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101.
102.
Amal A. Hassan Faten H. Fahmy Abd El-Shafy A. Nafeh Mohamed A. Abu-elmagd 《国际可持续能源杂志》2017,36(6):545-562
The optimal design of renewable-based distributed generations (DGs) is a challenging issue in order to maximise their benefits and to overcome power quality problems. Therefore, this paper proposes a methodology for optimal allocation and sizing of renewable DG units to minimise total power losses over radial distribution systems. The planning problem is formulated as a single objective nonlinear mixed integer-constrained optimisation problem and is solved by using the augmented Lagrangian genetic algorithm (ALGA) by combining the objective function and the nonlinear constraints. In that case, the ALGA solves a sequence of sub-problems where the objective function penalises the constraints violation in order to obtain the best solution. The proposed technique is applied to IEEE radial test systems including 33-bus, 69-bus and 119-bus and is implemented with different scenarios including all possible combinations and various types of renewable DG units to prove the effectiveness of the proposed methodology. 相似文献
103.
Hamida Y. Mostafa Ebaa A. El-Shamy Amal S. Farag Nadia G. Kandile 《Egyptian Journal of Petroleum》2013,22(4):471-479
Neat ethylacetoacetate (EAA) and its mixtures with a co-solvent and an anti-solvent have been studied for refining of heavy wax distillate fraction to produce substantially non-carcinogenic base oil. The co-solvent and anti-solvent used are dipropylene glycol (DPG) and ethylene glycol (EG) respectively. The solubility characteristics of the main solvent and its mixed solvent systems were studied. Selection of the optimum solvent mixture and extraction variables has been studied. The effect of co-solvent and anti-solvent addition on the carcinogenic potential and raffinate quality has been determined under clearly comparable conditions. 相似文献
104.
Amal Elleuch Ahlem Boussetta Kamel Halouani Yongdan Li 《International Journal of Hydrogen Energy》2013
NiO-Samaria-Doped-Ceria (NiO-SDC) composite powders was synthesized by a traditional mechanical mixing process and tested as anode material for Direct Carbon Fuel Cell (DCFC), which uses almond shell biochar as fuel and molten carbonate-doped ceria composite as electrolyte. A three-layer pellet cell, viz. cathode (Lithiated NiO-SDC), composite electrolyte and anode (NiO-SDC) is fabricated by a die-pressing, screen printing and sintering method. 相似文献
105.
Devi Chandrasekhar Kakarla Krishna Murthy Jyothinagaram Amal Kumar Das Venimadhav Adyam 《Journal of the American Ceramic Society》2014,97(9):2858-2866
We have prepared polycrystalline R2NiMnO6 (R = Nd, Eu, Gd, Dy, and Y) samples by conventional solid‐state reaction and all the samples have shown monoclinic structure with P21/n space group. With the decrease in rare‐earth ionic size (<rR>), the <Ni–O–Mn> bond angle decreases, correspondingly a decrease in ferromagnetic (FM) Curie temperature is noticed. In the dielectric measurement, the dielectric anomaly shifts to high temperature with the decrease in the <rR> and shows no correlation with the FM Curie temperature and hints the absence of apparent magnetodielectric (MD) coupling. Appearance of multiple relaxations in the dielectric study suggests the electrical heterogeneity of the system. The dielectric/impedance analysis has revealed a close correlation between dc conductivity and the dielectrics; in fact, both dc resistivity and the grain relaxations follow the variable range hopping mechanism. The thermal activation of charge carriers at the grain boundary led to Maxwell–Wagner interfacial polarization. Finally, dielectric study under magnetic field showed no effect, it implies that not only the intrinsic MD is absent, but also the extrinsic MD due to the lack of magnetoresistance. 相似文献
106.
Amal A. Hafiz A. M. Badawi F. I. El-Deeb E. A. Soliman M. Y. El-Awady D. E. Mohamed 《Journal of surfactants and detergents》2010,13(2):165-172
A novel series of ferrocenyl surfactants was synthesized by the reaction of ferrocene disulfonic acid with different primary
and tertiary fatty amines to produce the corresponding ammonium salts Fc[SO3
−
+NH3(CH2)
n
CH3]2, where n = 9, 11, or 15 and Fc[SO3− +NH(CH3)2(CH2)
n
CH3]2, where n = 7 or 11, respectively, and where Fc = ferrocene. Chemical structures were confirmed by microelemental analysis, FTIR, and
1H NMR spectroscopy. The critical micelle concentration of each prepared surfactant was determined using equilibrium surface
tension. Furthermore, air/water interface parameters including effectiveness (π
CMC), efficiency (Pc20), maximum surface excess (Гmax), and minimum surface area (A
min) were determined at 30, 40, and 50 °C. Thermodynamic parameters (ΔG°, ΔS°, and ΔH°) for both micellization and adsorption processes were recorded. The new synthesized surfactants were screened as antimicrobial
agents against different bacterial and fungal organisms. 相似文献
107.
108.
Amal M. Nassar Nehal S. Ahmed Rasha S. Kamal Abdel-Azim A. Abdel Azim E. I. El-Nagdy 《Petroleum Science and Technology》2005,23(5):537-546
This work is confined to the preparation and characterization of acrylate polymeric additives. These additives were prepared by esterification of acrylic acid with different alcohols (decyl, 1-dodecyl, 1-tetradecyl, and hexadecyl) and then copolymerization of the prepared esters with different moles of styrene. The molecular weights of the prepared copolymers were determined by GPC. The efficiency of the prepared copolymers for improving the viscosity index of the lube oil was studied. It was found that the efficiency increases with increasing the molecular weight of the prepared copolymers. 相似文献
109.
110.
Sachin Sharma Meena Malik Chander Prabha Amal Al-Rasheed Mona Alduailij Sultan Almakdi 《计算机、材料和连续体(英文)》2023,75(1):393-407
Watermarking of digital images is required in diversified applications ranging from medical imaging to commercial images used over the web.
Usually, the copyright information is embossed over the image in the form of
a logo at the corner or diagonal text in the background. However, this form
of visible watermarking is not suitable for a large class of applications. In all
such cases, a hidden watermark is embedded inside the original image as proof
of ownership. A large number of techniques and algorithms are proposed
by researchers for invisible watermarking. In this paper, we focus on issues
that are critical for security aspects in the most common domains like digital
photography copyrighting, online image stores, etc. The requirements of this
class of application include robustness (resistance to attack), blindness (direct
extraction without original image), high embedding capacity, high Peak Signal
to Noise Ratio (PSNR), and high Structural Similarity Matrix (SSIM). Most
of these requirements are conflicting, which means that an attempt to maximize one requirement harms the other. In this paper, a blind type of image
watermarking scheme is proposed using Lifting Wavelet Transform (LWT)
as the baseline. Using this technique, custom binary watermarks in the form
of a binary string can be embedded. Hu’s Invariant moments’ coefficients
are used as a key to extract the watermark. A Stochastic variant of the
Firefly algorithm (FA) is used for the optimization of the technique. Under
a prespecified size of embedding data, high PSNR and SSIM are obtained
using the Stochastic Gradient variant of the Firefly technique. The simulation
is done using Matrix Laboratory (MATLAB) tool and it is shown that the
proposed technique outperforms the benchmark techniques of watermarking
considering PSNR and SSIM as quality metrics. 相似文献