Exploratory Investigation for Some Universities' E-Learning Systems during Covid-19 Pandemic

Fatima Rayan Awad, Ahmed,Thowiba E., Ahmed,Rashid A., Saeed,Elmustafa Sayed, Ali,Ghada Elnour Elterafi, Abdelrhman,Somia Yousif Ahmed, Abutiraima International Journal of Computer ScienceNetwork S 2022 International journal of computer science and netw Vol.22 No.12

COVID pandemic has reshaped the world as it has been known to us and the education system is one of the most affected by it. Due to social distancing, quarantines and isolations have made it impossible for the knowledge transition to the masses using conventional methods. For cope with pandemic, the only other way available for some of the fortunate countries is the use of E-learning having somewhat the same traditional teaching method. This paper is concerned with the study of the preparedness of the learning system in some Sudanese universities due to the impact of the COVID-19 pandemic. Critical analysis has been performed to evaluate the current developing scenario, usage of the facilities available in open-source platforms, and the interaction of the universities folks with e-learning systems. The impact of such measures has been thoroughly investigated in this paper for Sudan which is already deprived of a proper education system. The investigation shows that the interact of the staff and the students with the system was acceptable where more than 85% of those enrolled to the system were interact properly and efficiently. The lecturers conducted through the platform were attended with more than 75% of the students. We also found that most of the lecturer were avoid to exam students by utilize the platform; where only 45% of the uploaded courses were conducted exams over Moodle platform. As Moodle is an open source and still need to be improved to be used for high examination credibility.

Heat transfer characteristics and entropy generation for wing-shaped-tubes with longitudinal external fins in cross-flow

Sayed Ahmed E. Sayed Ahmed,Osama M. Mesalhy,Mohamed A. Abdelatief 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.6

A numerical study is conducted to clarify heat transfer characteristics, effectiveness and entropy generation for a bundle of wingshaped-tubes attached to Longitudinal fins (LF) at downstream side. The air-side Re a ranged from 1.8 x 10 3 to 9.7 x 10 3 . The fin height (h f ) and fin thickness (δ) have been changed as: (2 mm ≤ h f ≤ 12 mm) and (1.5 mm ≤ δ ≤ 3.5 mm). The analysis of entropy generation is based on the principle of minimizing the rate of total entropy generation that includes the generation of entropy due to heat transfer and friction losses. The temperature field around the wing-shaped-tubes with (LF) is predicted using commercial CFD FLUENT 6.3.26 software package. Correlations of Nu a , St a , and Bejan number (Be), as well as the irreversibility distribution ratio (Φ) in terms of Re a and design parameters for the studied bundle are presented. Results indicated that, installing fins with heights from 2 to 12 mm results in an increase in Nu a from 11 to 36% comparing with that of wing-shaped tubes without fins (NOF). The highest and lowest values of effectiveness (ε) at every value of the considered Re a range are occurred at h f = 6 mm and (NOF), respectively. The wing-shaped-tubes heat exchanger with h f = 6 mm has the highest values of (ε), efficiency index (η) and area goodness factor (G a ) and also the lowest values of Φ and hence the best performance comparing with other arrangements. The minimum values of Φ are occurred at h f = 6 mm. (Be) decreases with increasing Re a for all studied h f . The heat transfer irreversibility predominates for (1800 ≤ Re a ≤ 4200) while the opposite is true for (6950 < Re a ≤ 9700). δ has negligible effect on Nu a and heat transfer irreversibility. Comparisons between the experimental and numerical results of the present study and those, previously, obtained for similar available studies showed good agreements.

Synthesis and Pharmacological Screening for Muscle Relaxant, Anticonvulsant, and Sedative Activities of Certain Organic Compounds Produced by Michael Addition

Said , Makarem M.,Ahmed, Amany A. E.,El-Alfy, Abir T. The Pharmaceutical Society of Korea 2004 Archives of Pharmacal Research Vol.27 No.12

Michael addition of certain nucleophiles on ${\alpha}$ , ${\beta}$-unsaturated ketones 1 led to the formation of adducts 2-7 as well as the reaction of arylidene derivatives with secondary amines afforded the amino compounds 9 and 11. Also, dialkylmalonates were treated with ${\alpha}$-cyano cinnamide to afford 13. On the other hand, double Michael cycloaddition of ethylcyanoacetate or tetrachlorophthalic anhydride to the suitable divinylketone were synthesized to produce 15-17. Selected compounds (13 and 6) were screened for muscle relaxant, anticonvulsant, and sedative activities using established pharmacological models. Their activities were compared with that of phenobarbital sodium taken as standard. Compound 6 was the most potent muscle relaxant while compounds 13a and 13c offered the highest anticonvulsant activity. Meanwhile compound 13c showed the highest potentiation of phenobarbital induced sleep in mice.

Life Span Extension of Caenorhabditis elegans by Novel Pyridoperimidine Derivative

Ahmed A. R. Sayed,Kamal M. El-Shaieb,Aboul-Fetouh E. Mourad 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.1

Zwitterions formed from the addition of triphenylphosphine to dialky acetylene-dicarboxylates attack the nucleus of both 1H-perimidine (1) and 1H-benzo[d]imidazole (9) to form novel pyrido[1,2,3-cd]perimidine and imidazo[4,5,1-ij]quinoline derivatives in moderate yields (64-72%). The biological activity of the products has been studied. Compound 3a was found to extend life span of wild type Caenorhabditis elegans under standard laboratory conditions. Both heat stress and induced chemical stress resistance of wild type C. elegans were improved in a reverse dose-dependent manner due to 3a treatment. In addition, treatment of worms with compound 3a significantly attenuated the formation of advanced glycation end products in a reverse dose-dependent manner.

CONTINUATION THEOREM OF FRACTIONAL ORDER EVOLUTIONARY INTEGRAL EQUATIONS

Ahmed M. A. El-Sayed,Mohamed A. E. Aly 한국전산응용수학회 2002 Journal of applied mathematics & informatics Vol.9 No.2

The fractional order evolutionary integral equations have been considered by the first author in \cite{AMA.4}, the existence, uniqueness and some other properties of the solution have been proved. Here we study the continuation of the solution and its fractional order derivative. Also we study the generality of this problem and prove that the fractional order diffusion problem, the fractional order wave problem and the initial value problem of the equation of evolution are special cases of it. The abstract diffusion-wave problem will be given also as an application. The fractional order evolutionary integral equations have been considered by the first author in \cite{AMA.4}, the existence, uniqueness and some other properties of the solution have been proved. Here we study the continuation of the solution and its fractional order derivative. Also we study the generality of this problem and prove that the fractional order diffusion problem, the fractional order wave problem and the initial value problem of the equation of evolution are special cases of it. The abstract diffusion-wave problem will be given also as an application.

Shear behaviour of thin-walled composite cold-formed steel/PE-ECC beams

Ahmed M. Sheta,Xing Ma,Yan Zhuge,Mohamed A. ElGawady,Julie E. Mills,El-Sayed Abd-Elaal 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.46 No.1

The novel composite cold-formed steel (CFS)/engineered cementitious composites (ECC) beams have been recently presented. The new composite section exhibited superior structural performance as a flexural member, benefiting from the lightweight thin-walled CFS sections with improved buckling and torsional properties due to the restraints provided by thinlayered ECC. This paper investigated the shear performance of the new composite CFS/ECC section. Twenty-eight simply supported beams, with a shear span-to-depth ratio of 1.0, were assembled back-to-back and tested under a 3-point loading scheme. Bare CFS, composite CFS/ECC utilising ECC with Polyethylene fibres (PE-ECC), composite CFS/MOR, and CFS/HSC utilising high-strength mortar (MOR) and high-strength concrete (HSC) as replacements for PE-ECC were compared. Different failure modes were observed in tests: shear buckling modes in bare CFS sections, contact shear buckling modes in composite CFS/MOR and CFS/HSC sections, and shear yielding or block shear rupture in composite CFS/ECC sections. As a result, composite CFS/ECC sections showed up to 96.0% improvement in shear capacities over bare CFS, 28.0% improvement over composite CFS/MOR and 13.0% over composite CFS/HSC sections, although MOR and HSC were with higher compressive strength than PE-ECC. Finally, shear strength prediction formulae are proposed for the new composite sections after considering the contributions from the CFS and ECC components.

Transition Metal Complexes Derived From 2-hydroxy-4-(p-tolyldiazenyl)benzylidene)-2-(p-tolylamino)acetohydrazide Synthesis, Structural Characterization, and Biological Activities

Alhakimi, Ahmed N.,Shakdofa, Mohamad M.E.,Saeed, S. El-Sayed,Shakdofa, Adel M.E.,Al-Fakeh, Maged S.,Abdu, Ashwaq M.,Alhagri, Ibrahim A. Korean Chemical Society 2021 대한화학회지 Vol.65 No.2

Mononuclear Cu(II), Ni(II), Co(II), Mn(II), Zn(II), Fe(III), Ru(III), and UO2(II) complexes of 2-hydroxy-4-(p-tolyldiazenyl)benzylidene)-2-(p-tolylamino)acetohydrazide (H2L) were prepared by direct method. The ligand and its complexes were isolated in solid state and characterized by analytical techniques such as elemental and thermal analyses, molar conductance, magnetic susceptibility measurements and spectroscopic techniques such as UV-Visible, IR, 1H-NMR and 13C-NMR. The spectral data indicated that the ligand acted as neutral/monobasic bidentate or monobasic/dibasic tridentate ligand bonded to the metal ions through the oxygen atom of ketonic or enolic carbonyl group, azomethine nitrogen atom and deprotonated/protonated phenolic oxygen atom forming either tetragonally distorted octahedral or octahedral. Antimicrobial activities of the ligand and its complexes were evaluated against Escherichia coli, Bacillus subtilis and Aspergillus niger by well diffusion method. The results of antifungal activity showed that the Fe(III) complex (10) exhibited higher antifungal against Aspergillus niger than the other complexes. However, the results of antibacterial activity revealed that Cu(II) complex (4) is the most active against Escherichia coli while the Cu(II) complex (5) and Fe(III) complex (10) exhibited higher antibacterial effect on Bacillus subtilis than the other complexes.

CONTINUATION THEOREM OF FRACTIONAL ORDER EVOLUTIONARY INTEGRAL EQUATIONS

El-Sayed, Ahmed M.A.,Aly, Mohamed A.E. 한국전산응용수학회 2002 The Korean journal of computational & applied math Vol.9 No.2

The fractional order evolutionary integral equations have been considered by first author in [6], the existence, uniqueness and some other properties of the solution have been proved. Here we study the continuation of the solution and its fractional order derivative. Also we study the generality of this problem and prove that the fractional order diffusion problem, the fractional order wave problem and the initial value problem of the equation of evolution are special cases of it. The abstract diffusion-wave problem will be given also as an application.

Corrosion inhibition performance and computational studies of pyridine and pyran derivatives for API X-65 steel in 6 M H2SO4

Kurls E. Anwer,Ahmed A. Farag,Eslam A. Mohamed,Eman M. Azmy,Galal H. Sayed 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.97 No.-

The present investigation aims to synthesize and explore the influence of pyridine and pyran derivativeson the API X-65 steel corrosion in a 6 M H2SO4 solution. The compound was examined at differentconcentrations to optimized the best concentration for the corrosion inhibition effect, weight lossmeasurements, potentiodynamic polarization measurement (PDP), electrochemical impedance spectroscopy(EIS), scanning electron microscopy (SEM) and theoretical methods were used to evaluating theinhibition efficiency. The obtained adsorption data achieved the model of Langmuir isotherm. Thepyridine derivatives showed higher inhibition than pyran derivatives. The PDP tests proposed thatpyridine and pyran derivatives are mixed-type inhibitors. The EIS parameters demonstrate that thedouble-layer capacitance (Cdl) decreases with the increase of inhibitor concentration, which implies areduces dielectric constant. It was observed from experimental data that the inhibition efficiency reached92.7%, 89.1, 94.7, and 85.2% for concentration 2.66 10 3M of I, II, III and IV, respectively indicating theinhibition order is III > I > II > IV. The parameters derived from the theoretical quantum chemicalcalculations were found adequately correlated with the obtained experimental results.

Proanthocyanidin-Rich Date Seed Extract Protects Against Chemically Induced Hepatorenal Toxicity

Atallah F. Ahmed,Jawaher H. Al-Qahtani,Hanan M. Al-Yousef,Mansour S. Al-Said,AbdelKader E. Ashour,Mohammed Al-Sohaibani,Syed Rafatullah 한국식품영양과학회 2015 Journal of medicinal food Vol.18 No.3

A hydroacetone extract was prepared from seeds of Phoenix dactylifera L. var. Khalas, which is an industrial by-product of date processing. The proanthocyanidin nature of the extract (coded as DTX) was characterized by phytochemical and nuclear magnetic resonance (NMR) analyses. The total phenol/proanthocyanidin content and antioxidant activity of DTX were estimated by Folin–Ciocalteu, vanillin-sulfuric acid, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays, respectively. The hepatorenal protective activity of DTX was evaluated using CCl4-induced toxicity model in rats, in comparison with silymarin (SYL). Results of the histopathological examination and measurements of various hepatorenal serum indices and tissue biochemical markers demonstrated that DTX displayed marked protective potential against CCl4-induced liver and kidney injury at 100 mg/kg/rat. Relative to the control CCl4-intoxicated group, pretreatment with DTX significantly (P<.001) suppressed the elevated serum levels of alanine aminotransferase and aspartate aminotransferase (ALT and AST), alkaline phosphatase (ALP), γ-glutamyl transferase (GGT), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), bilirubin, creatinine, and calcium, whereas it significantly (P<.001) increased the diminished serum levels of high-density lipoprotein cholesterol (HDL-C) and total protein (TP). Moreover, DTX significantly decreased malondialdehyde (MDA) formation and increased TP synthesis in hepatorenal tissues compared with the intoxicated control. The improvement in biochemical parameters by DTX was observed in a dose-dependent manner and confirmed by restoration of normal histological features. The acute toxicity test of DTX in rats revealed safety of the extract. This study reveals that DTX enhances the recovery from xenobiotics-induced toxicity initiated by free radicals.