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Maria A Founti - One of the best experts on this subject based on the ideXlab platform.
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A generalized methodology for the definition of reactive porous materials physical properties: Prediction of Gypsum Board properties
Construction and Building Materials, 2013Co-Authors: Dimos A Kontogeorgos, Maria A FountiAbstract:Abstract This paper presents an integrated methodology for the prediction of the physical properties of porous materials implemented in Gypsum plaster Boards. The methodology, coupled with the reaction kinetics of Gypsum Boards thermo-chemistry, is programmed in an in-house developed code named GPRO in order to predict the physical properties related to microstructure, heat and mass transfer, of Gypsum Boards at elevated temperatures. To support the above, the authors propose a correlation between the tortuosity factor and the volume porosity of a porous material, applicable for the whole porosity range, and a correlation for the shrinkage percentage of different Gypsum Board types versus temperature. The predictions agree well with experimental data, accurately capture the main thermo-chemical processes taking place in a heated Gypsum Board. In the long run and after validation with appropriate experimental data the utilization of such a code could be an extremely useful tool, especially in cases where experimental measurements could be a time and cost intensive procedure. The current work presents such an experimental validation for one typical Gypsum Board.
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Gypsum Board dehydration kinetics at autogenous water vapour partial pressure
Thermochimica Acta, 2012Co-Authors: Dimos A Kontogeorgos, Maria A FountiAbstract:Abstract In this paper, the dehydration kinetics of a commercial Gypsum Board, at autogenous water vapour partial pressure, are investigated. Differential scanning calorimetry measurements, under non isothermal conditions and in an inert atmosphere, were carried out at temperatures up to 300 °C, with different heating rates. Samples of deionized water and commercial Gypsum Board, in conjunction with pin hole lid crucibles, were used in order to study the evaporation of the free moisture and the dehydration of the chemically bound water at autogenous water vapour pressure conditions. Model-free and model-fitting approaches were used for the definition of the kinetic parameters of the examined reactions.
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Gypsum Board reaction kinetics at elevated temperatures
Thermochimica Acta, 2012Co-Authors: Dimos A Kontogeorgos, Maria A FountiAbstract:Abstract The scope of this work is to provide a framework that can facilitate the detailed simulation of Gypsum Board thermo-chemistry at ambient and elevated temperature conditions. The paper reviews Gypsum Board thermo-chemistry, presents a methodological approach for the calculation of composition and reaction energy, and focuses on methods calculating the ‘kinetic triplet’. The chemical kinetics of three main reactions that take place when a Gypsum Board is exposed at elevated temperatures: evaporation of free moisture content, dehydration of chemically bound water and crystal mesh reorganization were investigated using Differential Scanning Calorimetry measurements under non isothermal conditions and in an inert atmosphere. Experiments using samples of deionized water and commercial Gypsum Board were carried out at temperatures up to 600 °C, with different heating rates. Mass and energy balance equations were considered in order to define the initial composition of a Gypsum Board and the energy that is absorbed/produced after the completion of the examined reactions. Model-free and model-fitting approaches were used for the definition of the kinetic parameters of the examined reactions. The approach minimizes the need for expensive and detailed experiments necessary for the determination of the Gypsum Board behavior at elevated temperatures.
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Gypsum Board reaction kinetics at elevated temperatures
Thermochimica Acta, 2012Co-Authors: Dimos A Kontogeorgos, Maria A FountiAbstract:The scope of this work is to provide a framework that can facilitate the detailed simulation of Gypsum Board thermo-chemistry at ambient and elevated temperature conditions. The paper reviews Gypsum Board thermo-chemistry, presents a methodological approach for the calculation of composition and reaction energy, and focuses on methods calculating the 'kinetic triplet'. The chemical kinetics of three main reactions that take place when a Gypsum Board is exposed at elevated temperatures: evaporation of free moisture content, dehydration of chemically bound water and crystal mesh reorganization were investigated using Differential Scanning Calorimetry measurements under non isothermal conditions and in an inert atmosphere. Experiments using samples of deionized water and commercial Gypsum Board were carried out at temperatures up to 600°C, with different heating rates. Mass and energy balance equations were considered in order to define the initial composition of a Gypsum Board and the energy that is absorbed/produced after the completion of the examined reactions. Model-free and model-fitting approaches were used for the definition of the kinetic parameters of the examined reactions. The approach minimizes the need for expensive and detailed experiments necessary for the determination of the Gypsum Board behavior at elevated temperatures. © 2011 Elsevier B.V. All rights reserved.
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Gypsum Board dehydration kinetics at autogenous water vapour partial pressure
Thermochimica Acta, 2012Co-Authors: Dimos A Kontogeorgos, Maria A FountiAbstract:In this paper, the dehydration kinetics of a commercial Gypsum Board, at autogenous water vapour partial pressure, are investigated. Differential scanning calorimetry measurements, under non isothermal conditions and in an inert atmosphere, were carried out at temperatures up to 300°C, with different heating rates. Samples of deionized water and commercial Gypsum Board, in conjunction with pin hole lid crucibles, were used in order to study the evaporation of the free moisture and the dehydration of the chemically bound water at autogenous water vapour pressure conditions. Model-free and model-fitting approaches were used for the definition of the kinetic parameters of the examined reactions. © 2012 Elsevier B.V. All rights reserved.
Dimos A Kontogeorgos - One of the best experts on this subject based on the ideXlab platform.
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A generalized methodology for the definition of reactive porous materials physical properties: Prediction of Gypsum Board properties
Construction and Building Materials, 2013Co-Authors: Dimos A Kontogeorgos, Maria A FountiAbstract:Abstract This paper presents an integrated methodology for the prediction of the physical properties of porous materials implemented in Gypsum plaster Boards. The methodology, coupled with the reaction kinetics of Gypsum Boards thermo-chemistry, is programmed in an in-house developed code named GPRO in order to predict the physical properties related to microstructure, heat and mass transfer, of Gypsum Boards at elevated temperatures. To support the above, the authors propose a correlation between the tortuosity factor and the volume porosity of a porous material, applicable for the whole porosity range, and a correlation for the shrinkage percentage of different Gypsum Board types versus temperature. The predictions agree well with experimental data, accurately capture the main thermo-chemical processes taking place in a heated Gypsum Board. In the long run and after validation with appropriate experimental data the utilization of such a code could be an extremely useful tool, especially in cases where experimental measurements could be a time and cost intensive procedure. The current work presents such an experimental validation for one typical Gypsum Board.
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Gypsum Board dehydration kinetics at autogenous water vapour partial pressure
Thermochimica Acta, 2012Co-Authors: Dimos A Kontogeorgos, Maria A FountiAbstract:Abstract In this paper, the dehydration kinetics of a commercial Gypsum Board, at autogenous water vapour partial pressure, are investigated. Differential scanning calorimetry measurements, under non isothermal conditions and in an inert atmosphere, were carried out at temperatures up to 300 °C, with different heating rates. Samples of deionized water and commercial Gypsum Board, in conjunction with pin hole lid crucibles, were used in order to study the evaporation of the free moisture and the dehydration of the chemically bound water at autogenous water vapour pressure conditions. Model-free and model-fitting approaches were used for the definition of the kinetic parameters of the examined reactions.
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Gypsum Board reaction kinetics at elevated temperatures
Thermochimica Acta, 2012Co-Authors: Dimos A Kontogeorgos, Maria A FountiAbstract:Abstract The scope of this work is to provide a framework that can facilitate the detailed simulation of Gypsum Board thermo-chemistry at ambient and elevated temperature conditions. The paper reviews Gypsum Board thermo-chemistry, presents a methodological approach for the calculation of composition and reaction energy, and focuses on methods calculating the ‘kinetic triplet’. The chemical kinetics of three main reactions that take place when a Gypsum Board is exposed at elevated temperatures: evaporation of free moisture content, dehydration of chemically bound water and crystal mesh reorganization were investigated using Differential Scanning Calorimetry measurements under non isothermal conditions and in an inert atmosphere. Experiments using samples of deionized water and commercial Gypsum Board were carried out at temperatures up to 600 °C, with different heating rates. Mass and energy balance equations were considered in order to define the initial composition of a Gypsum Board and the energy that is absorbed/produced after the completion of the examined reactions. Model-free and model-fitting approaches were used for the definition of the kinetic parameters of the examined reactions. The approach minimizes the need for expensive and detailed experiments necessary for the determination of the Gypsum Board behavior at elevated temperatures.
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Gypsum Board reaction kinetics at elevated temperatures
Thermochimica Acta, 2012Co-Authors: Dimos A Kontogeorgos, Maria A FountiAbstract:The scope of this work is to provide a framework that can facilitate the detailed simulation of Gypsum Board thermo-chemistry at ambient and elevated temperature conditions. The paper reviews Gypsum Board thermo-chemistry, presents a methodological approach for the calculation of composition and reaction energy, and focuses on methods calculating the 'kinetic triplet'. The chemical kinetics of three main reactions that take place when a Gypsum Board is exposed at elevated temperatures: evaporation of free moisture content, dehydration of chemically bound water and crystal mesh reorganization were investigated using Differential Scanning Calorimetry measurements under non isothermal conditions and in an inert atmosphere. Experiments using samples of deionized water and commercial Gypsum Board were carried out at temperatures up to 600°C, with different heating rates. Mass and energy balance equations were considered in order to define the initial composition of a Gypsum Board and the energy that is absorbed/produced after the completion of the examined reactions. Model-free and model-fitting approaches were used for the definition of the kinetic parameters of the examined reactions. The approach minimizes the need for expensive and detailed experiments necessary for the determination of the Gypsum Board behavior at elevated temperatures. © 2011 Elsevier B.V. All rights reserved.
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Gypsum Board dehydration kinetics at autogenous water vapour partial pressure
Thermochimica Acta, 2012Co-Authors: Dimos A Kontogeorgos, Maria A FountiAbstract:In this paper, the dehydration kinetics of a commercial Gypsum Board, at autogenous water vapour partial pressure, are investigated. Differential scanning calorimetry measurements, under non isothermal conditions and in an inert atmosphere, were carried out at temperatures up to 300°C, with different heating rates. Samples of deionized water and commercial Gypsum Board, in conjunction with pin hole lid crucibles, were used in order to study the evaporation of the free moisture and the dehydration of the chemically bound water at autogenous water vapour pressure conditions. Model-free and model-fitting approaches were used for the definition of the kinetic parameters of the examined reactions. © 2012 Elsevier B.V. All rights reserved.
Trevor R.t. Nightingale - One of the best experts on this subject based on the ideXlab platform.
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On predicting structure borne sound transmission from wood studs to direct-attached Gypsum Board
2004Co-Authors: Trevor R.t. Nightingale, Klaus Köhler, J. RohlfingAbstract:A number of assumptions and simplifications are introduced when applying the mobility approach to predict structure borne transmission from wood studs to Gypsum Board that is directly attached by screws or nails. This paper examines the error introduced by three of the many simplifications. It is shown that studs do deform volumetrically, and there is a strong dependence on contact area between the studs and Gypsum Board. Also transmission at ill-defined contact points between the fastening points becomes important when there are few fasteners. Assumptions that ignore these factors may introduce bias errors but these oppose each other so that it is possible to achieve reasonable agreement between measured and predicted results despite incorrect theoretical foundations.
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On transmission of structure borne power from wood studs to Gypsum Board mounted on resilient metal channels - Part 2: Some simplifications for modelling
Canadian Acoustics - Acoustique Canadienne, 2004Co-Authors: Trevor R.t. Nightingale, Andreas MayrAbstract:The simplifications used while creating a model for structure borne transmission from a wood stud to a Gypsum Board mounted on RCs are discussed. Above 400 Hz power transmission is determined by stud translation, is propotional to the number of RCs, and is independent of number and location of fasteners between Gypsum Board and RCs. In this frequency range it is possible to use the mobility approach if RCs can be approximated by a series of idealised springs located at points of intersection between stud and RCs. The dynamic stiffness of each spring is equal to that of the RC at a stud.
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On transmission of structure borne power from wood studs to Gypsum Board mounted on resilient metal channels - Part 1: Force and moment transmission
Canadian Acoustics - Acoustique Canadienne, 2004Co-Authors: Andreas Mayr, Trevor R.t. NightingaleAbstract:The assumptions relating to power flow as a function of position and number of fasteners between the Gypsum Board and RC's was examined. It was observed that studs had both a rotational and translation motion but the translation displacement coupled more strongly than rotation. It was also observed that if the rotation velocity was less than or equal to the translation velocity, then structure borne transmission due to the rotation component could be ignored for frequencies below 2500 Hz. The results show that there is little effect associated with either the location or the number of fasteners attaching the Gypsum Board to the RC's about 315 Hz.
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On using ordinary mobilities to predict structure borne power flow from studs to directly attached Gypsum Board of a wood stud wall—Effect of simplifying assumptions
Journal of the Acoustical Society of America, 2003Co-Authors: Trevor R.t. Nightingale, Katrin KohlerAbstract:This paper reports on the effect of simplifying assumptions made when applying ordinary point mobilities (from thin plate/beam theory) to predict structure borne power, and hence velocity level difference (VLD), from a stud to Gypsum Board attached by screws. The systematic study showed for practical purposes the fastening points of a Gypsum Board sheet were sufficiently far from an edge so that the measured mobilities approached those of a drive point located near the sheet center. The mobility of a stud does not change appreciably when attached to the wall head and sole plates. Above the transition frequency from line to point connection where fastener spacing is greater than one half wavelength VLD is inversely proportional to the number of fasteners. Measurements indicate above 1000 Hz local and volumetric deformation of the stud are important causing a very significant VLD across the stud. Deep beam theory, which includes area of the contact between the stud and Gypsum Board must be included. Between 125–1000 Hz, where the basic assumptions are reasonably satisfied, there is very good agreement between measured VLD and predicted using thin plate/beam mobilities. Predictions indicate agreement above 1000 Hz is greatly improved using deep beam theory.
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On structureborne power flow from wood studs to direct-attached Gypsum Board
Canadian Acoustics - Acoustique Canadienne, 2003Co-Authors: Trevor R.t. Nightingale, Klaus KöhlerAbstract:A wall consisting of a single layer of Gypsum Board attached to a single row of wood studs which acts as one or more subsystems depending on frequency was shown. The ratio of transmitted power to source (stud) energy was reasonably independent of screw location, which was to be expected as the measured mobilities do not change appreciably if the distance from the edge was greater than 50 mm. Since the tud was highly damped and have low modal density the energy will not be uniform and the power flow will not be the same at all points.
Sumin Kim - One of the best experts on this subject based on the ideXlab platform.
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Analysis of walls of functional Gypsum Board added with porous material and phase change material to improve hygrothermal performance
Energy and Buildings, 2019Co-Authors: Ji Hun Park, Jongki Lee, Yujin Kang, Jae D. Chang, Sumin KimAbstract:Abstract Gypsum Board is widely used as a finishing material, and it is mixed with functional materials to improve the comfort level of indoor air, provide thermal insulation, and satisfy moisture properties. In addition, Phase change material (PCM) is also used as a functional material to reduce energy consumption. Recently, there have been many studies on improving moisture problems, such as condensation and mold growth. Therefore, the hygrothermal behavior of building materials must be carefully considered to reduce the risk of moisture problems. The objective of this study was to improve the thermal and moisture performance of Gypsum Board, and achieve energy savings by adding porous material and PCM. The characteristics of functional Gypsum Board (FGB) with expanded vermiculite (EV), expanded perlite (EP), nano carbon material (C300), and n-octadecane (PCM) were analyzed by fourier transform infrared (FTIR) spectroscopy for structural stability. The thermal conductivities of the various FGBs were analyzed by TCi thermal conductivity analyzer, and their hygroscopic properties were analyzed based on ISO 12,571 and 12,572. In addition, the hygrothermal performance of walls applied with FGB was evaluated using Wame und Feuchte instationar (WUFI) simulation; the wall composition was concrete wall. As a result, the thermal conductivities of FGB were decreased by 15%, compared with the conventional Gypsum Board. In the case of moisture properties, the water vapor resistance and water content of FGB were increased, compared with the conventional Gypsum Board (SR). However, the simulation results showed that there were no moisture problems, such as condensation, mold growth, or structural damage.
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Energy-Efficient Heat Storage using Gypsum Board with Fatty Acid Ester as Layered Phase Change Material
Energy technology, 2017Co-Authors: Su Gwang Jeong, Seong Jin Chang, Jongki Lee, Sumin KimAbstract:The thermal performance of phase change materials (PCMs) for energy savings is important in various fields. Fatty acid waxes are types of organic fatty acid ester PCMs made from under-used and renewable feedstocks. However, they possess one major drawback, namely their phase instability in the liquid state. Therefore, to improve stability during phase transitions, a new method of leakage prevention was developed to form the layer. The thermal properties of the layered PCM Gypsum Boards were analyzed by differential scanning calorimetry (DSC), phase change, enthalpy, and leakage tests. Finally, a dynamic heat transfer analysis of the layered PCM Gypsum Board was performed for the evaluation of the peak temperature reduction time lag effects of the prepared specimen. The latent heats of palm wax (PW) and beeswax (BW) were 178.1 and 173.6 J g−1 during heating, 159.7 and 140.9 J g−1, during freezing, respectively. Furthermore, the peak temperatures of the three wax-infused layered PCM Gypsum Board samples were reduced by 4.6, 6.6 and 0.9 °C, respectively, compared with reference Gypsum Board.
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Energy performance evaluation of heat-storage Gypsum Board with hybrid SSPCM composite
Journal of Industrial and Engineering Chemistry, 2017Co-Authors: Su Gwang Jeong, Seong Jin Chang, Seunghwan Wi, Jongki Lee, Sumin KimAbstract:Gypsum Board with hybrid shape-stabilized PCM (hybrid SSPCM) was developed and it is composed of n-octadecane and beeswax based SSPCM. The characteristics of the hybrid SSPCM Gypsum Boards were analyzed by fourier transform infrared (FTIR) spectroscopy, differential scanning calorimeter (DSC), enthalpy analysis, thermogravimetric analysis (TGA) and thermal conductivity analyzer (TCi). From the analyses, the hybrid SSPCM led to enhanced thermal storage property and that the Gypsum Board with 30 wt% of hybrid SSPCM has a high latent heat capacity. And the SSPCM led to a enhancement of the thermal conductivity of Gypsum Board by thermal conductivity analysis.
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Development of heat storage Gypsum Board with paraffin-based mixed SSPCM for application to buildings
Journal of Adhesion Science and Technology, 2016Co-Authors: Su Gwang Jeong, Seong Jin Chang, Yujin Kang, Hwayoung Lee, Sumin KimAbstract:AbstractLatent heat thermal energy storage using phase change materials (PCMs) is considered to be the method with the most potential to solve the energy shortage problem. In this study, paraffin-based mixed shape-stabilized PCM (SSPCM) (PBMS) was made by vacuum impregnation method. The prepared PBMS was added to Gypsum powder as a fine aggregate. In the experiment, the n-hexadecane and n-octadecane was used as the PCM and the materials have latent heat capacities of 254.7 and 247.6 J/g, and melting points of 20.84 and 30.4 °C, respectively. The PBMS was prepared by an impregnation method in a vacuum, following the manufacturing process. The physical and thermal properties of the PBMS Gypsum Board were analyzed by Fourier transform infrared spectrometry (FTIS), differential scanning calorimetry, enthalpy analysis, and thermogravimetric analysis. From the Fourier transform infrared analysis, PBMS could be maintained in the structure of the Gypsum Board due to its physical rather than chemical bonding. From...
G. Carisse - One of the best experts on this subject based on the ideXlab platform.
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a model for predicting heat transfer through Gypsum Board wood stud walls exposed to fire
Fire and Materials, 1994Co-Authors: J. R. Mehaffey, P. Cuerrier, G. CarisseAbstract:To facilitate the development of cost-effective and flexible design options there is a need to develop models to predict the fire resistance of wood-frame building assemblies. Such assemblies often derive much of their fire resistance from a protective membrane composed of Gypsum Board. A simple two-dimensional computer model is presented to predict heat transfer through Gypsum-Board/wood-stud walls exposed to fire. Input data for the thermophysical properties of Gypsum Board were measured exploying standard bench-scale tests. Input data for wood were selected from the literature. Small-and full-scale fire resistance tests were conducted on Gypsum-Board/wood-stud wall assemblies to provide data for the validation of the model. The model is shown to predict heat transfer through these walls rather well.
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A model for predicting heat transfer through Gypsum‐Board/wood‐stud walls exposed to fire
Fire and Materials, 1994Co-Authors: J. R. Mehaffey, P. Cuerrier, G. CarisseAbstract:To facilitate the development of cost-effective and flexible design options there is a need to develop models to predict the fire resistance of wood-frame building assemblies. Such assemblies often derive much of their fire resistance from a protective membrane composed of Gypsum Board. A simple two-dimensional computer model is presented to predict heat transfer through Gypsum-Board/wood-stud walls exposed to fire. Input data for the thermophysical properties of Gypsum Board were measured exploying standard bench-scale tests. Input data for wood were selected from the literature. Small- and full-scale fire resistance tests were conducted on Gypsum-Board/wood-stud wall assemblies to provide data for the validation of the model. The model is shown to predict heat transfer through these walls rather well.
