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971.
Kinetic and intraparticle diffusion studies of carbon nanotubes-titania for desulfurization of fuels
The authors report on the kinetics, pseudo first-order model, pseudo second-order model, and intraparticle diffusion mechanism. Thus, the experimental data of the adsorption of thiophene, benzothiophene, and dibenzothiophene on a material of carbon nanotubes-titania were fitted to the kinetics and intraparticle diffusion models. The kinetics parameters of qe and correlation coefficient indicated that the data are not fitted with the pseudo first-order model while they are well fitted to the pseudo second-order model with R2 of more than 0.99 and the maximum adsorption capacities qe calculated from the pseudo second order model are in accordance with the experimental values for the three sulfur compounds in a model fuel. The results indicated that the adsorbent has a higher adsorption efficiency toward DBT over the other two sulfur compounds. Fitting the data to the intraparticle diffusion model indicated the intraparticle diffusion was not only rate-controlling step and hence it can be suggested that the surface adsorption and intraparticle diffusion were concurrently operating. The experimental results demonstrate that the combining of titania and carbon nanotubes is a promising material, which can be used in desulfurization. 相似文献
972.
Channel‐based radio‐frequency fingerprinting such as a channel impulse response (CIR), channel transfer function (CTF), and frequency coherence function (FCF) have been recently proposed to improve the accuracy at the physical layer; however, their empirical performance, advantages, and limitations have not been well reported. This paper provides a comprehensive empirical performance evaluation of RF location fingerprinting, focusing on a comparison of received‐signal strength, CIR‐, CTF‐, and FCF‐based fingerprinting using the weighted k‐nearest neighbor pattern recognition technique. Frequency domain channel measurements in the IEEE 802.11 band taken on a university campus were used to evaluate the accuracy of the fingerprinting types and their robustness to human‐induced motion perturbations of the channel. The localization performance was analyzed, and the results are described using the spatial and temporal radio propagation characteristics. In particular, we introduce the coherence region to explain the spatial properties and investigate the impact of the Doppler spread in time‐varying channels on the time coherence of RF fingerprint structures. 相似文献
973.
Natural convection and melting of ice as a phase change material dispersed with copper nanoparticles are numerically investigated. Square cavity filled with nano-mixture (Cu−ice) subjected to sinusoidal temperature distributions from the hot bottom boundary. The phase change process and heat transfer are formulated and solved using the enthalpy-based lattice Boltzmann method. Home-built numerical code is developed and validated. The effect of Rayleigh number (Ra = 104, 105, and 106) and copper nanoparticle concentration (ϕ = 0%, 1%, 3%, and 5%) on the flow characteristics and thermal performance of NePCM during the melting process is examined. According to the numerical results, the melting and charging times decrease by increasing the Rayleigh number. It is also observed that increasing the volume fraction of nanoparticle decrease melting time by up to 10%. 相似文献
974.
Belhousse Samia Tighilt Fatma-Zohra Hamdani Khaled Aouali Ibtissam Benouart Samir Belhaneche Naima Lasmi Kahina Manseri Amar Sam Sabrina 《Journal of Applied Electrochemistry》2022,52(5):793-800
Journal of Applied Electrochemistry - In this work, poly(3,4-propylenedioxythiophene) (PProDOT)-based counter electrode (CE) was elaborated. The PProDOT polymer was electropolymerized by using... 相似文献
975.
Tuning the parameters of any evolutionary algorithm is considered as a very difficult task. In this paper, we present a new adaptive multi-objective technique which consists of a hybridization between a particular particle swarm optimization approach (Tribes) and tabu search (TS) technique. The main idea behind this hybridization is to combine the rapid convergence of Tribes with the high efficient exploitation of a local search technique based on TS. In addition, we propose three different places where the local search can be applied: TS applied on the particles of the archive, TS applied only on the best particle of each tribe and TS applied on each particle of the swarm. The aim of those propositions is to study the impact of the place where the local search is applied on the performance of our hybridized Tribes. The mechanisms proposed are validated using 10 different functions from specialized literature of multi-objective optimization. The obtained results show that using this kind of hybridization is justified as it is able to improve the quality of the solutions in the majority of cases. 相似文献
976.
Khaled AbouAitah Urszula Piotrowska Jacek Wojnarowicz Anna Swiderska-Sroda Ahmed H. H. El-Desoky Witold Lojkowski 《International journal of molecular sciences》2021,22(10)
Hybrid nanostructures can be developed with inorganic nanoparticles (NPs) such as zinc oxide (ZnO) and natural antibacterials. ZnO NPs can also exert antibacterial effects, and we used them here to examine their dual action in combination with a natural antibacterial agent, protocatechuic acid (PCA). To produce hybrid nanoformulations, we functionalized ZnO NPs with four types of silane organic molecules and successfully linked them to PCA. Physicochemical assessment confirmed PCA content up to ~18% in hybrid nanoformulations, with a PCA entrapment efficiency of ~72%, indicating successful connection. We then investigated the in vitro release kinetics and antibacterial effects of the hybrid against Staphylococcus aureus. PCA release from hybrid nanoformulations varied with silane surface modification. Within 98 h, only 8% of the total encapsulated PCA was released, suggesting sustained long-term release. We used nanoformulation solutions collected at days 3, 5, and 7 by disc diffusion or log reduction to evaluate their antibacterial effect against S. aureus. The hybrid nanoformulation showed efficient antibacterial and bactericidal effects that also depended on the surface modification and at a lower minimum inhibition concentration compared with the separate components. A hybrid nanoformulation of the PCA prodrug and ZnO NPs offers effective sustained-release inhibition of S. aureus growth. 相似文献
977.
Studies of the DLR Mediterranean – Concentrated Solar Project indicate Iran can be a part of the Mediterranean renewable power generation chain in 2050 to provide the electrical power demand of Europe. However, Iran as a developing country and due to its large area has some limitations on the number of synoptic stations. Hence, the aim of this study is to determine the theoretical solar irradiation potential in Iran by using an Niroo Research Institute irradiation model based on the geographical and meteorological data. Monthly, seasonal, and annual values of irradiation on the ground surface, and extracted solar energy from different tracking systems, are estimated across the country. A typical photovoltaic system, parabolic trough, and dish concentrator are considered and extracted solar energy of them is illustrated on the map. Results of this study make clear that the presented solar atlas can provide appropriate tools for primary study of solar energy potential and extracted energy in Iran. 相似文献
978.
Azizi Hamid Panahi Damon Fazeli Fateh Tian Junyu Samk Khaled Abu Zurob Hatem S. 《Metallurgical and Materials Transactions A》2021,52(6):2402-2410
Metallurgical and Materials Transactions A - In this study, the effect of ausforming temperature and strain on the bainite transformation in a model alloy containing 0.39 pct C, 2.0 pct Mn, 1.9 pct... 相似文献
979.
Ahmed Mohammed Qian Wang Saleh Alyahya Nick Bennett 《The International Journal of Advanced Manufacturing Technology》2017,91(5-8):1661-1670
In this paper, we investigated the design and optimization of a proposed radio-frequency identification (RFID)-enabled automated warehousing system in terms of the optimal number of storage racks and collection points that should be established in an efficient and cost-effective approach. To this aim, a fuzzy tri-criterion programming model was developed and used for obtaining trade-off decisions by measuring three conflicting objectives. These are minimization of the warehouse total cost, maximization of the warehouse capacity utilization, and minimization of the travel time of products from storage racks to collection points. To reveal the alternative Pareto optimal solutions using the developed model, a new approach was developed and compared with a recently developed fuzzy approach so-called Selim and Ozkarahan (SO). A decision-making algorithm was used to select the best Pareto optimal solution, and the applicability of the developed model was examined using a case study. Research findings demonstrate that the developed model is capable of generating an optimal solution as an aid for the design of the proposed RFID-enabled automated warehousing system. 相似文献
980.