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El‑Sayed M. Sherif,Fahamsyah H. Latief,Hany S. Abdo,Nabeel H. Alharthi 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.6
In this study, manufacturing of Ti–5Al and Ti–5Al–5Cu alloys were accomplished employing mechanical alloying technique. The corrosion resistance in 3.5 wt% NaCl solution of Ti–5Al and Ti–5Al–5Cu alloys was investigated using cyclicpolarization (CPP), electrochemical impedance spectroscopy (EIS) and chronoamperometric current–time measurements. The corroded surfaces of Ti–5Al and Ti–5Al–5Cu were examined by the use of a scanning electron microscopy and energydispersive X-ray spectroscopy. It is found that Ti–5Al suffers both uniform and pitting corrosion, particularly with prolongingthe time of exposure period in the chloride solution. While, the addition of Cu, Ti–5Al–5Cu alloy, increases the intensity ofuniform corrosion and decreases the probability of pitting attack. Prolonging the immersion time to 48 h before measurementdecreases the corrosion of Ti–5Al alloy, while increases the corrosion of Ti–5Al–5Cu.
Alleviation of salt stress in Triticum aestivum by biopriming with Phanerochaete chrysosporium
Hanan El-Sayed Dief,El-Sayed A. Hashem,Salwa Fawzan,Ashraf S. A. El-Sayed 한국작물학회 2021 Journal of crop science and biotechnology Vol.24 No.1
Wheat is one of the most important cereals, vital basic crop in Egypt, covering approximately 32.6% of the total winter land. However, sensitivity to abiotic stress especially salinity is one the major current hurdles that reduce the global yield of this crop. Plant biopriming with fungi is the recent technology that might alleviate the salt stress eff ect. Thus, the objective of this work was to examine the eff ect of Triticum aestivum grains biopriming with Phanerochaete chrysosporium on the response of wheat to salt stress. From the physiological and biochemical parameters, biopriming of wheat grains with P. chrysosporium significantly alleviates the salt stress and markedly increases the growth parameters, photosynthetic pigments and osmolytes (soluble sugars, soluble protein and proline) contents. In addition, it alleviates the oxidative damage, as indicated by the lower accumulation of malondealdehyde and increasing the activity of antioxidant enzymes; superoxide dismutase, catalase, and ascorbate peroxidase in wheat seedlings. Results indicate the potential of using P. chrysosporium biopriming for reducing the deteriorating eff ects of salinity.
On Some Fractional Quadratic Integral Inequalities
El-Sayed, Ahmed M.A.,Hashem, Hind H.G. Department of Mathematics 2020 Kyungpook mathematical journal Vol.60 No.1
Integral inequalities provide a very useful and handy tool for the study of qualitative as well as quantitative properties of solutions of differential and integral equations. The main object of this work is to generalize some integral inequalities of quadratic type not only for integer order but also for arbitrary (fractional) order. We also study some inequalities of Pachpatte type.
Experimental Verification of Resistance-Demand Approach for Shear of HSC Beams
El-Sayed, Ahmed K.,Shuraim, Ahmed B. Korea Concrete Institute 2016 International Journal of Concrete Structures and M Vol.10 No.4
The resistance-demand approach has emerged as an effective approach for determining the shear capacity of reinforced concrete beams. This approach is based on the fact that both the shear resistance and shear demand are correlated with flexural tensile strain from compatibility and equilibrium requirements. The basic shear strength, under a given loading is determined from the intersection of the demand and resistance curves. This paper verifies the applicability of resistance-demand procedure for predicting the shear capacity of high strength concrete beams without web reinforcement. A total of 18 beams were constructed and tested in four-point bending up to failure. The test variables included the longitudinal reinforcement ratio, the shear span to depth ratio, and the beam depth. The shear capacity of the beams was predicted using the proposed procedure and compared with the experimental values. The results of the comparison showed good prediction capability and can be useful to design practice.
A Trust Region Method for Solving the Decentralized Static Output Feedback Design Problem
El--Sayed M. E. Mostafa 한국전산응용수학회 2005 Journal of applied mathematics & informatics Vol.18 No.1-2
The decentralized static output feedback design problem is considered. A constrained trust region method is developed that solves this optimal control problem when a complete set of state variables is not available. The considered problem is interpreted as a non-linear (nonconvex) constrained matrix optimization problem. Then, a decentralized constrained trust region method is developed for this problem class exploiting the diagonal structure of the problem and using inexact computations.Finally, numerical results are given for the proposed method.
Status of Sperm Motiltity Treated with Endocrine Disruptors In Vitro
El-Sayed A. Mohamed,Sung-Jae Yoon,Woo-Sung Kwon,Yoo-Jin Park,Kyu-Hyun Jeong,Myung-Geol Pang 한국동물생명공학회(구 한국동물번식학회) 2011 발생공학 국제심포지엄 및 학술대회 Vol.2011 No.1
In the last few decades with the industrial revolution many environmental contaminants have estrogenic activity (endocrine disruptors, EDs) are released into the environment affecting the male reproductive system and male fertility. Sperm motility is one of the initial tests performed to assess sperm function; only motile sperm can achieve fertilization in vivo. The present study aimed to investigate the possible effects of a group of EDs that represent a widespread chemicals in the environment genistein (Gen), is a naturally occurring isoflavone (100 μM), bisphenol A (BPA), that is used in the manufacture of plastics and other products and released largely into the environment (100 μM), nonylphenol (NP) is an important environmental toxicant and potential endocrine disrupting chemical (10 μg/ml), TCDD, that is formed as an unwanted by-product in the manufacture of chlorinated hydrocarbons (2.5 μg/ml), atrazine (Atraz) is a herbicides (500 μM), dibromochloropropane (DBCP) is a pesticide (10 μg/ml), and diazinone (Diaz) is a insecticide (500 μM) on human sperm motility and kinematic characteristics. Human spermatozoa were incubated in Ham's F10 media with/without the tested chemicals or DMSO as positive control for 6 hr at 37℃ in 5% CO2. Then, sperm motility was assessed using computer assisted semen analyzer. Interestingly, all the chemicals tested significantly decreased sperm motility as compared to the control groups. However, only Diaz significantly decreased sperm kinematic characteristics namely, VCL, VSL, STR, VAP, and ALH. We suggest that the environmental chemicals may have an effect on male fertility via decreasing sperm motility.
El-Said I. El-Shafey,Haider A. J. Al-Lawati,Wafa S. H. Al-Saidi 한국탄소학회 2016 Carbon Letters Vol.19 No.-
Date palm leaflets were used as a precursor to prepare dehydrated carbon (DC) via phosphoric acid treatment at 150°C. DC, acidified with H3PO4, was converted to activated carbon (AC) at 500°C under a nitrogen atmosphere. DC shows very low surface area (6.1 m2/g) while AC possesses very high surface area (829 m2/g). The removal of lisinopril (LIS) and chlorpheniramine (CP) from an aqueous solution was tested at different pH, contact time, concentration, and temperature on both carbons. The optimal initial pH for LIS removal was 4.0 and 5.0 for DC and AC, respectively. However, for CP, initial pH 9.0 showed maximum adsorption on both carbons. Adsorption kinetics showed faster removal on AC than DC with adsorption data closely following the pseudo second order kinetic model. Adsorption increases with temperature (25°C–45°C) and activation energy (Ea) is in a range of 19–25 kJ mol/L. Equilibrium studies show higher adsorption on AC than DC. Thermodynamic parameters show that drug removal is endothermic and spontaneous with physical adsorption dominating the adsorption process. Column adsorption data show good fitting to the Thomas model. Despite its very low surface area, DC shows ~70% of AC drug adsorption capacity in addition of being inexpensive and easily prepared.