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71.
Fatemeh Sadat Sangsefidi Masoud Salavati-Niasari Hossein Khojasteh Mehdi Shabani-Nooshabadi 《International Journal of Hydrogen Energy》2017,42(21):14608-14620
Pure CuO–CeO2 nanocomposites were synthesized by simple thermal decomposition method in presence of various Cu salts as a copper source and fructose as a green capping agent. In this study, the effect of various parameters such as the type of copper sources, temperature and time of reaction on the morphology and the particles size were studied. The products were characterized via X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), N2 adsorption (BET), vibrating sample magnetometer (VSM), and infrared spectrum (FT-IR). The optical property of the nanocomposite was examined via UV–vis (DRS) spectroscopy and the band gap was calculated to 3 eV. Also, the hydrogen storage capacity of CuO–CeO2 nanocomposites and CeO2 nanoparticles were investigated via chronopotentiometry method for the first time. The discharge capacity of CeO2 nanoparticles and CuO–CeO2 nanocomposites in 1 mA current and 20 cycles obtained 2150 and 2450 mAh/g, respectively. 相似文献
72.
Mohammad Mahdi Tavakoli Rouhollah Tavakoli Parviz Davami Hossein Aashuri 《Journal of Computational Electronics》2014,13(2):425-431
In the present work, a quantitative phase-field approach is introduced to study the phase-coarsening phenomena in solder alloys, Pb-Sn alloy here. The most important part of this work is to introduce a simple and versatile approach to quantify the experimental and simulation data, without putting into difficulties corresponding to the stochastic nature of phenomenon, in order to compute unknown physical data required to perform numerical simulation. For this purpose, at first, the evolution of microstructure vs. time is studied experimentally by the conventional optical microscopy. Then, unknown physical data, the interface mobility here, is computed by fitting the time evolution of the total interface perimeter of the simulation results to that of the experimental data. In fact, by this approach, the physical data is computed such that it will be applied to predict reality in the subsequent simulations, i.e., the presented method can be accounted as the calibration of the corresponding mathematical model and numerical method. The validity of the presented approach is supported by comparing simulation data to experimental ones. 相似文献
73.
Hossein Vojoudi Jahan B. Ghasemi Ahmadreza Hajihosseinloo Bahareh Bastan Alireza Badiei 《Advanced Powder Technology》2021,32(4):1060-1069
A hybrid nanocomposite of alumina and hematite was synthesized by ultrasonic spray pyrolysis technique. The study of microscopic images, mapping analysis, and XRD patterns revealed that the Al2O3 – Fe2O3 nanocomposite was composed of separated spherical particles with a thin layer ball-shaped structure that metal oxides are uniformly distributed in the wall of hollow sphere particles, led to a coherent and monotonous construction. A series of coefficients of equilibrium sorption of polycyclic aromatic hydrocarbons (PAHs) as hazardous materials were measured on the prepared composite material in a batch technique. The free or pure Al2O3 or Fe2O3 showed negligible removal efficiency for the mentioned analytes. The various significant variables, such as initial analyte concentration, solution pH, adsorbent dose, and contact time to remove analyte, were studied in the aqueous solutions. Adsorption data were modeled to Langmuir, Freundlich, and Temkin isotherms, and a good correlation found in the case of Langmuir isotherm and adsorption capacity for anthracene, phenanthrene, and naphthalene were 370, 333, and 322 mg g?1, respectively. Investigation of the kinetic models proved a pseudo-second-order, and the prepared adsorbent can be reused more than 7 times without a significant decrease of adsorption performance. 相似文献
74.
Hamed Safajou Mojgan Ghanbari Omid Amiri Hossein Khojasteh Farzad Namvar Sahar Zinatloo-Ajabshir Masoud Salavati-Niasari 《International Journal of Hydrogen Energy》2021,46(39):20534-20546
Recently, nanocomposite photocatalysts based on semiconductors have attracted much attention due to their suitable bandgap. Combination of tow of several semiconductors can slow down the electron-hole recombination. In this regard, we have depicted an eco-friendly and green fabrication technique to synthesize RGO/Cu nanocomposite by the reduction of graphene oxide and Cu2+ ion utilizing spearmint extract as a reductant and capping agent. The sample was identified by FTIR, XRD, FESEM, EDS, HRTEM, and CV. The results of photocatalytic performance revealed that RGO/Cu is an efficient catalyst for degrading organic pollutants. This compound can eliminate Rhodamine B (RhB) and Methylene blue (MB) 91.0% and 72.0%, respectively. 相似文献
75.
Hossein Pourmohamadian Ghanbar Ali Sheikhzadeh Mehdi Rahimi-Nasrabadi Hassan Basirat Tabrizi 《Journal of Materials Science: Materials in Electronics》2017,28(14):9990-9997
In the present study, the microencapsulated phase change material with palmitic acid as core and inorganic SiO2 shell was successfully fabricated by a sol–gel method in alkaline medium via sodium silicate precursor. The chemical compositions, crystalloid phase, microstructure and morphology of PA@SiO2 microcapsule were studied by Fourier transform infrared spectroscopy, X-ray diffractometer, scanning electron microscopy and transmission electron microscopy. Differential scanning calorimetry and thermogravimetric analysis were used to determine the thermal properties and thermal stability of microcapsules, respectively. According to the XRD and FT-IR results, all the characteristic peaks of PA and SiO2 were observed and there is no chemical reaction between them. Scanning electron microscopy images indicated that the microcapsule synthesized in pH 11 had a perfect spherical shape with smooth surfaces compared with other samples, and transmission electron microscopy images confirm that the PA have been well encapsulated by SiO2. Differential scanning calorimetry analysis showed that the microcapsules indicated similar phase change behaviors as those of pristine PA, which melt at 67.2?°C with a latent heat of 111.2 J/g and freezing at 56.5?°C with a latent heat of 103.2 J/g. TGA analysis indicated that the thermal stability of the PA was also improved due to the protection of SiO2 shell toward the encapsulated PA. 相似文献
76.
Hossein Asadi Alireza Haghdoost Morteza Ramezani Nima Elyasi Amirali Baniasadi 《Microelectronics Reliability》2014
Reliability of the current microprocessor technology is seriously challenged by radiation-induced soft errors. Accurate Vulnerability Factor (VF) modeling of system components is crucial in designing cost-effective protection schemes in high-performance processors. Although Statistical Fault Injection (SFI) techniques can be used to provide relatively accurate VF estimations, they are often very time-consuming. Unlike SFI techniques, recently proposed analytical models can be used to compute VF in a timely fashion. However, VFs computed by such models are inaccurate as the system-level impact of soft errors is overlooked. 相似文献
77.
Soolmaz Abbasalizadeh Hossein Miar-Naimi 《Analog Integrated Circuits and Signal Processing》2017,90(3):669-679
This paper presents an accurate analysis for deriving transient oscillation amplitude of Rotary Traveling Wave Oscillators (RTWOs) as a transmission-line based and high frequency circuit. The procedure of the paper is based on considering the nonlinear behavior of negative transconductors that are used for loss compensation of the transmission line. Finally, a closed-form expression for the time-domain amplitude of the RTWOs is obtained. The proposed useful and accurate expression could be used for designing the RTWOs for high performance-high speed systems. Also, it enables us to analyze and synthesize the oscillators with the desired transient behavior. This aspect of the RTWOs is not studied in previous works. The proposed theoretical results are then compared with accurate simulations. Simulations have been done in 0.18 μm CMOS technology with 1.8 V supply voltage. Results show less than 10% difference in steady state oscillation amplitude of theoretical expression and simulations. Considering the nonlinear equation of the RTWOs amplitude, complicated type of solving, simplifications and its numerical solution, the proposed derived expression has a good agreement with simulations. 相似文献
79.
Hossein Azadi Sanne de Jong Ben Derudder Philippe De Maeyer Frank Witlox 《Renewable & Sustainable Energy Reviews》2012,16(6):3599-3603
While biofuels have currently been regarded as a good alternative for fossil fuels, there remain many debates on their impacts on human and environment. This paper tried to shed light on bio-ethanol in Brazil as one of the main producers and exporters in the world. The main question was to understand “how sustainable is bio-ethanol production in Brazil?” To answer, the political motives of producing bio-ethanol followed by its ecological and socio-economic impacts were discussed. The paper concluded that although bio-ethanol production in Brazil seems environmentally friendly, it might socio-economically be hazardous. 相似文献
80.
Fatemeh Fakhrmoosavi Ali Zockaie Khaled Abdelghany Hossein Hashemi 《Computer-Aided Civil and Infrastructure Engineering》2019,34(10):859-876
Path finding problem has a broad application in different fields of engineering. Travel time uncertainty is a critical factor affecting this problem and the route choice of transportation users. The major downside of the existing algorithms for the reliable path finding problem is their inefficiency in computational time. This study aims to develop a network contraction approach to reduce the network size of each specific origin and destination (OD) pair in stochastic time‐dependent networks. The network contraction is based on the comparison of optimistic and pessimistic solutions resulting from minimum and maximum travel time realizations of a Monte‐Carlo simulation (MCS)‐based approach. In this respect, the researchers propose a learning approach to utilize the information of the realizations in the initial iterations of the MCS approach. Implementation of this approach is in place for several OD pairs of two real‐world large‐scale applications. First, it is calibrated for the Chicago downtown network; the performance and accuracy of the proposed approach are investigated by comparing the results against that of the approach without any network contraction. In addition, the Salt Lake City network illustrates the transferability of the approach to other networks. The results demonstrate significant computational improvements, with an acceptable accuracy level relative to the approach without network contraction. 相似文献