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Search Results: 1 - 10 of 494477 matches for " A. Y. Hatata "
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High Power Interleaved Boost Converter for Photovoltaic Applications  [PDF]
Ahmed A. Hafez, A. Y. Hatata, M. I. Alsubaihi, R. M. Alotaibi, F. T. Alqahtani, S. O. Alotaibi, A. M. Alhusayni, M. D. Alharbi
Journal of Power and Energy Engineering (JPEE) , 2018, DOI: 10.4236/jpee.2018.65001
Abstract: Interfacing DC sources to load/power grid requires DC converters that produce minimum level of current ripples. This is to limit the losses and hence increase the life span of these sources. This article proposes a simple inter-leaved boost converter that interfaces PhotoVoltaic (PV) module into a common DC-link. The article also addresses the faulty mode operation of the proposed circuit while advising the appropriate remedy actions. A MATLAB and Simulink dynamic platform are used to simulate the transient performance of the proposed converter. The results revealed the effectiveness and the viability of the proposed converter in reducing the ripples in the PV current without employing bulky input inductors or increasing the switching frequency.
Byuons, Quantum Information Channel, Consciousness and Universe  [PDF]
Y. A. Baurov
Open Journal of Microphysics (OJM) , 2011, DOI: 10.4236/ojm.2011.12007
Abstract: The physics of consciousness and universal mind is shown on the base of theory of byuons, the theory of “life’ of special unobservable discrete objects—byuons from which the surrounding space and the world of elementary particles are formed. An essential distinction of that theory from the modern models in the classical and quantum field theories is that the potentials of physical fields (gravitational, electromagnetic, asf.) gain exactly fixable, measurable values. Basic axioms and some conclusions of this theory are discussed. The theory of byuons predicts the existence of a new force and a new quantum information channel in nature. All objects of the Universe are shown to be united into the unique information field due to the huge interval of uncertainty in the coordinate (Δx = L = 1028 cm) of objects 4b (object formed during four-contact byuon-byuon interaction ( mc24b = 33 eV)) forming the surrounding physical space. It is a new quantum information channel.
Quantum Bit Error Avoidance  [PDF]
A. Y. Shiekh
Journal of Applied Mathematics and Physics (JAMP) , 2018, DOI: 10.4236/jamp.2018.611200
Abstract: Qubit errors might be avoided by using the quantum Zeno effect to inhibit evolution.
Association of IL-4-590 C>T and IL-13-1112 C>T Gene Polymorphisms with the Susceptibility to Type 2 Diabetes Mellitus
Afaf Alsaid,Mohammed El-Missiry,El-Sayed Hatata,Mohammad Tarabay,Ahmad Settin
Disease Markers , 2013, DOI: 10.1155/2013/107470
Abstract: Background. The goal of the study is to investigate the association of IL-4-590 and IL-13-1112 genetic polymorphisms with type 2 diabetes mellitus (T2DM) in Egyptian patients. Subjects and Methods. The study included 135 cases with T2DM and 75 healthy unrelated age-matched controls from the same locality of Egypt. DNA was extracted and processed by the ARMS-PCR technique for characterization of genetic variants of IL-4-590 C>T and IL-13-1112 C>T polymorphisms. Results. Egyptian cases with T2DM showed a lower frequency of the IL-4-590 CC homozygous genotype compared to controls (10.4% versus 43.48%) with a higher CT heterozygous genotype (85.2% versus 47.8%). Similarly, cases showed a lower frequency of the IL-13-1112 CC genotype (20.7% versus 56.8%) with a higher frequency of the heterozygous IL-13-1112 CT genotype (76.3% versus 41.3%). Both polymorphisms showed significantly positive associations with T2DM in the dominant, codominant, and overdominant models of inheritance. On the other hand, comparing genotypes of subgroups related to gender, positive family history, and positive consanguinity showed a nonsignificant difference ( ). Conclusion. Heterozygous genotypes (IL-4-590 CT and IL-13-1112 CT) could be considered as risk factors, while the homozygous wild types (-590 CC and -1112 CC) might be considered protective to T2DM. 1. Introduction Type 2 diabetes mellitus (T2DM) is believed to be a multifactorial disease that is influenced by genetic and environmental factors. People with a family history of the T2DM are at a higher risk of developing the disease since they share genetic background in addition to likely similar environments [1]. Interleukin 4 (IL-4) was originally discovered as a low molecular weight T cell-derived polypeptide of 129 amino acids, which is encoded by the IL-4 gene on chromosome 5q23.31. It is secreted by helper T cells (CD4) type 2 (Th2) lymphocytes, and natural killer (NK) T cells, and by cells of the innate immune system, including mast cells, basophils, and eosinophils [2]. Interleukin 4 regulates proliferation, apoptosis, gene expression, and differentiation in many hematopoietic cells; in particular, it directs the Ig class switch to IgG1 and IgE and downregulates the production of Thl cells [3, 4]. IL-4 is suggested to protect human islets from cytotoxic damage induced by proinflammatory and Th1 cytokines. Another study showed that a long-term exposure of rat pancreatic islets to IL-4 resulted in an inhibitory action to some of the islet functions [5]. Interleukin 13 is a 12-kDa-protein product, produced by Th2 cells
The Sources of Extracellular Adenosine in Hippocampus and Neostriatum of the Rat Brain  [PDF]
M. A. Pak, Y. Yetkin
World Journal of Neuroscience (WJNS) , 2014, DOI: 10.4236/wjns.2014.42010
Abstract:

Endogenous adenosine can enter the extracellular space either by direct release or via formation from adenine nucleotides. We have compared the effects of substances blocking the ecto-5'-nucleotidase with a, b-methylene adenosine 5'-diphosphate (AOPCP) or adenosine kinase with iodotubercidin (Itu) on field potentials in the hippocampus and the neostriatum in vitro evoked by stimulation of the stratum radiatum or the cortico-striatal pathway respectively. AOPCP enhanced the amplitude of the population spikes by 34% in the hippocampus and by 26.5% in the neostriatum. DPCPX, a selective A1-receptor antagonist, increased the amplitude of the population spikes by 68% in the hippocampus and by 53.5% in the neostriatum. Thus both, release of adenosine from the intracellular space and, extracellular dephosphorylation of adenine nucleotides to a lesser extent, contribute to the effective levels of adenosine in the extracellular space in hippocampus and neostriatum.

Commissioning and Optimization of a Total Skin Electron Therapy Technique Using a High Dose Rate Electron Facility  [PDF]
Y. A. M. Yousif, Casper A. Willemse
International Journal of Medical Physics,Clinical Engineering and Radiation Oncology (IJMPCERO) , 2015, DOI: 10.4236/ijmpcero.2015.43024
Abstract: Total skin electron therapy (TSET) is used for the treatment of Mycosis Fungoides. Several tech-niques have been developed, in order to achieve homogeneous dose distribution over the complete body surface. To implement a TSET technique, one has to optimize a variety of parameters. Monte Carlo simulation of TSET can facilitate this optimization. The aim of this study was to commission and optimize a TSET technique using the 4 and 6 MeV electron and the high dose rate facility on the Elekta Precise accelerator. The EGS4nrc/BEAMnrc Monte Carlo code was used. The beam data were calculated and measured at two different scoring planes for a single beam. The Model was validated by comparing the simulation with measurements. Two different vertical angles were used to obtain a uniform dose. The angle was optimized for best dose uniformity. The Rando phantom is placed on a rotating platform and rotates 60 degrees apart to facilitate the six patient position orientations. The doses delivered in a phantom by complete treatment were measured with Kodak EDR2 films and TLDs. The dose distribution varied among various scanning directions by 2 - 3 mm and 3 - 4 mm for 4 and 6 MeV respectively. The composite percentage depth dose of all six dual fields for the 4 and 6 MeV yielded an R80 of ~4 mm and ~6 mm, respectively. Dose uniformity was ±6% for 4 MeV and ±5% for 6 MeV. The bremsstrahlung contamination was 0.9% - 1.3%. Good agreements were found with published literature and inline with international protocols.
The Combination Operator of Information Sources by a New Expressive Matrix  [PDF]
A. Boualem, Y. Dahmani, A. Maatoug
Journal of Geographic Information System (JGIS) , 2015, DOI: 10.4236/jgis.2015.74034
Abstract: The multi-sensors fusion refers to the synergistic combination of sensory data from multiple sensors to provide more accurate and reliable information. The potential benefits of the Fusion are multi-sensors’ redundancy and extra information acquired. The fusion of redundant information can reduce the overall uncertainty and thus helps to provide information specified more precisely. Several sensors providing redundant information can also be used to increase reliability in the case of error, omission or failure of sensors. The combination operators are exponential and are more complex in terms of calculation; the Dempster-Shafer operator is exponential for more than three (3) information sources[1] [2]. Our work focuses on the definition of another formulation of this operation, and puts it in a matrix form to illuminate the computational complexity, more precision guaranty and a minimal execution time. We propose to use each information source in a form of a matrix, which contains 0 value in lines that do not contain the masses (m(Ai) = 0) or once m(Ai) is not null (m(Ai) ≠ 0). The use of this expressed matrix attempts to ameliorate Dempster-Shafer operator via initialing either a criterion or criteria sources’ solution, increasing the efficiency of the Dempster-Shafer operator and facilitates the combination among the sources. We evaluate our approach by conducting a case study for showing the effectiveness of this matrix.
Experimental Evaluation of the Attenuation Effect of a Passive Damper on a Road Vehicle Bumper  [PDF]
A. Agyei-Agyemang, G. Y. Obeng, P. Y. Andoh
World Journal of Engineering and Technology (WJET) , 2014, DOI: 10.4236/wjet.2014.23021
Abstract: To mitigate the degree of damage to passengers caused by automobile collisions, a friction damper was built and used in experimental tests to test its effectiveness in impact energy attenuation. The study revealed that energy absorption capacity of a bumper can be improved with the addition of a friction damper. The results revealed that the addition of the friction damper to an automobile bumper to give a bumper-damper system could attenuate about 32.5 % more energy than with the bumper alone. It can be concluded that the effectiveness of automobile bumpers to withstand impact of vehicles by absorbing the kinetic energy from the impact can be improved with the use of a passive friction damper. That is, a passive friction damper system could be used to attenuate more road vehicle impact energy in collisions.
Effects of thermally modified green tea catechins on the oxidative and hydrolytic stability of butter  [PDF]
Magdalena Mika, Agnieszka Wikiera, Krzysztof ?ya
Health (Health) , 2009, DOI: 10.4236/health.2009.13032
Abstract: Green tea catechins are classified as (-)-epi-forms (2R, 3R) or (-)-forms (2S, 3R) with respect to stereoisomerism. The (-)-forms (2S, 3R) in catechin preparations obtained from green tea amounts to approximately 10% of total catechins, whereas the other 90% are (-)-epiforms (2R, 3R). High temperature induces the conversion of (-)-epiforms (2R, 3R) to (-)-forms (2S, 3R). This study investigated the effect of catechin prepa-rations containing 10, 20 and 30% (-)-forms (2S, 3R) on the oxidative and hydrolytic stability of butter. For comparison, butter with δ-tocopherol and BHT and butter without stabilizer were analysed. Butter stability was examined under conditions of refrigeration (8 oC) and freezing (-22 oC) and at temperature of 50 oC and 100 oC. Catechin preparations were more efficient butter stabilizers than BHT and δ-tocopherol. Thermal modification of catechins that led to the genera-tion of 20% of (-) forms (2S, 3R) improved their antioxidative efficacy, but longer treatment lead- ing to the formation of 30% of (-) forms (2S, 3R) decreased their antioxidative activity. The hy-drolytic stability of butter, however, increased as the amount of (-) forms (2S, 3R) increased.
Comparison of Iterative Wavefront Estimation Methods  [PDF]
Y. Pankratova, A. Larichev, N. Iroshnikov
Optics and Photonics Journal (OPJ) , 2013, DOI: 10.4236/opj.2013.32B022
Abstract:

The iterative reconstruction methods of the wavefront phase estimation from a set of discrete phase slope measurements have been considered. The values of the root-mean-square difference between the reconstructed and original wavefront have been received for Jacobi, Gauss-Seidel, Successive over-relaxation and Successive over-relaxation with Simpson Reconstructor methods. The method with the highest accuracy has been defined.

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