125 research outputs found
Magnetic properties of amorphous Fe80-xRxB20 ( with R= Pr, Nd, Sm, Gd, Dy, Ho, Er and Tm )
Amorphous Fe80-xRxB20 alloys (with R=Pr, Nd, Sm, Gd, Dy, Ho, Er and Tm ) have been prepared by melt spinning and their magnetic properties have been studied. The Gd moment at 4.2 K is found to be 7”B which agrees with the theoretical value indicating a collinear spin structure. The moments of the other rare-earth are lower than the theoretical value, implying a conical spin structure. The mean-field theory has been used to explain the temperature dependence of the magnetization. The exchange interactions between Fe-Fe and Fe-R atom pairs have also been evaluated.Amorphous Fe80-xRxB20 alloys (with R=Pr, Nd, Sm, Gd, Dy, Ho, Er and Tm ) have been prepared by melt spinning and their magnetic properties have been studied. The Gd moment at 4.2 K is found to be 7”B which agrees with the theoretical value indicating a collinear spin structure. The moments of the other rare-earth are lower than the theoretical value, implying a conical spin structure. The mean-field theory has been used to explain the temperature dependence of the magnetization. The exchange interactions between Fe-Fe and Fe-R atom pairs have also been evaluated
Magnetization study of Ni/Ag multilayers
The magnetic properties of Ni/Ag multilayers, prepared by evaporation in ultrahigh vacuum under controlled conditions, have been systematically studied by magnetic measurements. A spin-wave theory has been used to explain the temperature dependence of the magnetization and the approximate values for the bulk exchange interaction Jb and surface exchange interaction JS for various Ni layer thicknesses have been obtained.The magnetic properties of Ni/Ag multilayers, prepared by evaporation in ultrahigh vacuum under controlled conditions, have been systematically studied by magnetic measurements. A spin-wave theory has been used to explain the temperature dependence of the magnetization and the approximate values for the bulk exchange interaction Jb and surface exchange interaction JS for various Ni layer thicknesses have been obtained
Review of Person Re-identification Techniques
Person re-identification across different surveillance cameras with disjoint
fields of view has become one of the most interesting and challenging subjects
in the area of intelligent video surveillance. Although several methods have
been developed and proposed, certain limitations and unresolved issues remain.
In all of the existing re-identification approaches, feature vectors are
extracted from segmented still images or video frames. Different similarity or
dissimilarity measures have been applied to these vectors. Some methods have
used simple constant metrics, whereas others have utilised models to obtain
optimised metrics. Some have created models based on local colour or texture
information, and others have built models based on the gait of people. In
general, the main objective of all these approaches is to achieve a
higher-accuracy rate and lowercomputational costs. This study summarises
several developments in recent literature and discusses the various available
methods used in person re-identification. Specifically, their advantages and
disadvantages are mentioned and compared.Comment: Published 201
Characterization of harbor sediments from the English Channel: assessment of heavy metal enrichment, biological effect and mobility
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.For a full assessment of the environmental risk posed by dredged sediments not only the anthropogenic enrichment of contaminants, but also their mobility and biological impact should be considered. This study reports on the enrichment factor (EF), mobility, and Adverse Effect Index (AEI) of metals and metalloids in nine dredged sediments. Significant enrichment of As, Cd, Pb and Zn with respect to background values is detected, and calculated AEI values for these elements suggest that it is possible that a corresponding biological effect may be observed. Correlation coefficients also reveal a link between mobility in HCl and enrichment for Cd, Cr, Ni, Pb and Zn, however As and Cu do not display such a link, possibly suggesting that the source of contamination for these elements is less recent. Mobility and enrichment are two parameters which are often studied separately; however this paper shows that in some cases strong correlations occur
Morphology selection of nanoparticle dispersions by polymer media
A systematic theory of ultrathin polymer films as organizing media to achieve 2D nanoparticle arrangements was developed. The key physical variables to achieve nanoparticle dispersions and control morphology were determined.open727
Memory effects in annealed hybrid gold nanoparticles/block copolymer bilayers
We report on the use of the self-organization process of sputtered gold nanoparticles on a self-assembled block copolymer film deposited by horizontal precipitation Langmuir-Blodgett (HP-LB) method. The morphology and the phase-separation of a film of poly-n-butylacrylate-block-polyacrylic acid (PnBuA-b-PAA) were studied at the nanometric scale by using atomic force microscopy (AFM) and Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS). The templating capability of the PnBuA-b-PAA phase-separated film was studied by sputtering gold nanoparticles (NPs), forming a film of nanometric thickness. The effect of the polymer chain mobility onto the organization of gold nanoparticle layer was assessed by heating the obtained hybrid PnBuA-b-PAA/Au NPs bilayer at T >Tg. The nanoparticles' distribution onto the different copolymer domains was found strongly affected by the annealing treatment, showing a peculiar memory effect, which modifies the AFM phase response of the Au NPs layer onto the polar domains, without affecting their surfacial composition. The effect is discussed in terms of the peculiar morphological features induced by enhanced mobility of polymer chains on the Au NPs layer
ANTARES: the first undersea neutrino telescope
The ANTARES Neutrino Telescope was completed in May 2008 and is the first
operational Neutrino Telescope in the Mediterranean Sea. The main purpose of
the detector is to perform neutrino astronomy and the apparatus also offers
facilities for marine and Earth sciences. This paper describes the design, the
construction and the installation of the telescope in the deep sea, offshore
from Toulon in France. An illustration of the detector performance is given
The genome of the sea urchin Strongylocentrotus purpuratus
We report the sequence and analysis of the 814-megabase genome of the sea urchin Strongylocentrotus
purpuratus, a model for developmental and systems biology. The sequencing strategy combined
whole-genome shotgun and bacterial artificial chromosome (BAC) sequences. This use of BAC clones,
aided by a pooling strategy, overcame difficulties associated with high heterozygosity of the genome.
The genome encodes about 23,300 genes, including many previously thought to be vertebrate
innovations or known only outside the deuterostomes. This echinoderm genome provides an
evolutionary outgroup for the chordates and yields insights into the evolution of deuterostomes
Environmental sensing and response genes in cnidaria : the chemical defensome in the sea anemone Nematostella vectensis
Author Posting. © The Author(s), 2008. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Cell Biology and Toxicology 24 (2008): 483-502, doi:10.1007/s10565-008-9107-5.The starlet sea anemone Nematostella vectensis has been recently established as a
new model system for the study of the evolution of developmental processes, as cnidaria
occupy a key evolutionary position at the base of the bilateria. Cnidaria play important
roles in estuarine and reef communities, but are exposed to many environmental stressors.
Here I describe the genetic components of a âchemical defensomeâ in the genome of
N. vectensis, and review cnidarian molecular toxicology. Gene families that defend
against chemical stressors and the transcription factors that regulate these genes have
been termed a âchemical defensome,â and include the cytochromes P450 and other
oxidases, various conjugating enyzymes, the ATP-dependent efflux transporters,
oxidative detoxification proteins, as well as various transcription factors. These genes
account for about 1% (266/27200) of the predicted genes in the sea anemone genome,
similar to the proportion observed in tunicates and humans, but lower than that observed
in sea urchins. While there are comparable numbers of stress-response genes, the stress
sensor genes appear to be reduced in N. vectensis relative to many model protostomes
and deuterostomes. Cnidarian toxicology is understudied, especially given the important
ecological roles of many cnidarian species. New genomic resources should stimulate the
study of chemical stress sensing and response mechanisms in cnidaria, and allow us to
further illuminate the evolution of chemical defense gene networks.WHOI Ocean Life Institute and NIH R01-ES01591
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