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81.
Air pollution is a major health problem in developing countries and has adverse effects on human health and the environment. Non-thermal plasma is an effective air pollution treatment technology. In this research, the performance of a dielectric barrier discharge (DBD) plasma reactor packed with glass and ceramic pellets was evaluated in the removal of SO2 as a major air pollutant from air in ambient temperature. The response surface methodology was used to evaluate the effect of three key parameters (concentration of gas, gas flow rate, and voltage) as well as their simultaneous effects and interactions on the SO2 removal process. Reduced cubic models were derived to predict the SO2 removal efficiency (RE) and energy yield (EY). Analysis of variance results showed that the packed-bed reactors (PBRs) studied were more energy efficient and had a high SO2 RE which was at least four times more than that of the non-packed reactor. Moreover, the results showed that the performance of ceramic pellets was better than that of glass pellets in PBRs. This may be due to the porous surface of ceramic pellets which allows the formation of microdischarges in the fine cavities of a porous surface when placed in a plasma discharge zone. The maximum SO2 RE and EY were obtained at 94% and 0.81 g kWh−1, respectively under the optimal conditions of a concentration of gas of 750 ppm, a gas flow rate of 2 l min−1, and a voltage of 18 kV, which were achieved by the DBD plasma packed with ceramic pellets. Finally, the results of the model's predictions and the experiments showed good agreement. 相似文献
82.
83.
AbstractComfort has been one of the most important features of clothing, particularly for sportswear, which requires an effective transport of heat and moisture from the inner to the outer side of clothing. We herein report the use of a simple technique of spray coating and commercially available water repellents for a one-sided hydrophobic and self-initiated one-way water transport cotton fabric. The highlight of this work is the simplicity of the process and choice of chemicals that can be adopted easily by any textile finishing industry. On this fabric, water was able to diffuse and penetrate the fabric structure in one direction from the hydrophobic to the hydrophilic side but was unable to go the opposite direction. The directional transport improved with smaller droplets and lower add-on achievable by higher air pressure and longer distance of spray coating. From moisture management tests, the best result was obtained with the spray coating of Phobol NB-NH at an air pressure of 3.0?kgf/cm2 and a distance of 120?cm. Phobol NB-NH gave better result of transport and overall comfort properties than Phobotex RSY. 相似文献
84.
《Journal of the European Ceramic Society》2020,40(3):742-750
Elemental composition, crystal and grain structures, specific electrical resistivity, Seebeck coefficient, thermal conductivity, and thermoelectric figure-of-merit of n-type grained Bi1.9Gd0.1Te3 compounds, spark-plasma-sintered at TS = 690, 720, 750, 780 and 810 K, have been studied. All the samples are highly textured along the 001 direction parallel to the pressing direction. The average grain size measured along the pressing direction is much less as compared to the average grain size measured in the perpendicular direction. A strong anisotropy in the transport properties measured along directions parallel and perpendicular to the pressing direction was found within the 290 ÷ 630 K interval. Electrical resistivity decreases and thermal conductivity increases for parallel orientation as compared to these properties for perpendicular orientation. The TS - effect on thermoelectric figure-of-merit of textured Bi1.9Gd0.1Te3 compounds has been found and analyzed. Highest thermoelectric figure-of-merit (∼0.75) was observed for sample with TS = 750 K at perpendicular orientation. 相似文献
85.
《International Journal of Hydrogen Energy》2020,45(11):6138-6147
Hydrogen is considered as a clean and promising fuel, and hydrogen production on-board has attracted widespread research attention. In this work, a gliding arc discharge (GAD) plasma reactor was utilized to reform toluene at room temperature and atmosphere pressure. The performance of hydrogen production through oxidative reforming with toluene as raw material under different input power, oxygen to carbon molecular ratio (O/C), residence time and argon addition was investigated. The optimal yields of H2 and CO (48.6% and 44.3%) were obtained under the condition of the input power of 32 W, the O/C of 0.68, the residence time of 18.4 s and 10 vol% Ar addition. By analyses of spectrum lines and GC-MS, the plasma reforming mechanism of toluene was proposed. It is believed that N2(B3Πg) and Ar* could increase the formation of reactive oxygen species (O+, O (1D), O and so on), and N2(B3Πg) could impact directly the reforming of toluene. 相似文献
86.
87.
Role of MgO on densification and mechanical properties in spark plasma sintered Os0.9Re0.1B2 ceramic
《Ceramics International》2020,46(3):2612-2617
To promote the densification and therefore the mechanical properties of boride-based ceramics, MgO was added as sintering aid into Os0.9Re0.1B2 powders for densification by using spark plasma sintering (SPS). The Os0.9Re0.1B2 powders were synthesized by mechanochemical method from powder mixture of Os, Re and amorphous B. The role of MgO on densification, phase composition, microstructure and mechanical properties (hardness, fracture toughness and wear behavior) were studied by using X-ray diffraction (XRD), scanning electron microscope (SEM) with energy-dispersive spectroscopy (EDS), micro indentation and ball-on-disk tribometer. The results show that, with the introduction of MgO as sintering aid, the relative density of the Os0.9Re0.1B2 ceramic samples increased. When the MgO content reached 9 wt%, the as-sintered sample is almost fully dense. No obvious regularity was found from the samples with the addition of different content of MgO. Vickers hardness values of the samples with 0, 3 wt% and 9 wt% MgO are found to be very close with each other within the experimental error (~30 GPa), while the sample with the addition of 6 wt% MgO exhibits the highest hardness of ~35 GPa. The fracture toughness of the samples is decreased slightly with the addition of MgO. The friction coefficient and wear rate of the sample with the addition of 6 wt% MgO was also found to be the lowest among all samples, which indicate best wear resistance. As a whole, with the addition content of 6 wt% MgO, the Os0.9Re0.1B2 ceramic sample performs relatively excellent mechanical properties among four groups of samples. 相似文献
88.
《Ceramics International》2020,46(12):20068-20080
In this study, Al2O3–TiC composites synergistically reinforced with multi-walled carbon nanotubes (MWCNTs) and graphene nanoplates (GNPs) were prepared via spark plasma sintering (SPS). The effects of the MWCNT and GNP contents on the phase composition, mechanical properties, fracture mode, and toughening mechanism of the composites were systematically investigated. The experimental results indicated that the composite grains became more refined with the addition of MWCNTs and GNPs. The nanocomposites presented high compactness and excellent mechanical properties. The composite with 0.8 wt% MWCNTs and 0.2 wt% GNPs presented the best properties of all analysed specimens, and its relative density, hardness, and fracture toughness were 97.3%, 18.38 ± 0.6 GPa, and 9.40 ± 1.6 MPa m1/2, respectively. The crack deflection, bridging, branching, and drawing effects of MWCNTs and GNPs were the main toughening mechanisms of Al2O3–TiC composites synergistically reinforced with MWCNTs and GNPs. 相似文献
89.
90.
《International Journal of Hydrogen Energy》2020,45(39):20210-20215
This study examined the possibility of hydrogen production using a solution plasma process (SPP). The reactants were lignin model compounds and actual lignin oil. The highest amount of hydrogen was generated in SPP using m-cresol. The total amount of gas generated by the plasma reaction for 20 min using 23 g of m-cresol was 1.69 L, which comprised of 65.51% hydrogen and 29.85% CO. Furthermore, a maximum of 1.91 L of hydrogen was generated by a reaction between pyrolysis oil and ethanol with a weight ratio of 1:1. The presence of carbon black, a reaction byproduct, was measured by Fourier transform infrared spectroscopy, which revealed molybdenum trioxide peaks. It was confirmed that molybdenum used as an electrode was doped on carbon. 相似文献