Research Article
Thermomechanical Characterization and Numerical Modeling of Thermal Transfer of Plaster-based Insulating Composite Materials with Gradual Typha Contents
El Hadji Abdoul Aziz Cisse*
,
Papa Touty Traore,
Seydou Faye,
Moussa Dieng,
Mor Ndiaye,
Issa Diagne
Issue:
Volume 14, Issue 2, June 2025
Pages:
36-45
Received:
18 March 2025
Accepted:
2 April 2025
Published:
16 June 2025
DOI:
10.11648/j.am.20251402.11
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Abstract: The building and construction sectors are responsible for 39% of global greenhouse gas emissions, but they are among the largest consumers of energy. If all indicators show that demand would be exponential in the future. Decarbonization and reduction of energy consumption in buildings are urgent for environmental preservation and resilience to extreme temperature increases. This article aims to present environmentally friendly bio-sourced insulation as a more sustainable circular economy strategy. However, we present the results of thermal and mechanical characterization of plaster samples with the addition of typha fibers in different proportions. Thus, after having carried out the mechanical traction and compression tests by the press, a thermophysical characterization by the asymmetric hot plane method allowed us to have the conductivity and thermal effusivity of the different samples of plaster binder with 0%, 5%, 10%, 15% and 20% in typha. With these data, we modeled the heat transfer phenomena in a flat wall based on plaster-typha. A numerical resolution of the heat equation by the finite difference method is applied to this model along one dimension. After simulating the calculation code, the results obtained made it possible to know the evolution of the temperature as a function of time and the depth of the wall. In addition, the influence of the exchange coefficients was highlighted on both sides, in order to know the optimal thermal insulation thickness of each sample.
Abstract: The building and construction sectors are responsible for 39% of global greenhouse gas emissions, but they are among the largest consumers of energy. If all indicators show that demand would be exponential in the future. Decarbonization and reduction of energy consumption in buildings are urgent for environmental preservation and resilience to extr...
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Research Article
Effect of Heat Treatment on the Matrix Structure and Properties of Bч60 Ductile Cast Iron
Nguyen Hong Hai*,
Nguyen Hoang Viet
Issue:
Volume 14, Issue 2, June 2025
Pages:
46-54
Received:
6 May 2025
Accepted:
19 May 2025
Published:
30 June 2025
Abstract: Ductile iron represents a family of alloys with a wide range of properties achievable through controlled manipulation of the matrix microstructure. Furthermore, its lower cost compared to steel and superior properties to gray iron make ductile iron a favorable choice in many engineering applications. The higher carbon and silicon content in ductile iron significantly alters its mechanical properties. The elevated carbon content increases its susceptibility to quench cracking, while the higher silicon content decreases carbon solubility in austenite, leading to graphite precipitation and a ferritic matrix during slow cooling. Consequently, heat treatment is a critical process for optimizing ductile iron properties. Different grades of ductile iron castings are produced by obtaining different matrix microstructures, which are primarily achieved through heat treatment and cannot be readily obtained in the as-cast condition. This study investigates the effects of different heat treatment processes on the microstructure and mechanical properties of BЧ60 (VCh60) ductile iron, conforming to the Russian standard ГOCT 7293-85. To optimize the heat treatment parameters, this research utilized Thermo-Calc and JmatPro software to construct phase diagrams and generate Continuous Cooling Transformation (CCT) and Time-Temperature-Transformation (TTT) diagrams. These diagrams were instrumental in predicting optimal heat treatment parameters for achieving desired microstructures and mechanical properties. Consequently, this computational approach enabled the selection of appropriate heat treatment strategies for the investigated ductile iron.
Abstract: Ductile iron represents a family of alloys with a wide range of properties achievable through controlled manipulation of the matrix microstructure. Furthermore, its lower cost compared to steel and superior properties to gray iron make ductile iron a favorable choice in many engineering applications. The higher carbon and silicon content in ductile...
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Research Article
Effects of Tin Doping Concentration on the Structural and Optical Properties of Cadmium Oxide Nanoparticles
Issue:
Volume 14, Issue 2, June 2025
Pages:
55-64
Received:
23 May 2025
Accepted:
9 June 2025
Published:
30 June 2025
Abstract: Wet chemical process was successfully used to synthesize tin doped and undoped cadmium oxide nanoparticles. Cadmium acetate, sodium hydroxide, mercaptopropionic acid and tin chloride were used as starting materials for synthesizing the nanoparticles. The reaction was carried out in a single three-necked flask under reflux at 80°C for 2 hours and the solution was allowed to cool to room temperature. The precipitate was washed, dried, annealed and grounded to obtain the powder for further analysis. The phase and structure of the nanoparticles was studied using the X-ray diffraction equipment. Debye Scherrer’s equation was used to calculate the crystallite sizes of the doped and undoped nanoparticles. The XRD pattern displayed face centered cubic structure of cadmium oxide. When CdO was doped with Sn the intensity peaks decreased from 1650 a. u for pure CdO to 1235 a. u at 1% Sn doped and at 3.5% Sn doped, the intensity peak was 239 a. u. Increase in the doping concentration resulted in significant increase in grain size. Optical properties investigated for different doping concentration of tin showed that all the samples exhibited the well-defined absorption bands in the range of 298 nm to 340 nm. The bandgap energy was found to be 3.69 eV for pure CdO and a realistic decrease when doped. The corresponding PL spectra with the excitation wavelength of 320 nm displayed a narrow emission at 429 nm. The obtained results displayed good material properties of the NPs suitable for possible solar cell applications.
Abstract: Wet chemical process was successfully used to synthesize tin doped and undoped cadmium oxide nanoparticles. Cadmium acetate, sodium hydroxide, mercaptopropionic acid and tin chloride were used as starting materials for synthesizing the nanoparticles. The reaction was carried out in a single three-necked flask under reflux at 80°C for 2 hours and th...
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