723 research outputs found
The interfacial, emulsification and encapsulation properties of hydrophobically modified inulin
Octenyl- and dodecenyl succinic anhydride derivatives (OSA- and DDSA-) of inulin have been synthesised and their solution and interfacial properties have been determined and compared to a commercially available alkylated inulin, Inutec SP1. All samples formed micellar aggregates in solution above a critical concentration (critical aggregation concentration) and were able to ‘dissolve’ a hydrophobic dye. They were also able to form stable oil-in-water (O/W) emulsions as assessed by measurements of their droplet size as a function of time. DDSA-inulin with a high degree of substitution was found to be effective at encapsulating beta carotene using the solvent evaporation method which yielded a solid which dissolved readily in simulated gastric fluid. The results confirm the potential application of these materials in a number of areas including, drug delivery, pharmaceuticals, neutraceuticals, cosmetics and personal care
Observations of flux rope ? associated particle bursts with GEOTAIL in the distant tail
International audienceGeotail energetic particle, magnetic field data and plasma observations (EPIC, MGF and CPI experiments) have been examined for a number of energetic particle bursts in the distant tail (120ReGSM|By and/or Bz components, is consistent with the existence of closed field lines extending from Earth and wrapping around the core of the flux rope structure
Measuring the Broad-band X-Ray Spectrum from 400 eV to 40 keV in the Southwest Part of the Supernova Remnant RX J1713.7-3946
We report on results from Suzaku broadband X-ray observations of the
southwest part of the Galactic supernova remnant (SNR) RX J1713.7-3946 with an
energy coverage of 0.4-40 keV. The X-ray spectrum, presumably of synchrotron
origin, is known to be completely lineless, making this SNR ideally suited for
a detailed study of the X-ray spectral shape formed through efficient particle
acceleration at high speed shocks. With a sensitive hard X-ray measurement from
the HXD PIN on board Suzaku, we determine the hard X-ray spectrum in the 12--40
keV range to be described by a power law with photon index Gamma = 3.2+/- 0.2,
significantly steeper than the soft X-ray index of Gamma = 2.4+/- 0.05 measured
previously with ASCA and other missions. We find that a simple power law fails
to describe the full spectral range of 0.4-40 keV and instead a power-law with
an exponential cutoff with hard index Gamma = 1.50+/- 0.09 and high-energy
cutoff epsilon_c = 1.2+/- 0.3 keV formally provides an excellent fit over the
full bandpass. If we use the so-called SRCUT model, as an alternative model, it
gives the best-fit rolloff energy of epsilon_{roll} = 0.95+/- 0.04 keV.
Together with the TeV gamma-ray spectrum ranging from 0.3 to 100 TeV obtained
recently by HESS observations, our Suzaku observations of RX J1713.7-3946
provide stringent constraints on the highest energy particles accelerated in a
supernova shock.Comment: 11 pages, 11 figures, accepted for publication in Publications of the
Astronomical Society of Japan (PASJ
X-ray Temperature and Mass Measurements to the Virial Radius of Abell 1413 with Suzaku
We present X-ray observations of the northern outskirts of the relaxed galaxy
cluster A1413 with Suzaku, whose XIS instrument has the low intrinsic
background needed to make measurements of these low surface brightness regions.
We excise 15 point sources superimposed on the image above a flux of \fluxunit (2--10keV) using XMM-Newton and Suzaku images of the
cluster. We quantify all known systematic errors as part of our analysis, and
show our statistical errors encompasses them for the most part. Our results
extend previous measurements with Chandra and XMM-Newton, and show a
significant temperature drop to about 3keV at the virial radius, . Our
entropy profile in the outer region () joins smoothly onto that
of XMM-Newton, and shows a flatter slope compared with simple models, similar
to a few other clusters observed at the virial radius. The integrated mass of
the cluster at the virial radius is approximately
and varies by about 30% depending on the particular method used to measure it.Comment: 32pages, 9 figures, accepted for publication in PAS
Resonant Inelastic X-Ray Scattering at the K Edge of Ge
We study the resonant inelastic x-ray scattering (RIXS) at the edge of
Ge. We measure RIXS spectra with systematically varying momenta in the final
state. The spectra are a measure of exciting an electron-hole pair. We find a
single peak structure (except the elastic peak) as a function of photon energy,
which is nearly independent of final-state momenta. We analyze the experimental
data by means of the band structure calculation. The calculation reproduces
well the experimental shape, clarifying the implication of the spectral shape.Comment: 17 pages,9 figures, Please also see our related paper:
cond-mat/040500
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