26,826 research outputs found
Interaction of gases with lunar materials
The surface chemistry of Apollo 17 lunar fines samples 74220 (the orange soil) and 74241 (the gray control soil) has been studied by measuring the adsorption of nitrogen, argon, and oxygen (all at 77 K) and also water vapor (at 20 or 22 C). In agreement with results for samples from other missions, both samples had low initial specific surface areas, consisted of nonporous particles, and were attacked by water vapor at high relative pressure to give an increased specific surface area and create a pore system which gave rise to a capillary condensation hysteresis loop in the adsorption isotherms. In contrast to previous samples, both of the Apollo 17 soils were partially hydrophobic in their initial interaction with water vapor (both samples were completely hydrophilic after the reaction with water). The results are consistent with formation at high temperatures without subsequent exposure to significant amounts of water
Interaction of gases with lunar materials
Quantitative efforts to assess the surface properties of lunar fines, particularly water induced porosity are discussed. Data show that: (1) changes induced in lunar fines are not visible in high energy electron micrographs, (2) scanning micrographs show no change in particle size distribution as a result of reaction with water, (3) water induced changes are internal to the particles themselves, (4) normal laboratory atmosphere blocks alteration reaction with water, and (5) surface properties of mature lunar soils appear to be almost independent of chemical composition and mineralogy, but there are some variations in their reactivity toward water
Circuit breaker cases
A flammable plastic part was duplicated dimensionally using a nonflammable material in place of the flammable plastic. The material used was L-3203-6 with a 16-hour post-cure at 400 F. Initial efforts were made to determine shrinkage tolerances required to produce a mold which would produce a finished, workable part. The final twenty-five circuit breaker cases were shipped and the metal inserts when installed, produced a workable breaker. Initial submissions of cases were rejected as lacking sufficient rigidity though they met all other requirements. The plastic cases weighed 16.5 grams, whereas the Refset cases weighed 17 grams, not meeting the less-weight requirement. The data on shrinkage determinations, and mold and part dimensions are shown. The method of manufacture is also reported
Quantum signatures of chaos in the dynamics of a trapped ion
We show how a nonlinear chaotic system, the parametrically kicked nonlinear
oscillator, may be realised in the dynamics of a trapped, laser-cooled ion,
interacting with a sequence of standing wave pulses. Unlike the original
optical scheme [G.J.Milburn and C.A.Holmes, Phys. Rev A, 44, p4704, (1991)],
the trapped ion enables strongly quantum dynamics with minimal dissipation.
This should permit an experimental test of one of the quantum signatures of
chaos; irregular collapse and revival dynamics of the average vibrational
energy.Comment: 9 pages, 9 Postscript figures, Revtex, submitted to Phys. Rev.
Interdisciplinary Dissertation Research Among Public Health Doctoral Trainees, 2003-2015
Given the call for more interdisciplinary research in public health, the objectives of this study were to (1) examine the correlates of interdisciplinary dissertation completion and (2) identify secondary fields most common among interdisciplinary public health graduates.
METHODS:
We analyzed pooled cross-sectional data from 11 120 doctoral graduates in the Survey of Earned Doctorates, 2003-2015. The primary outcome was interdisciplinary dissertation completion. Covariates included primary public health field, sociodemographic characteristics, and institutional attributes.
RESULTS:
From 2003 to 2015, a total of 4005 of 11 120 (36.0%) doctoral graduates in public health reported interdisciplinary dissertations, with significant increases observed in recent years. Compared with general public health graduates, graduates of environmental health (odds ratio [OR] = 1.74; P < .001) and health services administration (OR = 1.38; P < .001) doctoral programs were significantly more likely to report completing interdisciplinary dissertation work, whereas graduates from biostatistics (OR = 0.51; P < .001) and epidemiology (OR = 0.76; P < .001) were less likely to do so. Completing an interdisciplinary dissertation was associated with being male, a non-US citizen, a graduate of a private institution, and a graduate of an institution with high but not the highest level of research activity. Many secondary dissertation fields reported by interdisciplinary graduates included other public health fields.
CONCLUSION:
Although interdisciplinary dissertation research among doctoral graduates in public health has increased in recent years, such work is bounded in certain fields of public health and certain types of graduates and institutions. Academic administrators and other stakeholders may use these results to inform greater interdisciplinary activity during doctoral training and to evaluate current and future collaborations across departments or schools
Reimagining quality in early childhood [Editorial]
This special issue brings together a collection of rich, complex and challenging contributions that attempt to offer generative approaches to reconfigure what might constitute ‘quality’ within early years education. The issue came about from a shared concern about what Moss (this issue) refers to as the ‘gravitational pull’ of quality in early childhood education; debates about quality have existed for a considerable time and, despite rigorous critique, remain resolute. This issue aims to revisit and extend the groundbreaking work undertaken by Gunilla Dahlberg, Peter Moss and Alan Pence (1999, 2007) in Beyond Quality in Early Childhood Education and Care: Postmodern Perspectives and in the subsequent revised edition. In both texts, the authors made the astute observation that the concept and language of quality cannot accommodate issues such as diversity and multiple perspectives, contextual specificity and subjectivity. They argue that we must ‘go beyond the concept of quality’ (Dahlberg et al., 2007: 6) and, in so doing, suggest working with a new concept: ‘meaning making’
‘Lots of Black people are on meds because they're seen as aggressive’: STOMP, COVID-19 and anti-racism in community learning disability services
Background
The STOMP agenda (Stopping Over-Medication of People with learning disabilities, autism, or both) drew focus to individuals with a diagnosis of a learning disability being prescribed psychotropic medication to manage ‘behaviours that challenge’. The following study is an audit of two community learning disability services in the London boroughs of Westminster and Kensington and Chelsea for compliance with national guidance on the use of medication in this population, the impact of the COVID-19 pandemic, and equality, diversity and anti-racism.
Method
Routinely collected data were audited relating to clients identified in each service, totalling 54 participants. Data were audited against five standards: minimum effective dose, medication reviews, alternative multidisciplinary input, the impact of the COVID-19 pandemic and equality, diversity and anti–racism. Comparisons were made to the overall caseload (N = 365) where appropriate.
Results
Evidence demonstrated a greater risk of receiving psychotropic medication to manage behaviours that challenge for service users from racialised backgrounds, further evidencing institutional and/or individualised racism within practice for this population. Prescriptions also increased in dosage during the COVID-19 pandemic exacerbated by insufficient provision of alternative input and regular multi-disciplinary review as required by national guidance.
Conclusions
Community learning disability teams require dedicated, co-produced STOMP pathways to review those at risk of over-medication. Additional research is required to explore individual and systemic factors contributing to ethnic disparities in medication prescription for behaviours that challenge among people with learning disabilities. Further recommendations are considered around developing data collection, service user involvement, and future directions.Accessible summary:
- Abuse at care home (Winterbourne View) led the NHS to start a campaign known as STOMP to make sure people with learning disabilities and/or autism got the right medication.
- We looked at the medications people with learning disabilities in our area were given. We looked at how often these medications were checked by a doctor. We looked at what other support people were given.
- We also looked at how people with learning disabilities were affected by COVID-19. We also looked at differences between people from different racial backgrounds.
- We found that some people were given more medications to manage their behaviour. We found that the medications were not checked as often as they should be. This happened most for Black, Brown, and Asian people.
- We spoke to a local service user project about our findings. They said they think racism is one of the reasons for more medications. They also said it is bad that people are on too much medication and that people should get more support
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