Behavioural, physiological and psychological responses of passengers to the thermal environment of boarding a flight in winter.

Science.gov (United States)

Wu, Yuxin; Liu, Hong; Li, Baizhan; Cheng, Yong; Mmereki, Daniel; Kong, Deyu

2018-06-01

In practice, passengers actively respond to the thermal environment when they board an aircraft in winter, which is not considered in the current standards. In this study, the behavioural, physiological and psychological responses to the thermal environment were examined at 22 °C (with 68 subjects), 20 °C and 26 °C (with 32 subjects). The results showed that the three air temperature levels had significant effect on nozzle usage and clothing adjustment behaviours, surface skin temperature, and thermal sensation vote (TSV). The walking/waiting states prior to boarding the aircraft cabin had a significant effect on the proportion of jacket removal, TSV and thermal comfort vote. After 10 min in the aircraft cabin, the subjects maintained their comfort in a wider range of the thermal environment when the behavioural adjustments existed compared to when they did not. Thus, a suggestion was made for behavioural adjustments to be provided in aircraft cabins. Practitioner Summary: Experimental investigation of human responses was conducted in an aircraft cabin. Analysis showed that the subjects maintained their comfort in a wider range of the thermal environment when the behavioural adjustments existed compared to when they did not. Thus, a suggestion was made for behavioural adjustments to be provided in aircraft cabins.

Thermal Behaviour of clay formations

International Nuclear Information System (INIS)

Tassoni, E.

1985-01-01

The programme carried out by ENEA to model the thermal-hydraulic-mechanical behaviour of the clay formations and to measure, in situ and in laboratory, the thermal properties of these rocks, is presented. An in situ heating experiment has been carried out in an open clay quarry in the area of Monterotondo, near Rome. The main goal of the experiment was to know the temperature field and the thermal effects caused by the high level radioactive waste disposed of in a clayey geological formation. The conclusions are as follows: - the thermal conduction codes are sufficiently accurate to forecast the temperature increases caused in the clay by the dissipation of the heat generated by high level radioactive waste; - the thermal conductivity deduced by means of the ''curve fitting'' method ranges from 0.015 to 0.017 W.cm -1 . 0 C -1 - the temperature variation associated with the transport of clay interstitial water caused by temperature gradient is negligible. A laboratory automated method has been designed to measure the thermal conductivity and diffusivity in clay samples. A review of experimental data concerning thermomechanical effects in rocks as well as results of thermal experiments performed at ISMES on clays are presented. Negative thermal dilation has been found both in the elastic and plastic range under constant stress. Thermoplastic deformation appears ten times greater than the thermoelastic one. A mathematical model is proposed in order to simulate the above and other effects that encompass thermal-elastic-plastic-pore water pressure response of clays at high temperature and effective pressure with undrained and transient drainage conditions. Implementation of the two versions into a finite element computer code is described

Small scale model and underground laboratory study of engineered barrier thermal behaviour

International Nuclear Information System (INIS)

Dardaine, M.; Beziat, A.; Gatabin, C.; Lefevre, I.; Plas, F.; Fontan, N.; Moyne, C.

1991-01-01

This is the final report of the contract CCE FI1W/0061, which had the objective of studying the thermal behaviour of the engineered barrier having the selected French clay Fo-Ca (natural calcic smectite) as its major constituent. After being installed this barrier was subjected simultaneously to the heat flux dissipated by the container and to a possible rehydration by contact with the host medium. It consists of three parts. The first part is devoted to R and D studies concerning detectors suitable for the point measurement of the water concentration. Among the techniques that can be envisaged, capacitor methods, which are very temperature sensitive, would require a great deal of effort to be satisfactory. On the other hand, the water concentration can, in principle, be derived from the measurement of the thermal conductivity in the transient regime. Although the carrying out of this measurement is somewhat critical, it can give good results under certain conditions. The second part reports experiments carried out in the laboratory concerning both the study of heat transfer during the so-called dry phase of the disposal (without any water being supplied externally) and the study of the phenomenon of fissuration. Finally, the third part describes the in situ experiment BACCHUS, carried out in the underground test facility at Mol (Belgium), in collaboration with the CEN/SCK. In the course of the five months of the thermal phase of this experiment a large variation in the amplitude of the temperature gradients was recorded, which may be explained, on one hand, by the convergence of the medium and, on the other hand, by a much more rapid rehydration than that predicted

Mathematical model of thermal and mechanical steady state fuel element behaviour TEDEF

International Nuclear Information System (INIS)

Dinic, N.; Kostic, Z.; Josipovic, M.

1987-01-01

In this paper a numerical model of thermal and thermomechanical behaviour of a cylindrical metal uranium fuel element is described. Presented are numerical method and computer program for solving the stationary temperature field and thermal stresses of a fuel element. The model development is a second phase of analysis of these phenomena, and may as well be used for analysing power nuclear reactor fuel elements behaviour. (author)

Experimental and numerical studies of hybrid PCM embedded in plastering mortar for enhanced thermal behaviour of buildings

International Nuclear Information System (INIS)

Kheradmand, Mohammad; Azenha, Miguel; Aguiar, José L.B. de; Castro-Gomes, João

2016-01-01

This paper proposes a methodology for improvement of energy efficiency in buildings through the innovative simultaneous incorporation of three distinct phase change materials (here termed as hybrid PCM) in plastering mortars for façade walls. The thermal performance of a hybrid PCM mortar was experimentally evaluated by comparing the behaviour of a prototype test cell (including hybrid PCM plastering mortar) subjected to realistic daily temperature profiles, with the behaviour of a similar prototype test cell, in which no PCM was added. A numerical simulation model was employed (using ANSYS-FLUENT) to validate the capacity of simulating temperature evolution within the prototype containing hybrid PCM, as well as to understand the contribution of hybrid PCM to energy efficiency. Incorporation of hybrid PCM into plastering mortars was found to have the potential to significantly reduce heating/cooling temperature demands for maintaining the interior temperature within comfort levels when compared to normal mortars (without PCM), or even mortars comprising a single type of PCM. - Highlights: • New concept of incorporation of more than 1 type of PCM in plastering mortars (hybrid PCM). • Assessment of thermal performance of hybrid PCM plastering mortar. • Thermo-physical properties of plastering mortars modified with PCMs incorporation. • Experimental and numerical simulations of thermal behaviour on laboratory scale prototype.

Studies on thermal reactions and sintering behaviour of red clays by irreversible dilatometry

Science.gov (United States)

Anil, Asha; Misra, S. N.; Misra, N. M.

2018-05-01

Thermal behavior of clays strongly influences that of ceramic bodies made thereof and hence, its study is must for assessing its utility in ceramic products as well as to set the body composition. Irreversible dilatometry is an effective thermal analysis tool for evaluating thermal reactions as well as sintering behavior of clays or clay based ceramic bodies. In this study, irreversible dilatometry of four red clay samples (S, M, R and G) of Gujarat region, which vary in their chemical and mineralogical compositions was carried out using a Dilatometer and compared. Chemical analysis and XRD of red clays were carried out. XRD showed that major clay minerals in S, M and R clays are kaolinite. However, clay marked R and G showed presence of both kaolinite and illite and /muscovite. Presence of non-clay minerals such as hematite, quartz, anatase were also observed in all clays. XRD results were in agreement with chemical analyses results. Rational analyses showed variation in amount of clay and non-clay minerals in red clay samples. Evaluation of dilatometric curves showed that clay marked as S, M and R exhibit patterns typical for kaolinitic clays. Variation in linear expansion (up to 550°C) and shrinkage (above 550°C) between these three clays was found to be related to difference in amount of quartz and kaolinite respectively. However, dilatometric curve of G exhibit a pattern similar to that for an illitic clay. This study confirmed that sintering of investigated kaolinitic and illitic and / muscovitic red clays initiates at above 1060°C and 860°C respectively and this behaviour strongly depends upon type and amount of minerals and their chemical compositions.

Thermal behaviour during the pyrolysis of low rank perhydrous coals

Energy Technology Data Exchange (ETDEWEB)

Arenillas, A.; Rubiera, F.; Pis, J.J.; Cuesta, M.J.; Suarez-Ruiz, I. [Instituto Nacional del Carbon, CSIC, Apartado 73, 33080 Oviedo (Spain); Iglesias, M.J. [Area de Quimica Organica, Universidad de Almeria, Carretera de Sacramento, 04120 Almeria (Spain); Jimenez, A. [Area de Cristalografia y Mineralogia, Departamento de Geologia, Campus de Llamaquique, 33005 Oviedo (Spain)

2003-08-01

Perhydrous coals are characterised by high H/C atomic ratios and so their chemical structure is substantially modified with respect to that of conventional coals. As a result, perhydrous coals show different physico-chemical properties to common coals (i.e. higher volatile matter content, enhancement of oil/tar potential, relatively lower porosity and higher fluidity during carbonisation). However, there is little information about thermal behaviour during the pyrolysis of this type of coal. In this work, six perhydrous coals (H/C ratio between 0.83 and 1.07) were pyrolysed and analysed by simultaneous thermogravimetry/mass spectrometry. The results of this work have revealed the influence of high H/C values on the thermal behaviour of the coals studied. During pyrolysis the perhydrous coals exhibit very well defined, symmetrical peaks in the mass loss rate profiles, while normal coals usually show a broader peak. The shape of such curves suggests that in perhydrous coals fragmentation processes prevailed over condensation reactions. The high hydrogen content of perhydrous coals may stabilise the free radicals formed during heat treatment, increasing the production of light components.

A thermal active restrained shrinkage ring test to study the early age concrete behaviour of massive structures

International Nuclear Information System (INIS)

Briffaut, M.; Benboudjema, F.; Torrenti, J.M.; Nahas, G.

2011-01-01

In massive concrete structures, cracking may occur during hardening, especially if autogenous and thermal strains are restrained. The concrete permeability due to this cracking may rise significantly and thus increase leakage (in tank, nuclear containment...) and reduce the durability. The restrained shrinkage ring test is used to study the early age concrete behaviour (delayed strains evolution and cracking). This test shows, at 20 o C and without drying, for a concrete mix which is representative of a French nuclear power plant containment vessel (w/c ratio equal to 0.57), that the amplitude of autogenous shrinkage (about 40 μm/m for the studied concrete mix) is not high enough to cause cracking. Indeed, in this configuration, thermal shrinkage is not significant, whereas this is a major concern for massive structures. Therefore, an active test has been developed to study cracking due to restrained thermal shrinkage. This test is an evolution of the classical restrained shrinkage ring test. It allows to take into account both autogenous and thermal shrinkages. Its principle is to create the thermal strain effects by increasing the temperature of the brass ring (by a fluid circulation) in order to expand it. With this test, the early age cracking due to restrained shrinkage, the influence of reinforcement and construction joints have been experimentally studied. It shows that, as expected, reinforcement leads to an increase of the number of cracks but a decrease of crack widths. Moreover, cracking occurs preferentially at the construction joint.

Effect of humidity on the hydration behaviour of prazosin hydrochloride polyhydrate: Thermal, sorption and crystallographic study

International Nuclear Information System (INIS)

Kumar, Lokesh; Bansal, Arvind K.

2011-01-01

Highlights: → Utility of TGA to differentiate between unbound and bound water was demonstrated. → Nature of the lattice arrangement in prazosin hydrochloride polyhydrate was confirmed to be expanded (non-stoichiometric) type hydrate. → Correlation of the DSC, TGA, PXRD and DVS for dehydration of prazosin hydrochloride polyhydrate was delineated. - Abstract: In this study, hydration behaviour of prazosin hydrochloride polyhydrate was assessed using differential scanning calorimetry, thermogravimetric analysis, powder X-ray diffraction and dynamic vapour sorption techniques. Differential scanning calorimetry and thermogravimetric analysis at faster heating rate (20 o C/min) showed single step water loss, attributed to both dihydrate and unbound water. In contrast, thermogravimetric analysis at slower heating rate (1 o C/min) showed unbound and dihydrate lattice water separately, with unbound water being lost initially, followed by loss of dihydrate water. Variable vacuum and variable humidity PXRD study revealed shift in diffraction peaks to higher values on removal of unbound water. Initial PXRD patterns were regained when kept again at ambient conditions. Dynamic vapour sorption depicted type I sorption isotherm with interstitial water, indicating that polyhydrate form show reversible behaviour with change in humidity. Correlation between thermal, sorption and crystallographic data established hydration behaviour to be characteristic of expanded channel type (non-stoichiometric) hydrate.

Thermal behaviour of Anopheles stephensi in response to infection with malaria and fungal entomopathogens

Directory of Open Access Journals (Sweden)

Read Andrew F

2009-04-01

Full Text Available Abstract Background Temperature is a critical determinant of the development of malaria parasites in mosquitoes, and hence the geographic distribution of malaria risk, but little is known about the thermal preferences of Anopheles. A number of other insects modify their thermal behaviour in response to infection. These alterations can be beneficial for the insect or for the infectious agent. Given current interest in developing fungal biopesticides for control of mosquitoes, Anopheles stephensi were examined to test whether mosquitoes showed thermally-mediated behaviour in response to infection with fungal entomopathogens and the rodent malaria, Plasmodium yoelii. Methods Over two experiments, groups of An. stephensi were infected with one of three entomopathogenic fungi, and/or P. yoelii. Infected and uninfected mosquitoes were released on to a thermal gradient (14 – 38°C for "snapshot" assessments of thermal preference during the first five days post-infection. Mosquito survival was monitored for eight days and, where appropriate, oocyst prevalence and intensity was assessed. Results and conclusion Both infected and uninfected An. stephensi showed a non-random distribution on the gradient, indicating some capacity to behaviourally thermoregulate. However, chosen resting temperatures were not altered by any of the infections. There is thus no evidence that thermally-mediated behaviours play a role in determining malaria prevalence or that they will influence the performance of fungal biopesticides against adult Anopheles.

Thermal Behaviour of Beams with Slant End-Plate Connection Subjected to Nonsymmetric Gravity Load

Directory of Open Access Journals (Sweden)

Farshad Zahmatkesh

2014-01-01

Full Text Available Research on the steel structures with confining of axial expansion in fixed beams has been quite intensive in the past decade. It is well established that the thermal behaviour has a key influence on steel structural behaviours. This paper describes mechanical behaviour of beams with bolted slant end-plate connection with nonsymmetric gravity load, subjected to temperature increase. Furthermore, the performance of slant connections of beams in steel moment frame structures in the elastic field is investigated. The proposed model proved that this flexible connection system could successfully decrease the extra thermal induced axial force by both of the friction force dissipation among two faces of slant connection and a small upward movement on the slant plane. The applicability of primary assumption is illustrated. The results from the proposed model are examined within various slant angles, thermal and friction factors. It can be concluded that higher thermal conditions are tolerable when slanting connection is used.

Effect of high heating rate on thermal decomposition behaviour of ...

Indian Academy of Sciences (India)

the thermal decomposition behaviour of the aforementioned powder at high heating rates was taken into considera- ... does not change the process of releasing hydrogen from titanium hydride ... from titanium hydride in a sequence of steps.

Effect of high heating rate on thermal decomposition behaviour of ...

Indian Academy of Sciences (India)

Effect of high heating rate on thermal decomposition behaviour of titanium hydride ... hydride powder, while switching it from internal diffusion to chemical reaction. ... TiH phase and oxides form on the powder surface, controlling the process.

EURISOL-DS Multi-MW Target: Thermal Behaviour of the fission target disk arrangement inspired by the MAFF project

CERN Document Server

Cyril Kharoua, Yacine Kadi and the EURISOL-DS Task#2 collaboration

This technical note summarises the design calculations performed within Task #2 of the European Isotope Separation On-Line Radioactive Ion Beam Facility Design Study (EURISOL-DS) [1] for the thermal behaviour of the fission target.A preliminary study was carried out in order to determine the heat deposition within the fissile material and estimate the temperature rise. This new solution takes into account the problems related to effusion/diffusion of radioactive isotopes inside a thick target. To enhance the extraction rates and the thermal behaviour it is proposed to study a solution where the fissile material is split into an arrangement of disks.

Subsurface thermal behaviour of tissue mimics embedded with large blood vessels during plasmonic photo-thermal therapy.

Science.gov (United States)

Paul, Anup; Narasimhan, Arunn; Das, Sarit K; Sengupta, Soujit; Pradeep, Thalappil

2016-11-01

The purpose of this study was to understand the subsurface thermal behaviour of a tissue phantom embedded with large blood vessels (LBVs) when exposed to near-infrared (NIR) radiation. The effect of the addition of nanoparticles to irradiated tissue on the thermal sink behaviour of LBVs was also studied. Experiments were performed on a tissue phantom embedded with a simulated blood vessel of 2.2 mm outer diameter (OD)/1.6 mm inner diameter (ID) with a blood flow rate of 10 mL/min. Type I collagen from bovine tendon and agar gel were used as tissue. Two different nanoparticles, gold mesoflowers (AuMS) and graphene nanostructures, were synthesised and characterised. Energy equations incorporating a laser source term based on multiple scattering theories were solved using finite element-based commercial software. The rise in temperature upon NIR irradiation was seen to vary according to the position of the blood vessel and presence of nanoparticles. While the maximum rise in temperature was about 10 °C for bare tissue, it was 19 °C for tissue embedded with gold nanostructures and 38 °C for graphene-embedded tissues. The axial temperature distribution predicted by computational simulation matched the experimental observations. A different subsurface temperature distribution has been obtained for different tissue vascular network models. The position of LBVs must be known in order to achieve optimal tissue necrosis. The simulation described here helps in predicting subsurface temperature distributions within tissues during plasmonic photo-thermal therapy so that the risks of damage and complications associated with in vivo experiments and therapy may be avoided.

Isobaric thermal expansivity behaviour against temperature and pressure of associating fluids

Energy Technology Data Exchange (ETDEWEB)

Navia, Paloma; Troncoso, Jacobo [Departamento de Fisica Aplicada, Facultad de Ciencias de Ourense, Campus As Lagoas, 32004 Ourense (Spain); Romani, Luis, E-mail: romani@uvigo.e [Departamento de Fisica Aplicada, Facultad de Ciencias de Ourense, Campus As Lagoas, 32004 Ourense (Spain)

2010-01-15

In order to study the influence of association on the isobaric thermal expansivity, this magnitude has been experimentally determined for a set of associating fluids within the temperature and pressure intervals (278.15 to 348.15) K and (5 to 55) MPa by means of calorimetric measurements. The 1-alcohol series, from methanol to 1-decanol, 2-pentanol, 3-pentanol, and 1-pentylamine were selected. With a view on checking the quality of the experimental data, they are compared with available literature values; good coherence was obtained for most of the studied liquids. The analysis of the experimental results reveals that the association capability presents a strong influence not only on the value of the isobaric thermal expansivity itself, but also on its behaviour against temperature and pressure.

Isobaric thermal expansivity behaviour against temperature and pressure of associating fluids

International Nuclear Information System (INIS)

Navia, Paloma; Troncoso, Jacobo; Romani, Luis

2010-01-01

In order to study the influence of association on the isobaric thermal expansivity, this magnitude has been experimentally determined for a set of associating fluids within the temperature and pressure intervals (278.15 to 348.15) K and (5 to 55) MPa by means of calorimetric measurements. The 1-alcohol series, from methanol to 1-decanol, 2-pentanol, 3-pentanol, and 1-pentylamine were selected. With a view on checking the quality of the experimental data, they are compared with available literature values; good coherence was obtained for most of the studied liquids. The analysis of the experimental results reveals that the association capability presents a strong influence not only on the value of the isobaric thermal expansivity itself, but also on its behaviour against temperature and pressure.

Thermal characteristics and corrosion behaviour of Mg–xZn alloys ...

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science; Volume 36; Issue 6. Thermal characteristics and corrosion behaviour of Mg–Zn alloys for biomedical applications. Amir Fereidouni Lotfabadi Mohd Hasbullah Idris Ali Ourdjini Mohammed Rafiq Abdul Kadir Saeed Farahany Hamid Reza Bakhsheshi-Rad. Volume 36 Issue 6 ...

Characterisation of Ground Thermal and Thermo-Mechanical Behaviour for Shallow Geothermal Energy Applications

DEFF Research Database (Denmark)

Vieira, Ana; Alberdi-Pagola, Maria; Christodoulides, Paul

2017-01-01

Increasing use of the ground as a thermal reservoir is expected in the near future. Shallow geothermal energy (SGE) systems have proved to be sustainable alternative solutions for buildings and infrastructure conditioning in many areas across the globe in the past decades. Recently novel solutions......-hydro-mechanical behaviour of soil is introduced and discussed. These coupled processes are important for confirming the structural integrity of energy geostructures, but routine methods for parameter determination are still lacking (Energies). Keywords: shallow geothermal systems; soil thermal behaviour; laboratory testing......, including energy geostructures, where SGE systems are coupled with foundation heat exchangers, have also been developed. The performance of these systems is dependent on a series of factors, among which the thermal properties of the soil play a major role. The purpose of this paper is to present...

The effect of real-time context-aware feedback on occupants' heating behaviour and thermal adaptation

OpenAIRE

Vellei, Marika; Natarajan, Sukumar; Biri, Benjamin; Padget, Julian; Walker, Ian

2016-01-01

Studies have shown that building energy demand in identical dwellings could vary by a factor of three. Differences in occupant behaviour – i.e. purchase, operation and maintenance – have been implicated as a strong source of these differences. The literature suggests that feedback on energy use to building occupants – particularly real-time feedback – can be used to prompt lower operation-related energy behaviours. This is particularly true for thermal demand which, in cold countries, account...

Simplified methods applied to the complete thermal and mechanical behaviour of a pressure vessel during a severe accident

International Nuclear Information System (INIS)

Dupas, P.

1996-01-01

EDF has developed a software package of simplified methods (proprietary ones from literature) in order to study the thermal and mechanical behaviour of a PWR pressure vessel during a severe accident involving a corium localization in the vessel lower head. Using a part of this package, we can evaluate for instance successively: the heat flux at the inner surface of the vessel (conductive or convective pool of corium); the thermal exchange coefficient between the vessel and the outside (dry pit or flooded pit, watertight thermal insulation or not); the complete thermal evolution of the vessel (temperature profile, melting); the possible global plastic failure of the vessel; the creep behaviour in the vessel. These simplified methods are low cost alternative to finite element calculations which are yet used to validate the previous methods, waiting for experimental results to come. (authors)

Thermal shock behaviour of different tungsten grades under varying conditions

Energy Technology Data Exchange (ETDEWEB)

Wirtz, Oliver Marius

2012-07-19

Thermonuclear fusion power plants are a promising option to ensure the energy supply for future generations, but in many fields of research enormous challenges have to be faced. A major step on the way to the prototype fusion reactor DEMO will be ITER which is build in Cadarache, southern France. One of the most critical issues is the field of in-vessel materials and components, in particular the plasma facing materials (PFM). PFMs that will be used in a device like ITER have to withstand severe environmental conditions in terms of steady state and transient thermal loads as well as high particle fluxes such as hydrogen, helium and neutrons. Candidate wall materials are beryllium, tungsten and carbon based materials like CFC (carbon fibre composite). Tungsten is the most promising material for an application in the divertor region with very severe loading conditions and it will most probably also be used as PFM for DEMO. Hence, this work focuses on the investigation of the thermal shock response of different tungsten grades in order to understand the damage mechanisms and to identify material parameters which influence this behaviour under ITER and DEMO relevant operation conditions. Therefore the microstructure and the mechanical and thermal properties of five industrially manufactured tungsten grades were characterised. All five tungsten grades were exposed to transient thermal events with very high power densities of up to 1.27 GWm{sup -2} at varying base temperatures between RT and 600 C in the electron beam device JUDITH 1. The pulse numbers were limited to a maximum of 1000 in order to avoid immoderate workload on the test facility and to have enough time to cover a wide range of loading conditions. The results of this damage mapping enable to define different damage and cracking thresholds for the investigated tungsten grades and to identify certain material parameters which influence the location of these thresholds and the distinction of the induced

Thermal shock behaviour of different tungsten grades under varying conditions

International Nuclear Information System (INIS)

Wirtz, Oliver Marius

2012-01-01

Thermonuclear fusion power plants are a promising option to ensure the energy supply for future generations, but in many fields of research enormous challenges have to be faced. A major step on the way to the prototype fusion reactor DEMO will be ITER which is build in Cadarache, southern France. One of the most critical issues is the field of in-vessel materials and components, in particular the plasma facing materials (PFM). PFMs that will be used in a device like ITER have to withstand severe environmental conditions in terms of steady state and transient thermal loads as well as high particle fluxes such as hydrogen, helium and neutrons. Candidate wall materials are beryllium, tungsten and carbon based materials like CFC (carbon fibre composite). Tungsten is the most promising material for an application in the divertor region with very severe loading conditions and it will most probably also be used as PFM for DEMO. Hence, this work focuses on the investigation of the thermal shock response of different tungsten grades in order to understand the damage mechanisms and to identify material parameters which influence this behaviour under ITER and DEMO relevant operation conditions. Therefore the microstructure and the mechanical and thermal properties of five industrially manufactured tungsten grades were characterised. All five tungsten grades were exposed to transient thermal events with very high power densities of up to 1.27 GWm -2 at varying base temperatures between RT and 600 C in the electron beam device JUDITH 1. The pulse numbers were limited to a maximum of 1000 in order to avoid immoderate workload on the test facility and to have enough time to cover a wide range of loading conditions. The results of this damage mapping enable to define different damage and cracking thresholds for the investigated tungsten grades and to identify certain material parameters which influence the location of these thresholds and the distinction of the induced damages

Economic thermoregulatory response explains mismatch between thermal physiology and behaviour in newts

Czech Academy of Sciences Publication Activity Database

Gvoždík, Lumír; Kristín, Peter

2017-01-01

Roč. 220, č. 6 (2017), s. 1106-1111 ISSN 0022-0949 R&D Projects: GA ČR(CZ) GA15-07140S Institutional support: RVO:68081766 Keywords : Aerobic scope * Amphibians * Preferred temperature * Specific dynamic action * Thermal niche * Thermoregulatory behaviour Subject RIV: EG - Zoology OBOR OECD: Biology (theoretical, mathematical, thermal, cryobiology, biological rhythm), Evolutionary biology Impact factor: 3.320, year: 2016

Thermal behaviour of nicotinic acid, sodium nicotinate and its compounds with some bivalent transition metal ions

Energy Technology Data Exchange (ETDEWEB)

Nascimento, A.L.C.S. do; Caires, F.J., E-mail: caires.flavio@yahoo.com.br; Gomes, D.J.C.; Gigante, A.C.; Ionashiro, M.

2014-01-10

Graphical abstract: - Highlights: • The transition metal ion nicotinates were synthesized. • The TG–DTA curves provided previously unreported information about thermal behaviour. • The gaseous products released were detected by TG–DSC coupled to FTIR. - Abstract: Solid-state M(L){sub 2}·nH{sub 2}O compounds, where M stands for bivalent transition metals (Mn, Fe, Co, Ni, Cu and Zn), L is nicotinate and n = 0–4.5, have been synthesized. Characterization and thermal behaviour of these compounds were investigated employing elemental analysis based on the mass losses observed in the TG–DTA curves, complexometry, X-ray diffractometry, infrared spectroscopy (FTIR), simultaneous thermogravimetric and differential thermal analysis (TG–DTA) and TG–DSC coupled to FTIR. The thermal behaviour of nicotinic acid and its sodium salt was also investigated. For the hydrated transition metal compounds, the dehydration and thermal decomposition of the anhydrous compounds occur in a single step. For the sodium nicotinate, the final residue up to 765 °C is sodium carbonate and for the transition metal nicotinates, the final residues are Mn{sub 3}O{sub 4}, Fe{sub 2}O{sub 3}, Co{sub 3}O{sub 4}, NiO, CuO and ZnO. The results also provided information concerning the thermal stability, thermal decomposition and identification of the gaseous products evolved during the thermal decomposition of the compounds.

Thermal behaviour of nicotinic acid, sodium nicotinate and its compounds with some bivalent transition metal ions

International Nuclear Information System (INIS)

Nascimento, A.L.C.S. do; Caires, F.J.; Gomes, D.J.C.; Gigante, A.C.; Ionashiro, M.

2014-01-01

Graphical abstract: - Highlights: • The transition metal ion nicotinates were synthesized. • The TG–DTA curves provided previously unreported information about thermal behaviour. • The gaseous products released were detected by TG–DSC coupled to FTIR. - Abstract: Solid-state M(L) 2 ·nH 2 O compounds, where M stands for bivalent transition metals (Mn, Fe, Co, Ni, Cu and Zn), L is nicotinate and n = 0–4.5, have been synthesized. Characterization and thermal behaviour of these compounds were investigated employing elemental analysis based on the mass losses observed in the TG–DTA curves, complexometry, X-ray diffractometry, infrared spectroscopy (FTIR), simultaneous thermogravimetric and differential thermal analysis (TG–DTA) and TG–DSC coupled to FTIR. The thermal behaviour of nicotinic acid and its sodium salt was also investigated. For the hydrated transition metal compounds, the dehydration and thermal decomposition of the anhydrous compounds occur in a single step. For the sodium nicotinate, the final residue up to 765 °C is sodium carbonate and for the transition metal nicotinates, the final residues are Mn 3 O 4 , Fe 2 O 3 , Co 3 O 4 , NiO, CuO and ZnO. The results also provided information concerning the thermal stability, thermal decomposition and identification of the gaseous products evolved during the thermal decomposition of the compounds

The effect of gamma irradiation on the thermal expansion behaviour of oriented polypropylene

International Nuclear Information System (INIS)

Godjevargov, L.; Novakovic, L.J.; Kostoski, D.

1991-01-01

Quenched and air-cooled samples of oriented polypropylene have been irradiated to 300 kGy adsorbed dose in the presence of air. The parallel thermal expansion coefficient decreases and becomes negative with increasing orientation. The effect of adsorbed dose on the thermal expansion behaviour is practically negligible. (author) 4 refs.; 4 figs

Combustion behaviour and deposition characteristics of Cynara Cardunculus/Greek lignite co-firing under various thermal shares in a thermal pilot-scale facility

Energy Technology Data Exchange (ETDEWEB)

Fuller, Aaron; Maier, Joerg; Scheffknecht, Guenter [Stuttgart Univ. (Germany). Inst. of Combustion and Power Plant Technology; Pawlak-Kruczek, Halina [Wroclaw Univ. of Technology (Poland). Inst. of Heat Engineering and Fluid Mechanics; Karampinis, Emmanouil; Grammelis, Panagiotis; Kakaras, Emmanuel [Centre for Research and Technology Hellas, Ptolemais (Greece). Chemical Process and Energy Resources Inst.; National Technical Univ. of Athens (Greece). Lab. of Steam Boilers and Thermal Plants

2013-06-01

The combustion of herbaceous biomass in industrial boilers, either as co-firing fuel or in dedicated combustion units, possess significant operating challenges due to increased risks for corrosion and slagging/fouling. The present work aims at investigating the combustion behaviour of Cynara Cardunculus (cardoon) in a range of thermal shares (0 to 100 %) with a Greek lignite. Combustion tests were performed in a 0.5 MW thermal input pulverised fuel pilot-scale test facility. Deposits were characterised in terms of morphological and ash fusion behaviour, and slagging/fouling tendencies were determined. (orig.)

Aprediction study for the behaviour of fuel cell membrane subjected to hygro and thermal stresses in running PEM fuel cell

OpenAIRE

Maher A.R. Sadiq Al-Baghdadi

2016-01-01

A three-dimensional, multi–phase, non-isothermal computational fluid dynamics model of a proton exchange membrane fuel cell has been used and developed to investigate the hygro and thermal stresses in polymer membrane, which developed during the cell operation due to the changes of temperature and relative humidity. The behaviour of the membrane during operation of a unit cell has been studied and investigated under real cell operating conditions. The results show that the non-uniform distrib...

Thermal expansion behaviour of high performance PEEK matrix composites

International Nuclear Information System (INIS)

Goyal, R K; Mulik, U P; Tiwari, A N; Negi, Y S

2008-01-01

The thermal expansion behaviour of high performance poly(ether-ether-ketone) (PEEK) composites reinforced with micro- (8 μm) and nano- (39 nm) sized Al 2 O 3 particles was studied. The distribution of Al 2 O 3 in the PEEK matrix was studied by scanning electron microscopy and transmission electron microscopy. The coefficient of thermal expansion (CTE) was reduced from 58 x 10 -6 deg. C -1 for pure PEEK to 22 x 10 -6 deg. C -1 at 43 vol% micro-Al 2 O 3 and to 23 x 10 -6 deg. C -1 at 12 vol% nano-Al 2 O 3 composites. For a given volume fraction, nano-Al 2 O 3 particles are more effective in reducing the CTE of composites than that of micro-Al 2 O 3 particles. This may be attributed to the much higher interfacial area or volume of nanocomposites than that of microcomposites. The upper limit and lower limit of the Schapery model separately fit closely the CTE of the micro- and nano-composites, respectively. Other models such as the rule of mixture and Kerner and Turner models were also correlated with the data

Thermal behaviour of strontium tartrate single crystals grown in gel

Indian Academy of Sciences (India)

Unknown

Keywords. Strontium tartrate; dopant; effect of magnetic field; thermal behaviour. 1. Introduction ... tals of such type of compounds cannot be grown by either slow evaporation or ... is observed under a stereo binocular microscope (Carl. Zeiss) and ... a depth of 1⋅8 cm due to the diffusion of the top solution. After about a week ...

Simulating the swelling and deformation behaviour in soft tissues using a convective thermal analogy

Directory of Open Access Journals (Sweden)

Herzog Walter

2002-12-01

Full Text Available Abstract Background It is generally accepted that cartilage adaptation and degeneration are mechanically mediated. Investigating the swelling behaviour of cartilage is important because the stress and strain state of cartilage is associated with the swelling and deformation behaviour. It is well accepted that the swelling of soft tissues is associated with mechanical, chemical, and electrical events. Method The purpose of the present study was to implement the triphasic theory into a commercial finite element tool (ABAQUS to solve practical problems in cartilage mechanics. Because of the mathematical identity between thermal and mass diffusion processes, the triphasic model was transferred into a convective thermal diffusion process in the commercial finite element software. The problem was solved using an iterative procedure. Results The proposed approach was validated using the one-dimensional numerical solutions and the experimental results of confined compression of articular cartilage described in the literature. The time-history of the force response of a cartilage specimen in confined compression, which was subjected to swelling caused by a sudden change of saline concentration, was predicted using the proposed approach and compared with the published experimental data. Conclusion The advantage of the proposed thermal analogy technique over previous studies is that it accounts for the convective diffusion of ion concentrations and the Donnan osmotic pressure in the interstitial fluid.

Synthesis and thermal behaviour of pauflerite, β-VOSO4, and its α-modification

International Nuclear Information System (INIS)

Paufler, Peter; Filatov, Stanislav K.; Krzhizhanovskaya, Maria G.; Bubnova, Rimma S.; Russian Academy of Sciences, St. Peterburg

2014-01-01

Powder α-VOSO 4 was prepared by dehydration of VOSO 4 . 3H 2 O. β-VOSO 4 was synthesized by boiling of V 2 O 5 in H 2 SO 4 . Thermal behaviour of VOSO 4 . 3H 2 O, α- and β-VOSO 4 modifications is studied by high-temperature powder X-ray diffraction and thermal analysis, including two-step dehydration of VOSO 4 . 3H 2 O, formation of α-VOSO 4 , thermal expansion and decomposition of both modifications into V 2 O 5 . Higher anisotropy of thermal expansion of the tetragonal α-modification α c = 39(2) . 10 -6 K -1 along the vanadyl ion and α a = 2.4(6) . 10 -6 K -1 in the perpendicular direction comparing to the orthorhombic β-modification (α a = 20.2(7), α b = 2.8(8), α c = 17.8(4) . 10 -6 K -1 ) is explained from a crystal chemical point of view.

Behaviour of Ti-doped CFCs under thermal fatigue tests

Energy Technology Data Exchange (ETDEWEB)

Centeno, A. [Instituto Nacional del Carbon (CSIC), Apdo. 73, 33080 Oviedo (Spain); Pintsuk, G.; Linke, J. [Forschungszentrum Juelich GmbH, EURATOM Association, 52425 Juelich (Germany); Gualco, C. [Ansaldo Energia, I-16152 Genoa (Italy); Blanco, C., E-mail: clara@incar.csic.es [Instituto Nacional del Carbon (CSIC), Apdo. 73, 33080 Oviedo (Spain); Santamaria, R.; Granda, M.; Menendez, R. [Instituto Nacional del Carbon (CSIC), Apdo. 73, 33080 Oviedo (Spain)

2011-01-15

In spite of the remarkable progress in the design of in-vessel components for the divertor of the first International Thermonuclear Experimental Reactor (ITER), a great effort is still put into the development of manufacturing technologies for carbon armour with improved properties. Newly developed 3D titanium-doped carbon fibre reinforced composites and their corresponding undoped counterparts were brazed to a CuCrZr heat sink to produce actively cooled flat tile mock-ups. By exposing the mock-ups to thermal fatigue tests in an electron beam test facility, the material behaviour and the brazing between the individual constituents in the mock-up was qualified. The mock-ups with titanium-doped CFCs exhibited a significantly improved thermal fatigue resistance compared with those undoped materials. The comparison of these mock-ups with those produced using pristine NB31, one of the reference materials as plasma facing material for ITER, showed almost identical results, indicating the high potential of Ti-doped CFCs due to their improved thermal shock resistance.

Temperature effect on the poro-mechanical or hydraulic behaviour of a carbonated rock and a mortar: experimental studies

International Nuclear Information System (INIS)

Lion, M.

2004-07-01

The main objective of this study is to evaluate the temperature effect on the hydraulic and poro-mechanical behaviour of a limestone. Many experimental tests (porosity and permeability measurements, uniaxial and hydrostatic compressions tests) were carried out in order to study the thermal treatments effect and so the thermal microcracking effect on rock behaviour. Moreover, an experimental device for permeability measurements under high temperatures (until 200 C) was realized. This experimental device permitted to study the permeability variation of the limestone under thermal stresses. Finally, the behaviour of cementitious materials was studied; the temperature effect on the permeability of a mortar was examined. (author)

The thermal fatigue behaviour of creep-resistant Ni-Cr cast steel

Directory of Open Access Journals (Sweden)

B. Piekarski

2007-12-01

Full Text Available The study gives a summary of the results of industrial and laboratory investigations regarding an assessment of the thermal fatigue behaviour of creep-resistant austenitic cast steel. The first part of the study was devoted to the problem of textural stresses forming in castings during service, indicating them as a cause of crack formation and propagation. Stresses are forming in carbides and in matrix surrounding these carbides due to considerable differences in the values of the coefficients of thermal expansion of these phases. The second part of the study shows the results of investigations carried out to assess the effect of carbon, chromium and nickel on crack resistance of austenitic cast steel. As a criterion of assessment the amount and propagation rate of cracks forming in the specimens as a result of rapid heating followed by cooling in running water was adopted. Tests were carried out on specimens made from 11 alloys. The chemical composition of these alloys was comprised in a range of the following values: (wt-%: 18-40 %Ni, 17-30 %Cr, 1.2-1.6%Si and 0.05-0.6 %C. The specimens were subjected to 75 cycles of heating to a temperature of 900oC followed by cooling in running water. After every 15 cycles the number of the cracks was counted and their length was measured. The results of the measurements were mathematically processed. It has been proved that the main factor responsible for an increase in the number of cracks is carbon content in the alloy. In general assessment of the results of investigations, the predominant role of carbon and of chromium in the next place in shaping the crack behaviour of creep-resistant austenitic cast steel should be stressed. Attention was also drawn to the effect of high-temperature corrosion as a factor definitely deteriorating the cast steel resistance to thermal fatigue.

Stress recovery and cyclic behaviour of an Fe-Mn-Si shape memory alloy after multiple thermal activation

Science.gov (United States)

Hosseini, E.; Ghafoori, E.; Leinenbach, C.; Motavalli, M.; Holdsworth, S. R.

2018-02-01

The stress recovery and cyclic deformation behaviour of Fe-17Mn-5Si-10Cr-4Ni-1(V,C) shape memory alloy (Fe-SMA) strips, which are often used for pre-stressed strengthening of structural members, were studied. The evolution of recovery stress under different constraint conditions was studied. The results showed that the magnitude of the tensile stress in the Fe-SMA member during thermal activation can have a signification effect on the final recovery stress. The higher the tensile load in the Fe-SMA (e.g., caused by dead load or thermal expansion of parent structure during heating phase), the lower the final recovery stress. Furthermore, this study investigated the cyclic behaviour of the activated SMA followed by a second thermal activation. Although the magnitude of the recovery stress decreased during the cyclic loading, the second thermal activation could retrieve a significant part of the relaxed recovery stress. This observation suggests that the relaxation of recovery stress during cyclic loading is due to a reversible phase transformation-induced deformation (i.e., forward austenite-to-martensite transformation) rather than an irreversible dislocation-induced plasticity. Retrieval of the relaxed recovery stress by the reactivation process has important practical implications as the prestressing loss in pre-stressed civil structures can be simply recovered by reheating of the Fe-SMA elements.

Achieving dynamic behaviour and thermal expansion in the organic solid state via co-crystallization.

Science.gov (United States)

Hutchins, Kristin M; Groeneman, Ryan H; Reinheimer, Eric W; Swenson, Dale C; MacGillivray, Leonard R

2015-08-01

Thermal expansion involves a response of a material to an external stimulus that typically involves an increase in a crystallographic axis (positive thermal expansion (PTE)), although shrinking with applied heat (negative thermal expansion (NTE)) is known in rarer cases. Here, we demonstrate a means to achieve dynamic molecular motion and thermal expansions in organic solids via co-crystallizations. One co-crystal component is known to exhibit dynamic behaviour in the solid state while the second, when varied systematically, affords co-crystals with linear thermal expansion coefficients that range from colossal to nearly zero. Two co-crystals exhibit rare NTE. We expect the approach to guide the design of molecular solids that enable predesigned motion related to thermal expansion processes.

Thermal studies on a mechanical prototype of A BIS MDT chamber

CERN Document Server

Petridou, C; Wotschack, J; Zisis, A

1998-01-01

The deformations of a BIS MDT chamber owing to temperature gradients between the two multilayers and between the two Faraday cages were studied on a mechanical prototype. The influence of thermal insulation on the thermal behaviour of the chamber is also reported.

Characterization and thermal behaviour of textile waste from the industrial city of Aleppo in Syria.

Science.gov (United States)

Majanny, Abdulkader; Nassour, Abdallah; Gose, Sven; Scholz, Reinhard; Nelles, Michael

2011-03-01

This paper describes the present waste management practices in the industrial city Alsheikh Najjar of Aleppo, mainly with regard to textile waste materials, and provides some insights into future prospects. As a first exploration for energy recovery from textile waste materials, the thermal behaviour of seven different types of textile waste were studied by thermogravimetry. There were assorted differential thermogravimetry peaks found over a particular range of temperatures. Pyrolysis experiments were carried out to identify the pyrolysis products such as gas, liquid, and solid residues known as char. In a subsequent analysis, the combustion behaviour of textile waste was determined and analysed. Typical parameters - reaction front velocity, ignition rate - were considered for the evaluation of the combustion behaviour and the results were compared with values observed for waste wood.

New WC-Cu thermal barriers for fusion applications: High temperature mechanical behaviour

Science.gov (United States)

Tejado, E.; Dias, M.; Correia, J. B.; Palacios, T.; Carvalho, P. A.; Alves, E.; Pastor, J. Y.

2018-01-01

The combination of tungsten carbide and copper as a thermal barrier could effectively reduce the thermal mismatch between tungsten and copper alloy, which are proposed as base armour and heat sink, respectively, in the divertor of future fusion reactors. Furthermore, since the optimum operating temperature windows for these divertor materials do not overlap, a compatible thermal barrier interlayer between them is required to guarantee a smooth thermal transition, which in addition may mitigate radiation damage. The aim of this work is to study the thermo-mechanical properties of WC-Cu cermets fabricated by hot pressing. Focus is placed on the temperature effect and composition dependence, as the volume fraction of copper varies from 25 to 50 and 75 vol%. To explore this behaviour, fracture experiments are performed within a temperature range from room temperature to 800 °C under vacuum. In addition, elastic modulus and thermal expansion coefficient are estimated from these tests. Results reveal a strong dependence of the performance on temperature and on the volume fraction of copper and, surprisingly, a slight percent of Cu (25 vol%) can effectively reduce the large difference in thermal expansion between tungsten and copper alloy, which is a critical point for in service applications. The thermal performance of these materials, together with their mechanical properties could indeed reduce the heat transfer from the PFM to the underlying element while supporting the high thermal stresses of the joint. Thus, the presence of these cermets could allow the reactor to operate above the ductile to brittle transition temperature of tungsten, without compromising the underlying materials.

Study of heat and hydraulic diffusions in clays under thermal loading

International Nuclear Information System (INIS)

Djeran, I.

1993-01-01

This study is a cost-sharing research programme on radioactive waste disposal and radioactive waste management. The thermal conductivity of clays is the fundamental parameter which governs the thermal diffusion and the pore pressure of the rock mass under thermal loading. Experiments have been undertaken in a reduced model, respecting representative boundary conditions. They show that the thermal conductivity depends on temperature in an unfavourable sense to the decrease of heat. On the other hand, the outflow of pore water, from the source to the exterior, has a low amplitude. A single model of porous medium allows the observations and illustrates the effects of the variation of conductivity on the behaviour of rock mass. Finally, thanks to the numerical formulations specially developed, we examine the incident of the particularities of proposed models on the thermohydromechanical behaviour of geometrically simple structures subjected to a given thermal loading

Thermal and mechanical behaviour of an experimental mock-up of a nuclear containment

International Nuclear Information System (INIS)

Chauvel, D.; Barre, F.

2007-01-01

In order to better understand the behaviour of a reactor containment submitted to combined pressure and temperature loads by means of studies of the concrete permeability and the state of cracking evolution, EDF and its French partners have built a prestressed concrete test model which represents a PWR containment typical section. The monitoring system was designed to follow the evolution of strains, temperature and state of cracking of the concrete wall from construction stage to air and steam tests. The measurements results as well as their comparison with theoretical laws or data and calculated values, allow to determine the main thermal and mechanical characteristics of the concrete, to analyse the thermo-mechanical behaviour of the structure and also to check the design criteria of prestressed concrete containments. (authors)

Behaviours of reinforced concrete containment models under thermal gradient and internal pressure

International Nuclear Information System (INIS)

Aoyagi, Y.; Ohnuma, H.; Yoshioka, Y.; Okada, K.; Ueda, M.

1979-01-01

The provisions for design concepts in Japanese Technical Standard of Concrete Containments for Nuclear Power Plants require to take account of thermal effects into design. The provisions also propose that the thermal effects could be relieved according to the degree of crack formation and creep of concrete, and may be neglected in estimating the ultimate strength capacity in extreme environmental loading conditions. This experimental study was carried out to clarify the above provisions by investigating the crack and deformation behaviours of two identical reinforced cylindrical models with dome and basement (wall outer diameter 160 cm, and wall thickness 10 cm). One of these models was hydraulically pressurized up to failure at room temperature and the other was subjected to similar internal pressure combined with the thermal gradient of approximately 40 to 50 0 C across the wall. Initial visual cracks were recognized when the stress induced by the thermal gradient reached at about 85% of bending strength of concrete used. The thermal stress of reinforcement calculated with the methods proposed by the authors using an average flexural rigidity considering the contribution of concrete showed good agreement with test results. The method based on the fully cracked section, however, was recognized to underestimate the measured stress. These cracks considerably reduced the initial deformation caused by subsequent internal pressure. (orig.)

Thermal behaviour of hafnium diethylenetriaminepentaacetate studied using the perturbed angular correlation technique

Energy Technology Data Exchange (ETDEWEB)

Chain, Cecilia Y. [Universidad Nacional de La Plata (Argentina). Dept. de Fisica; Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), La Plata (Argentina). IFLP-CCT; Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires (Argentina); Rivas, Patricia [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), La Plata (Argentina). IFLP-CCT; Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires (Argentina); Universidad Nacional de La Plata (Argentina). Facultad de Ciencias Agrarias y Forestales; Pasquevich, Alberto F. [Universidad Nacional de La Plata (Argentina). Dept. de Fisica; Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), La Plata (Argentina). IFLP-CCT; Comision de Investigaciones Cientificas de la Provincia de Buenos Aires (CIC-PBA) (Argentina)

2014-07-01

Polyaminecarboxilic ligands like diethylenetriaminepentaacetic acid form stable complexes with many heavy metal ions, excelling as cation chelants especially in the field of radiopharmacy. The aim of this work is to characterize, by using the Time Differential Perturbed Angular Correlations (TDPAC) technique, the hyperfine interactions at hafnium sites in hafnium diethylenetriaminepentaacetate and to investigate their evolution as temperature increases. TDPAC results for KHfDTPA.3H{sub 2}O obtained by chemical synthesis yield a well defined and highly asymmetric interaction of quadrupole frequency ω{sub Q} = 141 Mrad/s, which is consistent with the existence of a unique site for the metal in the crystal lattice. The thermal behaviour of the chelate is investigated by means of differential scanning calorimetry and thermogravimetrical analyses revealing that an endothermic dehydration of KHfDTPA.3H{sub 2}O takes place in one step between 80 C and 180 C. The anhydrous KHfDTPA thus arising is characterized by a fully asymmetric and well defined interaction of quadrupole frequency ω{sub Q} = 168 Mrad/s. (orig.)

Thermal behaviour of hafnium diethylenetriaminepentaacetate studied using the perturbed angular correlation technique

International Nuclear Information System (INIS)

Chain, Cecilia Y.; Rivas, Patricia

2014-01-01

Polyaminecarboxilic ligands like diethylenetriaminepentaacetic acid form stable complexes with many heavy metal ions, excelling as cation chelants especially in the field of radiopharmacy. The aim of this work is to characterize, by using the Time Differential Perturbed Angular Correlations (TDPAC) technique, the hyperfine interactions at hafnium sites in hafnium diethylenetriaminepentaacetate and to investigate their evolution as temperature increases. TDPAC results for KHfDTPA.3H 2 O obtained by chemical synthesis yield a well defined and highly asymmetric interaction of quadrupole frequency ω Q = 141 Mrad/s, which is consistent with the existence of a unique site for the metal in the crystal lattice. The thermal behaviour of the chelate is investigated by means of differential scanning calorimetry and thermogravimetrical analyses revealing that an endothermic dehydration of KHfDTPA.3H 2 O takes place in one step between 80 C and 180 C. The anhydrous KHfDTPA thus arising is characterized by a fully asymmetric and well defined interaction of quadrupole frequency ω Q = 168 Mrad/s. (orig.)

Structure, mechanical and thermal behaviour of mixtures of polyester resin and dental ceramic waste

Science.gov (United States)

Peña Rodríguez, G.; Martínez Maldonado, L.; Dulce Moreno, H. J.

2016-02-01

The tensile strength and bending strength, structure and thermal behaviour of mixtures of polyester resin (P-2000) and powders (ASTM sieve 200, dental ceramic wastes (dentals impressions, alginate and gypsum) was reported. The samples consisted of mixtures with percentage weights of 50-50%, 60-40%, 70-30%, 80-20%, 90-10%, where the resin was the majority phase, the Mekc (4% wt) was used as catalyst. The structure was studied using SEM and XRD, the thermal behaviour using DSC, TGA and DMA, while the mechanical strength was tested using standards ASTM D790 and D638. Irregular morphology and presence of small agglomerations was observed, with particle sizes between 29.63 and 38.67μm, the presence of different phases of calcium sulphate was found, and that to the increasing the concentration of the powder, the materials becomes more crystalline, increasing its density. An average service temperature of 69.15±4.60°C was found. Vickers hardness values are reported in ranges from 18.65 to 27.96. Considering the elastic modules was established that the materials become more rigid by having more powder concentration.

External Thermal Insulation Composite Systems: Critical Parameters for Surface Hygrothermal Behaviour

Directory of Open Access Journals (Sweden)

Eva Barreira

2014-01-01

Full Text Available External Thermal Insulation Composite Systems (ETICS are often used in Europe. Despite its thermal advantages, low cost, and ease of application, this system has serious problems of biological growth causing the cladding defacement. Recent studies pointed that biological growth is due to high values of surface moisture content, which mostly results from the combined effect of exterior surface condensation, wind-driven rain, and drying process. Based on numerical simulation, this paper points the most critical parameters involved in hygrothermal behaviour of ETICS, considering the influence of thermal and hygric properties of the external rendering, the effect of the characteristics of the façade, and the consequences of the exterior and interior climate on exterior surface condensation, wind-driven rain, and drying process. The model used was previously validated by comparison with the results of an “in situ” campaign. The results of the sensitivity analyses show that relative humidity and temperature of the exterior air, atmospheric radiation, and emissivity of the exterior rendering are the parameters that most influence exterior surface condensation. Wind-driven rain depends mostly on horizontal rain, building’s height, wind velocity, and orientation. The drying capacity is influenced by short-wave absorbance, incident solar radiation, and orientation.

Thermal behaviour of layered double hydroxides studied by emanation thermal analysis

Czech Academy of Sciences Publication Activity Database

Dorničák, V.; Balek, V.; Kovanda, F.; Večerníková, Eva

90-91, - (2003), s. 475-480 ISSN 1012-0394 Institutional research plan: CEZ:AV0Z4032918 Keywords : hydrotalcite * layered double hydroxides * thermal decomposition Subject RIV: CA - Inorganic Chemistry Impact factor: 0.687, year: 2003

Behavioural responses to thermal conditions affect seasonal mass change in a heat-sensitive northern ungulate.

Directory of Open Access Journals (Sweden)

Floris M van Beest

Full Text Available BACKGROUND: Empirical tests that link temperature-mediated changes in behaviour (activity and resource selection to individual fitness or condition are currently lacking for endotherms yet may be critical to understanding the effect of climate change on population dynamics. Moose (Alces alces are thought to suffer from heat stress in all seasons so provide a good biological model to test whether exposure to non-optimal ambient temperatures influence seasonal changes in body mass. Seasonal mass change is an important fitness correlate of large herbivores and affects reproductive success of female moose. METHODOLOGY/PRINCIPAL FINDINGS: Using GPS-collared adult female moose from two populations in southern Norway we quantified individual differences in seasonal activity budget and resource selection patterns as a function of seasonal temperatures thought to induce heat stress in moose. Individual body mass was recorded in early and late winter, and autumn to calculate seasonal mass changes (n = 52 over winter, n = 47 over summer. We found large individual differences in temperature-dependent resource selection patterns as well as within and between season variability in thermoregulatory strategies. As expected, individuals using an optimal strategy, selecting young successional forest (foraging habitat at low ambient temperatures and mature coniferous forest (thermal shelter during thermally stressful conditions, lost less mass in winter and gained more mass in summer. CONCLUSIONS/SIGNIFICANCE: This study provides evidence that behavioural responses to temperature have important consequences for seasonal mass change in moose living in the south of their distribution in Norway, and may be a contributing factor to recently observed declines in moose demographic performance. Although the mechanisms that underlie the observed temperature mediated habitat-fitness relationship remain to be tested, physiological state and individual variation in

Behavioural responses to thermal conditions affect seasonal mass change in a heat-sensitive northern ungulate.

Science.gov (United States)

van Beest, Floris M; Milner, Jos M

2013-01-01

Empirical tests that link temperature-mediated changes in behaviour (activity and resource selection) to individual fitness or condition are currently lacking for endotherms yet may be critical to understanding the effect of climate change on population dynamics. Moose (Alces alces) are thought to suffer from heat stress in all seasons so provide a good biological model to test whether exposure to non-optimal ambient temperatures influence seasonal changes in body mass. Seasonal mass change is an important fitness correlate of large herbivores and affects reproductive success of female moose. Using GPS-collared adult female moose from two populations in southern Norway we quantified individual differences in seasonal activity budget and resource selection patterns as a function of seasonal temperatures thought to induce heat stress in moose. Individual body mass was recorded in early and late winter, and autumn to calculate seasonal mass changes (n = 52 over winter, n = 47 over summer). We found large individual differences in temperature-dependent resource selection patterns as well as within and between season variability in thermoregulatory strategies. As expected, individuals using an optimal strategy, selecting young successional forest (foraging habitat) at low ambient temperatures and mature coniferous forest (thermal shelter) during thermally stressful conditions, lost less mass in winter and gained more mass in summer. This study provides evidence that behavioural responses to temperature have important consequences for seasonal mass change in moose living in the south of their distribution in Norway, and may be a contributing factor to recently observed declines in moose demographic performance. Although the mechanisms that underlie the observed temperature mediated habitat-fitness relationship remain to be tested, physiological state and individual variation in thermal tolerance are likely contributory factors. Climate-related effects on animal

Mechanical and thermal behaviour of isotactic polypropylene reinforced with inorganic fullerene-like WS2 nanoparticles: Effect of filler loading and temperature

International Nuclear Information System (INIS)

Díez-Pascual, Ana M.; Naffakh, Mohammed

2013-01-01

The thermal and mechanical behaviour of isotactic polypropylene (iPP) nanocomposites reinforced with different loadings of inorganic fullerene-like tungsten disulfide (IF-WS 2 ) nanoparticles was investigated. The IF-WS 2 noticeably enhanced the polymer stiffness and strength, ascribed to their uniform dispersion, the formation of a large nanoparticle–matrix interface combined with a nucleating effect on iPP crystallization. Their reinforcement effect was more pronounced at high temperatures. However, a drop in ductility and toughness was found at higher IF-WS 2 concentrations. The tensile behaviour of the nanocomposites was extremely sensitive to the strain rate and temperature, and their yield strength was properly described by the Eyring's equation. The activation energy increased while the activation volume decreased with increasing nanoparticle loading, indicating a reduction in polymer chain motion. The nanoparticles improved the thermomechanical properties of iPP: raised the glass transition and heat deflection temperatures while decreased the coefficient of thermal expansion. The nanocomposites also displayed superior flame retardancy with longer ignition time and reduced peak heat release rate. Further, a gradual rise in thermal conductivity was found with increasing IF-WS 2 loading both in the glassy and rubbery states. The results presented herein highlight the benefits and high potential of using IF-nanoparticles for enhancing the thermomechanical properties of thermoplastic polymers compared to other nanoscale fillers. - Graphical abstract: Display Omitted - Highlights: • The thermal and mechanical behaviour of iPP/IF-WS 2 nanocomposites was studied. • Low IF-WS 2 contents provide a good balance between stiffness, strength and toughness. • Their tensile behaviour is sensitive to the strain rate and temperature. • The nanocomposites exhibit superior thermal conductivity and flame retardancy than iPP. • The benefits of using IF-WS 2 compared

Capsaicin-induced neurogenic inflammation in pig skin: A behavioural study

DEFF Research Database (Denmark)

di Giminiani, Pierpaolo; Petersen, Lars Jelstrup; Herskin, Mette S

2014-01-01

Topical capsaicin is a well-established model of experimental hyperalgesia. Its application to the study of animals has been limited to few species. The effect of topical capsaicin on hyperalgesia in porcine skin was evaluated as part of a study of inflammatory pain in the pig. Two experiments were...... carried out on pigs of 27 ± 5 kg (n = 8) and 57 ± 3 kg (n = 16). Thermal and mechanical noxious stimuli were provided (CO2 laser and Pressure Application Measurement device) to assess avoidance behaviours. Capsaicin induced significant thermal hyperalgesia in the smaller pigs (P

Study of the influence of surface anisotropy and lattice structure on the behaviour of a small magnetic cluster

International Nuclear Information System (INIS)

Hernandez, Laura; Pinettes, Claire

2005-01-01

We have studied by Monte Carlo simulations the thermal behaviour of a small (N=13 particles) cluster described by a Heisenberg model, including nearest-neighbour ferromagnetic interactions and radial surface anisotropy, in an applied magnetic field. We have studied three different lattice structures: hexagonal close packed, face centered cubic and icosahedral. We show that the zero-field thermal behaviour depends not only on the value of the anisotropy constant but also on the lattice structure. The behaviour in an applied field, additionally depends, on the different orientations of the field with respect to the crystal axes. According to these relative orientations, hysteresis cycles show different step-like characteristics

Study of the influence of surface anisotropy and lattice structure on the behaviour of a small magnetic cluster

Energy Technology Data Exchange (ETDEWEB)

Hernandez, Laura [Laboratoire de Physique Theorique et Modelisation, CNRS-UMR 8089, Universite de Cergy-Pontoise, 5 mail Gay Lussac, Neuville-sur-Oise, 95031 Cergy-Pontoise, Cedex (France)]. E-mail: Laura.Hernandez@ptm.u-cergy.fr; Pinettes, Claire [Laboratoire de Physique Theorique et Modelisation, CNRS-UMR 8089, Universite de Cergy-Pontoise, 5 mail Gay Lussac, Neuville-sur-Oise, 95031 Cergy-Pontoise, Cedex (France)

2005-08-15

We have studied by Monte Carlo simulations the thermal behaviour of a small (N=13 particles) cluster described by a Heisenberg model, including nearest-neighbour ferromagnetic interactions and radial surface anisotropy, in an applied magnetic field. We have studied three different lattice structures: hexagonal close packed, face centered cubic and icosahedral. We show that the zero-field thermal behaviour depends not only on the value of the anisotropy constant but also on the lattice structure. The behaviour in an applied field, additionally depends, on the different orientations of the field with respect to the crystal axes. According to these relative orientations, hysteresis cycles show different step-like characteristics.

Long-term behaviour of binary Ti–49.7Ni (at.%) SMA actuators—the fatigue lives and evolution of strains on thermal cycling

International Nuclear Information System (INIS)

Karhu, Marjaana; Lindroos, Tomi

2010-01-01

Long-term behaviour and fatigue endurance are the key issues in the utilization of SMA actuators, but systematic research work is still needed in this field. This study concentrates on the effects of three major design parameters on the long-term behaviour of binary Ti–49.7Ni-based actuators: the effect of the temperature interval used in thermal cycling, the effect of the stress level used and the effect of the heat-treatment state of the wire used. The long-term behaviour of the wires was studied in a custom-built fatigue test frame in which the wires were thermally cycled under a constant stress level. The fatigue lives of tested specimens and the evolution of transformation and plastic strains on thermal cycling were recorded. Before the fatigue testing, a series of heat treatments was carried out to generate optimal actuator properties for the wires. One of the major conclusions of the study is that the temperature interval used for thermal cycling has a major effect on fatigue endurance: decreasing the temperature interval used for thermal cycling increased the fatigue life markedly. When the transformation is complete, a 20 °C increase of the final temperature reduced the fatigue lives at the most by half for the studied Ti–49.7Ni wires. With partial transformations the effect is more distinct: even the 5 °C increase in the final temperature reduced the fatigue life by half. The stress level and heat-treatment state used had a marked effect on the actuator properties of the wires, but the effects on fatigue endurance were minor. The fatigue test results reveal that designing and controlling long-term behaviour of binary Ti–49.7Ni actuators is very challenging because the properties are highly sensitive to the heat-treatment state of the wires. Even 5 min longer heat-treatment time could generate, at the most, double plastic strain values and 30% lower stabilized transformation strain values. The amount of plastic strain can be stated as one of

Simulation and analysis of the thermal and deformation behaviour of `as-received` and `hydrided` pressure tubes used in the circumferential temperature distribution experiments (end of life/pressure tube behaviour)

Energy Technology Data Exchange (ETDEWEB)

Muir, W C; Bayoumi, M H [Ontario Hydro, Toronto, ON (Canada)

1996-12-31

It is postulated that in-reactor pressure tubes may be subjected to radiation damage and dissolved deuterium which could change the pressure tube characteristics and lead to different behaviour than that of as-received pressure tubes under large LOCA (loss of coolant) conditions. A hydrided pressure tube was used to study the effect of dissolved hydrogen on thermal-mechanical behaviour. In the experiment, simulating an in-reactor (hydrided) pressure tube with circumferential differential temperature under boil-off conditions, the pressure tube ballooned into contact with the calandria tube. The pressure tube used in this experiment was hydrided in a furnace to a nominal value of 200 {mu}g/g dissolved hydrogen. This test was a repeat of the first supplementary boil-off test (S-5-1) which used an as-received pressure tube. The objective of this paper is to analyze the results obtained from the simulation of this Boil-Off test using the SMARTT computer code and to examine the effect of hydriding on the thermal and ballooning behaviour of the pressure tube by comparison with the results obtained from test S-5-1. A discussion of the results obtained from this comparison is presented together with an analysis of their application to the analysis of pressure tube behaviour in CANDU reactors. (author). 13 refs., 1 tab., 16 figs.

Simulation and analysis of the thermal and deformation behaviour of 'as-received' and 'hydrided' pressure tubes used in the circumferential temperature distribution experiments (end of life/pressure tube behaviour)

International Nuclear Information System (INIS)

Muir, W.C.; Bayoumi, M.H.

1995-01-01

It is postulated that in-reactor pressure tubes may be subjected to radiation damage and dissolved deuterium which could change the pressure tube characteristics and lead to different behaviour than that of as-received pressure tubes under large LOCA (loss of coolant) conditions. A hydrided pressure tube was used to study the effect of dissolved hydrogen on thermal-mechanical behaviour. In the experiment, simulating an in-reactor (hydrided) pressure tube with circumferential differential temperature under boil-off conditions, the pressure tube ballooned into contact with the calandria tube. The pressure tube used in this experiment was hydrided in a furnace to a nominal value of 200 μg/g dissolved hydrogen. This test was a repeat of the first supplementary boil-off test (S-5-1) which used an as-received pressure tube. The objective of this paper is to analyze the results obtained from the simulation of this Boil-Off test using the SMARTT computer code and to examine the effect of hydriding on the thermal and ballooning behaviour of the pressure tube by comparison with the results obtained from test S-5-1. A discussion of the results obtained from this comparison is presented together with an analysis of their application to the analysis of pressure tube behaviour in CANDU reactors. (author). 13 refs., 1 tab., 16 figs

Modelling window opening behaviour in Danish dwellings

DEFF Research Database (Denmark)

Andersen, Rune Vinther; Olesen, Bjarne W.; Toftum, Jørn

2011-01-01

In this paper we present and analyse data from two studies of window opening behaviour in residential buildings in Denmark. Based on measurements of indoor environment, weather and window opening behaviour in 15 dwellings, we propose a model that will predict window opening behaviour. The data...... showed that other factors than thermal effects impact the behaviour of the occupants. Some of these factors were included in the model. We present data from repeated questionnaire surveys that show that occupants tend to adjust heating setpoints, adjust clothing and operate windows when feeling thermally...

Statistical and time domain signal analysis of the thermal behaviour of wind turbine drive train components under dynamic operation conditions

International Nuclear Information System (INIS)

Nienhaus, K; Baltes, R; Bernet, C; Hilbert, M

2012-01-01

Gearboxes and generators are fundamental components of all electrical machines and the backbone of all electricity generation. Since the wind energy represents one of the key energy sources of the future, the number of wind turbines installed worldwide is rapidly increasing. Unlike in the past wind turbines are more often positioned in arctic as well as in desert like regions, and thereby exposed to harsh environmental conditions. Especially the temperature in those regions is a key factor that defines the design and choice of components and materials of the drive train. To optimize the design and health monitoring under varying temperatures it is important to understand the thermal behaviour dependent on environmental and machine parameters. This paper investigates the behaviour of the stator temperature of the double fed induction generator of a wind turbine. Therefore, different scenarios such as start of the turbine after a long period of no load, stop of the turbine after a long period of full load and others are isolated and analysed. For each scenario the dependences of the temperature on multiple wind turbine parameters such as power, speed and torque are studied. With the help of the regression analysis for multiple variables, it is pointed out which parameters have high impact on the thermal behaviour. Furthermore, an analysis was done to study the dependences in the time domain. The research conducted is based on 10 months of data of a 2 MW wind turbine using an adapted data acquisition system for high sampled data. The results appear promising, and lead to a better understanding of the thermal behaviour of a wind turbine drive train. Furthermore, the results represent the base of future research of drive trains under harsh environmental conditions, and it can be used to improve the fault diagnosis and design of electrical machines.

Experimental study and simulation of transformation induced plasticity, and multiphase behaviour of the 16MND5 vessel steel under aniso-thermal multiaxial loading

International Nuclear Information System (INIS)

Coret, M.

2001-01-01

This work deals with the aniso-thermal multiphase behaviour of the French vessel steel and more specially about the transformation plasticity in the cases of multiaxial non-proportional loadings paths. The first part of this report is devoted to the presentation of a high temperature tension-torsion experimental device enable of obtaining a large range of cooling rate. This experimental set-up is used to explore the transformation plasticity under proportional or non-proportional loading paths, during austenitic, bainitic and martensitic transformations. The results of the tests are compared to the Leblond's model. In the last part, we propose a two-scale behaviour model in which the type of each phase behaviour can be different. This meso-model is finally used to simulate two real tests on structures. (author) [fr

Inverse thermal analysis method to study solidification in cast iron

DEFF Research Database (Denmark)

Dioszegi, Atilla; Hattel, Jesper

2004-01-01

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

Phase behaviour, thermal expansion and compressibility of SnMo 2 O 8

Energy Technology Data Exchange (ETDEWEB)

Araujo, Luiza R.; Gallington, Leighanne C.; Wilkinson, Angus P.; Evans, John S.O. (Durham); (GIT)

2018-02-01

The phase behaviour and thermoelastic properties of SnMo2O8, derived from variable temperature and pressure synchrotron powder diffraction data, are reported. SnMo2O8 is a member of the AM2O8 family of negative thermal expansion (NTE) materials, but unexpectedly, has positive thermal expansion. Over the P-T space explored (298–513 K, ambient to 310 MPa) four different forms of SnMo2O8 are observed: α, β, γ and γ'. The γ to β transition is temperature-, pressure-, and time-dependent. SnMo2O8 is a much softer material (α and γ form have BT = 29 and 26 GPa at 298 K) than other members of the AM2O8 family. Counter-intuitively, its high temperature β phase becomes stiffer with increasing temperature (BT ~36 GPa at 490 K). The pressure dependence of the thermal expansion for each phase is reported.

Fatigue behaviour of the austenitic steel 1.4550 under mechanical and thermal cyclic loading

Energy Technology Data Exchange (ETDEWEB)

Siegele, D.; Fingerhuth, J.; Varfolomeev, I.; Moroz, S. [Fraunhofer Institute for Mechanics of Materials (IWM), Freiburg (Germany)

2014-07-01

Fatigue behaviour of the austenitic steel 1.4550 (X6CrNiNb18-10) under low-cycle fatigue and high-cycle thermal fatigue was investigated with in two research projects supported by the Federal Ministry of Economic Affairs and Energy and the Ministry of Education and Research. The objectives of the projects were the gain of deep understanding of the damage mechanisms under mechanical and thermal cyclic loading and the development of material models and simulation procedures for an improved lifetime assessment. In comparison to the advanced mechanism based material models engineering computational procedures were proven with respect to their applicability and conservatisms. For thermal cyclic loading, test equipment and technique were developed which allow for cyclic thermal loading with temperature ranges between 1 00 C and 300 C and frequencies between 0.1 and 1 Hz. As a result, tests with a temperature range of 150 C and lower showed no crack formation up to 300,000 cycles. For temperature ranges of 200 C and higher multiple crack patterns were observed with the deepest crack of about 1.3 mm after 1,000,000 cycles, whereas the difference in crack depth between 300,000 and 1,000,000 cycles was negligibly small. To model the fatigue lifetime, the D{sub TMF} damage parameter was applied to the low-cycle fatigue and the thermal, high frequent fatigue tests. For thermal fatigue, the analyses predicted in agreement with the tests crack initiation followed by crack propagation, subsequent retardation and arrest. This behaviour can be explained qualitatively and quantitatively using the methods of linear-elastic fracture mechanics, whereas the consideration of the interaction of multiple cracks is essential to describe the experimentally observed crack retardation. The results for thermal fatigue are in the scatterband of the mechanical p and thermo-mechanical fatigue results and the cycles to failure are 10 times higher than those estimated according to the KTA fatigue

Thermal hydraulic study of a corium molten pool

International Nuclear Information System (INIS)

Pigny, S.; Grand, D.; Seiler, J.M.; Durin, M.

1993-01-01

The thermohydraulic behaviour of a mass of molten core is investigated, in the frame of PWR severe accidents studies. The corium may be located in the vessel lower head or in an external core-catcher. It is assumed to be present in the container instantaneously. Its motion is described by one velocity field. It may be homogeneous or made of two stratified fluids. The residual power is assumed to be constant and uniform in the UO 2 phase. The radiative losses and the external water-cooling are taken into account. The thermal resistance of a peripheral crust is considered. The influence of the crust on the pool geometry may be studied. The wall behaviour is analysed by a conduction calculation. The interest of a sacrificial layer is underlined, so as the necessity of a multicomponent multiphase model to study the behaviour of a core catcher. It is also concluded that some experiments are needed for code validation about volume heated natural convection and multiphase flows. (author). 14 figs., 3 refs

Thermal behaviour of the ESR Relaxation time in slightly dirty superconductors

International Nuclear Information System (INIS)

Schwachheim, G.; Machado, S.F.; Tsallis, C.

1978-07-01

The thermal behaviour of the ESR relaxation rate in slightly dirty superconductors is discussed for both exchange and spin-orbit interactions between the conduction electrons and the impurities. The sensibility to the electronic density of states is exhibited by using, in a modified BCS framework, an heuristic analytic form which avoids two of three defects of a previous similar treatment. The sudden increase (decrease) of the relaxation rate immediately below the critical temperature for the exchange (spin-orbit) case is confirmed. Reasonable agreement with experimental data in LaRu 2 ; Gd is obtained [pt

Microwave-induced titanate nanotubes and the corresponding behaviour after thermal treatment

International Nuclear Information System (INIS)

Ou, H H; Lo, S L; Liou, Y H

2007-01-01

This study attempts to survey the influence of microwave irradiation on the characterizations of titanate nanotubes (TNTs) synthesized by microwave hydrothermal treatment (M-H treatment). Based on the performance of specific surface areas determined by the classic Brunauer-Emmett-Teller method (S BET ), TNTs synthesized at 130 deg. C for 1.5 h with and without 400 W irradiation presented S BET values of 256 and 76 m 2 g -1 , respectively. The result indicates that the formation kinetics of TNTs is significantly enhanced by M-H treatment. The microwave-induced TNTs are preferentially assigned for Na x H 2-x Ti 3 O 7 structure and the Na/H ratio appreciably increases with higher irradiation power. Regarding the behaviour of TNTs after thermal treatment, TNTs synthesized under 70 W presented anatase phase at 500 deg. C through rearrangement and restacking of [TiO 6 ]. Anatase-to-rutile transformation subsequently occurred at 700 deg. C. TNTs synthesized under 400 and 700 W presented a rod shape at 700 deg. C. The rod shape mainly comprise of Na 2 Ti 6 O 13 of which the (Ti 3 O 7 ) 2- layers with the topotactical connection proceed to form (Ti 6 O 13 ) 2- along the [110] direction during the thermal process

Cadmium fixation by synthetic hydroxyapatite in aqueous solution-Thermal behaviour

International Nuclear Information System (INIS)

Marchat, David; Bernache-Assollant, Didier; Champion, Eric

2007-01-01

This study deals with the mechanism of the cadmium uptake by synthetic hydroxyapatite (HA: Ca 10 (PO 4 ) 6 (OH) 2 ) in aqueous solution. The rate of cadmium fixation by hydroxyapatite was investigated at 10 and 50 deg. C using batch experiments. Inductively coupled plasma atomic emission spectrometry, X-ray diffraction, FT-IR spectroscopy and electron microscopy were used to characterize the starting HA and the samples. The thermal behaviour of the powders was determined with the help of three thermoanalytical techniques (TGA, DTA, and MS) and temperature programmed X-ray diffraction. Cadmium immobilization kinetics can be divided into two steps: substitution of Ca 2+ ions by Cd 2+ in the HA lattice at the particle's surface, followed by their incorporation into the hydroxyapatite bulk. This results in the formation of an apatite solid solution, which is very important because in this way decontamination and storage can be performed with the same material

Mixed oxide thermal behaviour at BOL: COMETHE III-J models and impact on power-to-melt

International Nuclear Information System (INIS)

Vliet, J. van

1979-01-01

The mixed oxide thermal behaviour at beginning of life is very important because it can impose a limitation to the fuel pin peak power, and therefore to the reactor thermal output. The relevant physical processes leading to fuel restructuring are modelled in COMETHE III-J in a kinetic way. This ensures that the temperature and power history are properly taken into account. These models are described and their impact on the calculated power to melt early in life is analysed. (author)

Behaviour of bentonite accessory minerals during the thermal stage

International Nuclear Information System (INIS)

Arcos, David; Bruno, Jordi; Benbow, Steven; Takase, Hiro

2000-03-01

This report discusses in a quantitative manner the evolution of the accessory minerals in the bentonite as a result of the thermal event exerted by the spent fuel in the near field. Three different modelling approaches have been used and the results compared between them. The three different approaches have been calculated using two Differential Algebraic Equation (DAE) solver: DYLAN (Model-1) and the Nag DAE solver, d02ngf (Model-2) and the third approach (Model-3) using the last version of PHREEQC. The results from these calculations indicate the feasibility of the modelling approach to model the migration of bentonite accessory minerals and relevant aqueous species throughout the thermal gradient. These calculations indicate that the migration of quartz and quartz polymorphs is a lesser problem. The aqueous speciation of Ca in the bentonite pore water is fundamental in order to define the potential migration of anhydrite during the thermal stage. If CaSO 4 (aq) is the predominant aqueous species, then anhydrite dissolves at the initial groundwater migration times through bentonite. However, if Ca 2+ is considered to be the dominant Ca species at the bentonite pore water, then anhydrite migrates towards the clay/granite interface. This is the main difference in the chemical systems considered in the three model approaches used in this work. The main process affecting the trace mineral behaviour in bentonite is cation exchange. This process controls the concentration of calcium, which results in a direct control of the calcite precipitation-dissolution

Physical and structural properties and thermal behaviour of starch-poly(ɛ-caprolactone) blend films for food packaging

OpenAIRE

Ortega Toro, Rodrigo; Contreras, Jessica; Talens Oliag, Pau; Chiralt A.

2015-01-01

Structural and physical properties (barrier, mechanical, and optical properties) and thermal behaviour of corn starch-PCL blend films, containing glycerol as plasticizer, obtained by compression moulding, at 160 °C and 130 bars, were studied. The stability on the films properties was also evaluated. Blend films showed phase separation of the polymers in a heterogeneous matrix with starch rich regions and PCL rich regions. Nevertheless, a small miscibility of PCL in the starch phase was detec...

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

International Nuclear Information System (INIS)

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

2002-01-01

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

Production of PVC/Abs/Nbr blend and the study of its physical and mechanical properties, thermal behaviour and its morphology

International Nuclear Information System (INIS)

Mehrabzadeh, M.; Honarkar, H.

2001-01-01

In this research a product of triplet blend of polyvinyl chloride, acrylonitrile-butadiene-styrene, acrylonitrile butadiene rubber (PVC/Abs/Nbr) is obtained. The physical, mechanical and thermal behaviour as well as morphology of the blend were studied. Results show that optimum properties in ratio PVC/Abs: 60/40 is obtained. For substituting the Nbr by a portion of Dop to modify the migration to surface, a triplet blend of PVC/Abs/Nbr was made. Experiments with constant amount of Nbr and variable Dop and vice versa were carried out. For preparation of triplet blend from PVC/Abs, a ratio of 60/40 was used. The best results were obtained for a blend with Nbr (10%) and PVC powder, 20% Nbr and PVC granules containing 34% Dop and the thermo formability of PVC/Abs/Nbr blend was examined as well

Physical, thermal and mechanical study of MPC formulated with LG-MgO incorporating Phase Change Materials as admixture

Science.gov (United States)

Maldonado-Alameda, A.; Lacasta, A. M.; Giro-Paloma, J.; Chimenos, J. M.; Formosa, J.

2017-10-01

The high environmental impact generated by using of Ordinary Portland Cement (OPC) has lead to the search for alternative materials in the field of civil and building engineering. In addition, there is a tendency to develop cements from industrial by-products, thus reducing pollution and emissions generated by their production. One of the best positioned cements to compete with OPC is Magnesium Phosphate Cement (MPC). The present work studies different dosages of MPC mortars formulated with low-grade MgO by-product (sustainable MPC) incorporating Microencapsulated Phase Change Materials (MPCM) and air entraining additive (AEA) as admixtures (Thermal Sustainable MPC) to improve the thermal behaviour of the material. The aim is developed a new eco-friendly material that leads to reducing energy consumption in buildings. The study is focused on the physical, thermal, and mechanical characterization of TS-MPC mortars to assess their potential use as a thermal prefabricated panel. The results allow to relate the amount of the MPCM and the additive percentage with the thermal and mechanical properties of the TS- MPC. Furthermore, is important to highlight the influence of MPCM not only in the thermal behaviour but also on the increase of the porosity. The experimental results show that the addition of both additives contributes substantially to the improvement of the thermal behaviour of the mortars and converts them on a suitable material to reduce thermal oscillations in buildings.

Local thermal-hydraulic behaviour in tight 7-rod bundles

International Nuclear Information System (INIS)

Cheng, X.; Yu, Y.Q.

2009-01-01

Advanced water-cooled reactor concepts with tight lattices have been proposed worldwide to improve the fuel utilization and the economic competitiveness. In the present work, experimental investigations were performed on thermal-hydraulic behaviour in tight hexagonal 7-rod bundles under both single-phase and two-phase conditions. Freon-12 was used as working fluid due to its convenient operating parameters. Tests were carried out under both single-phase and two-phase flow conditions. Rod surface temperatures are measured at a fixed axial elevation and in various circumferential positions. Test data with different radial power distributions are analyzed. Measured surface temperatures of unheated rods are used for the assessment of and comparison with numerical codes. In addition, numerical simulation using sub-channel analysis code MATRA and the computational fluid dynamics (CFD) code ANSYS-10 is carried out to understand the experimental data and to assess the validity of these codes in the prediction of flow and heat transfer behaviour in tight rod bundle geometries. Numerical results are compared with experimental data. A good agreement between the measured temperatures on the unheated rod surface and the CFD calculation is obtained. Both sub-channel analysis and CFD calculation indicates that the turbulent mixing in the tight rod bundle is significantly stronger than that computed with a well established correlation.

Studies on core melt behaviour in a BWR pressure vessel lower head

International Nuclear Information System (INIS)

Lindholm, I.; Ikonen, K.; Hedberg, K.

1999-01-01

Core debris behaviour in the Nordic BWR lower head was investigated numerically using MELCOR and MAAP4 codes. Lower head failure due to penetration failure was studied with more detailed PASULA code taking thermal boundary conditions from MELCOR calculations. Creep rupture failure mode was examined with the two integral codes. Also, the possibility to prevent vessel failure by late reflooding was assessed in this study. (authors)

Thermal preference predicts animal personality in Nile tilapia Oreochromis niloticus.

Science.gov (United States)

Cerqueira, Marco; Rey, Sonia; Silva, Tome; Featherstone, Zoe; Crumlish, Margaret; MacKenzie, Simon

2016-09-01

Environmental temperature gradients provide habitat structure in which fish orientate and individual thermal choice may reflect an essential integrated response to the environment. The use of subtle thermal gradients likely impacts upon specific physiological and behavioural processes reflected as a suite of traits described by animal personality. In this study, we examine the relationship between thermal choice, animal personality and the impact of infection upon this interaction. We predicted that thermal choice in Nile tilapia Oreochromis niloticus reflects distinct personality traits and that under a challenge individuals exhibit differential thermal distribution. Nile tilapia were screened following two different protocols: 1) a suite of individual behavioural tests to screen for personality and 2) thermal choice in a custom-built tank with a thermal gradient (TCH tank) ranging from 21 to 33 °C. A first set of fish were screened for behaviour and then thermal preference, and a second set were tested in the opposite fashion: thermal then behaviour. The final thermal distribution of the fish after 48 h was assessed reflecting final thermal preferendum. Additionally, fish were then challenged using a bacterial Streptococcus iniae model infection to assess the behavioural fever response of proactive and reactive fish. Results showed that individuals with preference for higher temperatures were also classified as proactive with behavioural tests and reactive contemporaries chose significantly lower water temperatures. All groups exhibited behavioural fever recovering personality-specific thermal preferences after 5 days. Our results show that thermal preference can be used as a proxy to assess personality traits in Nile tilapia and it is a central factor to understand the adaptive meaning of animal personality within a population. Importantly, response to infection by expressing behavioural fever overrides personality-related thermal choice. © 2016 The Authors

Reactivity study on thermal cracking of vacuum residues

Science.gov (United States)

León, A. Y.; Díaz, S. D.; Rodríguez, R. C.; Laverde, D.

2016-02-01

This study focused on the process reactivity of thermal cracking of vacuum residues from crude oils mixtures. The thermal cracking experiments were carried out under a nitrogen atmosphere at 120psi between 430 to 500°C for 20 minutes. Temperature conditions were established considering the maximum fractional conversion reported in tests of thermogravimetry performed in the temperature range of 25 to 600°C, with a constant heating rate of 5°C/min and a nitrogen flow rate of 50ml/min. The obtained products were separated in to gases, distillates and coke. The results indicate that the behaviour of thermal reactivity over the chemical composition is most prominent for the vacuum residues with higher content of asphaltenes, aromatics, and resins. Finally some correlations were obtained in order to predict the weight percentage of products from its physical and chemical properties such as CCR, SARA (saturates, aromatics, resins, asphaltenes) and density. The results provide new knowledge of the effect of temperature and the properties of vacuum residues in thermal conversion processes.

Thermal behaviour of chlorine in nuclear graphite at a microscopic scale

Energy Technology Data Exchange (ETDEWEB)

Vaudey, C.E., E-mail: vaudey@ipnl.in2p3.f [Universite de Lyon, Universite Lyon 1, CNRS/IN2P3, UMR5822, Institut de Physique Nucleaire de Lyon (IPNL), 4 rue Enrico Fermi, F-69622 Villeurbanne cedex (France); Toulhoat, N., E-mail: nelly.toulhoat@univ-lyon1.f [Universite de Lyon, Universite Lyon 1, CNRS/IN2P3, UMR5822, Institut de Physique Nucleaire de Lyon (IPNL), 4 rue Enrico Fermi, F-69622 Villeurbanne cedex (France); Commissariat a l' Energie Atomique CEA/DEN, Centre de Saclay, F-91191 Gif sur Yvette cedex (France); Moncoffre, N. [Universite de Lyon, Universite Lyon 1, CNRS/IN2P3, UMR5822, Institut de Physique Nucleaire de Lyon (IPNL), 4 rue Enrico Fermi, F-69622 Villeurbanne cedex (France); Bererd, N. [Universite de Lyon, Universite Lyon 1, CNRS/IN2P3, UMR5822, Institut de Physique Nucleaire de Lyon (IPNL), 4 rue Enrico Fermi, F-69622 Villeurbanne cedex (France); Universite de Lyon, UCBL-IUT A, departement chimie, 43 Bd du 11 novembre 1918, F-69622 Villeurbanne cedex (France); Raimbault, L. [Ecole des Mines de Paris, Centre de Geosciences, 35 rue Saint Honore, F-77305 Fontainebleau cedex (France); Sainsot, P. [Universite de Lyon, Universite Lyon 1, LaMCoS, INSA-Lyon, CNRS UMR5259, F-69621 Villeurbanne cedex (France); Rouzaud, J.N. [Laboratoire de Geologie de l' Ecole Normale Superieure, UMR CNRS-ENS 8538, 24 rue Lhomond, F-75231 Paris cedex 5 (France); Perrat-Mabilon, A. [Universite de Lyon, Universite Lyon 1, CNRS/IN2P3, UMR5822, Institut de Physique Nucleaire de Lyon (IPNL), 4 rue Enrico Fermi, F-69622 Villeurbanne cedex (France)

2009-12-15

In this paper, we present the study of thermal behaviour of {sup 36}Cl in nuclear graphite used in the St. Laurent A2 UNGG reactor (graphite moderated and CO{sub 2} cooled reactor). {sup 37}Cl, used to simulate {sup 36}Cl displaced from its original structural site by recoil, has been implanted into nuclear graphite samples (energy = 250 keV, fluence = 5 x 10{sup 13} at cm{sup -2}). The samples have been annealed in the 200-800 deg. C temperature range and analysed by SIMS. Structural modifications have been controlled by Raman microspectroscopy. This study shows that, in the considered temperature range and for a short annealing duration (4 h), chlorine is released almost athermally. At 500 deg. C, around 20% of the initial {sup 37}Cl content is released. At 800 deg. C, the release reaches a plateau and the loss of {sup 37}Cl is around 30%. Raman microspectroscopy shows that {sup 37}Cl implantation induces a structural disorder and that during annealing, the original structure is not completely recovered.

Synthesis, spectral properties and thermal behaviour of zinc(II) acetylsalicylate

Energy Technology Data Exchange (ETDEWEB)

Lambi, John N.; Nsehyuka, Alfred T.; Egbewatt, Nkongho; Cafferata, Lazaro F.R.; Arvia, Alejandro J

2003-03-05

The thermal behaviour of zinc(II) acetylsalicylate [Zn(acsa){sub 2}(H{sub 2}O){sub 2}] with respect to phase transitions, pyrolysis both in air and inert (N{sub 2}) atmosphere, and product identification has been investigated. The complex was synthesised by metathesis in hot ethanol solution using aspirin (acetylsalicylic acid) as precursor and characterised via electronic and IR spectral analyses. Optical observations showed that the white salt does not undergo a direct transition from the solid to the liquid phase but rather goes slowly through an intermediate mesophase around 80 deg. C before melting rapidly to the brick-brown isotropic liquid around 134-136 deg. C. No liquid crystalline phases are however formed. This result was complemented by that from thermogravimetric (TG) studies in the ca. 25-600 deg. C range, which showed three main weight-loss phases of 8.0, 50.0 and 14.0% (around 200, 250 and 400 deg. C) corresponding, respectively, to the elimination of CO{sub 2}, xanthone and acetic acid. The pyrolysis products, as identified using a combination of instrumental (GC-MS) and wet chemical techniques are: CO{sub 2}; non-stoichiometric zinc oxide, most likely in the form: Zn{sub 1+x}O (where 0.0000{<=}x{<=}0.0003); and a mixture of organic products resulting from further decomposition, charring and other attendant thermal effects at the relatively high temperatures (ca. 600 deg. C) involved. Six of the principal organic products were identified and included salsalate and benorylate which are pro-drugs of salicylic acid, a well-known pharmaceutical.

Contributions to the thermal behaviour of sulfates. 3

International Nuclear Information System (INIS)

Spiess, M.; Gruehn, R.

1979-01-01

The behaviour of CdSO 4 was studied by means of high temperature Guinier photographs in the temperature range of 20 to 960 0 C. Except N-CdSO 4 which is the thermodynamically stable modification at STP, there are 3 high temperature modifications (M, H1 and H2-CdSO 4 ) of which only metastable M-CdSO 4 can be obtained kineticly stable at room temperature. The lattice constants and the structure type of H1- and H2-CdSO 4 were determined. The structure of H1-CdSO 4 is closely related with that of N-CuSO 4 but in difference of N-CuSO 4 it has a superlattice. H1-CdSO 4 crystallizes orthorhombic with asub(325 0 C) = 17.80 A, bsub(325 0 C) = 7.35 A, csub(325 0 C) = 4.84 A, Z = 8. H2-CdSO 4 crystallizes hexagonal with asub(850 0 C) = 5.01 A, csub(850 0 C) =7.64 A, Z = 2 in a modified NaKSO 4 structure type (space group P 3m1) with Cd 2+ only in the Na + positions. The temperature and sequence of transitions as well as the thermal expansion of N- and M-CdSO 4 was determined. (author)

In-situ hybrid study of thermal behaviour of Znsbnd Ni and Znsbnd Nisbnd Al2O3 nanocrystallite thin films induced TEA/MEA by electrocodeposition

Science.gov (United States)

Abdulwahab, M.; Fayomi, O. S. I.; Popoola, A. P. I.; Dodo, M. R.

Our present investigation focuses on the thermal stability of already developed electroforms of Znsbnd Ni and Znsbnd Nisbnd Al2O3 thin films induced with triethylamine (TEA) and monoethylamine (MEA) as surfactant by electrocodeposition on mild steel substrate with the aim to re-examine its micro-hardness and degradation behaviour in static sodium chloride solution. In the event, the samples were thermally treated at 200 °C and air cooled. The results obtained showed that the developed composites are thermally stable with hardness value of the Znsbnd Nisbnd Al2O3 coated; 185 Hv increased to 190.5 Hv indicating a 2.89% improvement. Noticeably, in the Znsbnd Ni coatings, a decrease in the hardness with 26.67% was observed. The oxidation resistance was however favored for both composites.

Mechanical Behaviour of Stainless Steels under Dynamic Loading: An Investigation with Thermal Methods

Directory of Open Access Journals (Sweden)

Rosa De Finis

2016-11-01

Full Text Available Stainless steels are the most exploited materials due to their high mechanical strength and versatility in producing different alloys. Although there is great interest in these materials, mechanical characterisation, in particular fatigue characterisation, requires the application of several standardised procedures involving expensive and time-consuming experimental campaigns. As a matter of fact, the use of Standard Test Methods does not rely on a physical approach, since they are based on a statistical evaluation of the fatigue limit with a fixed probabilistic confidence. In this regard, Infra-Red thermography, the well-known, non-destructive technique, allows for the development of an approach based on evaluation of dissipative sources. In this work, an approach based on a simple analysis of a single thermographic sequence has been presented, which is capable of providing two indices of the damage processes occurring in material: the phase shift of thermoelastic signal φ and the amplitude of thermal signal at twice the loading frequency, S2. These thermal indices can provide synergetic information about the mechanical (fatigue and fracture behaviour of austenitic AISI 316L and martensitic X4 Cr Ni Mo 16-5-1; since they are related to different thermal effects that produce damage phenomena. In particular, the use of φ and S2 allows for estimation of the fatigue limit of stainless steels at loading ratio R = 0.5 in agreement with the applied Standard methods. Within Fracture Mechanics tests, both indices demonstrate the capacity to localize the plastic zone and determine the position of the crack tip. Finally, it will be shown that the value of the thermoelastic phase signal can be correlated with the mechanical behaviour of the specific material (austenitic or martensitic.

Crystal structure and thermal behaviour of boro-pollucite CsBSi2O6

International Nuclear Information System (INIS)

Bubnova, R.S.; Stepanov, N.K.; Filatov, S.K.; Levin, A.A.; Paufler, P.; Meyer, D.C.

2004-01-01

The crystal structure of Cs 0.82 B 1.09 Si 1.98 O 6 boro-pollucite at room temperature was determined by direct methods and refined in the l a 3-bar d space group using an anisotropic approximation of atomic thermal displacements (a = 13.009 (1) angstrom, Z = 16, R w = 0.027, R F = 0.037 for 141 independent observed (IFI ≥4σ F ) reflections). The occupancy factors have been refined for Cs and tetrahedral positions assuming the oxygen sites being fully occupied. The compound is isostructural to leucite pollucite high-temperature modification. Thermal behaviour of CsBSi 2 O 6 was investigated by DTA and TG, annealing at different temperatures with following wet chemical analysis and high-temperature X-ray powder diffraction methods. The CsBSi 2 O 6 cubic phase loses mass before melting and decomposes to form a new crystalline phase with close to CsBSi 3 O 8 stoichiometry in the temperature range of 1303 353 K. Thermal expansion of two boro-pollucite samples, which differed in the number of Cs + and/or B 3+ ions of a nominal composition CsBSi 2 O 6 was investigated in air as well as in vacuum. Temperature ranges of negative thermal expansion were found. (authors)

Thermal behaviour of high burnup PWR fuel under different fill gas conditions

International Nuclear Information System (INIS)

Tverberg, T.

2001-01-01

During its more than 40 years of existence, a large number of experiments have been carried out at the Halden Reactor Project focusing on different aspects related to nuclear reactor fuel. During recent years, the fuels testing program has mainly been focusing on aspects related to high burnup, in particular in terms of fuel thermal performance and fission gas release, and often involving reinstrumentation of commercially irradiated fuel. The paper describes such an experiment where a PWR rod, previously irradiated in a commercial reactor to a burnup of ∼50 MWd/kgUO 2 , was reinstrumented with a fuel central oxide thermocouple and a cladding extensometer together with a high pressure gas flow line, allowing for different fill gas compositions and pressures to be applied. The paper focuses on the thermal behaviour of such LWR rods with emphasis on how different fill gas conditions influence the fuel temperatures and gap conductance. Rod growth rate was also monitored during the irradiation in the Halden reactor. (author)

Parametric study of fuel rod behaviour during the RIA using the modified FALCON code

International Nuclear Information System (INIS)

Khvostov, G.; Zimmermann, M.A.; Ledergerber, G.

2010-01-01

Presented in the paper are the results of a parametric study with the use of optimised modules of the FALCON code (FALCON-PSI) that addresses the effects of the selected characteristics of fast thermal transients (e.g., impulse width), fuel rod design (e.g., active fuel attack length) and boundary conditions (e.g., the coolant conditions) on fuel behaviour during a RIA. Specifically, the analysis of the governing processes for the fuel rod behaviour during the RIA events simulated in the experimental facility of the Nuclear Safety Research Reactor (NSRR, Japan) are in the focus of the present study. The results obtained can be useful for a better transfer of the NSRR test results in relation to the corresponding behaviour in LWRs and furthermore might also support the planning of future additional experiments. (authors)

Thermal behaviour of the Debye-Waller factor and the specific heat of anharmonic crystals

International Nuclear Information System (INIS)

Lima, R.A.T. de; Tsallis, C.

1979-08-01

The influence of the cubic and quartic crystalline anharmonicity on the classical and quantum thermal behaviour of the specific heat, Debye temperaturetheta, Debye-Waller factor W, crystalline expansion and phonon spectrum is studied, within the framework of the Variational Method in Statistical Mechanics. The sistems, mainly focalized are the single oscillator, the mono-atomic linear chain and simple cubic crystal. The trial Hamiltonian is an harmonic one, therefore the various anharmonic influences are mainly absorbed into the renormalization of theta(T). Several differences between the classical and quantum results are exhibited. Satisfactory qualitative agreement with experience was obtained in the low-temperature regime, in particular in what concerns the existence of a minimum in theta(T) which has been observed in Cu, Al, Ag, Au and Pb. For the intermediate-temperature regime the customary linear behaviour of W(T) (hence theta(T) almost constant) is reobtained. Finally in the high-temperature regime, the present treatment leads to a √T - dependence for the W-factor, which implies in the wrong curvature with respect to experimental data. A possible explanation of this disagreement might be related to the melting phenomenon, which is not covered by the present theory. (Author) [pt

Thermal behaviour and corrosion resistance of nano-ZnO/polyurethane film

Science.gov (United States)

Virgawati, E.; Soegijono, B.

2018-03-01

Hybrid materials Nano-ZnO/polyurethane film was prepared with different zinc oxide (ZnO) content in polyurethane as a matrix. The film was deposited on low carbon steel plate using high volume low pressure (HVLP) method. To observe thermal behaviour of the film, the sample was investigated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Fourier transform infrared spectroscopy (FTIR) was used to see whether any chemical reaction of ZnO in polyurethane occured. TGA and FTIR results showed that the decomposition temperature shifted to a higher point and the chemical reaction of zinc oxide in polyurethane occurred. The surface morphology changed and the corrosion resistance increased with an increase of ZnO content

Effect of oxalic acid on the optical, thermal, dielectric and mechanical behaviour of ADP crystals

International Nuclear Information System (INIS)

Rajesh, P.; Ramasamy, P.

2009-01-01

The effect of the addition, over a concentration range from 1 to 5 mol%, of oxalic acid on the growth rate, optical transparency, hardness, dielectric behaviour, and SHG efficiency of ammonium dihydrogen phosphate single crystals grown by slow evaporation method has been investigated. UV-Vis studies show that the transparency of the oxalic acid added crystals decreased gradually. Thermal studies indicate that the decomposition temperatures of the crystal are decreased in oxalic acid added ADP crystals. It is observed from the dielectric measurements that the dielectric constant and dielectric loss increase with increase in temperature for all the crystals. Vicker's microhardness study reveals that the addition of higher concentration of oxalic acid decreases the hardness of the crystal. SHG efficiency of 1 mol% of oxalic acid is higher than the pure ADP.

COMETHE III J a computer code for predicting mechanical and thermal behaviour of a fuel pin

International Nuclear Information System (INIS)

Verbeek, P.; Hoppe, N.

1976-01-01

The design of fuel pins for power reactors requires a realistic evaluation of their thermal and mechanical performances throughout their irradiation life. This evaluation involves the knowledge of a number of parameters, very intricate and interconnected, for example, the temperature, the restructuring and the swelling rates of the fuel pellets, the dimensions, the stresses and the strains in the clad, the composition and the properties of gases, the inner gas pressure etc. This complex problem can only be properly handled by a computer programme which analyses the fuel pin thermal and mechanical behaviour at successive steps of its irradiation life. This report presents an overall description of the COMETHE III-J computer programme, designed to calculate the integral performance of oxide fuel pins with cylindrical metallic cladding irradiated in thermal or fast flux. (author)

Understanding and modelling of the aniso-thermal cyclic mechanical behaviour of the AISI 316LN austenitic stainless steel

International Nuclear Information System (INIS)

Gentet, D.

2009-11-01

The main subject of this report consists in proposing a mechanical model of the viscoplastic behaviour of an austenitic stainless steel under isothermal and aniso-thermal low cycle fatigue loadings at high temperatures (550-900 K). In this domain, numerous phenomena linked to dynamic strain ageing (DSA) and to dipolar dislocation structure formation may appear. Isothermal and aniso-thermal low cycle fatigue tension-compression tests were performed in order to verify some aspects about the effect of temperature on the mechanical behaviour. The study of the hysteresis loops and the observation of dislocation structures carried on transmission electron microscopy establish two different DSA mechanisms during isothermal tests. The effect of temperature history is shown for for particular temperature sequences. It is demonstrated that the stress amplitude increase when the sample is submitted to cycles at 'high temperature' is linked to the second mechanism of DSA. It comes from the increase of short range interaction between dislocations (chromium segregation), but it is also the consequence of the lack of dipolar structure annihilation at low temperature. From the experimental analysis of DSA mechanisms and dipolar restoration, a macroscopic aniso-thermal model is developed using physical internal variables (densities of dislocations). The equations of a polycrystalline model are rewritten with the aim of getting a simple multi-scale approach which can be used on finite elements analysis software. Between 550 and 873 K, the simulation results are in good accordance with the macroscopic and microscopic observations of low cycle fatigue, relaxation, and 2D-ratchetting tests. (author)

Studies on the sintering behaviour of uranium dioxide powder compacts

International Nuclear Information System (INIS)

Das, P.; Chowdhury, R.

1988-01-01

Uranium dioxide fuel pellets are normally made from their precursor ammonium diuranate, followed by calcination, subsequent reduction to sinterable grade powders and a post operation treatment of pressing and sintering. The low temperature calcined powders, usually exhibiting non-crystalline behaviour (under X-ray diffraction studies) progressively transforms into a crystalline variety on subsequent heat treatment at higher temperature. It is observed however that powders calcined between 800 to 900 0 C exhibit enhanced densification behaviour when sintered at higher temperatures. The isothermal shrinkage versus time plot of the sintered compacts are well described by a hyperbolic relationship which takes care of the observed shrinkage (λ) as caused due to a cumulative effect from the initial sintering of the powder compacts at zero time (α) and that caused due to the structural transformation from a non-crystalline modification with increased thermal treatment (β). The derived equation is a modification of the sintering mechanism of the viscous flow type proposed by Frenkel, involving sintering of an amorphous phase, the viscosity of the latter is presumed to increase with increasing thermal treatment to assume the final modified form as λ=t/(α+βt), where t = time, λ = shrinkage and α and β are the unknown parameters. (orig.)

Characterisation of Ground Thermal and Thermo-Mechanical Behaviour for Shallow Geothermal Energy Applications

Directory of Open Access Journals (Sweden)

Ana Vieira

2017-12-01

Full Text Available Increasing use of the ground as a thermal reservoir is expected in the near future. Shallow geothermal energy (SGE systems have proved to be sustainable alternative solutions for buildings and infrastructure conditioning in many areas across the globe in the past decades. Recently novel solutions, including energy geostructures, where SGE systems are coupled with foundation heat exchangers, have also been developed. The performance of these systems is dependent on a series of factors, among which the thermal properties of the soil play a major role. The purpose of this paper is to present, in an integrated manner, the main methods and procedures to assess ground thermal properties for SGE systems and to carry out a critical review of the methods. In particular, laboratory testing through either steady-state or transient methods are discussed and a new synthesis comparing results for different techniques is presented. In situ testing including all variations of the thermal response test is presented in detail, including a first comparison between new and traditional approaches. The issue of different scales between laboratory and in situ measurements is then analysed in detail. Finally, the thermo-hydro-mechanical behaviour of soil is introduced and discussed. These coupled processes are important for confirming the structural integrity of energy geostructures, but routine methods for parameter determination are still lacking.

Functional architecture of behavioural thermoregulation.

Science.gov (United States)

Flouris, Andreas D

2011-01-01

The human thermoregulatory system relies primarily on behavioural adaptation and secondarily on autonomic and endocrine responses for thermal homeostasis. This is because autonomic and endocrine responses have a limited capacity in preventing hyper/hypothermia in extreme environments. Until recently, the neuroanatomy of behavioural thermoregulation as well as the neuroanatomic substrate of the various thermoregulatory behaviours remained largely unknown. However, this situation has changed in recent years as behavioural thermoregulation has become a topic of considerable attention. The present review evaluates the current knowledge on behavioural thermoregulation in order to summarize the present state-of-the-art and to point towards future research directions. Findings on the fundamental distinction between thermal (dis)comfort and sensation are reviewed showing that the former drives behaviour while the latter initiates autonomic thermoregulation. Moreover, the thermosensitive neurons and thermoeffector functions of behavioural thermoregulation are presented and analysed in a detailed discussion.

Advances on study of temperature effects on hydro-mechanical behaviour of densely compacted bentonite

International Nuclear Information System (INIS)

Ye Weimin; Wan Min; Chen Bao; Liu Yuemiao; Cui Yujun

2008-01-01

During the operation of a multiple-barrier geological repository, bentonite that works as a buffer/fill material of an artificial barrier will suffer complex coupling effects of thermal (T), hydrological (H), mechanical (M) process, which comes from heat of the nuclear waste radiation, mechanical stress from parent rock mass and seepage action of groundwater. The scientific results show that temperature has influence on the water retention, saturated permeability, swelling pressure, swelling strain and thermal strain of compacted bentonite. As a whole, the research about GMZ (Gao Miaozi) bentonite, which may potentially be chose as Chinese buffer/backfill material for high radioactive nuclear waste disposal, has a long way to go compare to developed contraries. Based on comprehensive laboratory tests and advanced theoretical framework, both of the study on behaviour of compacted GMZ bentonite under HTM coupling conditions, and the establishment of a constitutive relation for prediction of behaviour of compacted bentonite under multi-field coupling conditions are important in theoretic and practical way. (authors)

Correlation and Prediction of Thermal Properties and Phase Behaviour for a Class of Aqueous Electrolyte Systems

DEFF Research Database (Denmark)

Thomsen, Kaj; Rasmussen, Peter; Gani, Rafiqul

1996-01-01

An extended UNIQUAC model is used to describe phase behaviour (VLE, SLE) and thermal properties (heat of mixing, heat capacity) for aqueous solutions containing ions like (Na+, K+, H+) (Cl-, NO3-, SO42-, OH-, CO3-). A linear temperature dependence of the binary interaction parameters allows good...... agreement with experimental data in the temperature range 0-110 degrees C. Copyright (C) 1996 Elsevier Science Ltd...

Thermal and mechanical behaviour of sub micron sized fly ash reinforced polyester resin composite

Science.gov (United States)

Nantha Kumar, P.; Rajadurai, A.; Muthuramalingam, T.

2018-04-01

The utilization of particles reinforced resin matrix composites is being increased owing to its lower density and high strength to weight ratio. In the present study, an attempt has been made to synthesize fly ash particles reinforced polyester resin composite for engine cowling application. The thermal stability and mechanical behaviours such as hardness and flexural strength of the composite with 2, 3 and 4 weight % of reinforcement is studied and analyzed. The thermo gravimetric analysis indicates that the higher addition of reinforcement increases the decomposition temperature due to its refractory nature. It is also observed that the hardness increases with higher filler addition owing to the resistance of FA particles towards penetration. The flexural strength is found to increase up to the addition of 3% of FA particles, whereas the polyester resin composite prepared with 4% FA particles addition is observed to have low flexural strength owing to agglomeration of particles.

Study of the thermal behaviour of traditional wine cellars: the case of the area of ''Tierras Sorianas del Cid'' (Spain)

Energy Technology Data Exchange (ETDEWEB)

Guerrero, I.C.; Ocana, S.M. [Universidad Politecnica de Madrid (Spain). Dpto. de Construccion y Vias Rurales

2005-01-01

This article studies the hygro-thermal behaviour of two traditional underground wine cellars from Morcuera (Soria, Spain). The differences between them are analyzed and our hypothesis is that one of these constructions is better than the other for the ageing of wines. The hypothesis takes into consideration the existence of a temperature difference of over 20{sup o}C between them as a basis for reaching the aforementioned conclusion. However, the relative humidity inside both of them is 100%, which could pose problems if the presence of mould is not controlled. This study is based on fieldwork for the inventory and cataloguing of traditional agrarian constructions in the ''Tierras Sorianas'' area. The objective of this investigation is to highlight some advantages of traditional building techniques over modern construction practices from the energy-saving viewpoint. (author)

Evaluation of Thermal and Thermomechanical Behaviour of Bio-Based Polyamide 11 Based Composites Reinforced with Lignocellulosic Fibres

Directory of Open Access Journals (Sweden)

Helena Oliver-Ortega

2017-10-01

Full Text Available In this work, polyamide 11 (PA11 and stone ground wood fibres (SGW were used, as an alternative to non-bio-based polymer matrices and reinforcements, to obtain short fibre reinforced composites. The impact of the reinforcement on the thermal degradation, thermal transitions and microstructure of PA11-based composites were studied. Natural fibres have lower degradation temperatures than PA11, thus, composites showed lower onset degradation temperatures than PA11, as well. The thermal transition and the semi-crystalline structure of the composites were similar to PA11. On the other hand, when SGW was submitted to an annealing treatment, the composites prepared with these fibres increased its crystallinity, with increasing fibre contents, compared to PA11. The differences between the glass transition temperatures of annealed and untreated composites decreased with the fibre contents. Thus, the fibres had a higher impact in the composites mechanical behaviour than on the mobility of the amorphous phase. The crystalline structure of PA11 and PA11-SGW composites, after annealing, was transformed to α’ more stable phase, without any negative impact on the properties of the fibres.

A comparative analysis of the effect of gaseous fission products release on the thermal behaviour of oxide fuel rods

International Nuclear Information System (INIS)

Totev, T.L.; Kolev, I.G.

1992-01-01

Four different models of gaseous fission product release are compared in order to assess the relative effect of thermal characteristics of the fuel rods. The results show that the use of Weisman and EPRI models at a high burnup (over 50000 MW.d/tU) leads to almost the same figures of maximum fuel temperature and gas gap thermal conductivity. The use of Beyer-Hann (Betelle) and Pazdera-Valach (Rzez) models leads to under prediction of the fuel element thermal characteristics. A conclusion has been made that the Weisman model is the most suitable for the WWER-type fuel elements behaviour prediction. 10 refs., 7 figs

Growth, optical, thermal and dielectric studies of an amino acid organic nonlinear optical material: L-Alanine

International Nuclear Information System (INIS)

Caroline, M. Lydia; Sankar, R.; Indirani, R.M.; Vasudevan, S.

2009-01-01

Good transparent bulk single crystals of L-alanine (nonlinear optical material) have been grown successfully by slow cooling technique from aqueous solution at pH value of 2.0. Optically transparent crystals with dimensions 2.4 cm x 1.2 cm x 1.6 cm, were grown by optimizing the growth parameters within a growth period of 2 weeks. The crystallinity of L-alanine crystal was confirmed by the powder X-ray diffraction study and diffraction peaks are indexed. The vibrational structure of the molecule is elucidated from FTIR spectra. The thermal behaviour of the grown crystal was investigated by thermogravimetric (TG) and differential thermal analyses (DTA) techniques in a nitrogen atmosphere. The result showed that the material starts decomposing at 297 deg. C. Its optical behaviour has been examined by UV-vis spectral analysis, which shows the absence of absorbance between the wavelengths ranging from 200 to 1200 nm. The NLO property was confirmed by the powder technique of Kurtz and Perry. The dielectric behaviour of the sample was also studied for the first time

Experimental study of thermo-hydro-mechanical behaviour of Callovo-Oxfordian Clay-stone

International Nuclear Information System (INIS)

Mohajerani, M.

2011-01-01

During the different phases of the exothermic radioactive waste deep disposal (excavation, operation) and after permanent closure, the host rock is submitted to various coupled mechanical, hydraulic and thermal phenomena. Hence, a thorough investigation of the thermo-hydro-mechanical behaviour of the rock is necessary to complete existing data and to better understand and model the short and long term behaviour of the Callovo-Oxfordian (COx) clay formation in Bure (Meuse/Haute-Marne - M/HM), considered by ANDRA as a potential host rock in France.In this work, the compression - swelling behaviour of the COx Clay-stone was first investigated by carrying out a series of high-pressure oedometric tests. The results, interpreted in terms of coupling between damage and swelling, showed that the magnitude of swelling was linked to the density of the fissures created during compression. In a second step, the hydro-mechanical and thermo-hydro-mechanical behaviour of the saturated Clay-stone under a mean stress close to the in situ one were investigated by using two devices with short drainage path (10 mm), namely a isotropic cell and a newly designed hollow cylinder triaxial cell with local displacement measurements. These devices helped to solve two majors problems related to testing very low permeability materials: i) a satisfactory previous sample saturation (indicated by good Skempton values) and ii) satisfactory drainage conditions. Some typical constitutive parameters (Skempton and Biot's coefficients, drained and undrained compressibility coefficients) have been determined at ambient temperature through isotropic compression tests that also confirmed the transverse isotropy of the Clay-stone. The consistency of the obtained parameters has been checked in a saturated poro-elastic framework. Two aspects of the thermo-hydro-mechanical behaviour of the COx Clay-stone have then been investigated through different heating tests and through drained and undrained isotropic

Comparison of the thermal shock performance of different tungsten grades and the influence of microstructure on the damage behaviour

International Nuclear Information System (INIS)

Wirtz, M; Linke, J; Pintsuk, G; Singheiser, L; Uytdenhouwen, I

2011-01-01

The thermal shock performances of two new tungsten grades with 1 and 5 wt% of tantalum were characterized with the electron beam facility JUDITH 1. As a reference material, ultra-high-purity tungsten (W-UHP) with a purity of 99.9999 wt% was used. The induced thermal shock crack networks and surface modifications were analysed by a scanning electron microscope, light microscopy and laser profilometry. Damage and cracking thresholds were defined for all materials as a function of absorbed power density and base temperature. The materials showed significantly different thermal shock behaviour, which is, among others, expressed by differences in cracking patterns, i.e. crack distance and depth. These results allow us to quantify the influence of the materials' mechanical and thermal properties on the thermal shock performance. Furthermore, the specific grain structure of the materials has a significant influence on crack propagation towards the bulk material.

Thermal stability study of crystalline and novel spray-dried amorphous nilotinib hydrochloride.

Science.gov (United States)

Herbrink, Maikel; Vromans, Herman; Schellens, Jan; Beijnen, Jos; Nuijen, Bastiaan

2018-01-30

The thermal characteristics and the thermal degradation of crystalline and amorphous nilotinib hydrochloride (NH) were studied. The spray drying technique was successfully utilized for the amorphization of NH and was evaluated by spectroscopic techniques and differential scanning calorimetry (DSC). The ethanolic spray drying process yielded amorphous NH with a glass transition temperature (T g ) of 147°C. Thermal characterization of the amorphous phase was performed by heat capacity measurements using modulated DSC (mDSC). Thermal degradation was studied by thermogravimetric analysis (TGA). The derived thermodynamic properties of the amorphous NH indicate fragile behaviour and a low crystallization tendency. NH was found to be molecularly stable up to 193°C. After which, the thermal degradation displayed two phases. The values of the thermal degradation parameters were estimated using the Ozawa-Flynn-Wall and Friedman non-isothermal, model-free, isoconversional methods The results indicate the two phases to be single-step reactions. The examination of the physical stability of amorphous NH during storage and at elevated temperatures showed stability at 180°C for at least 5h and at 20-25°C/60% RH for at least 6 months. During these periods, no crystallization was observed. This study is the first to report the thermal characteristics of NH. Additionally, it is also the first to describe the full thermal analysis of a spray-dried amorphous drug. The thermal data may be used in the projection of future production processes and storage conditions of amorphous NH. Copyright © 2017 Elsevier B.V. All rights reserved.

Thermal conductivity and magnon-phonon resonant interaction in antiferromagnetic ferrous chloride

International Nuclear Information System (INIS)

Laurence, Guy

1973-01-01

An apparatus has been studied and built to measure thermal conductivity between 0,3 K and 80 K. The thermal conductivity in the c plane and along the c axis have been measured in FeCl 2 . These results show an anomalous behaviour of the thermal conductivity below the Neel temperature. A calculation of the thermal conductivity of magneto-elastic modes arising from a magnon-phonon resonant interaction renders an account of this behaviour. From the present results, the magneto-elastic coupling constant G 44 is found to be 3,5 meV. Finally, an experimental study of the thermal conductivity magnetic field dependence of FeCl 2 was performed.(author) [fr

Energy improvement of a conventional dwelling in Argentina through thermal simulation

Energy Technology Data Exchange (ETDEWEB)

Filippin, C. [CONICET-CC302, Santa Rosa 6300, La Pampa (Argentina); Flores Larsen, S. [INENCO-Instituto de Investigaciones en Energias No Convencionales, Universidad Nacional de Salta, CONICET, Avda. Bolivia 5150, CP 4400 Salta Capital (Argentina); Lopez Gay, E.

2008-10-15

This paper analyses the design, technology, thermal behaviour, and energy consumption of both a conventional and a refurbished dwelling located in a region with a temperate-cold climate in central Argentina. The thermal behaviour and the energy consumption of the conventional building were monitored during winter. The experimental data were analysed and included in a simulation of the transient thermal behaviour of the house. Measurements and simulation were in agreement, showing a mean deviation below 0.5{sup o}C. To reduce the heating and cooling loads, the dwelling was refurbished and its thermal behaviour was studied through a computer simulation, for the critical seasons (winter and summer) and for two occupancy schedules (with and without inhabitants). The refurbishment included passive solar heating, shading, and an insulated envelope. These successful changes allowed energy savings of 66% and 52% for winter and summer, respectively. (author)

Contribution to the thermal study of a dielectric barrier discharge reactor

International Nuclear Information System (INIS)

Dubus, Nicolas

2009-01-01

This thesis aims to study the thermal behaviour of a laboratory Dielectric Barrier Discharge (DBD) reactor. An experimental study was first realized to measure temperatures at different points of the reactor by using optic fibers. These measurements were performed in transient and steady states. To examine the influence of heat losses, not insulated and insulated reactors were considered. The influence of the nature and the form of the applied voltage was else considered. Experiments were conducted with a sinusoidal voltage and a pulsed power supply. (author) [fr

Predicting micro thermal habitat of lizards in a dynamic thermal environment

NARCIS (Netherlands)

Fei, T.; Skidmore, A.K.; Venus, V.; Wang, T.; Toxopeus, A.G.; Bian, B.M.; Liu, Y.

2012-01-01

Understanding behavioural thermoregulation and its consequences is a central topic in ecology. In this study, a spatial explicit model was developed to simulate the movement and thermal habitat use of lizards in a controlled environment. The model incorporates a lizard's transient body temperatures

Experimental study of the permeability of concrete under variable thermal and hydric conditions

International Nuclear Information System (INIS)

Chen, W.

2011-01-01

The main objective of this study is to evaluate the variable thermal and hydric effect, with fissuration effect on the hydraulic behaviour of two concretes. Many experimental tests (saturation and permeability measurements, uniaxial and triaxial compressions tests) were carried out in order to investigate the temperature and saturation influence on the behaviour hydraulic on sound and micro-cracked concrete. Moreover, an experimental device for permeability measurement on macro-cracked concrete was realized, it allows to study the behaviour of macro-cracked of concrete confined and subjected to dry gas flow or very moist air at different temperatures. Multiaxial mechanical tests are coupled to the permeability measurements of sound concrete and micro-cracked by freezing and thawing, which allow to measuring the permeability under deviatoric load-unload with the effect of pre-cracking under stress. We also effectuated a test of relative permeability of concrete as a function of water saturation, subjected to drying and re-saturation, conditioning by the different relative humidity imposed. (author)

Influence of thermal residual stress on behaviour of metal matrix composites reinforced with particles

Science.gov (United States)

Guzmán, R. E.; Hernández Arroyo, E.

2016-02-01

The properties of a metallic matrix composites materials (MMC's) reinforced with particles can be affected by different events occurring within the material in a manufacturing process. The existence of residual stresses resulting from the manufacturing process of these materials (MMC's) can markedly differentiate the curves obtained in tensile tests obtained from compression tests. One of the themes developed in this work is the influence of residual stresses on the mechanical behaviour of these materials. The objective of this research work presented is numerically estimate the thermal residual stresses using a unit cell model for the Mg ZC71 alloy reinforced with SiC particles with volume fraction of 12% (hot-forging technology). The MMC's microstructure is represented as a three dimensional prismatic cube-shaped with a cylindrical reinforcing particle located in the centre of the prism. These cell models are widely used in predicting stress/strain behaviour of MMC's materials, in this analysis the uniaxial stress/strain response of the composite can be obtained through the calculation using the commercial finite-element code.

Effects of different architectural solutions on the thermal behaviour in an unconditioned rural building. The case of an Italian winery

Directory of Open Access Journals (Sweden)

Daniele Torreggiani

2018-02-01

Full Text Available Referring to the wine sector, in the Mediterranean area, most of the wine farms make use of unconditioned above-ground buildings constructed without a specific attention to temperature control, where indoor temperatures easily show trends in disagreement with correct wine-ageing and conservation. Moreover the suitable temperature ranges can differ from wine to wine, and are considerably different from ideal temperatures for human comfort. This study aimed at testing the effectiveness of different architectural elements in improving the thermal behaviour of unconditioned farm buildings, by means of energy simulations validated on an Italian case-study, comparing the data provided by the simulations with different temperature ranges. Results showed the building thermal performance depends on the chosen intervals, some solution played negative or positive role according to the analysed range and in general roof and wall interventions were more effective than orientation and solar shading, and the combination of more strategies allow to achieve improved results.

Thermal behaviour of a spherical addition to molten metals

Energy Technology Data Exchange (ETDEWEB)

Roehmen, E.

1995-05-01

This thesis presents a numerical model for describing the thermal behaviour of a spherical alloy addition when added to a melt. It is assumed that: no significant heat of solution between the alloy addition and the melt is involved, the dissolution rate is dominated by heat transfer from the melt, the heat flow into the addition is spherically symmetric, the additions have a well defined melting point, there are no solid phase transformations, heat conduction can be represented by Fourier`s law, and the heat transfer from the melt can be described by an average heat transfer coefficient. The model is validated by comparison with experimental data obtained from immersion experiments on: (1) a 4.88 cm diameter Al sphere chilled in liquid nitrogen to -196 {sup o}C and then immersed in water of 3.8 {sup o}C and 18.1 {sup o}C, (2) 4.90 cm diameter Al spheres at room temperatures immersed in molten Al of 720 {sup o}C, and (3) 3.72 cm diameter 75 wt% FeSi spheres at 150 {sup o}C immersed in molten steel of 1600 {sup o}C. The shell thickness and temperatures at the sphere centre and surface were recorded as functions of time. For model and experiment to agree, it was found that the density, specific heat and thermal conductivity of the alloy addition must depend on temperature, and an inner heat transfer resistance across the sphere-shell interphase must be included. The sensible heat of the melt that solidifies should be included in the heat balance only when the shell is expanding. The inner heat transfer resistance is shown to be very important in determining the melting/dissolution time for alloy additions that react strongly with the melt. 70 refs., 60 figs., 36 tabs.

Thermal behaviour analysis of SRF cavities and superconducting HOM couplers

International Nuclear Information System (INIS)

Fouaidy, M.; Junquera, T.

1993-01-01

Two individual papers appear in this report, titled Thermal model calculations in superconducting RF cavities, and Thermal study of HOM couplers for superconducting RF cavities. Both were indexed separately for the INIS database. (R.P.)

The summer thermal behaviour of 'skin' materials for vertical surfaces in Athens, Greece, as a decisive parameter for their selection

Energy Technology Data Exchange (ETDEWEB)

Bougiatioti, F.; Evangelinos, E.; Poulakos, G.; Zacharopoulos, E. [National Technical University of Athens, School of Architecture, Department of Architectural Technology, 42, Patission Street, 10682 Athens (Greece)

2009-04-15

This paper analyses the thermal behaviour of the materials, which are widely used on the vertical surfaces of Greek cities. This analysis is based on surface temperatures measurements, which were carried out both in situ in various buildings of Athens, Greece and experimentally on samples of building materials exposed to solar radiation on a building's flat roof. The study includes surfacing materials, which are usually applied on building facades around Greece. The study leads to a number of conclusions concerning the effect of colour and orientation on the summer surface temperatures of materials, used on vertical city surfaces. These conclusions indicate how surfacing materials should be chosen in order to help mitigate the urban heat island and improve thermal comfort conditions in the outdoor spaces of Greek cities during the overheated summer period. (author)

Influence of PCMs in thermal insulation on thermal behaviour of building envelopes

Science.gov (United States)

Dydek, K.; Furmański, P.; Łapka, P.

2016-09-01

A model of heat transfer through a wall consisting of a layer of concrete and PCM enhanced thermal insulation is considered. The model accounts for heat conduction in both layers, thermal radiation and heat absorption/release due to phase change in the insulation as well as time variation in the ambient temperature and insolation. Local thermal equilibrium between encapsulated PCM and light-weight thermal insulation was assumed. Radiation emission, absorption and scattering were also accounted for in the model. Comparison of different cases of heat flow through the building envelope was carried out. These cases included presence or absence of PCM and thermal radiation in the insulation, effect of emissivity of the PCM microcapsules as well as an effect of solar radiation or its lack on the ambient side of the envelope. Two ways of the PCM distribution in thermal insulation were also considered. The results of simulations were presented for conditions corresponding to the mean summer and winter seasons in Warsaw. It was found that thermal radiation plays an important role in heat transfer through thermal insulation layer of the wall while the presence of the PCM in it significantly contributes to damping of temperature fluctuations and a decrease in heat fluxes flowing into or lost by the interior of the building. The similar effect was observed for a decrease in emissivity of the microcapsules containing PCM.

Preparation, characterization and thermal behaviour study of double selenates of lanthanides, yttrium and beryllium

International Nuclear Information System (INIS)

Ribeiro, C.A.

1988-01-01

The lanthanides (III) and yttrium (III) double selenates were studied using common analytical methods, atomic absorption, X-ray diffraction infra-red absorption, thermogravimetry and differential thermal analysis. These compounds were prepared from the mixture of lanthanides (III) and yttrium (III) selenates aqueous solution and basic beryllium selenates aqueous solution, obeying equimolar relation (1:1) to the cation

Model investigation of fuel rod behaviour

International Nuclear Information System (INIS)

Girgis, M.M.; Wiesenack, W.; Stegemann, D.

1985-06-01

Thermal and mechanical behaviour of fuel rods can be explained but unsatisfactorily by models based of an axial symmetry concept. Recently developed models include, with respect to their thermal components, a simple method for the computation of the temperature distribution within the fuel, and they also take into account the influence of excentrically placed pellets for the computation of heat transfer in the cold gap. Additionally, a finite-element model is used to evaluate the effects of cracking and fragmentation on the thermal behaviour of pellets. The reaction of fuel and fuel cladding to external and internal loadings and the axial interaction between fuel and cladding are described in the mechanical portion of the model. A special case of axial coupling is the so-called random stacking interaction caused by fuel pellets placed excentrically at the cladding and sliding radially and axially. In the comparison of measurement results, both thermal and mechanical behaviour of different rods from the OECD Halden Reactor Project are subject to investigations. (RF) [de

Thermal pressure and isochoric thermal conductivity of solid CO2

International Nuclear Information System (INIS)

Purs'kij, O.Yi.

2005-01-01

The analysis of the correlation between the thermal pressure and the isochoric thermal conductivity of solid CO 2 has been carried out. The temperature dependences of the thermal pressure and isochoric thermal conductivity for samples with various molar volumes have been obtained. The isothermal pressure dependences of the thermal conductivity of solid CO 2 have been calculated. The form of the temperature dependence of the isochoric thermal conductivity taking the thermal pressure into account has been revealed. Behaviour of the isochoric thermal conductivity is explained by phonon-phonon interaction and additional influence of the thermal pressure

Temperature effect on the poro-mechanical or hydraulic behaviour of a carbonated rock and a mortar: experimental studies; Influence de la temperature sur le comportement poromecanique ou hydraulique d'une roche carbonatee et d'un mortier: etudes experimentales

Energy Technology Data Exchange (ETDEWEB)

Lion, M

2004-07-15

The main objective of this study is to evaluate the temperature effect on the hydraulic and poro-mechanical behaviour of a limestone. Many experimental tests (porosity and permeability measurements, uniaxial and hydrostatic compressions tests) were carried out in order to study the thermal treatments effect and so the thermal microcracking effect on rock behaviour. Moreover, an experimental device for permeability measurements under high temperatures (until 200 C) was realized. This experimental device permitted to study the permeability variation of the limestone under thermal stresses. Finally, the behaviour of cementitious materials was studied; the temperature effect on the permeability of a mortar was examined. (author)

STUDY OF THERMAL BEHAVIOUR ON TITANIUM ALLOYS (TI-6AL-4V

Directory of Open Access Journals (Sweden)

VASUDEVAN D

2017-08-01

Full Text Available Titanium is recognized for its strategic importance as a unique lightweight, high strength alloyed structurally efficient metal for critical, high-performance aircraft, such as jet engine and airframe components. Titanium is called as the "space age metal" and is recognized for its high strength-to-weight ratio. Today, titanium alloys are common, readily available engineered metals that compete directly with stainless steel and Specialty steels, copper alloys, nickel based alloys and composites. Titanium alloys are needed to be heat treated in order to reduce residual stress developed during fabrication and to increase the strength. Titanium (Ti-6Al-4V alloy is an alpha, beta alloy which is solution treated at a temperature of 950 ºC to attain beta phase. This beta phase is maintained by quenching and subsequent aging to increase strength. Thermal cycling process was carried out for Ti-6Al-4V specimens using forced air cooling. Heat treated titanium alloy specimen was used to carry out various tests before and after thermal cycling, The test, like tensile properties, co-efficient of thermal expansion, Microstructure, Compression test, Vickers Hardness was examined by the following test. Coefficient of Thermal expansion was measured using Dilatometer. Tensile test was carried out at room temperature using an Instron type machine. Vickers's hardness measurement was done on the same specimen as used for the microstructural observation from near the surface to the inside specimen. Compression test was carried out at room temperature using an Instron type machine. Ti‐6Al‐4V alloy is a workhorse of titanium industry; it accounts for about 60 percent of the total titanium alloy production. The high cost of titanium makes net shape manufacturing routes very attractive. Casting is a near net shape manufacturing route that offers significant cost advantages over forgings or complicated machined parts.

Application of radionuclide techniques to study the wear behaviour of peripherally treated and coated components

International Nuclear Information System (INIS)

Hirsch, E.; Mayer, K.H.; Rodrian, U.; Scheidemantel, N.; Schweizer, R.

1990-07-01

Technically and economically important machinery components (helical gear wheels, camshafts, rams, valve rockers) were to be optimized with regard to their wear behaviour under operation-oriented load conditions, and the process parameters required both for peripheral layer heating and surface coating were to be determined. Based on earlier experiments, the treatment parameters and the basic materials were varied. The layer structure was studied, characterized and correlated wi the wear behaviour. The wearing parts were activated in the reactor by thermal neutrons, or in the cyclotron by charged particles. By labelling various parts by means of different radioisotopes, up to three components may be measured at the same time in practice, provided that the circumstances are favourable. (BBR) [de

Thermal decomposition studies on tri-iso-amyl phosphate in n-dodecane-nitric acid system

International Nuclear Information System (INIS)

Chandran, K.; Sreenivasalu, B.; Suresh, A.; Sivaraman, N.; Anthonysamy, S.

2014-01-01

Tri-iso-amyl Phosphate (TiAP) is a promising alternative solvent to TBP, with near similar extraction behaviour and physical properties but lower aqueous phase solubility and does not form third phase during the extraction of Pu(IV). In addition to the solubilised extractant, inadvertent entrainment of the extractant into the aqueous stream is a concern during the evaporation operation as the extractant comes into contact with higher nitric acid concentrations and metal nitrates. Hence the thermal decomposition behaviour of TiAP-HNO 3 systems has been studied using an adiabatic calorimeter in closed air ambience, under heat-wait-search mode (H-W-S)

Predicting electrical and thermal abuse behaviours of practical lithium-ion cells from accelerating rate calorimeter studies on small samples in electrolyte

Science.gov (United States)

Richard, M. N.; Dahn, J. R.

An accelerating rate calorimeter (ARC) is used to measure the thermal stability of de-intercalated Li 1+ xMn 2- xO 4 in LiPF 6 EC:DEC (33:67) electrolyte. Self-heating is detected well after the 80°C onset of self-heating measured for lithium intercalated mesocarbon microbead (MCMB) electrodes in LiPF 6 EC:DEC (33:67) electrolyte. As a result, the initial self-heating measured in a practical carbon/Li 1+ xMn 2- xO 4 lithium-ion cell is caused by reactions at the anode. In previous work, we have proposed a model for the reactions that cause self-heating in MCMB electrodes in electrolyte. By assuming that a cell self-heats only because reactions occur at the anode, the model can be used to predict the power generated by the amount of MCMB in practical cells with an inert cathode. The calculated chemically generated power can be combined with power loss measurements, due to the transfer of heat to the environment, to predict the short-circuit behaviour and the oven exposure behaviour for a cell containing an MCMB anode and an inert cathode. The results agree qualitatively with short-circuit and oven exposure results measured on NEC Moli energy 18650 cells containing an Li 1+ xMn 2- xO 4 cathode.

A dynamic Monte Carlo study of anomalous current voltage behaviour in organic solar cells

International Nuclear Information System (INIS)

Feron, K.; Fell, C. J.; Zhou, X.; Belcher, W. J.; Dastoor, P. C.

2014-01-01

We present a dynamic Monte Carlo (DMC) study of s-shaped current-voltage (I-V) behaviour in organic solar cells. This anomalous behaviour causes a substantial decrease in fill factor and thus power conversion efficiency. We show that this s-shaped behaviour is induced by charge traps that are located at the electrode interface rather than in the bulk of the active layer, and that the anomaly becomes more pronounced with increasing trap depth or density. Furthermore, the s-shape anomaly is correlated with interface recombination, but not bulk recombination, thus highlighting the importance of controlling the electrode interface. While thermal annealing is known to remove the s-shape anomaly, the reason has been not clear, since these treatments induce multiple simultaneous changes to the organic solar cell structure. The DMC modelling indicates that it is the removal of aluminium clusters at the electrode, which act as charge traps, that removes the anomalous I-V behaviour. Finally, this work shows that the s-shape becomes less pronounced with increasing electron-hole recombination rate; suggesting that efficient organic photovoltaic material systems are more susceptible to these electrode interface effects

Investigation of Ageing Behaviour of Nitrile-Butadiene Rubber with Added Graphene in an Accelerated Thermal Ageing Environment

Directory of Open Access Journals (Sweden)

Fei-Zhou Li

2018-01-01

Full Text Available In this paper, the thermal ageing of nitrile-butadiene rubber (NBR reinforced with different graphene (GE concentrations has been investigated. NBR and NBR-GE composites were exposed to an accelerated thermal ageing environment produced by an air-circulating oven for seven days. The mechanical properties, chemical changes, and thermal stability of ageing samples and neat samples were evaluated. The results showed that the surface damage of NBR was severe and inhomogeneous, and the degree of ageing was most serious on the edge region of the voids, but NBR-GE composites were changed slightly before and after ageing. The tensile strength increased with the increase of GE concentration, up to a maximum value, and decreased with further increases in GE concentration. The GE embedded crosslinked network limited the segment movement of chains in the stretch direction and played a role in the composites properties, and the GE sheets (contained the functional groups of −OH, −C=O and C=C after ageing. This behaviour may indicate greater interface adhesion between the GE and NBR. In addition, results obtained by thermogravimetric analysis (TGA indicated that the thermal stability of NBR significantly changed with accelerated thermal ageing environment, but with addition of a certain amount of GE to NBR, the thermal stability of NBR could be improved. The NBR/GE composites exhibited good comprehensive performance with a mass fraction of GE of 10 %. Before and after the thermal ageing, the failure mechanism of NBR-GE composites appeared intergranular and ductile fracture, respectively.

Effect of Maleic Acid Content on the Thermal Stability, Swelling Behaviour and Network Structure of Gelatin -Based Hydrogels Prepared by Gamma Irradiation

International Nuclear Information System (INIS)

Eid, M.; Dessouki, A.M.; Abdel-Ghaffar, M.A.

2005-01-01

The preparation of highly swelling hydrogels containing diprotic acid and gelatin carried out by gamma-irradiation of acrylamide/maleic acid/gelatine/water mixture at ambient temperature. Poly (acrylamide/maleic acid/gelatin) p(AAm/MA/G) hydrogels were prepared in different MA and G contents at low dose rate (0.94 kGy/h), and moderate dose rate (3.84 kGy/h). The prepared hydrogels were confirmed by FT1R . The effect of copolymer composition, dose and dose rate on the swelling behaviour and the type of water diffusion in the network structure of the hydrogels was discussed. Increasing of MA content and G in the initial mixture leads to an increase in the amount of MA and G in the gel system and decrease in the gelation percent. The swelling behaviours of the hydrogel prepared at moderate dose rate increased with increasing MA mole content in the gel system. On the other hand, no systematic dependence of swelling on MA content was observed for the hydrogels obtained at low dose rate. Pore structure of the hydrogels was monitored by using scanning electron microscopy. Systematic swelling of P(AAm/MA/G) hydrogels prepared at moderate dose rates can be explained by the homogeneous pore size distribution of network. Thermogravimetric analysis (TGA) was employed to study the effect of network structure formation on the thermal behavior of the copolymer. To give a better understanding of the thermal stability of polymers, the rate of the thermal decomposition of P(AAm/MA/G) hydrogels has been evaluated

A meta-analysis of the effects of measuring theory of planned behaviour constructs on behaviour within prospective studies.

Science.gov (United States)

Mankarious, Evon; Kothe, Emily

2015-01-01

Measurement reactivity effects, such as the mere measurement effect, have been proposed as a reason for behavioural changes in a number of theory of planned behaviour intervention studies. However, it is unclear whether such changes are the result of the mere measurement effect or of other artefacts of intervention study design. The aim of this study is to determine the size and direction of changes in health behaviours from baseline to follow-up in prospective studies using the theory of planned behaviour. Electronic databases were searched for the theory of planned behaviour studies which measured health behaviours at two or more time points. Change in behaviour was calculated for all studies. Sixty-six studies were included. Mean effect sizes across all studies were small and negative (d = -.03). Effect size was moderated by behaviour, behaviour type and follow-up length. Subgroup analyses showed significant decreases in socially undesirable behaviour (d = -.28), binge drinking (d = -.17), risk driving (d = -.20), sugar snack consumption (d = -.43) and sun-protective behaviour (d = -.18). Measurement of intention at baseline resulted in significant decreases in undesirable behaviour. Changes in undesirable behaviours reported in other studies may be the result of the mere measurement effect.

Thermal cycling behaviour and thermal stability of uranium-molybdenum alloys of low molybdenum content; Comportement au cyclage thermique et stabilite thermique des alliaces uranium-molybdene de faibles teneurs en molybdene

Energy Technology Data Exchange (ETDEWEB)

Decours, J; Fabrique, B; Peault, O [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

We have studied the behaviour during thermal cycling of as-cast U-Mo alloys whose molybdenum content varies from 0.5 to 3 per cent; results are given concerning grain stability during extended heat treatments and the effect of treatments combining protracted heating with thermal cycling. The thermal cycling treatments were carried out at 550, 575, 600 and 625 deg C for 1000 cycles; the protracted heating experiments were done at 550, 575, 600 and 625 deg C for 2000 hours (4000 hrs at 625 deg C). The 0.5 per cent alloy resists much better to the thermal cycling than does the non-alloyed uranium. This resistance is, however, much lower than that of alloys containing over l per cent, even at 550 deg C it improves after a heat treatment for grain-refining. Alloys of over 1.1 per cent have a very good resistance to a cycling treatment even at 625 deg C, and this behaviour improves with increasing concentrations up to 3 per cent. An increase in the temperature up to the {gamma}-phase has few disadvantages provided that it is followed by rapid cooling (50 to 100 deg C/min). The {alpha} grain is fine, the {gamma}-phase is of the modular form, and the behaviour during a thermal cycling treatment is satisfactory. If this cooling is slow (15 deg /hr) the {alpha}-grain is coarse and cycling treatment behaviour is identical to that of the 0.5 per cent alloy. The protracted heat treatments showed that the {alpha}-grain exhibits satisfactory stability after 2000 hours at 575, 600 and 625 deg C, and after 4000 hours at 625 deg C. A heat cycling treatment carried out after these tests affects only very little the behaviour of these alloys during cycling. (authors) [French] Nous avons etudie le comportement au cyclage thermique des alliages U-Mo, brut de coulee, dont la teneur varie de 0,5 a 3 pour cent de molybdene, les resultats de stabilite du grain au cours de traitements thermiques de longue duree, ainsi que ceux des traitements combines de longue duree et de cyclage. Les

Study of improving the thermal response of a construction material containing a phase change material

Science.gov (United States)

Laaouatni, A.; Martaj, N.; Bennacer, R.; Elomari, M.; El Ganaoui, M.

2016-09-01

The use of phase change materials (PCMs) for improving the thermal comfort in buildings has become an attractive application. This solution contributes to increasing the thermal inertia of the building envelope and reducing power consumption. A building element filled with a PCM and equipped with ventilation tubes is proposed, both for increasing inertia and contributing to refreshing building envelope. A numerical simulation is conducted by the finite element method in COMSOL Multiphysics, which aims to test the thermal behaviour of the developed solution. An experimental study is carried out on a concrete block containing a PCM with ventilation tubes. The objective is to see the effect of PCM coupled with ventilation on increasing the inertia of the block. The results show the ability of this new solution to ensure an important thermal inertia of a building.

Numerical simulation of the transient thermal-hydraulic behaviour of the ITER blanket cooling system under the draining operational procedure

Energy Technology Data Exchange (ETDEWEB)

Di Maio, P.A. [Dipartimento di Energia, Ingegneria dell’Informazione e Modelli Matematici, Università di Palermo Viale delle Scienze, 90128 Palermo (Italy); Dell’Orco, G.; Furmanek, A. [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St Paul Lez Durance Cedex (France); Garitta, S. [Dipartimento di Energia, Ingegneria dell’Informazione e Modelli Matematici, Università di Palermo Viale delle Scienze, 90128 Palermo (Italy); Merola, M.; Mitteau, R.; Raffray, R. [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St Paul Lez Durance Cedex (France); Spagnuolo, G.A. [Dipartimento di Energia, Ingegneria dell’Informazione e Modelli Matematici, Università di Palermo Viale delle Scienze, 90128 Palermo (Italy); Vallone, E., E-mail: eug.vallone@gmail.com [Dipartimento di Energia, Ingegneria dell’Informazione e Modelli Matematici, Università di Palermo Viale delle Scienze, 90128 Palermo (Italy)

2015-10-15

Highlights: • ITER blanket cooling system hydraulic behaviour is studied under draining transient. • A computational approach based on the finite volume method has been followed. • Draining efficiency has been assessed in term of transient duration and residual water. • Transient duration ranges from ∼40 to 50 s, under the reference draining scenario. • Residual water is predicted to range from few tens of gram up to few kilograms. - Abstract: Within the framework of the research and development activities supported by the ITER Organization on the blanket system issues, an intense analysis campaign has been performed at the University of Palermo with the aim to investigate the thermal-hydraulic behaviour of the cooling system of a standard 20° sector of ITER blanket during the draining transient operational procedure. The analysis has been carried out following a theoretical-computational approach based on the finite volume method and adopting the RELAP5 system code. In a first phase, attention has been focused on the development and validation of the finite volume models of the cooling circuits of the most demanding modules belonging to the standard blanket sector. In later phase, attention has been put to the numerical simulation of the thermal-hydraulic transient behaviour of each cooling circuit during the draining operational procedure. The draining procedure efficiency has been assessed in terms of both transient duration and residual amount of coolant inside the circuit, observing that the former ranges typically between 40 and 120 s and the latter reaches at most ∼8 kg, in the case of the cooling circuit of twinned modules #6–7. Potential variations to operational parameters and/or to circuit lay-out have been proposed and investigated to optimize the circuit draining performances. In this paper, the set-up of the finite volume models is briefly described and the key results are summarized and critically discussed.

Anomalous thermodynamic behaviour of novel compounds: inelastic neutron scattering and lattice dynamics studies

International Nuclear Information System (INIS)

Mittal, R.

2014-01-01

The understanding of the thermodynamic properties of solids has important applications in diverse areas like condensed matter physics, materials science, mineralogy, geophysics, etc. We have been extensively investigating anomalous thermodynamic properties of compounds using the techniques of inelastic neutron scattering and lattice dynamics. We would present some of the results from our recent studies. Studies of materials exhibiting anomalous thermal expansion are of interest due to their fundamental scientific importance and potential applications in ceramic, optical and electronic industry etc. We have studied the thermodynamic properties of negative thermal expansion (NTE) compounds ZrW 2 O 8 , HfW 2 O 8 , ZrMo 2 O 8 , ZrV 2 O 7 , HfV 2 O 7 , Zn(CN) 2 , Cu 2 O, Ag 2 O, Ag 3 Co(CN) 6 and Ag 3 Fe(CN) 6 . Our calculations predicted that large softening of the phonon spectrum involving librational and translational modes below 10 MeV would be responsible for anomalous thermal expansion behaviour. High pressure inelastic neutron scattering experiments carried by us on cubic ZrW 2 O 8 , ZrMo 2 O 8 and Zn(CN) 2 confirmed the phonon softening. Our studies indicate that unusual phonon softening of low energy modes is able to account for the thermal expansion behaviour in these compounds. Superionic conduction in fluorite-structured (anti-fluorite, Li 2 O) oxides (MO 2 , M= U, Th) have applications in energy storage, conversion and nuclear industry. The possible role of phonon in initiation of diffusion has been studied in Li 2 O. We found that in the superionic regime lithium atoms may exhibit macroscopic movement along (100) direction. The microscopic modeling or simulation is found to play a pivotal role in understanding the conduction processes at high temperatures in Li 2 O. We have also studied zircon structured compounds MSiO 4 (M=Zr, Hf, Th, U), RPO 4 , (R=rare earth atom). The compounds are known to transform to the scheelite (body centered tetragonal, I4 1 /a

Thermal Responsive Envelope

DEFF Research Database (Denmark)

Foged, Isak Worre; Pasold, Anke

2015-01-01

The paper presents an architectural computational method and model, which, through additive and subtractive processes, create composite elements with bending behaviour based on thermal variations in the surrounding climatic environment. The present effort is focused on the manipulation of assembly...... alterations, their respective durability and copper’s architectural (visual and transformative) aesthetic qualities. Through the use of an evolutionary solver, the composite structure of the elements are organised to find the bending behaviour specified by and for the thermal environments. The entire model...... in which the behavioural composites are organised in modules and how they act and perform. Furthermore, a large full-scale prototype is made as a demonstrator and experimental setup for post-construct analysis and evaluation of the design research. The work finds that the presented method and model can...

Hydraulic and thermal behaviour of a corrugated plane canal. Application to plate-based heat exchangers

International Nuclear Information System (INIS)

Amblard, Alain

1986-01-01

As corrugations are often used in heat exchangers in order to promote heat exchange mechanisms through a reduction of boundary layer thickness, an increase of turbulence within the boundary layer, and an increase of exchange surface, the objectives of this research thesis are, on the one hand, to determine the influence of corrugation geometry on heat exchange and friction laws, and, on the other hand, to develop a computing software to describe the flow and heat exchange in the elementary canal. This study is limited to the case of single-phase forced convection in water. After a bibliographical overview on the hydraulic and thermal behaviour of corrugated surfaces used in heat exchangers, the author presents the different studied geometries, and the experimental installation used to determine the friction and exchange coefficient in a vertical duct formed by two corrugated plates. Experimental results are presented and compared with respect to the shape of exchange surfaces. The author then reports the use of two-dimensional code used to describe the flow in an exchanger duct [fr

Synergistic effects and kinetics thermal behaviour of petroleum coke/biomass blends during H2O co-gasification

International Nuclear Information System (INIS)

Edreis, Elbager M.A.; Luo, Guangqian; Li, Aijun; Xu, Chaofen; Yao, Hong

2014-01-01

Highlights: • Sugar cane bagasse and blends gasification presented two stages at all H 2 O values. • Petroleum coke showed only one char gasification stage at (>700 °C) at 75% H 2 O. • Significant interactions are existed in the both reaction stages of samples. • Higher H 2 O concentration and PC content lead to higher kinetic parameter values. • All the models are successfully utilized to predict the experimental data. - Abstract: This study investigates the possible synergistic interactions between the Sudanese lower sulphur petroleum coke (PC) and sugar cane bagasse (SCB) during H 2 O co-gasification with three concentration values (25%, 50% and 75% v/v) using a thermogravimetric analyser (TGA) at 20 °C/min. The kinetic thermal behaviour, and effects of both H 2 O concentration and fuel blending ratio were investigated. The results show that, significant interactions existed in both reaction stages of samples, and become less when PC content and H 2 O concentration are 50%. Petroleum coke showed only one char gasification stage at (>700 °C) at 75% H 2 O. Some kinetics models like homogeneous and shrinking core models were studied by the Coats–Redfern method in order to observe the optimum reaction mechanism for the H 2 O gasification of samples, describe the best reactive behaviour and determine the kinetic parameters. The results showed that, the co-gasification behaviour and kinetic parameters have a significantly influenced by increasing both H 2 O concentration and PC content. The boundary controlled reaction model (R2) shows the lowest values of activation energy (E) for all samples and H 2 O concentrations. Finally, all the models are successfully utilized to predict the experimental data under all H 2 O concentration values

Analysis and optimization of the thermal behaviour of a sprinkled greenhouse with underground heating: Increased value of power station waste heat -Application to greenhouse cultivation energy independence

International Nuclear Information System (INIS)

Lemaitre, P.

1986-12-01

A global thermal approach to sprinkled greenhouse cultivation was developed, which led to monographs which can be used for preliminary studies. As a second step, the thermal behaviour of this particular greenhouse was used to define the relevant parameters for the optimisation of the procedure and the ideal characteristics of the material to be used for the shelter. At the same time, a physical model of a buried tubular heat exchanger was built, together with a flexible and thoroughly tested computer program. An example of its use to help determine the dimensions for ground heating systems is presented. The various waste heat recovery procedures described have been studied, leading to an internal economic study including a comparison with other means of greenhouse heating [fr

The model of the thermal and hydraulic behaviour of a out-of-pile test loop; Model thermohidraulickog ponasanja vanreaktorskog exksperimentalnog cirkulacionog kola

Energy Technology Data Exchange (ETDEWEB)

Vehauc, A; Stosic, Z [Institut za nuklearne nauke Boris Kidric, Voinca, Belgrade (Yugoslavia)

1988-07-01

A complex circulation loop was modeled and a simulation program developed for the determination of the pressure, temperature, velocity and flow rate distribution in legs of the loop. The model was used to study the thermal and hydraulic behaviour of an out-of-pile test loop at IBK-ITE. For a given set of conditions in the test section, the model yields data on all the operating modes possible with the existing control system and in consequence on the optimum operating conditions for the loop as a whole. (author)

Experimental and numerical study of the mechanical behaviour modelling of a metal-ceramic composite: MoTiC30%

International Nuclear Information System (INIS)

Cedat, D.

2008-11-01

In the scope of refractory materials development for structural applications in the core of the future nuclear reactors, several studies have been developed. The aim of this work is to increase the knowledge of the mechanical behaviour and the damage of the ceramic-metal composite Mo(TiC)x% under the temperature range [25-700 C]. The identification of the third phase, formed by diffusion during the sintering step was identified by microstructural characterization. Experimental study also revealed the percolation of the ceramic particles through the structure. Mechanical tests highlight the main characteristics of the material: the macroscopic behaviour depends on the strain rate on the first hand and the temperature on the other hand. These mechanisms are attributed to the thermally activated behaviour of molybdenum. Simulations have been made on several microstructures considering elastic-brittle inclusion in a viscoelastic matrix. A polycrystalline model was used to simulate the evolution of the mechanical behaviour of the composite. The numerical aggregate, used for the simulation, was built from a 3D reconstruction technique thanks to acquisition of FIB/EBSD/SEM data. (author)

Thermal decomposition of Yttrium(III) isovalerate in argon

DEFF Research Database (Denmark)

Grivel, Jean-Claude; Yue, Zhao; Tang, Xiao

2016-01-01

The thermal behaviour of yttrium(III) isovalerate (Y(C4H9CO2)3) was studied in argon by means of thermogravimetry, differential thermal analysis, FTIR-spectroscopy, hot-stage optical microscopy and X-ray diffraction with a laboratory Cu-tube source as well as with a synchrotron radiation source...

Modeling of the mechanical behaviour of welded structures: behaviour laws and rupture criteria

International Nuclear Information System (INIS)

Paris, T.; Delaplanche, D.; Saanouni, K.

2006-01-01

In the framework of the technological developments carried out in the CEA, the analysis of the mechanical behaviour of the heterogeneous welded bonds Ta/TA6V is a main preoccupation. Indeed, the welding of these two materials which cannot be distinguished by their mechanical and thermal properties induces strong microstructural heterogeneities in the melted zone. In order to characterize the behaviour of the welded joints and to develop a model of mechanical behaviour, a four points bending test on a notched specimen has been developed and implemented. This new test has allowed to obtain a macroscopic response of strength-displacement type but to analyze too more finely, with an optical extensometry and images correlation method, the influence of the heterogeneities on the local deformation of the welded joint. The confrontation of these results to a metallurgical study allows to validate the first conclusions deduced of the mechanical characterization tests and to conclude as for the local mechanisms governing the behaviour and the damage of the melted zone. The mechanical behaviour can be restored by an elasto-viscoplastic model with isotropic and non linear kinematic strain hardening coupled to this damage. The proposed model allows to identify the macroscopic behaviour of the weld bead. (O.M.)

Modelling of thermal behaviour of iron oxide layers on boiler tubes

Science.gov (United States)

Angelo, J. D.; Bennecer, A.; Kaczmarczyk, S.; Picton, P.

2016-05-01

Slender boiler tubes are subject to localised swelling when they are expose to excessive heat. The latter is due to the formation of an oxide layer, which acts as an insulation barrier. This excessive heat can lead to microstructural changes in the material that would reduce the mechanical strength and would eventually lead to critical and catastrophic failure. Detecting such creep damage remains a formidable challenge for boiler operators. It involves a costly process of shutting down the plant, performing electromagnetic and ultrasonic non-destructive inspection, repairing or replacing damaged tubes and finally restarting the plant to resume its service. This research explores through a model developed using a finite element computer simulation platform the thermal behaviour of slender tubes under constant temperature exceeding 723 °K. Our simulation results demonstrate that hematite layers up to 15 μm thickness inside the tubes do not act as insulation. They clearly show the process of long term overheating on the outside of boiler tubes which in turn leads to initiation of flaws.

A novel method for delivering ramped cooling reveals rat behaviours at innocuous and noxious temperatures: A comparative study of human psychophysics and rat behaviour.

Science.gov (United States)

Dunham, James P; Hulse, Richard P; Donaldson, Lucy F

2015-07-15

Thermal sensory testing in rodents informs human pain research. There are important differences in the methodology for delivering thermal stimuli to humans and rodents. This is particularly true in cold pain research. These differences confound extrapolation and de-value nociceptive tests in rodents. We investigated cooling-induced behaviours in rats and psychophysical thresholds in humans using ramped cooling stimulation protocols. A Peltier device mounted upon force transducers simultaneously applied a ramped cooling stimulus whilst measuring contact with rat hind paw or human finger pad. Rat withdrawals and human detection, discomfort and pain thresholds were measured. Ramped cooling of a rat hind paw revealed two distinct responses: Brief paw removal followed by paw replacement, usually with more weight borne than prior to the removal (temperature inter-quartile range: 19.1 °C to 2.8 °C). Full withdrawal was evoked at colder temperatures (inter quartile range: -11.3 °C to -11.8 °C). The profile of human cool detection threshold and cold pain threshold were remarkably similar to that of the rat withdrawals behaviours. Previous rat cold evoked behaviours utilise static temperature stimuli. By utilising ramped cold stimuli this novel methodology better reflects thermal testing in patients. Brief paw removal in the rat is driven by non-nociceptive afferents, as is the perception of cooling in humans. This is in contrast to the nociceptor-driven withdrawal from colder temperatures. These findings have important implications for the interpretation of data generated in older cold pain models and consequently our understanding of cold perception and pain. Copyright © 2015. Published by Elsevier B.V.

The simulation of transients in thermal plant. Part I: Mathematical model

International Nuclear Information System (INIS)

Morini, G.L.; Piva, S.

2007-01-01

This paper deals with the simulation of the transient behaviour of thermal plant with control systems. It is always more difficult for a designer to predict the effects on the plant of the control processes because of the increasing complexity of plants and control systems. The easiest way to obtain information about the dynamic behaviour of a thermal plant at the design-stage involves assessing the suitability of specific computer codes. To this end, the present work demonstrates that nowadays it is possible, by using the opportunities offered by some general purpose calculation systems, to obtain such significant information. It is described how a 'thermal-library' of customized blocks (one for each component of a thermal plant such as valves, boilers, and pumps) can be built and used, in an intuitive way, to study any kind of plant. As an example, the dynamic behaviour of a residential heating system will be shown in a companion paper, forming part II of the present article

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

International Nuclear Information System (INIS)

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

2017-01-01

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

Characteristics of naturally occurring radioactive materials (NORMs) in the oil and gas industries and their behaviour under thermal treatment: an overview

International Nuclear Information System (INIS)

Mohamad Puad Ali; Shamsuddin A H; Muhd Noor Muhd Yunus

1999-01-01

Activities and work practices in which radiation exposure of workers and members of the public is increased due to the presence of NORM are receiving increased attention from regulatory agencies and, to lesser extent, from the general public. In Malaysia the main sources of NORM are from the technological activities of tin mining, ore and heavy mineral processing, combustion of coal to generate power, and oil and gas extraction. Sludge that contains NORM arising from the oil and gas extraction activities lately has received special attention by the Malaysian regulatory authorities. These sludge are considered as scheduled waste (contains heavy metals) by Department of Environmental (DOE) and low level radioactive waste (contains NORM) by the Atomic Energy Licensing Board (AELB), and its cannot be disposed freely without proper control. From literature, the present methods of treatment practiced via land farming and storing are not recommended and will have long term impact to the environment. The other possible method can be considered to treat this sludge is by using thermal treatment technology but before this technology can be fully applied, a study has to be carried out to determine the behaviour of the various elements present in the sludge. This paper reviewed the radiological characteristic of NORMs in relation with the oil and gas production activities in Malaysia and also their behaviour when under going thermal treatment at certain temperature and combustion time. (Author)

Effect of nano-ZrO2 addition on microstructure, mechanical property and thermal shock behaviour of dense chromic oxide refractory material

International Nuclear Information System (INIS)

Lu, Lixia; Ding, Chunhui; Zhanga, Chi; Yanga, De'an; Di, Lizhi

2015-01-01

To obtain a good performance hot-face lining material in gasifier, nano-ZrO 2 , up to 5 wt %, was added into chromic oxide powder with 3 wt % TiO 2 followed by sintering at 1500°C for 2.5 h. The effect of nano-ZrO 2 addition on microstructure, mechanical property and thermal shock behaviour was studied. ZrO 2 promoted densification at contents higher than 1 wt %. Microcracks and phase transformation toughened the dense chromic oxide refractory material. The main reason for decrease of strength was the existence microcracks in specimens and weakening of intergranular fracture. Dense chromic oxide refractory material with 2∼3 wt % nano-ZrO 2 possessed good densification, uniform microstructure, normal mechanical property and proper thermal shock resistance. The rupture strength retention ratio was nearly twice than that of chromic oxide material without ZrO 2 after three cycles of quenching test from 950°C to cold water. (author)

A thermal analysis study on proprietary quick-setting mixed binder system

International Nuclear Information System (INIS)

Deneanu, N.; Dulama, M.; Diaconescu, C.

2013-01-01

The present paper presents a study, by thermal analysis, of the hydration of a mixed binder system consist of Portland composite cement type CEM II/A-M(S-LL) 32,5 R and calcium aluminate cement type GORKAL 70, patented by the authors for embedding spent radioactive solvents. Cement hydration reactions are often affected by the presence of a spent radioactive solvent, usually retarded. This process can be monitored by thermal analysis and often quantified. The data are being used as a reference to compare the changes in the cement blend hydration during the solidification caused by the presence of the spent radioactive solvents itself or by emulsifier additives which are being availed. Detailed analysis of DTG (derivative thermo gravimetric) decomposition profiles of portlandite and carbonate enabled the evaluation of admixture-related parameters concerning portlandite formation and also indicated the behaviour of specific carbonates during the hydration process. (authors)

Study of Error Propagation in the Transformations of Dynamic Thermal Models of Buildings

Directory of Open Access Journals (Sweden)

Loïc Raillon

2017-01-01

Full Text Available Dynamic behaviour of a system may be described by models with different forms: thermal (RC networks, state-space representations, transfer functions, and ARX models. These models, which describe the same process, are used in the design, simulation, optimal predictive control, parameter identification, fault detection and diagnosis, and so on. Since more forms are available, it is interesting to know which one is the most suitable by estimating the sensitivity of the model to transform into a physical model, which is represented by a thermal network. A procedure for the study of error by Monte Carlo simulation and of factor prioritization is exemplified on a simple, but representative, thermal model of a building. The analysis of the propagation of errors and of the influence of the errors on the parameter estimation shows that the transformation from state-space representation to transfer function is more robust than the other way around. Therefore, if only one model is chosen, the state-space representation is preferable.

Lithium-deficient Li YMn2O4 spinels (0.9 ≤ Y < 1): Lithium content, synthesis temperature, thermal behaviour and electrochemical properties

International Nuclear Information System (INIS)

Pascual, Laura; Perez-Revenga, M. Luz; Rojas, Rosa M.; Rojo, Jose M.; Amarilla, J. Manuel

2006-01-01

Lithium-deficient Li Y Mn 2 O 4 spinels (LD-Li Y Mn 2 O 4 ) with nominal composition (0.9 ≤ Y 2 O 3 and LiNO 3 at temperatures ranging from 700 deg. C to 850 deg. C. X-ray diffraction data show that LD-Li Y Mn 2 O 4 spinels are obtained as single phases in the range Y = 0.975-1 at 700 deg. C and 750 deg. C. Morphological characterization by transmission electron microscopy shows that the particle size of LD-Li Y Mn 2 O 4 spinels increases on decreasing the Li-content. The influence of the Li-content and the synthesis temperature on the thermal and electrochemical behaviours has been systematically studied. Thermal analysis studies indicate that the temperature of the first thermal effect in the differential thermal analysis (DTA)/thermogravimetric (TG) curves, T C1 , linearly increases on decreasing the Li-content. The electrochemical properties of LD-Li Y Mn 2 O 4 spinels, determined by galvanostatic cycling, notably change with the synthesis conditions. So, the first discharge capacity, Q disch. , at C rate increases on rising the Li-content and the synthesis temperature. The sample Li 0.975 Mn 2 O 4 synthesized at 700 deg. C has a Q disch. = 123 mAh g -1 and a capacity retention of 99.77% per cycle. This LD-Li Y Mn 2 O 4 sample had the best electrochemical characteristics of the series

Occupants’ behavioural adaptation in workplaces with non-central heating and cooling systems

International Nuclear Information System (INIS)

Liu Jing; Yao Runming; Wang Juan; Li Baizhan

2012-01-01

Occupants’ behaviour when improving the indoor environment plays a significant role in saving energy in buildings. Therefore the key step to reducing energy consumption and carbon emissions from buildings is to understand how occupants interact with the environment they are exposed to in terms of achieving thermal comfort and well-being; though such interaction is complex. This paper presents a dynamic process of occupant behaviours involving technological, personal and psychological adaptations in response to varied thermal conditions based on the data covering four seasons gathered from the field study in Chongqing, China. It demonstrates that occupants are active players in environmental control and their adaptive responses are driven strongly by ambient thermal stimuli and vary from season to season and from time to time, even on the same day. Positive, dynamic, behavioural adaptation will help save energy used in heating and cooling buildings. However, when environmental parameters cannot fully satisfy occupants’ requirements, negative behaviours could conflict with energy saving. The survey revealed that about 23% of windows are partly open for fresh air when air-conditioners are in operation in summer. This paper addresses the issues how the building and environmental systems should be designed, operated and managed in a way that meets the requirements of energy efficiency without compromising wellbeing and productivity. - Highlights: ► A year-long field study of observing user behaviour in workplace. ► Occupants’ behavioural adaptation plays an important role in reducing energy from buildings. ► Occupants actively and dynamically respond to outdoor climate change. ► Positive behavioural adaptations will eliminate the use of heating/cooling facilities. ► The poor use of heating/cooling facilities will cause a significant waste of energy.

Seasonal analysis of the thermal behaviour of traditional underground wine cellars in Spain

Energy Technology Data Exchange (ETDEWEB)

Mazarron, Fernando R.; Canas, Ignacio [Departamento de Construccion y Vias Rurales, Escuela Tecnica Superior de Ingenieros Agronomos, Universidad Politecnica de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain)

2009-11-15

Traditional underground wine cellars are a good example of bioclimatic construction, providing optimum conditions for maturing wine with no energy consumption. This article studies the annual thermal behaviour of traditional underground wine cellars in one of the most well-known wine producing areas in Spain, the Ribera del Duero. For this we have applied a method based on multiple regression analysis using experimental data monitored for 1 year. The results show that the interior air temperature is fundamentally conditioned by the undisturbed temperature of the ground at the average depth of the wine cellar and by the temperature of the outside air (R{sup 2} varies between 0.937 and 0.974, with an average of 0.964 for the three wine cellars studied). However, the stability of the wine cellar during changes of outside temperature differs according to the time of year. In the spring and summer, the stability is excellent and the influence of the ground temperature is much greater than that of the outside air temperature (beta coefficient for the ground temperature is 0.85 compared to 0.17 for the outside air temperature). In the autumn and winter, the stability of the wine cellar is reduced by the increased ventilation, reducing the influence of the ground temperature ({beta} = 0.70) and increasing that of the outside air ({beta} = 0.42). (author)

Experimental study on the thermo-mechanical behaviour of stiff clay under non-isotropic stress state

International Nuclear Information System (INIS)

Tang, Anh Minh; Cui, Yu-Jun; Li, Xiang-Ling

2012-01-01

Document available in extended abstract form only. Stiff clay is usually considered as possible host-rock for geological radioactive waste disposal due to its low permeability and its self-sealing capacity. Boom Clay, for instance, is one of the clays currently considered by the Belgian radioactive waste management agency Ondraf/Niras as a potential host for a geological repository. In order to analyse the performance of this material, it is important to understand its behaviour under the coupled thermo-hydro-mechanical solicitations. In laboratory, several studies have been performed to study the volume change of clay under coupled thermomechanical loading. The results show that heating under drained conditions can induce thermal dilation at low confining stress and thermal contraction at high confining stress. On the other hand, compression tests performed at constant temperature show that the compressibility parameters of soil can be modified by temperature change. These features are now well considered in constitutive laws based on the framework of elasto-plasticity. Under undrained conditions, heating can increase pore-water pressure and this behaviour can be simulated using the theoretical thermo-poro-elastic framework. The temperature effect on the soil behaviour under triaxial compression is also often considered. It is commonly accepted that heating decreases the shear strength of clay but this softening can be hidden by the thermal contraction that occurs during heating which can induce at the same time soil hardening. In spite of these existing works, laboratory tests considering the thermo-mechanical loading path that the soil can be subjected to are still rare. Actually, in the case of geological radioactive waste disposal, after the installation of waste canisters, the soil is expected to be heated under non-isotropic stress state. Most of the existing laboratory works show heating tests in odometer cell or triaxial cell under isotropic stress

Organizational Behaviour Study Material

OpenAIRE

P. Sreeramana Aithal

2016-01-01

An overview of Organizational Behaviour – History of Organisational Behaviour and its emergence as a disciple-emerging perspective Organizational Behaviour. Individual process in organisation – Learning, perception and attribution- Individual differences - Basic concepts of motivation - Advanced concepts of motivation. Group process in Organisation – Group dynamics, leadership theories - Power, politics and conflict - inter- personal communication. Enhancing individu...

A study of the coefficient of thermal expansion of nuclear graphites

International Nuclear Information System (INIS)

Hacker, P.J.

2001-02-01

This thesis presents the results of a study of the Coefficient of Thermal Expansion (CTE) of two grades of nuclear graphite that are used as the moderator in the Magnox and Advanced Gas-Cooled reactors operated in the UK. This work has two main aims, the first is to characterise those elements of the graphite microstructure that control CTE within these materials and to relate these to the effects induced within the reactor. The second is to develop a microstructural model, of general applicability, that can initially be applied to model the CTE changes within the graphites under reactor conditions (neutron irradiation and radiolytic oxidation). These aims have been met by study in three interlinked areas, theoretical, experimental and modelling. Previous to this study, a loose assembly of single crystals together with changes in small scale nanometric porosity (Mrozowski cracks) were used to describe CTE behaviour of nuclear graphite both as-received and under reactor conditions. Within the experimental part of this thesis the graphite nanostructure was studied using, primarily, Transmission Electron Microscopy (TEM). This work concluded that structure on this scale was complex and that the loose assembly of single crystals was a poor microstructural approximation for modelling the CTE of these materials. Other experimental programmes measured the CTE of highly oxidised samples and simulated the effects of irradiation. The former discovered that CTE remained largely unaffected to high weight losses. This insensitivity was explained by ''The Continuous Network Hypothesis'' that was also related to classical percolation theory. The final part of the thesis modelled an abstraction of the key microstructural features identified in the previous parts of the thesis. This approach has been applied to AGR moderator graphite where it has successfully modelled the thermal expansion behaviour of the as-received, irradiated and oxidised material. (author)

A preliminary study on the thermal conductivity and flammability of WPC based on some tropical woods

International Nuclear Information System (INIS)

Chia, L.H.L.; Chua, P.H.; Lee, E.E.N.

1985-01-01

Selected local woods and their wood-polymer combinations or composites (WPC) were tested for their thermal conductivity and their fire resistance. WPC were prepared by polymerizing monomers 'in situ' in oven dried woods by gamma radiation. The monomers included acrylonitrile (AN), 60% styrene-40% acrylonitrile (STAN), methyl methacrylate (MMA), 95% methyl methacrylate-5% dioxane (MD), and vinylidene chloride (VDC). A reduction in thermal conductivity was exhibited by all the composites prepared. W-PAN showed the greatest reduction in thermal conductivity and W-PSTAN in general showed the least. An explanation is suggested for this behaviour. The polymers PMMA and PMD were found to enhance flammability of the woods while PVDC, PAN, and PSTAN imparted fire resistance to the woods. Of the six local woods studied, Ramin-and-Keruing-polymer composites showed the highest flammable tendencies obtained. The correlation of thermal conductivity to flammability is discussed. (author)

Thermal expansion behaviour of granites

Czech Academy of Sciences Publication Activity Database

Plevová, Eva; Vaculíková, Lenka; Kožušníková, Alena; Ritz, M.; Simha Martynková, G.

2016-01-01

Roč. 123, č. 2 (2016), s. 1555-1561 ISSN 1388-6150 R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406 Institutional support: RVO:68145535 Keywords : thermomechanical analysis * differential thermal analysis * granites Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.953, year: 2016 http://link.springer.com/article/10.1007/s10973-015-4996-z

The simulation of transients in thermal plant. Part II: Applications

International Nuclear Information System (INIS)

Morini, G.L.; Piva, S.

2008-01-01

This paper deals with the simulation of the transients of thermal plant with control systems. In the companion paper forming part I of this article [G.L. Morini, S. Piva, The simulation of transients in thermal plant. Part I: Mathematical model, Applied Thermal Engineering 27 (2007) 2138-2144] it has been described how a 'thermal-library' of customised blocks can be built and used, in an intuitive way, to study the transients of any kind of thermal plant. Each component of plant such as valves, boilers, and pumps, is represented by a single block. In this paper, the 'thermal-library' approach is demonstrated by the analysis of the dynamic behaviour of a central heating plant of a typical apartment house during a sinusoidal variation of the external temperature. A comparison of the behaviour of such a plant with three way valve working either in flow rate or in temperature control, is presented and discussed. Finally, the results show the delaying effect of the thermal capacity of the building on the performance of the control system

Assessing the thermal-hydraulic behaviour of steam generators in a CANDU-6 type NPP in the event of MSSV blockage on the open-setting

International Nuclear Information System (INIS)

Dinca, Elena

2004-01-01

This work aims at achieving an analysis regarding the thermal-hydraulic behaviour of a CANDU-6 type NPP in the event of the blockage on open-setting of an MSSV (Main Steam Safety Valve) for steam relief from steam generators. The systems studied are main steam and feedwater mixture in the secondary circuit, particularly being analyzed the behaviour of the steam generators as well as the primary heat transfer and the control system of heavy water pressure and inventory in the primary system. One supposes that the MSSV blockage occurs directly after its opening in the event of an accident that led to the a steam pressure rise in the steam generators up to the threshold value of MSSV o penning. The analysis was applied to two events of initiation which lead to MSSV o penning, namely a Class IV loss of electric supply and loss of vacuum in turbine condenser. In the simulation of the events selected for analysis a long elapse of time is supposed (3600 seconds) and no operator intervention while the NPP is operating at rating power and equilibrium fuel regime. Each of the two events were analyzed for two distinct sets of conditions of event initiation and evolution. The study was focussed on the behaviour of NPP, particularly of the steam generators, and on the estimation of the amount of water in the secondary circuit released into the atmosphere during the event. The analysis is of deterministic type and supplies information required by the Probabilistic Safety Assessment (PSA) applied to nuclear facilities in establishing the operation procedures and documentation. The analysis was based on design data for a CANDU-6 NPP and the HYDN3 code for thermal-hydraulic computation in CANDU type NPPs. In the paper there are presented the analysis, methodology, models, hypotheses and the input data as well as the analyzed cases. Within the computing code some models were developed to allow simulating the event sequences chosen for analyses. The results are plotted and

Behaviour of the Callovo-Oxfordian clay around a converging heated borehole: thermal free wall experiment

International Nuclear Information System (INIS)

Garitte, B.; Gens, A.; Vaunat, J.; Armand, G.; Conil, N.

2012-01-01

Document available in extended abstract form only. ANDRA has launched several heating experiments in the Meuse-Haute Marne Underground Laboratory (e.g. TER and TED). In these experiments, the heater-rock contact was ensured by a metal tubing that prevented any convergence of the heating borehole. The Thermal Free Wall experiment was run by ANDRA to investigate whether the rock behaviour around an un-cased borehole was similar as in the previous experiments. Additionally, the temperature increase in the TFW was applied faster than in the previous experiments in order to investigate the rock response to a heavier thermal load. It consists in a main borehole containing the heater and two instrumentation boreholes equipped with a temperature and a pore water pressure sensor each. The sensors installed in borehole TER1906 are at approximately 40 cm from the heater borehole wall in the bedding plane. The TER1907 sensors are in the direction perpendicular to the bedding planes at about 70 cm from the heater borehole. The boreholes were drilled from the GEX gallery in the direction of the major in situ stress (16 MPa). The heater has an effective heating length of 3.29 m and is located between 7 and 10 m from the GEX gallery. It was emplaced on a base to centre it in the borehole and to have a void between the heater and the rock mass for free convergence. Heating started on 10 January 2011 and lasted 56 days. One of the requirements of the experiment was to apply a relatively fast heating ramp in comparison with the previous tests in order to investigate the rock behaviour under stronger thermal load. The increase from 21 C to 90 C at the external heater wall was achieved in 14 hours. The initial pore water pressure is about 3.2 MPa, somewhat lower than the undisturbed pore water pressure at the level of the laboratory (4.5 MPa). This difference is attributed to the presence of the GEX gallery that was excavated in July-September 2005. In this work, we present the

Behaviour and fatigue damage study of cast aluminium alloys; Etude du comportement et de l'endommagement en fatigue d'alliages d'aluminium de fonderie

Energy Technology Data Exchange (ETDEWEB)

Barlas, B.

2004-02-15

This study is aimed at determining the influence of chemical composition and heat treatment of cast aluminium alloys Al-Si-Cu-Mg on mechanical behaviour and fatigue life of structures. The industrial frame of this study concerns cylinder-heads of high efficiency diesel engines, for Renault and Montupet companies. The experimental means involved in this work are as well microscopic (TEM, microhardness, image analysis), mechanical (LCF and aniso-thermal tests, macro-hardness) and numerical (simulation of the stability of the hardening phases, behaviour and damage model identification, cylinder-head life time calculation). The link between micro and macro approaches is provided by the means of an internal microscopic variable representing thermal aging through coarsening of the precipitates and implemented into the macroscopic model. (author)

Thermal stability of carbon-encapsulated Fe-Nd-B nanoparticles

International Nuclear Information System (INIS)

Bystrzejewski, M.; Cudzilo, S.; Huczko, A.; Lange, H.

2006-01-01

Thermal stability of various magnetic nanomaterials is very essential, due to their prospective future applications. In this paper, thermal behaviour of the carbon-encapsulated Fe-Nd-B nanoparticles is studied. These nanostructures were produced by direct current arcing of carbon anodes filled with Nd 2 Fe 14 B material. The thermogravimetry and differential thermal analysis curves were recorded in an oxygen atmosphere. The thermal processes were monitored by X-ray diffraction to follow the changes in the phase composition. The investigated samples have been thermally stable up to 600 K

Corrosion behaviour of zirconium alloys out or under irradiation

International Nuclear Information System (INIS)

Thomazet, J.; Billot, P.

1997-01-01

This article describes and compares the results obtained after studies carried out in autoclaves, in loops and in reactor in power on the behaviour of some products. Inversions of behaviour are observed between results of studies in autoclaves and after irradiation. On the contrary, a study in loop under thermal flux reproduces the classifying of tested products without however ensure a reliable quantification. Studies in autoclave are nevertheless useful for a first analysis of effects of modifications of manufacturing range. Nevertheless, a deep analysis of involved phenomena requires a better knowledge of corrosion mechanisms. (O.M.)

IFPE/IFA-533, Fuel Thermal Behaviour at High Burnup, Halden Reactor

International Nuclear Information System (INIS)

Gyori, Cs.; Turnbull, J.A.

1997-01-01

Description: After twelve years irradiation in the Halden Boiling Water Reactor two fuel rods (Rod 807 and Rod 808) were re-instrumented with fuel centre thermocouples and reloaded into the reactor in order to investigate the fuel thermal behaviour at high burnup. The fuel rods were pre-irradiated with four other rods in the upper cluster of IFA-409 (IFA=Instrumented Fuel Assembly) from May 1973 to June 1985. After base irradiation the four neighbouring rods were re-instrumented with pressure transducers and ramp tested in IFA-535.5 and IFA-535.6 providing useful data about fission gas release (FGR) presented in the Fuel Performance Database as well (Ref. 1). The two rods re-instrumented with fuel centre thermocouples have been irradiated as IFA-533.2 from April 1992. As the irradiation history of IFA-533.2 in the first months was very similar to the history of the ramp tests, the fuel temperature and FGR data measured in the different IFAs can complement each other, although the fuel-cladding gap sizes were slightly different and due to re-instrumentation the internal gas conditions were also dissimilar

Thermal annealing behaviour of sulphur-35 produced in pile-irradiated mixed crystals AlCl/sub 3/-FeCl/sub 3/

Energy Technology Data Exchange (ETDEWEB)

Dyakovich, V; Todorovski, D S; Kostadinova, Z D [Sofia Univ. (Bulgaria). Khimicheski Fakultet

1983-12-19

The regression analysis of the experimental results on the thermal annealing behaviour of /sup 35/S produced in pile-irradiated mixed crystals AlCl/sub 3/-FeCl/sub 3/ confirms some suppositions made in a previous paper. The chemical state of /sup 35/S is defined by the target prehistory and the iron concentration. The influence of Fe/sup 3 +/ can be observed indirectly through its influence on the defect structure formed.

Cognitive behavioural therapy (CBT – case studies

Directory of Open Access Journals (Sweden)

Martyna Głuszek-Osuch

2016-04-01

Full Text Available The objective of the present study is to further elucitate the specifics cognitive behavioural therapy (CBT based on the treatment of 2 patients. The theoretical background of the therapy is based on the idea that the learning processes determine behaviour (behavioural therapy, acquisition and consolidation of beliefs and view of the world (cognitive therapy. The CBT is short-term (usually 12–20 weekly sessions. It assumes close links between the patient’s thoughts (about self, the world and the future and his/her emotions, behaviour and physiology. The patient’s work in between sessions consists in observation of their own thoughts, behaviours, and emotions, and introduction of changes within the scope of their thoughts and behaviours. The goal of cognitive behavioural therapy is autonomy and independence of a patient, attainment of the patient’s objectives, and remedying the most important problems of the patient. The therapist should be active, warm and empathic. Cognitive behavioural therapy is structured and active. Between sessions, the patient receives homework assignments to complete. During therapy, information is collected by experiments and verification of hypotheses. It should be emphasized that for changes to occur in the process of psychotherapy it is necessary to establish a strong therapeutic alliance.

Reentrant behaviour in polyvinyl alcohol-borax hydrogels

Science.gov (United States)

Lawrence, Mathias B.; Desa, J. A. E.; Aswal, V. K.

2018-01-01

Polyvinyl alcohol (PVA) hydrogels, cross-linked with varying concentrations of borax, were studied with small angle neutron scattering (SANS), x-ray diffraction (XRD) and differential thermal analysis (DTA). The SANS data satisfy the Ornstein-Zernike approximation. The hydrogels are modelled as PVA chains bound by borate cross-links. Water occupies the spaces within the three-dimensional hydrogel network. The mesh size ξ indicates reentrant behaviour i.e. at first, ξ increases and later decreases as a function of borax concentration. The behaviour is explained on the basis of the balance between the charged di-diol cross-links and the shielding by free ions in the solvent. XRD and DTA show the molecular size of water in the solvent and the glass transition temperature commensurate with reentrant behaviour.

Studies on polymer electrolyte poly(vinyl) pyrrolidone (PVP) complexed with ionic liquid: Effect of complexation on thermal stability, conductivity and relaxation behaviour

Energy Technology Data Exchange (ETDEWEB)

Saroj, A.L. [Department of Physics, Banaras Hindu University, Varanasi, 221005 (India); Singh, R.K., E-mail: rksingh_17@rediffmail.com [Department of Physics, Banaras Hindu University, Varanasi, 221005 (India); Chandra, S. [Department of Physics, Banaras Hindu University, Varanasi, 221005 (India)

2013-03-01

Highlights: Black-Right-Pointing-Pointer PVP + IL based polymer electrolyte films have been prepared and studied. Black-Right-Pointing-Pointer The complexation/interaction of PVP with IL has been confirmed by FT-IR analysis. Black-Right-Pointing-Pointer The conductivity and relaxation frequency increases with increasing IL content. Black-Right-Pointing-Pointer Two relaxation peaks for complexed and uncomplexed PVP with IL have been observed. - Abstract: Polymer electrolyte films of PVP + x wt% ionic liquid (IL) (1-ethyl-3-methylimidazolium tetrafluoroborate [EMIM][BF{sub 4}]) for x = 0, 5, 10, 15, 20, 25 wt% have been prepared using solution cast technique. These films were characterized by TGA, DSC, FT-IR and ac impedance spectroscopy techniques. From XRD studies it is found that the inclusion of IL increases the amorphocity of polymeric membranes. DSC thermograms show that the glass transition (T{sub g}) and melting temperatures (T{sub m}) of PVP shift upon complexation with IL. FT-IR analysis shows the complexation of PVP with IL. Thermogravimetric studies show that PVP decomposes in a single step while PVP/IL membranes exhibit two step decomposition; lower value of decomposition temperature corresponds to the decomposition of PVP/IL complex while the higher decomposition temperature has been attributed to the decomposition of PVP. The decomposition temperature of PVP/IL complex decreases with the increasing amount of IL in the PVP membrane. Temperature dependence of conductivity and dielectric relaxation frequencies have also been studied for PVP and PVP/IL membranes. Both show thermally activated Arrhenius behaviour.

A methodology for modelling energy-related human behaviour: Application to window opening behaviour in residential buildings

DEFF Research Database (Denmark)

Fabi, Valentina; Andersen, Rune Korsholm; Corgnati, Stefano P.

2013-01-01

that affect the results accuracy. Above all, the real energy performance can be affected by the actual behaviour of the building occupants. Thus, there are great benefits to be derived from improving models that simulate the behaviour of human beings within the context of engineered complex systems...... for modelling the human behaviour related to the control of indoor environment. The procedure is applied at models of occupants’ interactions with windows (opening and closing behaviour). Models of occupants’ window opening behaviour were inferred based on measurements and implemented in a simulation program......An energy simulation of a building is a mathematical representation of its physical behaviour considering all the thermal, lighting, acoustics aspects. However, a simulation cannot precisely replicate a real construction because all the simulations are based on a number of key assumptions...

Experimental and Numerical Study on the Tensile Behaviour of UACS/Al Fibre Metal Laminate

Science.gov (United States)

Xue, Jia; Wang, Wen-Xue; Zhang, Jia-Zhen; Wu, Su-Jun; Li, Hang

2015-10-01

A new fibre metal laminate fabricated with aluminium sheets and unidirectionally arrayed chopped strand (UACS) plies is proposed. The UACS ply is made by cutting parallel slits into a unidirectional carbon fibre prepreg. The UACS/Al laminate may be viewed as aluminium laminate reinforced by highly aligned, discontinuous carbon fibres. The tensile behaviour of UACS/Al laminate, including thermal residual stress and failure progression, is investigated through experiments and numerical simulation. Finite element analysis was used to simulate the onset and propagation of intra-laminar fractures occurring within slits of the UACS plies and delamination along the interfaces. The finite element models feature intra-laminar cohesive elements inserted into the slits and inter-laminar cohesive elements inserted at the interfaces. Good agreement are obtained between experimental results and finite element analysis, and certain limitations of the finite element models are observed and discussed. The combined experimental and numerical studies provide a detailed understanding of the tensile behaviour of UACS/Al laminates.

Investigation of the electrochemical behaviour of thermally prepared Pt-IrO2 electrodes

Directory of Open Access Journals (Sweden)

Konan Honoré Kondro

2008-04-01

Full Text Available Different IrO2 electrodes in which the molar percentage of platinum (Pt varies from 0 %mol Pt to 100 %mol Pt were prepared on titanium (Ti substrate by thermal decomposition techniques. The electrodes were characterized physically (SEM, XPS and electrochemically and then applied to methanol oxidation. The SEM micrographs indicated that the electrodes present different morphologies depending on the amount of platinum in the deposit and the cracks observed on the 0 %mol Pt electrode diminish in size tending to a compact and rough surface for 70 %mol Pt electrode. XPS results indicate good quality of the coating layer deposited on the titanium substrate. The voltammetric investigations in the supporting electrolyte indicate that the electrodes with low amount of platinum (less than 10 %mol Pt behave as pure IrO2. But in the case of electrodes containing more than 40 %mol Pt, the voltammograms are like that of platinum. Electrocatalytic activity towards methanol oxidation was observed with the electrodes containing high amount of platinum. Its oxidation begins at a potential of about 210 mV lower on such electrodes than the pure platinum electrode (100 %mol Pt. But for electrode containing low quantity of Pt, the surface of the coating is essentially composed of IrO2 and methanol oxidation occurs in the domain of water decomposition solely. The increase of the electrocatalytic behaviour of the electrodes containing high amount of Pt towards methanol oxidation is due to the bifunctional behaviour of the electrodes.

Effect of maleic acid content on the thermal stability, swelling behaviour and network structure of gelatin-based hydrogels prepared by gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Eid, M. [National Center For Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo 11731 (Egypt)], E-mail: mona_eid2000@yahoo.com; Abdel-Ghaffar, M.A. [National Research Center, Dokki, Cairo (Egypt); Dessouki, A.M. [National Center For Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo 11731 (Egypt)

2009-01-15

The highly swelling Poly (acrylamide/maleic acid/gelatin) P(AAm/MA/G) hydrogels were prepared by gamma-irradiation at low dose rate (0.94 kGy/h) and moderate dose rate (3.84 kGy/h). The hydrogels were confirmed by FTIR. The effect of copolymer composition, dose and dose rate on the swelling behaviour was discussed. Increasing of MA content and G in the initial mixture leads to an increase in the amount of MA and G in the gel system and decrease in the gelation %. The swelling behaviours of the hydrogel prepared at moderate dose rate increased with increasing MA mole content in the gel system but, there is no systematic dependence of swelling on MA content was observed for the hydrogels obtained at low dose rate. Pore structure of the hydrogels was monitored by using scanning electron microscopy. Thermogravimetric analysis (TGA) and the rate of the thermal decomposition of P(AAm/MA/G) hydrogels has been evaluated to give a better understanding of the thermal stability of polymers, The X-ray data of P(AAm/MA/G) hydrogels was discussed to investigate some features namely the degree of ordering and crystallite size.

Thermal systems; Systemes thermiques

Energy Technology Data Exchange (ETDEWEB)

Lalot, S. [Valenciennes Univ. et du Hainaut Cambresis, LME, 59 (France); Lecoeuche, S. [Ecole des Mines de Douai, Dept. GIP, 59 - Douai (France)]|[Lille Univ. des Sciences et Technologies, 59 - Villeneuve d' Ascq (France); Ahmad, M.; Sallee, H.; Quenard, D. [CSTB, 38 - Saint Martin d' Heres (France); Bontemps, A. [Universite Joseph Fourier, LEGI/GRETh, 38 - Grenoble (France); Gascoin, N.; Gillard, P.; Bernard, S. [Laboratoire d' Energetique, Explosion, Structure, 18 - Bourges (France); Gascoin, N.; Toure, Y. [Laboratoire Vision et Robotique, 18 - Bourges (France); Daniau, E.; Bouchez, M. [MBDA, 18 - Bourges (France); Dobrovicescu, A.; Stanciu, D. [Bucarest Univ. Polytechnique, Faculte de Genie Mecanique (Romania); Stoian, M. [Reims Univ. Champagne Ardenne, Faculte des Sciences, UTAP/LTM, 51 (France); Bruch, A.; Fourmigue, J.F.; Colasson, S. [CEA Grenoble, Lab. Greth, 38 (France); Bontemps, A. [Universite Joseph Fourier, LEGI/GRETh, 38 - Grenoble (France); Voicu, I.; Mare, T.; Miriel, J. [Institut National des Sciences Appliquees (INSA), LGCGM, IUT, 35 - Rennes (France); Galanis, N. [Sherbrooke Univ., Genie Mecanique, QC (Canada); Nemer, M.; Clodic, D. [Ecole des Mines de Paris, Centre Energetique et Procedes, 75 (France); Lasbet, Y.; Auvity, B.; Castelain, C.; Peerhossaini, H. [Nantes Univ., Ecole Polytechnique, Lab. de Thermocinetiquede Nantes, UMR-CNRS 6607, 44 (France)

2005-07-01

This session about thermal systems gathers 26 articles dealing with: neural model of a compact heat exchanger; experimental study and numerical simulation of the thermal behaviour of test-cells with walls made of a combination of phase change materials and super-insulating materials; hydraulic and thermal modeling of a supercritical fluid with pyrolysis inside a heated channel: pre-dimensioning of an experimental study; energy analysis of the heat recovery devices of a cryogenic system; numerical simulation of the thermo-hydraulic behaviour of a supercritical CO{sub 2} flow inside a vertical tube; mixed convection inside dual-tube exchangers; development of a nodal approach with homogenization for the simulation of the brazing cycle of a heat exchanger; chaotic exchanger for the cooling of low temperature fuel cells; structural optimization of the internal fins of a cylindrical generator; a new experimental approach for the study of the local boiling inside the channels of exchangers with plates and fins; experimental study of the flow regimes of boiling hydrocarbons on a bundle of staggered tubes; energy study of heat recovery exchangers used in Claude-type refrigerating systems; general model of Carnot engine submitted to various operating constraints; the free pistons Stirling cogeneration system; natural gas supplied cogeneration system with polymer membrane fuel cell; influence of the CRN coating on the heat flux inside the tool during the wood unrolling process; transport and mixture of a passive scalar injected inside the wake of a Ahmed body; control of a laser welding-brazing process by infrared thermography; 2D self-adaptative method for contours detection: application to the images of an aniso-thermal jet; exergy and exergy-economical study of an 'Ericsson' engine-based micro-cogeneration system; simplified air-conditioning of telephone switching equipments; parametric study of the 'low-energy' individual dwelling; brief synthesis of

Effect of moisture content and temperature on thermal behaviour of sesame seed

Directory of Open Access Journals (Sweden)

Seyed-Hassan Miraei ASHTIANI

2014-08-01

Full Text Available The specific heat, thermal diffusivity and thermal conductivity of two varieties (white and brown of sesame seeds were evaluated as a function of moisture content and temperature. The experiments were conducted in the temperature range of 25-70˚C and the moisture content range of 3.86-19.83% (dry basis for white and 3.07-18.99% (dry basis for brown varieties. The specific heat of white and brown sesame seeds ranged 1062-3058 and 906-2958 J/(kg·˚C, respectively. Thermal diffusivity and thermal conductivity values also increased with increasing either moisture content or temperature. Thermal diffusivity varied between 4.66×10-8 and 8.59×10-8 m2/s for white and 4.36×10-8-8.08×10-8 m2/s for brown varieties. Thermal conductivity ranged 0.031-0.149 and 0.023-0.135 W/(m·˚C for white and brown varieties, respectively. Results showed that the moisture content and temperature had significant effects (p≤0.01 on the studied properties.

Refuge behaviour from outdoor thermal environmental stress and seasonal differences of thermal sense in tropical urban climate

Science.gov (United States)

Kurazumi, Y.; Ishii, J.; Fukagawa, K.; Kondo, E.; Aruninta, A.

2017-12-01

Thermal sensation affects body temperature regulation. As a starting point for behavioral body temperature regulation taken to improve from a poor thermal environment to a more pleasant environment, thermal sense of thermal environment stimulus is important. The poupose of this sutudy is to use the outdoor thermal environment evaluation index ETFe to quantify effects on thermal sensations of the human body of a tropical region climate with small annual temperature differences, and to examine seasonal differences in thermal sensation. It was found temperature preferences were lower in the winter season than in the dry season, and that a tolerance for higher temperatures in the dry season than in the winter season. It was found effects of seasonal differences of the thermal environment appear in quantitative changes in thermal sensations. It was found that effects of seasonal differences of the thermal environment do not greatly affect quantitative changes in thermal comfort.

Crystallization behaviour and thermal stability of two aluminium-based metallic glass powder materials

Energy Technology Data Exchange (ETDEWEB)

Li, X.P.; Yan, M. [University of Queensland, School of Mechanical and Mining Engineering, ARC Centre of Excellence for Design in Light Metals, Brisbane, QLD 4072 (Australia); Yang, B.J. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Wang, J.Q., E-mail: jqwang@imr.ac.cn [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Schaffer, G.B. [University of Queensland, School of Mechanical and Mining Engineering, ARC Centre of Excellence for Design in Light Metals, Brisbane, QLD 4072 (Australia); Qian, M., E-mail: ma.qian@uq.edu.au [University of Queensland, School of Mechanical and Mining Engineering, ARC Centre of Excellence for Design in Light Metals, Brisbane, QLD 4072 (Australia)

2011-12-15

Highlights: Black-Right-Pointing-Pointer The crystallization paths and products of Al{sub 86}Ni{sub 7}Y{sub 4.5}Co{sub 1}La{sub 1.5} powder have been identified. Black-Right-Pointing-Pointer The thermal stability of Al{sub 86}Ni{sub 7}Y{sub 4.5}Co{sub 1}La{sub 1.5} powder has been assessed. Black-Right-Pointing-Pointer The Al{sub 86}Ni{sub 7}Y{sub 4.5}Co{sub 1}La{sub 1.5} powder shows a wide processing window of 75 K. Black-Right-Pointing-Pointer The powder has the potential to be consolidated into thick BMG components based on the findings. Black-Right-Pointing-Pointer The Al{sub 85}Ni{sub 5}Y{sub 6}Co{sub 2}Fe{sub 2} powder shows similar characteristics but inferior thermal stability. - Abstract: The crystallization behaviour and thermal stability of two Al-based metallic glass powder materials, Al{sub 85}Ni{sub 5}Y{sub 6}Co{sub 2}Fe{sub 2} and Al{sub 86}Ni{sub 6}Y{sub 4.5}Co{sub 2}La{sub 1.5}, have been investigated using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and electron microscopy. Both alloy powders show a distinct three-stage crystallization process with a similar gap of {approx}75 K between the onset crystallization temperature (T{sub x}) and the second crystallization temperature. Crystallization occurs by the precipitation and growth of fcc-Al, without intermetallic formation. The apparent activation energy for each stage of crystallization was determined from DSC analyses and the phases resulting from each crystallization stage were identified by XRD and electron microscopy. The critical cooling rate for each alloy powder was calculated from the DSC data. These results are necessary to inform the consolidation of amorphous powder particles of Al{sub 85}Ni{sub 5}Y{sub 6}Co{sub 2}Fe{sub 2} or Al{sub 86}Ni{sub 6}Y{sub 4.5}Co{sub 2}La{sub 1.5} into thick (>1 mm) metallic glass components.

Heat transfer in fish: are short excursions between habitats a thermoregulatory behaviour to exploit resources in an unfavourable thermal environment?

Science.gov (United States)

Pépino, Marc; Goyer, Katerine; Magnan, Pierre

2015-11-01

Temperature is the primary environmental factor affecting physiological processes in ectotherms. Heat-transfer models describe how the fish's internal temperature responds to a fluctuating thermal environment. Specifically, the rate coefficient (k), defined as the instantaneous rate of change in body temperature in relation to the difference between ambient and body temperature, summarizes the combined effects of direct thermal conduction through body mass, passive convection (intracellular and intercellular fluids) and forced convective heat transfer (cardiovascular system). The k-coefficient is widely used in fish ecology to understand how body temperature responds to changes in water temperature. The main objective of this study was to estimate the k-coefficient of brook charr equipped with internal temperature-sensitive transmitters in controlled laboratory experiments. Fish were first transferred from acclimation tanks (10°C) to tanks at 14, 19 or 23°C (warming experiments) and were then returned to the acclimation tanks (10°C; cooling experiments), thus producing six step changes in ambient temperature. We used non-linear mixed models to estimate the k-coefficient. Model comparisons indicated that the model incorporating the k-coefficient as a function of absolute temperature difference (dT: 4, 9 and 13°C) best described body temperature change. By simulating body temperature in a heterogeneous thermal environment, we provide theoretical predictions of maximum excursion duration between feeding and resting areas. Our simulations suggest that short (i.e. behaviour adopted by cold freshwater fish species to sustain body temperature below a critical temperature threshold, enabling them to exploit resources in an unfavourable thermal environment. © 2015. Published by The Company of Biologists Ltd.

Prosocial behaviours of young adolescents: a focus group study.

Science.gov (United States)

Bergin, Christi; Talley, Susan; Hamer, Lynne

2003-02-01

This study investigated young adolescents' perceptions of their peers' prosocial behaviours. In eight focus groups, 53 11- to 13-year olds described specific prosocial acts of their peers. Results suggest that traditional research has not addressed the diversity of prosocial behaviours that youth enact, nor emphasized behaviours that are salient to young adolescents. Such behaviours included standing up for others, encouraging others, helping others develop skills, including others who are left out, and being humorous. Facilitating emotional regulation of others emerged as an important component of prosocial behaviour. These data can help guide future research on prosocial development to include a broader array of authentic behaviours of young adolescents.

Numerical modelling and experimental studies of thermal behaviour of building integrated thermal energy storage unit in a form of a ceiling panel

International Nuclear Information System (INIS)

Jaworski, Maciej; Łapka, Piotr; Furmański, Piotr

2014-01-01

the proposed heat storage unit to effectively control the air temperature inside the building. However, detailed measurement of the temperature of PCM composite have shown some disadvantages of the panel used in the study, e.g. thickness of the walls and distribution of PCM should be optimized. This can be achieved with the aid of the numerical simulator developed in this research. Practical implications: The proposed ceiling panel, optimised from the point of view of thermal performance in a given environmental conditions, can be used as a part of ventilation systems in residential and office buildings

Study of the reflective behaviour of carbon fibres reinforced polymer composite up to 450°C

Science.gov (United States)

Le Louët, Violaine; Rousseau, Benoit; Le Corre, Steven; Boyard, Nicolas; Tardif, Xavier; Delmas, Jérôme; Delaunay, Didier

2017-10-01

This study aims at characterizing the radiative properties of a carbon/PEEK composite, a material known to be opaque for usual thicknesses and to scatter thermal radiation in the infrared spectral range. The scattering behaviour is probed here at room temperature with a variable angle reflectivity unit linked to a Fourier Transform InfraRed Spectrometer (0.6-25 µm), for different fibre orientations and various angles of incidence. Moreover, in order to study the influence of temperature, particularly of the polymer matrix melting, a compact cell, based on a customized resistive heater, is adapted to the sample compartment of the spectrometer to measure the thermal dependency of the normal reflectivity. The new sample holder can be used at a temperature ranging between 20 and 450°C and with a temperature stability lower than 0.1 K. For the carbon/PEEK composite, the effects of the polymer phase change are observed to be small, confirming the predominant role of carbon on those composites optical properties.

Kaolin from Acoculco (Puebla, Mexico) as a raw material: mineralogical and thermal characterization

OpenAIRE

Garcia Vallès, Maite; Pi, T.; Alfonso, P.; Canet, C.; Martínez Manent, Salvador; Jiménez-Franco, A.; Tarragó Aymerich, Mariona; Hernández-Cruz, B.

2015-01-01

The present study determined the mineralogy and thermal properties of kaolin from Acoculco (Puebla), at the eastern Trans-Mexican Volcanic Belt and compared it with the nearby deposits of Agua Blanca (Hidalgo) and Huayacocotla (Veracruz). The mineralogy of the kaolins was determined by X-ray diffraction, infrared spectroscopy and scanning electron microscopy. Thermal behaviour was studied by differential thermal analysis, dilatometry and hot-stage microscopy. The Acoculco deposit is composed ...

Shared decision-making behaviours in health professionals: a systematic review of studies based on the Theory of Planned Behaviour.

Science.gov (United States)

Thompson-Leduc, Philippe; Clayman, Marla L; Turcotte, Stéphane; Légaré, France

2015-10-01

Shared decision making (SDM) requires health professionals to change their practice. Socio-cognitive theories, such as the Theory of Planned Behaviour (TPB), provide the needed theoretical underpinnings for designing behaviour change interventions. We systematically reviewed studies that used the TPB to assess SDM behaviours in health professionals to explore how theory is being used to explain influences on SDM intentions and/or behaviours, and which construct is identified as most influential. We searched PsycINFO, MEDLINE, EMBASE, CINAHL, Index to theses, Proquest dissertations and Current Contents for all years up to April 2012. We included all studies in French or English that used the TPB and related socio-cognitive theories to assess SDM behavioural intentions or behaviours in health professionals. We used Makoul & Clayman's integrative SDM model to identify SDM behaviours. We extracted study characteristics, nature of the socio-cognitive theory, SDM behaviour, and theory-based determinants of the SDM behavioural intention or behaviour. We computed simple frequency counts. Of 12,388 titles, we assessed 136 full-text articles for eligibility. We kept 20 eligible studies, all published in English between 1996 and 2012. Studies were conducted in Canada (n = 8), the USA (n = 6), the Netherlands (n = 3), the United Kingdom (n = 2) and Australia (n = 1). The determinant most frequently and significantly associated with intention was the subjective norm (n = 15/21 analyses). There was great variance in the way socio-cognitive theories predicted SDM intention and/or behaviour, but frequency of significance indicated that subjective norm was most influential. © 2014 The Authors Health Expectations Published by John Wiley & Sons Ltd.

Thermal and mechanical behaviour of an experimental mock-up of a nuclear containment; Comportement thermique et mecanique d'une maquette experimentale d'enceinte de confinement nucleaire

Energy Technology Data Exchange (ETDEWEB)

Chauvel, D. [Electricite de France (EDF/SEPTEN), 69 - Villeurbanne (France); Barre, F. [Coyne et Bellier, 92 - Gennevilliers (France)

2007-07-01

In order to better understand the behaviour of a reactor containment submitted to combined pressure and temperature loads by means of studies of the concrete permeability and the state of cracking evolution, EDF and its French partners have built a prestressed concrete test model which represents a PWR containment typical section. The monitoring system was designed to follow the evolution of strains, temperature and state of cracking of the concrete wall from construction stage to air and steam tests. The measurements results as well as their comparison with theoretical laws or data and calculated values, allow to determine the main thermal and mechanical characteristics of the concrete, to analyse the thermo-mechanical behaviour of the structure and also to check the design criteria of prestressed concrete containments. (authors)

Thermomechanical and calorimetric behaviours of supported glass-forming films: A study based on thermodynamics with internal variables

International Nuclear Information System (INIS)

Lion, Alexander; Engelhard, Marco; Johlitz, Michael

2012-01-01

In order to understand the temperature-dependent response behaviour of thin thermoviscoelastic films which are deposited on relative stiff but thermally deformable substrates it is important to consider the lateral geometric constraints. They are generated by differences in the thermal expansion properties between the substrate and the film and provoke internal stresses. Since glass-forming materials exhibit distinct temperature history-dependent thermal expansion and calorimetric properties, primarily in the vicinity of the glass transition, the situation is rather complicated. In this article, a recently developed three-dimensional model of thermodynamics with internal variables is applied and adapted to simulate this type of behaviour. Explicit relations are obtained for the specific heat of the film, the normal strain and the lateral stresses. Numerical simulations demonstrate that the magnitude of the internal stress at temperatures below the glass transition depends strongly on the cooling rate. It is also shown that the specific heat of the supported film is principally different from the isobaric specific heat of the bulk material: the glassy limit of the specific heat of the film is reduced but the glass transition temperature is almost uninfluenced. The simulated behaviour is in accordance with experimental observations from literature. - Highlights: ► For the specific heat, stress and strain of the film, explicit equations were derived. ► The constraints of the substrate reduce the glassy limit of specific heat of the film. ► Glass transition temperatures of free bulk material and supported film are equal. ► Simulations are in good agreement with experimental observations from literature.

Materials behaviour in PWRs core

International Nuclear Information System (INIS)

Barbu, A.; Massoud, J.P.

2008-01-01

Like in any industrial facility, the materials of PWR reactors are submitted to mechanical, thermal or chemical stresses during particularly long durations of operation: 40 years, and even 60 years. Materials closer to the nuclear fuel are submitted to intense bombardment of particles (mainly neutrons) coming from the nuclear reactions inside the core. In such conditions, the damages can be numerous and various: irradiation aging, thermal aging, friction wear, generalized corrosion, stress corrosion etc.. The understanding of the materials behaviour inside the cores of reactors in operation is a major concern for the nuclear industry and its long term forecast is a necessity. This article describes the main ways of materials degradation without and under irradiation, with the means used to foresee their behaviour using physics-based models. Content: 1 - structures, components and materials: structure materials, nuclear materials; 2 - main ways of degradation without irradiation: thermal aging, stress corrosion, wear; 3 - main ways of degradation under irradiation: microscopic damaging - point defects, dimensional alterations, evolution of mechanical characteristics under irradiation, irradiation-assisted stress corrosion cracking (IASCC), synergies; 4 - forecast of materials evolution under irradiation using physics-based models: primary damage - fast dynamics, primary damage annealing - slow kinetics microstructural evolution, impact of microstructural changes on the macroscopic behaviour, insight on modeling methods; 5 - materials change characterization techniques: microscopic techniques - direct defects observation, nuclear techniques using a particle beam, global measurements, mechanical characterizations; 6 - perspectives. (J.S.)

Thermomechanical behaviour of bolted assemblies

International Nuclear Information System (INIS)

Scliffet, L.

1995-01-01

This paper presents first results obtained in an R and D study on the thermomechanical behaviour of bolted assemblies. Thermal shocks during operating transients both severely distort such assemblies and cause variations in stud pre-loads. So during a hot shock, the thermal gradient in the flange induced over-tightening due to the differential thermal expansion involved. Over-tightening can reach 70% of the nominal value, usually after 10 to 15 mn, after which the stress relaxes as soon as the heating affects the stud. A series of hot shocks causes assembly fatigue, notably resulting in thread plasticization, making it impossible to tighten the studs. In the case of cold transients, the reverse phenomenon is observed. The hot flange contracts sharply upon contact with the cold fluid, causing stress relief in the expanded studs. The resulting loss of tensile stress, which reaches up to 50%, can then cause severe leakage, especially if the nominal tightening capacity is already impaired. The study presented is based on tests and modelling. (author). 16 figs

Thermal modelling of Li-ion polymer battery for electric vehicle drive cycles

Science.gov (United States)

Chacko, Salvio; Chung, Yongmann M.

2012-09-01

Time-dependent, thermal behaviour of a lithium-ion (Li-ion) polymer cell has been modelled for electric vehicle (EV) drive cycles with a view to developing an effective battery thermal management system. The fully coupled, three-dimensional transient electro-thermal model has been implemented based on a finite volume method. To support the numerical study, a high energy density Li-ion polymer pouch cell was tested in a climatic chamber for electric load cycles consisting of various charge and discharge rates, and a good agreement was found between the model predictions and the experimental data. The cell-level thermal behaviour under stressful conditions such as high power draw and high ambient temperature was predicted with the model. A significant temperature increase was observed in the stressful condition, corresponding to a repeated acceleration and deceleration, indicating that an effective battery thermal management system would be required to maintain the optimal cell performance and also to achieve a full battery lifesapn.

Mapping Thermal Habitat of Ectotherms Based on Behavioral Thermoregulation in a Controlled Thermal Environment

Science.gov (United States)

Fei, T.; Skidmore, A.; Liu, Y.

2012-07-01

Thermal environment is especially important to ectotherm because a lot of physiological functions rely on the body temperature such as thermoregulation. The so-called behavioural thermoregulation function made use of the heterogeneity of the thermal properties within an individual's habitat to sustain the animal's physiological processes. This function links the spatial utilization and distribution of individual ectotherm with the thermal properties of habitat (thermal habitat). In this study we modelled the relationship between the two by a spatial explicit model that simulates the movements of a lizard in a controlled environment. The model incorporates a lizard's transient body temperatures with a cellular automaton algorithm as a way to link the physiology knowledge of the animal with the spatial utilization of its microhabitat. On a larger spatial scale, 'thermal roughness' of the habitat was defined and used to predict the habitat occupancy of the target species. The results showed the habitat occupancy can be modelled by the cellular automaton based algorithm at a smaller scale, and can be modelled by the thermal roughness index at a larger scale.

Dynamic thermal performance of alveolar brick construction system

International Nuclear Information System (INIS)

Gracia, A. de; Castell, A.; Medrano, M.; Cabeza, L.F.

2011-01-01

Highlights: → Even though U-value does not measure thermal inertia, it is the commonly used parameter. → The thermal performance analysis of buildings must include the evaluation of transient parameters. → Transient parameters of alveolar brick constructive system show good agreement with its low energy consumption. -- Abstract: Alveolar bricks are being introduced in building sector due to the simplicity of their construction system and to the elimination of the insulation material. Nevertheless, it is not clear if this new system is energetically efficient and which is its thermal behaviour. This paper presents an experimental and theoretical study to evaluate the thermal behaviour of the alveolar brick construction system, compared with a traditional Mediterranean brick system with insulation. The experimental study consists of measuring the thermal performance of four real house-like cubicles. The thermal transmittance in steady-state, also known as U-value, is calculated theoretically and experimentally for each cubicle, presenting the insulated cubicles as the best construction system, with differences around 45% in comparison to the alveolar one. On the other hand, experimental results show significantly smaller differences on the energy consumption between the alveolar and insulated construction systems during summer period (around 13% higher for the alveolar cubicle). These values demonstrate the high thermal efficiency of the alveolar system. In addition, the lack of agreement between the measured energy consumption and the calculated U-values, guides the authors to analyze the thermal inertia of the different building components. Therefore, several transient parameters, extracted from the heat transfer matrix and from experimental data, are also evaluated. It can be concluded that the alveolar brick construction system presents higher thermal inertia than the insulated one, justifying the low measured energy consumption.

Mechanical properties and thermal behaviour of LLDPE/MWNTs nanocomposites

Directory of Open Access Journals (Sweden)

Tai Jin-hua

2012-12-01

Full Text Available Multi-walled carbon nanotubes (MWNTs were incorporated into a linear low-density polyethylene (LLDPE matrix through using screw extrusion and injection technique. The effect of different weight percent loadings of MWNTs on the morphology, mechanical, and thermal of LLDPE/MWNTs nanocomposite had been investigated. It was found that, at low concentration of MWNTs, it could uniformly disperse into a linear low-density polyethylene matrix and provide LLDPE/MWNTs nanocomposites much improved mechanical properties. Thermal analysis showed that a clear improvement of thermal stability for LLDPE/MWNTs nanocomposites increased with increasing MWNTs content.

Geographical differences in maternal basking behaviour and offspring growth rate in a climatically widespread viviparous reptile.

Science.gov (United States)

Cadby, Chloé D; Jones, Susan M; Wapstra, Erik

2014-04-01

In reptiles, the thermal environment during embryonic development affects offspring phenotypic traits and potentially offspring fitness. In viviparous species, mothers can potentially manipulate the embryonic thermal environment through their basking behaviour and, thus, may be able to manipulate offspring phenotype and increase offspring fitness. One way in which mothers can maximise offspring phenotype (and thus potentially affect offspring fitness) is by fine-tuning their basking behaviour to the environment in order to buffer the embryo from deleterious developmental temperatures. In widespread species, it is unclear whether populations that have evolved under different climatic conditions will exhibit different maternal behaviours and/or thermal effects on offspring phenotype. To test this, we provided extended or reduced basking opportunity to gravid spotted skinks (Niveoscincus ocellatus) and their offspring from two populations at the climatic extremes of the species' distribution. Gravid females fine-tuned their basking behaviour to the basking opportunity, which allowed them to buffer their embryos from potentially negative thermal effects. This fine-tuning of female basking behaviour appears to have led to the expression of geographical differences in basking behaviour, with females from the cold alpine regions being more opportunistic in their basking behaviour than females from the warmer regions. However, those differences in maternal behaviour did not preclude the evolution of geographic differences in thermal effects: offspring growth varied between populations, potentially suggesting local adaptation to basking conditions. Our results demonstrate that maternal effects and phenotypic plasticity can play a significant role in allowing species to cope in changing environmental conditions, which is particularly relevant in the context of climate change.

Dielectric and polarization behaviour of cellulose electro-active paper (EAPap)

International Nuclear Information System (INIS)

Yun, Gyu-Young; Kim, Joo-Hyung; Kim, Jaehwan

2009-01-01

Dielectric and polarization behaviour of electro-active paper (EAPap) were studied to understand the detailed material behaviour of EAPap as a novel smart material. It was revealed that the dielectric constant of EAPap was temperature and frequency dependent. The largest change in the dielectric constant was observed near 0 0 C while the highest dielectric constant was obtained at around 100 0 C, which might be related to the dipolar behaviour of the hydroxyl structure of cellulose and adsorbed or existing internal water molecules in cellulose EAPap. By thermal stimulated current measurement for polarization behaviour of cellulose EAPap, it was shown that the maximum current was observed in the temperature range 105-110 0 C. Compared with the polarization behaviour in the low temperature range, abnormal polarization was observed under an applied field mainly due to the trapped space charge in EAPap, which indicates that cellulose EAPap has a similar material behaviour to that of electret polymers. (fast track communication)

Ambazone-lipoic acid salt: Structural and thermal characterization

Energy Technology Data Exchange (ETDEWEB)

Kacso, Irina [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath street, 400293 Cluj-Napoca (Romania); Racz, Csaba-Pal; Santa, Szabolcs [Babes-Bolyai' University, Faculty of Chemistry, 11 Arany Janos street, Cluj-Napoca (Romania); Rus, Lucia [' Iuliu Hatieganu' University of Medicine and Pharmacy, Faculty of Pharmacy, 6 Louis Pasteur street, 400349 Cluj-Napoca (Romania); Dadarlat, Dorin; Borodi, Gheorghe [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath street, 400293 Cluj-Napoca (Romania); Bratu, Ioan, E-mail: ibratu@gmail.com [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath street, 400293 Cluj-Napoca (Romania)

2012-12-20

Highlights: Black-Right-Pointing-Pointer Salt of Ambazone with lipoic acid obtained by solvent-drop grinding. Black-Right-Pointing-Pointer Ambazone lipoate salt crystallizes in monoclinic system. Black-Right-Pointing-Pointer FTIR data suggest the deprotonation of the lipoic acid. Black-Right-Pointing-Pointer Thermal behaviour different of ambazone salt as compared to the starting compounds. - Abstract: A suitable method for increasing the solubility, dissolution rate and consequently the bioavailability of poor soluble acidic or basic drugs is their salt formation. The aim of this study is to investigate the structural and thermal properties of the compound obtained by solvent drop grinding (SDG) method at room temperature, starting from the 1:1 molar ratios of ambazone (AMB) and {alpha}-lipoic acid (LA). The structural characterization was performed with X-ray powder diffraction (XRPD) and infrared spectroscopy (FTIR). The thermal behaviour of the obtained compound (AMB{center_dot}LA) was investigated by differential scanning calorimetry (DSC) and thermogravimetry (TG). The photopyroelectric calorimetry, in front detection configuration (FPPE), was applied to measure and compare the room temperature values of one dynamic thermal parameter (thermal effusivity) for starting and resulting compounds. Both structural and supporting calorimetric techniques pointed out a salt structure for AMB{center_dot}LA compound as compared to those of the starting materials.

Thermal cycling behaviour of lanthanum zirconate as EB-PVD thermal barrier coating

International Nuclear Information System (INIS)

Bobzin, K.; Lugscheider, E.; Bagcivan, N.

2006-01-01

Thermal cycling tests with two different EB-PVD thermal barrier coatings (TBC) were performed in a furnace cycle test. The results of these tests showed an increase of endurable cycle number when pyrochloric La 2 Zr 2 O 7 was used as TBC. 1865 cycles were reached with La 2 Zr 2 O 7 and 1380 cycles with 7 weigth-% yttria stabilised zirconia (YSZ) EB-PVD TBC. Additional investigation was made with scanning electron microscope (SEM) to investigate morphology and to determine chemical composition by electron dispersive x-ray spectroscopy (EDS) analysis. X-Ray diffraction was performed to analyze structural constitution of deposited coatings. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

Behavioural fever is a synergic signal amplifying the innate immune response

OpenAIRE

Bolta?a, Sebastian; Rey, Sonia; Roher, Nerea; Vargas, Reynaldo; Huerta, Mario; Huntingford, Felicity Anne; Goetz, Frederick William; Moore, Janice; Garcia-Valtanen, Pablo; Estepa, Amparo; MacKenzie, S.

2013-01-01

Behavioural fever, defined as an acute change in thermal preference driven by pathogen recognition, has been reported in a variety of invertebrates and ectothermic vertebrates. It has been suggested, but so far not confirmed, that such changes in thermal regime favour the immune response and thus promote survival. Here, we show that zebrafish display behavioural fever that acts to promote extensive and highly specific temperature-dependent changes in the brain transcriptome. The observed coup...

Surface analytical investigations of the thermal behaviour of passivated Zircaloy-4 surfaces and of the reaction behaviour of iodine with Zircaloy-4 surfaces

International Nuclear Information System (INIS)

Kaufmann, R.

1988-07-01

In the first part of the present work the thermal behaviour of atmospherically oxidized Zircaloy-4 samples was investigated at various temperatures. In a next step the amount of iodine adsorbed at the metallic surface was determined as well at room temperature with varying iodine exposures as for constant exposure but varying temperatures. Furthermore, the zirconium iodide species resulting from the interaction of iodine with the Zircaloy-4 and desorbed at higher temperatures were identified by means of residual gas analysis. During these studies it was found that the oxidic overlayer of the passivated Zircaloy-4 samples is decomposed at temperatures above 200 0 C. The iodine uptake at metallic surfaces (cleaned by Ar-ion sputtering) at room temperature slows markedly down after formation of a closed zirconium-iodide overlayer and consequently the further reaction proceeds diffusion-controlled. At 200 0 C ZrI 4 is formed being the thermodynamically most stable Zr-iodide. During desorption experiments using iodine exposed Zircaloy-4 samples the release of ZrI 4 was proved. The results obtained from the various experiments are finally discussed with respect to the iodine-induced stress corrosion cracking process and the underlying basic mechanisms and a transport mechanism for the SCC in nuclear fuel rods is proposed. (orig./RB) [de

Survey about the climatic behaviour of mobile homes; Untersuchungen zum klimatischen Verhalten von Wohnmobilen

Energy Technology Data Exchange (ETDEWEB)

Leimer, H.P.; Stein, F. [Hochschule fuer Angewandte Wissenschaft und Kunst HAWK, Hildesheim (Germany). BBS Institut Forschungs- und Materialpruefinst. fuer Angewandte Bauphysik und Werkstoffe des Bauwesens

2006-02-15

Traveling with mobile homes gains more and more importance in the mobile world. Very dif-ferent regions are visited during any seasons. A basic premise is the maintenance of a comfortable climate in-side the vehicle. In the context of a research program the thermal and energetic behaviour of mobile homes and the thermal-hygric behaviour of the exterior building elements were investigated subject to the surrounding climate, the user's behaviour and the building elements. (orig.)

Evaluation of thermal ratcheting of reactor vessel wall near the sodium surface

International Nuclear Information System (INIS)

Take, Kohji; Fujioka, Terutaka; Yano, Kazutaka

1989-01-01

Plastic ratcheting of reactor vessels may occur by an axially moving thermal gradient without primary stress. So there is a need to establish a proper prediction method for the plastic ratcheting. In this study, inelastic FEM analyses of reactor vessel model by using an advanced constitutive equation were carried out in order to comprehend plastic ratcheting behaviour of cylinder which subject to an axially moving thermal gradient. As a result of analyses, a basic mechanism of this ratcheting was found. And it also indicated that cyclic hardening behaviour will became important for development of evaluation method. (author)

Thermal loading study for FY 1995

International Nuclear Information System (INIS)

1996-01-01

This report provides the results of sensitivity analyses designed to assist the test planners in focusing their in-situ measurements on parameters that appear to be important to waste isolation. Additionally, the study provides a preliminary assessment of the feasibility of certain thermal management options. A decision on thermal loading is a critical part of the scientific and engineering basis for evaluating regulatory compliance of the potential repository for waste isolation. To show, with reasonable assurance, that the natural and engineered barriers will perform adequately under expected repository conditions (thermally perturbed) will require an integrated approach based on thermal testing (laboratory, and in-situ), natural analog observations, and analytic modeling. The Office of Civilian Radioactive Waste Management needed input to assist in the planning of the thermal testing program. Additionally, designers required information on the viability of various thermal management concepts. An approximately 18-month Thermal Loading Study was conducted from March, 1994 until September 30, 1995 to address these issues. This report documents the findings of that study. 89 refs., 71 figs., 33 tabs

Magnetic and thermal behaviour of the amorphous ferromagnet Fe79B16Si5

International Nuclear Information System (INIS)

Shaisha, E.E.; Bahgat, A.A.

1985-01-01

Spin waves in the amorphous ferromagnet Fe 79 B 16 Si 5 are studied by Moessbauer effect spectroscopy. The magnetic hyperfine field (MHF) is measured at the Fe sites of such a ferromagnet, which exhibits a temperature dependence of the form, H(T)/H(0) = (1 - BT/sup 3/2/ - CT/sup 5/2/), indicative of spin wave excitations in amorphous ferromagnets. The T/sup 3/2/ behaviour and the distribution of the exchange interactions are studied in detail as a function of the MHF. The spin wave excitations constant B/sub 3/2/ = BT/sub C//sup 3/2/ = 0.3 +- 0.05 and C/sub 5/2/ = CT/sub C//sup 5/2/ = 0.3 +- 0.05,Are obtained by fitting the experimental data, and where T/sub C/ = 670 K. The results sh=ow that the contribution of C/sub 5/2/ is extremely effective above 124 K, while the ratio C/sub 5/2//C/sub 3/2/ = 1.0 indicates that the present magnetic interaction is of long range order character. On the other hand, fluctuations of the exchange interaction constant are found to decrease with increasing temperature. Some information regarding the directions of the magnetic moments are obtained during the study of the magnetic anisotropy course. The values of the Einstein and Debye temperatures as measured from the thermal shift results are theta/sub E/ = 250 K and theta/sub D/ = 350 K,And from the Moessbauer factor measurements theta/sub E/ = 165 K and theta/sub D/ = 285 K. (autho=r)

Ecological behaviour of high-thermal origin cesium aerosols

International Nuclear Information System (INIS)

Raiies, A.H.; Ronneau, C.; Apers, D.; Myttenaer, S.

1988-01-01

Nine-fold Cs enrichment of the forming aerosols' surface in a result of heating UO 2 pellets up to 2000degC. Such aerosols contain up to 90% of the dissoluble Cs fraction in aqueous environment, that explains ecological behaviour of 134 Cs and 137 Cs

An experimental study of client-side Spotify peering behaviour

OpenAIRE

Ellis, M.; Strowes, S.; Perkins, C.

2011-01-01

Spotify is a popular music-streaming service which has seen widespread use across Europe. While Spotify’s server-side behaviour has previously been studied, little is known about the client-side behaviour. In this paper, we describe an experimental study where we collect packet headers for Spotify traffic over multiple 24-hour time frames at a client host. Two distinct types of behaviour are observed, when tracks are being downloaded, and when the client is only serving requests from other pe...

Thermal diffusion of chlorine in uranium dioxide studied by secondary ion mass spectrometry and X-ray absorption spectroscopy

Science.gov (United States)

Pipon, Y.; Toulhoat, N.; Moncoffre, N.; Raimbault, L.; Scheidegger, A. M.; Farges, F.; Carlot, G.

2007-05-01

In a nuclear reactor, 35Cl present as an impurity in the nuclear fuel is activated by thermal neutron capture. During interim storage or geological disposal of the nuclear fuel, 36Cl may be released from the fuel to the geo/biosphere and contribute significantly to the 'instant release fraction'. In order to elucidate the diffusion mechanisms, both irradiation and thermal effects must be assessed. This paper deals with the thermal diffusion of chlorine in depleted UO2. For this purpose, sintered UO2 pellets were implanted with 37Cl at an ion fluence of 1013 cm-2 and successively annealed in the 1175-1475 K temperature range. The implanted chlorine is used to simulate the behaviour of the displaced one due to recoil and to interactions with the fission fragments during reactor operation. The behaviour of the pristine and the implanted chlorine was investigated during thermal annealing. SIMS and μ-XAS (at the Cl-K edge) analyses show that: the thermal migration of implanted chlorine becomes significant at 1275 K; this temperature and the calculated activation energy of 4.3 eV points out the great ability of chlorine to migrate in UO2 at relatively low temperatures, the behaviour of the implanted chlorine which aggregates into 'hot spots' during annealing before its effusion is clearly different from that of the pristine one which remains homogenously distributed after annealing, the 'hot spot' and the pristine chlorine seem to be in different structural environments. Both types of chlorine are assumed to have a valence state of -I, the comparison between an U2O2Cl5 reference compound and the pristine chlorine environment shows a contribution of the U2O2Cl5 to the pristine chlorine.

Thermal diffusion of chlorine in uranium dioxide studied by secondary ion mass spectrometry and X-ray absorption spectroscopy

International Nuclear Information System (INIS)

Pipon, Y.; Toulhoat, N.; Moncoffre, N.; Raimbault, L.; Scheidegger, A.M.; Farges, F.; Carlot, G.

2007-01-01

In a nuclear reactor, 35 Cl present as an impurity in the nuclear fuel is activated by thermal neutron capture. During interim storage or geological disposal of the nuclear fuel, 36 Cl may be released from the fuel to the geo/biosphere and contribute significantly to the 'instant release fraction'. In order to elucidate the diffusion mechanisms, both irradiation and thermal effects must be assessed. This paper deals with the thermal diffusion of chlorine in depleted UO 2 . For this purpose, sintered UO 2 pellets were implanted with 37 Cl at an ion fluence of 10 13 cm -2 and successively annealed in the 1175-1475K temperature range. The implanted chlorine is used to simulate the behaviour of the displaced one due to recoil and to interactions with the fission fragments during reactor operation. The behaviour of the pristine and the implanted chlorine was investigated during thermal annealing. SIMS and μ-XAS (at the Cl-K edge) analyses show that: (1) the thermal migration of implanted chlorine becomes significant at 1275K; this temperature and the calculated activation energy of 4.3eV points out the great ability of chlorine to migrate in UO 2 at relatively low temperatures; (2) the behaviour of the implanted chlorine which aggregates into 'hot spots' during annealing before its effusion is clearly different from that of the pristine one which remains homogenously distributed after annealing; (3) the 'hot spot' and the pristine chlorine seem to be in different structural environments. Both types of chlorine are assumed to have a valence state of -I; (4) the comparison between an U 2 O 2 Cl 5 reference compound and the pristine chlorine environment shows a contribution of the U 2 O 2 Cl 5 to the pristine chlorine

Behaviour of antimony during thermal treatment of Sb-rich halogenated waste

International Nuclear Information System (INIS)

Klein, J.; Dorge, S.; Trouve, G.; Venditti, D.; Durecu, S.

2009-01-01

Antimony compounds have a wide range of industrial applications, particularly as additives in flame retardants. To ensure environmentally friendly waste incineration of Sb-rich wastes, it is essential to strengthen the knowledge about the fate of antimony and the potential formation of harmful species. Investigations should be conducted particularly in relation with the main operational parameters controlling the process, chiefly temperature, residence time and air supply in the oven and in the post-combustion zone, prior final adapted cleaning of the flue-gas stream. Experimental studies focusing on antimony behaviour were undertaken through laboratory-scale thermal treatment at 850 deg. C and 1100 deg. C of a Sb-rich halogenated waste, originating from the sector of flame retardants formulation. The configuration of our laboratory experimental device allowed to achieve only low oxidative conditions in the waste bed, but high oxidative strength coupled with high temperature and sufficient gas residence time in the post-combustion zone, as prescribed during the incineration of hazardous wastes. Atomic absorption spectroscopy was used to assess the partition of antimony in the different compartments of the process. The oxidation degree of antimony in the gas-phase was determined by the use of electrochemical techniques, namely polarography coupled with anodic stripping voltamperometry. The partition of antimony between the residual ash and the gas-phase under moderate oxidative conditions in the waste bed was constant, whatever the temperature: the volatilization rate for antimony was ∼64%, while a ∼36% fraction remained in the residual bottom ashes. But interestingly, while at 850 o C, antimony was mainly present in the gas-phase at a +III oxidation degree, an increase in temperature of 250 o C favoured the presence of antimony to its highest oxidation degree +V in the flue-gas stream, a valence known to be involved in less toxic species.

Behaviour of antimony during thermal treatment of Sb-rich halogenated waste

Energy Technology Data Exchange (ETDEWEB)

Klein, J. [Laboratoire Gestion des Risques et Environnement, 25 rue de Chemnitz, 68200 Mulhouse (France); Dorge, S., E-mail: sophie.dorge@uha.fr [Laboratoire Gestion des Risques et Environnement, 25 rue de Chemnitz, 68200 Mulhouse (France); Trouve, G. [Laboratoire Gestion des Risques et Environnement, 25 rue de Chemnitz, 68200 Mulhouse (France); Venditti, D.; Durecu, S. [TREDI Departement de Recherche, Technopole de Nancy-Brabois, 9 avenue de la Foret de Haye, BP 184, 54505 Vandoeuvre-les-Nancy (France)

2009-07-30

Antimony compounds have a wide range of industrial applications, particularly as additives in flame retardants. To ensure environmentally friendly waste incineration of Sb-rich wastes, it is essential to strengthen the knowledge about the fate of antimony and the potential formation of harmful species. Investigations should be conducted particularly in relation with the main operational parameters controlling the process, chiefly temperature, residence time and air supply in the oven and in the post-combustion zone, prior final adapted cleaning of the flue-gas stream. Experimental studies focusing on antimony behaviour were undertaken through laboratory-scale thermal treatment at 850 deg. C and 1100 deg. C of a Sb-rich halogenated waste, originating from the sector of flame retardants formulation. The configuration of our laboratory experimental device allowed to achieve only low oxidative conditions in the waste bed, but high oxidative strength coupled with high temperature and sufficient gas residence time in the post-combustion zone, as prescribed during the incineration of hazardous wastes. Atomic absorption spectroscopy was used to assess the partition of antimony in the different compartments of the process. The oxidation degree of antimony in the gas-phase was determined by the use of electrochemical techniques, namely polarography coupled with anodic stripping voltamperometry. The partition of antimony between the residual ash and the gas-phase under moderate oxidative conditions in the waste bed was constant, whatever the temperature: the volatilization rate for antimony was {approx}64%, while a {approx}36% fraction remained in the residual bottom ashes. But interestingly, while at 850 {sup o}C, antimony was mainly present in the gas-phase at a +III oxidation degree, an increase in temperature of 250 {sup o}C favoured the presence of antimony to its highest oxidation degree +V in the flue-gas stream, a valence known to be involved in less toxic species.

HTR fuel modelling with the ATLAS code. Thermal mechanical behaviour and fission product release assessment

International Nuclear Information System (INIS)

Guillermier, Pierre; Daniel, Lucile; Gauthier, Laurent

2009-01-01

To support AREVA NP in its design on HTR reactor and its HTR fuel R and D program, the Commissariat a l'Energie Atomique developed the ATLAS code (Advanced Thermal mechanicaL Analysis Software) with the objectives: - to quantify, with a statistical approach, the failed particle fraction and fission product release of a HTR fuel core under normal and accidental conditions (compact or pebble design). - to simulate irradiation tests or benchmark in order to compare measurements or others code results with ATLAS evaluation. These two objectives aim at qualifying the code in order to predict fuel behaviour and to design fuel according to core performance and safety requirements. A statistical calculation uses numerous deterministic calculations. The finite element method is used for these deterministic calculations, in order to be able to choose among three types of meshes, depending on what must be simulated: - One-dimensional calculation of one single particle, for intact particles or particles with fully debonded layers. - Two-dimensional calculations of one single particle, in the case of particles which are cracked, partially debonded or shaped in various ways. - Three-dimensional calculations of a whole compact slice, in order to simulate the interactions between the particles, the thermal gradient and the transport of fission products up to the coolant. - Some calculations of a whole pebble, using homogenization methods are being studied. The temperatures, displacements, stresses, strains and fission product concentrations are calculated on each mesh of the model. Statistical calculations are done using these results, taking into account ceramic failure mode, but also fabrication tolerances and material property uncertainties, variations of the loads (fluence, temperature, burn-up) and core data parameters. The statistical method used in ATLAS is the importance sampling. The model of migration of long-lived fission products in the coated particle and more

Study of the thermal and mechanical behaviour of granite applied to the nuclear waste repository: conclusions drawn from the Fanay-Augeres experiment

International Nuclear Information System (INIS)

Rejeb, A.; Vouille, G.; Gros, J.C.

1993-01-01

The considerable advances made in nuclear technology in recent years have brought with them a sizeable accumulation of nuclear waste. Leaving aside the low-activity wastes which are stored at ground level, the problem of high-activity wastes still remains. A concerted research effort has been dedicated to perfecting certain methods for waste disposal. At present, this effort has been directed towards evaluating feasibility and the long-term safety of burying these wastes in deep-lying and stable geological repositories. A priori, many types of rocks are suitable for isolating nuclear wastes: clay, salt, granite, schists, basalt and tuff. These wastes are exothermic owing to their radioactive decay which decreases continuously with time. From the geotechnical point of view, storage of these high-activity wastes in a deep-lying geological environment will increase temperature in the host rock accompanied by changes in stresses and strains. Quantifying these changes, by means of a thermomechanical analysis, is of prime importance when the mechanical behaviour of the storage drifts has to be ensured by avoiding major modifications to the characteristics of the geological barrier. This article summarises the present state of knowledge acquired about the thermomechanical behaviour of granite, and presents the results as research requirements for better characterisation in the laboratory and in situ as well as a more realistic model. We also stress the results of research carried out by the Centre de Geotechnique et d'Exploitation du sous-sol (CGES) of the Ecole des Mines de Paris (ENSMP) on the Fanay-Augeres Thermal, Hydraulic and Mechanical experiment organised by the Institut de Protection et de Surete Nucleaire (IPSN) in the context of a shared-costs contract with the Commission of the European Communities (CEC). (authors). 4 figs., 10 refs

Calibration of mathematical models for simulation of thermal, seepage and mechanical behaviour of boom clay

International Nuclear Information System (INIS)

Baldi, G.; Borsetto, M.; Hueckel, T.

1987-01-01

This report presents results of research on the verification of the validity of a generalized thermo-elastoplastic-hydraulic mathematical model elaborated at Ismes for description of the behaviour of boom clay. The model is described in Section 2. Experimental results performed at Ismes for the identification of the material constants in athermal and thermal drained conditions are then presented. Procedures for the identification are described in Section 4. The undrained consolidated constant total stress heating test is then discussed. The undrained test shows the possibility of clay yielding due to effective pressure decrease during heating, caused by water pressure growth. The test has been simulated numerically, confirming the interpretation of the experiment. Further simulation of plane strain and plane stress central heating axisymmetric problem shows again a formation of a yielded clay zone around the heater. Interpretation of the results and recommendations for further research are given

An experimental study on thermal conductivity and viscosity of nanofluids containing carbon nanotubes

Science.gov (United States)

2014-01-01

Recently, there has been considerable interest in the use of nanofluids for enhancing thermal performance. It has been shown that carbon nanotubes (CNTs) are capable of enhancing the thermal performance of conventional working liquids. Although much work has been devoted on the impact of CNT concentrations on the thermo-physical properties of nanofluids, the effects of preparation methods on the stability, thermal conductivity and viscosity of CNT suspensions are not well understood. This study is focused on providing experimental data on the effects of ultrasonication, temperature and surfactant on the thermo-physical properties of multi-walled carbon nanotube (MWCNT) nanofluids. Three types of surfactants were used in the experiments, namely, gum arabic (GA), sodium dodecylbenzene sulfonate (SDBS) and sodium dodecyl sulfate (SDS). The thermal conductivity and viscosity of the nanofluid suspensions were measured at various temperatures. The results showed that the use of GA in the nanofluid leads to superior thermal conductivity compared to the use of SDBS and SDS. With distilled water as the base liquid, the samples were prepared with 0.5 wt.% MWCNTs and 0.25% GA and sonicated at various times. The results showed that the sonication time influences the thermal conductivity, viscosity and dispersion of nanofluids. The thermal conductivity of nanofluids was typically enhanced with an increase in temperature and sonication time. In the present study, the maximum thermal conductivity enhancement was found to be 22.31% (the ratio of 1.22) at temperature of 45°C and sonication time of 40 min. The viscosity of nanofluids exhibited non-Newtonian shear-thinning behaviour. It was found that the viscosity of MWCNT nanofluids increases to a maximum value at a sonication time of 7 min and subsequently decreases with a further increase in sonication time. The presented data clearly indicated that the viscosity and thermal conductivity of nanofluids are influenced by the

Thermomechanical and calorimetric behaviours of supported glass-forming films: A study based on thermodynamics with internal variables

Energy Technology Data Exchange (ETDEWEB)

Lion, Alexander, E-mail: alexander.lion@unibw.de; Engelhard, Marco; Johlitz, Michael

2012-11-01

In order to understand the temperature-dependent response behaviour of thin thermoviscoelastic films which are deposited on relative stiff but thermally deformable substrates it is important to consider the lateral geometric constraints. They are generated by differences in the thermal expansion properties between the substrate and the film and provoke internal stresses. Since glass-forming materials exhibit distinct temperature history-dependent thermal expansion and calorimetric properties, primarily in the vicinity of the glass transition, the situation is rather complicated. In this article, a recently developed three-dimensional model of thermodynamics with internal variables is applied and adapted to simulate this type of behaviour. Explicit relations are obtained for the specific heat of the film, the normal strain and the lateral stresses. Numerical simulations demonstrate that the magnitude of the internal stress at temperatures below the glass transition depends strongly on the cooling rate. It is also shown that the specific heat of the supported film is principally different from the isobaric specific heat of the bulk material: the glassy limit of the specific heat of the film is reduced but the glass transition temperature is almost uninfluenced. The simulated behaviour is in accordance with experimental observations from literature. - Highlights: Black-Right-Pointing-Pointer For the specific heat, stress and strain of the film, explicit equations were derived. Black-Right-Pointing-Pointer The constraints of the substrate reduce the glassy limit of specific heat of the film. Black-Right-Pointing-Pointer Glass transition temperatures of free bulk material and supported film are equal. Black-Right-Pointing-Pointer Simulations are in good agreement with experimental observations from literature.

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

Energy Technology Data Exchange (ETDEWEB)

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

1980-01-01

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

Closure of the concrete supercontainer in hot cell under thermal load

Energy Technology Data Exchange (ETDEWEB)

Craeye, Bart, E-mail: bart.craeye@artesis.b [Artesis Univerity College of Antwerp, Applied Engineering and Technology, Antwerp (Belgium); De Schutter, Geert [Magnel Laboratory for Concrete Research, Ghent University, Technologiepark-Zwijnaarde 904, 9052 Ghent (Belgium); Wacquier, William; Van Humbeeck, Hughes [ONDRAF/NIRAS, Belgian Agency for Radioactive Waste and Enriched Fissile Materials (Belgium); Van Cotthem, Alain [Tractebel Development Engineering, Consulting Company (Belgium); Areias, Lou [SCK.CEN, Belgian Nuclear Research Center (Belgium)

2011-05-15

Research highlights: We model the behaviour of the supercontainer for the disposal of high-level waste and spent fuel assemblies during fabrication at ground surface. We study the early-age cracking behaviour of the buffer and evaluate the crack creating mechanisms. In case accurate measures are taken, cracking of the buffer can be avoided. - Abstract: For the final disposal of long-lived, heat-emitting vitrified high-level waste (HLW) in a clayey host rock, an intensive study is conducted to investigate the early-age behaviour of concrete supercontainers. Self-compacting concrete (SCC) is taken as the reference concrete type as it facilitates the casting process in combination with an improved homogeneity compared to the traditional concrete compositions. A laboratory characterization program is conducted to obtain the relevant thermal, mechanical and maturity-related properties of the SCC. These obtained data are implemented into the material database of the finite element tool HEAT to study the behaviour of the concrete layers during the different construction stages of the supercontainer: (i) Stage 1: Fabrication of the concrete buffer inside a stainless steel envelope. No early-age cracking is expected in case accurate measures are taken to reduce the thermal gradient between the outer surface and the middle of the buffer, e.g. by providing insulation and excluding wind. (ii) Stages 2-4: Emplacement of the carbon steel overpack containing the HLW canisters, filling the remaining annular gap with cementitious filler and closure by fitting the lid under thermal load. The construction stages (2-4) for the closure of the supercontainer are executed in hot cell. In this study, the crack creating mechanism and the behaviour of the concrete supercontainer during these construction stages in hot cell are investigated. In case precautionary measures are taken, such as reducing the coefficient of thermal expansion (CTE) of the overpack, prolonging the preceding cooling

Closure of the concrete supercontainer in hot cell under thermal load

International Nuclear Information System (INIS)

Craeye, Bart; De Schutter, Geert; Wacquier, William; Van Humbeeck, Hughes; Van Cotthem, Alain; Areias, Lou

2011-01-01

Research highlights: → We model the behaviour of the supercontainer for the disposal of high-level waste and spent fuel assemblies during fabrication at ground surface. → We study the early-age cracking behaviour of the buffer and evaluate the crack creating mechanisms. → In case accurate measures are taken, cracking of the buffer can be avoided. - Abstract: For the final disposal of long-lived, heat-emitting vitrified high-level waste (HLW) in a clayey host rock, an intensive study is conducted to investigate the early-age behaviour of concrete supercontainers. Self-compacting concrete (SCC) is taken as the reference concrete type as it facilitates the casting process in combination with an improved homogeneity compared to the traditional concrete compositions. A laboratory characterization program is conducted to obtain the relevant thermal, mechanical and maturity-related properties of the SCC. These obtained data are implemented into the material database of the finite element tool HEAT to study the behaviour of the concrete layers during the different construction stages of the supercontainer: (i) Stage 1: Fabrication of the concrete buffer inside a stainless steel envelope. No early-age cracking is expected in case accurate measures are taken to reduce the thermal gradient between the outer surface and the middle of the buffer, e.g. by providing insulation and excluding wind. (ii) Stages 2-4: Emplacement of the carbon steel overpack containing the HLW canisters, filling the remaining annular gap with cementitious filler and closure by fitting the lid under thermal load. The construction stages (2-4) for the closure of the supercontainer are executed in hot cell. In this study, the crack creating mechanism and the behaviour of the concrete supercontainer during these construction stages in hot cell are investigated. In case precautionary measures are taken, such as reducing the coefficient of thermal expansion (CTE) of the overpack, prolonging the

Parental behaviour in paediatric chronic pain: a qualitative observational study.

Science.gov (United States)

Dunford, Emma; Thompson, Miles; Gauntlett-Gilbert, Jeremy

2014-10-01

Parental behaviour appears to influence the adjustment of children with chronic pain. However, research in this area has failed to produce consistent evidence. Studies have tended to rely on self-report measures derived from adult pain populations. This qualitative, observational research provides descriptive data of parental behaviour in a clinical environment. A qualitative observational study was made of parents and adolescents in a physically stressful setting. Modified grounded theory was used to analyse verbal and non-verbal behaviours. Eight parent-adolescent dyads seeking treatment for chronic pain were videoed during physical exercise sessions. Verbal and non-verbal behaviours were recorded and transcribed. Four overarching categories emerged: 'monitoring', 'protecting', 'encouraging' and 'instructing'. These often had both verbal and non-verbal aspects. Within these categories, more precise behavioural groups were also identified. This research identifies categories of parental behaviour that were derived directly from observation, rather than imposed on the basis of results from different populations. Four categories of behaviour were derived, which clarify and extend dimensions used in existing self-report instruments. Careful description of parental behaviours showed features that past research has neglected, and highlighted potential drawbacks of apparently positive parental actions. © The Author(s) 2013.

Morphology, thermal, electrical and electrochemical stability of nano

Indian Academy of Sciences (India)

In the present work, an attempt has been made to develop nano aluminium oxide (Al2O3)-filled polyvinyl alcohol (PVA) composite gel electrolytes. Surface morphological studies, thermal behaviour, electrochemical stability and electrical characterization of these composite gel electrolytes have been performed. An increase ...

Synergic effects of thermal mass and natural ventilation on the thermal behaviour of traditional massive buildings

Science.gov (United States)

Gagliano, A.; Nocera, F.; Patania, F.; Moschella, A.; Detommaso, M.; Evola, G.

2016-05-01

The energy policies about energy efficiency in buildings currently focus on new buildings and on existing buildings in case of energy retrofit. However, historic and heritage buildings, that are the trademark of numerous European cities, should also deserve attention; nevertheless, their energy efficiency is nowadays not deeply investigated. In this context, this study evaluates the thermal performance of a traditional massive building situated in a Mediterranean city. Dynamic numerical simulations were carried out on a yearly basis through the software DesignBuilder, both in free-running conditions and in the presence of an air-conditioning (AC) system. The results highlight that the massive envelope of traditional residential buildings helps in maintaining small fluctuations of the indoor temperature, thus limiting the need for AC in the mid-season and in summer. This feature is highly emphasised by exploiting natural ventilation at night, which allows reducing the building energy demand for cooling by about 30%.The research also indicates that, for Mediterranean climate, the increase in thermal insulation does not always induce positive effects on the thermal performance in summer, and that it might even produce an increase in the heat loads due to the transmission through the envelope.

Elution behaviour of solid residues from thermal waste treatment and disposal

International Nuclear Information System (INIS)

Vetter, G.

1992-01-01

In the research part carried through so far, the leaching behaviour of residues of different waste combustion methods was compared with that of other materials frequently deposited at landfills as regards heavy metals and anions. Furthermore, specifically residues from different types of waste subjected to the Siemens semicoking process were investigated. The leaching behaviour of well vitrified slags approaches very much the favourable values of melting-chamber granulate from a black-coal-fired power plant. By contrast, poorly vitrified slags or slags from an ordinary waste combustion plant yield eluate concentrations exceeding in part the limiting values applicable to landfilling material. With vitrified slags, the type of waste burnt has no recognizable influence on leaching behaviour. (orig.) [de

BEHAVIOURAL STUDIES ON SOME RHODESIAN RODENTS

African Journals Online (AJOL)

behaviour, . courtship, parental and juvenile behaviour and activity patterns. ... behavioural observations were facilitated by the development of a glass-fronted ~'double-storey" cage which ..... Adolescent siblings in both single sex and mixed groups ..... Wild rodents as Laboratory Animals and their contribution to medical.

A Longitudinal Study of Gender-Related Cognition and Behaviour

Science.gov (United States)

Campbell, Anne; Shirley, Louisa; Candy, Julia

2004-01-01

Gender schema theory proposes that children's acquisition of gender labels and gender stereotypes informs gender-congruent behaviour. Most previous studies have been cross-sectional and do not address the temporal relationship between knowledge and behaviour. We report the results of a longitudinal study of gender knowledge and sex-typed behaviour…

Health behaviours of young, rural residents: a case study.

Science.gov (United States)

Bourke, Lisa; Humphreys, John; Lukaitis, Fiona

2009-04-01

To analyse self-reported health behaviours of young people from a rural community and the factors influencing their behaviours. Interviews were conducted with 19 young people, 11 parents and 10 key informants from a small rural Victorian community, asking about teenage health behaviours and the factors influencing these behaviours. Young people ate both healthy and unhealthy foods, most participated in physical activity, few smoked and most drank alcohol. The study found that community level factors, including community norms, peers, access issues and geographic isolation, were particularly powerful in shaping health behaviours, especially alcohol consumption. Smoking was influenced by social participation in the community and national media health campaigns. Diet and exercise behaviour were influenced by access and availability, convenience, family, peers and local and non-local cultural influences. The rural context, including less access to and choice of facilities and services, lower incomes, lack of transport and local social patterns (including community norms and acceptance), impact significantly on young people's health behaviours. Although national health promotion campaigns are useful aspects of behaviour modification, much greater focus on the role and importance of the local contexts in shaping health decisions of young rural people is required.

Passenger thermal perceptions, thermal comfort requirements, and adaptations in short- and long-haul vehicles.

Science.gov (United States)

Lin, Tzu-Ping; Hwang, Ruey-Lung; Huang, Kuo-Tsang; Sun, Chen-Yi; Huang, Ying-Che

2010-05-01

While thermal comfort in mass transportation vehicles is relevant to service quality and energy consumption, benchmarks for such comfort that reflect the thermal adaptations of passengers are currently lacking. This study reports a field experiment involving simultaneous physical measurements and a questionnaire survey, collecting data from 2,129 respondents, that evaluated thermal comfort in short- and long-haul buses and trains. Experimental results indicate that high air temperature, strong solar radiation, and low air movement explain why passengers feel thermally uncomfortable. The overall insulation of clothing worn by passengers and thermal adaptive behaviour in vehicles differ from those in their living and working spaces. Passengers in short-haul vehicles habitually adjust the air outlets to increase thermal comfort, while passengers in long-haul vehicles prefer to draw the drapes to reduce discomfort from extended exposure to solar radiation. The neutral temperatures for short- and long-haul vehicles are 26.2 degrees C and 27.4 degrees C, while the comfort zones are 22.4-28.9 degrees C and 22.4-30.1 degrees C, respectively. The results of this study provide a valuable reference for practitioners involved in determining the adequate control and management of in-vehicle thermal environments, as well as facilitating design of buses and trains, ultimately contributing to efforts to achieve a balance between the thermal comfort satisfaction of passengers and energy conserving measures for air-conditioning in mass transportation vehicles.

Simple thermal to thermal face verification method based on local texture descriptors

Science.gov (United States)

Grudzien, A.; Palka, Norbert; Kowalski, M.

2017-08-01

Biometrics is a science that studies and analyzes physical structure of a human body and behaviour of people. Biometrics found many applications ranging from border control systems, forensics systems for criminal investigations to systems for access control. Unique identifiers, also referred to as modalities are used to distinguish individuals. One of the most common and natural human identifiers is a face. As a result of decades of investigations, face recognition achieved high level of maturity, however recognition in visible spectrum is still challenging due to illumination aspects or new ways of spoofing. One of the alternatives is recognition of face in different parts of light spectrum, e.g. in infrared spectrum. Thermal infrared offer new possibilities for human recognition due to its specific properties as well as mature equipment. In this paper we present the scheme of subject's verification methodology by using facial images in thermal range. The study is focused on the local feature extraction methods and on the similarity metrics. We present comparison of two local texture-based descriptors for thermal 1-to-1 face recognition.

Energy expenditure in frontotemporal dementia: a behavioural and imaging study

Science.gov (United States)

Ahmed, Rebekah M; Landin-Romero, Ramon; Collet, Tinh-Hai; van der Klaauw, Agatha A; Devenney, Emma; Henning, Elana; Kiernan, Matthew C; Piguet, Olivier; Farooqi, I Sadaf; Hodges, John R

2017-01-01

Abstract See Finger (doi:10.1093/aww312) for a scientific commentary on this article. Abnormal eating behaviour and metabolic parameters including insulin resistance, dyslipidaemia and body mass index are increasingly recognized as important components of neurodegenerative disease and may contribute to survival. It has previously been established that behavioural variant frontotemporal dementia is associated with abnormal eating behaviour characterized by increased sweet preference. In this study, it was hypothesized that behavioural variant frontotemporal dementia might also be associated with altered energy expenditure. A cohort of 19 patients with behavioural variant frontotemporal dementia, 13 with Alzheimer’s disease and 16 (age- and sex-matched) healthy control subjects were studied using Actiheart devices (CamNtech) to assess resting and stressed heart rate. Actiheart devices were fitted for 7 days to measure sleeping heart rate, activity levels, and resting, active and total energy expenditure. Using high resolution structural magnetic resonance imaging the neural correlates of increased resting heart rate were investigated including cortical thickness and region of interest analyses. In behavioural variant frontotemporal dementia, resting (P = 0.001), stressed (P = 0.037) and sleeping heart rate (P = 0.038) were increased compared to control subjects, and resting heart rate (P = 0.020) compared to Alzheimer disease patients. Behavioural variant frontotemporal dementia was associated with decreased activity levels compared to controls (P = 0.002) and increased resting energy expenditure (P = 0.045) and total energy expenditure (P = 0.035). Increased resting heart rate correlated with behavioural (Cambridge Behavioural Inventory) and cognitive measures (Addenbrooke’s Cognitive Examination). Increased resting heart rate in behavioural variant frontotemporal dementia correlated with atrophy involving the mesial temporal cortex, insula, and amygdala

Sustainable Consumer Behaviour: A Collection of Empirical Studies

OpenAIRE

Gerrit Antonides

2017-01-01

We summarise the contributions in this special issue on sustainable consumer behaviour and place them in perspective. Several studies focus on macro- and meso-issues, and others on micro-issues of consumer behaviour. The studies employ a variety of methods, including surveys, field experiments, eye tracking, scale development, and contingent valuation. The 12 contributions from authors of 13 different countries show the wide and varied application of consumer research focused on sustainabilit...

A study on specific heat capacities of Li-ion cell components and their influence on thermal management

Science.gov (United States)

Loges, André; Herberger, Sabrina; Seegert, Philipp; Wetzel, Thomas

2016-12-01

Thermal models of Li-ion cells on various geometrical scales and with various complexity have been developed in the past to account for the temperature dependent behaviour of Li-ion cells. These models require accurate data on thermal material properties to offer reliable validation and interpretation of the results. In this context a thorough study on the specific heat capacities of Li-ion cells starting from raw materials and electrode coatings to representative unit cells of jelly rolls/electrode stacks with lumped values was conducted. The specific heat capacity is reported as a function of temperature and state of charge (SOC). Seven Li-ion cells from different manufactures with different cell chemistry, application and design were considered and generally applicable correlations were developed. A 2D thermal model of an automotive Li-ion cell for plug-in hybrid electric vehicle (PHEV) application illustrates the influence of specific heat capacity on the effectivity of cooling concepts and the temperature development of Li-ion cells.

Temperature-dependent behaviours are genetically variable in the nematode Caenorhabditis briggsae.

Science.gov (United States)

Stegeman, Gregory W; de Mesquita, Matthew Bueno; Ryu, William S; Cutter, Asher D

2013-03-01

Temperature-dependent behaviours in Caenorhabditis elegans, such as thermotaxis and isothermal tracking, are complex behavioural responses that integrate sensation, foraging and learning, and have driven investigations to discover many essential genetic and neural pathways. The ease of manipulation of the Caenorhabditis model system also has encouraged its application to comparative analyses of phenotypic evolution, particularly contrasts of the classic model C. elegans with C. briggsae. And yet few studies have investigated natural genetic variation in behaviour in any nematode. Here we measure thermotaxis and isothermal tracking behaviour in genetically distinct strains of C. briggsae, further motivated by the latitudinal differentiation in C. briggsae that is associated with temperature-dependent fitness differences in this species. We demonstrate that C. briggsae performs thermotaxis and isothermal tracking largely similar to that of C. elegans, with a tendency to prefer its rearing temperature. Comparisons of these behaviours among strains reveal substantial heritable natural variation within each species that corresponds to three general patterns of behavioural response. However, intraspecific genetic differences in thermal behaviour often exceed interspecific differences. These patterns of temperature-dependent behaviour motivate further development of C. briggsae as a model system for dissecting the genetic underpinnings of complex behavioural traits.

Behaviour of oil in freezing environments : a literature review

International Nuclear Information System (INIS)

Fingas, M.F.; Hollebone, B.P.

2002-01-01

Oils spilled in icy waters undergo complex behaviour and fate processes. This paper reviewed the available information regarding the physical fate and behaviour of crude oil and petroleum products spilled in Arctic environments. Specific mathematical relationships that can be used to predict the behaviour of oil in icy environments were also reviewed and behavioural mechanisms were summarized according the most probable fate and final deposition scenarios of oil spills in water. The study evaluates spreading models for oil on ice, under ice, in snow, in brash ice and between blocks of ice. The ability of ice sheets to trap oil is also discussed with particular reference to oil storage capacity. The effect of oil on ice formation and the thermal effects of oil inclusion in ice was examined, along with the migration of oil through ice, including movement through brine channels. It was concluded that more research is needed to better predict oil behaviour and fate in ice infested waters, particularly in the area of quantification. 32 refs

Psychiatric Nurses' Attitudes Towards Violent Behaviour: A Brazilian Study.

Science.gov (United States)

Dias, Maraína Gomes Pires Fernandes; de Vargas, Divane

2018-02-13

This study examines nurses' attitudes towards violent behaviour and the management of aggressiveness. A convenience sample of 185 nurses working in psychiatric urgent care and emergency services in Brazil responded to the MAVAS-BR. The results show that nurses' attitudes are more reflective of the external and situational models of violent behaviour and the use of control methods to manage aggressiveness. The mapping of this phenomenon using the same tools in a different context from those traditionally studied while observing similar results suggests a pattern of attitudes towards violent behaviour and the management of aggressiveness among nurses around the world.

The thermal environment of the human being on the global scale

OpenAIRE

Jendritzky, Gerd; Tinz, Birger

2009-01-01

Background: The close relationship between human health, performance, well-being and the thermal environment is obvious. Nevertheless, most studies of climate and climate change impacts show amazing shortcomings in the assessment of the environment. Populations living in different climates have different susceptibilities, due to socio-economic reasons, and different customary behavioural adaptations. The global distribution of risks of hazardous thermal exposure has not been analysed before. ...

Sustainable Consumer Behaviour: A Collection of Empirical Studies

Directory of Open Access Journals (Sweden)

Gerrit Antonides

2017-09-01

Full Text Available We summarise the contributions in this special issue on sustainable consumer behaviour and place them in perspective. Several studies focus on macro- and meso-issues, and others on micro-issues of consumer behaviour. The studies employ a variety of methods, including surveys, field experiments, eye tracking, scale development, and contingent valuation. The 12 contributions from authors of 13 different countries show the wide and varied application of consumer research focused on sustainability issues.

Investigations on fiberoptic behaviour during gamma irradiation

International Nuclear Information System (INIS)

Siehs, J.

1980-12-01

Investigations on the behaviour of bulk glasses and fiber optics under gamma irradiation and two types of annealing processes (thermal and optical) have been investigated. The samples were irradiated in the thermal column of the TRIGA Mark II Reactor, Vienna. The irradiation induced losses of transmission were measured in a dual beam spectrophotometer. The transmission was measured one hour after reactor shut-down. Thermal annealing was done at 300, 400 and 500 0 C. Photo bleaching was investigated with a quartz-lamp, an arc-lamp and an UV-laser light. (author)

Long-term thermal two- and three-dimensional analysis of roller compacted concrete dams supported by monitoring verification

Energy Technology Data Exchange (ETDEWEB)

Kuzmanovic, V.; Savic, L. [Belgrade Univ. (Serbia). Faculty of Civil Engineering; Stefanakos, J. [National Technical Univ. of Athens (Greece). Dept. of Water Resources and Environmental Engineering

2010-04-15

This study investigated the long-term thermal-field evolution of roller compacted concrete (RCC) dams. Thermal computational analyses of the dams are needed as a result of the layer-based construction technologies used to build the dams. Two-dimensional (2-D) and 3-D unsteady phased models of the RCC dams were used to determine the time evolution of thermal field in a dam based on the Platanovryssi dam in Greece. The finite element method (FEM) was used to account for the dam geometry, different types of concrete used; actual initial and boundary conditions; the thermal and mechanical properties of the dam as a function of aging and temperature; and the RCC construction technology. The influence of all the parameters on the thermal behaviour of the RCC gravity dam was analyzed. Results of the study showed that the 2-D model accurately described the RCC dam thermal field. The thermal behaviour of the dam was influenced primarily by the thermal properties of the mixture and the boundary conditions. Variations of layer thickness did not significantly influence the temperature field. 18 refs., 3 tabs., 10 figs.

Developing smartphone apps for behavioural studies: The AlcoRisk app case study.

Science.gov (United States)

Smith, Anthony; de Salas, Kristy; Lewis, Ian; Schüz, Benjamin

2017-08-01

Smartphone apps have emerged as valuable research tools to sample human behaviours at their time of occurrence within natural environments. Human behaviour sampling methods, such as Ecological Momentary Assessment (EMA), aim to facilitate research that is situated in ecologically valid real world environments rather than laboratory environments. Researchers have trialled a range of EMA smartphone apps to sample human behaviours such as dieting, physical activity and smoking. Software development processes for EMA smartphones apps, however, are not widely documented with little guidance provided for the integration of complex multidisciplinary behavioural and technical fields. In this paper, the AlcoRisk app for studying alcohol consumption and risk taking tendencies is presented alongside a software development process that integrates these multidisciplinary fields. The software development process consists of three stages including requirements analysis, feature and interface design followed by app implementation. Results from a preliminary feasibility study support the efficacy of the AlcoRisk app's software development process. Copyright © 2017 Elsevier Inc. All rights reserved.

Integrated Monitoring of Mola mola Behaviour in Space and Time.

Directory of Open Access Journals (Sweden)

Lara L Sousa

Full Text Available Over the last decade, ocean sunfish movements have been monitored worldwide using various satellite tracking methods. This study reports the near-real time monitoring of fine-scale (< 10 m behaviour of sunfish. The study was conducted in southern Portugal in May 2014 and involved satellite tags and underwater and surface robotic vehicles to measure both the movements and the contextual environment of the fish. A total of four individuals were tracked using custom-made GPS satellite tags providing geolocation estimates of fine-scale resolution. These accurate positions further informed sunfish areas of restricted search (ARS, which were directly correlated to steep thermal frontal zones. Simultaneously, and for two different occasions, an Autonomous Underwater Vehicle (AUV video-recorded the path of the tracked fish and detected buoyant particles in the water column. Importantly, the densities of these particles were also directly correlated to steep thermal gradients. Thus, both sunfish foraging behaviour (ARS and possibly prey densities, were found to be influenced by analogous environmental conditions. In addition, the dynamic structure of the water transited by the tracked individuals was described by a Lagrangian modelling approach. The model informed the distribution of zooplankton in the region, both horizontally and in the water column, and the resultant simulated densities positively correlated with sunfish ARS behaviour estimator (rs = 0.184, p<0.001. The model also revealed that tracked fish opportunistically displace with respect to subsurface current flow. Thus, we show how physical forcing and current structure provide a rationale for a predator's fine-scale behaviour observed over a two weeks in May 2014.

Transient thermal analysis of Vega launcher structures

Energy Technology Data Exchange (ETDEWEB)

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

2008-12-15

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

Melting behaviour of raw materials and recycled stone wool waste

DEFF Research Database (Denmark)

Schultz-Falk, Vickie; Agersted, Karsten; Jensen, Peter Arendt

2018-01-01

Stone wool is a widely used material for building insulation, to provide thermal comfort along with fire stability and acoustic comfort for all types of buildings. Stone wool waste generated either during production or during renovation or demolition of buildings can be recycled back into the sto...... wool melt production. This study investigates and compares the thermal response and melting behaviour of a conventional stone wool charge and stone wool waste. The study combines differential scanning calorimetry (DSC), hot stage microscopy (HSM) and X-ray diffraction (XRD). DSC reveals...... that the conventional charge and stone wool waste have fundamentally different thermal responses, where the charge experiences gas release, phase transition and melting of the individual raw materials. The stone wool waste experiences glass transition, crystallization and finally melting. Both DSC and HSM measurements...

Long-term behaviour of heat-resistant steels and high-temperature materials

International Nuclear Information System (INIS)

1987-01-01

This book contains 10 lectures with the following subjects: On the effect of thermal pretreatment on the structure and creep behaviour of the alloy 800 H (V. Guttmann, J. Timm); Material properties of heat resistant ferritic and austenitic steels after cold forming (W. Bendick, H. Weber); Investigations for judging the working behaviour of components made of alloy 800 and alloy 617 under creep stress (H.J. Penkalla, F. Schubert); Creep behaviour of gas turbine materials in hot gas (K.H. Kloos et al.); Effect of small cold forming on the creep beahviour of gas turbine blades made of Nimonic 90 (K.H. Keienburg et al.); Investigations on creep fatigue alternating load strength of nickel alloys (G. Raule); Change of structure, creep fatigue behaviour and life of X20 Cr Mo V 12 1 (by G. Eggeler et al.); Investigations on thermal fatigue behaviour (K.H. Mayer et al.); Creep behaviour of similar welds of the steels 13 Cr Mo 4 4, 14 MoV 6 3, 10 Cr Mo 910 and GS-17 Cr Mo V 5 11 (K. Niel et al.); Determining the creep crack behaviour of heat resistant steels with samples of different geometry (K. Maile, R. Tscheuschner). (orig.,/MM) [de

Thermal behaviour of chrome shavings and of sludges recovered after digestion of tanned solid wastes with calcium hydroxide

International Nuclear Information System (INIS)

Tahiri, S.; Albizane, A.; Messaoudi, A.; Azzi, M.; Bennazha, J.; Younssi, S. Alami; Bouhria, M.

2007-01-01

The thermal behaviour of chrome shavings and of sludges recovered after digestion of tanned wastes with Ca(OH) 2 was studied. Ashes obtained after incineration of wastes at various temperatures were analysed by X-ray diffraction and EDX method. The main crystallized phases present in the ash obtained at 600 deg. C are Cr 2 O 3 and NaCl. The diffractograms revealed an increase in the intensities of the chromium oxide peaks and a very notable decrease of the amount of sodium chloride at 1100 deg. C. EDX analysis revealed a total disappearance of the chlorine peak at this temperature. Scanning electron micrographs show that the waste lost its fibrous aspect when the temperature increases. Formation of aggregates was noted after 550 deg. C. Combustion of organic matters and decarbonation phenomenon are the main stages observed on GTA and DTA curves of sludges. These phenomena are, respectively, exothermic and endothermic. The diffractogram of sludges recorded at 550 deg. C, in the presence of a constant oxygen surplus, revealed the presence of CaCrO 4 and CaCO 3

Parametric study for design of thermal sleeves

International Nuclear Information System (INIS)

Mukherjee, A.B.; Mehra, V.K.

1985-01-01

Thermal sleeves are used inside nozzle in many reactor components. Basic aim in design of thermal sleeve is to arrive at a set of dimensions for gap and annulus length, which will give rise to minimum thermal gradient in the base metal of the associated nozzle. Study includes the minimisation of the thermal gradient in the crotch zone by suitable choice of gap and annulus length. Three different geometries of nozzle radii 50.00 mm., 100 mm. and 200.0 mm. are studied for single and two concentric thermal sleeves model. The paper also presents effect of parameters like velocity of flow, temperature of fluid, materials etc. on the design of thermal sleeves. (orig.)

Proximity and Gaze Influences Facial Temperature: A Thermal Infrared Imaging Study.

Directory of Open Access Journals (Sweden)

Stephanos eIoannou

2014-08-01

Full Text Available Direct gaze and interpersonal proximity are known to lead to changes in psycho-physiology, behaviour and brain function. We know little, however, about subtler facial reactions such as rise and fall in temperature, which may be sensitive to contextual effects and functional in social interactions. Using thermal infrared imaging cameras 18 female adult participants were filmed at two interpersonal distances (intimate and social and two gaze conditions (averted and direct. The order of variation in distance was counterbalanced: half the participants experienced a female experimenter’s gaze at the social distance first before the intimate distance (a socially ‘normal’ order and half experienced the intimate distance first and then the social distance (an odd social order. At both distances averted gaze always preceded direct gaze. We found strong correlations in thermal changes between six areas of the face (forehead, chin, cheeks, nose, maxilliary and periorbital regions for all experimental conditions and developed a composite measure of thermal shifts for all analyses. Interpersonal proximity led to a thermal rise, but only in the ‘normal’ social order. Direct gaze, compared to averted gaze, led to a thermal increase at both distances with a stronger effect at intimate distance, in both orders of distance variation. Participants reported direct gaze as more intrusive than averted gaze, especially at the intimate distance. These results demonstrate the powerful effects of another person’s gaze on psycho-physiological responses, even at a distance and independent of context.

Integrated Monitoring of Mola mola Behaviour in Space and Time

Science.gov (United States)

Sousa, Lara L.; López-Castejón, Francisco; Gilabert, Javier; Relvas, Paulo; Couto, Ana; Queiroz, Nuno; Caldas, Renato; Dias, Paulo Sousa; Dias, Hugo; Faria, Margarida; Ferreira, Filipe; Ferreira, António Sérgio; Fortuna, João; Gomes, Ricardo Joel; Loureiro, Bruno; Martins, Ricardo; Madureira, Luis; Neiva, Jorge; Oliveira, Marina; Pereira, João; Pinto, José; Py, Frederic; Queirós, Hugo; Silva, Daniel; Sujit, P. B.; Zolich, Artur; Johansen, Tor Arne; de Sousa, João Borges; Rajan, Kanna

2016-01-01

Over the last decade, ocean sunfish movements have been monitored worldwide using various satellite tracking methods. This study reports the near-real time monitoring of fine-scale (behaviour of sunfish. The study was conducted in southern Portugal in May 2014 and involved satellite tags and underwater and surface robotic vehicles to measure both the movements and the contextual environment of the fish. A total of four individuals were tracked using custom-made GPS satellite tags providing geolocation estimates of fine-scale resolution. These accurate positions further informed sunfish areas of restricted search (ARS), which were directly correlated to steep thermal frontal zones. Simultaneously, and for two different occasions, an Autonomous Underwater Vehicle (AUV) video-recorded the path of the tracked fish and detected buoyant particles in the water column. Importantly, the densities of these particles were also directly correlated to steep thermal gradients. Thus, both sunfish foraging behaviour (ARS) and possibly prey densities, were found to be influenced by analogous environmental conditions. In addition, the dynamic structure of the water transited by the tracked individuals was described by a Lagrangian modelling approach. The model informed the distribution of zooplankton in the region, both horizontally and in the water column, and the resultant simulated densities positively correlated with sunfish ARS behaviour estimator (rs = 0.184, pbehaviour observed over a two weeks in May 2014. PMID:27494028

The characterisation of VSe2: a study of the thermal expansion

International Nuclear Information System (INIS)

Wiegers, G.A.

1981-01-01

The thermal expansion of VSe 2 from 40-1175 K has been determined by x-ray diffraction. The lattice expansion is linear with temperature from 40 to about 300 K with αsub(a) = 18.6 x 10 -6 K -1 and αsub(c) = 9.8 x 10 -6 K -1 . The behaviour αsub(a) > αsub(c) is anomalous for a layer compound. From the relation between the thermal expansion and the elastic constants it follows that either the elastic constants of VSe 2 are anomalous for a layer compound or the elastic constants are normal but there is a large anisotropy in the Gruneisen functions γsub(a) and γsub(c) (γsub(a) > γsub(c)) together with a relatively large value of the cross compliance constant s 13 . The latter possibility is probably true. The physical origin lies in the electronic structure; the exceptionally high ratio c/a (1.823 at 40 K, 1.818 at 300 K) due to a band Jahn-Teller type distortion, decreases at increasing temperature. The expansion above about 300 K is no longer linear; with increasing temperature the expansion of the a axis increases while that of the c axis becomes almost zero. The non-linear behaviour is ascribed to the formation of Frenkel defects: intrasandwich vanadium is transferred to the interstitial sites in the Van der Waals gap. (author)

The impact of thermal wave characteristics on thermal dose distribution during thermal therapy: A numerical study

International Nuclear Information System (INIS)

Shih, T.-C.; Kou, H.-S.; Liauh, C.-T.; Lin, W.-L.

2005-01-01

The aim of this study was to investigate the effects of the propagation speed of a thermal wave in terms of the thermal relaxation time on the temperature/thermal dose distributions in living tissue during thermal therapies. The temperature field in tissue was solved by the finite difference method, and the thermal dose was calculated from the formulation proposed by Sapareto and Dewey [Int. J. Radiat. Oncol. Biol. Phys. 10, 787-800 (1984)]. Under the same total deposited energy, for a rapid heating process the time lagging behavior of the peak temperature became pronounced and the level of the peak temperature was decreased with increasing the thermal relaxation time. When the heating duration was longer than the thermal relaxation time of tissues, there was no significant difference between the thermal dose distributions with/without considering the effect of the thermal relaxation time. In other words, when the heating duration is comparable to or shorter than the thermal relaxation time of tissue, the results of the wave bioheat transfer equation (WBHTE) are fully different from that of the Pennes' bioheat transfer equation (PBHTE). Besides, for a rapid heating process the dimension of thermal lesion was still significantly affected by perfusion, because this is what is predicted by the WBHTE but not by the PBHTE, i.e., the wave feature of the temperature field cannot fully be predicted by the PBHTE

Study on wall recycling behaviour in CPD spherical tokamak

International Nuclear Information System (INIS)

Bhattacharyay, R.; Zushi, H.; Hirooka, Y.; Sakamoto, M.; Yoshinaga, T.; Okamoto, K.; Kawasaki, S.; Hanada, K.; Sato, K.N.; Nakamura, K.; Idei, H.; Ryoukai, T.; Nakashima, H.; Higashijima, A.

2008-01-01

Experiments to study wall recycling behaviour have been performed in the small spherical tokamak compact plasma-wall interaction experimental device (CPD) from the viewpoint of global as well as local plasma wall interaction condition. Electron cyclotron resonance (ECR) plasma of typically ∼50 to 400 ms duration is produced using ∼40 to 80 kW RF power. In order to study the global wall recycling behaviour, pressure measurements are carried out just before and after the ECR plasma in the absence of any external pumping. The recycling behaviour is found to change from release to pumping beyond a certain level of pressure value which is again found to be a function of shot history. The real-time local wall behaviour is studied in similar RF plasma using a rotating tungsten limiter, actively coated with lithium. Measurement of H α light intensity in front of the rotating surface has indicated a clear reduction (∼10%) in the steady-state hydrogen recycling with continuous Li gettering of several minutes

Thermal expansion

International Nuclear Information System (INIS)

Yun, Y.

2015-01-01

Thermal expansion of fuel pellet is an important property which limits the lifetime of the fuels in reactors, because it affects both the pellet and cladding mechanical interaction and the gap conductivity. By fitting a number of available measured data, recommended equations have been presented and successfully used to estimate thermal expansion coefficient of the nuclear fuel pellet. However, due to large scatter of the measured data, non-consensus data have been omitted in formulating the equations. Also, the equation is strongly governed by the lack of appropriate experimental data. For those reasons, it is important to develop theoretical methodologies to better describe thermal expansion behaviour of nuclear fuel. In particular, first-principles and molecular dynamics simulations have been certainly contributed to predict reliable thermal expansion without fitting the measured data. Furthermore, the two theoretical techniques have improved on understanding the change of fuel dimension by describing the atomic-scale processes associated with lattice expansion in the fuels. (author)

A Langevin model for fluctuating contact angle behaviour parametrised using molecular dynamics.

Science.gov (United States)

Smith, E R; Müller, E A; Craster, R V; Matar, O K

2016-12-06

Molecular dynamics simulations are employed to develop a theoretical model to predict the fluid-solid contact angle as a function of wall-sliding speed incorporating thermal fluctuations. A liquid bridge between counter-sliding walls is studied, with liquid-vapour interface-tracking, to explore the impact of wall-sliding speed on contact angle. The behaviour of the macroscopic contact angle varies linearly over a range of capillary numbers beyond which the liquid bridge pinches off, a behaviour supported by experimental results. Nonetheless, the liquid bridge provides an ideal test case to study molecular scale thermal fluctuations, which are shown to be well described by Gaussian distributions. A Langevin model for contact angle is parametrised to incorporate the mean, fluctuation and auto-correlations over a range of sliding speeds and temperatures. The resulting equations can be used as a proxy for the fully-detailed molecular dynamics simulation allowing them to be integrated within a continuum-scale solver.

Thermal-hydraulic code selection for modular high temperature gas-cooled reactors

Energy Technology Data Exchange (ETDEWEB)

Komen, E M.J.; Bogaard, J.P.A. van den

1995-06-01

In order to study the transient thermal-hydraulic system behaviour of modular high temperature gas-cooled reactors, the thermal-hydraulic computer codes RELAP5, MELCOR, THATCH, MORECA, and VSOP are considered at the Netherlands Energy Research Foundation ECN. This report presents the selection of the most appropriate codes. To cover the range of relevant accidents, a suite of three codes is recommended for analyses of HTR-M and MHTGR reactors. (orig.).

Non linear thermal behaviour induced by damage of ceramic matrix composite

International Nuclear Information System (INIS)

El-Yagoubi, J.

2011-10-01

In this work the relationship between the evolution of damage and the loss of thermal properties of Ceramic Matrix Composites is investigated by a multi-scale approach. Research are conducted both experimentally and theoretically. The implemented approach is to consider two significant scales (micro and meso) where different damage mechanisms are operating and then assess the effect on the effective thermal properties by homogenization techniques. Particular attention has been given to the development of a thorough experimental work combining various characterization tools (mechanical, thermal and microstructural). At the two aforementioned scales, an experimental setup was designed to perform thermal measurements on CMC under tensile test. Thermal diffusivity of mini-composites is estimated using Lock-in thermography. Also, transverse diffusivity mapping as well as global in-plane diffusivity of woven CMC are determined by suitable rear face flash methods. The evolution of damage is then derived from acoustic emission activity along with postmortem microstructural observations. Experimental results are systematically compared to simulations. At microscale, a micromechanical-based model is used to simulate the loss of thermal conductivity of a mini-composite under tensile test. At mesoscale, a multi-scale Finite Element Model is proposed to compute the effect of damage on thermal properties of woven CMC. (author) [fr

Green synthesis of silver nanoparticles using green tea leaves: Experimental study on the morphological, rheological and antibacterial behaviour

Science.gov (United States)

Nakhjavani, Maryam; Nikkhah, V.; Sarafraz, M. M.; Shoja, Saeed; Sarafraz, Marzieh

2017-10-01

In this paper, silver nanoparticles are produced via green synthesis method using green tea leaves. The introduced method is cost-effective and available, which provides condition to manipulate and control the average nanoparticle size. The produced particles were characterized using x-ray diffraction, scanning electron microscopic images, UV visualization, digital light scattering, zeta potential measurement and thermal conductivity measurement. Results demonstrated that the produced samples of silver nanoparticles are pure in structure (based on the x-ray diffraction test), almost identical in terms of morphology (spherical and to some extent cubic) and show longer stability when dispersed in deionized water. The UV-visualization showed a peak in 450 nm, which is in accordance with the previous studies reported in the literature. Results also showed that small particles have higher thermal and antimicrobial performance. As green tea leaves are used for extracting the silver nanoparticles, the method is eco-friendly. The thermal behaviour of silver nanoparticle was also analysed by dispersing the nanoparticles inside the deionized water. Results showed that thermal conductivity of the silver nano-fluid is higher than that of obtained for the deionized water. Activity of Ag nanoparticles against some bacteria was also examined to find the suitable antibacterial application for the produced particles.

Nociceptive responses to thermal and mechanical stimulations in awake pigs

DEFF Research Database (Denmark)

di Giminiani, Pierpaolo; Petersen, Lars Jelstrup; Herskin, Mette S.

2013-01-01

body sizes (30 and 60 kg) were exposed to thermal (CO(2) laser) and mechanical (pressure application measurement device) stimulations to the flank and the hind legs in a balanced order. The median response latency and the type of behavioural response were recorded. RESULTS: Small pigs exhibited...... animal studies in a large species require further examination. This manuscript describes the initial development of a porcine model of cutaneous nociception and focuses on interactions between the sensory modality, body size and the anatomical location of the stimulation site. METHODS: Pigs of different...... significantly lower pain thresholds (shorter latency to response) than large pigs to thermal and mechanical stimulations. Stimulations at the two anatomical locations elicited very distinct sets of behavioural responses, with different levels of sensitivity between the flank and the hind legs. Furthermore...

The effect of low-concentration inorganic materials on the behaviour of supercritical water

Energy Technology Data Exchange (ETDEWEB)

Imre, A.R., E-mail: imre@aeki.kfki.h [KFKI Atomic Energy Research Institute, POB 49, Budapest (Hungary); Hazi, G.; Horvath, A.; Maraczy, Cs. [KFKI Atomic Energy Research Institute, POB 49, Budapest (Hungary); Mazur, V.; Artemenko, S. [Odessa State Academy of Refrigeration, 1/3 Dvoryanslaya Str., 65026, Odessa (Ukraine)

2011-01-15

Research highlights: Small amount of inorganic materials (like corrosion products) can be dissolved in the supercritical water. Pseudo-critical temperature and other properties will be changed. Thermal and hydraulic behaviours of the SCW with small amount of contaminants differ in great extent from the behaviour of pure SCW. - Abstract: Supercritical water is a promising working fluid in the new Generation IV nuclear power plants. Due to the presence of the pseudo-critical line, the thermo-hydraulics (thermal and flow properties) and the physical chemistry of the supercritical water differ significantly from the pressurized hot water used in pressurized water reactors. In this study we would like to analyse the effect of small amount of inorganic material on the thermo-hydraulics of the supercritical water cooled nuclear reactors and other, non-nuclear supercritical water loops.

Contribution to the study of thermal-hydraulic problems in nuclear reactors

International Nuclear Information System (INIS)

Cognet, G.

1998-01-01

In nuclear reactors, whatever the type considered, Pressurized Water Water Reactors (PWRs), Fast Breeder reactors (FBRs)..., thermal-hydraulics, the science of fluid mechanics and thermal behaviour, plays an essential role, both in nominal operating and accidental conditions. Fluid can either be the primary fluid (liquid or gas) or a very specific fluid called corium, which, in case of severe accident, could result from core and environning structure melting. The work reported here represents a 20-year contribution to thermal-hydraulic issues which could occur in FBRs and PWRs. Working on these two types of reactors, both in nominal and severe accident situations, has allowed me to compare the problems and to realize the importance of communication between research teams. The evolution in the complexity of studied problems, unavoidable in order to reduce costs and significantly improve safety, has led me from numerical modelling of single-phase flow turbulence to high temperature real melt experiments. The difficulties encountered in understanding the observed phenomena and in increasing experimental databases for computer code qualification have often entailed my participation in specific measurement device developments or adaptations, in particular non-intrusive devices generally based on optical techniques. Being concerned about the end-use of this research work, I actively participated in 'in-situ' thermalhydraulic experiments in the FBRs: Phenix and Super-Phenix, of which I appreciated their undeniable scientific contribution. In my opinion, the thermal-hydraulic questions related to severe accidents are the most complex as they are at the cross-roads of several scientific specialities. Consequently, they require a multi-disciplinary approach and a continuous see-saw motion between experimentalists and modelling teams. After a brief description of the various problems encountered, the main ones are reported. Finally, the importance for research teams to

Lanthanide phosphonates: Synthesis, thermal stability and magnetic characterization

Energy Technology Data Exchange (ETDEWEB)

Amghouz, Z., E-mail: amghouz.uo@uniovi.es [Departamentos de Quimica Fisica y Analitica y Quimica Organica e Inorganica, Universidad de Oviedo - CINN, 33006 Oviedo (Spain); Garcia, J.R.; Garcia-Granda, S. [Departamentos de Quimica Fisica y Analitica y Quimica Organica e Inorganica, Universidad de Oviedo - CINN, 33006 Oviedo (Spain); Clearfield, A. [Department of Chemistry, Texas A and M University, College Station, TX 77842-3012 (United States); Rodriguez Fernandez, J.; Pedro, I. de [CITIMAC, Facultad de Ciencias, Universidad de Cantabria, 39005 Santander (Spain); Blanco, J.A. [Departamento de Fisica, Universidad de Oviedo, 33007 Oviedo (Spain)

2012-09-25

Highlights: Black-Right-Pointing-Pointer Report of the complete series of lanthanide 1,4-phenylbis(phosphonate). Black-Right-Pointing-Pointer Synthesis under conventional hydrothermal synthesis or microwave-assisted hydrothermal synthesis. Black-Right-Pointing-Pointer Cation size is the key factor for the structural and particles size variations. Black-Right-Pointing-Pointer Thermal behaviour is characterized by unusual very high thermal stability. - Abstract: Series of novel organic-inorganic hybrids materials based on trivalent lanthanides (Ln = Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) and 1,4-phenylbis(phosphonate) obtained under hydrothermal conditions either by oven heat or microwave irradiation. The anhydrous compounds containing La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, and Ho, are isostructural. However, the compounds based on Y, Er, Tm, Yb, and Lu are hydrated and their structures have not yet been solved. The series of compounds are characterized by PXRD, TEM, SEM-EDX and thermal analyses (TG-MS and DSC). TEM study show a variable particles size with a minimum mean-particle size of ca. 30 nm. These compounds exhibit unusual very high thermal stability. The size of particles and the thermal stability are depending on lanthanide(III) cation features. All the investigated materials show paramagnetic behaviour. The magnetic susceptibility data follow a Curie-Weiss laws with paramagnetic effective moments in good agreement with those expected for Ln{sup 3+} free ions.

Window opening behaviour modelled from measurements in Danish dwellings

DEFF Research Database (Denmark)

Andersen, Rune Korsholm; Fabi, Valentina; Toftum, Jorn

2013-01-01

environment.Measurements of occupant's window opening behaviour were conducted in 15 dwellings in Denmark during eight months. Indoor and outdoor environmental conditions were monitored in an effort to relate the behaviour of the occupants to the environmental conditions. The dwellings were categorized......A method of defining occupants' window opening behaviour patterns in simulation programs, based on measurements is proposed.Occupants' window opening behaviour has a strong effect on indoor environment and the energy consumed to sustain it. Only few models of window opening behaviour exist...... and these are solely based on the thermal indoor/outdoor environment. Consequently, users of simulation software are often left with little or no guidance for the modelling of occupants' window opening behaviour, resulting in potentially large discrepancies between real and simulated energy consumption and indoor...

Thermal behaviour of pure and binary Fe(NO3)3.9H2O and (NH4)6Mo7O24.4H2O systems

International Nuclear Information System (INIS)

Shaheen, W.M.

2007-01-01

Thermal behaviour of pure ferric nitrate, ammonium molybdate and their mixtures in different ratios were investigated by means of thermal analysis (TG, DTG and DTA) techniques. Relative thermal analysis (RTA) graphical treatment of derivatographic curves of the components in the pure and binary system has been carried out as well. A series of Fe 2 O 3 -MoO 3 systems were prepared from pure and binary salts by heating at 350, 550, 750 and 1000 deg. C. The X-ray diffraction (XRD) analysis was used to characterize the phases produced from thermal treatment of investigated solids. The results revealed that pure ferric nitrate decomposed to Fe 2 O 3 at 250, while pure ammonium molybdate decomposed into MoO 3 and 340 deg. C and then melted at 790 deg. C. For the binary components, crystalline ferric or molybdenum oxides were detected beside ferric molybdate Fe 2 (MoO 4 ) 3 phase starting from 350 deg. C. Fe 2 (MoO 4 ) 3 phase was formed as a result of solid-solid interactions between the produced oxides. The thermal stability of the formed compound was significantly affected by the composition of the mixture and treatment temperature. The presence of two-component solids in the binary systems affected the thermal decomposition of their individual salt and affected their physical and chemical behaviour. The catalytic activity of the obtained pure and mixed oxides was measured using the decomposition of hydrogen peroxide reaction as a model reaction at 20-50 deg. C. It was found that the mixed oxide solids had catalytic activity higher than single oxides thermally treated at 350 and 550 deg. C. This is attributed to the increase in the concentration of active sites via creation of new ion pairs in case of binary systems. The rise in calcination temperature up to 750 and 1000 deg. C brought about drastic decrease in the activity of all solids because of changing catalyst composition and/or sintering process. The activation energies of H 2 O 2 decomposition were determined

Microstructure analysis and damage patterns of thermally cycled Ti–49.7Ni (at.%) wires

International Nuclear Information System (INIS)

Karhu, Marjaana; Lindroos, Tomi

2012-01-01

Long-term behaviour and fatigue endurance are the key issues in the utilization of SMA actuators, but systematic research work is still needed in this field. This study concentrates on the effects of three major design parameters on the long-term behaviour of binary Ti–49.7Ni-based actuators: the effect of the temperature interval used on thermal cycling, the effect of the stress level used and the effect of the heat-treatment state of the wire used. The long-term behaviour of the wires was studied in a custom-built fatigue test frame in which the wires were thermally cycled under a constant stress level. Before the fatigue testing, a series of heat treatments was carried out to generate optimal actuator properties for the wires. This paper concentrates on the systematic fractographic analysis of the fatigue fractured Ti–49.7Ni wires. The aim was to discover the relationships between the macro-scale behaviour and the microstructural changes of the material. During thermal cycling the surfaces of the Ti–49.7Ni wires were examined with an optical microscope. Clear connections between the detected surface defects and fracture nucleation sites were not established. Multiple cracks were initiated and grew during thermal cycling. SEM examinations showed that the fracture surfaces can be divided into different and separate zones: a smooth surface region with radial marks indicating the fatigue crack propagation area, a rougher ductile fracture surface region area and the roughest surface region on the interface of these two surfaces. It was detected that the size of the crack propagation area is related to the fatigue lives of the thermally cycled wires. Surface cracking and subsequent crack growth proved to be responsible for the accumulation of fatigue damage in the studied wires. It was detected from the fracture surface cross-sections that cracks were not initiated at the oxide layer. The major factor for nucleating the surface cracking and then shortening the

Shopping behaviour and attribute evaluation of expatriates – A cross-cultural study

NARCIS (Netherlands)

Wijnen, G.J.; Kemperman, A.D.A.M.; Janssen, I.I.

2011-01-01

This study explores how shopping centre attributes can be adapted to culture-related shopping behaviour of expatriates. The study is relevant since only limited information is available on consumer behaviour of this target group and since insight in the heterogeneity of consumer shopping behaviour

The relation between intrapersonal and interpersonal staff behaviour towards clients with ID and challenging behaviour: a validation study of the Staff-Client Interactive Behaviour Inventory

NARCIS (Netherlands)

Willems, A.P.A.M; Embregts, P.J.C.M.; Stams, G.J.J.M.; Moonen, X.M.H.

2010-01-01

Background: Interpersonal staff behaviour is one of the instigating factors associated with challenging behaviour in clients with intellectual disabilities (ID). There are several studies focusing on the influence of intrapersonal staff characteristics - such as beliefs, attributions and emotional

Conceptual Thermal Treatment Technologies Feasibility Study

International Nuclear Information System (INIS)

Suer, A.

1996-01-01

This report presents a conceptual Thermal Treatment Technologies Feasibility Study (FS) for the Savannah River Site (SRS) focusing exclusively on thermal treatment technologies for contaminated soil, sediment, or sludge remediation projects

Occupant behaviour and robustness of building design

DEFF Research Database (Denmark)

Buso, Tiziana; Fabi, Valentina; Andersen, Rune Korsholm

2015-01-01

in a dynamic building energy simulation tool (IDA ICE). The analysis was carried out by simulating 15 building envelope designs in different thermal zones of an Office Reference Building in 3 climates: Stockholm, Frankfurt and Athens.In general, robustness towards changes in occupants' behaviour increased......Occupant behaviour can cause major discrepancies between the designed and the real total energy use in buildings. A possible solution to reduce the differences between predictions and actual performances is designing robust buildings, i.e. buildings whose performances show little variations...... with alternating occupant behaviour patterns. The aim of this work was to investigate how alternating occupant behaviour patterns impact the performance of different envelope design solutions in terms of building robustness. Probabilistic models of occupants' window opening and use of shading were implemented...

Integrated Monitoring of Mola mola Behaviour in Space and Time.

Science.gov (United States)

Sousa, Lara L; López-Castejón, Francisco; Gilabert, Javier; Relvas, Paulo; Couto, Ana; Queiroz, Nuno; Caldas, Renato; Dias, Paulo Sousa; Dias, Hugo; Faria, Margarida; Ferreira, Filipe; Ferreira, António Sérgio; Fortuna, João; Gomes, Ricardo Joel; Loureiro, Bruno; Martins, Ricardo; Madureira, Luis; Neiva, Jorge; Oliveira, Marina; Pereira, João; Pinto, José; Py, Frederic; Queirós, Hugo; Silva, Daniel; Sujit, P B; Zolich, Artur; Johansen, Tor Arne; de Sousa, João Borges; Rajan, Kanna

2016-01-01

Over the last decade, ocean sunfish movements have been monitored worldwide using various satellite tracking methods. This study reports the near-real time monitoring of fine-scale (vehicles to measure both the movements and the contextual environment of the fish. A total of four individuals were tracked using custom-made GPS satellite tags providing geolocation estimates of fine-scale resolution. These accurate positions further informed sunfish areas of restricted search (ARS), which were directly correlated to steep thermal frontal zones. Simultaneously, and for two different occasions, an Autonomous Underwater Vehicle (AUV) video-recorded the path of the tracked fish and detected buoyant particles in the water column. Importantly, the densities of these particles were also directly correlated to steep thermal gradients. Thus, both sunfish foraging behaviour (ARS) and possibly prey densities, were found to be influenced by analogous environmental conditions. In addition, the dynamic structure of the water transited by the tracked individuals was described by a Lagrangian modelling approach. The model informed the distribution of zooplankton in the region, both horizontally and in the water column, and the resultant simulated densities positively correlated with sunfish ARS behaviour estimator (rs = 0.184, pstructure provide a rationale for a predator's fine-scale behaviour observed over a two weeks in May 2014.

Fire behaviour - A preliminary study. | W.S.W. | African Journal of ...

African Journals Online (AJOL)

Fire behaviour - A preliminary study. ... be taken cognisance of in any future research on fire in relation to vegetation. Keywords: behaviour; botany; environmental conditions; fire; fire behaviour; fire ecology; fires; grass; grasses; management; rate of spread; recovery; south africa; vegetation; veld; veld management; yield ...

Study of the hydro-mechanical behaviour of expanded graphite gaskets; Etude du comportement et de l`etancheite de joints en graphite expnase

Energy Technology Data Exchange (ETDEWEB)

Patron, E. [Electricite de France (EDF), Direction des Etudes et Recherches, 92 - Clamart (France)

1997-12-31

The poro-mechanical behaviour models developed by O. Coussy permit to consider various phenomena observed experimentally: thermo-hydro-mechanical couplings, plasticity, etc. The aim of this study is to implement the simplest poro-mechanical model (i.e. the isotropic linear poro-elastic model) to model the gasket hydro-mechanical behaviour. First, isotropic poro-elastic characteristics of expanded graphite have been estimated from these tests conducted at Departement Mecanique et Technologie des Composants (MTC) and data from literature. Then, analytical solutions of the tightness tests developed at the MTC Department have been carried out. These calculations provide a first estimation of porosity variations during a tightness tests with metal/metal contact or in elastic recovery, and during a `hot thermal transient`. Thickness controlled numerical calculations have proved the analytical calculations relevance. With regard to simulation of tests with metal/metal contact or `hot thermal transient`, stress controlled numerical calculations have pointed out: - a greater vertical displacement on the inner side of the graphite ring and - a z dependence of the radial displacement and thus a porous differential variation between the upper and lower faces of the ring. (author). 21 refs.

Mechanical, Thermal Degradation, and Flammability Studies on Surface Modified Sisal Fiber Reinforced Recycled Polypropylene Composites

Directory of Open Access Journals (Sweden)

Arun Kumar Gupta

2012-01-01

Full Text Available The effect of surface treated sisal fiber on the mechanical, thermal, flammability, and morphological properties of sisal fiber (SF reinforced recycled polypropylene (RPP composites was investigated. The surface of sisal fiber was modified with different chemical reagent such as silane, glycidyl methacrylate (GMA, and O-hydroxybenzene diazonium chloride (OBDC to improve the compatibility with the matrix polymer. The experimental results revealed an improvement in the tensile strength to 11%, 20%, and 31.36% and impact strength to 78.72%, 77%, and 81% for silane, GMA, and OBDC treated sisal fiber reinforced recycled Polypropylene (RPP/SF composites, respectively, as compared to RPP. The thermogravimetric analysis (TGA, differential scanning calorimeter (DSC, and heat deflection temperature (HDT results revealed improved thermal stability as compared with RPP. The flammability behaviour of silane, GMA, and OBDC treated SF/RPP composites was studied by the horizontal burning rate by UL-94. The morphological analysis through scanning electron micrograph (SEM supports improves surface interaction between fiber surface and polymer matrix.

Engagement as a source of positive consumer behaviour: a study ...

African Journals Online (AJOL)

Engagement as a source of positive consumer behaviour: a study amongst South African football fans. ... Remember me ... Further, the potential of fan engagement as a predictor of positive consumer behaviours (match attendance and ...

Establishing the thermal threshold of the tropical mussel Perna viridis in the face of global warming.

Science.gov (United States)

Goh, B P L; Lai, C H

2014-08-30

With increasing recognition that maximum oxygen demand is the unifying limit in tolerance, the first line of thermal sensitivity is, as a corollary, due to capacity limitations at a high level of organisational complexity before individual, molecular or membrane functions become disturbed. In this study the tropical mussel Perna viridis were subjected to temperature change of 0.4 °C per hour from ambient to 8-36 °C. By comparing thermal mortality against biochemical indices (hsp70, gluthathione), physiological indices (glycogen, FRAP, NRRT) and behavioural indices (clearance rate), a hierarchy of thermal tolerance was therein elucidated, ranging from systemic to cellular to molecular levels. Generally, while biochemical indices indicated a stress signal much earlier than the more integrated behavioural indices, failure of the latter (indicating a tolerance limit and transition to pejus state) occurred much earlier than the other indices tending towards thermal extremities at both ends of the thermal spectrum. Copyright © 2013 Elsevier Ltd. All rights reserved.

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 ...

Thermally-assisted Magma Emplacement Explains Restless Calderas.

Science.gov (United States)

Amoruso, Antonella; Crescentini, Luca; D'Antonio, Massimo; Acocella, Valerio

2017-08-11

Many calderas show repeated unrest over centuries. Though probably induced by magma, this unique behaviour is not understood and its dynamics remains elusive. To better understand these restless calderas, we interpret deformation data and build thermal models of Campi Flegrei caldera, Italy. Campi Flegrei experienced at least 4 major unrest episodes in the last decades. Our results indicate that the inflation and deflation of magmatic sources at the same location explain most deformation, at least since the build-up of the last 1538 AD eruption. However, such a repeated magma emplacement requires a persistently hot crust. Our thermal models show that this repeated emplacement was assisted by the thermal anomaly created by magma that was intruded at shallow depth ~3 ka before the last eruption. This may explain the persistence of the magmatic sources promoting the restless behaviour of the Campi Flegrei caldera; moreover, it explains the crystallization, re-melting and mixing among compositionally distinct magmas recorded in young volcanic rocks. Our model of thermally-assisted unrest may have a wider applicability, possibly explaining also the dynamics of other restless calderas.

In-situ experiments for the determination of rock properties and behaviour at the Meuse/Haute Marne Centre

Directory of Open Access Journals (Sweden)

Conil N.

2010-06-01

Full Text Available Andra is in charge of studying the feasibility of a disposal facility for longlived high-level nuclear waste (LL-HLW in a deep geological environment. With this aim, dedicated experiments have been carried out for several years at the Meuse/Haute Marne Underground Research Laboratory excavated in a 500 m deep argillaceous rock formation. These experiments include determining the feasibility of the excavation of disposal cells for LL-HLW, consisting of 40 meter long, 70 cm in diameter, horizontal cased micro tunnels. The hydro mechanical impact of the excavation of such openings on the rock mass behaviour is continuously monitored as well as their mean term mechanical behaviour. Since LL-HLW produce heat, the impact of temperature on the surrounding rock mass and on the micro tunnel steel casing will also be studied. Specific instrumentation has been developed to study this impact. The first step of the microtunnel excavation tests, carried out in 2009, has led to improving the excavation method and the drilling machine. These improvements will be tested in the next step of the excavation tests planned for 2010. The THM experiment dedicated to studying the behaviour of the rock mass under thermal solicitation started early 2010. The behaviour of a steel casing in contact with the rock mass and under thermal solicitation will be studied in an experiment scheduled to start in September 2010.

Evaluation of a thermal SCWR core with sub-channel analysis

International Nuclear Information System (INIS)

Liu Xiaojing; Cheng Xu

2008-01-01

A previous study shows that the two-row fuel assembly has much more favorable neutron-physical and thermal-hydraulic behaviour than the existing one-row fuel assemblies. With this new developed two-row fuel assembly, a thermal SCWR core design is proposed Assessment of this design is carried out in this paper. The performance of this new core design is investigated with 3-D coupled thermal-hydraulic/neutronic calculations. During the coupling procedure, the thermal-hydraulic behaviour is analyzed using a single-channel code and the neutron-physical performance is computed with a 3-D reactor physical code. This paper presents the main results achieved so far related to the distribution of some neutronic and thermal-hydraulic parameters. Since the power distribution in some fuel assemblies is extremely uneven, sub-channel analysis is applied to the hottest and most non-uniform assembly in the core. The sub-channel analysis is performed with the power and thermal hydraulic parameters from the coupling results. It provides the hot channel factor and the maximal cladding surface temperature more precisely. The power and mass flux distribution in these assemblies are illustrated in detail for the demonstration purpose. The difference of the results evaluated with two different methods, i.e. sub-channel analysis and single-channel analysis, shows the importance of applying sub-channel analysis. A sensitivity analysis of some important parameters is also carried out. (author)

Building a foundation to study distributed information behaviour

Directory of Open Access Journals (Sweden)

Terry L. von Thaden

2007-01-01

Full Text Available Introduction. The purpose of this research is to assess information behaviour as it pertains to operational teams in dynamic safety critical operations. Method. In this paper, I describe some of the problems faced by crews on modern flight decks and suggest a framework modelled on Information Science, Human Factors, and Activity Theory research to assess the distribution of information actions, namely information identification, gathering and use, by teams of users in a dynamic, safety critical environment. Analysis. By analysing the information behaviour of crews who have accidents and those who do not, researchers may be able to ascertain how they (fail to make use of essential, safety critical information in their information environment. The ultimate goal of this research is to differentiate information behaviour among the distinct outcomes. Results. This research affords the possibility to discern differences in distributed information behaviour illustrating that crews who err to the point of an accident appear to practice different distributed information behaviour than those who do not. This foundation serves to operationalise team sense-making through illustrating the social practice of information structuring within the activity of the work environment. Conclusion. . The distributed information behaviour framework provides a useful structure to study the patterning and organization of information distributed over space and time, to reach a common goal. This framework may allow researchers and investigators alike to identify critical information activity in the negotiation of meaning in high reliability safety critical work, eventually informing safer practice. This framework is applicable to other domains.

Modelling the mechanical behaviour of heterogeneous Ta/TA6V welded joints: behaviour and failure criteria

International Nuclear Information System (INIS)

Paris, Th.

2008-12-01

As laser welding of two different materials (heterogeneous welding) leads to a joint having a characteristic size close to the millimetre, i.e. much smaller than that of a structure, and as such a junction displays completely different mechanical properties because of the metallurgical transformations induced by intense thermal loading, the aim of this research thesis is to develop a behaviour model, flexible and robust enough, to represent all together the mechanical behaviours of the Ta, the TA6V and the melted zone. This model must be able to take plasticity and visco-plasticity into account, and also to provide a failure criterion through damage mechanics and its coupling with the behaviour. The author first reports the experimental characterization of the base materials (Ta and TA6V) by using tensile tests under different strain rates and different directions, relaxation tests and fatigue shear tests. He also characterizes the melted zone by describing the influence of a thermal treatment (induced by welding) on the formation of the melted zone, and by using different tests: four point bending on notched specimens, nano-indentation test, and longitudinal tensile test. In a second part, the author develops the model within the framework of continuum thermodynamics, and explores the numerical issues. The last part deals with the validation of the model for the concerned materials (Ta and TA6V) and melted zone

Mathematical modelling and TMCP simulation for optimisation of steel behaviour

International Nuclear Information System (INIS)

Siwecki, T.

2001-01-01

Physically based mathematical models for prediction of steel behaviour and microstructure evolution in connection with thermal and thermomechanical controlled processing (TMCP) development in Swedish Institute for Metals Research are discussed. The models can be used for computer predictions of recrystallization and grain growth of austenite after deformation, precipitation or dissolution of microalloying carbonitride in austenite, flow stress during hot working, phase transformation behaviour during accelerated cooling as well as the final microstructure and mechanical properties. The database, which contains information about steel behaviour for a large number of HSLA steels, is also presented. Optimization of TMCP parameters for improving the properties of the steel are discussed in relation to the microstructure and mechanical properties. The effect of TMCP parameters (reheating temperature, rolling schedules and finish rolling temperature as well as accelerated control cooling) on steel properties was studied in laboratory scale. (author)

Thermal conductivity and thermal rectification in graphene nanoribbons: a molecular dynamics study.

Science.gov (United States)

Hu, Jiuning; Ruan, Xiulin; Chen, Yong P

2009-07-01

We have used molecular dynamics to calculate the thermal conductivity of symmetric and asymmetric graphene nanoribbons (GNRs) of several nanometers in size (up to approximately 4 nm wide and approximately 10 nm long). For symmetric nanoribbons, the calculated thermal conductivity (e.g., approximately 2000 W/m-K at 400 K for a 1.5 nm x 5.7 nm zigzag GNR) is on the similar order of magnitude of the experimentally measured value for graphene. We have investigated the effects of edge chirality and found that nanoribbons with zigzag edges have appreciably larger thermal conductivity than nanoribbons with armchair edges. For asymmetric nanoribbons, we have found significant thermal rectification. Among various triangularly shaped GNRs we investigated, the GNR with armchair bottom edge and a vertex angle of 30 degrees gives the maximal thermal rectification. We also studied the effect of defects and found that vacancies and edge roughness in the nanoribbons can significantly decrease the thermal conductivity. However, substantial thermal rectification is observed even in the presence of edge roughness.

Experimental investigation of the thermal conductivity of the green refractory concrete

International Nuclear Information System (INIS)

Santos, W.N. dos; Sylos Cintra Filho, J. de; Baldo, J.B.

1989-01-01

In this work the thermal conductivity of an aluminous refractory concrete, cured at 22 0 C and dried at 110 0 C is experimentally measured and the resulting behaviour is analysed as a function of temperature, from room temperature up to 1000 0 C. The experimental technique employed was the hot wire parallel technique, and the calculations which lead the the material thermal conductivity are carried out by using a non linear least squares fitting method. Experimental results show, among others, the strong influence of the adsorbed water in the behaviour of the thermal conductivity of the green refractory concrete, at temperatures below 200 0 C [pt

Behavioural fever is a synergic signal amplifying the innate immune response.

Science.gov (United States)

Boltaña, Sebastian; Rey, Sonia; Roher, Nerea; Vargas, Reynaldo; Huerta, Mario; Huntingford, Felicity Anne; Goetz, Frederick William; Moore, Janice; Garcia-Valtanen, Pablo; Estepa, Amparo; Mackenzie, S

2013-09-07

Behavioural fever, defined as an acute change in thermal preference driven by pathogen recognition, has been reported in a variety of invertebrates and ectothermic vertebrates. It has been suggested, but so far not confirmed, that such changes in thermal regime favour the immune response and thus promote survival. Here, we show that zebrafish display behavioural fever that acts to promote extensive and highly specific temperature-dependent changes in the brain transcriptome. The observed coupling of the immune response to fever acts at the gene-environment level to promote a robust, highly specific time-dependent anti-viral response that, under viral infection, increases survival. Fish that are not offered a choice of temperatures and that therefore cannot express behavioural fever show decreased survival under viral challenge. This phenomenon provides an underlying explanation for the varied functional responses observed during systemic fever. Given the effects of behavioural fever on survival and the fact that it exists across considerable phylogenetic space, such immunity-environment interactions are likely to be under strong positive selection.

Thermal conductivity of gypsum plasterboards : at ambient temperature and exposed to fire

NARCIS (Netherlands)

Korte, de A.C.J.; Brouwers, H.J.H.; Wald, F.; Kallerova, P.; Chlouba, J.

2009-01-01

One of the more complicated thermal properties to calculate for gypsum plasterboard is the thermal conductivity. The thermal conductivity is important because it plays an important role in the fire behaviour of gypsum plasterboards. Plasterboard often protects steel structures of buildings, because

Structural characterization and thermal behaviour of biological hydroxyapatite

Czech Academy of Sciences Publication Activity Database

Kohutová, A.; Honcová, P.; Svoboda, L.; Bezdička, Petr; Maříková, Monika

2012-01-01

Roč. 108, č. 1 (2012), s. 163-170 ISSN 1388-6150 Institutional research plan: CEZ:AV0Z40320502 Keywords : hydroxyapatite * hard tissues * X-ray powder diffraction * scanning electron microscope * thermal analysis * mass spectrometry Subject RIV: CA - Inorganic Chemistry Impact factor: 1.982, year: 2012

Patients' and practitioners' views on health behaviour change: a qualitative study.

Science.gov (United States)

Elwell, Laura; Povey, Rachel; Grogan, Sarah; Allen, Candia; Prestwich, Andrew

2013-01-01

This study was designed to examine patients' and health professionals' perspectives on lifestyle behaviour change and to inform the development of a lifestyle behaviour change intervention to be used in primary care. Focus groups were conducted with seven patients and 13 health professionals where they were asked to discuss lifestyle behaviour change in relation to the design and development phase of a tailored lifestyle behaviour change intervention package. An inductive thematic analysis of transcripts suggested a range of issues that are relevant to the development and implementation of lifestyle change interventions such as time, lack of resources and starting interventions too late, as well as personal circumstances and the continuous effort that behaviour change requires. They were interpreted as two superordinate themes of 'internal and external influences on behaviour change' and 'behaviour change initiation and maintenance'. The results are discussed in relation to the implications they may have for researchers and health service commissioners designing interventions and practitioners implementing lifestyle change interventions in primary care. Many factors are involved in patients' and health care professionals' understanding of interventions and lifestyle behaviour change. These should be taken into consideration when designing interventions based on behaviour change theories.

Thermal and hydraulic behaviour of CANDU cores under severe accident conditions - final report

International Nuclear Information System (INIS)

Rogers, J.T.

1984-06-01

This volume of appendices presents listings and sample runs of the computer codes used in the study of the thermalhydraulic behaviour of CANDU reactor cores during severe loss of coolant accidents. The codes, written in standard FORTRAN, are MODBOIL, to calculate moderator temperatures, pressures and water levels; DEBRIS, to calculate the transient temperature distribution in the debris of calandria and pressure tubes and fuel pellets; MOLTENPOOL, to calculate the temperature history in a pool of molten debris; CONFILM, to calculate the behaviour of a condensing film of vaporized core debris on the calandria wall, and BLDG, to calculate the pressurization of the containment during the expulsion of moderator through pressure relief ducts. In addition there are discussions of the average condensation heat transfer coefficient for vaporized core material on the calandria wall, and of vapor explosions

Contribution to the study of the thermal interaction between uranium oxide and sodium

International Nuclear Information System (INIS)

Newman, W.H.

1982-01-01

A description is given of the experimental results of the fuel-coolant interactions carried out in the CORECT II device at the Grenoble Nuclear Study Centre. A description is then given of a theoretical model of interaction which comprises three points: first a study of the coolant, that is to say of its hydrodynamic and thermodynamic behaviour, then the study of the fuel, namely the phenomena of fragmentation and heat transfer between the fuel and the coolant, and last the treatment of heat leaks to the structures. A study follows on the effect of the various parameters on the theoretical model as well as the effects of the assumptions on the fragmentation, transfer and losses of heat. Last, the interpretations of a few experiments carried out with two models of fragmentation are described. A discussion of these interpretations enables some generalizations to be made on the nature of the thermal interaction [fr

Thermal Nanosystems and Nanomaterials

CERN Document Server

Volz, Sebastian

2009-01-01

Heat transfer laws for conduction, radiation and convection change when the dimensions of the systems in question shrink. The altered behaviours can be used efficiently in energy conversion, respectively bio- and high-performance materials to control microelectronic devices. To understand and model those thermal mechanisms, specific metrologies have to be established. This book provides an overview of actual devices and materials involving micro-nanoscale heat transfer mechanisms. These are clearly explained and exemplified by a large spectrum of relevant physical models, while the most advanced nanoscale thermal metrologies are presented.

Behaviour of plasma spray coatings under disruption simulation

International Nuclear Information System (INIS)

Brossa, F.; Rigon, G.; Looman, B.

1988-01-01

The behaviour of metallic and ceramic protective coatings under disruption simulations was studied correlating the damage with their physical and structural parameters. Plasma Spray (PS) and Vacuum Plasma Spray (VPS) were the techniques used for the production of the coatings. W-5% Re was selected for divertor plates, and TiC, TiO 2 , Al 2 O 3 , low-Z ceramic materials for the first wall protection on 316 SS, Cu and Al as substrates. An electron beam gun was used to simulate the plasma disruptions. The tests were carried out from 0.6 to 6 MJ/m 2 . The thermal effects were studied by metallographic and EDXA analysis. The damage was observed comparing the degree of protection provided by each coating to discover the minimum thickness necessary to prevent the underlying material from melting. Good protective coatings must have a high melting point, great porosity and low thermal conductivity. Such coatings act as thermal barriers, increasing the surface temperature and radiating back large parts of the energy. (orig.)

Thermal fatigue of a 304L austenitic stainless steel: simulation of the initiation and of the propagation of the short cracks in isothermal and aniso-thermal fatigue

International Nuclear Information System (INIS)

Haddar, N.

2003-04-01

The elbow pipes of thermal plants cooling systems are submitted to thermal variations of short range and of variable frequency. These variations bound to temperature changes of the fluids present a risk of cracks and leakages. In order to solve this problem, EDF has started the 'CRECO RNE 808' plan: 'thermal fatigue of 304L austenitic stainless steels' to study experimentally on a volume part, the initiation and the beginning of the propagation of cracks in thermal fatigue on austenitic stainless steels. The aim of this study is more particularly to compare the behaviour and the damage of the material in mechanic-thermal fatigue (cycling in temperature and cycling in deformation) and in isothermal fatigue (the utmost conditions have been determined by EDF for the metal: Tmax = 165 degrees C and Tmin = 90 degrees C; the frequency of the thermal variations can reach a Hertz). A lot of experimental results are given. A model of lifetime is introduced and validated. (O.M.)

Preliminary study of coach verbal behaviour according to game actions

OpenAIRE

Guzmán Luján, José Francisco; Calpe Gómez, Vicente

2012-01-01

The aim of this study was to analyse the interaction between game actions in high-level handball and verbal behaviour performed by the coach. For this purpose, a match of the 1st National Division of male Spanish handball was analysed. The type of behaviour and the content of the message reported by the coach were recorded using a modified version of Coaching Behaviour Assessment System (CBAS) and Coach Analysis and Intervention System (CAIS). About game actions, they were grouped into positi...

Modeling of the dilution of thermal discharges into the sea

International Nuclear Information System (INIS)

Boulot, F.; Hauguel, A.

1981-01-01

The report describes the differences in behaviour existing between tidal and tideless oceans with resulting consequences for mathematical modeling of thermal discharges and their dispersion off the coast where plant is located. Examples of studies performed at sites on the Channel and in the Mediterranean sea are also explained [fr

Thermal Fatigue of Die-Casting Dies: An Overview

Directory of Open Access Journals (Sweden)

Abdulhadi Hassan A.

2016-01-01

Full Text Available Coupled studies by experimental and numerical simulations are necessary for an increased understanding of the material behaviour as related to the interaction between the thermal and mechanical conditions. This paper focus on the mechanisms of thermal fatigue in the failure of dies and cores used in the die casting of aluminum alloys. The thermal fatigue resistance is expressed by two crack parameters which are the average maximum crack and the average cracked area. Samples of various types of H13 steel were compared with a standard H13 steel by testing under identical thermal fatigue cycles. To determine the thermal constraint developed in the sample during the test, a finite difference technique was used to obtain the temperature distribution, based on temperature measurements at the boundaries. The resulting stresses and strains were computed, and the strain calculated at the edge or weakest point of the sample was used to correlate the number of cycles to crack initiation. As the strain at the edge increased, the number of cycles to failure decreased. The influence of various factors on thermal fatigue behavior was studied including austenitizing temperature, surface condition, stress relieving, casting, vacuum melting, and resulfurization. The thermal fatigue resistance improved as the austenitizing temperature increased from 1750 to 2050ºF.

Investigation of the electrochemical behaviour of thermally prepared ...

African Journals Online (AJOL)

Different IrO2 electrodes in which the molar percentage of platinum (Pt) varies from 0 %mol Pt to 100 %mol Pt were prepared on titanium (Ti) substrate by thermal decomposition techniques. The electrodes were characterized physically (SEM, XPS) and electrochemically and then applied to methanol oxidation. The SEM ...

Contribution of modulated DSc to study the thermal behaviour of PET films drawn in hot water

International Nuclear Information System (INIS)

Zumalian, Abubaker

2003-01-01

PET films uni-axially drawn in hot water are studied by means of conventional DSc and modulated DSc. The glass transition is studied by modulated DSc which allows access to the values of the glass transition temperature T g and the variations of δ C p = C p 1-C p g (difference between thermal capacity in the liquid-like and glassy states at T = T g ). Variations of T g with the water content (which act as plasticizer) and with the drawing (which rigidifies the amorphous phase) are discussed in regard to the structure engaged in these materials. The variations of δ C p are also interpreted with the help of a three phase model and a strong-fragile glass former liquid concept. We show that the fragility of the medium increases by the conjugated effects of deformation and water as soon as a strain induced crystalline phase is obtained, and it decreases drastically when the rigid amorphous phase occurs. (author)

Thermal and structural study of guava (Psidium guajava L powders obtained by two dehydration methods

Directory of Open Access Journals (Sweden)

Coralia Osorio

2011-01-01

Full Text Available Two food products (powders were obtained by hot-air drying or lyophilisation methods on the whole guava fruits. The powders were characterised by sensory and thermal analyses (TGA-DSC, infrared spectroscopy (IR, X-ray diffraction (XRD and scanning electron microscopy (SEM. Thermal, morphological and structural characterisations showed a similar behaviour for the two solids. TGA-DSC and IR showed the presence of pectin as the main constituent of solids. A semi-crystalline profile was evidenced by XRD, and lamellar/spherical morphologies were observed by SEM. Sensory analyses revealed an aroma highly related to guava. These value-added food products are an alternative to process guava and avoid loss during postharvest handling.

Shuttle APS propellant thermal conditioner study

Science.gov (United States)

Pearson, W. E.

1971-01-01

A study program was performed to allow selection of thermal conditioner assemblies for superheating O2 and H2 at supercritical pressures. The application was the auxiliary propulsion system (APS) for the space shuttle vehicle. The O2/H2 APS propellant feed system included propellant conditioners, of which the thermal conditioner assemblies were a part. Cryogens, pumped to pressures above critical, were directed to the thermal conditioner assembly included: (1) a gas generator assembly with ignition system and bipropellant valves, which burned superheated O2 and H2 at rich conditions; (2) a heat exchanger assembly for thermal conditioning of the cryogenic propellant; and (3) a dump nozzle for heat exchanger exhaust.

Mirror benders for high thermal loading

International Nuclear Information System (INIS)

Bailey, W.; Vickery, A.P.

1983-01-01

The thermal conditions in high power mirrors can be very complex and the exact calculation of their thermal behaviour requires very detailed calculations. However by making some simplifying assumptions it is possible to make an analysis which indicates the sort of performance that can be expected. Further by consideration of the simplifying assumptions it is possible to see how the design may contain features to mitigate the effects that occur in the real world. A simple treatment of thermal perturbations in mirror benders is presented. The design features which can help a bender to operate with a high thermal flux are looked at. In conclusion, the way to proceed to higher thermal loadings when passive methods prove inadequate is suggested. (author)

Thermal behaviour of selected Czech marble samples

Czech Academy of Sciences Publication Activity Database

Plevová, Eva; Kožušníková, Alena; Vaculíková, Lenka; Simha Martynková, G.

2010-01-01

Roč. 101, č. 2 (2010), s. 657-664 ISSN 1388-6150. [Conference on Calorimetry and Thermal Analysis /10./. Zakopane, 30.08.2009-03.09.2009] R&D Projects: GA ČR GP105/07/P416; GA ČR GA105/08/1398 Institutional research plan: CEZ:AV0Z30860518 Keywords : TMA * anisotropy * optical microscopy * marbles Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.752, year: 2010 http://www.springerlink.com/content/l47881208wk471t1/fulltext.pdf

The analogic model ''RIC'' of thermal behaviour of mass concrete

International Nuclear Information System (INIS)

Gonzalez Redondo, M.; Gonzalez de Posada, F.; Plana Claver, J.

1997-01-01

In order to study the thermal field and calorific flows in heat sources (i.e. mass concrete during setting) we have conceived, built and experimented with an analogical electric model. This model, named RIC, consists of resistors (R) and capacitors (C) in which nodes an electric current (I) has been injected. Several analogical constants were used for the mathematical approximation. Thus, this paper describes the analogical RIC model, simulating heat generation, boundary and initial conditions and concreting. (Author) 4 refs

Thermal shock behaviour of mullite-cordierite refractory materials

Czech Academy of Sciences Publication Activity Database

Boccaccini, D. N.; Leonelli, C.; Romagnoli, M.; Pellacani, G. C.; Veronesi, P.; Dlouhý, Ivo; Boccaccini, A. R.

2007-01-01

Roč. 106, č. 3 (2007), s. 142-148 ISSN 1743-6753 R&D Projects: GA AV ČR IAA200410502 Institutional research plan: CEZ:AV0Z20410507 Keywords : refraktory materials * thermal shock * fracutre toughness Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 1.074, year: 2007

Hazardous Health Behaviour among Medical Students: a Study from Turkey.

Science.gov (United States)

Nacar, Melis; Cetinkaya, Fevziye; Baykan, Zeynep; Yilmazel, Gulay; Elmali, Ferhan

2015-01-01

Hazardous health behaviour in young people is an important factor that affects the individual risk for non-communicable diseases and other disorders later in life. This study aimed to determine the hazardous health behaviour of first and last class medical students of Erciyes University. This descriptive study was carried out with 240 medical students from the first and 130 students from the last (sixth) class. Data were obtained by questionnaire between March-April 2012. In total, 339 students were included with a response rate of 91.6%. Socio-demographic characteristics, school success, self-reported economic difficulties, health perceptions, hazardous health behaviour related to chronic disease, tobacco, alcohol, substance use, body weight, height, traffic, violence and nutrition were assessed in line with the literature. Of the participants; 64.0% were from first and 36.0% were from the last class. Mean ages for the first and last classes were 19.4 ± 1.5 and 24.0 ± 1.5 years, respectively. In the current study, males exhibited more hazardous behaviour than females. Sime 19.8% of the students in the study group used alcohol, 35.4% used a waterpipe, and 24.8% used tobacco at least once. These rates increased in both genders in the last class and the increase in males was significant. Some 3.8% of the students in the current study used pleasure-inducing illegal substances at least once. All the students participating in the current study were single, the number of males reported not using condoms (8.6%) was 4.56 times higher compared to females. Some 64.0% of the students did not perform physical activity lasting at least 30 minutes for five times a week, 13.0% did not sleep for mean 7-8 hours daily, males having a 2.9 times higher risk. More than 1/3 of the students did not consume cooked vegetable dishes and 1/4 did not consume fresh fruits and salads, the rates were higher among males. In the current study, hazardous health behaviour was prevalent among

Models for MOX fuel behaviour. A selective review

International Nuclear Information System (INIS)

Massih, Ali R.

2006-01-01

This report reviews the basic physical properties of light water reactor mixed-oxide (MOX) fuel comprising nuclear characteristics, thermal properties such as melting temperature, thermal conductivity, thermal expansion, and heat capacity, and compares these with properties of conventional UO 2 fuel. These properties are generally well understood for MOX fuel and are well described by appropriate models developed for engineering analysis. Moreover, certain modelling approaches of MOX fuel in-reactor behaviour, regarding densification, swelling, fission product gas release, helium release, fuel creep and grain growth, are evaluated and compared with the models for UO 2 . In MOX fuel the presence of plutonium rich agglomerates adds to the complexity of fuel behaviour on the micro scale. In addition, we survey the recent fuel performance experience and post irradiation examinations on several types of MOX fuel types. We discuss the data from these examinations, regarding densification, swelling, fission product gas release and the evolution of the microstructure during irradiation. The results of our review indicate that in general MOX fuel has a higher fission gas release and helium release than UO 2 fuel. Part of this increase is due to the higher operating temperatures of MOX fuel relative to UO 2 fuel due to the lower thermal conductivity of MOX material. But this effect by itself seems to be insufficient to make for the difference in the observed fission gas release of UO 2 vs. MOX fuel. Furthermore, the irradiation induced creep rate of MOX fuel is higher than that of UO 2 . This effect can reduce the pellet-clad interaction intensity in fuel rods. Finally, we suggest that certain physical based approaches discussed in the report are implemented in the fuel performance code to account for the behaviour of MOX fuel during irradiation

Models for MOX fuel behaviour. A selective review

Energy Technology Data Exchange (ETDEWEB)

Massih, Ali R. [Quantum Technologies AB, Uppsala Science Park (Sweden)

2006-12-15

This report reviews the basic physical properties of light water reactor mixed-oxide (MOX) fuel comprising nuclear characteristics, thermal properties such as melting temperature, thermal conductivity, thermal expansion, and heat capacity, and compares these with properties of conventional UO{sub 2} fuel. These properties are generally well understood for MOX fuel and are well described by appropriate models developed for engineering analysis. Moreover, certain modelling approaches of MOX fuel in-reactor behaviour, regarding densification, swelling, fission product gas release, helium release, fuel creep and grain growth, are evaluated and compared with the models for UO{sub 2}. In MOX fuel the presence of plutonium rich agglomerates adds to the complexity of fuel behaviour on the micro scale. In addition, we survey the recent fuel performance experience and post irradiation examinations on several types of MOX fuel types. We discuss the data from these examinations, regarding densification, swelling, fission product gas release and the evolution of the microstructure during irradiation. The results of our review indicate that in general MOX fuel has a higher fission gas release and helium release than UO{sub 2} fuel. Part of this increase is due to the higher operating temperatures of MOX fuel relative to UO{sub 2} fuel due to the lower thermal conductivity of MOX material. But this effect by itself seems to be insufficient to make for the difference in the observed fission gas release of UO{sub 2} vs. MOX fuel. Furthermore, the irradiation induced creep rate of MOX fuel is higher than that of UO{sub 2}. This effect can reduce the pellet-clad interaction intensity in fuel rods. Finally, we suggest that certain physical based approaches discussed in the report are implemented in the fuel performance code to account for the behaviour of MOX fuel during irradiation.

Moderators of the intention-behaviour and perceived behavioural control-behaviour relationships for leisure-time physical activity

Directory of Open Access Journals (Sweden)

Godin Gaston

2008-02-01

Full Text Available Abstract Background Intention is a key determinant of action. However, there is a gap between intention and behavioural performance that remains to be explained. Therefore, the aim of this study was to identify moderators of the intention-behaviour and perceived behavioural control (PBC- behaviour relationships for leisure-time physical activity. Method This was tested in reference to Ajzen's Theory of Planned Behaviour. A sample of 300 volunteers, 192 women and 108 men, aged 18 to 55, participated in the study. At baseline, the participants completed a self-administrated psychosocial questionnaire assessing Ajzen's theory variables (i.e., intention and perceived behavioural control. The behavioural measure was obtained by mail three months later. Results Multiple hierarchical regression analyses indicated that age and annual income moderated the intention-behaviour and PBC-behaviour relationships. However, in the final model predicting behaviour (R2 = .46, only the interaction term of PBC by annual income (β = .24, p = 0.0003 significantly contributed to the prediction of behaviour along with intention (β = .49, p = 0.0009 and past behaviour (β = .44, p Conclusion Physical activity promotion programs would benefit not only from focusing on increasing the intention of low intenders, but also from targeting factors that moderate the perceived behavioural control-behaviour relationships.

Empowering behaviour and leader fairness and integrity: studying perceptions of ethical leader behaviour from a levels-of-analysis perspective

NARCIS (Netherlands)

de Hoogh, A.H.B.; den Hartog, D.N.

2009-01-01

Ethical leadership is seen as important by many researchers and practitioners. However, empirical research on ethical leader behaviour is limited and to date multilevel research is hardly found in this area. This study examines the relationships of two forms of perceived ethical leader behaviour

Thermal loading study for FY 1996. Volume 2

International Nuclear Information System (INIS)

1996-01-01

The primary objective of this study was to provide recommendations for Mined Geologic Disposal System requirements affected by thermal loading that will provide sufficient definition to facilitate development of design concepts and support life cycle cost determinations. The study reevaluated and/or redefined selected thermal goals used for design and are currently contained in the requirements documents or the Controlled Design Assumption Document. The study provided recommendations as to what, if any, actions (such as edge loading and limiting of the heat variability between waste packages) are needed and must be accommodated in the design. Additionally, the study provided recommendations as to what alternative thermal loads should be maintained for continued flexibility. This report contains seven appendices: Technical basis for evaluation of thermal goals below the potential nuclear was repository at Yucca Mountain; Thermal-mechanical evaluation of the 200 C drift-wall temperature goal; Evaluation of ground stability and support; Coupled ventilation and hydrothermal evaluations; Heat flow and temperature calculations for continuously ventilated emplacement drifts; Thermal management using aging and/or waste package selection; and Waste stream evaluations

Measurements of Silicon Detector Thermal Runaway

CERN Document Server

Heusch, C A; Moser, H G

1999-01-01

We measured thermal runaway properties of previously irradiated silicon detectors cooled by TPG bars. We simulated their expected behaviour to measure the energy gap in the detector material and to test the validity of various underlying assumptions.

Study on thermal wave based on the thermal mass theory

Institute of Scientific and Technical Information of China (English)

无

2009-01-01

The conservation equations for heat conduction are established based on the concept of thermal mass.We obtain a general heat conduction law which takes into account the spatial and temporal inertia of thermal mass.The general law introduces a damped thermal wave equation.It reduces to the well-known CV model when the spatial inertia of heat flux and temperature and the temporal inertia of temperature are neglected,which indicates that the CV model only considers the temporal inertia of heat flux.Numerical simulations on the propagation and superposition of thermal waves show that for small thermal perturbation the CV model agrees with the thermal wave equation based on the thermal mass theory.For larger thermal perturbation,however,the physically impossible phenomenon pre-dicted by CV model,i.e.the negative temperature induced by the thermal wave superposition,is eliminated by the general heat conduction law,which demonstrates that the present heat conduction law based on the thermal mass theory is more reasonable.

Study on thermal wave based on the thermal mass theory

Institute of Scientific and Technical Information of China (English)

HU RuiFeng; CAO BingYang

2009-01-01

The conservation equations for heat conduction are established based on the concept of thermal mass. We obtain a general heat conduction law which takes into account the spatial and temporal inertia of thermal mass. The general law introduces a damped thermal wave equation. It reduces to the well-known CV model when the spatial inertia of heat flux and temperature and the temporal inertia of temperature are neglected, which indicates that the CV model only considers the temporal inertia of heat flux. Numerical simulations on the propagation and superposition of thermal waves show that for small thermal perturbation the CV model agrees with the thermal wave equation based on the thermal mass theory. For larger thermal perturbation, however, the physically impossible phenomenon pre-dicted by CV model, i.e. the negative temperature induced by the thermal wave superposition, is eliminated by the general heat conduction law, which demonstrates that the present heat conduction law based on the thermal mass theory is more reasonable.

Large format lithium ion pouch cell full thermal characterisation for improved electric vehicle thermal management

Science.gov (United States)

Grandjean, Thomas; Barai, Anup; Hosseinzadeh, Elham; Guo, Yue; McGordon, Andrew; Marco, James

2017-08-01

It is crucial to maintain temperature homogeneity in lithium ion batteries in order to prevent adverse voltage distributions and differential ageing within the cell. As such, the thermal behaviour of a large-format 20 Ah lithium iron phosphate pouch cell is investigated over a wide range of ambient temperatures and C rates during both charging and discharging. Whilst previous studies have only considered one surface, this article presents experimental results, which characterise both surfaces of the cell exposed to similar thermal media and boundary conditions, allowing for thermal gradients in-plane and perpendicular to the stack to be quantified. Temperature gradients, caused by self-heating, are found to increase with increasing C rate and decreasing temperature to such an extent that 13.4 ± 0.7% capacity can be extracted using a 10C discharge compared to a 0.5C discharge, both at -10 °C ambient temperature. The former condition causes an 18.8 ± 1.1 °C in plane gradient and a 19.7 ± 0.8 °C thermal gradient perpendicular to the stack, which results in large current density distributions and local state of charge differences within the cell. The implications of these thermal and electrical inhomogeneities on ageing and battery pack design for the automotive industry are discussed.

Mesophase properties after anthracene thermal exposure

Czech Academy of Sciences Publication Activity Database

Šugárková, Věra; Plevová, Eva; Kaloč, M.

-, - (2008), s. 62-70. ISBN 978-80-248-1939-6 Grant - others:GA ČR GA105/00/1698 Institutional research plan: CEZ:AV0Z30860518 Keywords : mesophase * anthracene * thermal behaviour * anisotropy Subject RIV: CC - Organic Chemistry

The insensitivity of thermal preferences to various thermal gradient profiles in newts

Czech Academy of Sciences Publication Activity Database

Marek, Vojtěch; Gvoždík, Lumír

2012-01-01

Roč. 30, č. 1 (2012), s. 35-41 ISSN 0289-0771 R&D Projects: GA ČR GAP506/10/2170; GA MŠk LC06073 Institutional research plan: CEZ:AV0Z60930519 Keywords : Amphibians * Behavioural thermoregulation * Ectotherms * Preferred body temperature s * Thermal gradient * Triturus Subject RIV: EG - Zoology Impact factor: 1.000, year: 2012

Clay behaviour under thermal gradients elastic and plastic strains

International Nuclear Information System (INIS)

Pintado, Xavier; Autio, Jorma; Punkkinen, Olli

2010-01-01

Document available in extended abstract form only. The nuclear waste repositories will generate strong temperature gradients at the clay barrier. The heat and water transport generate volume change in the clay. An experimental work is proposed here. The clay reference is the MX-80. The test device imposes a fixed heat flow in one side of the sample and maintains constant the temperature on the other side. Two samples are tested for symmetry. The samples are unconfined and the total mass of water remains constant. This situation creates a strong thermal gradient in the samples. The final radial strains in some places of the sample, the total vertical strain and the water content distribution will be measured just at the end of the test and some weeks later in order to distinguish the elastic strains from the plastic strains. The test period mustn't be longer than two weeks because a large quantity of water loses through the rubber membrane and the heads of the sample. The maximum temperature reached in the cooper is 90 degrees because with higher temperature, the rubber membrane is damaged. This test is already simulated by a numerical code. Thermal, thermo-hydraulic and thermo-hydro-mechanical analyses are being done. These analyses allow studying the different fluxes inside the sample and its quantification. Water content distribution is compared with the water content calculated from the reference parameters in the clay. The water distribution and the change of diameter after the test will also be studied. This experimental work will allow to know what is the percentage of the strains elastic or plastic and check the mechanical model. The experimental diameter change is compared with the diameter change calculated from the reference parameters of the clay. (authors)

Experimental Preparation and Numerical Simulation of High Thermal Conductive Cu/CNTs Nanocomposites

Directory of Open Access Journals (Sweden)

Muhsan Ali Samer

2014-07-01

Full Text Available Due to the rapid growth of high performance electronics devices accompanied by overheating problem, heat dissipater nanocomposites material having ultra-high thermal conductivity and low coefficient of thermal expansion was proposed. In this work, a nanocomposite material made of copper (Cu reinforced by multi-walled carbon nanotubes (CNTs up to 10 vol. % was prepared and their thermal behaviour was measured experimentally and evaluated using numerical simulation. In order to numerically predict the thermal behaviour of Cu/CNTs composites, three different prediction methods were performed. The results showed that rules of mixture method records the highest thermal conductivity for all predicted composites. In contrast, the prediction model which takes into account the influence of the interface thermal resistance between CNTs and copper particles, has shown the lowest thermal conductivity which considered as the closest results to the experimental measurement. The experimentally measured thermal conductivities showed remarkable increase after adding 5 vol.% CNTs and higher than the thermal conductivities predicted via Nan models, indicating that the improved fabrication technique of powder injection molding that has been used to produced Cu/CNTs nanocomposites has overcome the challenges assumed in the mathematical models.

Thermally-induced crystallization behaviour of 80GeSe2–20Ga2Se3 glass as probed by combined X-ray diffraction and PAL spectroscopy

International Nuclear Information System (INIS)

Shpotyuk, O.; Calvez, L.; Petracovschi, E.; Klym, H.; Ingram, A.; Demchenko, P.

2014-01-01

Highlights: • Chalcogenide Ge–Ga–Se glasses were annealed at 380 °C for 10, 25 and 50 h. • Crystallization of glasses during annealing indicates formation of crystals. • Structural changes are described by two-state positron trapping model. • Modification leading to nucleation and fragmentation of free volume of glasses. • The Ge–Ga–Se systems cannot be classified as typical pseudo-binary system. -- Abstract: Crystallization behaviour of 80GeSe 2 –20Ga 2 Se 3 glass caused by thermal annealing at 380 °C for 10, 25 and 50 h are studied using X-ray diffraction and positron annihilation lifetime spectroscopy. It is shown that the structural changes caused by crystallization can be adequately described by positron trapping modes determined within two-state model. The observed changes in defect-related component in the fit of experimental positron lifetime spectra for annealed glasses testifies in a favour of structural fragmentation of larger free volume entities into smaller ones with preceding nucleation in the initial stage of thermal annealing. Because of strong deviation in defect-free bulk positron lifetime from corresponding additive values proper to boundary constituents, the studied glasses cannot be considered as typical representatives of pseudo-binary cut-section

Thermo-fluid behaviour of periodic cellular metals

CERN Document Server

Lu, Tian Jian; Wen, Ting

2013-01-01

Thermo-Fluid Behaviour of Periodic Cellular Metals introduces the study of coupled thermo-fluid behaviour of cellular metals with periodic structure in response to thermal loads, which is an interdisciplinary research area that requires a concurrent-engineering approach.  The book, for the first time, systematically adopts experimental, numerical, and analytical approaches, presents the fluid flow and heat transfer in periodic cellular metals under forced convection conditions, aiming to establish structure-property relationships for tailoring material structures to achieve properties and performance levels that are customized for defined multifunctional applications. The book, as a textbook and reference book, is intended for both academic and industrial people, including graduate students, researchers and engineers. Dr. Tian Jian Lu is a professor at the School of Aerospace, Xi’an Jiaotong University, Xi’an, China. Dr. Feng Xu is a professor at the Key Laboratory of Biomedical Information Engineering o...

Thermal shock behaviour of mullite-bonded porous silicon carbide ceramics with yttria addition

International Nuclear Information System (INIS)

Ding Shuqiang; Zeng Yuping; Jiang Dongliang

2007-01-01

Thermal shock resistance of mullite (3Al 2 O 3 · 2SiO 2 )-bonded porous silicon carbide (SiC) ceramics with 3.0 wt% yttria (Y 2 O 3 ) addition was evaluated by a water-quenching technique. The thermal shock damage was investigated as a function of the quenching temperature, quenching cycles and specimen thickness. The residual flexural strength of the quenched specimens decreases with increasing quenching temperature and specimen thickness due to the larger thermal stress caused by thermal shock. However, quenching cycles at the temperature difference of 1200 deg. C have no effect on the residual strength since the same thermal stress was produced in repeated thermal shock processes. The good thermal shock damage resistance of the specimens is contributed mainly by the low strength and moderate elastic modulus. Moreover, the pores prevent the continuous propagation of cracks and alleviate further damage

Can temperate insects take the heat? A case study of the physiological and behavioural responses in a common ant, Iridomyrmex purpureus (Formicidae), with potential climate change.

Science.gov (United States)

Andrew, Nigel R; Hart, Robert A; Jung, Myung-Pyo; Hemmings, Zac; Terblanche, John S

2013-09-01

Insects in temperate regions are predicted to be at low risk of climate change relative to tropical species. However, these assumptions have generally been poorly examined in all regions, and such forecasting fails to account for microclimatic variation and behavioural optimisation. Here, we test how a population of the dominant ant species, Iridomyrmex purpureus, from temperate Australia responds to thermal stress. We show that ants regularly forage for short periods (minutes) at soil temperatures well above their upper thermal limits (upper lethal temperature = 45.8 ± 1.3°C; CT(max) = 46.1°C) determined over slightly longer periods (hours) and do not show any signs of a classic thermal performance curve in voluntary locomotion across soil surface temperatures of 18.6-57°C (equating to a body temperature of 24.5-43.1°C). Although ants were present all year round, and dynamically altered several aspects of their thermal biology to cope with low temperatures and seasonal variation, temperature-dependence of running speed remained invariant and ants were unable to elevate high temperature tolerance using plastic responses. Measurements of microclimate temperature were higher than ant body temperatures during the hottest part of the day, but exhibited a stronger relationship with each other than air temperatures from the closest weather station. Generally close associations of ant activity and performance with microclimatic conditions, possibly to maximise foraging times, suggest I. purpureus displays highly opportunistic thermal responses and readily adjusts behaviour to cope with high trail temperatures. Increasing frequency or duration of high temperatures is therefore likely to result in an immediate reduction in foraging efficiency. In summary, these results suggest that (1) soil-dwelling temperate insect populations may be at higher risks of thermal stress with increased frequency or duration of high temperatures resulting from climate change than

Modeling of droplet dynamic and thermal behaviour during spray ...

Indian Academy of Sciences (India)

Unknown

Supersonic atomization; droplets; thermal history; solid fraction; secondary dendrite arm spacing. 1. Introduction .... velocity with distance as illustrated in (1) (Eon-Sik Lee and Ahn ...... Uhlenwinkel and U Fritsching (Bremen, Germany: Univer-.

Experimental study and modelling of high temperature creep flow and damage behaviour of 9Cr1Mo-NbV steel weldments

International Nuclear Information System (INIS)

Gaffard, V.

2004-12-01

Chromium martensitic stainless steels are under development since the 70's with the prospect of using them as structural components in thermal and nuclear power plants. The modified 9Cr1Mo-NbV steel is already used, especially in England and Japan, as a material for structural components in thermal power plants where welding is a commonly used joining technique. New generations of chromium martensitic stainless steels with improved mechanical properties for high pressure and temperature use are currently under development. However, observations of several in-service premature failures of welded components in 9Cr1Mo-NbV steel, outline a strong need for understanding the high temperature creep flow and damage behaviour of 9Cr1Mo-NbV steels and weldments. The present study aimed at experimentally determining and then modelling the high temperature creep flow and damage behaviour of both 9Cr1Mo-NbV steels and weldments (typically in the temperature range from 450 C to 650 C). The base metal was first studied as the reference material. It was especially evidenced that tempered chromium martensitic steels exhibit a change in both creep flow and damage behaviour for long term creep exposure. As a consequence, the classically performed extrapolation of 1,000 hours creep data to 100,000 hours creep lifetime predictions might be very hazardous. Based on experimental observations, a new model, integrating and coupling multiple creep flow and damage mechanisms, was developed in the framework of the mechanics of porous media. It was then successfully used to represent creep flow and damage behaviour of the base metal from high to low stress levels even for complex multiaxial loading conditions. Although the high temperature creep properties of the base metal are quite good, the occurrence of premature failure in weldments in high temperature creep conditions largely focused the attention of the scientific community. The lower creep strength of the weld component was also

Delamination behaviour of GdBCO coated conductor tapes under transverse tension

International Nuclear Information System (INIS)

Gorospe, A.; Nisay, A.; Dizon, J.R.; Shin, H.S.

2013-01-01

Highlights: •Installation of a test frame which gives precisely aligned transverse load. •Investigation of I c degradation behaviour depending on the type of sample delamination. •Inhomogeneity of the CC tapes caused large variation on delamination strength. •SEM and EDS analysis of delamination sites under transverse loading. -- Abstract: The electromechanical property behaviour of 2G coated conductor (CC) tapes fabricated by multi-layer deposition process both in the in-plane and transverse direction should be understood. The CC tapes are used in the fabrication of epoxy resin-impregnated coils. In such case, the Lorentz force due to the high magnetic field applied as well as the thermal stress due to the difference in coefficient of thermal expansion (CTE) among constituent layers during cooling to cryogenic temperature will induce transversely applied load to the surface of CC tapes in coils. Hence, the CC tape should have a good mechanical property in the transverse direction in order to maintain its superior performance under magnetic field. In this study, a test frame which gives precisely aligned transverse load was devised. Using the fixture, the delamination behaviours including the delamination strength of the GdBCO CC tapes under transverse tensile loading were investigated. Large variation on the delamination strength of the CC tapes was recorded and might have resulted from the slit edge effect and the inhomogeneity of the CC tapes. The I c degradation behaviour under transverse load was related to the location where delamination occurred in the sample

Development of Thermally Actuated, High Temperature Composite Morphing Concepts

Science.gov (United States)

2016-03-31

set of applications exists in gas turbine engines, which stand to benefit greatly from aerodynamic control in their combustors, turbines, and nozzles...Modelling Development 27 3.1 Mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 3.1.1 Achieving Snap-Through Behaviour ...Fabrication of Hybrid Laminate Shell and Strip Specimens . . . . . . 35 3.3.2 Measurement of Thermal Curvatures and Snap-Through Behaviour of Hybrid

Development of Thermally Actuated, High-Temperature Composite Morphing Concepts

Science.gov (United States)

2016-05-11

set of applications exists in gas turbine engines, which stand to benefit greatly from aerodynamic control in their combustors, turbines, and nozzles...Modelling Development 27 3.1 Mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 3.1.1 Achieving Snap-Through Behaviour ...Fabrication of Hybrid Laminate Shell and Strip Specimens . . . . . . 35 3.3.2 Measurement of Thermal Curvatures and Snap-Through Behaviour of Hybrid

Gas turbine blades and disks. Materials and component behaviour

International Nuclear Information System (INIS)

1990-01-01

This progress report summarizes the research results obtained by the special research programme 339 in the years 1988 and 1989. Emphasis is given to the following aspects and problems: Optimisation of structure, protective coatings, connection between structure parameters and mechanical materials behaviour, tribologic materials and component behaviour, impacts of overall loads, and of stress and deformation state in the inelastic regime under mechanical and thermal load, and impacts of the manufacturing process on component behaviour, quality assurance. Eleven of the fifteen papers of the report have been separately analysed for the ENERGY database, and thirteen for the DELURA database. (orig./MM) With 191 figs., 13 tabs [de

Thermal properties of heterogeneous fuels

International Nuclear Information System (INIS)

Staicu, D.; Beauvy, M.

1998-01-01

Fresh or irradiated nuclear fuels are composites or solid solutions more or less heterogeneous, and their thermal conductivities are strongly dependent on the microstructure. The effective thermal conductivities of these heterogeneous solids must be determined for the modelling of the behaviour under irradiation. Different methods (analytical or numerical) published in the literature can be used for the calculation of this effective thermal conductivity. They are analysed and discussed, but finally only few of them are really useful because the assumptions selected are often not compatible with the complex microstructures observed in the fuels. Numerical calculations of the effective thermal conductivity of various fuels based on the microstructure information provided in our laboratory by optical microscopy or electron micro-probe analysis images, have been done for the validation of these methods. The conditions necessary for accurate results on effective thermal conductivity through these numerical calculations are discussed. (author)

Face recognition in the thermal infrared domain

Science.gov (United States)

Kowalski, M.; Grudzień, A.; Palka, N.; Szustakowski, M.

2017-10-01

Biometrics refers to unique human characteristics. Each unique characteristic may be used to label and describe individuals and for automatic recognition of a person based on physiological or behavioural properties. One of the most natural and the most popular biometric trait is a face. The most common research methods on face recognition are based on visible light. State-of-the-art face recognition systems operating in the visible light spectrum achieve very high level of recognition accuracy under controlled environmental conditions. Thermal infrared imagery seems to be a promising alternative or complement to visible range imaging due to its relatively high resistance to illumination changes. A thermal infrared image of the human face presents its unique heat-signature and can be used for recognition. The characteristics of thermal images maintain advantages over visible light images, and can be used to improve algorithms of human face recognition in several aspects. Mid-wavelength or far-wavelength infrared also referred to as thermal infrared seems to be promising alternatives. We present the study on 1:1 recognition in thermal infrared domain. The two approaches we are considering are stand-off face verification of non-moving person as well as stop-less face verification on-the-move. The paper presents methodology of our studies and challenges for face recognition systems in the thermal infrared domain.

Thermal insulation of the high-temperature helium-cooled reactors

International Nuclear Information System (INIS)

Kharlamov, A.G.; Grebennik, V.N.

1979-01-01

Unlike the well-known thermal insulation methods, development of high-temperature helium reactors (HTGR) raises quite new problems. To understand these problems, it is necessary to consider behaviour of thermal insulation inside the helium circuit of HTGR and requirements imposed on it. Substantiation of these requirements is given in the presented paper

Deep ultra violet and visible Raman spectroscopy studies of ion implanted 6H-SiC: Recrytallisation behaviour and thermal decomposition/thermal etching of the near surface region

Energy Technology Data Exchange (ETDEWEB)

Kuhudzai, R.J., E-mail: rj.kuhudzai@tuks.co.za [Physics Department, University of Pretoria, Pretoria (South Africa); Malherbe, J.B.; Berg, N.G. van der; Hlatshwayo, T.T.; Odutemowo, O.; Prinsloo, L.C. [Physics Department, University of Pretoria, Pretoria (South Africa); Buys, A.V. [Laboratory for Microscopy and Microanalysis, University of Pretoria (South Africa); Erasmus, R. [School of Physics, University of the Witwatersrand, Johannesburg (South Africa); Wendler, E. [Institut Für Festköperphysik, Friedrich-Schiller-Universität Jena, Jena (Germany)

2015-12-15

The recystallisation behaviour and thermal decomposition of the near surface amorphised region of 6H-SiC have been investigated by Raman spectroscopy. 360 keV ions of iodine and silver were implanted at room temperature into wafers of 6H-SiC resulting in the amorphisation of the near surface region. Vacuum annealing of the samples was performed at 1200 °C for 5 h and then sequentially from 1200 to 1600 °C in steps of 100 °C for 30 h at each annealing temperature. Raman spectroscopy was performed using two laser wavelength excitation regimes, the 514 nm laser (visible region) and the 244 nm laser (deep ultraviolet region, DUV). Measurements in the visible region for samples annealed at 1200 °C for 5 h showed that the characteristic 6H-SiC peaks, namely, the Transverse Optical (TO) and Longitudinal Optical (LO) are similar to the virgin samples, albeit with lower intensity due to some retained defects upon recystallisation of the SiC surface region. The similarities between the virgin spectra and the annealed sample were due to the deep penetration of the 514 nm laser into 6H-SiC resulting in the signal from the bulk undamaged 6H-SiC contributing to the overall spectra. However, DUV laser excitation, which only probes the near surface region, shows that after annealing the peaks are broader and asymmetrical compared to the virgin samples. DUV Raman spectra of samples annealed at 1600 °C indicate that SiC has completely decomposed and the top surface layer is now covered by a carbon layer. However the deeper penetrating laser in the visible region showed that the extent of decomposition at 1600 °C was greater for the silver implanted samples than for the iodine implanted samples.

Thermal behaviour of nitrogen implanted into zirconium

International Nuclear Information System (INIS)

Miyagawa, S.; Ikeyama, M.; Saitoh, K.; Nakao, S.; Niwa, H.; Tanemura, S.; Miyagawa, Y.

1994-01-01

Zirconium films were implanted with 15 N ions of energy 50keV to a total fluence of 1x10 18 ionscm -2 in an attempt to study the formation process and thermal stability of ZrN layers produced by high fluence implantation of nitrogen. Subsequent to the implantation at room temperature, samples were annealed at temperatures of 300 C-900 C. The depth profiles of the implanted nitrogen were measured by nuclear reaction analysis using the 15 N(p,αγ) 12 C at E R =429keV, and the surfaces were examined by thin film X-ray diffraction (XRD) and scanning electron microscopy. There were many blisters 0.2-0.4μm in diameter on the surface of the as-implanted samples and double peaks were observed in the nitrogen depth profiles; they were in both sides of the mean projected range. It was found that most of the blisters became extinct after annealing above 400 C, and the XRD peak (111) intensity was increased with the increase in the annealing temperature. Moreover, 14 N and 15 N implantations were superimposed on Zr samples in order to study the atomic migration of nitrogen at each stage of high fluence implantation. It was found that the decrease in the peak at the deeper layers was related to blister extinction and nitrogen diffusion into underling zirconium which could be correlated with radiation damage induced by post-implanted ions. ((orig.))

The automated analysis of clustering behaviour of piglets from thermal images in response to immune challenge by vaccination.

Science.gov (United States)

Cook, N J; Bench, C J; Liu, T; Chabot, B; Schaefer, A L

2018-01-01

An automated method of estimating the spatial distribution of piglets within a pen was used to assess huddling behaviour under normal conditions and during a febrile response to vaccination. The automated method was compared with a manual assessment of clustering activity. Huddling behaviour was partly related to environmental conditions and clock time such that more huddling occurred during the night and at lower ambient air temperatures. There were no positive relationships between maximum pig temperatures and environmental conditions, suggesting that the narrow range of air temperatures in this study was not a significant factor for pig temperature. Spatial distribution affected radiated pig temperature measurements by IR thermography. Higher temperatures were recorded in groups of animals displaying huddling behaviour. Huddling behaviour was affected by febrile responses to vaccination with increased huddling occurring 3 to 8 h post-vaccination. The automated method of assessing spatial distribution from an IR image successfully identified periods of huddling associated with a febrile response, and to changing environmental temperatures. Infrared imaging could be used to quantify temperature and behaviour from the same images.

A STUDY OF THE CHANGING CONSUMER BUYING BEHAVIOUR IN ORGANISED RETAILING IN LUCKNOW CITY

OpenAIRE

Dr Zubair Ahmad

2018-01-01

The major factor of consumer behaviour in organised retailing is the changing buying behaviour. Various management thinkers have conducted several studies to understand the relationship of buying behaviour and organised retailing. Consumer behaviour is defined as the behaviour that consumers display in searching for, purchasing, using, evaluating and disposing of products and services that they expect will satisfy their needs. (L.G. Schiffman, L.L. Kanuk, 2005). Consumer buying behaviour ...

Thermal effects in highly dispersed iron catalysts

International Nuclear Information System (INIS)

Alvarez, A.M.; Cagnoli, M.V.; Gallegos, N.G.; Marchetti, S.G.; Yeramian, A.A.; Mercader, R.C.

1994-01-01

The Moessbauer spectra of three Fe/SiO 2 catalysts with 5 wt% iron content show the presence of several Fe species and display different magnetic behaviours when the precursors are subjected to various thermal treatments. Based on the Moessbauer parameters and CO chemisorption measurements, the average crystal sizes of the catalysts are estimated and discussed in connection with the thermal pretreatment severity and magnetic properties of the samples. (orig.)

Concept of scaled test facility for simulating the PWR thermalhydraulic behaviour

International Nuclear Information System (INIS)

Silva Filho, E.

1990-01-01

This work deals with the design of a scaled test facility of a typical pressurized water reactor plant, to simulation of small break Loss-of-Coolant Accident. The computer code RELAP 5/ MOD1 has been utilized to simulate the accident and to compare the test facility behaviour with the reactor plant one. The results demonstrate similar thermal-hydraulic behaviours of the two sistema. (author)

Modeling of the mechanical behaviour of welded structures: behaviour laws and rupture criteria; Modelisation du comportement mecanique de structures soudees: lois de comportement et criteres de rupture

Energy Technology Data Exchange (ETDEWEB)

Paris, T.; Delaplanche, D. [CEA Valduc, Laboratoire Calcul et Simulations, 21120 Is-sur-Tille (France); Saanouni, K. [LASMIS-CNRS-FRE 2719, Universite de Technologie de Troyes BP 2060 - 10010 Troyes - (France)

2006-07-01

In the framework of the technological developments carried out in the CEA, the analysis of the mechanical behaviour of the heterogeneous welded bonds Ta/TA6V is a main preoccupation. Indeed, the welding of these two materials which cannot be distinguished by their mechanical and thermal properties induces strong microstructural heterogeneities in the melted zone. In order to characterize the behaviour of the welded joints and to develop a model of mechanical behaviour, a four points bending test on a notched specimen has been developed and implemented. This new test has allowed to obtain a macroscopic response of strength-displacement type but to analyze too more finely, with an optical extensometry and images correlation method, the influence of the heterogeneities on the local deformation of the welded joint. The confrontation of these results to a metallurgical study allows to validate the first conclusions deduced of the mechanical characterization tests and to conclude as for the local mechanisms governing the behaviour and the damage of the melted zone. The mechanical behaviour can be restored by an elasto-viscoplastic model with isotropic and non linear kinematic strain hardening coupled to this damage. The proposed model allows to identify the macroscopic behaviour of the weld bead. (O.M.)

Urban area thermal monitoring: Liepaja case study using satellite and aerial thermal data

Science.gov (United States)

Gulbe, Linda; Caune, Vairis; Korats, Gundars

2017-12-01

The aim of this study is to explore large (60 m/pixel) and small scale (individual building level) temperature distribution patterns from thermal remote sensing data and to conclude what kind of information could be extracted from thermal remote sensing on regular basis. Landsat program provides frequent large scale thermal images useful for analysis of city temperature patterns. During the study correlation between temperature patterns and vegetation content based on NDVI and building coverage based on OpenStreetMap data was studied. Landsat based temperature patterns were independent from the season, negatively correlated with vegetation content and positively correlated with building coverage. Small scale analysis included spatial and raster descriptor analysis for polygons corresponding to roofs of individual buildings for evaluating insulation of roofs. Remote sensing and spatial descriptors are poorly related to heat consumption data, however, thermal aerial data median and entropy can help to identify poorly insulated roofs. Automated quantitative roof analysis has high potential for acquiring city wide information about roof insulation, but quality is limited by reference data quality and information on building types, and roof materials would be crucial for further studies.

Studies on thermal properties and thermal control effectiveness of a new shape-stabilized phase change material with high thermal conductivity

International Nuclear Information System (INIS)

Cheng Wenlong; Liu Na; Wu Wanfan

2012-01-01

In order to overcome the difficulty of conventional phase change materials (PCMs) in packaging, the shape-stabilized PCMs are proposed to be used in the electronic device thermal control. However, the conventional shape-stabilized PCMs have the drawback of lower thermal conductivity, so a new shape-stabilized PCM with high thermal conductivity, which is suitable for thermal control of electronic devices, is prepared. The thermal properties of n-octadecane-based shape-stabilized PCM are tested and analyzed. The heat storage/release performance is studied by numerical simulation. Its thermal control effect for electronic devices is also discussed. The results show that the expanded graphite (EG) can greatly improve the thermal conductivity of the material with little effect on latent heat and phase change temperature. When the mass fraction of EG is 5%, thermal conductivity has reached 1.76 W/(m K), which is over 4 times than that of the original one. Moreover, the material has larger latent heat and good thermal stability. The simulation results show that the material can have good heat storage/release performance. The analysis of the effect of thermal parameters on thermal control effect for electronic devices provides references to the design of phase change thermal control unit. - Highlights: ► A new shape-stabilized PCM with higher thermal conductivity is prepared. ► The material overcomes the packaging difficulty of traditional PCMs used in thermal control unit. ► The EG greatly improves thermal conductivity with little effect on latent heat. ► The material has high thermal stability and good heat storage/release performance. ► The effectiveness of the material for electronic device thermal control is proved.

Degradation Behaviour of Gamma Irradiated Poly(Acrylic Acid)-graft-Chitosan Superabsorbent Hydrogel

Science.gov (United States)

Ria Barleany, Dhena; Ilhami, Alpin; Yusuf Yudanto, Dea; Erizal

2018-03-01

A series of superabsorbent hydrogels were prepared from chitosan and partially neutralized acrylic acid at room temperature by gamma irradiation technique. The effect of irradiation and chitosan addition to the degradation behaviour of polymer were investigated. The gel content, swelling capacity, Equillibrium Degree of Swelling (EDS), Fourier Transform Infra Red (FTIR), and Scanning Electron Microscopy (SEM) study were also performed. Natural degradation in soil and thermal degradation by using of TGA analysis were observed. The variation of chitosan compositions were 0.5, 1, 1.5, and 2 g and the total irradiation doses were 5, 10, 15, and 20 kGy. The highest water capacity of 583.3 g water/g dry hydrogel was resulted from 5 kGy total irradiation dose and 0,5 g addition of chitosan. From the thermal degradation evaluation by using of TGA analysis showed that irradiation dose did not give a significant influence to the degradation rate. The rate of thermal degradation was ranged between 2.42 to 2.55 mg/min. In the natural test of degradation behaviour by using of soil medium, the hydrogel product with chitosan addition was found to have better degradability compared with the poly(acrylic acid) polymer without chitosan.

Negative Symptoms and Avoidance of Social Interaction: A Study of Non-Verbal Behaviour.

Science.gov (United States)

Worswick, Elizabeth; Dimic, Sara; Wildgrube, Christiane; Priebe, Stefan

2018-01-01

Non-verbal behaviour is fundamental to social interaction. Patients with schizophrenia display an expressivity deficit of non-verbal behaviour, exhibiting behaviour that differs from both healthy subjects and patients with different psychiatric diagnoses. The present study aimed to explore the association between non-verbal behaviour and symptom domains, overcoming methodological shortcomings of previous studies. Standardised interviews with 63 outpatients diagnosed with schizophrenia were videotaped. Symptoms were assessed using the Clinical Assessment Interview for Negative Symptoms (CAINS), the Positive and Negative Syndrome Scale (PANSS) and the Calgary Depression Scale. Independent raters later analysed the videos for non-verbal behaviour, using a modified version of the Ethological Coding System for Interviews (ECSI). Patients with a higher level of negative symptoms displayed significantly fewer prosocial (e.g., nodding and smiling), gesture, and displacement behaviours (e.g., fumbling), but significantly more flight behaviours (e.g., looking away, freezing). No gender differences were found, and these associations held true when adjusted for antipsychotic medication dosage. Negative symptoms are associated with both a lower level of actively engaging non-verbal behaviour and an increased active avoidance of social contact. Future research should aim to identify the mechanisms behind flight behaviour, with implications for the development of treatments to improve social functioning. © 2017 S. Karger AG, Basel.

Theoretical study of laser feedback interferometry for dynamical material's behaviour studies

International Nuclear Information System (INIS)

Le-Barbier, Laura

2017-01-01

The purpose of this thesis is to study the feasibility of optical feedback interferometry (OFI) for measuring velocities for dynamical material's behaviour studies. Dynamical material's behaviour studies permit to analyse the shocked material when subjects to shocks (laser shocks, isentropic compression, projectiles, etc.). In these conditions, we seek to measure velocities up to 10 km/s. The OFI technique is regularly used as an embedded system to measure slow velocities in various fields. However, very few studies have been performed for determining velocities measurement limits for this system. As a matter of fact, the optical feedback induces nonlinear effects into the laser's cavity: it disrupts the laser's emitted optical power. Depending on the optical feedback strength, the laser can show chaotic behaviour, then it is no longer possible to get the information for the target's velocity or displacement regarding the signal. In this study, we have been developing mathematical models and performing a wide range of numerical simulations to study the performances and the limits of the OFI technique. We have been also studying the influence of the targets reflectivity, the length and the modulation frequency of the external cavity. (author) [fr

Grip on challenging behaviour: a multidisciplinary care programme for managing behavioural problems in nursing home residents with dementia. Study protocol

NARCIS (Netherlands)

Zwijsen, S.A.; Smalbrugge, M.; Zuidema, S.U.; Koopmans, R.T.C.M.; Bosmans, J.E.; Tulder, M.W. van; Eefsting, J.A.; Gerritsen, D.L.; Pot, A.M.

2011-01-01

BACKGROUND: Behavioural problems are common in nursing home residents with dementia and they often are burdensome for both residents and nursing staff. In this study, the effectiveness and cost-effectiveness of a new care programme for managing behavioural problems will be evaluated. METHODS/DESIGN:

Grip on challenging behaviour: a multidisciplinary care programme for managing behavioural problems in nursing home residents with dementia. Study protocol

NARCIS (Netherlands)

Zwijsen, S.A.; Smalbrugge, M.; Zuidema, S.U.; Koopmans, R.T.C.M.; Bosmans, J.E.; van Tulder, M.W.; Eefsting, J.A.; Gerritsen, D.L.; Pot, A.M.

2011-01-01

Background: Behavioural problems are common in nursing home residents with dementia and they often are burdensome for both residents and nursing staff. In this study, the effectiveness and cost-effectiveness of a new care programme for managing behavioural problems will be evaluated. Methods/Design.

Synthesis, microstructure and thermal expansion studies

Indian Academy of Sciences (India)

Abstract. We report on the synthesis, microstructure and thermal expansion studies on Ca0.5+/2Sr0.5+/2Zr4P6−2Si2O24 ( = 0.00 to 1.00) system which belongs to NZP family of low thermal expansion ceramics. The ceramics synthesized by co-precipitation method at lower calcination and the sintering temperatures ...

Design and simulation of a low concentrating photovoltaic/thermal system

International Nuclear Information System (INIS)

Rosell, J.I.; Vallverdu, X.; Lechon, M.A.; Ibanez, M.

2005-01-01

The advantages of photovoltaic/thermal (PV/T) collectors and low solar concentration technologies are combined into a photovoltaic/thermal system to increase the solar energy conversion efficiency. This paper presents a prototype 11X concentration rate and two axis tracking system. The main novelty is the coupling of a linear Fresnel concentrator with a channel photovoltaic/thermal collector. An analytical model to simulate the thermal behaviour of the prototype is proposed and validated. Measured thermal performance of the solar system gives values above 60%. Theoretical analysis confirms that thermal conduction between the PV cells and the absorber plate is a critical parameter

A new approach for categorizing pig lying behaviour based on a Delaunay triangulation method.

Science.gov (United States)

Nasirahmadi, A; Hensel, O; Edwards, S A; Sturm, B

2017-01-01

Machine vision-based monitoring of pig lying behaviour is a fast and non-intrusive approach that could be used to improve animal health and welfare. Four pens with 22 pigs in each were selected at a commercial pig farm and monitored for 15 days using top view cameras. Three thermal categories were selected relative to room setpoint temperature. An image processing technique based on Delaunay triangulation (DT) was utilized. Different lying patterns (close, normal and far) were defined regarding the perimeter of each DT triangle and the percentages of each lying pattern were obtained in each thermal category. A method using a multilayer perceptron (MLP) neural network, to automatically classify group lying behaviour of pigs into three thermal categories, was developed and tested for its feasibility. The DT features (mean value of perimeters, maximum and minimum length of sides of triangles) were calculated as inputs for the MLP classifier. The network was trained, validated and tested and the results revealed that MLP could classify lying features into the three thermal categories with high overall accuracy (95.6%). The technique indicates that a combination of image processing, MLP classification and mathematical modelling can be used as a precise method for quantifying pig lying behaviour in welfare investigations.

Evaluating the impact of method bias in health behaviour research: a meta-analytic examination of studies utilising the theories of reasoned action and planned behaviour.

Science.gov (United States)

McDermott, Máirtín S; Sharma, Rajeev

2017-12-01

The methods employed to measure behaviour in research testing the theories of reasoned action/planned behaviour (TRA/TPB) within the context of health behaviours have the potential to significantly bias findings. One bias yet to be examined in that literature is that due to common method variance (CMV). CMV introduces a variance in scores attributable to the method used to measure a construct, rather than the construct it represents. The primary aim of this study was to evaluate the impact of method bias on the associations of health behaviours with TRA/TPB variables. Data were sourced from four meta-analyses (177 studies). The method used to measure behaviour for each effect size was coded for susceptibility to bias. The moderating impact of method type was assessed using meta-regression. Method type significantly moderated the associations of intentions, attitudes and social norms with behaviour, but not that between perceived behavioural control and behaviour. The magnitude of the moderating effect of method type appeared consistent between cross-sectional and prospective studies, but varied across behaviours. The current findings strongly suggest that method bias significantly inflates associations in TRA/TPB research, and poses a potentially serious validity threat to the cumulative findings reported in that field.

Temperature effect on the behaviour of engineered clay barriers

International Nuclear Information System (INIS)

Tang, A.M.

2005-11-01

The present work deals with the thermo-hydro-mechanical behaviour of compacted swelling clay used for engineered barriers in high-level radioactive repositories. The MX80 bentonite was chosen for this work. Firstly, an experimental work on the thermal conductivity of the compacted bentonite was performed. The results evidenced the effects of dry density, water content, volumetric fraction of soil components, microstructure, and mineralogy. This experimental work gave rise to the proposition of a theoretical model for estimate the thermal conductivity of compacted bentonites. Secondly, after a calibration of suction generated by saturated saline solution in function of temperature, water retention curves were determined at different temperatures. The experimental results showed a decrease of the water retention capacity of soil after heating. A simple model based on the interfacial tension air-water was formulated to simulate this effect. Thirdly, a new isotropic cell enabling a simultaneous control of suction, temperature and mechanical stress was developed. With this new cell, an experimental work on the thermo-mechanical behaviour of the unsaturated compacted bentonite was performed. Finally, a constitutive model was developed for simulate the thermo-hydro-mechanical behaviours obtained experimentally. (author)

Sexual behaviour of women in rural South Africa: a descriptive study

Directory of Open Access Journals (Sweden)

Jan Henk Dubbink

2016-07-01

Full Text Available Abstract Background Sexual behaviour is a core determinant of the HIV and sexually transmitted infection (STI epidemics in women living in rural South Africa. Knowledge of sexual behaviour in these areas is limited, but constitutes essential information for a combination prevention approach of behavioural change and biomedical interventions. Methods This descriptive study was conducted in rural Mopani District, South Africa, as part of a larger study on STI. Women of reproductive age (18–49 years who reported sexual activity were included regardless of the reason for visiting the facility. Questionnaires were administered to 570 women. We report sexual behaviour by age group, ethnic group and self-reported HIV status. Results Young women (34 years; there was no difference for condom use during last sex act (36 % overall. Sotho women were more likely to report concurrent sexual partners whereas Shangaan women reported more frequent intravaginal cleansing and vaginal scarring practice in our analysis. HIV-infected women were older, had a higher number of lifetime sexual partners, reported more frequent condom use during the last sex act and were more likely to have a known HIV-infected partner than women without HIV infection; hormonal contraceptive use, fellatio, and a circumcised partner were less often reported. Conclusions This study provides insight into women’s sexual behaviour in a rural South African region. There are important differences in sexual behaviour by age group and ethnicity and HIV status; these should be taken into account when designing tailor-made prevention packages.

Study Behaviour: A counselling approach | Okpechi | Global Journal ...

African Journals Online (AJOL)

The researcher recommended that students should take their studies seriously as their failure and success lies on it. He equally draws the attention of students to the essentials of study behaviour, time management, organisation of study task, etc. Global Journal of Educational Research Vol. 5 (1&2) 2006: pp. 5-11 ...

Coordination behaviour of some f-block elements with o-vanillin and its derivatives (Paper No. AL-09)

International Nuclear Information System (INIS)

Agarwala, B.V.; Shukla, M.K.; Hingorani, S.

1990-02-01

Five new complexes of La(III), Ce(III) and UO 2 have been prepared with o-vanillin and its derivatives. Their coordination behaviour and structural elucidation have been described by elemental, magnetic moments, IR, electronic spectral and thermal studies. (author). 1 tab

Econometric Studies of Stock Market Behaviour

DEFF Research Database (Denmark)

Rasmussen, Anne-Sofie Reng

This thesis consists of three sefcontained essays, all centering around the topic of stock market behaviour. The papers focus on the empirical performance of a number of asset pricing models, all attempting to quantify and price asset risk. We look at how well these models actually do in describing...... the historic behaviour of the stock market, allowing us to get further insight into what drives the markes....

Thermal behaviour of solar air heater with compound parabolic concentrator

International Nuclear Information System (INIS)

Tchinda, Rene

2008-01-01

A mathematical model for computing the thermal performance of an air heater with a truncated compound parabolic concentrator having a flat one-sided absorber is presented. A computer code that employs an iterative solution procedure is constructed to solve the governing energy equations and to estimate the performance parameters of the collector. The effects of the air mass flow rate, the wind speed and the collector length on the thermal performance of the present air heater are investigated. Predictions for the performance of the solar heater also exhibit reasonable agreement, with experimental data with an average error of 7%

Theoretical Modelling Methods for Thermal Management of Batteries

Directory of Open Access Journals (Sweden)

Bahman Shabani

2015-09-01

Full Text Available The main challenge associated with renewable energy generation is the intermittency of the renewable source of power. Because of this, back-up generation sources fuelled by fossil fuels are required. In stationary applications whether it is a back-up diesel generator or connection to the grid, these systems are yet to be truly emissions-free. One solution to the problem is the utilisation of electrochemical energy storage systems (ESS to store the excess renewable energy and then reusing this energy when the renewable energy source is insufficient to meet the demand. The performance of an ESS amongst other things is affected by the design, materials used and the operating temperature of the system. The operating temperature is critical since operating an ESS at low ambient temperatures affects its capacity and charge acceptance while operating the ESS at high ambient temperatures affects its lifetime and suggests safety risks. Safety risks are magnified in renewable energy storage applications given the scale of the ESS required to meet the energy demand. This necessity has propelled significant effort to model the thermal behaviour of ESS. Understanding and modelling the thermal behaviour of these systems is a crucial consideration before designing an efficient thermal management system that would operate safely and extend the lifetime of the ESS. This is vital in order to eliminate intermittency and add value to renewable sources of power. This paper concentrates on reviewing theoretical approaches used to simulate the operating temperatures of ESS and the subsequent endeavours of modelling thermal management systems for these systems. The intent of this review is to present some of the different methods of modelling the thermal behaviour of ESS highlighting the advantages and disadvantages of each approach.

Thermal enhancement of charge and discharge cycles for adsorbed natural gas storage

KAUST Repository

Rahman, Kazi Afzalur

2011-07-01

The usage of adsorbed natural gas (ANG) storage is hindered by the thermal management during the adsorption and desorption processes. An effective thermal enhancement is thus essential for the development of the ANG technology and the motivation for this study is the investigation of a gas storage system with internal thermal control. We employed a fin-tube type heat exchanger that is placed in a pressurized cylinder. A distributed-parameter model is used for the theoretical modeling and simulations are conducted at assorted charging and discharging conditions. These studies included the transient thermal behaviours of the elements within the ANG-charged cylinder and parameters such as pressure and temperature profiles of adsorbent have been obtained during charge and discharge cycles, and results are compared with a conventional compressed methane vessel. © 2011 Elsevier Ltd. All rights reserved.

Micromechanical modelling of fuel viscoplastic behaviour

International Nuclear Information System (INIS)

Masson, R.; Blanc, V.; Gatt, J.M.; Julien, J.; Michel, B.; Largenton, R.

2015-01-01

To identify the effect of microstructural parameters on the viscoplastic behaviour of nuclear fuels, micromechanical (also called homogenisation) approaches are used. These approaches aim at deriving effective properties of heterogeneous material from the properties of their constituents. They stand on full-field computations of representative volume elements of microstructures as well as on mean-field semi-analytical models. For light water reactor fuels, these approaches have been applied to the modelling of the effect of two microstructural parameters: the porosity effects on the thermal creep of dioxide uranium fuels (transient conditions of irradiation) as well as the plutonium content effect on the viscoplastic behaviour (nominal conditions of irradiations) of mixed oxide fuels (MOX). (authors)

Effect of ultrafiltration process on physico-chemical, rheological, microstructure and thermal properties of syrups from male and female date palm saps.

Science.gov (United States)

Makhlouf-Gafsi, Ines; Baklouti, Samia; Mokni, Abir; Danthine, Sabine; Attia, Hamadi; Blecker, Christophe; Besbes, Souhail; Masmoudi, Manel

2016-07-15

This study investigates the effect of the ultrafiltration process on physicochemical, rheological, microstructure and thermal properties of syrups from male and female date palm sap. All the studied syrups switched from pseudoplastic rheological behaviour (n=0.783) to Newtonian behaviour (n∼1) from 10 to 50 °C respectively and present similar thermal profiles. Results revealed that the ultrafiltration process significantly affects the rheological behaviour of the male and female syrups. These differences on rheological properties are attributed to the variation of chemical composition between sap and sap permeate syrups. Furthermore, the effect of temperature on viscosity of the syrups was investigated during heating and cooling processes at the same shear rate (50s(-1)). This study provides idea of the stability of the syrup by evaluating the area between heating and cooling curves. Actually, the syrup prepared from male sap permeate is the most stable between the four studied syrups. Copyright © 2016 Elsevier Ltd. All rights reserved.

VUJE's experience in the field of thermal-hydraulic behaviour of WWER

International Nuclear Information System (INIS)

Klepach, J.

1995-01-01

The thermal-hydraulic behavior (THB) of NPP coolant system and its consequences to nuclear safety of WWER reactors in previous Czechoslovakia has been studied in the VUJE (Nuclear Power Plants Research Institute, Trnava, SK). The institute takes part in the development and verification of its own (SLAP, LENKA, PUMKO, SICHTA, TRACO etc.) and international (DYNAMIKA5) codes for thermal-hydraulic analysis. The verification efforts are concentrated on the WWER specific features such as horizontal steam generators, control and safety system functioning, etc. The whole range of NPP accident analyses is covered by the VUJe staff. The author outlined briefly the WWER specific features as design and implemented improvements in Bohunice V-1 and Mochovce V-1 (WWER 230 model). The pros and cons of the WWER design compared against western type PWR are described. It is believed that although the WWERs are designed under the rules and standards of 1960s, their safety and operational performance can be improved to acceptable level by thorough analysis and appropriate measures. 5 figs

Thermal fatigue. Fluid-structure interaction at thermal mixing events

International Nuclear Information System (INIS)

Schuler, X.; Herter, K.H.; Moogk, S.; Laurien, E.; Kloeren, D.; Kulenovic, R.; Kuschewski, M.

2012-01-01

In the framework of the network research project ''Thermal Fatigue - Basics of the system-, outflow- and material-characteristics of piping under thermal fatigue'' funded by the German Federal Ministry of Education and Research (BMBF) fundamental numerical and experimental investigations on the material behaviour under transient thermal-mechanical stress conditions (high cycle fatigue - HCF) are carried out. The project's background and its network of scientific working groups with their individual working tasks are briefly introduced. The main focus is especially on the joint research tasks within the sub-projects of MPA and IKE which are dealing with thermal mixing of flows in a T-junction configuration and the fluidstructure- interactions (FSI). Therefore, experiments were performed with the newly established FSI test facility at MPA which enables single-phase flow experiments of water in typical power plant piping diameters (DN40 and DN80) at high pressure (maximum 75 bar) and temperatures (maximum 280 C). The experimental results serve as validation data base for numerical modelling of thermal flow mixing by means of thermo-fluid dynamics simulations applying CFD techniques and carried out by IKE as well as for modelling of thermal and mechanical loads of the piping structure by structural mechanics simulations with FEM methods which are executed by MPA. The FSI test facility will be described inclusively the applied measurement techniques, e. g. in particular the novel near-wall LED-induced Fluorescence method for non-intrusive flow temperature measurements. First experimental data and numerical results from CFD and FEM simulations of the thermal mixing of flows in the T-junction are presented.

Sexual behaviours and associated factors among students at Bahir Dar University: a cross sectional study

OpenAIRE

Mulu, Wondemagegn; Yimer, Mulat; Abera, Bayeh

2014-01-01

Background Sexual behaviour is the core of sexuality matters in adolescents and youths. Their modest or dynamic behaviour vulnerable them to risky sexual behaviours. In Ethiopia, there is scarcity of multicentered representative data on sexual behaviours in students to have a national picture at higher education. This study therefore conducted to assess sexual behaviours and associated factors at Bahir Dar University, Ethiopia. Methods A cross sectional study was conducted among Bahir Dar Uni...

Mechanism of crack initiation and crack growth under thermal and mechanical fatigue loading

Energy Technology Data Exchange (ETDEWEB)

Utz, S.; Soppa, E.; Silcher, H.; Kohler, C. [Stuttgart Univ. (Germany). Materials Testing Inst.

2013-07-01

The present contribution is focused on the experimental investigations and numerical simulations of the deformation behaviour and crack development in the austenitic stainless steel X6CrNiNb18-10 under thermal and mechanical cyclic loading in HCF and LCF regimes. The main objective of this research is the understanding of the basic mechanisms of fatigue damage and the development of simulation methods, which can be applied further in safety evaluations of nuclear power plant components. In this context the modelling of crack initiation and crack growth inside the material structure induced by varying thermal or mechanical loads are of particular interest. The mechanisms of crack initiation depend among other things on the type of loading, microstructure, material properties and temperature. The Nb-stabilized austenitic stainless steel in the solution-annealed condition was chosen for the investigations. Experiments with two kinds of cyclic loading - pure thermal and pure mechanical - were carried out and simulated. The fatigue behaviour of the steel X6CrNiNb18-10 under thermal loading was studied within the framework of the joint research project [4]. Interrupted thermal cyclic tests in the temperature range of 150 C to 300 C combined with non-destructive residual stress measurements (XRD) and various microscopic investigations, e.g. in SEM (Scanning Electron Microscope), were used to study the effects of thermal cyclic loading on the material. This thermal cyclic loading leads to thermal induced stresses and strains. As a result intrusions and extrusions appear inside the grains (at the surface), at which microcracks arise and evolve to a dominant crack. Finally, these microcracks cause a continuous and significant decrease of residual stresses. The fatigue behaviour of the steel X6CrNiNb18-10 under mechanical loading at room temperature was studied within the framework of the research project [5], [8]. With a combination of interrupted LCF tests and EBSD

Mechanism of crack initiation and crack growth under thermal and mechanical fatigue loading

International Nuclear Information System (INIS)

Utz, S.; Soppa, E.; Silcher, H.; Kohler, C.

2013-01-01

The present contribution is focused on the experimental investigations and numerical simulations of the deformation behaviour and crack development in the austenitic stainless steel X6CrNiNb18-10 under thermal and mechanical cyclic loading in HCF and LCF regimes. The main objective of this research is the understanding of the basic mechanisms of fatigue damage and the development of simulation methods, which can be applied further in safety evaluations of nuclear power plant components. In this context the modelling of crack initiation and crack growth inside the material structure induced by varying thermal or mechanical loads are of particular interest. The mechanisms of crack initiation depend among other things on the type of loading, microstructure, material properties and temperature. The Nb-stabilized austenitic stainless steel in the solution-annealed condition was chosen for the investigations. Experiments with two kinds of cyclic loading - pure thermal and pure mechanical - were carried out and simulated. The fatigue behaviour of the steel X6CrNiNb18-10 under thermal loading was studied within the framework of the joint research project [4]. Interrupted thermal cyclic tests in the temperature range of 150 C to 300 C combined with non-destructive residual stress measurements (XRD) and various microscopic investigations, e.g. in SEM (Scanning Electron Microscope), were used to study the effects of thermal cyclic loading on the material. This thermal cyclic loading leads to thermal induced stresses and strains. As a result intrusions and extrusions appear inside the grains (at the surface), at which microcracks arise and evolve to a dominant crack. Finally, these microcracks cause a continuous and significant decrease of residual stresses. The fatigue behaviour of the steel X6CrNiNb18-10 under mechanical loading at room temperature was studied within the framework of the research project [5], [8]. With a combination of interrupted LCF tests and EBSD

Determination of thermal conductivity in foundry mould mixtures

Directory of Open Access Journals (Sweden)

G. Solenički

2010-01-01

Full Text Available For a thorough understanding of the behaviour of foundry mould mixtures, a good knowledge of thermal properties of mould materials is needed. Laboratory determination of thermal conductivity of mould mixtures enables a better control over scabbing defects which are a major problem in green sand mould mixtures. A special instrument has been designed for that purpose and it is described in this work.

Study on thermal conductive BN/novolac resin composites

International Nuclear Information System (INIS)

Li, Shasha; Qi, Shuhua; Liu, Nailiang; Cao, Peng

2011-01-01

Highlights: → Boron nitride (BN) particles were used to modify novolac resin. → BN particles were pretreated by γ-aminopropyltriethoxysilane. → The thermal conductivity trend of composite almost agrees with the predicted data from the Maxwell-Eucken model. → At BN concentration of 80 wt.%, thermal conductivity value of composite is 4.5 times that of pure novolac resin. → Combined use of the larger and smaller particles with a mass ratio of 1:2 provides the composites with the maximum thermal conductivity among the testing systems. → The composite thermal property also increases with an increase in the BN concentration. - Abstract: In this study, γ-aminopropyltriethoxysilane-treated boron nitride (BN) particles were used to modify novolac resin. The effect of varying the BN concentration, particle size, and hybrid BN fillers with the binary particle size distribution on the thermal conductivity of the composites was investigated. Scanning electron microscopy (SEM) imaging showed homogeneously dispersed treated BN particles in the matrix. Furthermore, the thermal conductivity increased as the BN concentration was increased. This behavior was also observed when the filler size was increased. Experimentally obtained thermal conductivity values agree with the predicted data from the Maxwell-Eucken model well at less than 70 wt.% BN loading. A larger particle size BN-filled novolac resin exhibits a higher thermal conductivity than a smaller particle size BN-filled one. The combined use of 0.5 and 15 μm particles with a mass ratio of 2:1 achieved the maximum thermal conductivity among the testing systems. The thermal resistance properties of the composites were also studied.

Thermal fatigue behaviour for a 316 L type steel

Science.gov (United States)

Fissolo, A.; Marini, B.; Nais, G.; Wident, P.

1996-10-01

This paper deals with initiation and growth of cracks produced by thermal fatigue loadings on 316 L steel, which is a reference material for the first wall of the next fusion reactor ITER. Two types of facilities have been built. As for true components, thermal cycles have been repeatedly applied on the surface of the specimen. The first is mainly concerned with initiation, which is detected with a light microscope. The second allows one to determine the propagation of a single crack. Crack initiation is analyzed using the French RCC-MR code procedure, and the strain-controlled isothermal fatigue curves. To predict crack growth, a model previously proposed by Haigh and Skelton is applied. This is based on determination of effective stress intensity factors, which takes into account both plastic strain and crack closure phenomena. It is shown that estimations obtained with such methodologies are in good agreement with experimental data.

Thermal preference of juvenile Dover sole (Solea solea in relation to thermal acclimation and optimal growth temperature.

Directory of Open Access Journals (Sweden)

Edward Schram

Full Text Available Dover sole (Solea solea is an obligate ectotherm with a natural thermal habitat ranging from approximately 5 to 27°C. Thermal optima for growth lie in the range of 20 to 25°C. More precise information on thermal optima for growth is needed for cost-effective Dover sole aquaculture. The main objective of this study was to determine the optimal growth temperature of juvenile Dover sole (Solea solea and in addition to test the hypothesis that the final preferendum equals the optimal growth temperature. Temperature preference was measured in a circular preference chamber for Dover sole acclimated to 18, 22 and 28°C. Optimal growth temperature was measured by rearing Dover sole at 19, 22, 25 and 28°C. The optimal growth temperature resulting from this growth experiment was 22.7°C for Dover sole with a size between 30 to 50 g. The temperature preferred by juvenile Dover sole increases with acclimation temperature and exceeds the optimal temperature for growth. A final preferendum could not be detected. Although a confounding effect of behavioural fever on temperature preference could not be entirely excluded, thermal preference and thermal optima for physiological processes seem to be unrelated in Dover sole.

Contribution of thermal infrared images on the understanding of the subsurface/atmosphere exchanges on Earth.

Science.gov (United States)

Lopez, Teodolina; Antoine, Raphaël; Baratoux, David; Rabinowicz, Michel

2017-04-01

High temporal resolution of space-based thermal infrared images (METEOSAT, MODIS) and the development of field thermal cameras have permitted the development of thermal remote sensing in Earth Sciences. Thermal images are influenced by many factors such as atmosphere, solar radiation, topography and physico-chemical properties of the surface. However, considering these limitations, we have discovered that thermal images can be used in order to better understand subsurface hydrology. In order to reduce as much as possible the impact of these perturbing factors, our approach combine 1) field observations and 2) numerical modelling of surface/subsurface thermal processes. Thermal images of the Piton de la Fournaise volcano (Réunion Island), acquired by hand, show that the Formica Leo inactive scoria cone and some fractures close to the Bory-Dolomieu caldera are always warmer, inducing a thermal difference with the surrounding of at least 5°C and a Self-Potential anomaly [1, 2]. Topography cannot explain this thermal behaviour, but Piton de la Fournaise is known as highly permeable. This fact allows the development of an air convection within the whole permeable structure volcanic edifice [2]. Cold air enters the base of the volcano, and exits warmer upslope, as the air is warmed by the geothermal flow [1,2]. Then, we have decided to understand the interaction between subsurface hydrogeological flows and the humidity in the atmosphere. In the Lake Chad basin, regions on both sides of Lake Chad present a different thermal behaviour during the diurnal cycle and between seasons [3]. We propose that this thermal behaviour can only be explained by lateral variations of the surface permeability that directly impact the process of evaporation/condensation cycle. These studies bring new highlights on the understanding of the exchanges between subsurface and the atmosphere, as the presence of a very permeable media and/or variations of the surface permeability may enhance or

Modelling of thermal and mechanical behaviour of pebble beds

International Nuclear Information System (INIS)

Boccaccini, L.V.; Buehler, L.; Hermsmeyer, S.; Wolf, F.

2001-01-01

FZK (Forshungzentrum Karlsruhe) is developing a Helium Cooled Pebble Bed (HCPB) Blanket Concept for fusion power reactors based on the use of ceramic breeder materials and beryllium multiplier in the form of pebble beds. The design of such a blanket requires models and computer codes describing the thermal-mechanical behavior of pebble beds to evaluate the temperatures, stresses, deformations and mechanical interactions between pebble beds and the structure with required accuracy and reliability. The objective to describe the beginning of life condition for the HCPB blanket seems near to be reached. Mechanical models that describe the thermo-mechanical behavior of granular materials used in form of pebble beds are implemented in a commercial structure code. These models have been calibrated using the results of a large series of dedicated experiments. The modeling work is practically concluded for ceramic breeder; it will be carried on in the next year for beryllium to obtain the required correlations for creep and the thermal conductivity. The difficulties for application in large components (such as the HCPB blanket) are the limitations of the present commercial codes to manage such a set of constitutive equations under complex load conditions and large mesh number. The further objective is to model the thermal cycles during operation; the present correlations have to be adapted for the release phase. A complete description of the blanket behavior during irradiation is at the present out of our capability; this objective requires an extensive R and D program that at the present is only at the beginning. (Y.Tanaka)

A prediction of rate-dependent behaviour in ferroelectric polycrystals

International Nuclear Information System (INIS)

Kim, Sang-Joo

2007-01-01

Rate-dependent behaviour of a polycrystalline ferroelectric material is predicted based on thermal activation theory and a representative volume element model. First, the behaviour of a ferroelectric single crystal is calculated from a recently proposed three-dimensional free energy model [S.J. Kim, S. Seelecke, Int. J. Solids Struct. 44 (2007) 1196-1209]. Then, from the calculated single crystal responses, poling behaviour of a ferroelectric polycrystal is obtained in three different ways, two representative volume element models and Gaussian integration method. It is found that a dodecahedron representative volume element consisting of 210 crystallites is the best choice among the three methods. Finally, the behaviour of a ferroelectric polycrystal under various electric and stress loads is calculated using the chosen RVE model. The calculated responses are compared qualitatively with experimental observations, and the effects of crystal orientation and polycrystallinity are discussed

Influence of Cu, Co and Ni cations incorporated in brucite-type layers on thermal behaviour of hydrotalcites and reducibility of the derived mixed oxide systems

Energy Technology Data Exchange (ETDEWEB)

Chmielarz, Lucjan; Kustrowski, Piotr; Rafalska-Lasocha, Alicja; Dziembaj, Roman

2002-01-03

Thermal decomposition of M-Mg-Al-CO{sub 3}-NO{sub 3} hydrotalcites (where M is Cu{sup 2+}, Co{sup 2+} or Ni{sup 2+}) with intended M/Mg (0.10/0.61) and M/Al (0.10/0.29) ratios prepared under the same conditions was studied using high temperature X-ray diffraction (HT-XRD) and thermogravimetry coupling with mass spectrometry (TGA-DTA-MS). Introduction of transition metals to the brucite-like layers of hydrotalcites changed their thermal behaviour. The decomposition of nitrate or carbonate anions was coupled with oxidation from Ni{sup 2+} to Ni{sup 3+} and Co{sup 2+} to Co{sup 3+}. Further increase of temperature resulted in reduction of these cations. Reduction from Cu{sup 2+} to Cu{sup +} was also observed above 700 deg. C. Stabilisation of carbonate anions by Cu{sup 2+} introduced into hydrotalcite matrix was found at temperatures above 600 deg. C. The thermal treatment of hydrotalcite precursors resulted in the formation of mixed oxide and spinel phases, which were stable after cooling to ambient temperature with exception of CuO phase that appeared during cooling down due to segregation effects. Reducibility of the hydrotalcites calcined at different temperatures was determined by temperature-programmed reduction (TPR) experiments. Specific surface areas of hydrotalcites calcined at 600 deg. C ranged from 226 to 196 m{sup 2}/g dropping with increase in the calcination temperatures to values ranging between 138 and 49 m{sup 2}/g depending on transition metal contents.

Analysis of the thermal fragmentation as a mechanism for the initiation of steam explosion

International Nuclear Information System (INIS)

Lamome, J.; Meignen, R.

2007-01-01

We propose a theoretical study of the film behaviour and its stability during the phenomenon of drop thermal fragmentation. We discuss the role of the various possible influences on the film collapse and instability processes. First, we discuss the possibility of simple fuel/coolant contacts as a mechanism for the drop instability. Under this assumption, we then describe and test our model on Nelson and Duda explodability maps, with a particular emphasis on the description of the film evolution. The reasonable agreement obtained allows us to analyse the effect of various parameters as the ambient pressure, subcooling and trigger pulse shape on the film behaviour in Nelson and Duda experiments. The perspectives of this work are then shortly discussed including extrapolation to more prototypic situations and the role of thermal fragmentation itself. (authors)

Experimental thermal hydraulics in support of FBR

International Nuclear Information System (INIS)

Padmakumar, G.; Anand Babu, C.; Kalyanasundaram, P.; Vaidyanathan, G.

2009-01-01

The thermal hydraulic design plays a crucial role for the safe and economical deployment of Liquid Metal Cooled Fast Breeder Reactor (LMFBR). Robust experimental programmes are required in support of LMFBR thermal hydraulics design. The philosophy of testing has been to construct small scale models to understand the physical behaviour and to build larger scale models to optimize the component design. The experiments are conducted either in sodium or using a simulant like water/air. The paper gives a brief account of the various thermal hydraulic experiments carried out in support of the design of Prototype Fast Breeder Reactor (PFBR). (author)

Behavioural Spillover in the Environmental Domain: An Intervention Study

DEFF Research Database (Denmark)

Lanzini, Pietro; Thøgersen, John

2014-01-01

This study tests hypotheses about behavioural spillover in the environmental domain as well as the impacts of monetary inducements and verbal praise on behavioural spillover by means of a field experiment. A sample of 194 students from a large university in Denmark were randomly allocated...... to a control group or to one of two experimental conditions where they were encouraged to purchase "green" products by means of either financial compensation and incentives or verbal encouragement and praise. Participants answered a baseline survey containing questions concerning a wide range...... of environmentally relevant behaviours and after a six weeks intervention period where they were requested to keep track of their purchases by means of a shopping diary they answered a second survey with the same content as the first. This allowed us to analyse the change in self-reported pro- environmental...

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

Science.gov (United States)

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

1995-05-01

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

"Why not bathe the baby today?": A qualitative study of thermal care beliefs and practices in four African sites.

Science.gov (United States)

Adejuyigbe, Ebunoluwa Aderonke; Bee, Margaret Helen; Amare, Yared; Omotara, Babatunji Abayomi; Iganus, Ruth Buus; Manzi, Fatuma; Shamba, Donat Dominic; Skordis-Worrall, Jolene; Odebiyi, Adetanwa; Hill, Zelee Elizabeth

2015-10-14

Recommendations for care in the first week of a newborn's life include thermal care practices such as drying and wrapping, skin to skin contact, immediate breastfeeding and delayed bathing. This paper examines beliefs and practices related to neonatal thermal care in three African countries. Data were collected in the same way in each site and included 16-20 narrative interviews with recent mothers, eight observations of neonatal bathing, and in-depth interviews with 12-16 mothers, 9-12 grandmothers, eight health workers and 0-12 birth attendants in each site. We found similarities across sites in relation to understanding the importance of warmth, a lack of opportunities for skin to skin care, beliefs about the importance of several baths per day and beliefs that the Vernix caseosa was related to poor maternal behaviours. There was variation between sites in beliefs and practices around wrapping and drying after delivery, and the timing of the first bath with recent behavior change in some sites. There was near universal early bathing of babies in both Nigerian sites. This was linked to a deep-rooted belief about body odour. When asked about keeping the baby warm, respondents across the sites rarely mentioned recommended thermal care practices, suggesting that these are not perceived as salient. More effort is needed to promote appropriate thermal care practices both in facilities and at home. Programmers should be aware that changing deep rooted practices, such as early bathing in Nigeria, may take time and should utilize the current beliefs in the importance of neonatal warmth to facilitate behaviour change.

Spectroscopic, thermal and biological studies of coordination

Indian Academy of Sciences (India)

Spectroscopic, thermal and biological studies of coordination compounds of sulfasalazine drug: Mn(II), Hg(II), Cr(III), ZrO(II), VO(II) and Y(III) transition metal ... The thermal decomposition of the complexes as well as thermodynamic parameters ( *}, *, * and *) were estimated using Coats–Redfern and ...

Use of stable sulphur isotopes to monitor directly the behaviour of sulphur in coal during thermal desulphurization

Science.gov (United States)

Liu, Chao-Li; Hackley, Keith C.; Coleman, D.D.

1987-01-01

A method has been developed using stable sulphur isotope analyses to monitor the behaviour of sulphur forms in a coal during thermal desulphurization. In this method, the natural stable isotopic composition of the pyritic and organic sulphur in coal is used as a tracer to follow their mobility during the desulphurization process. This tracer method is based on the fact that the isotopic compositions of pyritic and organic sulphur are significantly different in some coals. Isotopic results of pyrolysis experiments at temperatures ranging from 350 to 750 ??C indicate that the sulphur released with the volatiles is predominantly organic sulphur. The pyritic sulphur is evolved in significant quantities only when pyrolysis temperatures exceed 500 ??C. The presence of pyrite seems to have no effect on the amount of organic sulphur evolved during pyrolysis. The chemical and isotopic mass balances achieved from three different samples of the Herrin (No. 6) coal of the Illinois Basin demonstrate that this stable isotope tracer method is quantitative. The main disadvantage of this tracing technique is that not all coals contain isotopically distinct organic and pyritic sulphur. ?? 1987.

Hyperhidrosis-psychiatric Study and Behaviour Therapy

Directory of Open Access Journals (Sweden)

P V Pradhan

1984-01-01

Full Text Available Eleven patients suffering from hyperhidrosis were psychiatrically studied. Seven of them were given behaviour therapy. Majority of the patients had -an unhappy childhood and long - standing and continuing psychological stress. None of them had obvious, coexisting psychiatric condition.. Thus, hyperhidrosis was the sole, expression of their psychological conflicts. Of the 7 patients treated 71% showed improvement with relaxation and systemic desentiziation which,was maintained for a_ period of at least 6 months.

The behavioural consequences of sex reversal in dragons

Science.gov (United States)

Li, Hong; Holleley, Clare E.; Elphick, Melanie; Georges, Arthur

2016-01-01

Sex differences in morphology, physiology, and behaviour are caused by sex-linked genes, as well as by circulating sex-steroid levels. Thus, a shift from genotypic to environmental sex determination may create an organism that exhibits a mixture of male-like and female-like traits. We studied a lizard species (Central Bearded Dragon, Pogona vitticeps), in which the high-temperature incubation of eggs transforms genetically male individuals into functional females. Although they are reproductively female, sex-reversed dragons (individuals with ZZ genotype reversed to female phenotype) resemble genetic males rather than females in morphology (relative tail length), general behaviour (boldness and activity level), and thermoregulatory tactics. Indeed, sex-reversed ‘females’ are more male-like in some behavioural traits than are genetic males. This novel phenotype may impose strong selection on the frequency of sex reversal within natural populations, facilitating rapid shifts in sex-determining systems. A single period of high incubation temperatures (generating thermally induced sex reversal) can produce functionally female individuals with male-like (or novel) traits that enhance individual fitness, allowing the new temperature-dependent sex-determining system to rapidly replace the previous genetically based one.

Mango seed uses: thermal behaviour of mango seed almond fat and its mixtures with cocoa butter.

Science.gov (United States)

Solís-Fuentes, J A; Durán-de-Bazúa, M C

2004-03-01

This paper deals with the physicochemical characterization, including thermal behaviour, by differential scanning calorimetry of mango seed almond fat (MAF), alone and in mixtures with cocoa butter (CB). Results showed that mango almond seeds contain about 5.28-11.26% (dw) of fat. The refraction index is 1.466, the saponification index 189.0 and the iodine index 41.76. Fatty acids found in MAF are oleic, stearic, and palmitic acids (40.81%, 39.07% and 9.29% (w/w), respectively) as well as smaller amounts of linoleic, with arachidic, behenic, lignoceric, and linolenic acids, among others. Calorimetric analysis showed that MAF crystallizes between 14.6 and -24.27 degrees C with a DeltaHc of 56.06 J/g and melts between -17.1 and 53.8 degrees C, with fusion maxima at 18.54 degrees C and 40.0 degrees C for the alpha and beta polymorphic forms. Their fusion enthalpies are 70.12 and 115.7 J/g. The MAF solids content profile is very similar to that of CB, both in stabilized and non-stabilized samples. The mixing compatibility was analyzed using isosolids curves of mixtures of different compositions.

Thermal fatigue behaviour for a 316 L type steel

International Nuclear Information System (INIS)

Fissolo, A.; Marini, B.; Nais, G.; Wident, P.

1996-01-01

This paper deals with initiation and growth of cracks produced by thermal fatigue loadings on 316 L steel, which is a reference material for the first wall of the next fusion reactor ITER. Two types of facilities have been built. As for true components, thermal cycles have been repeatedly applied on the surface of the specimen. The first is mainly concerned with initiation, which is detected with a light microscope. The second allows one to determine the propagation of a single crack. Crack initiation is analyzed using the French RCC-MR code procedure, and the strain-controlled isothermal fatigue curves. To predict crack growth, a model previously proposed by Haigh and Skelton is applied. This is based on determination of effective stress intensity factors, which takes into account both plastic strain and crack closure phenomena. It is shown that estimations obtained with such methodologies are in good agreement with experimental data. (orig.)

Thermal stability of inorganic and organic compounds in atmospheric particulate matter

Science.gov (United States)

Perrino, Cinzia; Marconi, Elisabetta; Tofful, Luca; Farao, Carmela; Materazzi, Stefano; Canepari, Silvia

2012-07-01

The thermal behaviour of atmospheric particulate matter (PM) has been investigated by using different analytical approaches to explore the added value offered by these technique in environmental studies. The thermogravimetric analysis (TGA), carried out on both certified material and real PM samples, has shown that several mass losses can be detected starting from 80 °C up to above 500 °C, when pyrolysis occur. Thermo-optical analysis of PM and ion chromatographic analysis of the residual have shown that the mass losses in the temperature range 80-180 °C are not justified by the release of either organic or inorganic compounds; it can be thus attributed to the release of weakly and strongly bound water. Release of water has also been evidenced in the temperature range 225-275 °C. The release of ammonium chloride and nitrate has been detected only above 80 °C. This indicates that the release of nitric acid, hydrochloric acid and ammonia, which is observed downstream of the filters during the sampling of atmospheric PM at ambient temperature, cannot be reproduced off-line, after the end of the sampling. We successfully explored one of the possible explanations, that is the desorption of HNO3, HCl and NH3 adsorbed on collected particles. NH4NO3 and NH4Cl, which can be thermally released by the filter, exhibit a different thermal behaviour from NaNO3 and NaCl, which are thermally stable up to 370 °C. This different behaviour can be used to discriminate between natural and secondary sources of atmospheric inorganic salts, as the interconversion that is observed when heating mixtures of pure salts resulted to be not relevant when heating real PM samples.

Investigations of bi-directional flow behaviour of a large vertical opening in containment

International Nuclear Information System (INIS)

Sharma, Pavan K.; Markandeya, S.G.; Ghosh, A.K.; Kushwaha, H.S.

2002-01-01

Full text: In the complex codes developed for fire analysis and for containment thermal hydraulic analysis. The junction in the multi-compartment geometries are often modeled as uni-directional junctions. However, certain large size junctions are known to depict bi-directional flow behaviour under specific circumstances. Detailed investigations have been carried out to understand the bi-directionality of a junction by analyzing an earlier reported case study of fire in an enclosure. A computer code FDS was used for the analysis. The paper presents the details of the analysis, the results obtained and further studies required to be conducted so that the findings can be applied to the fire/containment thermal hydraulics analysis codes successfully

Probe branes thermalization in external electric and magnetic fields

International Nuclear Information System (INIS)

Ali-Akbari, M.; Ebrahim, H.; Rezaei, Z.

2014-01-01

We study thermalization on rotating probe branes in AdS 5 ×S 5 background in the presence of constant external electric and magnetic fields. In the AdS/CFT framework this corresponds to thermalization in the flavour sector in field theory. The horizon appears on the worldvolume of the probe brane due to its rotation in one of the sphere directions. For both electric and magnetic fields the behaviour of the temperature is independent of the probe brane dimension. We also study the open string metric and the fluctuations of the probe brane in such a set-up. We show that the temperatures obtained from open string metric and observed by the fluctuations are larger than the one calculated from the induced metric

Study of thermal conductivity of multilayer insulation

International Nuclear Information System (INIS)

Dutta, D.; Sundaram, S.; Nath, G.K.; Sethuram, N.P.; Chandrasekharan, T.; Varadarajan, T.G.

1994-01-01

This paper presents experimental determination of the apparent thermal conductivity of multilayer insulation for a cryogenic system. The variation of thermal conductivity with residual gas pressure is studied and the optimum vacuum for good insulating performance is determined. Evaporation loss technique for heat-inleak determination is employed. (author)

Hygienic food handling behaviours. An application of the Theory of Planned Behaviour.

Science.gov (United States)

Mullan, Barbara A; Wong, Cara L

2009-06-01

It is estimated that 5.4 million Australians get sick annually from eating contaminated food and that up to 20% of this illness results from food handling behaviour. A study was undertaken to investigate the efficacy of the Theory of Planned Behaviour (TPB) including past behaviour in predicting safe food handling intention and behaviour. One hundred and nine participants completed questionnaires regarding their attitudes, perceived behavioural control (PBC), subjective norm, intentions and past behaviour. Behaviour was measured 4 weeks later. The TPB predicted a high proportion of variance in both intentions and behaviour, and past behaviour/habit was found to be the strongest predictor of behaviour. The results of the present study suggest interventions aimed at increasing safe food handling intentions should focus on the impact of normative influences and perceptions of control over their food handling environment; whereas interventions to change actual behaviour should attempt to increase hygienic food handling as a habitual behaviour.

Personal Values and Moral Disengagement Promote Aggressive and Rule-Breaking Behaviours in Adolescents With Disruptive Behaviour Disorders: A Pilot Study.

Science.gov (United States)

Paciello, Marinella; Muratori, Pietro; Ruglioni, Laura; Milone, Annarita; Buonanno, Carlo; Capo, Rosario; Lochman, John E; Barcaccia, Barbara

2017-01-01

The pilot study presented in this article investigated the role of moral-cognitive features in understanding aggressive and rule-breaking behaviours in adolescents with Disruptive Behaviour Disorder (DBD). We collected two samples. The community sample was composed of 85 adolescents, whereas the DBD sample was composed of 30 adolescents. Compared with a community sample, adolescents with DBD are more inclined to use moral disengagement (MD) to legitimize their aggressive and rule-breaking behaviours. Moreover, regression models showed that self-enhancement values and MD foster externalizing behaviours taking into account both gender and the group they belonged to, that is, either clinical or community sample. Instead, self-transcendence values could prevent externalizing problems by inhibiting MD. Implications of these findings for assessment and therapeutic interventions are discussed. © The Author(s) 2015.

Rumination-focused cognitive behaviour therapy vs. cognitive behaviour therapy for depression: study protocol for a randomised controlled superiority trial.

Science.gov (United States)

Hvenegaard, Morten; Watkins, Ed R; Poulsen, Stig; Rosenberg, Nicole K; Gondan, Matthias; Grafton, Ben; Austin, Stephen F; Howard, Henriette; Moeller, Stine B

2015-08-11

Cognitive behavioural therapy is an effective treatment for depression. However, one third of the patients do not respond satisfactorily, and relapse rates of around 30 % within the first post-treatment year were reported in a recent meta-analysis. In total, 30-50 % of remitted patients present with residual symptoms by the end of treatment. A common residual symptom is rumination, a process of recurrent negative thinking and dwelling on negative affect. Rumination has been demonstrated as a major factor in vulnerability to depression, predicting the onset, severity, and duration of future depression. Rumination-focused cognitive behavioural therapy is a psychotherapeutic treatment targeting rumination. Because rumination plays a major role in the initiation and maintenance of depression, targeting rumination with rumination-focused cognitive behavioural therapy may be more effective in treating depression and reducing relapse than standard cognitive behavioural therapy. This study is a two-arm pragmatic randomised controlled superiority trial comparing the effectiveness of group-based rumination-focused cognitive behaviour therapy with the effectiveness of group-based cognitive behavioural therapy for treatment of depression. One hundred twenty-eight patients with depression will be recruited from and given treatment in an outpatient service at a psychiatric hospital in Denmark. Our primary outcome will be severity of depressive symptoms (Hamilton Rating Scale for Depression) at completion of treatment. Secondary outcomes will be level of rumination, worry, anxiety, quality of life, behavioural activation, experimental measures of cognitive flexibility, and emotional attentional bias. A 6-month follow-up is planned and will include the primary outcome measure and assessment of relapse. The clinical outcome of this trial may guide clinicians to decide on the merits of including rumination-focused cognitive behavioural therapy in the treatment of depression in

Thermal preference, thermal tolerance and the thermal de-pendence of digestive performance in two Phrynocephalus lizards (Agamidae), with a review of species studied

OpenAIRE

Yanfu QU, Hong LI, Jianfang GAO, Xuefeng XU, Xiang JI

2011-01-01

We reported data on thermal preference, thermal tolerance and the thermal dependence of digestive performance for two Phrynocephalus lizards (P. frontalis and P. versicolor), and compared data among lizards so far studied worldwide. Mean values for selected body temperature (Tsel) and critical thermal maximum (CTMax) were greater in P. versicolor, whereas mean values for critical thermal minimum (CTMin) did not differ between the two species. The two lizards differed in food intake, but not i...

Behaviour genetics of Drosophila: Non-sexual behaviour

Indian Academy of Sciences (India)

Unknown

netic and molecular studies helped to reveal the genetic basis of circadian time keeping and rhythmic behaviours. In ... methods of behavioural analysis from psychology and ethology. ... new properties of neurons, they help to dissect neuronal.

Experimental investigation on the heterogeneous kinetic process of the low thermal decomposition of ammonium perchlorate particles

Energy Technology Data Exchange (ETDEWEB)

Longuet, Baptiste [Laboratoire Energetique Explosions et Structures Universite d' Orleans (Germany); Gillard, Philippe [Laboratoire Energetic Explosions et Structures, Universite d' Orleans, Bourges (France)

2009-02-15

The thermal decomposition of ammonium perchlorate has been extensively studied in the past. Nevertheless, the various results published illustrate, on the one hand, significant differences regarding the influence of different parameters on the decomposition and on the other hand, a lack of useful quantitative laws to predict the thermal behaviour of this crystal under a range of conditions (temperature, duration of exposure, presence of confinement). (Abstract Copyright [2009], Wiley Periodicals, Inc.)

School Collective Efficacy and Bullying Behaviour: A Multilevel Study

Science.gov (United States)

Olsson, Gabriella; Låftman, Sara Brolin; Modin, Bitte

2017-01-01

As with other forms of violent behaviour, bullying is the result of multiple influences acting on different societal levels. Yet the majority of studies on bullying focus primarily on the characteristics of individual bullies and bullied. Fewer studies have explored how the characteristics of central contexts in young people’s lives are related to bullying behaviour over and above the influence of individual-level characteristics. This study explores how teacher-rated school collective efficacy is related to student-reported bullying behaviour (traditional and cyberbullying victimization and perpetration). A central focus is to explore if school collective efficacy is related similarly to both traditional bullying and cyberbullying. Analyses are based on combined information from two independent data collections conducted in 2016 among 11th grade students (n = 6067) and teachers (n = 1251) in 58 upper secondary schools in Stockholm. The statistical method used is multilevel modelling, estimating two-level binary logistic regression models. The results demonstrate statistically significant between-school differences in all outcomes, except traditional bullying perpetration. Strong school collective efficacy is related to less traditional bullying perpetration and less cyberbullying victimization and perpetration, indicating that collective norm regulation and school social cohesion may contribute to reducing the occurrence of bullying. PMID:29261114

School Collective Efficacy and Bullying Behaviour: A Multilevel Study

Directory of Open Access Journals (Sweden)

Gabriella Olsson

2017-12-01

Full Text Available As with other forms of violent behaviour, bullying is the result of multiple influences acting on different societal levels. Yet the majority of studies on bullying focus primarily on the characteristics of individual bullies and bullied. Fewer studies have explored how the characteristics of central contexts in young people’s lives are related to bullying behaviour over and above the influence of individual-level characteristics. This study explores how teacher-rated school collective efficacy is related to student-reported bullying behaviour (traditional and cyberbullying victimization and perpetration. A central focus is to explore if school collective efficacy is related similarly to both traditional bullying and cyberbullying. Analyses are based on combined information from two independent data collections conducted in 2016 among 11th grade students (n = 6067 and teachers (n = 1251 in 58 upper secondary schools in Stockholm. The statistical method used is multilevel modelling, estimating two-level binary logistic regression models. The results demonstrate statistically significant between-school differences in all outcomes, except traditional bullying perpetration. Strong school collective efficacy is related to less traditional bullying perpetration and less cyberbullying victimization and perpetration, indicating that collective norm regulation and school social cohesion may contribute to reducing the occurrence of bullying.

School Collective Efficacy and Bullying Behaviour: A Multilevel Study.

Science.gov (United States)

Olsson, Gabriella; Låftman, Sara Brolin; Modin, Bitte

2017-12-20

As with other forms of violent behaviour, bullying is the result of multiple influences acting on different societal levels. Yet the majority of studies on bullying focus primarily on the characteristics of individual bullies and bullied. Fewer studies have explored how the characteristics of central contexts in young people's lives are related to bullying behaviour over and above the influence of individual-level characteristics. This study explores how teacher-rated school collective efficacy is related to student-reported bullying behaviour (traditional and cyberbullying victimization and perpetration). A central focus is to explore if school collective efficacy is related similarly to both traditional bullying and cyberbullying. Analyses are based on combined information from two independent data collections conducted in 2016 among 11th grade students ( n = 6067) and teachers ( n = 1251) in 58 upper secondary schools in Stockholm. The statistical method used is multilevel modelling, estimating two-level binary logistic regression models. The results demonstrate statistically significant between-school differences in all outcomes, except traditional bullying perpetration. Strong school collective efficacy is related to less traditional bullying perpetration and less cyberbullying victimization and perpetration, indicating that collective norm regulation and school social cohesion may contribute to reducing the occurrence of bullying.

Pelagic behaviour of reservoir fishes: sinusoidal swimming and associated behaviour

OpenAIRE

JAROLÍM, Oldřich

2009-01-01

Annotation Long-term fixed-location hydroacoustic study with uplooking transducer was performed during 2005 in Římov reservoir, Czech Republic. It dealt mainly with fish behaviour in the open water of reservoir, especially with sinusoidal swimming behaviour. The dependence of pelagic fish behaviour on environmental conditions was also studied.

The effectiveness of common thermo-regulatory behaviours in a cool temperate grasshopper.

Science.gov (United States)

Harris, Rebecca M B; McQuillan, Peter; Hughes, Lesley

2015-08-01

Behavioural thermoregulation has the potential to alleviate the short-term impacts of climate change on some small ectotherms, without the need for changes to species distributions or genetic adaptation. We illustrate this by measuring the effect of behaviour in a cool temperate species of grasshopper (Phaulacridium vittatum) over a range of spatial and temporal scales in laboratory and natural field experiments. Microhabitat selection at the site scale was tested in free-ranging grasshoppers and related to changing thermal quality over a daily period. Artificial warming experiments were then used to measure the temperature at which common thermoregulatory behaviours are initiated and the subsequent reductions in body temperature. Behavioural means such as timing of activity, choice of substrates with optimum surface temperatures, shade seeking and postural adjustments (e.g. stilting, vertical orientation) were found to be highly effective at maintaining preferred body temperature. The maximum voluntarily tolerated temperature (MVT) was determined to be 44°C±0.4°C, indicating the upper bounds of thermal flexibility in this species. Behavioural thermoregulation effectively enables small ectotherms to regulate exposure to changing environmental temperatures and utilize the spatially and temporally heterogeneous environments they occupy. Species such as the wingless grasshopper, although adapted to cool temperate conditions, are likely to be well equipped to respond successfully to coarse scale climate change. Copyright © 2015 Elsevier Ltd. All rights reserved.

Leverage of Behavioural Patterns of Window Opening and Heating Set Point Adjustments on Energy Consumption and Thermal Comfort in Residential Buildings

DEFF Research Database (Denmark)

Corgnati, Stefano Paolo; D'Oca, Simona; Fabi, Valentina

2014-01-01

The current trend in reduction in energy use in buildings is oriented towards sustainable measures and techniques aimed to energy need restraint. Even so, studies have underlined large differences in energy consumption in similar buildings, suggesting strong influence of occupant behaviour...... through a better and more accurate prediction of energy use; however, they are still unable to replicate the actual dynamics that govern energy uses within buildings. Furthermore, occupant behaviour is currently described by static profiles, based on assumptions and average values of typical behaviour......, considering different behavioural patterns and preferences among indoor environmental quality, is arising. Final goal of this research is to simulate, in a more accurate way, the variation in actual energy consumption due to human interaction within buildings. In this effort, the study has highlighted which...

Thermal treatment of petroleum contaminated soils - A case study

International Nuclear Information System (INIS)

Bubier, T.W.; Bilello. C.M.

1993-01-01

Thermal treatment is a cost-effective treatment method for removing chemicals from contaminated soils. However, detailed applicability studies are lacking. The goals of this paper are to (1) present the results of a thermal treatment study and (2) discuss the specific elements which must be evaluated prior to determining whether thermal treatment is a feasible option for a remediation project. Results of data collected during a pilot study involving thermal treatment of petroleum contaminated soils at a Marine Terminal are presented. The pilot study consisted of thermally treating the C8 through C40 + (gasoline, kerosene, diesel, motor oil, bunker fuel, etc.) hydrocarbon contaminated soils at treatment temperatures ranging from 250 degrees Fahrenheit (degree F) up to 550 degrees F. The low-temperature thermal treatment unit consisted of a rotary kiln with a temperature capacity of approximately 600 degrees F, a baghouse, and a catalytic oxidizer. The soil was monitored for concentrations of petroleum hydrocarbons and volatile organic compounds before and after treatment. The results of the pilot study were used to determine if thermal treatment technology is a cost-efficient and effective option of remediating the estimated 300,000 tons of petroleum contaminated soil to acceptable cleanup levels. The low-temperature thermal treatment pilot study was effective in desorbing the short chain hydrocarbons (gasoline and diesel) but was not effective in desorbing the long-chain petroleum hydrocarbons, such as motor oils and bunker fuels, from the soil. This was primarily due to the boiling points of motor oil and bunker fuels which were higher than the temperature capacity of the pilot study treatment equipment. Additional factors that influenced the effectiveness of the desorption process included configuration of the treatment equipment, soil moisture content, soil particle size, and type and concentration of petroleum hydrocarbons

French studies on the thermal effluents of electric power plants

International Nuclear Information System (INIS)

Dezes-Cadiere, H.

1976-01-01

This report presents a synthesis of studies made in France in the thermal effluent field: thermal power plant cooling systems, transfer and dispersion of thermal effluents in the receptive media, effects of thermal effluents on water physicochemistry and biochemistry, effects of thermal effluents on aquatic ecosystems, and, possibilities of waste heat recovery with the view of utilization in agriculture, aquaculture and district heating. A catalogue of French organizations working or having data on thermal effluents is presented, as also an alphabetical list of the contacted persons. A bibliography of French documents concerning the previously mentioned studies is finally given (193 refs.) [fr

Study of thermal phenomena in niobium superconducting cavities when stiffened by thermal spray coating; Etude des phenomenes thermiques dans les cavites acceleratrices supraconductrices en niobium rigidifiees par projection thermique

Energy Technology Data Exchange (ETDEWEB)

Bousson, S

2000-02-01

The first objective of this thesis is to study a new superconducting cavity stiffening method based on thermal spraying. The principle is to add on the cavity external walls a copper layer using the thermal spraying process. Several tests on samples allowed to measure the thermal and mechanical properties of the layers deposited by several different processes. Measurements performed on 3 and 1.3 GHz niobium cavities, before and after copper deposition, proved the interest and feasibility of the method. The study showed the need to have very dense layers (porosity reduced to the minimum in order to have good mechanical characteristics), and not oxidised (to reduce the coating thermal resistance). As a conclusion, the spraying process performed under controlled atmosphere seems to be the most suited for superconducting cavity stiffening. The tools and analysing methods which have been developed for this study allowed to investigate other phenomena involved in the cavity thermal stability, and particularly the quench, a phenomenon often studied but not in its dynamic. A model is proposed in this thesis to analyse the quench dynamic behaviour using only the fast RF signal measurement during a quench. It has been shown that the quench propagation velocity depends essentially on the accelerating field and the niobium thermal conductivity. A study on the thermometer response time used as diagnostics on cavities proved that the transients during a quench are not efficiently measured with Allen-Bradley sensors: for this application Cernox thermometers are to be preferred due to their lower time response. The development of a thermometer acquisition device for the 3 GHz cavities, used for the study on cavity stiffening, has been adapted for anomalous heating measurements on high gradient 1.3 GHz cavities. It has been possible to prove that anomalous RF losses are responsible of the quality factor degradation, that they are not localised in a small of the cavity, but

Mechanical spectroscopy of thermal stress relaxation in aluminium alloys reinforced with short alumina fibres

Energy Technology Data Exchange (ETDEWEB)

Carreno-Morelli, E.; Schaller, R. [Ecole Polytechnique Federale, Lausanne (Switzerland). Inst. de Genie Atomique; Urreta, S.E.

1998-05-01

The mechanical behaviour under low temperature thermal cycling of aluminium-based composites reinforced with short Al{sub 2}O{sub 3} SAFFIL fibres has been investigated by mechanical spectroscopy (mechanical loss and elastic shear modulus measurements). A mechanical loss maximum has been observed during cooling which originates in the relaxation of thermal stresses at the interfaces due to the differential thermal expansion between matrix and reinforcement. The maximum height increases with the volumetric fibre content. In addition, if the matrix strength is increased by the appropriated choice of alloy and thermal treatment, the maximum diminishes and shifts to lower temperatures. No damage accumulation at the interfaces has been detected during long period thermal cycling in the range 100 to 500 K. A description of the damping behaviour is made in terms of the development of microplastic zones which surround the fibres. (orig.) 9 refs.

Thermal fatigue. Fluid-structure interaction at thermal mixing events

Energy Technology Data Exchange (ETDEWEB)

Schuler, X.; Herter, K.H.; Moogk, S. [Stuttgart Univ. (Germany). MPA; Laurien, E.; Kloeren, D.; Kulenovic, R.; Kuschewski, M. [Stuttgart Univ. (Germany). Inst. of Nuclear Technology and Energy Systems

2012-07-01

In the framework of the network research project ''Thermal Fatigue - Basics of the system-, outflow- and material-characteristics of piping under thermal fatigue'' funded by the German Federal Ministry of Education and Research (BMBF) fundamental numerical and experimental investigations on the material behaviour under transient thermal-mechanical stress conditions (high cycle fatigue - HCF) are carried out. The project's background and its network of scientific working groups with their individual working tasks are briefly introduced. The main focus is especially on the joint research tasks within the sub-projects of MPA and IKE which are dealing with thermal mixing of flows in a T-junction configuration and the fluidstructure- interactions (FSI). Therefore, experiments were performed with the newly established FSI test facility at MPA which enables single-phase flow experiments of water in typical power plant piping diameters (DN40 and DN80) at high pressure (maximum 75 bar) and temperatures (maximum 280 C). The experimental results serve as validation data base for numerical modelling of thermal flow mixing by means of thermo-fluid dynamics simulations applying CFD techniques and carried out by IKE as well as for modelling of thermal and mechanical loads of the piping structure by structural mechanics simulations with FEM methods which are executed by MPA. The FSI test facility will be described inclusively the applied measurement techniques, e. g. in particular the novel near-wall LED-induced Fluorescence method for non-intrusive flow temperature measurements. First experimental data and numerical results from CFD and FEM simulations of the thermal mixing of flows in the T-junction are presented.

Thermal oxidative degradation behaviours of flame-retardant thermotropic liquid crystal copolyester/PET blends

International Nuclear Information System (INIS)

Du Xiaohua; Zhao Chengshou; Wang Yuzhong; Zhou Qian; Deng Yi; Qu Minghai; Yang Bing

2006-01-01

The flame retardancy and the thermal oxidative degradation behaviors of the blend of poly(ethylene terephthalate) (PET) with a kind of phosphorus-containing thermotropic liquid crystal copolyester (TLCP) with high flame retardancy (limited oxygen index, 70%) have been investigated by oxygen index test (LOI), UL-94 rating and thermogravimetric analysis (TGA) in air. The results show that TLCP can dramatically improve the flame retardancy and the melt dripping behavior of PET. Moreover, the apparent activation energies of thermal oxidative degradation of the blends were evaluated using Kissinger and Flynn-Wall-Ozawa methods. It is found that addition of TLCP improve thermal stability and restrain thermal decomposition of PET in air, especially at the primary degradation stage. Py-GC/MS analysis shows that there are remarkable changes in the pyrolysis products when TLCP are blended into PET. The interaction between TLCP and PET has changed their thermal oxidative degradation mechanism

Does behavioural thermoregulation underlie seasonal movements in Lake Erie walleye?

Science.gov (United States)

Raby, Graham D.; Vandergoot, Christopher; Hayden, Todd A.; Faust, Matthew D.; Kraus, Richard T.; Dettmers, John M.; Cooke, Steven J.; Zhao, Yingming; Fisk, Aaron T.; Krueger, Charles C.

2018-01-01

Thermoregulation is presumed to be a widespread determinant of behaviour in fishes, but has not often been investigated as a mechanism shaping long-distance migrations. We used acoustic telemetry and animal-borne thermal loggers to test the hypothesis that seasonal migration in adult walleye (Sander vitreus) in Lake Erie is size- and (or) sex-specific and related to behavioural thermoregulation. Female walleye migrated out of the warm, shallow western basin earlier than did males and were 1.8 times more likely to be detected on acoustic receivers in the deeper and cooler eastern basin. The few fish that remained in the western basin were restricted to a smaller range of higher temperatures (≥20 °C) than those that migrated to the central and eastern basins (∼16–21 °C). However, temperature records from walleye in the central basin were nearly indistinguishable from those in the eastern basin, suggesting thermal preferences alone could not explain migration to the eastern basin. As such, our effort to understand the mechanisms that cause migratory behaviours has generated mixed evidence on the role of temperature and that factors like foraging opportunities may have synergistic roles in the migration.

Thermal behaviour of titanium dioxide nanoparticles prepared by precipitation from aqueous solutions

Czech Academy of Sciences Publication Activity Database

Pulišová, Petra; Boháček, Jaroslav; Šubrt, Jan; Szatmáry, Lórant; Bezdička, Petr; Večerníková, Eva; Balek, V.

2010-01-01

Roč. 101, č. 2 (2010), s. 607-613 ISSN 1388-6150 R&D Projects: GA MŠk 1M0577 Institutional research plan: CEZ:AV0Z40320502 Keywords : thermogravimetry * differential thermal analysis * emanation thermal analysis Subject RIV: CA - Inorganic Chemistry Impact factor: 1.752, year: 2010

Stimulus control and affect in dietary behaviours. An intensive longitudinal study.

Science.gov (United States)

Schüz, Benjamin; Bower, Jodie; Ferguson, Stuart G

2015-04-01

Dietary behaviours are substantially influenced by environmental and internal stimuli, such as mood, social situation, and food availability. However, little is known about the role of stimulus control for eating in non-clinical populations, and no studies so far have looked at eating and drinking behaviour simultaneously. 53 individuals from the general population took part in an intensive longitudinal study with repeated, real-time assessments of eating and drinking using Ecological Momentary Assessment. Eating was assessed as main meals and snacks, drinks assessments were separated along alcoholic and non-alcoholic drinks. Situational and internal stimuli were assessed during both eating and drinking events, and during randomly selected non-eating occasions. Hierarchical multinomial logistic random effects models were used to analyse data, comparing dietary events to non-eating occasions. Several situational and affective antecedents of dietary behaviours could be identified. Meals were significantly associated with having food available and observing others eat. Snacking was associated with negative affect, having food available, and observing others eat. Engaging in activities and being with others decreased the likelihood of eating behaviours. Non-alcoholic drinks were associated with observing others eat, and less activities and company. Alcoholic drinks were associated with less negative affect and arousal, and with observing others eat. RESULTS support the role of stimulus control in dietary behaviours, with support for both internal and external, in particular availability and social stimuli. The findings for negative affect support the idea of comfort eating, and results point to the formation of eating habits via cue-behaviour associations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fission product chemistry and aerosol behaviour in the primary circuit of a pressurised water reactor under severe accident conditions

International Nuclear Information System (INIS)

Bowsher, B.R.

1985-09-01

Three key accident sequences are considered covering a representative range of different environments of pressure, flow, temperature history and degree of zircaloy oxidation, and their principle thermal hydraulic and physical characteristics affecting chemistry behaviour are identified. Inventories, chemical forms and timing of fission product release are summarized together with the major sources of structural materials and their release characteristics. Chemistry of each main fission product species is reviewed from available experimental and/or theoretical data. Studies modelling primary circuit fission product behaviour are reviewed. Requirements for further study are assessed. (UK)

Study of thermal conductivity of multilayer insulation

Energy Technology Data Exchange (ETDEWEB)

Dutta, D; Sundaram, S; Nath, G K; Sethuram, N P; Chandrasekharan, T; Varadarajan, T G [Heavy Water Division, Bhabha Atomic Research Centre, Mumbai (India)

1994-06-01

This paper presents experimental determination of the apparent thermal conductivity of multilayer insulation for a cryogenic system. The variation of thermal conductivity with residual gas pressure is studied and the optimum vacuum for good insulating performance is determined. Evaporation loss technique for heat-inleak determination is employed. (author). 3 refs., 3 figs.