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Optical properties and radiative rates of Nd^(3+) doped zinc-sodium phosphate glasses

Journal of Rare Earths 2019年第3期37卷 253-259页

作者： A.A.El-maaref Shimaa Badr Kh.S.Shaaban E.A.abdel wahab m.m.ElOkr Physics department Faculty of Science Al-Azhar University modern Academy for Engineering & Technology Chemistry department Faculty of Science Al-Azhar University

Preparation using melt quenching technique and optical characterizations of Nd^(3+) doped Zn-Na phosphate glasses are presented. The structure of the present glasses was studied using X-ray diffraction and FT-IR spectroscopy. UV-vis spectra of the present glasses were analyzed at different concentrations of Nd_2 O_3. The effect of neodymium concentration on the density and energy band gap was investigated. The density of the present glasses slightly increases with the increasing of Nd_2 O_3. A small variation of energy band gap with the increasing of neodymium content is observed as well, while E_g values decrease with the increase of Nd_2 O_3 content. The E_g values lie between 4.36 and 4.69 eV. Based on the measured optical spectra, Judd-Ofelt theory was used to determine the optical parameters such as line strengths, optical intensity parameters(Ω_t), transition probabilities, and transition lifetimes. Hypersensitive transitions were identified in the absorption spectrum, the greatest line strengths are recorded at the transitions^2 G_(7/2)+ ~4 G_(5/2), ~4 S_(3/2) + ~4 F_(7/2) and ~4 d_(1/2) + ~4 d_(3/2)+ ~4 d_(5/2) + ~2 I_(11/2) with wavelengths of 580, 475 and 355 nm,respectively. Lifetimes of the important ~4 F_(3/2) laser-level were determined; which show decreasing trend with the increasing of Nd_2 O_3 content and are found to be between 0.838 and 1.595 ms. The uncertainty of the present results was estimated. The RmS deviations were determined, which show lower values than those in the literature.

关键词： Phosphate glass UV-vis spectroscopy Judd-Ofelt Radiative rates Rear earth ions

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determination of the Normal Contact Stiffness and Integration Time Step for the Finite Element modeling of Bristle-Surface Interaction

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Computers, materials & Continua 2018年第7期56卷 169-184页

作者： Libardo V.Vanegas-Useche magd m.abdel-wahab Graham A.Parker Facultad de Ingeniería mecánica Universidad Tecnológica de Pereira.Pereira 660003Colombia division of Computational mechanics Ton Duc Thang UniversityHo Chi Minh CityVietnam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh CityVietnam Soete Laboratory Faculty of Engineering and ArchitectureGhent UniversityTechnologiepark Zwijnaarde 903Zwijnaarde B-9052Belgium Faculty of Engineering and Physical Sciences University of Surrey.GuildfordUK

In finite element modeling of impact,it is necessary to define appropriate values of the normal contact stiffness,Kn,and the Integration Time Step(ITS).Because impacts are usually of very short duration,very small ITSs are ***,the selection of a suitable value of Kn is a critical issue,as the impact behavior depends dramatically on this *** this work,a number of experimental tests and finite element analyses have been performed in order to obtain an appropriate value of Kn for the interaction between a bristle of a gutter brush for road sweeping and a concrete ***,a suitable ITS is *** experiments consist of releasing a steel bristle that is placed vertically at a certain distance from a concrete surface and tracking the ***,in the finite element analyses,a beam is modeled in free fall and impacting a surface;contact and target elements are attached to the beam and the surface,*** results of the experiments and the modeling are integrated through the principle of conservation of energy,the principle of linear impulse and momentum,and Newton’s second *** results demonstrate that,for the case studied,Kn and the impact time tend to be independent of the velocity just before impact and that Kn has a very large variation,as concrete is a composite material with a rough ***,the ratio between the largest height of the bristle after impact and the initial height tends to be constant.

关键词： Brush street sweeping finite element modeling contact mechanics

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Numerical Analysis of Tilted Cutting and F128 Brushes

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Computer modeling in Engineering & Sciences 2019年第10期121卷 23-47页

作者： Libardo V.Vanegas-Useche magd m.abdel-wahab Graham A.Parker Facultad de Ingeniería mecánica Universidad Tecnológica de PereiraLa JulitaPereira 660003Colombia division of Computational mechanics Ton Duc Thang UniversityHo Chi Minh CityViet Nam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh CityViet Nam Soete Laboratory Faculty of Engineering and ArchitectureGhent UniversityTechnologiepark Zwijnaarde 46B-9052 ZwijnaardeBelgium Faculty of Engineering and Physical Sciences University of Surrey.Guildford GU27XHUK.

Road sweeping is an essential service that has to be conducted for public health,as well as aesthetic *** many countries,sweeping vehicles are used for this *** usually comprise a gutter brush that sweeps the debris that is located in the road *** work studies the performance of two kinds of gutter brushes:a cutting brush and a flicking(F128)*** is carried out by means of a 3-d dynamic,nonlinear Finite Element(FE)brush model developed by the *** this model,inertia forces are applied to the bristle,and its clamped end is ***,the surface(road)is rotated,translated,and ***-road interaction is modelled as flexible-to-rigid *** particular,the aim of this article is to compare the performance of a conventional brush and a brush rotating at variable *** brushes normally work tilted,FE analyses are carried out for tilted cutting and F128 brushes,rotating at speeds that fluctuate at different *** is concluded that brush oscillations have a significant effect on bristle tip velocities and bristle-road ***,at certain frequencies,oscillations seem to improve sweeping performance of the F128 ***,they do not appear to improve significantly the performance of the cutting brush.

关键词： Gutter brushes cutting brush flicking brush FEm variable speed brushing

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Polygonal Finite Element for Two-dimensional Lid-driven Cavity Flow

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Computers, materials & Continua 2022年第3期70卷 4217-4239页

作者： T.Vu-Huu C.Le-Thanh H.Nguyen-Xuan m.abdel-wahab Faculty of Civil Engineering Vietnam Maritime University484 Lach Tray Str.Hai PhongVietnam Faculty of Civil Engineering and Electricity Ho Chi Minh City Open UniversityVietnam CIRTech Institute Ho ChiMinh City University of Technology(HUTECH)Ho Chi Minh CityVietnam department of Architectural Engineering Sejong University209 NeungdongroGwangjinguSeoul05006Republic of Korea Soete Laboratory Faculty of Engineering and ArchitectureGhent UniversityTechnologiepark Zwijnaarde903B-9052ZwijnaardeBelgium

This paper investigates a polygonal finite element(PFE)to solve a two-dimensional(2d)incompressible steady fluid problem in a cavity *** is a well-known standard benchmark(i.e.,lid-driven cavity flow)-to evaluate the numerical methods in solving fluid problems controlled by the Navier-Stokes(N-S)equation *** approximation solutions provided in this research are based on our developed equal-order mixed PFE,called *** is an exciting development based on constructing the mixed scheme method of two equal-order discretisation spaces for both fluid pressure and velocity fields of flows and our proposed stabilisation *** this research,to handle the nonlinear problem of N-S,the Picard iteration scheme is *** proposed method’s performance and convergence are validated by several simulations coded by commercial software,i.e.,*** this research,the benchmark is executed with variousReynolds numbers up to the maximum Re=*** results then numerously compared to available sources in the literature.

关键词： Lid-driven cavity incompressible steady Navier-Stokes equations polygonal finite element method

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Novel CYP1B1 mutations and a possible prognostic use for surgical management of congenital glaucoma

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International Journal of Ophthalmology(English edition) 2019年第4期12卷 607-614页

作者： m.ham.d m.Khafagy Nadia El-Guendy marwa A Tantawy m.ham.d a.Eldaly Hala m.Elhilali abdel Hady A.abdel wahab Ophthalmology department Faculty of Medicine Cairo University Cancer Biology department National Cancer Institute Cairo University Research department Children's Cancer Hospital

AIm: To identify CYP1B1 gene mutations and evaluate their possible role as a prognostic factor for success rates in the surgical management of Egyptian congenital glaucoma ***: Totally 42 eyes of 29 primary congenital glaucoma patients were operated on with combined trabeculotomy/trabeculectomy with mitomycin-C and followed up at 1 d, 1 wk, 1, 6 and 12 mo postoperatively. Genomic dNA was extracted from peripheral blood leukocytes. Coding regions of CYP1B1 gene were amplified using 13 pairs of primers, screened for mutations using single-strand conformation polymorphism followed by sequencing of both strands. Efficacy of the operation was graded as either a success [maintaining intraocular pressure(IOP) less than 21 mm Hg with or without antiglaucoma medication], or a failure(IOP more than 21 mm Hg with topical antiglaucoma medications). RESULTS: Seven novel mutations out of a total of 15 different mutations were found in the CYP1B1 genes of 14 patients(48.2%). The presence of CYP1B1 gene mutations did not correlate with the failure of the surgery(P=0.156, odds ratio=3.611, 95%CI, 0.56 to 22.89); while the positive consanguinity strongly correlated with failure of the initial procedure(P=0.016, odds ratio=11.25, 95%CI, 1.57 to 80.30). However, the Kaplan-meier survival analysis revealed a significantly lower time of IOP control in the subgroup with mutations in CYP1B1 versus the congenital primary glaucoma group without mutations(log rank test, P=0.015).CONCLUSION: Seven new CYP1B1 mutations are identified in Egyptian patients. Patients harboring confirmed mutations suffered from early failure of the initial surgery. CYP1B1 mutations could be considered as a prognostic factor for surgery in primary congenital glaucoma.

关键词： CYP1B1 mutations primary congenital glaucoma intraocular pressure trabeculotomy/trabeculectomy with mitomycin-C.

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Nano-confined ammonia borane for chemical hydrogen storage

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Frontiers of Chemical Science and Engineering 2012年第1期6卷 27-33页

作者： m. A.wahab Huijun ZHAO X. d. YAO ARC Centre of Excellence for Functional Nanomaterials Australian Institute for Engineering and Nanotechnology the University of Queensland St Lucia 4072 Australia Centre for Clean Energy and Environment Griffith University Gold Coast 4222 Australia Queensland micro-and Nanotechnology Centre Griffith University Nathan 4111 Australia

There is a great demand for a sufficient and sustainable energy supply. Hence, the search for applicable hydrogen storage materials is extremely important owing to the diversified merits of hydrogen energy. In this regard, ammonia borane （NH3BH3, AB） containing 19.6wt-% hydrogen has been considered as a promising material for hydrogen storage applications to realize the ＂hydrogen economy＂, but with limits from slow kinetics of hydrogen release and by-product of trace gases such as ammonia and borazine. In this review, we introduce the recent research on AB, regarding to the nanoconfinement effect on improving the kinetics at a relatively low temperature and the prevention/reduction of undesirable gas formation.

关键词： ammonia borane hydrogen storage

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Preparation of quantum size of tin oxide: Structural and physical characterization

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Progress in Natural Science:materials International 2016年第2期26卷 145-151页

作者： N.m.Shaalan d.hamad A.Y.abdel-Latief m.A.abdel-Rahim Physics department Faculty of Science Assiut University

SnO2NPs were successfully prepared via a hydrothermal method. X-ray diffraction analysis con fi rmed the rutile tetragonal structure of SnO2NPs. The crystallite size increased from 1.18 to 5.06 nm with increasing the preparation temperature from 100 to 180 °C. The SEm photography of the products exhibited the agglomeration of the SnO2nanocrystals to large view particles, while TEm images con fi rmed the polycrystalline phase and crystallite size those analyzed from XRd. The UV–vis absorption of ethanol suspended SnO2NPs was measured. The optical band-gap energies（Eg） were signi fi cantly blue-shifted due to quantum con fi nement. Fluorescence spectra came to con fi rm this shift, where a clear shift in the maximum emission peak was observed. Stokes shift of SnO2nanocrystals was found to be crystallite size dependent.

关键词： Nanostructures Tin dioxide Luminescence Optical properties

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HBV vaccine efficacy and detection and genotyping of vaccineé asymptomatic breakthrough HBV infection in Egypt

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World Journal of Hepatology 2011年第6期3卷 147-156页

作者： Eman AE Abushady magda mA Gameel John d Klena Salwa F Ahmed Kouka SE abdel-wahab Sanya m Fahmy microbiology department Faculty of Medicine Nourthern Border UniversityArar 1321Saudi Arabia microbiology department Faculty of MedicineAL-Azhar UniversityCairo R695-11651Egypt molecular Epidemiology unit Clinical Trials ProgramNAMRU-3Cairo 11157Egypt Pediatric department Faculty of MedicineAL-Azhar UniversityCairo R695-11651Egypt

AIm:To evaluate the impact of mass vaccination against the hepatitis B virus (HBV) in Egypt,and to search for vaccinee asymptomatic breakthrough HBV infection and its ***:Seven hundred serum samples from vaccinated children and adults (aged 2-47 years) were used for quantitative and qualitative detection of HBsAb by *** hundred and sixty serum samples representing undetectable or low or high HBsAb were screened for markers of active HBV infection (HBsAg,HBcAb (IgG) and HBeAb by ELISA,plus HBsAg by AxSYm) and HBV-dNA genotyping by nested multiplex PCR and by dNA ***:It was found that 65% of children aged 2-4 years,and 20.5% aged 4-13 years,as well as 45% adults were good responders to HBV vaccination mounting protective level *** responders were 28%,59.5% and 34%,and non-responders were 7%,20% and 21% respectively,in the three studied *** of asymptomatic HBV infections were HBsAg detected by ELISA in 2.5% vs 11.39% by *** markers were HBcAb (IgG) in 1.38%,HBeAb in 0.83%,and HBV-dNA in 7.8%.All had HBV genotype E ***:It is concluded that HBV vaccine is efficient in controlling HBV infection among children and *** vaccine breakthrough infection was by HBV genotype E.A booster dose of vaccine is recommended,probably four years after initial vaccination.

关键词： HBV vaccine evaluation Egyptain children Adults Genotype E vaccine escape HBV

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Neurogenesis dynamics in the olfactory bulb:deciphering circuitry organization, function, and adaptive plasticity

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Neural Regeneration Research 2025年第6期20卷 1565-1581页

作者： moawiah m.Naffaa department of Psychology and Neuroscience Duke UniversityDurhamNCUSA department of Cell Biology Duke University School of MedicineDurhamNCUSA

Adult neurogenesis persists after birth in the subventricular zone, with new neurons migrating to the granule cell layer and glomerular layers of the olfactory bulb, where they integrate into existing circuitry as inhibitory interneurons. The generation of these new neurons in the olfactory bulb supports both structural and functional plasticity, aiding in circuit remodeling triggered by memory and learning processes. However, the presence of these neurons, coupled with the cellular diversity within the olfactory bulb, presents an ongoing challenge in understanding its network organization and function. moreover,the continuous integration of new neurons in the olfactory bulb plays a pivotal role in regulating olfactory information processing. This adaptive process responds to changes in epithelial composition and contributes to the formation of olfactory memories by modulating cellular connectivity within the olfactory bulb and interacting intricately with higher-order brain regions. The role of adult neurogenesis in olfactory bulb functions remains a topic of debate. Nevertheless, the functionality of the olfactory bulb is intricately linked to the organization of granule cells around mitral and tufted cells. This organizational pattern significantly impacts output, network behavior, and synaptic plasticity, which are crucial for olfactory perception and memory. Additionally, this organization is further shaped by axon terminals originating from cortical and subcortical regions. despite the crucial role of olfactory bulb in brain functions and behaviors related to olfaction, these complex and highly interconnected processes have not been comprehensively studied as a whole. Therefore, this manuscript aims to discuss our current understanding and explore how neural plasticity and olfactory neurogenesis contribute to enhancing the adaptability of the olfactory system. These mechanisms are thought to support olfactory learning and memory, potentially through increased

关键词： network adaptability neurogenesis neuronal communication olfactory bulb olfactory learning olfactory memory synaptic plasticity

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Additive neurorestorative effects of exercise and docosahexaenoic acid intake in a mouse model of Parkinson’s disease

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Neural Regeneration Research 2025年第2期20卷 574-586页

作者： Olivier Kerdiles méryl-Farelle Oye mintsa mi-mba Katherine Coulombe Cyntia Tremblay VincentÉmond martine Saint-Pierre Clémence Rouxel Line Berthiaume Pierre Julien Francesca Cicchetti Frédéric Calon Facultéde pharmacie UniversitéLaval1050 Avenue de la MédecineQuebecQCCanada Axe Neuroscience Centre de recherche du CHU de Québec-UniversitéLaval(Pavillon CHUL)2705 Boulevard LaurierQuebecQCCanada Institute of Nutrition and Functional Foods QuebecQCCanada Optinutribrain International Associated Laboratory(NutriNeuro FranceINAFCanada)QuebecQCCanada Axe Endocrinologie et Néphrologie Centre de recherche du CHU de Québec-UniversitéLavalQuebecQCCanada département de médecine Facultéde MédecineUniversitéLavalQuebecQCCanada département de Psychiatrie et Neurosciences Facultéde MédecineQuebecQCCanada

There is a need to develop interventions to slow or reverse the degeneration of dopamine neurons in Parkinson’s disease after *** that preclinical and clinical studies suggest benefits of dietary n-3 polyunsaturated fatty acids,such as docosahexaenoic acid,and exercise in Parkinson’s disease,we investigated whether both could synergistically interact to induce recovery of the dopaminergic ***,mice received a unilateral stereotactic injection of 6-hydroxydopamine into the striatum to establish an animal model of nigrostriatal *** weeks after lesion,animals were fed a docosahexaenoic acid-enriched or a control diet for the next 8 *** this period,the animals had access to a running wheel,which they could use or *** acid treatment,voluntary exercise,or the combination of both had no effect on(i)distance traveled in the open field test,(ii)the percentage of contraversive rotations in the apomorphine-induction test or(iii)the number of tyrosine-hydroxylase-positive cells in the substantia nigra pars ***,the docosahexaenoic acid diet increased the number of tyrosine-hydroxylase-positive terminals and induced a rise in dopamine concentrations in the lesioned *** to docosahexaenoic acid treatment or exercise alone,the combination of docosahexaenoic acid and exercise(i)improved forelimb balance in the stepping test,(ii)decreased the striatal dOPAC/dopamine ratio and(iii)led to increased dopamine transporter levels in the lesioned *** present results suggest that the combination of exercise and docosahexaenoic acid may act synergistically in the striatum of mice with a unilateral lesion of the dopaminergic system and provide support for clinical trials combining nutrition and physical exercise in the treatment of Parkinson’s disease.

关键词： 6-hydroxydopamine dopamine dopamine transporter exercise neurorestoration Parkinson’s disease polyunsaturated fatty acids omega-3

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