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Effect of Sintering Temperature and Heating Rate on Crystallite Size,Densification Behaviour and Mechanical Properties of Al-MWCNT Nanocomposite Consolidated via Spark Plasma Sintering

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Acta Metallurgica Sinica(English Letters) 2018年第10期31卷 1019-1030页

作者： Lavish kumar Singh Alok Bhadauria Subhodeep jana Tapas Laha Department of Metallurgical and Materials Engineering Indian Institute of Technology Kharagpur Kharagpur India Centre for Healthcare Science and Technology Indian Institute of Engineering Science and Technology Shibpur India

Powder mixture of ball-milled aluminium and functionalized multi-walled carbon nanotubes was compacted via spark plasma sintering （SPS） to study effects of sintering temperature and heating rate. An increase in sintering temperature led to an increase in crystallite size and density, whereas an increase in heating rate exerted the opposite effect. The crystallite size and relative density increased by 85.0% and 14.3%, respectively, upon increasing the sintering temperature from 400 to 600℃, whereas increasing the heating rate from 25 to 100 ℃/min led to respective reduction by 30.0% of crystallite size and 1.8% of relative density. The total punch displacement during SPS for the nanocomposite sintered at 600 ℃ （1.96 mm） was much higher than that of the sample sintered at 400 ℃ （1.02 mm） confirming positive impact of high sintering temperature on densification behaviour. The maximum improvement in mechanical properties was exhibited by the nanocomposite sintered at 600 ℃ at a heating rate of 50℃/min displaying microhardness of 81 4- 3.6 VHN and elastic modulus of 89 4- 5.3 GPa. The nanocomposites consolidated at 400 ℃ and 100 ℃/min, in spite of having relatively smaller crystallite size, exhibited poor mechanical properties indicating the detrimental effect of porosity on the mechanical properties.

关键词： Al nanocomposite Multi-walled carbon nanotubes Ball milling Spark plasma sintering Densification behaviour Mechanical properties

A nonautonomous mat hematical model to assess the impact of algae on the abatement of atmospheric carbon dioxide

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International Journal of Biomathematics 2021年第7期14卷 227-264页

作者： Pankaj kumar Tiwari Rajesh kumar Singh Debaldev jana Yun Kang Arvind kumar Misra Department of Basic Science and Humanities Indian Institute of Information Technology Bhagalpur 813210 India Government Shahid Kedamath P.G.College Mauganj Rewa 486331India Department of Mathematics&SRM Research Institute SRM Institute of Science and Technology Kattankulathur 603203 Tamil NaduIndia Science and Mathematics Faculty Arizona State University Mesa AZ 85212USA Department of Mathematics Institute of Science Banaras Hindu UniversityVaranasi 221005India

The world's oceans have played an important role in sequestering atmospheric carbon dioxide through solubility and the action of *** of atmospheric carbon dioxide by photoautotrophic algal cultures has the potential to diminish the release of carbon dioxide into the atmosphere,thereby helping to alleviate the trend toward global *** work investigates the role of algae in controlling the level of atmospheric carbon *** Rank Correlation Coefficients(PRCCs)technique is used to address how the concentration of atmospheric carbon dioxide is affected by changes in a specific parameter disregarding the uncertainty over the rest of the model *** related to algal growth are shown to significantly reduce the level of atmospheric CO_(2).Further,we explore the dynamics of nonautonomous system by incorporating the seasonal variations of sonic ecologically important model *** nonautonomous system exhibits globally attractive positive periodic solution,and also the appearance of double periodic solution is ***,by letting the seasonally forced parameters as almost periodic functions of time,we show almost periodic behavior of the *** findings suggest that the policy makers should focus on continuous addition of nutrients in the ocean to accelerate the algal growth thereby reducing the level of carbon dioxide in the atmosphere.

关键词： Mathematical model algae atmospheric CO2 sensitivity analysis:seasonality periodic solution

Solid and liquid state characterization of tetrahydrocurcumin using XRPD, FT-IR, DSC, TGA, LC-MS, GC-MS, and NMR and its biological activities

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Journal of Pharmaceutical Analysis 2020年第4期10卷 334-345页

作者： Mahendra kumar Trivedi Parthasarathi Panda Kalyan kumar Sethi Mayank Gangwar Sambhu Charan Mondal Snehasis jana Trivedi Global Inc. Henderson89052NevadaUSA Trivedi Science Research Laboratory Pvt.Ltd. Thane(W)-400604MaharashtraIndia

Tetrahydrocurcumin(THC)is one of the major metabolites of curcumin(CUR),an ancient bioactive natural polyphenolic *** research article describes both the solid and liquid state characterization of THC using advanced spectroscopic and thermo-analytical ***-inflammatory,anti-oxidant,and neuroprotective activities of THC were investigated using in vitro cell *** chromatography-mass spectrometry analysis revealed that our sample comprised 95.15%THC,0.51%tetrahydrodemethoxycurcumin(THDC),3.40%hexahydrocurcumin,and 0.94%*** chromatography-mass spectrometry analysis indicated the presence of 96.68%THC and 3.32%*** in solution existed as keto-enol tautomers in three different forms at different retention time,but the enol form was found to be dominant,which was also supported by nuclear magnetic resonance *** was thermally stable up to 335.55*** exhibited more suppression of cytokines(TNF-a,IL-1b,and MIP-1a)than CUR in a concentration-dependent manner in mouse splenocytes,while NK-cell and phagocytosis activity was increased in *** showed a significant reduction of free radicals(LPO)along with improved antioxidant enzymes(SOD and catalase)and increased free radical scavenging activity against ABTSt radicals in HepG2 *** displayed higher protection capability than CUR from oxidative stress and neuronal damage by improving cell viability against H2O2 induced HepG2 cells and MPPt induced SH-SY5Y cells,respectively,in a concentration-dependent ***,a variation of the biological activities of THC might rely on its keto-enol form and the presence of other THC analogs as *** present study could be advantageous for further research on THC for better understanding its physicochemical properties and biological variation.

关键词： Tetrahydrocurcumin Liquid chromatography-mass spectrometry Spectroscopic and thermal analysis Keto-enol tautomer Anti-inflammatory Antioxidant

Virome identification in wheat in the Czech Republic using small RNA deep sequencing

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Journal of Integrative Agriculture 2020年第7期19卷 1825-1833页

作者： Khushwant SINGH jana JAROSOVA Jan FOUSEK CHEN Huan Jiban kumar KUNDU Plant Virus and Vector Interactions Group Division of Crop Protection and Plant HeatthCrop Research InstitutePrague 16106Czech Republic Zhejiang Tianke High-Technology Development Co. Ltd.Hangzhou 310012P.R.China

High-throughput deep-sequencing technology and bioinformatics analysis of the small RNA(sRNA)population isolated from plants allows universal virus detection and complete virome reconstruction for a given *** the present sRNA deep-sequencing analysis of virus-infected wheat samples in the Czech Republic,samples were firstly tested for barley yellow dwarf viruses(BYDVs),wheat streak mosaic virus(WSMV)and wheat dwarf virus(WDV)using ELISA,RT-PCR and *** sRNA sequencing of these samples yielded more than^60 million single-end 50-bp reads with high confidence for nine field samples of ***,16.5%of reads were virus-specific and 83.5%were mapped to the *** 21-nt reads(-7.7E+06 reads)were found than 24-nt(~6.20E+06 reads)or 22-nt(-4.30E+06 reads)*** novo assembly of the high-quality contigs revealed the presence of three earlier repoted viruses in the Czech Republic:BYDVs(31.48%),WSMV(24.23%)and WDV(2666%).We also showed the presence of cereal yellow dwarf virus(14.33%;two species CYDV-RPS and CYDV-RPV family Luteoviridae/Polerovirus)and wheat yellow dwarf virus(WYDV,3.30%;Luteoviridae).Phylogenetic analysis showed CYDV and WYDV grouped separately from ***,several recombination breakpoints were found among the groups of yellow dwarf viruses(BYDVs,CYDV,and WYDV).Using RNA deep sequencing,we confirmed the presence of the three known viruses(BYDVs,WSMV,and WDV)and the first record of two species of CYDV and WYDV in wheat in the Czech Republic.

关键词： NGS sRNA BYDVs CYDV WSMV WYDV WDV

Wheat streak mosaic virus： incidence in field crops, potential reservoir within grass species and uptake in winter wheat cultivars

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Journal of Integrative Agriculture 2017年第3期16卷 523-531页

作者： jana Chalupniková Jiban kumar Kundu Khushwant Singh Pavla Bartaková Eva Beoni Division of Crop Protection and Plant Health Crop Research Institute Prague 16106 Czech Republic Department of Experimental Plant Biology Faculty of Science Charles University in Prague Prague 12843 Czech Republic

Wheat streak mosaic virus（WSMV）has become a re-emerging pathogen in cereal crops in the Czech *** was first reported in the former Czechoslovakia in the early 1980s,and then no record of the virus was documented until *** incidence of the virus was recorded in recent years in several winter wheat fields and many grass ***,we surveyed the incidence of WSMV in cereal *** results demonstrated the existence of the virus in winter wheat and volunteer wheat during each year of the monitoring period,which spanned from 2013–*** the range of infected samples was low（6.4%of the total tested samples）,a high incidence of well-distributed virus was *** at least six fields,the virus reached severe and potentially epidemic *** accordance with our previous report detailing WSMV infection of native grasses,we tested several grass species commonly grown in the Czech *** found that some grass species acted as experimental hosts and possible reservoirs of the virus;these included Anthoxanthum odoratum（sweet vernal grass）,Arrhenatherum elatius（false oat-grass）,Lolium multiflorum（Italian rye-grass）,Bromus japonicus（Japanese chess）,Echinochloa crus-galli（barnyard grass）,Holcus lanatus（meadow soft grass）and Holcus mollis（creeping soft grass）.Some of these grass species are also important weeds of cereals,which may be the potential source of WSMV infection in cereal *** widely used winter wheat cultivars were tested in the field after artificial inoculation with WSMV to evaluate virus titre by ***,the tested cultivars had a low virus titre,which is associated with mild disease symptoms and may provide a good level of crop resistance to WSMV.

关键词： WSMV survey grass species cereal crops

Accretion properties of MAXI J1813-095 during its failed outburst in 2018

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Research in Astronomy and Astrophysics 2021年第5期21卷 235-246页

作者： Arghajit jana Gaurava K.Jaisawal Sachindra Naik Neeraj kumari Debjit Chatterjee KaushikChatterjee Riya Bhowmick Sandip KChakrabarti Hsiang-Kuang Chang dipak Debnath Astronomy&Astrophysics Division Physical Research LaboratoryNavrangpuraAhmedabad 380009India National Space Institute Technical University of DenmarkElektrovej327-328DK-2800 LyngbyDenmark High Energy Astrophysics Indian Centre for Space PhysicsGaria St RoadKolkata 700084India Department of Physics Indian Institute of TechnologyGandhinagar 382355GujaratIndia Indian Institute of Astrophysics KoramangalaBangalore 560034India Department of Physics “National Tsing Hua University”Hsinchu 30013China

We present the results obtained from detailed timing and spectral studies of a black hole candidate MAXI J1813-095 using Swift,NICER,and NuSTAR observations during its 2018 *** timing behavior of the source is mainly studied by examining NICER light curves in the 0.5−10 keV *** did not find any signature of quasi-periodic oscillations in the power density spectra of the *** carry out spectral analysis with a combined disk blackbody&power law model,and physical two-component advective flow(TCAF)*** the combined disk blackbody&power-law model,we extracted thermal and non-thermal fluxes,photon index and inner disk *** also find evidence for weak reflection in the *** have tested the physical TCAF model on a broadband spectrum from NuSTAR and Swift/*** parameters like mass accretion rates,the size of Compton clouds and the shock strength are *** result affirms that the source remained in the hard state during the entire outburst which indicates a‘failed’*** estimate the mass of the black hole as 7.4±1.5M⊙from the spectral study with the TCAF *** apply the LAOR model for the Fe K line *** this,the spin parameter of the black hole is ascertained as a^(∗)>*** inclination angle of the system is estimated to be in the range of 28°−45°from the reflection *** find the source distance to be∼6 kpc.

关键词： X-Rays:binaries stars individual:(MAXI J1813-095) stars:black holes accretion,accretion disks–shock waves radiation:dynamics

Finite-size-effect on a very large length scale in NBT-based lead-free piezoelectrics

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Journal of Advanced Dielectrics 2019年第5期9卷 35-41页

作者： Anupam Mishra dipak kumar Khatua Gobinda Das Adhikary Naveen kumar Uma Shankar Rajeev Ranjany Department of Materials Engineering Indian Institute of Science Bangalore-560012 India

Na_(0.5)Bi_(0.5)TiO_(3)-based lead-free piezoelectrics are considered for potential replacement of the lead-based commercial piezoceramics in high-power transducer *** have examined the role of grain size in influencing the structural-polar inhomogeneity of stoichiometric and off-stoichiometric Na_(0.5)Bi_(0.5)TiO_(3)(NBT),and its morphotropic-phase-boundary(MPB)derivative 0.94Na_(0.5)Bi_(0.5)TiO_(3)-0.06BaTiO_(3)(NBT-6BT).Our study reveals that size effect comes into play in these systems on a very large length scale(on the scale of microns)considerably affecting its global structure and properties.

关键词： Lead-free piezoelectrics Na_(0.5)Bi_(0.5)TiO_(3) size effect crystal structure depolarization temperature

Analysis of a fractional-order SIS epidemic model with saturated treatment

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International Journal of Modeling, Simulation, and Scientific Computing 2021年第1期12卷 185-212页

作者： Soovoojeet jana Manotosh Mandal Swapan kumar Nandi T.K.Kar Department of Mathematics Ramsaday College Amta-711401HowrahWest BengalIndia Department of Mathematics Tamralipta Mahavidyalaya Tamluk-721636West BengalIndia Department of Mathematics Nayabasat P.M.Sikshaniketan Paschim Medinipur-721253West BengalIndia Department of Mathematics Indian Institute of Engineering Science and Technology Shibpur Howrah-711103West BengalIndia

In this paper,we propose and analyze a fractional-order SIS epidemic model with the saturated treatment and disease *** existence and uniqueness,nonnegativity and finiteness of solutions for our suggested model have been *** equilibria of the model are found and their local and global stability analyses are also ***,the conditions for fractional backward and fractional Hopf bifurcation are also analyzed in both the commensurate and incommensurate fractional-order *** study how the control parameter and the order of the fractional derivative play role in local as well as global stability of equilibrium points and Hopf *** have demonstrated the analytical results of our proposed model system through several numerical simulations.

关键词： Caputo fractional differentiation SIS epidemic model global asymptotic stability treatment control fractional Hopf bifurcation fractional backward bifurcation

Analysis of a fuzzy epidemic model with saturated treatment and disease transmission

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International Journal of Biomathematics 2018年第1期11卷 23-40页

作者： Swapan kumar Nandi Soovoojeet jana Manotosh Manadal T. K. Kar Department of MathematicsNayabasat P. M. Sikshaniketan Paschim Medinipur 721253 West Bengal India Department of Mathematics Ramsaday College Amta 711501 West Bengal India Department of Mathematics Tamralipta MahavidyalayaTamluk 721636 West Bengal India Department of MathematicsIndian Institute of Engineering Science and Technology Shibpur Howrah 711103 West Bengal India

In this paper, we describe an SIS epidemic model where both the disease transmission rate and treatment function are considered in saturated forms. The dynamical behavior of the system is analyzed. The system is customized by considering the disease trans- mission rate and treatment control as fuzzy numbers and then fuzzy expected value of the infected individuals is determined. The fuzzy basic reproduction number is investi- gated and a threshold condition of pathogen is derived at which the system undergoes a backward bifurcation.

关键词： SIS epidemic model fuzzy expected value fuzzy basic reproduction number backward bifurcation.