Youth and the future: effective youth services for the year 2015

This report provides an understanding of the services required by young people in the year 2015, based on a thorough analysis of recent trends and expert projections of those trends. The report analyses key social and economic changes for young people in Australia over the past 10 to 20 years including movements in population, education, employment/unemployment and the labour market, incomes, family and household structure, health, and crime and justice

Biometric surveillance in schools : cause for concern or case for curriculum?

This article critically examines the draft consultation paper issued by the Scottish Government to local authorities on the use of biometric technologies in schools in September 2008 (see http://www.scotland.gov.uk/Publications/2008/09/08135019/0). Coming at a time when a number of schools are considering using biometric systems to register and confirm the identity of pupils in a number of settings (cashless catering systems, automated registration of pupils' arrival in school and school library automation), this guidance is undoubtedly welcome. The present focus seems to be on using fingerprints, but as the guidance acknowledges, the debate in future may encompass iris prints, voice prints and facial recognition systems, which are already in use in non-educational settings. The article notes broader developments in school surveillance in Scotland and in the rest of the UK and argues that serious attention must be given to the educational considerations which arise. Schools must prepare pupils for life in the newly emergent 'surveillance society', not by uncritically habituating them to the surveillance systems installed in their schools, but by critically engaging them in thought about the way surveillance technologies work in the wider world, the various rationales given to them, and the implications - in terms of privacy, safety and inclusion - of being a 'surveilled subject'

Selective laser melting of an Al(86)Ni(6)Y(4.5)Co(2)La(1.5) metallic glass: processing, microstructure evolution and mechanical properties

In this study, single line scans at different laser powers were carried out using selective laser meting (SLM) equipment on a pre-fabricated porous Al86Ni6Y4.5Co2La1.5 metallic glass (MG) preform. The densification, microstructural evolution, phase transformation and mechanical properties of the scan tracks were systematically investigated. It was found that the morphology of the scan track was influenced by the energy distribution of the laser beam and the heat transfer competition between convection and conduction in the melt pool. Due to the Gaussian distribution of laser energy and heat transfer process, different regions of the scan track experienced different thermal histories, resulting in a gradient microstructure and mechanical properties. Higher laser powers caused higher thermal stresses, which led to the formation of cracks; while low power reduced the strength of the laser track, also inducing cracking. The thermal fluctuation at high laser power produced an inhomogeneous chemical distribution which gave rise to severe crystallization of the MG, despite the high cooling rate. The crystallization occurred both within the heat affected zone (HAZ) and at the edge of melt pool. However, by choosing an appropriate laser power crack-free scan tracks could be produced with no crystallization. This work provides the necessary fundamental understanding that will lead to the fabrication of large-size, crack-free MG with high density, controllable microstructure and mechanical properties using SLM. (C) 2014 Elsevier B.V. All rights reserved

Improved deformation behavior in Ti-Zr-Fe-Mn alloys comprising the C14 type Laves and β phases

Laves phase alloys are promising materials for several structural applications, but the extreme brittleness is the predominant shortcoming of a Laves matrix. One potential solution to overcome this shortcoming is to alloy Laves matrix with some soft matrix. A group of Ti-35Zr-5Fe-xMn (x = 0, 2, 4, 6, 8 wt%) alloys was cast with an aim to improve deformation in Laves alloy compositions. The phase and microstructure analyses reveal dual phase matrices, including a β phase and a C14 type Laves phase in the investigated alloys. The mechanical properties such as yield strength, hardness and plastic strain for the investigated alloys are found to be significantly sensitive to volume fraction of the Laves phase. Ti-35Zr-5Fe shows impressive ultimate compressive strength (~1.7 GPa), yield strength (1138 MPa) and large plastic strain (23.2 %). The fracture mechanisms are dependent on the microstructure of the alloys. Additionally, the work-hardening ability of the investigated alloys have also been evaluated based on the analyses of slip band patterns formed around the micro-hardness indentations. Notably, the extreme brittleness is not encountered in all the Ti-35Zr-5Fe-xMn alloys and all exhibit very good compressive elongation including the maximum (32.5 %) in Ti-35Zr-5Fe

Effect of the GaAsP shell on optical properties of self-catalyzed GaAs nanowires grown on silicon

We realize growth of self-catalyzed core-shell GaAs/GaAsP nanowires (NWs) on Si substrates using molecular-beam epitaxy. Transmission electron microscopy (TEM) of single GaAs/GaAsP NWs confirms their high crystal quality and shows domination of the zinc-blende phase. This is further confirmed in optics of single NWs, studied using cw and time-resolved photoluminescence (PL). A detailed comparison with uncapped GaAs NWs emphasizes the effect of the GaAsP capping in suppressing the non-radiative surface states: significant PL enhancement in the core-shell structures exceeding 2000 times at 10K is observed; in uncapped NWs PL is quenched at 60K whereas single core-shell GaAs/GaAsP NWs exhibit bright emission even at room temperature. From analysis of the PL temperature dependence in both types of NW we are able to determine the main carrier escape mechanisms leading to the PL quench

The effects of sample position and gas flow pattern on the sintering of a 7xxx aluminum alloy

The effects of sample position and gas flow pattern on the sintering of a 7xxx aluminum alloy Al-7Zn-2.5Mg-1Cu in flowing nitrogen have been investigated both experimentally and numerically. The near-surface pore distribution and sintered density of the samples show a strong dependency on the sample separation distance over the range from 2 mm to 40 mm. The open porosity in each sample increases with increasing separation distance while the closed porosity remains essentially unchanged. A two-dimensional computational fluid dynamics (CFD) model has been developed to analyze the gas flow behavior near the sample surfaces during isothermal sintering. The streamlines, velocity profile, and volume flow rate in the cavity between each two samples are presented as a function of the sample separation distance at a fixed nitrogen flow rate of 6 L/min. The CFD modeling results provide essential details for understanding the near-surface pore distribution and density of the sintered samples. It is proposed that the different gas flow patterns near the sample surfaces result in variations of the oxygen content from the incoming nitrogen flow in the local sintering atmosphere, which affects the self-gettering process of the aluminum compacts during sintering. This leads to the development of different near-surface pore distributions and sintered densities

Modelling of Short-Term Interactions Between Concrete Support and the Excavated Damage Zone Around Galleries Drilled in Callovo–Oxfordian Claystone

peer reviewedProduction of energy from nuclear power plants generates high-level radioactive nuclear waste, harmful during dozens of thousand years. Deep geological disposal of nuclear waste represents the most reliable solutions for its safe isolation. Confinement of radioactive wastes relies on the multi-barrier concept in which isolation is provided by a series of engineered (canister, backfill) and natural (host rock) barriers. Few underground research laboratories have been built all over the world to test and validate storage solutions. The underground drilling process of disposal drifts may generate cracks, fractures/strain localisation in shear bands within the rock surrounding the gallery especially in argillaceous rocks. These degradations affect the hydro-mechanical properties of the material, such as permeability, e.g. creating a preferential flow path for radionuclide migration. Hydraulic conductivity increase within this zone must remain limited to preserve the natural barrier. In addition galleries are currently reinforced by different types of concrete supports such as shotcrete and/or prefab elements. Their purpose is twofold: avoiding partial collapse of the tunnel during drilling operations and limiting convergence of the surrounding rock. Properties of both concrete and rock mass are time dependent, due to shotcrete hydration and hydromechanical couplings within the host rock. By the use of a hydro-mechanical coupled Finite Element Code with a Second Gradient regularization, this paper aims at investigating and predicting support and rock interactions (convergence, stress field). The effect of shotcrete hydration evolution, spraying time and use of compressible wedges is studied in order to determine their relative influence

Elevated Peripheral Neutrophils and Matrix Metalloproteinase 9 as Biomarkers of Functional Outcome Following Subarachnoid Hemorrhage

There is growing evidence supporting the role of inflammation in early brain injury and cerebral vasospasm following subarachnoid hemorrhage (SAH). Matrix metalloproteinases (MMPs) are released by inflammatory cells and can mediate early brain injury via disruption of the extracellular matrix and mediate vasospasm by cleaving endothelin-1 into vasoactive fragments. We hypothesize that inflammation marked by neutrophil elevation and MMP-9 release in human SAH is associated with vasospasm and with poor clinical outcome. We enrolled consecutive SAH subjects (N = 55), banked serial blood and cerebrospinal fluid (CSF) samples, and evaluated their 3-month modified Rankin scores (mRS). Vasospasm was defined as >50% vessel caliber reduction on angiography 6–8 days post-SAH. A poor outcome was defined as mRS > 2. We compared blood leukocyte and neutrophil counts during post-SAH days 0–14 with respect to vasospasm and 3-month outcome. In a subset of SAH subjects (N = 35), we compared blood and CSF MMP-9 by enzyme-linked immunosorbent assay (ELISA) on post-SAH days 0–1, 2–3, 4–5, 6–8, and 10–14 with respect to vasospasm and to 3-month outcome. Persistent elevation of blood leukocyte (p = 0.0003) and neutrophil (p = 0.0002) counts during post-SAH days 0–14 are independently associated with vasospasm after adjustment for major confounders. In the same time period, blood neutrophil count (post-SAH days 2–3, p = 0.018), blood MMP-9 (post-SAH days 4–5, p = 0.045), and CSF MMP-9 (post-SAH days 2–3, p = 0.05) are associated with poor 3-month SAH clinical outcome. Neutrophil count correlates with blood MMP-9 (post-SAH days 6–8, R = 0.39; p = 0.055; post-SAH days 10–14, R = 0.79; p < 0.0001), and blood MMP-9 correlates with CSF MMP-9 (post-SAH days 4–5, R = 0.72; p = 0.0002). Elevation of CSF MMP-9 during post-SAH days 0–14 is associated with poor 3-month outcome (p = 0.0078). Neither CSF nor blood MMP-9 correlates with vasospasm. Early rise in blood neutrophil count and blood and CSF MMP-9 are associated with poor 3-month SAH clinical outcome. In blood, neutrophil count correlates with MMP-9 levels, suggesting that neutrophils may be an important source of blood MMP-9 early in SAH. Similarly, CSF and blood MMP-9 correlate positively early in the course of SAH, suggesting that blood may be an important source of CSF MMP-9. Blood and CSF MMP-9 are associated with clinical outcome but not with vasospasm, suggesting that MMP-9 may mediate brain injury independent of vasospasm in SAH. Future in vitro studies are needed to investigate the role of MMP-9 in SAH-related brain injury. Larger clinical studies are needed to validate blood and CSF MMP-9 as potential biomarkers for SAH outcome

The 'teen brain' research: implications for practitioners

This article discusses advances in developmental cognitive neuroscience over the last decade, outlining major developments, how these are reshaping our ideas about youth and adolescence and considering the implications for working with young people. The authors also discuss the implications of this research for the concept of youth itself, arguing that it can no longer be seen as separate from adulthood. Youth is emergence into adulthood. The social environment, including policy settings, will significantly determine the shape of adulthood as it emerges