Papers by Keyword: Thermal

Abstract: The building sector is one of the biggest consumers of energy in the world and it is pushing the scientific community to find various alternative solutions to solve the problem of thermal insulation of buildings. Therefore, the selection of appropriate building materials is a major challenge for improving the thermal comfort and energy performance of buildings. In this scenario, the interest of plaster-based composites as insulating materials increases, in particular for new applications, as insulators for the building envelope, and this deserves to be studied. In this investigation, new plaster-based composites with cork were produced and tested at lab scale, in order to obtain cheap solutions with improved thermo-physical and acoustic performance. The results show that it is possible to improve the thermal, mechanical, and acoustic performance of construction biomaterials by using plaster as a binder and cork as a natural reinforcement: thermal conductivity was equal to 0.097 W/m.K, the compressive strength to about 2.30 MPa, and the transmission loss to about 40 dB. Keywords: Plaster-Gypsum; Cork; Thermal, Mechanical and Acoustic Properties.

Abstract: This research Investigates the new composite materials are fabricated of two or more materials raised. The fibers material from the sources of natural recycled materials provides certain benefits above synthetic strengthening material given that very less cost, equivalent strength, less density, and the slightest discarded difficulties. In the current experiments, silk and fiber-reinforced epoxy composite material is fabricated and the mechanical properties for the composite materials are assessed. New composite materials samples with the dissimilar fiber weight ratio were made utilizing the compression Molding processes with the pressure of 150 pa at a temperature of 80 °C. All samples were exposed to the mechanical test like a tensile test, impact loading, flexural hardness, and microscopy. The performing results are the maximum stress is 33.4MPa, elastic modulus for the new composite material is 1380 MPa, and hardness value is 20.64 Hv for the material resistance to scratch, SEM analysis of the microstructure of new composite materials with different angles of layers that are more strength use in industrial applications.

Abstract: The reinforcement effect of nanofiller in polymer enhanced the thermal stability, physical and mechanical properties of poly (lactic acid) (PLA) composites with good reinforcing capabilities for bio-based polymers. In this paper, the effect of reinforcement of titanium dioxide (TiO₂) nanofiller on the mechanical properties and thermal behavior of PLA matrix are reported. PLA/TiO₂ nanocomposites with different percentages of 2.0, 3.5, 5.0 and 7.0 %∙w/w were prepared by using solvent casting method and hot press machine. TiO₂ were dispersed in PLA matrix using mechanical mixer and ultrasonication technique. The mechanical properties and thermal behavior of PLA nanocomposites were characterized using dynamic mechanical analysis (DMA) and differential scanning calorimeter (DSC). The increased in storage modulus by the addition of nanofiller with the highest increment provided by 2.0 %·w/w TiO₂ indicated a strong influence and better interfacial bonding between nanofiller and PLA matrix. An increased in storage modulus started at 100 °C that linked to the cold crystallization (T_cc) of PLA composites is in agreement with DSC result. The T_cc shifted to higher temperature as the content of nanofiller increased and this result were observed at 2.0 %·w/w of the nanofiller content. Reinforcement of nanofiller increased the melting temperature from lower filler loading until 5.0 %·w/w. The incorporation of TiO₂ nanofiller as the reinforcement agent for PLA has a potential in biopolymer medical engineering and packaging industry, a highly competitive application with a great demand of cost and performance.

Abstract: The addition of nanoclay within polymer matrix is anticipate to enhance the properties of the polymer system. Nonetheless, one of the key elements in property enhancements of a polymer nanocomposites is the surface modifications of the nanoclay. This is due to the affinity between polymer matrix and nanoclay is of important factors should be considered. In this study, amorphous polyamide were melt blended with different nanoclay grades with different surface modifications in order to evaluate the best clay grade for the polymer system. The thermal analysis carried out on the amorphous polyamide nanocomposites were carried out by means of differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) whereas the mechanical properties were investigated using tensile testing. It was observed that there were changes in the glass transition temperature (T_g) of the nanocomposites due to clay additions. Further, the storage modulus was found to increase as a result of nanoclay incorporation. The type of clay grades significantly affects the mechanical properties of the amorphous polyamide nanocomposites.

Abstract: Engineering Science Based on Modelling and Simulation (M & S) is defined as the discipline that provides the scientific and mathematical basis for simulation of engineering systems. These systems range from microelectronic devices to automobiles, aircraft, and even oilfield and city infrastructure. In a word, M & S combines knowledge and techniques in the fields of traditional engineering - electrical, mechanical, civil, chemical, aerospace, nuclear, biomedical and materials science - with the knowledge and techniques of fields such as computer science, mathematics and physics, and social sciences. One of the problems that arise during solar cell operation is that of heating them because of permanent solar radiation. Since the layers of which they are made are very small and thick it is almost impossible to experimentally determine the temperature in each layer. In this sense, the finite element method comes and provides a very good prediction and gives results impossible to obtain by other methods. This article models and then simulates the thermal composition of two types of solar cells, one of them having an additional layer of silicon carbide that aims to lower the temperature in the lower layer, where the electronic components stick to degradable materials under the influence of heat.

Abstract: The present study investigated the effects of untreated (UM) and treated (TM) muscovite fillers on the morphological and thermal properties of acrylonitrile-butadiene-styrene (ABS) composites. The TM produced from a two-stage ion-exchange process and ABS composites were compounded using melt blending. ABS/muscovite layered silicate composites were characterized using Field emission scanning electron microscope (FESEM) and transmission electron microscopy (TEM) while the thermal properties was investigated through Thermogravimetric (TGA) analysis. It was found that ABS/TM recorded higher thermal properties when compared to neat ABS and ABS/UM. The FESEM images showed better dispersion of ABS/TM compared to ABS/UM. Finally, mixed morphology of intercalated-exfoliated structure of composites was proven by TEM analysis.

Abstract: Despite growing interest in sustainable office buildings and technological advancements, often either comfort or energy is sacrificed at the expense of the other in the conventional approach. Designers and architects tend to lean towards fully glazed buildings in a multi-floor office building due to its light structure, transparency and more access to daylight compared to traditional buildings. However, their energy efficiency and impact on occupant comfort – thermal, glare and visual – are questioned. Some practitioners, therefore, prefer a fully sealed façade with a low glazing ratio to reduce energy consumption. This paper argues that wellness and energy savings are not contradictory aspects of design. It is shown that measures to create an exceptional, healthy environment for occupants drive conservation and energy efficiency. Such design needs special considerations at the early stages that significantly affect decisions regarding passive strategies. To help drive first decisions, an accurate and fast simulation tool that considers dynamic thermal, daylight and airflow models is required. However, some passive measures such as natural ventilation are more difficult to simulate and validate due to the complex, non-linear relationship between wind forces and thermal buoyancy. The aim of this paper is to demonstrate the use of TRNLizard, an integrated thermal, daylight and airflow simulation tool based on Rhinoceros 5, Grasshopper, TRNSYS18, DaySIM and TRNFlow to develop and validate the concept for an energy efficient office building with a healthy, comfortable environment. The office building is located in Germany with a highly glazed façade and night ventilation for passive cooling. It is shown that night flushing reduces annual end-use cooling energy and peak cooling load of mechanical air conditioning systems by 55% and 15%, respectively.

Abstract: This research examines the influences of minor addition of Zn on the thermal and mechanical properties in Sn-0.7Cu solder alloy. The addition of 0.5, 1.0 and 1.5 wt.% of Zn were added into Sn-0.7Cu by using conventional casting method. It show that minor Zn addition has refined and promoted the nucleation of β-Sn phase. The vickers hardness show a increases the hardness of Sn-0.7Cu solder alloy with increasing amount of Zn. For thermal properties, with a small addition of Zn, it did not change the melting but has a slight decrease the undercooling of Sn-0.7Cu solder alloy.

Abstract: This work reports on mechanical and thermal properties of a novel polymer blend. Blends were prepared by mixing silicone rubber with diphenyl – 4,4 – dissocyanate in different ratios. Graphene nanoplatelets was added as conductive filler to improve the electrical conductivity of the blends. The mechanical properties, including tensile and tear performances were measured by a material testing system. The thermal stability of the blends was measured by thermogravimetric analysis. Incorporation 20 vol.% of silicone rubber can help to improve the thermal stability of the blend, meanwhile optimum mechanical properties of the blends is achieved.

Abstract: Building structures have been designed such that they are able to withstand the adverse effects of the environment for a certain time. The terms "for a certain time" and "the surrounding environment" are used for a purpose here, and that is because the phenomenon of ageing buildings is currently an increasingly discussed problem that is faced by every larger city. The materials used in the buildings, such as façade cladding, age just as the buildings themselves do. An immense pressure has been currently put on designers to use environmentally friendly materials not only for new buildings but also for the retrofitting of existing ones. The aim of this paper is to demonstrate that wood or wood composite materials are convenient solution for restoration of façades of administrative or commercial buildings, however, since the new cladding have to be connected with an old load-bearing structure, the designers have to overcome many limitations. One of the main difficulties is high thermal and moisture expansion of these materials which has a direct impact on the appearance of the façade. The obtained results showed that expansion properties should be studied closely when using wooden elements in the design and that a neglection can lead to a premature failure of the system.