1,099 research outputs found
Performance of 2 1/4 Cr-1 Mo steel in a coal liquefaction dissolver vessel environment
Smooth-bar and notched-bar tensile specimens of bainitic 2 1/4 Cr-1 Mo steel were exposed with and without an applied stress to argon gas or to a coal slurry-H(,2) environment for various conditions of time, temperature and pressure. Room temperature mechanical properties determined after each coal slurry-H(,2) exposure were compared to those of like samples exposed to the same conditions in argon. The coal slurry exposures produced very little change in the room temperature mechanical properties even after 1000 hours at temperatures as high as 426(DEGREES)C and total pressures of 27.6 MPa;Corrosion samples were exposed in both the liquid phase and the gaseous phase above the coal slurry-H(,2) environment. Scale growth rates, electron microprobe analyses and X-ray analyses of the scale region were obtained;Smooth-bar and notched-bar tensile specimens of normalized and tempered (bainitic) 2 1/4 Cr-1 Mo steel were exposed to hydrogen gas at 5.2 to 27.6 MPa in the temperature range from 482(DEGREES) to 593(DEGREES)C. Exposed samples were in three conditions: unloaded, with an applied load, or lightly prestrained. Applied stress, plastic deformation and increasing exposure times all lowered the temperature, at any given pressure, for the formation of hydrogen attack bubbles. The results have been plotted on Nelson Curve coordinates;Fatigue crack growth tests were conducted on normalized and tempered (bainitic) 2 1/4 Cr-1 Mo steel. Crack growth rates were determined for near threshold to intermediate growth rate regions at room temperature and 427(DEGREES)C. Testing was done in a partial vacuum, moist air, hydrogen and coal slurry gases. Crack growth rates for various hydrogen pressures were examined. The results suggest that corrosion products of the coal slurry gases may mitigate the tendency of hydrogen to enhance fatigue crack growth. Possible mechanisms are suggested;J integral tests were performed to determine JIC on normalizedand tempered (bainitic) 2 1/4 Cr-1 Mo steel. J values were obtainedfrom deep cracked compact tension specimens using single andmultiple specimen techniques. Testing was carried out in vacuum,argon, hydrogen and coal slurry gases at 427(DEGREES)C. Single specimentests were made using an electropotential crack growthmeasurement system described in detail. Values of J(,IC) for the singlespecimen tests are compared to those obtained from the multiple;specimen tests;(\u271)DOE Report IS-T-1024. This work was performed under ContractW-7405-Eng-82 with the Department of Oil, Gas, and Energy
"New" and distributed leadership in quality and safety in healthcare, or "old" and hierarchical? : An interview study with strategic stakeholders
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Unmet needs, quality of life and support networks of people with dementia living at home
<p>Abstract</p> <p>Background</p> <p>There is lack of evidence about the unmet needs of people with dementia (PWD) living at home and the predictors of high levels of unmet needs. The main aim of this study was to identify the relationship between unmet needs, social networks and quality of life of PWD living at home.</p> <p>Methods</p> <p>One hundred and fifty two community dwelling PWD and 128 carers were interviewed about PWD's needs, social networks, quality of life and other functional and psychological factors. All the interviews with PWD were carried out at their homes. Interviews with carers were undertaken either at PWD's home, their own home or at the health centre. Whenever possible, PWD and carers were interviewed separately. The data collection took place between November 2005 and July 2007. The majority of participants (129, 84.9%) were recruited from National Health Services (NHS) and the rest (23, 15.1%) were recruited from other organisations such as social services and voluntary organizations in the UK.</p> <p>Results</p> <p>The most frequent unmet needs for PWD were daytime activities (77, 50.7%), company (60, 39.5%), and help with psychological distress (47, 30.9%). Higher number of behavioural and psychological symptoms, low-community involvement social networks, having a younger carer and higher carer's anxiety were found to be predictors of higher unmet needs in PWD. Social networks and behavioural and psychological symptoms had an indirect effect on PWD's self-rated quality of life through unmet needs.</p> <p>Conclusions</p> <p>Interventions aiming to reduce unmet needs, through the treatment of behavioural and psychological symptoms and the involvement of PWD in the community, would potentially improve PWD's quality of life.</p
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A multilevel neo-institutional analysis of infection prevention and control in English hospitals: coerced safety culture change?
Despite committed policy, regulative and professional efforts on healthcare safety, little is known about how such macro-interventions permeate organisations and shape culture over time. Informed by neo-institutional theory, we examined how inter-organisational influences shaped safety practices and inter-subjective meanings following efforts for coerced culture change. We traced macro-influences from 2000 to 2015 in infection prevention and control (IPC). Safety perceptions and meanings were inductively analysed from 130 in-depth qualitative interviews with senior- and middle-level managers from 30 English hospitals. A total of 869 institutional interventions were identified; 69% had a regulative component. In this context of forced implementation of safety practices, staff experienced inherent tensions concerning the scope of safety, their ability to be open and prioritisation of external mandates over local need. These tensions stemmed from conflicts among three co-existing institutional logics prevalent in the NHS. In response to requests for change, staff flexibly drew from a repertoire of cognitive, material and symbolic resources within and outside their organisations. They crafted 'strategies of action', guided by a situated assessment of first-hand practice experiences complementing collective evaluations of interventions such as 'pragmatic', 'sensible' and also 'legitimate'. Macro-institutional forces exerted influence either directly on individuals or indirectly by enriching the organisational cultural repertoire
BlackCAT: A catalogue of stellar-mass black holes in X-ray transients
During the last ~50 years, the population of black hole candidates in X-ray
binaries has increased considerably with 59 Galactic objects detected in
transient low-mass X-ray binaries, plus a few in persistent systems (including
~5 extragalactic binaries). We collect near-infrared, optical and X-ray
information spread over hundreds of references in order to study the population
of black holes in X-ray transients as a whole. We present the most updated
catalogue of black hole transients, which contains X-ray, optical and
near-infrared observations together with their astrometric and dynamical
properties. It provides new useful information in both statistical and
observational parameters providing a thorough and complete overview of the
black hole population in the Milky Way. Analysing the distances and spatial
distribution of the observed systems, we estimate a total population of ~1300
Galactic black hole transients. This means that we have already discovered less
than ~5% of the total Galactic distribution. The complete version of this
catalogue will be continuously updated online and in the Virtual Observatory,
including finding charts and data in other wavelengths.Comment: http://www.astro.puc.cl/BlackCAT - Accepted for publication in
Astronomy & Astrophysics. 20 pages, 8 figures, 5 Table
International variation in childhood cancer mortality rates from 2001 to 2015: Comparison of trends in the International Cancer Benchmarking Partnership countries
Despite improved survival rates, cancer remains one of the most common causes of childhood death. The International Cancer Benchmarking Partnership (ICBP) showed variation in cancer survival for adults. We aimed to assess and compare trends over time in cancer mortality between children, adolescents and young adults (AYAs) and adults in the six countries involved in the ICBP: United Kingdom, Denmark, Australia, Canada, Norway and Sweden. Trends in mortality between 2001 and 2015 in the six original ICBP countries were examined. Age standardised mortality rates (ASR per million) were calculated for all cancers, leukaemia, malignant and benign central nervous system (CNS) tumours, and non-CNS solid tumours. ASRs were reported for children (age 0-14 years), AYAs aged 15 to 39 years and adults aged 40 years and above. Average annual percentage change (AAPC) in mortality rates per country were estimated using Joinpoint regression. For all cancers combined, significant temporal reductions were observed in all countries and all age groups. However, the overall AAPC was greater for children (-2.9; 95% confidence interval = -4.0 to -1.7) compared to AYAs (-1.8; -2.1 to -1.5) and adults aged >40 years (-1.5; -1.6 to -1.4). This pattern was mirrored for leukaemia, CNS tumours and non-CNS solid tumours, with the difference being most pronounced for leukaemia: AAPC for children -4.6 (-6.1 to -3.1) vs AYAs -3.2 (-4.2 to -2.1) and over 40s -1.1 (-1.3 to -0.8). AAPCs varied between countries in children for all cancers except leukaemia, and in adults over 40 for all cancers combined, but not in subgroups. Improvements in cancer mortality rates in ICBP countries have been most marked among children aged 0 to 14 in comparison to 15 to 39 and over 40 year olds. This may reflect better care, including centralised service provision, treatment protocols and higher trial recruitment rates in children compared to older patients.</p
Social meanings and understandings in patient-nurse interaction in the community practice setting: a grounded theory study
Provisional: Background: The patient-nurse relationship is a traditional concern of healthcare research. However, patient-nurse interaction is under examined from a social perspective. Current research focuses mostly on specific contexts of care delivery and experience related to medical condition or illness, or to nurses' speciality. Consequentially, this paper is about the social meanings and understandings at play within situated patient-nurse interaction in the community practice setting in a transforming healthcare service. Methods: Grounded theory methodology was used and the research process was characterised by principles of theoretical sensitivity and constant comparative analysis. The field of study was four health centres in the community. The participants were patients and nurses representative of those attending or working in the health centres and meeting there by scheduled appointment. Data collection methods were observations, informal interviews and semi-structured interviews. Results: Key properties of 'Being a good patient, being a good nurse', 'Institutional experiences' and 'Expectations about healthcare' were associated with the construction of a category entitled 'Experience'. Those key properties captured that in an evolving healthcare environment individuals continually re-constructed their reality of being a patient or nurse as they endeavoured to perform appropriately; articulation of past and present healthcare experiences was important in that process. Modus operandi in role as patient was influenced by past experiences in healthcare and by those in non-healthcare institutions in terms of engagement and involvement (or not) in interaction. Patients' expectations about interaction in healthcare included some uncertainly as they strived to make sense of the changing roles and expertise of nurses and, differentiating between the roles and expertise of nurses and doctors. Conclusions: The importance of social meanings and understandings in patient-nurse interaction is not fully apparent to nurses, but important in the patient experience. Seeking understanding from a social perspective makes a contribution to enhancing knowledge about patient-nurse interaction with subsequent impact on practice, in particular the development of the patient-nurse relationship. The implications are that the meanings and understandings patients and nurses generate from experiences beyond and within their situated interaction are pivotal to the development of their relationship in the transforming community healthcare environment
High aboveground carbon stock of African tropical montane forests
Tropical forests store 40-50 per cent of terrestrial vegetation carbon(1). However, spatial variations in aboveground live tree biomass carbon (AGC) stocks remain poorly understood, in particular in tropical montane forests(2). Owing to climatic and soil changes with increasing elevation(3), AGC stocks are lower in tropical montane forests compared with lowland forests(2). Here we assemble and analyse a dataset of structurally intact old-growth forests (AfriMont) spanning 44 montane sites in 12 African countries. We find that montane sites in the AfriMont plot network have a mean AGC stock of 149.4 megagrams of carbon per hectare (95% confidence interval 137.1-164.2), which is comparable to lowland forests in the African Tropical Rainforest Observation Network(4) and about 70 per cent and 32 per cent higher than averages from plot networks in montane(2,5,6) and lowland(7) forests in the Neotropics, respectively. Notably, our results are two-thirds higher than the Intergovernmental Panel on Climate Change default values for these forests in Africa(8). We find that the low stem density and high abundance of large trees of African lowland forests(4) is mirrored in the montane forests sampled. This carbon store is endangered: we estimate that 0.8 million hectares of old-growth African montane forest have been lost since 2000. We provide country-specific montane forest AGC stock estimates modelled from our plot network to help to guide forest conservation and reforestation interventions. Our findings highlight the need for conserving these biodiverse(9,10) and carbon-rich ecosystems. The aboveground carbon stock of a montane African forest network is comparable to that of a lowland African forest network and two-thirds higher than default values for these montane forests.Peer reviewe
Empirical Legal Studies Before 1940: A Bibliographic Essay
The modern empirical legal studies movement has well-known antecedents in the law and society and law and economics traditions of the latter half of the 20th century. Less well known is the body of empirical research on legal phenomena from the period prior to World War II. This paper is an extensive bibliographic essay that surveys the English language empirical legal research from approximately 1940 and earlier. The essay is arranged around the themes in the research: criminal justice, civil justice (general studies of civil litigation, auto accident litigation and compensation, divorce, small claims, jurisdiction and procedure, civil juries), debt and bankruptcy, banking, appellate courts, legal needs, legal profession (including legal education), and judicial staffing and selection. Accompanying the essay is an extensive bibliography of research articles, books, and reports
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