov (United States)

    Majewski, Grzegorz; Telejko, Marek; Orman, Łukasz J.

    2017-06-01

    Analysis of thermal comfort in the ENERGIS Building, an intelligent building in the campus of the Kielce University of Technology, Poland is the focus of this paper. For this purpose, air temperature, air relative humidity, air flow rate and carbon dioxide concentration were measured and the mean radiant temperature was determined. Thermal sensations of the students occupying the rooms of the building were evaluated with the use of a questionnaire. The students used a seven-point scale of thermal comfort. The microclimate measurement results were used to determine the Predicted Mean Vote and the Predicted Percentage Dissatisfied indices.

  4. Temperature and thermal stress analysis of a switching tube anode

    International Nuclear Information System (INIS)

    Sutton, S.B.

    1979-01-01

    In the design of high power density switching tubes which are subjected to cyclic thermal loads, the temperature induced stresses must be minimized in order to maximize the life expectancy of the tube. Following are details of an analysis performed for the Magnetic Fusion Program at the Lawrence Livermore Laboratory on a proposed tube. The tube configuration is given. The problem was simplified to one-dimensional approximations for both the thermal and stress analyses. The underlying assumptions and their implications are discussed

  5. NUMERICAL THERMAL ANALYSIS OF A CAR BRAKING SYSTEM

    Directory of Open Access Journals (Sweden)

    Patryk Różyło

    2017-06-01

    Full Text Available The study involved performing a numerical thermal analysis of selected components in a car braking system. The primary goal of the study was to determine the regions which are the most susceptible to variations in temperature, and to determine the degree of thermal impact upon them. The analysis was performed using the Abaqus environment. The examined components of the braking system were made of materials reflecting the mechanical properties of the real subassemblies. The FEM analysis enabled determination of the distribution of temperature in the system with respect to the properties of the investigated materials and applied boundary conditions.

  6. Thermal Analysis of Fluidized Bed and Fixed Bed Latent Heat Thermal Storage System

    Science.gov (United States)

    Beemkumar, N.; Karthikeyan, A.; Shiva Keshava Reddy, Kota; Rajesh, Kona; Anderson, A.

    2017-05-01

    Thermal energy storage technology is essential because its stores available energy at low cost. Objective of the work is to store the thermal energy in a most efficient method. This work is deal with thermal analysis of fluidized bed and fixed bed latent heat thermal storage (LHTS) system with different encapsulation materials (aluminium, brass and copper). D-Mannitol has been used as phase change material (PCM). Encapsulation material which is in orbicular shape with 4 inch diameter and 2 mm thickness orbicular shaped product is used. Therminol-66 is used as a heat transfer fluid (HTF). Arrangement of encapsulation material is done in two ways namely fluidized bed and fixed bed thermal storage system. Comparison was made between the performance of fixed bed and fluidized bed with different encapsulation material. It is observed that from the economical point of view aluminium in fluidized bed LHTS System has highest efficiency than copper and brass. The thermal energy storage system can be analyzed with fixed bed by varying mass flow rate of oil paves a way to find effective heat energy transfer.

  7. Nonlinear Transient Thermal Analysis by the Force-Derivative Method

    Science.gov (United States)

    Balakrishnan, Narayani V.; Hou, Gene

    1997-01-01

    High-speed vehicles such as the Space Shuttle Orbiter must withstand severe aerodynamic heating during reentry through the atmosphere. The Shuttle skin and substructure are constructed primarily of aluminum, which must be protected during reentry with a thermal protection system (TPS) from being overheated beyond the allowable temperature limit, so that the structural integrity is maintained for subsequent flights. High-temperature reusable surface insulation (HRSI), a popular choice of passive insulation system, typically absorbs the incoming radiative or convective heat at its surface and then re-radiates most of it to the atmosphere while conducting the smallest amount possible to the structure by virtue of its low diffusivity. In order to ensure a successful thermal performance of the Shuttle under a prescribed reentry flight profile, a preflight reentry heating thermal analysis of the Shuttle must be done. The surface temperature profile, the transient response of the HRSI interior, and the structural temperatures are all required to evaluate the functioning of the HRSI. Transient temperature distributions which identify the regions of high temperature gradients, are also required to compute the thermal loads for a structural thermal stress analysis. Furthermore, a nonlinear analysis is necessary to account for the temperature-dependent thermal properties of the HRSI as well as to model radiation losses.

  8. High Order Differential Frequency Hopping: Design and Analysis

    Directory of Open Access Journals (Sweden)

    Yong Li

    2015-01-01

    Full Text Available This paper considers spectrally efficient differential frequency hopping (DFH system design. Relying on time-frequency diversity over large spectrum and high speed frequency hopping, DFH systems are robust against hostile jamming interference. However, the spectral efficiency of conventional DFH systems is very low due to only using the frequency of each channel. To improve the system capacity, in this paper, we propose an innovative high order differential frequency hopping (HODFH scheme. Unlike in traditional DFH where the message is carried by the frequency relationship between the adjacent hops using one order differential coding, in HODFH, the message is carried by the frequency and phase relationship using two-order or higher order differential coding. As a result, system efficiency is increased significantly since the additional information transmission is achieved by the higher order differential coding at no extra cost on either bandwidth or power. Quantitative performance analysis on the proposed scheme demonstrates that transmission through the frequency and phase relationship using two-order or higher order differential coding essentially introduces another dimension to the signal space, and the corresponding coding gain can increase the system efficiency.

  9. Thermal Analysis of LANL Ion Exchange Column

    International Nuclear Information System (INIS)

    Laurinat, J.E.

    1999-01-01

    This document reports results from an ion exchange column heat transfer analysis requested by Los Alamos National Laboratory (LANL). The object of the analysis is to demonstrate that the decay heat from the Pu-238 will not cause resin bed temperatures to increase to a level where the resin significantly degrades

  10. Thermal stress analysis of a planar SOFC stack

    Science.gov (United States)

    Lin, Chih-Kuang; Chen, Tsung-Ting; Chyou, Yau-Pin; Chiang, Lieh-Kwang

    The aim of this study is, by using finite element analysis (FEA), to characterize the thermal stress distribution in a planar solid oxide fuel cell (SOFC) stack during various stages. The temperature profiles generated by an integrated thermo-electrochemical model were applied to calculate the thermal stress distributions in a multiple-cell SOFC stack by using a three-dimensional (3D) FEA model. The constructed 3D FEA model consists of the complete components used in a practical SOFC stack, including positive electrode-electrolyte-negative electrode (PEN) assembly, interconnect, nickel mesh, and gas-tight glass-ceramic seals. Incorporation of the glass-ceramic sealant, which was never considered in previous studies, into the 3D FEA model would produce more realistic results in thermal stress analysis and enhance the reliability of predicting potential failure locations in an SOFC stack. The effects of stack support condition, viscous behavior of the glass-ceramic sealant, temperature gradient, and thermal expansion mismatch between components were characterized. Modeling results indicated that a change in the support condition at the bottom frame of the SOFC stack would not cause significant changes in thermal stress distribution. Thermal stress distribution did not differ significantly in each unit cell of the multiple-cell stack due to a comparable in-plane temperature profile. By considering the viscous characteristics of the glass-ceramic sealant at temperatures above the glass-transition temperature, relaxation of thermal stresses in the PEN was predicted. The thermal expansion behavior of the metallic interconnect/frame had a greater influence on the thermal stress distribution in the PEN than did that of the glass-ceramic sealant due to the domination of interconnect/frame in the volume of a planar SOFC assembly.

  11. Long term energy performance analysis of Egbin thermal power ...

    African Journals Online (AJOL)

    This study is aimed at providing an energy performance analysis of Egbin thermal power plant. The plant operates on Regenerative Rankine cycle with steam as its working fluid .The model equations were formulated based on some performance parameters used in power plant analysis. The considered criteria were plant ...

  12. Differential Response of Coral Assemblages to Thermal Stress Underscores the Complexity in Predicting Bleaching Susceptibility.

    Science.gov (United States)

    Chou, Loke Ming; Toh, Tai Chong; Toh, Kok Ben; Ng, Chin Soon Lionel; Cabaitan, Patrick; Tun, Karenne; Goh, Eugene; Afiq-Rosli, Lutfi; Taira, Daisuke; Du, Rosa Celia Poquita; Loke, Hai Xin; Khalis, Aizat; Li, Jinghan; Song, Tiancheng

    2016-01-01

    Coral bleaching events have been predicted to occur more frequently in the coming decades with global warming. The susceptibility of corals to bleaching during thermal stress episodes is dependent on many factors and an understanding of these underlying drivers is crucial for conservation management. In 2013, a mild bleaching episode ensued in response to elevated sea temperature on the sediment-burdened reefs in Singapore. Surveys of seven sites highlighted variable bleaching susceptibility among coral genera-Pachyseris and Podabacia were the most impacted (31% of colonies of both genera bleached). The most susceptible genera such as Acropora and Pocillopora, which were expected to bleach, did not. Susceptibility varied between less than 6% and more than 11% of the corals bleached, at four and three sites respectively. Analysis of four of the most bleached genera revealed that a statistical model that included a combination of the factors (genus, colony size and site) provided a better explanation of the observed bleaching patterns than any single factor alone. This underscored the complexity in predicting the coral susceptibility to future thermal stress events and the importance of monitoring coral bleaching episodes to facilitate more effective management of coral reefs under climate change.

  13. Differential Response of Coral Assemblages to Thermal Stress Underscores the Complexity in Predicting Bleaching Susceptibility

    Science.gov (United States)

    Toh, Kok Ben; Ng, Chin Soon Lionel; Cabaitan, Patrick; Tun, Karenne; Goh, Eugene; Afiq-Rosli, Lutfi; Taira, Daisuke; Du, Rosa Celia Poquita; Loke, Hai Xin; Khalis, Aizat; Li, Jinghan; Song, Tiancheng

    2016-01-01

    Coral bleaching events have been predicted to occur more frequently in the coming decades with global warming. The susceptibility of corals to bleaching during thermal stress episodes is dependent on many factors and an understanding of these underlying drivers is crucial for conservation management. In 2013, a mild bleaching episode ensued in response to elevated sea temperature on the sediment-burdened reefs in Singapore. Surveys of seven sites highlighted variable bleaching susceptibility among coral genera–Pachyseris and Podabacia were the most impacted (31% of colonies of both genera bleached). The most susceptible genera such as Acropora and Pocillopora, which were expected to bleach, did not. Susceptibility varied between less than 6% and more than 11% of the corals bleached, at four and three sites respectively. Analysis of four of the most bleached genera revealed that a statistical model that included a combination of the factors (genus, colony size and site) provided a better explanation of the observed bleaching patterns than any single factor alone. This underscored the complexity in predicting the coral susceptibility to future thermal stress events and the importance of monitoring coral bleaching episodes to facilitate more effective management of coral reefs under climate change. PMID:27438593

  14. Differential Response of Coral Assemblages to Thermal Stress Underscores the Complexity in Predicting Bleaching Susceptibility.

    Directory of Open Access Journals (Sweden)

    Loke Ming Chou

    Full Text Available Coral bleaching events have been predicted to occur more frequently in the coming decades with global warming. The susceptibility of corals to bleaching during thermal stress episodes is dependent on many factors and an understanding of these underlying drivers is crucial for conservation management. In 2013, a mild bleaching episode ensued in response to elevated sea temperature on the sediment-burdened reefs in Singapore. Surveys of seven sites highlighted variable bleaching susceptibility among coral genera-Pachyseris and Podabacia were the most impacted (31% of colonies of both genera bleached. The most susceptible genera such as Acropora and Pocillopora, which were expected to bleach, did not. Susceptibility varied between less than 6% and more than 11% of the corals bleached, at four and three sites respectively. Analysis of four of the most bleached genera revealed that a statistical model that included a combination of the factors (genus, colony size and site provided a better explanation of the observed bleaching patterns than any single factor alone. This underscored the complexity in predicting the coral susceptibility to future thermal stress events and the importance of monitoring coral bleaching episodes to facilitate more effective management of coral reefs under climate change.

  15. Variational analysis and generalized differentiation I basic theory

    CERN Document Server

    Mordukhovich, Boris S

    2006-01-01

    Contains a study of the basic concepts and principles of variational analysis and generalized differentiation in both finite-dimensional and infinite-dimensional spaces. This title presents many applications to problems in optimization, equilibria, stability and sensitivity, control theory, economics, mechanics, and more.

  16. Function spaces and partial differential equations volume 2 : contemporary analysis

    CERN Document Server

    Taheri, Ali

    2015-01-01

    This is a book written primarily for graduate students and early researchers in the fields of Analysis and Partial Differential Equations (PDEs). Coverage of the material is essentially self-contained, extensive and novel with great attention to details and rigour.

  17. Molecular marker analysis to differentiate a clonal selection of ...

    African Journals Online (AJOL)

    Lalit Kumar

    2013-04-03

    Apr 3, 2013 ... Microsatellite and amplified fragment length polymorphism (AFLP) markers were used to differentiate. Manjari Naveen, a clonal selection of Centennial Seedless variety of grape. Twenty one (21) microsatellite primers could not detect variation between parent variety and its clone. AFLP analysis.

  18. Research on the Compression Algorithm of the Infrared Thermal Image Sequence Based on Differential Evolution and Double Exponential Decay Model

    Science.gov (United States)

    Zhang, Jin-Yu; Meng, Xiang-Bing; Xu, Wei; Zhang, Wei; Zhang, Yong

    2014-01-01

    This paper has proposed a new thermal wave image sequence compression algorithm by combining double exponential decay fitting model and differential evolution algorithm. This study benchmarked fitting compression results and precision of the proposed method was benchmarked to that of the traditional methods via experiment; it investigated the fitting compression performance under the long time series and improved model and validated the algorithm by practical thermal image sequence compression and reconstruction. The results show that the proposed algorithm is a fast and highly precise infrared image data processing method. PMID:24696649

  19. Research on the Compression Algorithm of the Infrared Thermal Image Sequence Based on Differential Evolution and Double Exponential Decay Model

    Directory of Open Access Journals (Sweden)

    Jin-Yu Zhang

    2014-01-01

    Full Text Available This paper has proposed a new thermal wave image sequence compression algorithm by combining double exponential decay fitting model and differential evolution algorithm. This study benchmarked fitting compression results and precision of the proposed method was benchmarked to that of the traditional methods via experiment; it investigated the fitting compression performance under the long time series and improved model and validated the algorithm by practical thermal image sequence compression and reconstruction. The results show that the proposed algorithm is a fast and highly precise infrared image data processing method.

  20. Use of emanation thermal analysis to characterize thermal reactivity of brannerite mineral

    Czech Academy of Sciences Publication Activity Database

    Balek, V.; Vance, E.R.; Zeleňák, V.; Málek, Z.; Šubrt, Jan

    2007-01-01

    Roč. 88, č. 1 (2007), s. 93-98 ISSN 1388-6150 Grant - others:GA MŠk(CZ) LA 292; GA MŠk(CZ) ME 879 Institutional research plan: CEZ:AV0Z40320502 Keywords : brannerite * emanation thermal analysis Subject RIV: CA - Inorganic Chemistry Impact factor: 1.483, year: 2007

  1. Thermodynamic study of ibuprofen by adiabatic calorimetry and thermal analysis

    International Nuclear Information System (INIS)

    Xu Fen; Sun Lixian; Tan Zhicheng; Liang Jianguo; Li Ruilian

    2004-01-01

    Molar heat capacities of ibuprofen were precisely measured with a small sample precision automated adiabatic calorimeter over the temperature range from 80 to 400 K. The polynomial functions of C p,m (J K -1 mol -1 ) versus T were established on the heat capacity measurements by means of the least fitting square method. The functions are as follows: for solid ibuprofen, at the temperature range of 79.105 K≤T≤333.297 K, C p,m =144.27+77.046X+3.5171X 2 +10.925X 3 +11.224X 4 , where X=(T-206.201)/127.096; for liquid ibuprofen, at the temperature range of 353.406 K≤T≤378.785 K, C p,m =325.79+8.9696X-1.6073X 2 -1.5145X 3 , where X=(T-366.095)/12.690. A fusion transition at T=348.02 K was found from the C p -T curve. The molar enthalpy and entropy of the fusion transition were determined to be 26.65 kJ mol -1 and 76.58 J mol -1 K -1 , respectively. The thermodynamic functions on the base of the reference temperature of 298.15 K, (H T -H 298.15 ) and (S T -S 298.15 ), were derived. Thermal characteristic of ibuprofen was studied by thermo-gravimetric analysis (TG-DTG) and differential scanning calorimeter (DSC). The temperature of fusion, the molar enthalpy and entropy of fusion obtained by DSC were well consistent with those obtained by adiabatic calorimeter. The evaporation process of ibuprofen was investigated further by TG and DTG, and the activation energy of the evaporation process was determined to be 80.3±1.4 kJ mol -1

  2. Application of thermal analysis methods in the study of sintered uranium dioxide preparation. I

    International Nuclear Information System (INIS)

    Landspersky, H.; Urbanek, V.

    1978-01-01

    Thermal analysis was used in the study of drying ammonium polyuranate gel prepared by internal gelation of uranyl nitrate solutions with urea and urotropine. The analysis of the differential curves of weight changes with linear temperature increase showed that temperatures above 180 degC should be used for drying to prepare a high-quality product which can easily be further heat treated. For the first water fractions released at temperatures up to 140 degC an activation energy of 49.6 kJ/mol was found which only slightly exceeds the evaporation heat of water. (Ha)

  3. Thermal analysis of RFETS SS and C

    International Nuclear Information System (INIS)

    Korinko, P.S.

    2000-01-01

    In support of the gas generation test program (GGTP) for the 9975 shipping container, thermogravimetric analysis (TGA) was conducted. The objective of this activity was to determine the moisture content as an input to the gas generation model

  4. Thermal Analysis for Condition Monitoring of Machine Tool Spindles

    International Nuclear Information System (INIS)

    Clough, D; Fletcher, S; Longstaff, A P; Willoughby, P

    2012-01-01

    Decreasing tolerances on parts manufactured, or inspected, on machine tools increases the requirement to have a greater understanding of machine tool capabilities, error sources and factors affecting asset availability. Continuous usage of a machine tool during production processes causes heat generation typically at the moving elements, resulting in distortion of the machine structure. These effects, known as thermal errors, can contribute a significant percentage of the total error in a machine tool. There are a number of design solutions available to the machine tool builder to reduce thermal error including, liquid cooling systems, low thermal expansion materials and symmetric machine tool structures. However, these can only reduce the error not eliminate it altogether. It is therefore advisable, particularly in the production of high value parts, for manufacturers to obtain a thermal profile of their machine, to ensure it is capable of producing in tolerance parts. This paper considers factors affecting practical implementation of condition monitoring of the thermal errors. In particular is the requirement to find links between temperature, which is easily measureable during production and the errors which are not. To this end, various methods of testing including the advantages of thermal images are shown. Results are presented from machines in typical manufacturing environments, which also highlight the value of condition monitoring using thermal analysis.

  5. Transient Thermal Analysis of 3-D Integrated Circuits Packages by the DGTD Method

    KAUST Repository

    Li, Ping

    2017-03-11

    Since accurate thermal analysis plays a critical role in the thermal design and management of the 3-D system-level integration, in this paper, a discontinuous Galerkin time-domain (DGTD) algorithm is proposed to achieve this purpose. Such as the parabolic partial differential equation (PDE), the transient thermal equation cannot be directly solved by the DGTD method. To address this issue, the heat flux, as an auxiliary variable, is introduced to reduce the Laplace operator to a divergence operator. The resulting PDE is hyperbolic, which can be further written into a conservative form. By properly choosing the definition of the numerical flux used for the information exchange between neighboring elements, the hyperbolic thermal PDE can be solved by the DGTD together with the auxiliary differential equation. The proposed algorithm is a kind of element-level domain decomposition method, which is suitable to deal with multiscale geometries in 3-D integrated systems. To verify the accuracy and robustness of the developed DGTD algorithm, several representative examples are benchmarked.

  6. Some selected quantitative methods of thermal image analysis in Matlab.

    Science.gov (United States)

    Koprowski, Robert

    2016-05-01

    The paper presents a new algorithm based on some selected automatic quantitative methods for analysing thermal images. It shows the practical implementation of these image analysis methods in Matlab. It enables to perform fully automated and reproducible measurements of selected parameters in thermal images. The paper also shows two examples of the use of the proposed image analysis methods for the area of ​​the skin of a human foot and face. The full source code of the developed application is also provided as an attachment. The main window of the program during dynamic analysis of the foot thermal image. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Thermal stratification and fatigue stress analysis for pressurizer surge line

    International Nuclear Information System (INIS)

    Yu Xiaofei; Zhang Yixiong

    2011-01-01

    Thermal stratification of pressurizer surge line induced by the inside fluid results in the global bending moments, local thermal stresses, unexpected displacements and support loadings of the pipe system. In order to avoid a costly three-dimensional computation, a combined 1D/2D technique has been developed and implemented to analyze the thermal stratification and fatigue stress of pressurize surge line of QINSHAN Phase II Extension Nuclear Power Project in this paper, using the computer codes SYSTUS and ROCOCO. According to the mechanical analysis results of stratification, the maximum stress and cumulative usage factor are obtained. The results indicate that the stress and fatigue intensity considering thermal stratification satisfies RCC-M criterion. (authors)

  8. Thermoreflectance spectroscopy—Analysis of thermal processes in semiconductor lasers

    Science.gov (United States)

    Pierścińska, D.

    2018-01-01

    This review focuses on theoretical foundations, experimental implementation and an overview of experimental results of the thermoreflectance spectroscopy as a powerful technique for temperature monitoring and analysis of thermal processes in semiconductor lasers. This is an optical, non-contact, high spatial resolution technique providing high temperature resolution and mapping capabilities. Thermoreflectance is a thermometric technique based on measuring of relative change of reflectivity of the surface of laser facet, which provides thermal images useful in hot spot detection and reliability studies. In this paper, principles and experimental implementation of the technique as a thermography tool is discussed. Some exemplary applications of TR to various types of lasers are presented, proving that thermoreflectance technique provides new insight into heat management problems in semiconductor lasers and in particular, that it allows studying thermal degradation processes occurring at laser facets. Additionally, thermal processes and basic mechanisms of degradation of the semiconductor laser are discussed.

  9. Development of regulatory technology for thermal-hydraulic safety analysis

    International Nuclear Information System (INIS)

    Bang, Young Seok; Lee, S. H.; Ryu, Y. H.

    2001-02-01

    The present study aims to develop the regulation capability in thermal-hydraulic safety analysis which was required for the reasonable safety regulation in the current NPP, the next generation reactors, and the future-type reactors. The fourth fiscal year of the first phase of the research was focused on the following research topics: Investigation on the current status of the thermal-hydraulic safety analysis technology outside and inside of the country; Review on the improved features of the thermal-hydraulic safety analysis regulatory audit code, RELAP5/MOD3; Assessments of code with LOFT L9-3 ATWS experiment and LSTF SB-SG-10 multiple SGTR experiment; Application of the RELAP5/CANDU code to analyses of SLB and LBLOCA and evaluation of its effect on safety; Application of the code to IAEA PHWR ISP analysis; Assessments of RELAP5 and TRAC with UPTF downcomer injection test and Analysis of LBLOCA with RELAP5 for the performance evaluation of KNGR DVI; Setup of a coupled 3-D kinetics and thermal-hydraulics and application it to a reactivity accident analysis; and Extension of database and improvement of plant input decks. For supporting the resolution of safety issues, loss of RHR event during midloop operation was analyzed for Kori Unit 3, issues on high burnup fuel were reviewed and performance of FRAPCON-3 assessed. Also MSLB was analyzed to figure out the sensitivity of downcomer temperature supporting the PTS risk evaluation of Kori Unit 1. Thermal stratification in pipe was analyzed using the method proposed. And a method predicting the thermal-hydraulic performance of IRWST of KNGR was explored. The PWR ECCS performance criteria was issued as a MOST Article 200-19.and a regulatory guide on evaluation methodology was improved to cover concerns raised from the related licensing review process

  10. Tensor analysis and elementary differential geometry for physicists and engineers

    CERN Document Server

    Nguyen-Schäfer, Hung

    2014-01-01

    Tensors and methods of differential geometry are very useful mathematical tools in many fields of modern physics and computational engineering including relativity physics, electrodynamics, computational fluid dynamics (CFD), continuum mechanics, aero and vibroacoustics, and cybernetics. This book comprehensively presents topics, such as bra-ket notation, tensor analysis, and elementary differential geometry of a moving surface. Moreover, authors intentionally abstain from giving mathematically rigorous definitions and derivations that are however dealt with as precisely as possible. The reader is provided with hands-on calculations and worked-out examples at which he will learn how to handle the bra-ket notation, tensors and differential geometry and to use them in the physical and engineering world. The target audience primarily comprises graduate students in physics and engineering, research scientists, and practicing engineers.

  11. Automated thermal mapping techniques using chromatic image analysis

    Science.gov (United States)

    Buck, Gregory M.

    1989-01-01

    Thermal imaging techniques are introduced using a chromatic image analysis system and temperature sensitive coatings. These techniques are used for thermal mapping and surface heat transfer measurements on aerothermodynamic test models in hypersonic wind tunnels. Measurements are made on complex vehicle configurations in a timely manner and at minimal expense. The image analysis system uses separate wavelength filtered images to analyze surface spectral intensity data. The system was initially developed for quantitative surface temperature mapping using two-color thermographic phosphors but was found useful in interpreting phase change paint and liquid crystal data as well.

  12. Thermal performance analysis of a phase change thermal storage unit for space heating

    Energy Technology Data Exchange (ETDEWEB)

    Halawa, E.; Saman, W. [Institute for Sustainable Systems and Technologies School of Advanced Manufacturing and Mechanical Engineering, University of South Australia, Mawson Lakes SA 5095 (Australia)

    2011-01-15

    This paper presents the results of a comprehensive numerical study on the thermal performance of an air based phase change thermal storage unit (TSU) for space heating. The unit is designed for integration into space heating and cooling systems. The unit consists of a number of one dimensional phase change material (PCM) slabs contained in a rectangular duct where air passes between the slabs. The numerical analysis was based on an experimentally validated model. A parametric study has been carried out including the study on the effects of charge and discharge temperature differences, air mass flow rate, slab thicknesses, air gaps and slab dimensions on the air outlet temperatures and heat transfer rates of the thermal storage unit. The paper introduces and discusses quantities called charge and discharge temperature differences which play an important role in the melting and freezing processes. (author)

  13. On the analysis of the thermal line shift and thermal line width of ions in solids

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Brian M., E-mail: brian.m.walsh@nasa.gov [NASA Langley Research Center, Hampton, VA 23681 (United States); Di Bartolo, Baldassare, E-mail: baldassare.dibartolo@bc.edu [Boston College, Department of Physics, Chestnut Hill, MA 23667 (United States)

    2015-02-15

    A method of analysis for the thermally induced line shift and line width of spectral lines regarding the Raman process of ions in solids utilizing rational approximations for the Debye functions is presented. The {sup 2}E level unsplit R-line in V{sup 2+}:MgO is used as an example to illustrate the utility of the methods discussed here in providing a new analytical tool for researchers. - Highlights: • We use rational approximations for Debye functions. • We discuss limits and ranges of applicability of the rational approximations. • We formulate expressions for thermal shift and thermal linewidth for Raman processes using the rational approximations of the Debye functions. • We present an application of the methods to analyze the temperature dependent linewidth and lineshift in V2+:MgO.

  14. Analysis of pharmacogenomic variants associated with population differentiation.

    Directory of Open Access Journals (Sweden)

    Bora Yeon

    Full Text Available In the present study, we systematically investigated population differentiation of drug-related (DR genes in order to identify common genetic features underlying population-specific responses to drugs. To do so, we used the International HapMap project release 27 Data and Pharmacogenomics Knowledge Base (PharmGKB database. First, we compared four measures for assessing population differentiation: the chi-square test, the analysis of variance (ANOVA F-test, Fst, and Nearest Shrunken Centroid Method (NSCM. Fst showed high sensitivity with stable specificity among varying sample sizes; thus, we selected Fst for determining population differentiation. Second, we divided DR genes from PharmGKB into two groups based on the degree of population differentiation as assessed by Fst: genes with a high level of differentiation (HD gene group and genes with a low level of differentiation (LD gene group. Last, we conducted a gene ontology (GO analysis and pathway analysis. Using all genes in the human genome as the background, the GO analysis and pathway analysis of the HD genes identified terms related to cell communication. "Cell communication" and "cell-cell signaling" had the lowest Benjamini-Hochberg's q-values (0.0002 and 0.0006, respectively, and "drug binding" was highly enriched (16.51 despite its relatively high q-value (0.0142. Among the 17 genes related to cell communication identified in the HD gene group, five genes (STX4, PPARD, DCK, GRIK4, and DRD3 contained single nucleotide polymorphisms with Fst values greater than 0.5. Specifically, the Fst values for rs10871454, rs6922548, rs3775289, rs1954787, and rs167771 were 0.682, 0.620, 0.573, 0.531, and 0.510, respectively. In the analysis using DR genes as the background, the HD gene group contained six significant terms. Five were related to reproduction, and one was "Wnt signaling pathway," which has been implicated in cancer. Our analysis suggests that the HD gene group from PharmGKB is

  15. Analysis of pharmacogenomic variants associated with population differentiation.

    Science.gov (United States)

    Yeon, Bora; Ahn, Eunyong; Kim, Kyung-Im; Kim, In-Wha; Oh, Jung Mi; Park, Taesung

    2015-01-01

    In the present study, we systematically investigated population differentiation of drug-related (DR) genes in order to identify common genetic features underlying population-specific responses to drugs. To do so, we used the International HapMap project release 27 Data and Pharmacogenomics Knowledge Base (PharmGKB) database. First, we compared four measures for assessing population differentiation: the chi-square test, the analysis of variance (ANOVA) F-test, Fst, and Nearest Shrunken Centroid Method (NSCM). Fst showed high sensitivity with stable specificity among varying sample sizes; thus, we selected Fst for determining population differentiation. Second, we divided DR genes from PharmGKB into two groups based on the degree of population differentiation as assessed by Fst: genes with a high level of differentiation (HD gene group) and genes with a low level of differentiation (LD gene group). Last, we conducted a gene ontology (GO) analysis and pathway analysis. Using all genes in the human genome as the background, the GO analysis and pathway analysis of the HD genes identified terms related to cell communication. "Cell communication" and "cell-cell signaling" had the lowest Benjamini-Hochberg's q-values (0.0002 and 0.0006, respectively), and "drug binding" was highly enriched (16.51) despite its relatively high q-value (0.0142). Among the 17 genes related to cell communication identified in the HD gene group, five genes (STX4, PPARD, DCK, GRIK4, and DRD3) contained single nucleotide polymorphisms with Fst values greater than 0.5. Specifically, the Fst values for rs10871454, rs6922548, rs3775289, rs1954787, and rs167771 were 0.682, 0.620, 0.573, 0.531, and 0.510, respectively. In the analysis using DR genes as the background, the HD gene group contained six significant terms. Five were related to reproduction, and one was "Wnt signaling pathway," which has been implicated in cancer. Our analysis suggests that the HD gene group from PharmGKB is associated with

  16. Functional analysis in the study of differential and integral equations

    International Nuclear Information System (INIS)

    Sell, G.R.

    1976-01-01

    This paper illustrates the use of functional analysis in the study of differential equations. Our particular starting point, the theory of flows or dynamical systems, originated with the work of H. Poincare, who is the founder of the qualitative theory of ordinary differential equations. In the qualitative theory one tries to describe the behaviour of a solution, or a collection of solutions, without ''solving'' the differential equation. As a starting point one assumes the existence, and sometimes the uniqueness, of solutions and then one tries to describe the asymptotic behaviour, as time t→+infinity, of these solutions. We compare the notion of a flow with that of a C 0 -group of bounded linear operators on a Banach space. We shall show how the concept C 0 -group, or more generally a C 0 -semigroup, can be used to study the behaviour of solutions of certain differential and integral equations. Our main objective is to show how the concept of a C 0 -group and especially the notion of weak-compactness can be used to prove the existence of an invariant measure for a flow on a compact Hausdorff space. Applications to the theory of ordinary differential equations are included. (author)

  17. Global thermal analysis of air-air cooled motor based on thermal network

    Science.gov (United States)

    Hu, Tian; Leng, Xue; Shen, Li; Liu, Haidong

    2018-02-01

    The air-air cooled motors with high efficiency, large starting torque, strong overload capacity, low noise, small vibration and other characteristics, are widely used in different department of national industry, but its cooling structure is complex, it requires the motor thermal management technology should be high. The thermal network method is a common method to calculate the temperature field of the motor, it has the advantages of small computation time and short time consuming, it can save a lot of time in the initial design phase of the motor. The domain analysis of air-air cooled motor and its cooler was based on thermal network method, the combined thermal network model was based, the main components of motor internal and external cooler temperature were calculated and analyzed, and the temperature rise test results were compared to verify the correctness of the combined thermal network model, the calculation method can satisfy the need of engineering design, and provide a reference for the initial and optimum design of the motor.

  18. CFD Analysis of Thermal Control System Using NX Thermal and Flow

    Science.gov (United States)

    Fortier, C. R.; Harris, M. F. (Editor); McConnell, S. (Editor)

    2014-01-01

    The Thermal Control Subsystem (TCS) is a key part of the Advanced Plant Habitat (APH) for the International Space Station (ISS). The purpose of this subsystem is to provide thermal control, mainly cooling, to the other APH subsystems. One of these subsystems, the Environmental Control Subsystem (ECS), controls the temperature and humidity of the growth chamber (GC) air to optimize the growth of plants in the habitat. The TCS provides thermal control to the ECS with three cold plates, which use Thermoelectric Coolers (TECs) to heat or cool water as needed to control the air temperature in the ECS system. In order to optimize the TCS design, pressure drop and heat transfer analyses were needed. The analysis for this system was performed in Siemens NX Thermal/Flow software (Version 8.5). NX Thermal/Flow has the ability to perform 1D or 3D flow solutions. The 1D flow solver can be used to represent simple geometries, such as pipes and tubes. The 1D flow method also has the ability to simulate either fluid only or fluid and wall regions. The 3D flow solver is similar to other Computational Fluid Dynamic (CFD) software. TCS performance was analyzed using both the 1D and 3D solvers. Each method produced different results, which will be evaluated and discussed.

  19. Evaluation of antioxidants stability by thermal analysis and its protective effect in heated edible vegetable oil

    Directory of Open Access Journals (Sweden)

    Seme Youssef Reda

    2011-06-01

    Full Text Available In this work, through the use of thermal analysis techniques, the thermal stabilities of some antioxidants were investigated, in order to evaluate their resistance to thermal oxidation in oils, by heating canola vegetable oil, and to suggest that antioxidants would be more appropriate to increase the resistance of vegetable oils in the thermal degradation process in frying. The techniques used were: Thermal Gravimetric (TG and Differential Scanning Calorimetry (DSC analyses, as well as an allusion to a possible protective action of the vegetable oils, based on the thermal oxidation of canola vegetable oil in the laboratory under constant heating at 180 ºC/8 hours for 10 days. The studied antioxidants were: ascorbic acid, sorbic acid, citric acid, sodium erythorbate, BHT (3,5-di-tert-butyl-4-hydroxytoluene, BHA (2, 3-tert-butyl-4-methoxyphenol, TBHQ (tertiary butyl hydroquinone, PG (propyl gallate - described as antioxidants by ANVISA and the FDA; and also the phytic acid antioxidant and the SAIB (sucrose acetate isobutyrate additive, which is used in the food industry, in order to test its behavior as an antioxidant in vegetable oil. The following antioxidants: citric acid, sodium erythorbate, BHA, BHT, TBHQ and sorbic acid decompose at temperatures below 180 ºC, and therefore, have little protective action in vegetable oils undergoing frying processes. The antioxidants below: phytic acid, ascorbic acid and PG, are the most resistant and begin their decomposition processes at temperatures between 180 and 200 ºC. The thermal analytical techniques have also shown that the SAIB antioxidant is the most resistant to oxidative action, and it can be a useful choice in the thermal decomposition prevention of edible oils, improving stability regarding oxidative processes.

  20. Thermal analysis of physical and chemical changes occuring during regeneration of activated carbon

    Directory of Open Access Journals (Sweden)

    Radić Dejan B.

    2017-01-01

    Full Text Available High-temperature thermal process is a commercial way of regeneration of spent granular activated carbon. The paper presents results of thermal analysis conducted in order to examine high-temperature regeneration of spent activated carbon, produced from coconut shells, previously used in drinking water treatment. Results of performed thermogravimetric analysis, derivative thermogravimetric analysis, and differential thermal analysis, enabled a number of hypotheses to be made about different phases of activated carbon regeneration, values of characteristic parameters during particular process phases, as well as catalytic impact of inorganic materials on development of regeneration process. Samples of activated carbon were heated up to 1000°C in thermogravimetric analyser while maintaining adequate oxidizing or reducing conditions. Based on diagrams of thermal analysis for samples of spent activated carbon, temperature intervals of the first intense mass change phase (180-215°C, maximum of exothermic processes (400-450°C, beginning of the second intense mass change phase (635-700°C, and maximum endothermic processes (800-815°C were deter-mined. Analysing and comparing the diagrams of thermal analysis for new, previously regenerated and spent activated carbon, hypothesis about physical and chemical transformations of organic and inorganic adsorbate in spent activated carbon are given. Transformation of an organic adsorbate in the pores of activated carbon, results in loss of mass and an exothermic reaction with oxygen in the vapour phase. The reactions of inorganic adsorbate also result the loss of mass of activated carbon during its heating and endothermic reactions of their degradation at high temperatures.

  1. Development of analysis methodology on turbulent thermal stripping

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Geun Jong; Jeon, Won Dae; Han, Jin Woo; Gu, Byong Kook [Changwon National University, Changwon(Korea)

    2001-03-01

    For developing analysis methodology, important governing factors of thermal stripping phenomena are identified as geometric configuration and flow characteristics such as velocity. Along these factors, performance of turbulence models in existing analysis methodology are evaluated against experimental data. Status of DNS application is also accessed based on literature. Evaluation results are reflected in setting up the new analysis methodology. From the evaluation of existing analysis methodology, Full Reynolds Stress model is identified as best one among other turbulence models. And LES is found to be able to provide time dependent turbulence values. Further improvements in near-wall region and temperature variance equation are required for FRS and implementation of new sub-grid scale models is also required for LES. Through these improvements, new reliable analysis methodology for thermal stripping can be developed. 30 refs., 26 figs., 6 tabs. (Author)

  2. Determination of Polymers Thermal Degradation by Color Change Analysis

    Directory of Open Access Journals (Sweden)

    Andrés Felipe Rojas González

    2016-01-01

    Full Text Available Context: It has been observed that thermal degradation of thermoplastic polymers, when they are reprocessed by injection, extrusion and extrusion / injection, undergo color changes in the product, although it not has been established as this change occurs. Method: It analyzed the effect on thermal degradation caused by polymer type, processing type, polymer grade, rotation speed of the extrusion screw and number of reprocessing, which is quantified by the color change using an empirical equation, with experimental data obtained by analysis through a microcolor colorimeter. Results: It was found that the color change analysis provides information about progress of the thermal degradation and stability of thermoplastic polymers, which are undergoing to multiple reprocessing events and processes. Conclusions: It was established that this technique can be implemented as a simple and efficient measure of thermoplastic products quality control, according to their color change.

  3. PANTHER - Polarisation Analysis with Thermal neutron

    International Nuclear Information System (INIS)

    Deen, P.P.; Fennell, T.; Schober, H.; Orecchini, A.; Rols, S.; Andersen, K.H.; Stewart, J.R.

    2011-01-01

    PANTHER will build on the success of IN4, the world's most intense time-of-flight spectrometer. A large position-sensitive detector (PSD) will improve data collection rates significantly, the background will be greatly reduced, and it will incorporate features indispensable for magnetic studies (small angles, polarisation analysis, high magnetic field devices). The new instrument will enable rapid surveys of (Q,ω) space, as well as more detailed studies in fields ranging from magnetism to the structural excitations - phonon densities of states, dispersion of collective modes and molecular vibrations - that govern the behaviour of many important physical and chemical systems. (authors)

  4. Chromatic Image Analysis For Quantitative Thermal Mapping

    Science.gov (United States)

    Buck, Gregory M.

    1995-01-01

    Chromatic image analysis system (CIAS) developed for use in noncontact measurements of temperatures on aerothermodynamic models in hypersonic wind tunnels. Based on concept of temperature coupled to shift in color spectrum for optical measurement. Video camera images fluorescence emitted by phosphor-coated model at two wavelengths. Temperature map of model then computed from relative brightnesses in video images of model at those wavelengths. Eliminates need for intrusive, time-consuming, contact temperature measurements by gauges, making it possible to map temperatures on complex surfaces in timely manner and at reduced cost.

  5. Thermal-economic analysis of cogeneration systems

    International Nuclear Information System (INIS)

    Walter, A.C.S.; Bajay, S.V.

    1992-01-01

    Approximately 80 countries produce sugar, and fortuitously alcohol, from sugar cane. In all these countries the cogeneration technology of steam turbines is utilized, although almost always inefficient. The greater potential of cogeneration in Brazil is in sugar and alcohol sector, because of the use of sugar cane bagasse as combustible. This work applies the techniques of simulation and economic analysis to different configuration of plants, to determine power generation and associated costs of each alternative. The application of the same procedure at operating condition of several configurations in transient system permits the determination of production profile of exceeding during one day. (C.M.)

  6. A simple differential steady-state method to measure the thermal conductivity of solid bulk materials with high accuracy.

    Science.gov (United States)

    Kraemer, D; Chen, G

    2014-02-01

    Accurate measurements of thermal conductivity are of great importance for materials research and development. Steady-state methods determine thermal conductivity directly from the proportionality between heat flow and an applied temperature difference (Fourier Law). Although theoretically simple, in practice, achieving high accuracies with steady-state methods is challenging and requires rather complex experimental setups due to temperature sensor uncertainties and parasitic heat loss. We developed a simple differential steady-state method in which the sample is mounted between an electric heater and a temperature-controlled heat sink. Our method calibrates for parasitic heat losses from the electric heater during the measurement by maintaining a constant heater temperature close to the environmental temperature while varying the heat sink temperature. This enables a large signal-to-noise ratio which permits accurate measurements of samples with small thermal conductance values without an additional heater calibration measurement or sophisticated heater guards to eliminate parasitic heater losses. Additionally, the differential nature of the method largely eliminates the uncertainties of the temperature sensors, permitting measurements with small temperature differences, which is advantageous for samples with high thermal conductance values and/or with strongly temperature-dependent thermal conductivities. In order to accelerate measurements of more than one sample, the proposed method allows for measuring several samples consecutively at each temperature measurement point without adding significant error. We demonstrate the method by performing thermal conductivity measurements on commercial bulk thermoelectric Bi2Te3 samples in the temperature range of 30-150 °C with an error below 3%.

  7. Thermodynamic analysis of thermal efficiency and power of Minto engine

    International Nuclear Information System (INIS)

    He, Wei; Hou, Jingxin; Zhang, Yang; Ji, Jie

    2011-01-01

    Minto engine is a kind of liquid piston heat engine that operates on a small temperature gradient. But there is no power formula for it yet. And its thermal efficiency is low and formula sometimes is misused. In this paper, deriving the power formula and simplifying the thermal efficiency formula of Minto engine based on energy distribution analysis will be discussed. To improve the original Minto engine, a new design of improved Minto engine is proposed and thermal efficiency formula and power formula are also given. A computer program was developed to analyze thermal efficiency and power of original and improved Minto engines operating between low and high-temperature heat sources. The simulation results show that thermal efficiency of improved Minto engine can reach over 7% between 293.15 K and 353.15 K which is much higher than that of original one; the temperature difference between upper and lower containers is lower than half of that between low and high temperature of heat sources when the original Minto engines output the maximum power; on the contrary, it is higher in the improved Minto engines. -- Highlights: ► The thermal efficiency formula of Minto engine is simplified and the power formula is established. ► A high-powered design of improved Minto engine is proposed. ► A computer simulation program based on real operating environment is developed.

  8. Thermal Management Tools for Propulsion System Trade Studies and Analysis

    Science.gov (United States)

    McCarthy, Kevin; Hodge, Ernie

    2011-01-01

    Energy-related subsystems in modern aircraft are more tightly coupled with less design margin. These subsystems include thermal management subsystems, vehicle electric power generation and distribution, aircraft engines, and flight control. Tighter coupling, lower design margins, and higher system complexity all make preliminary trade studies difficult. A suite of thermal management analysis tools has been developed to facilitate trade studies during preliminary design of air-vehicle propulsion systems. Simulink blocksets (from MathWorks) for developing quasi-steady-state and transient system models of aircraft thermal management systems and related energy systems have been developed. These blocksets extend the Simulink modeling environment in the thermal sciences and aircraft systems disciplines. The blocksets include blocks for modeling aircraft system heat loads, heat exchangers, pumps, reservoirs, fuel tanks, and other components at varying levels of model fidelity. The blocksets have been applied in a first-principles, physics-based modeling and simulation architecture for rapid prototyping of aircraft thermal management and related systems. They have been applied in representative modern aircraft thermal management system studies. The modeling and simulation architecture has also been used to conduct trade studies in a vehicle level model that incorporates coupling effects among the aircraft mission, engine cycle, fuel, and multi-phase heat-transfer materials.

  9. Differential and directional effects of perfusion on electrical and thermal conductivities in liver.

    Science.gov (United States)

    Podhajsky, Ronald J; Yi, Ming; Mahajan, Roop L

    2009-01-01

    Two different measurement probes--an electrical probe and a thermal conductivity probe--were designed, fabricated, calibrated, and used in experimental studies on a pig liver model that was designed to control perfusion rates. These probes were fabricated by photolithography and mounted in 1.5-mm diameter catheters. We measured the local impedance and thermal conductivity, respectively, of the artificially perfused liver at different flow rates and, by rotating the probes, in different directions. The results show that both the local electrical conductivity and the thermal conductivity varied location to location, that thermal conductivity increased with decreased distance to large blood vessels, and that significant directional differences exist in both electrical and thermal conductivities. Measurements at different perfusion rates demonstrated that both the local electrical and local thermal conductivities increased linearly with the square root of perfusion rate. These correlations may be of great value to many energy-based biomedical applications.

  10. Thermal Analysis of Bending Under Tension Test

    DEFF Research Database (Denmark)

    Ceron, Ermanno; Martins, Paulo A.F.; Bay, Niels

    2014-01-01

    during testing is similar to the one in the production tool. A universal sheet tribo-tester has been developed, which can run multiple tests automatically from coil. This allows emulating the temperature increase as in production. The present work performs finite element analysis of the evolution......The tribological conditions in deep drawing can be simulated in the Bending Under Tension test to evaluate the performance of new lubricants, tool materials, etc. Deep drawing production with automatic handling runs normally at high rate. This implies considerable heating of the tools, which...... sometimes can cause lubricant film breakdown and galling. In order to replicate the production conditions in bending under tension testing it is thus important to control the tool/workpiece interface temperature. This can be done by pre-heating the tool, but it is essential that the interface temperature...

  11. On the interpretation of differential scanning calorimetry results for thermoelastic martensitic transformations: Athermal versus thermally activated kinetics

    International Nuclear Information System (INIS)

    Van Humbeeck, J.; Planes, A.

    1996-01-01

    Experimentally, two distinct classes of martensitic transformations are considered: athermal and isothermal. In the former class, on cooling, at some well-defined start temperature (M s ), isolated small regions of the martensitic product begin to appear in the parent phase. The transformation at any temperature appears to be instantaneous in practical time scales, and the amount of transformed material (x) does not depend on time, i.e., it increases at each step of lowering temperature. The transition is not completed until the temperature is lowered below M f (martensite finish temperature). The transformation temperatures are only determined by chemical (composition and degree of order) and microstructural factors. The external controlling parameter (T or applied stress) determines the free energy difference between the high and the low temperature phases, which provides the driving force for the transition. In the development of athermal martensite activation kinetics is secondary. Athermal martensite, as observed in the well known shape memory alloys Cu-Zn-Al, Cu-Al-Ni and Ni-Ti, cannot be attributed to a thermally activated mechanism for which kinetics are generally described by the Arrhenius rate equation. However, the latter has been applied by Lipe and Morris to results for the Martensitic Transformation of Cu-Al-Ni-B-Mn obtained by conventional Differential Scanning Calorimetry (DSC). It is the concern of the authors of this letter to point out the incongruences arising from the analysis of calorimetric results, corresponding to forward and reverse thermoelastic martensitic transformations, in terms of standard kinetic analysis based on the Arrhenius rate equation

  12. Product analysis for polyethylene degradation by radiation and thermal ageing

    International Nuclear Information System (INIS)

    Sugimoto, Masaki; Shimada, Akihiko; Kudoh, Hisaaki; Tamura, Kiyotoshi; Seguchi, Tadao

    2013-01-01

    The oxidation products in crosslinked polyethylene for cable insulation formed during thermal and radiation ageing were analyzed by FTIR-ATR. The products were composed of carboxylic acid, carboxylic ester, and carboxylic anhydride for all ageing conditions. The relative yields of carboxylic ester and carboxylic anhydride increased with an increase of temperature for radiation and thermal ageing. The carboxylic acid was the primary oxidation product and the ester and anhydride were secondary products formed by the thermally induced reactions of the carboxylic acids. The carboxylic acid could be produced by chain scission at any temperature followed by the oxidation of the free radicals formed in the polyethylene. The results of the analysis led to formulation of a new oxidation mechanism which was different from the chain reactions via peroxy radicals and peroxides. - Highlights: ► Products analysis of polyethylene degradation by radiation and thermal ageing. ► Components of carbonyl compounds produced in polyethylene by thermal and radiation oxidation were determined by FTIR. ► Carbonyl compounds comprised carboxylic acid, carboxylic ester, and carboxylic anhydride. ► Carboxylic acid was the primary oxidation product of chain scission at any oxidation temperature. ► Carboxylic ester and carboxylic anhydride are secondary products formed from carboxylic acid at higher temperature.

  13. Analysis of piping response to thermal and operational transients

    International Nuclear Information System (INIS)

    Wang, C.Y.

    1987-01-01

    The reactor piping system is an extremely complex three-dimensional structure. Maintaining its structural integrity is essential to the safe operation of the reactor and the steam-supply system. In the safety analysis, various transient loads can be imposed on the piping which may cause plastic deformation and possible damage to the system, including those generated from hydrodynamic wave propagations, thermal and operational transients, as well as the seismic events. At Argonne National Laboratory (ANL), a three-dimensional (3-D) piping code, SHAPS, aimed for short-duration transients due to wave propagation, has been developed. Since 1984, the development work has been shifted to the long-duration accidents originating from the thermal and operational transient. As a result, a new version of the code, SHAPS-2, is being established. This paper describes many features related to this later development. To analyze piping response generated from thermal and operational transients, a 3-D implicit finite element algorithm has been developed for calculating the hoop, flexural, axial, and torsional deformations induced by the thermomechanical loads. The analysis appropriately accounts for stresses arising from the temperature dependence of the elastic material properties, the thermal expansion of the materials, and the changes in the temperature-dependent yield surface. Thermal softening, failure, strain rate, creep, and stress ratching can also be considered

  14. Thermal analysis as an aid to forensics: Alkane melting and oxidative stability of wool

    International Nuclear Information System (INIS)

    Alan Riga, D.

    1998-01-01

    Interdisciplinary methods and thermal analytical techniques in particular are effective tools in aiding the identification and characterization of materials in question involved in civil or criminal law. Forensic material science uses systematic knowledge of the physical or material world gained through analysis, observation and experimentation. Thermal analytical data can be used to aid the legal system in interpreting technical variations in quite often a complex system.Calorimetry and thermal microscopic methods helped define a commercial product composed of alkanes that was involved in a major law suit. The solid-state structures of a number of normal alkanes have unique crystal structures. These alkanes melt and freeze below room temperature to more than 60C below zero. Mixtures of specific alkanes have attributes of pure chemicals. The X-ray diffraction structure of a mixture of alkanes is the same as a pure alkane, but the melting and freezing temperature are significantly lower than predicted. The jury ruled that the product containing n-alkanes had the appropriate melting characteristics. The thermal-physical properties made a commercial fluid truly unique and there was no advertising infringement according to the law and the jury trialA combination of thermogravimetry, differential thermal analysis, infrared spectroscopy and macrophotography were used to conduct an extensive modeling and analysis of physical evidence obtained in a mobile home fire and explosion. A person's death was allegedly linked to the misuse of a kerosene space heater. The thermal analytical techniques showed that external heating was the cause of the space heater's deformation, not a firing of the heater with gasoline and kerosene. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  15. Thermal analysis as an aid to forensics: Alkane melting and oxidative stability of wool

    Energy Technology Data Exchange (ETDEWEB)

    Alan Riga, D. [Professor of Chemistry, Cleveland State University and TechCon Inc., 6325 Aldenham Dr., Cleveland, OH 44143-3331 (United States)

    1998-12-21

    Interdisciplinary methods and thermal analytical techniques in particular are effective tools in aiding the identification and characterization of materials in question involved in civil or criminal law. Forensic material science uses systematic knowledge of the physical or material world gained through analysis, observation and experimentation. Thermal analytical data can be used to aid the legal system in interpreting technical variations in quite often a complex system.Calorimetry and thermal microscopic methods helped define a commercial product composed of alkanes that was involved in a major law suit. The solid-state structures of a number of normal alkanes have unique crystal structures. These alkanes melt and freeze below room temperature to more than 60C below zero. Mixtures of specific alkanes have attributes of pure chemicals. The X-ray diffraction structure of a mixture of alkanes is the same as a pure alkane, but the melting and freezing temperature are significantly lower than predicted. The jury ruled that the product containing n-alkanes had the appropriate melting characteristics. The thermal-physical properties made a commercial fluid truly unique and there was no advertising infringement according to the law and the jury trialA combination of thermogravimetry, differential thermal analysis, infrared spectroscopy and macrophotography were used to conduct an extensive modeling and analysis of physical evidence obtained in a mobile home fire and explosion. A person's death was allegedly linked to the misuse of a kerosene space heater. The thermal analytical techniques showed that external heating was the cause of the space heater's deformation, not a firing of the heater with gasoline and kerosene. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  16. Heat transfer and thermal stress analysis in grooved tubes

    Indian Academy of Sciences (India)

    Heat transfer and thermal stresses, induced by temperature differencesin the internally grooved tubes of heat transfer equipment, have been analysed numerically. The analysis has been conducted for four different kinds of internally grooved tubes and three different mean inlet water velocities. Constant temperature was ...

  17. Thermal analysis of building roof assisted with water heater and ...

    Indian Academy of Sciences (India)

    D Prakash

    2018-03-14

    Mar 14, 2018 ... Thermal analysis; building roof; solar water heating system; roof ... These solar collec- ... several benefits, such as its wide range of storage temper- ... rugated plate, rear plate and back insulation material [12]. ..... [7] Weiss W and Rommel M 2008 Process heat collectors. State of the art within Task 33/IV.

  18. Emanation thermal analysis of SiC based materials

    Czech Academy of Sciences Publication Activity Database

    Bálek, V.; Zeleňák, V.; Mitsuhashi, T.; Bakardjieva, Snejana; Šubrt, Jan; Haneda, H.

    2002-01-01

    Roč. 67, č. 1 (2002), s. 83-89 ISSN 1418-2874 R&D Projects: GA MŠk ME 180 Grant - others:EFDA(XE) TTMA-001 Institutional research plan: CEZ:AV0Z4032918 Keywords : emanation thermal analysis * SEM * SiC nanocomposites Subject RIV: CA - Inorganic Chemistry Impact factor: 0.598, year: 2002

  19. Thermal stresses in the space shuttle orbiter: Analysis versus test

    International Nuclear Information System (INIS)

    Grooms, H.R.; Gibson, W.F. Jr.; Benson, P.L.

    1984-01-01

    Significant temperature differences occur between the internal structure and the outer skin of the Space Shuttle Orbiter as it returns from space. These temperature differences cause important thermal stresses. A finite element model containing thousands of degrees of freedom is used to predict these stresses. A ground test was performed to verify the prediction method. The analysis and test results compare favorably. (orig.)

  20. Thermo-economic analysis of Shiraz solar thermal power plant

    Energy Technology Data Exchange (ETDEWEB)

    Yaghoubi, M. [Academy of Science, Tehran (Iran, Islamic Republic of); Mokhtari, A.; Hesami, R. [Shiraz Univ., Shiraz (Iran, Islamic Republic of). School of Engineering

    2007-07-01

    The Shiraz solar thermal power plant in Iran has 48 parabolic trough collectors (PTCs) which are used to heat the working oil. There is potential to significantly increase the performance and reduce the cost of PTC solar thermal electric technologies. Conventional energy analysis based on the first law of thermodynamics does qualitatively assess the various losses occurring in the components. Therefore, exergy analysis, based on the second law of thermodynamics, can be applied to better assess various losses quantitatively as well as qualitatively. This paper presented a newly developed exergy-economic model for the Shiraz solar thermal power plant. The objective was to find the minimum exergetic production cost (EPC), based on the second law of thermodynamics. The application of exergy-economic analysis includes the evaluation of utility supply costs for production plants, and the energy costs for process operations. The purpose of the analysis was to minimize the total operating costs of the solar thermal power plant by assuming a fixed rate of electricity production and process steam. 21 refs., 3 tabs., 8 figs.

  1. Occupancy Analysis of Sports Arenas Using Thermal Imaging

    DEFF Research Database (Denmark)

    Gade, Rikke; Jørgensen, Anders; Moeslund, Thomas B.

    2012-01-01

    This paper presents a system for automatic analysis of the occupancy of sports arenas. By using a thermal camera for image capturing the number of persons and their location on the court are found without violating any privacy issues. The images are binarised with an automatic threshold method...

  2. Improving differential die-away analysis via the use of neutron poisons in detectors

    International Nuclear Information System (INIS)

    Jordan, Kelly A.; Vujic, Jasmina; Phillips, Emmanuel; Gozani, Tsahi

    2007-01-01

    Differential Die-Away Analysis (DDAA) is an active interrogation technique to detect special nuclear material (SNM). In DDAA, a pulsed neutron generator produces pulses of neutrons that are directed into a cargo to be interrogated. As each pulse passes through the cargo, the neutrons are thermalized and absorbed. If SNM is present, the thermalized neutrons from the source will cause fissions that produce a new source of neutrons. The number of thermal neutrons decay exponentially with the diffusion decay time of the inspected medium, on the order of hundreds of μs. An external neutron detector which is designed to detect only epithermal neutrons, will measure only a single decaying exponential when there is no SNM present, and two exponentials when SNM is present. This paper shows that in many cases, a gain in detection sensitivity can be realized by introducing a thermal neutron poison (such as boron) into the detector. This poison will reduce the efficiency of the detector, but decrease its decay time. A decreased decay time will cause the separation between the detector and fission signal exponentials to occur at an earlier time. There is a balance between efficiency and time constant for a detector. The boron concentration to achieve the maximum sensitivity, and its magnitude, will be different for different detector designs

  3. Analysis of Heat Transfer in Power Split Device for Hybrid Electric Vehicle Using Thermal Network Method

    Directory of Open Access Journals (Sweden)

    Jixin Wang

    2014-06-01

    Full Text Available This paper presents a rational prediction of temperature field on the differential hybrid system (DHS based on the thermal network method (TNM. The whole thermal network model is built by considering both the contact thermal resistance between gasket and planet gear and the temperature effect on the physical property parameters of lubricant. The contact thermal resistance is obtained by using the concept of contact branch thermal resistance and G-W elastic model. By building an elaborate thermal network model and computing models for power losses and thermal resistances between components, the whole temperature field of DHS under typical operating condition is predicted. Results show that thermal network method can be effectively used to predict the temperature distribution and the rule of temperature variation, the surface roughness significantly affects contact thermal conduction, and the decrease in the thermal resistance of the natural convection between air and DHS housing can effectively improve the thermal environment of DHS.

  4. Spent nuclear fuel storage pool thermal-hydraulic analysis

    International Nuclear Information System (INIS)

    Gay, R.R.

    1984-01-01

    Storage methods and requirements for spent nuclear fuel at U.S. commercial light water reactors are reviewed in Section 1. Methods of increasing current at-reactor storage capabilities are also outlined. In Section 2 the development of analytical methods for the thermal-hydraulic analysis of spent fuel pools is chronicled, leading up to a discussion of the GFLOW code which is described in Section 3. In Section 4 the verification of GFLOW by comparisons of the code's predictions to experimental data taken inside the fuel storage pool at the Maine Yankee nuclear power plant is presented. The predictions of GFLOW using 72, 224, and 1584 node models of the storage pool are compared to each other and to the experimental data. An example of thermal licensing analysis for Maine Yankee using the GFLOW code is given in Section 5. The GFLOW licensing analysis is compared to previous licensing analysis performed by Yankee Atomic using the RELAP-4 computer code

  5. Thermal analysis of compositionally modulated Fe/Y films

    International Nuclear Information System (INIS)

    Kajiura, M.; Morishita, T.; Togami, Y.; Tsushima, K.

    1987-01-01

    Structures of compositionally modulated Fe/Y films were studied by thermal analysis. The exothermic peak found in the DSC curve of (Fe 12 A/Y 12 A) most probably corresponds to crystallization of an amorphous material. SEM analysis suggested that the composition of crystallized (Fe 12 A/Y 12 A) was YFe2. It is concluded that a compositionally modulated (Fe 12 A/Y 12 A) is amorphous in structure as well as in magnetic properties

  6. CFD and thermal analysis applications at General Motors

    International Nuclear Information System (INIS)

    Johnson, J.P.

    2002-01-01

    The presentation will include a brief history of the growth of CFD and thermal analysis in GM's vehicle program divisions. Its relationship to the underlying computer infrastructure will be sketched. Application results will be presented for calculations in aerodynamics, flow through heat exchangers, engine compartment thermal studies, HVAC systems and others. Current technical challenges will be outlined including grid generation, turbulence modeling, heat transfer, and solution algorithms. The introduction of CFD and heat transfer results into Virtual Vehicle Reviews, and its potential impact on a company's CAE infrastructure will be noted. Finally, some broad comments will be made on the management of CFD and heat transfer technology across a global corporate enterprise. (author)

  7. Interim report on nuclear waste depository thermal analysis

    International Nuclear Information System (INIS)

    Altenbach, T.J.

    1978-01-01

    A thermal analysis of a deep geologic depository for spent nuclear fuel is being conducted. The TRUMP finite difference heat transfer code is used to analyze a 3-dimensional model of the depository. The model uses a unit cell consisting of one spent fuel canister buried in salt beneath a ventilated room in the depository. A base case was studied along with several parametric variations. It is concluded that this method is appropriate for analyzing the thermal response of the system, and that the most important parameter in determining the maximum temperatures is the canister heat generation rate. The effects of room ventilation and different depository media are secondary

  8. Thermally emissive sensing materials for chemical spectroscopy analysis

    Science.gov (United States)

    Poole, Zsolt; Ohodnicki, Paul R.

    2018-05-08

    A sensor using thermally emissive materials for chemical spectroscopy analysis includes an emissive material, wherein the emissive material includes the thermally emissive materials which emit electromagnetic radiation, wherein the electromagnetic radiation is modified due to chemical composition in an environment; and a detector adapted to detect the electromagnetic radiation, wherein the electromagnetic radiation is indicative of the chemical interaction changes and hence chemical composition and/or chemical composition changes of the environment. The emissive material can be utilized with an optical fiber sensor, with the optical fiber sensor operating without the emissive material probed with a light source external to the material.

  9. Study of aging mechanism of ammonium dinitramide using thermal analysis and spectrometry

    OpenAIRE

    Matsunaga, Hiroki; Yoshino, Satoru; Kumasaki, Mieko; Miyake, Atsumi; Habu, Hiroto; 松永, 浩貴; 吉野, 悟; 熊崎, 美枝子; 三宅, 淳巳; 羽生, 宏人

    2011-01-01

    To get better information about aging mechanism of ammonium dinitramide (ADN) during storage, thermal analysis and spectrometry were carried out. The infrared, Raman, ultraviolet spectrometry and the sealed cell differential scanning calorimetry (SC-DSC) of AND (1998) which has been stored for 11 years in a dark place suggested that ADN has degraded to ammonium nitrate (AN) during the storage. The amount of ADN in AND (1998) was determined to be 57 wt.% at the surface region and 89 wt.% at th...

  10. Thermal analysis and prediction of phase equilibria in ternary Pb-Zn-Ag system

    Directory of Open Access Journals (Sweden)

    Živković D.

    2011-01-01

    Full Text Available Ternary Pb-Zn-Ag system is typical for some physicochemical processes going on in refining phase in the extractive metallurgy of lead. Therefore, investigation of mentioned system is important from both theoretical and practical research of the phenomena occurring during the lead desilverizing process. The results of experimental investigation using differential thermal analysis (DTA and thermodynamic calculation of phase equilibria in Pb-Zn-Ag system according to CALPHAD method, in the sections with Zn:Ag mass ratio equal to 90:10, 70:30 and 50:50, are presented in this paper.

  11. Mathematical model for thermal and entropy analysis of thermal solar collectors by using Maxwell nanofluids with slip conditions, thermal radiation and variable thermal conductivity

    Science.gov (United States)

    Aziz, Asim; Jamshed, Wasim; Aziz, Taha

    2018-04-01

    In the present research a simplified mathematical model for the solar thermal collectors is considered in the form of non-uniform unsteady stretching surface. The non-Newtonian Maxwell nanofluid model is utilized for the working fluid along with slip and convective boundary conditions and comprehensive analysis of entropy generation in the system is also observed. The effect of thermal radiation and variable thermal conductivity are also included in the present model. The mathematical formulation is carried out through a boundary layer approach and the numerical computations are carried out for Cu-water and TiO2-water nanofluids. Results are presented for the velocity, temperature and entropy generation profiles, skin friction coefficient and Nusselt number. The discussion is concluded on the effect of various governing parameters on the motion, temperature variation, entropy generation, velocity gradient and the rate of heat transfer at the boundary.

  12. A computational model for thermal fluid design analysis of nuclear thermal rockets

    International Nuclear Information System (INIS)

    Given, J.A.; Anghaie, S.

    1997-01-01

    A computational model for simulation and design analysis of nuclear thermal propulsion systems has been developed. The model simulates a full-topping expander cycle engine system and the thermofluid dynamics of the core coolant flow, accounting for the real gas properties of the hydrogen propellant/coolant throughout the system. Core thermofluid studies reveal that near-wall heat transfer models currently available may not be applicable to conditions encountered within some nuclear rocket cores. Additionally, the possibility of a core thermal fluid instability at low mass fluxes and the effects of the core power distribution are investigated. Results indicate that for tubular core coolant channels, thermal fluid instability is not an issue within the possible range of operating conditions in these systems. Findings also show the advantages of having a nonflat centrally peaking axial core power profile from a fluid dynamic standpoint. The effects of rocket operating conditions on system performance are also investigated. Results show that high temperature and low pressure operation is limited by core structural considerations, while low temperature and high pressure operation is limited by system performance constraints. The utility of these programs for finding these operational limits, optimum operating conditions, and thermal fluid effects is demonstrated

  13. Chemical and thermal analysis for characterisation of building materials

    International Nuclear Information System (INIS)

    Kumar, S.C.; Sudersanan, M.; Ravindran, P.V.; Kalekar, B.B.; Mathur, P.K.

    2000-01-01

    Cement and other construction materials are extensively used for the construction of shielding materials for nuclear and high energy radiations. The design and optimum utilisation of such materials need an accurate analysis of their chemical composition. The moisture content and presence of bound water and other volatile materials are also important. The use of thermal analysis supplements the data obtained by chemical analysis and enables a distinction of moisture and chemically bound water. It also enables an identification of the process leading to the loss on ignition. The work carried out on the analysis of sand, cement and other aggregate materials used for the preparation of concrete is described in the paper. (author)

  14. Neisseria meningitidis rifampicin resistant strains: analysis of protein differentially expressed

    Directory of Open Access Journals (Sweden)

    Schininà Maria

    2010-09-01

    Full Text Available Abstract Background Several mutations have been described as responsible for rifampicin resistance in Neisseria meningitidis. However, the intriguing question on why these strains are so rare remains open. The aim of this study was to investigate the protein content and to identify differential expression in specific proteins in two rifampicin resistant and one susceptible meningococci using two-dimensional electrophoresis (2-DE combined with mass spectrometry. Results In our experimental conditions, able to resolve soluble proteins with an isoelectric point between 4 and 7, twenty-three proteins have been found differentially expressed in the two resistant strains compared to the susceptible. Some of them, involved in the main metabolic pathways, showed an increased expression, mainly in the catabolism of pyruvate and in the tricarboxylic acid cycle. A decreased expression of proteins belonging to gene regulation and to those involved in the folding of polypeptides has also been observed. 2-DE analysis showed the presence of four proteins displaying a shift in their isoelectric point in both resistant strains, confirmed by the presence of amino acid changes in the sequence analysis, absent in the susceptible. Conclusions The analysis of differentially expressed proteins suggests that an intricate series of events occurs in N. meningitidis rifampicin resistant strains and the results here reported may be considered a starting point in understanding their decreased invasion capacity. In fact, they support the hypothesis that the presence of more than one protein differentially expressed, having a role in the metabolism of the meningococcus, influences its ability to infect and to spread in the population. Different reports have described and discussed how a drug resistant pathogen shows a high biological cost for survival and that may also explain why, for some pathogens, the rate of resistant organisms is relatively low considering the

  15. Horizontal steam generator PGV-1000 thermal-hydraulic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ubra, O. [Skoda Company, Prague (Switzerland); Doubek, M. [Czech Technical Univ., Prague (Switzerland)

    1995-12-31

    A computer program for the steady state thermal-hydraulic analysis of horizontal steam generator PGV-1000 is presented. The program provides the capability to analyze steam generator PGV-1000 primary side flow and temperature distribution, primary side pressure drops, heat transfer between the primary and secondary sides and multidimensional heat flux distribution. A special attention is paid to the thermal-hydraulics of the secondary side. The code predicts 3-D distribution of the void fraction at the secondary side, mass redistribution under the submerged perforated sheet and the steam generator level profile. By means of developed computer program a detailed thermal-hydraulic study of the PGV-1000 has been carried out. A wide range of calculations has been performed and a set of important steam generator characteristics has been obtained. Some of them are presented in the paper. (orig.). 5 refs.

  16. Photovoltaic thermal module concepts and their performance analysis: A review

    International Nuclear Information System (INIS)

    Hasan, M. Arif; Sumathy, K.

    2010-01-01

    This paper presents a review of the available literature covering the latest module aspects of different photovoltaic/thermal (PV/T) collectors and their performances in terms of electrical as well as thermal output. The review covers detailed description of flat-plate and concentrating PV/T systems, using liquid or air as the working fluid, numerical model analysis, experimental work and qualitative evaluation of thermal and electrical output. Also an in-depth review on the performance parameters such as, optimum mass flow rate, PV/T dimensions, air channel geometry is presented in this study. Based on the thorough review, it is clear that PV/T modules are very promising devices and there exists lot of scope to further improve their performances. Appropriate recommendations are made which will aid PV/T systems to improve their efficiency and reducing their cost, making them more competitive in the present market. (author)

  17. Non-linear elastic thermal stress analysis with phase changes

    International Nuclear Information System (INIS)

    Amada, S.; Yang, W.H.

    1978-01-01

    The non-linear elastic, thermal stress analysis with temperature induced phase changes in the materials is presented. An infinite plate (or body) with a circular hole (or tunnel) is subjected to a thermal loading on its inner surface. The peak temperature around the hole reaches beyond the melting point of the material. The non-linear diffusion equation is solved numerically using the finite difference method. The material properties change rapidly at temperatures where the change of crystal structures and solid-liquid transition occur. The elastic stresses induced by the transient non-homogeneous temperature distribution are calculated. The stresses change remarkably when the phase changes occur and there are residual stresses remaining in the plate after one cycle of thermal loading. (Auth.)

  18. Horizontal steam generator PGV-1000 thermal-hydraulic analysis

    International Nuclear Information System (INIS)

    Ubra, O.; Doubek, M.

    1995-01-01

    A computer program for the steady state thermal-hydraulic analysis of horizontal steam generator PGV-1000 is presented. The program provides the capability to analyze steam generator PGV-1000 primary side flow and temperature distribution, primary side pressure drops, heat transfer between the primary and secondary sides and multidimensional heat flux distribution. A special attention is paid to the thermal-hydraulics of the secondary side. The code predicts 3-D distribution of the void fraction at the secondary side, mass redistribution under the submerged perforated sheet and the steam generator level profile. By means of developed computer program a detailed thermal-hydraulic study of the PGV-1000 has been carried out. A wide range of calculations has been performed and a set of important steam generator characteristics has been obtained. Some of them are presented in the paper. (orig.)

  19. Horizontal steam generator PGV-1000 thermal-hydraulic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ubra, O [Skoda Company, Prague (Switzerland); Doubek, M [Czech Technical Univ., Prague (Switzerland)

    1996-12-31

    A computer program for the steady state thermal-hydraulic analysis of horizontal steam generator PGV-1000 is presented. The program provides the capability to analyze steam generator PGV-1000 primary side flow and temperature distribution, primary side pressure drops, heat transfer between the primary and secondary sides and multidimensional heat flux distribution. A special attention is paid to the thermal-hydraulics of the secondary side. The code predicts 3-D distribution of the void fraction at the secondary side, mass redistribution under the submerged perforated sheet and the steam generator level profile. By means of developed computer program a detailed thermal-hydraulic study of the PGV-1000 has been carried out. A wide range of calculations has been performed and a set of important steam generator characteristics has been obtained. Some of them are presented in the paper. (orig.). 5 refs.

  20. Photovoltaic thermal module concepts and their performance analysis: A review

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, M. Arif; Sumathy, K. [Department of Mechanical Engineering, North Dakota State University, Fargo, ND (United States)

    2010-09-15

    This paper presents a review of the available literature covering the latest module aspects of different photovoltaic/thermal (PV/T) collectors and their performances in terms of electrical as well as thermal output. The review covers detailed description of flat-plate and concentrating PV/T systems, using liquid or air as the working fluid, numerical model analysis, experimental work and qualitative evaluation of thermal and electrical output. Also an in-depth review on the performance parameters such as, optimum mass flow rate, PV/T dimensions, air channel geometry is presented in this study. Based on the thorough review, it is clear that PV/T modules are very promising devices and there exists lot of scope to further improve their performances. Appropriate recommendations are made which will aid PV/T systems to improve their efficiency and reducing their cost, making them more competitive in the present market. (author)

  1. Kinetic analysis of overlapping multistep thermal decomposition comprising exothermic and endothermic processes: thermolysis of ammonium dinitramide.

    Science.gov (United States)

    Muravyev, Nikita V; Koga, Nobuyoshi; Meerov, Dmitry B; Pivkina, Alla N

    2017-01-25

    This study focused on kinetic modeling of a specific type of multistep heterogeneous reaction comprising exothermic and endothermic reaction steps, as exemplified by the practical kinetic analysis of the experimental kinetic curves for the thermal decomposition of molten ammonium dinitramide (ADN). It is known that the thermal decomposition of ADN occurs as a consecutive two step mass-loss process comprising the decomposition of ADN and subsequent evaporation/decomposition of in situ generated ammonium nitrate. These reaction steps provide exothermic and endothermic contributions, respectively, to the overall thermal effect. The overall reaction process was deconvoluted into two reaction steps using simultaneously recorded thermogravimetry and differential scanning calorimetry (TG-DSC) curves by considering the different physical meanings of the kinetic data derived from TG and DSC by P value analysis. The kinetic data thus separated into exothermic and endothermic reaction steps were kinetically characterized using kinetic computation methods including isoconversional method, combined kinetic analysis, and master plot method. The overall kinetic behavior was reproduced as the sum of the kinetic equations for each reaction step considering the contributions to the rate data derived from TG and DSC. During reproduction of the kinetic behavior, the kinetic parameters and contributions of each reaction step were optimized using kinetic deconvolution analysis. As a result, the thermal decomposition of ADN was successfully modeled as partially overlapping exothermic and endothermic reaction steps. The logic of the kinetic modeling was critically examined, and the practical usefulness of phenomenological modeling for the thermal decomposition of ADN was illustrated to demonstrate the validity of the methodology and its applicability to similar complex reaction processes.

  2. Detection of Certain Spices Subjected to Gamma Irradiation By Using Thermal Analysis Technique

    International Nuclear Information System (INIS)

    Sayed, M.S.; Ali, H.G.M.; Abdeldaiem, M.H.

    2013-01-01

    The present investigation was carried out to apply a detection method of some irradiated spices using thermal analysis technique. Black pepper, cumin and ginger were irradiated using gamma irradiation at dose levels 5, 10 and 15 kGy and stored for 12 months at room temperature. Thermal analysis techniques TGA and DTA were studied for characterizing irradiated spices. Thermo gravimetric analysis (TGA) is a method where the measurement of mass as a function of heating is recorded. TGA was used to determine the moisture and ash contents and thermal stabilities. Non-significant changes of the weight loss percent due to the irradiation were occurred on the studied spices up to 10 kGy. The weight loss was decreased at the first step up to 100 degree C due to the release of water of hydration. Another sharp decreasing in weight loss percent at the second step 220-300 degree C may be due to volatilization of the sample. The final weight loss weight loss stage up to 500 degree C may be due to burn out the fixed carbon remaining in the sample. As the irradiation dose increased from control up to 15 kGy, the weight loss percent at the dehydration step was decreased. The kinetics of the spices decomposition were studied in order to ascertain the type of weight loss mechanism and calculate the activation energy (E a ). The differential thermal analysis (DTA) of the studied samples showed two main characteristic peaks; endothermic one due to the dehydration process and the second peak may be due to the partial volatilization of the aromatic compounds of the main constituent of the studied spices. It could be concluded that using gamma irradiation (up to 15.0 kGy) for black pepper, cumin and ginger are thermally stable to human consumption.

  3. Thermodynamic study of ibuprofen by adiabatic calorimetry and thermal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Xu Fen; Sun Lixian; Tan Zhicheng; Liang Jianguo; Li Ruilian

    2004-03-23

    Molar heat capacities of ibuprofen were precisely measured with a small sample precision automated adiabatic calorimeter over the temperature range from 80 to 400 K. The polynomial functions of C{sub p,m} (J K{sup -1} mol{sup -1}) versus T were established on the heat capacity measurements by means of the least fitting square method. The functions are as follows: for solid ibuprofen, at the temperature range of 79.105 K{<=}T{<=}333.297 K, C{sub p,m}=144.27+77.046X+3.5171X{sup 2}+10.925X{sup 3}+11.224X{sup 4}, where X=(T-206.201)/127.096; for liquid ibuprofen, at the temperature range of 353.406 K{<=}T{<=}378.785 K, C{sub p,m}=325.79+8.9696X-1.6073X{sup 2}-1.5145X{sup 3}, where X=(T-366.095)/12.690. A fusion transition at T=348.02 K was found from the C{sub p}-T curve. The molar enthalpy and entropy of the fusion transition were determined to be 26.65 kJ mol{sup -1} and 76.58 J mol{sup -1} K{sup -1}, respectively. The thermodynamic functions on the base of the reference temperature of 298.15 K, (H{sub T}-H{sub 298.15}) and (S{sub T}-S{sub 298.15}), were derived. Thermal characteristic of ibuprofen was studied by thermo-gravimetric analysis (TG-DTG) and differential scanning calorimeter (DSC). The temperature of fusion, the molar enthalpy and entropy of fusion obtained by DSC were well consistent with those obtained by adiabatic calorimeter. The evaporation process of ibuprofen was investigated further by TG and DTG, and the activation energy of the evaporation process was determined to be 80.3{+-}1.4 kJ mol{sup -1}.

  4. Kinetic analysis of thermally relativistic flow with dissipation

    International Nuclear Information System (INIS)

    Yano, Ryosuke; Suzuki, Kojiro

    2011-01-01

    Nonequilibrium flow of thermally relativistic matter with dissipation is considered in the framework of the relativistic kinetic theory. As an object of the analysis, the supersonic rarefied flow of thermally relativistic matter around the triangle prism is analyzed using the Anderson-Witting model. Obtained numerical results indicate that the flow field changes in accordance with the flow velocity and temperature of the uniform flow owing to both effects derived from the Lorentz contraction and thermally relativistic effects, even when the Mach number of the uniform flow is fixed. The profiles of the heat flux along the stagnation streamline can be approximated on the basis of the relativistic Navier-Stokes-Fourier (NSF) law except for a strong nonequilibrium regime such as the middle of the shock wave and the vicinity of the wall, whereas the profile of the heat flux behind the triangle prism cannot be approximated on the basis of the relativistic NSF law owing to rarefied effects via the expansion behind the triangle prism. Additionally, the heat flux via the gradient of the static pressure is non-negligible owing to thermally relativistic effects. The profile of the dynamic pressure is different from that approximated on the basis of the NSF law, which is obtained by the Eckart decomposition. Finally, variations of convections of the mass and momentum owing to the effects derived from the Lorentz contraction and thermally relativistic effects are numerically confirmed.

  5. Thermal analysis of the vertical disposal for HLW

    International Nuclear Information System (INIS)

    Zhao Honggang; Wang Ju; Liu Yuemiao; Su Rui

    2013-01-01

    The temperature on the canister surface is set to be no more than 100℃ in the high level radioactive waste (HLW) repository, it is a criterion to dictate the thermal dimension of the repository. The factors that affect the temperature on the canister surface include the initial power of the canister, the thermal properties of material as the engineered barrier system (EBS), the gaps around the canister in the EBS, the initial ground temperature and thermal properties of the host rock, the repository layout, etc. This article examines the thermal properties of the material in host rock and the EBS, the thermal conductivity properties of the different gaps in the EBS, the temperature evolution around the single canister by using the analysis method and the numerical method. The findings are as follows: 1) The most important and the sensitive parameter is the initial disposal power of the canister; 2) The two key factors that affect the highest temperature on the canister surface are the parameter of uncertainty and nature variability of material as the host rock and the EBS, and the gaps around the canister in the EBS; 3) The temperature difference between the canister and bentonite is no more than 10℃ , and the bigger the inner gaps are, the bigger the temperature difference will be; when the gap between the bentonite and the host rock is filled with water, the temperature difference becomes small, but it will be 1∼3℃ higher than the gaps filled will air. (authors)

  6. Thermal hydrodynamic analysis of a countercurrent gas centrifuge

    International Nuclear Information System (INIS)

    Andrade, Delvonei Alves de

    1999-01-01

    The influence of the thermal countercurrent on the separative performance of countercurrent centrifuges is treated in this work. The methodology used consists in modeling the gas flow inside the rotor under thermal boundary conditions supplied by the structural thermal model. The gas flow model, also called hydrodynamical model, is based on the Finite Volume Method for cylindrical geometry with azimuthal symmetry. The structural thermal model is based on the Nodal Method and take into account simultaneously, the conduction convection and radiation phenomena. The procedure adopted for this study consisted in the definition of the operational and geometric conditions of a centrifuge which was used as a pattern to the accomplished analysis. This configuration, called 'Standard Centrifuge', was used for the accomplishment of several simulations where the importance of the realistic boundary thermal conditions for the numerical evaluation of the centrifuge separative capacity was evidenced. A selective alteration for the optical properties based on simple engineering procedures was proposed. An improvement of 5% was obtained with this alteration. (author)

  7. Thermal analysis of wood of the main tree species of Central Siberia

    Directory of Open Access Journals (Sweden)

    S. R. Loskutov

    2015-12-01

    Full Text Available Thermal decomposition of wood from coniferous and deciduous species of Siberia has been studied using thermogravimetry (TG and differential scanning calorimetry (DSC. The tree species were larch Larix sibirica Ledeb., Scots pine Pinus sylvestris L., spruce Picea obovata Ledeb., fir Abies sibirica Ledeb., Siberian pine Pinus sibirica Du Tour., birch Betula pendula Roth., and aspen Populus tremula L. Thermal analysis of wood samples was carried out under oxidative (air and inert (argon atmospheres from 25 to 700 °С at heating rates 10, 20, 40 °С • min–1 (TG/DTG and from 25 to 590 °С at heating rates 10, 40 °С • min–1 (DSC. The stages of thermal decomposition, the temperature intervals, the mass loss, the mass loss rate, the temperature of DTG/DSC peaks, and heating effects were determined for each tree species. The kinetic thermal degradation parameters of wood were obtained by the Broido and Ozawa–Flynn–Wall models. The wood of coniferous and deciduous species of Siberia was characterized on the base of analysis of activation energy values at various stages of thermal decomposition and the relations of activation energy on conversion level of wood substance of different tree species, and also the comparison of mass loss at the same stages of thermal destruction, heating effects, residual mass and other parameters of TG/DTG, DSC. In our opinion, the results of this work present interest for researchers and specialists in the field of forest pyrology, wood science, dendrochemistry.

  8. Ionic liquid thermal stabilities: decomposition mechanisms and analysis tools.

    Science.gov (United States)

    Maton, Cedric; De Vos, Nils; Stevens, Christian V

    2013-07-07

    The increasing amount of papers published on ionic liquids generates an extensive quantity of data. The thermal stability data of divergent ionic liquids are collected in this paper with attention to the experimental set-up. The influence and importance of the latter parameters are broadly addressed. Both ramped temperature and isothermal thermogravimetric analysis are discussed, along with state-of-the-art methods, such as TGA-MS and pyrolysis-GC. The strengths and weaknesses of the different methodologies known to date demonstrate that analysis methods should be in line with the application. The combination of data from advanced analysis methods allows us to obtain in-depth information on the degradation processes. Aided with computational methods, the kinetics and thermodynamics of thermal degradation are revealed piece by piece. The better understanding of the behaviour of ionic liquids at high temperature allows selective and application driven design, as well as mathematical prediction for engineering purposes.

  9. Experimental analysis on physical and mechanical properties of thermal shock damage of granite

    Directory of Open Access Journals (Sweden)

    He Xiao

    2017-01-01

    Full Text Available The purpose of this study was to explore the changes of mechanical and physical properties of granite under different thermal loading effects. Uniaxial compression experiments studying the rules of the influence of temperature load on mechanical properties of granite were carried out. After high-temperature heating at above 600 °C, granite tended to have stronger ductility and plasticity as well as declined peak stress and compressive strength. Thermogravimetry - differential scanning calorimetry (TG-DSC analysis results showed that, thermal load at different temperatures induced reactions such as water loss, oxidation and crystallization in the microstructure of granite, which led to physical changes of granite. Hence it is concluded that, heating can significantly weaken the mechanical performance of granite, which provides an important support for the optimization of heating assisted processing of granite. It also reveals that, heating assisted cutting technique can effectively lower energy consumption and improve processing efficiency.

  10. Magneto-thermal-acoustic differential-frequency imaging of magnetic nanoparticle with magnetic spatial localization: a theoretical prediction

    Science.gov (United States)

    Piao, Daqing

    2017-02-01

    The magneto-thermo-acoustic effect that we predicted in 2013 refers to the generation of acoustic-pressure wave from magnetic nanoparticle (MNP) when thermally mediated under an alternating magnetic field (AMF) at a pulsed or frequency-chirped application. Several independent experimental studies have since validated magneto-thermoacoustic effect, and a latest report has discovered acoustic-wave generation from MNP at the second-harmonic frequency of the AMF when operating continuously. We propose that applying two AMFs with differing frequencies to MNP will produce acoustic-pressure wave at the summation and difference of the two frequencies, in addition to the two second-harmonic frequencies. Analysis of the specific absorption dynamics of the MNP when exposed to two AMFs of differing frequencies has shown some interesting patterns of acoustic-intensity at the multiple frequency components. The ratio of the acoustic-intensity at the summation-frequency over that of the difference-frequency is determined by the frequency-ratio of the two AMFs, but remains independent of the AMF strengths. The ratio of the acoustic-intensity at the summation- or difference-frequency over that at each of the two second-harmonic frequencies is determined by both the frequency-ratio and the field-strength-ratio of the two AMFs. The results indicate a potential strategy for localization of the source of a continuous-wave magneto-thermalacoustic signal by examining the frequency spectrum of full-field non-differentiating acoustic detection, with the field-strength ratio changed continuously at a fixed frequency-ratio. The practicalities and challenges of this magnetic spatial localization approach for magneto-thermo-acoustic imaging using a simple envisioned set of two AMFs arranged in parallel to each other are discussed.

  11. Cellular attachment and differentiation on titania nanotubes exposed to air- or nitrogen-based non-thermal atmospheric pressure plasma.

    Directory of Open Access Journals (Sweden)

    Hye Yeon Seo

    Full Text Available The surface topography and chemistry of titanium implants are important factors for successful osseointegration. However, chemical modification of an implant surface using currently available methods often results in the disruption of topographical features and the loss of beneficial effects during the shelf life of the implant. Therefore, the aim of this study was to apply the recently highlighted portable non-thermal atmospheric pressure plasma jet (NTAPPJ, elicited from one of two different gas sources (nitrogen and air, to TiO2 nanotube surfaces to further improve their osteogenic properties while preserving the topographical morphology. The surface treatment was performed before implantation to avoid age-related decay. The surface chemistry and morphology of the TiO2 nanotube surfaces before and after the NTAPPJ treatment were determined using a field-emission scanning electron microscope, a surface profiler, a contact angle goniometer, and an X-ray photoelectron spectroscope. The MC3T3-E1 cell viability, attachment and morphology were confirmed using calcein AM and ethidium homodimer-1 staining, and analysis of gene expression using rat mesenchymal stem cells was performed using a real-time reverse-transcription polymerase chain reaction. The results indicated that both portable nitrogen- and air-based NTAPPJ could be used on TiO2 nanotube surfaces easily and without topographical disruption. NTAPPJ resulted in a significant increase in the hydrophilicity of the surfaces as well as changes in the surface chemistry, which consequently increased the cell viability, attachment and differentiation compared with the control samples. The nitrogen-based NTAPPJ treatment group exhibited a higher osteogenic gene expression level than the air-based NTAPPJ treatment group due to the lower atomic percentage of carbon on the surface that resulted from treatment. It was concluded that NTAPPJ treatment of TiO2 nanotube surfaces results in an increase in

  12. Improving thermal efficiency and increasing production rate in the double moving beds thermally coupled reactors by using differential evolution (DE) technique

    International Nuclear Information System (INIS)

    Karimi, Mohsen; Rahimpour, Mohammad Reza; Rafiei, Razieh; Shariati, Alireza; Iranshahi, Davood

    2016-01-01

    Highlights: • Double moving bed thermally coupled reactor is modeled in two dimensions. • The required heat of naphtha process is attained with nitrobenzene hydrogenation. • DE optimization method is applied to optimize operating conditions. • Hydrogen, aromatic and aniline productions increase in the proposed configuration. - Abstract: According to the global requirements for energy saving and the control of global warming, multifunctional auto-thermal reactors as a novel concept in the process integration (PI) have risen up in the recent years. In the novel modification presented in this study, the required heat of endothermic naphtha reforming process has been supplied by nitrobenzene hydrogenation reaction. In addition, the enhancement of reactor performance, such as the increase of production rate, has become a key issue in the diverse industries. Thus, Differential Evolution (DE) technique is applied to optimize the operating conditions (temperature and pressure) and designing parameters of a thermally coupled reactor with double moving beds. Ultimately, the obtained results of the proposed model are compared with non-optimized and conventional model. This model results in noticeable reduction in the operational costs as well as enhancement of the net profit of the plant. The increase in the hydrogen and aromatic production shows the superiority of the proposed model.

  13. PC analysis of stochastic differential equations driven by Wiener noise

    KAUST Repository

    Le Maitre, Olivier

    2015-03-01

    A polynomial chaos (PC) analysis with stochastic expansion coefficients is proposed for stochastic differential equations driven by additive or multiplicative Wiener noise. It is shown that for this setting, a Galerkin formalism naturally leads to the definition of a hierarchy of stochastic differential equations governing the evolution of the PC modes. Under the mild assumption that the Wiener and uncertain parameters can be treated as independent random variables, it is also shown that the Galerkin formalism naturally separates parametric uncertainty and stochastic forcing dependences. This enables us to perform an orthogonal decomposition of the process variance, and consequently identify contributions arising from the uncertainty in parameters, the stochastic forcing, and a coupled term. Insight gained from this decomposition is illustrated in light of implementation to simplified linear and non-linear problems; the case of a stochastic bifurcation is also considered.

  14. Teacher knowledge of error analysis in differential calculus

    Directory of Open Access Journals (Sweden)

    Eunice K. Moru

    2014-12-01

    Full Text Available The study investigated teacher knowledge of error analysis in differential calculus. Two teachers were the sample of the study: one a subject specialist and the other a mathematics education specialist. Questionnaires and interviews were used for data collection. The findings of the study reflect that the teachers’ knowledge of error analysis was characterised by the following assertions, which are backed up with some evidence: (1 teachers identified the errors correctly, (2 the generalised error identification resulted in opaque analysis, (3 some of the identified errors were not interpreted from multiple perspectives, (4 teachers’ evaluation of errors was either local or global and (5 in remedying errors accuracy and efficiency were emphasised more than conceptual understanding. The implications of the findings of the study for teaching include engaging in error analysis continuously as this is one way of improving knowledge for teaching.

  15. Quantitative subsurface analysis using frequency modulated thermal wave imaging

    Science.gov (United States)

    Subhani, S. K.; Suresh, B.; Ghali, V. S.

    2018-01-01

    Quantitative depth analysis of the anomaly with an enhanced depth resolution is a challenging task towards the estimation of depth of the subsurface anomaly using thermography. Frequency modulated thermal wave imaging introduced earlier provides a complete depth scanning of the object by stimulating it with a suitable band of frequencies and further analyzing the subsequent thermal response using a suitable post processing approach to resolve subsurface details. But conventional Fourier transform based methods used for post processing unscramble the frequencies with a limited frequency resolution and contribute for a finite depth resolution. Spectral zooming provided by chirp z transform facilitates enhanced frequency resolution which can further improves the depth resolution to axially explore finest subsurface features. Quantitative depth analysis with this augmented depth resolution is proposed to provide a closest estimate to the actual depth of subsurface anomaly. This manuscript experimentally validates this enhanced depth resolution using non stationary thermal wave imaging and offers an ever first and unique solution for quantitative depth estimation in frequency modulated thermal wave imaging.

  16. Using fractal analysis of thermal signatures for thyroid disease evaluation

    Science.gov (United States)

    Gavriloaia, Gheorghe; Sofron, Emil; Gavriloaia, Mariuca-Roxana; Ghemigean, Adina-Mariana

    2010-11-01

    The skin is the largest organ of the body and it protects against heat, light, injury and infection. Skin temperature is an important parameter for diagnosing diseases. Thermal analysis is non-invasive, painless, and relatively inexpensive, showing a great potential research. Since the thyroid regulates metabolic rate it is intimately connected to body temperature, more than, any modification of its function generates a specific thermal image on the neck skin. The shapes of thermal signatures are often irregular in size and shape. Euclidean geometry is not able to evaluate their shape for different thyroid diseases, and fractal geometry is used in this paper. Different thyroid diseases generate different shapes, and their complexity are evaluated by specific mathematical approaches, fractal analysis, in order to the evaluate selfsimilarity and lacunarity. Two kinds of thyroid diseases, hyperthyroidism and papillary cancer are analyzed in this paper. The results are encouraging and show the ability to continue research for thermal signature to be used in early diagnosis of thyroid diseases.

  17. Thermal Analysis of the Fastrac Chamber/Nozzle

    Science.gov (United States)

    Davis, Darrell

    2001-01-01

    This paper will describe the thermal analysis techniques used to predict temperatures in the film-cooled ablative rocket nozzle used on the Fastrac 60K rocket engine. A model was developed that predicts char and pyrolysis depths, liner thermal gradients, and temperatures of the bondline between the overwrap and liner. Correlation of the model was accomplished by thermal analog tests performed at Southern Research, and specially instrumented hot fire tests at the Marshall Space Flight Center. Infrared thermography was instrumental in defining nozzle hot wall surface temperatures. In-depth and outboard thermocouple data was used to correlate the kinetic decomposition routine used to predict char and pyrolysis depths. These depths were anchored with measured char and pyrolysis depths from cross-sectioned hot-fire nozzles. For the X-34 flight analysis, the model includes the ablative Thermal Protection System (TPS) material that protects the overwrap from the recirculating plume. Results from model correlation, hot-fire testing, and flight predictions will be discussed.

  18. Thermal Analysis of the MC-1 Chamber/Nozzle

    Science.gov (United States)

    Davis, Darrell W.; Phelps, Lisa H. (Technical Monitor)

    2001-01-01

    This paper will describe the thermal analysis techniques used to predict temperatures in the film-cooled ablative rocket nozzle used on the MC-1 60K rocket engine. A model was developed that predicts char and pyrolysis depths, liner thermal gradients, and temperatures of the bondline between the overwrap and liner. Correlation of the model was accomplished by thermal analog tests performed at Southern Research, and specially instrumented hot fire tests at the Marshall Space Flight Center. Infrared thermography was instrumental in defining nozzle hot wall surface temperatures. In-depth and outboard thermocouple data was used to correlate the kinetic decomposition routine used to predict char and pyrolysis depths. These depths were anchored with measured char and pyrolysis depths from cross-sectioned hot-fire nozzles. For the X-34 flight analysis, the model includes the ablative Thermal Protection System (TPS) material that protects the overwrap from the recirculating plume. Results from model correlation, hot-fire testing, and flight predictions will be discussed.

  19. COMTA - a computer code for fuel mechanical and thermal analysis

    International Nuclear Information System (INIS)

    Basu, S.; Sawhney, S.S.; Anand, A.K.; Anantharaman, K.; Mehta, S.K.

    1979-01-01

    COMTA is a generalized computer code for integrity analysis of the free standing fuel cladding, with natural UO 2 or mixed oxide fuel pellets. Thermal and Mechanical analysis is done simultaneously for any power history of the fuel pin. For analysis, the fuel cladding is assumed to be axisymmetric and is subjected to axisymmetric load due to contact pressure, gas pressure, coolant pressure and thermal loads. Axial variation of load is neglected and creep and plasticity are assumed to occur at constant volume. The pellet is assumed to be made of concentric annuli. The fission gas release integral is dependent on the temperature and the power produced in each annulus. To calculate the temperature distribution in the fuel pin, the variation of bulk coolant temperature is given as an input to the code. Gap conductance is calculated at every time step, considering fuel densification, fuel relocation and gap closure, filler gas dilution by released fission gas, gap closure by expansion and irradiation swelling. Overall gap conductance is contributed by heat transfer due to the three modes; conduction convection and radiation as per modified Ross and Stoute model. Equilibrium equations, compatibility equations, stress strain relationships (including thermal strains and permanent strains due to creep and plasticity) are used to obtain triaxial stresses and strains. Thermal strain is assumed to be zero at hot zero power conditions. The boundary conditions are obtained for radial stresses at outside and inside surfaces by making these equal to coolant pressure and internal pressure respectively. A multi-mechanism creep model which accounts for thermal and irradiation creep is used to calculate the overall creep rate. Effective plastic strain is a function of effective stress and material constants. (orig.)

  20. Evaluation of thermal stability of paraffin wax by differential scanning calorimetry; Avaliacao da estabilidade termica de parafina por calorimetria diferencial de varredura

    Energy Technology Data Exchange (ETDEWEB)

    Godinho, K.O.; Silva, A.G.P.; Holanda, J.N.F. [Universidade Estadual do Norte Fluminense (LAMAV/UENF), Campos dos Goytacazes, RJ (Brazil). Grupo de Materiais Ceramicos], Email: holanda@uenf.br

    2010-07-01

    Phase change materials for heat storage are used as passive solar energy storage materials, which can be impregnated into construction materials. In this work the thermal stability (heating/cooling cycle) of the paraffin wax was investigated using differential scanning calorimetry. The latent heat and fusion temperature were determined for the following thermal cycles: 0, 30, 180 and 360. The thermal stability for paraffin wax infiltrated in support of gypsum was also determined. The experimental results showed that the paraffin wax showed good thermal stability in the states pure and infiltrated for up to 360 thermal cycles. (author)

  1. Differential network analysis with multiply imputed lipidomic data.

    Directory of Open Access Journals (Sweden)

    Maiju Kujala

    Full Text Available The importance of lipids for cell function and health has been widely recognized, e.g., a disorder in the lipid composition of cells has been related to atherosclerosis caused cardiovascular disease (CVD. Lipidomics analyses are characterized by large yet not a huge number of mutually correlated variables measured and their associations to outcomes are potentially of a complex nature. Differential network analysis provides a formal statistical method capable of inferential analysis to examine differences in network structures of the lipids under two biological conditions. It also guides us to identify potential relationships requiring further biological investigation. We provide a recipe to conduct permutation test on association scores resulted from partial least square regression with multiple imputed lipidomic data from the LUdwigshafen RIsk and Cardiovascular Health (LURIC study, particularly paying attention to the left-censored missing values typical for a wide range of data sets in life sciences. Left-censored missing values are low-level concentrations that are known to exist somewhere between zero and a lower limit of quantification. To make full use of the LURIC data with the missing values, we utilize state of the art multiple imputation techniques and propose solutions to the challenges that incomplete data sets bring to differential network analysis. The customized network analysis helps us to understand the complexities of the underlying biological processes by identifying lipids and lipid classes that interact with each other, and by recognizing the most important differentially expressed lipids between two subgroups of coronary artery disease (CAD patients, the patients that had a fatal CVD event and the ones who remained stable during two year follow-up.

  2. Thermal analysis of the effect of thick thermal barrier coatings on diesel engine performance

    International Nuclear Information System (INIS)

    Hoag, K.L.; Frisch, S.R.; Yonushonis, T.M.

    1986-01-01

    The reduction of heat rejection from the diesel engine combustion chamber has been the subject of a great deal of focus in recent years. In the pursuit of this goal, Cummins Engine Company has received a contract from the Department of Energy for the development of thick thermal barrier coatings for combustion chamber surfaces. This contract involves the analysis of the impact of coatings on diesel engine performance, bench test evaluation of various coating designs, and single cylinder engine tests. The efforts reported in this paper center on the analysis of the effects of coatings on engine performance and heat rejection. For this analysis the conventional water cooled engine was compared with an engine having limited oil cooling, and utilizing zirocnia coated cylinder had firedecks and piston crowns. The analysis showed little or no benefits of similarly coating the valves or cylinder liner

  3. Pressure thermal shock analysis for nuclear reactor pressure vessel

    International Nuclear Information System (INIS)

    Galik, G.; Kutis, V.; Jakubec, J.; Paulech, J.; Murin, J.

    2015-01-01

    The appearance of structural weaknesses within the reactor pressure vessel or its structural failure caused by crack formation during pressure thermal shock processes pose as a severe environmental hazard. Coolant mixing during ECC cold water injection was simulated in a detailed CFD analysis. The temperature distribution acting on the pipe wall internal surface was calculated. Although, the results show the formation of high temperature differences and intense gradients, an additional structural analysis is required to determine the possibility of structural damage from PTS. Such an analysis will be the subject of follow-up research. (authors)

  4. Quantification and analysis of color stability based on thermal transient behavior in white LED lamps.

    Science.gov (United States)

    Nisa Khan, M

    2017-09-20

    We present measurement and analysis of color stability over time for two categories of white LED lamps based on their thermal management scheme, which also affects their transient lumen depreciation. We previously reported that lumen depreciation in LED lamps can be minimized by properly designing the heat sink configuration that allows lamps to reach a thermal equilibrium condition quickly. Although it is well known that lumen depreciation degrades color stability of white light since color coordinates vary with total lumen power by definition, quantification and characterization of color shifts based on thermal transient behavior have not been previously reported in literature for LED lamps. Here we provide experimental data and analysis of transient color shifts for two categories of household LED lamps (from a total of six lamps in two categories) and demonstrate that reaching thermal equilibrium more quickly provides better stability for color rendering, color temperature, and less deviation of color coordinates from the Planckian blackbody locus line, which are all very important characterization parameters of color for white light. We report for the first time that a lamp's color degradation from the turn-on time primarily depends on thermal transient behavior of the semiconductor LED chip, which experiences a wavelength shift as well as a decrease in its dominant wavelength peak value with time, which in turn degrades the phosphor conversion. For the first time, we also provide a comprehensive quantitative analysis that differentiates color degradation due to the heat rise in GaN/GaInN LED chips and subsequently the boards these chips are mounted on-from that caused by phosphor heating in a white LED module. Finally, we briefly discuss why there are some inevitable trade-offs between omnidirectionality and color and luminous output stability in current household LED lamps and what will help eliminate these trade-offs in future lamp designs.

  5. Method translation and full metadata transfer from thermal to differential flow modulated comprehensive two dimensional gas chromatography: Profiling of suspected fragrance allergens.

    Science.gov (United States)

    Cordero, Chiara; Rubiolo, Patrizia; Reichenbach, Stephen E; Carretta, Andrea; Cobelli, Luigi; Giardina, Matthew; Bicchi, Carlo

    2017-01-13

    The possibility to transfer methods from thermal to differential-flow modulated comprehensive two-dimensional gas chromatographic (GC×GC) platforms is of high interest to improve GC×GC flexibility and increase the compatibility of results from different platforms. The principles of method translation are here applied to an original method, developed for a loop-type thermal modulated GC×GC-MS/FID system, suitable for quali-quantitative screening of suspected fragrance allergens. The analysis conditions were translated to a reverse-injection differential flow modulated platform (GC×2GC-MS/FID) with a dual-parallel secondary column and dual detection. The experimental results, for a model mixture of suspected volatile allergens and for raw fragrance mixtures of different composition, confirmed the feasibility of translating methods by preserving 1 D elution order, as well as the relative alignment of resulting 2D peak patterns. A correct translation produced several benefits including an effective transfer of metadata (compound names, MS fragmentation pattern, response factors) by automatic template transformation and matching from the original/reference method to its translated counterpart. The correct translation provided: (a) 2D pattern repeatability, (b) MS fragmentation pattern reliability for identity confirmation, and (c) comparable response factors and quantitation accuracy within a concentration range of three orders of magnitude. The adoption of a narrow bore (i.e. 0.1mm d c ) first-dimension column to operate under close-to-optimal conditions with the differential-flow modulation GC×GC platform was also advantageous in halving the total analysis under the translated conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Transient thermal performance analysis of micro heat pipes

    International Nuclear Information System (INIS)

    Liu, Xiangdong; Chen, Yongping

    2013-01-01

    A theoretical analysis of transient fluid flow and heat transfer in a triangular micro heat pipes (MHP) has been conducted to study the thermal response characteristics. By introducing the system identification theory, the quantitative evaluation of the MHP's transient thermal performance is realized. The results indicate that the evaporation and condensation processes are both extended into the adiabatic section. During the start-up process, the capillary radius along axial direction of MHP decreases drastically while the liquid velocity increases quickly at the early transient stage and an approximately linear decrease in wall temperature arises along the axial direction. The MHP behaves as a first-order LTI control system with the constant input power as the 'step input' and the evaporator wall temperature as the 'output'. Two corresponding evaluation criteria derived from the control theory, time constant and temperature constant, are able to quantitatively evaluate the thermal response speed and temperature level of MHP under start-up, which show that a larger triangular groove's hydraulic diameter within 0.18–0.42 mm is able to accelerate the start-up and decrease the start-up temperature level of MHP. Additionally, the MHP starts up fastest using the fluid of ethanol and most slowly using the working fluid of methanol, and the start-up temperature reaches maximum level for acetone and minimum level for the methanol. -- Highlights: • Transient thermal response of micro heat pipe is simulated by an improved model. • Control theory is introduced to quantify the thermal response of micro heat pipe. • Evaluation criteria are proposed to represent thermal response of micro heat pipe. • Effects of groove dimensions and working fluids on start-up of micro heat pipe are evaluated

  7. Study on the characterization and thermal decomposition of uranium compounds by thermogravimetry (TG) and differential scanning calorimetry (DSC)

    International Nuclear Information System (INIS)

    Dantas, J.M.; Abrao, A.

    1981-04-01

    A contribution to the characterization of several uranium compounds obtained at the IPEN' Uranium Pilot Plant is given. Particularly, samples of ammonium diuranate (ADU) and uranium oxides were studied. The main objective was to know the stoichiometry of the ADU and the oxides resulting from its thermal transformation. ADU samples were prepared by batchwise precipitation, stationary dewatering into stove and batchwise thermal decomposition, or, alternatively, continuous precipitation, continuous filtration, continuous drying and continuous thermal decomposition inside a temperature gradient electrical furnace. All ADU were precipitated using NH 3 gas from uranul sulfate or uranyl nitrate solutions. The thermal decomposition of ADU and uranium oxides were studied in an air atmosphere by thermogravimetry (TG) and differential scanning calorimetry (DSC). Any correlation between the parameters of precipitation, drying, calcination and the hystory of the obtaintion of the several uraniumm compounds and their initial and final composition was looked for. Heating program was established to have the U 3 O 8 oxide as the final product. Intermediary phases were tentatively identified. Temperatures at which occurred the absorption water elimination, crystallization water elimination, evolution or oxidation of NH 3 , decomposition of NO -3 ion and oxygen evolution and the exo- and endothermic process for each sample were identified. (Author) [pt

  8. Thermal analysis of high temperature phase transformations of steel

    Directory of Open Access Journals (Sweden)

    K. Gryc

    2013-10-01

    Full Text Available The series of thermal analysis measurements of high temperature phase transformations of real grain oriented electrical steel grade under conditions of two analytical devices (Netzsch STA 449 F3 Jupiter; Setaram SETSYS 18TM were carried out. Two thermo analytical methods were used (DTA and Direct thermal analysis. The different weight of samples was used (200 mg, 23 g. The stability/reproducibility of results obtained by used methodologies was verified. The liquidus and solidus temperatures for close to equilibrium conditions and during cooling (20 °C/min; 80 °C/min were determined. It has been shown that the higher cooling rate lead to lower temperatures for start and end of solidification process of studied steel grade.

  9. Thermal analysis of cement pastes with superabsorbent polymers

    DEFF Research Database (Denmark)

    Esteves, Luis Pedro; Jensen, Ole Mejlhede; Lukosiute, Irena

    2013-01-01

    Thermal analysis of cement systems is very helpful in the understanding of many different properties of cementitious compounds, both for the original reacting compounds, and also for the resulting hydration products. Superabsorbent polymers can be added to cement systems with many different reasons......, so it is relevant that fundamental knowledge of this new compound on the development of hydration is well understood [1-3]. This paper reports research on thermal analysis of cement pastes with superabsorbent polymers. We have studied several parameters: the concentration of SAP in the system......, the effect of particle size distribution, and their influence on the hydration process with focus on cement-silica systems. This is done at different thermodynamic conditions, so the energy of activation in the different systems can be accessed. This paper provides information relevant to hydration modelling...

  10. The utilisation of thermal analysis to optimise radiocarbon dating procedures

    International Nuclear Information System (INIS)

    Brandova, D.; Keller, W.A.; Maciejewski, M.

    1999-01-01

    Thermal analysis combined with mass spectrometry was applied to radiocarbon dating procedures (age determination of carbon-containing samples). Experiments carried out under an oxygen atmosphere were used to determine carbon content and combustion range of soil and wood samples. Composition of the shell sample and its decomposition were investigated. The quantification of CO 2 formed by the oxidation of carbon was done by the application of pulse thermal analysis. Experiments carried out under an inert atmosphere determined the combustion range of coal with CuO as an oxygen source. To eliminate a possible source of contamination in the radiocarbon dating procedures the adsorption of CO 2 by CuO was investigated. (author)

  11. Computational Analysis on Performance of Thermal Energy Storage (TES) Diffuser

    Science.gov (United States)

    Adib, M. A. H. M.; Adnan, F.; Ismail, A. R.; Kardigama, K.; Salaam, H. A.; Ahmad, Z.; Johari, N. H.; Anuar, Z.; Azmi, N. S. N.

    2012-09-01

    Application of thermal energy storage (TES) system reduces cost and energy consumption. The performance of the overall operation is affected by diffuser design. In this study, computational analysis is used to determine the thermocline thickness. Three dimensional simulations with different tank height-to-diameter ratio (HD), diffuser opening and the effect of difference number of diffuser holes are investigated. Medium HD tanks simulations with double ring octagonal diffuser show good thermocline behavior and clear distinction between warm and cold water. The result show, the best performance of thermocline thickness during 50% time charging occur in medium tank with height-to-diameter ratio of 4.0 and double ring octagonal diffuser with 48 holes (9mm opening ~ 60%) acceptable compared to diffuser with 6mm ~ 40% and 12mm ~ 80% opening. The conclusion is computational analysis method are very useful in the study on performance of thermal energy storage (TES).

  12. Computational Analysis on Performance of Thermal Energy Storage (TES) Diffuser

    International Nuclear Information System (INIS)

    Adib, M A H M; Ismail, A R; Kardigama, K; Salaam, H A; Ahmad, Z; Johari, N H; Anuar, Z; Azmi, N S N; Adnan, F

    2012-01-01

    Application of thermal energy storage (TES) system reduces cost and energy consumption. The performance of the overall operation is affected by diffuser design. In this study, computational analysis is used to determine the thermocline thickness. Three dimensional simulations with different tank height-to-diameter ratio (HD), diffuser opening and the effect of difference number of diffuser holes are investigated. Medium HD tanks simulations with double ring octagonal diffuser show good thermocline behavior and clear distinction between warm and cold water. The result show, the best performance of thermocline thickness during 50% time charging occur in medium tank with height-to-diameter ratio of 4.0 and double ring octagonal diffuser with 48 holes (9mm opening ∼ 60%) acceptable compared to diffuser with 6mm ∼ 40% and 12mm ∼ 80% opening. The conclusion is computational analysis method are very useful in the study on performance of thermal energy storage (TES).

  13. Infrared X-ray and thermal analysis of terbium soaps

    International Nuclear Information System (INIS)

    Mehrotra, K.N.; Sharma, N.

    1996-01-01

    Terbium sops (laureate, myristate and palmitate) were synthesized by direct metathesis of corresponding potassium soap with an aqueous solution of terbium nitrate. The physico-chemical characteristics of soaps in solid state were investigated by IR spectra, X-ray diffraction patterns and TGA measurements. The IR results revealed that the fatty acids exist in dimeric state through hydrogen bonding while the soaps possess partial ionic character. The X-ray analysis showed that the soaps have double layer structure with molecular axes slightly inclined to the basal plane. The thermal analysis suggested that the decomposition of soaps occur in two steps. The energy of activation, order of reaction and various kinetic parameters (i.e. frequency factor, entropy of activation and free energy) for the thermal decomposition of soaps were evaluated. (author). 26 refs, 4 figs, 4 tabs

  14. Thermal test and analysis of a spent fuel storage cask

    International Nuclear Information System (INIS)

    Yamakawa, H.; Gomi, Y.; Ozaki, S.; Kosaki, A.

    1993-01-01

    A thermal test simulated with full-scale cask model for the normal storage was performed to verify the storage skill of the spent fuels of the cask. The maximum temperature at each point in the test was lower than the allowable temperature. The integrity of the cask was maintained. It was observed that the safety of containment system was also kept according to the check of the seal before and after the thermal test. Therefore it was shown that using the present skill, it is possible to store spent fuels in the dry-type cask safely. Moreover, because of the good agreement between analysis and experimental results, it was shown that the analysis model was successfully established to estimate the temperature distribution of the fuel cladding and the seal portion. (J.P.N.)

  15. An Analysis on a Dynamic Amplifier and Calibration Methods for a Pseudo-Differential Dynamic Comparator

    Science.gov (United States)

    Paik, Daehwa; Miyahara, Masaya; Matsuzawa, Akira

    This paper analyzes a pseudo-differential dynamic comparator with a dynamic pre-amplifier. The transient gain of a dynamic pre-amplifier is derived and applied to equations of the thermal noise and the regeneration time of a comparator. This analysis enhances understanding of the roles of transistor's parameters in pre-amplifier's gain. Based on the calculated gain, two calibration methods are also analyzed. One is calibration of a load capacitance and the other is calibration of a bypass current. The analysis helps designers' estimation for the accuracy of calibration, dead-zone of a comparator with a calibration circuit, and the influence of PVT variation. The analyzed comparator uses 90-nm CMOS technology as an example and each estimation is compared with simulation results.

  16. Thermal Analysis: A Complementary Method to Study the Shurijeh Clay Minerals

    Directory of Open Access Journals (Sweden)

    Golnaz Jozanikohan

    2015-06-01

    Full Text Available Clay minerals are considered the most important components of clastic reservoir rock evaluation studies. The Shurijeh gas reservoir Formation, represented by shaly sandstones of the Late Jurassic-Early Cretaceous age, is the main reservoir rock in the Eastern Kopet-Dagh sedimentary Basin, NE Iran. In this study, X-ray diffraction (XRD, X-ray fluorescence (XRF, scanning electron microscopic (SEM studies, and thermal analysis including differential thermal analysis (DTA, and thermogravimetric analysis (TGA techniques were utilized in the characterization of the Shurijeh clay minerals in ten representative samples. The XRF studies showed that silica and aluminum oxides are present quantities. The XRD test was then used to determine the mineralogical composition of bulk components, as well as the clay fraction. The XRD patterns indicated the presence of dominant amount of quartz and plagioclase, with moderate to minor amounts of alkali feldspar, anhydrite, carbonates (calcite and dolomite, hematite and clay minerals. The most common clays in the Shurijeh Formation were illite, chlorite, and kaolinite. However, in very few samples, glauconite, smectite, and mixed layer clay minerals of both illite-smectite and chlorite-smectite types were also recognized. The XRD results were quantified, using the elemental information from the XRF test, showing that each Shurijeh exhibited low to moderate amounts of clay minerals, typically up to 21%. The amount of illite, the most dominant clay mineral, reached maximum of 13.5%, while the other clay types were significantly smaller. Based on the use of SEM and thermal data, the results of the identification of clay minerals, corresponded with the powder X-ray diffraction analysis, which can be taken into account as an evidence of the effectiveness of the thermal analysis technique in clay typing, as a complementary method besides the XRD.

  17. Investigation of Water Absorption and Diffusion in Microparticles Containing Xylitol to Provide a Cooling Effect by Thermal Analysis

    Science.gov (United States)

    Salaün, F.; Bedek, G.; Devaux, E.; Dupont, D.; Deranton, D.

    2009-08-01

    Polyurethane microparticles containing xylitol as a sweat sensor system were prepared by interfacial polymerization. The structural and thermal properties of the resultant microparticles were studied. The surface morphology and chemical structure of microparticles were investigated using an optical microscope (OM) and a Fourier-transform infrared spectroscope (FTIR), respectively. The thermal properties of samples were investigated by thermogravimetric analysis (TGA) and by differential scanning calorimetry (DSC). Thus, two types of microparticles were synthesized by varying the percentage of monomers introduced. The obtained morphology is directly related to the synthesis conditions. DSC analysis indicated that the mass content of crystalline xylitol was up to 63.8 %, which resulted in a high enthalpy of dilution of 127.7 J · g-1. Furthermore, the water release rate monitored by TGA analysis was found to be faster from the microparticles than from raw xylitol. Thus, the microparticles could be applied for thermal energy storage and moisture sensor enhancement.

  18. Development of realistic thermal hydraulic system analysis code

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Jae; Chung, B. D; Kim, K. D. [and others

    2002-05-01

    The realistic safety analysis system is essential for nuclear safety research, advanced reactor development, safety analysis in nuclear industry and 'in-house' plant design capability development. In this project, we have developed a best-estimate multi-dimensional thermal-hydraulic system code, MARS, which is based on the integrated version of the RELAP5 and COBRA-TF codes. To improve the realistic analysis capability, we have improved the models for multi-dimensional two-phase flow phenomena and for advanced two-phase flow modeling. In addition, the GUI (Graphic User Interface) feature were developed to enhance the user's convenience. To develop the coupled analysis capability, the MARS code were linked with the three-dimensional reactor kinetics code (MASTER), the core thermal analysis code (COBRA-III/CP), and the best-estimate containment analysis code (CONTEMPT), resulting in MARS/MASTER/COBRA/CONTEMPT. Currently, the MARS code system has been distributed to 18 domestic organizations, including research, industrial, regulatory organizations and universities. The MARS has been being widely used for the safety research of existing PWRs, advanced PWR, CANDU and research reactor, the pre-test analysis of TH experiments, and others.

  19. Development of realistic thermal hydraulic system analysis code

    International Nuclear Information System (INIS)

    Lee, Won Jae; Chung, B. D; Kim, K. D.

    2002-05-01

    The realistic safety analysis system is essential for nuclear safety research, advanced reactor development, safety analysis in nuclear industry and 'in-house' plant design capability development. In this project, we have developed a best-estimate multi-dimensional thermal-hydraulic system code, MARS, which is based on the integrated version of the RELAP5 and COBRA-TF codes. To improve the realistic analysis capability, we have improved the models for multi-dimensional two-phase flow phenomena and for advanced two-phase flow modeling. In addition, the GUI (Graphic User Interface) feature were developed to enhance the user's convenience. To develop the coupled analysis capability, the MARS code were linked with the three-dimensional reactor kinetics code (MASTER), the core thermal analysis code (COBRA-III/CP), and the best-estimate containment analysis code (CONTEMPT), resulting in MARS/MASTER/COBRA/CONTEMPT. Currently, the MARS code system has been distributed to 18 domestic organizations, including research, industrial, regulatory organizations and universities. The MARS has been being widely used for the safety research of existing PWRs, advanced PWR, CANDU and research reactor, the pre-test analysis of TH experiments, and others

  20. Preliminary hazards analysis of thermal scrap stabilization system. Revision 1

    International Nuclear Information System (INIS)

    Lewis, W.S.

    1994-01-01

    This preliminary analysis examined the HA-21I glovebox and its supporting systems for potential process hazards. Upon further analysis, the thermal stabilization system has been installed in gloveboxes HC-21A and HC-21C. The use of HC-21C and HC-21A simplified the initial safety analysis. In addition, these gloveboxes were cleaner and required less modification for operation than glovebox HA-21I. While this document refers to glovebox HA-21I for the hazards analysis performed, glovebox HC-21C is sufficiently similar that the following analysis is also valid for HC-21C. This hazards analysis document is being re-released as revision 1 to include the updated flowsheet document (Appendix C) and the updated design basis (Appendix D). The revised Process Flow Schematic has also been included (Appendix E). This Current revision incorporates the recommendations provided from the original hazards analysis as well. The System Design Description (SDD) has also been appended (Appendix H) to document the bases for Safety Classification of thermal stabilization equipment

  1. Thermal-hydraulic analysis for wire-wrapped PWR cores

    Energy Technology Data Exchange (ETDEWEB)

    Diller, P. [General Electric Company, 3901 Castle Hayne Rd., Wilmington, NC 28401 (United States)], E-mail: pdiller@gmail.com; Todreas, N. [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)], E-mail: todreas@mit.edu; Hejzlar, P. [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2009-08-15

    This work focuses on the steady-state and transient thermal-hydraulic analyses for PWR cores using wire wraps in a hexagonal array with either U (45% w/o)-ZrH{sub 1.6} (referred to as U-ZrH{sub 1.6}) or UO{sub 2} fuels. Equivalences (thermal-hydraulic and neutronic) were created between grid spacer and wire wrap designs, and were used to apply results calculated for grid spacers to wire wrap designs. Design limits were placed on the pressure drop, critical heat flux (CHF), fuel and cladding temperature and vibrations. The vibrations limits were imposed for flow-induced vibrations (FIV) and thermal-hydraulic vibrations (THV). The transient analysis examined an overpower accident, loss of coolant accident (LOCA) and loss of flow accident (LOFA). The thermal-hydraulic performance of U-ZrH{sub 1.6} and UO{sub 2} were found very similar. Relative to grid spacer designs, wire wrap designs were found to have smaller fretting wear, substantially lower pressure drop and higher CHF. As a result, wire wrap cores were found to offer substantially higher maximum powers than grid spacer cores, allowing for a 25% power increase relative to the grid spacer uprate [Shuffler, C.A., Malen, J.A., Trant, J.M., Todreas, N.E., 2009a. Thermal-hydraulic analysis for grid supported and inverted fueled PWR cores. Nuclear Technology (this special issue devoted to hydride fuel in LWRs)] and a 58% power increase relative to the reference core.

  2. Application of thermal analysis in nuclear waste management

    International Nuclear Information System (INIS)

    Raje, Naina; Kalekar, Bhupesh; Acharekar, Darshana; Reddy, A.V.R.

    2009-01-01

    Thermal decomposition of zirconium raffinate and ammonium nitrate has been studied using simultaneous TG - DTA - MS/FTIR measurements. Based on non-isothermal analysis, isothermal measurements have been carried out at different temperatures to fix the calcination temperature/s. Decomposition of ammonium nitrate was studied in inert, oxidizing and reducing environments and the results suggest that the decomposition mechanism is same in inert/oxidizing atmosphere but is different in reducing environment. (author)

  3. Thermal analysis of NNWSI conceptual waste package designs

    International Nuclear Information System (INIS)

    Stein, W.; Hockman, J.N.; O'Neal, W.C.

    1984-04-01

    Lawrence Livermore National Laboratory is involved in the design and testing of high-level nuclear waste packages. Many of the aspects of waste package design and testing (e.g., corrosion and leaching) depend in part on the temperature history of the emplaced packages. This report discusses thermal modeling and analysis of various emplaced waste package conceptual designs including the models used, the assumptions and approximations made, and the results obtained. 16 references

  4. The analysis of thermal-hydraulic models in MELCOR code

    Energy Technology Data Exchange (ETDEWEB)

    Kim, M H; Hur, C; Kim, D K; Cho, H J [POhang Univ., of Science and TECHnology, Pohang (Korea, Republic of)

    1996-07-15

    The objective of the present work is to verify the prediction and analysis capability of MELCOR code about the progression of severe accidents in light water reactor and also to evaluate appropriateness of thermal-hydraulic models used in MELCOR code. Comparing the results of experiment and calculation with MELCOR code is carried out to achieve the above objective. Specially, the comparison between the CORA-13 experiment and the MELCOR code calculation was performed.

  5. Proceedings of the 11th Thermal and Fluids Analysis Workshop

    Science.gov (United States)

    Sakowski, Barbara

    2002-07-01

    The Eleventh Thermal & Fluids Analysis WorkShop (TFAWS 2000) was held the week of August 21-25 at The Forum in downtown Cleveland. This year's annual event focused on building stronger links between research community and the engineering design/application world and celebrated the theme "Bridging the Gap Between Research and Design". Dr. Simon Ostrach delivered the keynote address "Research for Design (R4D)" and encouraged a more deliberate approach to performing research with near-term engineering design applications in mind. Over 100 persons attended TFAWS 2000, including participants from five different countries. This year's conference devoted a full-day seminar to the discussion of analysis and design tools associated with aeropropulsion research at the Glenn Research Center. As in previous years, the workshop also included hands-on instruction in state-of-the-art analysis tools, paper sessions on selected topics, short courses and application software demonstrations. TFAWS 2000 was co-hosted by the Thermal/Fluids Systems Design and Analysis Branch of NASA GRC and by the Ohio Aerospace Institute and was co-chaired by Barbara A. Sakowski and James R. Yuko. The annual NASA Delegates meeting is a standard component of TFAWS where the civil servants of the various centers represented discuss current and future events which affect the Community of Applied Thermal and Fluid ANalystS (CATFANS). At this year's delegates meeting the following goals (among others) were set by the collective body of delegates participation of all Centers in the NASA material properties database (TPSX) update: (1) developing and collaboratively supporting multi-center proposals; (2) expanding the scope of TFAWS to include other federal laboratories; (3) initiation of a white papers on thermal tools and standards; and (4) formation of an Agency-wide TFAWS steering committee.

  6. Thermal Analysis of Iodine Satellite (iSAT)

    Science.gov (United States)

    Mauro, Stephanie

    2015-01-01

    This paper presents the progress of the thermal analysis and design of the Iodine Satellite (iSAT). The purpose of the iSAT spacecraft (SC) is to demonstrate the ability of the iodine Hall Thruster propulsion system throughout a one year mission in an effort to mature the system for use on future satellites. The benefit of this propulsion system is that it uses a propellant, iodine, that is easy to store and provides a high thrust-to-mass ratio. The spacecraft will also act as a bus for an earth observation payload, the Long Wave Infrared (LWIR) Camera. Four phases of the mission, determined to either be critical to achieving requirements or phases of thermal concern, are modeled. The phases are the Right Ascension of the Ascending Node (RAAN) Change, Altitude Reduction, De-Orbit, and Science Phases. Each phase was modeled in a worst case hot environment and the coldest phase, the Science Phase, was also modeled in a worst case cold environment. The thermal environments of the spacecraft are especially important to model because iSAT has a very high power density. The satellite is the size of a 12 unit cubesat, and dissipates slightly more than 75 Watts of power as heat at times. The maximum temperatures for several components are above their maximum operational limit for one or more cases. The analysis done for the first Design and Analysis Cycle (DAC1) showed that many components were above or within 5 degrees Centigrade of their maximum operation limit. The battery is a component of concern because although it is not over its operational temperature limit, efficiency greatly decreases if it operates at the currently predicted temperatures. In the second Design and Analysis Cycle (DAC2), many steps were taken to mitigate the overheating of components, including isolating several high temperature components, removal of components, and rearrangement of systems. These changes have greatly increased the thermal margin available.

  7. Multivariable Discriminant Analysis for the Differential Diagnosis of Microcytic Anemia

    Directory of Open Access Journals (Sweden)

    Eloísa Urrechaga

    2013-01-01

    Full Text Available Introduction. Iron deficiency anemia and thalassemia are the most common causes of microcytic anemia. Powerful statistical computer programming enables sensitive discriminant analyses to aid in the diagnosis. We aimed at investigating the performance of the multiple discriminant analysis (MDA to the differential diagnosis of microcytic anemia. Methods. The training group was composed of 200 β-thalassemia carriers, 65 α-thalassemia carriers, 170 iron deficiency anemia (IDA, and 45 mixed cases of thalassemia and acute phase response or iron deficiency. A set of potential predictor parameters that could detect differences among groups were selected: Red Blood Cells (RBC, hemoglobin (Hb, mean cell volume (MCV, mean cell hemoglobin (MCH, and RBC distribution width (RDW. The functions obtained with MDA analysis were applied to a set of 628 consecutive patients with microcytic anemia. Results. For classifying patients into two groups (genetic anemia and acquired anemia, only one function was needed; 87.9% β-thalassemia carriers, and 83.3% α-thalassemia carriers, and 72.1% in the mixed group were correctly classified. Conclusion. Linear discriminant functions based on hemogram data can aid in differentiating between IDA and thalassemia, so samples can be efficiently selected for further analysis to confirm the presence of genetic anemia.

  8. Clonal analysis of stem cells in differentiation and disease.

    Science.gov (United States)

    Colom, Bartomeu; Jones, Philip H

    2016-12-01

    Tracking the fate of individual cells and their progeny by clonal analysis has redefined the concept of stem cells and their role in health and disease. The maintenance of cell turnover in adult tissues is achieved by the collective action of populations of stem cells with an equal likelihood of self-renewal or differentiation. Following injury stem cells exhibit striking plasticity, switching from homeostatic behavior in order to repair damaged tissues. The effects of disease states on stem cells are also being uncovered, with new insights into how somatic mutations trigger clonal expansion in early neoplasia. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  9. Numerical analysis and nuclear standard code application to thermal fatigue

    International Nuclear Information System (INIS)

    Merola, M.

    1992-01-01

    The present work describes the Joint Research Centre Ispra contribution to the IAEA benchmark exercise 'Lifetime Behaviour of the First Wall of Fusion Machines'. The results of the numerical analysis of the reference thermal fatigue experiment are presented. Then a discussion on the numerical analysis of thermal stress is tackled, pointing out its particular aspects in view of their influence on the stress field evaluation. As far as the design-allowable number of cycles are concerned the American nuclear code ASME and the French code RCC-MR are applied and the reasons for the different results obtained are investigated. As regards a realistic fatigue lifetime evaluation, the main problems to be solved are brought out. This work, is intended as a preliminary basis for a discussion focusing on the main characteristics of the thermal fatigue problem from both a numerical and a lifetime assessment point of view. In fact the present margin of discretion left to the analyst may cause undue discrepancies in the results obtained. A sensitivity analysis of the main parameters involved is desirable and more precise design procedures should be stated

  10. Thermal analysis of the horizontal disposal for HLW

    International Nuclear Information System (INIS)

    Zhao Honggang

    2012-01-01

    The temperature on the canister surface is set to be not more than 100 in the repository, a criterion which dictates the dimension of the repository. The factors that affect the highest temperature on the canister surface include the initial power of the canister, the material thermal properties of the engineered barrier system (EBS), the gaps around the canister in the EBS, the initial ground temperature and thermal properties of the host rock, the repository layout, etc. The article examines the material thermal properties of the host rock and the EBS, the thermal conductivity properties of the different gaps in the EBS, the temperature evolution around the single canister by using the analysis method and the numerical method for horizontal disposal concept. The findings are as follows: 1) The most important and the most sensitive parameter is the initial disposal power of the canister; 2) The two key factors that affect the highest temperature on the canister surface are the material parameter's uncertainty and nature variability of the host rock and the EBS, and the gaps around the canister in the EBS; 3) The temperature offsets between the canister and bentonite is not more than 10, and the bigger the inner gaps, the bigger temperature offsets between the canister and bentonite; When the gap between the bentonite and the host rock is filled with water, the gap's temperature offsets is small, but it will be 1∼3 higher when the gaps between the bentonite and the host rock is filled with air. (author)

  11. Thermal spike analysis of highly charged ion tracks

    International Nuclear Information System (INIS)

    Karlušić, M.; Jakšić, M.

    2012-01-01

    The irradiation of material using swift heavy ion or highly charged ion causes excitation of the electron subsystem at nanometer scale along the ion trajectory. According to the thermal spike model, energy deposited into the electron subsystem leads to temperature increase due to electron–phonon coupling. If ion-induced excitation is sufficiently intensive, then melting of the material can occur, and permanent damage (i.e., ion track) can be formed upon rapid cooling. We present an extension of the analytical thermal spike model of Szenes for the analysis of surface ion track produced after the impact of highly charged ion. By applying the model to existing experimental data, more than 60% of the potential energy of the highly charged ion was shown to be retained in the material during the impact and transformed into the energy of the thermal spike. This value is much higher than 20–40% of the transferred energy into the thermal spike by swift heavy ion. Thresholds for formation of highly charged ion track in different materials show uniform behavior depending only on few material parameters.

  12. Performance analysis of photovoltaic thermal (PVT) water collectors

    International Nuclear Information System (INIS)

    Fudholi, Ahmad; Sopian, Kamaruzzaman; Yazdi, Mohammad H.; Ruslan, Mohd Hafidz; Ibrahim, Adnan; Kazem, Hussein A.

    2014-01-01

    Highlights: • Performances analysis of PVT collector based on energy efficiencies. • New absorber designs of PVT collectors were presented. • Comparison present study with other absorber collector designs was presented. • High efficiencies were obtained for spiral flow absorber. - Abstract: The electrical and thermal performances of photovoltaic thermal (PVT) water collectors were determined under 500–800 W/m 2 solar radiation levels. At each solar radiation level, mass flow rates ranging from 0.011 kg/s to 0.041 kg/s were introduced. The PVT collectors were tested with respect to PV efficiency, thermal efficiency, and a combination of both (PVT efficiency). The results show that the spiral flow absorber exhibited the highest performance at a solar radiation level of 800 W/m 2 and mass flow rate of 0.041 kg/s. This absorber produced a PVT efficiency of 68.4%, a PV efficiency of 13.8%, and a thermal efficiency of 54.6%. It also produced a primary-energy saving efficiency ranging from 79% to 91% at a mass flow rate of 0.011–0.041 kg/s

  13. Analysis of an Attached Sunspace with a Thermal Inertia Floor

    Directory of Open Access Journals (Sweden)

    María José Suárez López

    2018-05-01

    Full Text Available An attached sunspace is a partially or fully glazed enclosure, usually located on the first floor, facing south (in the Northern Hemisphere and adjacent to a conditioned room. Because of the length and orientation of the glazed area, the temperature in the sunspace is usually higher than outside the building. As a Trombe–Mitchel wall, the sunspace has a considerable mass that accumulates thermal energy, but in this case the thermal mass is located in the floor. This capacity to accumulate thermal energy confers the attached sunspace features beyond passive insulation. The sunspace studied in this paper is part of an experimental building located in the North of Spain that was built in the frame of the so-called ARFRISOL project. It consists of a south-facing glazed exterior wall with both clear glass and semi-transparent photovoltaic panels, an intermediate space with a thick layer of sand over a concrete floor, and a partially glazed interior wall. In this paper, a three-dimensional computational model has been implemented to analyse the thermal behaviour inside the sunspace. This analysis takes into account, among other factors, the effects of sun position, incident solar irradiation and temperature both inside and outside.

  14. Spaceborne Differential SAR Interferometry: Data Analysis Tools for Deformation Measurement

    Directory of Open Access Journals (Sweden)

    Michele Crosetto

    2011-02-01

    Full Text Available This paper is focused on spaceborne Differential Interferometric SAR (DInSAR for land deformation measurement and monitoring. In the last two decades several DInSAR data analysis procedures have been proposed. The objective of this paper is to describe the DInSAR data processing and analysis tools developed at the Institute of Geomatics in almost ten years of research activities. Four main DInSAR analysis procedures are described, which range from the standard DInSAR analysis based on a single interferogram to more advanced Persistent Scatterer Interferometry (PSI approaches. These different procedures guarantee a sufficient flexibility in DInSAR data processing. In order to provide a technical insight into these analysis procedures, a whole section discusses their main data processing and analysis steps, especially those needed in PSI analyses. A specific section is devoted to the core of our PSI analysis tools: the so-called 2+1D phase unwrapping procedure, which couples a 2D phase unwrapping, performed interferogram-wise, with a kind of 1D phase unwrapping along time, performed pixel-wise. In the last part of the paper, some examples of DInSAR results are discussed, which were derived by standard DInSAR or PSI analyses. Most of these results were derived from X-band SAR data coming from the TerraSAR-X and CosmoSkyMed sensors.

  15. Methodology for a thermal analysis of a proposed SFR transport cask with the thermal code SYRTHES

    International Nuclear Information System (INIS)

    Peniguel, C.; Rupp, I.; Schneider, J. P.

    2010-01-01

    Fast reactors with liquid metal coolant have received a renewed interest owing to the need of a more efficient usage of the primary uranium resources, and they are one of the proposal for the next Generation IV. In the framework of the 2006 French law on sustainable management of radioactive materials and waste, an evaluation of the industrial perspectives of minor actinides transmutation advantages and drawbacks in Generation IV fast spectrum reactors system is requested for 2012. The CEA is in charge of studying the global problem, but on some aspects, EDF is interested to do its own exploratory studies. Among other points, transport is seen as important for the nuclear industry, to link points of production and treatment. Nuclear fuel is generally transported in thick walled rail or truck casks. These packages are designed to provide confinement, shielding and criticality protection during normal and severe transport conditions. Heat generated within the fuel (and a contribution of solar heating) makes the package becoming quite hot, but one must demonstrate that the cladding temperature does not exceed a long term temperature limit during normal transport. This paper presents a thermal study done on a package in which 9 SFR assemblies are included. Each of them is of hexagonal shape and contains 271 fuel pins. The approach followed for these calculations is to rely on an explicit representation of all pins. For these calculations a 2D analysis is performed thanks to the thermal code SYRTHES. Conduction is solved thanks to a finite element method, while thermal radiation is handled through a radiosity approach. The main aim of this paper is to present a possible numerical methodology to handle the thermal problem. (authors)

  16. A performance analysis of solar chimney thermal power systems

    Directory of Open Access Journals (Sweden)

    Al-Dabbas Awwad Mohammed

    2011-01-01

    Full Text Available The objective of this study was to evaluate the solar chimney performance theoretically (techno-economic. A mathematical model was developed to estimate the following parameter: Power output, Pressure drop across the turbine, the max chimney height, Airflow temperature, and the overall efficiency of solar chimney. The mathematical model was validated with experimental data from the prototype in Manzanares power. It can be concluded that the differential pressure of collector-chimney transition section in the system, is increase with the increase of solar radiation intensity. The specific system costs are between 2000 Eur/kW and 5000 Eur/kW depending on the system size, system concept and storage size. Hence, a 50 MWe solar thermal power plant will cost 100-250 Eur million. At very good sites, today’s solar thermal power plants can generate electricity in the range of 0.15 Eur/kWh, and series production could soon bring down these costs below 0.10 Eur /kWh.

  17. Analysis of thermal impact in tidal rivers and estuaries

    International Nuclear Information System (INIS)

    Haeuser, J.; Eppel, D.; Tanzer, F.

    1980-01-01

    The paper presents a far field mathematical model for numerical simulation of transient one or two-dimensional thermal distributions in regions with severe reversing flow conditions. The Eulerian formulation employs the integral form of the conservation principles for mass and thermal energy. The two-dimensional (2 D) solution area is spanned by discrete elements of variable size and shape. The three-dimensional geometry of the flow region is accounted for by spatially intergrating over the enclosure surfaces of the discrete element. The derivation of the two-dimensional depth-averaged temperatur equations includes the constributions of the vertical variations of velocity and temperature. Surface heat transfer as well as turbulent effects are taken into account. Important mathematical and computational features of the model are summarized. There is a discussion of the four main algorithms, necessary to treat flow regions with complex shoreline geometries, viz. (i) specification of the boundary (ii) determination of all discrete element midpoints lying within the (possibly multiconnected) solution area (iii) construction of discrete elements of irregular geometry exactly matching the (curved) boundary, (iv) treatment of boundary condiditons and numerical solution of the resulting mathematical system of weakly coupled, ordinary differential equations derived from the conservation principles. Preliminary results of a computer simulation are compared with the available data for a section of the Lower Elbe river. The calculation of the two-dimensional temperature distribution includes existing power plants and industrial sites. (orig.) [de

  18. Thermal decomposition of natural polysaccharides: Chitin and chitosan

    Directory of Open Access Journals (Sweden)

    Kuchina Yu.A.

    2015-03-01

    Full Text Available The results of the thermal analysis of shrimp’s chitin and chitosan have been presented (samples of polysaccharide differed by the deacetylation degree have been studied. The thermal analysis has been carried out by differential thermogravimetry and differential scanning calorimetry. Activation energy of process of chitin and chitosan thermal destruction has been calculated

  19. thermal analysis of a small scale solid waste-fired steam boiler

    African Journals Online (AJOL)

    user

    Thermal analysis of a small scale solid waste-fired steam generator is presented in this paper. The analysis was based on the chosen design specifications which are operating steam ... include: wind, bio-energy, geothermal, solar thermal,.

  20. Thermal analysis and its application in evaluation of fluorinated polyimide membranes for gas separation

    KAUST Repository

    Qiu, Wulin; Chen, Chien-Chiang; Kincer, Matthew R.; Koros, William J.

    2011-01-01

    by reaction with acetic anhydride to produce polyimide (PI). The resulting polymers were characterized using thermal analysis techniques including TGA, derivative weight analysis, TGA-MS, and DSC. The decarboxylation-induced thermal cross-linking, ester cross

  1. Rate process analysis of thermal damage in cartilage

    International Nuclear Information System (INIS)

    Diaz, Sergio H; Nelson, J Stuart; Wong, Brian J F

    2003-01-01

    Cartilage laser thermoforming (CLT) is a new surgical procedure that allows in situ treatment of deformities in the head and neck with less morbidity than traditional approaches. While some animal and human studies have shown promising results, the clinical feasibility of CLT depends on preservation of chondrocyte viability, which has not been extensively studied. The present paper characterizes cellular damage due to heat in rabbit nasal cartilage. Damage was modelled as a first order rate process for which two experimentally derived coefficients, A=1.2x10 70 s -1 and E a =4.5x10 5 J mole -1 , were determined by quantifying the decrease in concentration of healthy chondrocytes in tissue samples as a function of exposure time to constant-temperature water baths. After immersion, chondrocytes were enzymatically isolated from the matrix and stained with a two-component fluorescent dye. The dye binds nuclear DNA differentially depending upon chondrocyte viability. A flow cytometer was used to detect differential cell fluorescence to determine the percentage of live and dead cells in each sample. As a result, a damage kinetic model was obtained that can be used to predict the onset, extent and severity of cellular injury to thermal exposure

  2. DDASAC, Double-Precision Differential or Algebraic Sensitivity Analysis

    International Nuclear Information System (INIS)

    Caracotsios, M.; Stewart, W.E.; Petzold, L.

    1997-01-01

    1 - Description of program or function: DDASAC solves nonlinear initial-value problems involving stiff implicit systems of ordinary differential and algebraic equations. Purely algebraic nonlinear systems can also be solved, given an initial guess within the region of attraction of a solution. Options include automatic reconciliation of inconsistent initial states and derivatives, automatic initial step selection, direct concurrent parametric sensitivity analysis, and stopping at a prescribed value of any user-defined functional of the current solution vector. Local error control (in the max-norm or the 2-norm) is provided for the state vector and can include the sensitivities on request. 2 - Method of solution: Reconciliation of initial conditions is done with a damped Newton algorithm adapted from Bain and Stewart (1991). Initial step selection is done by the first-order algorithm of Shampine (1987), extended here to differential-algebraic equation systems. The solution is continued with the DASSL predictor- corrector algorithm (Petzold 1983, Brenan et al. 1989) with the initial acceleration phase detected and with row scaling of the Jacobian added. The backward-difference formulas for the predictor and corrector are expressed in divide-difference form, and the fixed-leading-coefficient form of the corrector (Jackson and Sacks-Davis 1980, Brenan et al. 1989) is used. Weights for error tests are updated in each step with the user's tolerances at the predicted state. Sensitivity analysis is performed directly on the corrector equations as given by Catacotsios and Stewart (1985) and is extended here to the initialization when needed. 3 - Restrictions on the complexity of the problem: This algorithm, like DASSL, performs well on differential-algebraic systems of index 0 and 1 but not on higher-index systems; see Brenan et al. (1989). The user assigns the work array lengths and the output unit. The machine number range and precision are determined at run time by a

  3. Development of intelligent system for a thermal analysis instrument

    International Nuclear Information System (INIS)

    Xu Xiaoli; Wu Guoxin; Shi Yongchao

    2005-01-01

    The key techniques for the intelligent analysis instrument developed are proposed. Based on the technique of virtual instrumentation, the intelligent PID control algorithm to control the temperature of thermal analysis instrument is described. The dynamic character and the robust performance of traditional PID controls are improved through the dynamic gain factor, temperature rate change factor, the forecast factor, and the temperature correction factor is introduced. Using the graphic development environment of LabVIEW, the design of system modularization and the graphic display are implemented. By means of multiple mathematical modules, intelligent data processing is realized

  4. Deformation analysis considering thermal expansion of injection mold

    International Nuclear Information System (INIS)

    Kim, Jun Hyung; Yi, Dae Eun; Jang, Jeong Hui; Lee, Min Seok

    2015-01-01

    In the design of injection molds, the temperature distribution and deformation of the mold is one of the most important parameters that affect the flow characteristics, flash generation, and surface appearance, etc. Plastic injection analyses have been carried out to predict the temperature distribution of the mold and the pressure distribution on the cavity surface. As the input loads, we transfer the temperature and pressure results to the structural analysis. We compare the structural analysis results with the thermal expansion effect using the actual flash and step size of a smartphone cover part. To reduce the flash problem, we proposed a new mold design, and verified the results by performing simulations

  5. Deformation analysis considering thermal expansion of injection mold

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jun Hyung; Yi, Dae Eun; Jang, Jeong Hui; Lee, Min Seok [Samsung Electronics Co., LTD., Seoul (Korea, Republic of)

    2015-09-15

    In the design of injection molds, the temperature distribution and deformation of the mold is one of the most important parameters that affect the flow characteristics, flash generation, and surface appearance, etc. Plastic injection analyses have been carried out to predict the temperature distribution of the mold and the pressure distribution on the cavity surface. As the input loads, we transfer the temperature and pressure results to the structural analysis. We compare the structural analysis results with the thermal expansion effect using the actual flash and step size of a smartphone cover part. To reduce the flash problem, we proposed a new mold design, and verified the results by performing simulations.

  6. Thermal-hydraulic analysis of PWR cores in transient condition

    International Nuclear Information System (INIS)

    Silva Galetti, M.R. da.

    1984-01-01

    A calculational methodology for thermal - hydraulic analysis of PWR cores under steady-state and transient condition was selected and made available to users. An evaluation of the COBRA-IIIP/MIT code, used for subchannel analysis, was done through comparison of the code results with experimental data on steady state and transient conditions. As a result, a comparison study allowing spatial and temporal localization of critical heat flux was obtained. A sensitivity study of the simulation model to variations in some empirically determined parameter is also presented. Two transient cases from Angra I FSAR were analysed, showing the evolution of minimum DNBR with time. (Author) [pt

  7. Diurnal thermal analysis of microencapsulated PCM-concrete composite walls

    International Nuclear Information System (INIS)

    Thiele, Alexander M.; Sant, Gaurav; Pilon, Laurent

    2015-01-01

    Highlights: • Transient heat conduction across microencapsulated PCM-concrete walls was simulated. • Equivalent homogeneous wall with effective thermal properties was rigorously derived. • Adding PCM to the wall increases daily energy savings and delays peak thermal load. • Energy savings is maximum when PCM melting temperature equals indoor temperature. • Energy savings are limited in extreme climates but time delay can be large. - Abstract: This paper examines the benefits of adding microencapsulated phase change material (PCM) to concrete used in building envelopes to reduce energy consumption and costs. First, it establishes that the time-dependent thermal behavior of microencapsulated PCM-concrete composite walls can be accurately predicted by an equivalent homogeneous wall with appropriate effective thermal properties. The results demonstrate that adding microencapsulated PCM to concrete resulted in a reduction and a time-shift in the maximum heat flux through the composite wall subjected to diurnal sinusoidal outdoor temperature and solar radiation heat flux. The effects of the PCM volume fraction, latent heat of fusion, phase change temperature and temperature window, and outdoor temperature were evaluated. Several design rules were established including (i) increasing the PCM volume fraction and/or enthalpy of phase change increased the energy flux reduction and the time delay, (ii) the energy flux reduction was maximized when the PCM phase change temperature was close to the desired indoor temperature, (iii) the optimum phase change temperature to maximize the time delay increased with increasing average outdoor temperature, (iv) in extremely hot or cold climates, the thermal load could be delayed even though the reduction in daily energy flux was small, and (v) the choice of phase change temperature window had little effect on the energy flux reduction and on the time delay. This analysis can serve as a framework to design PCM composite walls

  8. Two-dimensional disruption thermal analysis code DREAM

    International Nuclear Information System (INIS)

    Yamazaki, Seiichiro; Kobayashi, Takeshi; Seki, Masahiro.

    1988-08-01

    When a plasma disruption takes place in a tokamak type fusion reactor, plasma facing components such as first wall and divertor/limiter are subjected to an intense heat load with very high heat flux and short duration. At the surface of the wall, temperature rapidly rises, and melting and evaporation occurs, it causes reduction of wall thickness and crack initiation/propagation. As lifetime of the components is significantly affected by them, the transient analysis in consideration of phase changes (melting/evaporation) and radiation heat loss is required in the design of these components. This paper describes the computer code DREAM developed to perform the two-dimensional transient thermal analysis that takes phase changes and radiation into account. The input and output of the code and a sample analysis on a disruption simulation experiment are also reported. The user's input manual is added as an appendix. The profiles and time variations of temperature, and melting and evaporated thicknesses of the material subjected to intense heat load can be obtained, using this computer code. This code also gives the temperature data for elastoplastic analysis with FEM structural analysis codes (ADINA, MARC, etc.) to evaluate the thermal stress and crack propagation behavior within the wall materials. (author)

  9. Thermal analysis of an instrumented capsule using an ANSYS program

    International Nuclear Information System (INIS)

    Choi, Myoung Hwan; Choo, Kee Nam; Kang, Young Hwan; Cho, Man Soon; Sohn, Jae Min; Kim, Bong Goo

    2006-01-01

    An instrumented capsule has been used for an irradiation test of various nuclear materials in the research reactor, HANARO. To obtain the design data of the instrumented capsule, a thermal analysis is performed using a finite element analysis program, ANSYS. The 2-dimensional model for a cross section of the capsule including the specimens is generated, and a gamma-heating rate of the materials for the HANARO power of 24 or 30 MW is considered as an input force. The effect of the gap size and the control rod position on the temperature of the specimens or other components is discussed. From the analysis it is found that the gap between the thermal media and the external tube has a significant effect on the temperature of the specimen. In the case of the material capsule, the maximum temperature for the reactor power of 24 MW is 255degC for an irradiation test and 257degC for a FE analysis at the center stage of the capsule in the axial direction. It is expected that the analysis models using an ANSYS program will be useful in designing the instrumented capsules for an irradiation test and estimating the test results. (author)

  10. Transient thermal analysis of semiconductor diode lasers under pulsed operation

    Science.gov (United States)

    Veerabathran, G. K.; Sprengel, S.; Karl, S.; Andrejew, A.; Schmeiduch, H.; Amann, M.-C.

    2017-02-01

    Self-heating in semiconductor lasers is often assumed negligible during pulsed operation, provided the pulses are `short'. However, there is no consensus on the upper limit of pulse width for a given device to avoid-self heating. In this paper, we present an experimental and theoretical analysis of the effect of pulse width on laser characteristics. First, a measurement method is introduced to study thermal transients of edge-emitting lasers during pulsed operation. This method can also be applied to lasers that do not operate in continuous-wave mode. Secondly, an analytical thermal model is presented which is used to fit the experimental data to extract important parameters for thermal analysis. Although commercial numerical tools are available for such transient analyses, this model is more suitable for parameter extraction due to its analytical nature. Thirdly, to validate this approach, it was used to study a GaSb-based inter-band laser and an InP-based quantum cascade laser (QCL). The maximum pulse-width for less than 5% error in the measured threshold currents was determined to be 200 and 25 ns for the GaSb-based laser and QCL, respectively.

  11. Drift scale thermomechanical analysis for thermal loading and retrievability studies

    International Nuclear Information System (INIS)

    Tsai, F.C.

    1995-01-01

    The repository portion of the Mined Geologic Disposal System for the disposal of spent nuclear fuel and high-level radioactive waste is currently in the advanced conceptual design stage. In support of systems studies, a numerical method was used to estimate the stability of emplacement drifts. Thermomechanical analyses, using the Discontinuous Deformation Analysis code, were performed using input data from Yucca Mountain documents. The analysis found that the stresses produced in the rock at thermal loads of 27.4 kilograms uranium per m2 (KgU/m2) would exceed stability criteria and could result in tunnel instability. At thermal loads between 20.5 KgU/m2, the drift is predicted to be stable and its structural integrity remains after thermal loading. In this case, the smaller diameter drift emplacement appears to have better stability. However, local rock spalling may occur. According to the numerical prediction, more rock fall may occur during the retrieval period due to the stress relaxation caused by the rapid cooling in the immediate drift area

  12. Thermal analysis and structural characterization of chitinous exoskeleton from two marine invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Juárez-de la Rosa, B.A., E-mail: balej05@yahoo.com.mx [Laboratory of Natural Polymers, CIAD – Coordinación Guaymas, Carretera al Varadero Nacional km. 6.6, Col. Las Playitas, 85480 Guaymas, Sonora (Mexico); Applied Physics Department, CINVESTAV-IPN Unidad Mérida, Carretera antigua a Progreso, km. 6. Apdo, Postal 73, Cordemex, 97310 Mérida, Yucatan (Mexico); May-Crespo, J.; Quintana-Owen, P.; Gónzalez-Gómez, W.S. [Applied Physics Department, CINVESTAV-IPN Unidad Mérida, Carretera antigua a Progreso, km. 6. Apdo, Postal 73, Cordemex, 97310 Mérida, Yucatan (Mexico); Yañez-Limón, J.M. [Materials and Engineering Science, CINVESTAV-IPN, Unidad Querétaro, Libramiento Norponiente No. 2000, Fracc. Real de Juriquilla, 76230 Santiago de Querétaro, Querétaro (Mexico); Alvarado-Gil, J.J., E-mail: jjag@mda.cinvestav.mx [Applied Physics Department, CINVESTAV-IPN Unidad Mérida, Carretera antigua a Progreso, km. 6. Apdo, Postal 73, Cordemex, 97310 Mérida, Yucatan (Mexico)

    2015-06-20

    Highlights: • Thermal analysis of exoskeletons: Antipathes caribbeana and Limulus polyphemus. • DMTA revealed Limulus has a stronger structure with a stepper glass transition. • DSC measurements exhibited a much larger water holding capacity in Antipathes. • X-ray diffraction analysis shows a higher crystallinity index in Limulus • FTIR showed α-chitin structures and high temperature C–N groups prevalence. - ABSTRACT: Thermomechanical and structural properties of two marine species exoskeletons, Antipathes caribbeana (black coral) and Limulus polyphemus (xiphosure), were studied using dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). DMTA curves indicate the viscoelastic behavior and glass transition around 255 °C, black coral presented a second transition (175 °C) associated to the acetamide group attached to the α-chitin chain. DSC measurements showed a endothermic peak around 100 °C, with enthalpies of 4.02 and 118.04 J/g, indicating strong differences between exoskeletons respect to their water holding capacity and strength water–polymer interaction. A comparative analysis involving DSC and X-ray diffraction showed that lower values ΔH in xiphosure correspond to a material with a higher crystallinity (30), in contrast black coral exhibits higher values ΔH and a lower crystallinity (19). FTIR confirmed α-chitin based structure, at higher temperature diminishes the amide bands and a new one appears, related to C–N groups.

  13. Thermal analysis and structural characterization of chitinous exoskeleton from two marine invertebrates

    International Nuclear Information System (INIS)

    Juárez-de la Rosa, B.A.; May-Crespo, J.; Quintana-Owen, P.; Gónzalez-Gómez, W.S.; Yañez-Limón, J.M.; Alvarado-Gil, J.J.

    2015-01-01

    Highlights: • Thermal analysis of exoskeletons: Antipathes caribbeana and Limulus polyphemus. • DMTA revealed Limulus has a stronger structure with a stepper glass transition. • DSC measurements exhibited a much larger water holding capacity in Antipathes. • X-ray diffraction analysis shows a higher crystallinity index in Limulus • FTIR showed α-chitin structures and high temperature C–N groups prevalence. - ABSTRACT: Thermomechanical and structural properties of two marine species exoskeletons, Antipathes caribbeana (black coral) and Limulus polyphemus (xiphosure), were studied using dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). DMTA curves indicate the viscoelastic behavior and glass transition around 255 °C, black coral presented a second transition (175 °C) associated to the acetamide group attached to the α-chitin chain. DSC measurements showed a endothermic peak around 100 °C, with enthalpies of 4.02 and 118.04 J/g, indicating strong differences between exoskeletons respect to their water holding capacity and strength water–polymer interaction. A comparative analysis involving DSC and X-ray diffraction showed that lower values ΔH in xiphosure correspond to a material with a higher crystallinity (30), in contrast black coral exhibits higher values ΔH and a lower crystallinity (19). FTIR confirmed α-chitin based structure, at higher temperature diminishes the amide bands and a new one appears, related to C–N groups

  14. Differentiation of closely related fungi by electronic nose analysis

    DEFF Research Database (Denmark)

    Karlshøj, Kristian; Nielsen, Per Væggemose; Larsen, Thomas Ostenfeld

    2007-01-01

    the electronic nose potentially responded to, volatile metabolites were collected, by diffusive sampling overnight onto tubes containing Tenax TA, between the 7th and 8th day of Incubation.Volatiles were analyzed by gas chromatography coupled to mass spectrometry and the results indicated that mail alcohols...... as well as the noacheese ociated P. expansum have been investigated by electronic nose, GC-MS, and LGMS analysis. The isolates were inoculated on yeast extract sucroseagar in 20-mL headspace flasks and electronicnose analysis was performed daily for a-74period. To assess which volatile metabolites...... by high pressure liquid chromatography, coupled-to a diode array detector and a time of flight mass spectrometer. Several mycotoxins were detected in samples from the specles P.nordicum, P.roqueforti, P.paneum, P.carneum, and P.expansum. Differentiation of closely related mycotoxin producing fungi...

  15. Thermal fatigue crack growth analysis in a nozzle corner

    International Nuclear Information System (INIS)

    Blauel, J.G.; Hodulak, L.

    1983-01-01

    Calculations of the crack growth under local thermal shock fatigue are performed. Estimates of crack growth are based on stress distributions obtained by a finite element analysis for thermal transients in the structure without crack. Stress intensity factors are calculated using interpolation formulae derived from known basic solutions for part-through cracks under constant and linearly varying load. The crack propagation at selected parts of the crack front is calculated stepwise by integration of the Paris law with material constants C and n interpolated from test results on compact specimens at constant temperatures. Experimental results for the model vessel test MB1 at an internal pressure of 14 N/mm 2 and a temperature of 320 0 C exposed to a repeated local spraying with cold water are presented and compared to predictions

  16. Parametric thermal analysis of 75 MHz heavy ion RFQ

    International Nuclear Information System (INIS)

    Mishra, N.K.; Mehrotra, N.; Verma, V.; Gupta, A.K.; Bhagwat, P.V.

    2015-01-01

    An ECR based Heavy Ion Accelerator comprising of a superconducting Electron Cyclotron Resonance (ECR) Ion Source, normal conducting RFQ (Radio Frequency Quadrupole) and superconducting Niobium resonators is being developed at BARC under XII plan. A state-of-the-art 18 GHz superconducting ECR ion source (PK-ISIS) jointly configured with Pantechnik, France is operational at Van-de-Graaff, BARC. The electromagnetic design of the improved version of 75 MHz heavy ion RFQ has been reported earlier. The previous thermal study of 51 cm RFQ model showed large temperature variation axially along the vane tip. A new coolant flow scheme has been worked out to optimize the axial temperature gradient. In this paper the thermal analysis including parametric study of coolant flow rates and inlet temperature variation will be presented. (author)

  17. Thermal and Electrical Analysis of Mars Rover RTGs

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Alfred; Or, Chuen T; Skrabek, Emanuel A

    2012-01-19

    The RTG designs described in the preceding paper in these proceedings were analyzed for their thermal and electrical performance. Each analysis consisted of coupled thermal, thermoelectric, and electrical analyses, using Fairchild-generated specialized computer codes. These were supplemented with preliminary structural and mass analyses. For each design, various cases representing different operating conditions (water-cooled/radiation-cooled, BOM/EOM, summer/winter, day/night) and different thermoelectric performance assumptions (from conservative to optimistic) were analyzed; and for every case, the heat flow rates, temperatures and electrical performance of each layer of thermoelectric elements and of the overall RTG were determined. The analyses were performed in great detail, to obtain accurate answers permitting meaningful comparisons between different designs. The results presented show the RTG performance achievable with current technology, and the performance improvements that would be achievable with various technology developments.

  18. Stochastic thermal stress analysis of clad cylindrical fuel elements

    International Nuclear Information System (INIS)

    Barrett, P.R.

    1975-01-01

    After a review of deterministic elastic thermal stress analysis by means of the displacement method for a cylindrical system in which the temperature distribution is not only radially variable but azimuthally and axially variable also, a method is shown for the determination of the statistical moments of the stress components when (a) the outer boundary of the cladding is a stochastic quantity, and (b) the uncertainties in the elastic and thermal constants of the materials and in the magnitude of the heat generation term are taken into account. A typical model is proposed for describing the statistics of the outer radius of the cladding which is a stochastic variable owing to uncertainties produced by the extrusion process. The theory is illustrated by means of a simple example by examining a meaningful reliability index and the relative importance of each of the uncertainties. (Auth.)

  19. A statistical framework for differential network analysis from microarray data

    Directory of Open Access Journals (Sweden)

    Datta Somnath

    2010-02-01

    Full Text Available Abstract Background It has been long well known that genes do not act alone; rather groups of genes act in consort during a biological process. Consequently, the expression levels of genes are dependent on each other. Experimental techniques to detect such interacting pairs of genes have been in place for quite some time. With the advent of microarray technology, newer computational techniques to detect such interaction or association between gene expressions are being proposed which lead to an association network. While most microarray analyses look for genes that are differentially expressed, it is of potentially greater significance to identify how entire association network structures change between two or more biological settings, say normal versus diseased cell types. Results We provide a recipe for conducting a differential analysis of networks constructed from microarray data under two experimental settings. At the core of our approach lies a connectivity score that represents the strength of genetic association or interaction between two genes. We use this score to propose formal statistical tests for each of following queries: (i whether the overall modular structures of the two networks are different, (ii whether the connectivity of a particular set of "interesting genes" has changed between the two networks, and (iii whether the connectivity of a given single gene has changed between the two networks. A number of examples of this score is provided. We carried out our method on two types of simulated data: Gaussian networks and networks based on differential equations. We show that, for appropriate choices of the connectivity scores and tuning parameters, our method works well on simulated data. We also analyze a real data set involving normal versus heavy mice and identify an interesting set of genes that may play key roles in obesity. Conclusions Examining changes in network structure can provide valuable information about the

  20. Uncertainty and sensitivity analysis of the nuclear fuel thermal behavior

    Energy Technology Data Exchange (ETDEWEB)

    Boulore, A., E-mail: antoine.boulore@cea.fr [Commissariat a l' Energie Atomique (CEA), DEN, Fuel Research Department, 13108 Saint-Paul-lez-Durance (France); Struzik, C. [Commissariat a l' Energie Atomique (CEA), DEN, Fuel Research Department, 13108 Saint-Paul-lez-Durance (France); Gaudier, F. [Commissariat a l' Energie Atomique (CEA), DEN, Systems and Structure Modeling Department, 91191 Gif-sur-Yvette (France)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer A complete quantitative method for uncertainty propagation and sensitivity analysis is applied. Black-Right-Pointing-Pointer The thermal conductivity of UO{sub 2} is modeled as a random variable. Black-Right-Pointing-Pointer The first source of uncertainty is the linear heat rate. Black-Right-Pointing-Pointer The second source of uncertainty is the thermal conductivity of the fuel. - Abstract: In the global framework of nuclear fuel behavior simulation, the response of the models describing the physical phenomena occurring during the irradiation in reactor is mainly conditioned by the confidence in the calculated temperature of the fuel. Amongst all parameters influencing the temperature calculation in our fuel rod simulation code (METEOR V2), several sources of uncertainty have been identified as being the most sensitive: thermal conductivity of UO{sub 2}, radial distribution of power in the fuel pellet, local linear heat rate in the fuel rod, geometry of the pellet and thermal transfer in the gap. Expert judgment and inverse methods have been used to model the uncertainty of these parameters using theoretical distributions and correlation matrices. Propagation of these uncertainties in the METEOR V2 code using the URANIE framework and a Monte-Carlo technique has been performed in different experimental irradiations of UO{sub 2} fuel. At every time step of the simulated experiments, we get a temperature statistical distribution which results from the initial distributions of the uncertain parameters. We then can estimate confidence intervals of the calculated temperature. In order to quantify the sensitivity of the calculated temperature to each of the uncertain input parameters and data, we have also performed a sensitivity analysis using the Sobol' indices at first order.

  1. An Optimized Thermal Analysis of Electronic Unit Used in Aircraft

    International Nuclear Information System (INIS)

    Shah, A.N.; Mir, F.; Farooq, M.; Farooq, M.

    2014-01-01

    In a field where change and growth is inevitable, new electronic packaging problems continuously arise. Smaller, but more powerful devices are prone to overheating causing intermittent system failures, corrupted signals and outright system failure. Current study is focused on the analysis of the optimized working of electronic equipment from thermal point of view. In order to achieve the objective, an approach was developed for the thermal analysis of Printed Circuit Board (PCB) including the heat dissipation of its electronic components and then removal of the heat in a sophisticated manner by considering the conduction and convection modes of heat transfer. Mathematical modeling was carried out for a certain problem to address the thermal design, and then a program was developed in MATLAB for the solution of model by using Newton-Raphson method. The proposed unit is to be mounted on an aircraft having suspected thermal characteristics owing to abrupt changes in pressure and temperature as aircraft moves quickly from a lower altitude to higher altitude. In current study, dominant mode of heat transfer was conduction revealing that the major portion of heat transfer takes place by copper cladding and that heat conduction along the length of PCB can be improved enormously by using even thin layer of copper. The results confirmed that temperatures of all the electronic components were within derated values. Meanwhile, it was known that convection also plays a significant role in the reduction of temperatures of the components. The reduction in nodal temperature was in the range of 13 to 42 %. Furthermore, altitude variation from sea level to 15240 m (above sea level) caused the reduction in pressure from 1atm to 0.1095 atm. Consequently, the temperature of the electronic components increased from 73.25 degree C to 83.83 degree C for first node 'a', and from 66.04 degree C to 68.47 degree C for last node 'n' because of the decrease in the convective heat transfer

  2. Comments on the interpretation of differential scanning calorimetry results for thermoelastic martensitic transformations: Athermal versus thermally activated kinetics

    International Nuclear Information System (INIS)

    Morris, A.; Lipe, T.

    1996-01-01

    In a previous article Van Humbeeck and Planes have made a number of criticisms of the authors' recent paper concerning the interpretation of the results obtained by Differential Scanning Calorimetry (DSC) from the Martensitic Transformation of Cu-Al-Ni-Mn-B alloys. Although the martensitic transformation of these shape memory alloys is generally classified as athermal, it has been confirmed that the capacity of the alloys to undergo a more complete thermoelastic transformation (i.e. better reversibility of the transformation) increased with the Mn content. This behavior has been explained by interpreting the DSC results obtained during thermal cycling in terms of a thermally activated mechanism controlling the direct and reverse transformations. When the heating rate increases during the reverse transformation the DSC curves shift towards higher temperatures while they shift towards the lower temperatures when the cooling rate was increased during the direct transformation. Since the starting transformation temperatures (As, Ms) do not shift, Van Humbeeck and Planes state that there is no real peak shift and assume that the DCS experiments were carried out without taking into account the thermal lag effect between sample and cell. On the following line they deduce a time constant, τ, of 60 seconds because the peak maximum shifts. In fact the assumption made by Van Humbeeck and Planes is false

  3. Thermal analysis of LOFT modular DTT for LOCE transient

    International Nuclear Information System (INIS)

    Martin, C.M.

    1978-01-01

    A thermal analysis was performed on the LOFT modular drag-disc turbine transducer (MDTT) modular assembly. The purpose of this analysis was to determine the maximum temperature difference between the MDTT shroud and end cap during a LOCE. This temperature difference is needed for stress analysis of the MDTT endcap to fairing welds. The thermal analysis was done using TRIPLE, a three dimensional finite element code. A three dimensional model of the MDTT was made and transient temperature solutions were found for the different MDTT locations. The fluid temperature transients used for the solutions at all locations were from RELAP4 predictions of the LOFT L2-4 test which is considered the most severe temperature transient. Results of these calculations show the maximum temperature difference is 92 0 C (165 0 F) and occurs in the intact loop cold leg. This value and those found at other locations, are evaluated from the best available RELAP predicted temperatures during a nuclear LOCE

  4. Integrated Software Environment for Pressurized Thermal Shock Analysis

    Directory of Open Access Journals (Sweden)

    Dino Araneo

    2011-01-01

    Full Text Available The present paper describes the main features and an application to a real Nuclear Power Plant (NPP of an Integrated Software Environment (in the following referred to as “platform” developed at University of Pisa (UNIPI to perform Pressurized Thermal Shock (PTS analysis. The platform is written in Java for the portability and it implements all the steps foreseen in the methodology developed at UNIPI for the deterministic analysis of PTS scenarios. The methodology starts with the thermal hydraulic analysis of the NPP with a system code (such as Relap5-3D and Cathare2, during a selected transient scenario. The results so obtained are then processed to provide boundary conditions for the next step, that is, a CFD calculation. Once the system pressure and the RPV wall temperature are known, the stresses inside the RPV wall can be calculated by mean a Finite Element (FE code. The last step of the methodology is the Fracture Mechanics (FM analysis, using weight functions, aimed at evaluating the stress intensity factor (KI at crack tip to be compared with the critical stress intensity factor KIc. The platform automates all these steps foreseen in the methodology once the user specifies a number of boundary conditions at the beginning of the simulation.

  5. Application of monitoring, diagnosis, and prognosis in thermal performance analysis for nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyeong Min; Heo, Gyun Young [Kyung Hee University, Yongin (Korea, Republic of); Na, Man Gyun [Chosun University, Gwangju (Korea, Republic of)

    2014-12-15

    As condition-based maintenance (CBM) has risen as a new trend, there has been an active movement to apply information technology for effective implementation of CBM in power plants. This motivation is widespread in operations and maintenance, including monitoring, diagnosis, prognosis, and decision-making on asset management. Thermal efficiency analysis in nuclear power plants (NPPs) is a longstanding concern being updated with new methodologies in an advanced IT environment. It is also a prominent way to differentiate competitiveness in terms of operations and maintenance costs. Although thermal performance tests implemented using industrial codes and standards can provide officially trustworthy results, they are essentially resource-consuming and maybe even a hind-sighted technique rather than a foresighted one, considering their periodicity. Therefore, if more accurate performance monitoring can be achieved using advanced data analysis techniques, we can expect more optimized operations and maintenance. This paper proposes a framework and describes associated methodologies for in-situ thermal performance analysis, which differs from conventional performance monitoring. The methodologies are effective for monitoring, diagnosis, and prognosis in pursuit of CBM. Our enabling techniques cover the intelligent removal of random and systematic errors, deviation detection between a best condition and a currently measured condition, degradation diagnosis using a structured knowledge base, and prognosis for decision-making about maintenance tasks. We also discuss how our new methods can be incorporated with existing performance tests. We provide guidance and directions for developers and end-users interested in in-situ thermal performance management, particularly in NPPs with large steam turbines.

  6. Application of monitoring, diagnosis, and prognosis in thermal performance analysis for nuclear power plants

    International Nuclear Information System (INIS)

    Kim, Hyeong Min; Heo, Gyun Young; Na, Man Gyun

    2014-01-01

    As condition-based maintenance (CBM) has risen as a new trend, there has been an active movement to apply information technology for effective implementation of CBM in power plants. This motivation is widespread in operations and maintenance, including monitoring, diagnosis, prognosis, and decision-making on asset management. Thermal efficiency analysis in nuclear power plants (NPPs) is a longstanding concern being updated with new methodologies in an advanced IT environment. It is also a prominent way to differentiate competitiveness in terms of operations and maintenance costs. Although thermal performance tests implemented using industrial codes and standards can provide officially trustworthy results, they are essentially resource-consuming and maybe even a hind-sighted technique rather than a foresighted one, considering their periodicity. Therefore, if more accurate performance monitoring can be achieved using advanced data analysis techniques, we can expect more optimized operations and maintenance. This paper proposes a framework and describes associated methodologies for in-situ thermal performance analysis, which differs from conventional performance monitoring. The methodologies are effective for monitoring, diagnosis, and prognosis in pursuit of CBM. Our enabling techniques cover the intelligent removal of random and systematic errors, deviation detection between a best condition and a currently measured condition, degradation diagnosis using a structured knowledge base, and prognosis for decision-making about maintenance tasks. We also discuss how our new methods can be incorporated with existing performance tests. We provide guidance and directions for developers and end-users interested in in-situ thermal performance management, particularly in NPPs with large steam turbines.

  7. Penalized differential pathway analysis of integrative oncogenomics studies.

    Science.gov (United States)

    van Wieringen, Wessel N; van de Wiel, Mark A

    2014-04-01

    Through integration of genomic data from multiple sources, we may obtain a more accurate and complete picture of the molecular mechanisms underlying tumorigenesis. We discuss the integration of DNA copy number and mRNA gene expression data from an observational integrative genomics study involving cancer patients. The two molecular levels involved are linked through the central dogma of molecular biology. DNA copy number aberrations abound in the cancer cell. Here we investigate how these aberrations affect gene expression levels within a pathway using observational integrative genomics data of cancer patients. In particular, we aim to identify differential edges between regulatory networks of two groups involving these molecular levels. Motivated by the rate equations, the regulatory mechanism between DNA copy number aberrations and gene expression levels within a pathway is modeled by a simultaneous-equations model, for the one- and two-group case. The latter facilitates the identification of differential interactions between the two groups. Model parameters are estimated by penalized least squares using the lasso (L1) penalty to obtain a sparse pathway topology. Simulations show that the inclusion of DNA copy number data benefits the discovery of gene-gene interactions. In addition, the simulations reveal that cis-effects tend to be over-estimated in a univariate (single gene) analysis. In the application to real data from integrative oncogenomic studies we show that inclusion of prior information on the regulatory network architecture benefits the reproducibility of all edges. Furthermore, analyses of the TP53 and TGFb signaling pathways between ER+ and ER- samples from an integrative genomics breast cancer study identify reproducible differential regulatory patterns that corroborate with existing literature.

  8. Thermal Performance Analysis of a Geologic Borehole Repository

    Energy Technology Data Exchange (ETDEWEB)

    Reagin, Lauren [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-08-16

    The Brazilian Nuclear Research Institute (IPEN) proposed a design for the disposal of Disused Sealed Radioactive Sources (DSRS) based on the IAEA Borehole Disposal of Sealed Radioactive Sources (BOSS) design that would allow the entirety of Brazil’s inventory of DSRS to be disposed in a single borehole. The proposed IPEN design allows for 170 waste packages (WPs) containing DSRS (such as Co-60 and Cs-137) to be stacked on top of each other inside the borehole. The primary objective of this work was to evaluate the thermal performance of a conservative approach to the IPEN proposal with the equivalent of two WPs and two different inside configurations using Co-60 as the radioactive heat source. The current WP configuration (heterogeneous) for the IPEN proposal has 60% of the WP volume being occupied by a nuclear radioactive heat source and the remaining 40% as vacant space. The second configuration (homogeneous) considered for this project was a homogeneous case where 100% of the WP volume was occupied by a nuclear radioactive heat source. The computational models for the thermal analyses of the WP configurations with the Co-60 heat source considered three different cooling mechanisms (conduction, radiation, and convection) and the effect of mesh size on the results from the thermal analysis. The results of the analyses yielded maximum temperatures inside the WPs for both of the WP configurations and various mesh sizes. The heterogeneous WP considered the cooling mechanisms of conduction, convection, and radiation. The temperature results from the heterogeneous WP analysis suggest that the model is cooled predominantly by conduction with effect of radiation and natural convection on cooling being negligible. From the thermal analysis comparing the two WP configurations, the results suggest that either WP configuration could be used for the design. The mesh sensitivity results verify the meshes used, and results obtained from the thermal analyses were close to

  9. Study of thermal decomposition and characterization of uranium compounds by thermogravimetry and differential calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, J M; Abrao, A [Instituto de Pesquisas Energeticas e Nucleares, Sao Paulo (Brazil). Centro de Engenharia Quimica

    1980-01-01

    The thermal behaviour of different types of ammonium diuranates, produced in the pilot plants of Instituto de Pesquisas Energeticas e Nucleares (Sao Paulo, Brazil), is studied. It was observed that: the contents of absorption and crystallization waters, as well as the content of absorption ammonia vary as a function of drying conditions; the contents of occluded ammonium nitrate vary according to the washing step; ammonia contents vary as a function of pH and of the original solution - greater ammonia concentrations are observed when diuranates are precipitate in uranyl nitrate solutions at higher pH's (9.0). Thermal instability of the intermediate compound varies as a function of the type of the occluded ion, NO/sup -//sub 3/ or SO sup(=)/sub 4/. The thermoanalytical curves show that the diuranates obtained by continuous precipitation have a more reproducible chemical composition than those obtained by batch precipitation.

  10. Degradation of rocks, through cracking caused by differential thermal expansion, in relation to nuclear waste repositories

    International Nuclear Information System (INIS)

    McLaren, J.R.; Davidge, R.W.; Titchell, I.; Sincock, K.; Bromley, A.

    1982-01-01

    Heating to temperatures up to 500 0 C gives a reduction in Young's modulus and increases in permeability of granitic rocks and it is likely that a major reason is grain boundary cracking. The cracking of grain boundary facets in polycrystalline multiphase materials showing anistropic thermal expansion behaviour is controlled by several microstructural factors in addition to the intrinsic thermal and elastic properties. Of specific interest are the relative orientations of the two grains meeting at the facet, and the size of the facet; these factors thus introduce two statistical aspects to the problem and these are introduced to give quantitative data on crack density versus temperature. The theory is compared with experimental measurements of Young's modulus and permeability for various rocks as a function of temperature. There is good qualitative agreement, and the additional (mainly microstructural) data required for a quantitative comparison are defined. 6 figures, 2 tables

  11. Differential DNA Methylation Analysis without a Reference Genome

    Directory of Open Access Journals (Sweden)

    Johanna Klughammer

    2015-12-01

    Full Text Available Genome-wide DNA methylation mapping uncovers epigenetic changes associated with animal development, environmental adaptation, and species evolution. To address the lack of high-throughput methods for DNA methylation analysis in non-model organisms, we developed an integrated approach for studying DNA methylation differences independent of a reference genome. Experimentally, our method relies on an optimized 96-well protocol for reduced representation bisulfite sequencing (RRBS, which we have validated in nine species (human, mouse, rat, cow, dog, chicken, carp, sea bass, and zebrafish. Bioinformatically, we developed the RefFreeDMA software to deduce ad hoc genomes directly from RRBS reads and to pinpoint differentially methylated regions between samples or groups of individuals (http://RefFreeDMA.computational-epigenetics.org. The identified regions are interpreted using motif enrichment analysis and/or cross-mapping to annotated genomes. We validated our method by reference-free analysis of cell-type-specific DNA methylation in the blood of human, cow, and carp. In summary, we present a cost-effective method for epigenome analysis in ecology and evolution, which enables epigenome-wide association studies in natural populations and species without a reference genome.

  12. Interactions of coal gangue and pine sawdust during combustion of their blends studied using differential thermogravimetric analysis.

    Science.gov (United States)

    Zhang, Yuanyuan; Zhang, Zhezi; Zhu, Mingming; Cheng, Fangqin; Zhang, Dongke

    2016-08-01

    The interactions between coal gangue and pine sawdust during the combustion process were studied using thermogravimetric analysis. The effect of the blending ratio, oxygen concentration and heating rate on the weight loss (TG) and differential thermogravimetric (TGA) profiles was examined. The TG and DTG curves of the blends were not additives of those of the individual materials, suggesting that interactions between coal gangue and pine sawdust had occurred during the combustion, especially in the temperature range of 400-600°C. Kinetic analysis confirmed that the combustion of coal gangue, pine sawdust and their blends was chemical reaction controlled. Further analysis revealed that the interactions between coal gangue and pine sawdust were primarily due to thermal effects rather than structural changes, with the thermal inertia of coal gangue dominating over the behaviour of the blends. The interactions decreased with decreasing the coal gangue ratio in the blend, oxygen concentration and heating rate. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Thermal Hydraulic Analysis on Containment Filtered Venting System

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Young Suk; Park, Tong Kyu; Lee, Doo Yong; Lee, Byung Chul [FNC Technology Co. Ltd., Yongin (Korea, Republic of); Lee, Sang Won; Kim, Hyeong Taek [KHNP-Central Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In this study, the thermal hydraulic conditions (e. g. pressure and flow rate) at each component have been examined and the sensitivity analysis on CFVS design parameters (e. g. water inventory, volumetric flow rate). The purpose is to know the possible range of flow conditions at each component to determine the optimum size of filtration system. GOTHIC code has been used to simulate the thermal-hydraulic behavior inside of CFVS. The behavior of flows in the CFVS has been investigated. The vessel water level and the flow rates during the CFVS operation are examined. It was observed that the vessel water level would be changed significantly due to steam condensation/thermal expansion and steam evaporation. Therefore, the vessel size and the initial water inventory should be carefully determined to keep the minimum water level required for filtration components and not to flood the components in the upper side of the vessel. It has been also observed that the volumetric flow rate is maintained during the CFVS operation, which is beneficial for pool scrubbing units. However, regarding the significant variations at the orifice downstream, careful design would be necessary.

  14. Comparative environmental analysis of waste brominated plastic thermal treatments

    International Nuclear Information System (INIS)

    Bientinesi, M.; Petarca, L.

    2009-01-01

    The aim of this research activity is to investigate the environmental impact of different thermal treatments of waste electric and electronic equipment (WEEE), applying a life cycle assessment methodology. Two scenarios were assessed, which both allow the recovery of bromine: (A) the co-combustion of WEEE and green waste in a municipal solid waste combustion plant, and (B) the staged-gasification of WEEE and combustion of produced syngas in gas turbines. Mass and energy balances on the two scenarios were set and the analysis of the life cycle inventory and the life cycle impact assessment were conducted. Two impact assessment methods (Ecoindicator 99 and Impact 2002+) were slightly modified and then used with both scenarios. The results showed that scenario B (staged-gasification) had a potentially smaller environmental impact than scenario A (co-combustion). In particular, the thermal treatment of staged-gasification was more energy efficient than co-combustion, and therefore scenario B performed better than scenario A, mainly in the impact categories of 'fossil fuels' and 'climate change'. Moreover, the results showed that scenario B allows a higher recovery of bromine than scenario A; however, Br recovery leads to environmental benefits for both the scenarios. Finally the study demonstrates that WEEE thermal treatment for energy and matter recovery is an eco-efficient way to dispose of this kind of waste

  15. Thermal and structural analysis of the TPX divertor

    International Nuclear Information System (INIS)

    Reis, E.E.; Baxi, C.B.; Chin, E.; Redler, K.M.

    1995-01-01

    The high heat flux on the surfaces of the TPX divertor will require a design in which a carbon-carbon (C-C) tile material is brazed to water cooled copper tubes. Thermal and structural analyses were performed to assist in the design selection of a divertor tile concept and C-C material. The relevancy of finite element analysis (FEA) for evaluating tile design was examined by conducting a literature survey to compare FEA stress results to subsequent brazing and thermal test results. The thermal responses for five tile concepts and four C-C materials were analyzed for a steady-state heat flux of 7.5 MW/m 2 . Elastic-plastic stress analyses were performed to calculate the residual stresses due to brazing C-C tiles to soft copper heat sinks for the various tile designs. Monoblock and archblock divertor tile concepts were analyzed for residual stresses in which elevated temperature creep effects were included with the elastic-plastic behavior of the copper heat sink for an assumed braze cooldown cycle. As a result of these 2D studies, the archblock concept with a 3D fine weave C-C was initially found to be a preferred design for the divertor. A 3D elastic-plastic analysis for brazing of the arch block tile was performed to investigate the singularity effects at the C-C to copper interface in the direction of the tube axis. This analysis showed that the large residual stresses at the tube and tile edge intersection would produce cracks in the C-C and possible delamination along the braze interface. These results, coupled with the difficulties experienced in brazing archblocks for the Tore Supra Limiter, required that other tile designs be considered

  16. Thermal design and analysis of high power star sensors

    Directory of Open Access Journals (Sweden)

    Fan Jiang

    2015-09-01

    Full Text Available The requirement for the temperature stability is very high in the star sensors as the high precision needs for the altitude information. Thermal design and analysis thus is important for the high power star sensors and their supporters. CCD, normally with Peltier thermoelectric cooler (PTC, is the most important sensor component in the star sensors, which is also the main heat source in the star sensors suite. The major objective for the thermal design in this paper is to design a radiator to optimize the heat diffusion for CCD and PTC. The structural configuration of star sensors, the heat sources and orbit parameters were firstly introduced in this paper. The influences of the geometrical parameters and coating material characteristics of radiators on the heat diffusion were investigated by heat flux analysis. Carbon–carbon composites were then chosen to improve the thermal conductivity for the sensor supporters by studying the heat transfer path. The design is validated by simulation analysis and experiments on orbit. The satellite data show that the temperatures of three star sensors are from 17.8 °C to 19.6 °C, while the simulation results are from 18.1 °C to 20.1 °C. The temperatures of radiator are from 16.1 °C to 16.8 °C and the corresponding simulation results are from 16.0 °C to 16.5 °C. The temperature variety of each star sensor is less than 2 °C, which satisfies the design objectives.

  17. A green approach towards adoption of chemical reaction model on 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane decomposition by differential isoconversional kinetic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Das, Mitali; Shu, Chi-Min, E-mail: shucm@yuntech.edu.tw

    2016-01-15

    Highlights: • Thermally degraded DBPH products are identified. • An appropriate mathematical model was selected for decomposition study. • Differential isoconversional analysis was performed to obtain kinetic parameters. • Simulation on thermal analysis model was conducted for the best storage conditions. - Abstract: This study investigated the thermal degradation products of 2,5-dimethyl-2,5-di-(tert-butylperoxy) hexane (DBPH), by TG/GC/MS to identify runaway reaction and thermal safety parameters. It also included the determination of time to maximum rate under adiabatic conditions (TMR{sub ad}) and self-accelerating decomposition temperature obtained through Advanced Kinetics and Technology Solutions. The apparent activation energy (E{sub a}) was calculated from differential isoconversional kinetic analysis method using differential scanning calorimetry experiments. The E{sub a} value obtained by Friedman analysis is in the range of 118.0–149.0 kJ mol{sup −1}. The TMR{sub ad} was 24.0 h with an apparent onset temperature of 82.4 °C. This study has also established an efficient benchmark for a thermal hazard assessment of DBPH that can be applied to assure safer storage conditions.

  18. Thermal diffusivity measurement of erythritol and numerical analysis of heat storage performance on a fin-type heat exchanger

    International Nuclear Information System (INIS)

    Zamengo, Massimiliano; Funada, Tomohiro; Morikawa, Junko

    2017-01-01

    Highlights: • Thermal diffusivity of Erythritol was measured by temperature wave method. • Thermal diffusivity was measured in function of temperature and during phase change. • Database of temperature-dependent thermal properties is used for numerical analysis. • Heat transfer and heat storage were analyzed in a fin-type heat exchanger. • Use of temperature-dependent properties in calculations lead to longer melting time. - Abstract: Temperature dependency of thermal diffusivity of erythritol was measured by temperature wave analysis (TWA) method. This modulating technique allowed measuring thermal diffusivity continuously, even during the phase transition solid-liquid. Together with specific heat capacity and specific enthalpy measured by differential scanning calorimetry, the values of measured properties were utilized in a bi-dimensional numerical model for analysis of heat transfer and heat storage performance. The geometry of the model is representative of a cross section of a fin-type heat exchanger, in which erythritol is filling the interspaces between fins. Time-dependent temperature change and heat storage performance were analyzed by considering the variation of thermophysical properties as a function of temperature. The numerical method can be utilized for a fast parametric analysis of heat transfer and heat storage performance into heat storage systems of phase-change materials and composites.

  19. Analysis of backward differentiation formula for nonlinear differential-algebraic equations with 2 delays.

    Science.gov (United States)

    Sun, Leping

    2016-01-01

    This paper is concerned with the backward differential formula or BDF methods for a class of nonlinear 2-delay differential algebraic equations. We obtain two sufficient conditions under which the methods are stable and asymptotically stable. At last, examples show that our methods are true.

  20. Thermal Analysis of Concrete Storage Cask with Bird Screen Meshes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ju-Chan; Bang, K.S.; Yu, S.H.; Cho, S.S.; Choi, W.S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    In this study, a thermal analysis of the cask with bird screen meshes has been performed using a porous media model. The overpack consists of a structural material, a concrete shielding, and a ventilation system. Heat is removed from the cask to the environment by a passive means only. Air inlet and outlet ducts are installed at the bottom and top of the cask for a ventilation system. Bird screen meshes are installed at the air inlet and outlet ducts to inhibit intrusion of debris from the external environment. The presence of this screens introduce an additional resistance to air flow through the ducts. Five types of meshes for bird screen were considered in this study. The bird screen meshes at the inlet and outlet vents reduce the open area for flow by about 44 - 79 %. Flow resistance coefficients for porous media model were deduced from the fluid flow analysis of bird screen meshes. Thermal analyses for the concrete cask have been carried out using a porous media model. The analysis results agreed well with the test results. Therefore, it was shown that the porous media model for the screen mesh was established to estimate the cask temperatures.

  1. Experimental investigation of thermal neutron analysis based landmine detection technology

    International Nuclear Information System (INIS)

    Zeng Jun; Chu Chengsheng; Ding Ge; Xiang Qingpei; Hao Fanhua; Luo Xiaobing

    2013-01-01

    Background: Recently, the prompt gamma-rays neutron activation analysis method is wildly used in coal analysis and explosive detection, however there were less application about landmine detection using neutron method especially in the domestic research. Purpose: In order to verify the feasibility of Thermal Neutron Analysis (TNA) method used in landmine detection, and explore the characteristic of this technology. Methods: An experimental system of TNA landmine detection was built based on LaBr 3 (Ce) fast scintillator detector and 252 Cf isotope neutron source. The system is comprised of the thermal neutron transition system, the shield system, and the detector system. Results: On the basis of the TNA, the wide energy area calibration method especially to the high energy area was investigated, and the least detection time for a typical mine was defined. In this study, the 72-type anti-tank mine, the 500 g TNT sample and several interferential objects are tested in loess, red soil, magnetic soil and sand respectively. Conclusions: The experimental results indicate that TNA is a reliable demining method, and it can be used to confirm the existence of Anti-Tank Mines (ATM) and large Anti-Personnel Mines (APM) in complicated condition. (authors)

  2. Thermal Analysis of Concrete Storage Cask with Bird Screen Meshes

    International Nuclear Information System (INIS)

    Lee, Ju-Chan; Bang, K.S.; Yu, S.H.; Cho, S.S.; Choi, W.S.

    2016-01-01

    In this study, a thermal analysis of the cask with bird screen meshes has been performed using a porous media model. The overpack consists of a structural material, a concrete shielding, and a ventilation system. Heat is removed from the cask to the environment by a passive means only. Air inlet and outlet ducts are installed at the bottom and top of the cask for a ventilation system. Bird screen meshes are installed at the air inlet and outlet ducts to inhibit intrusion of debris from the external environment. The presence of this screens introduce an additional resistance to air flow through the ducts. Five types of meshes for bird screen were considered in this study. The bird screen meshes at the inlet and outlet vents reduce the open area for flow by about 44 - 79 %. Flow resistance coefficients for porous media model were deduced from the fluid flow analysis of bird screen meshes. Thermal analyses for the concrete cask have been carried out using a porous media model. The analysis results agreed well with the test results. Therefore, it was shown that the porous media model for the screen mesh was established to estimate the cask temperatures

  3. Measuring energy expenditure in sports by thermal video analysis

    DEFF Research Database (Denmark)

    Gade, Rikke; Larsen, Ryan Godsk; Moeslund, Thomas B.

    2017-01-01

    Estimation of human energy expenditure in sports and exercise contributes to performance analyses and tracking of physical activity levels. The focus of this work is to develop a video-based method for estimation of energy expenditure in athletes. We propose a method using thermal video analysis...... to automatically extract the cyclic motion pattern, in walking and running represented as steps, and analyse the frequency. Experiments are performed with one subject in two different tests, each at 5, 8, 10, and 12 km/h. The results of our proposed video-based method is compared to concurrent measurements...

  4. Thermal coupling system analysis of a nuclear desalination plant

    International Nuclear Information System (INIS)

    Adak, A.K.; Srivastava, V.K.; Tewari, P.K.

    2010-01-01

    When a nuclear reactor is used to supply steam for desalination plant, the method of coupling has a significant technical and economic impact. The exact method of coupling depends upon the type of reactor and type of desalination plant. As a part of Nuclear Desalination Demonstration Project (NDDP), BARC has successfully commissioned a 4500 m 3 /day MSF desalination plant coupled to Madras Atomic Power Station (MAPS) at Kalpakkam. Desalination plant coupled to nuclear power plant of Pressurized Heavy Water Reactor (PHWR) type is a good example of dual-purpose nuclear desalination plant. This paper presents the thermal coupling system analysis of this plant along with technical and safety aspects. (author)

  5. Transient thermal analysis of cryocondensation pump for JET

    International Nuclear Information System (INIS)

    Baxi, C.B.; Obert, W.

    1993-08-01

    A cryopump with pumping speed of 50,000 1/sec is planned to be installed in the Joint European Torus (JET) as part of the pumped divertor. The purpose of this pump is to control the plasma impurities. The pump consists of a helium panel cooled by supercritical helium and a nitrogen shield cooled by liquid nitrogen. This paper presents the following transient thermal flow analysis for this cryopump: 1. Consequences of loss of torus vacuum on helium panel. 2. Cool down of the nitrogen shield form 300 K to 80 K

  6. Momentum integral network method for thermal-hydraulic transient analysis

    International Nuclear Information System (INIS)

    Van Tuyle, G.J.

    1983-01-01

    A new momentum integral network method has been developed, and tested in the MINET computer code. The method was developed in order to facilitate the transient analysis of complex fluid flow and heat transfer networks, such as those found in the balance of plant of power generating facilities. The method employed in the MINET code is a major extension of a momentum integral method reported by Meyer. Meyer integrated the momentum equation over several linked nodes, called a segment, and used a segment average pressure, evaluated from the pressures at both ends. Nodal mass and energy conservation determined nodal flows and enthalpies, accounting for fluid compression and thermal expansion

  7. Progressive reduction of the thermal wall system by modal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtari, A.; Meslem, A.; Bounif, A.; Kadi, L. [Universite des Sciences et de la Technologie, Oran (Algeria)

    1993-12-31

    A reduction method of thermal systems called ``progress`` using the modal Analysis is presented. It allows to do, at each time of simulation, a synthesis information in the system evolution. Consequently, the limited number of descriptive and significant parameters (proper modes), can produce some extremely useful indication about dynamic evolution. However this method can eliminate proper modes of which the energetic contribution will be neglected or amortized. Some examples were studied, showing the efficiency of this method by reducing the computing time, as well as, having high precision on predicted dynamic response over time of simulation. (Authors). 4 refs., 4 figs.

  8. Viscoelastic Plate Analysis Based on Gâteaux Differential

    Directory of Open Access Journals (Sweden)

    Kadıoğlu Fethi

    2016-01-01

    Full Text Available In this study, it is aimed to analyze the quasi-static response of viscoelastic Kirchhoff plates with mixed finite element formulation based on the Gâteaux differential. Although the static response of elastic plate, beam and shell structures is a widely studied topic, there are few studies that exist in the literature pertaining to the analysis of the viscoelastic structural elements especially with complex geometries, loading conditions and constitutive relations. The developed mixed finite element model in transformed Laplace-Carson space has four unknowns as displacement, bending and twisting moments in addition to the dynamic and geometric boundary condition terms. Four-parameter solid model is employed for modelling the viscoelastic behaviour. For transformation of the solutions obtained in the Laplace-Carson domain to the time domain, different numerical inverse transform techniques are employed. The developed solution technique is applied to several quasi-static example problems for the verification of the suggested numerical procedure.

  9. Corals and Their Microbiomes Are Differentially Affected by Exposure to Elevated Nutrients and a Natural Thermal Anomaly

    Directory of Open Access Journals (Sweden)

    Lu Wang

    2018-03-01

    Full Text Available Nutrient pollution can increase the prevalence and severity of coral disease and bleaching in ambient temperature conditions or during experimental thermal challenge. However, there have been few opportunities to study the effects of nutrient pollution during natural thermal anomalies. Here we present results from an experiment conducted during the 2014 bleaching event in the Florida Keys, USA, that exposed Agaricia sp. (Undaria and Siderastrea siderea corals to 3 types of elevated nutrients: nitrogen alone, phosphorous alone, and the combination of nitrogen and phosphorus. Overall, bleaching prevalence and severity was high regardless of treatment, but nitrogen enrichment alone both prolonged bleaching and increased coral mortality in Agaricia corals. At the same time, the elevated temperatures increased the prevalence of Dark Spot Syndrome (DSS, a disease typically associated with cold temperatures in Siderastrea siderea corals. However, nutrient exposure alone did not increase the prevalence or severity of disease, suggesting that thermal stress overwhelms the effects of nutrient pollution on this disease during such an extreme thermal event. Analysis of 78 Siderastrea siderea microbial metagenomes also showed that the thermal event was correlated with significant shifts in the composition and function of the associated microbiomes, and corals with DSS had microbiomes distinct from apparently healthy corals. In particular, we identified shifts in viral, archaeal, and fungal families. These shifts were likely driven by the extreme temperatures or other environmental co-variates occurring during the 2014 bleaching event. However, no microbial taxa were correlated with signs of DSS. Furthermore, although nutrient exposure did not affect microbial alpha diversity, it did significantly affect microbiome beta-diversity, an effect that was independent of time. These results suggest that strong thermal anomalies and local nutrient pollution both

  10. Modal analysis of the thermal conductivity of nanowires: examining unique thermal transport features

    Science.gov (United States)

    Samaraweera, Nalaka; Larkin, Jason M.; Chan, Kin L.; Mithraratne, Kumar

    2018-06-01

    In this study, unique thermal transport features of nanowires over bulk materials are investigated using a combined analysis based on lattice dynamics and equilibrium molecular dynamics (EMD). The evaluation of the thermal conductivity (TC) of Lenard–Jones nanowires becomes feasible due to the multi-step normal mode decomposition (NMD) procedure implemented in the study. A convergence issue of the TC of nanowires is addressed by the NMD implementation for two case studies, which employ pristine nanowires (PNW) and superlattice nanowires. Interestingly, mode relaxation times at low frequencies of acoustic branches exhibit signs of approaching constant values, thus indicating the convergence of TC. The TC evaluation procedure is further verified by implementing EMD-based Green–Kubo analysis, which is based on a fundamentally different physical perspective. Having verified the NMD procedure, the non-monotonic trend of the TC of nanowires is addressed. It is shown that the principal cause for the observed trend is due to the competing effects of long wavelength phonons and phonon–surface scatterings as the nanowire’s cross-sectional width is changed. A computational procedure is developed to decompose the different modal contribution to the TC of shell alloy nanowires (SANWs) using virtual crystal NMD and the Allen–Feldman theory. Several important conclusions can be drawn from the results. A propagons to non-propagons boundary appeared, resulting in a cut-off frequency (ω cut); moreover, as alloy atomic mass is increased, ω cut shifts to lower frequencies. The existence of non-propagons partly causes the low TC of SANWs. It can be seen that modes with low frequencies demonstrate a similar behavior to corresponding modes of PNWs. Moreover, lower group velocities associated with higher alloy atomic mass resulted in a lower TC of SANWs.

  11. Analysis result for OECD benchmark on thermal fatigue problem

    International Nuclear Information System (INIS)

    Kamaya, Masayuki; Nakamura, Akira; Fujii, Yuzou

    2005-01-01

    The main objective of this analysis is to understand the crack growth behavior under three-dimensional (3D) thermal fatigue by conducting 3D crack initiation and propagation analyses. The possibility of crack propagation through the wall thickness of pipe, and the accuracy of the prediction of crack initiation and propagation are of major interest. In this report, in order to estimate the heat transfer coefficients and evaluate the thermal stress, conventional finite element analysis (FEA) is conducted. Then, the crack driving force is evaluated by using the finite element alternating method (FEAM), which can derive the stress intensity factor (SIF) under 3D mechanical loading based on finite element analysis without generating the mesh for a cracked body. Through these two realistic 3D numerical analyses, it has been tried to predict the crack initiation and propagation behavior. The thermal fatigue crack initiation and propagation behavior were numerically analyzed. The conventional FEA was conducted in order to estimate the heat transfer coefficient and evaluate the thermal stress. Then, the FEAM was conducted to evaluate the SIFs of surface single cracks and interacting multiple cracks, and crack growth was evaluated. The results are summarized as follows: 1. The heat transfer coefficients were estimated as H air = 40 W/m 2 K and H water = 5000 W/m 2 K. This allows simulation of the change in temperature with time at the crack initiation points obtained by the experiment. 2. The maximum stress occurred along the line of symmetry and the maximum Mises equivalent stress was 572 MPa. 3. By taking the effect of mean stress into account according to the modified Goodman diagram, the equivalent stress range and the number of cycles to crack initiation were estimated as 1093 MPa and 3.8x10 4 , respectively, although the tensile strength was assumed to be 600 MPa. 4. It was shown from the evaluated SIFs that longitudinal cracks can penetrate the wall of the pipe

  12. Three dimensional, thermal stress analysis of a welded plate

    International Nuclear Information System (INIS)

    Koening, H.A.; Lai, C.K.-F.; Morral, J.E.

    1985-01-01

    A general finite element thermal stress analysis has been developed. The analysis can be uncoupled to solve either the heat transfer problem or the stress problem independently and it can accommodate non-linear material behavior, initial states of stress and strain, and moving boundary conditions. A unique feature of the model it that it properly accounts for the latent heat effect during phase changes. Applying the moving heat flux boundary condition to simulate arc welding, the model has been used to predict the transient thermal mechanical response of a welded plate. It is the absorption and liberation of latent heat in the fusion zone of a weld which complicates numerical methods of treating welding. For pure materials and eutectic alloys the latent heat effect is less of a problem because phase changes take place at a specific temperature. But for most alloys, phase changes take place over a range of temperatures bounded by the solidus, T S , and liquidus, T L , and the latent heat effect occurs continuously over the temperature range. (author)

  13. A powerful methodology for reactor vessel pressurized thermal shock analysis

    International Nuclear Information System (INIS)

    Boucau, J.; Mager, T.

    1994-01-01

    The recent operating experience of the Pressurized Water Reactor (PWR) Industry has focused increasing attention on the issue of reactor vessel pressurized thermal shock (PTS). More specifically, the review of the old WWER-type of reactors (WWER 440/230) has indicated a sensitive behaviour to neutron embrittlement. This led already to some remedial actions including safety injection water preheating or vessel annealing. Such measures are usually taken based on the analysis of a selected number of conservative PTS events. Consideration of all postulated cooldown events would draw attention to the impact of operator action and control system effects on reactor vessel PTS. Westinghouse has developed a methodology which couples event sequence analysis with probabilistic fracture mechanics analyses, to identify those events that are of primary concern for reactor vessel integrity. Operating experience is utilized to aid in defining the appropriate event sequences and event frequencies of occurrence for the evaluation. Once the event sequences of concern are identified, detailed deterministic thermal-hydraulic and structural evaluations can be performed to determine the conditions required to minimize the extension of postulated flaws or enhance flaw arrest in the reactor vessel. The results of these analyses can then be used to better define further modifications in vessel and plant system design and to operating procedures. The purpose of the present paper will be to describe this methodology and to show its benefits for decision making. (author). 1 ref., 3 figs

  14. Simultaneous thermal analysis and thermodilatometry of hybrid fiber reinforced UHPC

    Science.gov (United States)

    Scheinherrová, Lenka; Fořt, Jan; Pavlík, Zbyšek; Černý, Robert

    2017-07-01

    Development of concrete technology and the availability of variety of materials such as silica fume, mineral microfillers and high-range water-reducing admixtures make possible to produce Ultra-High Performance Concrete (UHPC) with compressive strength higher than 160 MPa. However, UHPC is prone to spall under high temperatures what limits its use for special applications only, such as offshore and marine structures, industrial floors, security barriers etc. The spalling is caused by the thermal stresses due to the temperature gradient during heating, and by the splitting force owing to the release of water vapour. Hybrid fibre reinforcement based on combination of steel and polymer fibres is generally accepted by concrete community as a functional solution preventing spalling. In this way, Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) is produced possessing high mechanical strength, durability and resistance to water and salt ingress. Since UHPFRC find use in construction industry in tunnel linings, precast tunnel segments, and high-rise buildings, its behaviour during the high-temperature exposure and its residual parameters are of the particular importance. On this account, Simultaneous Thermal Analysis (STA) and Thermodilatometry Analysis (TDA) were done in the paper to identify the structural and chemical changes in UHPFRC during its high-temperature load. Based on the experimental results, several physical and chemical processes that studied material underwent at high-temperatures were recognized. The obtained data revealed changes in the composition of the studied material and allowed identification of critical temperatures for material damage.

  15. Turbopump Design and Analysis Approach for Nuclear Thermal Rockets

    International Nuclear Information System (INIS)

    Chen, Shucheng S.; Veres, Joseph P.; Fittje, James E.

    2006-01-01

    A rocket propulsion system, whether it is a chemical rocket or a nuclear thermal rocket, is fairly complex in detail but rather simple in principle. Among all the interacting parts, three components stand out: they are pumps and turbines (turbopumps), and the thrust chamber. To obtain an understanding of the overall rocket propulsion system characteristics, one starts from analyzing the interactions among these three components. It is therefore of utmost importance to be able to satisfactorily characterize the turbopump, level by level, at all phases of a vehicle design cycle. Here at the NASA Glenn Research Center, as the starting phase of a rocket engine design, specifically a Nuclear Thermal Rocket Engine design, we adopted the approach of using a high level system cycle analysis code (NESS) to obtain an initial analysis of the operational characteristics of a turbopump required in the propulsion system. A set of turbopump design codes (PumpDes and TurbDes) were then executed to obtain sizing and performance parameters of the turbopump that were consistent with the mission requirements. A set of turbopump analyses codes (PUMPA and TURBA) were applied to obtain the full performance map for each of the turbopump components; a two dimensional layout of the turbopump based on these mean line analyses was also generated. Adequacy of the turbopump conceptual design will later be determined by further analyses and evaluation. In this paper, descriptions and discussions of the aforementioned approach are provided and future outlooks are discussed

  16. Thermal Analysis of Fission Moly Target Solid Waste Storage

    Energy Technology Data Exchange (ETDEWEB)

    Son, Hyung Min; Park, Jonghark [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    There are various ways to produce Mo-99. Among them, nuclear transmutation of uranium target became the major one owing to its superior specific activity. After the fission molybdenum (FM) target is irradiated, it is transported to treatment facility to extract wanted isotope. During the process, various forms of wastes are produced including filter cake and other solid wastes. The filter cake is mostly consisted of decaying uranium compounds. The solid wastes are then packaged and moved to storage facility which will stay there for considerable amount of time. Being the continuous source of heat, the solid wastes are required to be cooled for the certain amount of time before transported to the storage area. In this study, temperature evaluation of the storage facility is carried out with pre-cooling time sensitivity to check its thermal integrity. In this study, thermal analysis on the FM target solid waste storage is performed. Finite volume method is utilized to numerically discretize and solve the geometry of interest. Analysis shows that the developed method can simulate temperature behavior during storage process, but needs to be checked against other code to see calculation accuracy. Highest temperature distribution is observed when every hole is filled with waste containers. Sensitivity results on pre-cooling time shows that at least 13 months of cooling is necessary to keep the structure integrity.

  17. Spatial differentiation of China's summer tourist destinations based on climatic suitability using the Universal Thermal Climate Index

    Science.gov (United States)

    Yang, Jun; Zhang, Zhenchao; Li, Xueming; Xi, Jianchao; Feng, Zhangxian

    2017-11-01

    As a result of global warming and the gradual exacerbation of the urban heat island effect, vacationing in the summer to escape the heat has become a compelling tourism demand. This study examines the spatial differentiation of China's summer tourist destinations based on meteorological observations and tourism resources data from 1960 to 2014. The Universal Thermal Climate Index and analytic hierarchy process model were used to analyze climatic suitability. The findings are as follows. First, the spatial distribution of China's summer tourism resources exhibits a double-peak characteristic, with concentrations in the mid- and high-latitude and high-altitude regions. Second, the most influential destinations in China based on the composite index were Guiyang, Qingdao, Harbin, and Dalian. These findings can helpful for people who are planning their summer vacations, as well as tourism managers who benefit from such increases in the number of tourists.

  18. Characterization of phase change materials for thermal control of photovoltaics using Differential Scanning Calorimetry and Temperature History Method

    International Nuclear Information System (INIS)

    Hasan, A.; McCormack, S.J.; Huang, M.J.; Norton, B.

    2014-01-01

    Highlights: • Five PCM are characterized using tow techniques for PV temperature regulation. • Thermophysical properties of interest are determined and compared with literature. • Determined PCM properties are discussed as criteria for PV temperature regulation. • One PCM identified as potential candidate for PV temperature regulation. - Abstract: Five solid–liquid phase change materials comprising three basic classes, paraffin waxes, salt hydrates and mixtures of fatty acids were thermophysically characterized for thermal regulation applications in photovoltaics. The PCM were investigated using Differential Scanning Calorimetry and Temperature History Method to find their thermophysical properties of interest. The relationship between thermophysical properties of the PCM and their choice as temperature regulators in photovoltaics is discussed in relation to the ambient conditions under which PV systems operate

  19. Transient Thermal Analysis of 3-D Integrated Circuits Packages by the DGTD Method

    KAUST Repository

    Li, Ping; Dong, Yilin; Tang, Min; Mao, Junfa; Jiang, Li Jun; Bagci, Hakan

    2017-01-01

    Since accurate thermal analysis plays a critical role in the thermal design and management of the 3-D system-level integration, in this paper, a discontinuous Galerkin time-domain (DGTD) algorithm is proposed to achieve this purpose

  20. Thermal analysis of cryoprotective solutions for red blood cells.

    Science.gov (United States)

    Iijima, T

    1998-05-01

    A differential scanning calorimeter was used to study the thermal behavior of glycerol-water solutions (binary system) and the more complex glycerol-based cryoprotective solutions that are used clinically in order to examine the cryoprotective role of glycerol in preserving frozen red blood cells. The melting and glass transition temperatures for the clinically used cryoprotective solutions were as expected, based on the nonequilibriumphase diagram for cryoprotective solutions incorporating isotonic phosphate-buffered saline. Two zones were identified in which solidification occurred without the formation of ice crystals: a glassy state that is crystallographically amorphous was found for glycerol concentrations between 40 and 55% in the binary system and between 45 and 60% in the complex system; a glassy state in the complete absence of ice was found at glycerol concentrations greater than 55% for the binary system or 60% for the complex system. In clinical practice, cryoprotectants are used at initial concentrations lower than those at which these two glassy states occur but there is an increase in the effective glycerol concentration inside and outside the cells as ice forms during the freezing process.

  1. Development of thermal hydraulic analysis code for IHX of FBR

    International Nuclear Information System (INIS)

    Kumagai, Hiromichi; Naohara, Nobuyuki

    1991-01-01

    In order to obtain flow resistance correlations for thermal-hydrauric analysis code concerned with an intermediate heat exchanger (IHX) of FBR, the hydraulic experiment by air was carried out through a bundle of tubes arranged in an in-line and staggard fashion. The main results are summarized as follows. (1) On pressure loss per unit length of a tube bundle, which is densely a regular triangle arrangement, the in-line fashion is almost the same as the staggard one. (2) In case of 30deg sector model for IHX tube bundle, pressure loss is 1/3 in comparison with the in-line or staggard arrangement. (3) By this experimental data, flow resistance correlations for thermalhydrauric analysis code are obtained. (author)

  2. LOFT ECC Pitot Tube and Thermocouple Rake Penetration thermal analysis

    International Nuclear Information System (INIS)

    Tolan, B.J.

    1977-01-01

    A thermal analysis of the LOFT ECC Pitot Tube and Thermocouple Rake Penetration was performed using COUPLE, a two-dimensional finite element computer code. Four transients which conservatively cover all transients the rake will be exposed to were included in this analysis in order to comply with the ASME Code Section III requirements. The transients conservatively cover hot and cold leg operation, and nuclear and nonnuclear operation. The four transients include the LOCE with ECC injection transient, the single control rod drop transient, the scram transient, and the heatup with 0 to 100% load change transient. Temperature distributions in the rake were obtained for each of the four transients and several plots of node temperatures vs. time are given

  3. Thermal stress analysis of the fuel storage facility

    International Nuclear Information System (INIS)

    Chen, W.W.

    1991-12-01

    This paper presents the results of a nonlinear finite-element analysis to determine the structural integrity of the walls of the nuclear fuel storage room in the Radio Isotope Power System Facility of the Fuels and Materials Examination Facility (FMEF) Project. The analysis was performed to assess the effects of thermal loading on the walls that would result from a loss-of-cooling accident. The results obtained from using the same three-dimensional finite-element model with different types of elements, the eight-node brick element and the nonlinear concrete element, and the calculated results using the analytical solutions, are compared. The concrete responses in terms of octahedral normal and shearing stresses are described. The crack and crush states of the concrete were determined on the basis of multiaxial failure criteria

  4. Thermal hydraulic analysis of the encapsulated nuclear heat source

    Energy Technology Data Exchange (ETDEWEB)

    Sienicki, J.J.; Wade, D.C. [Argonne National Lab., IL (United States)

    2001-07-01

    An analysis has been carried out of the steady state thermal hydraulic performance of the Encapsulated Nuclear Heat Source (ENHS) 125 MWt, heavy liquid metal coolant (HLMC) reactor concept at nominal operating power and shutdown decay heat levels. The analysis includes the development and application of correlation-type analytical solutions based upon first principles modeling of the ENHS concept that encompass both pure as well as gas injection augmented natural circulation conditions, and primary-to-intermediate coolant heat transfer. The results indicate that natural circulation of the primary coolant is effective in removing heat from the core and transferring it to the intermediate coolant without the attainment of excessive coolant temperatures. (authors)

  5. Validation of the TEXSAN thermal-hydraulic analysis program

    International Nuclear Information System (INIS)

    Burns, S.P.; Klein, D.E.

    1992-01-01

    The TEXSAN thermal-hydraulic analysis program has been developed by the University of Texas at Austin (UT) to simulate buoyancy driven fluid flow and heat transfer in spent fuel and high level nuclear waste (HLW) shipping applications. As part of the TEXSAN software quality assurance program, the software has been subjected to a series of test cases intended to validate its capabilities. The validation tests include many physical phenomena which arise in spent fuel and HLW shipping applications. This paper describes some of the principal results of the TEXSAN validation tests and compares them to solutions available in the open literature. The TEXSAN validation effort has shown that the TEXSAN program is stable and consistent under a range of operating conditions and provides accuracy comparable with other heat transfer programs and evaluation techniques. The modeling capabilities and the interactive user interface employed by the TEXSAN program should make it a useful tool in HLW transportation analysis

  6. PDASAC, Partial Differential Sensitivity Analysis of Stiff System

    International Nuclear Information System (INIS)

    Caracotsios, M.; Stewart, W.E.

    2001-01-01

    1 - Description of program or function: PDASAC solves stiff, nonlinear initial-boundary-value problems in a timelike dimension t and a space dimension x. Plane, circular cylindrical or spherical boundaries can be handled. Mixed-order systems of partial differential and algebraic equations can be analyzed with members of order or 0 or 1 in t, 0, 1 or 2 in x. Parametric sensitivities of the calculated states are computed simultaneously on request, via the Jacobian of the state equations. Initial and boundary conditions are efficiently reconciled. Local error control (in the max-norm or the 2-norm) is provided for the state vector and can include the parametric sensitivities if desired. 2 - Method of solution: The method of lines is used, with a user- selected x-grid and a minimum-bandwidth finite-difference approximations of the x-derivatives. Starting conditions are reconciled with a damped Newton algorithm adapted from Bain and Stewart (1991). Initial step selection is done by the first-order algorithms of Shampine (1987), extended here to differential- algebraic equation systems. The solution is continued with the DASSL predictor-corrector algorithm (Petzold 1983, Brenan et al. 1989) with the initial acceleration phase deleted and with row scaling of the Jacobian added. The predictor and corrector are expressed in divided-difference form, with the fixed-leading-coefficient form of corrector (Jackson and Sacks-Davis 1989; Brenan et al. 1989). Weights for the error tests are updated in each step with the user's tolerances at the predicted state. Sensitivity analysis is performed directly on the corrector equations of Caracotsios and Stewart (1985) and is extended here to the initialization when needed. 3 - Restrictions on the complexity of the problem: This algorithm, like DASSL, performs well on differential-algebraic equation systems of index 0 and 1 but not on higher-index systems; see Brenan et al. (1989). The user assigned the work array lengths and the output

  7. Thermal hydraulic analysis of the JMTR improved LEU-core

    Energy Technology Data Exchange (ETDEWEB)

    Tabata, Toshio; Nagao, Yoshiharu; Komukai, Bunsaku; Naka, Michihiro; Fujiki, Kazuo [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Takeda, Takashi [Radioactive Waste Management and Nuclear Facility Decommissioning Technology Center, Tokai, Ibaraki (Japan)

    2003-01-01

    After the investigation of the new core arrangement for the JMTR reactor in order to enhance the fuel burn-up and consequently extend the operation period, the ''improved LEU core'' that utilized 2 additional fuel elements instead of formerly installed reflector elements, was adopted. This report describes the results of the thermal-hydraulic analysis of the improved LEU core as a part of safety analysis for the licensing. The analysis covers steady state, abnormal operational transients and accidents, which were described in the annexes of the licensing documents as design bases events. Calculation conditions for the computer codes were conservatively determined based on the neutronic analysis results and others. The results of the analysis, that revealed the safety criteria were satisfied on the fuel temperature, DNBR and primary coolant temperature, were used in the licensing. The operation license of the JMTR with the improved LEU core was granted in March 2001, and the reactor operation with new core started in November 2001 as 142nd operation cycle. (author)

  8. Phase Equilibria in the Bi-In-Sn-Zn System. Thermal Analysis vs. Calculations

    Directory of Open Access Journals (Sweden)

    Dębski A.

    2017-12-01

    Full Text Available With the use of the differential thermal analysis (DTA, studies of the phase transitions were conducted for 90 of alloys from the quaternary Bi-In-Sn-Zn system and for the constant ratio of Bi:In and Bi:Sn. The studies were conducted for the alloys prepared from the purity metals (Bi, In, Sn, Zn = 99.999 mas. % by way of melting in a graphite crucible in a glove-box filled with Ar, in which the impurities level was less than 0.1 ppm. After melting and thorough mixing, the liquid alloys were poured out into a graphite test mold. The phase transition temperature data obtained from the DTA investigations were next confronted with those determined from the calculations based on the binary and ternary optimized thermodynamic parameters available in the literature. It was found that the experimental and the calculated phase transition temperatures were in good agreement.

  9. Using thermal analysis techniques for identifying the flash point temperatures of some lubricant and base oils

    Directory of Open Access Journals (Sweden)

    Aksam Abdelkhalik

    2018-03-01

    Full Text Available The flash point (FP temperatures of some lubricant and base oils were measured according to ASTM D92 and ASTM D93. In addition, the thermal stability of the oils was studied using differential scanning calorimeter (DSC and thermogravimetric analysis (TGA under nitrogen atmosphere. The DSC results showed that the FP temperatures, for each oil, were found during the first decomposition step and the temperature at the peak of the first decomposition step was usually higher than FP temperatures. The TGA results indicated that the temperature at which 17.5% weigh loss take placed (T17.5% was nearly identical with the FP temperature (±10 °C that was measured according to ASTM D92. The deviation percentage between FP and T17.5% was in the range from −0.8% to 3.6%. Keywords: Flash point, TGA, DSC

  10. PDE Modeling of a Microfluidic Thermal Process for Genetic Analysis Application

    Directory of Open Access Journals (Sweden)

    Reza Banaei Khosroushahi

    2013-01-01

    Full Text Available This paper details the infinite dimensional dynamics of a prototype microfluidic thermal process that is used for genetic analysis purposes. Highly effective infinite dimensional dynamics, in addition to collocated sensor and actuator architecture, require the development of a precise control framework to meet the very tight performance requirements of this system, which are not fully attainable through conventional lumped modeling and controller design approaches. The general partial differential equations describing the dynamics of the system are separated into steady-state and transient parts which are derived for a carefully chosen three-dimensional axisymmetric model. These equations are solved analytically, and the results are verified using an experimentally verified precise finite element method (FEM model. The final combined result is a framework for designing a precise tracking controller applicable to the selected lab-on-a-chip device.

  11. Polymeric thermal analysis of C + H and C + H + Ar ion implanted UHMWPE samples

    International Nuclear Information System (INIS)

    Kaya, N.; Oztarhan, Ahmet M.; Urkac, E.S.; Ila, D.; Budak, S.; Oks, E.; Nikolaev, A.; Ezdesir, A.; Tihminlioglu, F.; Tek, Z.; Cetiner, S.; Muntele, C.

    2007-01-01

    Chemical surface characterization of C + H hybrid ion implanted UHMWPE samples were carried out using DSC (differential scanning calorimeter) and TGA (thermal gravimetric analysis) techniques. Samples were implanted with a fluence of 10 17 ion/cm 2 and an extraction voltage of 30 kV. The study of TGA and DSC curves showed that: (1) Polymeric decomposition temperature increased (2) T m , ΔC p and ΔH m values changed while ΔC p and ΔH m increased. T g value could not be measured, because of some experimental limitations. However, the increase in ΔH m values showed that T g values increased (3) the branch density which indicated the increase in number of cross-link (M c ) decreased in ion implanted samples and (4) increase in ΔH m values indicated increase in crystallinity of implanted surface of UHMWPE samples

  12. An algorithm for nonlinear thermal analysis of fuel bearing pads

    International Nuclear Information System (INIS)

    Attia, M.H.; D'Silva, N.

    1983-01-01

    An algorithm has been developed for accurate prediction of the temperature field in a CANDU fuel bearing pad and the extent of the nucleate boiling in the crevice region. The methodology recognizes the nonlinear nature of the problem due to the fact that local boiling is both controlling and being controlled by the conditions of heat transfer at the boundaries. The finite difference model accounts for the volumetric effect of the thermal contact resistance at the bearing pad/pressure tube interface. It also allows the evaluation of the thermal barrier effect caused by applying an oxide film on the radiused surface of the bearing pad. Information pertaining to the distribution of the coefficient of heat transfer over water-cooled surfaces has been generated. Analysis of the results indicated the significance of considering the nonlinear behaviour of the system in determining its state of equilibrium. It also indicated that, depending on the thickness of the oxide layer and the position of the bearing pad along the core of the reactor, the nucleate boiling process can be prevented

  13. ANALYSIS OF THERMAL-CHEMICAL CHARACTERISTICS OF BIOMASS ENERGY PELLETS

    Directory of Open Access Journals (Sweden)

    Zorica Gluvakov

    2014-09-01

    Full Text Available In modern life conditions, when emphasis is on environmental protection and sustainable development, fuels produced from biomass are increasingly gaining in importance, and it is necessary to consider the quality of end products obtained from biomass. Based on the existing European standards, collected literature and existing laboratory methods, this paper presents results of testing individual thermal - chemical properties of biomass energy pellets after extrusion and cooling the compressed material. Analysing samples based on standard methods, data were obtained on the basis of which individual thermal-chemical properties of pellets were estimated. Comparing the obtained results with the standards and literature sources, it can be said that moisture content, ash content and calorific values are the most important parameters for quality analysis which decide on applicability and use-value of biomass energy pellets, as biofuel. This paper also shows the impact of biofuels on the quality of environmental protection. The conclusion provides a clear statement of quality of biomass energy pellets.

  14. Challenges in thermal and hydraulic analysis of ADS target systems

    International Nuclear Information System (INIS)

    Groetzbach, G.; Batta, A.; Lefhalm, C.-H.; Otic, I.

    2004-01-01

    The liquid metal cooled spallation targets of Accelerator Driven nuclear reactor Systems obey high thermal loads; in addition some flow and cooling conditions are of a prototypical character; in contrast the operating conditions for the engaged materials are narrow; thus, the target development requires a very careful analysis by experimental and numerical means. Especially the cooling of the steel window, which is heated by the proton beam, needs special care. Some of the main goals of the experimental and numerical analyses of the thermal dynamics of those systems are discusses. The prediction of locally detached flows and of flows with larger recirculation areas suffers from insufficient turbulence modeling; this has to be compensated by using prototypical model experiments, e.g. with water, to select the adequate models and numerical schemes. The well known problems with the Reynolds analogy in predicting the heat transfer in liquid metals requires always prototypic liquid metal experiments to select and adapt the turbulent heat flux models. The uncertainties in liquid metal experiments cannot be neglected; so it is necessary to perform CFD calculations and experiments always hand in hand and to develop improve turbulent heat flux models. One contribution to an improved 3 or 4-equation model is deduced from recent Direct Numerical Simulation (DNS) data. (author)

  15. Thermal hydraulics analysis of LIBRA-SP target chamber

    International Nuclear Information System (INIS)

    Mogahed, E.A.

    1996-01-01

    LIBRA-SP is a conceptual design study of an inertially confined 1000 MWe fusion power reactor utilizing self-pinched light ion beams. There are 24 ion beams which are arranged around the reactor cavity. The reaction chamber is an upright cylinder with an inverted conical roof resembling a mushroom, and a pool floor. The vertical sides of the cylinder are occupied by a blanket zone consisting of many perforated rigid HT-9 ferritic steel tubes called PERITs (PEr-forated RIgid Tube). The breeding/cooling material, liquid lead-lithium, flows through the PERITs, providing protection to the reflector/vacuum chamber so as to make it a lifetime component. The neutronics analysis and cavity hydrodynamics calculations are performed to account for the neutron heating and also to determine the effects of vaporization/condensation processes on the surface heat flux. The steady state nuclear heating distribution at the midplane is used for thermal hydraulics calculations. The maximum surface temperature of the HT-9 is chosen to not exceed 625 degree C to avoid drastic deterioration of the metal's mechanical properties. This choice restricts the thermal hydraulics performance of the reaction cavity. The inlet first surface coolant bulk temperature is 370 degree C, and the heat exchanger inlet coolant bulk temperature is 502 degree C. 4 refs., 6 figs., 2 tabs

  16. Thermal analysis on x-ray tube for exhaust process

    Science.gov (United States)

    Kumar, Rakesh; Rao Ratnala, Srinivas; Veeresh Kumar, G. B.; Shivakumar Gouda, P. S.

    2018-02-01

    It is great importance in the use of X-rays for medical purposes that the dose given to both the patient and the operator is carefully controlled. There are many types of the X- ray tubes used for different applications based on their capacity and power supplied. In present thesis maxi ray 165 tube is analysed for thermal exhaust processes with ±5% accuracy. Exhaust process is usually done to remove all the air particles and to degasify the insert under high vacuum at 2e-05Torr. The tube glass is made up of Pyrex material, 95%Tungsten and 5%rhenium is used as target material for which the melting point temperature is 3350°C. Various materials are used for various parts; during the operation of X- ray tube these waste gases are released due to high temperature which in turn disturbs the flow of electrons. Thus, before using the X-ray tube for practical applications it has to undergo exhaust processes. Initially we build MX 165 model to carry out thermal analysis, and then we simulate the bearing temperature profiles with FE model to match with test results with ±5%accuracy. At last implement the critical protocols required for manufacturing processes like MF Heating, E-beam, Seasoning and FT.

  17. FFTF vertical sodium storage tank preliminary thermal analysis

    International Nuclear Information System (INIS)

    Irwin, J.J.

    1995-01-01

    In the FFTF Shutdown Program, sodium from the primary and secondary heat transport loops, Interim Decay Storage (IDS), and Fuel Storage Facility (FSF) will be transferred to four large storage tanks for temporary storage. Three of the storage tanks will be cylindrical vertical tanks having a diameter of 28 feet, height of 22 feet and fabricated from carbon steel. The fourth tank is a horizontal cylindrical tank but is not the subject of this report. The storage tanks will be located near the FFTF in the 400 Area and rest on a steel-lined concrete slab in an enclosed building. The purpose of this work is to document the thermal analyses that were performed to ensure that the vertical FFTF sodium storage tank design is feasible from a thermal standpoint. The key criterion for this analysis is the time to heat up the storage tank containing frozen sodium at ambient temperature to 400 F. Normal operating conditions include an ambient temperature range of 32 F to 120 F. A key parameter in the evaluation of the sodium storage tank is the type of insulation. The baseline case assumed six inches of calcium silicate insulation. An alternate case assumed refractory fiber (Cerablanket) insulation also with a thickness of six inches. Both cases assumed a total electrical trace heat load of 60 kW, with 24 kW evenly distributed on the bottom head and 36 kW evenly distributed on the tank side wall

  18. Thermal Hydraulic Analysis of RPV Support Cooling System for HTGR

    International Nuclear Information System (INIS)

    Min Qi; Wu Xinxin; Li Xiaowei; Zhang Li; He Shuyan

    2014-01-01

    Passive safety is now of great interest for future generation reactors because of its reduction of human interaction and avoidance of failures of active components. reactor pressure vessel (RPV) support cooling system (SCS) for high temperature gas-cooled reactor (HTGR) is a passive safety system and is used to cool the concrete seats for the four RPV supports at its bottom. The SCS should have enough cooling capacity to ensure the temperature of the concrete seats for the supports not exceeding the limit temperature. The SCS system is composed of a natural circulation water loop and an air cooling tower. In the water loop, there is a heat exchanger embedded in the concrete seat, heat is transferred by thermal conduction and convection to the cooling water. Then the water is cooled by the air cooler mounted in the air cooling tower. The driving forces for water and air are offered by the density differences caused by the temperature differences. In this paper, the thermal hydraulic analysis for this system was presented. Methods for decoupling the natural circulation and heat transfer between the water loop and air flow were introduced. The operating parameters for different working conditions and environment temperatures were calculated. (author)

  19. Space Shuttle Communications Coverage Analysis for Thermal Tile Inspection

    Science.gov (United States)

    Kroll, Quin D.; Hwu, Shian U.; Upanavage, Matthew; Boster, John P.; Chavez, Mark A.

    2009-01-01

    The space shuttle ultra-high frequency Space-to-Space Communication System has to provide adequate communication coverage for astronauts who are performing thermal tile inspection and repair on the underside of the space shuttle orbiter (SSO). Careful planning and quantitative assessment are necessary to ensure successful system operations and mission safety in this work environment. This study assesses communication systems performance for astronauts who are working in the underside, non-line-of-sight shadow region on the space shuttle. All of the space shuttle and International Space Station (ISS) transmitting antennas are blocked by the SSO structure. To ensure communication coverage at planned inspection worksites, the signal strength and link margin between the SSO/ISS antennas and the extravehicular activity astronauts, whose line-of-sight is blocked by vehicle structure, was analyzed. Investigations were performed using rigorous computational electromagnetic modeling techniques. Signal strength was obtained by computing the reflected and diffracted fields along the signal propagation paths between transmitting and receiving antennas. Radio frequency (RF) coverage was determined for thermal tile inspection and repair missions using the results of this computation. Analysis results from this paper are important in formulating the limits on reliable communication range and RF coverage at planned underside inspection and repair worksites.

  20. Characterization and thermal stability of uranium peroxides by thermogravimetry and differential scanning calorimetry

    International Nuclear Information System (INIS)

    Souza Junior, P.T. de; Abrao, A.

    1982-01-01

    The characterization and thermal behaviour of uranium peroxide samples prepared by precipitation with hydrogen peroxide from uranyl nitrate solution is described. The latter was obtained by dissolution of ammonium diuranate and ammonium uranyl tricarbonate. TG and DTG curves were recorded in the temperature range from room temperature to 700 0 C. DSC curves were recorded from room temperature to 600 0 C. The heating rate was 5 0 C/min. Based upon the DTG curves of a great number of samples, the uranium peroxides were classified in five groups. The collected information was used to recognise the temperature at which the peroxide decomposes and to know its sequential conversion to UO 3 and U 3 O 8 , the evolution of molecules of water of crystallization and absorption, and the elimination of occluded nitrate ions. The results allowed to conclude that no NH + 4 nor H 2 O 2 molecules were occluded by uranium peroxide. The stoichiometric composition of representative samples for the five groups is indicated. (Author) [pt

  1. Differential responses of the coral host and their algal symbiont to thermal stress.

    Directory of Open Access Journals (Sweden)

    William Leggat

    Full Text Available The success of any symbiosis under stress conditions is dependent upon the responses of both partners to that stress. The coral symbiosis is particularly susceptible to small increases of temperature above the long term summer maxima, which leads to the phenomenon known as coral bleaching, where the intracellular dinoflagellate symbionts are expelled. Here we for the first time used quantitative PCR to simultaneously examine the gene expression response of orthologs of the coral Acropora aspera and their dinoflagellate symbiont Symbiodinium. During an experimental bleaching event significant up-regulation of genes involved in stress response (HSP90 and HSP70 and carbon metabolism (glyceraldehyde-3-phosphate dehydrogenase, α-ketoglutarate dehydrogenase, glycogen synthase and glycogen phosphorylase from the coral host were observed. In contrast in the symbiont, HSP90 expression decreased, while HSP70 levels were increased on only one day, and only the α-ketoglutarate dehydrogenase expression levels were found to increase. In addition the changes seen in expression patterns of the coral host were much larger, up to 10.5 fold, compared to the symbiont response, which in all cases was less than 2-fold. This targeted study of the expression of key metabolic and stress genes demonstrates that the response of the coral and their symbiont vary significantly, also a response in the host transcriptome was observed prior to what has previously been thought to be the temperatures at which thermal stress events occur.

  2. Rice starch granule amylolysis--differentiating effects of particle size, morphology, thermal properties and crystalline polymorph.

    Science.gov (United States)

    Dhital, Sushil; Butardo, Vito M; Jobling, Stephen A; Gidley, Michael J

    2015-01-22

    The underlying mechanism of amylolysis of rice starch granules was investigated using isolated starch granules from wild-type, as well as SBEIIb mutant and down-regulated lines. Fused granule agglomerates isolated from mutant and transgenic lines were hydrolysed at similar rates by amylases, and had similar crystalline patterns and thermal properties as individual granules. Surface pores, a feature previously only reported for A-polymorphic starch granules, were also observed in B- and C-polymorphic rice starch granules. Although the microscopic patterns of hydrolysis among granules with different crystalline polymorphs were qualitatively similar, the extent and the rate of amylolysis were different, suggesting that B-type crystalline polymorphs are intrinsically more resistant to enzymatic hydrolysis than A-type in rice starch granules. It is proposed that the slightly longer branch lengths of amylopectin which leads to the formation of more stable B-type double helical structures compared to their A-type counterparts is the major parameter, with other factors such as granule size, surface pores and interior channels having secondary roles, in determining the rate of enzymatic hydrolysis of rice starch granules. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Analysis of carbon based materials under fusion relevant thermal loads

    International Nuclear Information System (INIS)

    Compan, Jeremie Saint-Helene

    2008-01-01

    how anisotropy can be tailored and on the strategies which were applied for the production of the investigated materials. Textures of fibers and microstructures of matrices were also described. Thermo-physical properties such as thermal conductivity and thermal expansion of some CFCs were studied for different materials' orientations. For the first time, some off-axis results of thermal conductivity and thermal expansion for fusion related CFCs are displayed. Room temperature bending and tensile loading of CFCs were performed and they allowed relating the microstructural findings to the anisotropic mechanical response. Fiber architecture of CFCs and interfacial shear strength between the fiber and the matrix appeared to be the main parameters which dictate the fracture mechanisms. In addition, the analysis of five batches of one CFC permitted to understand the difficulty of reproducing such advanced material. The differences in terms of needling process were related to the variations of the tensile properties in the various fibrous directions. Finally, fusion-relevant transient heat loads were simulated on the investigated CBMs within various high heat flux facilities, i.e. electron beam, ion beam and plasma gun. Erosion scenarios at different scales were compiled in relation to the CBM properties but also the type of the transient event. The locally preferential erosion and ejection of material from the surface of the CBM are comprehensively described as well as their implications. This ejection of hot particles from the CBM surface (so-called Brittle Destruction (BD) mechanism) was defined, explained and analyzed. An experimental thermal shock resistance criterion based on thermal-shock induced weight loss is presented. After analyzing the anisotropic response of CFCs to transient heat loads in their three orthotropic fiber directions, attempts to reduce BD were done by loading them under off-axis orientations. It partly succeeded and led to the observation of

  4. Assessment of RANS CFD modelling for pressurised thermal shock analysis

    International Nuclear Information System (INIS)

    Sander M Willemsen; Ed MJ Komen; Sander Willemsen

    2005-01-01

    in the cold leg and downcomer. The initial computations were performed using the commonly used porous medium representation for the core and omission of the lower plenum internals. These assumption, however, lead to unrealistic circumferential flow oscillations in the downcomer, and consequently, a wrong prediction of the thermal load on the RPV wall. Therefore, a detailed geometrical model with a refined numerical mesh was used, which suppressed these erroneous oscillations. Furthermore, it was confirmed that an extended k-ε or SST k-ω turbulence model which include turbulence production/destruction terms due to buoyancy has to be used in order to correctly predict the thermal stratification in the cold leg. The measurements in the downcomer show rapidly fluctuating signals, which indicate vigorous turbulent mixing and/or oscillations. It was found that reasonable agreement could be achieved with RANS type turbulence modelling for the prediction of the phenomena occurring in the downcomer. Improvement of these results can be expected from non-statistically averaged turbulent modelling like Large Eddy Simulations. It is concluded that the current RANS models already provide a significant improvement over thermal-hydraulic system code analysis, since three-dimensional effects are predicted and no tuning of the code to expensive experiments is needed. (authors)

  5. Thermal behaviour analysis of SRF cavities and superconducting HOM couplers

    International Nuclear Information System (INIS)

    Fouaidy, M.; Junquera, T.

    1993-01-01

    Two individual papers appear in this report, titled Thermal model calculations in superconducting RF cavities, and Thermal study of HOM couplers for superconducting RF cavities. Both were indexed separately for the INIS database. (R.P.)

  6. Orbital maneuvering vehicle thermal design and analysis techniques

    Science.gov (United States)

    Chapter, J.

    1986-01-01

    This paper describes the OMV thermal design that is required to maintain components within temperature limits for all mission phases. A key element in the OMV thermal design is the application of a motorized thermal shade assembly that is a replacement for the more conventional variable conductance heat pipes or louvers. The thermal shade assembly covers equipment module radiator areas, and based upon the radiator temperature input to onboard computer, opens and closes the shade, varying the effective radiator area. Thermal design verification thermal analyses results are presented. Selected thermal analyses methods, including several unique subroutines, are discussed. A representation of enclosure Script F equations, in matrix form, is also included. Personal computer application to the development of the OMV thermal design is summarized.

  7. Finite element analysis of thermal stress distribution in different ...

    African Journals Online (AJOL)

    Nigerian Journal of Clinical Practice. Journal Home ... Von Mises and thermal stress distributions were evaluated. Results: In all ... distribution. Key words: Amalgam, finite element method, glass ionomer cement, resin composite, thermal stress ...

  8. Heat transfer and thermal stress analysis in grooved tubes

    Indian Academy of Sciences (India)

    ANSYS (1997) computer code has been used to analyse the thermal ... The numerical method is used succesfully to solve the governing equations ... thermal stress is an important criterion for consideration in the design of new compact heat.

  9. Stability analysis of solutions to nonlinear stiff Volterra functional differential equations in Banach spaces

    Institute of Scientific and Technical Information of China (English)

    LI Shoufu

    2005-01-01

    A series of stability, contractivity and asymptotic stability results of the solutions to nonlinear stiff Volterra functional differential equations (VFDEs) in Banach spaces is obtained, which provides the unified theoretical foundation for the stability analysis of solutions to nonlinear stiff problems in ordinary differential equations(ODEs), delay differential equations(DDEs), integro-differential equations(IDEs) and VFDEs of other type which appear in practice.

  10. Nonlinear thermal reduced model for Microwave Circuit Analysis

    OpenAIRE

    Chang, Christophe; Sommet, Raphael; Quéré, Raymond; Dueme, Ph.

    2004-01-01

    With the constant increase of transistor power density, electro thermal modeling is becoming a necessity for accurate prediction of device electrical performances. For this reason, this paper deals with a methodology to obtain a precise nonlinear thermal model based on Model Order Reduction of a three dimensional thermal Finite Element (FE) description. This reduced thermal model is based on the Ritz vector approach which ensure the steady state solution in every case. An equi...

  11. Analysis of Caputo Impulsive Fractional Order Differential Equations with Applications

    Directory of Open Access Journals (Sweden)

    Lakshman Mahto

    2013-01-01

    Full Text Available We use Sadovskii's fixed point method to investigate the existence and uniqueness of solutions of Caputo impulsive fractional differential equations of order with one example of impulsive logistic model and few other examples as well. We also discuss Caputo impulsive fractional differential equations with finite delay. The results proven are new and compliment the existing one.

  12. Multivariate analysis of regional differentials of nuptiality in Bangladesh.

    Science.gov (United States)

    Chowdhury, A A; Islam, M A

    1981-01-01

    The importance of socioeconomics differentials in nuptiality has occupied a very important position in recent demographic research. An effort has been made in this paper to find out the nature and extent of the causal relationship between the dependent variable--nuptiality, and its determinants. Our findings suggest that education may play a vital role in raising mean age at marriage. This may be done by extending free and compulsory mass and primary education throughout the country. It has further been observed that urbanization through economic development is a precondition to increase the literacy rate and hence female labor force participation in the country's economy. Thus proper education will increase the female employment rate which in turn will raise the age at marriage. Equal distribution of population and insurance schemes for childless couples may also indirectly put a positive effect on nuptiality. Finally, this paper provides a guideline for using the path analysis technique in determining the factors causing the changes and the effects of these factors on nuptiality in Bangladesh. However, caution should be made in taking into account the causal ordering of the indices. Different ordering may give different results.

  13. Differential expression analysis for RNAseq using Poisson mixed models.

    Science.gov (United States)

    Sun, Shiquan; Hood, Michelle; Scott, Laura; Peng, Qinke; Mukherjee, Sayan; Tung, Jenny; Zhou, Xiang

    2017-06-20

    Identifying differentially expressed (DE) genes from RNA sequencing (RNAseq) studies is among the most common analyses in genomics. However, RNAseq DE analysis presents several statistical and computational challenges, including over-dispersed read counts and, in some settings, sample non-independence. Previous count-based methods rely on simple hierarchical Poisson models (e.g. negative binomial) to model independent over-dispersion, but do not account for sample non-independence due to relatedness, population structure and/or hidden confounders. Here, we present a Poisson mixed model with two random effects terms that account for both independent over-dispersion and sample non-independence. We also develop a scalable sampling-based inference algorithm using a latent variable representation of the Poisson distribution. With simulations, we show that our method properly controls for type I error and is generally more powerful than other widely used approaches, except in small samples (n <15) with other unfavorable properties (e.g. small effect sizes). We also apply our method to three real datasets that contain related individuals, population stratification or hidden confounders. Our results show that our method increases power in all three data compared to other approaches, though the power gain is smallest in the smallest sample (n = 6). Our method is implemented in MACAU, freely available at www.xzlab.org/software.html. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  14. Differential network analysis reveals genetic effects on catalepsy modules.

    Directory of Open Access Journals (Sweden)

    Ovidiu D Iancu

    Full Text Available We performed short-term bi-directional selective breeding for haloperidol-induced catalepsy, starting from three mouse populations of increasingly complex genetic structure: an F2 intercross, a heterogeneous stock (HS formed by crossing four inbred strains (HS4 and a heterogeneous stock (HS-CC formed from the inbred strain founders of the Collaborative Cross (CC. All three selections were successful, with large differences in haloperidol response emerging within three generations. Using a custom differential network analysis procedure, we found that gene coexpression patterns changed significantly; importantly, a number of these changes were concordant across genetic backgrounds. In contrast, absolute gene-expression changes were modest and not concordant across genetic backgrounds, in spite of the large and similar phenotypic differences. By inferring strain contributions from the parental lines, we are able to identify significant differences in allelic content between the selected lines concurrent with large changes in transcript connectivity. Importantly, this observation implies that genetic polymorphisms can affect transcript and module connectivity without large changes in absolute expression levels. We conclude that, in this case, selective breeding acts at the subnetwork level, with the same modules but not the same transcripts affected across the three selections.

  15. Differential Transcriptome Analysis between Paulownia fortunei and Its Synthesized Autopolyploid

    Directory of Open Access Journals (Sweden)

    Xiaoshen Zhang

    2014-03-01

    Full Text Available Paulownia fortunei is an ecologically and economically important tree species that is widely used as timber and chemical pulp. Its autotetraploid, which carries a number of valuable traits, was successfully induced with colchicine. To identify differences in gene expression between P. fortunei and its synthesized autotetraploid, we performed transcriptome sequencing using an Illumina Genome Analyzer IIx (GAIIx. About 94.8 million reads were generated and assembled into 383,056 transcripts, including 18,984 transcripts with a complete open reading frame. A conducted Basic Local Alignment Search Tool (BLAST search indicated that 16,004 complete transcripts had significant hits in the National Center for Biotechnology Information (NCBI non-redundant database. The complete transcripts were given functional assignments using three public protein databases. One thousand one hundred fifty eight differentially expressed complete transcripts were screened through a digital abundance analysis, including transcripts involved in energy metabolism and epigenetic regulation. Finally, the expression levels of several transcripts were confirmed by quantitative real-time PCR. Our results suggested that polyploidization caused epigenetic-related changes, which subsequently resulted in gene expression variation between diploid and autotetraploid P. fortunei. This might be the main mechanism affected by the polyploidization. Our results represent an extensive survey of the P. fortunei transcriptome and will facilitate subsequent functional genomics research in P. fortunei. Moreover, the gene expression profiles of P. fortunei and its autopolyploid will provide a valuable resource for the study of polyploidization.

  16. Isotopic analysis of boron by thermal ionization mass spectrometry

    International Nuclear Information System (INIS)

    Kakazu, M.H.; Sarkis, J.E.S.; Souza, I.M.S.

    1991-07-01

    This paper presents a methodology for isotopic analysis of boron by thermal ionization mass spectrometry technique through the ion intensity measurement of Na 2 BO + 2 in H 3 BO 3 , B o and B 4 C. The samples were loaded on single tantalum filaments by different methods. In the case of H 3 BO 3 , the method of neutralization with NaOH was used. For B 4 C the alcaline fusion with Na 2 CO 3 and for B o dissolution with 1:1 nitric sulfuric acid mixture followed by neutralization with NaOH was used. The isotopic ratio measurements were obtained by the use of s Faraday cup detector with external precision of ±0,4% and accuracy of ±0,1%, relative to H 3 BO 3 isotopic standard NBS 951. The effects of isotopic fractionation was studied in function of the time during the analyses and the different chemical forms of deposition. (author)

  17. Thermal dynamic analysis of sulfur removal from coal by electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.; Gao, J.; Meng, F. [Qinghua University, Beijing (China). Dept. of Thermal Engineering

    2002-06-01

    The electrolytic reactions about sulfur removal from coal were studied by using chemical thermal dynamic analysis. According to the thermodynamical data, the Gibbs free energy value of the electrolytic reactions of pyritic and organic sulfur removal from coal is higher than zero. So, these electrolytic reactions are not spontaneous chemical reactions. In order to carry out desulfurisation by electrolysis, a certain voltage is necessary and important. Because theoretic decomposition voltage of pyrite and some parts of organic sulfur model compound is not very high, electrolysis reactions are easily to be carried out by using electrolysis technology. Mn ion and Fe ion are added into electrolysis solutions to accelerate the desulfurisation reaction. The electrolytic decomposition of coal is discussed. Because the theoretical decomposition voltage of some organic model compound is not high, the coal decomposition might happen. 17 refs., 4 tabs.

  18. The analysis of thermal stability of detonation nanodiamond

    International Nuclear Information System (INIS)

    Efremov, V P; Zakatilova, E I

    2016-01-01

    The detonation nanodiamond is a new perspective material. Ammunition recycling with use of high explosives and obtaining nanodiamond as the result of the detonation synthesis have given a new motivation for searching of their application areas. In this work nanodiamond powder has been investigated by the method of synchronous thermal analysis. Experiments have been carried out at atmospheric pressure in the environment of argon. Nanodiamond powder has been heated in the closed corundum crucible at the temperature range of 30-1500 °C. The heating rates were varied from 2 K/min to 20 K/min. After the heat treatment, the samples have been studied by the x-ray diffraction and the electron microscopy. As one of the results of this work, it has been found that the detonation nanodiamond has not started the transition into graphite at the temperature below 800 °C. (paper)

  19. Thermal analysis of gyrotron traveling-wave tube collector

    International Nuclear Information System (INIS)

    Zheng Zhiqing; Luo Yong; Jiang Wei; Tang Yong

    2013-01-01

    In order to solve cooling problem of the gyrotron traveling-wave tube(TWT) collector and guarantee the gyrotron TWT's reliability and stability, the electron trajectories in the gyrotron TWT are simulated using CST electron simulation software. Thermal analysis of the collector with finite element software ANSYS is performed. The ways of applying boundary that affects the distribution of collector temperature are compared. The influence of the water temperature and flow rate on collector temperature distribution under actual heat fluxes (boundary condition) is researched. The size and number of collector fins are optimized, and a relatively perfect structure is obtained finally. The result estimated by simulation is consistent with the experiment and proves that the model and method employed in this work are suitable. (authors)

  20. TAPIR, Thermal Analysis of HTGR with Graphite Sleeve Fuel Elements

    International Nuclear Information System (INIS)

    Weicht, U.; Mueller, W.

    1983-01-01

    1 - Nature of the physical problem solved: Thermal analysis of a reactor core containing internally and/or externally gas cooled prismatic fuel elements of various geometries, rating, power distribution, and material properties. 2 - Method of solution: A fuel element in this programme is regarded as a sector of a fuelled annulus with graphite sleeves of any shape on either side and optional annular gaps between fuel and graphite and/or within the graphite. It may have any centre angle and the fuelled annulus may become a solid cylindrical rod. Heat generation in the fuel is assumed to be uniform over the cross section and peripheral heat flux into adjacent sectors is ignored. Fuel elements and coolant channels are treated separately, then linked together to fit a specified pattern. 3 - Restrictions on the complexity of the problem: Maxima of: 50 fuel elements; 50 cooled channels; 25 fuel geometries; 25 coolant channel geometries; 10 axial power distributions; 10 graphite conductivities

  1. Analysis of thermal systems using the entropy balance method

    Energy Technology Data Exchange (ETDEWEB)

    Huang, C L.D.; Fartaj, S A; Fenton, D L [Kansas State Univ., Manhattan, KS (United States). Dept. of Mechanical Engineering

    1992-04-01

    This study investigates the applicability of the second law of thermodynamics using an entropy balance method to analyse and design thermal systems. As examples, the entropy balance method is used to analyse a single stage chiller system and a single stage heat transformer, both with lithium-bromide/water as the working fluid. The entropy method yields not only the same information as is conveyed by the methods of energy and exergy analysis, but it also predicts clearly the influence of irreversibilities of individual components on the coefficient of performance and its effectiveness, based on the process properties, rather than on ambient conditions. Furthermore, this method is capable of presenting the overall distribution of the heat input by displaying the additional heat required to overcome irreversibility of each component without ambiguity. (Author).

  2. The analysis of thermal stability of detonation nanodiamond

    Science.gov (United States)

    Efremov, V. P.; Zakatilova, E. I.

    2016-11-01

    The detonation nanodiamond is a new perspective material. Ammunition recycling with use of high explosives and obtaining nanodiamond as the result of the detonation synthesis have given a new motivation for searching of their application areas. In this work nanodiamond powder has been investigated by the method of synchronous thermal analysis. Experiments have been carried out at atmospheric pressure in the environment of argon. Nanodiamond powder has been heated in the closed corundum crucible at the temperature range of 30-1500 °C. The heating rates were varied from 2 K/min to 20 K/min. After the heat treatment, the samples have been studied by the x-ray diffraction and the electron microscopy. As one of the results of this work, it has been found that the detonation nanodiamond has not started the transition into graphite at the temperature below 800 °C.

  3. Model-based analysis of thermal insulation coatings

    DEFF Research Database (Denmark)

    Kiil, Søren

    2014-01-01

    Thermal insulation properties of coatings based on selected functional filler materials are investigated. The underlying physics, thermal conductivity of a heterogeneous two-component coating, and porosity and thermal conductivity of hollow spheres (HS) are quantified and a mathematical model for...

  4. Modelling and analysis of radial thermal stresses and temperature ...

    African Journals Online (AJOL)

    A theoretical investigation has been undertaken to study operating temperatures, heat fluxes and radial thermal stresses in the valves of a modern diesel engine with and without air-cavity. Temperatures, heat fluxes and radial thermal stresses were measured theoretically for both cases under all four thermal loading ...

  5. Endocannabinoid Catabolic Enzymes Play Differential Roles in Thermal Homeostasis in Response to Environmental or Immune Challenge.

    Science.gov (United States)

    Nass, Sara R; Long, Jonathan Z; Schlosburg, Joel E; Cravatt, Benjamin F; Lichtman, Aron H; Kinsey, Steven G

    2015-06-01

    Cannabinoid receptor agonists, such as Δ(9)-THC, the primary active constituent of Cannabis sativa, have anti-pyrogenic effects in a variety of assays. Recently, attention has turned to the endogenous cannabinoid system and how endocannabinoids, including 2-arachidonoylglycerol (2-AG) and anandamide, regulate multiple homeostatic processes, including thermoregulation. Inhibiting endocannabinoid catabolic enzymes, monoacylglycerol lipase (MAGL) or fatty acid amide hydrolase (FAAH), elevates levels of 2-AG or anandamide in vivo, respectively. The purpose of this experiment was to test the hypothesis that endocannabinoid catabolic enzymes function to maintain thermal homeostasis in response to hypothermic challenge. In separate experiments, male C57BL/6J mice were administered a MAGL or FAAH inhibitor, and then challenged with the bacterial endotoxin lipopolysaccharide (LPS; 2 mg/kg ip) or a cold (4 °C) ambient environment. Systemic LPS administration caused a significant decrease in core body temperature after 6 h, and this hypothermia persisted for at least 12 h. Similarly, cold environment induced mild hypothermia that resolved within 30 min. JZL184 exacerbated hypothermia induced by either LPS or cold challenge, both of which effects were blocked by rimonabant, but not SR144528, indicating a CB1 cannabinoid receptor mechanism of action. In contrast, the FAAH inhibitor, PF-3845, had no effect on either LPS-induced or cold-induced hypothermia. These data indicate that unlike direct acting cannabinoid receptor agonists, which elicit profound hypothermic responses on their own, neither MAGL nor FAAH inhibitors affect normal body temperature. However, these endocannabinoid catabolic enzymes play distinct roles in thermoregulation following hypothermic challenges.

  6. Computer aided analysis, simulation and optimisation of thermal sterilisation processes.

    Science.gov (United States)

    Narayanan, C M; Banerjee, Arindam

    2013-04-01

    Although thermal sterilisation is a widely employed industrial process, little work is reported in the available literature including patents on the mathematical analysis and simulation of these processes. In the present work, software packages have been developed for computer aided optimum design of thermal sterilisation processes. Systems involving steam sparging, jacketed heating/cooling, helical coils submerged in agitated vessels and systems that employ external heat exchangers (double pipe, shell and tube and plate exchangers) have been considered. Both batch and continuous operations have been analysed and simulated. The dependence of del factor on system / operating parameters such as mass or volume of substrate to be sterilised per batch, speed of agitation, helix diameter, substrate to steam ratio, rate of substrate circulation through heat exchanger and that through holding tube have been analysed separately for each mode of sterilisation. Axial dispersion in the holding tube has also been adequately accounted for through an appropriately defined axial dispersion coefficient. The effect of exchanger characteristics/specifications on the system performance has also been analysed. The multiparameter computer aided design (CAD) software packages prepared are thus highly versatile in nature and they permit to make the most optimum choice of operating variables for the processes selected. The computed results have been compared with extensive data collected from a number of industries (distilleries, food processing and pharmaceutical industries) and pilot plants and satisfactory agreement has been observed between the two, thereby ascertaining the accuracy of the CAD softwares developed. No simplifying assumptions have been made during the analysis and the design of associated heating / cooling equipment has been performed utilising the most updated design correlations and computer softwares.

  7. Validation and further development of a novel thermal analysis method

    Energy Technology Data Exchange (ETDEWEB)

    Mathews, E.H.; Shuttleworth, A.G.; Rousseau, P.G. [Pretoria Univ. (South Africa). Dept. of Mechanical Engineering

    1994-12-31

    The design of thermal and energy efficient buildings requires inter alia the investigation of the passive performance, natural ventilation, mechanical ventilation as well as structural and evaporative cooling of the building. Only when these fail to achieve the desired thermal comfort should mechanical cooling systems be considered. Few computer programs have the ability to investigate all these comfort regulating methods at the design stage. The QUICK design program can simulate these options with the exception of mechanical cooling. In this paper, Quick`s applicability is extended to include the analysis of basic air-conditioning systems. Since the design of these systems is based on indoor loads, it was necessary to validate QUICK`s load predictions before extending it. This article addresses validation in general and proposes a procedure to establish the efficiency of a program`s load predictions. This proposed procedure is used to compare load predictions by the ASHRAE, CIBSE, CARRIER, CHEETAH, BSIMAC and QUICK methods for 46 case studies involving 36 buildings in various climatic conditions. Although significant differences in the results of the various methods were observed, it is concluded that QUICK can be used with the same confidence as the other methods. It was further shown that load prediction programs usually under-estimate the effect of building mass and therefore over-estimate the peak loads. The details for the 46 case studies are available to other researchers for further verification purposes. With the confidence gained in its load predictions, QUICK was extended to include air-conditioning system analysis. The program was then applied to different case studies. It is shown that system size and energy usage can be reduced by more than 60% by using a combination of passive and mechanical cooling systems as well as different control strategies. (author)

  8. Applications of artificial neural networks for thermal analysis of heat exchangers - A review

    International Nuclear Information System (INIS)

    Mohanraj, M.; Jayaraj, S.; Muraleedharan, C.

    2015-01-01

    Artificial neural networks (ANN) have been widely used for thermal analysis of heat exchangers during the last two decades. In this paper, the applications of ANN for thermal analysis of heat exchangers are reviewed. The reported investigations on thermal analysis of heat exchangers are categorized into four major groups, namely (i) modeling of heat exchangers, (ii) estimation of heat exchanger parameters, (iii) estimation of phase change characteristics in heat exchangers and (iv) control of heat exchangers. Most of the papers related to the applications of ANN for thermal analysis of heat exchangers are discussed. The limitations of ANN for thermal analysis of heat exchangers and its further research needs in this field are highlighted. ANN is gaining popularity as a tool, which can be successfully used for the thermal analysis of heat exchangers with acceptable accuracy. (authors)

  9. The thermal analysis of low heat generating radioactive wastes in land disposal facilities

    International Nuclear Information System (INIS)

    Lympany, S.D.

    1984-08-01

    A procedure is developed which allows a simple thermal analysis of a radioactive waste repository. The procedure is used to establish if the thermally induced groundwater flow is important when considering the transport of radionuclides from the repository, and thereby indicates if this flow should be taken into account in a detailed thermal assessment. (author)

  10. Hydration–dehydration behavior and thermodynamics of MX-80 montmorillonite studied using thermal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Tajeddine, L. [CNRS-IC2MP-UMR- Hydrasa, 5 Ave Albert, Turpain, (France); Gailhanou, H.; Blanc, P.; Lassin, A.; Gaboreau, S. [BRGM, 3 Av. Claude Guillemin, BP6009, Orléans F-45060 (France); Vieillard, P., E-mail: philippe.vieillard@univ-poitiers.fr [CNRS-IC2MP-UMR- Hydrasa, 5 Ave Albert, Turpain, (France)

    2015-03-20

    Highlights: • Adsorption–desorption of water on MX-80 is determined from TGA and DTA analysis. • From DTA analysis, three types of water behavior exist at various hydration states. • Surface area of DTA allows to determine the dehydration enthalpy per mole of water. • A maximum enthalpy is 12 kJ/mol for the adsorption and desorption processes. • Enthalpy of formation of water for adsorption and desorption processes are provided. - Abstract: The thermal dehydration of natural bentonite clay MX-80 chosen as a possible future backfill material, was investigated using thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The aim of this work is to provide a better understanding of the thermodynamics of the hydration–dehydration process of MX-80. The data obtained from thermogravimetry derivative curves at different relative humidities were used to determine the adsorption–desorption isotherm of MX-80. The total amount of water varies from 0.35 to 5.62 and from 0.78 to 6.12 mol adsorbed H{sub 2}O/mol of clay upon adsorption and desorption, respectively, for a RH between 11 and 91%. Furthermore, the heats released upon adsorption and desorption are not completely similar. Moreover, the analysis of DTA signals obtained at various hydration states provides insights about three types of water behavior in MX-80. Therefore, the surface area of DTA curves was taken into account to determine the dehydration enthalpy per mole of water; the values do not correlate with the amount of adsorbed water in MX-80, and the maximum enthalpy was approximately 12 kJ/mol for the adsorption and desorption studies. The values obtained were combined with the standard enthalpies of the formation of liquid water to obtain the corresponding enthalpy of the formation of water relative to dehydrated MX-80.

  11. The study of forms of bonding marshmallow moisture with different composition by method of thermal analysis

    Directory of Open Access Journals (Sweden)

    G. O. Magomedov

    2017-01-01

    Full Text Available Marshmallow is a sugar confectionary product with increased sugar content and energy value because of the significant content of carbohydrates, in particular sugar-sand. The main drawback of marshmallow is the rapid process of its drying during storage due to the crystallization of sucrose and the gradual removal of moisture from the product. A method for obtaining marshmallow without sugar on the basis of high-conversion glucose syrup. In the work, experimental studies were carried out to determine the content and ratio of free and bound forms of moisture in marshmallow on the basis of sugars and on the basis of  high-conversion glucose syrup by Differential Scanning Calorimetry (DSC and Thermogravimetry (TG. To study the patterns of thermal effects on the properties of marshmallow samples, the non-isothermal analysis method and the synchronous thermal analysis instrument (TG-DTA / DSC of the STA 449 F3 Jupiter were used. In the process of thermal exposure, the samples decompose sugars and other organic compounds, as a result of which the sample weight decreases due to evaporation of moisture. The process of dehydration in a control sample of marshmallow using sugar occurs in a less wide temperature range than in a sample of marshmallow on the basis of  high-conversion glucose syrup, which indicates a greater degree of moisture bonding in the developed sample. A quantitative evaluation of the forms of moisture bonding in the samples was carried out using the experimental curves obtained by the TG method. From the temperature curves, the endothermic effects were determined, which correspond to the release of moisture with different forms and energies. Substitution of sugar for treacle in the formula of marshmallow reduces the share of free moisture and increases the safety of the product without signs of staling.

  12. CFD thermal-hydraulic analysis of a CANDU fuel channel

    International Nuclear Information System (INIS)

    Catana, A.; Prisecaru, I.; Dupleac, D.; Danila, N.

    2009-01-01

    This paper presents the numerical investigation of a CANDU fuel channel using CFD (Computational fluid dynamics) methodology approach. Limited computer power available at Bucharest University POLITEHNICA forced the authors to analyse only segments of fuel channel namely the significant ones: fuel bundle junctions with adjacent segments, fuel bundle spacer planes with adjacent segments, regular segments of fuel bundles. The computer code used is FLUENT. Fuel bundles contained in pressure tubes forms a complex flow domain. The flow is characterized by high turbulence and in some parts of fuel channel also by multi-phase flow. The flow in the fuel channel has been simulated by solving the equations for conservation of mass and momentum. For turbulence modelling the standard k-e model is employed although other turbulence models can be used as well. In this paper we do not consider heat generation and heat transfer capabilities of CFD methods. Since we consider only some relatively short segments of a CANDU fuel channel we can assume, for this starting stage, that heat transfer is not very important for these short segments of fuel channel. The boundary conditions for CFD analysis are provided by system and sub-channel analysis. In this paper the discussion is focused on some flow parameters behaviour at the bundle junction, spacer's plane configuration, etc. In this paper we present results for Standard CANDU 6 Fuel Bundles as a basis for CFD thermal-hydraulic analysis of INR proposed SEU43 and other new nuclear fuels. (authors)

  13. CFD analysis of aircraft fuel tanks thermal behaviour

    Science.gov (United States)

    Zilio, C.; Longo, G. A.; Pernigotto, G.; Chiacchio, F.; Borrelli, P.; D'Errico, E.

    2017-11-01

    This work is carried out within the FP7 European research project TOICA (Thermal Overall Integrated Conception of Aircraft, http://www.toica-fp7.eu/). One of the tasks foreseen for the TOICA project is the analysis of fuel tanks as possible heat sinks for future aircrafts. In particular, in the present paper, commercial regional aircraft is considered as case study and CFD analysis with the commercial code STAR-CCM+ is performed in order to identify the potential capability to use fuel stored in the tanks as a heat sink for waste heat dissipated by other systems. The complex physical phenomena that characterize the heat transfer inside liquid fuel, at the fuel-ullage interface and inside the ullage are outlined. Boundary conditions, including the effect of different ground and flight conditions, are implemented in the numerical simulation approach. The analysis is implemented for a portion of aluminium wing fuel tank, including the leading edge effects. Effect of liquid fuel transfer among different tank compartments and the air flow in the ullage is included. According to Fuel Tank Flammability Assessment Method (FTFAM) proposed by the Federal Aviation Administration, the results are exploited in terms of exponential time constants and fuel temperature difference to the ambient for the different cases investigated.

  14. Exergy Analysis of Operating Lignite Fired Thermal Power Plant

    Directory of Open Access Journals (Sweden)

    K. Murugesan

    2009-01-01

    Full Text Available The energy assessment must be made through the energy quantity as well as the quality. But the usual energy analysisevaluates the energy generally on its quantity only. However, the exergy analysis assesses the energy on quantity as well asthe quality. The aim of the exergy analysis is to identify the magnitudes and the locations of real energy losses, in order toimprove the existing systems, processes or components. The present paper deals with an exergy analysis performed on anoperating 50MWe unit of lignite fired steam power plant at Thermal Power Station-I, Neyveli Lignite Corporation Limited,Neyveli, Tamil Nadu, India. The exergy losses occurred in the various subsystems of the plant and their components havebeen calculated using the mass, energy and exergy balance equations. The distribution of the exergy losses in several plantcomponents during the real time plant running conditions has been assessed to locate the process irreversibility. The Firstlaw efficiency (energy efficiency and the Second law efficiency (exergy efficiency of the plant have also been calculated.The comparison between the energy losses and the exergy losses of the individual components of the plant shows that themaximum energy losses of 39% occur in the condenser, whereas the maximum exergy losses of 42.73% occur in the combustor.The real losses of energy which has a scope for the improvement are given as maximum exergy losses that occurredin the combustor.

  15. Thermal Analysis, Structural Studies and Morphology of Spider Silk-like Block Copolymers

    Science.gov (United States)

    Huang, Wenwen

    Spider silk is a remarkable natural block copolymer, which offers a unique combination of low density, excellent mechanical properties, and thermal stability over a wide range of temperature, along with biocompatibility and biodegrability. The dragline silk of Nephila clavipes, is one of the most well understood and the best characterized spider silk, in which alanine-rich hydrophobic blocks and glycine-rich hydrophilic blocks are linked together generating a functional block copolymer with potential uses in biomedical applications such as guided tissue repair and drug delivery. To provide further insight into the relationships among peptide amino acid sequence, block length, and physical properties, in this thesis, we studied synthetic proteins inspired by the genetic sequences found in spider dragline silks, and used these bioengineered spider silk block copolymers to study thermal, structural and morphological features. To obtain a fuller understanding of the thermal dynamic properties of these novel materials, we use a model to calculate the heat capacity of spider silk block copolymer in the solid or liquid state, below or above the glass transition temperature, respectively. We characterize the thermal phase transitions by temperature modulated differential scanning calorimetry (TMDSC) and thermogravimetric analysis (TGA). We also determined the crystallinity by TMDSC and compared the result with Fourier transform infrared spectroscopy (FTIR) and wide angle X-ray diffraction (WAXD). To understand the protein-water interactions with respect to the protein amino acid sequence, we also modeled the specific reversing heat capacity of the protein-water system, Cp(T), based on the vibrational, rotational and translational motions of protein amino acid residues and water molecules. Advanced thermal analysis methods using TMDSC and TGA show two glass transitions were observed in all samples during heating. The low temperature glass transition, Tg(1), is related to

  16. Analysis of stability for stochastic delay integro-differential equations.

    Science.gov (United States)

    Zhang, Yu; Li, Longsuo

    2018-01-01

    In this paper, we concern stability of numerical methods applied to stochastic delay integro-differential equations. For linear stochastic delay integro-differential equations, it is shown that the mean-square stability is derived by the split-step backward Euler method without any restriction on step-size, while the Euler-Maruyama method could reproduce the mean-square stability under a step-size constraint. We also confirm the mean-square stability of the split-step backward Euler method for nonlinear stochastic delay integro-differential equations. The numerical experiments further verify the theoretical results.

  17. Stochastic analysis of uncertain thermal parameters for random thermal regime of frozen soil around a single freezing pipe

    Science.gov (United States)

    Wang, Tao; Zhou, Guoqing; Wang, Jianzhou; Zhou, Lei

    2018-03-01

    The artificial ground freezing method (AGF) is widely used in civil and mining engineering, and the thermal regime of frozen soil around the freezing pipe affects the safety of design and construction. The thermal parameters can be truly random due to heterogeneity of the soil properties, which lead to the randomness of thermal regime of frozen soil around the freezing pipe. The purpose of this paper is to study the one-dimensional (1D) random thermal regime problem on the basis of a stochastic analysis model and the Monte Carlo (MC) method. Considering the uncertain thermal parameters of frozen soil as random variables, stochastic processes and random fields, the corresponding stochastic thermal regime of frozen soil around a single freezing pipe are obtained and analyzed. Taking the variability of each stochastic parameter into account individually, the influences of each stochastic thermal parameter on stochastic thermal regime are investigated. The results show that the mean temperatures of frozen soil around the single freezing pipe with three analogy method are the same while the standard deviations are different. The distributions of standard deviation have a great difference at different radial coordinate location and the larger standard deviations are mainly at the phase change area. The computed data with random variable method and stochastic process method have a great difference from the measured data while the computed data with random field method well agree with the measured data. Each uncertain thermal parameter has a different effect on the standard deviation of frozen soil temperature around the single freezing pipe. These results can provide a theoretical basis for the design and construction of AGF.

  18. Mitigation method of thermal transient stress by thermalhydraulic-structure total analysis

    International Nuclear Information System (INIS)

    Kasahara, Naoto; Jinbo, Masakazu; Hosogai, Hiromi

    2003-01-01

    This study proposes a rational evaluation and mitigation method of thermal transient loads in fast reactor components by utilizing relationships among plant system parameters and stresses induced by thermal transients of plants. A thermalhydraulic-structure total analysis procedure helps us to grasp relationship among system parameters and thermal stresses. Furthermore, it enables mitigation of thermal transient loads by adjusting system parameters. In order to overcome huge computations, a thermalhydraulic-structure total analysis code and the Design of Experiments methodology are utilized. The efficiency of the proposed mitigation method is validated through thermal stress evaluation of an intermediate heat exchanger in Japanese demonstration fast reactor. (author)

  19. Thermal analysis experiment for elucidating sodium-water chemical reaction mechanism in steam generator of sodium-cooled fast reactor

    International Nuclear Information System (INIS)

    Kikuchi, Shin; Kurihara, Akikazu; Ohshima, Hiroyuki

    2012-01-01

    For the purpose of elucidating the mechanism of the sodium-water surface reaction in a steam generator of sodium-cooled fast reactors, kinetic study of the sodium (Na)-sodium hydroxide (NaOH) reaction has been carried out by using Differential Thermal Analysis (DTA) technique. The parameters, including melting points of Na and NaOH, phase transition temperature of NaOH, Na-NaOH reaction temperature, and decomposition temperature of sodium hydride (NaH) have been identified from DTA curves. Based on the measured reaction temperature, rate constant of sodium monoxide (Na 2 O) generation was obtained. Thermal analysis results indicated that Na 2 O generation at the secondary overall reaction should be considered during the sodium-water reaction. (author)

  20. Determination of structural and mechanical properties, diffractometry, and thermal analysis of chitosan and hydroxypropylmethylcellulose (HPMC films plasticized with sorbitol

    Directory of Open Access Journals (Sweden)

    Jefferson Rotta

    2011-06-01

    Full Text Available In this work, the structural, mechanical, diffractometric, and thermal parameters of chitosan-hydroxypropylmethylcellulose (HPMC films plasticized with sorbitol were studied. Solutions of HPMC (2% w/v in water and chitosan (2% w/v in 2% acetic acid solution were prepared. The concentration of sorbitol used was 10% (w/w to both polymers. This solutions were mixed at different proportions (100/0; 70/30; 50/50; 30/70, and 0/100 of chitosan and HPMC, respectively, and 20 mL was cast in Petri dishes for further analysis of dried films. The miscibility of polymers was assessed by X-ray diffraction, scanning electronic microscopy (SEM, differential scanning calorimetry (DSC, and thermal gravimetric analysis (TGA. The results obtained indicate that the films are not fully miscible at a dry state despite the weak hydrogen bonding between the polymer functional groups.

  1. Thermal safety analysis of a dry storage cask for the Korean standard spent fuel - 16159

    International Nuclear Information System (INIS)

    Cha, Jeonghun; Kim, S.N.; Choi, K.W.

    2009-01-01

    A conceptual dry storage facility, which is based on a commercial dry storage facility, was designed for the Korea standard spent nuclear fuel (SNF) and preliminary thermal safety analysis was performed in this study. To perform the preliminary thermal analysis, a thermal analysis method was proposed. The thermal analysis method consists of 2 parts. By using the method, the surface temperature of the storage canister corresponding to the SNF clad temperature was calculated and the adequate air duct area was decided using the calculation result. The initial temperature of the facility was calculated and the fire condition and half air duct blockage were analyzed. (authors)

  2. Fluid-structure interaction analysis for pressurizer surge line subjected to thermal stratification

    International Nuclear Information System (INIS)

    Kang, Dong Gu; Jhung, Myung Jo; Chang, Soon Heung

    2011-01-01

    Research highlights: → Temperature of surge line due to stratified flow is defined using CFD analysis. → Fluid-structure interaction analysis is performed to investigate the response characteristics due to thermal stress. → Fatigue usage factors due to thermal stratification are relatively low. → Simplifying temperature distribution in surge line is not always conservative. - Abstract: Serious mechanical damages such as cracks and plastic deformations due to excessive thermal stress caused by thermal stratification have been experienced in several nuclear power plants. In particular, the thermal stratification in the pressurizer surge line has been addressed as one of the significant safety and technical issues. In this study, a detailed unsteady computational fluid dynamics (CFD) analysis involving conjugate heat transfer analysis is performed to obtain the transient temperature distributions in the wall of the pressurizer surge line subjected to stratified internal flows either during out-surge or in-surge operation. The thermal loads from CFD calculations are transferred to the structural analysis code which is employed for the thermal stress analysis to investigate the response characteristics, and the fatigue analysis is ultimately performed. In addition, the thermal stress and fatigue analysis results obtained by applying the realistic temperature distributions from CFD calculations are compared with those by assuming the simplified temperature distributions to identify some requirements for a realistic and conservative thermal stress analysis from a safety point of view.

  3. Transmutation technology development; thermal hydraulic power analysis and structure analysis of the HYPER target beam window

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J. H.; Ju, E. S.; Song, M. K.; Jeon, Y. Z. [Gyeongsang National University, Jinju (Korea)

    2002-03-01

    A thermal hydraulic power analysis, a structure analysis and optimization computation for some design factor for the design of spallation target suitable for HYPER with 1000 MW thermal power in this study was performed. Heat generation formula was used which was evaluated recently based on the LAHET code, mainly to find the maximum beam current under given computation conditions. Thermal hydraulic power of HYPER target system was calculated using FLUENT code, structure conducted by inputting the data into ANSYS. On the temp of beam windows and the pressure distribution calculated using FLUENT. Data transformation program was composed apply the data calculated using FLUENT being commercial CFD code and ANSYS being FEM code for CFX structure analysis. A basic study was conducted on various singular target to obtain fundamental data on the shape for optimum target design. A thermal hydraulic power analysis and structure analysis were conducted on the shapes of parabolic, uniform, scanning beams to choose the optimum shape of beam current analysis was done according to some turbulent model to simulate the real flow. To evaluate the reliability of numerical analysis result, benchmarking of FLUENT code reformed at SNU and Korea Advanced Institute of Science and Technology and it was compared to CFX in the possession of Korea Atomic Energy Research Institute and evaluated. Reliable deviation was observed in the results calculated using FLUENT code, but temperature deviation of about 200 .deg. C was observed in the result from CFX analysis at optimum design condition. Several benchmarking were performed on the basis of numerical analysis concerning conventional HYPER. It was possible to allow a beam arrests of 17.3 mA in the case of the {phi} 350 mm parabolic beam suggested to the optimum in nuclear transmutation when stress equivalent to VON-MISES was calculated to be 140 MPa. 29 refs., 109 figs. (Author)

  4. Power Transformer Differential Protection Based on Neural Network Principal Component Analysis, Harmonic Restraint and Park's Plots

    OpenAIRE

    Tripathy, Manoj

    2012-01-01

    This paper describes a new approach for power transformer differential protection which is based on the wave-shape recognition technique. An algorithm based on neural network principal component analysis (NNPCA) with back-propagation learning is proposed for digital differential protection of power transformer. The principal component analysis is used to preprocess the data from power system in order to eliminate redundant information and enhance hidden pattern of differential current to disc...

  5. Generic repository design concepts and thermal analysis (FY11)

    International Nuclear Information System (INIS)

    Howard, Robert; Dupont, Mark; Blink, James A.; Fratoni, Massimiliano; Greenberg, Harris; Carter, Joe; Hardin, Ernest L.; Sutton, Mark A.

    2011-01-01

    Reference concepts for geologic disposal of used nuclear fuel and high-level radioactive waste in the U.S. are developed, including geologic settings and engineered barriers. Repository thermal analysis is demonstrated for a range of waste types from projected future, advanced nuclear fuel cycles. The results show significant differences among geologic media considered (clay/shale, crystalline rock, salt), and also that waste package size and waste loading must be limited to meet targeted maximum temperature values. In this study, the UFD R and D Campaign has developed a set of reference geologic disposal concepts for a range of waste types that could potentially be generated in advanced nuclear FCs. A disposal concept consists of three components: waste inventory, geologic setting, and concept of operations. Mature repository concepts have been developed in other countries for disposal of spent LWR fuel and HLW from reprocessing UNF, and these serve as starting points for developing this set. Additional design details and EBS concepts will be considered as the reference disposal concepts evolve. The waste inventory considered in this study includes: (1) direct disposal of SNF from the LWR fleet, including Gen III+ advanced LWRs being developed through the Nuclear Power 2010 Program, operating in a once-through cycle; (2) waste generated from reprocessing of LWR UOX UNF to recover U and Pu, and subsequent direct disposal of used Pu-MOX fuel (also used in LWRs) in a modified-open cycle; and (3) waste generated by continuous recycling of metal fuel from fast reactors operating in a TRU burner configuration, with additional TRU material input supplied from reprocessing of LWR UOX fuel. The geologic setting provides the natural barriers, and establishes the boundary conditions for performance of engineered barriers. The composition and physical properties of the host medium dictate design and construction approaches, and determine hydrologic and thermal responses of

  6. Generic repository design concepts and thermal analysis (FY11).

    Energy Technology Data Exchange (ETDEWEB)

    Howard, Robert (Oak Ridge National Laboratory, Oak Ridge, TN); Dupont, Mark (Savannah River Nuclear Solutions, Aiken, SC); Blink, James A. (Lawrence Livermore National Laboratory, Livermore, CA); Fratoni, Massimiliano (Lawrence Livermore National Laboratory, Livermore, CA); Greenberg, Harris (Lawrence Livermore National Laboratory, Livermore, CA); Carter, Joe (Savannah River Nuclear Solutions, Aiken, SC); Hardin, Ernest L.; Sutton, Mark A. (Lawrence Livermore National Laboratory, Livermore, CA)

    2011-08-01

    Reference concepts for geologic disposal of used nuclear fuel and high-level radioactive waste in the U.S. are developed, including geologic settings and engineered barriers. Repository thermal analysis is demonstrated for a range of waste types from projected future, advanced nuclear fuel cycles. The results show significant differences among geologic media considered (clay/shale, crystalline rock, salt), and also that waste package size and waste loading must be limited to meet targeted maximum temperature values. In this study, the UFD R&D Campaign has developed a set of reference geologic disposal concepts for a range of waste types that could potentially be generated in advanced nuclear FCs. A disposal concept consists of three components: waste inventory, geologic setting, and concept of operations. Mature repository concepts have been developed in other countries for disposal of spent LWR fuel and HLW from reprocessing UNF, and these serve as starting points for developing this set. Additional design details and EBS concepts will be considered as the reference disposal concepts evolve. The waste inventory considered in this study includes: (1) direct disposal of SNF from the LWR fleet, including Gen III+ advanced LWRs being developed through the Nuclear Power 2010 Program, operating in a once-through cycle; (2) waste generated from reprocessing of LWR UOX UNF to recover U and Pu, and subsequent direct disposal of used Pu-MOX fuel (also used in LWRs) in a modified-open cycle; and (3) waste generated by continuous recycling of metal fuel from fast reactors operating in a TRU burner configuration, with additional TRU material input supplied from reprocessing of LWR UOX fuel. The geologic setting provides the natural barriers, and establishes the boundary conditions for performance of engineered barriers. The composition and physical properties of the host medium dictate design and construction approaches, and determine hydrologic and thermal responses of the

  7. Thermal behavior analysis of U-Mo/Al dispersion fuel

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Ho Jin; Park, Jong Mang; Lee, Yoon Sang; Kim, Chang Kyu [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2004-07-01

    According to the non-proliferation policy under the reduced enrichment for research and test reactors (RERTR) program, low enriched uranium(LEU) fuel such as uranium silicide dispersion fuels are being used in research reactors. Because of a lower enrichment higher uranium density fuels are required for some high performance research reactors. Some uranium alloys with a high uranium density such as U-Mo alloys have been considered as one of the most promising candidates for a dispersion fuel due to the good irradiation performance. An international qualification program to replace the uranium silicide dispersion fuel with U-Mo dispersion fuel is being carried out under the RERTR program. Although U-Mo powders are conventionally supplied by the mechanical comminuting of as-cast U-Mo alloys, KAERI developed a centrifugal atomization method in order to simplify the preparation process and improve the properties. The centrifugally atomized powders have a rapidly solidified gamma uranium structure and a spherical shape. During the in-reactor operation of a dispersion fuel, interdiffusion or chemical reactions between the fuel particles and the matrix occurr. Intermetallic compounds in the form of UAlx are formed as a result of the diffusional reaction. Because the intermetallic compounds are less dense than the combined reactants, the volume of the fuel element increases after the reaction. In addition to the effect on the swelling performance, the reaction layers between the U-Mo and the Al matrix induces a degradation of the thermal properties of the U-Mo/Al dispersion fuels. It is important to investigate the thermal behavior of U-Mo/Al dispersion fuel according to reaction between the fuel particles and the matrix with the burnup and linear power. In this study, a finite element analysis was used for the calculation of the temperature distribution of the U-Mo/Al dispersion fuel with a burnup and linear power. Kinetics data of the reaction layers such as the growth

  8. Thermal behavior analysis of U-Mo/Al dispersion fuel

    International Nuclear Information System (INIS)

    Ryu, Ho Jin; Park, Jong Mang; Lee, Yoon Sang; Kim, Chang Kyu

    2004-01-01

    According to the non-proliferation policy under the reduced enrichment for research and test reactors (RERTR) program, low enriched uranium(LEU) fuel such as uranium silicide dispersion fuels are being used in research reactors. Because of a lower enrichment higher uranium density fuels are required for some high performance research reactors. Some uranium alloys with a high uranium density such as U-Mo alloys have been considered as one of the most promising candidates for a dispersion fuel due to the good irradiation performance. An international qualification program to replace the uranium silicide dispersion fuel with U-Mo dispersion fuel is being carried out under the RERTR program. Although U-Mo powders are conventionally supplied by the mechanical comminuting of as-cast U-Mo alloys, KAERI developed a centrifugal atomization method in order to simplify the preparation process and improve the properties. The centrifugally atomized powders have a rapidly solidified gamma uranium structure and a spherical shape. During the in-reactor operation of a dispersion fuel, interdiffusion or chemical reactions between the fuel particles and the matrix occurr. Intermetallic compounds in the form of UAlx are formed as a result of the diffusional reaction. Because the intermetallic compounds are less dense than the combined reactants, the volume of the fuel element increases after the reaction. In addition to the effect on the swelling performance, the reaction layers between the U-Mo and the Al matrix induces a degradation of the thermal properties of the U-Mo/Al dispersion fuels. It is important to investigate the thermal behavior of U-Mo/Al dispersion fuel according to reaction between the fuel particles and the matrix with the burnup and linear power. In this study, a finite element analysis was used for the calculation of the temperature distribution of the U-Mo/Al dispersion fuel with a burnup and linear power. Kinetics data of the reaction layers such as the growth

  9. Thermal Analysis by Structural Characterization as a Method for Assessing Heterogeneity in Complex Solid Pharmaceutical Dosage Forms.

    Science.gov (United States)

    Alhijjaj, Muqdad; Reading, Mike; Belton, Peter; Qi, Sheng

    2015-11-03

    Characterizing inter- and intrasample heterogeneity of solid and semisolid pharmaceutical products is important both for rational design of dosage forms and subsequent quality control during manufacture; however, most pharmaceutical products are multicomponent formulations that are challenging in this regard. Thermal analysis, in particular differential scanning calorimetry, is commonly used to obtain structural information, such as degree of crystallinity, or identify the presence of a particular polymorph, but the results are an average over the whole sample; it cannot directly provide information about the spatial distribution of phases. This study demonstrates the use of a new thermo-optical technique, thermal analysis by structural characterization (TASC), that can provide spatially resolved information on thermal transitions by applying a novel algorithm to images acquired by hot stage microscopy. We determined that TASC can be a low cost, relatively rapid method of characterizing heterogeneity and other aspects of structure. In the examples studied, it was found that high heating rates enabled screening times of 3-5 min per sample. In addition, this study demonstrated the higher sensitivity of TASC for detecting the metastable form of polyethylene glycol (PEG) compared to conventional differential scanning calorimetry (DSC). This preliminary work suggests that TASC will be a worthwhile additional tool for characterizing a broad range of materials.

  10. Numerical Analysis for Stochastic Partial Differential Delay Equations with Jumps

    OpenAIRE

    Li, Yan; Hu, Junhao

    2013-01-01

    We investigate the convergence rate of Euler-Maruyama method for a class of stochastic partial differential delay equations driven by both Brownian motion and Poisson point processes. We discretize in space by a Galerkin method and in time by using a stochastic exponential integrator. We generalize some results of Bao et al. (2011) and Jacob et al. (2009) in finite dimensions to a class of stochastic partial differential delay equations with jumps in infinite dimensions.

  11. The reexamination of thermal expansion of ferromagnetic superconductors and the pressure differential of its superconducting transition temperature-possible application to UGe2

    International Nuclear Information System (INIS)

    Konno, Rikio; Hatayama, Nobukuni

    2011-01-01

    The temperature dependence of thermal expansion of ferromagnetic superconductors below the superconducting transition temperature T scu of a majority spin conduction band is reexamined. In the previous study [to be published in J. M. Phys. B] the volume differential of the kinetic energy of conduction electrons is constant. However, in this study the volume differential of the kinetic energy of conduction electrons is inconstant. The superconducting gap of the majority spin conduction band used in this study has a line node. It is appropriate to UGe 2 . The pressure differential of its superconducting transition temperature is also investigated. We find that the thermal expansion coefficient has the divergence at the superconducting transition temperature. The thermodynamic Grueneisen's relation is satisfied.

  12. Differential proteome analysis of chikungunya virus infection on host cells.

    Directory of Open Access Journals (Sweden)

    Christina Li-Ping Thio

    Full Text Available BACKGROUND: Chikungunya virus (CHIKV is an emerging mosquito-borne alphavirus that has caused multiple unprecedented and re-emerging outbreaks in both tropical and temperate countries. Despite ongoing research efforts, the underlying factors involved in facilitating CHIKV replication during early infection remains ill-characterized. The present study serves to identify host proteins modulated in response to early CHIKV infection using a proteomics approach. METHODOLOGY AND PRINCIPAL FINDINGS: The whole cell proteome profiles of CHIKV-infected and mock control WRL-68 cells were compared and analyzed using two-dimensional gel electrophoresis (2-DGE. Fifty-three spots were found to be differentially modulated and 50 were successfully identified by MALDI-TOF/TOF. Eight were significantly up-regulated and 42 were down-regulated. The mRNA expressions of 15 genes were also found to correlate with the corresponding protein expression. STRING network analysis identified several biological processes to be affected, including mRNA processing, translation, energy production and cellular metabolism, ubiquitin-proteasome pathway (UPP and cell cycle regulation. CONCLUSION/SIGNIFICANCE: This study constitutes a first attempt to investigate alteration of the host cellular proteome during early CHIKV infection. Our proteomics data showed that during early infection, CHIKV affected the expression of proteins that are involved in mRNA processing, host metabolic machinery, UPP, and cyclin-dependent kinase 1 (CDK1 regulation (in favour of virus survival, replication and transmission. While results from this study complement the proteomics results obtained from previous late host response studies, functional characterization of these proteins is warranted to reinforce our understanding of their roles during early CHIKV infection in humans.

  13. The analysis of cholescintigraphy in differentiating the causes of jaundice

    International Nuclear Information System (INIS)

    Kim, Jung Gyun; Son, So Yeob; Bae, Kwang Su; Chung, Moo Chan; Choi, Deuk Lin; Kim, Ki Jung

    1985-01-01

    As a adjacent, 99m Tc-IDA complex cholescintigraphy has been used to differentiate the causes of jaundice, hepatocellular jaundice from the obstructive jaundice. So we conducted the retrospective study from the 41 cases of cholescintigraphy from the Mar. 83 to Sept. 84 at the dept. of radiology in the Soonchunhyang university to determine the etiology and differential points in the diagnosing the jaundice. The following results were obtained; 1. As a 1st-ordered parameter, the leading edge hepatic parenchymal transit time was very significant in differentiating the causes of jaundice, among he hepatocellular jaundice, obstructive jaundice due to tumor, and obstructive jaundice due to cholelithiasis. (ρ 2 -test) 2. As a 2nd-ordered parameter, hepatic clearance was very significant in differentiating the hepatocellular jaundice from the jaundice due to partial biliary obstruction. (ρ 2 -test) 4. The difference in bile duct dilatation among the hepatocellular jaundice obstructive jaundice due to tumor, and obstructive jaundice due to cholelithiasis, was significant in differentiating the causes of jaundice. (ρ 2 -test) 5. Intrahepatic stone showed scintigraphic intrahepatic pooling with partial stasis. 6. Cholescintigraphy was useful to differentiated the Rotor's syndrome from the Dubin-Johnson syndrome, supplying the additional criteria

  14. Numerical analysis for thermal waves in gas generated by impulsive heating of a boundary surface

    International Nuclear Information System (INIS)

    Utsumi, Takayuki; Kunugi, Tomoaki

    1996-01-01

    Thermal wave in gas generated by an impulsive heating of a solid boundary was analyzed numerically by the Differential Algebraic CIP (Cubic Interpolated Propagation) scheme. Numerical results for the ordinary heat conduction equation were obtained with a high accuracy. As for the hyperbolic thermal fluid dynamics equation, the fundamental feature of the experimental results by Brown and Churchill with regard to thermoacoustic convection was qualitatively reproduced by the DA-CIP scheme. (author)

  15. Revised Thermal Analysis of LANL Ion Exchange Column

    Energy Technology Data Exchange (ETDEWEB)

    Laurinat, J

    2006-04-11

    This document updates a previous calculation of the temperature distributions in a Los Alamos National Laboratory (LANL) ion exchange column.1 LANL operates two laboratory-scale anion exchange columns, in series, to extract Pu-238 from nitric acid solutions. The Defense Nuclear Facilities Safety Board has requested an updated analysis to calculate maximum temperatures for higher resin loading capacities obtained with a new formulation of the Reillex HPQ anion exchange resin. The increased resin loading capacity will not exceed 118 g plutonium per L of resin bed. Calculations were requested for normal operation of the resin bed at the minimum allowable solution feed rate of 30 mL/min and after an interruption of flow at the end of the feed stage, when one of the columns is fully loaded. The object of the analysis is to demonstrate that the decay heat from the Pu-238 will not cause resin bed temperatures to increase to a level where the resin significantly degrades. At low temperatures, resin bed temperatures increase primarily due to decay heat. At {approx}70 C a Low Temperature Exotherm (LTE) resulting from the reaction between 8-12 M HNO{sub 3} and the resin has been observed. The LTE has been attributed to an irreversible oxidation of pendant ethyl benzene groups at the termini of the resin polymer chains by nitric acid. The ethyl benzene groups are converted to benzoic acid moities. The resin can be treated to permanently remove the LTE by heating a resin suspension in 8M HNO{sub 3} for 30-45 minutes. No degradation of the resin performance is observed after the LTE removal treatment. In fact, heating the resin in boiling ({approx}115-120 C) 12 M HNO{sub 3} for 3 hr displays thermal stability analogous to resin that has been treated to remove the LTE. The analysis is based on a previous study of the SRS Frames Waste Recovery (FWR) column, performed in support of the Pu-238 production campaign for NASA's Cassini mission. In that study, temperature transients

  16. Molecular analysis of expansion, differentiation, and growth factor treatment of human chondrocytes identifies differentiation markers and growth-related genes.

    Science.gov (United States)

    Benz, Karin; Breit, Stephen; Lukoschek, Martin; Mau, Hans; Richter, Wiltrud

    2002-04-26

    This study is intended to optimise expansion and differentiation of cultured human chondrocytes by growth factor application and to identify molecular markers to monitor their differentiation state. We dissected the molecular consequences of matrix release, monolayer, and 3D-alginate culture, growth factor optimised expansion, and re-differentiation protocols by gene expression analysis. Among 19 common cartilage molecules assessed by cDNA array, six proved best to monitor differentiation. Instant down-regulation at release of cells from the matrix was strongest for COL 2A1, fibromodulin, and PRELP while LUM, CHI3L1, and CHI3L2 were expansion-related. Both gene sets reflected the physiologic effects of the most potent growth-inducing (PDGF-BB) and proteoglycan-inducing (BMP-4) factors. Only CRTAC1 expression correlated with 2D/3D switches while the molecular phenotype of native chondrocytes was not restored. The markers and optimised protocols we suggest can help to improve cell therapy of cartilage defects and chondrocyte differentiation from stem cell sources.

  17. Thermal radiation analysis for small satellites with single-node model using techniques of equivalent linearization

    International Nuclear Information System (INIS)

    Anh, N.D.; Hieu, N.N.; Chung, P.N.; Anh, N.T.

    2016-01-01

    Highlights: • Linearization criteria are presented for a single-node model of satellite thermal. • A nonlinear algebraic system for linearization coefficients is obtained. • The temperature evolutions obtained from different methods are explored. • The temperature mean and amplitudes versus the heat capacity are discussed. • The dual criterion approach yields smaller errors than other approximate methods. - Abstract: In this paper, the method of equivalent linearization is extended to the thermal analysis of satellite using both conventional and dual criteria of linearization. These criteria are applied to a differential nonlinear equation of single-node model of the heat transfer of a small satellite in the Low Earth Orbit. A system of nonlinear algebraic equations for linearization coefficients is obtained in the closed form and then solved by the iteration method. The temperature evolution, average values and amplitudes versus the heat capacity obtained by various approaches including Runge–Kutta algorithm, conventional and dual criteria of equivalent linearization, and Grande's approach are compared together. Numerical results reveal that temperature responses obtained from the method of linearization and Grande's approach are quite close to those obtained from the Runge–Kutta method. The dual criterion yields smaller errors than those of the remaining methods when the nonlinearity of the system increases, namely, when the heat capacity varies in the range [1.0, 3.0] × 10 4  J K −1 .

  18. Electrical equivalent thermal network for direct contact membrane distillation modeling and analysis

    KAUST Repository

    Karam, Ayman M.

    2016-09-19

    Membrane distillation (MD) is an emerging water desalination technology that offers several advantages compared to conventional desalination methods. Although progress has been made to model the physics of the process, there are two common limitations of existing models. Firstly, many of the models are based on the steady-state analysis of the process and secondly, some of the models are based on partial differential equations, which when discretized introduce many states which are not accessible in practice. This paper presents the derivation of a novel dynamic model, based on the analogy between electrical and thermal systems, for direct contact membrane distillation (DCMD). An analogous electrical thermal network is constructed and its elements are parameterized such that the response of the network models the DCMD process. The proposed model captures the spatial and temporal responses of the temperature distribution along the flow direction and is able to accurately predict the distilled water flux output. To demonstrate the adequacy of the proposed model, validation with time varying and steady-state experimental data is presented. (C) 2016 Elsevier Ltd. All rights reserved.

  19. An unsymmetrical porphyrin and its metal complexes: synthesis, spectroscopy, thermal analysis and liquid crystal properties

    Directory of Open Access Journals (Sweden)

    CHANGFU ZHUANG

    2009-09-01

    Full Text Available The synthesis and characterization of a new unsymmetrical porphyrin liquid crystal, 5-(4-stearoyloxyphenylphenyl-10,15,20-triphenylporphyrin (SPTPPH2 and its transition metal complexes (SPTPPM, M(II = Zn, Fe, Co, Ni, Cu or Mn are reported. Their structure and properties were studied by elemental analysis, and UV–Vis, IR, mass and 1H-HMR spectroscopy. Their luminescent properties were studied by excitation and emission spectroscopy. The quantum yields of the S1 ® S0 fluorescence were measured at room temperature. According to thermal studies, the complexes have a higher thermal stability (no decomposition until 200 °C. Differential scanning calorimetry (DSC data and an optical textural photograph, obtained using a polarizing microscope (POM, indicate that the porphyrin ligand had liquid crystalline character and that it exhibited more than one mesophase and a low-lying phase transition temperature, with transition temperatures of 19.3 and 79.4 °C; the temperature range of the liquid crystal (LC phase of the ligand was 70.1 °C.

  20. Water Outgassing from PBX-9502 powder by isoconversional thermal analysis

    International Nuclear Information System (INIS)

    Dinh, L.N.; Glascoe, E.L.; Small, W.

    2009-01-01

    Temperature programmed desorption/decomposition (TPD) were performed on PBX-9502 after 3 hours of vacuum pump. TPD data were analyzed by the technique of isoconversional analysis to obtain outgassing kinetics and moisture content of PBX-9502 powder as well as to construct water outgassing models for PBX-9502 powder as a function of time and temperature. Following 3 hours of vacuum pump, dry storage of PBX-9502 at 300K, quickly gives rise to 180-330 ppm moisture in the first few years. Thereafter, the moisture outgassing continues at a much slower rate, totaling only to ∼ 210-380 ppm after 100 years of storage. In an effort to understand the nature of the moisture outgassing in PBX-9502, we have measured moisture content and outgassing kinetics in PBX-9502 by the experimental technique of TPD and the isoconversional thermal analysis. The results of these measurements were then used to construct moisture outgassing models for PBX-9502 in a dry environment (following 3 hours of vacuum pump)