WorldWideScience

Sample records for thermal analysis evaluation

  1. Using thermal analysis to evaluate the fire effects on organic matter content of Andisols

    Directory of Open Access Journals (Sweden)

    J. Neris

    2013-09-01

    Full Text Available Soil organic compounds play a relevant role in aggregate stability and thus, in the susceptibility of soils to erosion. Thermal analysis (N2 and air and chemical oxidation techniques (dichromate and permanganate oxidation were used to evaluate the effects of a forest fire on the organic matter of Andisols. Both thermal analysis and chemical methods showed a decrease in the organic matter content and an increase in the recalcitrance of the remaining organic compounds in the burned zones. Thermal analysis indicated an increase in the thermal stability of the organic compounds of fire-affected soils and a lower content of both labile and recalcitrant pools as a consequence of the fire. However, this decrease was relatively higher in the labile pool and lower in the recalcitrant one, indicative of an increase in the recalcitrance of the remaining organic compounds. Apparently, black carbon did not burn under our experimental conditions. Under N2, the results showed a lower labile and a higher recalcitrant and refractory contents in burned and some unburned soils, possibly due to the lower decomposition rate under N2 flux. Thermal analysis using O2 and the chemical techniques showed a positive relation, but noticeable differences in the total amount of the labile pool. Thermal analysis methods provide direct quantitative information useful to characterize the soil organic matter quality and to evaluate the effects of fire on soils.

  2. Structural changes of wood during hydro-thermal and thermal treatments evaluated through NIR spectroscopy and principal component analysis

    Science.gov (United States)

    Popescu, Carmen-Mihaela; Navi, Parviz; Placencia Peña, María Inés; Popescu, Maria-Cristina

    2018-02-01

    Spruce wood samples were subjected to different conditions of thermal and hydro-thermal treatment by varying the temperature, relative humidity and period of exposure. The obtained treated samples were evaluated using near infrared spectroscopy (NIR), principal component analysis (PCA) and hierarchical cluster analysis (HCA) in order to evidence the structural changes which may occur during the applied treatment conditions. Following this, modification in all wood components were observed, modifications which were dependent on the temperature, amount of relative humidity and also the treatment time. Therefore, higher variations were evidenced for samples treated at higher temperatures and for longer periods. At the same time, the increase in the amount of water vapours in the medium induced a reduced rate of side chains and condensation reactions occurring in the wood structure. Further, by PCA and HCA was possible to discriminate the modifications in the wood samples according to treatment time and amount of relative humidity.

  3. 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.

  4. Powdered hydrogenation catalysts. An evaluation and characterization by thermal analysis and ESCA

    Energy Technology Data Exchange (ETDEWEB)

    Kosak, J.R.; Duch, M.W.

    1979-01-01

    An evaluation and characterization by thermal analysis and ESCA showed that both techniques are excellent tools for screening such catalysts, e.g., carbon-supported platinum (1, 4, or 5Vertical Bar3<) or palladium (5Vertical Bar3<) tested in the liquid-phase, batch hydrogenation of p-nitrotoluene at 120/sup 0/C and 500 psig hydrogen. Thermal analysis, a chemisorption technique combined with pressure differential scanning calorimetry, affords a fast, practical means for monitoring the reproducibility of both unreduced and reduced catalysts and yields direct information on catalyst behavior in the presence of hydrogen. ESCA measures relative metal dispersion and permits the evaluation of completeness of reduction in those catalysts after prereduction. The combination of the two techniques provides comparison data about metal dispersion on the support and information on the chemical state of the metal, the latter being particularly useful for characterizing catalyst selectivity. For unreduced or completely reduced catalysts, both techniques give similar hydrogenation performance predictions, but for prereduced catalysts with only partial metal conversion to the zero oxidation state, ESCA yields more reliable data.

  5. Comparative evaluation of thermal oxidative decomposition for oil-plant residues via thermogravimetric analysis: Thermal conversion characteristics, kinetics, and thermodynamics.

    Science.gov (United States)

    Chen, Jianbiao; Wang, Yanhong; Lang, Xuemei; Ren, Xiu'e; Fan, Shuanshi

    2017-11-01

    Thermal oxidative decomposition characteristics, kinetics, and thermodynamics of rape straw (RS), rapeseed meal (RM), camellia seed shell (CS), and camellia seed meal (CM) were evaluated via thermogravimetric analysis (TGA). TG-DTG-DSC curves demonstrated that the combustion of oil-plant residues proceeded in three stages, including dehydration, release and combustion of organic volatiles, and chars oxidation. As revealed by combustion characteristic parameters, the ignition, burnout, and comprehensive combustion performance of residues were quite distinct from each other, and were improved by increasing heating rate. The kinetic parameters were determined by Coats-Redfern approach. The results showed that the most possible combustion mechanisms were order reaction models. The existence of kinetic compensation effect was clearly observed. The thermodynamic parameters (ΔH, ΔG, ΔS) at peak temperatures were calculated through the activated complex theory. With the combustion proceeding, the variation trends of ΔH, ΔG, and ΔS for RS (RM) similar to those for CS (CM). Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Solar Thermal Concept Evaluation

    Science.gov (United States)

    Hawk, Clark W.; Bonometti, Joseph A.

    1995-01-01

    Concentrated solar thermal energy can be utilized in a variety of high temperature applications for both terrestrial and space environments. In each application, knowledge of the collector and absorber's heat exchange interaction is required. To understand this coupled mechanism, various concentrator types and geometries, as well as, their relationship to the physical absorber mechanics were investigated. To conduct experimental tests various parts of a 5,000 watt, thermal concentrator, facility were made and evaluated. This was in anticipation at a larger NASA facility proposed for construction. Although much of the work centered on solar thermal propulsion for an upper stage (less than one pound thrust range), the information generated and the facility's capabilities are applicable to material processing, power generation and similar uses. The numerical calculations used to design the laboratory mirror and the procedure for evaluating other solar collectors are presented here. The mirror design is based on a hexagonal faceted system, which uses a spherical approximation to the parabolic surface. The work began with a few two dimensional estimates and continued with a full, three dimensional, numerical algorithm written in FORTRAN code. This was compared to a full geometry, ray trace program, BEAM 4, which optimizes the curvatures, based on purely optical considerations. Founded on numerical results, the characteristics of a faceted concentrator were construed. The numerical methodologies themselves were evaluated and categorized. As a result, the three-dimensional FORTRAN code was the method chosen to construct the mirrors, due to its overall accuracy and superior results to the ray trace program. This information is being used to fabricate and subsequently, laser map the actual mirror surfaces. Evaluation of concentrator mirrors, thermal applications and scaling the results of the 10 foot diameter mirror to a much larger concentrator, were studied. Evaluations

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

    KAUST Repository

    Qiu, Wulin

    2011-08-01

    Seven polyimides based on (4,4′-hexafluoroisopropylidene) diphthalic anhydride, 6FDA, with different chemical structures were synthesized in a single pot two-step procedure by first producing a high molecular weight polyamic acid (PAA), followed 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-linking through a diol, and ion-exchange reactions of selected polyimide membranes were investigated. Cross-linking of polymer membranes was confirmed by solubility tests and CO 2 permeability measurements. The thermal analysis provides simple and timesaving opportunities to characterize the polymer properties, the ability to optimize polymer cross-linking conditions, and to monitor polymer functionalization to develop high performance polymeric membranes for gas separations. © 2011 Elsevier Ltd. All rights reserved.

  8. Numerical analysis of thermal stratification phenomena in upper plenum of a fast breeder reactor (1). Evaluation of thermal stratification phenomena near the region of flow holes

    Energy Technology Data Exchange (ETDEWEB)

    Suda, Kazunori; Muramatu, Toshiharu; Yamaguchi, Akira [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center

    2002-12-01

    Thermal stratification phenomena are observed in an upper plenum of liquid metal fast breeder reactors (LMFBRs) under reactor scram conditions, which give rise to thermal stress on structural components. Therefore it is important to evaluate characteristics of the phenomena in the design on the internal structures in an LMFBR plenum. To evaluate long-term characteristics of thermal stratification phenomena in a typical LMFBR upper plenum, numerical analysis was carried out with a multi-dimensional thermohydraulics code AQUA for a scram event from full power operation condition. Thereafter the numerical results were compared with extrapolated results of measured transient data on the 40% operation condition. From the thermohydraulic analysis by the AQUA code, the following results have been obtained. (Long-term characteristics of thermal stratification phenomena) The cold fluid region near the inside inner barrel was expanded with accumulation of the cold fluid in the lower region of the plenum after 300 seconds from the reactor scram, so that the fluid from core flowed to the lower region of the upper plenum. The characteristics of axial temperature distributions in the upper plenum were similar to them at the 300 seconds. The thermal stratification interface was located initially around intermediate position between upper lower flow holes. And an another thermal stratification interface was formed around the inner barrel support plate after 300 seconds from the scram, so that the cold fluid accumulated in the lower region of the plenum. But the thermal stratification interface around the inner barrel support plate was disappeared by mixture and heat conduction of coolant of circumferential direction. The thermal stratification interface which was located below in the upper flow holes, rose to the upward position of the upper flow holes at the 720 seconds. In annular gap region between the inner barrel and the reactor vessel wall, thermal stratification interface

  9. Evaluation of a 2-step thermal method for separating organic and elemental carbon for radiocarbon analysis

    NARCIS (Netherlands)

    Dusek, U.; Monaco, M.; Prokopiou, M.; Gongriep, F.; Hitzenberger, R.; Meijer, H. A. J.; Röckmann, T.

    2014-01-01

    We thoroughly characterized a system for thermal separation of organic carbon (OC) and elemental carbon (EC) for subsequent radiocarbon analysis. Different organic compounds as well as ambient aerosol filter samples were introduced into an oven system and combusted to CO2 in pure O2. The main

  10. Synchronized Analysis of FTIR Spectra and GCMS Chromatograms for Evaluation of the Thermally Degraded Vegetable Oils

    Directory of Open Access Journals (Sweden)

    Siong Fong Sim

    2014-01-01

    Full Text Available Fourier Transform Infrared (FTIR and Gas Chromatography Mass Spectrometry (GCMS are two common instruments used for analysis of edible oils. The output signal is often analysed on the software attached to the workstations. The processing software is usually individualised for a specific source. The output of GCMS cannot be analysed on the FTIR hence analysts often need to juggle between instruments when multiple techniques are employed. This could become exhaustive when a large dataset is involved. This paper reports a synchronised approach for analysis of signal from FTIR and GCMS. The algorithm is demonstrated on a dataset of edible oils to investigate the thermal degradation of seven types of edible oils treated at 100°C and 150°C. The synchronised routines identify peaks present in FTIR and GCMS spectra/chromatograms where the information is subsequently extracted onto peak tables for further analysis. In this study, it is found that palm based products and corn oils were relatively more stable with higher content of antioxidants tocopherols and squalene. As a conclusion, this approach allows simultaneous analysis of signal from multiple sources and samples enhancing the efficiency of the signal processing process.

  11. Fast Transient Thermal Analysis of Non-Fourier Heat Conduction Using Tikhonov Well-Conditioned Asymptotic Waveform Evaluation

    Directory of Open Access Journals (Sweden)

    Sohel Rana

    2014-01-01

    Full Text Available Non-Fourier heat conduction model with dual phase lag wave-diffusion model was analyzed by using well-conditioned asymptotic wave evaluation (WCAWE and finite element method (FEM. The non-Fourier heat conduction has been investigated where the maximum likelihood (ML and Tikhonov regularization technique were used successfully to predict the accurate and stable temperature responses without the loss of initial nonlinear/high frequency response. To reduce the increased computational time by Tikhonov WCAWE using ML (TWCAWE-ML, another well-conditioned scheme, called mass effect (ME T-WCAWE, is introduced. TWCAWE with ME (TWCAWE-ME showed more stable and accurate temperature spectrum in comparison to asymptotic wave evaluation (AWE and also partial Pade AWE without sacrificing the computational time. However, the TWCAWE-ML remains as the most stable and hence accurate model to analyze the fast transient thermal analysis of non-Fourier heat conduction model.

  12. Fast transient thermal analysis of non-Fourier heat conduction using Tikhonov well-conditioned asymptotic waveform evaluation.

    Science.gov (United States)

    Rana, Sohel; Kanesan, Jeevan; Reza, Ahmed Wasif; Ramiah, Harikrishnan

    2014-01-01

    Non-Fourier heat conduction model with dual phase lag wave-diffusion model was analyzed by using well-conditioned asymptotic wave evaluation (WCAWE) and finite element method (FEM). The non-Fourier heat conduction has been investigated where the maximum likelihood (ML) and Tikhonov regularization technique were used successfully to predict the accurate and stable temperature responses without the loss of initial nonlinear/high frequency response. To reduce the increased computational time by Tikhonov WCAWE using ML (TWCAWE-ML), another well-conditioned scheme, called mass effect (ME) T-WCAWE, is introduced. TWCAWE with ME (TWCAWE-ME) showed more stable and accurate temperature spectrum in comparison to asymptotic wave evaluation (AWE) and also partial Pade AWE without sacrificing the computational time. However, the TWCAWE-ML remains as the most stable and hence accurate model to analyze the fast transient thermal analysis of non-Fourier heat conduction model.

  13. Thermal analysis and performance optimization of a solar hot water plant with economic evaluation

    KAUST Repository

    Kim, Youngdeuk

    2012-05-01

    The main objective of this study is to optimize the long-term performance of an existing active-indirect solar hot water plant (SHWP), which supplies hot water at 65 °C for use in a flight kitchen, using a micro genetic algorithm in conjunction with a relatively detailed model of each component in the plant and solar radiation model based on the measured data. The performance of SHWP at Changi International Airport Services (CIASs), Singapore, is studied for better payback period using the monthly average hourly diffuse and beam radiations and ambient temperature data. The data input for solar radiation model is obtained from the Singapore Meteorological Service (SMS), and these data have been compared with long-term average data of NASA (surface meteorology and solar energy or SSE). The comparison shows a good agreement between the predicted and measured hourly-averaged, horizontal global radiation. The SHWP at CIAS, which comprises 1200m 2 of evacuated-tube collectors, 50m 3 water storage tanks and a gas-fired auxiliary boiler, is first analyzed using a baseline configuration, i.e., (i) the local solar insolation input, (ii) a coolant flow rate through the headers of collector based on ASHRAE standards, (iii) a thermal load demand pattern amounting to 100m 3/day, and (iv) the augmentation of water temperature by auxiliary when the supply temperature from solar tank drops below the set point. A comparison between the baseline configuration and the measured performance of CIAS plant gives reasonably good validation of the simulation code. Optimization is further carried out for the following parameters, namely; (i) total collector area of the plant, (ii) storage volume, and (iii) three daily thermal demands. These studies are performed for both the CIAS plant and a slightly modified plant where the hot water supply to the load is adjusted constant at times when the water temperature from tank may exceed the set temperature. It is found that the latter

  14. Evaluation of B&W UO2/ThO2 VIII experimental core: criticality and thermal disadvantage factor analysis

    Energy Technology Data Exchange (ETDEWEB)

    Carlo Parisi; Emanuele Negrenti

    2017-02-01

    In the framework of the OECD/NEA International Reactor Physics Experiment (IRPHE) Project, an evaluation of core VIII of the Babcock & Wilcox (B&W) Spectral Shift Control Reactor (SSCR) critical experiment program was performed. The SSCR concept, moderated and cooled by a variable mixture of heavy and light water, envisaged changing of the thermal neutron spectrum during the operation to encourage breeding and to sustain the core criticality. Core VIII contained 2188 fuel rods with 93% enriched UO2-ThO2 fuel in a moderator mixture of heavy and light water. The criticality experiment and measurements of the thermal disadvantage factor were evaluated.

  15. Thermal microactuator dimension analysis

    Science.gov (United States)

    Azman, N. D.; Ong, N. R.; Aziz, M. H. A.; Alcain, J. B.; Haimi, W. M. W. N.; Sauli, Z.

    2017-09-01

    The focus of this study was to analyse the stress and thermal flow of thermal microactuator with different type of materials and parameter using COMSOL Multiphysics software. Simulations were conducted on the existing thermal actuator and integrated it to be more efficient, low cost and low power consumption. In this simulation, the U-shaped actuator was designed and five different materials of the microactuator were studied. The result showed that Si Polycrystalline was the most suitable material used to produce thermal actuator for commercialization.

  16. Evaluating Different Green School Building Designs for Albania: Indoor Thermal Comfort, Energy Use Analysis with Solar Systems

    Science.gov (United States)

    Dalvi, Ambalika Rajendra

    Improving the conditions of schools in many parts of the world is gradually acquiring importance. The Green School movement is an integral part of this effort since it aims at improving indoor environmental conditions. This would in turn, enhance student- learning while minimizing adverse environmental impact through energy efficiency of comfort-related HVAC and lighting systems. This research, which is a part of a larger research project, aims at evaluating different school building designs in Albania in terms of energy use and indoor thermal comfort, and identify energy efficient options of existing schools. We start by identifying three different climate zones in Albania; Coastal (Durres), Hill/Pre-mountainous (Tirana), mountainous (Korca). Next, two prototypical school building designs are identified from the existing stock. Numerous scenarios are then identified for analysis which consists of combinations of climate zone, building type, building orientation, building upgrade levels, presence of renewable energy systems (solar photovoltaic and solar water heater). The existing building layouts, initially outlined in CAD software and then imported into a detailed building energy software program (eQuest) to perform annual simulations for all scenarios. The research also predicted indoor thermal comfort conditions of the various scenarios on the premise that windows could be opened to provide natural ventilation cooling when appropriate. This study also estimated the energy generated from solar photovoltaic systems and solar water heater systems when placed on the available roof area to determine the extent to which they are able to meet the required electric loads (plug and lights) and building heating loads respectively. The results showed that there is adequate indoor comfort without the need for mechanical cooling for the three climate zones, and that only heating is needed during the winter months.

  17. Thermal analysis evaluation of the reactivity of coal mixtures for injection in the blast furnace

    Directory of Open Access Journals (Sweden)

    Maria de Lourdes Ilha Gomes

    2006-03-01

    Full Text Available Pulverized Coal Injection (PCI is an important standard technology replacing coke partially by pulverized coal into the blast furnace that allows a significant reduction of hot metal costs and environmental impact, contributing to a decrease of coke requirements for ironmaking. Coals typically used in this process in Brazil are, at current time, exclusively imported from many countries, although economic important coal-measures occur in the southern part of the country. The Brazilian coals have a low rank, higher contents of inert components, proportioning nocoking properties and an expected high reactivity. Due to these caractheristics, these coals could be used for injection in the blast furnaces in order to decrease the dependency on high cost imported coals. The efficiency in the combustion and the coal reactivity are considered important parameters in the blast furnace, since a larger amount of char (unburned coal causes severe problems to the furnace operation. The aim of the present work is to compare the reactivity of a south Brazilian coal, obtained from Faxinal mine, with two imported coals and the blends of the Brazilian coal with the imported ones. The reactivity of these coals and their blends were evaluated in a thermogravimetric analyzer. In the experiments, various mass ratios of Faxinal coal and the imported coals were used to compose the blends. The gasification reaction with pure CO2 was conducted under isothermal conditions at 1050 °C and atmospheric pressure. The experimental results show the greater reactivity of the Faxinal coal. The additive behavior was confirmed. The blends with a composition of up to 50% Faxinal coal have parameters according to the usual limits used for PCI.

  18. 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...

  19. Evaluation of a two-step thermal method for separating organic and elemental carbon for radiocarbon analysis

    NARCIS (Netherlands)

    Dusek, U.; Monaco, M.; Prokopiou, M.; Gongriep, F.; Hitzenberger, R.; Meijer, H. A. J.; Rockmann, T.

    2014-01-01

    We thoroughly characterized a system for thermal separation of organic carbon (OC) and elemental carbon (EC) for subsequent radiocarbon analysis. Different organic compounds as well as ambient aerosol filter samples were introduced into an oven system and combusted to CO2 in pure O-2. The main

  20. Stability evaluation of tocopheryl acetate and ascorbyl tetraisopalmitate in isolation and incorporated in cosmetic formulations using thermal analysis

    Directory of Open Access Journals (Sweden)

    Mariana Mandelli de Almeida

    2010-03-01

    Full Text Available In view of the increase in the number of cosmetic preparations containing antioxidant vitamins, chiefly, due to their action in preventing the process of skin aging, there is a need to develop pre-formulation studies and to validate analytical methods in order to obtain high quality products. Thus, the objective of this research was to evaluate and compare the thermal behavior of tocopheryl acetate and ascorbyl tetraisopalmitate as raw materials, and incorporated into a base cream. Thermogravimetry (TG / DTG and differential scanning calorimetry (DSC were used for this purpose. Both vitamins were found to be stable up to 250ºC. The base cream (placebo and the sample (base cream containing the vitamins presented different weight loss. Thermal analysis has shown itself to be an excellent tool for the characterization of these vitamins and can be used in routine analysis for quality control of this type of cosmetic formulation.Considerando o potencial antioxidante das vitaminas utilizadas em produtos cosméticos, seu uso na prevenção do processo de envelhecimento da pele e a necessidade de estudos de pré-formulação que garantam o desenvolvimento de cosméticos de qualidade, foi objetivo deste trabalho avaliar e comparar o comportamento térmico dos ativos acetato de tocoferila e tetraisopalmitato de ascorbila, matérias-primas, isoladamente e incorporados em creme base. As técnicas termogravimetria/termogravimetria derivada (TG/DTG e calorimetria exploratória diferencial (DSC foram utilizadas para tal finalidade. Verificou-se que as vitaminas mantiveram-se estáveis até a temperatura de, aproximadamente, 250 ºC, observando-se diferença na perda de massa entre o creme base e o creme base associado às vitaminas. Assim sendo, a análise térmica mostrou-se como excelente ferramenta para caracterização das vitaminas e do creme base, podendo ser empregada em análises de rotina no controle de qualidade deste tipo de formulação cosmética.

  1. Accelerating evaluation of converged lattice thermal conductivity

    Science.gov (United States)

    Qin, Guangzhao; Hu, Ming

    2018-01-01

    High-throughput computational materials design is an emerging area in materials science, which is based on the fast evaluation of physical-related properties. The lattice thermal conductivity (κ) is a key property of materials for enormous implications. However, the high-throughput evaluation of κ remains a challenge due to the large resources costs and time-consuming procedures. In this paper, we propose a concise strategy to efficiently accelerate the evaluation process of obtaining accurate and converged κ. The strategy is in the framework of phonon Boltzmann transport equation (BTE) coupled with first-principles calculations. Based on the analysis of harmonic interatomic force constants (IFCs), the large enough cutoff radius (rcutoff), a critical parameter involved in calculating the anharmonic IFCs, can be directly determined to get satisfactory results. Moreover, we find a simple way to largely ( 10 times) accelerate the computations by fast reconstructing the anharmonic IFCs in the convergence test of κ with respect to the rcutof, which finally confirms the chosen rcutoff is appropriate. Two-dimensional graphene and phosphorene along with bulk SnSe are presented to validate our approach, and the long-debate divergence problem of thermal conductivity in low-dimensional systems is studied. The quantitative strategy proposed herein can be a good candidate for fast evaluating the reliable κ and thus provides useful tool for high-throughput materials screening and design with targeted thermal transport properties.

  2. Evaluation of the carbon content of aerosols from the burn- ing of biomass in the Brazilian Amazon using thermal, op- tical and thermal-optical analysis methods

    Energy Technology Data Exchange (ETDEWEB)

    Soto-Garcia, Lydia L.; Andreae, Meinrat O.; Andreae, Tracey W.; taxo, Paulo Ar-; Maenhaut, Willy; Kirchstetter, Thomas; Novakov, T.; Chow, Judith C.; Mayol-Bracero, Olga L.

    2011-06-03

    Aerosol samples were collected at a pasture site in the Amazon Basin as part of the project LBA-SMOCC-2002 (Large-Scale Biosphere-Atmosphere Experiment in Amazonia - Smoke Aerosols, Clouds, Rainfall and Climate: Aerosols from Biomass Burning Perturb Global and Regional Climate). Sampling was conducted during the late dry season, when the aerosol composition was dominated by biomass burning emissions, especially in the submicron fraction. A 13-stage Dekati low-pressure impactor (DLPI) was used to collect particles with nominal aerodynamic diameters (D{sub p}) ranging from 0.03 to 0.10 m. Gravimetric analyses of the DLPI substrates and filters were performed to obtain aerosol mass concentrations. The concentrations of total, apparent elemental, and organic carbon (TC, EC{sub a}, and OC) were determined using thermal and thermal-optical analysis (TOA) methods. A light transmission method (LTM) was used to determine the concentration of equivalent black carbon (BC{sub e}) or the absorbing fraction at 880 nm for the size-resolved samples. During the dry period, due to the pervasive presence of fires in the region upwind of the sampling site, concentrations of fine aerosols (D{sub p} < 2.5 {mu}m: average 59.8 {mu}g m{sup -3}) were higher than coarse aerosols (D{sub p} > 2.5 {mu}m: 4.1 {mu}g m{sup -3}). Carbonaceous matter, estimated as the sum of the particulate organic matter (i.e., OC x 1.8) plus BC{sub e}, comprised more than 90% to the total aerosol mass. Concentrations of EC{sub a} (estimated by thermal analysis with a correction for charring) and BCe (estimated by LTM) averaged 5.2 {+-} 1.3 and 3.1 {+-} 0.8 {mu}g m{sup -3}, respectively. The determination of EC was improved by extracting water-soluble organic material from the samples, which reduced the average light absorption {angstrom} exponent of particles in the size range of 0.1 to 1.0 {mu}m from > 2.0 to approximately 1.2. The size-resolved BC{sub e} measured by the LTM showed a clear maximum between 0.4 and

  3. Thermal-structural Analysis and Fatigue Life Evaluation of a Parallel Slide Gate Valve in Accordance with ASME B and PVC

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Ho; Han, Jeong Sam [Andong Nat’l Univ., Andong (Korea, Republic of); Jae Seung Choi [Key Valve Technologies Ltd., Siheung (Korea, Republic of)

    2017-02-15

    A parallel slide gate valve (PSGV) is located between the heat recovery steam generator (HRSG) and the steam turbine in a combined cycle power plant (CCPP). It is used to control the flow of steam and runs with repetitive operations such as startups, load changes, and shutdowns during its operation period. Therefore, it is necessary to evaluate the fatigue damage and the structural integrity under a large compressive thermal stress due to the temperature difference through the valve wall thickness during the startup operations. In this paper, the thermal-structural analysis and the fatigue life evaluation of a 16-inch PSGV, which is installed on the HP steam line, is performed according to the fatigue life assessment method described in the ASME B and PVC VIII-2; the method uses the equivalent stress from the elastic stress analysis.

  4. Thermal neutron scattering evaluation framework

    Science.gov (United States)

    Chapman, Chris; Leal, Luiz; Rahnema, Farzad; Danon, Yaron; Arbanas, Goran

    2017-09-01

    A neutron scattering kernel data evaluation framework for computation of model-dependent predictions and their uncertainties is outlined. In this framework, model parameters are fitted to double-differential cross section measurements and their uncertainties. For convenience, the initial implementation of this framework uses the molecular dynamics model implemented in the GROMACS code. It is applied to light water using the TIP4P/2005f interaction model. These trajectories computed by GROMACS are then processed using nMOLDYN to compute the density of states, which is then used to calculate the scattering kernel using the Gaussian approximation. Double differential cross sections computed from the scattering kernel are then fitted to double-differential scattering data measured at the Spallation Neutron Source detector at Oak Ridge National Laboratory. The fitting procedure is designed to yield optimized model-parameters and their uncertainties in the form of a covariance matrix, from which new evaluations of thermal neutron scattering kernel will be generated. The Unified Monte Carlo method will be used to fit the simulation data to the experimental data.

  5. Evaluation of thermal overload in boiler operators.

    Science.gov (United States)

    Braga, Camila Soares; Rodrigues, Valéria Antônia Justino; Campos, Julio César Costa; de Souza, Amaury Paulo; Minette, Luciano José; de Moraes, Angêlo Casali; Sensato, Guilherme Luciano

    2012-01-01

    The Brazilians educational institutions need a large energy demand for the operation of laundries, restaurants and accommodation of students. Much of that energy comes from steam generated in boilers with wood fuel. The laboral activity in boiler may present problems for the operator's health due to exposure to excessive heat, and its operation has a high degree of risk. This paper describes an analysis made the conditions of thermal environment in the operation of a B category boiler, located at a Higher Education Institution, located in the Zona da Mata Mineira The equipments used to collect data were Meter WBGT of the Heat Index; Meter of Wet Bulb Index and Globe Thermometer (WBGT); Politeste Instruments, an anemometer and an Infrared Thermometer. By the application of questionnaires, the second phase consisted of collecting data on environmental factors (temperature natural environment, globe temperature, relative humidity and air velocity). The study concluded that during the period evaluated, the activity had thermal overload.

  6. Evaluation of thermal-storage concepts for solar cooling applications

    Science.gov (United States)

    Hughes, P. J.; Morehouse, J. H.; Choi, M. K.; White, N. M.; Scholten, W. B.

    1981-10-01

    Various configuration concepts for utilizing thermal energy storage to improve the thermal and economic performance of solar cooling systems for buildings were analyzed. The storge concepts evaluated provide short-term thermal storge via the bulk containment of water or salt hydrates. The evaluations were made for both residential-size cooling systems (3-ton) and small commercial-size cooling systems (25-ton). The residential analysis considers energy requirements for space heating, space cooling and water heating, while the commercial building analysis is based only on energy requirements for space cooling. The commercial building analysis considered a total of 10 different thermal storage/solar systems, 5 each for absorption and Rankine chiller concepts. The residential analysis considered 4 thermal storage/solar systems, all utilizing an absorption chiller. The trade-offs considered include: cold-side versus hot-side storage, single vs multiple stage storage, and phase-change vs sensible heat storage.

  7. Efficiency of the Needle Probe Test for Evaluation of Thermal Conductivity of Composite Materials: Two-Scale Analysis

    Directory of Open Access Journals (Sweden)

    Łydżba Dariusz

    2014-03-01

    Full Text Available The needle probe test, as a thermal conductivity measurement method, has become very popular in recent years. In the present study, the efficiency of this methodology, for the case of composite materials, is investigated based on the numerical simulations. The material under study is a two-phase composite with periodic microstructure of “matrix-inclusion” type. Two-scale analysis, incorporating micromechanics approach, is performed. First, the effective thermal conductivity of the composite considered is found by the solution of the appropriate boundary value problem stated for the single unit cell. Next, numerical simulations of the needle probe test are carried out. In this case, two different locations of the measuring sensor are considered. It is shown that the “equivalent” conductivity, derived from the probe test, is strongly affected by the location of the sensor. Moreover, comparing the results obtained for different scales, one can notice that the “equivalent” conductivity cannot be interpreted as the effective one for the composites considered. Hence, a crude approximation of the effective property is proposed based on the volume fractions of constituents and the equivalent conductivities derived from different sensor locations.

  8. Remote sensing of thermal radiation from an aircraft - An analysis and evaluation of crop-freeze protection methods

    Science.gov (United States)

    Sutherland, R. A.; Hannah, H. E.; Cook, A. F.; Martsolf, J. D.

    1981-01-01

    Thermal images from an aircraft-mounted scanner are used to evaluate the effectiveness of crop-freeze protection devices. Data from flights made while using fuel oil heaters, a wind machine and an undercanopy irrigation system are compared. Results show that the overall protection provided by irrigation (at approximately 2 C) is comparable to the less energy-efficient heater-wind machine combination. Protection provided by the wind machine alone (at approximately 1 C) was found to decrease linearly with distance from the machine by approximately 1 C/100 m. The flights were made over a 1.5 hectare citrus grove at an altitude of 450 m with an 8-14 micron detector. General meteorological conditions during the experiments, conducted during the nighttime, were cold (at approximately -6 C) and calm with clear skies.

  9. Evaluation of combined photovoltaic/thermal collectors

    Energy Technology Data Exchange (ETDEWEB)

    Hendrie, S.D.

    1979-01-01

    The thermal and electric performance of an air and a liquid type combined photovoltaic/thermal solar collector has been evaluated, yielding close correlation with theoretical results. Maximum thermal efficiencies of 42.5% and 40% for the liquid and air collectors without electric power production decreased to 40.4% and 32.9% when electrical power was produced. Maximum electrical efficiencies of 6.8% were measured.

  10. Validation of CENDL and JEFF evaluated nuclear data files for TRIGA calculations through the analysis of integral parameters of TRX and BAPL benchmark lattices of thermal reactors

    Energy Technology Data Exchange (ETDEWEB)

    Uddin, M.N. [Department of Physics, Jahangirnagar University, Dhaka (Bangladesh); Sarker, M.M. [Reactor Physics and Engineering Division, Institute of Nuclear Science and Technology, Atomic Energy Research Establishment, Savar, GPO Box 3787, Dhaka 1000 (Bangladesh); Khan, M.J.H. [Reactor Physics and Engineering Division, Institute of Nuclear Science and Technology, Atomic Energy Research Establishment, Savar, GPO Box 3787, Dhaka 1000 (Bangladesh)], E-mail: jahirulkhan@yahoo.com; Islam, S.M.A. [Department of Physics, Jahangirnagar University, Dhaka (Bangladesh)

    2009-10-15

    The aim of this paper is to present the validation of evaluated nuclear data files CENDL-2.2 and JEFF-3.1.1 through the analysis of the integral parameters of TRX and BAPL benchmark lattices of thermal reactors for neutronics analysis of TRIGA Mark-II Research Reactor at AERE, Bangladesh. In this process, the 69-group cross-section library for lattice code WIMS was generated using the basic evaluated nuclear data files CENDL-2.2 and JEFF-3.1.1 with the help of nuclear data processing code NJOY99.0. Integral measurements on the thermal reactor lattices TRX-1, TRX-2, BAPL-UO{sub 2}-1, BAPL-UO{sub 2}-2 and BAPL-UO{sub 2}-3 served as standard benchmarks for testing nuclear data files and have also been selected for this analysis. The integral parameters of the said lattices were calculated using the lattice transport code WIMSD-5B based on the generated 69-group cross-section library. The calculated integral parameters were compared to the measured values as well as the results of Monte Carlo Code MCNP. It was found that in most cases, the values of integral parameters show a good agreement with the experiment and MCNP results. Besides, the group constants in WIMS format for the isotopes U-235 and U-238 between two data files have been compared using WIMS library utility code WILLIE and it was found that the group constants are identical with very insignificant difference. Therefore, this analysis reflects the validation of evaluated nuclear data files CENDL-2.2 and JEFF-3.1.1 through benchmarking the integral parameters of TRX and BAPL lattices and can also be essential to implement further neutronic analysis of TRIGA Mark-II research reactor at AERE, Dhaka, Bangladesh.

  11. Transient thermal analysis of a titanium multiwall thermal protection system

    Science.gov (United States)

    Blosser, M. L.

    1982-01-01

    The application of the SPAR thermal analyzer to the thermal analysis of a thermal protection system concept is discussed. The titanium multiwall thermal protection system concept consists of alternate flat and dimpled sheets which are joined together at the crests of the dimples and formed into 30 cm by 30 cm (12 in. by 12 in.) tiles. The tiles are mechanically attached to the structure. The complex tile geometry complicates thermal analysis. Three modes of heat transfer were considered: conduction through the gas inside the tile, conduction through the metal, and radiation between the various layers. The voids between the dimpled and flat sheets were designed to be small enough so that natural convection is insignificant (e.g., Grashof number 1000). A two step approach was used in the thermal analysis of the multiwall thermal protection system. First, an effective normal (through-the-thickness) thermal conductivity was obtained from a steady state analysis using a detailed SPAR finite element model of a small symmetric section of the multiwall tile. This effective conductivity was then used in simple one dimensional finite element models for preliminary analysis of several transient heat transfer problems.

  12. A Study on an Evaluation of PWR Piping Thermal Stratification

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H.; Kim, B.N.; Lee, S.K.; Jeong, I.S.; Chjung, B.S.; Lee, S.H. [Korea Electric Power Research Institute, Taejeon (Korea, Republic of)

    1997-12-31

    This report presents the determination of thermal stratification phenomenon of pressurizer surge line for Kori unit No.4. With this regards, the integrity of related piping was evaluated by both various stress analysis and fatigue analysis. (author). 23 refs., 61 figs., 22 tabs.

  13. Structural Technology Evaluation Analysis Program (STEAP). Task Order 0029: Thermal Stability of Fatigue Life-Enhanced Structures

    Science.gov (United States)

    2012-01-01

    thermal and mechanical effects. When studying the residual stress relaxation behavior of AISI 4140 steel under conventional fatigue at elevated...Vohringer and 28. E. Macherauch, “Residual stress relaxation in an AISI 4140 steel due to quasistatic and cyclic loading at higher temperatures...temperature,” Mater. Sci. Engr., A366, 412- 420 (2004). 30. W. Cao, M. Khadhraoui, B. Brenier, J.Y. Guedou and L. Castex, “Thermomechanical relaxation

  14. SPECTROSCOPIC STUDIES AND THERMAL ANALYSIS OF LEAD ...

    African Journals Online (AJOL)

    a

    KEY WORDS: Lead, Tin, Schiff base, Infrared spectra, Thermal analysis. INTRODUCTION ... elemental analysis, infrared spectra as well as by their thermal analysis (DTA and TG). Analysis results are reported in Table 1. The percentage of lead and tin metals were determined using ..... PbO + 5C + 10C2H2 + N2 + CO.

  15. RACLETTE: a model for evaluating the thermal response of plasma facing components to slow high power plasma transients. Part II: Analysis of ITER plasma facing components

    Science.gov (United States)

    Federici, Gianfranco; Raffray, A. René

    1997-04-01

    The transient thermal model RACLETTE (acronym of Rate Analysis Code for pLasma Energy Transfer Transient Evaluation) described in part I of this paper is applied here to analyse the heat transfer and erosion effects of various slow (100 ms-10 s) high power energy transients on the actively cooled plasma facing components (PFCs) of the International Thermonuclear Experimental Reactor (ITER). These have a strong bearing on the PFC design and need careful analysis. The relevant parameters affecting the heat transfer during the plasma excursions are established. The temperature variation with time and space is evaluated together with the extent of vaporisation and melting (the latter only for metals) for the different candidate armour materials considered for the design (i.e., Be for the primary first wall, Be and CFCs for the limiter, Be, W, and CFCs for the divertor plates) and including for certain cases low-density vapour shielding effects. The critical heat flux, the change of the coolant parameters and the possible severe degradation of the coolant heat removal capability that could result under certain conditions during these transients, for example for the limiter, are also evaluated. Based on the results, the design implications on the heat removal performance and erosion damage of the variuos ITER PFCs are critically discussed and some recommendations are made for the selection of the most adequate protection materials and optimum armour thickness.

  16. 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.

  17. Thermal gradient analysis of solidifying casting

    Directory of Open Access Journals (Sweden)

    J. Suchoń

    2008-08-01

    Full Text Available For description of casting solidification and crystallization process the thermal derivative analysis (TDA is commonly used. Besides the process kinetics considered in TDA method to describe the solidification process, the thermal gradient analysis can be also used for this purpose [1, 2]. In conducted studies analysis of thermal gradient distribution inside the solidifying wedge casting was shown which enabled determination of heat flow intensity on casting section.

  18. Evaluation of Structure Influence on Thermal Conductivity of Thermal Insulating Materials from Renewable Resources

    Directory of Open Access Journals (Sweden)

    Jolanta VĖJELIENĖ

    2011-07-01

    Full Text Available The development of new thermal insulation materials needs to evaluate properties and structure of raw material, technological factors that make influence on the thermal conductivity of material. One of the most promising raw materials for production of insulation material is straw. The use of natural fibres in insulation is closely linked to the ecological building sector, where selection of materials is based on factors including recyclable, renewable raw materials and low resource production techniques In current work results of research on structure and thermal conductivity of renewable resources for production thermal insulating materials are presented. Due to the high abundance of renewable resources and a good its structure as raw material for thermal insulation materials barley straw, reeds, cattails and bent grass stalks are used. Macro- and micro structure analysis of these substances is performed. Straw bales of these materials are used for determining thermal conductivity. It was found that the macrostructure has the greatest effect on thermal conductivity of materials. Thermal conductivity of material is determined by the formation of a bale due to the large amount of pores among the stalks of the plant, inside the stalk and inside the stalk wall.http://dx.doi.org/10.5755/j01.ms.17.2.494

  19. 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).

  20. Parallel thermal analysis technology using an infrared camera for high-throughput evaluation of active pharmaceutical ingredients: a case study of melting point determination.

    Science.gov (United States)

    Kawakami, Kohsaku

    2010-09-01

    Various techniques for physical characterization of active pharmaceutical ingredients, including X-ray powder diffraction, birefringence observation, Raman spectroscopy, and high-performance liquid chromatography, can be conducted using 96-well plates. The only exception among the important characterization items is the thermal analysis, which can be a limiting step in many cases, notably when screening the crystal/salt form. In this study, infrared thermal camera technology was applied for thermal characterization of pharmaceutical compounds. The melting temperature of model compounds was determined typically within 5 min, and the obtained melting temperature values agreed well with those from differential scanning calorimetry measurements. Since many compounds can be investigated simultaneously in this infrared technology, it should be promising for high-throughput thermal analysis in the pharmaceutical developmental process.

  1. Thermal Environment evaluation in Commercial kitchens

    DEFF Research Database (Denmark)

    Simone, Angela; Olesen, Bjarne W.

    2012-01-01

    The indoor climate in commercial kitchens is often unsatisfactory and the working conditions can have a significant effect on employees’ comfort and productivity. The type (fast food, casual, etc.) and climatic zone can influence the thermal conditions in the kitchens. Moreover, size and arrangem......The indoor climate in commercial kitchens is often unsatisfactory and the working conditions can have a significant effect on employees’ comfort and productivity. The type (fast food, casual, etc.) and climatic zone can influence the thermal conditions in the kitchens. Moreover, size...... and arrangement of the kitchen zones, appliances, etc., complicate further an evaluation of the indoor thermal environment in kitchens. In general, comfort criteria are expressed in international standards such as ASHRAE 55 or ISO EN7730. But are these standardised methods applicable for such environments...

  2. Development and evaluation of thermal model reduction algorithms for spacecraft

    Science.gov (United States)

    Deiml, Michael; Suderland, Martin; Reiss, Philipp; Czupalla, Markus

    2015-05-01

    This paper is concerned with the topic of the reduction of thermal models of spacecraft. The work presented here has been conducted in cooperation with the company OHB AG, formerly Kayser-Threde GmbH, and the Institute of Astronautics at Technische Universität München with the goal to shorten and automatize the time-consuming and manual process of thermal model reduction. The reduction of thermal models can be divided into the simplification of the geometry model for calculation of external heat flows and radiative couplings and into the reduction of the underlying mathematical model. For simplification a method has been developed which approximates the reduced geometry model with the help of an optimization algorithm. Different linear and nonlinear model reduction techniques have been evaluated for their applicability in reduction of the mathematical model. Thereby the compatibility with the thermal analysis tool ESATAN-TMS is of major concern, which restricts the useful application of these methods. Additional model reduction methods have been developed, which account to these constraints. The Matrix Reduction method allows the approximation of the differential equation to reference values exactly expect for numerical errors. The summation method enables a useful, applicable reduction of thermal models that can be used in industry. In this work a framework for model reduction of thermal models has been created, which can be used together with a newly developed graphical user interface for the reduction of thermal models in industry.

  3. 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...

  4. 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.

  5. ALTERNATIVE METHOD FOR ON SITE EVALUATION OF THERMAL TRANSMITTANCE

    Directory of Open Access Journals (Sweden)

    Aleksandar Janković

    2017-08-01

    Full Text Available Thermal transmittance or U-value is an indicator of the building envelope thermal properties and a key parameter for evaluation of heat losses through the building elements due to heat transmission. It can be determined by calculation based on thermal characteristics of the building element layers. However, this value does not take into account the effects of irregularities and degradation of certain elements of the envelope caused by aging, which may lead to errors in calculation of the heat losses. An effective and simple method for determination of thermal transmittance is in situ measurement, which is governed by the ISO 9869-1:2014 that defines heat flow meter method. This relatively expensive method leaves marks and damages surface of the building element. Furthermore, the final result is not always reliable, in particular when the building element is light or when the weather conditions are not suitable. In order to avoid the above mentioned problems and to estimate the real thermal transmittance value an alternative experimental method, here referred as the natural convection and radiation method, is proposed in this paper. For determination of thermal transmittance, this method requires only temperatures of inside and outside air, as well as the inner wall surface temperature. A detailed statistical analysis, performed by the software package SPSS ver. 20, shows several more advantages of this method comparing to the standard heat flow meter one, besides economic and non-destructive benefits.

  6. Quick Spacecraft Thermal Analysis Tool Project

    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...

  7. Exergy analysis of thermal comfort

    OpenAIRE

    Prek, Matjaž

    2015-01-01

    Traditional methods of human thermal comfort 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, thesecond law of thermodynamics introduces the concept of exergy. It enables the determination of exergy consumption within the human body dependent on personal and environmental factors. We show that the existing methods of comfort assessment could be further expanded by t...

  8. 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.

  9. 40 CFR 91.427 - Catalyst thermal stress resistance evaluation.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Catalyst thermal stress resistance... Procedures § 91.427 Catalyst thermal stress resistance evaluation. (a)(1) The purpose of the evaluation procedure specified in this section is to determine the effect of thermal stress on catalyst conversion...

  10. 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.

  11. Thermal strain analysis of optic fiber sensors.

    Science.gov (United States)

    Her, Shiuh-Chuan; Huang, Chih-Ying

    2013-01-31

    An optical fiber sensor surface bonded onto a host structure and subjected to a temperature change is analytically studied in this work. The analysis is developed in order to assess the thermal behavior of an optical fiber sensor designed for measuring the strain in the host structure. For a surface bonded optical fiber sensor, the measuring sensitivity is strongly dependent on the bonding characteristics which include the protective coating, adhesive layer and the bonding length. Thermal stresses can be generated due to a mismatch of thermal expansion coefficients between the optical fiber and host structure. The optical fiber thermal strain induced by the host structure is transferred via the adhesive layer and protective coating. In this investigation, an analytical expression of the thermal strain and stress in the optical fiber is presented. The theoretical predictions are validated using the finite element method. Numerical results show that the thermal strain and stress are linearly dependent on the difference in thermal expansion coefficients between the optical fiber and host structure and independent of the thermal expansion coefficients of the adhesive and coating.

  12. Thermal Strain Analysis of Optic Fiber Sensors

    Directory of Open Access Journals (Sweden)

    Chih-Ying Huang

    2013-01-01

    Full Text Available An optical fiber sensor surface bonded onto a host structure and subjected to a temperature change is analytically studied in this work. The analysis is developed in order to assess the thermal behavior of an optical fiber sensor designed for measuring the strain in the host structure. For a surface bonded optical fiber sensor, the measuring sensitivity is strongly dependent on the bonding characteristics which include the protective coating, adhesive layer and the bonding length. Thermal stresses can be generated due to a mismatch of thermal expansion coefficients between the optical fiber and host structure. The optical fiber thermal strain induced by the host structure is transferred via the adhesive layer and protective coating. In this investigation, an analytical expression of the thermal strain and stress in the optical fiber is presented. The theoretical predictions are validated using the finite element method. Numerical results show that the thermal strain and stress are linearly dependent on the difference in thermal expansion coefficients between the optical fiber and host structure and independent of the thermal expansion coefficients of the adhesive and coating.

  13. 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.

  14. Thermal analysis of underground power cable system

    Science.gov (United States)

    Rerak, Monika; Ocłoń, Paweł

    2017-10-01

    The paper presents the application of Finite Element Method in thermal analysis of underground power cable system. The computations were performed for power cables buried in-line in the ground at a depth of 2 meters. The developed mathematical model allows determining the two-dimensional temperature distribution in the soil, thermal backfill and power cables. The simulations studied the effect of soil and cable backfill thermal conductivity on the maximum temperature of the cable conductor. Also, the effect of cable diameter on the temperature of cable core was studied. Numerical analyses were performed based on a program written in MATLAB.

  15. Thermal Analysis of a TREAT Fuel Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Papadias, Dionissios [Argonne National Lab. (ANL), Argonne, IL (United States); Wright, Arthur E. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2014-07-09

    The objective of this study was to explore options as to reduce peak cladding temperatures despite an increase in peak fuel temperatures. A 3D thermal-hydraulic model for a single TREAT fuel assembly was benchmarked to reproduce results obtained with previous thermal models developed for a TREAT HEU fuel assembly. In exercising this model, and variants thereof depending on the scope of analysis, various options were explored to reduce the peak cladding temperatures.

  16. Thermal Analysis of AC Contactor Using Thermal Network Finite Difference Analysis Method

    Science.gov (United States)

    Niu, Chunping; Chen, Degui; Li, Xingwen; Geng, Yingsan

    To predict the thermal behavior of switchgear quickly, the Thermal Network Finite Difference Analysis method (TNFDA) is adopted in thermal analysis of AC contactor in the paper. The thermal network model is built with nodes, thermal resistors and heat generators, and it is solved using finite difference method (FDM). The main circuit and the control system are connected by thermal resistors network, which solves the problem of multi-sources interaction in the application of TNFDA. The temperature of conducting wires is calculated according to the heat transfer process and the fundamental equations of thermal conduction. It provides a method to solve the problem of boundary conditions in applying the TNFDA. The comparison between the results of TNFDA and measurements shows the feasibility and practicability of the method.

  17. Characterization of Nanocomposites by Thermal Analysis

    Science.gov (United States)

    Corcione, Carola Esposito; Frigione, Mariaenrica

    2012-01-01

    In materials research, the development of polymer nanocomposites (PN) is rapidly emerging as a multidisciplinary research field with results that could broaden the applications of polymers to many different industries. PN are polymer matrices (thermoplastics, thermosets or elastomers) that have been reinforced with small quantities of nano-sized particles, preferably characterized by high aspect ratios, such as layered silicates and carbon nanotubes. Thermal analysis (TA) is a useful tool to investigate a wide variety of properties of polymers and it can be also applied to PN in order to gain further insight into their structure. This review illustrates the versatile applications of TA methods in the emerging field of polymer nanomaterial research, presenting some examples of applications of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical thermal analysis (DMTA) and thermal mechanical analysis (TMA) for the characterization of nanocomposite materials.

  18. 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

  19. Evaluation of laser prostatectomy devices by thermal imaging

    Science.gov (United States)

    Molenaar, David G.; van Vliet, Remco J.; van Swol, Christiaan F. P.; Boon, Tom A.; Verdaasdonck, Rudolf M.

    1994-12-01

    The treatment of benign prostatic hyperplasia (BPH) using Nd:YAG laser light has become an accepted alternative to TURP. However, there is no consensus to the dosimetry using the various laser devices. In our study, we evaluate the optical and thermal characteristics of 7 commercially available side firing laser probes. For the thermal analysis, an optical method was used based on `Schlieren' techniques producing color images of the temperature distribution around the laser probe in water. Absolute temperatures were obtained after calibration measurements with thermocouples. Laser probes using metal mirrors for beam deflection heated up entirely. The local temperature rose up to 100 degrees centigrade, thus inducing vapor bubble formation that interfered with the emitted beam. Laser devices, using total internal reflection for deflection, showed far less heating primarily at the exit window, though Fresnel reflections and secondary beams indirectly heated up the (metal) housing of the tip. After clinical application, the absorption at the probe surface and hence temperature increased due to probe deterioration. Color Schlieren imaging is a powerful method for the thermal evaluation of laser devices. The thermal behavior of laser probes can be used as a guidance for the method of application and as an indication of the lifetime of the probes.

  20. Energy efficiency evaluation of a stationary lithium-ion battery container storage system via electro-thermal modeling and detailed component analysis

    Energy Technology Data Exchange (ETDEWEB)

    Schimpe, Michael; Naumann, Maik; Truong, Nam; Hesse, Holger C.; Santhanagopalan, Shriram; Saxon, Aron; Jossen, Andreas

    2018-01-01

    Energy efficiency is a key performance indicator for battery storage systems. A detailed electro-thermal model of a stationary lithium-ion battery system is developed and an evaluation of its energy efficiency is conducted. The model offers a holistic approach to calculating conversion losses and auxiliary power consumption. Sub-models for battery rack, power electronics, thermal management as well as the control and monitoring components are developed and coupled to a comprehensive model. The simulation is parametrized based on a prototype 192 kWh system using lithium iron phosphate batteries connected to the low voltage grid. The key loss mechanisms are identified, thoroughly analyzed and modeled. Generic profiles featuring various system operation modes are evaluated to show the characteristics of stationary battery systems. Typically the losses in the power electronics outweigh the losses in the battery at low power operating points. The auxiliary power consumption dominates for low system utilization rates. For estimation of real-world performance, the grid applications Primary Control Reserve, Secondary Control Reserve and the storage of surplus photovoltaic power are evaluated. Conversion round-trip efficiency is in the range of 70-80%. Overall system efficiency, which also considers system power consumption, is 8-13 percentage points lower for Primary Control Reserve and the photovoltaic-battery application. However, for Secondary Control Reserve, the total round-trip efficiency is found to be extremely low at 23% due to the low energy throughput of this application type.

  1. 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.

  2. Prediction of the biochar carbon stability by thermal analysis

    Science.gov (United States)

    Méndez, Ana; Cely, Paola; Plaza, César; Paz-Ferreiro, Jorge; Gascó, Gabriel

    2015-04-01

    Thermal analysis (DTA, DSC, TG and dTG) has been used for decades to characterize carbonaceous materials used as fuels (oil, coal). Our research group has used these techniques for the characterisation of different biochars in order to assess proportions of labile and recalcitrant organic matter and to study the evolution of soil organic matter in soils amended with biochar. Thermal analysis could be used to determine the proximate analysis, i.e., the percentage of humidity, volatile matter and fixed carbon or to calculate the thermostability index, previously identified as a reliable parameter for evaluating the level of stability of organic matter in organic wastes and biochar. Relationship between the stability of biochar, the raw material and the pyrolysis conditions could be established by thermal analysis techniques.

  3. Thermal fluid mixing behavior during medium break LOCA in evaluation of pressurized thermal shock

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jae Won; Bang, Young Seok; Seul, Kwang Won; Kim, Hho Jung [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

    1998-12-31

    Thermal fluid mixing behavior during a postulated medium-size hot leg break loss of coolant accident is analyzed for the international comparative assessment study on pressurized thermal shock (PTS-ICAS) proposed by OECD-NEA. The applicability of RELAP5 code to analyze the thermal fluid mixing behavior is evaluated through a simple modeling relevant to the problem constraints. Based on the calculation result, the onset of thermal stratification is investigated using Theofanous`s empirical correlation. Sensitivity calculations using a fine node model and crossflow model are also performed to evaluate the modeling capability on multi-dimensional characteristics related to thermal fluid mixing. 6 refs., 8 figs. (Author)

  4. Method of thermal derivative gradient analysis (TDGA

    Directory of Open Access Journals (Sweden)

    M. Cholewa

    2009-07-01

    Full Text Available In this work a concept of thermal analysis was shown, using for crystallization kinetics description the temperature derivatives after time and direction. Method of thermal derivative gradient analysis (TDGA is assigned for alloys and metals investigation as well as cast composites in range of solidification. The construction and operation characteristics were presented for the test stand including processing modules and probes together with thermocouples location. Authors presented examples of results interpretation for AlSi11 alloy castings with diversified wall thickness and at different pouring temperature.

  5. Building high-accuracy thermal simulation for evaluation of thermal comfort in real houses

    OpenAIRE

    Nguyen, Hoaison; Makino, Yoshiki; Lim, Azman Osman; Tan, Yasuo; Shinoda, Yoichi

    2013-01-01

    Thermal comfort is an essential aspect for the control and verification of many smart home services. In this research, we design and implement simulation which models thermal environment of a smart house testbed. Our simulation can be used to evaluate thermal comfort in various conditions of home environment. In order to increase the accuracy of the simulation, we measure thermal-related parameters of the house such as temperature, humidity, solar radiation by the use of sensors and perform p...

  6. 40 CFR 90.427 - Catalyst thermal stress resistance evaluation.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Catalyst thermal stress resistance... Gaseous Exhaust Test Procedures § 90.427 Catalyst thermal stress resistance evaluation. (a) The purpose of... catalyst conversion efficiency for Phase 1 engines. The thermal stress is imposed on the test catalyst by...

  7. 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.

  8. Decision analysis for evaluating and ranking small solar thermal power system technologies. Volume I. A brief introduction to multiattribute decision analysis

    Energy Technology Data Exchange (ETDEWEB)

    Feinberg, A.; Miles, R.F. Jr.

    1978-06-01

    Multiattribute decision analysis is a methodology for providing information to a decision maker for comparing and selecting between complex alternatives. A brief introduction to the principal concepts of the Keeney and Raiffa approach to multiattribute decision analysis is presented. The concepts of decision alternatives, outcomes, objectives, attributes and their states, attribute utility functions, and the necessary independence properties for the attribute states to be aggregated into a numerical representation of the preferences of the decision maker for the outcomes and the decision alternatives are presented. 50 references.

  9. The micro thermal analysis of polymers

    CERN Document Server

    Grandy, D B

    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 ...

  10. 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

  11. 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.

  12. Evaluation of the onset of failure under mechanical and thermal stresses on luting agent for metal-ceramic and metal crowns by finite element analysis

    Directory of Open Access Journals (Sweden)

    Hema Agnihotri

    2010-01-01

    Full Text Available Long-term clinical failures of cemented prosthesis depend, to a large extent, on the integrity of the luting agent. The causative factors that lead to microfracture and, hence, failure of the luting agents are the stresses acting inside the oral cavity. Therefore, the present study was designed to develop an understanding of the relationship between stresses in the tooth and the failure potential of the luting agent. Two-dimensional finite element stress analysis was performed on the mandibular second premolar. The behavior of zinc-phosphate and glass-ionomer were studied under different crowns (metal-ceramic and metal crown and loading conditions (mechanical force of 450 N acting vertically over the occlusal surface, thermal loads of 60° and 0°C. It was observed from the study that failure threshold of the luting agent was influenced both by the elastic modulus of the luting agent and by the type of the crown.

  13. 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...... was developed in order to investigate the thermal behaviour of the solidifying metal. Three cylindrically shaped cast samples surrounded by different cooling materials were introduced in the same mould allowing a common metallurgical background for samples solidifying at different cooling rates. The proposed...

  14. A multiway chemometric and kinetic study for evaluating the thermal stability of edible oils by ¹H NMR analysis: comparison of methods.

    Science.gov (United States)

    Cordella, C B Y; Tekye, T; Rutledge, D N; Leardi, R

    2012-01-15

    The degradation process of edible oils of different nature, submitted to heating at 170°C, 190°C and 210°C with aeration, was studied by means of (1)H nuclear magnetic resonance spectroscopy (NMR). In this study, secondary products such as aldehydes were detected and monitored over time. Two complementary analytical approaches were adopted to characterize the kinetics of the appearance of aldehydes in the heated oils. This first was a classical kinetic approach based on the assumption that the overall degradation reaction to form aldehydes follows a rate law of order 1. This approach allowed us to calculate a thermal stability criterion for classifying the oils according to their heat stability. A second approach was to use the spectral fingerprint corresponding to aldehydes in a multivariate data analysis procedure in order to give the major trend in the studied phenomena, taking into account the multiway nature of recorded data. The application of different 3-way and 4-way Tucker3 models led to a better understanding of the chemical stability of the oils studied and was used to determine the order of stability of these oils. This multiway approach provides additional information that 2-way processing (PCA) does not provide clearly, such as the overall contribution of the heating time factor on the chemical evolution of oils. In conclusion, this work shows that a fully chemometric study of NMR spectra allows to order the oils according to their thermal stability and to achieve a result in good agreement with existing analytical and kinetic studies in the literature. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Thermal analysis applied to irradiated propolis

    Science.gov (United States)

    Matsuda, Andrea Harumi; Machado, Luci Brocardo; del Mastro, Nélida Lucia

    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 60Co 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°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.

  16. 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.

  17. Advaced Spatio-Temporal Thermal Analysis of Electronic Systems

    Directory of Open Access Journals (Sweden)

    Miroslav Hrianka

    2003-01-01

    Full Text Available The article gives a brief review the of diagnostics and analysis possibilities by a spatio-temporal approach into electronic system in infrared bandwidth. The two dimensional image grabbed by the thermo vision camera provides information about the surface temperature distribution of an electronic system. The main idea is based on the analysis of the object which consists of a temporal sequence of a spatial thermal images. Advanced analysis is achieved by morphological image gradient spatio-temporal model: The mentioned method provides a total temperature system evaluation as well as it allows separate analysis in the chosen determined temperature area.

  18. Thermodynamical analysis of human thermal comfort

    OpenAIRE

    Prek, Matjaž

    2015-01-01

    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 environ...

  19. 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.

  20. Thermal morphing anisogrid smart space structures: thermal isolation design and linearity evaluation

    Science.gov (United States)

    Phoenix, Austin A.

    2017-04-01

    To meet the requirements for the next generation of space missions, a paradigm shift is required from current structures that are static, heavy and stiff, toward innovative structures that are adaptive, lightweight, versatile, and intelligent. A novel morphing structure, the thermally actuated anisogrid morphing boom, can be used to meet the design requirements by making the primary structure actively adapt to the on-orbit environment. The anisogrid structure is able to achieve high precision morphing control through the intelligent application of thermal gradients. This active primary structure improves structural and thermal stability performance, reduces mass, and enables new mission architectures. This effort attempts to address limits to the author's previous work by incorporating the impact of thermal coupling that was initially neglected. This paper introduces a thermally isolated version of the thermal morphing anisogrid structure in order to address the thermal losses between active members. To evaluate the isolation design the stiffness and thermal conductivity of these isolating interfaces need to be addressed. This paper investigates the performance of the thermal morphing system under a variety of structural and thermal isolation interface properties.

  1. Saturn Ring Data Analysis and Thermal Modeling

    Science.gov (United States)

    Dobson, Coleman

    2011-01-01

    CIRS, VIMS, UVIS, and ISS (Cassini's Composite Infrared Specrtometer, Visual and Infrared Mapping Spectrometer, Ultra Violet Imaging Spectrometer and Imaging Science Subsystem, respectively), have each operated in a multidimensional observation space and have acquired scans of the lit and unlit rings at multiple phase angles. To better understand physical and dynamical ring particle parametric dependence, we co-registered profiles from these three instruments, taken at a wide range of wavelengths, from ultraviolet through the thermal infrared, to associate changes in ring particle temperature with changes in observed brightness, specifically with albedos inferred by ISS, UVIS and VIMS. We work in a parameter space where the solar elevation range is constrained to 12 deg - 14 deg and the chosen radial region is the B3 region of the B ring; this region is the most optically thick region in Saturn's rings. From this compilation of multiple wavelength data, we construct and fit phase curves and color ratios using independent dynamical thermal models for ring structure and overplot Saturn, Saturn ring, and Solar spectra. Analysis of phase curve construction and color ratios reveals thermal emission to fall within the extrema of the ISS bandwidth and a geometrical dependence of reddening on phase angle, respectively. Analysis of spectra reveals Cassini CIRS Saturn spectra dominate Cassini CIRS B3 Ring Spectra from 19 to 1000 microns, while Earth-based B Ring Spectrum dominates Earth-based Saturn Spectrum from 0.4 to 4 microns. From our fits we test out dynamical thermal models; from the phase curves we derive ring albedos and non-lambertian properties of the ring particle surfaces; and from the color ratios we examine multiple scattering within the regolith of ring particles.

  2. Evaluating local and overall thermal comfort in buildings using thermal manikins

    Energy Technology Data Exchange (ETDEWEB)

    Foda, E.

    2012-07-01

    Evaluation methods of human thermal comfort that are based on whole-body heat balance with its surroundings may not be adequate for evaluations in non-uniform thermal conditions. Under these conditions, the human body's segments may experience a wide range of room physical parameters and the evaluation of the local (segmental) thermal comfort becomes necessary. In this work, subjective measurements of skin temperature were carried out to investigate the human body's local responses due to a step change in the room temperature; and the variability in the body's local temperatures under different indoor conditions and exposures as well as the physiological steady state local temperatures. Then, a multi-segmental model of human thermoregulation was developed based on these findings to predict the local skin temperatures of individuals' body segments with a good accuracy. The model predictability of skin temperature was verified for steady state and dynamic conditions using measured data at uniform neutral, cold and warm as well as different asymmetric thermal conditions. The model showed very good predictability with average absolute deviation ranged from 0.3-0.8 K. The model was then implemented onto the control system of the thermal manikin 'THERMINATOR' to adjust the segmental skin temperature set-points based on the indoor conditions. This new control for the manikin was experimentally validated for the prediction of local and overall thermal comfort using the equivalent temperature measure. THERMINATOR with the new control mode was then employed in the evaluation of localized floor-heating system variants towards maximum energy efficiency. This aimed at illustrating a design strategy using the thermal manikin to find the optimum geometry and surface area of a floor-heater for a single seated person. Furthermore, a psychological comfort model that is based on local skin temperature was adapted for the use with the model of human

  3. Evaluation of solar thermal storages with quantitative flow visualisation

    Energy Technology Data Exchange (ETDEWEB)

    Logie, W.; Frank, E.; Luzzi, A.

    2008-07-15

    The non-intrusive Quantitative Flow Visualisation (QFV) Techniques of Particle Imaging Velocimetry (PIV) and Laser Induced Fluorescence (LIF) have been evaluated in the context of experimental investigations on solar Thermal Energy Storages (TES). Much competence and experience has been gained in the integration of these powerful yet complex and time consuming flow analysis methods into the realm of laboratory experimentation. In addition to gathering experience in the application of QFV techniques, a number of charging and discharging variations were considered in light of exergetic evaluation for the influence they have on the ability of a TES to stratify. The contemporary awareness that poorly chosen pitch to diameter ratios by the design of immersed coil heat exchangers leads to a reduction in heat exchange and an increase in mixing phenomenon has been confirmed. The observation of two combitank (combined domestic hot water and space heating) configurations has shown that free convective heat transfer forces in the form of mixing energy play a significant role in the stratification efficiency of thermal energy storages. (author)

  4. Evaluating Evaporation with Satellite Thermal Data.

    Science.gov (United States)

    1987-11-01

    and Executive S~ury: se attachd Water surface tmiera e can be obtaind fron satellite Ueml remote senir. landsat and other satellite s emitted thermal...values with the lake’s surface temp ~eratuire by performing a linear regression to get an equation, or model, that defines the evaporation for a given...infrared radiation on a regular basis over uxfd of the earth’s surface . Evaporation is acccmplished by the net txansport of mas from the water surface

  5. An approach to evaluate the intra-urban thermal variability in summer using an urban indicator.

    Science.gov (United States)

    Massetti, Luciano; Petralli, Martina; Brandani, Giada; Orlandini, Simone

    2014-09-01

    Urban planners and managers need tools to evaluate the performance of the present state and future development of cities in terms of comfort and quality of life. In this paper, an approach to analyse the intra-urban summer thermal variability, using an urban planning indicator, is presented. The proportion of buildings and concrete surfaces in a specific buffer area are calculated. Besides, the relationship between urban and temperature indicators is investigated and used to produce thermal maps of the city. This approach is applied to the analysis of intra-urban variability in Florence (Italy), of two thermal indices (heat index and cooling degree days) used to evaluate impacts on thermal comfort and energy consumption for indoor cooling. Our results suggest that urban planning indicators can describe intra-urban thermal variability in a way that can easily be used by urban planners for evaluating the effects of future urbanization scenarios on human health. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Solar thermal plant impact analysis and requirements definition study

    Science.gov (United States)

    1982-01-01

    The technology and economics of solar thermal electric systems (STES) for electric power production is discussed. The impacts of and requirements for solar thermal electric power systems were evaluated.

  7. Thermal image analysis for detecting facemask leakage

    Science.gov (United States)

    Dowdall, Jonathan B.; Pavlidis, Ioannis T.; Levine, James

    2005-03-01

    Due to the modern advent of near ubiquitous accessibility to rapid international transportation the epidemiologic trends of highly communicable diseases can be devastating. With the recent emergence of diseases matching this pattern, such as Severe Acute Respiratory Syndrome (SARS), an area of overt concern has been the transmission of infection through respiratory droplets. Approved facemasks are typically effective physical barriers for preventing the spread of viruses through droplets, but breaches in a mask"s integrity can lead to an elevated risk of exposure and subsequent infection. Quality control mechanisms in place during the manufacturing process insure that masks are defect free when leaving the factory, but there remains little to detect damage caused by transportation or during usage. A system that could monitor masks in real-time while they were in use would facilitate a more secure environment for treatment and screening. To fulfill this necessity, we have devised a touchless method to detect mask breaches in real-time by utilizing the emissive properties of the mask in the thermal infrared spectrum. Specifically, we use a specialized thermal imaging system to detect minute air leakage in masks based on the principles of heat transfer and thermodynamics. The advantage of this passive modality is that thermal imaging does not require contact with the subject and can provide instant visualization and analysis. These capabilities can prove invaluable for protecting personnel in scenarios with elevated levels of transmission risk such as hospital clinics, border check points, and airports.

  8. Testing thermal comfort of trekking boots: an objective and subjective evaluation.

    Science.gov (United States)

    Arezes, P M; Neves, M M; Teixeira, S F; Leão, C P; Cunha, J L

    2013-07-01

    The study of the thermal comfort of the feet when using a specific type of shoe is of paramount importance, in particular if the main goal of the study is to attend to the needs of users. The main aim of this study was to propose a test battery for thermal comfort analysis and to apply it to the analysis of trekking boots. Methodologically, the project involves both objective and subjective evaluations. An objective evaluation of the thermal properties of the fabrics used in the boots was developed and applied. In addition, the thermal comfort provided when using the boots was also assessed both subjective and objectively. The evaluation of the thermal comfort during use, which was simulated in a laboratory environment, included the measurement of the temperature and moisture of the feet. The subjective assessment was performed using a questionnaire. From the results obtained, it was possible to define an optimal combination of fabrics to apply to trekking boots by considering the provided thermal insulation, air permeability and wicking. The results also revealed that the subjective perception of thermal comfort appears to be more related to the increase in temperature of the feet than to the moisture retention inside the boot. Although the evaluation of knits used in the boots indicated that a particular combination of fibres was optimal for use in the inner layer, the subjective and objective evaluation of thermal comfort revealed that the evaluation provided by users did not necessarily match the technical assessment data. No correlation was observed between the general comfort and specific thermal comfort assessments. Finally, the identification of thermal discomfort by specific foot areas would be useful in the process of designing and developing boots. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  9. Synthesis and Thermal Analysis of Vertically Aligned CNTS Grown on Copper Substrates (POSTPRINT)

    Science.gov (United States)

    2017-08-01

    AFRL-RQ-WP-TP-2017-0158 SYNTHESIS AND THERMAL ANALYSIS OF VERTICALLY ALIGNED CNTS GROWN ON COPPER SUBSTRATES (POSTPRINT) Levi Elston...AND SUBTITLE SYNTHESIS AND THERMAL ANALYSIS OF VERTICALLY ALIGNED CNTS GROWN ON COPPER SUBSTRATES (POSTPRINT) 5a. CONTRACT NUMBER In-house 5b...thermal interface material beyond synthesis . This effort extends prior work on carbon nanotube growth, by concentrating on ways to evaluate/measure CNT

  10. Analysis of thermally loaded transmissive optical elements

    Science.gov (United States)

    Michels, Gregory J.; Genberg, Victor L.

    2013-09-01

    The performance metrics of many optical systems are affected by temperature changes in the system through different physical phenomena. Temperature changes cause materials to expand and contract causing deformations of optical components. The resulting stress states in transmissive optics can cause refractive changes that can affect optical performance. In addition, the temperature changes themselves can cause changes in the refractive properties of transmissive optics. Complex distributions of refractive indices that relate to the thermal profile, the thermo-optic refractive index profile, within the optical media can be predicted by the finite element method. One current technique for representing such refractive index profiles is through the generation of optical path difference (OPD) maps by integration along integration paths. While computationally efficient, this method has limitations in its ability to represent the effect of the index changes for rays associated with multiple field points and multiple wavelengths. A more complete representation of the thermo-optic refractive index profile may be passed to the optical analysis software through the use of a user defined gradient index material. The interface consists of a dynamic link library (DLL) which supplies indices of refraction to a user defined gradient index lens as ray tracing calculations are being performed. The DLL obtains its refractive index description from a database derived from the thermal analysis of the optics. This process allows optical analysis software to perform accurate ray tracing for an arbitrary refractive index profile induced by changes in temperature.

  11. Autonomous Aerobraking: Thermal Analysis and Response Surface Development

    Science.gov (United States)

    Dec, John A.; Thornblom, Mark N.

    2011-01-01

    A high-fidelity thermal model of the Mars Reconnaissance Orbiter was developed for use in an autonomous aerobraking simulation study. Response surface equations were derived from the high-fidelity thermal model and integrated into the autonomous aerobraking simulation software. The high-fidelity thermal model was developed using the Thermal Desktop software and used in all phases of the analysis. The use of Thermal Desktop exclusively, represented a change from previously developed aerobraking thermal analysis methodologies. Comparisons were made between the Thermal Desktop solutions and those developed for the previous aerobraking thermal analyses performed on the Mars Reconnaissance Orbiter during aerobraking operations. A variable sensitivity screening study was performed to reduce the number of variables carried in the response surface equations. Thermal analysis and response surface equation development were performed for autonomous aerobraking missions at Mars and Venus.

  12. SPS extraction kicker magnet thermal analysis

    CERN Document Server

    Timmins, M

    2004-01-01

    As the SPS accelerator will be used for the CNGS project and as LHC injector, the proton beams passing through its extraction kickers will have a much higher intensity than in the past. The image currents generated by this beam may provoke a temperature increase in the magnet's ferrite core to temperatures above the Curie temperature, unless the heat produced is effectively removed. A further complication arises from the fact that a high voltage is applied to the ferrites. The solution adopted consists in transferring the heat via Aluminium Nitride insulators to a water cooling circuit. The heat transfer analysis and the calculated thermal distribution of the magnet are presented.

  13. Thermal Environment Evaluation in Commercial Kitchens of United States

    DEFF Research Database (Denmark)

    Simone, Angela; Olesen, Bjarne W.

    The indoor climate in commercial kitchens is often unsatisfactory and the working conditions can have a significant effect on employees’ comfort and productivity. The differences between type (fast food, dining, etc.) and climatic zone can have an influence on the environment conditions...... and on the employees´ perception of kitchens thermal conditions. Moreover, size and arrangement of the kitchen zones, appliances, etc., complicate further an evaluation of the indoor thermal environment in kitchens. The on field physical measurements together with the occupants´ feedback is the effective way...... of defining the values of thermal comfort parameters in kitchens. It can also help to evaluate if the standardized methods are applicable for such non-uniform environment, like commercial kitchens. By using an established method and procedure for evaluating the indoor thermal comfort in commercial kitchens...

  14. APPLICATIONS OF THERMAL-WAVE PHYSICS TO SEMICONDUCTOR MATERIALS ANALYSIS

    OpenAIRE

    Rosencwaig, A.

    1983-01-01

    Nonspectroscopic applications of thermal-wave physics, in particular those involving materials analysis through thermal-wave imaging, and quantitative thin-film thickness measurements, are described for the study of semiconductor materials and devices.

  15. Differential thermal analysis microsystem for explosive detection

    DEFF Research Database (Denmark)

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

    2011-01-01

    A micro differential thermal analysis (DTA) system is used for detection of trace explosive particles. The DTA system consists of two silicon micro chips with integrated heaters and temperature sensors. One chip is used for reference and one for the measurement sample. The sensor is constructed a...... of the Xsense project at the Technical University of Denmark (DTU) which combines four independent sensing techniques, these micro DNT sensors will be included in handheld explosives detectors with applications in homeland security and landmine clearance.......A micro differential thermal analysis (DTA) system is used for detection of trace explosive particles. The DTA system consists of two silicon micro chips with integrated heaters and temperature sensors. One chip is used for reference and one for the measurement sample. The sensor is constructed...... 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...

  16. Thermal Analysis of Cryogenic Hydrogen Liquid Separator

    Science.gov (United States)

    Congiardo, Jared F.; Fortier, Craig R. (Editor)

    2014-01-01

    During launch for the new Space Launch System (SLS) liquid hydrogen is bleed through the engines during replenish, pre-press, and extended pre-press to condition the engines prior to launch. The predicted bleed flow rates are larger than for the shuttle program. A consequence of the increased flow rates is having liquif hydrogen in the vent system, which the facilities was never designed to handle. To remedy the problem a liquid separator is being designed in the system to accumulated the liquid propellant and protect the facility flare stack (which can only handle gas). The attached document is a presentation of the current thermalfluid analysis performed for the separator and will be presented at the Thermal and Fluid Analysis Workshop (NASA workshop) next week in Cleveland, Ohio.

  17. Thermal analysis of superconducting undulator cryomodules

    Science.gov (United States)

    Shiroyanagi, Y.; Doose, C.; Fuerst, J.; Harkay, K.; Hasse, Q.; Ivanyushenkov, Y.; Kasa, M.

    2015-12-01

    A cryocooler-cooled superconducting undulator (SCU0) has been operating in the Advanced Photon Source (APS) storage ring since January of 2013. Based on lessons learned from the construction and operation of SCU0, a second superconducting undulator (SCU1) has been built and cold tested stand-alone. An excess cooling capacity measurement and static heat load analysis show a large improvement of cryogenic performance of SCU1 compared with SCU0. ANSYS-based thermal analysis of these cryomodules incorporating all the cooling circuits was completed. Comparisons between measured and calculated temperatures at the three operating conditions of the cryomodule (static, beam heat only, beam heat and magnet current) will be presented.

  18. Analysis in usability evaluations

    DEFF Research Database (Denmark)

    Følstad, Asbjørn; Lai-Chong Law, Effie; Hornbæk, Kasper

    2010-01-01

    While the planning and implementation of usability evaluations are well described in the literature, the analysis of the evaluation data is not. We present interviews with 11 usability professionals on how they conduct analysis, describing the resources, collaboration, creation of recommendations......, and prioritization involved. The interviews indicate a lack of structure in the analysis process and suggest activities, such as generating recommendations, that are unsupported by existing methods. We discuss how to better support analysis, and propose four themes for future research on analysis in usability...

  19. 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.

  20. Exergetic analysis of parabolic trough solar thermal power plants

    Science.gov (United States)

    Petrakopoulou, F.; Ruperez, B.; San Miguel, G.

    2014-12-01

    A very important component to achieve sustainable development in the energy sector is the improvement of energy efficiency of widely applied thermodynamic processes. Evaluation and optimization methods of energy processes play a crucial role in fulfilling this goal. A suitable method for the evaluation and optimization of energy conversion systems has been proven to be the exergetic analysis. In this work, two parabolic trough solar thermal power plants are simulated in detail using commercial software, and they are further analysed and compared using an exergetic analysis. The first plant uses a thermal fluid to produce the steam required in a steam generator, while the second one produces the steam directly in the solar field. The analysis involves the evaluation of the individual components of the power plants, as well as the performance evaluation of the overall structures. The main goal is to detect thermodynamic inefficiencies of the two different configurations and propose measures to minimize those. We find that the two examined plants have similar main sources of exergy destruction: the solar field (parabolic trough solar collectors), followed by the steam generator. This reveals the importance of an optimal design of these particular components, which could reduce inefficiencies present in the system. The differences in the exergy destruction and exergetic efficiencies of individual components of the two plants are analyzed in detail based on comparable operational conditions.

  1. Thermal Protection Systems Nondestructive Evaluation Tool Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address NASA's need for evaluation of bondline and in-depth integrity for lightweight rigid and/or flexible ablative materials, Physical Optics Corporation (POC)...

  2. thermal power stations' reliability evaluation in a hydrothermal system

    African Journals Online (AJOL)

    Dr Obe

    A quantitative tool for the evaluation of thermal power stations reliability in a hydrothermal system is presented. A reliable power station is one which would supply the required power within its installed capacity at any time within the specified voltage and frequency limits. Required for this evaluation are the station's installed ...

  3. Thermal analysis of spent nuclear fuels repository

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, F.; Salome, J.; Cardoso, F.; Velasquez, C.E.; Pereira, C. [Departamento de Engenharia Nuclear - Escola de Engenharia, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, Pampulha, Belo Horizonte MG, CEP 31270-901 (Brazil); Instituto Nacional de Ciencias e Tecnologia de Reatores Nucleares Inovadores - CNPq, Asa Norte, Brazilia (Brazil); Viana, C. [Departamento de Engenharia Nuclear - Escola de Engenharia, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, Pampulha, Belo Horizonte MG, CEP 31270-901 (Brazil); Barros, G.P. [Comissao Nacional de Energia Nuclear-CNEN, Rua Gal Severiano, n 90 - Botafogo, 22290-901, Rio de Janeiro, RJ (Brazil)

    2016-07-01

    In the first part, Pressurized Water Reactor (PWR), Very High-Temperature Reactor (VHTR) and Accelerator-Driven Subcritical Reactor System (ADS) spent fuels (SF) were evaluated to the thermal of the spent fuel pool (SFP) without an external cooling system. The goal is to compare the water boiling time of the pool storing different types of spent nuclear fuels. This study used the software ANSYS Workbench 16.2 - student version. For the VHTR, two types of fuel were analyzed: (Th,TRU)O{sub 2} and UO{sub 2}. This part of the studies were performed for wet storage condition using a single type of SF and decay heat values at times t=0 and t=10 years after the reactor discharge. The ANSYS CFX module was used and the results show that the time that water takes to reach the boiling point varies from 2.4 minutes for the case of VHTR-(Th,TRU)O{sub 2} SF at time t=0 year after reactor discharge until 32.4 hours for the case of PWR SF at time t=10 years after the discharge reactor. The second part of this work consists of modeling a geological repository. Firstly, the temperature evaluation of the spent fuel from a PWR was analyzed. A PWR canister was simulated using the ANSYS transient thermal module. Then the temperature of canister could be computed during the time spent on a portion of a geological repository. The mean temperature on the canister surface increased during the first nine years, reaching a plateau at 35.5 C. degrees between the tenth and twentieth years after the geological disposal. The idea is to extend this study for the other systems analyzed in the first part. The idea is to include in the study, the spent fuels from VHTR and ADS and to compare the canister behavior using different spent fuels. (authors)

  4. Theoretical consideration and evaluation of thermal diffusivity ...

    African Journals Online (AJOL)

    The aim of this study was to theoretically consider and evaluate the transient temperature-time response of resin/ionomer materials between ~2EC (melting ice temperature) and ~50EC, and indicate their suitability as lining materials. Specimens of materials, cylindrical in geometry, (6 mm diameter and 10 mm in length), ...

  5. 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.

  6. Objective and subjective thermal comfort evaluation in Hungary

    Directory of Open Access Journals (Sweden)

    Kajtar Laszlo

    2017-01-01

    Full Text Available Thermal comfort sensation can be predicted in the most exact way based on Fanger’s predicted mean vote (PMV model. This evaluation method takes all the six influencing factors into consideration: air temperature and humidity, air velocity, mean radiant temperature of surrounding surfaces, clothing insulation, and occupants’ activities. Fanger’s PMV method was developed for temperate climate and European people, with the participation of university students as subjects. Many researchers had investigated its validity in different geographic locations (i. e. climatic conditions, people and under non-laboratory circumstances. The results were summarised by van Hoof which had been published in the scientific references. The articles gave us the idea to elaborate the former measurement results. During the last decades thermal comfort was evaluated by our research team using subjective scientific questionnaires and applying the objective Fanger’s model in several office buildings in Hungary. The relation between the PMV and actual mean vote values were analysed based on these results. Investigations were carried out under steady-state conditions in winter time. We performed objective thermal comfort evaluations based on instrumental measurements using the PMV theory. Parallel to this we assessed the subjective thermal sensation using scientific questionnaires. The mathematical relationship between the actual mean vote and PMV was defined according to the evaluated thermal environment: AMV = PMV + 0.275, (arg. –1.7 ≤ PMV ≤ +0.5.

  7. Infrared thermal imaging in the diagnosis of musculoskeletal injuries: a systematic review and meta-analysis.

    Science.gov (United States)

    Sanchis-Sánchez, Enrique; Vergara-Hernández, Carlos; Cibrián, Rosa M; Salvador, Rosario; Sanchis, Enrique; Codoñer-Franch, Pilar

    2014-10-01

    Musculoskeletal injuries occur frequently. Diagnostic tests using ionizing radiation can lead to problems for patients, and infrared thermal imaging could be useful when diagnosing these injuries. A systematic review was performed to determine the diagnostic accuracy of infrared thermal imaging in patients with musculoskeletal injuries. A meta-analysis of three studies evaluating stress fractures was performed and found a lack of support for the usefulness of infrared thermal imaging in musculoskeletal injuries diagnosis.

  8. Evaluating the coefficient of thermal expansion using time periods of minimal thermal gradient for a temperature driven structural health monitoring

    Science.gov (United States)

    Reilly, J.; Abdel-Jaber, H.; Yarnold, M.; Glisic, B.

    2017-04-01

    Structural Health Monitoring aims to characterize the performance of a structure from a combination of recorded sensor data and analytic techniques. Many methods are concerned with quantifying the elastic response of the structure, treating temperature changes as noise in the analysis. While these elastic profiles do demonstrate a portion of structural behavior, thermal loads on a structure can induce comparable strains to elastic loads. Understanding this relationship between the temperature of the structure and the resultant strain and displacement can provide in depth knowledge of the structural condition. A necessary parameter for this form of analysis is the Coefficient of Thermal Expansion (CTE). The CTE of a material relates the amount of expansion or contraction a material undergoes per degree change in temperature, and can be determined from temperature-strain relationship given that the thermal strain can be isolated. Many times with concrete, the actual amount of expansion with temperature in situ varies from the given values for the CTE due to thermally generated elastic strain, which complicates evaluation of the CTE. To accurately characterize the relationship between temperature and strain on a structure, the actual thermal behavior of the structure needs to be analyzed. This rate can vary for different parts of a structure, depending on boundary conditions. In a case of unrestrained structures, the strain in the structure should be linearly related to the temperature change. Thermal gradients in a structure can affect this relationship, as they induce curvature and deplanations in the cross section. This paper proposes a method that addresses these challenges in evaluating the CTE.

  9. The evaluation of the overall thermal comfort inside a vehicle

    Science.gov (United States)

    Neacsu, Catalin; Tabacu, Ion; Ivanescu, Mariana; Vieru, Ionel

    2017-10-01

    The thermal comfort is one of the most important aspects of the modern vehicles that can influence the safety, the fuel consumption and the pollutions regulation. The objective of this paper is to compare the global and absolute thermal comfort indexes for two vehicles with different distribution air systems inside the car cockpit, one using only front air vents, and the other using both front and rear air vents. The methodology of calculus consists in using the 3D model of the interior vehicle, generally in a CAD format. Then, using a meshing software to create the finite element model of the interior surfaces inside the cockpit and the volume of internal air. Using the obtained finite element geometry, there will be conducted a Theseus FE calculus using the given boundary conditions. The results of the numerical simulation are presented in terms of graphs and figures and also PMV, PPD and DTS thermal comfort indexes. With the obtained results, we will then create the graphs that allows us to evaluate the global and absolute thermal comfort indexes. The results of the evaluation show us that the use of the method allow us to evaluate with a greater accuracy the thermal comfort for the whole vehicle, not only for each passenger, like the standard methods. This shows us that in terms of general and absolute thermal comfort, the vehicle that use front and rear systems is better than the version that use only a front system. The thermal comfort is an important aspect to be taken into account from the beginning of the design stage of a vehicle, by choosing the right air conditioning system. In addition, by using the numerical simulation, we are able to reduce the time needed for preliminary tests and be able to provide the vehicle to the market earlier, at a lower development cost.

  10. Evaluation of terrestrial photogrammetric point clouds derived from thermal imagery

    Science.gov (United States)

    Metcalf, Jeremy P.; Olsen, Richard C.

    2016-05-01

    Computer vision and photogrammetric techniques have been widely applied to digital imagery producing high density 3D point clouds. Using thermal imagery as input, the same techniques can be applied to infrared data to produce point clouds in 3D space, providing surface temperature information. The work presented here is an evaluation of the accuracy of 3D reconstruction of point clouds produced using thermal imagery. An urban scene was imaged over an area at the Naval Postgraduate School, Monterey, CA, viewing from above as with an airborne system. Terrestrial thermal and RGB imagery were collected from a rooftop overlooking the site using a FLIR SC8200 MWIR camera and a Canon T1i DSLR. In order to spatially align each dataset, ground control points were placed throughout the study area using Trimble R10 GNSS receivers operating in RTK mode. Each image dataset is processed to produce a dense point cloud for 3D evaluation.

  11. Thermal analysis of wood-steel hybrid construction

    OpenAIRE

    Fonseca, E.M.M.; Ramos, H.M.E.; Silva, H.J.G.; Ferreira, Débora

    2013-01-01

    The main objective of this work is to provide the thermal analysis in wood-steel hybrid elements for building constructions under fire conditions. A transient thermal analysis with nonlinear material behaviour will be solved with ANSYS program. The use of wood-steel hybrid models has major advantages as increased fire resistance, and improved high strength. Wood is a lightweight material, easy to assemble, great architectural features, thermal and acoustic characteristics. However, the high v...

  12. 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)

  13. 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...

  14. Analysis of thermally-degrading, confined HMX

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, M.L.; Schmitt, R.G.; Renlund, A.M.

    1996-12-01

    The response of a thermally-degrading, confined HMX pellet is analyzed using a Reactive Elastic-Plastic (REP) constitutive model which is founded on the collapse and growth of internal inclusions resulting from physical and chemical processes such as forced displacement, thermal expansion, and/or decomposition. Axial stress predictions compare adequately to data. Deficiencies in the model and future directions are discussed.

  15. 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.

  16. 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…

  17. THERMAL ANALYSIS, RHEOLOGY, X-RAY DIFFRACTOMETRY AND ATOMIC FORCE MICROSCOPY IN THE EVALUATION OF BINARY MIXTURES OF “STARCH-HYDROCOLLOIDS”

    Directory of Open Access Journals (Sweden)

    Crislaine Alberton

    2014-02-01

    Full Text Available Starch is arguably the most investigated biopolymer in the world and the cassava starch that is extracted from Manihot esculenta Crantz, represents an important vegetal crop in tropical countries, where its roots and derivatives serve as food and a source of energy. The main composition of these roots is 70-80% water, 16-24% starch and small quantities (<4% of protein, lipids vitamins and minerals. Hydrocolloids, or gums, are substances consisting of a hydrophilic long-chain with colloidal properties that, in water-based systems, produce gels. Starches and hydrocolloids are often used together in food systems to provide texture, water mobility, control moisture, improve product quality and stability, facilitate processing and reduce costs. In this study, the interactions between cassava and starch-hydrocolloids (1% of the following gums: CMC, jatahy, pectin and xanthan were investigated. The TG/DTG method made it possible to determine the thermal decomposition of each sample, which under air atmosphere occurs in three steps. Little difference was observed in the degree of relative crystallinity (XRD and in the average roughness or average diameter of the starch granules (NC-AFM. The viscosity and pasting properties (RVA increased, and were higher for starch treated with jatahy gum. A large decrease was observed in peak temperature and gelatinisation enthalpy for the treated samples (DSC.

  18. 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.

  19. ANALYSIS OF CARBONACEOUS AEROSOLS USING THE THERMAL OPTICAL TRANSMITTANCE AND THERMAL OPTICAL REFLECTANCE METHODS

    Science.gov (United States)

    Carbonaceous particulate typically represents a large fraction of PM2.5 (20 - 40%). Two primary techniques presently used for the analysis of particulate carbon are Thermal Optical Transmission (TOT - NIOSH Method 5040) and Thermal Optical Reflectance (TOR). These two methods b...

  20. The Use of Thermal Analysis and Photoacoustic Spectroscopy in the Evaluation of Maltodextrin Microencapsulation of Anthocyanins from Juçara Palm Fruit (Euterpe edulis Mart.) and Their Application in Food

    Science.gov (United States)

    Paula da Silva dos Passos, Ana; Madrona, Grasiele Scaramal; Marcolino, Vanessa Aparecida; Baesso, Mauro Luciano

    2015-01-01

    Summary Anthocyanins extracted from the pulp of the fruit of juçara palm (Euterpe edulis Mart.) were microencapsulated with maltodextrin in order to stabilise them. Photoacoustic spectroscopy was used to investigate the photostability of the microencapsulated samples. Complementary differential scanning calorimetry and scanning electron microscopy measurements were also performed. Lyophilised extract had 14 340.2 mg/L of total anthocyanins, and the microencapsulation efficiency of 93.6%. Temperature analysis showed that maltodextrin conferred protection up to 70 °C for 120 min. Scanning electron microscopy showed that the microencapsulated particles had a flake-like morphology with a smooth surface, characteristic of lyophilisation processes. In addition, when added to yogurt, a red colourant was predominant in the samples at pH from 1.5 up to 5.0. Thermal analysis showed a weak interaction between the sample and the encapsulating agent, and photoacoustic data indicated the photostability of the matrix when exposed to light. Yogurts containing microencapsulated anthocyanins showed a more intense pink colour than yogurts treated with pure dye, and sensory analysis demonstrated that they can have good acceptance on the market. Microencapsulation enabled the innovative application of anthocyanins from juçara palm fruit, and complementary techniques allied to the photoacoustic spectroscopy were effective tools for its evaluation. PMID:27904373

  1. The Use of Thermal Analysis and Photoacoustic Spectroscopy in the Evaluation of Maltodextrin Microencapsulation of Anthocyanins from Juçara Palm Fruit (Euterpe edulis Mart. and Their Application in Food

    Directory of Open Access Journals (Sweden)

    Ana Paula da Silva dos Passos

    2015-01-01

    Full Text Available Anthocyanins extracted from the pulp of the fruit of juçara palm (Euterpe edulis Mart. were microencapsulated with maltodextrin in order to stabilise them. Photoacoustic spectroscopy was used to investigate the photostability of the microencapsulated samples. Complementary differential scanning calorimetry and scanning electron microscopy measurements were also performed. Lyophilised extract had 14 340.2 mg/L of total anthocyanins, and the microencapsulation effi ciency of 93.6 %. Temperature analysis showed that maltodextrin conferred protection up to 70 °C for 120 min. Scanning electron microscopy showed that the microencapsulated particles had a flake-like morphology with a smooth surface, characteristic of lyophilisation processes. In addition, when added to yogurt, a red colourant was predominant in the samples at pH from 1.5 up to 5.0. Thermal analysis showed a weak interaction between the sample and the encapsulating agent, and photoacoustic data indicated the photostability of the matrix when exposed to light. Yogurts containing microencapsulated anthocyanins showed a more intense pink colour than yogurts treated with pure dye, and sensory analysis demonstrated that they can have good acceptance on the market. Microencapsulation enabled the innovative application of anthocyanins from juçara palm fruit, and complementary techniques allied to the photoacoustic spectroscopy were effective tools for its evaluation.

  2. The Use of Thermal Analysis and Photoacoustic Spectroscopy in the Evaluation of Maltodextrin Microencapsulation of Anthocyanins from Juçara Palm Fruit (Euterpe edulisMart.) and Their Application in Food.

    Science.gov (United States)

    Paula da Silva Dos Passos, Ana; Madrona, Grasiele Scaramal; Marcolino, Vanessa Aparecida; Baesso, Mauro Luciano; Matioli, Graciette

    2015-12-01

    Anthocyanins extracted from the pulp of the fruit of juçara palm ( Euterpe edulis Mart.) were microencapsulated with maltodextrin in order to stabilise them. Photoacoustic spectroscopy was used to investigate the photostability of the microencapsulated samples. Complementary differential scanning calorimetry and scanning electron microscopy measurements were also performed. Lyophilised extract had 14 340.2 mg/L of total anthocyanins, and the microencapsulation efficiency of 93.6%. Temperature analysis showed that maltodextrin conferred protection up to 70 °C for 120 min. Scanning electron microscopy showed that the microencapsulated particles had a flake-like morphology with a smooth surface, characteristic of lyophilisation processes. In addition, when added to yogurt, a red colourant was predominant in the samples at pH from 1.5 up to 5.0. Thermal analysis showed a weak interaction between the sample and the encapsulating agent, and photoacoustic data indicated the photostability of the matrix when exposed to light. Yogurts containing microencapsulated anthocyanins showed a more intense pink colour than yogurts treated with pure dye, and sensory analysis demonstrated that they can have good acceptance on the market. Microencapsulation enabled the innovative application of anthocyanins from juçara palm fruit, and complementary techniques allied to the photoacoustic spectroscopy were effective tools for its evaluation.

  3. 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.

  4. Thermal fatigue and creep evaluation for the bed in tritium SDS

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Woo-seok, E-mail: wschoi@kaeri.re.kr [Korea Atomic Energy Research Institute, Yuseong, Daejeon (Korea, Republic of); Park, Chang-gyu [Korea Atomic Energy Research Institute, Yuseong, Daejeon (Korea, Republic of); Ju, Yong-sun [KOASIS, Yuseong, Daejeon (Korea, Republic of); Kang, Hyun-goo; Jang, Min-ho; Yun, Sei-hun [National Fusion Research Institute, Yuseong, Daejeon (Korea, Republic of)

    2016-11-01

    Highlights: • To evaluate the integrity of the ITER tritium SDS bed, three kinds of assessments were conducted. • The structural analysis showed that the stress induced from the thermal load and the internal pressure is within the design stress intensity. • The combined fatigue and creep assessment was also performed according to the procedure of ASME code Subsection NH. • A new operation procedure to obtain more integrity margin was recommended. • The other operation procedure could be considered which makes the rapid operation possible giving up the marginal integrity. - Abstract: The primary vessel of ITER tritium SDS bed is made of stainless steel. It is heated beyond 500 °C to desorb tritium. During this process the primary vessel is subject to thermal stress. And it is also subject to thermal fatigue by the iterative process of absorption and desorption. In addition, its operation temperature range is in the thermal creep temperature region. Therefore, the tritium SDS bed should have sufficient design stress intensity under the high temperature operating conditions. It should also be free of damage due to fatigue during the design life. Thermal analysis and structural analysis was performed using a finite element method to calculate the temperature and the stress distribution of the ITER tritium SDS bed due to the internal pressure and thermal loads. The thermal fatigue and creep effects were also evaluated since the tritium SDS bed was heated to hot temperature region where creep occurs. Based on the distribution of the primary stress and secondary stress results, two evaluation cross-sections were selected. The evaluation showed that the calculated value on the cross-sections satisfied all of the limits of the design code requirements.

  5. Evaluation of thermal conductivity of heat-cured acrylic resin mixed with A1203

    Directory of Open Access Journals (Sweden)

    Ebadian B.

    2002-08-01

    Full Text Available One of the most important characteristics of denture base is thermal conductivity. This property has a major role in secretions of salivary glands and their enzymes, taste of the food and gustatory response. Polymethyl methacrylate used in prosthodontics is relatively an insulator. Different materials such as metal fillers and ceramics have been used to solve this problem. The aim of this study was the evaluation of AI2O3 effect on thermal conductivity of heat-cured acrylic resin. Acrylic resin was mixed with AI2O3 in two different weight rates (15 and 20 % of weight. So, group 1 and 2 were divided on this basis. Samples with pure acrylic resin were considered as control group. 18 cylindrical patterns were made in 9x9 mm dimensions and thermocouple wires embedded in each sample to act as conductor. The specimens were put in water with 70±1°C thermal range for 10 minutes. Then, thermal conductivity was measured. The results were analyzed with variance analysis and Dunken test. There was significant difference between thermal conductivity of all groups in all period times. It the first seconds, thermal conductivity in groups 1 and 2 were more than control group. Therefore, for developing of thermal conductivity of acrylic resin, A1203 can be used. Certainly, other characteristic of new resin should be evaluated.

  6. 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

  7. Thermal paint production: the techno-economic evaluation of muscovite as insulating additive.

    Directory of Open Access Journals (Sweden)

    Gabriela Fernandes Ribas

    2016-09-01

    Full Text Available Muscovite is known by its thermal and electrical insulating properties. Based on this, it was hypothesized that its addition on paints should increase the thermal resistance. The use of muscovite as mineral insulating is pointed out as advantageous due to its low cost compared to other materials used for this purpose, such as the ceramic microsphere. The use of a low cost material could open the access to the medium and low income families, implying two aspects: the life quality increase by thermal comfort and the increase of energy saving. Thus, this part of the population could open a new market to thermal paints. Aiming to contribute to this issue, this work evaluated the thermal insulation performance of commercial paints containing muscovite additions and determined the economic evaluation for its industrial production. The thermal paint was formulated by adding 10%, 20% and 40% of muscovite to the commercial paint. This was applied on steel reinforced mortar boards. Thermal insulation tests were carried out in bench scale using an adapted box. The economic evaluation of the industrial production of muscovite-based thermal paint was conducted, considering the Brazilian economic market in this activity. The results showed its ability as an insulating agent due to a reduction of 0.667 °C/mm board by the addition of 40% muscovite. The economic analysis also demonstrated the feasibility of the thermal paint industrial production. The payback is favorable to 5 years when compared to the Selic short-term lending rate, with 21.53% of internal rate return and a net present value of US$ 15,085.76.

  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. A new simplified model for evaluating thermal environment and thermal sensation: an approach to avoid occupational disorders

    OpenAIRE

    Morgado, Mariana; Talaia, Mário; Teixeira, Leonor

    2015-01-01

    Thermal heat stress is a cause of many occupational disorders that disrupt worker performance and the quality of work and, in extreme cases, can lead to death. In the industrial context, thermal discomfort is cited as one of the major causes of dissatisfaction in workplaces when people are exposed to extremely hot or cold thermal environments. Given the time that people spend in their workplaces, studies evaluating the comfort of the thermal environment are becoming increasingly important. Ho...

  10. Thermal analysis of a hypersonic wing test structure

    Science.gov (United States)

    Sandlin, Doral R.; Swanson, Neil J., Jr.

    1989-01-01

    The three-dimensional finite element modeling techniques developed for the thermal analysis of a hypersonic wing test structure (HWTS) are described. The computed results are compared to measured test data. In addition, the results of a NASA two-dimensional parameter finite difference local thermal model and the results of a contractor two-dimensional lumped parameter finite difference local thermal model will be presented.

  11. Comparative evaluation of thermal decomposition behavior and thermal stability of powdered ammonium nitrate under different atmosphere conditions.

    Science.gov (United States)

    Yang, Man; Chen, Xianfeng; Wang, Yujie; Yuan, Bihe; Niu, Yi; Zhang, Ying; Liao, Ruoyu; Zhang, Zumin

    2017-09-05

    In order to analyze the thermal decomposition characteristics of ammonium nitrate (AN), its thermal behavior and stability under different conditions are studied, including different atmospheres, heating rates and gas flow rates. The evolved decomposition gases of AN in air and nitrogen are analyzed with a quadrupole mass spectrometer. Thermal stability of AN at different heating rates and gas flow rates are studied by differential scanning calorimetry, thermogravimetric analysis, paired comparison method and safety parameter evaluation. Experimental results show that the major evolved decomposition gases in air are H2O, NH3, N2O, NO, NO2 and HNO3, while in nitrogen, H2O, NH3, NO and HNO3 are major components. Compared with nitrogen atmosphere, lower initial and end temperatures, higher heat flux and broader reaction temperature range are obtained in air. Meanwhile, higher air gas flow rate tends to achieve lower reaction temperature and to reduce thermal stability of AN. Self-accelerating decomposition temperature of AN in air is much lower than that in nitrogen. It is considered that thermostability of AN is influenced by atmosphere, heating rate and gas flow rate, thus changes of boundary conditions will influence its thermostability, which is helpful to its safe production, storage, transportation and utilization. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Periodontal plastic surgery: thermal effect analysis using Erbium:YAG Kesler's handpiece. Histochemical evaluation by Picrosirius red stain and polarization microscopy for collagen determination: in

    Science.gov (United States)

    Kesler, Gavriel; Koren, Rumelia; Kesler, Anat; Kristt, Don; Gal, Rivka

    2000-03-01

    Recent technological advances lead to an increase in the options for the treatment of the periodontal diseases. Lasers utilized for gingival soft tissue resurfacing mainly for esthetics purposes, require careful histopathological evaluation of the effects on tissue. Up to date no comparative clinical or histological studies have been performed, aiming at demonstration of the effects of laser irradiation on connective tissue, especially its most important component -- the collagen fibers. The alteration in the structures of this tissue plays the most important role in the healing process. The aim of the present study is to evaluate the influence of Erbium: YAG - Kesler's hand piece on gingival tissue. This handpiece is designed for gingival resurfacing, in cases of 'Gummy smile' and gingival pigmentation. The following irradiation parameters were used: energy per pulse -- 500 mJ, repetition rate 10 pps, spot size 3 mm. Gingival biopsies specimens of 10 patients, 6 with 'Gummy smile' and 4 with gingival pigmentation were examined before laser treatment, and at 7 and 14 days after laser treatment. The tissues were fixed in LNRS, embedded in paraffin, and sectioned into 5 micrometer thickness, dewaxed in xylol and stained with H&E and Picrosirius Red (PSR). The sections were examined by polarization microscopy. PSR is a collagen stain that differentiates collagen fiber density by the range of colors from green through yellow to red, and/or fiber size. This was utilized in the present study to evaluate the hypothesis that Erbium -- YAG (Er: YAG) laser energy is capable of remodeling the collagen fibers in the gingival connective tissue through a photothermal process. We found a significant difference between the structures of collagen fibers at the first week and at 14 days post treatment. In the normal gingiva the predominant polarization colors were in the red-orange range, signifying tightly packed, mature collagen. During the first postoperative week, collagen

  13. Environmental Assisted Fatigue Evaluation of Direct Vessel Injection Piping Considering Thermal Stratification

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Taesoon; Lee, Dohwan [KHNP CRI, Daejeon (Korea, Republic of)

    2016-10-15

    As the environmentally assisted fatigue (EAF) due to the primary water conditions is to be a critical issue, the fatigue evaluation for the components and pipes exposed to light water reactor coolant conditions has become increasingly important. Therefore, many studies to evaluate the fatigue life of the components and pipes in LWR coolant environments on fatigue life of materials have been conducted. Among many components and pipes of nuclear power plants, the direct vessel injection piping is known to one of the most vulnerable pipe systems because of thermal stratification occurred in that systems. Thermal stratification occurs because the density of water changes significantly with temperature. In this study, fatigue analysis for DVI piping using finite element analysis has been conducted and those results showed that the results met design conditions related with the environmental fatigue evaluation of safety class 1 pipes in nuclear power plants. Structural and fatigue integrity for the DVI piping system that thermal stratification occurred during the plant operation has conducted. First of all, thermal distribution of the piping system is calculated by computational fluid dynamic analysis to analyze the structural integrity of that piping system. And the fatigue life evaluation considering environmental effects was carried out. Our results showed that the DVI piping system had enough structural integrity and fatigue life during the design lifetime of 60 years.

  14. Thermal power systems small power systems applications project. Decision analysis for evaluating and ranking small solar thermal power system technologies. Volume 1: A brief introduction to multiattribute decision analysis. [explanation of multiattribute decision analysis methods used in evaluating alternatives for small powered systems

    Science.gov (United States)

    Feinberg, A.; Miles, R. F., Jr.

    1978-01-01

    The principal concepts of the Keeney and Raiffa approach to multiattribute decision analysis are described. Topics discussed include the concepts of decision alternatives, outcomes, objectives, attributes and their states, attribute utility functions, and the necessary independence properties for the attribute states to be aggregated into a numerical representation of the preferences of the decision maker for the outcomes and decision alternatives.

  15. Performance analysis of photovoltaic thermal air heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sopian, K.; Yigit, K.S.; Liu, H.T.; Kakac, S.; Veziroglu, T.N. [Miami Univ., Coral Gables, FL (United States). Dept. of Mechanical Engineering

    1996-11-01

    The performance of single-pass and double-pass combined photovoltaic thermal collectors are analyzed with steady-state models. The working fluid is air and the models are based on energy conservation at various nodes of the collector. Closed form solutions have been obtained for the differential equations of both the single-pass and double-pass collectors. Comparisons are made between the performances of the two types of combined photovoltaic thermal collectors. The results show that the new design, the double-pass photovoltaic thermal collector, has superior performance. Important parameters for both types of collector are identified, and their effects on the performances of the two types of collectors are presented in detail. (author)

  16. Thermal analysis of LED lamps for optimal driver integration

    NARCIS (Netherlands)

    Perpiñà, X.; Werkhoven, R.J.; Vellvehi, M.; Jakovenko, J.; Jordà, X.; Kunen, J.M.G.; Bancken, P.; Bolt, P.J.

    2015-01-01

    This paper studies the thermal influence of a light-emitting diode (LED) driver on a retrofit LED lamp, also reporting on a procedure for its thermal characterization and multiscale modeling. In this analysis, temperature is measured by infrared thermography and monitoring specific locations with

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

    African Journals Online (AJOL)

    The thermal energy transferred by unsteady flow of the coolant to the vessel was determined as internal energy change. Numerical algorithms for Matlab Code were implemented to generate data for transient analysis and simulation. The simulations indicated that the temperature variations and the the-rmal stresses were ...

  18. 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).

  19. Ground-based thermal imaging of stream surface temperatures: Technique and evaluation

    Science.gov (United States)

    Bonar, Scott A.; Petre, Sally J.

    2015-01-01

    We evaluated a ground-based handheld thermal imaging system for measuring water temperatures using data from eight southwestern USA streams and rivers. We found handheld thermal imagers could provide considerably more spatial information on water temperature (for our unit one image = 19,600 individual temperature measurements) than traditional methods could supply without a prohibitive amount of effort. Furthermore, they could provide measurements of stream surface temperature almost instantaneously compared with most traditional handheld thermometers (e.g., >20 s/reading). Spatial temperature analysis is important for measurement of subtle temperature differences across waterways, and identification of warm and cold groundwater inputs. Handheld thermal imaging is less expensive and equipment intensive than airborne thermal imaging methods and is useful under riparian canopies. Disadvantages of handheld thermal imagers include their current higher expense than thermometers, their susceptibility to interference when used incorrectly, and their slightly lower accuracy than traditional temperature measurement methods. Thermal imagers can only measure surface temperature, but this usually corresponds to subsurface temperatures in well-mixed streams and rivers. Using thermal imaging in select applications, such as where spatial investigations of water temperature are needed, or in conjunction with stationary temperature data loggers or handheld electronic or liquid-in-glass thermometers to characterize stream temperatures by both time and space, could provide valuable information on stream temperature dynamics. These tools will become increasingly important to fisheries biologists as costs continue to decline.

  20. Thermal Analysis of Bending Under Tension Test

    DEFF Research Database (Denmark)

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

    2014-01-01

    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......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...... 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...

  1. Evaluation of the thermal comfort of ceramic floor tiles

    Directory of Open Access Journals (Sweden)

    Carmeane Effting

    2007-09-01

    Full Text Available In places where people are bare feet, the thermal sensation of cold or hot depends on the environmental conditions and material properties including its microstructure and crustiness surface. The uncomforting can be characterized by heated floor surfaces in external environments which are exposed to sun radiation (swimming polls areas or by cold floor surfaces in internal environments (bed rooms, path rooms. The property named thermal effusivity which defines the interface temperature when two semi-infinite solids are putted in perfect contact. The introduction of the crustiness surface on the ceramic tiles interferes in the contact temperature and also it can be a strategy to obtain ceramic tiles more comfortable. Materials with low conductivities and densities can be obtained by porous inclusion are due particularly to the processing conditions usually employed. However, the presence of pores generally involves low mechanical strength. This work has the objective to evaluate the thermal comfort of ceramics floor obtained by incorporation of refractory raw materials (residue of the polishing of the porcelanato in industrial atomized ceramic powder, through the thermal and mechanical properties. The theoretical and experimental results show that the porosity and crustiness surface increases; there is sensitive improvement in the comfort by contact.

  2. Spectroscopic, morphological, thermal and dielectrical analysis of ...

    Indian Academy of Sciences (India)

    2017-09-27

    Sep 27, 2017 ... thesis of composite is evident from FTIR, XRD and SEM characterization techniques. The composite shows improved thermal stability as compared with pure PTh, which opens the gate for the material to be used for high-temperature appli- cation purposes. Dielectric study shows that the presence of.

  3. Thermal control analysis of a primary mirror for large-aperture telescope

    Science.gov (United States)

    Tan, Yufeng; Wang, Jihong; Ren, Ge; Xie, Zongliang; He, Bi

    2017-07-01

    Extraneous thermal loads on the primary mirror of a large-aperture telescope directly influence the optical performance of the telescope through temperature gradients within the mirror and thermal boundary layer at the face sheet. In this paper, we propose a new thermal control system consisting of a flushing and sucking system for eliminating the excessive heat of a primary mirror. First, a 2.8 m-aperture lightweighted primary mirror is fabricated. Second, a thermo-optic analysis using finite element analysis is conducted in natural and forced convection. Finally, the optical performance denoted by Zernike polynomials with and without our proposed thermal control system is evaluated and examined. The comparative results reveal that the image quality of the primary mirror in forced convection is significantly enhanced with obvious reduction of optical surface distortion, thereby demonstrating the effectiveness of our proposed thermal control system.

  4. Integration of Design, Thermal, Structural, and Optical Analysis, Including Thermal Animation

    Science.gov (United States)

    Amundsen, Ruth M.

    1993-01-01

    In many industries there has recently been a concerted movement toward 'quality management' and the issue of how to accomplish work more efficiently. Part of this effort is focused on concurrent engineering; the idea of integrating the design and analysis processes so that they are not separate, sequential processes (often involving design rework due to analytical findings) but instead form an integrated system with smooth transfers of information. Presented herein are several specific examples of concurrent engineering methods being carried out at Langley Research Center (LaRC): integration of thermal, structural and optical analyses to predict changes in optical performance based on thermal and structural effects; integration of the CAD design process with thermal and structural analyses; and integration of analysis and presentation by animating the thermal response of a system as an active color map -- a highly effective visual indication of heat flow.

  5. Transient Thermal Testing and Analysis of a Thermally Insulating Structural Sandwich Panel

    Science.gov (United States)

    Blosser, Max L.; Daryabeigi, Kamran; Bird, Richard K.; Knutson, Jeffrey R.

    2015-01-01

    A core configuration was devised for a thermally insulating structural sandwich panel. Two titanium prototype panels were constructed to illustrate the proposed sandwich panel geometry. The core of one of the titanium panels was filled with Saffil(trademark) alumina fibrous insulation and the panel was tested in a series of transient thermal tests. Finite element analysis was used to predict the thermal response of the panel using one- and two-dimensional models. Excellent agreement was obtained between predicted and measured temperature histories.

  6. a Study on the Thermal Vibration Analysis of the Graphite Disk Under Thermal Shock

    Science.gov (United States)

    Lee, Young-Shin; Kim, Jae-Hoon; Kim, Hyun-Soo; Kim, Duck-Hoi; Ku, Seong-Hoi; Moon, Soon-Il

    Graphite is applied to structural material of the high temperature reactor and nozzle of high energy rocket engine. The excessive vibration and stress field can be occurred for this material due to the severe thermal condition. In this study, the thermal stress and vibration characteristics of ATJ graphite under high temperature condition are investigated by finite element analysis (FEA). The specimen is designed as a disk shape in order to simulate the rocket nozzle combustion condition. The experiment of thermal heat is also conducted using by CO2 laser.

  7. Morphological and thermal evaluation of blends of polyethylene wax and paraffin

    Energy Technology Data Exchange (ETDEWEB)

    Akishino, J.K. [Graduate Program in Engineering and Materials Science, Federal University of Parana, Curitiba, PR (Brazil); Institute for the Development of Technology, LACTEC, PO Box 19067, 81531-990 Curitiba, PR (Brazil); Cerqueira, D.P. [Companhia de Eletricidade do Estado da Bahia—COELBA, Salvador, BA (Brazil); Silva, G.C. [Institute for the Development of Technology, LACTEC, PO Box 19067, 81531-990 Curitiba, PR (Brazil); Swinka-Filho, V. [Graduate Program in Engineering and Materials Science, Federal University of Parana, Curitiba, PR (Brazil); Institute for the Development of Technology, LACTEC, PO Box 19067, 81531-990 Curitiba, PR (Brazil); Munaro, M., E-mail: marilda@lactec.org.br [Graduate Program in Engineering and Materials Science, Federal University of Parana, Curitiba, PR (Brazil); Institute for the Development of Technology, LACTEC, PO Box 19067, 81531-990 Curitiba, PR (Brazil)

    2016-02-20

    Highlights: • Thermal properties of polyethylene wax and paraffin were investigated. • The blends were characterized by DSC, XRD and DMTA. • The melting temperatures were between those of the pure constituents. • The crystallinity decreased with addition of polyethylene wax. • The softening temperatures did not vary linearly with the composition. - Abstract: The thermal behavior and the morphology of blends of polyethylene wax and paraffin were investigated to evaluate the feasibility of using these materials to obtain a new temperature-indicating device to use in order to indicate failures in electrical connections due to overheating. The samples were evaluated with differential scanning calorimetry (DSC), X-ray diffraction (XRD) and dynamic mechanical thermal analysis (DMTA). The results showed that the crystallinity decreases as the concentration of polyethylene wax increases. In the compositions tested, the components were not miscible in the crystalline phase, and these compositions exhibited solid/liquid transitions at temperatures between those of the individual components.

  8. Evaluation of the solid-phase extraction (SPE) cartridge method in combination with thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) for the analysis of different VOCs in liquid matrices in varying pH conditions.

    Science.gov (United States)

    Pandey, Sudhir Kumar; Kim, Ki-Hyun

    2012-08-01

    In this study, the solid-phase extraction (SPE) method combined with thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) method is evaluated for the analysis of liquid-phase volatile organic compounds (LVOCs). Calibration experiments were performed on a number of polar and nonpolar LVOCs (including aromatic compounds, ester, ketones, and alcohol) as a function of solution pH. If the relative sensitivity of the SPE-TD-GC-MS method is compared between different VOCs across a wide range of pH (1, 4, 7, 10, and 13), optimum sensitivities for most VOCs are derived at the neutral pH. However, there were some exceptions to the general trend with the maximum sensitivity occurring either at a moderately basic pH (methyl isobutyl ketone and butyl acetate) or extremely acidic conditions (isobutyl alcohol). It was also noticed that the relative ordering of sensitivity was changed, as the pH conditions of the solution vary. The use of internal standard (IS: chlorobenzene) resulted in a notable improvement in both relative sensitivity and reproducibility for most compounds. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. 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 ...

  10. Determining in-situ thermal conductivity of coarse textured materials through numerical analysis of thermal

    Science.gov (United States)

    Saito, H.; Hamamoto, S.; Moldrup, P.; Komatsu, T.

    2013-12-01

    Ground source heat pump (GSHP) systems use ground or groundwater as a heat/cooling source, typically by circulating anti-freezing solution inside a vertically installed closed-loop tube known as a U-tube to transfer heat to/from the ground. Since GSHP systems are based on renewable energy and can achieve much higher coefficient of performance (COP) than conventional air source heat pump systems, use of GSHP systems has been rapidly increasing worldwide. However, environmental impacts by GSHP systems including thermal effects on subsurface physical-chemical and microbiological properties have not been fully investigated. To rigorously assess GSHP impact on the subsurface environment, ground thermal properties including thermal conductivity and heat capacity need to be accurately characterized. Ground thermal properties were investigated at two experimental sites at Tokyo University of Agriculture and Technology (TAT) and Saitama University (SA), both located in the Kanto area of Japan. Thermal properties were evaluated both by thermal probe measurements on boring core samples and by performing in-situ Thermal Response Tests (TRT) in 50-80 m deep U-tubes. At both TAT and SU sites, heat-pulse probe measurements gave unrealistic low thermal conductivities for coarse textured materials (dominated by particles > 75 micrometers). Such underestimation can be partly due to poor contact between probe and porous material and partly to markedly decreasing sample water content during drilling, carrying, and storing sandy/gravelly samples. A more reliable approach for estimating in-situ thermal conductivity of coarse textured materials is therefore needed, and may be based on the commonly used TRT test. However, analyses of TRT data is typically based on Kelvin's line source model and provides an average (effective) thermal property for the whole soil profile around the U-tube but not for each geological layer. The main objective of this study was therefore to develop a method

  11. A Multi-scale Approach to Urban Thermal Analysis

    Science.gov (United States)

    Gluch, Renne; Quattrochi, Dale A.

    2005-01-01

    An environmental consequence of urbanization is the urban heat island effect, a situation where urban areas are warmer than surrounding rural areas. The urban heat island phenomenon results from the replacement of natural landscapes with impervious surfaces such as concrete and asphalt and is linked to adverse economic and environmental impacts. In order to better understand the urban microclimate, a greater understanding of the urban thermal pattern (UTP), including an analysis of the thermal properties of individual land covers, is needed. This study examines the UTP by means of thermal land cover response for the Salt Lake City, Utah, study area at two scales: 1) the community level, and 2) the regional or valleywide level. Airborne ATLAS (Advanced Thermal Land Applications Sensor) data, a high spatial resolution (10-meter) dataset appropriate for an environment containing a concentration of diverse land covers, are used for both land cover and thermal analysis at the community level. The ATLAS data consist of 15 channels covering the visible, near-IR, mid-IR and thermal-IR wavelengths. At the regional level Landsat TM data are used for land cover analysis while the ATLAS channel 13 data are used for the thermal analysis. Results show that a heat island is evident at both the community and the valleywide level where there is an abundance of impervious surfaces. ATLAS data perform well in community level studies in terms of land cover and thermal exchanges, but other, more coarse-resolution data sets are more appropriate for large-area thermal studies. Thermal response per land cover is consistent at both levels, which suggests potential for urban climate modeling at multiple scales.

  12. THERMAL EVALUATION OF ALTERNATE SHIPPING CASK FOR GTRI EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Donna Post Guillen

    2014-06-01

    The Global Threat Reduction Initiative (GTRI) has many experiments yet to be irradiated in support of the High Performance Research Reactor fuels development program. Most of the experiments will be irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL), then later shipped to the Hot Fuel Examination Facility (HFEF) located at the Materials and Fuels Complex for post irradiation examination. To date, the General Electric (GE)-2000 cask has been used to transport GTRI experiments between these facilities. However, the availability of the GE-2000 cask to support future GTRI experiments is at risk. In addition, the internal cavity of the GE-2000 cask is too short to accommodate shipping the larger GTRI experiments. Therefore, an alternate shipping capability is being pursued. The Battelle Energy Alliance, LLC, Research Reactor (BRR) cask has been determined to be the best alternative to the GE-2000 cask. An evaluation of the thermal performance of the BRR cask is necessary before proceeding with fabrication of the newly designed cask hardware and the development of handling, shipping, and transport procedures. This paper presents the results of the thermal evaluation of the BRR cask loaded with a representative set of fueled and non-fueled experiments. When analyzed with identical payloads, experiment temperatures were found to be lower with the BRR cask than with the GE-2000 cask. From a thermal standpoint, the BRR cask was found to be a suitable alternate to the GE-2000 cask.

  13. Laser pulse heating of surfaces and thermal stress analysis

    CERN Document Server

    Yilbas, Bekir S; Al-Aqeeli, Nasser; Al-Qahtani, Hussain M

    2013-01-01

    This book introduces laser pulse heating and thermal stress analysis in materials surface. Analytical temperature treatments and stress developed in the surface region are also explored. The book will help the reader analyze the laser induced stress in the irradiated region and presents solutions for the stress field. Detailed thermal stress analysis in different laser pulse heating situations and different boundary conditions are also presented. Written for surface engineers.

  14. 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 ...

  15. 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.

  16. The Analysis of Thermal Comfort in Kitchen

    Science.gov (United States)

    Ilma Rahmillah, Fety; Hotma Uli Tumanggor, Agustina; Dila Sari, Amarria

    2017-06-01

    Human also has a thermoreceptor which is a non-specialized sensory receptor that has relative changes in temperature. Thermal comfort is a very important element for human body. Kitchen as an important part of a home is often forgotten. Cooking in the kitchen is a routine activity which is done from the morning until the evening; begin with preparing breakfast, lunch and dinner. The problem in this study was the occurance of heat when cooking in the kitchen without air conditioning in tropical countries. This research analyzes thermal comfort while doing cooking activities in conventional kitchen with gas stoves in tropical dry season. Two residential kitchens are observed by measuring the temperature and humidity as well as analyze other possible factors. Psychometric chart is used to assess the comfort zone in the kitchen. This research is using Predicted Mean Vote (PMV) Index and Predicted Percentage Dissatisfied (PPD) Index. By using online psychometric chart, the sensation is in warm condition with the range value of PMV between 1.73 up to 2.36 and PPD 63% untill 90%. However, 71% respondents perceived morning kitchen thermal as comfortable.

  17. 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

  18. The Evaluation of Feasibility of Thermal Energy Storage System at Riga TPP-2

    Science.gov (United States)

    Ivanova, P.; Linkevics, O.; Cers, A.

    2015-12-01

    The installation of thermal energy storage system (TES) provides the optimisation of energy source, energy security supply, power plant operation and energy production flexibility. The aim of the present research is to evaluate the feasibility of thermal energy system installation at Riga TPP-2. The six modes were investigated: four for non-heating periods and two for heating periods. Different research methods were used: data statistic processing, data analysis, analogy, forecasting, financial method and correlation and regression method. In the end, the best mode was chosen - the increase of cogeneration unit efficiency during the summer.

  19. The Evaluation of Feasibility of Thermal Energy Storage System at Riga TPP-2

    Directory of Open Access Journals (Sweden)

    Ivanova P.

    2015-12-01

    Full Text Available The installation of thermal energy storage system (TES provides the optimisation of energy source, energy security supply, power plant operation and energy production flexibility. The aim of the present research is to evaluate the feasibility of thermal energy system installation at Riga TPP–2. The six modes were investigated: four for non-heating periods and two for heating periods. Different research methods were used: data statistic processing, data analysis, analogy, forecasting, financial method and correlation and regression method. In the end, the best mode was chosen – the increase of cogeneration unit efficiency during the summer.

  20. FFTF horizontal sodium storage tank preliminary thermal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Irwin, J.J.

    1995-02-21

    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 drain tanks will be cylindrical vertical tanks having a diameter of 28 feet, height of 22 feet and fabricated from carbon steel. The vertical tanks were the subject of a previous report and are not the subject of this report. The fourth tank is a horizontal cylindrical tank 18 feet in diameter, having an overall length of 31 feet and fabricated from carbon steel. The purpose of this work is to document the thermal analyses that were performed to ensure that the FFTF horizontal 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 drain tank is the type of insulation. The baseline case assumed four inches of calcium silicate insulation. An alternate case assumed refractory fiber (Cerablanket) insulation also with a thickness of four inches. Both cases assumed a total electrical trace heat load of 60 kW, evenly distributed on the tank heads and on the tank side wall (cylinder).

  1. FFTF vertical sodium storage tank preliminary thermal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Irwin, J.J.

    1995-02-21

    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.

  2. Thermal analysis of disc brakes using finite element method

    Science.gov (United States)

    Jaenudin, Jamari, J.; Tauviqirrahman, M.

    2017-01-01

    Disc brakes are components of a vehicle that serve to slow or stop the rotation of the wheel. This paper discusses the phenomenon of heat distribution on the brake disc during braking. Heat distribution on the brake disc is caused by kinetic energy changing into mechanical energy. Energy changes occur during the braking process due to friction between the surface of the disc and a disc pad. The temperature resulting from this friction rises high. This thermal analysis on brake discs is aimed to evaluate the performance of an electric car in the braking process. The aim of this study is to analyze the thermal behavior of the brake discs using the Finite Element Method (FEM) through examining the heat distribution on the brake disc using 3-D modeling. Results obtained from the FEM reflect the effects of high heat due to the friction between the disc pad with the disc rotor. Results of the simulation study are used to identify the effect of the heat distribution that occurred during the braking process.

  3. Selection and Evaluation of Thermal Interface Materials for Reduction of the Thermal Contact Resistance of Thermoelectric Generators

    Science.gov (United States)

    Sakamoto, Tatsuya; Iida, Tsutomu; Sekiguchi, Takeshi; Taguchi, Yutaka; Hirayama, Naomi; Nishio, Keishi; Takanashi, Yoshifumi

    2014-10-01

    A variety of thermal interface materials (TIMs) were investigated to find a suitable TIM for improving the performance of thermoelectric power generators (TEGs) operating in the medium-temperature range (600-900 K). The thermal resistance at the thermal interface between which the TIM was inserted was evaluated. The TIMs were chosen on the basis of their thermal stability when used with TEGs operating at medium temperatures, their electrical insulating properties, their thermal conductivity, and their thickness. The results suggest that the boron nitride (BN)-based ceramic coating, Whity Paint, and the polyurethane-based sheet, TSU700-H, are suitable TIMs for the heat source and heat sink sides, respectively, of the TEG. Use of these effectively enhances TEG performance because they reduce the thermal contact resistance at the thermal interface.

  4. Status and subjects of thermal-hydraulic analysis for next-generation LWRs

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    The status and subjects on thermal-hydraulic analysis for next-generation light water reactors (LWRs) with passive safety systems were surveyed through about 5 years until March 1999 by subcommittee on improvement of reactor thermal-hydraulic analysis codes under the nuclear code committee in Japan Atomic Energy Research Institute. Based on the survey results and discussion, the status and subjects on system analysis for various types of proposed reactor were summarized in 1998 and those on multidimensional two-phase flow analysis were also reviewed, since the multidimensional analysis was recognized as one of the most important subjects through the investigation on system analysis. In this report, the status and subjects for the following were summarized from the survey results and discussion in 1998 and 1999; (1) BWR neutronic/thermal-hydraulic coupled analysis, (2) Evaluation of passive safety system performance and (3) Gas-liquid two-phase flow analysis. The contents in this report are the forefront of thermal-hydraulic analysis for LWRs including test results from several large-scale facilities. We expect that the contents can offer a guideline to improve reactor thermal-hydraulic analysis codes in future. (author)

  5. 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.

  6. 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

  7. Analysis of a Radioisotope Thermal Rocket Engine

    Science.gov (United States)

    Machado-Rodriguez, Jonathan P.; Landis, Geoffrey A.

    2017-01-01

    The Triton Hopper is a concept for a vehicle to explore the surface of Neptunes moon Triton, which uses a radioisotope heated rocket engine and in-situ propellant acquisition. The initial Triton Hopper conceptual design stores pressurized Nitrogen in a spherical tank to be used as the propellant. The aim of the research was to investigate the benefits of storing propellant at ambient temperature and heating it through a thermal block during engine operation, as opposed to storing gas at a high temperature.

  8. Feasibility of photoacoustic evaluations on dual-thermal treatment of ex vivo bladder tumors.

    Science.gov (United States)

    Nguyen, Van Phuc; Oh, Junghwan; Park, Suhyun; Wook Kang, Hyun

    2017-04-01

    A variety of thermal therapeutic methods have been investigated to treat bladder tumors but often cause bowel injury and bladder wall perforation due to high treatment dosage and limited clinical margins. The objective of the current study is to develop a dual-thermal modality to deeply coagulate the bladder tumors at low thermal dosage and to evaluate therapeutic outcomes with high contrast photoacoustic imaging (PAI). High intensity focused ultrasound (HIFU) is combined with 532 nm laser light to enhance therapeutic depth during thermal treatments on artificial tumor-injected bladder tissue ex vivo. PAI is employed to identify the margins of the tumors pre- and post-treatments. The dual-thermal modality achieves 3- and 1.8-fold higher transient temperature changes and 2.2- and 1.5-fold deeper tissue denaturation than laser and HIFU, respectively. PAI vividly identifies the position of the injected tumor and entails approximately 7.9 times higher image contrast from the coagulated tumor as that from the untreated tumor. Spectroscopic analysis exhibits that both 740 nm and 760 nm attains the maximum photoacoustic amplitudes from the treated areas. The proposed PAI-guided dual-thermal treatments (laser and HIFU) treatments can be a feasible therapeutic modality to treat bladder tumors in a controlled and efficient manner. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Evaluation of airborne thermal, magnetic, and electromagnetic characterization technologies

    Energy Technology Data Exchange (ETDEWEB)

    Josten, N.E.

    1992-03-01

    The identification of Buried Structures (IBS) or Aerial Surveillance Project was initiated by the US Department of Energy (DOE) Office of Technology Development to demonstrate airborne methods for locating and identifying buried waste and ordnance at the Idaho National Engineering Laboratory (INEL). Two technologies were demonstrated: (a) a thermal infrared imaging system built by Martin Marietta Missile Systems and (b) a magnetic and electromagnetic (EM) geophysical surveying system operated by EBASCO Environmental. The thermal system detects small differences in ground temperature caused by uneven heating and cooling of the ground by the sun. Waste materials on the ground can be detected when the temperature of the waste is different than the background temperature. The geophysical system uses conventional magnetic and EM sensors. These sensors detect disturbances caused by magnetic or conductive waste and naturally occurring magnetic or conductive features of subsurface soils and rock. Both systems are deployed by helicopter. Data were collected at four INEL sites. Tests at the Naval Ordnance Disposal Area (NODA) were made to evaluate capabilities for detecting ordnance on the ground surface. Tests at the Cold Simulated Waste Demonstration Pit were made to evaluate capabilities for detecting buried waste at a controlled site, where the location and depth of buried materials are known. Tests at the Subsurface Disposal Area and Stationary Low-Power Reactor-1 burial area were made to evaluate capabilities for characterizing hazardous waste at sites that are typical of DOE buried waste sites nationwide.

  10. Evaluation of Instrumentation and Dynamic Thermal Ratings for Overhead Lines

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, A. [New York Power Authority, White Plains, NY (United States)

    2013-01-31

    In 2010, a project was initiated through a partnership between the Department of Energy (DOE) and the New York Power Authority (NYPA) to evaluate EPRI's rating technology and instrumentation that can be used to monitor the thermal states of transmission lines and provide the required real-time data for real-time rating calculations. The project included the installation and maintenance of various instruments at three 230 kV line sites in northern New York. The instruments were monitored, and data collection and rating calculations were performed for about a three year period.

  11. Development of thermal models of footwear using finite element analysis.

    Science.gov (United States)

    Covill, D; Guan, Z W; Bailey, M; Raval, H

    2011-03-01

    Thermal comfort is increasingly becoming a crucial factor to be considered in footwear design. The climate inside a shoe is controlled by thermal and moisture conditions and is crucial to attain comfort. Research undertaken has shown that thermal conditions play a dominant role in shoe climate. Development of thermal models that are capable of predicting in-shoe temperature distributions is an effective way forward to undertake extensive parametric studies to assist optimized design. In this paper, two-dimensional and three-dimensional thermal models of in-shoe climate were developed using finite element analysis through commercial code Abaqus. The thermal material properties of the upper shoe, sole, and air were considered. Dry heat flux from the foot was calculated on the basis of typical blood flow in the arteries on the foot. Using the thermal models developed, in-shoe temperatures were predicted to cover various locations for controlled ambient temperatures of 15, 25, and 35 degrees C respectively. The predicted temperatures were compared with multipoint measured temperatures through microsensor technology. Reasonably good correlation was obtained, with averaged errors of 6, 2, and 1.5 per cent, based on the averaged in-shoe temperature for the above three ambient temperatures. The models can be further used to help design shoes with optimized thermal comfort.

  12. Application of spatial frequency response as a criterion for evaluating thermal imaging camera performance

    Science.gov (United States)

    Lock, Andrew; Amon, Francine

    2008-04-01

    Police, firefighters, and emergency medical personnel are examples of first responders that are utilizing thermal imaging cameras in a very practical way every day. However, few performance metrics have been developed to assist first responders in evaluating the performance of thermal imaging technology. This paper describes one possible metric for evaluating spatial resolution using an application of Spatial Frequency Response (SFR) calculations for thermal imaging. According to ISO 12233, the SFR is defined as the integrated area below the Modulation Transfer Function (MTF) curve derived from the discrete Fourier transform of a camera image representing a knife-edge target. This concept is modified slightly for use as a quantitative analysis of the camera's performance by integrating the area between the MTF curve and the camera's characteristic nonuniformity, or noise floor, determined at room temperature. The resulting value, which is termed the Effective SFR, can then be compared with a spatial resolution value obtained from human perception testing of task specific situations to determine the acceptability of the performance of thermal imaging cameras. The testing procedures described herein are being developed as part of a suite of tests for possible inclusion into a performance standard on thermal imaging cameras for first responders.

  13. Thermal Hydraulic Analysis Using GIS on Application of HTR to Thermal Recovery of Heavy Oil Reservoirs

    Directory of Open Access Journals (Sweden)

    Yangping Zhou

    2012-01-01

    Full Text Available At present, large water demand and carbon dioxide (CO2 emissions have emerged as challenges of steam injection for oil thermal recovery. This paper proposed a strategy of superheated steam injection by the high-temperature gas-cooled reactor (HTR for thermal recovery of heavy oil, which has less demand of water and emission of CO2. The paper outlines the problems of conventional steam injection and addresses the advantages of superheated steam injection by HTR from the aspects of technology, economy, and environment. A Geographic Information System (GIS embedded with a thermal hydraulic analysis function is designed and developed to analyze the strategy, which can make the analysis work more practical and credible. Thermal hydraulic analysis using this GIS is carried out by applying this strategy to a reference heavy oil field. Two kinds of injection are considered and compared: wet steam injection by conventional boilers and superheated steam injection by HTR. The heat loss, pressure drop, and possible phase transformation are calculated and analyzed when the steam flows through the pipeline and well tube and is finally injected into the oil reservoir. The result shows that the superheated steam injection from HTR is applicable and promising for thermal recovery of heavy oil reservoirs.

  14. ISS-CREAM Thermal and Fluid System Design and Analysis

    Science.gov (United States)

    Thorpe, Rosemary S.

    2015-01-01

    Thermal and Fluids Analysis Workshop (TFAWS), Silver Spring MD NCTS 21070-15. The ISS-CREAM (Cosmic Ray Energetics And Mass for the International Space Station) payload is being developed by an international team and will provide significant cosmic ray characterization over a long time frame. Cold fluid provided by the ISS Exposed Facility (EF) is the primary means of cooling for 5 science instruments and over 7 electronics boxes. Thermal fluid integrated design and analysis was performed for CREAM using a Thermal Desktop model. This presentation will provide some specific design and modeling examples from the fluid cooling system, complex SCD (Silicon Charge Detector) and calorimeter hardware, and integrated payload and ISS level modeling. Features of Thermal Desktop such as CAD simplification, meshing of complex hardware, External References (Xrefs), and FloCAD modeling will be discussed.

  15. Thermal Analysis and Calorimetry Techniques for Catalytic Investigations

    Science.gov (United States)

    Le Parlouër, Pierre

    The use of thermal analysis and calorimetry techniques is quite an old and known field of applications for the catalytic investigations and many publications have been published on the various topics including analysis of catalysts, investigation of the processes during the preparation of catalysts, desactivation of catalysts and interaction of reactants or catalytic poisons with the catalysts. Differential thermal analysis, calorimetry and thermogravimetry are also used to characterize the catalysts, especially in the field of gas-solid and gas-liquid interactions. Since the last years, many technical improvements have appeared in the design and the use of thermal analyzers and calorimeters, particularly for the characterization of catalysts. This chapter gives a detailed overview of the uptodate thermal techniques covering various techniques including Differential Thermal Analysis (DTA), Differential Scanning Calorimetry (DSC), the calorimetric techniques (including Isothermal Calorimetry, Titration Calorimetry), Thermogravimetric Analysis (TGA), the combined techniques (including TG-DTA and TG-DSC), the Evolved Gas Analysis (including TG-MS, TG-FTIR). Some examples of applications are given to illustrate the catalyst characterizations.

  16. Modelling Phase Change in a 3D Thermal Transient Analysis

    OpenAIRE

    Haque, EEU; Hampson, PR

    2016-01-01

    A 3D thermal transient analysis of a gap profiling technique which utilises phase change material (plasticine) is conducted in ANSYS. Phase change is modelled by assigning enthalpy of fusion over a wide temperature range based on Differential Scanning Calorimetry (DSC) results. Temperature dependent convection is approximated using Nusselt number correlations. A parametric study is conducted on the thermal contact conductance value between the profiling device (polymer) and adjacent (metal) s...

  17. Subjective evaluation to thermal environment. Onnetsu kankyo no shukanteki hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Taya, H. (Human Factors Reserach Department, Tsukuba (Japan))

    1991-11-10

    This paper introduces a subjective evaluation on a thermal environment. Providing human being with an appropriate and pleasant environment requires considerations from three aspects of economy, health, and comfort. Related with these are the productively optimal temperature, the physiologically optimal temperature, and the subjectively optimal temperature. While a human being makes subjective judgments on his or her environment through physiological reactions, the kinds of these subjective judgments include those on perception, evaluation, preference, receptivity, and permissibility. The subjective evaluation is measured by declaration of subjects. An evaluation method using a category scale or an SD scale is used for the measurement. The evaluation on cold-hot feeling and comfort using the category scale and that using the SD scale are explained, whereas the evaluation on preference relative to environmental temperatures is carried out by rating that the present environment should be made warmer'', can remain unchanged'' or should be made cooler''. 22 refs., 5 figs., 5 tabs.

  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. 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.

  20. Standard Practice for Evaluating Solar Absorptive Materials for Thermal Applications

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This practice covers a testing methodology for evaluating absorptive materials used in flat plate or concentrating collectors, with concentrating ratios not to exceed five, for solar thermal applications. This practice is not intended to be used for the evaluation of absorptive surfaces that are (1) used in direct contact with, or suspended in, a heat-transfer liquid, (that is, trickle collectors, direct absorption fluids, etc.); (2) used in evacuated collectors; or (3) used in collectors without cover plate(s). 1.2 Test methods included in this practice are property measurement tests and aging tests. Property measurement tests provide for the determination of various properties of absorptive materials, for example, absorptance, emittance, and appearance. Aging tests provide for exposure of absorptive materials to environments that may induce changes in the properties of test specimens. Measuring properties before and after an aging test provides a means of determining the effect of the exposure. 1.3 Th...

  1. 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 ...

  2. Thermal modal analysis of novel non-pneumatic mechanical elastic wheel based on FEM and EMA

    Directory of Open Access Journals (Sweden)

    Youqun Zhao

    2018-01-01

    Full Text Available A combination of Finite Element Method (FEM and Experiment Modal Analysis (EMA have been employed here to characterize the structural dynamic response of mechanical elastic wheel (ME-Wheel operating under a specific thermal environment. The influence of high thermal condition on the structural dynamic response of ME-Wheel is investigated. The obtained results indicate that the EMA results are in accordance with those obtained using the proposed Finite Element (FE model, indicting the high reliability of this FE model applied in analyzing the modal of ME-Wheel working under practical thermal environment. It demonstrates that the structural dynamic response of ME-Wheel operating under a specific thermal condition can be predicted and evaluated using the proposed analysis method, which is beneficial for the dynamic optimization design of the wheel structure to avoid tire temperature related vibration failure and improve safety of tire.

  3. Thermal modal analysis of novel non-pneumatic mechanical elastic wheel based on FEM and EMA

    Science.gov (United States)

    Zhao, Youqun; Zhu, Mingmin; Lin, Fen; Xiao, Zhen; Li, Haiqing; Deng, Yaoji

    2018-01-01

    A combination of Finite Element Method (FEM) and Experiment Modal Analysis (EMA) have been employed here to characterize the structural dynamic response of mechanical elastic wheel (ME-Wheel) operating under a specific thermal environment. The influence of high thermal condition on the structural dynamic response of ME-Wheel is investigated. The obtained results indicate that the EMA results are in accordance with those obtained using the proposed Finite Element (FE) model, indicting the high reliability of this FE model applied in analyzing the modal of ME-Wheel working under practical thermal environment. It demonstrates that the structural dynamic response of ME-Wheel operating under a specific thermal condition can be predicted and evaluated using the proposed analysis method, which is beneficial for the dynamic optimization design of the wheel structure to avoid tire temperature related vibration failure and improve safety of tire.

  4. A dynamic tester to evaluate the thermal and moisture behaviour of the surface of textiles.

    Science.gov (United States)

    Li, Wenbin; Xu, Weilin; Wang, Hao; Wang, Xin

    2016-01-01

    The thermal and moisture behaviour of the microclimate of textiles is crucial in determining the physiological comfort of apparel, but it has not been investigated sufficiently due to the lack of particular evaluation techniques. Based on sensing, temperature controlling and wireless communicating technology, a specially designed tester has been developed in this study to evaluate the thermal and moisture behaviour of the surface of textiles in moving status. A temperature acquisition system and a temperature controllable hotplate have been established to test temperature and simulate the heat of human body, respectively. Relative humidity of the surface of fabric in the dynamic process has been successfully tested through sensing. Meanwhile, wireless communication technology was applied to transport the acquired data of temperature and humidity to computer for further processing. Continuous power supply was achieved by intensive contact between an elastic copper plate and copper ring on the rotating shaft. This tester provides the platform to evaluate the thermal and moisture behaviour of textiles. It enables users to conduct a dynamic analysis on the temperature and humidity together with the thermal and moisture transport behaviour of the surface of fabric in moving condition. Development of this tester opens the door of investigation on the micro-climate of textiles in real time service, and eventually benefits the understanding of the sensation comfort and wellbeing of apparel wearers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Thermal Analysis of LANL Ion Exchange Column

    Energy Technology Data Exchange (ETDEWEB)

    Laurinat, J.E.

    1999-06-16

    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.

  6. SUPERALLOYS: AN INTRODUCTION WITH THERMAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    S. S. Raza

    2015-09-01

    Full Text Available Nickel based superalloys are commonly used materials in the aero industry and more specifically in the hot section of aero engines. These nickel and nickel iron based superalloys are precipitation strengthened alloys with a face centered cubic gamma matrix. Alloy 718, Allvac 718Plus and Waspaloy have been of great interest in the present study. Alloy 718 is a precipitation strengthened nickel-iron based alloy having gamma double prime phase (Ni3Nb as a main strengthening phase up to 650 °C. Waspaloy, another precipitation strengthened nickel base superalloy, has a very good strength at temperatures up to ~750 °C whereas Allvac 718Plus is a newly developed nickel based precipitation strengthened superalloy which retains good mechanical properties at up to ~700 °C. These three alloys were investigated in terms of how their respective solidification process reveals upon cooling.Latent heat of soloidification has been estimated for all three alloys. Differential thermal analyses (DTA have been used to approach the task. It was seen that Waspaloy has the smallest solidification range whereas Allvac 718Plus has the largest solidification interval in comparison. 

  7. Analysis of Thermal Radiation Effects on Temperatures in Turbine Engine Thermal Barrier Coatings

    Science.gov (United States)

    Siegel, Robert; Spuckler, Charles M.

    1998-01-01

    Thermal barrier coatings are important, and in some instances a necessity, for high temperature applications such as combustor liners, and turbine vanes and rotating blades for current and advanced turbine engines. Some of the insulating materials used for coatings, such as zirconia that currently has widespread use, are partially transparent to thermal radiation. A translucent coating permits energy to be transported internally by radiation, thereby increasing the total energy transfer and acting like an increase in thermal conductivity. This degrades the insulating ability of the coating. Because of the strong dependence of radiant emission on temperature, internal radiative transfer effects are increased as temperatures are raised. Hence evaluating the significance of internal radiation is of importance as temperatures are increased to obtain higher efficiencies in advanced engines.

  8. 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.

  9. Continued field evaluation of precutting for maintaining asphalt concrete pavements with thermal cracking.

    Science.gov (United States)

    2017-08-01

    In continuation of a previously completed project entitled Evaluate Presawn Transverse Thermal Cracks for Asphalt Concrete Pavement, this project was a further effort to understand important variables in the thermal cracking process through continued...

  10. 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.

  11. Thermal analysis of RFETS SS and C

    Energy Technology Data Exchange (ETDEWEB)

    Korinko, P.S.

    2000-02-04

    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.

  12. Evaluation of risk and benefit in thermal effusivity sensor for monitoring lubrication process in pharmaceutical product manufacturing.

    Science.gov (United States)

    Uchiyama, Jumpei; Kato, Yoshiteru; Uemoto, Yoshifumi

    2014-08-01

    In the process design of tablet manufacturing, understanding and control of the lubrication process is important from various viewpoints. A detailed analysis of thermal effusivity data in the lubrication process was conducted in this study. In addition, we evaluated the risk and benefit in the lubrication process by a detailed investigation. It was found that monitoring of thermal effusivity detected mainly the physical change of bulk density, which was changed by dispersal of the lubricant and the coating powder particle by the lubricant. The monitoring of thermal effusivity was almost the monitoring of bulk density, thermal effusivity could have a high correlation with tablet hardness. Moreover, as thermal effusivity sensor could detect not only the change of the conventional bulk density but also the fractional change of thermal conductivity and thermal capacity, two-phase progress of lubrication process could be revealed. However, each contribution of density, thermal conductivity, or heat capacity to thermal effusivity has the risk of fluctuation by formulation. After carefully considering the change factor with the risk to be changed by formulation, thermal effusivity sensor can be a useful tool for monitoring as process analytical technology, estimating tablet hardness and investigating the detailed mechanism of the lubrication process.

  13. An empirical analysis of thermal protective performance of fabrics used in protective clothing.

    Science.gov (United States)

    Mandal, Sumit; Song, Guowen

    2014-10-01

    Fabric-based protective clothing is widely used for occupational safety of firefighters/industrial workers. The aim of this paper is to study thermal protective performance provided by fabric systems and to propose an effective model for predicting the thermal protective performance under various thermal exposures. Different fabric systems that are commonly used to manufacture thermal protective clothing were selected. Laboratory simulations of the various thermal exposures were created to evaluate the protective performance of the selected fabric systems in terms of time required to generate second-degree burns. Through the characterization of selected fabric systems in a particular thermal exposure, various factors affecting the performances were statistically analyzed. The key factors for a particular thermal exposure were recognized based on the t-test analysis. Using these key factors, the performance predictive multiple linear regression and artificial neural network (ANN) models were developed and compared. The identified best-fit ANN models provide a basic tool to study thermal protective performance of a fabric. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  14. Application of computational fluid dynamics methods to improve thermal hydraulic code analysis

    Science.gov (United States)

    Sentell, Dennis Shannon, Jr.

    A computational fluid dynamics code is used to model the primary natural circulation loop of a proposed small modular reactor for comparison to experimental data and best-estimate thermal-hydraulic code results. Recent advances in computational fluid dynamics code modeling capabilities make them attractive alternatives to the current conservative approach of coupled best-estimate thermal hydraulic codes and uncertainty evaluations. The results from a computational fluid dynamics analysis are benchmarked against the experimental test results of a 1:3 length, 1:254 volume, full pressure and full temperature scale small modular reactor during steady-state power operations and during a depressurization transient. A comparative evaluation of the experimental data, the thermal hydraulic code results and the computational fluid dynamics code results provides an opportunity to validate the best-estimate thermal hydraulic code's treatment of a natural circulation loop and provide insights into expanded use of the computational fluid dynamics code in future designs and operations. Additionally, a sensitivity analysis is conducted to determine those physical phenomena most impactful on operations of the proposed reactor's natural circulation loop. The combination of the comparative evaluation and sensitivity analysis provides the resources for increased confidence in model developments for natural circulation loops and provides for reliability improvements of the thermal hydraulic code.

  15. Thermal performance analysis of a solar heating plant

    DEFF Research Database (Denmark)

    Fan, Jianhua; Huang, Junpeng; Andersen, Ola Lie

    Detailed measurements were carried out on a large scale solar heating plant located in southern Denmark in order to evaluate thermal performances of the plant. Based on the measurements, energy flows of the plant were evaluated. A modified Trnsys model of the Marstal solar heating plant...... was developed to calculate thermal performances of the plant. In the Trnsys model, three solar collector fields with a total solar collector area of 33,300 m2, a seasonal water pit heat storage of 75,000 m3, a simplified CO2 HP, a simplified ORC unit and a simplified wood chip boiler were included. The energy...... consumption of the district heating net was modeled by volume flow rate and given forward and return temperatures of the district heating net. Weather data from a weather station at the site of the plant were used in the calculations. The Trnsys calculated yearly thermal performance of the solar heating plant...

  16. Thermal and Electrical Performance Evaluation of PV/T Collectors in UAE

    OpenAIRE

    Kaya, Mustafa

    2013-01-01

    Photovoltaic Thermal/Hybrid collectors are an emerging technology that combines PV and solar thermal collectors by producing heat and electricity simultaneously. In this paper, thermal and electrical performance of PV/T collectors are analyzed and presented for the climate of RAK, UAE. Thermal performance evaluation is done following the collector output model presented in European standard EN 12975-2 and electrical performance evaluation is done by analyzing the effect of water circulation o...

  17. Thermal Performance Evaluation of Walls with Gas Filled Panel Insulation

    Energy Technology Data Exchange (ETDEWEB)

    Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Desjarlais, Andre Omer [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Atchley, Jerald Allen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-11-01

    Gas filled insulation panels (GFP) are very light weight and compact (when uninflated) advanced insulation products. GFPs consist of multiple layers of thin, low emittance (low-e) metalized aluminum. When expanded, the internal, low-e aluminum layers form a honeycomb structure. These baffled polymer chambers are enveloped by a sealed barrier and filled with either air or a low-conductivity gas. The sealed exterior aluminum foil barrier films provide thermal resistance, flammability protection, and properties to contain air or a low conductivity inert gas. This product was initially developed with a grant from the U.S. Department of Energy. The unexpanded product is nearly flat for easy storage and transport. Therefore, transportation volume and weight of the GFP to fill unit volume of wall cavity is much smaller compared to that of other conventional insulation products. This feature makes this product appealing to use at Army Contingency Basing, when transportation cost is significant compared to the cost of materials. The objective of this study is to evaluate thermal performance of walls, similar to those used at typical Barracks Hut (B-Hut) hard shelters, when GFPs are used in the wall cavities. Oak Ridge National Laboratory (ORNL) tested performance of the wall in the rotatable guarded hotbox (RGHB) according to the ASTM C 1363 standard test method.

  18. 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.

  19. Thermal Sensor Arrays for The Combinatorial Analysis of Thin Films

    Science.gov (United States)

    McCluskey, Patrick James

    2011-12-01

    Membrane-based thermal sensor arrays were developed for the high-throughput analysis of the thermophysical properties of thin films. The continuous growth of integrated circuits and microelectromechanical systems, as well as the development of functional materials and the optimization of materials properties, have produced the need for instruments capable of fast materials screening and analysis at reduced length scales. Two instruments were developed based on a similar architecture, one to measure thermal transport properties and the other to perform calorimetry measurements. Both have the capability to accelerate the pace of materials development and understanding using combinatorial measurement methods. The shared architecture of the instruments consists of a silicon-based micromachined array of thermal sensors. Each sensor consists of a SiN X membrane and a W heating element that also serves as a temperature gauge. The array design allows the simultaneous creation of a library of thin film samples by various deposition techniques while systematically varying a parameter of interest across the device. The membrane-based sensors have little thermal mass making them extremely sensitive to changes in thermal energy. The nano-thermal transport array has an array of sensors optimized for sensitivity to heat loss. The heat loss is determined from the temperature response of the sensor to an applied current. An analytical model is used with a linear regression analysis to fit the thermal properties of the samples to the temperature response. The assumptions of the analytical model are validated with a finite element model. Measured thermal properties include specific heat, thermal effusivity, thermal conductivity, and emissivity. The technique is demonstrated by measuring the thermal transport properties of sputter deposited Cu multilayers with a total film thickness from 15 to 470 nm. The experimental results compare well to a theory based on electronic thermal

  20. Thermal analysis of a multi-layer microchannel heat sink for cooling concentrator photovoltaic (CPV) cells

    Science.gov (United States)

    Siyabi, Idris Al; Shanks, Katie; Mallick, Tapas; Sundaram, Senthilarasu

    2017-09-01

    Concentrator Photovoltaic (CPV) technology is increasingly being considered as an alternative option for solar electricity generation. However, increasing the light concentration ratio could decrease the system output power due to the increase in the temperature of the cells. The performance of a multi-layer microchannel heat sink configuration was evaluated using numerical analysis. In this analysis, three dimensional incompressible laminar steady flow model was solved numerically. An electrical and thermal solar cell model was coupled for solar cell temperature and efficiency calculations. Thermal resistance, solar cell temperature and pumping power were used for the system efficiency evaluation. An increase in the number of microchannel layers exhibited the best overall performance in terms of the thermal resistance, solar cell temperature uniformity and pressure drop. The channel height and width has no effect on the solar cell maximum temperature. However, increasing channel height leads to a reduction in the pressure drop and hence less fluid pumping power.

  1. Synthesis, crystal structure, thermal analysis and dielectric ...

    Indian Academy of Sciences (India)

    In both the materials, the crystal structure has been determined by X-ray single crystal analysis at room temperature (293 K). The compound structures consist of K + (or NH 4 + ) cations and double chains of CdCl 6 octahedra sharing one edge extending along b -axis. The mixture of KA + /NH 4 + cations are located ...

  2. Fuel Thermo-physical Characterization Project: Evaluation of Models to Calculate Thermal Diffusivity of Layered Composites

    Energy Technology Data Exchange (ETDEWEB)

    Burkes, Douglas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Casella, Amanda J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gardner, Levi D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Casella, Andrew M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Huber, Tanja K. [Technische Universität München, Munich (Germany); Breitkreutz, Harald [Technische Universität München, Munich (Germany)

    2015-02-11

    The Office of Material Management and Minimization Fuel Thermo-physical Characterization Project at Pacific Northwest National Laboratory (PNNL) is tasked with using PNNL facilities and processes to receive irradiated low enriched uranium-molybdenum fuel plate samples and perform analyses in support of the Office of Material Management and Minimization Reactor Conversion Program. This work is in support of the Fuel Development Pillar that is managed by Idaho National Laboratory. A key portion of the scope associated with this project was to measure the thermal properties of fuel segments harvested from plates that were irradiated in the Advanced Test Reactor. Thermal diffusivity of samples prepared from the fuel segments was measured using laser flash analysis. Two models, one developed by PNNL and the other developed by the Technische Universität München (TUM), were evaluated to extract the thermal diffusivity of the uranium-molybdenum alloy from measurements made on the irradiated, layered composites. The experimental data of the “TC” irradiated fuel segment was evaluated using both models considering a three-layer and five-layer system. Both models are in acceptable agreement with one another and indicate that the zirconium diffusion barrier has a minimal impact on the overall thermal diffusivity of the monolithic U-Mo fuel.

  3. The influence of thermal treatment and type of insoluble poly(meth)acrylates on dissolution behavior of very soluble drug from hypromellose matrix tablets evaluated by multivariate data analysis.

    Science.gov (United States)

    Kubova, Katerina; Peček, Daniel; Hasserová, Kristýna; Doležel, Petr; Pavelková, Miroslava; Vyslouzil, Jakub; Muselík, Jan; Vetchy, David

    2017-03-01

    Hypromellose matrices exhibit extended burst effect immediately after contact with aqueous medium, especially when a water-soluble drug is incorporated. The objective of this study was to reduce burst effect and maintain complete dissolution of a very soluble levetiracetam over 12 h period from hypromellose K4M matrices to obtain zero-order kinetics. Desired changes were achieved by applying water dispersions of insoluble Eudragits(®) (NE, NM, RL, RS) as a granulation liquid to the drug/microcrystalline cellulose mixture during high-shear granulation (non-thermal treated set) and consequently by thermally treating granules or final tablets (TT), respectively. Applying Eudragit(®) water dispersions to the drug/microcrystalline cellulose mixture was recognized as an effective method of significantly reducing the burst release (25.4-33.7%) of levetiracetam in comparison with a reference sample without Eudragit(®). Multivariate data analysis showed that the addition of Eudragit(®) reduced burst effect, increased fitting with zero-order kinetics, and supported matrix erosion as the supplementary mechanism to predominant diffusion. Moreover, resulting PCA sub-model revealed the addition of Eudragit(®) RL and thermal treatment of tablets to be the most suitable method of all. For a 12 h dissolution profile, characterized by low burst effect and drug release close to 100% at the 12th hour, sample RL_TT was the most suitable.

  4. Finite element thermal analysis of convectively-cooled aircraft structures

    Science.gov (United States)

    Wieting, A. R.; Thornton, E. A.

    1981-01-01

    The design complexity and size of convectively-cooled engine and airframe structures for hypersonic transports necessitate the use of large general purpose computer programs for both thermal and structural analyses. Generally thermal analyses are based on the lumped-parameter finite difference technique, and structural analyses are based on the finite element technique. Differences in these techniques make it difficult to achieve an efficient interface. It appears, therefore, desirable to conduct an integrated analysis based on a common technique. A summary is provided of efforts by NASA concerned with the development of an integrated thermal structural analysis capability using the finite element method. Particular attention is given to the development of conduction/forced-convection finite element methodology and applications which illustrate the capabilities of the developed concepts.

  5. Multidisciplinary Analysis of a Microsystem Device for Thermal Control

    Science.gov (United States)

    Moran, Matthew E.

    2002-07-01

    A microelectromechanical (MEMS) device is under development that uses the Stirling cycle to provide cooling or heating directly to a thermally loaded surface. This MEMS cooler can be used strictly in the cooling mode, or switched between cooling and heating modes in milliseconds for precise temporal and spatial temperature control. Potential applications include cooling and thermal control of: microsystems, electronics, sensors, biomedical devices, and spacecraft components. A primary challenge for further development is the multidisciplinary analysis required to characterize and optimize its performance. This paper describes the first-order thermodynamic analysis performed on the MEMS cooler and the resulting ideal performance curves generated. The basis for additional coupled analyses such as fluid/gas dynamics, thermal, electrostatic, structural, dynamic, material, and processing is addressed. Scaling issues relevant to the device and the breakdown of continuum theory in the micro-domain is also examined.

  6. Thermal analysis of nanofluids in microfluidics using an infrared camera.

    Science.gov (United States)

    Yi, Pyshar; Kayani, Aminuddin A; Chrimes, Adam F; Ghorbani, Kamran; Nahavandi, Saeid; Kalantar-zadeh, Kourosh; Khoshmanesh, Khashayar

    2012-07-21

    We present the thermal analysis of liquid containing Al(2)O(3) nanoparticles in a microfluidic platform using an infrared camera. The small dimensions of the microchannel along with the low flow rates (less than 120 μl min(-1)) provide very low Reynolds numbers of less than 17.5, reflecting practical parameters for a microfluidic cooling platform. The heat analysis of nanofluids has never been investigated in such a regime, due to the deficiencies of conventional thermal measurement systems. The infrared camera allows non-contact, three dimensional and high resolution capability for temperature profiling. The system was studied at different w/w concentrations of thermally conductive Al(2)O(3) nanoparticles and the experiments were in excellent agreement with the computational fluid dynamics (CFD) simulations.

  7. 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.

  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. Finite element analysis for dental implants subjected to thermal loads

    Directory of Open Access Journals (Sweden)

    Mohamad Reza Khalili

    2013-10-01

    Full Text Available   Background and Aims: Dental implants have been studied for replacement of missing teeth for many years. Productivity of implants is extremely related to the stability and resistance under applied loads and the minimum stress in jaw bone. The purpose of this study was to study numerically the 3D model of implant under thermal loads.   Materials and Methods: Bone and the ITI implant were modeled in “Solidworks” software. To obtain the exact model, the bone was assumed as a linear orthotropic material. The implant system, including implant, abutment, framework and crown were modeled and located in the bone. After importing the model in Abaqus software, the material properties and boundary conditions and loads were applied and after meshing, the model was analyzed. In this analysis, the loads were applied in two steps. In the first step, the mechanical load was applied as tightening torque to the abutment and the abutment was tightened in the implant with 35 N.cm torque. In the second step, the thermal load originated from drinking cold and hot water was applied as thermal flux on the ceramic crown surface in this model.   Results: Thermal analysis results showed that the thermal gradient in the bone was about 5.5 and 4.9 degrees of centigrade in the case of drinking cold and hot water respectively , although the maximum gradient of the whole system was reduced to 14 degrees, which occurred, in the crown by drinking cold water.   Conclusion Thermal stresses were so small and it was because of the low thermal gradient. Maximum stresses occurred in the abutment were due to the tension preloads which were originated from the tightening torque.

  10. 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

    disposal system. Clay/shale, salt, and crystalline rock media are selected as the basis for reference mined geologic disposal concepts in this study, consistent with advanced international repository programs, and previous investigations in the U.S. The U.S. pursued deep geologic disposal programs in crystalline rock, shale, salt, and volcanic rock in the years leading up to the Nuclear Waste Policy Act, or NWPA (Rechard et al. 2011). The 1987 NWPA amendment act focused the U.S. program on unsaturated, volcanic rock at the Yucca Mountain site, culminating in the 2008 license application. Additional work on unsaturated, crystalline rock settings (e.g., volcanic tuff) is not required to support this generic study. Reference disposal concepts are selected for the media listed above and for deep borehole disposal, drawing from recent work in the U.S. and internationally. The main features of the repository concepts are discussed in Section 4.5 and summarized in Table ES-1. Temperature histories at the waste package surface and a specified distance into the host rock are calculated for combinations of waste types and reference disposal concepts, specifying waste package emplacement modes. Target maximum waste package surface temperatures are identified, enabling a sensitivity study to inform the tradeoff between the quantity of waste per disposal package, and decay storage duration, with respect to peak temperature at the waste package surface. For surface storage duration on the order of 100 years or less, waste package sizes for direct disposal of SNF are effectively limited to 4-PWR configurations (or equivalent size and output). Thermal results are summarized, along with recommendations for follow-on work including adding additional reference concepts, verification and uncertainty analysis for thermal calculations, developing descriptions of surface facilities and other system details, and cost estimation to support system-level evaluations.

  11. Thermal-Hydraulic Analysis Tasks for ANAV NPPs in Support of Plant Operation and Control

    Directory of Open Access Journals (Sweden)

    L. Batet

    2007-11-01

    Full Text Available Thermal-hydraulic analysis tasks aimed at supporting plant operation and control of nuclear power plants are an important issue for the Asociación Nuclear Ascó-Vandellòs (ANAV. ANAV is the consortium that runs the Ascó power plants (2 units and the Vandellòs-II power plant. The reactors are Westinghouse-design, 3-loop PWRs with an approximate electrical power of 1000 MW. The Technical University of Catalonia (UPC thermal-hydraulic analysis team has jointly worked together with ANAV engineers at different levels in the analysis and improvement of these reactors. This article is an illustration of the usefulness of computational analysis for operational support. The contents presented were operational between 1985 and 2001 and subsequently changed slightly following various organizational adjustments. The paper has two different parts. In the first part, it describes the specific aspects of thermal-hydraulic analysis tasks related to operation and control and, in the second part, it briefly presents the results of three examples of analyses that were performed. All the presented examples are related to actual situations in which the scenarios were studied by analysts using thermal-hydraulic codes and prepared nodalizations. The paper also includes a qualitative evaluation of the benefits obtained by ANAV through thermal-hydraulic analyses aimed at supporting operation and plant control.

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

    African Journals Online (AJOL)

    Purpose: Cervical lesions are restored with class V preparation. The aim of this study was to use a three-dimensional finite element method to carry out a thermal analysis of the temperature and stress distributions of three different restorative materials used for class V cavities of maxillary molar teeth. Materials and Methods: ...

  13. Scientific Ballooning Technologies Workshop STO-2 Thermal Design and Analysis

    Science.gov (United States)

    Ferguson, Doug

    2016-01-01

    The heritage thermal model for the full STO-2 (Stratospheric Terahertz Observatory II), vehicle has been updated to model the CSBF (Columbia Scientific Balloon Facility) SIP-14 (Scientific Instrument Package) in detail. Analysis of this model has been performed for the Antarctica FY2017 launch season. Model temperature predictions are compared to previous results from STO-2 review documents.

  14. 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 ...

  15. ICTAC nomenclature of thermal analysis (IUPAC Recommendations 2014)

    NARCIS (Netherlands)

    Lever, T.; Haines, P.; Rouquerol, J.; Charsley, E.L.; Ekeren, P.J. van; Burlett, D.J.

    2014-01-01

    The widespread use of thermal analysis (TA) by scientists as a laboratory technique carries with it a working vocabulary. This document is intended to provide those working in the field with a consistent set of definitions to permit clear and precise communication as well as understanding. Included

  16. 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 ...

  17. Evaluation of Erosion Resistance of Advanced Turbine Thermal Barrier Coatings

    Science.gov (United States)

    Zhu, Dongming; Kuczmarski, Maria A.; Miller, Robert A.; Cuy, Michael D.

    2007-01-01

    The erosion resistant turbine thermal barrier coating system is critical to aircraft engine performance and durability. By demonstrating advanced turbine material testing capabilities, we will be able to facilitate the critical turbine coating and subcomponent development and help establish advanced erosion-resistant turbine airfoil thermal barrier coatings design tools. The objective of this work is to determine erosion resistance of advanced thermal barrier coating systems under simulated engine erosion and/or thermal gradient environments, validating advanced turbine airfoil thermal barrier coating systems based on nano-tetragonal phase toughening design approaches.

  18. Evaluation Framework and Analyses for Thermal Energy Storage Integrated with Packaged Air Conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Kung, F.; Deru, M.; Bonnema, E.

    2013-10-01

    Few third-party guidance documents or tools are available for evaluating thermal energy storage (TES) integrated with packaged air conditioning (AC), as this type of TES is relatively new compared to TES integrated with chillers or hot water systems. To address this gap, researchers at the National Renewable Energy Laboratory conducted a project to improve the ability of potential technology adopters to evaluate TES technologies. Major project outcomes included: development of an evaluation framework to describe key metrics, methodologies, and issues to consider when assessing the performance of TES systems integrated with packaged AC; application of multiple concepts from the evaluation framework to analyze performance data from four demonstration sites; and production of a new simulation capability that enables modeling of TES integrated with packaged AC in EnergyPlus. This report includes the evaluation framework and analysis results from the project.

  19. Concrete containment analysis including thermal effects

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-01-01

    Pretest predictions were made by the staff of the Engineering Mechanics Program at ANL for the response of the 1:6-scale reinforced concrete containment model that was tested to failure by liner tearing and leakage at the Sandia National Laboratories. Questions have been raised in regard to possible effects of temperature in combination with internal pressure on the behavior of the model. Specifically, if the containment had been subjected to elevated temperature as well as internal pressure, what differences in pressure capacity, failure mechanism and location would have been predicted when compared to the analysis of internal pressure alone. The purpose of this paper is to address these questions. 3 refs., 9 figs.

  20. Mars Phoenix Scout Thermal Evolved Gas Analyzer (TEGA) Database: Thermal Database Development and Analysis

    Science.gov (United States)

    Sutter, B.; Archer, D.; Niles, P. B.; Stein, T. C.; Hamara, D.; Boynton, W. V.; Ming, D. W.

    2017-01-01

    The Mars Phoenix Scout Lander mission in 2008 examined the history of water, searched for organics, and evaluated the potential for past/present microbial habitability in a martian arctic ice-rich soil [1]. The Thermal Evolved Gas Analyzer (TEGA) instrument measured the isotopic composition of atmospheric CO2 and detected volatile bearing mineralogy (perchlorate, carbonate, hydrated mineral phases) in the martian soil [2-7]. The TEGA data are archived at the Planetary Data System (PDS) Geosciences Node but are reported in forms that require further processing to be of use to the non-TEGA expert. The soil and blank TEGA thermal data are reported as duty cycle and must be converted to differential power (mW) to allow for enthalpy calculations of exothermic/endothermic transitions. The exothermic/endothermic temperatures are also used to determine what phases (inorganic/organic) are present in the sample. The objectives of this work are to: 1) Describe how interpretable thermal data can be created from TEGA data sets on the PDS and 2) Provide additional thermal data interpretation of two Phoenix soils (Baby Bear, Wicked Witch) and include interpretations from three unreported soils (Rosy Red 1, 2, and Burning Coals).

  1. Young’s modulus evaluation and thermal shock behavior of a porous SiC/cordierite composite material

    Directory of Open Access Journals (Sweden)

    Pošarac-Marković M.

    2015-01-01

    Full Text Available Porous SiC/Cordierite Composite Material with graphite content (10% was synthesized. Evaluation of Young modulus of elasticity and thermal shock behavior of these samples was presented. Thermal shock behavior was monitored using water quench test, and non destructive methods such are UPVT and image analysis were also used for accompaniment the level of destruction of the samples during water quench test. Based on the level of destruction graphical modeling of critical number of cycles was given. This approach was implemented on discussion of the influence of the graphite content on thermal stability behavior of the samples. [Projekat Ministarstva nauke Republike Srbije, br. III 45012

  2. Ocean Thermal Energy Conversion (OTEC) Programmatic Environmental Analysis--Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Authors, Various

    1980-01-01

    The programmatic environmental analysis is an initial assessment of Ocean Thermal Energy Conversion (OTEC) technology considering development, demonstration and commercialization. It is concluded that the OTEC development program should continue because the development, demonstration, and commercialization on a single-plant deployment basis should not present significant environmental impacts. However, several areas within the OTEC program require further investigation in order to assess the potential for environmental impacts from OTEC operation, particularly in large-scale deployments and in defining alternatives to closed-cycle biofouling control: (1) Larger-scale deployments of OTEC clusters or parks require further investigations in order to assess optimal platform siting distances necessary to minimize adverse environmental impacts. (2) The deployment and operation of the preoperational platform (OTEC-1) and future demonstration platforms must be carefully monitored to refine environmental assessment predictions, and to provide design modifications which may mitigate or reduce environmental impacts for larger-scale operations. These platforms will provide a valuable opportunity to fully evaluate the intake and discharge configurations, biofouling control methods, and both short-term and long-term environmental effects associated with platform operations. (3) Successful development of OTEC technology to use the maximal resource capabilities and to minimize environmental effects will require a concerted environmental management program, encompassing many different disciplines and environmental specialties. This volume contains these appendices: Appendix A -- Deployment Scenario; Appendix B -- OTEC Regional Characterization; and Appendix C -- Impact and Related Calculations.

  3. Thermal analysis and combustion kinetic of heavy oils

    Energy Technology Data Exchange (ETDEWEB)

    Santos, R.G. [Centre for Petroleum Studies, State University of Campinas(Brazil); Vargas, J.A.V.; Trevisan, O.V. [Department of Petroleum Engineering, Faculty of Mechanical Engineering, State University of Campinas (Brazil)

    2011-07-01

    In the oilfield sector, a thermal method named in-situ combustion (ISC) is used as an enhanced recovery method. ISC consists of the injection of gas into the reservoir, a combustion front is created producing heat which reduces the oil viscosity. For this method to be successful, understanding of the thermal and kinetic parameters involved is required; the aim of this paper is to evaluate those parameters for different crude oils. Experiments were conducted using accelerating rate calorimetry on Brazilian heavy oil samples under a heat-wait-seek-mode. Results showed that accelerating rate calorimetry is efficient in resolving the three main regions of reaction of the oil and that between 200 degree C and 300 degree C oxygen addition reactions are dominant while bond scission reactions dominate from 350 degree C. This study demonstrated that accelerating rate calorimetry is an efficient method to determine thermal and kinetic parameters of oxidation reaction of heavy oil.

  4. Thermal Analysis of an Industrial Furnace

    Directory of Open Access Journals (Sweden)

    Mirko Filipponi

    2016-10-01

    Full Text Available Industries, which are mainly responsible for high energy consumption, need to invest in research projects in order to develop new managing systems for rational energy use, and to tackle the devastating effects of climate change caused by human behavior. The study described in this paper concerns the forging industry, where the production processes generally start with the heating of steel in furnaces, and continue with other processes, such as heat treatments and different forms of machining. One of the most critical operations, in terms of energy loss, is the opening of the furnace doors for insertion and extraction operations. During this time, the temperature of the furnaces decreases by hundreds of degrees in a few minutes. Because the dispersed heat needs to be supplied again through the combustion of fuel, increasing the consumption of energy and the pollutant emissions, the evaluation of the amount of lost energy is crucial for the development of systems which can contain this loss. To perform this study, CFD simulation software was used. Results show that when the door opens, because of temperature and pressure differences between the furnace and the ambient air, turbulence is created. Results also show that the amount of energy lost for an opening of 10 min for radiation, convection and conduction is equal to 5606 MJ where convection is the main contributor, with 5020 MJ. The model created, after being validated, has been applied to perform other simulations, in order to improve the energy performance of the furnace. Results show that reducing the opening time of the door saves energy and limits pollutant emissions.

  5. Evaluation of heat sink materials for thermal management of lithium batteries

    Science.gov (United States)

    Dimpault-Darcy, E. C.; Miller, K.

    1988-01-01

    Aluminum, neopentyl glycol (NPG), and resins FT and KT are evaluated theoretically and experimentally as heat sink materials for lithium battery packs. The thermal performances of the two resins are compared in a thermal vacuum experiment. As solutions to the sublimation property were not immediately apparent, a theoretical comparison of the thermal performance of NPG versus KT, Al, and no material, is presented.

  6. Modelling Phase Change in a 3D Thermal Transient Analysis

    Directory of Open Access Journals (Sweden)

    E Haque

    2016-09-01

    Full Text Available A 3D thermal transient analysis of a gap profiling technique which utilises phase change material (plasticine is conducted in ANSYS. Phase change is modelled by assigning enthalpy of fusion over a wide temperature range based on Differential Scanning Calorimetry (DSC results. Temperature dependent convection is approximated using Nusselt number correlations. A parametric study is conducted on the thermal contact conductance value between the profiling device (polymer and adjacent (metal surfaces. Initial temperatures are established using a liner extrapolation based on experimental data. Results yield good correlation with experimental data.

  7. Modeling and analysis of AGS thermal shock experiments

    Energy Technology Data Exchange (ETDEWEB)

    Taleyarkhan, R.P.; Kim, S.H.; Haines, J.R.

    1998-11-01

    An overview is provided on modeling and analysis of thermal shock experiments conducted with high-energy, short-pulse energy deposition in a mercury filled container in the Alternating Gradient Synchrotron (AGS) facility at Brookhaven National Laboratory (BNL). The simulation framework utilized along with results of simulations for pressure and strain profiles are presented. While the magnitude of peak strain predictions versus data are in reasonable agreement, the temporal variations were found to differ significantly in selected cases, indicating lack of modeling of certain physical phenomena or due to uncertainties in the experimental data gathering techniques. Key thermal-shock related issues and uncertainties are highlighted.

  8. Electrical and Thermal Performance Analysis for a Highly Concentrating Photovoltaic/Thermal System

    Directory of Open Access Journals (Sweden)

    Ning Xu

    2015-01-01

    Full Text Available A 30 kW highly concentrating photovoltaic/thermal (HCPV/T system has been constructed and tested outdoors. The HCPV/T system consists of 32 modules, each of which consists of point-focus Fresnel lens and triple-junction solar cells with a geometric concentrating ratio of 1090x. The modules are connected to produce both electrical and thermal energy. Performance analysis has been conducted from the viewpoint of thermodynamics. The experimental results show that highest photovoltaic efficiency of 30% and instantaneous thermal efficiency of 30% can be achieved at the same time, which means the total solar energy conversion efficiency of the HCPV/T system is higher than 60%. The photovoltaic efficiency increases with direct irradiance when the direct irradiance is below 580 W/m2, but it remains nearly unchanged when the direct irradiation is higher than 580 W/m2. The instantaneous thermal efficiency decreases during water heating process. However, the electrical performance of the system is not affected obviously by water temperature. Highest exergetic efficiency of 35.4% can be produced by the HCPV/T system. The exergetic efficiency is mainly affected by irradiation level, which is similar to the characteristics of photovoltaic performance.

  9. Evaluation of Thermal Endurance Characteristics of Flexible Polyurethane Foams by Dynamic Compression Modulus

    National Research Council Canada - National Science Library

    Adachi, Hiromasa; Hasegawa, Teruo

    2005-01-01

      For evaluation of thermal endurance in foamed plastics, temperature and time dependence of compression dynamic modulus of four flexible polyurethane foams was investigated by dynamic viscoelastic measurements...

  10. 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.

  11. Majorana Demonstrator Bolted Joint Mechanical and Thermal Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Aguayo Navarrete, Estanislao; Reid, Douglas J.; Fast, James E.

    2012-06-01

    The MAJORANA DEMONSTRATOR is designed to probe for neutrinoless double-beta decay, an extremely rare process with a half-life in the order of 1026 years. The experiment uses an ultra-low background, high-purity germanium detector array. The germanium crystals are both the source and the detector in this experiment. Operating these crystals as ionizing radiation detectors requires having them under cryogenic conditions (below 90 K). A liquid nitrogen thermosyphon is used to extract the heat from the detectors. The detector channels are arranged in strings and thermally coupled to the thermosyphon through a cold plate. The cold plate is joined to the thermosyphon by a bolted joint. This circular plate is housed inside the cryostat can. This document provides a detailed study of the bolted joint that connects the cold plate and the thermosyphon. An analysis of the mechanical and thermal properties of this bolted joint is presented. The force applied to the joint is derived from the torque applied to each one of the six bolts that form the joint. The thermal conductivity of the joint is measured as a function of applied force. The required heat conductivity for a successful experiment is the combination of the thermal conductivity of the detector string and this joint. The thermal behavior of the joint is experimentally implemented and analyzed in this study.

  12. Examination of cadmium safety rod thermal test specimens and failure mechanism evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, J.K.; Peacock, H.B.; Iyer, N.C.

    1992-01-01

    The reactor safety rods may be subjected to high temperatures due to gamma heating after the core coolant level has dropped during the ECS phase of a hypothetical LOCA event. Accordingly, an experimental cadmium safety rod testing subtask was established as part of a task to address the response of reactor core components to this accident. Companion reports describe the experiments and a structural evaluation (finite element analysis) of the safety rod. This report deals primarily with the examination of the test specimens, evaluation of possible failure mechanisms, and confirmatory separate effects experiments. It is concluded that the failures observed in the cadmium safety rod thermal tests which occurred at low temperature (T < 600{degrees}C) with slow thermal ramp rates (slow cladding strain rates) resulted from localized dissolution of the stainless steel cladding by the cadmium/aluminum solution and subsequent ductility exhaustion and rupture. The slow thermal ramp rate is believed to be the root cause for the failures; specifically, the slow ramp rate led to localized cladding shear deformation which ruptured the protective oxide film on the cladding inner surface and allowed dissolution to initiate. The test results and proposed failure mechanism support the conclusion that the rods would not fail below 500{degrees}C even at slow ramp rates. The safety rod thermal test specimen failures which occurred at high temperature (T > 800{degrees}C) with fast thermal ramp rates are concluded to be mechanical in nature without significant environmental degradation. Based on these tests, tasks were initiated to design and manufacture B{sub 4}C safety rods to replace the cadmium safety rods. The B{sub 4}C safety rods have been manufactured at this time and it is currently planned to charge them to the reactor in the near future. 60 refs.

  13. Validation Database Based Thermal Analysis of an Advanced RPS Concept

    Science.gov (United States)

    Balint, Tibor S.; Emis, Nickolas D.

    2006-01-01

    Advanced RPS concepts can be conceived, designed and assessed using high-end computational analysis tools. These predictions may provide an initial insight into the potential performance of these models, but verification and validation are necessary and required steps to gain confidence in the numerical analysis results. This paper discusses the findings from a numerical validation exercise for a small advanced RPS concept, based on a thermal analysis methodology developed at JPL and on a validation database obtained from experiments performed at Oregon State University. Both the numerical and experimental configurations utilized a single GPHS module enabled design, resembling a Mod-RTG concept. The analysis focused on operating and environmental conditions during the storage phase only. This validation exercise helped to refine key thermal analysis and modeling parameters, such as heat transfer coefficients, and conductivity and radiation heat transfer values. Improved understanding of the Mod-RTG concept through validation of the thermal model allows for future improvements to this power system concept.

  14. DOE-Managed HLW and SNF Research: FY15 EBS and Thermal Analysis Work Package Status.

    Energy Technology Data Exchange (ETDEWEB)

    Matteo, Edward N. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Hadgu, Teklu [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    This report examines the technical elements necessary to evaluate EBS concepts and perform thermal analysis of DOE-Managed SNF and HLW in the disposal settings of primary interest – argillite, crystalline, salt, and deep borehole. As the disposal design concept is composed of waste inventory, geologic setting, and engineered concept of operation, the engineered barrier system (EBS) falls into the last component of engineered concept of operation. The waste inventory for DOE-Managed HLW and SNF is closely examined, with specific attention to the number of waste packages, the size of waste packages, and the thermal output per package. As expected, the DOE-Managed HLW and SNF inventory has a much smaller volume, and hence smaller number of canisters, as well a lower thermal output, relative to a waste inventory that would include commercial spent nuclear fuel (CSNF). A survey of available data and methods from previous studies of thermal analysis indicates that, in some cases, thermo-hydrologic modeling will be necessary to appropriately address the problem. This report also outlines scope for FY16 work -- a key challenge identified is developing a methodology to effectively and efficiently evaluate EBS performance in each disposal setting on the basis of thermal analyses results.

  15. Physico-Geometrical Kinetics of Solid-State Reactions in an Undergraduate Thermal Analysis Laboratory

    Science.gov (United States)

    Koga, Nobuyoshi; Goshi, Yuri; Yoshikawa, Masahiro; Tatsuoka, Tomoyuki

    2014-01-01

    An undergraduate kinetic experiment of the thermal decomposition of solids by microscopic observation and thermal analysis was developed by investigating a suitable reaction, applicable techniques of thermal analysis and microscopic observation, and a reliable kinetic calculation method. The thermal decomposition of sodium hydrogen carbonate is…

  16. Nano-Localized Thermal Analysis and Mapping of Surface and Sub-Surface Thermal Properties Using Scanning Thermal Microscopy (SThM).

    Science.gov (United States)

    Pereira, Maria J; Amaral, Joao S; Silva, Nuno J O; Amaral, Vitor S

    2016-12-01

    Determining and acting on thermo-physical properties at the nanoscale is essential for understanding/managing heat distribution in micro/nanostructured materials and miniaturized devices. Adequate thermal nano-characterization techniques are required to address thermal issues compromising device performance. Scanning thermal microscopy (SThM) is a probing and acting technique based on atomic force microscopy using a nano-probe designed to act as a thermometer and resistive heater, achieving high spatial resolution. Enabling direct observation and mapping of thermal properties such as thermal conductivity, SThM is becoming a powerful tool with a critical role in several fields, from material science to device thermal management. We present an overview of the different thermal probes, followed by the contribution of SThM in three currently significant research topics. First, in thermal conductivity contrast studies of graphene monolayers deposited on different substrates, SThM proves itself a reliable technique to clarify the intriguing thermal properties of graphene, which is considered an important contributor to improve the performance of downscaled devices and materials. Second, SThM's ability to perform sub-surface imaging is highlighted by thermal conductivity contrast analysis of polymeric composites. Finally, an approach to induce and study local structural transitions in ferromagnetic shape memory alloy Ni-Mn-Ga thin films using localized nano-thermal analysis is presented.

  17. 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.

  18. Infrared thermal facial image sequence registration analysis and verification

    Science.gov (United States)

    Chen, Chieh-Li; Jian, Bo-Lin

    2015-03-01

    To study the emotional responses of subjects to the International Affective Picture System (IAPS), infrared thermal facial image sequence is preprocessed for registration before further analysis such that the variance caused by minor and irregular subject movements is reduced. Without affecting the comfort level and inducing minimal harm, this study proposes an infrared thermal facial image sequence registration process that will reduce the deviations caused by the unconscious head shaking of the subjects. A fixed image for registration is produced through the localization of the centroid of the eye region as well as image translation and rotation processes. Thermal image sequencing will then be automatically registered using the two-stage genetic algorithm proposed. The deviation before and after image registration will be demonstrated by image quality indices. The results show that the infrared thermal image sequence registration process proposed in this study is effective in localizing facial images accurately, which will be beneficial to the correlation analysis of psychological information related to the facial area.

  19. Integrity evaluation of lower thermal shield under exposure to HFBR environment

    Energy Technology Data Exchange (ETDEWEB)

    Kassir, M.; Weeks, J.; Bandyopadhyay, K. [Brookhaven National Lab., Upton, NY (United States); Shewmon, P. [Ohio State Univ., Columbus, OH (United States)

    1998-01-01

    The effects of exposure to the HFBR environment on the carbon steel in the HFBR lower thermal shield were evaluated. Corrosion was found to be a non-significant degradation process. Radiation embrittlement has occurred; portions of the plate closest to the reactor are currently operating in the lower-shelf region of the Charpy impact curve (i.e., below the fracture toughness transition temperature). In this region, the effects of radiation on the mechanical properties of carbon steel are believed to have been saturated, so that no further deterioration is anticipated. A fracture toughness analysis shows that a large factor of safety (> 1.5) exists against propagation of credible hypothetical flaws. Therefore, the existing lower thermal shield structure is suitable for continued operation of the HFBR.

  20. Damage evaluation under thermal fatigue of a vertical target full scale component for the ITER divertor

    Energy Technology Data Exchange (ETDEWEB)

    Missirlian, M. [Association Euratom-CEA, CEA/DSM/DRFC, CEA/Cadarache, F-13108 Saint Paul Lez Durance cedex (France)]. E-mail: missir@drfc.cad.cea.fr; Escourbiac, F. [Association Euratom-CEA, CEA/DSM/DRFC, CEA/Cadarache, F-13108 Saint Paul Lez Durance cedex (France); Merola, M. [EFDA Close Support Unit, Garching (Germany); Durocher, A. [Association Euratom-CEA, CEA/DSM/DRFC, CEA/Cadarache, F-13108 Saint Paul Lez Durance cedex (France); Bobin-Vastra, I. [FRAMATOME, Le Creusot (France); Schedler, B. [PLANSEE , Aktiengesellschaft-A-6600 Reutte (Austria)

    2007-08-01

    An extensive development programme has been carried out in the EU on high heat flux components within the ITER project. In this framework, a Full Scale Vertical Target (VTFS) prototype was manufactured with all the main features of the corresponding ITER divertor design. The fatigue cycling campaign on CFC and W armoured regions, proved the capability of such a component to meet the ITER requirements in terms of heat flux performances for the vertical target. This paper discusses thermographic examination and thermal fatigue testing results obtained on this component. The study includes thermal analysis, with a tentative proposal to evaluate with finite element approach the location/size of defects and the possible propagation during fatigue cycling.

  1. Evaluation of the effectiveness of a thermal hygienization reactor

    Directory of Open Access Journals (Sweden)

    Daniel Borski

    2011-01-01

    Full Text Available For reasons of limiting the spread of serious transmissible diseases, with regard to the requirement for reducing landfill of biodegradable waste (which may or contains animal by-products and thus presents a potential risk to human and animal health and with a focus on supporting its separate collection, there has been created a legal framework for processing and hygienization of materials containing animal by-products. For the above reasons new technologies are being developed and implemented. These technologies are able to ensure the processing of biological waste containing animal by-products. As a practical result of the effort to ensure the hygienization of biowaste, a hygienization unit of own design, which uses the thermal way of hygienization, is presented in this work. The general part of the work defines a legislative framework for the assignment and gives technical parameters and minimum requirements for conversion that hygienization unit should be able to perform, including the limits for digestion residues and compost.In the experimental section there are described operational tests which document the technological process of hygienization depending on the aeration of the contents of the reactor. Experiment III outlines the validation process which uses contamination by indicator organisms, including subsequent checking of their occurrence as well as processing of the results of experiments and evaluation of the process of hygienization.

  2. Evaluation of thermal shock resistance of cordierite honeycombs

    Indian Academy of Sciences (India)

    A comparative study on thermal shock resistance (TSR) of extruded cordierite honeycombs is presented. TSR is an important property that predicts the life of these products in thermal environments used for automobile pollution control as catalytic converter or as diesel particulate filter. TSR was experimentally studied by ...

  3. Comparative Batch and Column Evaluation of Thermal and Wet ...

    African Journals Online (AJOL)

    ABSTRACT: The efficiency of regenerated spent commercial activated carbon for synthetic dye removal was studied using thermal and wet ... Keywords: Activated Carbon, Methyl Red, Chromatography Capacity, Wet and Thermal Regeneration. INTRODUCTION ... processes in wastewater treatment. A number of techniques ...

  4. Thermal Analysis of Nanofluids Using Modeling and Molecular Dynamics Simulation

    Science.gov (United States)

    Namboori, P. K. Krishnan; Vasavi, C. S.; Gopal, K. Varun; Gopakumar, Deepa; Ramachandran, K. I.; Narayanan, B. Sabarish

    2010-10-01

    Nanofluids are nanotechnology-based heat transfer fluids obtained by suspending nanometer-sized particles in conventional heat transfer fluids in a stable manner. In many of the physical phenomena such as boiling and properties such as latent heat, thermal conductivity and heat transfer coefficient, there is significant change on addition of nanoparticles. These exceptional qualities of Nanofluids mainly depend on the atomic level mechanisms, which in turn govern all mechanical properties like strength, Young's modulus, Poisson's ratio, compressibility etc. Control over the fundamental thermo physical properties of the working medium will help to understand these unique phenomena of nanofluids to a great extent. Macroscopic modeling approaches, which are based on conventional relations of thermodynamics, have been proved to be incompetent to explain this difference. Atomistic `modeling and simulation' has been emerged out as an efficient alternative for this. The enhancement of thermal conductivity of water by suspending nanoparticle inclusions has been experimented and proved to be an effective method of enhancing convective heat dissipation. This work mainly deals with characterization of the thermal conductivity of nanofluids. Nano particle sized aluminium oxide; copper oxide and titanium dioxide have been taken in this work for the analysis of thermal conductivity. The effect of thermal conductivity on parameters like volume concentration of the fluid, nature of particle material and size of the particle has been computationally formulated. It has been found that there is an increase in effective thermal conductivity of the fluid by the addition of nanomaterials ascertaining an improvement in the heat transfer behavior of nanofluids. This facilitates the reduction in size of such heat transfer systems (radiators) and lead to increased energy and fuel efficiency, lower pollution and improved reliability.

  5. Experimental design for the evaluation of high-T(sub c) superconductive thermal bridges in a sensor satellite

    Science.gov (United States)

    Scott, Elaine P.; Lee, Kasey M.

    1994-01-01

    Infrared sensor satellites, which consist of cryogenic infrared sensor detectors, electrical instrumentation, and data acquisition systems, are used to monitor the conditions of the earth's upper atmosphere in order to evaluate its present and future changes. Currently, the electrical connections (instrumentation), which act as thermal bridges between the cryogenic infrared sensor and the significantly warmer data acquisition unit of the sensor satellite system, constitute a significant portion of the heat load on the cryogen. As a part of extending the mission life of the sensor satellite system, the researchers at the National Aeronautics and Space Administration's Langley Research Center (NASA-LaRC) are evaluating the effectiveness of replacing the currently used manganin wires with high-temperature superconductive (HTS) materials as the electrical connections (thermal bridges). In conjunction with the study being conducted at NASA-LaRC, the proposed research is to design a space experiment to determine the thermal savings on a cryogenic subsystem when manganin leads are replaced by HTS leads printed onto a substrate with a low thermal conductivity, and to determine the thermal conductivities of HTS materials. The experiment is designed to compare manganin wires with two different types of superconductors on substrates by determining the heat loss by the thermal bridges and providing temperature measurements for the estimation of thermal conductivity. A conductive mathematical model has been developed and used as a key tool in the design process and subsequent analysis.

  6. Noise analysis to evaluate chick thermal comfort Análise de ruído para a avaliação do conforto térmico de pintinhos

    Directory of Open Access Journals (Sweden)

    Daniella Jorge de Moura

    2008-01-01

    Full Text Available The relationship between thermal environment and chick performance has widely been evaluated, however the consideration that the assessment of the comfort may be estimated by interpreting both amplitude and frequency of bird vocalization under tropical housing conditions is a new concept. This research had as objective of estimating thermal comfort for chicks during the heating phase using this new concept. An experiment was carried out inside a climate controlled chamber (A for establishing the behavioral pattern related to environmental temperature limits. Forty five chicks were reared inside a 2.3 m² box. A video camera was placed 2.0 m above the birds and the images were captured and registered in a computer. From the pattern determined in the controlled chamber an evaluation of the results was proceeded in a commercial broiler farm (experiment B using similar bird density in order to validate the data. Environmental temperature, and both amplitude and frequency of the vocalizations of the chick group reared under heating were continuously recorded in both experiments. A correlation between group behavioral pattern and their vocalization, was found, evaluated not only by the noise amplitude but also by the noise frequency spectrum. When the thermal inertia is maintained by adequate use of curtains the birds vocalized less which is coincident with the low sudden variation of the temperature of the environmental. It was possible to estimate the thermal comfort for chicks at the heating stage by recording the amplitude and the frequency of the noise emitted by the reared group.A relação entre o ambiente térmico e o desempenho de pintinhos tem sido estudada, entretanto a consideração de que a medida de conforto térmico possa ser estimada pela interpretação da amplitude e da freqüência da vocalização, em condições tropicais de alojamento é um conceito novo. Esta pesquisa teve como objetivo estimar uma medida de bem-estar t

  7. An integrated chemical, thermal, and microbiological approach to compost stability evaluation.

    Science.gov (United States)

    Mondini, Claudio; Dell'Abate, Maria Teresa; Leita, Liviana; Benedetti, Anna

    2003-01-01

    The evaluation of compost stability is of the utmost importance for the reliability of composting as a recycling strategy. To date there is no single parameter that can give a sure indication of the stability of composts from different starting materials. This paper investigates different methods of evaluating the dynamics of transformation of materials and the stability level of the end products in a composting process. The following parameters were determined on compost samples of different ages from cotton (Gossypium herbaceum L.) cardings and yard wastes: humification index (HI), degree of humification (DH), thermogravimetry (TG) microbial biomass C (B(C)), and ninhydrin-reactive N (B(NIN)). Finally, from TG, derivative thermogravimetry (DTG) and differential scanning calorimetry (DSC) thermal stability parameters were deduced. Humification parameters in the end products (0.2 and 81% for HI and DH, respectively) showed the effective stability reached by the organic matter (OM). Thermal analysis evidenced the presence of two main organic pools with different thermal stability. During composting a relative increase in the more stable organic pool was indicated by the variation of the thermostability index R1 from 0.41 to 0.74. The parameter R1 was significantly correlated with both HI (r = -0.94; P composting materials, provides a more complete description of the stability and quality reached by the organic materials.

  8. 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...

  9. 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.

  10. Thermal analysis studies of poly(etheretherketone)/hydroxyapatite biocomposite mixtures.

    Science.gov (United States)

    Meenan, B J; McClorey, C; Akay, M

    2000-08-01

    Biocomposite formulations which have the potential to combine the proven mechanical performance of poly(etheretherketone) (PEEK) with the inherent bioactivity of hydroxyapatite (HA), may have a utility as load-bearing materials in a medical implant context. The effect of thermal processing on the relevant properties of the PEEK and/or HA components in any fabricated composite structure is, however, an important consideration for their effective exploitation. This paper reports the results of a detailed thermal characterization study of a series of PEEK/HA mixtures using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and modulated differential scanning calorimetry (MDSC). The TGA analyses show minimal weight loss for all of the mixtures and for a pure PEEK sample up to approximately 530 degrees C. Above this point there is a sharp on-set of decomposition for the PEEK component in each case. The temperature at which this feature occurs varies for each mixture in the approximate range 539-556 degrees C. This observation is supported by the presence of exotherms in the corresponding DSC scans, in the same temperature region, which are also assigned to PEEK decomposition. The temperature at which the degradation on-set occurs is found to decrease with increasing HA contribution. The use of the modulated DSC technique allows a number of important thermal events, not easily identifiable from the data obtained by the conventional method, to be clearly observed. In particular, the glass transition temperature (Tg) of the polymer can now be accurately determined. Using these thermal analysis data, calculations of the % crystallinity of PEEK in the mixtures have been made and compared with that of a 100% polymer sample. From these studies it is evident that the presence of HA does not adversely affect the degree of crystallinity of the PEEK component in the mixtures of interest over the thermal range studied. Copyright 2000 Kluwer Academic

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

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, W.S.

    1994-08-23

    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.

  12. Thermal stress analysis of reusable surface insulation for shuttle

    Science.gov (United States)

    Ojalvo, I. U.; Levy, A.; Austin, F.

    1974-01-01

    An iterative procedure for accurately determining tile stresses associated with static mechanical and thermally induced internal loads is presented. The necessary conditions for convergence of the method are derived. An user-oriented computer program based upon the present method of analysis was developed. The program is capable of analyzing multi-tiled panels and determining the associated stresses. Typical numerical results from this computer program are presented.

  13. 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.

  14. ICTAC Nomenclature of Thermal Analysis (IUPAC Recommendations 2014

    Directory of Open Access Journals (Sweden)

    Macan J. (translator

    2015-09-01

    Full Text Available The widespread use of thermal analysis (TA by scientists as a laboratory technique carries with it a working vocabulary. This document is intended to provide those working in the field with a consistent set of definitions to permit clear and precise communication as well as understanding. Included in the document are the definitions of 13 techniques, 54 terms within the glossary, as well as symbols and units.

  15. Systems Analysis for Thermal Infrared ` THz Torch' Applications

    Science.gov (United States)

    Hu, Fangjing; Sun, Jingye; Brindley, Helen E.; Liang, Xiaoxin; Lucyszyn, Stepan

    2015-05-01

    The ` THz Torch' concept was recently introduced by the authors for providing secure wireless communications over short distances within the thermal infrared (10-100 THz). Unlike conventional systems, thermal infrared can exploit front-end thermodynamics with engineered blackbody radiation. For the first time, a detailed power link budget analysis is given for this new form of wireless link. The mathematical modeling of a short end-to-end link is provided, which integrates thermodynamics into conventional signal and noise power analysis. As expected from the Friis formula for noise, it is found that the noise contribution from the pyroelectric detector dominates intrinsic noise. From output signal and noise voltage measurements, experimental values for signal-to-noise ratio (SNR) are obtained and compared with calculated predictions. As with conventional communications systems, it is shown for the first time that the measured SNR and measured bit error rate found with this thermodynamics-based system resembles classical empirical models. Our system analysis can serve as an invaluable tool for the development of thermal infrared systems, accurately characterizing each individual channel and, thus, enables the performance of multi-channel ` THz Torch' systems to be optimized.

  16. Engineering Aerothermal Analysis for X-34 Thermal Protection System Design

    Science.gov (United States)

    Wurster, Kathryn E.; Riley, Christopher J.; Zoby, E. Vincent

    1998-01-01

    Design of the thermal protection system for any hypersonic flight vehicle requires determination of both the peak temperatures over the surface and the heating-rate history along the flight profile. In this paper, the process used to generate the aerothermal environments required for the X-34 Testbed Technology Demonstrator thermal protection system design is described as it has evolved from a relatively simplistic approach based on engineering methods applied to critical areas to one of detailed analyses over the entire vehicle. A brief description of the trajectory development leading to the selection of the thermal protection system design trajectory is included. Comparisons of engineering heating predictions with wind-tunnel test data and with results obtained using a Navier-Stokes flowfield code and an inviscid/boundary layer method are shown. Good agreement is demonstrated among all these methods for both the ground-test condition and the peak heating flight condition. Finally, the detailed analysis using engineering methods to interpolate the surface-heating-rate results from the inviscid/boundary layer method to predict the required thermal environments is described and results presented.

  17. On the thermal stability of a radiating plasma subject to nonlocal thermal conduction. I - Linear analysis

    Science.gov (United States)

    Chun, E.; Rosner, R.

    1993-01-01

    We study the linear stability of an optically thin uniform radiating plasma subject to nonlocal heat transport. We derive the dispersion relation appropriate to this problem, and the marginal wavenumbers for instability. Our analysis indicates that nonlocal heat transport acts to reduce the stabilizing influence of thermal conduction, and that there are critical values for the electron mean free path such that the plasma is always unstable. Our results may be applied to a number of astrophysical plasmas, one such example being the halos of clusters of galaxies.

  18. Evaluation on thermal explosion induced by slightly exothermic interface reaction.

    Science.gov (United States)

    Yu, Ma-Hong; Li, Yong-Fu; Sun, Jin-Hua; Hasegawa, Kazutoshi

    2004-09-10

    An asphalt-salt mixture (ASM), which once caused a fire and explosion in a reprocessing plant, was prepared by imitating the real bituminization process of waste on a lab scale to evaluate its actual thermal hazards. Heat flux reaction calorimeters were used to measure the release of heat for the simulated ASM at a constant heating rate and at a constant temperature, respectively. Experimental results show that the reaction in the ASM below about 250 degrees C is a slightly exothermic interface reaction between the asphalt and the salt particles contained in the asphalt, and that the heat release rate increases sharply above about 250 degrees C due to melting of the salt particles. The reaction rates were formulated on the basis of an assumed reaction model, and the kinetic parameters were determined. Using the model with the kinetic parameters, temperature changes with time and drum-radius axes for the ASM-filled drum were numerically simulated assuming a one-dimensional infinite cylinder system, where the drum was being cooled at an ambient temperature of 50 degrees C. The minimum filling temperature, at which the runaway reaction (MFTRR) can occur for the simulated ASM in the drum is about 194 degrees C. Furthermore, a very good linear correlation exists between this MFTRR and the initial radius of salt particles formed in the bituminization product. The critical filling temperature to the runaway reaction is about 162 degrees C for the asphalt-salt mixture, containing zero-size salt particles, filled in the same drum at an ambient temperature of 50 degrees C. Thus, the runaway reaction will never occur in the drum filled with the asphalt-salt mixture under the conditions of the filling temperature below 162 degrees C and a constant ambient temperature of 50 degrees C. As a consequence, the ASM explosion occurred in the reprocessing plant likely was due to a slightly exothermically reaction and self heating.

  19. Evaluation of Electrical and Thermal Conductivity of Polymeric ...

    African Journals Online (AJOL)

    PROF HORSFALL

    for the electrical and thermal conductivities of the doped polymers it was observed that both conductivities .... ceramic insulators when very hot may conduct quite well. The more ... Doping also lead to the formation of polarons and bipolarons ...

  20. Evaluation of Fire Test Methods for Aircraft Thermal Acoustical Insulation

    Science.gov (United States)

    1997-09-01

    This report presents the results of laboratory round robin flammability testing performed on thermal acoustical insulation blankets and the films used as insulation coverings. This work was requested by the aircraft industry as a result of actual inc...

  1. Evaluation of solar thermal storage for base load electricity generation

    Directory of Open Access Journals (Sweden)

    Adinberg R.

    2012-10-01

    Full Text Available In order to stabilize solar electric power production during the day and prolong the daily operating cycle for several hours in the nighttime, solar thermal power plants have the options of using either or both solar thermal storage and fossil fuel hybridization. The share of solar energy in the annual electricity production capacity of hybrid solar-fossil power plants without energy storage is only about 20%. As it follows from the computer simulations performed for base load electricity demand, a solar annual capacity as high as 70% can be attained by use of a reasonably large thermal storage capacity of 22 full load operating hours. In this study, the overall power system performance is analyzed with emphasis on energy storage characteristics promoting a high level of sustainability for solar termal electricity production. The basic system parameters, including thermal storage capacity, solar collector size, and annual average daily discharge time, are presented and discussed.

  2. Various startup system designs of HPLWR and their thermal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Qi [School of Physics and Engineering, Sun Yat-sen University, Guangzhou (China); Cai, Jiejin, E-mail: chiven77@hotmail.com [School of Physics and Engineering, Sun Yat-sen University, Guangzhou (China); Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-sen University, Guangzhou (China)

    2013-12-15

    Highlights: • An axial one-dimensional (1D) single channel model is developed for the HPLWR core. • Various startup systems for HPLWR have been investigated and found feasible. • Characteristics of the component required for HPLWR startup designs are studied. -- Abstract: This paper summarizes the results of various startup system designs and their thermal analysis of the high performance light water reactor (HPLWR) which is the European version of the various supercritical water cooled reactor proposals. In order to study the thermal-hydraulic characteristics of the HPLWR core, a simplified axial one-dimensional (1D) single channel model is developed, which consists of fuel, cladding, coolant and moderator. The model is verified by the related results of Seppälä (2008). Both constant pressure startup systems and sliding pressure startup systems of HPLWR are presented. In constant pressure startup system, the reactor starts at supercritical pressure. It appears that compared with other SCWR designs, the weight of the component required for constant pressure startup of HPLWR is medium and reasonable. Constant pressure startup systems are found feasible from thermal analysis. And for sliding pressure startup, the reactor starts at subcritical pressure. The adequate core power of 25% with 28% flow rate and a feedwater temperature of 280 °C are determined during pressurization phase. The thermal analysis results show that the sliding pressure startup systems for HPLWR are also feasible. Considering the same flow rate as the supercritical-pressure light water-cooled fast reactor (SCFR), the component weight required is reduced in HPLWR.

  3. Reduced order models for thermal analysis : final report : LDRD Project No. 137807.

    Energy Technology Data Exchange (ETDEWEB)

    Hogan, Roy E., Jr.; Gartling, David K.

    2010-09-01

    This LDRD Senior's Council Project is focused on the development, implementation and evaluation of Reduced Order Models (ROM) for application in the thermal analysis of complex engineering problems. Two basic approaches to developing a ROM for combined thermal conduction and enclosure radiation problems are considered. As a prerequisite to a ROM a fully coupled solution method for conduction/radiation models is required; a parallel implementation is explored for this class of problems. High-fidelity models of large, complex systems are now used routinely to verify design and performance. However, there are applications where the high-fidelity model is too large to be used repetitively in a design mode. One such application is the design of a control system that oversees the functioning of the complex, high-fidelity model. Examples include control systems for manufacturing processes such as brazing and annealing furnaces as well as control systems for the thermal management of optical systems. A reduced order model (ROM) seeks to reduce the number of degrees of freedom needed to represent the overall behavior of the large system without a significant loss in accuracy. The reduction in the number of degrees of freedom of the ROM leads to immediate increases in computational efficiency and allows many design parameters and perturbations to be quickly and effectively evaluated. Reduced order models are routinely used in solid mechanics where techniques such as modal analysis have reached a high state of refinement. Similar techniques have recently been applied in standard thermal conduction problems e.g. though the general use of ROM for heat transfer is not yet widespread. One major difficulty with the development of ROM for general thermal analysis is the need to include the very nonlinear effects of enclosure radiation in many applications. Many ROM methods have considered only linear or mildly nonlinear problems. In the present study a reduced order model is

  4. Evaluation of the thermal comfort of ceramic floor tiles

    OpenAIRE

    Carmeane Effting; Saulo Güths; Orestes Estevam Alarcon

    2007-01-01

    In places where people are bare feet, the thermal sensation of cold or hot depends on the environmental conditions and material properties including its microstructure and crustiness surface. The uncomforting can be characterized by heated floor surfaces in external environments which are exposed to sun radiation (swimming polls areas) or by cold floor surfaces in internal environments (bed rooms, path rooms). The property named thermal effusivity which defines the interface temperature when ...

  5. Deformation Analysis of Impact Damaged Composite Tube Using Thermal Shearography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Koung Suk; Chang, Ho Seob; Jang, Su Ok; Jang, Wan Sik; Jung, Hyun Chul [Chosun University, Kwangju (Korea, Republic of); Lee, Seung Seok [Korea Research Institute of Standard and Science, Daejeon (Korea, Republic of)

    2008-06-15

    Composite materials are widely used as structural materials for aerospace engineering because of its excellent mechanical properties such as light weight, high stiffness, and low thermal expansion. In driving, impact damage is one of the common but dangerous damages, caused by internal failure of the laminas interface which is not detected by in the surface. Many techniques to detect defects or delaminate between laminates have been reported. Shearography is a kind of laser speckle pattern interferometry with the advantages of non-destructive, non-contact, high resolution and displacement slope measurement. In this paper, the shearography is used to evaluate non-destructively impact damaged surface of the composite material and a measuring method using shearography for the thermal deformation of an impact damaged composite material is discussed. The basic principles of the technique are also described briefly.

  6. A theoretical analysis of local thermal equilibrium in fibrous materials

    Directory of Open Access Journals (Sweden)

    Tian Mingwei

    2015-01-01

    Full Text Available The internal heat exchange between each phase and the Local Thermal Equilibrium (LTE scenarios in multi-phase fibrous materials are considered in this paper. Based on the two-phase heat transfer model, a criterion is proposed to evaluate the LTE condition, using derived characteristic parameters. Furthermore, the LTE situations in isothermal/adiabatic boundary cases with two different heat sources (constant heat flux and constant temperature are assessed as special transient cases to test the proposed criterion system, and the influence of such different cases on their LTE status are elucidated. In addition, it is demonstrated that even the convective boundary problems can be generally estimated using this approach. Finally, effects on LTE of the material properties (thermal conductivity, volumetric heat capacity of each phase, sample porosity and pore hydraulic radius are investigated, illustrated and discussed in our study.

  7. Thermal transient analysis of steel hollow sections exposed to fire

    Directory of Open Access Journals (Sweden)

    Lenka Lausova

    2016-03-01

    Full Text Available The paper describes a study of non-uniform temperature distribution across the section of steel structures where elevated temperature causes additive internal forces due to restrained conditions. The work provides comparison of a heat field at the time of fire in the non-protected steel hollow cross-sections of different sizes. The study compares simplified calculations according to valid standard and numerical simulations in finite element analysis of steel structures exposed to fire loading from three sides. Numerical thermal analysis is also compared with results obtained from the fire testing in VSB-Technical University of Ostrava.

  8. 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.

  9. Haar Wavelet Collocation Method for Thermal Analysis of Porous Fin with Temperature-dependent Thermal Conductivity and Internal Heat Generation

    Directory of Open Access Journals (Sweden)

    George OGUNTALA

    2017-08-01

    Full Text Available In this study, the thermal performance analysis of porous fin with temperature-dependent thermal conductivity and internal heat generation is carried out using Haar wavelet collocation method. The effects of various parameters on the thermal characteristics of the porous fin are investigated. It is found that as the porosity increases, the rate of heat transfer from the fin increases and the thermal performance of the porous fin increases. The numerical solutions by the Haar wavelet collocation method are in good agreement with the standard numerical solutions.

  10. HANFORD DOUBLE SHELL TANK THERMAL AND SEISMIC PROJECT SUMMARY OF COMBINED THERMAL AND OPERATING LOADS WITH SEISMIC ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    MACKEY TC; DEIBLER JE; RINKER MW; JOHNSON KI; ABATT FG; KARRI NK; PILLI SP; STOOPS KL

    2009-01-15

    This report summarizes the results of the Double-Shell Tank Thermal and Operating Loads Analysis (TaLA) combined with the Seismic Analysis. This combined analysis provides a thorough, defensible, and documented analysis that will become a part of the overall analysis of record for the Hanford double-shell tanks (DSTs). The bases of the analytical work presented herein are two ANSYS{reg_sign} finite element models that were developed to represent a bounding-case tank. The TaLA model includes the effects of temperature on material properties, creep, concrete cracking, and various waste and annulus pressure-loading conditions. The seismic model considers the interaction of the tanks with the surrounding soil including a range of soil properties, and the effects of the waste contents during a seismic event. The structural evaluations completed with the representative tank models do not reveal any structural deficiencies with the integrity of the DSTs. The analyses represent 60 years of use, which extends well beyond the current date. In addition, the temperature loads imposed on the model are significantly more severe than any service to date or proposed for the future. Bounding material properties were also selected to provide the most severe combinations. While the focus of the analyses was a bounding-case tank, it was necessary during various evaluations to conduct tank-specific analyses. The primary tank buckling evaluation was carried out on a tank-specific basis because of the sensitivity to waste height, specific gravity, tank wall thickness, and primary tank vapor space vacuum limit. For this analysis, the occurrence of maximum tank vacuum was classified as a service level C, emergency load condition. The only area of potential concern in the analysis was with the buckling evaluation of the AP tank, which showed the current limit on demand of l2-inch water gauge vacuum to exceed the allowable of 10.4 inches. This determination was based on analysis at the

  11. Thermal performance evaluation of a massive brick wall under real weather conditions via the Conduction Transfer function method

    Directory of Open Access Journals (Sweden)

    Emilio Sassine

    2017-12-01

    Full Text Available The reliable estimation of buildings energy needs for cooling and heating is essential for any eventual thermal improvement of the envelope or the HVAC equipment. This paper presents an interesting method to evaluate the thermal performance of a massive wall by using the frequency-domain regression (FDR method to calculate CTF coefficients by means of the Fourier transform. The method is based on the EN ISO 13786 (2007 procedure by using the Taylor expansion for the elements of the heat matrix. Numerical results were validated through an experimental heating box with stochastic boundary conditions on one side of the wall representing real weather conditions and constant temperature profile on the other side representing the inside ambiance in real cases. Finally, a frequency analysis was performed in order to assess the validity and accuracy of the method used. The results show that development to the second order is sufficient to predict the thermal behavior of the studied massive wall in the range of frequencies encountered in the building applications (one hour time step. This method is useful for thermal transfer analysis in real weather conditions where the outside temperature is stochastic; it also allows the evaluation of the thermal performance of a wall through a frequency analysis.

  12. Comparative analysis of green actions to improve outdoor thermal comfort inside typical urban street canyons

    OpenAIRE

    Lobaccaro, Gabriele; Acero, Juan A.

    2015-01-01

    Urban microclimate analyses are being used more and more to address the planning decision process to create livable and healthy public spaces. The study, conducted in collaboration with the municipality of Bilbao (Basque Country, Spain), presents a comparative analysis of green actions to improve outdoor thermal comfort conditions. The evaluation was performed in three typical urban street canyons characterized by different geometric proportions and five urban greenery scenario...

  13. Kinetic study of Mongolian coals by thermal analysis

    Directory of Open Access Journals (Sweden)

    Jargalmaa S

    2018-02-01

    Full Text Available Thermal analysis was used for the thermal characterization of the coal samples. The experiments were performed to study the pyrolysis and gasification kinetics of typical Mongolian brown coals. Low rank coals from Shivee ovoo, Ulaan ovoo, Aduun chuluun and Baganuur deposits have been investigated. Coal samples were heated in the thermogravimetric apparatus under argon at a temperature ranges of 25-1020ºC with heating rates of 10, 20, 30 and 40ºC/min. Thermogravimetry (TG and derivative thermogravimetry (DTG were performed to measure weight changes and rates of weight losses used for calculating the kinetic parameters. The activation energy (Ea was calculated from the experimental results by using an Arrhenius type kinetic model.

  14. 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.

  15. Application of thermal analysis techniques in activated carbon production

    Science.gov (United States)

    Donnals, G.L.; DeBarr, J.A.; Rostam-Abadi, M.; Lizzio, A.A.; Brady, T.A.

    1996-01-01

    Thermal analysis techniques have been used at the ISGS as an aid in the development and characterization of carbon adsorbents. Promising adsorbents from fly ash, tires, and Illinois coals have been produced for various applications. Process conditions determined in the preparation of gram quantities of carbons were used as guides in the preparation of larger samples. TG techniques developed to characterize the carbon adsorbents included the measurement of the kinetics of SO2 adsorption, the performance of rapid proximate analyses, and the determination of equilibrium methane adsorption capacities. Thermal regeneration of carbons was assessed by TG to predict the life cycle of carbon adsorbents in different applications. TPD was used to determine the nature of surface functional groups and their effect on a carbon's adsorption properties.

  16. Fluid and thermal performance analysis of PMSM used for driving

    Science.gov (United States)

    Ding, Shuye; Cui, Guanghui; Li, Zhongyu; Guan, Tianyu

    2016-03-01

    The permanent magnet synchronous motor (PMSM) is widely used in ships under frequency conversion control system. The fluid flow performance and temperature distribution of the PMSM are difficult to clarify due to its complex structure and variable frequency control condition. Therefore, in order to investigate the fluid and thermal characteristics of the PMSM, a 50 kW PMSM was taken as an example in this study, and a 3-D coupling analysis model of fluid and thermal was established. The fluid and temperature fields were calculated by using finite volume method. The cooling medium's properties, such a velocity, streamlines, and temperature, were then analyzed. The correctness of the proposed model, and the rationality of the solution method, were verified by a temperature test of the PMSM. In this study, the changing rheology on the performance of the cooling medium and the working temperature of the PMSM were revealed, which could be helpful for designing the PMSM.

  17. Thermal Hazard Evaluation of Lauroyl Peroxide Mixed with Nitric Acid

    Directory of Open Access Journals (Sweden)

    Chi-Min Shu

    2012-07-01

    Full Text Available Many thermal runaway incidents have been caused by organic peroxides due to the peroxy group, –O–O–, which is essentially unstable and active. Lauroyl peroxide (LPO is also sensitive to thermal sources and is incompatible with many materials, such as acids, bases, metals, and ions. From the thermal decomposition reaction of various concentrations of nitric acid (HNO3 (from lower to higher concentrations with LPO, experimental data were obtained as to its exothermic onset temperature (T0, heat of decomposition (ΔHd, isothermal time to maximum rate (TMRiso, and other safety parameters exclusively for loss prevention of runaway reactions and thermal explosions. As a novel finding, LPO mixed with HNO3 can produce the detonation product of 1-nitrododecane. We used differential scanning calorimetry (DSC, thermal activity monitor III (TAM III, and gas chromatography/mass spectrometer (GC/MS analyses of the reactivity for LPO and itself mixed with HNO3 to corroborate the decomposition reactions and reaction mechanisms in these investigations.

  18. Standard Practice for Evaluating Thermal Insulation Materials for Use in Solar Collectors

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1994-01-01

    1.1 This practice sets forth a testing methodology for evaluating the properties of thermal insulation materials to be used in solar collectors with concentration ratios of less than 10. Tests are given herein to evaluate the pH, surface burning characteristics, moisture adsorption, water absorption, thermal resistance, linear shrinkage (or expansion), hot surface performance, and accelerated aging. This practice provides a test for surface burning characteristics but does not provide a methodology for determining combustibility performance of thermal insulation materials. 1.2 The tests shall apply to blanket, rigid board, loose-fill, and foam thermal insulation materials used in solar collectors. Other thermal insulation materials shall be tested in accordance with the provisions set forth herein and should not be excluded from consideration. 1.3 The assumption is made that elevated temperature, moisture, and applied stresses are the primary factors contributing to the degradation of thermal insulation mat...

  19. Assessing swine thermal comfort by image analysis of postural behaviors.

    Science.gov (United States)

    Xin, H

    1999-01-01

    Postural behavior is an integral response of animals to complex environmental factors. Huddling, nearly contacting one another on the side, and spreading are common postural behaviors of group-housed animals undergoing cold, comfortable, and warm/hot sensations, respectively. These postural patterns have been routinely used by animal caretakers to assess thermal comfort of the animals and to make according adjustment on the environmental settings or management schemes. This manual adjustment approach, however, has the inherent limitations of daily discontinuity and inconsistency between caretakers in interpretation of the animal comfort behavior. The goal of this project was to explore a novel, automated image analysis system that would assess the thermal comfort of swine and make proper environmental adjustments to enhance animal wellbeing and production efficiency. This paper describes the progress and on-going work toward the achievement of our proposed goal. The feasibility of classifying the thermal comfort state of young pigs by neural network (NN) analysis of their postural images was first examined. It included exploration of using certain feature selections of the postural behavioral images as the input to a three-layer NN that was trained to classify the corresponding thermal comfort state as being cold, comfortable, or warm. The image feature selections, a critical step for the classification, examined in this study included Fourier coefficient (FC), moment (M), perimeter and area (P&A), and combination of M and P&A of the processed binary postural images. The result was positive, with the combination of M and P&A as the input feature to the NN yielding the highest correct classification rate. Subsequent work included the development of hardware and computational algorithms that enable automatic image segmentation, motion detection, and the selection of the behavioral images suitable for use in the classification. Work is in progress to quantify the

  20. Evaluating the thermal reduction effect of plant layers on rooftops

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Chih-Fang [Department of Landscape Design and Management, National Chin-Yi University of Technology, No. 35, Lane 215, Sec. 1, Jhongshan Road, Taiping City, Taichung County 411 (China)

    2008-07-01

    This study examines the thermal reduction effect of plant layers on rooftops through experiments performed in a controlled environment. The relevant parameters are coverage ratio (CR) and total leaf thickness (TLT). Both parameters are positively correlated with thermal reduction ratio (TRR). The TRR data of all experiments were plotted on a grid system with CR on the x-axis and TLT on the y-axis. A TRR map was then drawn using the curve fitting process. The applicability of the TRR map drawn for Codiaeum variegatum (1) was further confirmed by performing experiments with Cordyline terminalis (1) and Ixora duffii (1) and by results of experiments on C. variegatum (2), C. terminalis (2), Duranta repens, and I. duffii (2) in outdoor environments. The TRR map provides quantitative and straightforward guidance on thermal reduction planting arrangements for green roofs. (author)

  1. Reusable surface insulation thermal protection systems test evaluation status

    Science.gov (United States)

    Strouhal, G.; Tillian, D. J.

    1973-01-01

    Changes in coating morphology of mullite, silica, and ceramic mullite fiber at two heating rates are described followed by a discussion of the changes in surface chemistry that occur during convective heating tests. Subsequently, the surface chemistry changes observed are compared to similar data obtained from radiantly heated coatings and the significance of the difference between the results is discussed. Finally, the changes in chemistry of the coatings in cross section before and after convectively heated cyclic testing are discussed and the significance of surface chemistry changes are described. Results indicate that the thermal conductivity of mullite surface insulation is higher than that of silica insulation, based on thermal response data. Acoustic excitation of cracked silica tiles does not lead to catastrophic failure such as spallation or tile loss. Cracks in mullite material after thermal exposure lead to fracturing of the coating and surface insulation material after acoustic excitation.

  2. Evaluation of thermal conditions inside a vehicle cabin

    Directory of Open Access Journals (Sweden)

    Orzechowski Tadeusz

    2016-01-01

    Full Text Available There are several important factors influencing road accidents. Temperature inside the vehicle is ranked third after alcohol and seat belts. For this reason, maintaining thermal comfort in the passenger compartment is essential. Thermal comfort is provided by the air conditioning system, which consumes much energy. In the case of electrically powered vehicles, this results in a shorter range. Optimization of such systems is therefore required. This paper proposes a set of equations describing the thermal conditions inside the vehicle, which are the result of appropriate energy balances for air, interior elements, and glass. Variable transmission conditions are included for transparent materials exposed to short and long wave radiation. The study focused on unsteady air-conditioning of the vehicle interior. The measurement data was compared with the results obtained through numerical solutions of the proposed set of equations.

  3. Evaluation of thermal conditions inside a vehicle cabin

    Science.gov (United States)

    Orzechowski, Tadeusz; Skrobacki, Zbigniew

    2016-03-01

    There are several important factors influencing road accidents. Temperature inside the vehicle is ranked third after alcohol and seat belts. For this reason, maintaining thermal comfort in the passenger compartment is essential. Thermal comfort is provided by the air conditioning system, which consumes much energy. In the case of electrically powered vehicles, this results in a shorter range. Optimization of such systems is therefore required. This paper proposes a set of equations describing the thermal conditions inside the vehicle, which are the result of appropriate energy balances for air, interior elements, and glass. Variable transmission conditions are included for transparent materials exposed to short and long wave radiation. The study focused on unsteady air-conditioning of the vehicle interior. The measurement data was compared with the results obtained through numerical solutions of the proposed set of equations.

  4. A Facile Approach to Evaluate Thermal Insulation Performance of Paper Cups

    OpenAIRE

    Yudi Kuang; Gang Chen; Zhiqiang Fang

    2015-01-01

    Paper cups are ubiquitous in daily life for serving water, soup, coffee, tea, and milk due to their convenience, biodegradability, recyclability, and sustainability. The thermal insulation performance of paper cups is of significance because they are used to supply hot food or drinks. Using an effective thermal conductivity to accurately evaluate the thermal insulation performance of paper cups is complex due to the inclusion of complicated components and a multilayer structure. Moreover, an ...

  5. Development of Innovative Aerogel Based Plasters: Preliminary Thermal and Acoustic Performance Evaluation

    OpenAIRE

    Cinzia Buratti; Elisa Moretti; Elisa Belloni; Fabrizio Agosti

    2014-01-01

    The thermal and acoustic properties of innovative insulating systems used as building coatings were investigated: Granular silica aerogel was mixed with natural plaster in different percentages. This coating solution is transpiring and insulating, thanks to the use of a natural lime coat and aerogel, a highly porous light material with very low thermal conductivity. The thermal conductivity of the proposed solution was evaluated by means of a Heat Flow meter apparatus (EN ISO 12667), consider...

  6. Evaluation of the Thermodynamic Models for the Thermal Diffusion Factor

    DEFF Research Database (Denmark)

    Gonzalez-Bagnoli, Mariana G.; Shapiro, Alexander; Stenby, Erling Halfdan

    2003-01-01

    Over the years, several thermodynamic models for the thermal diffusion factors for binary mixtures have been proposed. The goal of this paper is to test some of these models in combination with different equations of state. We tested the following models: those proposed by Rutherford and Drickamer...... we applied different thermodynamic models, such as the Soave-Redlich-Kwong and the Peng-Robinson equations of state. The necessity to try different thermo-dynamic models is caused by the high sensitivity of the thermal diffusion factors to the values of the partial molar properties. Two different...

  7. High Performance Flat Plate Solar Thermal Collector Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Rockenbaugh, Caleb [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dean, Jesse [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lovullo, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lisell, Lars [National Renewable Energy Lab. (NREL), Golden, CO (United States); Barker, Greg [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hanckock, Ed [National Renewable Energy Lab. (NREL), Golden, CO (United States); Norton, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-09-01

    This report was prepared for the General Services Administration by the National Renewable Energy Laboratory. The Honeycomb Solar Thermal Collector (HSTC) is a flat plate solar thermal collector that shows promising high efficiencies over a wide range of climate zones. The technical objectives of this study are to: 1) verify collector performance, 2) compare that performance to other market-available collectors, 3) verify overheat protection, and 4) analyze the economic performance of the HSTC both at the demonstration sites and across a matrix of climate zones and utility markets.

  8. Analysis of the variation of range parameters of thermal cameras

    Science.gov (United States)

    Bareła, Jarosław; Kastek, Mariusz; Firmanty, Krzysztof; Krupiński, Michał

    2016-10-01

    Measured range characteristics may vary considerably (up to several dozen percent) between different samples of the same camera type. The question is whether the manufacturing process somehow lacks repeatability or the commonly used measurement procedures themselves need improvement. The presented paper attempts to deal with the aforementioned question. The measurement method has been thoroughly analyzed as well as the measurement test bed. Camera components (such as detector and optics) have also been analyzed and their key parameters have been measured, including noise figures of the entire system. Laboratory measurements are the most precise method used to determine range parameters of a thermal camera. However, in order to obtain reliable results several important conditions have to be fulfilled. One must have the test equipment capable of measurement accuracy (uncertainty) significantly better than the magnitudes of measured quantities. The measurements must be performed in a controlled environment thus excluding the influence of varying environmental conditions. The personnel must be well-trained, experienced in testing the thermal imaging devices and familiar with the applied measurement procedures. The measurement data recorded for several dozen of cooled thermal cameras (from one of leading camera manufacturers) have been the basis of the presented analysis. The measurements were conducted in the accredited research laboratory of Institute of Optoelectronics (Military University of Technology).

  9. Development of thermal-hydraulic models for the safety evaluation of CANDU reactors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Young; Jung, Yun Sik; Hwang, Gi Suk; Kim, Nam Seok [Handong Univ., Pohang (Korea, Republic of); No, Hee Cheon [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    2004-02-15

    The objective of the present research is to evaluate the safety analysis for CANDU and to improve the Horizontal Stratification Entrainment Model (HSEM) of RELAP5/MOD3.3. This report includes two items the one is the experimental study of entrainment at horizontal pipe with {+-} 36 .deg. C , {+-} 72 .deg. C branch pies, the other is the model improvement of the moderator heat sink in the Calandria. The off-take experiments on onset of entrainment and branch quality were investigated by using water and air as working fluid, and the experimental data were compared by the previous correlations. The previous correlations could not expect experimental results, thus the weak points of the previous correlations were investigated. The improvement of the previous model continues as the next year research. The thermal hydraulic scaling analysis of SPEL, STERN and ideal linear scaling analysis have been studied. As a result, a new scaling method were needed to design a new experimental facility (HGU). A new scaling method with 1/8 length scale was applied. From these results, the thermal hydraulic model for CFD code simulation was designed and test apparatus has been made. The moderator temperature distribution experiments and CFD code simulation will be continued in next year.

  10. Citation analysis in research evaluation

    CERN Document Server

    Moed, Henk F

    2005-01-01

    This book is written for members of the scholarly research community, and for persons involved in research evaluation and research policy. More specifically, it is directed towards the following four main groups of readers: - All scientists and scholars who have been or will be subjected to a quantitative assessment of research performance using citation analysis. - Research policy makers and managers who wish to become conversant with the basic features of citation analysis, and about its potentialities and limitations. - Members of peer review committees and other evaluators, who consider th

  11. Computational fluid dynamics evaluation of liquid food thermal process in a brick shaped package

    Directory of Open Access Journals (Sweden)

    Pedro Esteves Duarte Augusto

    2012-03-01

    Full Text Available Food processes must ensure safety and high-quality products for a growing demand consumer creating the need for better knowledge of its unit operations. The Computational Fluid Dynamics (CFD has been widely used for better understanding the food thermal processes, and it is one of the safest and most frequently used methods for food preservation. However, there is no single study in the literature describing thermal process of liquid foods in a brick shaped package. The present study evaluated such process and the influence of its orientation on the process lethality. It demonstrated the potential of using CFD to evaluate thermal processes of liquid foods and the importance of rheological characterization and convection in thermal processing of liquid foods. It also showed that packaging orientation does not result in different sterilization values during thermal process of the evaluated fluids in the brick shaped package.

  12. 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.

  13. Analysis of the thermal properties of nanomodified epoxy composite

    Directory of Open Access Journals (Sweden)

    FOMIN Nikolay Egorovich

    2014-02-01

    Full Text Available The paper presents the results of experimental research of epoxy composites modified by nanoparticles. The results were obtained by the method of thermogravimetric analysis. The dependences between the intensity of the processes of thermal degradation in the air and technological factors and content of nanoparticles have been determined. The optimal concentration of 5 types of nanomodifiers besed on carbon nanoclusters adducts, which are functionalized carbon compounds has been revealed. The obvious advantage of these modifiers is their high solubility in polar solvents, that makes the use of these modifiers easier and allows disusing the additional sonication. Investigation of thermooxidation processes of modified epoxy resins was performed in a dynamic mode using TGA/SDTA851e module of STARe System in the temperature range 25÷800⁰C in air atmosphere with simultaneous removal of the gaseous decomposition products. Aluminum oxide (Al₂O₃ was used as the etalon, the temperature speed set was 10 deg./min. It was found out that the process of thermal degradation consists of two stages. The first step is characterized by the main oxidative degradation of polymer and the loss of up to 80% of the original sample weight, the second step is accompanied by the further oxidative decomposition of epoxy composite related to the carbon skeleton destruction. It was proved experimentally that injection of modifiers changes thermal-oxidative decomposition processes and also changes specific energy of epoxy composite according to the type and concentration of nanomodifier. It was shown that the injection of optimal amounts of modifier allows increase of the thermal and energy characteristics, and as a result, the durability of epoxy coatings exposed to aggressive climatic factors.

  14. Evaluation of Electrical and Thermal Conductivity of Polymeric ...

    African Journals Online (AJOL)

    PROF HORSFALL

    application was compressed in a wooden mold to form tablets of the doped polymers. On testing for the electrical and thermal conductivities of the doped polymers it was observed that both conductivities were greatly enhanced as the concentrations of the dopants increased. Hence it is evident that those polymeric materials ...

  15. Evaluation of electrical and thermal conductivity of polymeric wastes ...

    African Journals Online (AJOL)

    The mixture on melting with heat application was compressed in a wooden mold to form tablets of the doped polymers. On testing for the electrical and thermal conductivities of the doped polymers it was observed that both conductivities were greatly enhanced as the concentrations of the dopants increased. Hence it is ...

  16. Comparative Batch and Column Evaluation of Thermal and Wet ...

    African Journals Online (AJOL)

    The efficiency of regenerated spent commercial activated carbon for synthetic dye removal was studied using thermal and wet oxidative regeneration methods. Two types of experiments were carried out, batch adsorption experiments and continous flow (fixed bed) column experiment to study the mechanism of dye removal ...

  17. Structural analysis of a thermal insulation retainer assembly

    Science.gov (United States)

    Greene, William H.; Gray, Carl E., Jr.

    1989-01-01

    In January 1989 an accident occurred in the National Transonic Facility wind tunnel at NASA Langley Research Center that was believed to be caused by the failure of a thermal insulation retainer. A structural analysis of this retainer assembly was performed in order to understand the possible failure mechanisms. Two loading conditions are important and were considered in the analysis. The first is the centrifugal force due to the fact that this retainer is located on the fan drive shaft. The second loading is a differential temperature between the retainer assembly and the underlying shaft. Geometrically nonlinear analysis is required to predict the stiffness of this component and to account for varying contact regions between various components in the assembly. High, local stresses develop in the band part of the assembly near discontinuities under both the centrifugal and thermal loadings. The presence of an aluminum ring during a portion of the part's operating life was found to increase the stresses in other regions of the band. Under the centrifugal load, high bending stresses develop near the intersection of the band with joints in the assembly. These high bending stresses are believed to be the most likely cause for failure of the assembly.

  18. Thermal/Fluid Analysis of a Composite Heat Exchanger for Use on the RLV Rocket Engine

    Science.gov (United States)

    Nguyen, Dalton

    2002-01-01

    As part of efforts to design a regeneratively cooled composite nozzle ramp for use on the reusable vehicle (RLV) rocket engine, an C-SiC composites heat exchanger concept was proposed for thermal performance evaluation. To test the feasibility of the concept, sample heat exchanger panels were made to fit the Glenn Research Center's cell 22 for testing. Operation of the heat exchanger was demonstrated in a combustion environment with high heat fluxes similar to the RLV Aerospike Ramp. Test measurements were reviewed and found to be valuable for the on going fluid and thermal analysis of the actual RLV composite ramp. Since the cooling fluid for the heat exchanger is water while the RLV Ramp cooling fluid is LH2, fluid and thermal models were constructed to correlate to the specific test set-up. The knowledge gained from this work will be helpful for analyzing the thermal response of the actual RLV Composite Ramp. The coolant thermal properties for the models are taken from test data. The heat exchanger's cooling performance was analyzed using the Generalized Fluid System Simulation Program (GFSSP). Temperatures of the heat exchanger's structure were predicted in finite element models using Patran and Sinda. Results from the analytical models and the tests show that RSC's heat exchanger satisfied the combustion environments in a series of 16 tests.

  19. Thermal hydrodynamic analysis of a countercurrent gas centrifuge; Analise termo hidrodinamica de uma centrifuga a contracorrente

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Delvonei Alves de

    1999-07-01

    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)

  20. Thermal-mechanical coupled analysis of a brake disk rotor

    Science.gov (United States)

    Belhocine, Ali; Bouchetara, Mostefa

    2013-08-01

    The main purpose of this study is to analyze the thermomechanical behavior of the dry contact between the brake disk and pads during the braking phase. The simulation strategy is based on computer code ANSYS11. The modeling of transient temperature in the disk is actually used to identify the factor of geometric design of the disk to install the ventilation system in vehicles The thermal-structural analysis is then used with coupling to determine the deformation and the Von Mises stress established in the disk, the contact pressure distribution in pads. The results are satisfactory when compared to those of the specialized literature.

  1. Thermal states of the Kitaev honeycomb model: Bures metric analysis

    Science.gov (United States)

    Abasto, Damian F.; Zanardi, Paolo

    2009-01-01

    We analyze the Bures metric over the canonical thermal states for the Kitaev honeycomb mode. In this way the effects of finite temperature on topological phase transitions can be studied. Different regions in the parameter space of the model can be clearly identified in terms of different temperature scaling behavior of the Bures metric tensor. Furthermore, we show a simple relation between the metric elements and the crossover temperature between the quasicritical and the quasiclassical regions. These results extend the analysis of Zhao and Zhou [e-print arXiv:/0803.0814v1] and Yang [Phys. Rev. A 78, 012304 (2008)] to finite temperatures.

  2. Thermal analysis of the airflow around ATLAS muon end cap

    CERN Document Server

    Gasser, D

    2003-01-01

    A thermal analysis of the airflow inside the UX15 cavern and through the ATLAS detector is presented. This study is done using a CFD (Computational Fluid Dynamics) model. This model includes a simplified geometry of the detector and the experimental cavern, the ventilation flow rate and the released heat dissipation figures are taken into account. This analysis aims at estimate the temperature gradients that develop in the muons end cap area. Indeed, light rays seen by CCD camera will be used in this area in order to align the muon chambers. The rays should not be too much distorted by temperature difference, which would hinder the chamber alignment. The simulation results show that a light ray projected through the whole end cap area should not encounter a gradient higher than 5 K. Nevertheless, the results of this analysis are valid if and only if the spaces represented as empty in the model are allowed to remain empty in ATLAS.

  3. Thermal mechanical analysis of applications with internal heat generation

    Science.gov (United States)

    Govindarajan, Srisharan Garg

    control blade, spatial variations in temperature within the control blade occur from the non-uniform heat generation within the BORAL as a result of the non-uniform thermal neutron flux along the longitudinal direction when the control blade is partially withdrawn. There is also variation in the heating profile through the thickness and about the circumferential width of the control blade. Mathematical curve-fits are generated for the non-uniform volumetric heat generation profile caused by the thermal neutron absorption and the functions are applied as heating conditions within a finite element model of the control blade built using the commercial finite element code Abaqus FEA. The finite element model is solved as a fully coupled thermal mechanical problem as in the case of the annular target. The resulting deflection is compared with the channel gap to determine if there is a significant risk of the control blade binding during reactor operation. Hence, this dissertation will consist of two sections. The first section will seek to present the thermal and structural safety analyses of the annular targets for the production of molybdenum-99. Since there hasn't been any detailed, documented, study on these annular targets in the past, the work complied in this dissertation will help to understand the thermal-mechanical behavior and failure margins of the target during in-vessel irradiation. As the work presented in this dissertation provides a general performance analysis envelope for the annular target, the tools developed in the process can also be used as useful references for future analyses that are specific to any reactor. The numerical analysis approach adopted and the analytical models developed, can also be applied to other applications, outside the Mo-99 project domain, where internal heat generation exists such as in electronic components and nuclear reactor control blades. The second section will focus on estimating the thermally induced deflection and hence

  4. Identification and analysis of factors affecting thermal shock resistance of ceramic materials in solar receivers

    Science.gov (United States)

    Hasselman, D. P. H.; Singh, J. P.; Satyamurthy, K.

    1980-01-01

    An analysis was conducted of the possible modes of thermal stress failure of brittle ceramics for potential use in point-focussing solar receivers. The pertinent materials properties which control thermal stress resistance were identified for conditions of steady-state and transient heat flow, convective and radiative heat transfer, thermal buckling and thermal fatigue as well as catastrophic crack propagation. Selection rules for materials with optimum thermal stress resistance for a particular thermal environment were identified. Recommendations for materials for particular components were made. The general requirements for a thermal shock testing program quantitatively meaningful for point-focussing solar receivers were outlined. Recommendations for follow-on theoretical analyses were made.

  5. design analysis and performance evaluation

    African Journals Online (AJOL)

    The design analysis and performance evaluation of an active solar crop dryer was undertaken by drying marched cassava. The drying rate, system drying, collector and pick-up efficiencies were 1.6kg/day (14%/day), 9%, 46% and 29% respectively. Comparatively, the drying rate for sun drying was 0.9kg/day. The collector ...

  6. Heat transfer and thermal stress analysis in grooved tubes

    Indian Academy of Sciences (India)

    The maximum thermal stress ratio positions inside the tube have been indicated as MX for all investigated cases. In the light of the thermal stress values, various designs can be applied to reduce thermal stress in grooved tubes. Keywords. Heat transfer; thermal stress; grooved tubes. 1. Introduction. Heat transfer in pipe flow ...

  7. Structural and Thermal Safety Analysis Report for the Type B Radioactive Waste Transport Package

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D. H.; Seo, K. S.; Lee, J. C.; Bang, K. S

    2007-09-15

    We carried out structural safety evaluation for the type B radioactive waste transport package. Requirements for type B packages according to the related regulations such as IAEA Safety Standard Series No. TS-R-1, Korea Most Act. 2001-23 and US 10 CFR Part 71 were evaluated. General requirements for packages such as those for a lifting attachment, a tie-down attachment and pressure condition were considered. For the type B radioactive waste transport package, the structural, thermal and containment analyses were carried out under the normal transport conditions. Also the safety analysis were conducted under the accidental transport conditions. The 9 m drop test, 1 m puncture test, fire test and water immersion test under the accidental transport conditions were consecutively done. The type B radioactive waste transport packages were maintained the structural and thermal integrities.

  8. Thermal behavior analysis of PWR fuel during RIA at various fuel burnups using modified theatre code

    Directory of Open Access Journals (Sweden)

    Nawaz Amjad

    2016-01-01

    Full Text Available The fuel irradiation and burnup causes geometrical and dimensional changes in the fuel rod which affects its thermal resistance and ultimately affects the fuel rod behavior during steady-state and transient conditions. The consistent analysis of fuel rod thermal performance is essential for precise evaluation of reactor safety in operational transients and accidents. In this work, analysis of PWR fuel rod thermal performance is carried out under steady-state and transient conditions at different fuel burnups. The analysis is performed by using thermal hydraulic code, THEATRe. The code is modified by adding burnup dependent fuel rod behavior models. The original code uses as-fabricated fuel rod dimensions during steady-state and transient conditions which can be modified to perform more consistent reactor safety analysis. AP1000 reactor is considered as a reference reactor for this analysis. The effect of burnup on steady-state fuel rod parameters has been investigated. For transient analysis, hypothetical reactivity initiated accident was simulated by considering a triangular power pulse of variable pulse height (relative to the full power reactor operating conditions and pulse width at different fuel burnups which corresponds to fresh fuel, low and medium burnup fuels. The effect of power pulse height, pulse width and fuel burnup on fuel rod temperatures has been investigated. The results of reactivity initiated accident analysis show that the fuel failure mechanisms are different for fresh fuel and fuel at different burnup levels. The fuel failure in fresh fuel is expected due to fuel melting as fuel temperature increases with increase in pulse energy (pulse height. However, at relatively higher burnups, the fuel failure is expected due to cladding failure caused by strong pellet clad mechanical interaction, where, the contact pressure increases beyond the cladding yield strength.

  9. Quantitative measurement of carbon nanotubes released from their composites by thermal carbon analysis

    Science.gov (United States)

    Ogura, I.; Kotake, M.; Ata, S.; Honda, K.

    2017-06-01

    The release of free carbon nanotubes (CNTs) and CNTs partly embedded in matrix debris into the air may occur during mechanical and abrasion processes involving CNT composites. Since the harmful effects of CNT-matrix mixtures have not yet been fully evaluated, it is considered that any exposure to CNTs, including CNT-matrix mixtures, should be measured and controlled. Thermal carbon analysis, such as Method 5040 of the National Institute for Occupational Safety and Health, is one of the most reliable quantitative methods for measuring CNTs in the air. However, when CNTs are released together with polymer matrices, this technique may be inapplicable. In this study, we evaluated the potential for using thermal carbon analysis to determine CNTs in the presence of polymer matrices. Our results showed that thermal carbon analysis was potentially capable of determining CNTs in distinction from polyamide 12, polybutylene terephthalate, polypropylene, and polyoxymethylene. However, it was difficult to determine CNTs in the presence of polyethylene terephthalate, polycarbonate, polyetheretherketone, or polyamide 6.

  10. A Facile Approach to Evaluate Thermal Insulation Performance of Paper Cups

    Directory of Open Access Journals (Sweden)

    Yudi Kuang

    2015-01-01

    Full Text Available Paper cups are ubiquitous in daily life for serving water, soup, coffee, tea, and milk due to their convenience, biodegradability, recyclability, and sustainability. The thermal insulation performance of paper cups is of significance because they are used to supply hot food or drinks. Using an effective thermal conductivity to accurately evaluate the thermal insulation performance of paper cups is complex due to the inclusion of complicated components and a multilayer structure. Moreover, an effective thermal conductivity is unsuitable for evaluating thermal insulation performance of paper cups in the case of fluctuating temperature. In this work, we propose a facile approach to precisely analyze the thermal insulation performance of paper cups in a particular range of temperature by using an evaluation model based on the MISO (Multiple-Input Single-Output technical theory, which includes a characterization parameter (temperature factor and a measurement apparatus. A series of experiments was conducted according to this evaluation model, and the results show that this evaluation model enables accurate characterization of the thermal insulation performance of paper cups and provides an efficient theoretical basis for selecting paper materials for paper cups.

  11. Risk analysis of the thermal sterilization process. Analysis of factors affecting the thermal resistance of microorganisms.

    Science.gov (United States)

    Akterian, S G; Fernandez, P S; Hendrickx, M E; Tobback, P P; Periago, P M; Martinez, A

    1999-03-01

    A risk analysis was applied to experimental heat resistance data. This analysis is an approach for processing experimental thermobacteriological data in order to study the variability of D and z values of target microorganisms depending on the deviations range of environmental factors, to determine the critical factors and to specify their critical tolerance. This analysis is based on sets of sensitivity functions applied to a specific case of experimental data related to the thermoresistance of Clostridium sporogenes and Bacillus stearothermophilus spores. The effect of the following factors was analyzed: the type of target microorganism; nature of the heating substrate; pH, temperature; type of acid employed and NaCl concentration. The type of target microorganism to be inactivated, the nature of the substrate (reference or real food) and the heating temperature were identified as critical factors, determining about 90% of the alteration of the microbiological risk. The effect of the type of acid used for the acidification of products and the concentration of NaCl can be assumed to be negligible factors for the purposes of engineering calculations. The critical non-uniformity in temperature during thermobacteriological studies was set as 0.5% and the critical tolerances of pH value and NaCl concentration were 5%. These results are related to a specific case study, for that reason their direct generalization is not correct.

  12. Fracture evaluation of thermally sprayed coatings in dependence on cohesive strength

    Science.gov (United States)

    Schubert, J.; Česánek, Z.

    2017-05-01

    Measuring the cohesive strength of thermally sprayed coatings is relatively difficult matter, which can be accessed in many directions. This issue is nowadays solved by use of Scratch test method. This method is not completely sufficient for the cohesive strength testing because the coating is under load of combined stresses during the Scratch test. The reason to develop this method was need for exact measurement of tensile cohesion toughness of thermally sprayed coatings, which could provide results as close to a classic tensile test as possible. Another reason for development of this method was the impossibility of direct comparison with results obtained by other methods. Tested coatings were prepared using HP / HVOF (Stellite 6, NiCrBSi, CrC-NiCr and Hastelloy C-276). These coatings were selected as commonly used in commercial sector and also on because of rising customer demand for ability to provide such coating characteristics. The tested coatings were evaluated in terms of cohesive strength (method based on tensile strength test). Final fractures were evaluated by optical microscopy together with scanning electron microscopy and EDS analysis. As expected higher cohesive strength showed metallic coatings with top results of coating Stellite 6. Carbide coatings showed approximately third of the cohesion strength in comparison with metal based coating.

  13. THERMIT2. BWR & PWR Thermal-Hydraulic Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kazimi, M.S.; Kao, S.P.; Kelly, J.E. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    1992-02-27

    THERMIT2, the most recent release of THERMIT, is intended for thermal-hydraulic analysis of both boiling and pressurized water reactor cores. It solves the three-dimensional, two-fluid equations describing the two-phase flow and heat transfer dynamics in rectangular coordinates. The two-fluid model uses separate partial differential equations expressing conservation of mass, momentum, and energy for each fluid. By expressing the exchange of mass, momentum, and energy between the fluids with physically-based mathematical models, the relative motion and thermal non-equilibrium between the fluids can exist. THERMIT2 offers the choice of either pressure or velocity boundary conditions at the top and bottom of the core. THERMIT2 includes a two-phase turbulent mixing model which provides subchannel analysis capability. THERMIT2 also solves the radial heat conduction equations for fuel pin temperatures, and calculates the heat flux from fuel pin to coolant with appropriate heat transfer models described by a boiling curve.

  14. Thermal analysis of two-dimensional structures in fire

    Directory of Open Access Journals (Sweden)

    I. Pierin

    Full Text Available The structural materials, as reinforced concrete, steel, wood and aluminum, when heated have their mechanical proprieties degraded. In fire, the structures are subject to elevated temperatures and consequently the load capacity of the structural elements is reduced. The Brazilian and European standards show the minimal dimensions for the structural elements had an adequate bearing capacity in fire. However, several structural checks are not contemplated in methods provided by the standards. In these situations, the knowledge of the temperature distributions inside of structural elements as function of time of exposition is required. The aim of this paper is present software developed by the authors called ATERM. The software performs the thermal transient analysis of two-dimensional structures. The structure may be formed of any material and heating is provided by means of a curve of temperature versus time. The data input and the visualization of the results is performed thought the GiD software. Several examples are compared with software Super TempCalc and ANSYS. Some conclusions and recommendations about the thermal analysis are presented

  15. 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.

  16. Integrated Thermal-Energy Analysis of Innovative Translucent White Marble for Building Envelope Application

    Directory of Open Access Journals (Sweden)

    Federica Rosso

    2014-08-01

    Full Text Available Marble is a natural material, used in the construction field since antiquity. It has always been used to communicate monumentality and solidity. Nowadays new technologies permit marble to express new languages: particularly, translucent marble technology overturns the concept of solidity. The main issue to address is the lack of thermal-energy performance of such a thin stone layer as the only facade component. Conversely, Bianco Carrara and Statuario marbles, for instance, have intrinsic benefits as natural cool materials, due to their high solar reflectance and thermal emissivity. Thus, this paper analyzes the thermal-energy and environmental behavior of marble facade for a new designed building in New York City. An integrated analysis of the energy performance of the marble skin is performed through a preliminary experimental characterization, carried out for two different types of naturally white marble, for comparative purposes. Then, a dynamic simulation model of the building is developed to evaluate year-round benefits and drawbacks of the translucent marble envelope in terms of indoor thermal comfort and air-conditioning requirement. The analysis showed how the proposed marble facade is able to decrease the energy requirement for cooling up to 6%, demonstrating possible relevant perspectives for marble-based facades, even in energy-efficient buildings.

  17. 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

  18. Evaluation of Thermal Endurance Characteristics of Hard Polyurethane Foams by Dynamic Compression Modulus

    National Research Council Canada - National Science Library

    Adachi, Hiromasa; Hasegawa, Teruo

    2004-01-01

      For evaluation of thermal endurance in foamed plastics, temperature and time characteristics of compression dynamic modulus of four hard polyurethane foams were investigated by the dynamic viscoelastic measurements...

  19. AMRL Evaluation of the JP-8+100 Jet Fuel Thermal Stability Additive

    National Research Council Canada - National Science Library

    Rawson, Paul

    2001-01-01

    ... 90%. An AED-designed rig capable of quantitatively evaluating jet fuel thermal stability was used to investigate jet fuels produced by different Australian refineries with various fuel finishing processes...

  20. Thermoregulatory strategies in an aquatic ectotherm from thermally-constrained habitats: An evaluation of current approaches.

    Science.gov (United States)

    Piasečná, Karin; Pončová, Alena; Tejedo, Miguel; Gvoždík, Lumír

    2015-08-01

    Many ectotherms employ diverse behavioral adjustments to effectively buffer the spatio-temporal variation in environmental temperatures, whereas others remain passive to thermal heterogeneity. Thermoregulatory studies are frequently performed on species living in thermally benign habitats, which complicate understanding of the thermoregulation-thermoconformity continuum. The need for new empirical data from ectotherms exposed to thermally challenging conditions requires the evaluation of available methods for quantifying thermoregulatory strategies. We evaluated the applicability of various thermoregulatory indices using fire salamander larvae, Salamandra salamandra, in two aquatic habitats, a forest pool and well, as examples of disparate thermally-constrained environments. Water temperatures in the well were lower and less variable than in the pool. Thermal conditions prevented larvae from reaching their preferred body temperature range in both water bodies. In contrast to their thermoregulatory abilities examined in a laboratory thermal gradient, field body temperatures only matched the mean and range of operative temperatures, showing thermal passivity of larvae in both habitats. Despite apparent thermoconformity, thermoregulatory indices indicated various strategies from active thermoregulation, to thermoconformity, and even thermal evasion, which revealed their limited applicability under thermally-constrained conditions. Salamander larvae abandoned behavioral thermoregulation despite varying opportunities to increase their body temperature above average water temperatures. Thermoconformity represents a favored strategy in these ectotherms living in more thermally-constrained environments than those examined in previous thermoregulatory studies. To understand thermal ecology and its impact on population dynamics, the quantification of thermoregulatory strategies of ectotherms in thermally-constrained habitats requires the careful choice of an appropriate

  1. Non-destructive high-resolution thermal imaging techniques to evaluate wildlife and delicate biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Lavers, C; Franklin, P; Franklin, P; Plowman, A; Sayers, G; Bol, J; Shepard, D; Fields, D, E-mail: brnc-radarcomms1@nrta.mod.u [Sensors Team, Plymouth University at Britannia Royal Naval College, Dartmouth, Devon (United Kingdom) and Paignton Zoological Park, Paignton, Devon (United Kingdom); Thermal Wave Imaging, Inc., 845 Livernoise St, Ferndale, MI (United States); Buckfast Butterfly and Otter Sanctuary, Buckfast, Devon (United Kingdom)

    2009-07-01

    Thermal imaging cameras now allows routine monitoring of dangerous yet endangered wildlife in captivity. This study looks at the potential applications of radiometrically calibrated thermal data to wildlife, as well as providing parameters for future materials applications. We present a non-destructive active testing technique suitable for enhancing imagery contrast of thin or delicate biological specimens yielding improved thermal contrast at room temperature, for analysis of sample thermal properties. A broad spectrum of animals is studied with different textured surfaces, reflective and emissive properties in the infra red part of the electromagnetic spectrum. Some surface features offer biomimetic materials design opportunities.

  2. Thermal analysis of the ambient air around a particle detector

    CERN Document Server

    Gasser, D

    2003-01-01

    The ATLAS particle detector will be in operation at CERN in a few years. The so-called "end cap muon chambers", which form a sub-system of this detector, need to be aligned accurately by means of light rays. Despite the significant amount of heat released in the air by the detector, the rays must not be too much distorted by temperature difference. In order to predict ambient temperature gradient, a thermal analysis is done using a CFD (Computational Fluid Dynamics) model. Because of the complexity of ATLAS geometry, relevant assumptions need to be made in order to get a suitable model for numerical analysis and which give reliable results at the same time.

  3. Thermal stress analysis of the fuel storage facility

    Energy Technology Data Exchange (ETDEWEB)

    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. Analysis of Thermal Performance in a Bidirectional Thermocycler by Including Thermal Contact Characteristics

    Directory of Open Access Journals (Sweden)

    Jyh Jian Chen

    2014-12-01

    Full Text Available This paper illustrates an application of a technique for predicting the thermal characteristics of a bidirectional thermocycling device for polymerase chain reaction (PCR. The micromilling chamber is oscillated by a servo motor and contacted with different isothermal heating blocks to successfully amplify the DNA templates. Because a comprehensive database of contact resistance factors does not exist, it causes researchers to not take thermal contact resistance into consideration at all. We are motivated to accurately determine the thermal characteristics of the reaction chamber with thermal contact effects existing between the heater surface and the chamber surface. Numerical results show that the thermal contact effects between the heating blocks and the reaction chamber dominate the temperature variations and the ramping rates inside the PCR chamber. However, the influences of various temperatures of the ambient conditions on the sample temperature during three PCR steps can be negligible. The experimental temperature profiles are compared well with the numerical simulations by considering the thermal contact conductance coefficient which is empirical by the experimental fitting. To take thermal contact conductance coefficients into consideration in the thermal simulation is recommended to predict a reasonable temperature profile of the reaction chamber during various thermal cycling processes. Finally, the PCR experiments present that Hygromycin B DNA templates are amplified successfully. Furthermore, our group is the first group to introduce the thermal contact effect into theoretical study that has been applied to the design of a PCR device, and to perform the PCR process in a bidirectional thermocycler.

  5. Thermal Analysis of Low Layer Density Multilayer Insulation Test Results

    Science.gov (United States)

    Johnson, Wesley L.

    2011-01-01

    Investigation of the thermal performance of low layer density multilayer insulations is important for designing long-duration space exploration missions involving the storage of cryogenic propellants. Theoretical calculations show an analytical optimal layer density, as widely reported in the literature. However, the appropriate test data by which to evaluate these calculations have been only recently obtained. As part of a recent research project, NASA procured several multilayer insulation test coupons for calorimeter testing. These coupons were configured to allow for the layer density to be varied from 0.5 to 2.6 layer/mm. The coupon testing was completed using the cylindrical Cryostat-l00 apparatus by the Cryogenics Test Laboratory at Kennedy Space Center. The results show the properties of the insulation as a function of layer density for multiple points. Overlaying these new results with data from the literature reveals a minimum layer density; however, the value is higher than predicted. Additionally, the data show that the transition region between high vacuum and no vacuum is dependent on the spacing of the reflective layers. Historically this spacing has not been taken into account as thermal performance was calculated as a function of pressure and temperature only; however the recent testing shows that the data is dependent on the Knudsen number which takes into account pressure, temperature, and layer spacing. These results aid in the understanding of the performance parameters of MLI and help to complete the body of literature on the topic.

  6. 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.

  7. Status and subjects of thermal-hydraulic analysis for next-generation LWRs with passive safety systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The present status and subjects on thermal-hydraulic analysis for next-generation light water reactors (LWRs) with passive safety systems were summarized based on survey results and discussion by subcommittee on improvement of reactor thermal-hydraulic analysis codes under nuclear code committee in Japan Atomic Energy Research Institute. This survey was performed to promote the research of improvement of reactor thermal-hydraulic analysis codes in future. In the first part of this report, the status and subjects on system analysis and those on evaluation of passive safety system performance are summarized for various types of reactor proposed before. In the second part, the status and subjects on multidimensional two-phase flow analysis are reviewed, since the multidimensional analysis was recognized as one of most important subjects through the investigation in the first part. Besides, databases for bubbly flow and annular dispersed flow were explored, those are needed to assess and verify each multidimensional analytical method. The contents in this report are the forefront of thermal-hydraulic analysis for LWRs and those include current findings for the development of multidimensional two-phase flow analytical method. Thus, we expect that the contents can offer various useful information against the improvement of reactor thermal-hydraulic analysis codes in future. (author)

  8. Evaluation of thermal striping for the plugging system in the secondary auxiliary cooling system in JOYO

    Energy Technology Data Exchange (ETDEWEB)

    Isozaki, Kazunori; Ogawa, Tooru; Kubo, Atsuhiko; Aoki, Hiroshi; Ozawa, Kenji [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center; Sugaya, Kazushi

    1998-05-01

    Scrutiny based on the convenient evaluation to verify whether we have the place where thermal striping in the pipe confluence part was thought to be a primary factor for the heavy accident or not has been done in JOYO. As the result, the big temperature difference ({Delta}Tin) existed at the inner pipe confluence part of the plugging system in the secondary main and auxiliary cooling system. Therefore, detailed evaluation of thermal striping was needed. With the thermocouples of high response installed, the temperature fluctuation in outer surface of the pipe was measured on the secondary auxiliary plugging system for the reason why the temperature difference ({Delta}Tin) was the biggest. And, the temperature fluctuation in inner surface of the pipe and stress occurring in the pipe plate thickness direction was evaluated by means of non-linear structure analysis system FINAS`. The above-mentioned evaluation results were as follows. (1) The maximum temperature fluctuation occurring in the pipe was always located from the center of inner pipe confluence to 10 mm position of the down-stream side. (2) The maximum temperature fluctuation range was about 33degC in outer surface of the pipe. And, controlling frequency of the temperature fluctuation was 0.04 Hz and 0.09 Hz. (3) Time delay was almost never contained in the temperature fluctuation elements between inner and outer surface of the pipe. And, the big temperature distribution did not occur in the pipe plate thickness direction was confirmed that the big temperature distribution did not occur in the pipe plate thickness direction. The temperature fluctuation range in the pipe inner surface was almost the same as that of the pipe outer surface. It was confirmed that the stress occurring there was enough lowered than the design fatigue limit of SUS304 which was the materials in the confluence part of the plugging system inner part in the secondary main and auxiliary cooling system. (J.P.N.)

  9. 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)

  10. Measurement of two-dimensional thermal neutron flux in a water phantom and evaluation of dose distribution characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Kazuyoshi; Kumada, Hiroaki; Kishi, Toshiaki; Torii, Yoshiya; Horiguchi, Yoji [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-03-01

    To evaluate nitrogen dose, boron dose and gamma-ray dose occurred by neutron capture reaction of the hydrogen at the medical irradiation, two-dimensional distribution of the thermal neutron flux is very important because these doses are proportional to the thermal neutron distribution. This report describes the measurement of the two-dimensional thermal neutron distribution in a head water phantom by neutron beams of the JRR-4 and evaluation of the dose distribution characteristic. Thermal neutron flux in the phantom was measured by gold wire placed in the spokewise of every 30 degrees in order to avoid the interaction. Distribution of the thermal neutron flux was also calculated using two-dimensional Lagrange's interpolation program (radius, angle direction) developed this time. As a result of the analysis, it was confirmed to become distorted distribution which has annular peak at outside of the void, though improved dose profile of the deep direction was confirmed in the case which the radiation field in the phantom contains void. (author)

  11. Thermally-Induced Crack Evaluation in H13 Tool Steel

    Directory of Open Access Journals (Sweden)

    Hassan Abdulrssoul Abdulhadi

    2017-11-01

    Full Text Available This study reported the effect of thermal wear on cylindrical tool steel (AISI H13 under aluminum die-casting conditions. The AISIH13 steels were immersed in the molten aluminum alloy at 700 °C before water-quenching at room temperature. The process involved an alternating heating and cooling of each sample for a period of 24 s. The design of the immersion test apparatus stylistically simulated aluminum alloy dies casting conditions. The testing phase was performed at 1850, 3000, and 5000 cycles. The samples were subjected to visual inspection after each phase of testing, before being examined for metallographic studies, surface crack measurement, and hardness characteristics. Furthermore, the samples were segmented and examined under optical and Scanning Electron Microscopy (SEM. The areas around the crack zones were additionally examined under Energy Dispersive X-ray Spectroscopy (EDXS. The crack’s maximum length and Vickers hardness profiles were obtained; and from the metallographic study, an increase in the number of cycles during the testing phase resulted in an increase in the surface crack formation; suggesting an increase in the thermal stress at higher cycle numbers. The crack length of Region I (spherically shaped was about 47 to 127 µm, with a high oxygen content that was analyzed within 140 µm from the surface of the sample. At 700 °C, there is a formation of aluminum oxides, which was in contact with the surface of the H13 sample. These stresses propagate the thermal wear crack length into the tool material of spherically shaped Region I and cylindrically shape Region II, while hardness parameters presented a different observation. The crack length of Region I was about 32% higher than the crack length of Region II.

  12. Evaluation of the gas production economics of the gas hydrate cyclic thermal injection model. [Cyclic thermal injection

    Energy Technology Data Exchange (ETDEWEB)

    Kuuskraa, V.A.; Hammersheimb, E.; Sawyer, W.

    1985-05-01

    The objective of the work performed under this directive is to assess whether gas hydrates could potentially be technically and economically recoverable. The technical potential and economics of recovering gas from a representative hydrate reservoir will be established using the cyclic thermal injection model, HYDMOD, appropriately modified for this effort, integrated with economics model for gas production on the North Slope of Alaska, and in the deep offshore Atlantic. The results from this effort are presented in this document. In Section 1, the engineering cost and financial analysis model used in performing the economic analysis of gas production from hydrates -- the Hydrates Gas Economics Model (HGEM) -- is described. Section 2 contains a users guide for HGEM. In Section 3, a preliminary economic assessment of the gas production economics of the gas hydrate cyclic thermal injection model is presented. Section 4 contains a summary critique of existing hydrate gas recovery models. Finally, Section 5 summarizes the model modification made to HYDMOD, the cyclic thermal injection model for hydrate gas recovery, in order to perform this analysis.

  13. Neutronic and thermal-hydraulic analysis of fission molybdenum-99 production at Tehran Research Reactor using LEU plate targets.

    Science.gov (United States)

    Abedi, Ebrahim; Ebrahimkhani, Marzieh; Davari, Amin; Mirvakili, Seyed Mohammad; Tabasi, Mohsen; Maragheh, Mohammad Ghannadi

    2016-12-01

    Efficient and safe production of molybdenum-99 ( 99 Mo) radiopharmaceutical at Tehran Research Reactor (TRR) via fission of LEU targets is studied. Neutronic calculations are performed to evaluate produced 99 Mo activity, core neutronic safety parameters and also the power deposition values in target plates during a 7 days irradiation interval. Thermal-hydraulic analysis has been also carried out to obtain thermal behavior of these plates. Using Thermal-hydraulic analysis, it can be concluded that the safety parameters are satisfied in the current study. Consequently, the present neutronic and thermal-hydraulic calculations show efficient 99 Mo production is accessible at significant activity values in TRR current core configuration. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. 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.

  15. Modeling and Analysis of AGS (1998) Thermal Shock Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Haines, J.R.; Kim, S.H.; Taleyarkhan, R.P.

    1999-11-14

    An overview is provided on modeling and analysis of thermal shock experiments conducted during 1998 with high-energy, short-pulse energy deposition in a mercury filled container in the Alternating Gradient Synchrotron (AGS) facility at Brookhaven National Laboratory (BNL). The simulation framework utilized along with the results of simulations for pressure and strain profiles are presented. While the magnitude of penk strain predictions versus data are in reasonable agreement, the temporal variations were found to differ significantly in selected cases, indicating lack of modeling of certain physical phenomena or due to uncertainties in the experimental data gathering techniques. Key thermal-shock related issues and uncertainties are highlighted. Specific experiments conducted at BNL's AGS facility during 1998 (the subject of this paper) involved high-energy (24 GeV) proton energy deposition in the mercury target over a time frame of - 0.1s. The target consisted of an - 1 m. long cylindrical stainless steel shell with a hemispherical dome at the leading edge. It was filled with mercury at room temperature and pressure. Several optical strain gages were attached to the surface of the steel target. Figure 1 shows a schematic representation of the test vessel along with the main dimensions and positions of three optical strain gages at which meaningful data were obtained. As

  16. Internal Thermal Control System Hose Heat Transfer Fluid Thermal Expansion Evaluation Test Report

    Science.gov (United States)

    Wieland, P. O.; Hawk, H. D.

    2001-01-01

    During assembly of the International Space Station, the Internal Thermal Control Systems in adjacent modules are connected by jumper hoses referred to as integrated hose assemblies (IHAs). A test of an IHA has been performed at the Marshall Space Flight Center to determine whether the pressure in an IHA filled with heat transfer fluid would exceed the maximum design pressure when subjected to elevated temperatures (up to 60 C (140 F)) that may be experienced during storage or transportation. The results of the test show that the pressure in the IHA remains below 227 kPa (33 psia) (well below the 689 kPa (100 psia) maximum design pressure) even at a temperature of 71 C (160 F), with no indication of leakage or damage to the hose. Therefore, based on the results of this test, the IHA can safely be filled with coolant prior to launch. The test and results are documented in this Technical Memorandum.

  17. Macroevolution of thermal tolerance in intertidal crabs from Neotropical provinces: A phylogenetic comparative evaluation of critical limits.

    Science.gov (United States)

    Faria, Samuel C; Faleiros, Rogério O; Brayner, Fábio A; Alves, Luiz C; Bianchini, Adalto; Romero, Carolina; Buranelli, Raquel C; Mantelatto, Fernando L; McNamara, John C

    2017-05-01

    Thermal tolerance underpins most biogeographical patterns in ectothermic animals. Macroevolutionary patterns of thermal limits have been historically evaluated, but a role for the phylogenetic component in physiological variation has been neglected. Three marine zoogeographical provinces are recognized throughout the Neotropical region based on mean seawater temperature (Tm): the Brazilian (Tm = 26 °C), Argentinian (Tm = 15 °C), and Magellanic (Tm = 9 °C) provinces. Microhabitat temperature (MHT) was measured, and the upper (UL 50) and lower (LL 50) critical thermal limits were established for 12 eubrachyuran crab species from intertidal zones within these three provinces. A molecular phylogenetic analysis was performed by maximum likelihood using the 16S mitochondrial gene, also considering other representative species to enable comparative evaluations. We tested for: (1) phylogenetic pattern of MHT, UL 50, and LL 50; (2) effect of zoogeographical province on the evolution of both limits; and (3) evolutionary correlation between MHT and thermal limits. MHT and UL 50 showed strong phylogenetic signal at the species level while LL 50 was unrelated to phylogeny, suggesting a more plastic evolution. Province seems to have affected the evolution of thermal tolerance, and only UL 50 was dependent on MHT. UL 50 was similar between the two northern provinces compared to the southernmost while LL 50 differed markedly among provinces. Apparently, critical limits are subject to different environmental pressures and thus manifest unique evolutionary histories. An asymmetrical macroevolutionary scenario for eubrachyuran thermal tolerance seems likely, as the critical thermal limits are differentially inherited and environmentally driven.

  18. Geomechanical characterization of the Upper Carboniferous under thermal stress for the evaluation of a High Temperature - Mine Thermal Energy Storage (HT-MTES)

    Science.gov (United States)

    Hahn, Florian; Brüggemann, Nina; Bracke, Rolf; Alber, Michael

    2017-04-01

    The goal of this R&D project is to create a technically and economically feasible conceptual model for a High Temperature - Mine Thermal Energy Storage (HT-MTES) for the energetic reuse of a mine on the example of the Prosper-Haniel coal mine in Bottrop, Germany. This project is funded by the "Initiative Energy Storage" program of the German Federal Ministries BMWi, BMU and BMBF. At the end of 2018, the last operative coal mine in North Rhine-Westphalia, Germany (Prosper-Haniel), is going to be closed down, plugged and abandoned. Large amounts of subsurface infrastructures, resembled mainly by open parts of former galleries and mining faces are going to be flooded, after the mine is closed down and therefore have the potential to become an enormous geothermal reservoir for a seasonal heat storage. During the summer non-used (waste) heat from solar thermal power plants, garbage incineration, combined heat and power plants (CHP) or industrial production processes can be stored within dedicated drifts of the mine. During the winter season, this surplus heat can be extracted and directly utilized in commercial and/or residential areas. For the evaluation of such a HT-MTES within a former coal mine, the corresponding geomechanical parameters of the Upper Carboniferous under thermal stress needs to be evaluated. Therefore the main rock types of the Upper Carboniferous (claystone, siltstone and sandstone) are subject to a geomechanical characterization before and after thermal cyclic loadings of temperatures up to 200 °C. The samples have been collected directly from the coal mine Prosper-Haniel within a depth range of 1000 - 1200 m. Unconfined compressive and tensile strengths, as well as triaxial tests were performed at room temperature. Furthermore, a range of petrophysical properties like density, thin-section analysis and P-wave velocities were determined. First results show an indication that the overall strength properties of the samples are not effected by

  19. Experimental and theoretical analysis of a method to predict thermal runaway in Li-ion cells

    Science.gov (United States)

    Shah, Krishna; Chalise, Divya; Jain, Ankur

    2016-10-01

    Thermal runaway is a well-known safety concern in Li-ion cells. Methods to predict and prevent thermal runaway are critically needed for enhanced safety and performance. While much work has been done on understanding the kinetics of various heat generation processes during thermal runaway, relatively lesser work exists on understanding how heat removal from the cell influences thermal runaway. Through a unified analysis of heat generation and heat removal, this paper derives and experimentally validates a non-dimensional parameter whose value governs whether or not thermal runaway will occur in a Li-ion cell. This parameter is named the Thermal Runaway Number (TRN), and comprises contributions from thermal transport within and outside the cell, as well as the temperature dependence of heat generation rate. Experimental data using a 26650 thermal test cell are in good agreement with the model, and demonstrate the dependence of thermal runaway on various thermal transport and heat generation parameters. This parameter is used to predict the thermal design space in which the cell will or will not experience thermal runaway. By combining all thermal processes contributing to thermal runaway in a single parameter, this work contributes towards a unified understanding of thermal runaway, and provides the fundamental basis for design tools for safe, high-performance Li-ion batteries.

  20. Comparative evaluation of distributed-collector solar thermal electric power plants

    Science.gov (United States)

    Fujita, T.; El Gabalawi, N.; Herrera, G. G.; Caputo, R. S.

    1978-01-01

    Distributed-collector solar thermal-electric power plants are compared by projecting power plant economics of selected systems to the 1990-2000 timeframe. The approach taken is to evaluate the performance of the selected systems under the same weather conditions. Capital and operational costs are estimated for each system. Energy costs are calculated for different plant sizes based on the plant performance and the corresponding capital and maintenance costs. Optimum systems are then determined as the systems with the minimum energy costs for a given load factor. The optimum system is comprised of the best combination of subsystems which give the minimum energy cost for every plant size. Sensitivity analysis is done around the optimum point for various plant parameters.

  1. Regional economic impact analysis and project evaluation

    National Research Council Canada - National Science Library

    Davis, H. Craig

    1990-01-01

    ...: PROJECT EVALUATION ANALYSIS 6 Cost-Benefit Analysis: The Evaluation of Social Costs and Benefits 95 Case Study 1: The Evaluation of Recreation Benefits at Graf ham Water 114 Case Study 2: Cost...

  2. Evaluation of Ultrasonic and Thermal Nondestructive Evaluation for the Characterization of Aging Degradation in Braided Composite Materials

    Science.gov (United States)

    Martin, Richard E.

    2010-01-01

    This paper examines the ability of traditional nondestructive evaluation (NDE) techniques to measure the degradation of braided polymer composite materials subjected to thermal-humidity cycling to simulate aging. A series of braided composite coupons were examined using immersion ultrasonic and pulsed thermography techniques in the as received condition. These same specimens were then examined following extended thermal-humidity cycling. Results of this examination did not show a significant change in the resulting (NDE) signals.

  3. Occupancy Analysis of Sports Arenas Using Thermal Imaging

    DEFF Research Database (Denmark)

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

    2012-01-01

    . Reflections due to shiny surfaces are eliminated by analysing symmetric patterns. Occlusions are dealt with through a concavity anal- ysis of the binary regions. The system is tested in five different sports arenas, for more than three full weeks altogether. These tests showed that after a short......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...... initialisation routine the system operates independent of the different environments. The system can very precisely distinguish between zero, some or many persons on the court and give a good indication of which parts of the court that has been used....

  4. Thermal analysis of microcrystalline cellulose prepared from esparto grass

    Directory of Open Access Journals (Sweden)

    Trache D.

    2013-07-01

    Full Text Available Alfa fibres are extracted from the plant Stippa tenacissima, or esparto grass (alfa is the Arab name for esparto, and grows in the dry regions of North Africa. It belongs to the graminacies family and grows to a height of about 1 m. These fibres are mostly used in the production of paper. Recently, they have been used as reinforcement in the production of biodegradable composites. The aim of the present work was to prepare microcrystalline cellulose from esparto grass using the hydrolysis process. The products obtained are characterized with thermogravimetric analysis. As a result, the thermal decomposing patterns of the cellulosic preparations, obtained by hydrochloric hydrolysis gave additional evidence to the relatively higher stability of the more crystalline cellulosic preparations. In the main decomposition stage, the cleavage of the glycosidic linkages of cellulose reduces the polymerization degree leading to the formation of CO2, H2O and other hydrocarbon derivatives.

  5. Evaluations of Strength of Thermal Sprayed Coating for Complex Loading

    Science.gov (United States)

    Kaneko, Kenji; Ohmori, Akira

    Fracture strength of WC-12Co thermal sprayed coating is investigated experimentally and analytically. In the experiments, one pair of butt cylindrical specimen with coating is subjected to combined tension with torsion stresses. Fracture loci were obtained for three kinds of thickness of the coating in σ-τ stress plane. Stress distributions at crack tip singular point on fractured surfaces are analyzed by Finite-Element-Method and approximated by the expression σ=KR-λ where R means normalized thickness coordinate. It is found that the normal stress distributions are common to all cases of testing stress conditions and so fracture condition of the brittle coating is represented as K≥Kcr in the normal stress distribution even under mixed deformation mode I and III. The delamination critical shear stress distribution could also be obtained.

  6. Effects of holmium laser on dental structure in vivo: thermal evaluation and histological analysis on pulpal tissue; Efeitos in vivo do laser de holmio em estrutura dental: monitoracao termica e analise histologica do tecido pulpar

    Energy Technology Data Exchange (ETDEWEB)

    Strefezza, Claudia

    2001-07-01

    Previous in vitro studies have demonstrated that Ho:YLF laser is capable of inducing physical and chemical changes on dental surfaces treated for caries prevention. The temperature in the pulp chamber was in vitro evaluated to as a function of the power and frequency of the laser irradiation. The purpose of this work is to verify the occurrence of pulp inflammation after Ho:YLF laser irradiation using different parameters in rabbits' teeth. The premolars and molars of ten rabbits (NZB) were divided in two groups according to the irradiation energy values of a Ho:YLF laser prototype operating at 2.065{mu}m wave length, frequency of O,5Hz and pulse length of 250{mu}s. An group A teeth were irradiated with using ten pulses of 334mJ/pulse of a Ho:YLF laser prototype operating at O.5Hz, and group B, with 512mJ/pulse. Animals were killed by transcardiac perfusion and the samples were prepared for histopathological analysis. The in vitro temperature monitoring revealed an increase of 1 deg C for the 334mJ/pulse energy and 4.5 deg C for the 512mJ/pulse energy. SEM observations showed the occurrence of melting and resolidification in dental surface. From the in vivo analysis it can be concluded that both employed laser parameters did not induce to any inflammatory response from the pulp. (author)

  7. Use of FT-IR, FT-Raman and thermal analysis to evaluate the gel formation of curdlan produced by Agrobacterium sp. IFO 13140 and determination of its rheological properties with food applicability.

    Science.gov (United States)

    Mangolim, Camila Sampaio; da Silva, Thamara Thaiane; Fenelon, Vanderson Carvalho; do Nascimento, Adriane; Sato, Francielle; Matioli, Graciette

    2017-10-01

    Curdlan is a linear polysaccharide composed of glucose units joined by β-(1,3) bonds that possesses unique gelation properties. This study aimed to characterize the structure and evaluate the gelling properties of curdlan produced by Agrobacterium sp. IFO 13140 and its gels, as well as apply it in food. FT-Raman analysis highlighted the structural changes that occurred during the formation of gels, with variations related to the hydrogen bonds and hydrophobic interactions, which occur with the formation of the low-set and high-set gels, respectively. Rheological analysis showed that the pre-gelled commercial curdlan and the curdlan produced by Agrobacterium sp. IFO 13140 differed in terms of gelation properties, which depends of the degree of polymerization of the polysaccharide, but when applied to pasta products, both improved the texture parameters. The curdlan gels were found to have great potential as gelling agents to improve texture, water retention capacity and stability of food products. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Thermal power evaluation of the TRIGA nuclear reactor at CDTN in operations of long duration

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Amir Zacarias; Ferreira, Andrea Vidal; Rezende, Hugo Cesar, E-mail: amir@cdtn.b, E-mail: avf@cdtn.b, E-mail: hcr@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2010-07-01

    The standard operations of nuclear research reactor IPR-R1 TRIGA located at CDTN (Belo Horizonte) usually have duration of not more than 8h. However in 2009 two operations for samples irradiations lasted about 12 hours each at a power of 100 kW. These long lasting operations started in the evening and most of them were carried out at night, when there are only small fluctuations in atmosphere temperature. Therefore the conditions were ideal for evaluating the thermal balance of the power dissipated by the reactor core through the forced cooling system. Heat balance is the standard methodology for power calibration of the IPR-R1 reactor. As in any reactor operation, the main operating parameters were monitored and stored by the Data Acquisition System developed for the reactor. These data have been used for the analysis and calculation of the evolution of several neutronic and thermalhydraulic parameters involved in the reactor operation. This paper analyzes the two long lasting operations of the IPR-R1 TRIGA and compares the recorded results for the power dissipated through the primary cooling loop with the results of the power calibration conducted in March 2009. The results corresponded to those of the thermal power calibration within the uncertainty of this methodology, indicating system stability over a period of six months. (author)

  9. Evaluation of Air Mixing and Thermal Comfort From High Sidewall Supply Air Jets

    Energy Technology Data Exchange (ETDEWEB)

    Ridouane, E. H.

    2011-09-01

    Uniform mixing of conditioned air with room air is an essential factor for providing comfort in homes. The higher the supply flow rates the easier to reach good mixing in the space. In high performance homes, however, the flow rates required to meet the small remaining thermal loads are not large enough to maintain uniform mixing in the space. The objective of this study is to resolve this issue and maintain uniform temperatures within future homes. We used computational fluid dynamics modeling to evaluate the performance of high sidewall air supply for residential applications in heating and cooling modes. Parameters of the study are the supply velocity, supply temperature, diffuser dimensions, and room dimensions. Laboratory experiments supported the study of thermal mixing in heating mode; we used the results to develop a correlation to predict high sidewall diffuser performance. For cooling mode, numerical analysis is presented. The results provide information to guide the selection of high sidewall supply diffusers to maintain proper room mixing for heating and cooling of high performance homes. It is proven that these systems can achieve good mixing and provide acceptable comfort levels. Recommendations are given on the operating conditions to guarantee occupant comfort.

  10. Sensitivity analysis of radiative transfer for atmospheric remote sensing in thermal IR: atmospheric weighting functions and surface partials

    Science.gov (United States)

    Ustinov, E. A.

    2003-01-01

    In this presentation, we apply the adjoint sensitivity analysis of radiative transfer in thermal IR to the general case of the analytic evaluation of the weighting functions of atmospheric parameters together with the partial derivatives for the surface parameters. Applications to remote sensing of atmospheres of Mars and Venus are discussed.

  11. On a thermal analysis of a second stripper for rare isotope accelerator.

    Energy Technology Data Exchange (ETDEWEB)

    Momozaki, Y.; Nolen, J.; Nuclear Engineering Division

    2008-08-04

    This memo summarizes simple calculations and results of the thermal analysis on the second stripper to be used in the driver linac of Rare Isotope Accelerator (RIA). Both liquid (Sodium) and solid (Titanium and Vanadium) stripper concepts were considered. These calculations were intended to provide basic information to evaluate the feasibility of liquid (thick film) and solid (rotating wheel) second strippers. Nuclear physics calculations to estimate the volumetric heat generation in the stripper material were performed by 'LISE for Excel'. In the thermal calculations, the strippers were modeled as a thin 2D plate with uniform heat generation within the beam spot. Then, temperature distributions were computed by assuming that the heat spreads conductively in the plate in radial direction without radiative heat losses to surroundings.

  12. 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.

  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. Total-Factor Energy Efficiency (TFEE Evaluation on Thermal Power Industry with DEA, Malmquist and Multiple Regression Techniques

    Directory of Open Access Journals (Sweden)

    Jin-Peng Liu

    2017-07-01

    Full Text Available Under the background of a new round of power market reform, realizing the goals of energy saving and emission reduction, reducing the coal consumption and ensuring the sustainable development are the key issues for thermal power industry. With the biggest economy and energy consumption scales in the world, China should promote the energy efficiency of thermal power industry to solve these problems. Therefore, from multiple perspectives, the factors influential to the energy efficiency of thermal power industry were identified. Based on the economic, social and environmental factors, a combination model with Data Envelopment Analysis (DEA and Malmquist index was constructed to evaluate the total-factor energy efficiency (TFEE in thermal power industry. With the empirical studies from national and provincial levels, the TFEE index can be factorized into the technical efficiency index (TECH, the technical progress index (TPCH, the pure efficiency index (PECH and the scale efficiency index (SECH. The analysis showed that the TFEE was mainly determined by TECH and PECH. Meanwhile, by panel data regression model, unit coal consumption, talents and government supervision were selected as important indexes to have positive effects on TFEE in thermal power industry. In addition, the negative indexes, such as energy price and installed capacity, were also analyzed to control their undesired effects. Finally, considering the analysis results, measures for improving energy efficiency of thermal power industry were discussed widely, such as strengthening technology research and design (R&D, enforcing pollutant and emission reduction, distributing capital and labor rationally and improving the government supervision. Relative study results and suggestions can provide references for Chinese government and enterprises to enhance the energy efficiency level.

  15. Fluid-structure interaction analysis for pressurizer surge line subjected to thermal stratification

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Dong Gu [Korea Institute of Nuclear Safety, 19 Guseong-dong, Yuseong-gu, Daejeon 305-338 (Korea, Republic of); Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Jhung, Myung Jo, E-mail: mjj@kins.re.k [Korea Institute of Nuclear Safety, 19 Guseong-dong, Yuseong-gu, Daejeon 305-338 (Korea, Republic of); Chang, Soon Heung [Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2011-01-15

    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.

  16. In vivo evaluation of cp Ti implants with modified surfaces by laser beam with and without hydroxyapatite chemical deposition and without and with thermal treatment: topographic characterization and histomorphometric analysis in rabbits.

    Science.gov (United States)

    Queiroz, Thallita Pereira; de Molon, Rafael Scaf; Souza, Francisley Ávila; Margonar, Rogério; Thomazini, Anahi Herrera Aparecida; Guastaldi, Antônio Carlos; Hochuli-Vieira, Eduardo

    2017-03-01

    We aimed to assess the surfaces of commercially pure titanium implants (cp Ti) with modified surfaces by laser beam (LS) with and without hydroxyapatite (HA) deposition, without (HAB) and with (HABT) thermal treatment. Furthermore, we have compared them with implants with surfaces modified by acid treatment (AS) and with machined surfaces (MS) utilizing histomorphometric and descriptive histologic analyses. Surface topography characterization was analyzed by scanning electron microscopy (SEM), X-ray energy-dispersive spectroscopy (EDX), and surface roughness (Ra) before implant installation. Forty-five rabbits received seventy-five implants in their left and right tibias and were randomly divided into five groups (n = 5 implants per group): (1) cp Ti implant modified by LS, (2) cp Ti implant modified by laser beam associated with HA deposition without heat treatment (HAB), (3) cp Ti implant modified by laser beam associated with HA deposition with heat treatment (HABT), (4) cp Ti implant with modified surface by means of acid treatment (Master Porous) commercially available (AS), and (5) cp Ti implant with MS commercially available. After 30, 60, and 90 days, the animals were euthanized and the implants and surrounding bone were removed and prepared by a non-decalcified histological process. The percentage of bone-to-implant contact (BIC) and the bone area fraction occupancy (BAFO) between the first three threads was evaluated to the higher cortical region. BIC (%) was statistically superior (p < 0.001) on the LS (69.36 ± 7.91, 71.67 ± 8.79, and 79.69 ± 3.3), HAB (73.22 ± 3.75, 69.48 ± 1.89, and 75.7 ± 4.62), and HABT (65.41 ± 5.51, 71.3 ± 2.5, and 79.68 ± 5.01) compared with AS (49.15 ± 5.76, 41.94 ± 2.85, and 57.18 ± 7.81) and MS (36.69 ± 7.24, 52.52 ± 2.75, and 51.31 ± 6.96) in the 30, 60, and 90-day periods, respectively. BAFO (%) of HAB at 30 days (90.17 ± 6.24) was statistically superior (p < 0.01) to

  17. Evaluation of Strategies to Improve the Thermal Performance of Steel Frames in Curtain Wall Systems

    Directory of Open Access Journals (Sweden)

    Ji Hyun Oh

    2016-12-01

    Full Text Available Recently, metal curtain wall systems have been widely used in high-rise buildings due to many advantages, including being lightweight, rapid construction, and aesthetic features. Since the metal frame may lead to lower energy performance, thermal discomfort, and condensation risk due to the high thermal conductivity, its thermal performance can be important for the improvement of the overall thermal performance of the curtain wall system, as well as the energy efficiency of the building envelope. This study aims to evaluate variety of design strategies to improve the thermal performance of steel curtain wall frames. Five base cases and three further steps were selected for two different head profile shapes based on a state-of-the art technology review, and their thermal transmittances were calculated through simulations according to the ISO 12631 standard which is an international standard for calculating thermal transmittance of curtain wall system. Measured results that were obtained from hot-box tests were compared with the calculated results to validate the simulation method of this study. The shape of the head profile did not strongly influence the overall thermal transmittance, and the choice of strategies for the rabbet space was more important. More effective strategies could be decided according to the steps for variation development. This result can serve as a guideline for the design of high-performance curtain wall frames.

  18. A model for managing and evaluating solar radiation for indoor thermal comfort

    Energy Technology Data Exchange (ETDEWEB)

    La Gennusa, Maria; Rizzo, Gianfranco [Dipartimento di Ricerche Energetiche ed Ambientali (DREAM), Universita degli Studi di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Nucara, Antonino; Pietrafesa, Matilde [Dipartimento di Informatica, Matematica, Elettronica e Trasporti (DIMET), Universita Mediterranea di Reggio Calabria, Feo di Vito, 89060 Reggio Calabria (Italy)

    2007-05-15

    Thermal comfort of people occupying indoor spaces depends, to a large extent, on the direct component of solar radiation incident on the human body. In turn, even the diffuse component of the solar radiation could affect the thermal sensations of people. Despite this evidence, at the present there is a lack in the availability of simple and reliable methods capable of taking into account the influence of the solar radiation on thermal balance in the human body. In this work a comprehensive method is presented for the computation of the mean radiant temperature of people in thermal moderate indoor environments in the presence of solar radiation. The effects produced on the amount of solar radiation entering rooms in the presence of shadowing devices are also analysed. Finally, an application of the method is provided for a non-parallelepiped room equipped with a south window: results are shown in terms of the mean radiant temperature. A simple evaluation of thermal comfort conditions, referring to the present international standards, is also provided. The model can be easily linked to the computerized methods for analyzing the thermal behaviour of buildings, and is intended as a support for the thermal comfort evaluation methods. (author)

  19. A comparative evaluation and power generation potential analysis of Mediterranean solar thermal power plants. Preliminary study. Materials vol. 3. Availability of areas and sites. Systemvergleich und Potential von solaerthermischen Anlagen im Mittelmeerraum. Vorstudie. Materialband 3. Verfuegbare Flaechen

    Energy Technology Data Exchange (ETDEWEB)

    Kern, J.; Klaiss, H.; Schiel, W.; Sigler, M.; Meyer, J.; Staiss, F.

    1991-07-01

    This comprehensive study determines power generation potential of Mediterranean solar thermal power plants. The technical potential depends on insolation, the availability of areas and sites, and on power demands. Volume III compiles the results of the site selection studies. In the northern Mediterranean countries areas which are suited for larger power plant arrays are scarce, whereas extensive areas are found in the southern countries. Weak infrastructures may account for short- to medium-term restrictions. (BWI).

  20. Durability evaluation method for contact component interconnections in printed circuit boards under thermal loads

    Science.gov (United States)

    Azin, Anton; Zhukov, Andrey A.; Ponomarev, Sergey A.; Ponomarev, Sergey V.

    2017-11-01

    In designing sophisticated printed circuit boards, required evaluation of the product life cycle is relevant in terms of presumably applied load conditions during operation. The paper describes the durability evaluation method of printed circuit board components with contact output such as ball grid array (BGA) and pitch grid array (PGA) under thermal loads. Experiment data and numerical simulation results of soldered connections have been obtained. This method is demonstrated by a practical application example-evaluating of printed circuit board durability under cyclic thermal loads. The application of proposed method for printed circuit boards would make it possible to predict the service life of these designed products.

  1. FIELD EVALUATION OF TERRA THERM IN SITU THERMAL DESTRUCTION (ISTD) TREATMENT OF HEXACHLOROCYCLOPENTADIENE

    Science.gov (United States)

    This report summarizes the U.S. Environmental Protection Agency (EPA) Superfund Innovative Technology Evaluation (SITE) Program evaluation of the In Situ Thermal Destruction (ISTD) technology, developed by others, was refined by TerraTherm, Inc. The demonstration was designed to ...

  2. Thermal analysis method of heat pipe embedded equipment panel of communications satellite

    Science.gov (United States)

    Tsunoda, Hiroaki

    The thermal analysis method for the heat pipe embedded equipment panel of communications satellite is presented. The analytical model of the honeycomb sandwich panel embedded with heat pipes is developed and evaluated by the experiments. The new method to predict temperature distribution of the entire communications equipment panel precisely without the increase of computer CPU memory size is proposed. It works even when the large number of communications transponders are put on the panel. The correctness of the method is also confirmed by the experiment.

  3. 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

  4. Reusable Solid Rocket Motor Nozzle Joint-4 Thermal Analysis

    Science.gov (United States)

    Clayton, J. Louie

    2001-01-01

    This study provides for development and test verification of a thermal model used for prediction of joint heating environments, structural temperatures and seal erosions in the Space Shuttle Reusable Solid Rocket Motor (RSRM) Nozzle Joint-4. The heating environments are a result of rapid pressurization of the joint free volume assuming a leak path has occurred in the filler material used for assembly gap close out. Combustion gases flow along the leak path from nozzle environment to joint O-ring gland resulting in local heating to the metal housing and erosion of seal materials. Analysis of this condition was based on usage of the NASA Joint Pressurization Routine (JPR) for environment determination and the Systems Improved Numerical Differencing Analyzer (SINDA) for structural temperature prediction. Model generated temperatures, pressures and seal erosions are compared to hot fire test data for several different leak path situations. Investigated in the hot fire test program were nozzle joint-4 O-ring erosion sensitivities to leak path width in both open and confined joint geometries. Model predictions were in generally good agreement with the test data for the confined leak path cases. Worst case flight predictions are provided using the test-calibrated model. Analysis issues are discussed based on model calibration procedures.

  5. Thermal buckling comparative analysis using Different FE (Finite Element) tools

    Energy Technology Data Exchange (ETDEWEB)

    Banasiak, Waldemar; Labouriau, Pedro [INTECSEA do Brasil, Rio de Janeiro, RJ (Brazil); Burnett, Christopher [INTECSEA UK, Surrey (United Kingdom); Falepin, Hendrik [Fugro Engineers SA/NV, Brussels (Belgium)

    2009-12-19

    High operational temperature and pressure in offshore pipelines may lead to unexpected lateral movements, sometimes call lateral buckling, which can have serious consequences for the integrity of the pipeline. The phenomenon of lateral buckling in offshore pipelines needs to be analysed in the design phase using FEM. The analysis should take into account many parameters, including operational temperature and pressure, fluid characteristic, seabed profile, soil parameters, coatings of the pipe, free spans etc. The buckling initiation force is sensitive to small changes of any initial geometric out-of-straightness, thus the modeling of the as-laid state of the pipeline is an important part of the design process. Recently some dedicated finite elements programs have been created making modeling of the offshore environment more convenient that has been the case with the use of general purpose finite element software. The present paper aims to compare thermal buckling analysis of sub sea pipeline performed using different finite elements tools, i.e. general purpose programs (ANSYS, ABAQUS) and dedicated software (SAGE Profile 3D) for a single pipeline resting on an the seabed. The analyses considered the pipeline resting on a flat seabed with a small levels of out-of straightness initiating the lateral buckling. The results show the quite good agreement of results of buckling in elastic range and in the conclusions next comparative analyses with sensitivity cases are recommended. (author)

  6. Simultaneous Thermal Analysis of Remediated Nitrate Salt Surrogates

    Energy Technology Data Exchange (ETDEWEB)

    Wayne, David Matthew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-13

    The actinide engineering and science group (MET-1) have completed simultaneous thermal analysis and offgas analysis by mass spectrometry (STA-MS) of remediated nitrate salt (RNS) surrogates formulated by the high explosives science and technology group (M-7). The 1.0 to 1.5g surrogate samples were first analyzed as received, then a new set was analyzed with 100-200mL 10M HNO3 +0.3 MHF added, and a third set was analyzed after 200 mL of a concentrated Pu-AM spike (in 10M HNO3 +0.3 MHF) was added. The acid and spike solutions were formulated by the actinide analytical chemistry group (C-AAC) using reagent-grade HNO3 and HF, which was also used to dissolve a small quantity of mixed, high-fired PuO2/ AmO2 oxide.

  7. Evaluation of Perfusion and Thermal Parameters of Skin Tissue Using Cold Provocation and Thermographic Measurements

    Directory of Open Access Journals (Sweden)

    Strąkowska Maria

    2016-09-01

    Full Text Available Measurement of the perfusion coefficient and thermal parameters of skin tissue using dynamic thermography is presented in this paper. A novel approach based on cold provocation and thermal modelling of skin tissue is presented. The measurement was performed on a person’s forearm using a special cooling device equipped with the Peltier module. The proposed method first cools the skin, and then measures the changes of its temperature matching the measurement results with a heat transfer model to estimate the skin perfusion and other thermal parameters. In order to assess correctness of the proposed approach, the uncertainty analysis was performed.

  8. Thermal stress analysis of STS VOD ladle according to the reinforcement of back filler

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S. W.; Bae, S. I.; Song, J. I. [Changwon National Univ., Changwon (Korea, Republic of); Ham, K. C. [Inha Technical College, Incheon (Korea, Republic of)

    2000-07-01

    We analyzed thermal stress of the STS VOD ladle by the variation of material property of refractory, and determined the location of back filler using FE analysis. Thermal distribution of refractory of ladle between hot face and back face were decreased by the increasing the thermal conductivity, and thermal stress of refractory were decreased about 2 to 4 times with the decreasing the young's modulus coefficients. Back filler, which is constructed to absorb the thermal expansion of dolomite refractory, has relatively low thermal conductivity. Inner side of refractory of ladle maintained high temperature, but temperature of outer side of ladle decreased low. Consequently, inner expansion and outer contraction were appeared, and thermal stress were increased, so thermal stress by the construction of back filler were increased.

  9. Characterisation of dissolved organic matter fluorescence properties by PARAFAC analysis and thermal quenching.

    Science.gov (United States)

    Carstea, Elfrida M; Baker, Andy; Bieroza, Magdalena; Reynolds, Darren M; Bridgeman, John

    2014-09-15

    The fluorescence intensity of dissolved organic matter (DOM) in aqueous samples is known to be highly influenced by temperature. Although several studies have demonstrated the effect of thermal quenching on the fluorescence of DOM, no research has been undertaken to assess the effects of temperature by combining fluorescence excitation - emission matrices (EEM) and parallel factor analysis (PARAFAC) modelling. This study further extends previous research on thermal quenching by evaluating the impact of temperature on the fluorescence of DOM from a wide range of environmental samples, in the range 20 °C - 0 °C. Fluorescence intensity increased linearly with respect to temperature decrease at all temperatures down to 0 °C. Results showed that temperature affected the PARAFAC components associated with humic-like and tryptophan-like components of DOM differently, depending on the water type. The terrestrial humic-like components, C1 and C2 presented the highest thermal quenching in rural water samples and the lowest in urban water samples, while C3, the tryptophan-like component, and C4, a reprocessed humic-like component, showed opposite results. These results were attributed to the availability and abundance of the components or to the degree of exposure to the heat source. The variable thermal quenching of the humic-like components also indicated that although the PARAFAC model generated the same components across sites, the DOM composition of each component differed between them. This study has shown that thermal quenching can provide additional information on the characteristics and composition of DOM and highlighted the importance of correcting fluorescence data collected in situ. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. 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.

  11. Simulated Solar Flare X-Ray and Thermal Cycling Durability Evaluation of Hubble Space Telescope Thermal Control Candidate Replacement Materials

    Science.gov (United States)

    deGroh, Kim K.; Banks, Bruce A.; Sechkar, Edward A.; Scheiman, David A.

    1998-01-01

    During the Hubble Space Telescope (HST) second servicing mission (SM2), astronauts noticed that the multilayer insulation (MLI) covering the telescope was damaged. Large pieces of the outer layer of MLI (aluminized Teflon fluorinated ethylene propylene (Al-FEP)) were torn in several locations around the telescope. A piece of curled up Al-FEP was retrieved by the astronauts and was found to be severely embrittled, as witnessed by ground testing. Goddard Space Flight Center (GSFC) organized a HST MLI Failure Review Board (FRB) to determine the damage mechanism of FEP in the HST environment, and to recommend replacement insulation material to be installed on HST during the third servicing mission (SM3) in 1999. Candidate thermal control replacement materials were chosen by the FRB and tested for environmental durability under various exposures and durations. This paper describes durability testing of candidate materials which were exposed to charged particle radiation, simulated solar flare x-ray radiation and thermal cycling under load. Samples were evaluated for changes in solar absorptance and tear resistance. Descriptions of environmental exposures and durability evaluations of these materials are presented.

  12. Infrared thermography - a non-invasive tool to evaluate thermal status of neonatal pigs based on surface temperature

    DEFF Research Database (Denmark)

    Sund Kammersgaard, Trine; Malmkvist, Jens; Pedersen, Lene Juul

    2013-01-01

    Hypothermia is a major cause of mortality in neonatal pigs. Infrared (IR) thermography is a promising non-invasive method to assess thermal status, but has not been evaluated for use on neonatal pigs from birth. The aim of this study was to evaluate the application of IR thermography as a non-invasive...... acquired at 11 sampling times between birth and 48 h after birth. The maximum (IRmax), minimum, average of the full body and ear minimum IR surface temperatures were derived from the thermograms. IRmax had the highest correlation with RT (0.82) and was therefore used in the statistical analysis...

  13. The Modeling and Simulation of Thermal Analysis at Hydro Generator Stator Winding Insulation

    Directory of Open Access Journals (Sweden)

    Mihaela Raduca

    2006-10-01

    Full Text Available This paper presents the modelling and simulation of thermal analysis at hydro generator stator winding. The winding stator is supplied at high voltage of 11 kV for high power hydro generator. To present the thermal analysis for stator winding is presented at supply of coil by 11 kV, when coil is heat and thermal transfer in insulation at ambient temperature.

  14. Using wavelet analysis to derive seepage rates from thermal records

    Science.gov (United States)

    Banzhaf, S.; Onderka, M.; Krein, A.; Scheytt, T.

    2012-04-01

    The use of thermal records to detect loosing and gaining reaches of streams and also to determine water fluxes between surface water and groundwater has attracted researchers in hydrological sciences worldwide. This method is attractive due to the high resolution and quality of the temperature data and the relatively low costs of the equipment needed to collect the data in the streambed and therefore is widely applied. Stream water temperature fluctuates on different time scales, with strong diurnal and seasonal fluctuations. When the temperature signal propagates into the aquifer, it is attenuated and shifted in time, where the degree of signal attenuation and its shift are determined by the fluid flow velocity, thermal properties of the sediment matrix, and the frequency of the temperature signal. High-frequency signals (diurnal or smaller) are damped more than low-frequency signals (seasonal or annual). Vertical fluxes can be estimated from the amplitude ratios of temperature oscillations measured between two depths in the stream bed by using the one-dimensional heat transport equation by STALLMAN (1965) when the sediment properties between this two depths are assumed to be homogeneous. However, before this calculations can be performed a time-frequency analysis has to be performed. In contrast to the Fourier transform, which is most common, the use of wavelets allows also to capture non steady-state frequency responses. This, of course, is a huge advantage of the wavelet analysis for hydrological applications as most environmental signals are non steady-state. Wavelet transform decomposes a signal into a time-frequency space and therefore localized intermittent periodicities in the signal can be detected. The wavelet power spectrum that is yielded then allows to separate these different periods, e.g. daily cycles and seasonal signals. To test this method, temperature data that was recorded for a period of 2 years in a stream and its riverbank at a field site in

  15. Evaluation of Melanoidins Formed from Black Garlic after Different Thermal Processing Steps.

    Science.gov (United States)

    Kang, Ok-Ju

    2016-12-01

    The objective of this study was to evaluate the characteristics of melanoidins formed from black garlic (BG) after different thermal processing steps. The melanoidins formed from BG during thermal processing were produced in large amounts, and the initial (280 nm), intermediate (360 nm), and final stage product (420 nm) had similar tendencies. Compounds like degraded proteins, peptides, and phenolic acids were present in the melanoidins during thermal processing. All the melanoidin samples showed different absorptions in the UV-visible spectra, although these had similar shapes. Moreover, the carbon, hydrogen, and oxygen content of melanoidins formed from BG during thermal processing decreased initially, and then increased. However, the nitrogen content increased during thermal processing. As thermal processing progressed, the molecular weight of all the melanoidin samples showed increasing intensities, whereas the major peaks of each melanoidin sample had different retention times. Furthermore, the melanoidins formed from BG after different thermal processing steps contained -OH, -CH, amide I, and III groups. The crystallinity of the melanoidins was majorly formed at 31.58° and 43.62° (2θ).

  16. Design and Evaluation of a Thermal Tactile Display for Colour Rendering

    Directory of Open Access Journals (Sweden)

    Zhen Jia

    2015-11-01

    Full Text Available This paper proposes a novel method of manipulating both thermal change rate and thermal intensity to convey colour information by using a thermal tactile display. The colour-space transformation from {red, green, blue} to {hue, saturation, intensity} is introduced, and the mapping between colour and temperature is established based on warm and cold colours. Considering the lower resolution of the tactile channel, six limited stimulation levels are generated to represent colours. Based on the semi-infinite body model, the thermal response within the skin for each stimulation form is investigated. The Peltier element of the display is designed to convey different thermal stimuli to the human finger. Two experiments are performed to evaluate the performance of the display: colour identification and discrimination. Experimental results indicate that there is a response bias among the perceived colours for the traditional method of only employing thermal intensity, but there is no response bias for the proposed method; subjects’ mean recognition accuracy with the proposed method is significantly higher than that gained using the traditional method. Furthermore, colour information of the captured images can be reliably discriminated by using this devised thermal tactile display.

  17. Thermal Analysis for Ion-Exchange Column System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Si Y.; King, William D.

    2012-12-20

    Models have been developed to simulate the thermal characteristics of crystalline silicotitanate ion exchange media fully loaded with radioactive cesium either in a column configuration or distributed within a waste storage tank. This work was conducted to support the design and operation of a waste treatment process focused on treating dissolved, high-sodium salt waste solutions for the removal of specific radionuclides. The ion exchange column will be installed inside a high level waste storage tank at the Savannah River Site. After cesium loading, the ion exchange media may be transferred to the waste tank floor for interim storage. Models were used to predict temperature profiles in these areas of the system where the cesium-loaded media is expected to lead to localized regions of elevated temperature due to radiolytic decay. Normal operating conditions and accident scenarios (including loss of solution flow, inadvertent drainage, and loss of active cooling) were evaluated for the ion exchange column using bounding conditions to establish the design safety basis. The modeling results demonstrate that the baseline design using one central and four outer cooling tubes provides a highly efficient cooling mechanism for reducing the maximum column temperature. In-tank modeling results revealed that an idealized hemispherical mound shape leads to the highest tank floor temperatures. In contrast, even large volumes of CST distributed in a flat layer with a cylindrical shape do not result in significant floor heating.

  18. Comparative analysis of thermal behavior in hollow nuclear fuel pellets

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Beatriz M. dos; Alvim, Antonio C.M., E-mail: bmachado@nuclear.ufrj.br, E-mail: aalvim@gmail.com [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2017-11-01

    The increase in energy demand in Brazil and in the world is a real problem and several solutions are being considered to mitigate it. Maximization of energy generation, within the safety standards of fuel resources already known, is one of them. In this respect, nuclear energy is a crucial technology to sustain energy demand on several countries. Performances of a solid cylindrical and an annular rod have been verified and compared; where it has been proven that the annular rod can reach a higher nominal power in relation to the solid one. In this paper, the temperature profiles of two distinct nuclear fuel pellets, one of them annular and the other in the shape of a hollow biconcave disc (like the cross section of a red blood cell), were compared to analyze the efficiency and safety of both. The finite differences method allowed the evaluation of the thermal behavior of these pellets, where one specific physical condition was analyzed, regarding convection and conduction at the lateral edges. The results show that the temperature profile of the hollow biconcave disc pellet is lower, about 70 deg C below, when compared to the temperature profile of the annular pellet, considering the same simulation parameters for both pellets. (author)

  19. Analysis Methods of HTLS Conductors in Terms of Mechanical and Thermal Criteria

    Directory of Open Access Journals (Sweden)

    Paweł Kubek

    2013-03-01

    Full Text Available A thermal modernization allows increasing the thermal rating of the existing lines. This especially concerns the older overhead lines designed for the +40°C temperature conductor limit. This paper presents reconductoring as the attractive method of existing line thermal modernization. The article provides an overview of issues related to the selection of the HTLS conductor for thermal uprating of existing overhead transmission lines. Some aspects related to the extension of the thermal, electrical and mechanical models used so far for analysis of HTLS conductors are presented in the paper.

  20. Using thermal infrared imagery produced by unmanned air vehicles to evaluate locations of ecological road structures

    Directory of Open Access Journals (Sweden)

    Sercan Gülci

    2016-07-01

    Full Text Available The aerial photos and satellite images are widely used and cost efficient data for monitoring and analysis of large areas in forestry activities. Nowadays, accurate and high resolution remote sensing data can be generated for large areas by using Unmanned Aerial Vehicles (UAV integrated with sensors working in various spectral bands. Besides, the UAV systems (UAVs have been used in interdisciplinary studies to produce data of large scale forested areas for desired time periods (i.e. in different seasons or different times of a day. In recent years, it has become more important to conduct studies on determination of wildlife corridors for controlling and planning of habitat fragmentation of wild animals that need vast living areas. The wildlife corridors are a very important base for the determination of a road network planning and placement of ecological road structures (passages, as well as for the assessment of special and sensitive areas such as riparian zones within the forest. It is possible to evaluate wildlife corridors for large areas within a shorter time by using data produced by ground measurements, and remote sensing and viewer systems (i.e. photo-trap, radar and etc., as well as by using remote sensing data generated by UAVs. Ecological behaviors and activities (i.e. sheltering, feeding, mating, etc. of wild animals vary spatially and temporally. Some species are active in their habitats at day time, while some species are active during the night time. One of the most effective methods for evaluation of night time animals is utilizing heat sensitive thermal cameras that can be used to collect thermal infrared images with the night vision feature. When the weather conditions are suitable for a flight, UAVs assist for determining location of corridors effectively and accurately for moving wild animals at any time of the day. Then, the most suitable locations for ecological road structures can be determined based on wildlife corridor

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

    Indian Academy of Sciences (India)

    Administrator

    fraction, particle size and shape of nanoparticles also influence the thermal conductivity enhancement of nano- fluids. Zhang et al (2007) investigated the heat transfer per- formance of TiO2/water nanofluid for various volume fractions and temperatures. They observed that the effec- tive thermal conductivities of nanofluids ...

  2. Analysis of thermal comfort in Lagos, Nigeria | Komolafe | Global ...

    African Journals Online (AJOL)

    This paper reports a thermal comfort survey conducted in three locations in Lagos between July 1996 and June 1997 in which 50 fully acclimatized subjects cast over 6,000 individual votes of their subjective assessments of the thermal environments. The survey covered only residential buildings constructed of sandcrete ...

  3. Thermal analysis and two-directional air flow thermal management for lithium-ion battery pack

    Science.gov (United States)

    Yu, Kuahai; Yang, Xi; Cheng, Yongzhou; Li, Changhao

    2014-12-01

    Thermal management is a routine but crucial strategy to ensure thermal stability and long-term durability of the lithium-ion batteries. An air-flow-integrated thermal management system is designed in the present study to dissipate heat generation and uniformize the distribution of temperature in the lithium-ion batteries. The system contains of two types of air ducts with independent intake channels and fans. One is to cool the batteries through the regular channel, and the other minimizes the heat accumulations in the middle pack of batteries through jet cooling. A three-dimensional anisotropic heat transfer model is developed to describe the thermal behavior of the lithium-ion batteries with the integration of heat generation theory, and validated through both simulations and experiments. Moreover, the simulations and experiments show that the maximum temperature can be decreased to 33.1 °C through the new thermal management system in comparison with 42.3 °C through the traditional ones, and temperature uniformity of the lithium-ion battery packs is enhanced, significantly.

  4. Thermal and structural analysis of a filter vessel ceramic tubesheet

    Energy Technology Data Exchange (ETDEWEB)

    Mallett, R.H. [Mallett Technology, Inc., Research Triangle Park, NC (United States); Swindeman, R.W. [Oak Ridge National Lab., TN (United States); Zievers, J.F. [Industrial Filter & Pump Mfg. Co., Cicero, IL (United States)

    1995-08-01

    A ceramic tubesheet assembly for a hot gas filter vessel is analyzed using the finite element method to determine stresses under differential pressure loading. The stresses include local concentration effects. Selection of the stress measures for evaluation of structural integrity is discussed. Specification of stress limits based upon limited data is considered. Stress results from this ongoing design analysis technology project are shown for one design concept.

  5. Evaluation of thermal cameras in quality systems according to ISO 9000 or EN 45000 standards

    Science.gov (United States)

    Chrzanowski, Krzysztof

    2001-03-01

    According to the international standards ISO 9001-9004 and EN 45001-45003 the industrial plants and the accreditation laboratories that implemented the quality systems according to these standards are required to evaluate an uncertainty of measurements. Manufacturers of thermal cameras do not offer any data that could enable estimation of measurement uncertainty of these imagers. Difficulties in determining the measurement uncertainty is an important limitation of thermal cameras for applications in the industrial plants and the cooperating accreditation laboratories that have implemented these quality systems. A set of parameters for characterization of commercial thermal cameras, a measuring set, some results of testing of these cameras, a mathematical model of uncertainty, and a software that enables quick calculation of uncertainty of temperature measurements with thermal cameras are presented in this paper.

  6. Evaluation and optimization of non enzymatic browning of “cajuina” during thermal treatment

    Directory of Open Access Journals (Sweden)

    L. F. Damasceno

    2008-06-01

    Full Text Available "Cajuina" is a very popular drink in the Brazilian northeastern region and is produced by clarifying cashew apple juice. To preserve "cajuina" from chancing, the clarified cashew apple juice is submitted to thermal treatment where a desired final color should be obtained. To optimize color formation while maintaining high vitamin C and low 5-hydroxymethylfurfural (5-HMF concentrations the thermal treatment of "cajuina" needs to be studied and the non enzymatic mechanism should be better understood and controlled. In this work the effect of thermal treatment on "cajuina" (clarified cashew apple juice was studied at temperatures from 88°C to 121°C. Changes in color were measured and the variation in vitamin C, 5-hydroxymethylfurfural (5-HMF and sugar content were used to evaluate non enzymatic browning. The kinetic models were used to optimize the thermal treatment to produce "cajuina" with an absorbance at 420 nm of 0.023.

  7. Analysis on energy consumption index system of thermal power plant

    Science.gov (United States)

    Qian, J. B.; Zhang, N.; Li, H. F.

    2017-05-01

    Currently, the increasingly tense situation in the context of resources, energy conservation is a realistic choice to ease the energy constraint contradictions, reduce energy consumption thermal power plants has become an inevitable development direction. And combined with computer network technology to build thermal power “small index” to monitor and optimize the management system, the power plant is the application of information technology and to meet the power requirements of the product market competition. This paper, first described the research status of thermal power saving theory, then attempted to establish the small index system and build “small index” monitoring and optimization management system in thermal power plant. Finally elaborated key issues in the field of small thermal power plant technical and economic indicators to be further studied and resolved.

  8. Monte Carlo analysis: error of extrapolated thermal conductivity from molecular dynamics simulations

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiang-Yang [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Andersson, Anders David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-11-07

    In this short report, we give an analysis of the extrapolated thermal conductivity of UO2 from earlier molecular dynamics (MD) simulations [1]. Because almost all material properties are functions of temperature, e.g. fission gas release, the fuel thermal conductivity is the most important parameter from a model sensitivity perspective [2]. Thus, it is useful to perform such analysis.

  9. Analysis of Thermal Stability of Different Counter on 28nm FPGA

    DEFF Research Database (Denmark)

    Gupta, Daizy; Yadav, Amit; Hussain, Dil muhammed Akbar

    2016-01-01

    In this paper we are presenting the power analysis for thermal awareness of different counters. The technique we are using to do the analysis is based on 28 nm FPGA tech-nique. In this work during implementation on FPGA, we are going to analyze thermal stability of different counters in temperature...

  10. Analysis of in-cavity thermal and pressure characteristics in aluminum alloy die casting

    Energy Technology Data Exchange (ETDEWEB)

    Venkatasamy, Vasanth Kumar [The Ohio State Univ., Columbus, OH (United States)

    1996-01-01

    The lack of effective control of the die casting process is the primary reason for the occurrence of defective die cast products. A reliable process control system must be capable of measuring the process variables, comparing them to the standard or ideal values and making suitable alterations in the process to eliminate any deviation from the ideal. This study attempted to facilitate the development of such a process control system. A two pronged approach was used to achieve this objective. The experimental approach addressed some of the problems in the measurement of process variables. The analytical approach addressed some of the problems in the design of the process and subsequent identification of the ideal process variable values. The experimental approach concentrated on the measurement of in-cavity pressure and thermal characteristics of the die casting process. Kistler direct pressure sensors were evaluated and utilized for cavity pressure measurement during the die casting campaign. Thermal probes using staggered thermocouples were developed and utilized for the simultaneous measurement of die surface temperatures and heat flow rate through the die. The measured thermal and pressure characteristics were related to the injection characteristics measured using the shot control equipment of the Buhler H-250SC die casting machine used in the campaign. The analytical approach concentrated on the verification of the predictions of a computer numerical solidification analysis by comparison with the experimental data obtained as an output of the die casting campaign. Particular attention was paid to the predictions of thermal characteristics like freezing time and die surface temperature. A sensitivity analysis was also performed to determine the effect of changes in individual variables on the predictions of BINORM.

  11. Switching system for image enhancement and analysis of fused thermal and RGBD data

    Science.gov (United States)

    Agaian, Sos S.; Sridharan, Vijay; Blanton, Michael, Jr.

    2012-06-01

    insulation, leakages of heat, water and refrigerant, and computing the true value of observed thermal losses/gains as they are related not only to thermal properties, but geometries as well. The data generated from this analysis can be used in many other domains and process evaluation fields such as medical, geological, architectural and others.

  12. Evaluation of robust functions for data reconciliation in thermal systems

    Directory of Open Access Journals (Sweden)

    Regina Luana Santos de França

    2016-04-01

    Full Text Available Process variables regularly control and evaluate industrial processes. Information with gross errors may in some cases not be attenuated by function reconciliation and change the calculation of process balance, leading optimization results towards non-feasible regions or to optimal sites. A promising alternative for reconciling functions is the use of robust functions. Current paper considers the above scenario and evaluates the fitness of some robust functions in solving in steady state chemical processes data reconciliation problems represented by linear and nonlinear systems in the presence of gross errors. Traditional Cauchy, Fair, Contaminated Normal and Logistic robust functions are used in the reconciliation problem where their estimates are compared to those obtained with the use of the latest features, such as New Target and Alarm. Rates for gross errors in tests were limited between 4 and 10σ of the measured current and elaborated a region of outliers. Results showed that New Target and Alarm functions are different from the others as the magnitude of the gross error increases, tending towards true rates specified by set point.

  13. Energy Consumption of Insulated Material Using Thermal Effect Analysis

    Directory of Open Access Journals (Sweden)

    Fadzil M. A.

    2017-01-01

    Full Text Available Wall is one of the structures elements that resist direct heat from the atmosphere. Modification on several structures is relevance to reduce filtrate thermal movement on wall. Insulation material seems to be suitable to be implemented since its purpose meets the heat resistance requirement. Insulation material applied as to generate positive impact in energy saving through reduction in total building energy consumption. Fiberglass is one of the insulation materials that can be used to insulate a space from heat and sound. Fiberglass is flammable insulation material with R Value rated of R-2.9 to R-3.8 which meets the requirement in minimizing heat transfer. Finite element software, ABAQUS v6.13 employed for analyze non insulated wall and other insulated wall with different wall thicknesses. The several calculations related to overall heat movement, total energy consumption per unit area of wall, life cycle cost analysis and determination of optimal insulation thickness is calculated due to show the potential of the implementation in minimize heat transfer and generate potential energy saving in building operation. It is hoped that the study can contribute to better understanding on the potential building wall retrofitting works in increasing building serviceability and creating potential benefits for building owner.

  14. Thermal Analysis of Solid Fuels in an Inert Atmosphere

    Science.gov (United States)

    Kijo-Kleczkowska, Agnieszka; Szumera, Magdalena; Środa, Katarzyna

    2017-12-01

    The paper takes the analysis of thermal studies of different types of fuels. It allowed diversification of fuels depending on their composition and origin. Consideration of coal, biomass and waste (coal mule, sewage sludge) as fuel is nowadays an important aspect of energy in our country. It should be emphasized that Poland power engineering is based up to 95% on coal - the primary fuel. Mining industry, forced to deliver power engineering more and better fuel, must however, use a deeper cleaning of coal. This results in a continuous increase waste in the form of mule flotation. The best method of disposing these mule is combustion and co-combustion with other fuels. On the other hand, commonly increasing awareness state of the environment and the need to reduce CO2 emissions energy industry have committed to implement alternative solutions in order to gain power, through, i.a.: development technologies use of biomass, which is one of the most promising renewable energy sources in Poland. The paper presents the results of research TG-DTA fuels made in an inert atmosphere.

  15. The thermal analysis and derivative bronzes cast to plaster moulds

    Directory of Open Access Journals (Sweden)

    B. Pisarek

    2009-07-01

    Full Text Available It plaster moulds gets casted the alloys of following metals: Al, Cu, Ag, Au in precise and artistic founding. The investigation of the crys-tallization of bronzes in hot plaster moulds the method of the thermal analysis and derivative (TDA was not realized out so far. Probe TDAg and tripod enabling the execution of measurements on inductive casting machine INDUTHERM-VC 500D were designed for this technology especially. It was confirmed that one the method TDA can identify the crystallization process of the bronze in hot plaster moulds. The investigations of the superficial distribution of the concentration of elements in the microstructure of the studied grades of the bronze on X-ray microanalizer were conducted. It results that they be subject to in bronze CuSn10-C (B10 and the CuSn5Zn5Pb5-C (B555 of strong microsegregation from conducted investigations: Pb, Sn and Sb. The single separates of intermetallic phase κ was identified in the bronze B10 rich first of all in Zn, Sn, Sb and Fe, and two intermetallic phase, one rich were identified in the bronze B555 first of all in Zn, Sb, (Nor, Fe and second rich in Sn, Sb, (Nor, Fe. The most homogeneous microstructure from the bronze CuAl10Fe5Ni5-C (BA1055 is characterizes among the studied grades of the bronze in the cast state.

  16. Thermal-Hydraulics analysis of pressurized water reactor core by using single heated channel model

    Directory of Open Access Journals (Sweden)

    Reza Akbari

    2017-08-01

    Full Text Available Thermal hydraulics of nuclear reactor as a basis of reactor safety has a very important role in reactor design and control. The thermal-hydraulic analysis provides input data to the reactor-physics analysis, whereas the latter gives information about the distribution of heat sources, which is needed to perform the thermal-hydraulic analysis. In this study single heated channel model as a very fast model for predicting thermal hydraulics behavior of pressurized water reactor core has been developed. For verifying the results of this model, we used RELAP5 code as US nuclear regulatory approved thermal hydraulics code. The results of developed single heated channel model have been checked with RELAP5 results for WWER-1000. This comparison shows the capability of single heated channel model for predicting thermal hydraulics behavior of reactor core.

  17. Theoretical analysis of three methods for calculating thermal insulation of clothing from thermal manikin.

    Science.gov (United States)

    Huang, Jianhua

    2012-07-01

    There are three methods for calculating thermal insulation of clothing measured with a thermal manikin, i.e. the global method, the serial method, and the parallel method. Under the condition of homogeneous clothing insulation, these three methods yield the same insulation values. If the local heat flux is uniform over the manikin body, the global and serial methods provide the same insulation value. In most cases, the serial method gives a higher insulation value than the global method. There is a possibility that the insulation value from the serial method is lower than the value from the global method. The serial method always gives higher insulation value than the parallel method. The insulation value from the parallel method is higher or lower than the value from the global method, depending on the relationship between the heat loss distribution and the surface temperatures. Under the circumstance of uniform surface temperature distribution over the manikin body, the global and parallel methods give the same insulation value. If the constant surface temperature mode is used in the manikin test, the parallel method can be used to calculate the thermal insulation of clothing. If the constant heat flux mode is used in the manikin test, the serial method can be used to calculate the thermal insulation of clothing. The global method should be used for calculating thermal insulation of clothing for all manikin control modes, especially for thermal comfort regulation mode. The global method should be chosen by clothing manufacturers for labelling their products. The serial and parallel methods provide more information with respect to the different parts of clothing.

  18. Heating, ventilating, and air conditioning deactivation thermal analysis of PUREX Plant

    Energy Technology Data Exchange (ETDEWEB)

    Chen, W.W.; Gregonis, R.A. [Westinghouse Hanford Company, Richland, WA (United States)

    1997-08-01

    Thermal analysis was performed for the proposed Plutonium Uranium Extraction Plant exhaust system after deactivation. The purpose of the analysis was to determine if enough condensation will occur to plug or damage the filtration components. A heat transfer and fluid flow analysis was performed to evaluate the thermal characteristics of the underground duct system, the deep-bed glass fiber filter No. 2, and the high-efficiency particulate air filters in the fourth filter building. The analysis is based on extreme variations of air temperature, relative humidity, and dew point temperature using 15 years of Hanford Site weather data as a basis. The results will be used to evaluate the need for the electric heaters proposed for the canyon exhaust to prevent condensation. Results of the analysis indicate that a condition may exist in the underground ductwork where the duct temperature can lead or lag changes in the ambient air temperature. This condition may contribute to condensation on the inside surfaces of the underground exhaust duct. A worst case conservative analysis was performed assuming that all of the water is removed from the moist air over the inside surface of the concrete duct area in the fully developed turbulent boundary layer while the moist air in the free stream will not condense. The total moisture accumulated in 24 hours is negligible. Water puddling would not be expected. The results of the analyses agree with plant operating experiences. The filters were designed to resist high humidity and direct wetting, filter plugging caused by slight condensation in the upstream duct is not a concern. 19 refs., 2 figs.

  19. Stress analysis in curved composites due to thermal loading

    Science.gov (United States)

    Polk, Jared Cornelius

    Many structures in aircraft, cars, trucks, ships, machines, tools, bridges, and buildings, consist of curved sections. These sections vary from straight line segments that have curvature at either one or both ends, segments with compound curvatures, segments with two mutually perpendicular curvatures or Gaussian curvatures, and segments with a simple curvature. With the advancements made in multi-purpose composites over the past 60 years, composites slowly but steadily have been appearing in these various vehicles, compound structures, and buildings. These composite sections provide added benefits over isotropic, polymeric, and ceramic materials by generally having a higher specific strength, higher specific stiffnesses, longer fatigue life, lower density, possibilities in reduction of life cycle and/or acquisition cost, and greater adaptability to intended function of structure via material composition and geometry. To be able to design and manufacture a safe composite laminate or structure, it is imperative that the stress distributions, their causes, and effects are thoroughly understood in order to successfully accomplish mission objectives and manufacture a safe and reliable composite. The objective of the thesis work is to expand upon the knowledge of simply curved composite structures by exploring and ascertaining all pertinent parameters, phenomenon, and trends in stress variations in curved laminates due to thermal loading. The simply curved composites consist of composites with one radius of curvature throughout the span of the specimen about only one axis. Analytical beam theory, classical lamination theory, and finite element analysis were used to ascertain stress variations in a flat, isotropic beam. An analytical method was developed to ascertain the stress variations in an isotropic, simply curved beam under thermal loading that is under both free-free and fixed-fixed constraint conditions. This is the first such solution to Author's best knowledge

  20. Evaluation of thermal antinociceptive effects after intramuscular administration of buprenorphine hydrochloride to American kestrels (Falco sparverius).

    Science.gov (United States)

    Ceulemans, Susanne M; Guzman, David Sanchez-Migallon; Olsen, Glenn H; Beaufrère, Hugues; Paul-Murphy, Joanne R

    2014-08-01

    To evaluate the thermal antinociceptive effects and duration of action of buprenorphine hydrochloride after IM administration to American kestrels (Falco sparverius). 12 healthy 3-year-old American kestrels. Buprenorphine hydrochloride (0.1, 0.3, and 0.6 mg/kg) and a control treatment (saline [0.9% NaCl] solution) were administered IM in a randomized crossover experimental design. Foot withdrawal response to a thermal stimulus was determined 1 hour before (baseline) and 1.5, 3, and 6 hours after treatment administration. Agitation-sedation scores were determined 3 to 5 minutes before each thermal stimulus. Adverse effects were monitored for 6 hours after treatment administration. Buprenorphine hydrochloride at 0.1, 0.3, and 0.6 mg/kg, IM, increased thermal threshold for 6 hours, compared with the response for the control treatment. There were no significant differences among buprenorphine treatments. A mild sedative effect was detected at a dose of 0.6 mg of buprenorphine/kg. At the doses tested, buprenorphine hydrochloride resulted in thermal antinociception in American kestrels for at least 6 hours, which suggested that buprenorphine has analgesic effects in this species. Further studies with longer evaluation periods and additional forms of noxious stimuli, formulations, dosages, and routes of administration are needed to fully evaluate the analgesic effects of buprenorphine in American kestrels.

  1. Analysis of non-thermal velocities in the solar corona

    Directory of Open Access Journals (Sweden)

    L. Contesse

    2004-09-01

    Full Text Available We describe new ground-based spectroscopic observations made using a 40-cm aperture coronagraph over a whole range of radial distances (up to heights of 12' above the limb and along four different heliocentric directions N, E, S and W. The analysis is limited to the study of the brightest forbidden emission line of Fe XIV at 530.3nm, in order to reach the best possible signal-to-noise ratio. To make the results statistically more significant, the extracted parameters are averaged over the whole length of the slit, and measurements are repeated fives times at each position; the corresponding dispersions in the results obtained along the slit are given. Central line profile intensities and full line widths (FWHM are plotted and compared to measurements published by other authors closer to the limb. We found widths and turbulent (non-thermal velocities of significantly higher values above the polar regions, especially when a coronal hole is present along the line of sight. We do not see a definitely decreasing behaviour of widths and turbulent velocities in equatorial directions for larger radial distances, as reported in the literature, although lower values are measured compared to the values in polar regions. The variation in the high corona is rather flat and a correlation diagram indicates that it is different for different regions and different radial distances. This seems to be the first analysis of the profiles of this coronal line, up to large heights above the limb for both equatorial and polar regions.

  2. Thermal Fatigue Evaluation of Pb-Free Solder Joints: Results, Lessons Learned, and Future Trends

    Science.gov (United States)

    Coyle, Richard J.; Sweatman, Keith; Arfaei, Babak

    2015-09-01

    Thermal fatigue is a major source of failure of solder joints in surface mount electronic components and it is critically important in high reliability applications such as telecommunication, military, and aeronautics. The electronic packaging industry has seen an increase in the number of Pb-free solder alloy choices beyond the common near-eutectic Sn-Ag-Cu alloys first established as replacements for eutectic SnPb. This paper discusses the results from Pb-free solder joint reliability programs sponsored by two industry consortia. The characteristic life in accelerated thermal cycling is reported for 12 different Pb-free solder alloys and a SnPb control in 9 different accelerated thermal cycling test profiles in terms of the effects of component type, accelerated thermal cycling profile and dwell time. Microstructural analysis on assembled and failed samples was performed to investigate the effect of initial microstructure and its evolution during accelerated thermal cycling test. A significant finding from the study is that the beneficial effect of Ag on accelerated thermal cycling reliability (measured by characteristic lifetime) diminishes as the severity of the accelerated thermal cycling, defined by greater ΔT, higher peak temperature, and longer dwell time increases. The results also indicate that all the Pb-free solders are more reliable in accelerated thermal cycling than the SnPb alloy they have replaced. Suggestions are made for future work, particularly with respect to the continued evolution of alloy development for emerging application requirements and the value of using advanced analytical methods to provide a better understanding of the effect of microstructure and its evolution on accelerated thermal cycling performance.

  3. Thermoeconomic Coherence: A Methodology for the Analysis and Optimisation of Thermal Systems

    Directory of Open Access Journals (Sweden)

    Antonio Rovira

    2016-07-01

    Full Text Available In the field of thermal systems, different approaches and methodologies have been proposed to merge thermodynamics and economics. They are usually referred as thermoeconomic methodologies and their objective is to find the optimum design of the thermal system given a specific objective function. Some thermoeconomic analyses go beyond that objective and attempt to find whether every component of the system is correctly designed or to quantify the inefficiencies of the components in economic terms. This paper takes another step in that direction and presents a new methodology to measure the thermoeconomic coherence of thermal systems, as well as the contribution of each parameter of the system to that coherence. It is based on the equality of marginal costs in the optimum. The methodology establishes a criterion to design coherently the system. Additionally, it may be used to evaluate how much a specific design is far from the optimum, which components are undersized or oversized and to measure the strength of the restrictions of the system. Finally, it may be extended to the analysis of uncertainties of the design process, providing a coherent design and sizing of the components with high uncertainties.

  4. Thermal Hydraulic Analysis of 3 MW TRIGA Research Reactor of Bangladesh Considering Different Cycles of Burnup

    Directory of Open Access Journals (Sweden)

    M.H. Altaf

    2014-12-01

    Full Text Available Burnup dependent steady state thermal hydraulic analysis of TRIGA Mark-II research reactor has been carried out utilizing coupled point kinetics, neutronics and thermal hydraulics code EUREKA-2/RR. From the previous calculations of neutronics parameters including percentage burnup of individual fuel elements performed so far for 700 MWD burnt core of TRIGA reactor showed that the fuel rod predicted as hottest at the beginning of cycle (fresh core was found to remain as the hottest until 200 MWD of burn, but, with the progress of core burn, the hottest rod was found to be shifted and another rod in the core became the hottest. The present study intends to evaluate the thermal hydraulic parameters of these hottest fuel rods at different cycles of burnup, from beginning to 700 MWD core burnt considering reactor operates under steady state condition. Peak fuel centerline temperature, maximum cladding and coolant temperatures of the hottest channels were calculated. It revealed that maximum temperature reported for fuel clad and fuel centerline found to lie below their melting points which indicate that there is no chance of burnout on the fuel cladding surface and no blister in the fuel meat throughout the considered cycles of core burnt.

  5. Thermal Hydraulics Design and Analysis Methodology for a Solid-Core Nuclear Thermal Rocket Engine Thrust Chamber

    Science.gov (United States)

    Wang, Ten-See; Canabal, Francisco; Chen, Yen-Sen; Cheng, Gary; Ito, Yasushi

    2013-01-01

    Nuclear thermal propulsion is a leading candidate for in-space propulsion for human Mars missions. This chapter describes a thermal hydraulics design and analysis methodology developed at the NASA Marshall Space Flight Center, in support of the nuclear thermal propulsion development effort. The objective of this campaign is to bridge the design methods in the Rover/NERVA era, with a modern computational fluid dynamics and heat transfer methodology, to predict thermal, fluid, and hydrogen environments of a hypothetical solid-core, nuclear thermal engine the Small Engine, designed in the 1960s. The computational methodology is based on an unstructured-grid, pressure-based, all speeds, chemically reacting, computational fluid dynamics and heat transfer platform, while formulations of flow and heat transfer through porous and solid media were implemented to describe those of hydrogen flow channels inside the solid24 core. Design analyses of a single flow element and the entire solid-core thrust chamber of the Small Engine were performed and the results are presented herein

  6. Model-based analysis of thermal insulation coatings

    DEFF Research Database (Denmark)

    Kiil, Søren

    2014-01-01

    conducted exploring the effects of the following parameters: pigment (hollow spheres) volume concentration (PVC), average sphere size or sphere size distribution, thermal conductivities of binder and sphere wall material, and sphere wall thickness. All the parameters affected the thermal conductivity...... of an epoxy coating, but simulations revealed that the most important parameters are the PVC, the sphere wall thickness, and the sphere wall material. The model can be used, qualitatively, to get an indication of the effect of important model parameters on the thermal conductivity of an HS-based coating...

  7. Ablative Thermal Response Analysis Using the Finite Element Method

    Science.gov (United States)

    Dec John A.; Braun, Robert D.

    2009-01-01

    A review of the classic techniques used to solve ablative thermal response problems is presented. The advantages and disadvantages of both the finite element and finite difference methods are described. As a first step in developing a three dimensional finite element based ablative thermal response capability, a one dimensional computer tool has been developed. The finite element method is used to discretize the governing differential equations and Galerkin's method of weighted residuals is used to derive the element equations. A code to code comparison between the current 1-D tool and the 1-D Fully Implicit Ablation and Thermal Response Program (FIAT) has been performed.

  8. Hemp Thermal Insulation Concrete with Alternative Binders, Analysis of their Thermal and Mechanical Properties

    Science.gov (United States)

    Sinka, M.; Sahmenko, G.; Korjakins, A.; Radina, L.; Bajare, D.

    2015-11-01

    One of the main challenges that construction industry faces today is how to address the demands for more sustainable, environmentally friendly and carbon neutral construction materials and building upkeep processes. One of the answers to these demands is lime-hemp concrete (LHC) building materials - carbon negative materials that have sufficient thermal insulation capabilities to be used as thermal insulation materials for new as well as for existing buildings. But one problem needs to be overcome before these materials can be used on a large scale - current manufacturing technology allows these materials to be used only as self-bearing thermal insulation material with large labour intensity in the manufacturing process. In order to lower the labour intensity and allow the material to be used in wider applications, a LHC block and board production is necessary, which in turn calls for the binders different from the classically used ones, as they show insufficient mechanical strength for this new use. The particular study focuses on alternative binders produced using gypsum-cement compositions ensuring they are usable in outdoor applications together with hemp shives. Physical, mechanical, thermal and water absorption properties of hemp concrete with various binders are addressed in the current study.

  9. Dynamic response analysis of an aircraft structure under thermal-acoustic loads

    Science.gov (United States)

    Cheng, H.; Li, H. B.; Zhang, W.; Wu, Z. Q.; Liu, B. R.

    2016-09-01

    Future hypersonic aircraft will be exposed to extreme combined environments includes large magnitude thermal and acoustic loads. It presents a significant challenge for the integrity of these vehicles. Thermal-acoustic test is used to test structures for dynamic response and sonic fatigue due to combined loads. In this research, the numerical simulation process for the thermal acoustic test is presented, and the effects of thermal loads on vibro-acoustic response are investigated. To simulate the radiation heating system, Monte Carlo theory and thermal network theory was used to calculate the temperature distribution. Considering the thermal stress, the high temperature modal parameters are obtained with structural finite element methods. Based on acoustic finite element, modal-based vibro-acoustic analysis is carried out to compute structural responses. These researches are very vital to optimum thermal-acoustic test and structure designs for future hypersonic vehicles structure

  10. Analysis of regenerative thermal storage geometries for solar gas turbines

    CSIR Research Space (South Africa)

    Klein, P

    2014-08-01

    Full Text Available Ceramic heat regenerators are suited to providing thermal storage for concentrating solar power stations based on a recuperated gas turbine cycle. Randomly packed beds of spheres and saddles; honeycombs and checker bricks were identified...

  11. Variation in heat sink shape for thermal analysis

    Science.gov (United States)

    Wong, C. M.; Aziz, M. H. B. A.; Ong, N. R.; Alcain, J. B.; Sauli, Z.

    2017-09-01

    The concern about the thermal performance of microelectronics is on the increase due to recent over-heating induced failures which have led to product recalls. Removal of excess heat from microelectronic systems with the use of heat sinks could improve thermal efficiency of the system. The shape of the heat sink model with difference fin configuration has significant influence on cooling performances. This paper investigates the effect of change in heat sink geometry on an electronic package through COMSOL Multiphysics software as well as the thermal performance of difference heat sink geometry corresponding to various air inlet velocities. Based on this study, plate fin heat sink has better thermal performance than strip pin fin and circular pin fin heat sink due to less obstruction of the heat sink design.

  12. Analysis and Experimental on Aircraft Insulation Thermal Bridge Effect

    Directory of Open Access Journals (Sweden)

    XIA Tian

    2017-06-01

    Full Text Available Two kinds of typical aircraft insulation structures were designed for the heat bridge in the metal ribs of aircraft insulation structures. In order to study the influence of heat bridge effect on thermal insulation performance, each configuration was analyzed by the transient heat transfer FEA, check point temperature was obtained in the hot surface temperature of 100 ℃, 200 ℃, 300 ℃, 424 ℃ respectively, and the validity of FEA was proved by insulation performance experiment. The result showed that the thermal bridge has a great influence to the insulation performance of insulation structure, and the thermal bridge influence should be considered adequately when the insulation structure designed. Additionally, the blocking method for thermal bridge is also put forward.

  13. Quantitative analysis of silica aerogel-based thermal insulation coatings

    DEFF Research Database (Denmark)

    Kiil, Søren

    2015-01-01

    A mathematical heat transfer model for a silica aerogel-based thermal insulation coating was developed. The model can estimate the thermal conductivity of a two-component (binder-aerogel) coating with potential binder intrusion into the nano-porous aerogel structure. The latter is modelled using......, to get an indication of the effect of important model parameters on the thermal conductivity of an insulation coating. With relevant data available for service life exposure conditions and raw material costs, the model can also be used as an optimization algorithm....... and experimental data with shell thickness and/or thermal conductivity of the shell as adjustable parameters. However, the experimental data was not sufficiently detailed to allow a separation of the effects of the two parameters. In the ideal case of no aerogel binder intrusion, a comparison with a coating...

  14. Recent advances on thermal analysis of stretchable electronics

    Directory of Open Access Journals (Sweden)

    Yuhang Li

    2016-01-01

    Full Text Available Stretchable electronics, which offers the performance of conventional wafer-based devices and mechanical properties of a rubber band, enables many novel applications that are not possible through conventional electronics due to its brittle nature. One effective strategy to realize stretchable electronics is to design the inorganic semiconductor material in a stretchable format on a compliant elastomeric substrate. Engineering thermal management is essential for the development of stretchable electronics to avoid adverse thermal effects on its performance as well as in applications involving human body and biological tissues where even 1–2 °C temperature increase is not allowed. This article reviews the recent advances in thermal management of stretchable inorganic electronics with focuses on the thermal models and their comparisons to experiments and finite element simulations.

  15. EVALUATION OF FLAT-PLATE PHOTOVOLTAIC THERMAL HYBRID SYSTEMS FOR SOLAR ENERGY UTILIZATION.

    Energy Technology Data Exchange (ETDEWEB)

    ANDREWS,J.W.

    1981-06-01

    The technical and economic attractiveness of combined photovoltaic/thermal (PV/T) solar energy collectors was evaluated. The study was limited to flat-plate collectors since concentrating photovoltaic collectors require active cooling and thus are inherently PV/T collectors, the only decision being whether to use the thermal energy or to dump it. it was also specified at the outset that reduction in required roof area was not to be used as an argument for combining the collection of thermal and electrical energy into one module. Three tests of economic viability were identified, all of which PV/T must pass if it is to be considered a promising alternative: PV/T must prove to be competitive with photovoltaic-only, thermal-only, and side-by-side photovoltaic-plus-thermal collectors and systems. These three tests were applied to systems using low-temperature (unglazed) collectors and to systems using medium-temperature (glazed) collectors in Los Angeles, New York, and Tampa. For photovoltaics, the 1986 DOE cost goals were assumed to have been realized, and for thermal energy collection two technologies were considered: a current technology based on metal and glass, and a future technology based on thin-film plastics. The study showed that for medium-temperature applications PV/T is not an attractive option in any of the locations studied. For low-temperature applications, PV/T appears to be marginally attractive.

  16. PCB-level Electro thermal Coupling Simulation Analysis

    Science.gov (United States)

    Zhou, Runjing; Shao, Xuchen

    2017-10-01

    Power transmission network needs to transmit more current with the increase of the power density. The problem of temperature rise and the reliability is becoming more and more serious. In order to accurately design the power supply system, we must consider the influence of the power supply system including Joule heat, air convection and other factors. Therefore, this paper analyzes the relationship between the electric circuit and the thermal circuit on the basis of the theory of electric circuit and thermal circuit.

  17. Evaluations of thermocline and half cycle figure of merit of a thermal energy storage tank

    Directory of Open Access Journals (Sweden)

    Abd Majid Mohd Amin

    2017-01-01

    Full Text Available Two main criteria that are commonly used to evaluate thermal energy storage systems are thermocline thickness and half cycle figure of merit. For the thermocline thickness, the preference is to achieve as thin as possible the thermocline thickness. While the preference for half cycle figure of merit is to achieve the value of greater than 90 per cent. These two criteria were used to evaluate a thermal storage system at University Teknologi PETRONAS district cooling plant. The capacity of the thermal energy storage tank of the plant is 10,000 RTh. Operating data was used for the evaluation. The values of evaluated thermocline thickness ranges from 2.248 meters to 5.445 meters with an average of 3.251 meters. These values are very much higher in comparison to findings of other studies. One possible reason is due to higher flow rates. For the half cycle figure of merit the evaluated values ranges from 0.9469 to 0.9847, with the average of 0.9698, which are within the acceptable range. For future work a model should be developed which could automatically evaluate both the thermocline thickness and half cycle figure of merit. This would enable both of these parameters to be continuously evaluated.

  18. Analysis of human factors on urban heat island and simulation of urban thermal environment in Lanzhou city, China

    Science.gov (United States)

    Pan, Jinghu

    2015-01-01

    Urban heat island (UHI) effect is a global phenomenon caused by urbanization. Because of the number and complexity of factors contributing to the urban thermal environment, traditional statistical methods are insufficient for acquiring data and analyzing the impact of human activities on the thermal environment, especially for identifying which factors are dominant. The UHI elements were extracted using thermal infrared remote sensing data to retrieve the land surface temperatures of Lanzhou city, and then adopting an object-oriented fractal net evolution approach to create an image segmentation of the land surface temperature (LST). The effects of urban expansion on the urban thermal environment were quantitatively analyzed. A comprehensive evaluation system of the urban thermal environment was constructed, the spatial pattern of the urban thermal environment in Lanzhou was assessed, and principal influencing factors were identified using spatial principal component analysis (SPCA) and multisource spatial data. We found that in the last 20 years, the UHI effect in Lanzhou city has been strengthened, as the UHI ratio index has increased from 0.385 in 1993 to 0.579 in 2001 and to 0.653 in 2011. The UHI expansion had a spatiotemporal consistency with the urban expansion. The four major factors that affect the spatial pattern of the urban thermal environment in Lanzhou can be ranked in the following order: landscape configuration, anthropogenic heat release, urban construction, and gradient from man-made to natural land cover. These four together accounted for 91.27% of the variance. A linear model was thus successfully constructed, implying that SPCA is helpful in identifying major contributors to UHI. Regression analysis indicated that the instantaneous LST and the simulated thermal environment have a good linear relationship, the correlation coefficient between the two reached 0.8011, highly significant at a confidence level of 0.001.

  19. Analysis of thermal water utilization in the northeastern Slovenia

    Directory of Open Access Journals (Sweden)

    Nina Rman

    2012-12-01

    Full Text Available The presented research aims at identification of thermal water users in NE Slovenia, at finding type and amountof the produced thermal water as well as its utilization practice. The energetic overview has been upgradedby a description of current observational monitoring practice and thermal waste water management, but technologicalproblems of thermal water use and their mitigation are discussed also. We have ascertained that 14 of 26active geothermalwells tap the Mura Formation aquifer in which the only reinjection well is perforated also. Totalthermal water abstraction summed to 3.29 million m3 in 2011. Cascade use of thermal water is abundant, whereindividual space and sanitary water heating is followed by heating of spa infrastructure and balneology. Greenhouseheating systems and district heating were also identified. Operational monitoring of these geothermal wellsis generally insufficient, and geothermal aquifers are overexploited due to decades of historical water abstraction.All these facts indicate the need for applying appropriate measures which will improve their natural conditions aswell as simultaneously enable further and even higher thermal water utilization in the future.

  20. MRI-based evaluation of MR-HIFU induced thermal effects

    NARCIS (Netherlands)

    Lam, M.K.

    2016-01-01

    High intensity focused ultrasound (HIFU) is novel technology for non-invasive thermal therapy and can be combined with magnetic resonance imaging (MRI). MRI-guided HIFU (MR-HIFU) allows for real-time acquisition of MRI scans during the HIFU treatment, for planning, monitoring and evaluation. The

  1. Sensors, Data Acquisition, and Burn Algorithms for Evaluating Clothing Against Battlefield, Flame, and Thermal Threats

    Science.gov (United States)

    2010-08-01

    from Review and Evaluation of Thermal Sensors for Use in Testing Firefighters Protective Clothing, NIST GCR 99-773, a report from NCSU to the National...Garments Using the PyroMan System, 2003, both published by the Center for Research on Textile Protection and Comfort, NCSU. The objective was to

  2. Evaluating piezo-electric transducer response to thermal shock from in-cylinder pressure data

    NARCIS (Netherlands)

    Rosseel, E.; Sierens, R.; Baert, R.S.G.

    1999-01-01

    One of the major effects limiting the accuracy of piezo-electric transducers for performing in-cyclinder pressure measurements is their sensitivity to the cyclic thermal loading effects of the intermittent combustion process. This paper compares 5 different methods for evaluating the effect of this

  3. EVALUATION OF THE APPLICATION OF A THERMAL INSULATION SYSTEM: IN-SITU COMPARISSON OF SEASONAL AND DAILY CLIMATIC FLUCTUATIONS

    Directory of Open Access Journals (Sweden)

    Jan Fořt

    2017-06-01

    Full Text Available The current outdated state of many institutional and administrative buildings in the EU region poses a significant burden from the energy sustainability point of view. According to the contemporary EU requirements on the energy efficiency of buildings maintenance, an evaluation of performed improvements is essential for the assessment of expended investments. This paper describes the effect of building envelope reconstruction works consisting in the installation of a thermal insulation system. Here, a long-term continuous monitoring is used for the extensive assessment of the seasonal and daily temperature and relative humidity fluctuations. The obtained results include temperature and relative humidity profiles in the wall cross-section as a response to the changing exterior climatic conditions. The analysis of measured data reveals substantial improvements in thermal stability of the analyzed wall during temperature peaks. While the indoor temperatures exceeding 28 °C are recorded during summer before application of the thermal insulation layer, the thermal stability of the indoor environment is distinctly upgraded after performed improvements. Based on the complex long-term monitoring, a relevant experience is gained for the future work on energy sustainability and fulfilment of the EU directives.

  4. Evaluation of High Temperature Composites Thermal Properties under Different Heat Flux Conditions

    Directory of Open Access Journals (Sweden)

    Ahmad Reza Bahramian

    2014-06-01

    Full Text Available The thermal protection of structures in vehicles, at instantaneous high thermal shocks, would be more effective and economically feasible among other thermal protection methods using the passive heat shields especially charring the ablative composites. The most important limitations reported are lack of compiled knowledge on designing heat shield with optimal thickness under real conditions and high surface erosion rate and low mechanical strength of char layer of a composite created by ablation process. In this paper SiAlON ceramic composites, reinforced with short carbon fiber, are identified as high performance heat shields for challenging these limitations. Ablation rate and effective thermal diffusivity at different external heat fluxes are determined and calculated using oxyacetylene flame test and modeling of temperature distributions in ablation process for evaluation of thermal protection performance and effective thermal diffusivity of this composite, as a thermal protection system. The results of this work have indicated that the carbon fiber reinforced SiAlON ceramic composite can be considered as a high ablation heat shield. Under the same condition of ablation test, SiAlON ceramic composites reinforced by carbon fiber show higher ablation performance relative to other commercial carbon fiber reinforced composite heat shields. At 8500 and 5000 kWm-2 external heat flux the ablation rates of this composite are 0.075 and 0.026 mms-1, respectively. Also, at 2500 kWm-2 external heat flux and test duration time of less than 25 s, this composite displays an adequate thermal shock protection with maximum flexural strength loss of about 23.4 %.

  5. Evaluation of the thermal behaviour of different 'local climate zones' in Belgium

    Science.gov (United States)

    Verdonck, Marie-Leen; Demuzere, Matthias; Hooyberghs, Hans; Van Coillie, Frieke

    2016-04-01

    Urban areas are one of the most important human habitats; already 50% of the world's population is living there and this percentage is expected to rise to 70% by 2050. Global warming and the increasing world population will only put more pressure on the living conditions in these habitats. From a thermal comfort point of view it is clear that there is a need for sustainable urban planning that integrates the thermal behaviour of these new developments. To develop sustainable urban planning it is key to know what the influence of a new development will be on the thermal behaviour of the city. Classifying the city according to the local climate zone (LCZ) scheme can provide insights in the thermal behaviour of a city. The WUDAPT LCZ classification framework makes it possible to do so in a spatially explicit manner. This study presents an evaluation of the thermal behaviour of LCZ in three different Belgian cities (Brussels, Antwerp, Ghent) based on modelled air and surface temperature. First LCZ maps were delineated for the three cities. The maps were built based on Landsat and high resolution LiDAR images conform to the WUDAPT LCZ classification framework. Meter- resolution LiDAR images provide useful information on building height and were used to improve the LCZ maps. An accuracy assessment stage was added to confirm the validity of the maps. Secondly, the LCZ maps were used as input data for the URBCLIM model to model air and surface temperature. With the modelling results we characterized the thermal behaviour of every LCZ. In a next step the results for the different cities are compared and the generic character of the WUDAPT LCZ classification framework is evaluated. The main incentive for this study is to investigate whether LCZ maps can be used to foresee the influence of future urban growth scenario's on the thermal comfort in cities in Belgium.

  6. Fourier domain target transformation analysis in the thermal infrared

    Science.gov (United States)

    Anderson, D. L.

    1993-01-01

    Remote sensing uses of principal component analysis (PCA) of multispectral images include band selection and optimal color selection for display of information content. PCA has also been used for quantitative determination of mineral types and abundances given end member spectra. The preliminary results of the investigation of target transformation PCA (TTPCA) in the fourier domain to both identify end member spectra in an unknown spectrum, and to then calculate the relative concentrations of these selected end members are presented. Identification of endmember spectra in an unknown sample has previously been performed through bandmatching, expert systems, and binary classifiers. Both bandmatching and expert system techniques require the analyst to select bands or combinations of bands unique to each endmember. Thermal infrared mineral spectra have broad spectral features which vary subtly with composition. This makes identification of unique features difficult. Alternatively, whole spectra can be used in the classification process, in which case there is not need for an expert to identify unique spectra. Use of binary classifiers on whole spectra to identify endmember components has met with some success. These techniques can be used, along with a least squares fit approach on the endmembers identified, to derive compositional information. An alternative to the approach outlined above usese target transformation in conjunction with PCA to both identify and quantify the composition of unknown spectra. Preprocessing of the library and unknown spectra into the fourier domain, and using only a specific number of the components, allows for significant data volume reduction while maintaining a linear relationship in a Beer's Law sense. The approach taken here is to iteratively calculate concentrations, reducing the number of endmember components until only non-negative concentrations remain.

  7. Thermal analysis of optical reference cavities for low sensitivity to environmental temperature fluctuations.

    Science.gov (United States)

    Dai, Xiaojiao; Jiang, Yanyi; Hang, Chao; Bi, Zhiyi; Ma, Longsheng

    2015-02-23

    The temperature stability of optical reference cavities is significant in state-of-the-art ultra-stable narrow-linewidth laser systems. In this paper, the thermal time constant and thermal sensitivity of reference cavities are analyzed when reference cavities respond to environmental perturbations via heat transfer of thermal conduction and thermal radiation separately. The analysis as well as simulation results indicate that a reference cavity enclosed in multiple layers of thermal shields with larger mass, higher thermal capacity and lower emissivity is found to have a larger thermal time constant and thus a smaller sensitivity to environmental temperature perturbations. The design of thermal shields for reference cavities may vary according to experimentally achievable temperature stability and the coefficient of thermal expansion of reference cavities. A temperature fluctuation-induced length instability of reference cavities as low as 6 × 10(-16) on a day timescale can be achieved if a two-layer thermal shield is inserted between a cavity with the coefficient of thermal expansion of 1 × 10(-10) /K and an outer vacuum chamber with temperature fluctuation amplitude of 1 mK and period of 24 hours.

  8. Evaluation of the of thermal shock resistance of a castable containing andalusite aggregates by thermal shock cycles; Avaliacao da resistencia ao dano por choque termico por ciclagem de um concreto refratario contendo agregados de andaluzita

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, G.C.R.; Santos, E.M.B.; Ribeiro, S., E-mail: girribeiro@yahoo.com.br [Universidade de Sao Paulo (DEMAR/EEL/USP), Lorena, SP (Brazil). Escola de Engenharia de. Departamento de Engenharia de Materiais; Resende, W.S. [Industrias Brasileiras de Artigos Refratarios (IBAR), Lorena, SP (Brazil); Rodrigues, J.A. [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil)

    2011-07-01

    The thermal shock resistance of refractory materials is one of the most important characteristics that determine their performance in many applications, since abrupt and drastic differences in temperature can damage them. Resistance to thermal shock damage can be evaluated based on thermal cycles, i.e., successive heating and cooling cycles followed by an analysis of the drop in Young's modulus occurring in each cycle. The aim of this study was to evaluate the resistance to thermal shock damage in a commercial refractory concrete with andalusite aggregate. Concrete samples that were sintered at 1000 deg C and 1450 deg C for 5 hours to predict and were subjected to 30 thermal shock cycles, soaking in the furnace for 20 minutes at a temperature of 1000 deg C, and subsequent cooling in circulating water at 25 deg C. The results showed a decrease in Young's modulus and rupture around 72% for samples sintered at 1000 ° C, and 82% in sintered at 1450 ° C. The refractory sintered at 1450 deg C would show lower thermal shock resistance than the refractory sintered at 1000 deg C. (author)

  9. Coupled neutronic-thermal-hydraulics analysis in a coolant subchannel of a PWR using CFD techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Felipe P.; Su, Jian, E-mail: sujian@nuclear.ufrj.br [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2017-07-01

    The high capacity of Computational Fluid Dynamics code to predict multi-dimensional thermal-hydraulics behaviour and the increased availability of capable computer systems are making that method a good tool to simulate phenomena of thermal-hydraulics nature in nuclear reactors. However, since there are no neutron kinetics models available in commercial CFD codes to the present day, the application of CFD in the nuclear reactor safety analyses is still limited. The present work proposes the implementation of the point kinetics model (PKM) in ANSYS - Fluent to predict the neutronic behaviour in a Westinghouse Sequoyah nuclear reactor, coupling with the phenomena of heat conduction in the rod and thermal-hydraulics in the cooling fluid, via the reactivity feedback. Firstly, a mesh convergence and turbulence model study was performed, using the Reynolds-Average Navier-Stokes method, with square arrayed rod bundle featuring pitch to diameter ratio of 1:32. Secondly, simulations using the k-! SST turbulence model were performed with an axial distribution of the power generation in the fuel to analyse the heat transfer through the gap and cladding, and its in fluence on the thermal-hydraulics behaviour of the cooling fluid. The wall shear stress distribution for the centre-line rods and the dimensionless velocity were evaluated to validate the model, as well as the in fluence of the mass flow rate variation on the friction factor. The coupled model enabled to perform a dynamic analysis of the nuclear reactor during events of insertion of reactivity and shutdown of primary coolant pumps. (author)

  10. Thermal Performance Analysis of Solar Collectors Installed for Combisystem in the Apartment Building

    Science.gov (United States)

    Žandeckis, A.; Timma, L.; Blumberga, D.; Rochas, C.; Rošā, M.

    2012-01-01

    The paper focuses on the application of wood pellet and solar combisystem for space heating and hot water preparation at apartment buildings under the climate of Northern Europe. A pilot project has been implemented in the city of Sigulda (N 57° 09.410 E 024° 52.194), Latvia. The system was designed and optimised using TRNSYS - a dynamic simulation tool. The pilot project was continuously monitored. To the analysis the heat transfer fluid flow rate and the influence of the inlet temperature on the performance of solar collectors were subjected. The thermal performance of a solar collector loop was studied using a direct method. A multiple regression analysis was carried out using STATGRAPHICS Centurion 16.1.15 with the aim to identify the operational and weather parameters of the system which cause the strongest influence on the collector's performance. The parameters to be used for the system's optimisation have been evaluated.

  11. Finite element methodology for transient conduction/forced-convection thermal analysis

    Science.gov (United States)

    Thornton, E. A.; Wieting, A. R.

    1979-01-01

    Finite element methodology for steady state thermal analysis of convectively cooled structures has been extended for transient analysis. The finite elements are based on representing the fluid passages by fluid bulk-temperature nodes and fluid-solid interface nodes. The formulation of the finite element equations for a typical flow passage is based on the weighted residual method with upwind weighting functions. Computer implementation of the convective finite element methodology using explicit and implicit time integration algorithms is described. Accuracy and efficiency of the methodology is evaluated by comparisons with analytical solutions and finite-difference lumped-parameter analyses. The comparative analyses demonstrate that finite element conduction/conduction methodology may be used to predict transient temperatures with an accuracy equal or superior to the lumped-parameter finite-difference method.

  12. Heat transfer analysis of skin during thermal therapy using thermal wave equation.

    Science.gov (United States)

    Kashcooli, Meisam; Salimpour, Mohammad Reza; Shirani, Ebrahim

    2017-02-01

    Specifying exact geometry of vessel network and its effect on temperature distribution in living tissues is one of the most complicated problems of the bioheat field. In this paper, the effects of blood vessels on temperature distribution in a skin tissue subjected to various thermal therapy conditions are investigated. Present model consists of counter-current multilevel vessel network embedded in a three-dimensional triple-layered skin structure. Branching angles of vessels are calculated using the physiological principle of minimum work. Length and diameter ratios are specified using length doubling rule and Cube law, respectively. By solving continuity, momentum and energy equations for blood flow and Pennes and modified Pennes bioheat equations for the tissue, temperature distributions in the tissue are measured. Effects of considering modified Pennes bioheat equation are investigated, comprehensively. It is also observed that blood has an impressive role in temperature distribution of the tissue, especially at high temperatures. The effects of different parameters such as boundary conditions, relaxation time, thermal properties of skin, metabolism and pulse heat flux on temperature distribution are investigated. Tremendous effect of boundary condition type at the lower boundary is noted. It seems that neither insulation nor constant temperature at this boundary can completely describe the real physical phenomena. It is expected that real temperature at the lower levels is somewhat between two predicted values. The effect of temperature on the thermal properties of skin tissue is considered. It is shown that considering temperature dependent values for thermal conductivity is important in the temperature distribution estimation of skin tissue; however, the effect of temperature dependent values for specific heat capacity is negligible. It is seen that considering modified Pennes equation in processes with high heat flux during low times is significant

  13. Thermal stress analysis of the NASA Dryden hypersonic wing test structure

    Science.gov (United States)

    Morris, Glenn

    1990-01-01

    Present interest in hypersonic vehicles has resulted in a renewed interest in thermal stress analysis of airframe structures. While there are numerous texts and papers on thermal stress analysis, practical examples and experience on light gage aircraft structures are fairly limited. A research program has been undertaken at General Dynamics to demonstrate the present state of the art, verify methods of analysis, gain experience in their use, and develop engineering judgement in thermal stress analysis. The approach for this project has been to conduct a series of analyses of this sample problem and compare analysis results with test data. This comparison will give an idea of how to use our present methods of thermal stress analysis, and how accurate we can expect them to be.

  14. Applications of sample-controlled thermal analysis (SCTA) to kinetic analysis and synthesis of materials

    OpenAIRE

    Pérez-Maqueda, Luis A.; Criado Luque, J.M.; Sánchez-Jiménez, P.E.; Diánez, M. J.

    2015-01-01

    The advantages of the sample-controlled thermal analysis (SCTA) for both the kinetic analysis of solid-state reactions and the synthesis of materials are reviewed. This method implies an intelligent control of the temperature by the solid-state reaction under study in such a way that the reaction rate as a function of the time fits a profile previously defined by the user. It has been shown that SCTA has important advantages for discriminating the kinetic model of solid-state reactions as com...

  15. A scaling analysis for thermal fragmentation on small airless bodies

    Science.gov (United States)

    El Mir, Charles; Hazeli, Kavan; Ramesh, KT; Delbo, Marco

    2016-10-01

    The presence of regolith on airless bodies has typically been attributed to impact ejecta re-accumulation and gradual breakdown of boulders by micrometeoritic impacts. However, ejecta velocities for small kilometer-sized asteroids often exceed the gravitational escape velocity, limiting to a great extent the amount of retained debris following a high-velocity impact event. Close-surface images of small (sub-km) asteroid surfaces have shown the presence of a coarse-grained regolith layer on these bodies, suggesting that a different mechanism could be involved in the regolith generation process.Recently, the existence of regolith on sufficiently small planetary bodies has also been attributed to cyclic stresses that develop within boulders due to the large diurnal temperature variation, which eventually lead to fracture by thermal fatigue. It was demonstrated that thermal fatigue can be orders of magnitude faster than fragmentation by classical impact mechanisms, in terms of breaking down cm-sized rocks on small airless bodies. Larger (10 cm-size) rocks were shown to potentially break up faster than smaller (cm) rocks, an observation that is in contrast to the predictions of mechanical disruption models. This observation is justified by the existence of higher internal thermal stresses resulting from the larger temperature gradient in bigger rocks, but it is not clear that this conclusion can be extrapolated or scaled for meter-sized boulders.In the current study, we present a computational and analytical approach that examines thermally driven crack growth within asteroidal rocks over a large range of lengthscales. We first examine the main length and timescales involved in the thermally-driven fatigue crack growth, and identify a critical lengthscale comparable to the thermal skin depth, after which thermal fatigue becomes slower, providing bounds on the thermal fragmentation mechanism. We also develop a simple scaling method to estimate the time required for

  16. CRYogenic Orbital TEstbed Ground Test Article Thermal Analysis

    Science.gov (United States)

    Piryk, David; Schallhorn, Paul; Walls, Laurie; Stopnitzky, Benny; Rhys, Noah; Wollen, Mark

    2012-01-01

    The purpose of this study was to anchor thermal and fluid system models to CRYOTE ground test data. The CRYOTE ground test artide was jointly developed by Innovative Engineering Solutions, United Launch Alliance and NASA KSC. The test article was constructed out of a titanium alloy tank, Sapphire 77 composite skin (similar to G10), an external secondary payload adapter ring, thermal vent system, multi layer insulation and various data acquisition instrumentation. In efforts to understand heat loads throughout this system, the GTA (filled with liquid nitrogen for safety purposes) was subjected to a series of tests in a vacuum chamber at Marshall Space Flight Center. By anchoring analytical models against test data, higher fidelity thermal environment predictions can be made for future flight articles which would eventually demonstrate critical cryogenic fluid management technologies such as system chilldown, transfer, pressure control and long term storage. Significant factors that influenced heat loads included radiative environments, multi-layer insulation performance, tank fill levels and pressures and even contact conductance coefficients. This report demonstrates how analytical thermal/fluid networks were established and includes supporting rationale for specific thermal responses.

  17. Finite Element Analysis of PVC window profile &aluminium window profile with and without thermal break

    OpenAIRE

    ENG. Mohammad Buhemdi

    2016-01-01

    Examine a thermal analysis .Numerous analogies exist between thermal and structuralanalysis for PVC window profile &aluminium window profile with and without thermalbreak ,Finite Element Analysis, commonly called FEA, is a method of numerical analysis. FEA isused for solving problems in many engineering disciplines such as machine design,acoustics, electromagnetism, soil mechanics, fluid dynamics, and many others. Inmathematical terms, FEA is a numerical technique used for solving...

  18. Thermal analysis method of high capacity communications satellite with heat pipes

    Science.gov (United States)

    Tsunoda, Hiroaki; Nakajima, Katsuhiko; Miyasaka, Akihiro

    Thermal analysis method for heat pipe embedded communications equipment panel is treated in this paper. The main problem of the thermal analysis is how to construct the mathematical model under the limitation of computer CPU memory size. The mathematical model for the heat pipe embedded panel is first established based on the experiments. The essence of this method is to divide panel area into several small regions and perform thermal analysis independently using the fact of low thermal conductivity of honeycomb sandwich panel. To check the correctness of this method, the experiment using the test panel which thermally simulates the north communications equipment panel of two-ton class high capacity communications satellite has been conducted. The experiment shows the method works well.

  19. Evaluating Thermal Comfort in a Naturally Conditioned Office in a Temperate Climate Zone

    Directory of Open Access Journals (Sweden)

    Andrés Gallardo

    2016-07-01

    Full Text Available This study aims to determine the optimal approach for evaluating thermal comfort in an office that uses natural ventilation as the main conditioning strategy; the office is located in Quito-Ecuador. The performance of the adaptive model included in CEN Standard EN15251 and the traditional PMV model are compared with reports of thermal environment satisfaction surveys presented simultaneously to all occupants of the office to determine which of the two comfort models is most suitable to evaluate the thermal environment. The results indicate that office occupants have developed some degree of adaptation to the climatic conditions of the city where the office is located (which only demands heating operation, and tend to accept and even prefer lower operative temperatures than those considered optimum by applying the PMV model. This is an indication that occupants of naturally conditioned buildings are usually able to match their comfort temperature to their normal environment. Therefore, the application of the adaptive model included in CEN Standard EN15251 seems like the optimal approach for evaluating thermal comfort in naturally conditioned buildings, because it takes into consideration the adaptive principle that indicates that if a change occurs such as to produce discomfort, people tend to react in ways which restore their comfort.

  20. Automotive Underhood Thermal Management Analysis Using 3-D Coupled Thermal-Hydrodynamic Computer Models: Thermal Radiation Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Pannala, S; D' Azevedo, E; Zacharia, T

    2002-02-26

    The goal of the radiation modeling effort was to develop and implement a radiation algorithm that is fast and accurate for the underhood environment. As part of this CRADA, a net-radiation model was chosen to simulate radiative heat transfer in an underhood of a car. The assumptions (diffuse-gray and uniform radiative properties in each element) reduce the problem tremendously and all the view factors for radiation thermal calculations can be calculated once and for all at the beginning of the simulation. The cost for online integration of heat exchanges due to radiation is found to be less than 15% of the baseline CHAD code and thus very manageable. The off-line view factor calculation is constructed to be very modular and has been completely integrated to read CHAD grid files and the output from this code can be read into the latest version of CHAD. Further integration has to be performed to accomplish the same with STAR-CD. The main outcome of this effort is to obtain a highly scalable and portable simulation capability to model view factors for underhood environment (for e.g. a view factor calculation which took 14 hours on a single processor only took 14 minutes on 64 processors). The code has also been validated using a simple test case where analytical solutions are available. This simulation capability gives underhood designers in the automotive companies the ability to account for thermal radiation - which usually is critical in the underhood environment and also turns out to be one of the most computationally expensive components of underhood simulations. This report starts off with the original work plan as elucidated in the proposal in section B. This is followed by Technical work plan to accomplish the goals of the project in section C. In section D, background to the current work is provided with references to the previous efforts this project leverages on. The results are discussed in section 1E. This report ends with conclusions and future scope of

  1. A Strategy for Evaluating Pathway Analysis Methods

    Science.gov (United States)

    2017-10-13

    1 A strategy for evaluating pathway analysis methods Chenggang Yu, Hyung Jun Woo, Xueping Yu+, Tatsuya Oyama, Anders Wallqvist, Jaques Reifman... practically applying such pathway analysis (PA) methods, we must first evaluate their performance and reliability, using datasets where the pathways...unavailable. Furthermore, previous evaluation strategies that have focused on defining ‘true answers’ are unable to systematically and objectively assess PA

  2. Heat Transfer Analysis of Thermal Protection Structures for Hypersonic Vehicles

    Science.gov (United States)

    Zhou, Chen; Wang, Zhijin; Hou, Tianjiao

    2017-11-01

    This research aims to develop an analytical approach to study the heat transfer problem of thermal protection systems (TPS) for hypersonic vehicles. Laplace transform and integral method are used to describe the temperature distribution through the TPS subject to aerodynamic heating during flight. Time-dependent incident heat flux is also taken into account. Two different cases with heat flux and radiation boundary conditions are studied and discussed. The results are compared with those obtained by finite element analyses and show a good agreement. Although temperature profiles of such problems can be readily accessed via numerical simulations, analytical solutions give a greater insight into the physical essence of the heat transfer problem. Furthermore, with the analytical approach, rapid thermal analyses and even thermal optimization can be achieved during the preliminary TPS design.

  3. Analysis of tracer and thermal transients during reinjection

    Energy Technology Data Exchange (ETDEWEB)

    Kocabas, I.

    1989-10-01

    This work studied tracer and thermal transients during reinjection in geothermal reserviors and developed a new technique which combines the results from interwell tracer tests and thermal injection-backflow tests to estimate the thermal breakthrough times. Tracer tests are essential to determine the degree of connectivity between the injection wells and the producing wells. To analyze the tracer return profiles quantitatively, we employed three mathematical models namely, the convection-dispersion (CD) model, matrix diffusion (MD) model, and the Avodnin (AD) model, which were developed to study tracer and heat transport in a single vertical fracture. We considered three types of tracer tests namely, interwell tracer tests without recirculation, interwell tracer tests with recirculation, and injection-backflow tracer tests. To estimate the model parameters, we used a nonlinear regression program to match tracer return profiles to the solutions.

  4. STATISTICAL ANALYSIS OF A SODA LIME GLASS THERMAL SHOCK RESISTANCE

    Directory of Open Access Journals (Sweden)

    Gilbert FANTOZZI

    2011-09-01

    Full Text Available Comparatively to the as received soda lime glass samples, the strength distribution after thermal shocks showed the appearance of a second branch in the Weibull curves. This branch is observed for temperature differences (ΔT equal or higher than the critical temperature difference (ΔTc for both water and motor oil cooling baths. The dispersion is more spread out in these two baths in comparison with the olive oil bath probably because of more pronounced slow crack growth effect. The Weibull modulus varies according to the used cooling bath and the considered temperature difference. In the case of thermal shock caused by air blast cooling at T = 20°C, a bimodal distribution is observed for only the critical state. The initial cracking time, obtained by acoustic emission, corresponds to the unstable propagation of the most critical defect. The number of cracks induced by thermal shock is proportional to the number of acoustic events.

  5. Thermal analysis of a reflective baffle designed for space applications

    Science.gov (United States)

    Beck, T.; Lüthi, B. S.; Messina, G.; Piazza, D.; Seiferlin, K.; Thomas, N.

    2011-09-01

    The implementation and results from thermal mathematical modelling of a Stavroudis-type reflective baffle for the BepiColombo laser altimeter (BELA) are presented. BELA and other instruments on board the European Space Agency's Mercury Planetary Orbiter are exposed to a harsh environment in Mercury orbit. This environment is briefly discussed and the detailed design solution for the baffle is presented. Special attention has been paid to the implementation of the thermal model because specific approximations were required. The results of the thermal mathematical models show the temperature behaviour in orbit and the feasibility of the solution. The work has applications to future missions which will go inside the orbit of Venus (e.g. ESA's Solar Orbiter).

  6. Targets for bulk hydrogen analysis using thermal neutrons

    CERN Document Server

    Csikai, J; Buczko, C M

    2002-01-01

    The reflection property of substances can be characterized by the reflection cross-section of thermal neutrons, sigma subbeta. A combination of the targets with thin polyethylene foils allowed an estimation of the flux depression of thermal neutrons caused by a bulk sample containing highly absorbing elements or compounds. Some new and more accurate sigma subbeta values were determined by using the combined target arrangement. For the ratio, R of the reflection and the elastic scattering cross-sections of thermal neutrons, R=sigma subbeta/sigma sub E sub L a value of 0.60+-0.02 was found on the basis of the data obtained for a number of elements from H to Pb. Using this correlation factor, and the sigma sub E sub L values, the unknown sigma subbeta data can be deduced. The equivalent thicknesses, to polyethylene or hydrogen, of the different target materials were determined from the sigma subbeta values.

  7. Analysis of Large- Capacity Water Heaters in Electric Thermal Storage Programs

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, Alan L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Anderson, David M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Winiarski, David W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carmichael, Robert T. [Cadeo Group, Washington D. C. (United States); Mayhorn, Ebony T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fisher, Andrew R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-17

    This report documents a national impact analysis of large tank heat pump water heaters (HPWH) in electric thermal storage (ETS) programs and conveys the findings related to concerns raised by utilities regarding the ability of large-tank heat pump water heaters to provide electric thermal storage services.

  8. A novel microfluidic system for the rapid analysis of protein thermal stability.

    Science.gov (United States)

    Yang, Xin; Liu, Jia; Xie, Ye Lei; Wang, Yang; Ying, Hong; Wu, Qiong; Huang, Wei; Jenkins, Gareth

    2014-06-07

    We describe a simple microfluidic device for the rapid analysis of protein thermal stability using a novel imaging method. The change in UV absorption upon thermal denaturation or aggregation of proteins is used to get a spatial image of proteins' folding or aggregation state along a linear temperature gradient.

  9. ANALYSIS OF EXCESSIVE HEATING ON THE THERMAL AND ELECTRICAL RESISTANCE OF A POLYMER ELECTROLYTE

    National Research Council Canada - National Science Library

    R. Atan; W. A. N. W. Mohamed

    2012-01-01

    .... An analytical method by which the electrical resistance is evaluated based on the polarisation curve and the thermal resistance from the mass balance, was applied to a 72-cell PEM fuel cell assembly...

  10. A Combined Method for Segmentation and Registration for an Advanced and Progressive Evaluation of Thermal Images

    Directory of Open Access Journals (Sweden)

    Emilio Z. Barcelos

    2014-11-01

    Full Text Available In this paper, a method that combines image analysis techniques, such as segmentation and registration, is proposed for an advanced and progressive evaluation of thermograms. The method is applied for the prevention of muscle injury in high-performance athletes, in collaboration with a Brazilian professional soccer club. The goal is to produce information on spatio-temporal variations of thermograms favoring the investigation of the athletes’ conditions along the competition. The proposed method improves on current practice by providing a means for automatically detecting adaptive body-shaped regions of interest, instead of the manual selection of simple shapes. Specifically, our approach combines the optimization features in Otsu’s method with a correction factor and post-processing techniques, enhancing thermal-image segmentation when compared to other methods. Additional contributions resulting from the combination of the segmentation and registration steps of our approach are the progressive analyses of thermograms in a unique spatial coordinate system and the accurate extraction of measurements and isotherms.

  11. GIS based evaluation of crop suitability for agricultural sustainability around Kolaghat thermal power plant, India.

    Science.gov (United States)

    Adak, Subhas; Adhikari, Kalyan; Brahmachari, Koushik

    2016-09-01

    Fly ash exhaust from Kolaghat thermal power plant, West Bengal, India,?? affects the areas within the radius of 3 - 4 km. Land information system indicated that surface texture within 4 km was silty loam and clay content increased with increase of distance. Soil pH was alkaline (7.58-8.01) in affected circles, whereas soil was acidic (5.95-6.41) in rest of block. Organic carbon (OC) is roving from 0.36 to 0.64% in the nearer circles which is lesser from others. The present Crop suitability analysis revealed that 96.98 % area was suitable (S1) for maize, sesame, jute, whereas these were cultivated in less than 1% of land. Flowers are the best suitable (S1) in 88.9 % but it was grown in 6.02 % area.? The present rice area within 4 km of KTPP is showing moderately suitable (S2) and S1 for the rest. Wheat is moderately suitable (S2) in the almost all the circles.? Cultivation of vegetable crops is limited in the affected circles while the highly suitable (S1) comprises 67.49 % for the remaining areas though it covered only 6.01 % of the block.? This evaluation precisely improves more than 300% from the earlier cropping intensity of 177.95 %. Suitability based land use allocation serves as stepping stone to promote agricultural sustainability. Geographic information system (GIS) model has been developed to assess site specific crop suitability for sustainable agricultural planning.

  12. A combined method for segmentation and registration for an advanced and progressive evaluation of thermal images.

    Science.gov (United States)

    Barcelos, Emilio Z; Caminhas, Walmir M; Ribeiro, Eraldo; Pimenta, Eduardo M; Palhares, Reinaldo M

    2014-11-19

    In this paper, a method that combines image analysis techniques, such as segmentation and registration, is proposed for an advanced and progressive evaluation of thermograms. The method is applied for the prevention of muscle injury in high-performance athletes, in collaboration with a Brazilian professional soccer club. The goal is to produce information on spatio-temporal variations of thermograms favoring the investigation of the athletes' conditions along the competition. The proposed method improves on current practice by providing a means for automatically detecting adaptive body-shaped regions of interest, instead of the manual selection of simple shapes. Specifically, our approach combines the optimization features in Otsu's method with a correction factor and post-processing techniques, enhancing thermal-image segmentation when compared to other methods. Additional contributions resulting from the combination of the segmentation and registration steps of our approach are the progressive analyses of thermograms in a unique spatial coordinate system and the accurate extraction of measurements and isotherms.

  13. Homotopy analysis method for variable thermal conductivity heat flux gage with edge contact resistance

    Energy Technology Data Exchange (ETDEWEB)

    Aziz, Abdul [Gonzaga Univ., Spokane, WA (United States). Dept. of Mechanical Engineering; Khani, Farzad [Bakhtar Institute of Higher Education, Ilam (Iran, Islamic Republic of). Dept. of Mathematics; Darvishi, Mohammad Taghi [Razi Univ., Kermanshah (Iran, Islamic Republic of). Dept. of Mathematics

    2010-10-15

    The homotopy analysis method (HAM) has been used to develop an analytical solution for the thermal performance of a circular-thin-foil heat flux gage with temperature dependent thermal conductivity and thermal contact resistance between the edge of the foil and the heat sink. Temperature distributions in the foil are presented illustrating the effect of incident heat flux, radiation emission from the foil, variable thermal conductivity, and contact resistance between the foil and the heat sink. The HAM results agree up to four places of decimal with the numerical solutions generated using the symbolic algebra package Maple. This close comparison vouches for the high accuracy and stability of the analytic solution. (orig.)

  14. Thermal Interface Evaluation of Heat Transfer from a Pumped Loop to Titanium-Water Thermosyphons

    Science.gov (United States)

    Jaworske, Donald A.; Sanzi, James L.; Gibson, Marc A.; Sechkar, Edward A.

    2009-01-01

    Titanium-water thermosyphons are being considered for use in the heat rejection system for lunar outpost fission surface power. Key to their use is heat transfer between a closed loop heat source and the heat pipe evaporators. This work describes laboratory testing of several interfaces that were evaluated for their thermal performance characteristics, in the temperature range of 350 to 400 K, utilizing a water closed loop heat source and multiple thermosyphon evaporator geometries. A gas gap calorimeter was used to measure heat flow at steady state. Thermocouples in the closed loop heat source and on the evaporator were used to measure thermal conductance. The interfaces were in two generic categories, those immersed in the water closed loop heat source and those clamped to the water closed loop heat source with differing thermal conductive agents. In general, immersed evaporators showed better overall performance than their clamped counterparts. Selected clamped evaporator geometries offered promise.

  15. A method for evaluating pressure locking and thermal binding of gate valves

    Energy Technology Data Exchange (ETDEWEB)

    Dogan, T.

    1996-12-01

    A method is described to evaluate the susceptibility of gate valves to pressure locking and thermal binding. Binding of the valve disc in the closed position due to high pressure water trapped in the bonnet cavity (pressure locking) or differential thermal expansion of the disk in the seat (thermal binding) represents a potential mechanism that can prevent safety-related systems from functioning when called upon. The method described here provides a general equation that can be applied to a given gate valve design and set of operating conditions to determine the susceptibility of the valve to fail due to disc binding. The paper is organized into three parts. The first part discusses the physical mechanisms that cause disc binding. The second part describes the mathematical equations. The third part discusses the conclusions.

  16. Nanostructural analysis of water distribution in hydrated multicomponent gels using thermal analysis and NMR relaxometry.

    Science.gov (United States)

    Codoni, Doroty; Belton, Peter; Qi, Sheng

    2015-06-01

    Highly complex, multicomponent gels and water-containing soft materials have varied applications in biomedical, pharmaceutical, and food sciences, but the characterization of these nanostructured materials is extremely challenging. The aim of this study was to use stearoyl macrogol-32 glycerides (Gelucire 50/13) gels containing seven different species of glycerides, PEG, and PEG-esters, as model, complex, multicomponent gels, to investigate the effect of water content on the micro- and nanoarchitecture of the gel interior. Thermal analysis and NMR relaxometry were used to probe the thermal and diffusional behavior of water molecules within the gel network. For the highly concentrated gels (low water content), the water activity was significantly lowered due to entrapment in the dense gel network. For the gels with intermediate water content, multiple populations of water molecules with different thermal responses and diffusion behavior were detected, indicating the presence of water in different microenvironments. This correlated with the network architecture of the freeze-dried gels observed using SEM. For the gels with high water content, increased quantities of water with similar diffusion characteristics as free water could be detected, indicating the presence of large water pockets in these gels. The results of this study provide new insights into structure of Gelucire gels, which have not been reported before because of the complexity of the material. They also demonstrate that the combination of thermal analysis and NMR relaxometry offers insights into the structure of soft materials not available by the use of each technique alone. However, we also note that in some instances the results of these measurements are overinterpreted and we suggest limitations of the methods that must be considered when using them.

  17. Investigation and analysis of human body thermal comfort in classroom

    Science.gov (United States)

    Zhai, Xue

    2017-05-01

    In this survey, we selected the 11th building of North China Electric Power University as the research object. Data were measured and distributed on each floor. We record the temperature of the classroom, humidity, wind speed, average radiation temperature and other environmental parameters. And we used spare time to create a questionnaire survey of the subjective feeling of the survey, to get everyone in the classroom TSV (hot feeling vote value) and TCV (thermal comfort vote). We analyzed the test data and survey data. What's more we discuss and reflect on the thermal comfort of the human body in different indoor temperature atmospheres.

  18. Analytical transient analysis of Peltier device for laser thermal tuning

    Science.gov (United States)

    Sheikhnejad, Yahya; Vujicic, Zoran; Almeida, Álvaro J.; Bastos, Ricardo; Shahpari, Ali; Teixeira, António L.

    2017-08-01

    Recently, industrial trends strongly favor the concepts of high density, low power consumption and low cost applications of Datacom and Telecom pluggable transceiver modules. Hence, thermal management plays an important role, especially in the design of high-performance compact optical transceivers. Extensive care should be taken on wavelength drift for thermal tuning lasers using thermoelectric cooler and indeed, accurate expression is needed to describe transient characteristics of the Peltier device to achieve maximum controllability. In this study, the exact solution of governing equation is presented, considering Joule heating, heat conduction, heat flux of laser diode and thermoelectric effect in one dimension.

  19. Vacuum Ultraviolet Radiation and Atomic Oxygen Durability Evaluation of HST Bi-Stem Thermal Shield Materials

    Science.gov (United States)

    Dever, Joyce; deGroh, Kim K.

    2002-01-01

    Bellows-type thermal shields were used on the bi-stems of replacement solar arrays installed on the Hubble Space Telescope (HST) during the first HST servicing mission (SMI) in December 1993. These thermal shields helped reduce the problem of thermal gradient- induced jitter observed with the original HST solar arrays during orbital thermal cycling and have been in use on HST for eight years. This paper describes ground testing of the candidate solar array bi-stem thermal shield materials including backside aluminized Teflon(R)FEP (fluorinated ethylene propylene) with and without atomic oxygen (AO) and ultraviolet radiation protective surface coatings for durability to AO and combined AO and vacuum ultraviolet (VOV) radiation. NASA Glenn Research Center (GRC) conducted VUV and AO exposures of samples of candidate thermal shield materials at HST operational temperatures and pre- and post-exposure analyses as part of an overall program coordinated by NASA Goddard Space Flight Center (GSFC) to determine the on-orbit durability of these materials. Coating adhesion problems were observed for samples having the AO- and combined AO/UV-protective coatings. Coating lamination occurred with rapid thermal cycling testing which simulated orbital thermal cycling. This lack of adhesion caused production of coating flakes from the material that would have posed a serious risk to HST optics if the coated materials were used for the bi-stem thermal shields. No serious degradation was observed for the uncoated aluminized Teflon(R) as evaluated by optical microscopy, although atomic force microscopy (AFM) microhardness testing revealed that an embrittled surface layer formed on the uncoated Teflon(R) surface due to vacuum ultraviolet radiation exposure. This embrittled layer was not completely removed by AO erosion, No cracks or particle flakes were produced for the embrittled uncoated material upon exposure to VUV and AO at operational temperatures to an equivalent exposure of

  20. Evaluation of stratified thermal-storage system for Oliver Springs Elementary School

    Science.gov (United States)

    Reid, R. L.; Bedinger, A. F. G.

    1982-08-01

    The thermal storage system at the Oliver Springs Elementary School consists of three cast-in-place concrete water storage tanks, each approximately 2956 ft(3) and using a flexible membrane device to resist temperature blending. The membrane can float up and down to suit variable conditions. The design goals of the heat recovery and thermal energy storage are to minimize the need to purchase energy for space heating, cooling, and water heating and to minimize electrical demand. The system is described and the history of the project is briefly reviewed. The automatic data acquisition system and the data analysis are also briefly discussed.

  1. Bioinformatics analysis of the early inflammatory response in a rat thermal injury model

    Directory of Open Access Journals (Sweden)

    Berthiaume Francois

    2007-01-01

    Full Text Available Abstract Background Thermal injury is among the most severe forms of trauma and its effects are both local and systemic. Response to thermal injury includes cellular protection mechanisms, inflammation, hypermetabolism, prolonged catabolism, organ dysfunction and immuno-suppression. It has been hypothesized that gene expression patterns in the liver will change with severe burns, thus reflecting the role the liver plays in the response to burn injury. Characterizing the molecular fingerprint (i.e., expression profile of the inflammatory response resulting from burns may help elucidate the activated mechanisms and suggest new therapeutic intervention. In this paper we propose a novel integrated framework for analyzing time-series transcriptional data, with emphasis on the burn-induced response within the context of the rat animal model. Our analysis robustly identifies critical expression motifs, indicative of the dynamic evolution of the inflammatory response and we further propose a putative reconstruction of the associated transcription factor activities. Results Implementation of our algorithm on data obtained from an animal (rat burn injury study identified 281 genes corresponding to 4 unique profiles. Enrichment evaluation upon both gene ontologies and transcription factors, verifies the inflammation-specific character of the selections and the rationalization of the burn-induced inflammatory response. Conducting the transcription network reconstruction and analysis, we have identified transcription factors, including AHR, Octamer Binding Proteins, Kruppel-like Factors, and cell cycle regulators as being highly important to an organism's response to burn response. These transcription factors are notable due to their roles in pathways that play a part in the gross physiological response to burn such as changes in the immune response and inflammation. Conclusion Our results indicate that our novel selection/classification algorithm has been

  2. Development of Innovative Aerogel Based Plasters: Preliminary Thermal and Acoustic Performance Evaluation

    Directory of Open Access Journals (Sweden)

    Cinzia Buratti

    2014-09-01

    Full Text Available The thermal and acoustic properties of innovative insulating systems used as building coatings were investigated: Granular silica aerogel was mixed with natural plaster in different percentages. This coating solution is transpiring and insulating, thanks to the use of a natural lime coat and aerogel, a highly porous light material with very low thermal conductivity. The thermal conductivity of the proposed solution was evaluated by means of a Heat Flow meter apparatus (EN ISO 12667, considering different percentages of aerogel. The natural plaster without aerogel has a thermal conductivity of about 0.50 W/m K; considering a percentage of granular aerogel of about 90% in volume, the thermal conductivity of the insulating natural coating falls to 0.050 W/m K. Increasing the percentage of granular aerogel, a value of about 0.018–0.020 W/m K can be reached. The acoustic properties were also evaluated in terms of the acoustic absorption coefficient, measured by means of a Kundt’s Tube (ISO 10534-2. Two samples composed by a plasterboard support, an insulation plaster with aerogel (thicknesses 10 mm and 30 mm respectively and a final coat were assembled. The results showed that the absorption coefficient strongly depends on the final coat, so the aerogel-based plaster layer moderately influences the final value. The application of this innovative solution can be a useful tool for new buildings, but also for the refurbishment of existing ones. This material is in development: until now, the best value of the thermal conductivity obtained from manufacturers is about 0.015 W/m K.

  3. Dynamic Analysis of the Titanium Alloy Plate under Thermal-acoustic Loadings

    Directory of Open Access Journals (Sweden)

    Zou Xuefeng

    2015-01-01

    Full Text Available Hypersonic vehicles structures suffer complex combined loadings generally. For the thin-walled structures and thermal protection systems of the aircraft, high temperature and intensity acoustic loadings are the significant factors that leading to their break. The object of this paper is typical simply supported titanium alloy plate, the finite element method was adopted to calculate the critical thermal buckling temperature the ordinal coupling method and Newmark method were adopted to calculate the thermal-acoustic dynamic response. Based on the FEM analysis, the power spectrum densities (PSD of center point was presented. Research results show that the thermal buckling of the typical simply supported titanium alloy plate occurs easily because of the low critical thermal buckling temperature, dynamic response of the thermal buckled plate suffering acoustic loads performs strong nonlinear characteristics and complex forms of exercise.

  4. Analysis of Solar-Heated Thermal Wadis to Support Extended-Duration Lunar Exploration

    Science.gov (United States)

    Balasubramaniam, R.; Wegeng, R. S.; Gokoglu, S. A.; Suzuki, N. H.; Sacksteder, K. R.

    2010-01-01

    The realization of the renewed exploration of the Moon presents many technical challenges; among them is the survival of lunar surface assets during periods of darkness when the lunar environment is very cold. Thermal wadis are engineered sources of stored solar energy using modified lunar regolith as a thermal storage mass that can enable the operation of lightweight robotic rovers or other assets in cold, dark environments without incurring potential mass, cost, and risk penalties associated with various onboard sources of thermal energy. Thermal wadi-assisted lunar rovers can conduct a variety of long-duration missions including exploration site surveys; teleoperated, crew-directed, or autonomous scientific expeditions; and logistics support for crewed exploration. This paper describes a thermal analysis of thermal wadi performance based on the known solar illumination of the moon and estimates of producible thermal properties of modified lunar regolith. Analysis was performed for the lunar equatorial region and for a potential Outpost location near the lunar south pole. The results are presented in some detail in the paper and indicate that thermal wadis can provide the desired thermal energy reserve, with significant margin, for the survival of rovers or other equipment during periods of darkness.

  5. Comparative evaluation of different thermally modified wood samples finishing with UV-curable and waterborne coatings

    Science.gov (United States)

    Herrera, René; Muszyńska, Monika; Krystofiak, Tomasz; Labidi, Jalel

    2015-12-01

    Thermally modified wood has been developed as an industrial method to improve durability and dimensional stability of wood and thus extends the range of uses and service life of wood-based products. Despite the improvements gained by treatment, surface finishing using coatings prevents esthetical changes such as color degradation or occasional growth of mold adding protection in outdoor use and extending the service life of products. The wood finishing process was carried out with commercially available waterborne and UV-curable coatings on industrially modified at 192, 200, 212 °C and unmodified European ash (Fraxinus excelsior L.) wood, using an industrial rollers system and a laboratory brushing system. Changes caused by thermal treatment which could affect the surface finish were measured and compared with control samples, such as water uptake, wettability and acidity. Following the wood finishing, surface properties and esthetic changes were evaluated; as well as the coatings performance. Thermally modified wood presented improved adherence compared with unmodified wood with a significant improvement in samples modified at 212 °C, which also present the highest hardness when UV-cured. Finishes with UV-curing maintain the hydrophobic effect of thermally modified wood, whereas waterborne finishes increase the surface wettability. Thermal modification did not negatively influence on the elastic properties of the coated substrate and thus allows this material to be finished with different coating systems in the same conditions as unmodified wood.

  6. Evaluation of thermal energy storage materials for advanced compressed air energy storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Zaloudek, F.R.; Wheeler, K.R.; Marksberry, L.

    1983-03-01

    Advanced Compressed-Air Energy Storage (ACAS) plants have the near-term potential to reduce the fuel consumption of compressed-air plants from 33 to 100%, depending upon their design. Fuel is saved by storing some or all of the heat of compression as sensible heat which is subsequently used to reheat the compressed air prior to expansion in the turbine generator. The thermal storage media required for this application must be low cost and durable. The objective of this project was to screen thermal store materials based on their thermal cycle durability, particulate formation and corrosion resistant characteristics. The materials investigated were iron oxide pellets, Denstone pebbles, cast-iron balls, and Dresser basalt rock. The study specifically addressed the problems of particle formation and thermal ratcheting of the materials during thermal cycling and the chemical attack on the materials by the high temperature and moist environment in an ACAS heat storage bed. The results indicate that from the durability standpoint Denstone, cast iron containing 27% or more chromium, and crushed Dresser basalt would possibly stand up to ACAS conditions. If costs are considered in addition to durability and performance, the crushed Dresser basalt would probably be the most desirable heat storage material for adiabatic and hybrid ACAS plants, and more in-depth longer term thermal cycling and materials testing of Dresser basalt is recommended. Also recommended is the redesign and costing analysis of both the hybrid and adiabatic ACAS facilities based upon the use of Dresser basalt as the thermal store material.

  7. Thermal degradation analysis of pongamia pinnata oil as alternative ...

    Indian Academy of Sciences (India)

    In this paper the feasibility of non-edible pongamia pinnata oil (PPO) as an alternative liquid dielectric which can be used in distribution transformers is examined. Hence, electrical, physical and chemical properties have been measured for thermally aged (with and without catalytic added) pongamia pinnata oil (PPO) and ...

  8. Thermal analysis of line-defect photonic crystal lasers

    DEFF Research Database (Denmark)

    Xue, Weiqi; Ottaviano, Luisa; Chen, Yaohui

    2015-01-01

    We report a systematic study of thermal effects in photonic crystal membrane lasers based on line-defect cavities. Two material platforms, InGaAsP and InP, are investigated experimentally and numerically. Lasers with quantum dot layers embedded in an InP membrane exhibit lasing at room temperature...

  9. Thermal comfort analysis of hostels in National Institute of ...

    Indian Academy of Sciences (India)

    Thermal comfort study was carried out in the hostels of National Institute of Technology Calicut,Kerala, which is located in a warm humid climatic zone of India. Measurements of ambient temperature, globe temperature, relative humidity, air velocity and illuminance were carried out in eight hostels, and in parallel a ...

  10. Microstructural analysis of thermal fatigue damage in 316L pipes

    OpenAIRE

    Gonzalez Sanchez, Sergio; Ruiz, Ana; Nilsson, Karl-Fredrik

    2013-01-01

    This report summarizes the data and main conclusions derived from microstructural characterisation of 316L pipes subjected to thermal fatigue with a peak temperature of 550°C. TOFD measurements are compared with measured crack depths from cut segments, and fracture mode and corrosion have been assessed by SEM and EDX, respectively.

  11. Analysis Of Electrical – Thermal Coupling Of Induction Machine ...

    African Journals Online (AJOL)

    The interaction of the Electrical and mechanical parts of Electrical machines gives rise to the heating of the machine's constituent parts. This consequently leads to an increase in temperature which if not properly monitored may lead to the breakdown of the machine. This paper therefore presents the Electrical and thermal ...

  12. Analysis of Nigeria research reactor-1 thermal power calibration methods

    Energy Technology Data Exchange (ETDEWEB)

    Agbo, Sunday Arome; Ahmed, Yusuf Aminu; Ewa, Ita Okon; Jibrin, Yahaya [Ahmadu Bello University, Zaria (Nigeria)

    2016-06-15

    This paper analyzes the accuracy of the methods used in calibrating the thermal power of Nigeria Research Reactor-1 (NIRR-1), a low-power miniature neutron source reactor located at the Centre for Energy Research and Training, Ahmadu Bello University, Zaria, Nigeria. The calibration was performed at three different power levels: low power (3.6 kW), half power (15 kW), and full power (30 kW). Two methods were used in the calibration, namely, slope and heat balance methods. The thermal power obtained by the heat balance method at low power, half power, and full power was 3.7 ± 0.2 kW, 15.2 ± 1.2 kW, and 30.7 ± 2.5 kW, respectively. The thermal power obtained by the slope method at half power and full power was 15.8 ± 0.7 kW and 30.2 ± 1.5 kW, respectively. It was observed that the slope method is more accurate with deviations of 4% and 5% for calibrations at half and full power, respectively, although the linear fit (slope method) on average temperature-rising rates during the thermal power calibration procedure at low power (3.6 kW) is not fitting. As such, the slope method of power calibration is not suitable at lower power for NIRR-1.

  13. 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...

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

    Indian Academy of Sciences (India)

    TEM image confirmed that the ends of MWCNTs were opened during their oxidation of them in HNO3 and TiO2 nanoparticles successfully attach to the outer surface of oxidized MWCNTs. Thermal conductivity measurements of nanofluids were analysed via two-factor completely randomized design and comparison of data ...

  15. Thermal degradation analysis of pongamia pinnata oil as alternative ...

    Indian Academy of Sciences (India)

    T Mariprasath

    Abstract. In this paper the feasibility of non-edible pongamia pinnata oil (PPO) as an alternative liquid dielectric which can be used in distribution transformers is examined. Hence, electrical, physical and chemical properties have been measured for thermally aged (with and without catalytic added) pongamia pinnata oil.

  16. Life cycle analysis of underground thermal energy storage

    NARCIS (Netherlands)

    Tomasetta, Camilla; van Ree, Derk; Griffioen, Jasper

    2015-01-01

    Underground Thermal Energy Storage (UTES) systems are used to buffer the seasonal difference between heat and cold supply and demand and, therefore, represent an interesting option to conserve energy. Even though UTES are considered environmental friendly solutions they are not completely free of

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

    Science.gov (United States)

    2016-02-01

    experimental setup to quantify the thermal response consisted of an ultrasonic horn operating at 20 kHz, an IR camera, a flat specimen, and a servo...μm. To increase the emissivity , the specimen was painted black in the region of interest on the side of the specimen facing the IR camera. Data

  18. Coupled thermal, structural and vibrational analysis of a hypersonic engine for flight test

    Energy Technology Data Exchange (ETDEWEB)

    Sook-Ying, Ho [Defence Science and Technology Organisation, SA (Australia); Paull, A. [Queensland Univ., Dept. of Mechanical Engineering (Australia)

    2006-07-15

    This paper describes a relatively simple and quick method for implementing aerodynamic heating models into a finite element code for non-linear transient thermal-structural and thermal-structural-vibrational analyses of a Mach 10 generic HyShot scram-jet engine. The thermal-structural-vibrational response of the engine was studied for the descent trajectory from 60 to 26 km. Aerodynamic heating fluxes, as a function of spatial position and time for varying trajectory points, were implemented in the transient heat analysis. Additionally, the combined effect of varying dynamic pressure and thermal loads with altitude was considered. This aero-thermal-structural analysis capability was used to assess the temperature distribution, engine geometry distortion and yielding of the structural material due to aerodynamic heating during the descent trajectory, and for optimising the wall thickness, nose radius of leading edge, etc. of the engine intake. A structural vibration analysis was also performed following the aero-thermal-structural analysis to determine the changes in natural frequencies of the structural vibration modes that occur at the various temperatures associated with the descent trajectory. This analysis provides a unique and relatively simple design strategy for predicting and mitigating the thermal-structural-vibrational response of hypersonic engines. (authors)

  19. Preliminary survey and evaluation of nonaquifer thermal energy storage concepts for seasonal storage

    Energy Technology Data Exchange (ETDEWEB)

    Blahnik, D.E.

    1980-11-01

    Thermal energy storage enables the capture and retention of heat energy (or cold) during one time period for use during another. Seasonal thermal energy storage (STES) involves a period of months between the input and recovery of energy. The purpose of this study was to make a preliminary investigation and evaluation of potential nonaquifer STES systems. Current literature was surveyed to determine the state of the art of thermal energy storage (TES) systems such as hot water pond storage, hot rock storage, cool ice storage, and other more sophisticated concepts which might have potential for future STES programs. The main energy sources for TES principally waste heat, and the main uses of the stored thermal energy, i.e., heating, cooling, and steam generation are described. This report reviews the development of sensible, latent, and thermochemical TES technologies, presents a preliminary evaluation of the TES methods most applicable to seasonal storage uses, outlines preliminary conclusions drawn from the review of current TES literature, and recommends further research based on these conclusions. A bibliography of the nonaquifer STES literature review, and examples of 53 different TES concepts drawn from the literature are provided. (LCL)

  20. Re-evaluation of effective carbon number (ECN) approach to predict response factors of 'compounds lacking authentic standards or surrogates' (CLASS) by thermal desorption analysis with GC-MS.

    Science.gov (United States)

    Szulejko, Jan E; Kim, Ki-Hyun

    2014-12-03

    In our recent study, we experimentally demonstrated the feasibility of an effective carbon number (ECN) approach for the prediction of the response factor (RF) values of 'compounds lacking authentic standards or surrogates' (CLASS) using a certified 54-mix containing 38 halogenated analytes as a pseudo-unknown. Although our recent analysis performed well in terms of RF predictive power for a 25-component learning set (for both Q-MS and TOF-MS detection), large physically unrealistic negative ECN and carbon number equivalent (CNE) values were noted for TOF-MS detection, e.g., ECN (acetic acid)=-16.96. Hence, to further improve the ECN-based quantitation procedure of CLASS, we re-challenged RF vs. ECN linear regression analysis with additional descriptors (i.e., Cl, Br, CC, and a group ECN offset (Ok)) using the 1-point RF values. With an Ok, all compound classes, e.g., halo-alkanes/-alkenes and aromatics can now be fitted to yield consistently positive set of ECN values for most analytes (e.g., 3 outliers out of 29, Q-MS detection). In this way, we were able to further refine our approach so that the absolute percentage difference (PD)±standard deviation (SD) between mass detected vs. mass loaded is reduced from 39.0±34.1% (previous work) to 13.1±12.0% (this work) for 29 C1C4 halocarbons (Q-MS detector). Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Comprehensive NMR analysis of compositional changes of black garlic during thermal processing.

    Science.gov (United States)

    Liang, Tingfu; Wei, Feifei; Lu, Yi; Kodani, Yoshinori; Nakada, Mitsuhiko; Miyakawa, Takuya; Tanokura, Masaru

    2015-01-21

    Black garlic is a processed food product obtained by subjecting whole raw garlic to thermal processing that causes chemical reactions, such as the Maillard reaction, which change the composition of the garlic. In this paper, we report a nuclear magnetic resonance (NMR)-based comprehensive analysis of raw garlic and black garlic extracts to determine the compositional changes resulting from thermal processing. (1)H NMR spectra with a detailed signal assignment showed that 38 components were altered by thermal processing of raw garlic. For example, the contents of 11 l-amino acids increased during the first step of thermal processing over 5 days and then decreased. Multivariate data analysis revealed changes in the contents of fructose, glucose, acetic acid, formic acid, pyroglutamic acid, cycloalliin, and 5-(hydroxymethyl)furfural (5-HMF). Our results provide comprehensive information on changes in NMR-detectable components during thermal processing of whole garlic.

  2. Quantitative Analysis of the Relationship Between Microstructures and Thermal Conductivity for YSZ Coatings

    Science.gov (United States)

    Chen, Ning; Song, Xuemei; Liu, Ziwei; Lin, Chucheng; Zeng, Yi; Huang, Liping; Zheng, Xuebing

    2017-04-01

    The thermal conductivities of as-sprayed yttria-stabilized zirconia thermal barrier coating prepared by atmospheric plasma spraying at different temperatures are investigated based on quantitative microstructural analysis. Multiple linear regression is used to develop quantitative models which describe the relationship between multiple elements such as porosity, grain boundary density, monoclinic phase content, temperature and thermal conductivity. Results reveal that the thermal conductivity of the coating is mainly determined by the porosity and grain boundary density below 300 °C and by the monoclinic phase content above 800 °C. Furthermore, based on the significance testing analysis, the confidence interval under a confidence level of 95% at different temperatures enables researchers to predict the thermal conductivity based on microstructural information.

  3. Thermal analysis of GFRP-reinforced continuous concrete decks subjected to top fire

    National Research Council Canada - National Science Library

    Hawileh, Rami A; Rasheed, Hayder A

    2017-01-01

    ...) bars subjected to top surface fire. A finite element (FE) model is developed and a detailed transient thermal analysis is performed on a continuous concrete bridge deck under the effect of various fire curves...

  4. Coupled Mechanical-Electrochemical-Thermal Analysis of Failure Propagation in Lithium-ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chao; Santhanagopalan, Shriram; Pesaran, Ahmad

    2016-07-28

    This is a presentation given at the 12th World Congress for Computational Mechanics on coupled mechanical-electrochemical-thermal analysis of failure propagation in lithium-ion batteries for electric vehicles.

  5. CFD analysis of turbulent heat transfer and thermal striping phenomena in T-junctions with liquid sodium

    Science.gov (United States)

    Ferrara, P.; Di Marco, P.

    2017-01-01

    This paper describes the methodology adopted to perform a CFD analysis with the aim to study thermal striping in T-junctions with liquid sodium; in particular, a portion of the Phenix reactor’s secondary circuit has been taken into account, by implementing a detailed 3D model of both fluid and solid domain; RANS and LES turbulence models are used and their results are compared, then frequency analysis of temperature fluctuations has been performed. One of the main results of this analysis is that LES turbulence models are not yet completely reliable in evaluating.

  6. Structural and Contact Analysis of a 3-Dimensional Disc-Pad Model with and without Thermal Effects

    Directory of Open Access Journals (Sweden)

    A. Belhocine

    2014-12-01

    Full Text Available The motivation of this work is to identify thermal effects on the structural and contact behaviour of a disc-pad assembly using a finite element approach. The first analysis is performed on the disc-pad model without the presence of thermal properties. Structural performance of the disc-pad model such as deformation and Von Mises stress is predicted. Next, thermomechanical analysis is performed on the same disc-pad model with the inclusion of convection, adiabatic and heat flux elements. The prediction results of temperature distribution, deformation, stress and contact pressure are presented. Comparison of the structural performance between the two analyses (mechanical and thermomechanical is also made. From this study, it can assist brake engineers to choose a suitable analysis in order to critically evaluate structural and contact behaviour of the disc brake assembly.

  7. Thermal Analysis of a Solar Powered Absorption Cooling System with Fully Mixed Thermal Storage at Startup

    Directory of Open Access Journals (Sweden)

    Camelia Stanciu

    2017-01-01

    Full Text Available A simple effect one stage ammonia-water absorption cooling system fueled by solar energy is analyzed. The considered system is composed by a parabolic trough collector concentrating solar energy into a tubular receiver for heating water. This is stored in a fully mixed thermal storage tank and used in the vapor generator of the absorption cooling system. Time dependent cooling load is considered for the air conditioning of a residential two-storey house. A parametric study is performed to analyze the operation stability of the cooling system with respect to solar collector and storage tank dimensions. The results emphasized that there is a specific storage tank dimension associated to a specific solar collector dimension that could ensure the longest continuous startup operation of the cooling system when constant mass flow rates inside the system are assumed.

  8. Current research on shear buckling and thermal loads with PASCO - Panel analysis and sizing code

    Science.gov (United States)

    Stroud, W. J.; Greene, W. H.; Anderson, M. S.

    1984-01-01

    The stiffened composite structural panel analysis and sizing code designated 'PASCO' encompasses both the generality required for the exploitation of composite materials' design flexibility and an accurate buckling analysis for the detection of complex buckling modes. PASCO can accordingly design for buckling, frequency, material strength, and panel stiffness requirements. Attention is given to an additional thermal loading design capability. Design studies illustrate the importance of the multiple load condition capability when thermal loads are present.

  9. Coupled Radiation Transport/Thermal Analysis of the Radiation Shield for a Space Nuclear Reactor.

    Science.gov (United States)

    1985-07-01

    thermal analysis of radiation shield are those of Beiriger (1968) and Thompson and Schwab (1969). Belriger (1968) conducted a thermal analysis of Pb-W...regarding how the temperature values were generated were not reported. Thompson and Schwab (1969) examined the accuracy of several neu- tronic models in...Publishing Company, Inc., 1984. Bathe, Klaus -Jurgen, Finite Element Procedures in Engineering Analy- sis, New Jersey: Prentice Hall, Inc., 1982. deckurts, K.H

  10. Stress and Displacement Analysis of Microreactors during Thermal and Vacuum Loading

    Science.gov (United States)

    2017-09-07

    ARL-TR-8121 ● SEP 2017 US Army Research Laboratory Stress and Displacement Analysis of Microreactors during Thermal and Vacuum...is no longer needed. Do not return it to the originator. ARL-TR-8121 ● SEP 2017 US Army Research Laboratory Stress and...TITLE AND SUBTITLE Stress and Displacement Analysis of Microreactors during Thermal and Vacuum Loading 5a. CONTRACT NUMBER 5b. GRANT NUMBER

  11. Preliminary Design and Analysis of the ARES Atmospheric Flight Vehicle Thermal Control System

    Science.gov (United States)

    Gasbarre, J. F.; Dillman, R. A.

    2003-01-01

    The Aerial Regional-scale Environmental Survey (ARES) is a proposed 2007 Mars Scout Mission that will be the first mission to deploy an atmospheric flight vehicle (AFV) on another planet. This paper will describe the preliminary design and analysis of the AFV thermal control system for its flight through the Martian atmosphere and also present other analyses broadening the scope of that design to include other phases of the ARES mission. Initial analyses are discussed and results of trade studies are presented which detail the design process for AFV thermal control. Finally, results of the most recent AFV thermal analysis are shown and the plans for future work are discussed.

  12. 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.

  13. Thermal analysis of the crotch absorber in APS

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, I.C.; Howell, J.

    1992-10-01

    A crotch absorber design for use in the Advanced Photon source (APS) has been proposed and analyzed. the absorber is placed downstream of sectors S2 and S4 in the curved storage ring chamber and will be subjected to a peak power of 120 W/mm{sup 2} per 100mA synchrotron radiation. A beryllium ring is brazed on the GlidCop cooling cylinder in order to diffuse the concentrated bending magnet heating. One concentric water channel and two annular return water channels are arranged in the GlidCop cylinder to enhance the cooling. A Bodner-Partom thermoviscoplastic constitutive equation and a modified Manson-Coffin fatigue relation are proposed to simulate the cyclic thermal loading, as well as to predict the thermal fatigue life of the crotch absorber. Results of temperature and stress using finite element computations are displayed and series of e-beam welder tests and microstructure measurements are reported.

  14. Thermal analysis of the crotch absorber in APS

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, I.C.; Howell, J.

    1992-01-01

    A crotch absorber design for use in the Advanced Photon source (APS) has been proposed and analyzed. the absorber is placed downstream of sectors S2 and S4 in the curved storage ring chamber and will be subjected to a peak power of 120 W/mm{sup 2} per 100mA synchrotron radiation. A beryllium ring is brazed on the GlidCop cooling cylinder in order to diffuse the concentrated bending magnet heating. One concentric water channel and two annular return water channels are arranged in the GlidCop cylinder to enhance the cooling. A Bodner-Partom thermoviscoplastic constitutive equation and a modified Manson-Coffin fatigue relation are proposed to simulate the cyclic thermal loading, as well as to predict the thermal fatigue life of the crotch absorber. Results of temperature and stress using finite element computations are displayed and series of e-beam welder tests and microstructure measurements are reported.

  15. Postbuckling analysis of a thermally driven microbeam under realistic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Tayefeh, Mohsen; Bahrami, Mohsen [Department of Mechanical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

    2006-04-01

    Thermal buckling behavior of line shape microactuators in a fully coupled field process is simulated. As a consequence of the miniaturizing, some effects belong to coupling of different physical fields appear, and some issues, which are minor at macroscopic scales, have to be taken into account. In order to have a robust design of these micro-systems, it is important to correctly analyze the coupling between electrical, thermal and mechanical fields. Rregarding effect of more physical aspects and ignoring the simplifying statements, the calculated results are consistent more with reported experimental measurements in the literature. recommended modifications not only improve the results to be consistent with experiments, but also play key roles for the development of MEMS actuators based on jouleheating effects such as Heactuators and Hexsil tweezers. While the simulation of micro actuators mostly consist of coupled field analyses, the results proves the requirement of transferring more detailed outputs from one field to another one as inputs.

  16. Thermal stress analysis of the SLAC fixed mask. Addendum

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, G.L.; Pierce, R.E.

    1985-07-25

    X-ray beams emerging from the new SLAC electron-positron storage ring (PEP) can impinge on the walls of tangential divertor channels. A fixed mask made of OFHC copper is installed in the channel to limit wall heating. The mask is cooled with water flowing axially at 30/sup 0/C. Beam strikes on the mask cause highly localized heating in the channel structure. Analyses were completed to determine the temperatures and thermally-induced stresses due to this heating. The current design and operating conditions should result in the entrance to the fixed mask operating at a peak temperature of 105/sup 0/C with a peak thermal stress at 26% of yield.

  17. Thermal extraction analysis of five Los Azufres production wells

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, Paul; Quijano, Luis

    1995-01-26

    Thermal energy extraction from five wells supplying 5-MWe wellhead generators in three zones of the Los Azufres geothermal field has been examined from production and chemical data compiled over 14-years of operation. The data, as annual means, are useful in observing small-scale changes in reservoir performance with continuous production. The chemical components are chloride for quality control and the geothermometer elements for reservoir temperatures. The flowrate and fluid enthalpy data are used to calculate the thermal extraction rates. Integration of these data provides an estimate of the total energy extracted from the zone surrounding the well. The combined production and chemical geothermometer data are used to model the produced fluid as coming from just-penetrating wells for which the annual produced mass originates from a series of concentric hemispheric shells moving out into the reservoir. Estimates are made of the drawdown distance into the reservoir and the far-field conditions.

  18. First wall thermal stress analysis for suddenly applied heat fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Dalessandro, J A

    1978-01-01

    The failure criterion for a solid first wall of an inertial confinement reactor is investigated. Analytical expressions for induced thermal stresses in a plate are given. Two materials have been chosen for this investigation: grade H-451 graphite and chemically vapor deposited (CVD) ..beta..-silicon carbide. Structural failure can be related to either the maximum compressive stress produced on the surface or the maximum tensile stress developed in the interior of the plate; however, it is shown that compressive failure would predominate. A basis for the choice of the thermal shock figure of merit, k(1 - ..nu..) sigma/E ..cap alpha.. kappa/sup 1/2/, is identified. The result is that graphite and silicon carbide rank comparably.

  19. Energy Consumption of Insulated Material Using Thermal Effect Analysis

    OpenAIRE

    Fadzil M. A.; Norliyati M. A.; Hilmi M. A.; Ridzuan A. R.; Wan Ibrahim M. H.; Assrul R. Z.

    2017-01-01

    Wall is one of the structures elements that resist direct heat from the atmosphere. Modification on several structures is relevance to reduce filtrate thermal movement on wall. Insulation material seems to be suitable to be implemented since its purpose meets the heat resistance requirement. Insulation material applied as to generate positive impact in energy saving through reduction in total building energy consumption. Fiberglass is one of the insulation materials that can be used to insula...

  20. Analysis of Nigeria Research Reactor-1 Thermal Power Calibration Methods

    Directory of Open Access Journals (Sweden)

    Sunday Arome Agbo

    2016-06-01

    Full Text Available This paper analyzes the accuracy of the methods used in calibrating the thermal power of Nigeria Research Reactor-1 (NIRR-1, a low-power miniature neutron source reactor located at the Centre for Energy Research and Training, Ahmadu Bello University, Zaria, Nigeria. The calibration was performed at three different power levels: low power (3.6 kW, half power (15 kW, and full power (30 kW. Two methods were used in the calibration, namely, slope and heat balance methods. The thermal power obtained by the heat balance method at low power, half power, and full power was 3.7 ± 0.2 kW, 15.2 ± 1.2 kW, and 30.7 ± 2.5 kW, respectively. The thermal power obtained by the slope method at half power and full power was 15.8 ± 0.7 kW and 30.2 ± 1.5 kW, respectively. It was observed that the slope method is more accurate with deviations of 4% and 5% for calibrations at half and full power, respectively, although the linear fit (slope method on average temperature-rising rates during the thermal power calibration procedure at low power (3.6 kW is not fitting. As such, the slope method of power calibration is not suitable at lower power for NIRR-1.