Self-organized metal nanostructures through laser driven thermocapillary convection

When ultrathin metal films are subjected to multiple cycles of rapid melting and resolidification by a ns pulsed laser, spatially correlated interfacial nanostructures can result from a competition among several possible thin film self-organizing processes. Here we investigate self-organization and the ensuing length scales when Co films (1-8 nm thick) on SiO_{\text{2}} surfaces are repeatedly and rapidly melted by non-uniform (interference) laser irradiation. Pattern evolution produces nanowires, which eventually break-up into nanoparticles exhibiting spatial order in the nearest neighbor spacing, \lambda_{NN2}.The scaling behavior is consistent with pattern formation by thermocapillary flow and a Rayleigh-like instability. For h_{0}\leq2 nm, a hydrodynamic instability of a spinodally unstable film leads to the formation of nanoparticles.Comment: 10 pages, 3 figure

Aerosol midlatitude cyclone indirect effects in observations and high-resolution simulations

Aerosol-cloud interactions are a major source of uncertainty in inferring the climate sensitivity from the observational record of temperature. The adjustment of clouds to aerosol is a poorly constrained aspect of these aerosol-cloud interactions. Here, we examine the response of midlatitude cyclone cloud properties to a change in cloud droplet number concentration (CDNC). Idealized experiments in high-resolution, convection-permitting global aquaplanet simulations with constant CDNC are compared to 13 years of remote-sensing observations. Observations and idealized aquaplanet simulations agree that increased warm conveyor belt (WCB) moisture flux into cyclones is consistent with higher cyclone liquid water path (CLWP). When CDNC is increased a larger LWP is needed to give the same rain rate. The LWP adjusts to allow the rain rate to be equal to the moisture flux into the cyclone along the WCB. This results in an increased CLWP for higher CDNC at a fixed WCB moisture flux in both observations and simulations. If observed cyclones in the top and bottom tercile of CDNC are contrasted it is found that they have not only higher CLWP but also cloud cover and albedo. The difference in cyclone albedo between the cyclones in the top and bottom third of CDNC is observed by CERES to be between 0.018 and 0.032, which is consistent with a 4.6-8.3gWmg‾² in-cyclone enhancement in upwelling shortwave when scaled by annual-mean insolation. Based on a regression model to observed cyclone properties, roughly 60g% of the observed variability in CLWP can be explained by CDNC and WCB moisture flux

Processfolio: uniting Academic Literacies and Critical Emancipatory Action Research for practitioner-led inquiry into EAP writing assessment

This paper reports on the design and implementation of an alternative form of writing assessment on a UK English for Academic Purposes (EAP) presessional course. The assessment, termed processfolio, was a response to research inquiry into how writing assessment in a local context negated student agency and inculcated disempowering models of teaching and learning academic writing. The project merged an Academic Literacies approach to writing (Lea and Street, 1998) with a Critical Emancipatory Action Research (Carr and Kemmis, 1986) framework and a Critical Realist(Bhaskar, 1989) perspective. Data collected from the folios and interviews with students and teachers on their experiences of the processfolio found that a small scale intervention has potential for agency to be exercised within the highly constrained context of a UK EAP pre-sessional. New directions in research are proposed which can engage students and teachers to work for change in UK EAP assessment within their internal and external constraints

Effect of deformation schedule on the microstructure and mechanical properties of a thermomechanically processed C-Mn-Si transformation-induced plasticity steel

Thermomechanical processing simulations were performed using a hot-torsion machine, in order to develop a comprehensive understanding of the effect of severe deformation in the recrystallized and nonrecrystallized austenite regions on the microstructural evolution and mechanical properties of the 0.2 wt pct C-1.55 wt pct Mn-1.5 wt pct Si transformation-induced plasticity (TRIP) steel. The deformation schedule affected all constituents (polygonal ferrite, bainite in different morphologies, retained austenite, and martensite) of the multiphased TRIP steel microstructure. The complex relationships between the volume fraction of the retained austenite, the morphology and distribution of all phases present in the microstructure, and the mechanical properties of TRIP steel were revealed. The bainite morphology had a more pronounced effect on the mechanical behavior than the refinement of the microstructure. The improvement of the mechanical properties of TRIP steel was achieved by variation of the volume fraction of the retained austenite rather than the overall refinement of the microstructure. <br /

Conditions for the occurrence of acicular ferrite transformation in HSLA steels

For the class of steels collectively known as high strength low alloy (HSLA), an acicular ferrite (AF) microstructure produces an excellent combination of strength and toughness. The conditions for the occurrence of the AF transformation are, however, still unclear, especially the effects of austenite deformation and continuous cooling. In this research, a commercial HSLA steel was used and subjected to deformation via plane strain compression with strains ranging from 0 to 0.5 and continuous cooling at rates between 5 and 50 °C s −1 . Based on the results obtained from optical microscopy, scanning electron microscopy and electron backscattering diffraction mapping, the introduction of intragranular nucleation sites and the suppression of bainitic ferrite (BF) laths lengthening were identified as the two key requirements for the occurrence of AF transformation. Austenite deformation is critical to meet these two conditions as it introduces a high density of dislocations that act as intragranular nucleation sites and deformation substructures, which suppress the lengthening of BF laths through the mechanism of mechanical stabilisation of austenite. However, the suppression effect of austenite deformation is only observed under relatively slow cooling rates or high transformation temperatures, i.e., conditions where the driving force for advancing the transformation interface is not sufficient to overcome the austenite deformation substructures

"More than just a run in the park": an exploration of parkrun as a shared leisure space

Over the last 13 years, parkrun has grown from a small time trial in Bushy Park, London, to become a global social movement. During this time, much has been claimed about the potential health-related benefits from participating, but comparatively little attention has been given to the social reasons for attending. The aim of this study was to better understand the meanings of participation for both runners and volunteers using an intrinsic case study that focused on a specific event, Colwick parkrun in Nottingham, England. Building on literature that positions leisure sites as third places, the article seeks to enhance our understanding of parkrun as a community-based initiative. Data collection included observation, participant observation, semi-structured interviews (N = 19), and a survey (N = 235). Several themes emerged, suggesting that participation in parkrun provides an inclusive leisure space for casual sociability, as well as facilitating a shared experience of exercising with others

Protocol for the development of a multidisciplinary clinical practice guideline for the care of patients with chronic subdural haematoma

Introduction: A common neurosurgical condition, chronic subdural haematoma (cSDH) typically affects older people with other underlying health conditions. The care of this potentially vulnerable cohort is often, however, fragmented and suboptimal. In other complex conditions, multidisciplinary guidelines have transformed patient experience and outcomes, but no such framework exists for cSDH. This paper outlines a protocol to develop the first comprehensive multidisciplinary guideline from diagnosis to long-term recovery with cSDH. Methods: The project will be guided by a steering group of key stakeholders and professional organisations and will feature patient and public involvement. Multidisciplinary thematic working groups will examine key aspects of care to formulate appropriate, patient-centered research questions, targeted with evidence review using the GRADE framework. The working groups will then formulate draft clinical recommendations to be used in a modified Delphi process to build consensus on guideline contents. Conclusions: We present a protocol for the development of a multidisciplinary guideline to inform the care of patients with a cSDH, developed by cross-disciplinary working groups and arrived at through a consensus-building process, including a modified online Delphi

A comparison of the clinical effectiveness and cost of specialised individually-delivered parent training for preschool attention-deficit/hyperactivity disorder and a generic, group-based programme: a multi-centre, randomised controlled trial of the New Forest Parenting Programme versus Incredible Years

Objective: To compare the efficacy and cost of specialised individually-delivered parent training (PT) for preschool children with attention-deficit/ hyperactivity disorder (ADHD) against generic group-based PT and treatment as usual (TAU). Design: Multi-centre, three-arm parallel group randomised controlled trial. Research Setting: National Health Service Trusts. Participants: Preschool children (33-54 months) fulfilling ADHD research diagnostic criteria. Interventions: New Forest Parenting Programme (NFPP) – 12 week individual, home-delivered ADHD PT programme; Incredible Years (IY) – 12 week group-based, PT programme initially designed for children with behaviour problems. Main outcome measures: Primary outcome - Parent ratings of child’s ADHD symptoms (Swanson, Nolan & Pelham Questionnaire - SNAP-IV). Secondary outcomes - teacher ratings (SNAP-IV) and direct observations of ADHD symptoms and parent/teacher ratings of conduct problems. NFPP, IY and TAU outcomes were measured at baseline (T1) and post-treatment (T2). NFPP and IY outcomes only were measured 6 months post treatment (T3). Researchers, but not therapists or parents, were blind to treatment allocation. Analysis employed mixed effect regression models (multiple imputation). Intervention and other costs were estimated using standardized approaches. Results: NFPP and IY did not differ on parent-rated SNAP-IV, ADHD combined symptoms (mean difference -0.009 95%CI [-0.191, 0.173], p=0.921) or any other measure. Small, non-significant, benefits of NFPP over TAU were seen for parent-rated SNAP-IV, ADHD combined symptoms (-0.189 95%CI [-0.380, 0.003], p=0.053). NFPP significantly reduced parent-rated conduct-problems compared to TAU across scales (p-values.05). The cost per family of providing NFPP in the trial was significantly lower than IY (£1,591 versus £2,103). Conclusions: Although, there were no differences between NFPP and IY with regards clinical effectiveness, individually-delivered NFPP cost less. However, this difference may be reduced when implemented in routine clinical practice. Clinical decisions should take into account parental preferences between delivery approaches. Funding: National Institute of Health Research. Trial Registration: Trial name: COPPI Trial; ISRCTN39288126