scholarly journals Mechanical and thermal characterization of compact blocks made of clayey earth with wood ashes addition

2020 ◽  
Vol 307 ◽  
pp. 01030
Author(s):  
Gbénondé Sèna Gladys Milohin ◽  
Sènouhoua Victor Gbaguidi ◽  
André Donnot ◽  
Malahimi Anjorin ◽  
Riad Benelmir
Keyword(s):  
Building Materials ◽  
Variable Mass ◽  
Thermal Characteristics ◽  
Thermal Characterization ◽  
Mechanical Tests ◽  
Thermal Tests ◽  
Hot Strip ◽  
Simple Compression ◽  
French Association

The objective of this study is to evaluate the influence of wood ashes on the mechanical and thermal characteristics of the clayey earth-ashes compound (CEAC) compressed blocks. Variable mass percentages of 0% to 60% of wood ashes were incorporated to clayey earth stabilized with 10% of cement. The physical characteristics of the clayey earth were determined according to the protocols of the french association of normalization. The manufactured blocks were subjected to mechanical tests: simple compression and tensile by bending. The thermal conductivity was then appreciated by the method of the hot strip. The blocks made with a mixture of “90% clayey earth” and “10% cement”, usually used in construction in Benin, served as a reference material. From the results obtained, it appears that the clayey earth used is a soil A2ts: fine clayed sand in a very dry state. The results of the mechanical and thermal tests show that for an addition of wood ashes between 10% and 20% by weight, the performances of the blocks are significantly improved. The CEAC blocks formulated from 80% of the mixture “90% of clayey earth and 10% of cement” and 20% of wood ashes can be used as building materials.

Thermal and Physico-Mechanical Characterization of Paraíba’s State Soils to Applying in Soil-Cement Bricks

2008 ◽  
Vol 591-593 ◽  
pp. 532-536 ◽  
Author(s):  
Crislene Rodrigues da Silva Morais ◽  
Marcelo Rodrigues Leite ◽  
Luciana de Figueiredo L. Lucena ◽  
Railda Shelsea T. Rocha do Nascimento
Keyword(s):  
Building Materials ◽  
Thermal Characteristics ◽  
Decisive Role ◽  
Thermal Characterization ◽  
Additional Time ◽  
Soil Cement ◽  
Three Samples ◽  
Production Techniques ◽  
Negative Impacts

Soils play a decisive role in the manufacture of building materials, especially, tiles and bricks. Production techniques cause negative impacts on the environment and add additional time to the production process. Three samples obtained from Paraíba State were characterized by thermal characterization, granulometric and physical-mechanical techniques. Thermal analysis was undertaken in two different atmospheres, at a flow rate of 110 ml/min and a heating rate of 10oC/min. Evaluation of the soils through their thermal characteristics for use in soil-cement bricks production is elucidated.

scholarly journals Thermal Characterization of Recycled Materials for Building Insulation

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3564
Author(s):  
Arnas Majumder ◽  
Laura Canale ◽  
Costantino Carlo Mastino ◽  
Antonio Pacitto ◽  
Andrea Frattolillo ◽  
...  
Keyword(s):  
Environmental Impact ◽  
Environmental Sustainability ◽  
Building Materials ◽  
Raw Materials ◽  
Natural Fibers ◽  
Thermal Characterization ◽  
Recycled Materials ◽  
Building Insulation ◽  
Operational Phase

The building sector is known to have a significant environmental impact, considering that it is the largest contributor to global greenhouse gas emissions of around 36% and is also responsible for about 40% of global energy consumption. Of this, about 50% takes place during the building operational phase, while around 10–20% is consumed in materials manufacturing, transport and building construction, maintenance, and demolition. Increasing the necessity of reducing the environmental impact of buildings has led to enhancing not only the thermal performances of building materials, but also the environmental sustainability of their production chains and waste prevention. As a consequence, novel thermo-insulating building materials or products have been developed by using both locally produced natural and waste/recycled materials that are able to provide good thermal performances while also having a lower environmental impact. In this context, the aim of this work is to provide a detailed analysis for the thermal characterization of recycled materials for building insulation. To this end, the thermal behavior of different materials representing industrial residual or wastes collected or recycled using Sardinian zero-km locally available raw materials was investigated, namely: (1) plasters with recycled materials; (2) plasters with natural fibers; and (3) building insulation materials with natural fibers. Results indicate that the investigated materials were able to improve not only the energy performances but also the environmental comfort in both new and in existing buildings. In particular, plasters and mortars with recycled materials and with natural fibers showed, respectively, values of thermal conductivity (at 20 °C) lower than 0.475 and 0.272 W/(m⋅K), while that of building materials with natural fibers was always lower than 0.162 W/(m⋅K) with lower values for compounds with recycled materials (0.107 W/(m⋅K)). Further developments are underway to analyze the mechanical properties of these materials.

scholarly journals Impact of spineless cactus cultivation (O. Ficus-indica) on the thermal characteristics of soil

2018 ◽  
Vol 13 (1) ◽  
pp. 1
Author(s):  
Willames De Albuquerque Soares
Keyword(s):  
Heat Capacity ◽  
Thermal Characteristics ◽  
Thermal Characterization ◽  
Biological Processes ◽  
Volumetric Heat Capacity ◽  
Average Value ◽  
Brazilian Semiarid ◽  
Cultivation Techniques ◽  
Soil Changes

Temperature is a fundamentally important factor for understanding the physical, chemical, and biological processes that occur in soil. However, there are few studies in the Brazilian semiarid zone that seek to understand how soil degradation affects its thermal characteristics. The objective of this study was to evaluate the influence of cultivation techniques on the thermal characterization of soil, using the model proposed by Johansen. The study was conducted in the Agreste region of the state of Pernambuco, Brazil on two plots of land, one with native vegetation (Caatinga) and the other with spineless cactus (O. ficus - indica). It was observed that the procedures used to prepare the soil for cultivation of spineless cactus caused a reduction in the capacity to transmit the surface temperature to the interior of the soil. Changes in the physical properties of the soil required for cultivation resulted in a reduction in the average value of the volumetric heat capacity of about 22%; an increase of approximately 5% in the average volumetric heat capacity and a 26% increase in the thermal diffusivity of the soil, as well as a reduction of approximately 50% in the heat flux from the surface of the soil.

Thermal Characterization of Non-Isolated DC to DC Convertor

2011 ◽  
Author(s):  
Shiladitya Chakravorty ◽  
Bahgat Sammakia ◽  
Varaprasad Calmidi
Keyword(s):  
Power Dissipation ◽  
High Performance ◽  
Field Effect Transistors ◽  
Thermal Characteristics ◽  
Thermal Characterization ◽  
Input Voltage ◽  
Thermal Design ◽  
Power Module ◽  
Improved Performance

Improved performance of semiconductor devices in recent years has resulted in consequent increase in power dissipation. Hence thermal characterization of components becomes important from an overall thermal design perspective of the system. This study looks at a high performance non-isolated point of load power module (a DC to DC converter) meant for advanced computing and server applications. Thermal characteristics of the module were experimentally analyzed by placing the power module on a bare test board (with no insulation) inside a wind tunnel with thermocouples attached to it. There were three devices on this module that dissipate power. There were two FETs (Field Effect Transistors) and an inductor which can be considered as sources. The consolidated power dissipation from the module was calculated by measuring the input voltage and input current while keeping the output voltage and current constant. Temperatures at various points on the module and the test card were recorded for different air flow velocities and overall power dissipation. Subsequently this set up was numerically analyzed using a commercially available computational fluid dynamics (CFD) code with the objective of comparing the results with experimental data previously obtained.

Thermal Characterization of Bacterial Cellulose/Polyvinyl Alcohol Nanocomposite

2015 ◽  
Vol 1123 ◽  
pp. 303-307 ◽  
Author(s):  
Akhmad Zainal Abidin ◽  
Hafis Pratama Rendra Graha
Keyword(s):  
Bacterial Cellulose ◽  
Melting Temperature ◽  
Healing Process ◽  
Thermal Characteristics ◽  
Cost Effective ◽  
Thermal Characterization ◽  
Fermentation Medium ◽  
Scanning Calorimetry ◽  
Regeneration Rate

Bacterial cellulose (BC) is a natural polymer which can be produced from various substrates easily found in Indonesia. Bacterial cellulose is believed to be a promising and cost effective bone scaffold in which a bone regeneration rate enhanced so the healing process is faster. In this experiment, Bacterial Cellulose (BC)/ Polyvin y l Alcohol (PVA) nanocomposite was made to give a further improvement in the properties. This nanocomposite was made thorough BC biosynthesis in Gluconacetobacter xylinus fermentation medium that was modified by addition of PVA. The PVA concentrations were varied as 0, 3, 6, 9, and 12 % w of fermentation medium. The culture had been agitated by magnetic stirrer for 28 days before freeze drying method was conducted to obtain dry BC/PVA nanocomposite. The product of BC/PVA nanocomposite was then studied for thermal characteristics using Differential Scanning Calorimetry (DSC) and Thermogravimetry Analysis (TGA). Pure BC has melting temperature (Tm) at 350 . 3oC and pure PVA at 181 . 3oC. Experimental results showed that the higher PVA content in fermentation medium decreased the melting temperature of BC/PVA nanocomposite produced.

Non-contact photopyroelectric approach for complete thermal characterization of porous building materials

2021 ◽  
pp. 178943
Author(s):  
Carmen Tripon ◽  
Nicoleta Cobȋrzan ◽  
Radu Fechete ◽  
Anca-Andreea Balog ◽  
Robert Gutt ◽  
...  
Keyword(s):  
Building Materials ◽  
Thermal Characterization ◽  
Porous Building Materials

Processing and thermal characteristics of human hair fiber-reinforced polymer composites

2019 ◽  
Vol 28 (4) ◽  
pp. 252-264
Author(s):  
Bishnu Prasad Nanda ◽  
Alok Satapathy
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Human Hair ◽  
Thermal Characteristics ◽  
Thermal Characterization ◽  
Fiber Reinforced Polymer Composites ◽  
Mathematical Correlation ◽  
Low Thermal Expansion ◽  
Hair Fiber

Human hair is a biofiber having an exceptional chemical composition, higher strength in tension, and slow decomposition rate. In the present work, composites are fabricated by simple hand layup technique with epoxy matrix and different proportions of hair fiber (0, 5, 10, 15, and 20 wt%). Physical, mechanical, microstructural, and thermal characterization of the composite samples has been done by following the proper ASTM standards. A theoretical model has been developed to predict the effective thermal conductivity of the composite. Based on this model, a mathematical correlation between the effective thermal conductivity of the composite and the fiber content is developed. The results obtained from this correlation are in good agreement with the experimental data. This study explores the possibility of fabricating a class of epoxy composites with higher mechanical strength, superior insulation capability, improved glass transition temperature, and a low thermal expansion coefficient.

scholarly journals Influence of Calcium Ions on the Thermal Characteristics of α-amylase from Thermophilic Anoxybacillus sp. GXS-BL

2019 ◽  
Vol 26 (2) ◽  
pp. 148-157 ◽  
Author(s):  
Si-Ming Liao ◽  
Ge Liang ◽  
Jing Zhu ◽  
Bo Lu ◽  
Li-Xin Peng ◽  
...  
Keyword(s):  
Calcium Ions ◽  
Thermal Denaturation ◽  
Thermal Inactivation ◽  
3D Structure ◽  
Thermal Characteristics ◽  
Thermal Characterization ◽  
Soluble Starch ◽  
Dsc Measurements ◽  
Irreversible Unfolding

Background: &#945;-Amylases are starch-degrading enzymes and used widely, the study on thermostability of &#945;-amylase is a central requirement for its application in life science and biotechnology. </P><P> Objective: In this article, our motivation is to study how the effect of Ca2+ ions on the structure and thermal characterization of &#945;-amylase (AGXA) from thermophilic Anoxybacillus sp.GXS-BL. </P><P> Methods: &#945;-Amylase activity was assayed with soluble starch as the substrate, and the amount of sugar released was determined by DNS method. For AGXA with calcium ions and without calcium ions, optimum temperature (Topt), half-inactivation temperature (T50) and thermal inactivation (halflife, t1/2) was evaluated. The thermal denaturation of the enzymes was determined by DSC and CD methods. 3D structure of AGXA was homology modeled with α-amylase (5A2A) as the template. </P><P> Results: With calcium ions, the values of Topt, T50, t1/2, Tm and &#916;H in AGXA were significantly higher than those of AGXA without calcium ions, showing calcium ions had stabilizing effects on &#945;-amylase structure with the increased temperature. Based on DSC measurements AGXA underwent thermal denaturation by adopting two-state irreversible unfolding processes. Based on the CD spectra, AGXA without calcium ions exhibited two transition states upon unfolding, including &#945;- helical contents increasing, and the transition from &#945;-helices to &#946;-sheet structures, which was obviously different in AGXA with Ca2+ ions, and up to 4 Ca2+ ions were located on the inter-domain or intra-domain regions according to the modeling structure. </P><P> Conclusion: These results reveal that Ca2+ ions have pronounced influences on the thermostability of AGXA structure.

scholarly journals Mechanical characterization and reinforcement of the adobe material of the Chellah archaeological site

2020 ◽  
Vol 150 ◽  
pp. 03022
Author(s):  
Sana Simou ◽  
Khadija Baba ◽  
Nacer Akkouri ◽  
Mohammed Lamrani ◽  
Mohammed Tajayout ◽  
...  
Keyword(s):  
Building Materials ◽  
Mechanical Characterization ◽  
Archaeological Site ◽  
Mechanical Tests ◽  
Actual State ◽  
Historical Buildings ◽  
Support Intervention ◽  
Sem Study ◽  
Wood Shaving

The evaluation of historical buildings has always posed significant challenges due to the difficulties associated with the characterization of complex geometries, the variability of the properties of building materials and the actual state of damage to these structures. This challenge is even more complex when it concerns historical adobe masonry buildings, because earthen masonry has a high variability and rapid deterioration over time if it is not properly maintained. In the context of the previous, it was important to provide information to support intervention projects in historic centres. This research involves the experimental analysis of the adobe material collected from the Chellah archaeological site (Rabat-Morocco), in order to study the mechanical behaviour of this material as well as that reinforced by wood shaving. A series of mechanical tests carried out, which include compressive and tensile strength on the adobe material and the mixture adobe/wood fibre in different proportions. The improvement of the mechanical properties of the reinforced adobe, led us to a SEM study, which was carried out on the surface of the test specimens to examine the morphology and observe the interfaces of the adobe/wood mixture, as well as the state of dispersion of the fibres in the adobe mixture.

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