208 research outputs found
Bi-spectral beam extraction in combination with a focusing feeder
Bi-spectral beam extraction combines neutrons from two different kind of
moderators into one beamline, expanding the spectral range and thereby the
utilization of an instrument. This idea can be realized by a mirror that
reflects long wavelength neutrons from an off-axis colder moderator into a
neutron guide aligned with another moderator emitting neutrons with shorter
wavelengths which will be transmitted through the mirror. The mirror used in
such systems is typically several meters long, which is a severe disadvantage
because it reduces the possible length of a focusing device in design concepts
requiring a narrow beam at a short distance from the source, as used in many
instruments under development for the planned European Spallation Source (ESS).
We propose a shortened extraction system consisting of several mirrors, and
show that such an extraction system is better suited for combination with a
feeder in an eye of the needle design, illustrated here in the context of a
possible ESS imaging beamline.Comment: Published in Nuclear Instruments and Methods in Physics Research,
Section
Computer simulation tests of optimized neutron powder diffractometer configurations
Recent work has developed a new mathematical approach to optimally choose beam elements for constant wavelength neutron powder diffractometers. This article compares Monte Carlo computer simulations of existing instruments with simulations of instruments using configurations chosen using the new approach. The simulations show that large performance improvements over current best practice are possible. The tests here are performed on instruments optimized for samples with a cubic structure which differs from the optimization for triclinic structure samples. A novel primary spectrometer design is discussed and simulation tests show that it performs as expected and allows a single instrument to operate flexibly over a wide range of measurement resolutio
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Motherhood, Moral Authority and the Charismatic Matriarch in the Aftermath of Lethal Violence
Images of maternal suffering are an evocative and powerful means of communication in a world where the private grief of victims has increasingly become subject to commodification and public consumption. This article looks at the influence of bereaved mothers as symbols of respect, peace and dignity in the aftermath of violence, and as a result their persuasive presence in family activism. Drawing upon two case studies, this article explores the importance of victims’ stories in public life and, in particular, the presence of the charismatic matriarch in creating communities of solidarity, raising awareness of harms that have previously gone unheard and prompting policy change. It considers the ‘canonical’ story of the mother in public life and concludes by arguing that more attention should be paid to victims’ stories and their influence on policy-making, politics and eventually in becoming public grievances
Patterns of Injury in Homicide Relationships: Clinical, Psychological, and Investigative Implications
Despite accounting for only 1.3% of all violent crime, homicide still, perhaps more than ever, garners widespread fascination. It has long been recognized as a complex event characterized by variations in behavioral style, level of violence, motivation, and personal interaction. Mixed findings and methodological variation (i.e., lack of standardized method of measuring injury severity, sampling bias, varying definitions of victim-offender relationships) regarding severity of wounding and victim-offender relationship highlight the need for more empirical research. The importance of considering multiple elements of a crime when attempting to obtain a psychological understanding of victim-offender dynamics has been neglected. In an effort to respond to these shortcomings, the current study employed a series of multinomial logistic regressions to examine various demographic and offense characteristics across a nonrandom, national U.S. sample of 242 homicide cases reflecting a variety of homicide subtypes and victim-offender relationships. Findings support the assertion that severe facial wounding is associated with more intimate relationships. While additional findings suggest that variations in wounding do indeed exist between relationships and homicide types, caution should be taken by investigators due to nuanced differences related to frequency and severity of wounds
Consistency and flexibility in solving spatial tasks: different horses show different cognitive styles
Individual animals vary in their behaviour and reactions to novel situations. These differences may extend to differences in cognition among individuals. We tested twenty-six horses for their ability to detour around symmetric and asymmetric obstacles. All of the animals were able to get around the barrier to reach a food target, but varied in their approach. Some horses moved slowly but were more accurate in choosing the shortest way. Other horses acted quickly, consistently detoured in the same direction, and did not reliably choose the shortest way. The remaining horses shifted from a faster, directionally consistent response with the symmetric barrier, to a slower but more accurate response with the asymmetric barrier. The asymmetric barrier induced a reduction in heart rate variability, suggesting that this is a more demanding task. The different approaches used to solve the asymmetric task may reflect distinct cognitive styles in horses, which vary among individuals, and could be linked to different personality traits. Understanding equine behaviour and cognition can inform horse welfare and management
Effect of synthesis conditions on formation pathways of metal organic framework (MOF-5) Crystals
Metal Organic Frameworks (MOFs) represent a class of nanoporous crystalline materials with far reaching potential in gas storage, catalysis, and medical devices. We investigated the effects of synthesis process parameters on production of MOF-5 from terephthalic acid and zinc nitrate in diethylformamide. Under favorable synthesis conditions, we systematically mapped a solid formation diagram in terms of time and temperature for both stirred and unstirred conditions. The synthesis of MOF-5 has been previously reported as a straightforward reaction progressing from precursor compounds in solution directly to the final MOF-5 solid phase product. However, we show that the solid phase formation process is far more complex, invariably transferring through metastable intermediate crystalline phases before the final MOF-5 phase is reached, providing new insights into the formation pathways of MOFs. We also identify process parameters suitable for scale-up and continuous manufacturing of high purity MOF-5
Health-related quality of life of children with attention-deficit/hyperactivity disorder versus children with diabetes and healthy controls
The impact of attention-deficit/hyperactivity disorder (ADHD) on health-related quality of life (HRQoL) is reported to be similar to that of other mental health and physical disorders. In this cross-sectional study, we hypothesized that children with ADHD and children with type 1 diabetes mellitus (T1DM) would have significantly worse HRQoL compared with healthy children, and that better clinical status in ADHD and T1DM would be associated with better HRQoL. Children were recruited from three outpatient services in Scotland. Responses to two frequently used validated HRQoL instruments, the Paediatric Quality of Life Inventory (PedsQL) and Child Health and Illness Profile-child edition (CHIP-CE), were obtained from parents/carers and children (6–16 years) with/without ADHD or T1DM. Child and parent/carer-completed HRQoL measurements were evaluated for 213 children with ADHD, 58 children with T1DM and 117 healthy children (control group). Significantly lower self and parent/carer ratings were observed across most PedsQL (P < 0.001) and CHIP-CE (P < 0.05) domains (indicating reduced HRQoL) for the ADHD group compared with the T1DM and control groups. Parent/carer and child ratings were significantly correlated for both measures of HRQoL (PedsQL total score: P < 0.001; CHIP-CE all domains: P < 0.001), but only with low-to-moderate strength. Correlation between ADHD severity and HRQoL was significant with both PedsQL and CHIP-CE for all parent/carer (P < 0.01) and most child (P < 0.05) ratings; more ADHD symptoms were associated with poorer HRQoL. These data demonstrate that ADHD has a significant impact on HRQoL (as observed in both parent/carer and child ratings), which seems to be greater than that for children with T1DM
An accessible Secondary Electron Hyperspectral Imaging approach to draw meaningful insights from scanning electron microscopy
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