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      • Rapid thermal annealing induced modification in structural and electronic structure properties of Ti<sub>0.95</sub>Co<sub>0.05</sub>O<sub>2@?δ</sub> thin films

        Rodrigues, E.C.,Sharma, S.K.,de Menezes, A.S.,Chae, K.H.,Gautam, S.,Aljawf, R.N.,Kumar, S. Pergamon Press 2016 Materials research bulletin Vol.83 No.-

        Thin film of Ti<SUB>0.95</SUB>Co<SUB>0.05</SUB>O<SUB>2-δ</SUB> was deposited on Si (100) using PLD method and annealed in O<SUB>2</SUB> and N<SUB>2</SUB> environment. Raman spectra confirm that all the films have rutile structure. Surface morphology indicates that the surface roughness and grain size increase with annealing. The electronic structure studied by NEXAFS spectroscopy at O K, Ti L<SUB>3,2</SUB> and Co L<SUB>3,2</SUB>-edges revealed that peak intensities decrease significantly for the film annealed N<SUB>2</SUB> environment. The ligand-field splitting estimated from the energy difference between the t<SUB>2g</SUB> and e<SUB>g</SUB> features in O K-edge spectra were 2.71eV for as-deposited and O<SUB>2</SUB> annealed film, whereas reduced more than double (@?1.32eV) for the film annealed in N<SUB>2</SUB>. Atomic multiplet calculations and experimentally observed NEXAFS spectra at Co L<SUB>3,2</SUB>-edge and Ti L<SUB>3,2</SUB>-edge confirm that Co present in 2+ and Ti in +4 valence state, whereas the multiplet structures of O<SUB>2</SUB> annealed film looks similar to Co metal.

      • SCISCIESCOPUS

        ARRAKIS: atlas of resonance rings as known in the S<sup>4</sup>G

        Comeró,n, S.,Salo, H.,Laurikainen, E.,Knapen, J. H.,Buta, R. J.,Herrera-Endoqui, M.,Laine, J.,Holwerda, B. W.,Sheth, K.,Regan, M. W.,Hinz, J. L.,Muñ,oz-Mateos, J. C.,Gil de Paz, A.,Men&eac Springer-Verlag 2014 Astronomy and astrophysics Vol.562 No.-

        <P>Context. Resonance rings and pseudorings (here collectively called rings) are thought to be related to the gathering of material near dynamical resonances caused by non-axisymmetries in galaxy discs. This means that they are the result of secular evolution processes that redistribute material and angular momentum in discs. Studying them may give clues on the formation and growth of bars and other disc non-axisymmetries. Aims. Our aims are to produce a catalogue and an atlas of the rings detected in the Spitzer Survey of Stellar Structure in Galaxies (S<SUP>4</SUP>G) and to conduct a statistical study of the data in the catalogue. Methods. We traced the contours of rings previously identified and fitted them with ellipses. We found the orientation of bars by studying the galaxy ellipse fits from the S<SUP>4</SUP>G pipeline 4. We used the galaxy orientation data obtained by the S<SUP>4</SUP>G pipeline 4 to obtain intrinsic ellipticities and orientations of rings and the bars. Results. ARRAKIS contains data on 724 ringed galaxies in the S<SUP>4</SUP>G. The frequency of resonance rings in the S<SUP>4</SUP>G is of 16 ±1% and 35 ±1% for outer and inner features, respectively. Outer rings are mostly found in Hubble stages −1 ≤T≤ 4. Inner rings are found in a broad distribution that covers the range −1 ≤T≤7. We confirm that outer rings have two preferred orientations, namely parallel and perpendicular to the bar. We confirm a tendency for inner rings to be oriented parallel to the bar, but we report the existence of a significant fraction (maybe as large as 50%) of inner features that have random orientations with respect to the bar. These misaligned inner rings are mostly found in late-type galaxies (T ≥4). We find that the fraction of barred galaxies hosting outer (inner) rings is ~1.7 times (~1.3 times) that in unbarred galaxies. Conclusions. We confirm several results from previous surveys as well as predictions from simulations of resonant rings and/or from manifold flux tube theory. We report that a significant fraction of inner rings in late-type galaxies have a random orientation with respect to the bar. This may be caused by spiral modes that are decoupled from the bar and dominate the Fourier amplitude spectrum at the radius of the inner ring. The fact that rings are only mildly favoured by bars suggests that those in unbarred galaxies either formed because of weak departures from the axisymmetry of the galactic potential or that they are born because of bars that were destroyed after the ring formation.</P>

      • KCI등재

        Rheological characteristics of coal–water slurry using microwave pretreatment – A statistical approach

        B.K. Sahoo,B.C. Meikap,S. De,M. Carsky 한국공업화학회 2011 Journal of Industrial and Engineering Chemistry Vol.17 No.1

        The present study addresses the treatment of microwave energy for rheological characteristics of coal–water slurries (CWS) performed in an online Bohlin viscometer. Detailed experimental investigations were carried out for high ash Indian coal (Jamadoba washery, 38% ash). Experiments were conducted at high power level (900 W) for all the test samples in microwave oven. The exposure times were fixed at 30, 60, 90 and 120 s. Before and after treatment, the test samples were ground and sieved into different fractions for chemical and physical analysis. Central composite design (CCD) was applied to study the influence of particle diameter, solid concentration, microwave (MW) exposure time and shear rate on apparent viscosity for rheology characteristics of coal–water slurry. A quadratic model was developed for apparent viscosity using Design-Expert software. The model was used to calculate the optimum operating conditions for minimization of apparent viscosity. The apparent viscosity (22.83 mPa s)produced at these operating conditions showed an excellent agreement with the amounts predicted by the models.

      • Expression profile of cystatin B ortholog from Manila clam (Ruditapes philippinarum) in host pathology with respect to its structural and functional properties

        Premachandra, H.K.A.,Elvitigala, D.A.S.,Whang, I.,Kim, E.,De Zoysa, M.,Lim, B.S.,Yeo, S.Y.,Kim, S.,Park, M.A.,Park, H.C.,Lee, J. Academic Press 2013 Fish & shellfish immunology Vol.34 No.6

        Cystatins are a well-characterized group of cysteine protease inhibitors, which play crucial roles in physiology and immunity. In the present study, an invertebrate ortholog of cystatin B was identified in Manila clam (Ruditapes philippinarum) (RpCytB) and characterized at the molecular level, demonstrating its inhibitory activity against the well-known cysteine protease, papain. The complete coding sequence of RpCytB (297 bp in length) encodes a 99 amino acid peptide with a calculated molecular mass of 11 kDa and a theoretical isoelectric point of 5.9. The derived peptide was found to harbor typical features of cystatin proteins, including the 'Q-X-V-X-G' motif, which was identified as QLVAG in RpCytB. Phylogenetic analysis of RpCytB revealed close evolutionary relationships with its invertebrate counterparts, especially those from mollusks. Recombinant RpCytB (rRpCytB) was overexpressed as a fusion with maltose binding protein (MBP) in Escherichia coli BL21 (DE3) cells. Purified rRpCytB fusion protein exhibited a detectable inhibitory activity against papain, while the control MBP showed an almost constant negligible activity. While quantitative RT-PCR detected ubiquitous RpCytB expression in all tissues examined, the expressions in hemocytes and gills were relatively higher. Upon in vivo immune challenge with lipopolysaccharide (LPS), the expression of RpCytB in gills and hemocytes was down-regulated. Similar challenges with poly I:C and intact Vibrio tapetis bacteria revealed a complicated transcriptional regulation, wherein mRNA expression levels fluctuated over time of exposure. Moreover, a precise induction of RpCytB expression after bacterial infection was detected in gills by in situ hybridization. Collectively, our findings in this study indicate that RpCytB expression is sensitive to host pathological conditions and may contribute cysteine protease inhibitory activity to modulate the immune response.

      • The SAURON project – XIII. SAURON–GALEX study of early-type galaxies: the ultraviolet colour–magnitude relations and Fundamental Planes

        Jeong, Hyunjin,Yi, Sukyoung K.,Bureau, Martin,Davies, Roger L.,Falcó,n-Barroso, Jesú,s,van de Ven, Glenn,Peletier, Reynier F.,Bacon, Roland,Cappellari, Michele,de Zeeuw, Tim,Emsellem, Eric Blackwell Publishing Ltd 2009 Monthly notices of the Royal Astronomical Society Vol.398 No.4

        <P>ABSTRACT</P><P>We present <I>Galaxy Evolution Explorer</I> far-ultraviolet (FUV) and near-ultraviolet (NUV) imaging of 34 nearby early-type galaxies from the SAURON representative sample of 48 E/S0 galaxies, all of which have ground-based optical imaging from the MDM Observatory. The surface brightness profiles of nine galaxies (≈26 per cent) show regions with blue UV−optical colours suggesting RSF. Five of these (≈15 per cent) show blue integrated UV–optical colours that set them aside in the NUV integrated colour–magnitude relation. These are objects with either exceptionally intense and localized NUV fluxes or blue UV−optical colours throughout. They also have other properties confirming they have had RSF, in particular Hβ absorption higher than expected for a quiescent population and a higher CO detection rate. This suggests that residual star formation is more common in early-type galaxies than we are used to believe. NUV blue galaxies are generally drawn from the lower stellar velocity dispersion (σ<SUB>e</SUB> < 200 km s<SUP>−1</SUP>) and thus lower dynamical mass part of the sample. We have also constructed the first UV Fundamental Planes and show that NUV blue galaxies bias the slopes and increase the scatters. If they are eliminated, the fits get closer to expectations from the virial theorem. Although our analysis is based on a limited sample, it seems that a dominant fraction of the tilt and scatter of the UV Fundamental Planes is due to the presence of young stars in preferentially low-mass early-type galaxies. Interestingly, the UV–optical radial colour profiles reveal a variety of behaviours, with many galaxies showing signs of RSF, a central UV-upturn phenomenon, smooth but large-scale age and metallicity gradients and in many cases a combination of these. In addition, FUV−NUV and FUV−<I>V</I> colours even bluer than those normally associated with UV-upturn galaxies are observed at the centre of some quiescent galaxies. Four out of the five UV-upturn galaxies are slow rotators. These objects should thus pose interesting challenges to stellar evolutionary models of the UV upturn.</P>

      • Differential cross section of @?n@?K<sup>+</sup>@?<sup>@?</sup> on bound neutrons with incident photons from 1.1 to 3.6 GeV

        CLAS Collaboration,Pereira, S.A.,Mirazita, M.,Rossi, P.,De Sanctis, E.,Niculescu, G.,Niculescu, I.,Stepanyan, S.,Adhikari, K.P.,Aghasyan, M.,Anghinolfi, M.,Baghdasaryan, H.,Ball, J.,Battaglieri, M.,Be North-Holland Pub. Co 2010 Physics letters: B Vol.688 No.4

        <P>Differential cross sections of the reaction gamma d -> K+Sigma(-)(p) have been measured with the CLAS detector at Jefferson Lab using incident photons with energies between 1.1 and 3.6 GeV. This is the first complete set of strangeness photoproduction data on the neutron covering a broad angular range. At energies close to threshold and up to E-gamma similar to 1.8 GeV. the shape of the angular distribution is suggestive of the presence of s-channel production mechanisms. For E-gamma > 1.8 GeV, a clear forward peak appears and becomes more prominent as the photon energy increases, suggesting contributions from t-channel production mechanisms. These data can be used to constrain future analysis of this reaction. (c) 2010 Elsevier B.V. All rights reserved.</P>

      • KCI등재

        Antimicrobial property of lemongrass (Cymbopogon citratus) oil against pathogenic bacteria isolated from pet turtles

        B.C.J. De Silva,정원기,사브리나 호세인,S.H.M.P. Wimalasena,H.N.K.S. Pathirana,허강준 한국실험동물학회 2017 Laboratory Animal Research Vol.33 No.2

        The usage of essential oils as antimicrobial agents is gaining attention. Besides, pet turtles were known to harbor a range of pathogenic bacteria while the turtle keeping is a growing trend worldwide.The current study examined the antimicrobial activity of lemon grass oil (LGO) against seven species of Gram negative bacteria namely; Aeromonas hydrophila, A. caviae, Citrobacter freundii, Salmonella enterica, Edwardsiella tarda, Pseudomonas aeruginosa, and Proteus mirabilis isolated from three popular species of pet turtles. Along with the results of disc diffusion, minimum inhibitory and minimum bactericidal concentration (MIC and MBC) tests, LGO was detected as effective against 6 species of bacteria excluding P. aeruginosa. MIC of LGO for the strains except P. aeruginosa ranged from 0.016 to 0.5% (V/V). The lowest MIC recorded in the E. tarda strain followed by A. hydrophilla, C. freundii, P. mirabilis, and S. enterica. Interestingly, all the bacterial species except E. tarda were showing high multiple antimicrobial resistance (MAR) index values ranging from 0.36 to 0.91 upon the 11 antibiotics tested although they were sensitive to LGO.

      • Neogene dinoflagellate cysts and acritarchs from the high northern latitudes and their relation to sea surface temperature

        Schreck, M.,Nam, S.I.,Clotten, C.,Fahl, K.,De Schepper, S.,Forwick, M.,Matthiessen, J. Elsevier Scientific Pub. Co 2017 Marine micropaleontology Vol.136 No.-

        Organic-walled dinoflagellate cysts and acritarchs are a vital tool for reconstructing past environmental change, in particular in the Neogene of the high northern latitudes where marine deposits are virtually barren of traditionally used calcareous microfossils. Yet only little is known about the paleoenvironmental value of fossil assemblages that do not have modern analogues, so that reconstructions remain qualitative. Thus, extracting their paleoecological signals still poses a major challenge, in particular on pre-Quaternary timescales. Here we unravel the relationship between species relative abundance and sea surface temperature for extinct dinoflagellate cyst and acritarch taxa from the Neogene of the Iceland Sea using palynological assemblages and organic geochemical (alkenone) data generated from the same set of samples. The reconstructed temperatures for the Miocene to Pliocene sequence of Ocean Drilling Program Site 907 range from 3 to 26<SUP>o</SUP>C and our database consists of 68 dinoflagellate cyst and acritarch samples calibrated to alkenone data. The temperature range of five extant species co-occurring in the fossil assemblage agrees well with their present-day distribution providing confidence to inferred temperature ranges for extinct taxa. The 14 extinct dinoflagellate cyst and acritarch species clearly exhibit a temperature dependency in their occurrence throughout the analysed section. The dinoflagellate cyst species Batiacasphaera hirsuta, Labyrinthodinium truncatum, Cerebrocysta irregulare, Cordosphaeridium minimum, Impagidinium elongatum and Operculodinium centrocarpum s.s., and the acritarch Lavradosphaera elongatum, which are confined to the Miocene, have highest relative abundances and restricted temperature ranges at the warm end of the reconstructed temperature spectrum. The latter five species disappear when Iceland Sea surface temperatures permanently drop below 20<SUP>o</SUP>C, thus indicating a distinct threshold on their occurrence. In contrast, species occurring in both the Miocene and Pliocene interval (Batiacasphaera micropapillata, Habibacysta tectata, Reticulatosphaera actinocoronata, Cymatiosphaera? invaginata) show a broader temperature range and a tolerance towards cooler conditions. Operculodinium? eirikianum may have a lower limit on its occurrence at around 10<SUP>o</SUP>C. The calibration of species relative abundance versus reconstructed sea surface temperature provides a quantitative assessment of temperature ranges for extinct Miocene to Pliocene species indicating that temperature is a decisive ecological factor for regional extinctions that may explain the frequently observed asynchronous highest occurrences across different ocean basins. It demonstrates that qualitative assessments of ecological preferences solely based on (paleo) biogeographic distribution should be treated with caution. In addition to enhancing knowledge on marine palynomorph paleoecology, this study ultimately improves the application of palynomorphs for paleoenvironmental reconstructions in the Neogene of the Arctic and subarctic seas, a region essential for understanding past global climate.

      • KCI등재

        Quinolone susceptibility and genetic characterization of Salmonella enterica subsp. enterica isolated from pet turtles

        B.C.J. De Silva,사브리나 호세인,S.H.M.P. Wimalasena,H.N.K.S. Pathirana,Mitchell Wendt,허강준 한국실험동물학회 2017 Laboratory Animal Research Vol.33 No.2

        Turtle-borne Salmonella enterica owns significance as a leading cause in human salmonellosis. The current study aimed to determine the quinolone susceptibility and the genetic characteristics of 21 strains of S. enterica subsp. enterica isolated from pet turtles. Susceptibility of four antimicrobials including nalidixic acid, ciprofloxacin, ofloxacin, and levofloxacin was examined in disk diffusion and MIC tests where the majority of the isolates were susceptible to all tested quinolones. In genetic characterization, none of the isolates were positive for qnr or aac(6’)-Ib genes and no any target site mutations could be detected in gyrA, gyrB, and parC quinolone resistance determining regions (QRDR). In addition, neighborjoining phylogenetic tree derived using gyrA gene sequences exhibited two distinct clads comprising; first, current study isolates, and second, quinolone-resistant isolates of human and animal origin. All results suggest that studied strains of S. enterica subsp. enterica isolated from pet turtles are susceptible to quinolones and genetically more conserved with regards to gyrA gene region.

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