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.

Bisphosphonate’s effect on the tongue in adult male albino rats and the possible protective role of rutin: light and scanning electron microscopic study

Dalia El-sayed El-ghazouly(Dalia El-sayed El-ghazouly ),Rania Ibrahim Yassien(Rania Ibrahim Yassien ) 대한해부학회 2024 Anatomy & Cell Biology Vol.57 No.1

Alendronate sodium (ALS) is a nitrogen-containing bisphosphonate used for the treatment of different bone disorders. However, its adverse effect on oral soft tissue has been detected. Rutin (RUT) is natural flavonoid with antioxidant and anti-inflammatory properties. This work aimed to investigate the possible effect of ALS on the tongue of adult male albino rats and to evaluate the possible protective role of RUT. Forty adult male albino rats were equally divided into four groups: group I (control), group II (RUT): Received RUT 50 mg/kg, group III (ALS): Received ALS 1 mg/kg, group IV (ALS+RUT): Received ALS and RUT with the same doses as pervious groups. The drugs were given once daily for 5 weeks. Tongue specimens were taken and processed for light and scanning electron microscopic inspection. ALS treated group revealed structural changes in the tongue in the form of decrease in the height of the filiform papillae with blunt ends, marked atrophy in some papillae with areas of focal loss, loss of some epithelial cells, pyknotic nuclei and cytoplasmic vacuoles in some epithelial cells. The lamina propria showed inflammatory cellular infiltration with congested blood vessels. Statistically, there were highly significant decrease in the number of proliferating cell nuclear antigen immunopositive cells, area percentage of Bcl-2 immunoexpression and highly significant increase in the collagen content compared to control group. Administration of RUT with ALS minimizes these changes. RUT protected the rat tongue against the histological and immunohistochemical changes induced by ALS through its antioxidant and anti-inflammatory properties.

SEMIGROUPS AND HIGHER ORDER GENERATORS

El-Sayed, A.M.A. Department of Mathematics 1992 Kyungpook mathematical journal Vol.32 No.1

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.

Electrochemical Biosensor consisted of conducting polymer layer on gold nanodots patterned Indium Tin Oxide electrode for rapid and simultaneous determination of purine bases

El-Said, Waleed Ahmed,Choi, Jeong-Woo Elsevier 2014 ELECTROCHIMICA ACTA Vol.123 No.-

Chronotype, Aerobic Performance, and Sleep Quality of Young Athletes Before and During Ramadan Observance

El-Jaziz Anas,Lotfi Said 대한수면학회 2023 sleep medicine research Vol.14 No.2

Background and Objective Intermittent fasting has become a popular topic in recent years, with many people turning to this dietary approach to improve their health and manage their weight. It has also been studied for its potential impact on various aspects of health, including sleep and physical performance. This study aimed to investigate the impacts of intermittent fasting during Ramadan and chronotype on sleep quality and aerobic performance in young athletes.Methods This study is a prospective cohort design with repeated measurements, including 117 amateur athletes (16.86 ± 1.07 years) from Morocco. The aerobic performance was measured with the 20-m shuttle-run test. We also assessed sleep quality with the Pittsburgh Sleep Quality Index. The chronotype was assessed by the Morningness-Eveningness Questionnaire. We examined the difference in means before and during Ramadan; then, we analyzed the correlation between all variables.Results The current study showed that while aerobic performance and sleep quality declined during Ramadan, those with good sleep quality performed better in all periods. It also showed that chronotype is correlated with the aerobic performance before but not during Ramadan. However, the chronotype is associated with the sleep quality before and during Ramadan.Conclusions During Ramadan, athletes must build coping strategies to improve their sleep quality and maintain optimal physical performance.

E-Folklore and cyber-communication among Emirati youth

El-Sayed el-Aswad 국립민속박물관 2014 International Journal of Intangible Heritage Vol.9 No.-

The objective of this article is to explain the emergence of anew mediated heritage-social sphere and the articulation ofa contemporary Emirati identity that transforms traditionaloral heritage into an innovative form of electronic folkheritage. The literature addressing changes in folkheritage caused by the flourishing of new media, as wellas off- and on-line social networking in the UAE, is scant. This research seeks to fill that gap by showing howEmirati nationals have succeeded in assimilating outsideinfluences without deserting their heritage, and howglobal and local forms of communication have generatedunique cultural patterns that help Emirati peoplemaintain their identity, authenticity and socialconnectivity in a globally changing world. The studyshows that the Internet provides information zones,enhancing people’s knowledge, and interaction zones,strengthening people’s social relationships. Tounderstand these two domains, this inquiry addressesonline heritage and cyber-communication as used byboth the UAE government (formal network) and ordinaryE-Folklore and cyber-communicationamong Emirati youthpeople (informal network). For the purpose of theorisinge-folklore, this research proposes a paradigm dealingwith the content and form of heritage by bridgingtraditional/oral and technical/textual forms ofcommunication. For Emirati young people, focusing oncontent allows for unusual engagement with the pastthrough technologies that have the potential to shape andinfluence their future heritage. Emirati folk heritage hasundergone a sort of ‘cyber-communication’ or‘internetisation’, which means a process through whichcore elements of folk heritage are mediated by theInternet, reaching diverse audiences and allowing forbroad public participation.

Foundations forlowcostbuildings

Sayed Abde lSalam,Mahmoud Samir El-kady 한국CDE학회 2017 Journal of computational design and engineering Vol.4 No.2

Attaining aneconomicalandsafedesignofstructuresisregardedasaprerequisiteforthestructuralengineer.Themarketpricesofreinforcingsteels havedramaticallysoaredinrecentyearsinternationally.Therefore,thepurposeofthecurrentpaperisnotjustreducingtheratioofreinforcing steelinthefoundationsforskeletonstructures,butratherminimizingthisratiothroughchoosingthemosteffectivefootingshape(folded stripfootings).Foldedfootingshavebeenusedasanalternativetotheconventionalrectangularstripfootings.Theheightofthestudiedmodel isten floors. Twodifferentfoundationsystemsareusedintheanalysisnamely;rectangularstripfootings,andfoldedstripfootingsrespectively. Bothfootingshapeswillbedesignedascontinuousfootingswithgridshapeunderthebuilding.Comparisonbetweenthetwosystems isalsopresentedregardingtheconcretesectionsandreinforcementratiounderthesameappliedloads.The finite elementanalysissoftware ADINAisusedinmodelingandanalysisofthestructuralandgeotechnicalbehaviorofbothtypesoffootings,withemphasisontheeffect ofchangingthefootingshapeonthestressesinthefootingconcretebodyandtheunderlyingsoils.Researchresultspresentstheinternalstresses withinthefootingandsoildomains,aswellasthecontactpressuredistributionforareinforcedfoldedstripfootingrestingondifferentsoil types.Theinfluence offoldinginclinationangle,andsoiltypeontheresultsarealsostudied.Resultsshowedthatfoldedstripfootingsareefficient inreducingtheamountofneededreinforcements,andsuchefficiency inreducingtherequiredsteelreinforcementinthefootingsisdepending ontheappliedfootingloads,andtosomedegreeonthesoiltypeandproperties.Reductioninthereinforcementratiobetweentherectangular andfoldedfootingtypesisabout26%infavorofthefoldedstripfootings.Acomparativeeconomicalstudyshowsthatthetotalcostof thereinforcedconcretesectionforthefoldedstripfootingsislessthanthetraditionalonebyabout18%.Thisdifferenceincostofbothtypesof footingsismainlyduetotherelativelysmallerinsteelreinforcementrationeededforthefoldedtypeascomparedwiththerectangularones. So, thefoldedstripfootingismoreeconomicalthantherectangularstripfooting.

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.

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.