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Influence of cerium ions on structure-dependent magnetic properties of Ba-Sr m-type hexaferrite nanocrystals

Journal of Rare Earths 2024年第2期42卷 364-372,I0005页

作者： Ram A.Pawar Sunil m.Patange P.m.Dighe sher singh m.ena.a.dullah gal-sehem. mehboobali Pannipara Santosh S.Jadhav Department of Physics ArtsCommerce and Science CollegeAhmednagar413711MaharashtraIndia Department of Physics Shri Krishna MahavidyalayaGunjotiDistOsmanabad413606MaharashtraIndia Padmashri Vikhe Patil College of Arts Science and CommercePravaranagarA/P.Loni(Kd)Tal.RahataDistAhmednagar413713MaharashtraIndia Solid State Physics Division Bhabha Atomic Research CentreMumbai400085MaharashtraIndia Department of Chemistry King Khalid UniversityAbha61413Saudi Arabia Department of Physics D.S.M's ArtsCommerce and Science CollegeJintur431509MaharashtraIndia

The present study is a systematic effort to investigate the structure-sensitive magnetic parameters of Ce^(3+) substituted Ba-Sr hexaferrite nanocrystals chemically formulated as Ba_(0.5)Sr_(0.5)Ce_(x)Fe_(12-x)O_(19) where x=0.0-0.2 with Δx=*** hexaferrite powders were prepared using the sol-gel self-ignition route and structurally characterized by means of powder X-ray diffraction and Fourier transform infrared *** creation of the m-type hexaferrite phase within the synthesized samples was revealed from the Rietveld refinement of the X-ray *** occurrence of a secondary phase of CeO_(2) was revealed within the hexaferrites for the substitution,x> *** refined X-ray diffraction data were utilized to compute the lattice parameters,X-ray density,and lattice parameter *** crystal structure plotted from the refined XRD data reveals the occupancy of the ions at different lattice *** XPS data of the hexaferrite were analyzed to confirm the oxidation states of the constituent *** nanocrystalline nature of the hexaferrites was revealed from the crystallite sizes calculated using Scherer's *** analysis of FTIR spectra confirms that only a fraction of Ce^(3+)accommodated in the lattice and the remaining Ce content reside in the form of the CeO_(2) *** morphology of the hexaferrites was analyzed from the FESEm profiles of the ferrite *** magnetic behavior study was performed by analyzing the Curie temperature,hysteresis loops,and hyperfine interactions by means of susceptibility,V.S.m,and mossbauer spectroscopy,*** hexaferrites with increasing coercivity,decreasing saturation magnetization,and decreasing Curie temperature are reported in the *** substituted Ce^(3+)ions inhibit the grain growth and create lattice imperfections giving rise to hexaferrites with tuned magnetic parameters suitable for different applications.

关键词： Ba-Sr hexaferrite Ce^(3+)substitution XPS Saturation magnetization Coercivity m?ssbauer spectroscopy

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Influence of edaphic factors on distribution and condition of Himalayan silver birch(Betula utilis ***)communities in the northwestern Indian Himalayas

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Journal of mountain Science 2024年第2期21卷 590-606页

作者： Khashti DASILA Renu RAWAL Tanay BARmAN sher singh SAmANT Anita PANDEY Veena PANDE G.B.Pant National Institute of Himalayan Environment Almora 263643India Centre of Excellence on Sustainable Land management Indian Council of Forestry Research and EducationDehradun 248006India Uttarakhand State Council for Science&Technology Dehradun 248015India Department of Biotechnology Graphic Era(Deemed to be University)Dehradun 248002India Department of Biotechnology Kumaun UniversityNainital 263136India

The basic concept of phytosociology is crucial for the assessment of species composition and dynamic ecological succession of forests supporting ecological services,functions,disturbance,and resilience that lead to the development of integrated areas such as ecological niche modeling and contribute to identifying the valuable bio-indicators which can be used in framing conservation and management *** is one of the most dominant tree species of treeline ecotone in the Himalayan *** species is also considered as indicator species for monitoring the past and recent climate change *** current study was carried out in the natural populations of *** from the sub-alpine zone of North-western Indian *** birch dominated forest harbors a total of 305 plant species comprising Angiosperms(51 families,160 genera and 277 species),Gymnosperms(03 families,05 genera and 07 species)and Pteridophytes(07 families,11 genera and 21 species)with Asteraceae,Ranunculaceae and Rosaceae as dominant *** forests are found dominant in shady moist habitat and North West *** characteristics,anthropogenic and developmental activities affect the population structure of *** and associated ***,the species has fair regeneration status in the study *** acidic nature of soil pH and spatial variation in edaphic characteristics may be due to geographical differences,rooting patterns and litter accumulation of below and above-ground *** estimation of a representative population of *** from each site showed that TAGBD,TCD and TBD were found maximum in ST3(Hamta Pass II site).The CCA analysis determined that environmental variables such as altitude,organic matter,available phosphorous,organic carbon,available nitrogen,and electrical conductivity played a significant role in determining tree species composition and distribution in *** dominated forests.

关键词： Species composition Indicator species Biomass North-western Indian Himalaya Regeneration Environmental variables

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Phytochemical analysis,antioxidant,acetylcholinesterase,andα-amylase inhibitors from Hippeastrum hybridum extract

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Journal of Traditional Chinese medicine 2024年第3期44卷 496-504页

作者： Naila sher mushtaq Ahmed Nadia mushtaq Department of Biotechnology University of Science and Technology Bannu-KPK 28100Pakistan Department of Botany University of Science and Technology Bannu-KPK 28100Pakistan

OBJECTIVE:To investigate the effects of Hippeastrum hybridum(HH)as a free radical scavenger,and an inhibitor of the two enzymes i-e Alpha-amylase(α-amylase)and acetylcholinesterase(AChE).mETHODS:In this study,HH plant was preliminary analyzed for phytochemical screening and then tested for its antioxidant,anti-α-amylase,and anti-AChE efficiency via standard ***:Phytochemical analysis shows the existence of different compounds;while Coumarins and quinones were *** total phenolic,flavonoid,and tannins content were found to be(78.52±0.69)mg GAE/g,(2.01±0.04)mg RUE/g,and(58.12±0.23)mg TAE/g of plant extract respectively.28.02%±0.02%alkaloid and 2.02%±0.05%saponins were present in the HH *** HH extract showed the anti-oxidant property with IC50(50%inhibition)of(151.01±0.13)(HH),(79.01±0.04)(Ascorbic acid)for ferric reducing,(91.48±0.13)(HH),(48.02±0.11)(Ascorbic acid)against Ammonium molybdenum,(156.02±0.31)(HH),(52.38±0.21)(Ascorbic acid)against DPPH,136.01±0.21(HH),52.02±0.31(Ascorbic acid)against H_(2)O_(2),and 154.12±0.03(HH),(40.05±0.15)(Ascorbic acid)μg/mL against ABTS *** analysis indicated that HH caused a competitive type of inhibition ofα-amylase(V_(max)remained constant and Km increases from 10.65 to84.37%)while Glucophage caused the un-competitive type of inhibition i-e both Km and V_(max)decreased from40.49 to 69.15%and 38.86 to 69.61%*** K_(i),(inhibition constant);K_(I),(dissociation constant),K_(m),(michaelis-menten constant),and IC50 were found to be62,364,68.1,and 38.08±0.22 for HH and 12,101.05,195,34.01±0.21 for ***,HH causes an anon-competitive type of inhibition of AChE i-e Km remains constant while V_(max)decreases from 60.5%to74.1%.The calculated K_(i),K_(I),K_(m),and IC50 were found to be 32,36.2,0.05,and 18.117±***:From the current results,it is concluded that HH extract contains bioactive compounds,and could be a good alternative to controlling oxidant

关键词： Hippeastrum hybridum phytochemicals antioxidant alpha-amylase acetylcholinesterase

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Control of Nozzle Flow Using Rectangular Ribs at Sonic and Supersonic mach Numbers

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Fluid Dynamics & materials Processing 2024年第8期20卷 1847-1866页

作者： Vigneshvaran Sethuraman Parvathy Rajendran sher Afghan Khan Abdul Aabid muneer Baig School of Aerospace Engineering Universiti Sains MalaysiaEngineering CampusNibong TebalPulau Pinang14300Malaysia Department of mechanical and Aerospace Engineering Faculty of EngineeringInternational Islamic University MalaysiaKuala Lumpur53100Malaysia Department of Engineering management College of EngineeringPrince Sultan UniversityP.O.Box 66833Riyadh11586Saudi Arabia

This study deals with base pressure management in a duct for various values of the mach number(m),namely,mach number corresponding to sonic and four supersonic *** addition to the mach number,the nozzle pressure ratio(NPR),the area ratio,the rib dimension,and the duct length are influential *** following specific values are examined at m=1,1.36,1.64,and 2,and NPRs between 1.5 and *** base pressure is determined by positioning ribs of varying heights at predetermined intervals throughout the length of the square *** the level of expansion is varied,it is seen that the base pressure initially drops for overexpanded flows and increases for under-expanded *** ribs are present,the flow field in the duct and pressure inside the duct fluctuate as the base pressure ***-expanded flows can achieve a base pressure value that is suitably high without experiencing excessive changes in the duct flow in terms of static pressure if a rib height around 10%of the duct height close to the nozzle exit is *** rib passive control does not negatively affect the duct’s flow field.

关键词： Base pressure internal flows ribs suddenly expanded flow wall pressure

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Effect of Sweptback Angle of a Delta Wing on Surface Pressure Distribution at Supersonic mach Numbers

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Fluid Dynamics & materials Processing 2024年第10期20卷 2353-2376页

作者： Shamitha Shetty Asha Crasta sher Afghan Khan Abdul Aabid muneer Baig mathematics Department Mangalore Institute of Technology and EngineeringVisvesvaraya Technological UniversityNear MoodabidreMangaluruKarnataka574225India Nitte meenakshi Institute of Technology Visvesvaraya Technological UniversityBangalore560064India Department of mechanical and Aerospace Engineering Faculty of EngineeringInternational Islamic University MalaysiaKuala Lumpur53100Malaysia Department of Engineering management College of Engineering Prince Sultan UniversityP.O.Box 66833Riyadh11586Saudi Arabia

The purpose of this work is to shed light on the effect of the pivot position on the surface pressure distribution over a 3D wing in different flight *** study is intended to support the design and development of aerospace vehicles where stability analysis,performance optimization,and aircraft design are of primary *** following parameters are considered:mach numbers(m)of 1.3,1.8,2.3,2.8,3.3,and 3.8,angle of incidence(θ)in the range from 5°to 25°,pivot position from h=0.2 to *** results of the CFD numerical simulations match available analytical data,thereby providing evidence for the reliability of the used *** findings provide valuable insights into the relationship between the surface pressure distribution,the mach number and the angle of incidence.

关键词： mach number angles of incidence stability analysis performance optimization

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Base Pressure Control with Semi-Circular Ribs at Critical mach Number

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Fluid Dynamics & materials Processing 2024年第9期20卷 2007-2028页

作者： Ambareen Khan sher Afghan Khan mohammed Nishat Akhtar Abdul Aabid muneer Baig School of Aerospace Engineering Universiti Sains MalaysiaPenang11600Malaysia Department of mechanical and Aerospace Engineering Faculty of EngineeringInternational Islamic University MalaysiaKuala Lumpur59000Malaysia Department of Engineering management College of EngineeringPrince Sultan UniversityP.O.Box 66833Riyadh11586Saudi Arabia

When better fuel-air mixing in the combustion chamber or a reduction in base drag are required in vehicles,rockets,and aeroplanes,the base pressure control is *** the base pressure and drag is necessary in both *** this work,semi-circular ribs with varying diameters(2,4,and 6 mm)positioned at six distinct positions(0.5D,1D,1.5D,2D,3D,and 4D)inside a square duct with a side of 15 mm are proposed as an efficient way to apply the passive control ***-depth research is done on optimising rib size for various rib *** to this study,the base pressure rises as rib height ***,the optimal location for the semi-circular ribs with a diameter of 2 mm is at *** 1D location appears to be optimal for the 4 mm size as *** the 6 mm size,however,the 4D position fills this function.

关键词： Base pressure nozzle pressure ratio base drag sonic mach number passive control

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Bibliographic survey and comprehensive review on mechanical and durability properties of microorganism based self-healing concrete

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Frontiers of Structural and Civil Engineering 2024年第9期18卷 1445-1465页

作者： md marghoobul HAQUE Kunal m.SHELOTE Namrata singh Supratic GUPTA Department of Civil Engineering Indian Institute of Technology DelhiNew Delhi 110016India

Concrete is the most widely utilized material for construction purposes,second only to water,in the ever-increasing need for construction *** is a brittle material and possesses a high risk of crack formation and consequent ***,which allows chemicals to enter and can cause concrete structures to lose their physico-mechanical and durability *** and rehabilitating concrete structures involves high costs and leads to various repair methods including coating,adhesives,polymers,supplementary cementitious materials(SCms),and *** of the latest technologies is the use of microorganisms in *** added microorganisms lead to calcite precipitation and thereby heal the cracks *** study presents a comprehensive literature survey on bacteria-included concrete,before which a bibliographic survey is performed using VOSViewer *** addition to regular bacterial concrete,this study focuses on also using SCms and fibers in bacterial concrete.A detailed literature review with data representation for various mechanical properties including compressive strength(CS),split tensile strength(SS),and flexure strength(FS),along with durability properties including carbonation,water absorption,resistance against chloride ion penetration,gas permeation,and resistance against cyclic freeze-and-thaw is presented.A study on the use of X-ray computed tomography(XCT)in bacterial concrete is highlighted,and the scope for future research,along with identification of the research gap,is presented.

关键词： bacterial concrete bibliographic survey biomineralization carbonation fibers

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Application of Response Surface methodology for Analysing and Optimizing the Finned Solar Air Heater

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Journal of Thermal Science 2024年第3期33卷 985-1009页

作者： Vineet singh Vinod singh YADAV Vaibhav TRIVEDI manoj KUmAR Niraj KUmAR Department of mechanical Engineering School of Engineering&TechnologyIFTM UniversityMoradabadUttar PradeshIndia Department of mechanical Engineering NITUttarakhandPauriUttarakhandIndia Department of Electronics and Communication Engineering Jaypee Institute of Information TechnologyNoidaUttar Pradesh201309India

In this research paper,a solar air heater with triangular fins has been experimentally analysed and ***,an experimental set-up of a solar air heater having triangular fins has been developed at the location of 28.10°N,78.23°*** heat transfer rate through fins and fins efficiency has been determined by the Finite Difference method model *** experimental data and modeled data of response parameters have been optimized in mINITAB-17 software by the Response Surface methodology *** creating the response surface design,three input parameters have been selected namely solar intensity,Reynolds number,and fin base-to-height *** range of solar intensity,Reynolds number,and fin base-to-height ratio is 600 to 1000W/m^(2),4000 to 6000,and 0.4 to 0.8 *** response surface design has been analyzed by calculating the outlet temperature,friction factor,Nusselt number,fin efficiency,thermal performance factor,and exergy *** optimum settings of input parameters:solar intensity is 1000 W/m^(2);Reynolds number is 4969.7,and the fin base to height ratio is 0.6060,on which these response:namely outlet temperature of 92.531℃,friction factor of 0.2350,Nusselt number of 127.761,thermal efficiency of 50.836%,thermal performance factor of 1.4947,and exergy efficiency of 8.762%.

关键词： solar air heater optimization fins exergy response surface methodology air

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Laser-induced graphene-coated wearable smart textile electrodes for biopotentials signal monitoring

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Frontiers of materials Science 2024年第1期18卷 95-111页

作者： C.m.Vidhya Yogita maithani Sakshi Kapoor J.P.singh Department of Physics Indian Institute of Technology DelhiHauz KhasNew Delhi 110016India

This paper describes how to produce a wearable dry electrode at a reasonable cost and how to use it for the monitoring of biopotentials in *** textiles in wearable technologies have made a great advancement in the health care management and living standards of *** was manufactured using the low-cost single-step process,laser ablation of polyimide,a commercial *** dispersions were made using solvent isopropyl alcohol which has low boiling point,nontoxicity,and environmental *** successive coating of the graphene dispersion on the cotton fabric to make it conductive,the sheet resistance of the resulting fabric dropped to 3% of its initial *** laser-induced graphene(LIG)cotton dry electrodes thus manufactured are comparable to Ag/AgCl wet electrodes in terms of the skin-to-electrode impedance,measuring between 78.0 and 7.2 kΩ for the frequency between 40 Hz and 1 *** LIG cotton electrode displayed a signal-to-noise ratio of 20.17 *** to its comfort,simplicity,and good performance over a longer period of time,the textile electrode appears suited for medical applications.

关键词： biopotential electrocardiogram electromyogram flexible electrode textile porous graphene

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Investigating the Evolution of Amati Parameters with Redshift

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Research in Astronomy and Astrophysics 2024年第1期24卷 188-200页

作者： meghendra singh Darshan singh Kanhaiya Lal Pandey Dinkar Verma Shashikant Gupta Delhi metro Rail Corporation Limited New Delhi 110001India GD Goenka University Gurugram 122103India Department of Physics Mata Raj Kaur Institute of Engineering and TechnologyRewari 123401India Department of Physics School of Advanced SciencesVellore Institute of TechnologyVellore 632014India

Gamma-ray bursts(GRBs) are among the brightest objects in the Universe and, hence, can be observed up to a very high redshift. Properly calibrated empirical correlations between intensity and spectral correlations of GRBs can be used to estimate the cosmological parameters. However, the possibility of the evolution of GRBs with redshift is a long-standing puzzle. In this work, we used 162 long-duration GRBs to determine whether GRBs below and above a certain redshift have different properties. The GRBs are split into two groups, and we fit the Amati relation for each group separately. Our findings demonstrate that estimations of the Amati parameters for the two groups are substantially dissimilar. We perform simulations to investigate whether the selection effects could cause the difference. Our analysis shows that the differences may be either intrinsic or due to systematic errors in the data, and the selection effects are not their true origin. However, in-depth analysis with a new data set comprised of 119 long GRBs shows that intrinsic scatter may partly be responsible for such effects.

关键词： Cosmology gamma rays:general (cosmology:)large-scale structure of universe galaxies:high-redshift

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