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Morphology of single inhalable particle inside public transit biodiesel fueled bus

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Journal of Environmental Sciences 2010年第2期22卷 263-270页

作者： k.ushik.k.Shandilya Ashok.kumar Department of Civil Engineering The University of Toledo

In an urban-transit bus, fueled by biodiesel in Toledo, Ohio, single inhalable particle samples in October 2008 were collected and detected by scanning electron microscopy and energy dispersive X-ray spectrometry （SEM/EDS）. Particle size analysis found bimodal distribution at 0.2 and 0.5 μm. The particle morphology was characterized by 14 different shape clusters： square, pentagon, hexagon, heptagon, octagon, nonagon, decagon, agglomerate, sphere, triangle, oblong, strip, line or stick. and unk.own, by quantitative order. The square particles were common in the samples. Round and triangle particles are more, and pentagon, hexagon, heptagon, octagon, nonagon, decagon, strip, line or stick. are less. Agglomerate particles were found in abundance. The surface of most particles was coarse with a fractal edge that can provide a suitable chemical reaction bed in the polluted atmospheric environment. The three sorts of surface patterns of squares were smooth, semi-smooth, and coarse. The three sorts of square surface patterns represented the morphological characteristics of single inhalable particles in the air inside the bus in Toledo. The size and shape distribution results were compared to those obtained for a bus using ultra low sulfur diesel.

关键词： individual particle environmental scanning electron microscope urban-public transit bus ultra low sulfur diesel

Dielectric, piezoelectric, and ferroelectric properties of lanthanum-modified PZTFN ceramics

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International Journal of Minerals,Metallurgy and Materials 2014年第10期21卷 1019-1027页

作者： Arvind kumar S.k.Mishra Research and Technology Development Centre Sharda University Dr. Harisingh Gour University

Specimens of Pb1-1.5xLax（Zr0.53 Ti0.47）1-y-zFeyNb2O3 （x = 0, 0.004, 0.008, 0.012, and 0.016, y = z = 0.01）（PZTFN） ceramics were synthesized by a semi-wet route. In the present study, the effect of La doping was investigated on the structural, microstructural, dielectric, piezoelectric, and ferroelectric properties of the ceramics. The results show that, the tetragonal （space group P4mm） and rhombohedral （space group R3c） phases are observed to coexist in the sample at x = 0.012. Microstructural investigations of all the samples reveal that La doping inhibits grain growth. Doping of La into PZTFN improves the dielectric, ferroelectric, and piezoelectric properties of the ceramics. The hys- teresis loops of all specimens exhibit nonlinear behavior. The dielectric, piezoelectric and ferroelectric properties show a maximum response atx 〉 0.012, which corresponds to the morphotropic phase boundary （MPB）.

关键词： ceramics lanthanum doping dielectric properties piezoelectricity ferroelectricity Rietveld refinement hysteresis loops

Investigation of magnetic, optical and electrical properties of La_3Ba_3Cu_6O_(14) synthesized by molten flux method

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Journal of Rare Earths 2015年第12期33卷 1341-1347页

作者： k.Agilandeswari A.Ruban kumar Department of Chemistry Auxilium College School of Advanced Sciences VIT University

The great deal of novel rare earth based semiconducting lanthanum barium copper oxide La3Ba3Cu6OI4 （LBC-336） were synthesized by low temperature molten salt synthesis （MSS） due to ＂dissolution precipitation mechanism＂. Here, we reported one pot synthesis of product by direct precipitation from a molten k.H-NaOH mixnare at 450 ℃ and single phase La3Ba3Cu6014 with tetragonal crystal system. The particle size of 140-200 nm were observed in both PXRD pattern and HRSEM micrographs and it showed a cubic morphology. The semiconducting nature was extracted from various parameters lik. optical band gap （1.8 eV）, AC conductivity （0.70 eV）, DC conductivity （0.70 eV）, and also Hall effect parameters lik. the charge carrier concentration values n=6,0x 1026 m-3 and it proved as a p-type semiconductor. The electrical phase trasition temperature from ferroelectric to antiferroelec- tric system （Tin=420 k. and anti-ferroelectric - paraelectric system （depolarization temperature Ta=673 k. which attributed to the space charge polarization contributed to the conduction mechanism. The magnetic phase transitions were from ferromagnetic to ferrimagnetic system （Curie temperature （Tc=70 k.） and it led to soft magnetic material and also held good for superconductor appli- cation upto 70 k.

关键词： molten flux synthesis band gap phase transitions semiconductor superconductors rare earths

Impedance and ferroelectric properties of Sr^(2+) modified PZT-PMN ceramics

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International Journal of Minerals,Metallurgy and Materials 2014年第6期21卷 595-603页

作者： Arvind kumar S.k.Mishra Research and Technology Development Centre Sharda University Dr. Harisingh Gour University

Sr^2＋ modified polycrystalline PZT-PMN ceramics were synthesized by a semi-wet route. Impedance spectroscopy studies indicate the bulk.and grain boundary effects of PZT-PMN material along with the negative temperature coefficient of resistance. The bulk.conductiv-ity exhibits an Arrhenius-type thermally activated hopping process which is supported by the AC conductivity behavior as a function of fre-quency and temperature. It is observed that the remnant polarization increases with an increase in the Sr2＋content in PZT-PMN.

关键词： piezoelectric ceramics ferroelectric materials ferroelectricity electrochemical properties strontium

Barnyard millet global core collection evaluation in the submontane Himalayan region of India using multivariate analysis

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The Crop Journal 2015年第6期3卷 517-525页

作者： Salej Sood Rajesh k.k.ulbe Arun kumar R. Pawan k. Agrawal Hari D.Upadhyaya Indian Council of Agricultural Research-Vivek.nanda Institute of Hill Agriculture International Crop Research Institute for the Semi-Arid Tropics (ICRISAT)

Barnyard millet(Echinochloa spp.) is one of the most underresearched crops with respect to characterization of genetic resources and genetic enhancement. A total of 95 germplasm lines representing global collection were evaluated in two rainy seasons at Almora,Uttarak.and, India for qualitative and quantitative traits and the data were subjected to multivariate analysis. High variation was observed for days to maturity, five-ear grain weight, and yield components. The first three principal component axes explained 73% of the total multivariate variation. Three major groups were detected by projection of the accessions on the first two principal components. The separation of accessions was based mainly on trait morphology. Almost all Indian and origin-unk.own accessions grouped together to form an Echinochloa frumentacea group. Japanese accessions grouped together except for a few outliers to form an Echinochloa esculenta group. The third group contained accessions from Russia, Japan, Cameroon, and Egypt. They formed a separate group on the scatterplot and represented accessions with lower values for all traits except basal tiller number. The interrelationships between the traits indicated that accessions with tall plants, long and broad leaves, longer inflorescences, and greater numbers of racemes should be given priority as donors or parents in varietal development initiatives. Cluster analysis identified two main clusters based on agro-morphological characters.

关键词： Agro-morphological variation Barnyard millet core germplasm Cluster analysis Echinochloa spp Principal component analysis

Effects of Sr^(2+) substitution on the structural, dielectric, and piezoelectric properties of PZT-PMN ceramics

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International Journal of Minerals,Metallurgy and Materials 2014年第2期21卷 175-180页

作者： Arvind kumar S.k. Mishra Research and Technology Development Centre Sharda University

This study described the structural, dielectric, and piezoelectric behavior of Pb1-xSrx[（Zr0.52Ti0.48）0.95（Mn1/3Nb2/3）0.05]O3 ceramics （PSZT-PMN, x=0, 0.025, 0.050, and 0.075）, prepared by a semi-wet route. X-ray diffraction, dielectric, and piezoelectric investigations were carried out to analyze the crystal structure. The relative dielectric constant and dielectric loss were both calculated as the functions of temperature. The room-temperature dielectric constant reaches a maximum for a Sr2＋-modified PZT-PMN ceramic with an x value of 0.050, which corresponds to the morphotropic phase boundary （MPB）. Raman spectroscopy studies also confirm the existence of this MPB for x=0.050. The piezoelectric strain coefficients （d33） value shows a maximum response for this composition. In addition, the phase transition temperature decreases significantly when the Sr2＋concentration increases in the PZT-PMN ceramics.

关键词： ceramic materials strontium substitution structural properties dielectric properties piezoelectricity

Effect of multiple rings on side force over an ogive-cylinder body at subsonic speed

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Chinese Journal of Aeronautics 2018年第6期31卷 1181-1188页

作者： Priyank.kumar J.k.PRASAD Department of Space Engineering & Rock.try Birla Institute of Technology

Experiments and computations were performed over an ogive-cylinder body having an lift-to-drag ratio of 16 at a diameter Reynolds number of 29000. The side force on the slender body augments with increasing angles of attack.for the case without a ring. This increase was mainly due to the increase in the asymmetry of the existing vortex pair in the wak. of the body. Attempts were made to completely reduce the existing side force at the angle of attack.ranging from 35° to 45°.Three rectangular cross-sectioned circumferential rings having a height of 3% of the local diameter were placed at axial distances of 2.5, 3.5 and 4.5 times the base diameter from the tip of the body so as to reduce the side force. The results obtained indicate that inclusion of three rings completely alleviated the side force on the slender body at the angle of attack.ranging from 0° to 45°. The presence of rings was found to alter the growth of the vortices that helped in the reduction of the side force. Computations performed were in reasonable agreement with the experiments.

关键词： Asymmetric vortex High angle of attack Ogive Side force Slender body Vortex lift

Bed dynamics of gas-solid fluidized bed with rod promoter

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China Particuology 2007年第4期5卷 261-266页

作者： Awadhesh kumar Gopendra k.Roy Department of Civil Engineering National Institute of TechnologyRourkela 769008OrissaIndia Department of Chemical Engineering National Institute of TechnologyRourkela 769008OrissaIndia

The dynamic characteristics of a gas-solid fluidized bed with different rod promoters have been investigated in terms of bed expansion and fluctuation, minimum fluidization velocity and distributor-to-bed pressure drop ratio at minimum fluidization velocity. Experimentation based on statistical design has been carried out and model equations using factorial design of experiments have been developed for the above mentioned quantities for a promoted gas-solid fluidized bed. The model equations have been tested with additional experimental data. The system variables include four types of rod promoters of varying block.ge volume, bed particles of four sizes and four initial static bed heights. A comparison between the predicted values of the output variables using the proposed model equation with their corresponding experimental ones shows fairly good agreement.

关键词： Dynamic characteristics Statistical design Gas-solid fluidization Rod promoter

Soy Protein Isolate Film by Incorporating Mandelic Acid as Well as Through Fermentation Mediated by Bacillus Subtilis

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Journal of Renewable Materials 2019年第2期7卷 103-115页

作者： Rak.sh kumar Priya Rani k.Dinesh kumar Department of Biotechnology Central University of South BiharGaya-824236India Department of Materials Science&Engineering Indian Institute of TechnologyPatna 801106India

Soy protein isolate(SPI)biopolymeric films were prepared by adding different contents of mandelic acid(1 to 5%wrt SPI)to glycerol plasticized SPI by solution casting ***,SPI was fermented by Bacillus subtilis to get fermented SPI films by solution *** mass determination of mandelic acid incorporated and fermented SPI films was carried out by sodium dodecyl sulphate-polyacrylamide gel electrophoresis(SDS-PAGE).Mandelic acid incorporated and fermented SPI films were characterized by Fourier-transform infrared spectroscopy(FT-IR),dynamic mechanical analysis(DMA),tensile strength,water uptak. and optical transmittance *** indicated that incorporation of mandelic acid in SPI resulted in high tensile strength(8.03 MPa)and highα-relaxation(Tα)as well as low water *** the other hand,films cannot be prepared from fermented SPI with SPI contents of 8%and 12%.However,film from fermented SPI with 16%SPI content could be prepared but it exhibited low tensile strength(3.18 MPa)and low Tαas well as high water *** resulting mandelic acid incorporated SPI films were also subjected to antimicrobial *** all the concentration of mandelic acid,we can easily observe the antimicrobial effect in mandelic acid incorporated SPI films unlik. fermented SPI *** work.will be helpful in fabricating antimicrobial SPI film from renewable resources.

关键词： Soy protein isolate mandelic acid fermentation film tensile properties antimicrobial properties