A New Soft-Fusion Approach for Multiple-Receiver Wireless Communication Systems

Ashraf M. Aziz,Ahmed M. ElBakly,Mohamed H.A. Azeem,Gamal A. Hamid 한국전자통신연구원 2011 ETRI Journal Vol.33 No.3

In this paper, a new soft-fusion approach for multiple-receiver wireless communication systems is proposed. In the proposed approach, each individual receiver provides the central receiver with a confidence level rather than a binary decision. The confidence levels associated with the local receiver are modeled by means of soft-membership functions. The proposed approach can be applied to wireless digital communication systems, such as amplitude shift keying, frequency shift keying, phase shift keying, multi-carrier code division multiple access, and multiple inputs multiple outputs sensor networks. The performance of the proposed approach is evaluated and compared to the performance of the optimal diversity, majority voting, optimal partial decision, and selection diversity in case of binary noncoherent frequency shift keying on a Rayleigh faded additive white Gaussian noise channel. It is shown that the proposed approach achieves considerable performance improvement over optimal partial decision, majority voting, and selection diversity. It is also shown that the proposed approach achieves a performance comparable to the optimal diversity scheme.

Anticancer activities of some newly synthesized pyrazole and pyrimidine derivatives

Ashraf M. Mohamed,Weal A. El-Sayed,Musaed A. Alsharari,Husam R. M. Al-Qalawi,Mousa O. Germoush 대한약학회 2013 Archives of Pharmacal Research Vol.36 No.9

A series of pyrazolopyridine and pyridopyrimidinederivatives 2–6 were newly synthesized using3,5-bisarylmethylene-1-methylpiperidone as the startingmaterial. The anticancer activities of the synthesizedcompounds were evaluated using 59 different human tumorcell lines, representing cancers of CNS, ovary, renal,breast, colon, lung, leukemia, and melanoma, prostate aswell as kidney. Some of the tested compounds, especiallythose with a fluorine substituent at the para-position in thephenyl ring and those with a pyridopyrimidine-2-thionewith a free –NH or –SH, exhibited greater in vitro antitumoractivities at low concentrations (log 10 [GI50] =-4.6) against the human tumor cell lines. Additionally,some of the compounds had moderate inhibitory effects onthe growth of the cancer cell lines. The detailed synthesis,spectroscopic data and antitumor properties of the synthesizedcompounds are reported.

UV-Visible spectroscopic and DFT studies of the binding of ciprofloxacin hydrochloride antibiotic drug with metal ions at numerous temperatures

Mohammed Ashraf Uddin,Bupasha Hekim Sutonu,Malik Abdul Rub,Shamim Mahbub,Maha Moteb Alotaibi,Abdullah M. Asiri,Shahed Rana,Md. Anamul Hoque,Mahbub Kabir 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.3

Ciprofloxacin hydrochloride (CPFH) is a very common antibiotic drug for the treatment of different types of bacterial infections. The activity of the drug depends on the complexation of the employed drug with different metals present in the body. In the current investigation, the complexation behavior of CPFH drug with numerous metal ions was explored by means of UV-Visible spectroscopic and density functional theory (DFT) techniques at various temperatures. The binding constants (Kf) of CPFH+metal ions complexes were determined from the Benesi-Hildebrand equation. The Kf values experience an alteration with the nature of metal ions employed and the change of temperature. The binding of CPFH with alkali earth metals decreases with the increase of metal size and increases with the increase of temperature, while the opposite effect of temperature was observed for transition metals. The Gibbs free energy of binding (Go) for the complexation between CPFH and metal ions was negative in all cases, which reveals that the complexation phenomenon is spontaneous. The values of enthalpy and entropy connote the presence of both hydrophobic and electrostatic interactions. The complexation of CPFH was observed to be endothermic in the case of alkali earth metals while exothermic for transition metals. The intrinsic enthalpy gain (Ho, *) values signify the higher stability of metal-drug complexes. The compensation temperature (TC) values were found to be comparable to the biological systems. DFT studies show the formulation of 1 : 1 complexes with transition metals as well as the square planar geometry of the complexes. HOMO and LUMO analyses reveal that the stability of CPFH-Ni complexes is higher than that of CPFH-Co/CPFH-Zn complexes.

Vibration analysis of functionally graded graphene platelet-reinforced composite doubly-curved shallow shells on elastic foundations

Mohammed Sobhy,Ashraf M. Zenkour 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.33 No.2

Based on a four-variable shear deformation shell theory, the free vibration analysis of functionally graded graphene platelet-reinforced composite (FGGPRC) doubly-curved shallow shells with different boundary conditions is investigated in this work. The doubly-curved shells are composed of multi nanocomposite layers that are reinforced with graphene platelets. The graphene platelets are uniformly distributed in each individual layer. While, the volume faction of the graphene is graded from layer to other in accordance with a novel distribution law. Based on the suggested distribution law, four types of FGGPRC doubly-curved shells are studied. The present shells are assumed to be rested on elastic foundations. The material properties of each layer are calculated using a micromechanical model. Four equations of motion are deduced utilizing Hamilton's principle and then converted to an eigenvalue problem employing an analytical method. The obtained results are checked by introducing some comparison examples. A detailed parametric investigation is performed to illustrate the influences of the distribution type of volume fraction, shell curvatures, elastic foundation stiffness and boundary conditions on the vibration of FGGPRC doubly-curved shells.

Dynamic characteristics of transmission line conductors and behaviour under turbulent downburst loading

Mohamed M. Darwish,Ashraf A. El Damatty,Horia Hangan 한국풍공학회 2010 Wind and Structures, An International Journal (WAS Vol.13 No.4

During the past decade, many electrical transmission tower structures have failed during downburst events. This study is a part of a research program aimed to understand the behaviour of transmission lines under such localized wind events. The present study focuses on the assessment of the dynamic behaviour of the line conductors under downburst loading. A non-linear numerical model, accounting for large deformations and the effect of pretension loading, is developed and used to predict the natural frequencies and mode shapes of conductors at various loading stages. A turbulence signal is extracted from a set of full-scale data. It is added to the mean component of the downburst wind field previously evaluated from a CFD analysis. Dynamic analysis is performed using various downburst configurations. The study reveals that the response is affected by the background component, while the resonant component turns to be negligible due large aerodynamic damping of the conductors.

Perovskite nanomaterials with exceptional photocatalytic properties for oxidative desulfurization of dibenzothiophene

Mohamed R.Madkour,Samira Abdel-Azim,Ashraf M. Ashmawy,Elsayed M. Elnaggar,Delvin Aman 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.127 No.-

LaTiO3, LaZnO3, and Zn-doped LaTiO3 (LaZn0.5Ti0.5O3) perovskite catalysts are used for the aerobic photocatalyticoxidative desulfurization (APODS) of organosulfur compounds such as dibenzothiophene (DBT). Several techniques were used to characterize the synthesized photocatalyst, XRD, SEM, TEM, EDX, UV–Vis, DRS, PL, and XPS physisorption analyses. XRD patterns of LaZn0.5Ti0.5O3 is similar to pure LaTiO3 withoutany impurities confirming the insertion of atomic zinc into the LaTiO3 lattice structure. According tothe obtained results, synthesized doped perovskite exhibits a more significant photocatalytic reactionthan pure perovskite in removing DBT in the following order LaZn0.5Ti0.5O3 > LaZnO3 > LaTiO3 in the values99.97, 91.38 and 76.05 % within 180 minutes under sunlight. The pseudo-first-order kinetic reactionmodel fits well with the results of the kinetic study. A reaction mechanism for LaZn0.5Ti0.5O3 was proposedusing UV– Vis and XPS. At wavelengths above 400 nm, UV–Vis DRS confirms the absorption edgesof the compound, which in this case equates to a visible light absorber with a band gap of 2.9 (eV). Superoxide radicals and holes were determined to be the primary active species in the photocatalyticprocess due to the reactive species and oxygen bubbles acting as trapping agents. The developed photocatalyticmaterial was also highly regenerative and recyclable. The photocatalyst LaZn0.5Ti0.5O3 is first utilizedin the photocatalytic oxidation of DBT. LaZn0.5Ti0.5O3 is a promising photocatalyst for environmentalcontrol and relevant applications, especially in solar energy.

INVESTIGATION OF THE CONTRIBUTION OF MICROBIAL BIOFLOC TO NITROGEN REMOVAL UNDER DIFFERENT ENVIRONMENTAL CONDITIONS USING PCR-DGGE TECHNIQUE

Ashraf Suloma,Rania S Mabroke,Azab M. Tahoun,Abd El-Naem F.A Zidan,Osama M. El?Husseiny,Wael El-Menofy,Mohamed H.M. El-Shafiey,Hesham R.A. Mola 한국수산과학회 양식분과 2015 한국수산과학회 양식분과 학술대회 Vol.2015 No.5

Behavior of self supported transmission line towers under stationary downburst loading

Mohamed M. Darwish,Ashraf A. El Damatty 한국풍공학회 2011 Wind and Structures, An International Journal (WAS Vol.14 No.5

During the past decade, many electrical transmission tower structures have failed during downburst events. This study is a part of a research program aimed to understand the behaviour of transmission lines under such localized wind events. The present study focuses on assessing the behaviour of self supported transmission line towers under downburst loading. A parametric study is performed to determine the critical downburst configurations causing maximum axial forces for various members of a tower. The sensitivity of the internal forces developing in the tower’s members to changes in the downburst size and location was studied. The structural behaviour associated with the critical downburst configurations is described and compared to the behaviour under ‘normal’ wind loads.

Size-dependent vibration and electro-magneto-elastic bending responses of sandwich piezomagnetic curved nanobeams

Mohammed Arefi,Ashraf M. Zenkour 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.29 No.5

Size-dependent free vibration responses and magneto-electro-elastic bending results of a three layers piezomagnetic curved beam rest on Pasternak's foundation are presented in this paper. The governing equations of motion are derived based on first-order shear deformation theory and nonlocal piezo-elasticity theory. The curved beam is containing a nanocore and two piezomagnetic face-sheets. The piezomagnetic layers are imposed to applied electric and magnetic potentials and transverse uniform loadings. The analytical results are presented for simply-supported curved beam to study influence of some parameters on vibration and bending results. The important parameters are spring and shear parameters of foundation, applied electric and magnetic potentials, nonlocal parameter and radius of curvature of curved beam. It is concluded that the increase in radius of curvature tends to an increase in the stiffness of curved beam and consequently natural frequencies increase and bending results decrease. In addition, it is concluded that with increase of nonlocal parameter of curved beam, the stiffness of structure is decreased that leads to decrease of natural frequency and increase of bending results.

Protective effect of hydrogen sulfide against cold restraint stress-induced gastric mucosal injury in rats

Esam M. Aboubakr,Ashraf Taye,Mohamed A. El-Moselhy,Magdy K. Hassan 대한약학회 2013 Archives of Pharmacal Research Vol.36 No.12

Hydrogen sulfide (H2S) is an endogenous gaseousmediator plays a potential role in modulating gastricinflammatory responses. However, its putative protectiverole remains to be defined. The present study aimed toevaluate role of the exogenously released and endogenouslysynthesized H2S in cold restraint stress (CRS)-induced oxidativegastric damage in rats. Rats were restrained, andmaintained at 4 C for 3 h. The H2S donor, sodium hydrosulfide(NaHS) (60 lmol/kg) was injected intraperitoneally(i.p.) before CRS. Our results revealed that NaHS pretreatmentsignificantly attenuated ulcer index, free and total acidoutput, and pepsin activity in gastric juice along withdecreased gastric mucosal carbonyl content and reactiveoxygen species production. This was accompanied byincreased gastric juice pH and mucin concentration inaddition to restoring the deficits in the gastric reduced glutathione,catalase as well as superoxide dismutase enzymeactivities. NaHS pretreatment markedly reduced the serumlevel of tumor necrosis factor (TNF-a) and myeloperoxidaseactivity compared to CRS-non-treated. Moreover, NaHSpreadministration significantly abrogated the inflammatoryand the deleterious responses of gastric mucosa in CRS. Theprotective effects of H2S were confirmed by gastric histopathologicalexamination. However, pretreatment withthe H2S-synthesizing enzyme, cystathionine-gamma-lyaseinhibitor, beta-cyano-L-alanine (50 mg/kg, i.p.) reversed thegastroprotection afforded by the endogenous H2S. Collectively, our results suggest that H2S can protect ratgastric mucosa against CRS-induced gastric ulcerationpossibly through mechanisms that involve anti-oxidant andanti-inflammatory actions alongside enhancement of gastricmucosal barrier and reduction in acid secretory parameters.