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Application of microalgal-ZnO-NPs for reusing polyester/cotton blended fabric wastes after modification by cellulases enzymes

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Waste Disposal and Sustainable Energy 2023年第4期5卷 471-482页

作者： Osama M.Darwesh naser g.al-balakocy Ahmed ghanem Ibrahim A.Matter Agricultural Microbiology Department National Research Centre33 EL-Buhouth St.DokkiCairo12622Egypt Protenic and Manmade Fibers Department National Research CentreDokkiCairo12622Egypt Packaging Materials Department National Research CentreCairo12622Egypt

Polyester/cotton(PET/C)blended fabric wastes are produced daily in huge amounts,which constitutes an economic loss and an environmental threat if it is not reused *** textile waste recycling technologies put much effort into developing fabric materials with unique properties,such as bioactivity or new optical goods based on modern technologies,especially *** this study,zinc oxide nanoparticles(ZnO-NPs)were biosynthesized using the aqueous extract of Dunaliella *** immobilized on PET/C waste fabrics after enzymatically activated with *** produced Dunaliella-ZnO-NPs(10–20 nm with a spherical shape)were characterized by High-resolution transmission electron microscopy(HRTEM),Fourier-transform infrared spectroscopy(FTIR),X-Ray diffraction analysis(XRD),and Scanning electron microscopy-energy dispersive X-ray analyzer(SEM-EDAX),and some functional groups,such as CH,CO,NH,and CN(due to the presence of carboxyl,proteins and hydroxyl groups),were detected,revealing the biosynthesis of *** analysis showed that the resulting ZnO-NPS had potent antimicrobial effects,Ultraviolet(UV)protection capabilities,and no cytotoxic effects on the normal human fibroblast cell line(BJ1).On the other hand,enzymatic treatments of PET/C fabric waste with cellulases enhanced the immobilization of biosynthetic nanoparticles on their *** PET/C fabrics loaded with Dunaliella-ZnO-NPs showed antibacterial and UV protection capabilities making them an eco-friendly and cost-effective candidate for numerous *** applications can include the manufacture of active packaging devices,wastewater treatment units,and many other environmental applications.

关键词： Wastewater remediation Polyester/cotton wastes Cytotoxicity Microalgal-ZnO-NPs Dunaliella sp. Microbial nanotechnology

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THIRD ORDER SHEAR DEFORMATION MODEL FOR LAMINATED SHELLS WITH FINITE ROTATIONS:FORMULATION AND CONSISTENT LINEARIZATION

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Acta Mechanica Sinica 2004年第5期20卷 484-498页

作者： Mohamed BalAH Hamdan naser al-gHAMEDY Department of Information and Computer Science King Fahd University of Petroleum & MineralsDhahran 31261Saudi Arabia (Department of Civil Engineering King Fahd University of Petroleum & MineralsDhahran 31261Saudi Arabia

The paper presents an approach for the formulation of general laminated shells based on a third order shear deformation theory. These shells undergo finite (unlimited in size) rotations and large overall motions but with small strains. A singularity-free parametrization of the rotation field is adopted. The constitutive equations, derived with respect to laminate curvilinear coordinates, are applicable to shell elements with an arbitrary number of orthotropic layers and where the material principal axes can vary from layer to layer. A careful consideration of the consistent linearization procedure pertinent to the proposed parametrization of finite rotations leads to symmetric tangent stiffness matrices. The matrix formulation adopted here makes it possible to implement the present formulation within the framework of the finite element method as a straightforward task.

关键词： laminated shells third order shear deformation theory finite rotations consistent linearization

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Effects of particle size and concentration on bubble coalescence and froth formation in a slurry bubble column

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Particuology 2018年第1期16卷 82-95页

作者： A.R. Sarhan J. naser g. Brooks Department of Mechanical and Product Design Engineering Swinburne University of Technology Hawthorn Victoria 3122 Australia Department of Mechanical Engineering University ofAnbar Ramadi Anbar 31001 lraq

A new approach for simulating the formation of a froth layer in a slurry bubble column is proposed. Froth is considered a separate phase, comprised of a mixture of gas, liquid, and solid. The simulation was carried out using commercial flow simulation software （FIRE v2014） for particle sizes of 60-150 μm at solid concentrations of 0-40vol%, and superficial gas velocities of 0.02-0.034m/s in a slurry bubble column with a hydraulic diameter of 0.2 m and height of 1.2 m. Modelling calculations were conducted using a Eulerian-Eulerian multiphase approach with k-ε turbulence. The population balance equations for bubble breakup, bubble coalescence rate, and the interfacial exchange of mass and momentum were included in the computational fluid dynamics code by writing subroutines in Fortran to track the number density of different bubble sizes. Flow structure, radial gas holdup, and Sauter mean bubble diameter distributions at different column heights were predicted in the pulp zone, while froth volume fraction and density were predicted in the froth zone. The model was validated using available experimental data, and the predicted and experimental results showed reasonable agreement. To demonstrate the effect of increasing solid concentration on the coalescence rate, a solid-effect multiplier in the coalescence effi- ciency equation was used. The solid-effect multiplier decreased with increasing slurry concentration, causing an increase in bubble coalescence efficiency. A slight decrease in the coalescence efficiency was also observed owing to increasing particle size, which led to a decrease in Sauter mean bubble diam- eter. The froth volume fraction increased with solid concentration. These results provide an improved understanding of the dynamics of slurry bubble reactors in the presence of hydrophilic particles.

关键词： Computational fluid dynamics Slurry concentration gas holdup Particle size Froth Coalescence efficiency

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Petrogenesis and Tectonic Implications of the Jabal Hadb Ad Dayheen granitic Complex, Central Arabian Shield

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Journal of Earth Science 2023年第1期34卷 20-36页

作者： Qinlong Tong Ziying Li Honghai Fan naser Jahdali Mubarak M.al-Nahdi CNNC Beijing Research Institute of Uranium geology National Key Laboratory of Remote Sensing Information and Image Analysis TechnologyBeijing100029China CNNC Key Laboratory of Uranium Resource Exploration and Evaluation Technology Beijing Research Institute of Uranium GeologyBeijing100029China Saudi geological Survey Jeddah21514Kingdom of Saudi Arabia

The Jabal Hadb Ad Dayheen granitic complex in central Saudi Arabia is an alkaline granitic ring complex associated with a collapsed caldera. It mainly consists of monzogranite in the center, biotite-hornblende porphyritic granite, and biotite-aegirine-riebeckite granite, intruded by some felsic and mafic dikes. The petrological and geochemical characteristics show that the granitic suites consist of metalminous-peralkaline A-type granites. The secondary ion mass spectrometry(SIMS) zircon U-Pb analysis yielded ^(206)Pb/^(238)U ages of 613.3 ± 8.1 – 603.8 ± 3.8, 602.4 ± 3.8, 596 ± 5.6 Ma for biotitehornblende porphyritic granite, microgranite, and biotite-aegirine-riebeckite granite, respectively. The trace element characteristics and positive ε_(Hf)(t) values(3.2–12.2) indicate that the granitic rocks of the Dayheen Ring Complex are mainly derived from the juvenile crust with the involvement of mantlederived materials. Combined with the regional tectonic evolution, the formation of the Dayheen Ring Complex mainly covered four periods:(1) subduction initiation and formation of arc terranes(870–620 Ma)—volcanic craters formed during this period provided the channel for alkaline complex intrusion;(2) collision between East and West gondwana continents and formation of the north East African Orogen(640–613 Ma)—monzogranite stock at the center of the ring complex emplaced during this period;(3) post-collision extension and collapse(613–602 Ma)—red metaluminous biotite-hornblende porphyritic granite and microgranite sheets in the rim of the Dayheen Ring Complex emplaced during this period;(4) within-plate extension(602 – 545 Ma) —white peralkaline biotite-aegirine-riebeckite granite and plenty of felsic and mafic dikes in the rim mainly formed during this period. The granitic rocks of the Dayheen Ring Complex mainly formed during the transitional stage of post-collison to within-plate extension after the collision between East and West gondwana continents, and part of them

关键词： ring complex A-type granite zircon zircon U-Pb dating tectonic evolution Arabian Shield

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CFD model simulation of bubble surface area flux in flotation column reactor in presence of minerals

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International Journal of Mining Science and Technology 2018年第6期28卷 999-1007页

作者： A.R.Sarhan J.naser g.Brooks Department of Mechanical and Product Design Engineering Swinburne University of TechnologyHawthornVictoria 3122Australia Department of Mechanical Engineering University of Anbar RamadiAnbar 31001Iraq

Bubble surface area flux(S_b) is one of the main design parameter in flotation column that typically employed to describe the gas dispersion properties, and it has a strong correlation with the flotation rate constant. There is a limited information available in the literature regarding the effect of particle type,density, wettability and concentration on Sb. In this paper, computational fluid dynamics(CFD) simulations are performed to study the gas–liquid–solid three-phase flow dynamics in flotation column by employing the Eulerian–Eulerian formulation with k-e turbulence model. The model is developed by writing Fortran subroutine and incorporating then into the commercial CFD code AVL FIRE, *** paper studies the effects of superficial gas velocities and particle type, density, wettability and concentration on Sband bubble concentration in the flotation column. The model has been validated against published experimental data. It was found that the CFD model was able to predict, where the response variable as indicated by R-Square value of 0.98. These results suggest that the developed CFD model is reasonable to describe the flotation column reactor. From the CFD results, it is also found that Sb decreased with increasing solid concentration and hydrophobicity, but increased with increasing superficial gas velocity. For example, approximately 28% reduction in the surface area flux is observed when coal concentration is increased from 0 to 10%, by volume. While for the same solid concentration and gas flow rate, the bubble surface area flux is approximately increased by 7% in the presences of sphalerite.A possible explanation for this might be that increasing solid concentration and hydrophobicity promotes the bubble coalescence rate leading to the increase in bubble size. also, it was found that the bubble concentration would decrease with addition of hydrophobic particle(i.e., coal). For instance, under the same operating conditions, approximately 23% reduc

关键词： CFD Froth flotation Bubble surface area flux Solid properties Bubble concentration

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