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Regression analysis of squeezing-induced hybrid nanofluid flow in Darcy-Forchheimer porous medium

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Applied mathematics and mechanics(English Edition) 2025年第1期46卷 193-208页

作者： k.mUHAmmAD m.SARFRAZ Department of Humanities and Sciences School of Electrical Engineering and Computer Science National University of Sciences and Technology Department of mathematics Quaid-i-Azam University

This article presents a mathematical model addressing a scenario involving a hybrid nanofluid flow between two infinite parallel plates. One plate remains stationary, while the other moves downward at a squeezing velocity. The space between these plates contains a Darcy-Forchheimer porous medium. A mixture of water-based fluid with gold(Au) and silicon dioxide(Si O2) nanoparticles is formulated. In contrast to the conventional Fourier's heat flux equation, this study employs the Cattaneo-Christov heat flux equation. A uniform magnetic field is applied perpendicular to the flow direction, invoking magnetohydrodynamic(mHD) effects. Further, the model accounts for Joule heating, which is the heat generated when an electric current passes through the fluid. The problem is solved via NDSolve in mATHEmATICA. Numerical and statistical analyses are conducted to provide insights into the behavior of the nanomaterials between the parallel plates with respect to the flow, energy transport, and skin *** findings of this study have potential applications in enhancing cooling systems and optimizing thermal management strategies. It is observed that the squeezing motion generates additional pressure gradients within the fluid, which enhances the flow rate but reduces the frictional drag. Consequently, the fluid is pushed more vigorously between the plates, increasing the flow velocity. As the fluid experiences higher flow rates due to the increased squeezing effect, it spends less time in the region between the plates. The thermal relaxation, however, abruptly changes the temperature, leading to a decrease in the temperature fluctuations.

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Correction of failure in antenna array using matrix pencil technique

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Chinese Physics B 2017年第6期26卷 491-498页

作者： S U khan m.k.a.rahim Advanced RF & microwave Research Group Department of Communication Engineering Faculty of Electrical Engineering Universiti Teknologi Malaysia 81310 Skudai Johor Malaysia

In this paper a non-iterative technique is developed for the correction of faulty antenna array based on matrix pencil technique（mPT）. The failure of a sensor in antenna array can damage the radiation power pattern in terms of sidelobes level and nulls. In the developed technique, the radiation pattern of the array is sampled to form discrete power pattern information set. Then this information set can be arranged in the form of Hankel matrix（Hm） and execute the singular value decomposition（SVD）. By removing nonprincipal values, we obtain an optimum lower rank estimation of Hm. This lower rank matrix corresponds to the corrected pattern. Then the proposed technique is employed to recover the weight excitation and position allocations from the estimated matrix. Numerical simulations confirm the efficiency of the proposed technique, which is compared with the available techniques in terms of sidelobes level and nulls.

关键词： array correction low rank estimation matrix pencil technique singular value decomposition

Efficacy of antimicrobials in preventing resistance in solid organ transplant recipients:A systematic review of clinical trials

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World Journal of Transplantation 2025年第1期15卷 156-164页

作者： Carlos m Ardila Pradeep k Yadalam Jaime Ramírez-Arbelaez Department of Basic Sciences Faculty of Dentistry Biomedical Stomatology Research GroupUniversidad de Antioquia U de AMedellín 0057Colombia Department of Postdoctoral Program CIFE University CenterCuernavaca 62330MorelosMexico Department of Periodontics Saveetha Dental CollegeSaveetha Institute of Medical and HealthSIMATSSaveetha UniversityChennai 600077Tamil NaduIndia Department of Transplantation Hospital San Vicente FundaciónRionegro 054047Colombia

BACkGROUND In the absence of effective antimicrobials,transplant surgery is not viable,and antirejection immunosuppressants cannot be administered,as resistant infections compromise the life-saving goal of organ *** To evaluate the efficacy of antimicrobials in preventing resistance in solid organ transplant *** A systematic review was conducted using a search methodology consistent with the preferred reporting items for systematic reviews and *** review included randomized clinical trials that evaluated the efficacy of antimicrobial agents(prophylactic or therapeutic)aimed at preventing antimicrobial *** search strategy involved analyzing multiple databases,including Pubmed/mEDLINE,Web of Science,Embase,Scopus,and SciELO,as well as examining gray literature sources on Google Scholar.A comprehensive electronic database search was conducted from the databases’inception until may 2024,with no language *** After the final phase of the eligibility assessment,this systematic review ultimate-ly included 7 articles.A total of 2318 patients were *** most studied microorganisms were cytomegalovirus,although vancomycinresistant enterococci,Clostridioides difficile,and multidrug-resistant Enterobacterales were also *** antimicrobials used in the interventions were mainly maribavir,valganciclovir,gancic-lovir,and *** concern,all clinical trials showed significant proportions of resistant microorga-nisms after the interventions,with no statistically significant differences between the groups(mean resistance 13.47%vs 14.39%),except for two studies that demonstrated greater efficacy of maribavir and valganciclovir(mean resistance 22.2%vs 41.1%in the control group;Pmicrobial-resistant microor

关键词： Antimicrobial resistance Antimicrobials Antivirals Solid organ transplant recipients Infections microorganisms Cytomegalovirus

Q-Switching Pulse Operation in 1.5-μm Region Using Copper Nanoparticles as Saturable Absorber

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Chinese Physics Letters 2017年第3期34卷 41-44页

作者： A.R.muhammad m.T.Ahmad R.Zakaria H.R.A.rahim S.F.A.Z.Yusoff k.S.Hamdan H.H.m.Yusof H.Arof S.W.Harun Department of Electrical Engineering Faculty of EngineeringUniversity of MalayaKuala Lumpur 50603Malaysia Photonics Research Centre Physics DepartmentFaculty of ScienceUniversity of MalayaKuala Lumpur 50603Malaysia

We demonstrate a passively Q-switched erbium-doped fiber laser （EDFL） using a copper nanoparticle （CuNP） thin film as the saturable absorber in a ring cavity. A stable Q-switched pulse operation is observed as the CuNP saturable absorber （SA） is introduced in the cavity. The pulse repetition rate of the EDFL is observed to be proportional to the pump power, and is limited to 101.2kHz by the maximum pump power of 113.7mW. On the other hand, the pulse width reduces from 10.19μs to 4.28μs as the pump power is varied from 26.1 mW to 113.7mW. The findings suggest that CuNP SA could be useful as a potential saturable absorber for the development of the robust, compact, efficient and low cost Q-switched fiber laser operating at 1.5-μm region.

关键词： Cu m Region Using Copper Nanoparticles as Saturable Absorber Q-Switching Pulse Operation in 1.5 SA kHz EDF

Does acid pickling of mg-Ca alloy enhance biomineralization?

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Journal of magnesium and Alloys 2021年第3期9卷 1028-1038页

作者： Shebeer A rahim VP muhammad Rabeeh m A Joseph T Hanas Department of mechanical Engineering National Institute of Technology CalicutKerala 673601India Nanomaterials Research Laboratory School of Materials Science and EngineeringNational Institute of Technology CalicutKerala 673601India

The mechanical and physical properties of biodegradable magnesium(mg)alloys make them suitable for temporary orthopaedic *** success of these alloys depends on their performance in the physiological *** the present work,surface modification of mg-Ca binary alloy by acid pickling for better biomineralization and controlled biodegradation is *** corrosion rates of nitric and phosphoric acid treated samples were analysed by conducting electrochemical corrosion *** vitro degradation behaviour was studied using immersion test in simulated body fluid(SBF).The sample surfaces were characterized using scanning electron microscope(SEm),energy dispersive X-ray spectroscopy(EDS),Fourier transform infrared spectroscopy(FTIR)and X-ray photoelectron spectroscopy(XPS).It is seen that acid pickling leads to significant improvement in biomineralization and develop in situ calcium phosphate(Ca P)coating on the sample *** addition,the treated samples recorded a reduced degradation rate in the SBF compared to untreated ***,acid pickling is suggested as an effective surface treatment method to tailor the biomineralization and degradation behaviour of the mg-Ca alloy in the physiological environment.

关键词： Inorganic acid pickling magnesium alloy Surface pretreatment Surface characterization Biomineralization Degradation rate

Inhibitive effect of Xylopia ferruginea extract on the corrosion of mild steel in 1m HCl medium

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International Journal of minerals,metallurgy and materials 2011年第4期18卷 413-418页

作者： Pandian Bothi Raja Afidah Abdul rahim1 Hasnah Osman1 khalijah Awang School of Chemical Sciences Universiti Sains Malaysia11800 PenangMalaysia Department of Chemistry Faculty of ScienceUniversity of Malaya50603 Kuala LumpurMalaysia

The alkaloid content of the leaves and stem bark of Xylopia ferruginea plant was isolated and tested for its anticorrosion potential on mild steel corrosion in a hydrochloric acid medium by using electrochemical impedance spectroscopy,potentiodynamic polarization measurement,scanning electron microscopy（SEm）,and Fourier transform infra red（FTIR） *** experimental results reveal the effective anticorrosion potential of the plant *** mixed mode of action exhibited by the plant extract is evidenced from the polarization *** images proof the formation of a protective layer over the mild steel surface,and this is supported by the FTIR *** possible mode of the corrosion inhibition mechanism has also been discussed.

关键词： steel corrosion hydrochloric acid plant extracts corrosion inhibitors polarization

Crystallization kinetics of overlapping phases in Se70Te15Sb15 using isoconversional methods

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Progress in Natural Science:materials International 2015年第2期25卷 169-177页

作者： m.A.Abdel-rahim m.m.Hafiz A.Z.mahmoud Physics Department Faculty of ScienceAssiut University Assiut 71516 Egypt

The crystallization kinetics of Se70Te15Sb15 chalcogenide glass was studied by Differential Scanning Calorimetry(DSC) under non-isothermal conditions. This glass was found to have a double glass transition and double overlapped crystalline phases. The overlapped crystalline phases were successfully separated using the Gaussian fit model. The activation energy, Ec, and Avrami index, n, were determined by analyzing the data using the matausita et. al. method. A strong heating rate depending on the activation energy for the two crystalline peaks was observed. The results indicated that the transformation from amorphous to crystalline phases is a complex process involving different mechanisms of nucleation and growth. The variation of activation energy with crystalline fraction was determined by kissenger–Akahira–Sunose(kAS) method. The obtained results of directly fitting the experimental DSC data to the calculated DSC curves indicated that the crystallization process of Se70Te15Sb15 glass cannot be satisfactorily described by the Johnson–mehl–Avrami(JmA) model. Simulation results indicated that the Sestak–Berggren(SB) model is more suitable to describe the crystallization process for the studied glass. The crystalline phases for the two events were identified by using x-ray diffraction(XRD) and scanning electron microscopy(SEm).

关键词： Chalcogenides glasses Differential Scanning Calorimetry(DSC) Electron microscopy X-ray diffraction

The sexually dimorphic expression of glutamate transporters and their implication in pain after spinal cord injury

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Neural Regeneration Research 2025年第11期20卷 3317-3329页

作者： Jennifer m.Colón-mercado Aranza I.Torrado-Tapias Iris k.Salgado Jose m.Santiago Samuel E.Ocasio Rivera Dina P.Bracho-Rincon Luis H.Pagan Rivera Jorge D.miranda Department of Physiology University of Puerto RicoMedical Sciences CampusSan JuanPRUSA National Institutes of Health National Human Genome Research InstituteBethesdaMDUSA Universidad Central del Caribe School of MedicineBayamónPRUSA University of Puerto Rico Carolina CampusCarolinaPRUSA Institute of Neurobiology San JuanPRUSA

In addition to the loss of motor function,~60% of patients develop pain after spinal cord *** cellular-molecular mechanisms are not well understood,but the data suggests that plasticity within the rostral,epicenter,and caudal penumbra of the injury site initiates a cellularmolecular interplay that acts as a rewiring mechanism leading to central neuropathic *** can lead to the formation of new connections triggering abnormal sensory *** excitatory glutamate transporters are responsible for the reuptake of extracellular glutamate which makes them a critical target to prevent neuronal hyperexcitability and *** previous studies showed a sexually dimorphic therapeutic window for spinal cord injury after treatment with the selective estrogen receptor modulator *** this study,we investigated the anti-allodynic effects of tamoxifen in male and female rats with spinal cord *** hypothesized that tamoxifen exerts anti-allodynic effects by increasing the expression of glutamate transporters,leading to reduced hyperexcitability of the secondary neuron or by decreasing aberrant *** and female rats received a moderate contusion to the thoracic spinal cord followed by subcutaneous slow-release treatment of tamoxifen or matrix pellets as a control(placebo).We used von Frey monofilaments and the“up-down method”to evaluate mechanical *** treatment decreased allodynia only in female rats with spinal cord injury revealing a sexdependent *** expression profile of glutamatergic transporters(excitatory amino acid transporter 1/glutamate aspartate transporter and excitatory amino acid transporter 2/glutamate transporter-1)revealed a sexual dimorphism in the rostral,epicenter,and caudal areas of the spinal cord with a pattern of expression primarily on *** rodents showed a significantly higher level of excitatory amino acid transporter-1 expression while male rodents showed increased

关键词： allodynia central neuropathic pain EAAT-1/GLAST EAAT-2/GLT-1 glutamate transporters selective estrogen receptor modulator sexual dimorphism spinal cord injury trauma

Nonlinear forced vibration in a subcritical regime of a porous functionally graded pipe conveying fluid with a retaining clip

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Applied mathematics and mechanics(English Edition) 2025年第1期46卷 101-122页

作者： m.GHOLAmI m.EFTEkHARI Department of mechanical Engineering Shahid Bahonar University of Kerman

This study examines the nonlinear behaviors of a clamped-clamped porous pipe made of a functionally graded material(FGm) that conveys fluids and is equipped with a retaining clip, focusing on primary resonance and subcritical dynamics. The nonlinear governing equations for the FGm pipe are derived by the extended Hamilton's principle, and subsequently discretized through the application of the Galerkin *** direct method of multi-scales is then used to solve the derived equations. A thorough analysis of various parameters, including the clip stiffness, the power-law index, the porosity, and the clip location, is conducted to gain a comprehensive understanding of the system's nonlinear dynamics. Through the analysis of the first natural frequency, the study highlights the influence of the flow velocity and the clip stiffness, while the comparisons with metallic pipes emphasize the role of FGm composition. The examination of the forced response curves reveals saddle-node bifurcations and their dependence on parameters such as the detuning parameter and the power-law index, offering valuable insights into the system's nonlinear resonant behavior. Furthermore, the frequency-response curves illustrate the hardening nonlinearities influenced by factors such as the porosity and the clip stiffness, revealing nuanced effects on the system response and resonance characteristics. This comprehensive analysis enhances the understanding of nonlinear behaviors in FGm porous pipes with a retaining clip, providing key insights for practical engineering applications in system design and optimization.

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