Two new methods to increase the contrast of track-etch neutron radiographs

In one method, fluorescent dye is deposited into tracks of radiograph and viewed under ultraviolet light. In second method, track-etch radiograph is placed between crossed polaroid filters, exposed to diffused light and resulting image is projected onto photographic film

Mixed Experiences: a study of the childhood narratives of mixed race people related to risks to their mental health and capacity for developing resilience

Background: The mixed race child population is growing proportionately faster than any other group. Whilst there is a body of research in this country, albeit small, that looks at the experiences of mixed race children, none of this research examines specifically the risks for mental health and the possibilities for developing resilience which may be related to growing up as a mixed race child. Methods: Twenty-one adults, recruited through the internet, were asked to reflect on their childhood experiences in relation to being mixed race. They were offered a choice of response methods. The majority chose to provide a written account. A thematic analysis was carried out, within a phenomenological framework. A further analysis was undertaken to assess whether risks to mental health or opportunities to develop resilience could be identified in the findings from the phenomenological analysis using known risk and resilience factors relating to the mental health of children and young people. Results: The data show that there are some additional risks to the mental health of mixed race young people. As well as difficulties experienced in establishing personal identity, they show that there are specific difficulties in secondary school and that young people of mixed race experience racism and prejudice from both black and white peers. The data indicate a capacity for building resilience, necessitated by their mixedness, linked to supportive families. Conclusions: The overarching findings from this study mirror many of those from other mixed race studies. However this study shows how mixed race young people may experience some additional risks to mental health which need to be understood and considered by professionals in health, social care, education and justice systems

Is There a Positive Intertemporal Tradeoff Between Risk and Return After All?

This paper develops an extended version of Turner, Startz, and Nelson's (1989) Markov-switching model of stock returns. The model is motivated as an alternative version of Campbell and Hentschel's (1992) volatility feedback model, with news about future dividends subject to a two-state Markov-switching variance. We are able to identify an endogenous volatility feedback effect by assuming that economic agents acquire information about market volatility that is not directly available to econometricians. Using this model, we find strong evidence for a positive tradeoff between volatility and the equity risk premium, especially for post-War stock returns.

Success factors for Indigenous entrepreneurs and community-based enterprises

Introduction: This resource sheet reviews the available literature on the key factors that have underpinned successful Indigenous entrepreneurs and community-based enterprises. It also explores the different characteristics of Indigenous entrepreneurs and community-based enterprises. Where possible, it also looks at the outcomes of government programs that have aimed to help these different types of Indigenous businesses. For the purposes of this resource sheet, the term ‘Indigenous entrepreneurialism’ (or ‘entrepreneur’) has been used to refer to Indigenous-owned private and commercial businesses that are run for a profit. Likewise, the term ‘community-based enterprise’ has been used to refer to businesses that have a more communal purpose (they are also known as ‘community-managed’ and ‘social’ enterprises). The two terms used in this resource sheet are defined below and were selected for convenience and because they were commonly used in the literature. Indigenous economic development is defined as the involvement by Indigenous people in employment, business, asset and wealth creation in the communities and regions where they live. One key aspect of improving Indigenous economic development is through Indigenous people operating their own private businesses or community-based enterprises (refer to the definition above). In the case of successful Indigenous entrepreneurs, self-employment and ownership of enterprises is believed to help individuals, families and communities improve self-sufficiency and decrease reliance on government welfare. This resource sheet is based on a literature review of approximately 30 sources. The review process used various search terms (for example, Indigenous economic development/Indigenous business; social enterprises, entrepreneurship) and research databases containing peer reviewed articles (AIFS Library catalogue; all of the EBSCO and Informit databases and collections) and general online resources from government or Indigenous community organisations

Exchange Rates and Stock Prices in the Long Run and Short Run

Using the ARDL bounds testing approach to cointegration this paper provides evidence of a stable long run relationship between the exchange rate and stock prices for the UK, Japan and Swiss currencies with respect to the US dollar. The resultant error correction models suggest a positive relationship between stock prices and the exchange rate, which in an out-of-sample forecast outperforms the random walk. We compare these results with a similar model incorporating interest rates, suggested by Solnik (1987), however this does not in general improve the results.stock prices; forecast; cointegration; exchange rates

Surface networks

© Copyright CASA, UCL. The desire to understand and exploit the structure of continuous surfaces is common to researchers in a range of disciplines. Few examples of the varied surfaces forming an integral part of modern subjects include terrain, population density, surface atmospheric pressure, physico-chemical surfaces, computer graphics, and metrological surfaces. The focus of the work here is a group of data structures called Surface Networks, which abstract 2-dimensional surfaces by storing only the most important (also called fundamental, critical or surface-specific) points and lines in the surfaces. Surface networks are intelligent and “natural ” data structures because they store a surface as a framework of “surface ” elements unlike the DEM or TIN data structures. This report presents an overview of the previous works and the ideas being developed by the authors of this report. The research on surface networks has fou

Electromagnetic Pulse from Final Gravitational Stellar Collapse

We employ an effective gravitational stellar final collapse model which contains the relevant physics involved in this complex phenomena: spherical radical infall in the Schwarzschild metric of the homogeneous core of an advanced star, giant magnetic dipole moment, magnetohydrodynamic material response and realistic equations of state (EOS). The electromagnetic pulse is computed both for medium size cores undergoing hydrodynamic bounce and large size cores undergoing black hole formation. We clearly show that there must exist two classes of neutron stars, separated by maximum allowable masses: those that collapsed as solitary stars (dynamical mass limit) and those that collapsed in binary systems allowing mass accretion (static neutron star mass). Our results show that the electromagnetic pulse spectrum associated with black hole formation is a universal signature, independent of the nuclear EOS. Our results also predict that there must exist black holes whose masses are less than the static neutron star stability limit.Comment: 9 pages, 8 figures, to be published in Astronomy and Astrophysic

Lidar observations of polar stratospheric clouds at McMurdo, Antarctica, during NOZE-2

SRI International operated a dual wavelength (1.064 micrometer and .532 micrometer) aerosol lidar at McMurdo Station, Antarctica, as part of the National Ozone Expedition-2 (NOZE-2). The objective of the project was to map the vertical distributions of polar stratospheric clouds (PSCs), which are believed to play an important role in the destruction of ozone in the Antarctic spring. Altitude, thickness, homogeneity, and duration of PSC events as well as information on particle shape, size or number density will be very useful in determining the exact role of PSCs in ozone destructions, and when combined with measurements of other investigators, additional properties of PSCs can be estimated. The results are currently being analyzed in terms of PSC properties which are useful for modeling the stratospheric ozone depletion mechanism