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Weak thermal stability and low-burning resistance of the rigid polyurethane foams are the classic problems in the usage of them. Therefore, it is required to improve these problems of the foams while reducing the cost of production. This study investigated the effects of dolomite (DOL) and intumescent flame retardant (IFR) system on thermal and combustion behaviors of rigid polyurethane foams (RPUFs). For this purpose, DOL (5, 10, and 15 wt%) and DOL/IFR (5/5, 10/5, and 5/10 wt%) combinations were added into RPUFs. Thermogravimetric analyses were performed to investigate the thermal decompositions of the foams and the thermal conductivity measurements were performed to examine the effects of DOL and DOL/IFR additions on the thermal insulation properties of the foams. Cone calorimeter and UL 94 tests were performed to investigate the fire resistances of the foams. The test results showed that up to 15 wt% DOL could be incorporated into the rigid polyurethane foams as filler without any problems in the foam productions, and the thermal and the combustion behaviors of the foams were slightly enhanced. In addition, it was determined that IFR should be used to improve the thermal stability and the fire resistance of the DOL added foams. Among DOL/IFR combinations, 5 wt% DOL and 10 wt% IFR addition satisfied the best performance in terms of the thermal stability and the fire resistance with reducing the smoke, CO, CO2 and NO emissions. In general, the additions of DOL and IFR slightly increased the thermal conductivity coefficients of the foams. © 2023 Wiley Periodicals LLC.

In this paper we show the results from indoor and outdoor measurements on solar cells and modules, manufactured with different bifacial and monofacial cell architectures and encapsulated in different configurations. Reflection/transmission, IV and IQE spectra of single-cell laminates were measured and used to determine the energy spectra for all heat loss and absorption processes, including thermalisation, recombination, entropy generation, parasitic absorption and electrical power generation. From these spectra, the effective heat input was calculated for front, rear and combined irradiance. The power output, bifacial gain and module operating temperature were monitored of single-cell laminates exposed to indoor irradiance as well as of full-size modules installed on our rooftop. We have found that the effective heat input for bifacial glass-glass modules is increasingly larger with increasing rear irradiance compared to monofacial modules. Measured temperatures of rooftop-installed modules strongly indicate that the effective heat transfer coefficient of glass-glass modules is higher than that of white back sheet modules. The observed combined effect of heat input and heat transfer is that only at rear irradiance fractions beyond 15% the additional heat input can cause the bifacial modules to be hotter than their monofacial counterpart, but the energy yield is still much higher due to the large bifacial gain. In the case of moderate albedo, the bifacial energy gain is not accompanied by a higher temperature of the bifacial module compared to the monofacial module. © 2018 Elsevier B.V.

The metal-organic framework Cu-2,3,6,7,10,11-hexahydroxytriphenylene (Cu3hhtp2-MOF), a copper-based graphene-like framework, is one of the few MOFs featuring inherent electrical conductivity. Here, we investigate the synthesis of this material with regard to the influence of different additives. It is shown that ammonia acts as a modulator leading to platelet-like particles in a water-based synthesis system. This material is thoroughly characterized by X-ray diffraction (XRD), electron microscopy, atomic force microscopy (AFM), physisorption, thermal behaviour, and electrical conductivity. The measured conductivity value of 0.045 S cm-1 surpasses all formerly reported measurements. The obtained platelets appear especially suitable for the preparation of different devices. As an example, we prepared thin and homogenous films by spray-coating water-based dispersions of this MOF on glass and on polymer substrates. In the films, the platelets are oriented parallel to the substrate and are in intimate contact. This leads to a high electrical conductivity combined with an easily accessible pore system. The applicability of such coatings is shown in a preliminary sensing test, showing quick and strong response and fast recovery. This work shows that control of the crystal morphology combined with suitable preparation procedures can enhance the performance of MOF-based devices.

In this paper we show the results from indoor and outdoor measurements on solar cells and modules, manufactured with different bifacial and monofacial cell architectures and encapsulated in different configurations. Reflection/transmission, IV and IQE spectra of single-cell laminates were measured and used to determine the energy spectra for all heat loss and absorption processes, including thermalisation, recombination, entropy generation, parasitic absorption and electrical power generation. From these spectra, the effective heat input was calculated for front, rear and combined irradiance. The power output, bifacial gain and module operating temperature were monitored of single-cell laminates exposed to indoor irradiance as well as of full-size modules installed on our rooftop. We have found that the effective heat input for bifacial glass-glass modules is increasingly larger with increasing rear irradiance compared to monofacial modules. Measured temperatures of rooftop-installed modules strongly indicate that the effective heat transfer coefficient of glass-glass modules is higher than that of white back sheet modules. The observed combined effect of heat input and heat transfer is that only at rear irradiance fractions beyond 15% the additional heat input can cause the bifacial modules to be hotter than their monofacial counterpart, but the energy yield is still much higher due to the large bifacial gain. In the case of moderate albedo, the bifacial energy gain is not accompanied by a higher temperature of the bifacial module compared to the monofacial module. © 2018 Elsevier B.V.

In concentrating photovoltaic (CPV) applications, the sunlight is focused onto solar cells up to thousands of times and, without an adequate cooling system, the cell�s temperature can dangerously raise over the operating temperature range in few seconds. In this study, an investigation on micro-finned heat sink for high concentrating photovoltaics has been conducted. The geometry of the system and the choice of the components play an important role in the thermal management of CPV. The size of cell, as well as the optics, can strongly affect the thermal behaviour of the CPV: the effects of the CPV geometry on the thermal performance of the heat sink are experimentally investigated and discussed in order to design an optimised system for passive cooling. A micro-fin array is developed to handle the heat generated by the cell and the system is studied in different conditions to prove the applicability of this passive solution to the harsh CPV conditions. It has been found that micro-fins are a suitable solution for passive cooling at concentrations up to 500�. Moreover, this kind of solutions shows the potential to achieve high mass-specific power values, proving its competitiveness in mobile or tracked systems, such as CPV. � 2015, Springer Science+Business Media New York.

Thermal pack management is dependent on the duty cycle and vehicle use. Thermal modelling of the pack for design, as well as active measures in operation to reduce thermal loads during operation can greatly improve the lifetime of the pack. Advances in state estimation, measurement techniques and control are coupled with the system design; and both are dependent on representative models. As the cells age, the thermal behaviour will change, and therefore a robust control technique and in-situ thermal model identification is often required. This paper focuses on methodologies towards thermal characterization of cell models and of a pack as a whole.

An attempt has been made to prepare and characterise ammonium thiocyanate (NH4SCN) salt and a multiwall carbon nanotube (MWNT)-doped polyvinyl alcohol-based nanofibre mats using an electrospinning process. The X-ray diffraction result shows an improvement in the amorphous nature of composite electrolyte fibre mats with increasing concentrations of the MWNT filler. The DSC behaviour of these nanofibre mat exhibits better thermal response upon dispersal of the filler. Composite electrolyte nanofibre mat doped with 6 wt% MWNT shows optimum conductivity, viz., 5.8 � 10-4 Scm-1. The temperature dependence of the bulk electrical conductivity displays a combination of Arrhenius and Vogel-Tammam-Fulcher nature. Dielectric loss studies have also been used to understand the conduction process in the system. Jonscher power law seems to be obeyed during ac conductivity measurements of the fibre mats. � 2012 Springer-Verlag.

International audience; SOI circuit exhibits excellent performance and rehabilitee but with the component miniaturization trend and the clock frequency increase, the self-heating phenomena that arise from the SOI structure itself must not be underestimated. In order to minimize this problem, several candidates have been identified to replace the buried silicon oxide (SiO2) by high thermal conductive dielectric layers such as HfO2, Si3N4, diamond or Al2O3. In order to elaborate a SOI structure using this kind of innovative buried dielectric, first of all, their direct bonding with silicon has to be studied. In this work, we investigate the bonding thermal behaviour of Si/Al2O3 and Al2O3/Al2O3 direct bonded structures: bondings are submitted to room temperature up to 900 A degrees C annealing. Amorphous or crystallized Al2O3 thin films were used in this study. Bonding energies are measured in an anhydrous atmosphere and bonding defectivity is analysed using scanning acoustic microscope (SAM). With amorphous a-Al2O3 layer, for T > 200 A degrees C, high bonding energy are obtained even if high defect density appeared when annealing temperature exceeded 400-500 A degrees C. Spontaneous debonding phenomena even occurred for a-Al2O3/a-Al2O3 direct bonding. This defectivity, unobservable using infrared camera, may be explained by chemical or structural Al2O3 modification such as gases desorption, internal stress or crystallisation state. Bonding with crystallized Al2O3 film has been also characterized by infrared spectroscopy and complementary analysis. No high defect density is observed with crystallized Al2O3 layer. Based on these results, an Al2O3 bonding mechanism is proposed.

Blends of poly(lactic acid) (PLA) and poly(épsilon-caprolactone) (PCL), loaded with different amounts of Amoxicillin antibiotic (AMOX) were electrospun to investigate their release properties and obtain a controlled and tuneable release. The processing parameters for electrospinning were set up and reliable membranes were obtained. Morphology and thermal behaviour were found dependent on the component ratio as well as on the incorporated drug amount. A very different release kinetics of the two pristine polymers, very rapid for PCL and very slow for PLA, reflected in intermediate release time. However comparing the release amount with that predicted by the mixture rule a preferential incorporation of AMOX into PLA can be inferred.

The success of a polymer/clay nanocomposite depends from a number of factors including the intrinsic properties of the clay, nanofiller dispersion and orientation, matrix/filler interactions, etc. This manuscript focuses on the effect of matrix/filler interphases on the final physical properties of nanocomposite. Two PA6/sepiolite nanocomposites masterbatches are prepared via in situ polymerisation and then diluted via melt-compounding to different filler contents: one based on unreactive pristine sepiolite and another based on reactive amino-silane functionalised sepiolite. This offers a unique comparison opportunity, in which only the latter nanocomposite has PA6 molecules grafted directly from the sepiolite clay. Both nanocomposites are characterised in terms of morphology, thermal behaviour, semi-static tensile tests and dynamic mechanical tests. Interestingly, the grafted-from nanocomposites presented an enhanced strain at break and work of fracture, up to 100% in correspondence of 5 wt.% of filler, which is explained by the presence of a "soft" interphase. © 2014 Elsevier Ltd. All rights reserved. 56 1 131 139 Cited By :6

Conference of 13th Conference of the International Building Performance Simulation Association, BS 2013 ; Conference Date: 26 August 2013 Through 28 August 2013; Conference Code:100481; International audience; In many countries, ambitious strategies and policies have been deployed to reduce building energy consumption. The method usually advised by standards is the building energy simulation with a large choice of software as TrnSys or EnergyPlus. These dynamic simulation tools are widely used and their results are reliable. However, their major drawback is their lack of flexibility and their complexity with respect to the source code. Moreover, these tools feature exhaustive descriptions of buildings' thermal behaviour, which can be time- consuming when such a degree of accuracy is not required. In this context, we chose to introduce our in-house model. Thus, we give in this article a brief description of this model. Then, we present a comparison and a validation of this model with the numerical software EnergyPlus 011 both small and high insulation monozone buildings. Moreover, we propose to study the effect of merging walls 011 the accuracy and the computation time.

TNO is developing the Optical Tube Asssemblies (OTAs) for the ESO VLT Four Laser Guide Star Facility. The OTAs are Galilean 20x beam expanders, expanding a Ø15 mm input beam to a steerable Ø300 mm output beam with a wavefront quality requirement of 50 nm rms. The allowed defocus under the influence of the changing environmental air temperature (0-15°C, -0.7°C/hr gradient) is only 0.2 waves. The thermal behaviour of the system has been analyzed by combining optical, lumped mass and FE analyses. A design that is passively athermalized over a large temperature range as well as under the influence of thermal gradients has been developed. Extensive thermal testing has shown the system performs as required. This paper describes the design and test results. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

This paper summarizes the work done in the SARNET European Network of Excellence on Severe Accidents (6th Framework Programme of the European Commission) on the capability of the ASTEC code to simulate in-vessel corium retention (IVR). This code, jointly developed by the French Institut de Radioprotection et de Sûreté Nucléaire (IRSN) and the German Gesellschaft für Anlagen und Reaktorsicherheit mbH (GRS) for simulation of severe accidents, is now considered as the European reference simulation tool. First, the DIVA module of ASTEC code is briefly introduced. This module treats the core degradation and corium thermal behaviour, when relocated in the reactor lower head. Former ASTEC V1.2 version assumed a predefined stratified molten pool configuration with a metallic layer on the top of the volumetrically heated oxide pool. In order to reflect the results of the MASCA project, improved models that enable modelling of more general corium pool configurations were implemented by the CEA (France) into the DIVA module of the ASTEC V1.3 code. In parallel, the CEA was working on ASTEC modelling of the external reactor vessel cooling (ERVC). The capability of the ASTEC CESAR circuit thermal-hydraulics to simulate the ERVC was tested. The conclusions were that the CESAR module is capable of simulating this system although some numerical and physical instabilities can occur. Developments were then made on the coupling between both DIVA and CESAR modules in close collaboration with IRSN. In specific conditions, code oscillations remain and an analysis was made to reduce the numerical part of these oscillations. A comparison of CESAR results of the SULTAN experiments (CEA) showed an agreement on the pressure differences. The ASTEC V1.2 code version was applied to IVR simulation for VVER-440/V213 reactors assuming defined corium mass, composition and decay heat. The external cooling of reactor wall was simulated by applying imposed coolant temperature and heat transfer coefficient (HTC). The obtained results (pool temperatures, heat flux distribution, reactor wall ablation) were compared with available predictions of other codes. The agreement was correct, in particular on the shape and depth of ablation, as well as the maximum heat flux in case of a thick metallic layer, while ASTEC calculated a lower maximum heat flux for a thin metallic layer. © 2009 Elsevier B.V. All rights reserved.

International audience; In this paper, we present the study of thermal behaviour of 36Cl in nuclear graphite used in the St. Laurent A2 UNGG reactor (graphite moderated and CO2 cooled reactor). 37Cl, used to simulate 36Cl displaced from its original structural site by recoil, has been implanted into nuclear graphite samples (energy = 250 keV, fluence = 5 × 1013 at cm-2). The samples have been annealed in the 200-800 °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 °C, around 20% of the initial 37Cl content is released. At 800 °C, the release reaches a plateau and the loss of 37Cl is around 30%. Raman microspectroscopy shows that 37Cl implantation induces a structural disorder and that during annealing, the original structure is not completely recovered. © 2009 Elsevier B.V. All rights reserved.

Automobile compartments arc exposed to unstable heat loads due to solar radiation, combined convection, conduction and radiation beat transfer through the cabin surfaces, air exchange and metabolic heat production of the occupants. In this study, a dynamic model of the heat loads that affect the thermal behaviour of the automobile compartment was developed in a Matlab-Simulink environment. Solar irradiation on cabin surfaces and thermal interactions between the driver and cabin interior can be calculated by the model. In order to determine mean radiant temperature and direct solar irradiation absorbed by the driver, view factors between the person and the interior surrounding surfaces were obtained by using a 3-D CFD model of cabin and driver. Experiments were also performed and the simulation results were compared with the measured and the obtained experimental data available in the literature. The effects of colour (white and black) and windows' optical properties (transmissivity, reflectivity and absorptivity coefficients) oil the thermal comfort were also investigated.

Nanocrystalline apatites with different Ca/P ratios were synthesized using eggshell as a calcium source by microwave processing. The apatites were found to have a minor amount of Mg, Sr, Si and Na ions inherited from the eggshells. The presence of several foreign ions results in a perturbed lattice structure indicated by an increase in lattice constants and shift in vibrational frequencies of the functional groups. The apatites were heat treated to investigate the influence of foreign ions on thermal stability. The minor amounts of ions do not affect the thermal stability. The differences in thermal behaviour of these apatites were due to the presence of HPO2- 4 ions only and not due to other ions because of their low content. � 2009 IOP Publishing Ltd.

Thin-walled components, i.e. fuselage frames of airplanes, are prone to an unstable process behavior during milling. Therefore, tools with a chamfer between the cutting edge and the flank face are often used for such machining tasks. During milling, the chamfered area comes into contact with the just cut surface. This contact leads to process damping forces and the induced heat into the workpiece in this contact zone is increased. Furthermore, the amount of induced heat depends on the process parameters. At certain spots on the machined surface this may lead to a local overheating, which can reduce stiffness significantly. When this occurs during milling of a thin-walled component, the component is often regarded as reject. In this paper, the influence of chamfers and process parameters on the induced heat into the workpiece is investigated experimentally. In addition, a simulation which predict the temperature in the workpiece in dependence of the process parameters is presented. Ministry of Economics, Labour and Transport of Lower Saxony/ZW3-80134969 DFG/DE 447/90-2