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Effect of Dy-substitution on structural and magnetic properties of Mn-Zn ferrite nanoparticles

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Journal of Rare Earths 2018年第1期36卷 86-94页

作者： K.v.Zipare s.s.Bandgar G.s.shahane Department of Electronics DBF Dayanand College of Arts and Science

This paper describes the structural and magnetic properties of Dy-substituted Mn-Zn ferrite nano- particles. Mn-Zn-Dy ferrite nanopafficles of the composition ***204 （x- 0.05, 0.1, 0.15 and 0.2） were synthesized by a facile chemical co-precipitation method. The samples were characterized through X-ray diffraction （XRD）, transmission electron microscopy （TEM）, Fourier transform infrared spectroscopy （FTIR）, vibrating sample magnetometer （vsM） and Curie temperature. The XRD patterns confirm the synthesis of single crystalline phase of Mn-Zn-Dy ferrite nanoparticles. Lattice parameter increases with increase in Dy-substitution which confirms the replacement of Fe3＋ ions by Dy3＋ ions. Crystallite size is of the order of 6-8 nm for all these samples. The particle sizes observed from TEM analysis are in good agreement with the XRD values. The magnetic measurements show super- paramagnetic nature of the samples. The saturation magnetization decreases with increase in Dy- concentration and can be correlated to modifications in the A-B exchange interactions as a result of the structural modifications due to Dy-substitution. The Curie temperature for ***204 nano- particles is 124 ℃ and decreases up to 84 ℃with the increase in the Dy-concentration. The decrease in Curie temperature can be attributed to the weakening of the superexchange interaction between A-site and B-site as a result of Dy-substitution. The low value of Curie temperature and higher value of ther- momagnetic coefficient kT shown by these samples makes them suitable for the preparation of tem- perature sensitive ferrofiuid for heat transfer applications.

关键词： Mn-Zn-Dy ferritesstructural characterizationMagnetic propertiesCurie temperatureRare earths

Dendritic spine degeneration:a primary mechanism in the aging process

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Neural Regeneration Research 2025年第6期20卷 1696-1698页

作者： Gonzalo Flores Leonardo Aguilar-Hernández Fernado García-Dolores Humberto Nicolini Andrea Judith vázquez-Hernández Hiram Tendilla-Beltrán Instituto de Fisiología Benemérita Universidad Autónoma de Puebla(BUAP)PueblaMexico Instituto de Ciencias Forenses(INCIFO) Tribunal Superior de Justicia de la Ciudad de México(TSJCDMX).Mexico CityMexico Instituto Nacional de Medicina Genómica(INMEGEN) Mexico CityMexico

Recent reports suggest that aging is not solely a physiological process in living beings;instead, it should be considered a pathological process or disease(Amorim et al., 2022). Consequently, this process involves a wide range of factors, spanning from genetic to environmental factors, and even includes the gut microbiome(GM)(Mayer et al., 2022). All these processes coincide at some point in the inflammatory process, oxidative stress, and apoptosis, at different degrees in various organs and systems that constitute a living organism(Mayer et al., 2022;AguilarHernández et al., 2023).

关键词： aging process stress

Comprehensive Application of Graphene: Emphasis on Biomedical Concerns

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Nano-Micro Letters 2019年第1期11卷 101-131页

作者： s.syama P.v.Mohanan Toxicology Division Biomedical Technology Wing Sree Chitra Tirunal Institute for Medical Sciences and Technology

Graphene, sp^2 hybridized carbon framework of one atom thickness, is reputed as the strongest material to date. It has marked its impact in manifold applications including electronics, sensors, composites, and catalysis. Current state-of-the-art graphene research revolves around its biomedical applications. The two-dimensional(2D) planar structure of graphene provides a large surface area for loading drugs/biomolecules and the possibility of conjugating fluorescent dyes for bioimaging. The high near-infrared absorbance makes graphene ideal for photothermal therapy. Henceforth, graphene turns out to be a reliable multifunctional material for use in diagnosis and treatment. It exhibits antibacterial property by directly interacting with the cell membrane. Potential application of graphene as a sca old for the attachment and proliferation of stem cells and neuronal cells is captivating in a tissue regeneration scenario. Fabrication of 2D graphene into a 3D structure is made possible with the help of 3D printing, a revolutionary technology having promising applications in tissue and organ engineering. However, apart from its advantageous application scope, use of graphene raises toxicity concerns. several reports have confirmed the potential toxicity of graphene and its derivatives, and the inconsistency may be due to the lack of standardized consensus protocols. The present review focuses on the hidden facts of graphene and its biomedical application, with special emphasis on drug delivery, biosensing, bioimaging, antibacterial, tissue engineering, and 3D printing applications.

关键词： Graphene Biomedical Bioprinting Toxicity Photothermal therapy

Calculation and Analysis of velocity and viscous Drag in an Artery with a Periodic Pressure Gradient

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Chinese Journal of Mechanical Engineering 2012年第4期25卷 715-721页

作者： ALIZADEH M sEYEDPOUR s M MOZAFARI v BABAZADEH shayan s Department of Mechanical Engineering Iran University of Science and TechnologyTehranIran Department of Mechanical Engineering Islamic Azad University of Science and ResearchTehranIran Department of Mechanical Engineering Tarbiat Modares UniversityTehranIran

Blood as a fluid that human and other living creatures are dependent on has been always considered by scientists and *** changes in blood pressure and its normal velocity can be a sign of a *** significant in blood fluid＇s mechanics is Constitutive equations and finding some relations for analysis and description of drag,velocity and periodic blood pressure in *** this paper,by considering available experimental quantities,for blood pressure and velocity in periodic time of a thigh artery of a living dog,at first it is written into Fourier series,then by solving Navier-stokes equations,a relation for curve drawing of vessel blood pressure with rigid wall is *** in another part of this paper,vessel wall is taken in to consideration that vessel wall is elastic and its pressure and velocity are written into complex Fourier *** this case,by solving Navier-stokes equations,some relations for blood velocity,viscous drag on vessel wall and blood pressure are *** this study by noting that vessel diameter is almost is large（3.7 mm）,and blood is considered as a Newtonian ***,available experimental quantities of pressure with obtained curve of solving Navier-stokes equations are *** blood analysis in rigid vessel,existence of 48% variance in pressure curve systole peak caused vessel blood flow analysis with elastic wall,results in new relations for blood flow *** Resultant curve is obtained from new relations holding 10% variance in systole peak.

关键词： artery newtonian fluid rigid & elastic wall newtonian fluid

Effect of Notch Location on Fatigue Life Prediction of strength Mismatched HsLA steel Weldments

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Journal of Materials science & Technology 2004年第2期20卷 129-135页

作者： s.Ravi v.Balasubramanian s.Nemat Nasser Department of Manufacturing Engineering Annamalai University Annamalainagar-608 002. Tamil Nadu IndiaDepartment of Manufacturing Engineering Annamalai University Annamalainagar-608 002. Tamil Nadu IndiaCentre of Excellence for Advanced Materials University of California at San Diego La Jolla CA 92093-0416 USA

Welding of high strength low alloy steels (HsLA) involves usage of low, even and high strength filler materials (electrodes) than the parent material depending on the application of the welded structures and the availability of the filler material. In the present investigation, the fatigue crack growth behaviour of weld metal (WM) and heat affected zone (HAZ) regions of under matched (UM), equal matched (EM) and over matched (OM) joints has been studied. The base material used in this investigation is HsLA-80 steel of weldable grade. shielded metal arc welding (sMAW) process has been used to fabricate the butt joints. Centre cracked tension (CCT) specimen has been used to evaluate the fatigue crack growth behaviour of the welded joints. Fatigue crack growth experiments have been conducted using servo hydraulic controlled fatigue testing machine at constant amplitude loading (R=0).A method has been proposed to predict the fatigue life of HsLA steel welds using fracture mechanics approach by incorporating influences of mismatch ratio (MMR) and notch location.

关键词： shielded metal arc welding High strength low alloy steel Mismatch ratio Notch location Fatigue crack growth Fatigue life

A spectral Atlas of F and G stars

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Chinese Journal of Astronomy and Astrophysics 2004年第3期4卷 279-283页

作者： v.G.Klochkova GangZhao v.E.Panchuk s.v.Ermakov NationalAstronomicalObservatories ChineseAcademyofSciencesBeijing100012 specialAstrophysicalObservatoryRussianAcademyofsciences NizhnijArkhyzKarachai-Cherkessia369167Russia

We present an atlas of a group of bright stars in the range of spectral classes F–G and luminosity classes I–v. The spectra were obtained with spectral resolution R ~ 15 000 within spectral region 4500–6620?. Typical spectra of stars with different metallicity [Fe/H] are included. We also show the digital version of the spectral data in FITs format.

关键词： stars: atlas stars: spectral class stars: F-G type

Toluene Alkylation with Methanol to p-Xylene over Heteropoly Acids supported by Clay

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Journal of Natural Gas Chemistry 2007年第1期16卷 42-45页

作者： v.v.Bokade s.s.Deshpande R.Patil s.Jain G.D.Yadav Catalysis Division National Chemical LaboratoryPune-411008India University Institute of Chemical Technology Mumbai-19India

The alkylation of toluene with methanol for the selective formation of p-xylene was systematically studied. very few studies have been reported on the use of superacids such as heteropolyacids on cheap supports, such as clay. This article deals with the use of different heteropoly acids （HPAs）, viz, Dodeca-Tungstophosphoric acid [***2O] （TPA）, Dodeca-Molyhdo phosphoric acid ammonium salt hydrate [H12Mo12N3O40P＋aq] （DMAA）, Dodeca-Molyhdo Phosphoric acid （PMA） on clay （MontmoriUonite, K-10） and as such plain clay. This comparative study reveals that 20%PMA/Clay shows 62% toluene conversion and 100% selectivity toward p-xylene.

关键词： toluene methanol p-xylene heteropoly acid clay

Grain boundary effect on structural, optical, and electrical properties of sol-gel synthesized Fe-doped snO_(2) nanoparticles

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Chinese Physics B 2021年第4期30卷 555-564页

作者： Archana v Lakshmi Mohan Kathirvel P saravanakumar s Department of sciences Amrita School of EngineeringCoimbatoreAmrita Vishwa VidyapeethamIndia Research and Development Center Bharathiar UniversityCoimbatore-641046TamilnaduIndia GRD Center for Materials Research Department of PhysicsP S G College of TechnologyCoimbatore-641004TamilnaduIndia Department of Physics N S S CollegePandalam-689501KeralaIndia

Tin oxide(snO_(2)) and iron-doped tin oxide(sn_(1-x)Fe_(x)O_(2),x=0.05 wt%,0.10 wt%) nanoparticles are synthesized by the simple sol-gel *** structural characterization using x-ray diffraction(XRD) confirms tetragonal rutile phases of the *** variations in lattice parameters and relative intensity with Fe-doping concentration validate the incorporation of iron into the *** compressive strain present in the lattice estimated by using peak profile analysis through using Williamson-Hall plot also exhibits the influence of grain boundary formation in the *** radiative recombination and quenching observed in optical characterization by using photoluminescence spectrum(PL) and the shift in the band gap estimated from Uv-visible diffused reflectance spectrum corroborate the grain boundary *** spectrum and the morphological analysis by using a field emission scanning electron microscope(FEsEM) also indicate the formation of grain *** compositional analysis by using energy dispersive x-ray spectrum(EDAX) confirms Fe in the snO_(2) *** conductivity studies exhibit that the impendence increases with doping concentration increasing and the loss factor decreases at high frequencies with doping concentration increasing,which makes the sn_(1-x)Fe_(x)O_(2) a potential candidate for device applications.

关键词： sol-gel compressive strain grain boundary AC conductivity

Multifunctional A356 alloy/PKsAnp composites:Microstructure and mechanical properties

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Defence Technology（防务技术） 2020年第3期16卷 731-736页

作者： v.s.Aigbodion I.C.Ezema Department of Metallurgical and Materials Engineering University of NigeriaNsukkaNigeria

Mechanical properties and microstructure of multifunctional composites produced with palm kernel shell ash nano particle(PKsAnp)-A356 alloy composites was *** composites were produced using Double layer feeding stir casting method(DLF-sCM) by adding 1 wt%-4 wt.% *** microstructure,density,electrical and mechanical properties were *** results shows that there was a uniform distribution of the PKsAnp in A356 *** mismatch at the interface between the PKsAnp and A356 alloy was 4.26%.Improvement of 30.47%,41.91%,49.52%,40.90% and 65.09% were obtained for hardness values,tensile,yield strength,%elongation and impact energy at 4 wt% *** work has established that the developed composites can be used for multifunctional applications where combination of toughness and strength is vital.

关键词： PKsAnp A356 alloy Microstructure Electrical and mechanical properties