Traditional building heating warms entire rooms, often leaving some dissatisfied with uneven warmth. Recently, the personalized heating system has addressed this by providing targeted warmth, enhancing comfort and satisfaction. The personalized heating system in this study is a new enclosed personalized heating system consisting of a semi-enclosed heating box and an insulated chair covered with a thick blanket. The study compares the heating effects of semi-enclosed and enclosed localized heating systems on the body and examined changes in subjects’ thermal sensations. Due to the lower heat loss of the enclosed personalized heating system compared to the semi-enclosed version, it created thermal micro-environments with higher ambient temperatures. The maximum air temperature increase within the enclosed system was twice that of the semi-enclosed system, with the heating film surface temperature rising by up to 6.87 ℃. Additionally, the temperature of the skin could increase by as much as 6.19 ℃, allowing individuals to maintain thermal neutrality even when the room temperature dropped as low as 8 ℃. A two-factor repeated measures analysis of variance revealed differences in temperature sensitivity across various body regions, with the thighs showing a notably higher response under high-power heating conditions. The corrective energy and power requirements of the enclosed personalized heating system also made it more energy-efficient than other personalized heating systems, with a minimum value reaching 6.07 W/K.
In order to understand the finishing effect of Waterborne Acrylic Paint under different painting methods and amount, bamboo-laminated lumber for furniture was coated with waterborne acrylic paint, then the effects of different painting methods and amount on the drying rate, smoothness, hardness, adhesion and wear resistance of the paint film were investigated. Further, the mechanism of film formation was described by thermal property analysis using thermogravimetry and differential scanning calorimeter. The results show that different painting methods have little effect on film properties, the drying time of primer and topcoat are not affected by them, which is 8/8.5 min for primer surface/solid and 6.5/7 min for topcoats. The film surface hardness and adhesion can reach B and 0 grade, the best wear resistance of the film is 51.24 mg·100 r−1 when using one-layer primer one-layer topcoat. Different coating amount has great influence on film properties, the drying speed of the film increases with the increase of the painting amount. The film properties reach the best when the painting amount is 80 g/m2, while too little painting amount leads to the decrease of hardness, and too much leads to the wear resistance weaken. Thermal analysis of the primer and topcoat show that water decomposition occurs at 100 ℃ and thermal decomposition of organic components occur at 350 ℃. Topcoats have better thermal stability than primers higher than that of topcoat, the topcoat displayed better thermal stability than the primer.
The need for global energy conservation has become more urgent because of the negative effects of excessive energy use, such as higher fuel consumption, greater environmental pollution, and depletion of the ozone layer. There has been a significant increase in the demand for central and high-capacity household air conditioning systems in Muscat in recent years. The need for this is influenced by factors such as arid climate, increasing temperatures, air pollution, and population increase. As a result, there has been a significant increase in electricity use, putting a strain on power resources. To tackle this difficulty, the incorporation of solar collectors as supplementary thermal compressors in air conditioning systems offers a chance to utilise renewable energy sources. The objective of this hybrid technique is to enhance the effectiveness of cooling systems, hence minimising the need for electricity and lowering the release of environmental pollutants.
Work is reported on thermal-induced redshifts of quantum particle plasmon. The redshifts are predicted to be caused indirectly by the quantum size effects. The particles are enlarged when temperature increases, and consequently, quantum size effects modify the plasmon but not the band structure. It has been modeled for metallic quantum particles. The results are also instructive to other quantum systems, such as complex molecules. Every electron inside the quantum particle is taken into account. Tiny quantum size effects are harvested, and the redshift becomes significant. Experimental evidence is also given for the spectral redshift. Faujasite zeolites were synthesized. Optical spectroscopy has been carried out, and the resulting spectra showed a significant redshift with the increase in temperature.
Heat transfer enhancement (HTE) is a topic of everlasting importance in thermal engineering research. The latest focuses in this field are on nanosolutions for more efficient thermal transmission fluids (a) and designs of metallic foams (b) Metallic foams provide extended surfaces for HTE and possess advantages such as a high value of Cp, high thermal conductivity (TC) and being light weight. nanosolutions, on the other hand, can be used as an efficient HT medium as they exhibit higher TCs in comparison to base fluids. This review paper summarizes the physical properties of nanosolutions and or within the metal foam, focusing on HT and flow properties of nanosolutions, metal foam and combined NS-metal foam systems. The inspiration novelty for this review is the basic transference identifications for the HT enhancement of nanosolutions in porous media. The aim of the work is to provide insight on how nanosolutions in conjunction with porous media can be useful for HTE.
This investigation derives formulas to predict the mixed convective surface conductance of a flat isotropic surface roughness having a convex perimeter in a Newtonian fluid with a steady forced flow in the plane of that roughness. Heat transfer measurements of a 30.5 cm square rough plate with forced air velocities between 0.1 m/s and 2.5 m/s were made by the present apparatus in two inclined and all five orthogonal orientations. The present work’s formulas are compared with 104 measurements in twelve data-sets. The twelve data-sets have root-mean-square relative error (RMSRE) values between 1.3% and 4% relative to the present theory. The present work’sformulas are also compared with 78 measurements in 28 data-sets on five vertical rough surfaces in horizontal flow from prior work. The five stucco data-sets have RMSRE values between 2.5% and 6.5%; the other data-sets have RMSRE values between 0.2% and 5%.
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