Prediction of melt depth in selected architectural materials during high power diode laser treatment

The development of an accurate analysis procedure for many laser applications, including the surface treatment of architectural materials, is extremely complicated due to the multitude of process parameters and materials characteristics involved. A one-dimensional analytical model based on Fourier’s law, with quasi-stationary situations in an isotropic and inhomogeneous workpiece with a parabolic meltpool geometry being assumed, was successfully developed. This model, with the inclusion of an empirically determined correction factor, predicted high power diode laser (HPDL) induced melt depths in clay quarry tiles, ceramic tiles and ordinary Portland cement (OPC) that were in close agreement with those obtained experimentally. It was observed, however, that as the incident laser line energy increased (>15 W mm-1 s-1/2), the calculated and the experimental melt depths began to diverge at an increasing rate. It is believed that this observed increasing discrepancy can be attributed to the fact the model developed neglects sideways conduction which, although it can be reasonably neglected at low energy densities, becomes significant at higher energy densities since one-dimensional heat transfer no longer holds true

Thermal noise from optical coatings in gravitational wave detectors

Gravitational waves are a prediction of Einstein's general theory of relativity. These waves are created by massive objects, like neutron stars or black holes, oscillating at speeds appreciable to the speed of light. The detectable effect on the Earth of these waves is extremely small, however, creating strains of the order of 10−21. There are a number of basic physics experiments around the world designed to detect these waves by using interferometers with very long arms, up to 4 km in length. The next-generation interferometers are currently being designed, and the thermal noise in the mirrors will set the sensitivity over much of the usable bandwidth. Thermal noise arising from mechanical loss in the optical coatings put on the mirrors will be a significant source of noise. Achieving higher sensitivity through lower mechanical loss coatings, while preserving the crucial optical and thermal properties, is an area of active research right now

Blue Labour or the Political History Blues

This article discusses the state of labour history and political history in Britain. Despite a continuing and sizeable output, it argues the former is very close to deserving an obituary, not unconnected to something of a methodolological malaise in the latter. Political history is not unhealthy, but out of fashion. Paradoxically, debate about history within the Labour party has been rife. Not only in its recent "crisis," but in the Blue Labour Project from 2010 that sought to rethink Labour's past, policy and vision after Blair. It explores Blue Labour through thinkers like Stears, Glasman and the journal Renewal. The gaps between current historical practice and its uses in Labour politics are revealing for both

Tories and Hunters : Swinton College and the landcapes of modern Conservatism

For twenty-eight years from 1948 Swinton College was the Conservative Party’s activist training base in North Yorkshire. It was founded by Butler, hosted Heath’s policy ‘away days’ in the late 1960s, promoted the rise of neoliberal ideas and, notwithstanding this, was closed by Thatcher. Housed in Lord Swinton’s stately home, it was also one of Macmillan’s preferred venues for grouse shooting and won the affection of figures like Powell and a generation of activists as a sort of Country Life picture of Englishness. This article merges these political and cultural histories to outline an alternative history of modern Conservatism, both upper and lower-case. It notes the parallels and linkages between the form of Butler’s original conception of the College’s role and Thatcher’s ideological project. It also examines the persistence of the public association between Conservatism and this lifestyle of elite houses, country sports and rural escape – Tories and Hunters. Despite Thatcher’s modernizing aims this association was, if anything, emboldened through the 1980s and after, suggesting limits to the degree of change represented by the New Right

The Hypothesis of Apraxia of Speech in Children with Autism Spectrum Disorder

In a sample of 46 children aged 4-7 years with Autism Spectrum Disorder (ASD) and intelligible speech, there was no statistical support for the hypothesis of concomitant Childhood Apraxia of Speech (CAS). Perceptual and acoustic measures of participants\u27 speech, prosody, and voice were compared with data from 40 typically-developing children, 13 preschool children with Speech Delay, and 15 participants aged 5-49 years with CAS in neurogenetic disorders. Speech Delay and Speech Errors, respectively, were modestly and substantially more prevalent in participants with ASD than reported population estimates. Double dissociations in speech, prosody, and voice impairments in ASD were interpreted as consistent with a speech attunement framework, rather than with the motor speech impairments that define CAS

Modulating calcium phosphate formation using CO2 laser engineering of a polymeric material

The use of simulated body fluid (SBF) is widely used as a screening technique to assess the ability of materials to promote calcium phosphate formation. This paper details the use of CO2 laser surface treatment of nylon® 6,6 to modulate calcium phosphate formation following immersion in SBF for 14 days. Through white light interferometry (WLI) it was determined that the laser surface processing gave rise to maximum Ra and Sa parameters of 1.3 and 4.4 µm, respectively. The use of X-ray photoelectron spectroscopy (XPS) enabled a maximum increase in surface oxygen content of 5.6 %at. to be identified. The laser-induced surface modifications gave rise to a modulation in the wettability characteristics such that the contact angle, θ, decreased for the whole area processed samples, as expected, and increased for the patterned samples. The increase in θ can be attributed to a transition in wetting nature to a mixed-state wetting regime. It was seen for all samples that calcium phosphate formed on each surface following 14 days. The largest increase in mass, Δg, owed to calcium phosphate formation, was brought about by the whole area processed sample irradiated with a fluence of 51 Jcm-2. No correlation between the calcium phosphate formation and the laser patterned surface properties was determined due to the likely affect of the mixed-state wetting regime. Strong correlations between θ, the surface energy parameters and the calcium phosphate formation for the whole area processed samples allow one to realize the potential for this surface treatment technique in predicting the bone forming ability of laser processed materials

Treatment initiation among persons diagnosed with drug resistant tuberculosis in Johannesburg, South Africa

In South Africa, roughly half of the drug-resistant TB cases diagnosed are reported to have been started on treatment. We determined the proportion of persons diagnosed with rifampicin resistant (RR-) TB who initiated treatment in Johannesburg after the introduction of decentralized RR-TB care in 2011

Comparing the effects of sun exposure and vitamin D supplementation on vitamin D insufficiency, and immune and cardio-metabolic function: the Sun Exposure and Vitamin D Supplementation (SEDS) Study

BACKGROUND Adults living in the sunny Australian climate are at high risk of skin cancer, but vitamin D deficiency (defined here as a serum 25-hydroxyvitamin D (25(OH)D) concentration of less than 50 nmol/L) is also common. Vitamin D deficiency may be a risk factor for a range of diseases. However, the optimal strategies to achieve and maintain vitamin D adequacy (sun exposure, vitamin D supplementation or both), and whether sun exposure itself has benefits over and above initiating synthesis of vitamin D, remain unclear. The Sun Exposure and Vitamin D Supplementation (SEDS) Study aims to compare the effectiveness of sun exposure and vitamin D supplementation for the management of vitamin D insufficiency, and to test whether these management strategies differentially affect markers of immune and cardio-metabolic function. METHODS/DESIGN The SEDS Study is a multi-centre, randomised controlled trial of two different daily doses of vitamin D supplementation, and placebo, in conjunction with guidance on two different patterns of sun exposure. Participants recruited from across Australia are aged 18-64 years and have a recent vitamin D test result showing a serum 25(OH)D level of 40-60 nmol/L. DISCUSSION This paper discusses the rationale behind the study design, and considers the challenges but necessity of data collection within a non-institutionalised adult population, in order to address the study aims. We also discuss the challenges of participant recruitment and retention, ongoing engagement of referring medical practitioners and address issues of compliance and participant retention. TRIAL REGISTRATION Australia New Zealand Clinical Trials Registry: ACTRN12613000290796 Registered 14 March 2013

10,12-Dimethyl­pteridino[6,7-f][1,10]phenanthroline-11,13(10H,12H)-dione–chloro­form (1/1)

In the title co-crystal, C18H12N6O2·CHCl3, intra­molecular Cl3C—H⋯N hydrogen-bonding inter­actions occur between a single CHCl3 and both N atoms at the 1,10-positions on the phenanthroline portion of the mol­ecule. The inter­planar distance between inversion-related mol­ecules is 3.241 (2) Å