On the use of conical reflectors in laser displacement interferometry
A laser interferometer with 90/spl deg/ conical reflectors was tested. Reflectors with a conic section of 90/spl deg/ in the meridional plane are of interest in a number of applications, including laser displacement interferometry, especially for measurements in submicrometre range, laser spectroscopy, and multi-pass optical cells.
MEASUREMENT OF THE GRAVITATIONAL CONSTANT USING THE ATTRACTION BETWEEN TWO FREELY FALLING DISCS: A PROPOSAL
The constant of gravitation, G, is the least well-known of the physical constants. A new, independent method of measurement, estimated as having a potential uncertainty at least as small as that achieved by existing methods, would be useful for an improvement in G determination. This experiment is based on the measurement of the relative motion of two freely falling test bodies (discs), caused by their gravitational attraction. The uncertainties are analyzed for two parallel tungsten discs with masses of about 30 kg. The use of test bodies with an incorporated optical system of multipass two-beam interferometers, as well as of multibeam interferometers, is proposed to measure their relative displacement. The estimations were made for laboratory experiment with free fall duration of 0.714 s. In this case, the relative displacement to be measured is about 0.1 μm. These estimates show that relative uncertainties lower than 5 × 10-5 can be obtained in G measurement in a single drop of the test bodies. The pro...
Realist Review of Programs, Policies, and Interventions to Enhance the Social, Emotional, and Spiritual Well-Being of Aboriginal and Torres Strait Islander Young People Living in Out-of-Home Care
The child protection system in Australia includes out-of-home care (OoHC) for children and young people at risk of harm and neglect. In Australia, Aboriginal and Torres Strait Islander children and young people are 9 times more likely to be placed in care than non-Aboriginal young people (Australian Institute of Health and Welfare, 2015). Australia’s history of colonization and subsequent policies have caused trauma to individuals, families, and communities and resulted in poor physical and mental health and mistrust of services. This review was undertaken to identify programs and policies currently in place that aim to improve the mental health and well-being of this vulnerable population. It provides an analysis of both the strengths of the current system as well as what has been inadequately addressed based on literature in the area.By incorporating an Aboriginal perspective, this review focuses on social, emotional, and spiritual well-being (SESWB) and the aspects of a child’s life and community that promote this. A realist review of the academic and grey literature was conducted in 2014. It included an extensive search of government and non-government (NGO) publications. The review identified nine programs or policies that are designed to improve the SESWB of Aboriginal young people in OoHC in local and international settings. These are the Aboriginal and Torres Strait Islander Child Placement Principle, cultural support plans, Aboriginal Community Controlled Organisations (ACCOs), family group decision-making, therapeutic care, and Panyappi Mentoring Program. Given that culturally competent service provision is important to SESWB, the review concludes that an increase in monitoring and evaluation is necessary to determine the effectiveness of programs and ensure their implementation and sustainability when warranted. Policy and research work is needed to adapt and devise programs promoting the SESWB of Aboriginal young people (at both the individual and system levels), determine their effectiveness, and ensure they are sustained when warranted.