11,510 research outputs found
Meeting the needs of adult mentally disordered offenders
It is essential that those responsible for commissioning special services for mentally disordered offenders (MDOs) take a whole systems approach to the assessment of need and planning of services. National statistics are no
substitute for regional and local surveys that collect data on local populations for whom services are being planned.
The results of research carried out under the auspices of The Wessex Consortium supplemented by some earlier community studies have been used to form a robust assessment of need upon which to base a local strategy for
managing MDOs.
Ten publications are submitted, representing a number of projects designed to identify the broad area of need of MDOs, ranging from secure hospital care to
various aspects of community care. Although there is an extensive literature on MDOs and their needs, most studies concentrate on secure hospital provision and fail to cover the fuller range of services required to provide a more comprehensive response to need.
The submitted works as a whole, represent a unique account of a spectrum of needs of MDOs from a defmed geographical area with some contributions having a more generalised importance. While some of the work has been undertaken by others elsewhere, the results are not directly comparable due to methodological differences, different sample groups/populations, etc.
Some of the studies are now being replicated in other parts of the country and the outcome of the research has supported a number of service developments within The Wessex Consortium area and the formation of national policy in
respect of forensic psychiatry
Ultraviolet and X-ray variability of NGC 4051 over 45 days with XMM-Newton and Swift
We analyse 15 XMM-Newton observations of the Seyfert galaxy NGC 4051 obtained
over 45 days to determine the ultraviolet (UV) light curve variability
characteristics and search for correlated UV/X-ray emission. The UV light curve
shows variability on all time scales, however with lower fractional rms than
the 0.2-10 keV X-rays. On days-weeks timescales the fractional variability of
the UV is Fvar ~ 8%, and on short (~ hours) timescales Fvar ~ 2%. The
within-observation excess variance in 4 of the 15 UV observations was found be
much higher than the remaining 11. This was caused by large systematic
uncertainties in the count rate masking the intrinsic source variance. For the
four "good" observations we fit an unbroken power-law model to the UV power
spectra with slope -2.0 +/- 0.5. We compute the UV/X-ray Cross-correlation
function for the "good" observations and find a correlation of ~ 0.5 at time
lag of ~ 3 ks, where the UV lags the X-rays. We also compute for the first time
the UV/X-ray Cross-spectrum in the range 0-28.5 ks, and find a low coherence
and an average time lag of ~ 3 ks. Combining the 15 XMM-Newton and the Swift
observations we compute the DCF over +/-40 days but are unable to recover a
significant correlation. The magnitude and direction of the lag estimate from
the 4 "good" observations indicates a scenario where ~ 25 % of the UV variance
is caused by thermal reprocessing of the incident X-ray emission.Comment: 11 pages, 8 figures. Accepted for publication in MNRA
The flux-dependent X-ray time lags in NGC 4051
We present an analysis of the X-ray time lags for the highly variable Seyfert
1 galaxy NGC 4051, based on a series of XMM-Newton observations taken in 2009.
We investigate the Fourier frequency dependent time lags in the light curves
between the 0.3--1.0 keV and 2.0--5.0 keV energy bands as a function of source
flux, including simultaneous modelling of the resulting lag-frequency spectra.
We find the shape of the lag-frequency spectra to vary significantly and
systematically with source flux. We model the lag-frequency spectra using
simple transfer functions, and find that two time lag components are required,
one in each energy band. The simplest acceptable fits have only the relative
contribution of the lagged component in the hard band varying with flux level,
which can be associated with changes in the energy spectrum. We discuss the
interpretation of these results in terms of the currently popular models for
X-ray time lags.Comment: 9 pages, 4 figures. Accepted for publication in MNRA
Coronal Line Emission from NLS1s
We discuss the optical coronal line spectra observed for a sample of 19
Narrow-Line Seyfert 1 galaxies. We find no correlation between the coronal line
strength and the soft X-ray power-law index derived from ROSAT PSPC data. There
is a trend for broader coronal lines to have larger equivalent widths. In
addition, a strong trend is found between line width and velocity relative to
the NLR. This trend is interpreted in terms of a decelerating outflow,
originating close to the nucleus.Comment: Contributed talk presented at the Joint MPE,AIP,ESO workshop on
NLS1s, Bad Honnef, Dec. 1999, to appear in New Astronomy Reviews; also
available at http://wave.xray.mpe.mpg.de/conferences/nls1-worksho
On characterising the variability properties of X-ray light curves from active galaxies
We review some practical aspects of measuring the amplitude of variability in
`red noise' light curves typical of those from Active Galactic Nuclei (AGN).
The quantities commonly used to estimate the variability amplitude in AGN light
curves, such as the fractional rms variability amplitude, F_var, and excess
variance, sigma_XS^2, are examined. Their statistical properties, relationship
to the power spectrum, and uses for investigating the nature of the variability
processes are discussed. We demonstrate that sigma_XS^2 (or similarly F_var)
shows large changes from one part of the light curve to the next, even when the
variability is produced by a stationary process. This limits the usefulness of
these estimators for quantifying differences in variability amplitude between
different sources or from epoch to epoch in one source. Some examples of the
expected scatter in the variance are tabulated for various typical power
spectral shapes, based on Monte Carlo simulations. The excess variance can be
useful for comparing the variability amplitudes of light curves in different
energy bands from the same observation. Monte Carlo simulations are used to
derive a description of the uncertainty in the amplitude expected between
different energy bands (due to measurement errors). Finally, these estimators
are used to demonstrate some variability properties of the bright Seyfert 1
galaxy Markarian 766. The source is found to show a strong, linear correlation
between rms amplitude and flux, and to show significant spectral variability.Comment: 14 pages. 12 figures. Accepted for publication in MNRA
New polyimide polymer has excellent processing characterisitcs with improved thermo-oxidative and hydrolytic stabilities
Polyimide P10P and its processing technique apply to most high temperature plastic products, devices and castings. Prepolymer, when used as varnish, impregnates fibers directly and is able to be processed into advanced composities. Material may also be used as molding powder and adhesive
A Comparison of Electrical Breakdown Characteristics of Composite Materials Prepared With Unmodified Micro and Nano Scale Barium Titanate
High permittivity polymer matrix composites (PMCs) have been widely researched, especially in the field of microelectronics. For this study, high permittivity materials were investigated for their potential to form part of a multi-layer electric field detector. The two main requirements for such composites were high permittivity and a dielectric strength comparable to most standard polymers used as dielectric materials. Polystyrene was selected as a host polymer due to its high dielectric strength and amorphous structure. Barium titanate, a ferroelectric ceramic from the perovskite family, was selected as a high permittivity filler. Polymer permittivity in PMCs is usually orders of magnitude lower compared to the filler permittivity, although the resultant permittivity of the composite is generally markedly lower than the permittivity of the filler may suggest. This is because very little energy is stored in the ceramic filler, such that any increase in composite permittivity is due to an increase in the average field with the polymer matrix.[1]Micro and nano scale barium titanate was blended into polystyrene in an effort to discern the initial differences between composites prepared with the two different filler types. It was found that the micro scale barium titanate was well dispersed and from studying SEM micrographs, appeared to have a good particle size distribution. The nanoscale barium titanate was found to be very poorly dispersed in polystyrene, with a wide particle size distributions formed of weakly bound aggregations and some seemingly chemically bonded agglomerations which were regular in shape with a surface texture which was indicative of tightly bound primary particles. Consistent with the differences in particle dispersion within the micro and nano composites, there was a marked difference in AC breakdown strength between the different materials. All electrical breakdown data was analysed using a 2 parameter Weibull distribution. Figure 1 compares the ? values for the micro and nano composites at different filler loadings.<br/
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