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.

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.

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.

Immune Defense of Rats Immunized with Fennel Honey, Propolis, and Bee Venom Against Induced Staphylococcal Infection

Sayed, S.M.,El-Ella, Ghada A. Abou,Wahba, Nahed M.,Nisr, Neveen A. El,Raddad, Khaled,Rahman, M.F. Abd El,Hafeez, M.M. Abd El,Aamer, Ahmed Abd El Fattah The Korean Society of Food Science and Nutrition 2009 Journal of medicinal food Vol.12 No.3

The objective of this work was to evaluate the potency of bee product-immunized rats to overcome an induced Staphylococcus aureus infection. Forty rats were divided to eight groups: T1, T3, and T5 received, respectively, fennel honey, ethanol, and aqueous propolis extracts orally, and T2, T4, and T6 were administered the respective materials intraperitoneally; T7 received bee venom by the bee sting technique; and T8 was the control group. All groups were challenged by a bovine clinical mastitis isolate of S. aureus. Each rat received 2mL of broth inoculated with $1{\times}10^5$ colony-forming units/mL intraperitoneally. Two weeks post-induced infection all rats were sacrificed and eviscerated for postmortem inspection and histopathological study. Three rats from T8 and one rat from T7 died before sacrifice. Another two rats, one each in T4 and T5, had morbidity manifestations. The remaining experimental animals showed apparently healthy conditions until time of sacrifice. Postmortem inspection revealed that all T8 rats showed different degrees of skeletal muscle and internal organ paleness with scattered focal pus nodules mainly on lungs and livers. All rats of the treated groups showed normal postmortem features except three rats. A dead rat in group T7 showed focal pus nodules on the lung surface only, whereas the affected two rats in groups T4 and T5 appeared normal except with some pus nodules, but much smaller than in the control, scattered on the hepatic surface and mesentery. Histopathological studies revealed that T8 rats had typical suppurative bronchopneumonia and or severe degenerative and necrobiotic changes in hepatic tissues. Three affected rats of the treated groups showed slight bronchopneumonia or degenerative hepatic changes only. The other animals of the treated groups showed completely normal parenchymatous organs with stimulated lymphatic tissues. It was concluded that all tested previously bee product-immunized rats could significantly challenge the induced S. aureus infection (P < .01). The effects were more pronounced in rats that had received fennel honey solution.

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.

Endocrine Disruptors Alter Sex Ratio Via Decreasing Y Chromosome-Bearing Spermatozoa Viability

El-Sayed A. Mohamed,Woo-Sung Kwon,Yoo-Jin Park,Sung-Jae Yoon,Kyu-Hyun Jeong,Myung-Geol Pang 한국동물생명공학회(구 한국동물번식학회) 2011 발생공학 국제심포지엄 및 학술대회 Vol.2011 No.1

In mammals, the meiosis division in testes produces equal numbers of two different types of gametes: X chromosome-bearing sperm (X-spermatozoa) and Y chromosomebearing sperm (Y-spermatozoa), which have equal potential to fertilize the oocytes. Therefore, the expected 1: 1 sex ratio is observed. However, under some conditions like endocrine disruptors (EDs) exposure the sex ratio is deviated than the expected with more males or more females. And recently many hypotheses have been postulated to explain the mechanism of sex ratio deviation; however none of them introduced a proven experimental explanation. To solve this enigma, we hypothesized that the differences between X- and Y-spermatozoa survivability under specific conditions due to differences in their chromosome contents are the key leading to the sex ratio alteration. To examine our hypothesis, we combined two techniques; first, hypo-osmotic swelling (HOS) test that was applied to test viability of spermatozoa and second, fluorescence in situ hybridization that was applied on HOS-treated spermatozoa to define sex chromosome composition. In the present study, human spermatozoa were incubated with a group of EDs represent a widespread chemicals in the environment bisphenol A (BPA, 100 μM), nonylphenol (NP, 10 μg/ml), 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD, 2.5 μg/ml), genistein (Gen, 100 μM), and the following pesticides, dibromochloropropane (DBCP, 10 μg/ml), atrazine (Atraz, 500 μM), and diazinone (Diaz, 500 μM) for 6 hr at 37℃ in 5% CO2. Then, the viability of spermatozoa and their sex chromosome contents were evaluated simultaneously. Among seven chemicals studied only four chemicals (Atraz, DBCP, TCDD, and Diaz) significantly decreased Y-sperm viability when compared to those of X-spermatozoa in the same treatment group and viability of Y-spermatozoa when compared to those in the negative and positive (DMSO) control groups (p<0.05). Also, in these four treatment groups the sex ratio of live sperm population was significantly lowered compared to the control groups (p<0.05). Otherwise, Gen, BPA, and NP did not show any significant effect on viability of Yspermatozoa or decreasing sex ratio in live sperm population as compared to the control groups. It has been proven that TCDD, DBCP, and the pesticides decrease the sex ratio, but the same effect was not observed in case of Gen, BPA, and NP. From the present findings, there is no doubt that the EDs may alter sex ratio via decreasing Y-spermatozoa viability.

New Delay Dependent Robust Stability Criteria for T–S Fuzzy Systems with Constant Delay

Said Idrissi,El Houssaine Tissir,Ismail Boumhidi,Noreddine Chaibi 제어·로봇·시스템학회 2013 International Journal of Control, Automation, and Vol.11 No.5

This paper deals with the problem of delay dependent robust stability for T–S fuzzy time delay systems. The approach based on constructing a new Lyapunov-Krasovskii functional by dividing uniformly the delay interval into N segment with N is positive integer, and using Finsler’s lemma. This new Lyapunov-Krasovskii functional is chosen with different weighted matrices corresponding to dif-ferent segments. The perturbations considered are norm bounded, and the results are expressed in terms of linear matrix inequality (LMIs). Numerical examples are provided to show the effectiveness of the present method, compared with some recent previous ones.

Removal of Pesticide (Oxamyl) from Water using Activated Carbons Developed from Apricot Stones

El-Nabarawy, Th.,Sayed Ahmed, S.A.,Youssef, A.M. Korean Carbon Society 2007 Carbon Letters Vol.8 No.4

Four stream- activated carbons were prepared by carbonizing apricot stones at $600^{\circ}C$ followed by gasification with steam at $950^{\circ}C$ to burn-off's=17, 32, 49 and 65%. The textural parameters of these activated carbons were determined from nitrogen adsorption results at 77 K. The total pore volume and the mean pore radius increased with the increase of % burn-off whereas the surface area increased with the increase of burn- off from 17 to 32 and further to 49%. Further increase of burn-off to 65% was associated with a considerable decrease in surface area as a result of pronounced pore widening due to pore erosion. The surface pH values of the carbons investigated range between 7.1 and 8.2. The adsorption of oxamyl onto the activated carbon followed pseudo-second order kinetics and the equilibrium adsorption isotherms fitted Langmuir adsorption model. The adsorption of oxamyl proved to be of the physical type and took place in non-micropores. The amount of oxamyl adsorbed expressed as $q_m$ depends to a large extent to the surface area located in non-micropores $S^{\propto}\;_n$, where a straight line relationship passing through the origin was obtained.

Characterization of Homocysteine γ-Lyase from Submerged and Solid Cultures of Aspergillus fumigatus ASH (JX006238)

( El Sayed Ashraf S ),( Salwa A Khalaf ),( Hani A Aziz ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.4

Among 25 isolates, Aspergillus fumigatus ASH (JX006238) was identified as a potent producer of homocysteine γ- lyase. The nutritional requirements to maximize the enzyme yield were optimized under submerged (SF) and solid-state fermentation (SSF) conditions, resulting in a 5.2- and 2.3-fold increase, respectively, after the last purification step. The enzyme exhibited a single homogenous band of 50 kDa on SDS-PAGE, along with an optimum pH of 7.8 and pH stability range of 6.5 to 7.8. It also showed a pI of 5.0, as detected by pH precipitation with no glycosyl residues. The highest enzyme activity was obtained at 37-40℃, with a Tm value of 70.1oC. The enzyme showed clear catalytic and thermal stability below 40℃, with T1/2 values of 18.1, 9.9, 5.9, 3.3, and 1.9 h at 30℃, 35℃, 40℃, 50℃, and 60℃, respectively. Additionally, the enzyme Kr values were 0.002, 0.054, 0.097, 0.184, and 0.341 S-1 at 30oC, 35oC, 40oC, 50℃, and 60℃, respectively. The enzyme displayed a strong affinity to homocysteine, followed by methionine and cysteine when compared with non-S amino acids, confirming its potency against homocysteinuriarelated diseases, and as an anti-cardiovascular agent and a specific biosensor for homocysteinuria. The enzyme showed its maximum affinity for homocysteine (Km 2.46 mM, Kcat 1.39 × 10-3 s-1), methionine (Km 4.1 mM, Kcat 0.97 × 10-3 s-1), and cysteine (Km 4.9 m M, Kcat 0.77 × 10-3 s-1). The enzyme was also strongly inhibited by hydroxylamine and DDT, confirming its pyridoxal 5`-phosphate (PLP) identity, yet not inhibited by EDTA. In vivo, using Swiss Albino mice, the enzyme showed no detectable negative effects on platelet aggregation, the RBC number, aspartate aminotransferase, alanine aminotransferase, or creatinine titer when compared with negative controls.

Thermal Hydraulic Analysis of Core Flow Bypass in a Typical Research Reactor

Said M.A. Ibrahim,Salah El-Din El-Morshedy,Abdelfatah Abdelmaksoud 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.1

The main objective of nuclear reactor safety is to maintain the nuclear fuel in a thermally safe conditionwith enough safety margins during normal operation and anticipated operational occurrences. In thisresearch, core flow bypass is studied under the conditions of the unavailability of safety systems. As corebypass occurs, the core flow rate is assumed to decrease exponentially with a time constant of 25 s tonew steady state values of 20, 40, 60, and 80% of the nominal core flow rate. The thermal hydraulic codePARET is used through these calculations. Reactor thermal hydraulic stability is reported for all cases ofcore flow bypass.