Welding and Diffusion Bonding : METHODS OF STUDY AND REGULATION OF WELDING STRESSES AND STRAINS IN ADVANCED STRUCTURES

LOBANOV Leonid Mikhailovich 대한금속재료학회 ( 구 대한금속학회 ) 1995 Advanced Material and Processing Vol.1 No.-

Dynamically Induced Anomalies of the Japan/East Sea Surface Temperature

Trusenkova, Olga,Lobanov, Vyacheslav,Kaplunenko, Dmitry Korea Institute of Ocean ScienceTechnology 2009 Ocean and Polar Research Vol.31 No.1

Variability of sea surface temperature (SST) in the Japan/East Sea (JES) was studied using complex empirical orthogonal function (CEOF) analysis. Two daily data sets were analyzed: (1) New Generation 0.05o-gridded SST from Tohoku University, Japan (July 2002-July 2006), and (2) 0.25o-gridded SST from the Japan Meteorological Agency (October 1993-November 2006). Linkages with wind stress curl were revealed using 6-h 1o-gridded surface zonal and meridional winds from ancillary data of the Sea- WiFS Project, a special National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) product (1998-2005). SST anomalies (SSTA) were obtained by removing the seasonal signal, estimated as the leading mode of the CEOF decomposition of the original SST. Leading CEOF modes of residual SSTA obtained from both data sets were consistent with each other and were characterized by annual, semiannual, and quasi-biennial time scales estimated with 95% statistical significance. The Semiannual Mode lagged 2 months behind the increased occurrence of the anticyclonic (AC) wind stress curl over the JES. Links to dynamic processes were investigated by numerical simulations using an oceanic model. The suggested dynamic forcings of SSTA are the inflow of subtropical water into the JES through the Korea Strait, divergence in the surface layer induced by Ekman suction, meridional shifts of the Subarctic Front in the western JES, AC eddy formation, and wind-driven strengthening/weakening of large-scale currents. Events of west-east SSTA movement were identified in July-September. The SSTA moved from the northeastern JES towards the continental coast along the path of the westward branch of the Tsushima Current at a speed consistent with the advective scale.

PHOTOMETRIC DECOMPOSITION OF MERGERS IN DISK GALAXIES

Mezcua, M.,Lobanov, A. P.,Mediavilla, E.,Karouzos, M. IOP Publishing 2014 The Astrophysical journal Vol.784 No.1

<P>Several observational studies and numerical simulations suggest that mergers must contribute to the evolution of galaxies; however, the role that they play is not yet fully understood. In this paper we study a sample of 52 double nucleus disk galaxies that are considered as candidates for a minor merger event. The luminosity of each of the nuclei and their relative separation are derived from a multi-component photometric fit of the galaxies in the Sloan Digital Sky Survey optical images. We find that the nuclei in most of the sources have projected separations <= 4 kpc. The ratio of nuclear luminosities indicates that most of the systems are likely in the coalescence stage of a major merger. This is supported by the existence of a single galaxy disk in 65% of the systems studied and the finding of a correlation between nuclear luminosity and host luminosity for the single-disk systems: those sources fitted with as single disk are in a more evolved stage of the merger and present an enhancement of the nuclear luminosity compared to the double-disk systems, as expected from simulations of galaxy mergers. Finally, we identify a sample of 19 double nucleus disk galaxies in which the two nuclei are physically separated by <= 1 kpc and constitute thus a sample of sub-kpc binary active galactic nucleus candidates.</P>

Acceleration of Relativstic Jets on Sub-parsec Scales

Sang-Sung Lee,Andrei Lobanov,Thomas P. Krichbaum,J. Anton Zensus 한국천문학회 2016 天文學會報 Vol.41 No.1

A History of Physical Oceanographic Research in the Japan/East Sea

Danchenkov, M. A.,Lobanov, V. B.,Riser, S. C.,Kim, K.,Takematsu, M.,Yoon, J.-H. The Oceanographic Society 2006 OCEANOGRAPHY -WASHINGTON DC- OCEANOGRAPHY SOCIETY- Vol.19 No.3

Dynamically Induced Anomalies of the Japan/East Sea Surface Temperature

Olga Trusenkova,Vyacheslav Lobanov,Dmitry Kaplunenko 한국해양과학기술원 2009 Ocean and Polar Research Vol.31 No.1

Variability of sea surface temperature (SST) in the Japan/East Sea (JES) was studied using complex empirical orthogonal function (CEOF) analysis. Two daily data sets were analyzed: (1) New Generation 0.05˚-gridded SST from Tohoku University, Japan (July 2002-July 2006), and (2) 0.25˚-gridded SST from the Japan Meteorological Agency (October 1993-November 2006). Linkages with wind stress curl were revealed using 6-h 1˚-gridded surface zonal and meridional winds from ancillary data of the Sea-WiFS Project, a special National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) product (1998-2005). SST anomalies (SSTA) were obtained by removing the seasonal signal, estimated as the leading mode of the CEOF decomposition of the original SST. Leading CEOF modes of residual SSTA obtained from both data sets were consistent with each other and were characterized by annual, semiannual, and quasi-biennial time scales estimated with 95% statistical significance. The Semiannual Mode lagged 2 months behind the increased occurrence of the anticyclonic (AC) wind stress curl over the JES. Links to dynamic processes were investigated by numerical simulations using an oceanic model. The suggested dynamic forcings of SSTA are the inflow of subtropical water into the JES through the Korea Strait, divergence in the surface layer induced by Ekman suction, meridional shifts of the Subarctic Front in the western JES, AC eddy formation, and wind-driven strengthening/weakening of large-scale currents. Events of west-east SSTA movement were identified in July-September. The SSTA moved from the northeastern JES towards the continental coast along the path of the westward branch of the Tsushima Current at a speed consistent with the advective scale. Variability of sea surface temperature (SST) in the Japan/East Sea (JES) was studied using complex empirical orthogonal function (CEOF) analysis. Two daily data sets were analyzed: (1) New Generation 0.05˚-gridded SST from Tohoku University, Japan (July 2002-July 2006), and (2) 0.25˚-gridded SST from the Japan Meteorological Agency (October 1993-November 2006). Linkages with wind stress curl were revealed using 6-h 1˚-gridded surface zonal and meridional winds from ancillary data of the Sea-WiFS Project, a special National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) product (1998-2005). SST anomalies (SSTA) were obtained by removing the seasonal signal, estimated as the leading mode of the CEOF decomposition of the original SST. Leading CEOF modes of residual SSTA obtained from both data sets were consistent with each other and were characterized by annual, semiannual, and quasi-biennial time scales estimated with 95% statistical significance. The Semiannual Mode lagged 2 months behind the increased occurrence of the anticyclonic (AC) wind stress curl over the JES. Links to dynamic processes were investigated by numerical simulations using an oceanic model. The suggested dynamic forcings of SSTA are the inflow of subtropical water into the JES through the Korea Strait, divergence in the surface layer induced by Ekman suction, meridional shifts of the Subarctic Front in the western JES, AC eddy formation, and wind-driven strengthening/weakening of large-scale currents. Events of west-east SSTA movement were identified in July-September. The SSTA moved from the northeastern JES towards the continental coast along the path of the westward branch of the Tsushima Current at a speed consistent with the advective scale.

Global millimeter VLBI array survey of ultracompact extragalactic radio sources at 86 GHz

Nair, Dhanya G.,Lobanov, Andrei P.,Krichbaum, Thomas P.,Ros, Eduardo,Zensus, Johann Anton,Kovalev, Yuri Y.,Lee, Sang-Sung,Mertens, Florent,Hagiwara, Yoshiaki,Bremer, Michael,Lindqvist, Michael,de Vice Springer-Verlag 2019 Astronomy and astrophysics Vol.622 No.-

<P><I>Context</I>. Very long baseline interferometry (VLBI) observations at 86 GHz (wavelength, <I>λ</I> = 3 mm) reach a resolution of about 50 <I>μ</I>as, probing the collimation and acceleration regions of relativistic outflows in active galactic nuclei (AGN). The physical conditions in these regions can be studied by performing 86 GHz VLBI surveys of representative samples of compact extragalactic radio sources.</P><P><I>Aims</I>. To extend the statistical studies of compact extragalactic jets, a large global 86 GHz VLBI survey of 162 compact radio sources was conducted in 2010-2011 using the Global Millimeter VLBI Array (GMVA).</P><P><I>Methods</I>. The survey observations were made in a snapshot mode, with up to five scans per target spread over a range of hour angles in order to optimize the visibility coverage. The survey data attained a typical baseline sensitivity of 0.1 Jy and a typical image sensitivity of 5 mJy beam<SUP>−1</SUP>, providing successful detections and images for all of the survey targets. For 138 objects, the survey provides the first ever VLBI images made at 86 GHz. Gaussian model fitting of the visibility data was applied to represent the structure of the observed sources and to estimate the flux densities and sizes of distinct emitting regions (components) in their jets. These estimates were used for calculating the brightness temperature (<I>T</I>b) at the jet base (core) and in one or more moving regions (jet components) downstream from the core. These model-fit-based estimates of <I>T</I>b were compared to the estimates of brightness temperature limits made directly from the visibility data, demonstrating a good agreement between the two methods.</P><P><I>Results</I>. The apparent brightness temperature estimates for the jet cores in our sample range from 2.5 × 10<SUP>9</SUP> K to 1.3 × 10<SUP>12</SUP> K, with the mean value of 1.8 × 10<SUP>11</SUP> K. The apparent brightness temperature estimates for the inner jet components in our sample range from 7.0 × 10<SUP>7</SUP> K to 4.0 × 10<SUP>11</SUP> K. A simple population model with a single intrinsic value of brightness temperature, <I>T</I>0, is applied to reproduce the observed distribution. It yields <I>T</I>0 = (3.77−0.14<SUP>+0.10</SUP>) × 10<SUP>11</SUP> K for the jet cores, implying that the inverse Compton losses dominate the emission. In the nearest jet components, <I>T</I>0 = (1.42−0.19<SUP>+0.16</SUP>) × 10<SUP>11</SUP> K is found, which is slightly higher than the equipartition limit of ∼5 × 10<SUP>10</SUP> K expected for these jet regions. For objects with sufficient structural detail detected, the adiabatic energy losses are shown to dominate the observed changes of brightness temperature along the jet.</P>

ACCELERATION OF COMPACT RADIO JETS ON SUB-PARSEC SCALES

Lee, Sang-Sung,Lobanov, Andrei P.,Krichbaum, Thomas P.,Zensus, J. Anton American Astronomical Society 2016 The Astrophysical journal Vol.826 No.2

<P>Jets of compact radio sources are highly relativistic and Doppler boosted, making studies of their intrinsic properties difficult. Observed brightness temperatures can be used to study the intrinsic physical properties of relativistic jets, and constrain models of jet formation in the inner jet region. We aim to observationally test such inner jet models. The very long baseline interferometry (VLBI) cores of compact radio sources are optically thick at a given frequency. The distance of the core from the central engine is inversely proportional to the frequency. Under the equipartition condition between the magnetic field energy and particle energy densities, the absolute distance of the VLBI core can be predicted. We compiled the brightness temperatures of VLBI cores at various radio frequencies of 2, 8, 15, and 86 GHz. We derive the brightness temperature on sub-parsec scales in the rest frame of the compact radio sources. We find that the brightness temperature increases with increasing distance from the central engine, indicating that the intrinsic jet speed (the Lorentz factor) increases along the jet. This implies that the jets are accelerated in the (sub-)parsec regions from the central engine.</P>

A Global 86 GHz VLBI Survey of Compact Radio Sources

S.-S. Lee,A.P. Lobanov,T.P. Krichbaum,A. Witzel,J.A. Zensus 한국천문학회 2006 天文學會報 Vol.31 No.2

Gene expression defines natural changes in mammalian lifespan

Fushan, Alexey A,Turanov, Anton A,Lee, Sang-Goo,Kim, Eun Bae,Lobanov, Alexei V,Yim, Sun Hee,Buffenstein, Rochelle,Lee, Sang-Rae,Chang, Kyu-Tae,Rhee, Hwanseok,Kim, Jong-So,Yang, Kap-Seok,Gladyshev, Vad BLACKWELL PUBLISHING 2015 AGING CELL Vol.14 No.3

<P>Mammals differ more than 100-fold in maximum lifespan, which can be altered in either direction during evolution, but the molecular basis for natural changes in longevity is not understood. Divergent evolution of mammals also led to extensive changes in gene expression within and between lineages. To understand the relationship between lifespan and variation in gene expression, we carried out RNA-seq-based gene expression analyses of liver, kidney, and brain of 33 diverse species of mammals. Our analysis uncovered parallel evolution of gene expression and lifespan, as well as the associated life-history traits, and identified the processes and pathways involved. These findings provide direct insights into how nature reversibly adjusts lifespan and other traits during adaptive radiation of lineages.</P>