712 research outputs found
Dipole-Field Contributions to Geometric-Phase-Induced False Electric-Dipole Moment Signals for Particles in Traps
It has been shown in an earlier publication that magnetic field gradients
applied to particles in traps can induce Larmor frequency shifts that may
falsely be interpreted as electric-dipole moment (EDM) signals. This study has
now been extended to include nonuniform magnetic field gradients due to the
presence of a local magnetic dipole. It is found that, in the high
orbit-frequency regime, the magnitude of the shifts can be enhanced beyond the
simple expectation of proportionality to the volume-averaged magnetic-field
gradient.Comment: 2 pages, no figure
Gravitationally enhanced depolarization of ultracold neutrons in magnetic-field gradients
Trapped ultracold neutrons (UCN) have for many years been the mainstay of experiments to search for the electric dipole moment (EDM) of the neutron, a critical parameter in constraining scenarios of new physics beyond the Standard Model. Because their energies are so low, UCN preferentially populate the lower region of their physical enclosure, and do not sample uniformly the ambient magnetic field throughout the storage volume. This leads to a substantial increase in the rate of depolarization, as well as to shifts in the measured frequency of the stored neutrons. Consequences for EDM measurements are discussed
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Normal mode Rossby waves and their effects on chemical composition in the late summer stratosphere
During past MANTRA campaigns, ground-based measurements of several long-lived chemical species have revealed quasi-periodic fluctuations on time scales of several days. These fluctuations could confound efforts to detect long-term trends from MANTRA, and need to be understood and accounted for. Using the Canadian Middle Atmosphere Model, we investigate the role of dynamical variability in the late summer stratosphere due to normal mode Rossby waves and the impact of this variability on fluctuations in chemical species. Zonal wavenumber 1, westward travelling waves are considered with average periods of 5, 10 and 16 days. Time-lagged correlations between the temperature and nitrous oxide, methane and ozone fields are calculated in order to assess the possible impact of these waves on the chemical species. Using Fourier-wavelet decomposition and correlating the fluctuations between the temperature and chemical fields, we determine that variations in the chemical species are well-correlated with the 5- and 10-day waves between 30 and 60 km, although the nature of the correlations depend strongly on altitude. Interannual variability of the waves is also examined
Needle exchange services in Knowsley: An investigation into the needs and experiences of staff and service users
This work was commissioned by Knowsley Council to inform the development of needle exchange (NEX) services in Knowsley and to ensure that they meet the needs of people who inject drugs (PWID) locally. The views and experiences of both service users and staff from drug services and pharmacies offering needle exchange services in Knowsley were sought regarding the extent to
which NEX are meeting the needs of PWID including their perceptions regarding the support available, NEX accessibility and service delivery. Findings are considered in the context of NICE guidelines on the optimal provision of needle and syringe programmes in England
“Once you’ve been there, you’re always recovering”: exploring experiences, outcomes, and benefits of substance misuse recovery
Purpose – Recovery is a central component of UK substance misuse policy, however, relatively little is known about the views and meanings of recovery by those experiencing it. The purpose of this paper is to explore these factors, and understand how service user experiences align to current understandings of “recovery capital”. Design/methodology/approach – This paper draws on qualitative interviews with 32 individuals from six UK recovery communities, including those commissioned by a statutory service (n=8) and a peer-led recovery community (n=24). Findings – Meanings of recovery differed between people in abstinence-based communities and those not; however, all had consistent views on their own recovery outcomes and the benefits they believed recovery brought. All viewed recovery as a process; a continuous journey with no end-point. Internal motivation, peer support, social networks and daily structure were integral to supporting individuals achieve and maintain recovery. Key benefits of recovery reflected recovery capital and included positive relationships, sense of belonging, increased self-worth and confidence, employment and education. Research limitations/implications – This research shows that recovery experiences and outcomes are not centred entirely on the individual but are wider, more holistic. Maintaining recovery involves being connected to themselves and to the wider environment: family, friends, peers and society. Although the recovery capital model has many elements that were discussed by the participants of this research, the discourse they used does not align with the model. To validly measure and quantify recovery outcomes, individuals need to identify with the measures themselves. Practical implications – From policy and commissioning perspectives, these findings suggest benefits of recovery that were viewed by participants as indicators of success: demonstrate elements which support recovery; and highlight key social value outcomes which people attribute to recovery. Social implications – These “softer”, qualitative benefits should be considered by policy-makers, commissioners, statutory and non-statutory services in order to evidence outcomes. However, it should also be recognised that a temporally static approach to assessing recovery may be in contradiction to the meaning and perspectives held by those in recovery communities who conceptualise it as a long term and ongoing process. Originality/value – This paper adds to understandings of experiences and meanings of recovery, with a particular focus on the measurement of outcomes and their meanings, and the role of abstention and continued drug use within the recovery process. © 2016, Emerald Group Publishing Limited
The Student Wellbeing Process Questionnaire (Student WPQ)
Recent research has used short questionnaires based on single item versions of
psychosocial concepts to assess well-being. This has largely been confined to
occupational samples and the present article describes the extension of this
process to university students. The Student Well-being Process Questionnaire
(Student WPQ) was used to examine predictors of positive well-being, negative
mental health and cognitive function. An online survey was used with 478
first and second year undergraduates as participants. Regression analyses
showed that positive well-being (e.g. happiness, positive affect and life satisfaction)
was predicted by positive personality (high optimism, self-esteem and
self-efficacy), high social support and low stressors and low negative coping
scores. Negative outcomes (e.g. perceived stress, anxiety and depression) were
predicted by high stressor, coping and conscientiousness scores, and low positive
personality and social support scores. Cognitive problems were predicted
by high stressor and negative coping scores and low positive personality
scores. A MANOVA showed that there were no significant interactions between
the predictor variables. The best predictor of all outcomes was a combined
score including all predictor variables. Overall, the present study shows
that the Student WPQ can provide useful information on predictors of different
aspects of well-being. Future research can include additional potential
predictors and other outcomes to determine whether other factors are significant
when established predictors are adjusted for
Quasielastic scattering in the interaction of ultracold neutrons with a liquid wall and application in a reanalysis of the Mambo I neutron-lifetime experiment
We develop a theory of ultracold and very cold neutron scattering on viscoelastic surface waves up to second-order perturbation theory. The results are applied to reanalyze the 1989 neutron-lifetime experiment using ultracold neutron storage in a Fomblin-coated vessel by Mampe et al. [Phys. Rev. Lett. 63, 593 (1989)]. Inclusion of this theory of the quasielastic scattering process in the data analysis shifts the neutron lifetime value from 887.6 ± 3 to 882.5 ± 2.1 s
Neutron Lifetime Measured with Stored Ultracold Neutrons
The neutron lifetime has been measured by counting the neutrons remaining in a fluid-walled bottle as a function of the duration of storage. Losses of neutrons caused by the wall reflections are eliminated by varying the bottle volume-to-surface ratio. The result obtained is τβ=887.6±3 s
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