OALib Journal期刊

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匹配条件: “ S. Elshokary” ,找到相关结果约324106条。
Hydrogen Production from an Alkali Electrolyzer Operating with Egypt Natural Resources  [PDF]
Mohamed H. Shedid, S. Elshokary
Smart Grid and Renewable Energy (SGRE) , 2015, DOI: 10.4236/sgre.2015.61002
Abstract: Egypt is bordered by coastal sea2450 km, while incident solar radiation is in the order of magnitudes of 1900-2200 W/m2 in that area of the world. The present work is aimed to assess the hydrogen production from the solar-hydrogen system composed of photovoltaic cell motivated by solar energy and supplies electricity to alkali electrolyzer. The electrolyzer uses sea and Nile water as electrolytes. Indoor tests are done to identify the optimum concentration ratio of the sea water to produce hydrogen. Experimental results showed that stand-alone sea water gives a higher production rate. The results of the outdoor tests revealed the need for about seven units of electrolyzer working with the sea water to produce the same amount of hydrogen that KOH solution electrolyte would provide. However, the efficiency of solar-hydrogen units working with the sea water gives a lower constant efficiency of about 0.13%, followed by Photovoltaic/electrolyzer unit using Nile water of approximately 0.005%. The KOH solution electrolyte provides an efficiency of approximately 8% at solar noon. The sea water is recommended to be used instead of KOH solution in all coming electrolyzers.
Degree Splitting of Root Square Mean Graphs  [PDF]
S. S. Sandhya, S. Somasundaram, S. Anusa
Applied Mathematics (AM) , 2015, DOI: 10.4236/am.2015.66086
Abstract: Let \"\" be an injective function. For a vertex labeling f, the induced edge labeling \"\" is defined by, \"\" or \"\"; then, the edge labels are distinct and are from \"\". Then f is called a root square mean labeling of G. In this paper, we prove root square mean labeling of some degree splitting graphs.
A Parameter Estimation Model of G-CSF: Mathematical Model of Cyclical Neutropenia  [PDF]
S. Balamuralitharan, S. Rajasekaran
American Journal of Computational Mathematics (AJCM) , 2012, DOI: 10.4236/ajcm.2012.21002
Abstract: We investigate the FFT (Fast Fourier Transform) model and G-CSF (granulocyte colony-stimulating factor) treatment of CN (Cyclical Neutropenia). We collect grey collies and normal dog’s data from CN and analyze the G-CSF treatment. The model develops the dynamics of circulating blood cells before and after the G-CSF treatment. This is quite natural and useful for the collection of laboratory data for investigation. The proposed interventions are practical. This reduces the quantity of G-CSF required for potential maintenance. This model gives us good result in treatment. The changes would be practical and reduce the risk side as well as the cost of treatment in G-CSF.
Synthesis, Thermal Behaviour, XRD, and Luminescent Properties of Lighter Lanthanidethiodipropionate Hydrates Containing Aminogunidine as Neutral Ligand  [PDF]
S. Packiaraj, S. Govindarajan
Open Journal of Inorganic Chemistry (OJIC) , 2014, DOI: 10.4236/ojic.2014.43006
Aminoguanidine lanthanide thiodipropionate hydrates of composition [Ln(Agun)2(tdp)3·nH2O], Agun = Aminoguanidine, tdp = thiodipropionic acid, where Ln = La, Pr, Nd and Sm if n = 2, have been prepared and characterized by physic-chemical techniques.
Bir Bibliyografik Kontrol Merkezi Yay nlar : al ma ekli ve Sat Metodu
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Türk Kütüphanecili?i , 1967,
Rain Attenuation at Terahertz  [PDF]
S. Ishii
Wireless Engineering and Technology (WET) , 2010, DOI: 10.4236/wet.2010.12014
Abstract: Rain attenuation values were calculated using empirical raindrop-size distributions, which were, Marshall-Palmer (M-P), Best, Polyakova-Shifrin (P-S) and Weibull raindrop-size distributions, and also calculated using a specific rain attenuation model for prediction methods recommended by ITU-R. Measurements of Terahertz wave taken at 313 GHz (0.96 mm) were compared with our calculations. Results showed that the propagation experiment was in very good agreement with a calculation from the specific attenuation model for use in prediction methods by ITU-R.
Frucht Graph is not Hyperenergetic  [PDF]
Intelligent Information Management (IIM) , 2009, DOI: 10.4236/iim.2009.12017
Abstract: If are the eigen values of a p-vertex graph , the energy of is . If , then is said to be hyperenergetic. We show that the Frucht graph, the graph used in the proof of well known Frucht’s theorem, is not hyperenergetic. Thus showing that every abstract group is isomorphic to the automorphism group of some non-hyperenergetic graph. AMS Mathematics Subject Classification: 05C50, 05C35
Synthesis, Permeability and Microstructure of the Optimal Nickel-Zinc Ferrites by Sol-Gel Route  [PDF]
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2010, DOI: 10.4236/jemaa.2010.21009
Abstract: The optimum ferrite can be obtained through free-microstructural defects where such defects are always encountered in the conventional ferrites often caused by chemical inhomogeneity. In this study, Ni-Zn ferrite was synthesized and fabricated by means of a sol-gel route. Thermal gravimetric analysis (TGA) was used to study the thermal transforma-tion of the ferrite in air. Parts of the sol-gel powder heated at elevated temperatures were characterized by X-ray dif-fraction (XRD) method and Scanning Electron Microscopy (SEM) to reveal the crystallized single-phase and the struc-ture of the obtained ferrite. Fourier transform infrared spectroscopy (FT-IR) was assisted to investigate the structure. The microstructures of the toroidal cores were obtained at two different sintering temperatures and compared with those obtained via the classic method. In addition to that, the magnetic properties were measured. The initial magnetic permeability was found to increase with the increasing of the frequency as a result of the domain wall motions and the corresponding loss was small. Therefore, a well defined polycrystalline microstructure ferrite via an easier preparation methodology as compared to the classic method is obtained.
Power Network Asymmetrical Faults Analysis Using Instantaneous Symmetrical Components  [PDF]
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2009, DOI: 10.4236/jemaa.2009.14031
Abstract: Although the application of Symmetrical Components to time-dependent variables was introduced by Lyon in 1954, for many years its application was essentially restricted to electric machines. Recently, thanks to its advantages, the Lyon transformation is also applied to power network calculation. In this paper, time-dependent symmetrical components are used to study the dynamic analysis of asymmetrical faults in a power system. The Lyon approach allows the calculation of the maximum values of overvoltages and overcurrents under transient conditions and to study network under non-sinusoidal conditions. Finally, some examples with longitudinal asymmetrical faults are illustrated.
Study of Tsunamis by Dimensional Analysis  [PDF]
S. Ghasemi
Engineering (ENG) , 2011, DOI: 10.4236/eng.2011.39111
Abstract: Tsunamis are among the most terrifying natural hazards known to man and have been responsible for tre-mendous loss of life and property throughout history. In this paper by means of dimensional analysis, important non-dimensional groups in Tsunamis was studied and an equation to calculate the power of tsunamis was obtained. Also by this method and using tsunami basic physics, the height of waves near the coastline was estimated and results were compared by reported values.

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