Electrochemical and Spectroscopic Study on the Corrosion of Ti–5Al and Ti–5Al–5Cu in Chloride Solutions

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.

Magnetic Properties of La3+-ion-doped Polycrystalline Z-type Hexaferrite Powders Synthesized via the Co-precipitation Method

M. M. Rashad,M. Rasly,I. A. Ibrahim,H. M. El-Sayed,A. A. Sattar 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.3

Co2Z-type hexagonal ferrite powders doped with La3+ ions (Ba3−XLaxCo2Fe24O41 where x =0.0, 0.05, 0.10 and 0.15) were prepared using a co-precipitation method. The results revealed thatsingle-phase Co2Z-type ferrite was formed from the precipitated precursor in the presence of sodiumdodecyl sulfate (SDS) as an anionic surfactant. The obtained precursor was preheated at 600 ℃ for4 h then post annealed at 1300 ℃ for 6 h. The crystallite size increased with increasing of La3+-ion molar ratio. The microstructure of the formed powders appeared to be a hexagonal-plateletlikestructure. The DC resistivity of the obtained Co2Z decreased with increasing La3+ content. The saturation magnetization (Ms = 53.7 - 55.5 emu/g) was slightly increased with increasingsubstitution of La3+ ion. Moreover, two resonance frequency peaks were observed through theimaginary part of complex magnetic permeability; meanwhile, a decrease in the real part of thecomplex magnetic permeability was observed through the X-band frequencies.

Antioxidative and anti-α-amylase activities of four wild plants consumed by pastoral nomads in Egypt

SJ Hossain,M El-Sayed,H Aoshima 경희대학교 융합한의과학연구소 2009 Oriental Pharmacy and Experimental Medicine Vol.9 No.3

In this study, four plants grown naturally in Egypt that are usually consumed by pastoral nomads were screened for their total phenolic contents, antioxidative, and anti-α-amylase activities. Dried powder of plant’s part was extracted in absolute or 70% ethanol. A polar extract of Panicum turgidum (PTPE) had the highest total polyphenol content {92.5 mg gallic acid equivalents (GAE)/g}, followed by an alkaloid extract of Withania somnifera (WSAlk; 77.5 mg GAE/g), and an ethanol extract of Leptadenia pyrotechnica (LPEE; 59.1 mg GAE/g). By employing different assays such as DPPH radical scavenging, reducing power, Fe+ chelating, H2O2 scavenging and total antioxidant capacity, it was shown that PTPE, WSEE (ethanol extract of W. somnifera), WSAlk and LPEE had promising antioxidant activity, though, their potency varied according to the different tests. WSAlk had the highest level of α-amylase inhibition (40.2%) in vitro, followed by WSEE (30.5%). Therefore, it can be concluded that these plants, especially extracts of PTPE, and WSAlk are beneficial to physiological health, and could be used in food and pharmaceutical industries to prepare dietary supplements, functional foods or food preservatives. In this study, four plants grown naturally in Egypt that are usually consumed by pastoral nomads were screened for their total phenolic contents, antioxidative, and anti-α-amylase activities. Dried powder of plant’s part was extracted in absolute or 70% ethanol. A polar extract of Panicum turgidum (PTPE) had the highest total polyphenol content {92.5 mg gallic acid equivalents (GAE)/g}, followed by an alkaloid extract of Withania somnifera (WSAlk; 77.5 mg GAE/g), and an ethanol extract of Leptadenia pyrotechnica (LPEE; 59.1 mg GAE/g). By employing different assays such as DPPH radical scavenging, reducing power, Fe+ chelating, H2O2 scavenging and total antioxidant capacity, it was shown that PTPE, WSEE (ethanol extract of W. somnifera), WSAlk and LPEE had promising antioxidant activity, though, their potency varied according to the different tests. WSAlk had the highest level of α-amylase inhibition (40.2%) in vitro, followed by WSEE (30.5%). Therefore, it can be concluded that these plants, especially extracts of PTPE, and WSAlk are beneficial to physiological health, and could be used in food and pharmaceutical industries to prepare dietary supplements, functional foods or food preservatives.

Predicting shear capacity of NSC and HSC slender beams without stirrups using artificial intelligence

H. El-Chabib,M. Nehdi,A. Said 한국계산역학회 2005 Computers and Concrete, An International Journal Vol.2 No.1

The use of high-strength concrete (HSC) has significantly increased over the last decade, especially in offshore structures, long-span bridges, and tall buildings. The behavior of such concrete is noticeably different from that of normal-strength concrete (NSC) due to its different microstructure and mode of failure. In particular, the shear capacity of structural members made of HSC is a concern and must be carefully evaluated. The shear fracture surface in HSC members is usually trans-granular (propagates across coarse aggregates) and is therefore smoother than that in NSC members, which reduces the effect of shear transfer mechanisms through aggregate interlock across cracks, thus reducing the ultimate shear strength. Current code provisions for shear design are mainly based on experimental results obtained on NSC members having compressive strength of up to 50MPa. The validity of such methods to calculate the shear strength of HSC members is still questionable. In this study, a new approach based on artificial neural networks (ANNs) was used to predict the shear capacity of NSC and HSC beams without shear reinforcement. Shear capacities predicted by the ANN model were compared to those of five other methods commonly used in shear investigations: the ACI method, the CSA simplified method, Response 2000, Eurocode-2, and Zsutty's method. A sensitivity analysis was conducted to evaluate the ability of ANNs to capture the effect of main shear design parameters (concrete compressive strength, amount of longitudinal reinforcement, beam size, and shear span to depth ratio) on the shear capacity of reinforced NSC and HSC beams. It was found that the ANN model outperformed all other considered methods, providing more accurate results of shear capacity, and better capturing the effect of basic shear design parameters. Therefore, it offers an efficient alternative to evaluate the shear capacity of NSC and HSC members without stirrups.

Electrical conduction mechanisms of thermally evaporated 5,10,15, 20-tetraphenyl-21H, 23H-porphine iron (III) chloride thin films

M.M. El-Nahass,H.S. Metwally,H.E.A. El-Sayed,A.M. Hassanien 한국물리학회 2014 Current Applied Physics Vol.14 No.2

The JeV characteristics of the Au/5,10,15, 20-tetraphenyl-21H, 23H-porphine iron (III) chloride (FeTPPCl)/ ITO device exhibits rectifying behavior in the dark which can be explained due to the formation of Schottky barrier at ITO/FeTPPCl junction and the typical junction parameters were estimated in temperatures from 302 to 368 K. The temperature dependence of DC electrical conductivity showed that FeTPPCl films behave as semiconducting materials. These results indicate that the DC electrical conduction is through an activated process having three conduction mechanisms in the investigated range of temperatures. A variable range hopping model, a polaron model and band to band transitions have been used to explain the conduction mechanisms for FeTPPCl films.

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.

Molluscicidal Activity and Clinico-pathological Effect of Agave lophantha

El-Sayed, M.M.,Abdel-Hadi, M.,El-Nahas, H.A. The Pharmaceutical Society of Korea 1991 Archives of Pharmacal Research Vol.14 No.1

Dry powder and different extracts of Agave lophantha were tested against Biomphalaria alexandrina. The results showed that the butanol extract has high molluscicidal activity. The activity of the dry powder has been found to be stable under the effect of some simulated field conditions. Also the toxicological effect of the plant on mice was tested through determination of certain parameters such as total protein, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and acid phosphatase enzymes as well as histopathological study on liver and kidney.

Research Articles : Studies on Fungi Isolated from Dermatomycoses Patients in Egypt

(A. H. M. El Said) 한국균학회 2002 Mycobiology Vol.30 No.3

Effects of sintering temperature and graphite addition on the mechanical properties of aluminum

F.H. Latief,El-Sayed M. Sherif 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.6

The effects of different sintering temperatures, namely 400, 500 and 600 8C, on the mechanical properties of four aluminum–graphite alloys were reported. Different percentages of exfoliated graphite nanoplatelets particles (xGnP) were added to pure aluminum by using the powder metallurgy technique to produce Al-0 wt.%xGnP, Al-1 wt.%xGnP, Al-3 wt.%xGnP, and Al-5 wt.%xGnP. The density,fracture surface, compression, and hardness measurements were carried out to report the mechanical properties of the different aluminum–xGnP alloys. Combined data indicated that the Vickers hardness and compressive strength increase, on the other hand, the density decreases with increasing the graphite content in the Al alloys.

Research Articles : Mycotoxins and Invertase Enzyme of the Mycoflora of Molasses in Upper Egypt

(A. H. M. El Said) 한국균학회 2002 Mycobiology Vol.30 No.3