1,056 research outputs found
Mass formulae for spherically symmetric stellar configurations in five dimensional space-time
An expression is derived where the mass is connected to an integral over the
pressure of gravitating matter in the frame work of five dimensional(5D)
space-time.Comment: 5 pages Latex, No figur
Aerosol meteorology of Maritime Continent for the 2012 7SEAS southwest monsoon intensive study - Part 2: Philippine receptor observations of fine-scale aerosol behavior
Abstract. The largest 7 Southeast Asian Studies (7SEAS) operations period within the Maritime Continent (MC) occurred in the August–September 2012 biomass burning season. Data included were observations aboard the M/Y Vasco, dispatched to the Palawan Archipelago and Sulu Sea of the Philippines for September 2012. At these locations, the Vasco observed MC smoke and pollution entering the southwest monsoon (SWM) monsoonal trough. Here we describe the research cruise findings and the finer-scale aerosol meteorology of this convectively active region. This 2012 cruise complemented a 2-week cruise in 2011 and was generally consistent with previous findings in terms of how smoke emission and transport related to monsoonal flows, tropical cyclones (TC), and the covariance between smoke transport events and the atmosphere's thermodynamic structure. Biomass burning plumes were usually mixed with significant amounts of anthropogenic pollution. Also key to aerosol behavior were squall lines and cold pools propagating across the South China Sea (SCS) and scavenging aerosol particles in their path. However, the 2012 cruise showed much higher modulation in aerosol frequency than its 2011 counterpart. Whereas in 2011 large synoptic-scale aerosol events transported high concentrations of smoke into the Philippines over days, in 2012 measured aerosol events exhibited a much shorter-term variation, sometimes only 3–12 h. Strong monsoonal flow reversals were also experienced in 2012. Nucleation events in cleaner and polluted conditions, as well as in urban plumes, were observed. Perhaps most interestingly, several cases of squall lines preceding major aerosol events were observed, as opposed to 2011 observations where these lines largely scavenged aerosol particles from the marine boundary layer. Combined, these observations indicate pockets of high and low particle counts that are not uncommon in the region. These perturbations are difficult to observe by satellite and very difficult to model. Indeed, the Navy Aerosol Analysis and Prediction System (NAAPS) simulations captured longer period aerosol events quite well but largely failed to capture the timing of high-frequency phenomena. Ultimately, the research findings of these cruises demonstrate the real world challenges of satellite-based missions, significant aerosol life cycle questions such as those the future Aerosol/Clouds/Ecosystems (ACE) will investigate, and the importance of small-scale phenomena such as sea breezes, squall lines, and nucleation events embedded within SWM patterns in dominating aerosol life cycle and potential relationships to clouds
“It’s the most important thing - I mean the schooling”: Father involvement in the education of children with autism
Father involvement in education has been shown to result in a range of positive outcomes for typically developing children. However, the nature of paternal involvement in the education of children with disabilities and especially autism has been under-researched and is little understood. This study aimed to explore the nature of the involvement of 25 UK fathers in the education and their children with autism, aged up to 19 years through the use of semi-structured interviews. Findings showed that fathers were highly engaged both directly and indirectly across several dimensions of their children’s education and schooling. Key areas of indirect engagement were involvement in administrative processes necessary for securing an appropriate educational placement; facilitating daily access to school and general support of children’s progress through attendance at school-based meetings and events. Direct support for learning occurred through homework assistance and working on school-related goals. Findings are discussed in relation to diversity and generative models of fatherhood. Implications for greater father inclusion in the education of children with autism are explored with reference to a gender-differentiated approach
Gravitational collapse with tachyon field and barotropic fluid
A particular class of space-time, with a tachyon field, \phi, and a
barotropic fluid constituting the matter content, is considered herein as a
model for gravitational collapse. For simplicity, the tachyon potential is
assumed to be of inverse square form i.e., V(\phi) \sim \phi^{-2}. Our purpose,
by making use of the specific kinematical features of the tachyon, which are
rather different from a standard scalar field, is to establish the several
types of asymptotic behavior that our matter content induces. Employing a
dynamical system analysis, complemented by a thorough numerical study, we find
classical solutions corresponding to a naked singularity or a black hole
formation. In particular, there is a subset where the fluid and tachyon
participate in an interesting tracking behaviour, depending sensitively on the
initial conditions for the energy densities of the tachyon field and barotropic
fluid. Two other classes of solutions are present, corresponding respectively,
to either a tachyon or a barotropic fluid regime. Which of these emerges as
dominant, will depend on the choice of the barotropic parameter, \gamma.
Furthermore, these collapsing scenarios both have as final state the formation
of a black hole.Comment: 18 pages, 7 figures. v3: minor changes. Final version to appear in
GR
Ethical and methodological issues in engaging young people living in poverty with participatory research methods
This paper discusses the methodological and ethical issues arising from a project that focused on conducting a qualitative study using participatory techniques with children and young people living in disadvantage. The main aim of the study was to explore the impact of poverty on children and young people's access to public and private services. The paper is based on the author's perspective of the first stage of the fieldwork from the project. It discusses the ethical implications of involving children and young people in the research process, in particular issues relating to access and recruitment, the role of young people's advisory groups, use of visual data and collection of data in young people's homes. The paper also identifies some strategies for addressing the difficulties encountered in relation to each of these aspects and it considers the benefits of adopting participatory methods when conducting research with children and young people
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Clouds, aerosols, and precipitation in the marine boundary layer: an ARM Mobile Facility Deployment
The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) deployment at Graciosa Island in the Azores generated a 21-month (April 2009–December 2010) comprehensive dataset documenting clouds, aerosols, and precipitation using the Atmospheric Radiation Measurement Program (ARM) Mobile Facility (AMF). The scientific aim of the deployment is to gain improved understanding of the interactions of clouds, aerosols, and precipitation in the marine boundary layer.
Graciosa Island straddles the boundary between the subtropics and midlatitudes in the northeast Atlantic Ocean and consequently experiences a great diversity of meteorological and cloudiness conditions. Low clouds are the dominant cloud type, with stratocumulus and cumulus occurring regularly. Approximately half of all clouds contained precipitation detectable as radar echoes below the cloud base. Radar and satellite observations show that clouds with tops from 1 to 11 km contribute more or less equally to surface-measured precipitation at Graciosa. A wide range of aerosol conditions was sampled during the deployment consistent with the diversity of sources as indicated by back-trajectory analysis. Preliminary findings suggest important two-way interactions between aerosols and clouds at Graciosa, with aerosols affecting light precipitation and cloud radiative properties while being controlled in part by precipitation scavenging.
The data from Graciosa are being compared with short-range forecasts made with a variety of models. A pilot analysis with two climate and two weather forecast models shows that they reproduce the observed time-varying vertical structure of lower-tropospheric cloud fairly well but the cloud-nucleating aerosol concentrations less well. The Graciosa site has been chosen to be a permanent fixed ARM site that became operational in October 2013
Informal community support for parents of pre-school children: A comparative study investigating the subjective experience of parents attending community-based toddler groups in different socio-economic situations
"Within the United Kingdom, the importance of the appropriate parenting of children in their early years has received significant political support. However, it has been found that positive outcomes for young children,
in terms of their present experience and future life chances, are often significantly weakened by the impact of poverty. A phenomenological scoping study was undertaken to explore the reasons why parents living in poverty access informal social support networks, in the form of community-based toddler groups. The study found that engagement with these networks has value for parents in terms of their mental well-being and their peer education, both of which support their ability to parent a young child appropriately.
Predicted and Measured Drainable Porosities for Field Soils
Experiments were conducted on large field cores to determine the relationship between drainage volume and water table depth for five soils. The measured drainage volumes were less than predicted from the soil water characteristics for three soils, but were in good agreement for the other two. Drainable porosities were calculated from both theoretical and experimental drainage volume-water table depth relationships by assuming that the unsaturated zone is essentially \u27drained to equilibrium, with the water table. The experimental drainable porosities thus obtained were less than predicted.
Drainable porosities for drainage in two-dimensions were calculated from experimental results for one-dimension by assuming an elliptical water table profile. These results gave nearly constant drainable porosities for the layered soils and a variable drain-able porosity for Wagram, a homogeneous, sandy soil
An impact and feasibility evaluation of a 6 week (9 hour) active play intervention on fathers' engagement with their preschool children: A feasibility study
Research has demonstrated the benefits of father involvement with their children and a link between uninvolved fatherhood and societal problems. Children’s Centres (n=15) received 6 x 90 minute active play sessions designed to foster six aspects of parental engagement. Fathers’ engagement and attitudes to child PA were measured pre- and post-intervention via questionnaire. Acceptability of the intervention was explored through participant and staff focus groups. Results showed no effect on overall time fathers spent with their child during the week (t (36) = 0.178, p = 0.860) and the weekend (t (36) =1.166, p = 0.252). Qualitative results demonstrated the sessions provided opportunities for fathers to spend quality time with their children. Parenting self-efficacy increased across the subscale control, t (36) = -2.97, p = 0.04. Fathers increased awareness of their role in motivating their child to play (z = -2.46, p = 0.01). Further longitudinal research is recommended.
Key Words: fathers’ engagement; childcare settings; parenting programmes; active play; parenting self-efficac
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