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Transient peristaltic diffusion of nanofluids: A model of micropumps in medical engineering

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Journal of Hydrodynamics 2018年第6期30卷 1001-1011页

作者： Dharmendra Tripathi Shashi bhushan o.anwar bég Noreen Sher Akbar Department of Science and Humanities National Institute of TechnologyUttarakhand–246174 India Department of Mechanical Engineering Manipal University Department of Aeronautical and Mechanical Engineering University of Salford DbS & H CEME National University of Sciences and TechnologyIslamabad Pakistan

Peristaltic micro-pumps offer an excellent mechanism for delivery of a variety of medicines including drugs, corneal solutions etc. The surge in deployment of nanoparticles in medicine has provided new potential for such pumps. In light of this we investigate the time-dependent peristaltic flow of nanofluids with diffusive effects through a finite non-uniform channel, this geometry being more representative of real micro-pumps. Creeping flow is taken into account(inertial forces are small compared with viscous forces) i.e., Reynolds number is low(Regth is also taken to be very large. The buongiorno formulation for nanofluids is employed with an oberbeck-boussinesq approximation. Closed-form solutions are developed for the non-dimensional governing equations subject to physically realistic boundary conditions. Mathematica symbolic software is employed to evaluate the evolution of nanoparticle fraction, temperature, axial velocity, transverse velocity and pressure difference distribution along the length of the pump channel with variation in thermal grashof number, basic-density(species i.e., mass) grashof number, brownian motion parameter and thermophoresis parameter.

关键词： Unsteady flow peristaltic pumps nanofluids medical engineering diffusive process grashof number thermophoresis

Effects of thermophoresis particle deposition and of the thermal conductivity in a porous plate with dissipative heat and mass transfer

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Acta Mechanica Sinica 2011年第3期27卷 389-398页

作者： Joaquín Zueco o.anwar bég L.M.Lpez-ochoa Thermal Engineering and Fluids Department Technical University of CartagenaETSII Campus Muralla del Mar Aerospace Engineering Department of Engineering and MathematicsSheaf BuildingSheffield Hallam University Mechanical Engineering Departament University of RiojaC/Luís de UlloaLogrono (La Rioja)20E-26004Spain

Network simulation method（NSM） is used to solve the laminar heat and mass transfer of an electricallyconducting,heat generating/absorbing fluid past a perforated horizontal surface in the presence of viscous and Joule heating problem. The governing partial differential equations are non-dimensionalized and transformed into a system of nonlinear ordinary differential similarity equations,in a single independent variable,畏. The resulting coupled,nonlinear equations are solved under appropriate transformed boundary conditions. Computations are performed for a wide range of the governing flow parameters,viz Prandtl number,thermophoretic coeffcient（a function of Knudsen number）,thermal conductivity parameter,wall transpiration parameter and Schmidt number. The numerical details are discussed with relevant applications. The present problem finds applications in optical fiber fabrication,aerosol filter precipitators,particle deposition on hydronautical blades,semiconductor wafer design,thermo-electronics and problems including nuclear reactor safety.

关键词： Thermophoresis . MHD . Network simulation model . Heat and mass transfer- Hartmann number

Analytical approach to entropy generation and heat transfer in CNT-nanofluid dynamics through a ciliated porous medium

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Journal of Hydrodynamics 2018年第2期30卷 296-306页

作者： Noreen Sher Akbar M.Shoaib Dharmendra Tripathi Shashi bhushan o.anwar bég DbS&H CEME National University of Sciences and Technology School of Natural Sciences National University of Sciences and Technology Department of Mechanical Engineering Manipal University Medical Energy and Propulsion Engineering Sciences Department of Aeronautical and Mechanical Engineering University of Salford

The transportation of biological and industrial nanofluids by natural propulsion like cilia movement and self-generated contraction-relaxation of flexible walls has significant applications in numerous emerging technologies. Inspired by multi-disciplinary progress and innovation in this direction, a thermo-fluid mechanical model is proposed to study the entropy generation and convective heat transfer of nanofluids fabricated by the dispersion of single-wall carbon nanotubes（SWCNT） nanoparticles in water as the base fluid. The regime studied comprises heat transfer and steady, viscous, incompressible flow, induced by metachronal wave propulsion due to beating cilia, through a cylindrical tube containing a sparse（i.e., high permeability） homogenous porous medium. The flow is of the creeping type and is restricted under the low Reynolds number and long wavelength approximations. Slip effects at the wall are incorporated and the generalized Darcy drag-force model is utilized to mimic porous media effects. Cilia boundary conditions for velocity components are employed to determine analytical solutions to the resulting non-dimensionalized boundary value problem. The influence of pertinent physical parameters on temperature, axial velocity, pressure rise and pressure gradient, entropy generation function, bejan number and stream-line distributions are computed numerically. A comparative study between SWCNT-nanofluids and pure water is also computed. The computations demonstrate that axial flow is accelerated with increasing slip parameter and Darcy number and is greater for SWCNT-nanofluids than for pure water. Furthermore the size of the bolus for SWCNT-nanofluids is larger than that of the pure water. The study is applicable in designing and fabricating nanoscale and microfluidics devices, artificial cilia and biomimetic micro-pumps.

关键词： Metachronal wave single-wall carbon nanotubes (SWCNT) entropy generation porous medium cilia motion heat transfer bejan number

Cilia-assisted hydromagnetic pumping of biorheological couple stress fluids

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Propulsion and Power Research 2019年第3期8卷 221-233页

作者： K.Ramesh D.Tripathi o.anwar bég Department of Mathematics Symbiosis Institute of TechnologySymbiosis International UniversityPune412115India Department of Mechanical Engineering Manipal University JaipurRajasthan303007India Fluid Mechanics/Propulsion Aeronautical/Mechanical Engineering DepartmentSalford UniversityManchesterUK

A theoretical study is conducted for magnetohydrodynamic pumping of electroconductive couple stress physiological liquids(***)through a two-dimensional ciliated channel.A geometric model is employed for the cilia which are distributed at equal intervals and produce a whip-like motion under fluid interaction which obeys an elliptic trajectory.A metachronal wave is mobilized by the synchronous beating of cilia and the direction of wave propagation is parallel to the direction of fluid flow.A transverse static magnetic field is imposed transverse to the channel *** Stokes’couple stress(polar)rheological model is utilized to characterize the *** normalized two-dimensional conservation equations for mass,longitudinal and transverse momentum are reduced with lubrication approximations(long wavelength and low Reynolds number assumptions)and feature a fourth order linear derivative in axial velocity representing couple stress contribution.A coordinate transformation is employed to map the unsteady problem from the wave laboratory frame to a steady problem in the wave *** slip conditions are imposed at the channel *** emerging linearized boundary value problem is solved analytically and expressions presented for axial(longitudinal)velocity,volumetric flow rate,shear stress function and pressure *** flow is effectively controlled by three geometric parameters,viz cilia eccentricity parameter,wave number and cilia length and two physical parameters,namely magnetohydrodynamic(MHD)body force parameter and couple stress non-Newtonian *** solutions are numerically evaluated with MATLAb *** velocity is observed to be enhanced in the core region with greater wave number whereas it is suppressed markedly with increasing cilia length,couple stress and magnetic parameters,with significant flattening of profiles with the latter two *** pressure gradient is decreased with eccentricity parameter whereas it is ele

关键词： Magneto hydrodynamics Metachronal waves Cilia Synchronous beating Polar couple stress fluid Physiological transport Magnetic blood pumps

Numerical solution of thermo-solutal mixed convective slip flow from a radiative plate with convective boundary condition

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Journal of Hydrodynamics 2016年第3期28卷 451-461页

作者： m.j.uddin o.anwar bég m.n.uddin a.i.md.ismail Department of Mathematics American International University-BangladeshDhakaBangladesh Fluid Mechanics Spray Research GroupPetroleum and Gas Engineering DivisionRoom G77Newton BuildingSchool of ComputingScience and Engineering(CSE)University of SalfordM54WTUK Department of Mathematical Sciences Ball State University2000 W University AvenueMuncieIN 47306USA School of Mathematical Sciences Universiti Sains MalaysiaPenang 11800Malaysia

A mathematical model for mixed convective slip flow with heat and mass transfer in the presence of thermal radiation is presented. A convective boundary condition is included and slip is simulated via the hydrodynamic slip parameter. Heat generation and absorption effects are also incorporated. The Rosseland diffusion flux model is employed. The governing partial differential conservation equations are reduced to a system of coupled, ordinary differential equations via Lie group theory method. The resulting coupled equations are solved using shooting method. The influences of the emerging parameters on dimensionless velocity, tempera- ture and concentration distributions are investigated. Increasing radiative-conductive parameter accelerates the boundary layer flow and increases temperature whereas it depresses concentration. An elevation in convection-conduction parameter also accelerates the flow and temperatures whereas it reduces concentrations. Velocity near the wall is considerably boosted with increasing momentum slip parameter although both temperature and concentration boundary layer thicknesses are decreased. The presence of a heat source is found to increase momentum and thermal boundary layer thicknesses but reduces concentration boundary layer thickness. Excelle- nt correlation of the numerical solutions with previous non-slip studies is demonstrated. The current study has applications in bio- reactor diffusion flows and high-temperature chemical materials processing systems.

关键词： slip flow thermal radiation lie group theory heat source/sink materials processing

Visible light-driven photo remediation of hazardous cationic dye via Ce-doped Wo_(3) nanostructures

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Journal of Rare Earths 2024年第5期42卷 869-878,I0003页

作者： Azra Haroon Kaseed anwar Arham S.Ahmed Department of Physics Aligarh Muslim University202002AligarhIndia Interdisciplinary Nanotechnology Centre Aligarh Muslim University202002AligarhIndia

Ce-doped Wo_(3) nanoparticles were successfully synthesized by the sol-gel method and characterized through advanced characterization *** high resolution transmission electron microscopy(HRTEM)and scanning electron microscopy(SEM)results show a reduction in the agglomeration of nanoparticles upon *** energy dispersive X-ray(EDX)analysis validates the existence of the Ce element in all the doped samples.X-ray photoelectron spectroscopy(XPS)and Raman spectra justify the presence of structural defects(oxygen vacancies)and successful formation of the monoclinic Wo_(3) phase,*** Kubelka-Munk function indicates a decrease in band gap with doping,while photoluminescence(PL)spectra show intense visible and UV emissions,Significantly,all doped samples exhibit higher photocatalytic performance than pure Wo_(3) nanoparticles,with the 6 wt%Ce-doped sample displaying the highest degradation *** with Ce can help to increase the surface area of Wo_(3),thereby improving its photoactivity,Moreover,a correlation between PL and photocatalysis is established in the light of oxygen vacancies suggesting a direct dependence of high photocatalytic activity on strong PL signals of Wo_(3) *** experiments further reveal that the degradation process is primarily driven by active species,providing insight into a plausible photocatalytic mechanism.

关键词： Wo_(3) Rare-earth element Environmental crisis oxygen vacancies Luminescence Photocatalysis

A Review on the Advancement of Renewable Natural Fiber Hybrid Composites: Prospects, Challenges, and Industrial Applications

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Journal of Renewable Materials 2024年第7期12卷 1237-1290页

作者： Mohammed Mohammed Jawad K.oleiwi Aeshah M.Mohammed anwar Ja’afar Mohamad Jawad Azlin F.osman Tijjani Adam bashir o.betar Subash C.b.gopinath Center of Excellence geopolymer&green Technology(CEgeogTech) Universiti Malaysia PerlisArau02600Malaysia Faculty of Chemical Engineering Technology Universiti Malaysia Perlis(UniMAP)Arau02600Malaysia Department of Materials Engineering University of TechnologyBaghdad10070Iraq Department of Chemical Materials University of Bagdad College of Education for Pure Science Ibn-AlhaithamBaghdad10001Iraq Department of Computer Techniques Engineering Al-Rafidain University CollegeBaghdad10001Iraq Faculty of Electronics Engineering Technology Universiti Malaysia PerlisKampus Uniciti Alam Sg.ChuchuhPerlis02100Malaysia Research Center(NANoCAT) University of MalayaKuala Lumpur50603Malaysia Institute of Nano Electronic Engineering Universiti Malaysia PerlisPerlis01000Malaysia Center for global Health Research Saveetha Medical College&HospitalSaveetha Institute of Medical and Technical Sciences(SIMATS)Tamil Nadu602105India

Naturalﬁbre(NFR)reinforced functional polymer composites are quickly becoming an indispensable sustainable material in the transportation industry because of their lightweight,lower cost in manufacture,and adaptability to a wide variety of ***,the major difﬁculties of using theseﬁbres are their existing poor dimensional stability and the extreme *** assessing the mechanical properties(MP)of composites,the interfacial bonding(Ib)happening between the NFR and the polymer matrix(PM)plays an incredibly signiﬁcant *** compared to NFR/syntheticﬁbre hybrid composites,hybrid composites(HC)made up of two separate NFR are less prevalent;yet,these hybrid composites also have the potential to be valuable materials in terms of environmental issues.A new dimension to theﬂexibility of composites reinforced with NFR is added by the cost-effective manufacture of hybrid composites utilising *** purpose of this study is to offer an over-view of the keyﬁndings that were presented on hybrid *** emphasis was focused on the factors that inﬂuence the performance of the naturalﬁber composites,diverse approaches to enhancing MP,physical,electri-cal,and thermal characteristics of the *** study in polymer science gains interest for applications in con-struction and automotive industries.

关键词： Renewable naturalﬁber hybrid composites sustainability nanomaterial greener material

Ultrahydrophobic melamine sponge via interfacial modification with reduced graphene oxide/titanium dioxide nanocomposite and polydimethylsiloxane for oily wastewater treatment

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Water Science and Engineering 2024年第2期17卷 139-149页

作者： Hamidatu Alhassan Ying Woan Soon anwar Usman Voo Nyuk Yoong Department of Physics Universiti Brunei DarussalamBandar Seri Begawan BE1410Brunei Department of Chemical Sciences Universiti Brunei DarussalamBandar Seri Begawan BE1410Brunei

Three-dimensional(3D)porous absorbents have attracted significant attention in the oily wastewater treatment technology due to their high porosity and *** their amphiphilic surface,they have a propensity to simultaneously absorb water and oil,which restricts their range of *** this study,a reduced graphene oxide and titanium dioxide nanocomposite(rgo/Tio_(2))was used to fabricate an ultra-hydrophobic melamine sponge(MS)through interfacial modification using a solution immersion *** further modify it,poly-dimethylsiloxane(PDMS)was grafted onto its surface to establish stronger covalent bonds with the *** water contact angle of the sponge(rgo/Tio_(2)/PDMS/MS)was 164.2°,which satisfies the condition for *** evidence of its water repellency was demonstrated by the Cassie-baxter theory and the lotus leaf *** a result of the increased density of rgo/Tio_(2)/PDMS/MS,it recorded an initial capacity that was 2 g/g lower than the raw MS for crude oil *** raw MS retained 53% of its initial absorption capacity after 20 cycles of absorption,while rgo/Tio_(2)/PDMS/MS retained 97%,suggesting good *** oil and organic solvent recovery(90%-96%)was demonstrated by rgo/Tio_(2)/PDMS/MS in oil-water *** a continuous separation system,it achieved a remarkable separation efficiency of 2.4×10^(6)L/(m^(3)·h),and in turbulent emulsion separation,it achieved a demulsification efficiency of 90%-91%.This study provides a practical substitute for massive oil spill cleaning.

关键词： oily wastewater Reduced graphene oxide Polydimethylsiloxane(PDMS) Emulsion separation Melamine sponge

Expansion of human umbilical cord derived mesenchymal stem cells in regenerative medicine

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World Journal of Stem Cells 2024年第4期16卷 410-433页

作者： Shafiqa Naeem Rajput bushra Kiran Naeem anwar Ali Asmat Salim Irfan Khan Dr.Panjwani Center for Molecular Medicine and Drug Research International Center for Chemical and Biological SciencesUniversity of KarachiKarachi 75270SindhPakistan Surgical Unit 4 Dr.Ruth KM Pfau Civil HospitalKarachi 74400Pakistan Department of Physiology University of KarachiKarachi 75270Pakistan Center for Regenerative Medicine and Stem Cells Research and Department of Ophthalmology and Visual SciencesThe Aga Khan UniversityKarachi 74800SindhPakistan

bACKgRoUND Stem cells are undifferentiated cells that possess the potential for self-renewal with the capacity to differentiate into multiple *** humans,their limited numbers pose a challenge in fulfilling the necessary demands for the regeneration and repair of damaged tissues or *** suggested that mesenchymal stem cells(MSCs),necessary for repair and regeneration via transplantation,require doses ranging from 10 to 400 million ***,the limited expansion of MSCs restricts their therapeutic *** To optimize a novel protocol to achieve qualitative and quantitative expansion of MSCs to reach the targeted number of cells for cellular transplantation and minimize the limitations in stem cell therapy *** Human umbilical cord(hUC)tissue derived MSCs were obtained and *** cultured cells were subjected to the following evaluation pro-cedures:Immunophenotyping,immunocytochemical staining,trilineage differentiation,population doubling time and number,gene expression markers for proliferation,cell cycle progression,senescence-associatedβ-galactosidase assay,human telomerase reverse transcriptase(hTERT)expression,mycoplasma,cytomegalovirus and endotoxin *** Analysis of pluripotent gene markers oct4,Sox2,and Nanog in recultured hUC-MSC revealed no significant *** immunophenotypic markers CD90,CD73,CD105,CD44,vimentin,CD29,Stro-1,and Lin28 were positively expressed by these recultured expanded MSCs,and were found negative for CD34,CD11b,CD19,CD45,and *** recultured hUC-MSC population continued to expand through passage *** gene expression of Pax6,bMP2,and TgFb1 showed no significant variation between recultured hUC-MSC ***,a significant increase(Potic phase of the cell cycle was observed in recultured *** senescence markers(hTERT expression andβ-galactosidase activity)did not show any negative effect on recultured hUC-

关键词： Human umbilical cord Mesenchymal stem cells Expansion Cell proliferation In vitro expansion Senescence