Investigation of Corrosion in Aluminum/Adhesive Lap-Splices Using Pulse-Echo Ultrasonic Techniques

Corrosion can exist in any layer of a simple aluminum/adhesive lap-splice. For lap- splices where only one aluminum surface is accessible, first layer corrosion is corrosion that occurs on or under the accessible skin; and second layer corrosion is that which exists behind the adhesive/scrim layer on the upper or lower surface of the inaccessible skin. Many different nondestructive evaluation (NDE) techniques can detect first layer corrosion, and much progress has been made quantifying corrosion that exists in this layer[l]. Due to the layered nature of a lap-splice, second layer corrosion is much more difficult to detect, and also more difficult to quantify. Current maintenance procedures also make it difficult for researchers to obtain lap-splice corrosion samples from serviceable aircraft. The detection of corrosion in lap-splice assemblies has been given an important inspection priority by the airline industry, and regular inspection procedures have been developed to meet these new requirements. During maintenance, if corrosion is suspected in a lap-splice area, the area is opened up for further inspection by removing the rivets, adhesive and sometimes the paint. If the corrosion damage is beyond the manufacturer’s tolerances, the corroded area is cut out and patch-repaired; otherwise, the corrosion is removed by chemical or mechanical means, leaving a serviceable but thinner metal skin when the joint is reassembled[2]. In either case the original character of the lap-splice has been destroyed by the maintenance process, and its use for NDE purposes is lost. In this light, it becomes necessary for researchers to fabricate their own laboratory samples and compare these artificial samples with actual in-service samples

Risky youth to risky adults: Sustained increased risk of crash in the DRIVE study 13 years on.

The objective of this study was to investigate if drivers who exhibit risky driving behaviours during youth (aged 17-24 years) have an increased risk of car crash up to 13 years later. We used data from the DRIVE study, a 2003/04 survey of 20,806 young novice drivers in New South Wales, Australia. The data were linked with police crash, hospital and deaths data up to 2016. We analysed differences in crash associated with 13 items of risky driving behaviours using negative binominal regression models adjusted for driver demographics, driving exposure and known crash risk factors. The items were summarised in one index and grouped into quintiles for the analysis. After adjusting for confounding, drivers of the third (RR 1.16, 95% CI 1.05-1.30), fourth (RR1.22, 95% CI1.09-1.36) and fifth quintile (RR 1.36, 95% CI 1.21-1.53) had higher crash rates compared to the lowest risk-takers. Drivers with the highest scores on the risky driving measure had higher rates of crash related hospital admission or death (RR 1.92, 95% CI 1.13-3.27), crashes in wet conditions (RR 1.35,95% CI 1.05-1.73), crashes in darkness (RR 1.55, 95% CI 1.25-1.93) and head-on crashes (RR 2.14, 95% CI 1.07-4.28), compared with drivers with the lowest scores. Novice adolescent drivers who reported high levels of risky driving when they first obtained a driver licence remained at increased risk of crash well into adulthood. Measures that successfully reduce early risky driving, have the potential to substantially reduce road crashes and transport related injuries and deaths over the lifespan

Preparing athletes and teams for the Olympic Games: experiences and lessons learned from the world's best sport psychologists

As part of an increased effort to understand the most effective ways to psychologically prepare athletes and teams for Olympic competition, a number of sport psychology consultants have offered best-practice insights into working in this context. These individual reports have typically comprised anecdotal reflections of working with particular sports or countries; therefore, a more holistic approach is needed so that developing practitioners can have access to - and utilise - a comprehensive evidence-base. The purpose of this paper is to provide a panel-type article, which offers lessons and advice for the next generation of aspiring practitioners on preparing athletes and teams for the Olympic Games from some of the world’s most recognised and experienced sport psychologists. The sample comprised 15 sport psychology practitioners who, collectively, have accumulated over 200 years of first-hand experience preparing athletes and/or teams from a range of nations for six summer and five winter Olympic Games. Interviews with the participants revealed 28 main themes and 5 categories: Olympic stressors, success and failure lessons, top tips for neophyte practitioners, differences within one’s own consulting work, and multidisciplinary consulting. It is hoped that the findings of this study can help the next generation of sport psychologists better face the realities of Olympic consultancy and plan their own professional development so that, ultimately, their aspirations to be the world’s best can become a reality

Critical fluctuation conductivity in layered superconductors in strong electric field

The paraconductivity, originating from critical superconducting order-parameter fluctuations in the vicinity of the critical temperature in a layered superconductor is calculated in the frame of the self-consistent Hartree approximation, for an arbitrarily strong electric field and zero magnetic field. The paraconductivity diverges less steep towards the critical temperature in the Hartree approximation than in the Gaussian one and it shows a distinctly enhanced variation with the electric field. Our results indicate that high electric fields can be effectively used to suppress order-parameter fluctuations in high-temperature superconductors.Comment: 11 pages, 2 figures, to be published in Phys. Rev.

Germline mutations in the oncogene EZH2 cause Weaver syndrome and increased human height.

The biological processes controlling human growth are diverse, complex and poorly understood. Genetic factors are important and human height has been shown to be a highly polygenic trait to which common and rare genetic variation contributes. Weaver syndrome is a human overgrowth condition characterised by tall stature, dysmorphic facial features, learning disability and variable additional features. We performed exome sequencing in four individuals with Weaver syndrome, identifying a mutation in the histone methyltransferase, EZH2, in each case. Sequencing of EZH2 in additional individuals with overgrowth identified a further 15 mutations. The EZH2 mutation spectrum in Weaver syndrome shows considerable overlap with the inactivating somatic EZH2 mutations recently reported in myeloid malignancies. Our data establish EZH2 mutations as the cause of Weaver syndrome and provide further links between histone modifications and regulation of human growth

The Procedure for Determining and Quality Assurance Program for the Calculation of Dose Coefficients Using DCAL Software

The development of a spallation neutron source with a mercury target may lead to the production of rare radionuclides. The dose coefficients for many of these radionuclides have not yet been published. A collaboration of universities and national labs has taken on the task of calculating dose coefficients for the rare radionuclides using the software package: DCAL. The working group developed a procedure for calculating dose coefficients and a quality assurance (QA) program to verify the calculations completed. The first portion of this QA program was to verify that each participating group could independently reproduce the dose coefficients for a known set of radionuclides. The second effort was to divide the group of radionuclides among the independent participants in a manner that assured that each radionuclide would be redundantly and independently calculated. The final aspect of this program was to resolve any discrepancies arising among the participants as a group of the whole. The output of the various software programs for six QA radionuclides, 144Nd, 201Au, 50V, 61Co, 41Ar, and 38S were compared among all members of the working group. Initially, a few differences in outputs were identified. This exercise identified weaknesses in the procedure, which have since been revised. After the revisions, dose coefficients were calculated and compared to published dose coefficients with good agreement. The present efforts involve generating dose coefficients for the rare radionuclides anticipated to be produced from the spallation neutron source should a mercury target be employed

An Interdatabase Comparison of Nuclear Decay and Structure Data Utilized in the Calculation of Dose Coefficients for Radionuclides Produced in a Spallation Neutron Source

Internal and external dose coefficient values have been calculated for 14 anthropogenic radionuclides which are not currently presented in Federal Guidance Reports Nos. 11, 12, and 13 or Publications 68 and 72 of the International Commission on Radiological Protection. Internal dose coefficient values are reported for inhalation and ingestion of 1 μm and 5 μm AMAD particulates along with the f1 values and absorption types for the adult worker. Internal dose coefficient values are also reported for inhalation and ingestion of 1 μm AMAD particulates as well as the f1 values and absorption types for members of the public. Additionally, external dose coefficient values for air submersion, exposure to contaminated ground surface, and exposure to soil contaminated to an infinite depth are also presented. Information obtained from this study will be used to support the siting and permitting of future accelerator-driven nuclear initiatives within the U.S. Department of Energy complex, including the Spallation Neutron Source (SNS) and Accelerator Production of Tritium (APT) Projects

More than sense of place? Exploring the emotional dimension of rural tourism experiences

It is widely suggested that participation in rural tourism is underpinned by a sense of rural place or “rurality”. However, although nature and the countryside have long been recognised as a source of spiritual or emotional fulfilment, few have explored the extent to which tourism, itself often claimed to be a sacred experience, offers an emotional/spiritual dimension in the rural context. This paper addresses that literature gap. Using in-depth interviews with rural tourists in the English Lake District, it explores the extent to which, within respondents’ individual understanding of spirituality, a relationship exists between sense of place and deeper, emotional experiences and, especially, whether participation in rural tourism may induce spiritual or emotional responses. The research revealed that all respondents felt a strong attachment to the Lake District; similarly, and irrespective of their openness to spirituality, engaging in rural tourism activities resulted in highly emotive experiences for all respondents, the description/interpretation of such experiences being determined by individual “beliefs”. However, sense of place was not a prerequisite to emotional or spiritual experiences. Being in and engaging with the landscape � effectively becoming part of it � especially through physical activity is fundamental to emotional responses

Nernst Effect and Anomalous Transport in Cuprates: A Preformed-Pair Alternative to the Vortex Scenario

We address those puzzling experiments in underdoped high $T_c$ superconductors which have been associated with normal state "vortices" and show these data can be understood as deriving from preformed pairs with onset temperature $T^* > T_c$. For uncorrelated bosons in small magnetic fields, and arbitrary $T^*/T_c$, we present the exact contribution to \textit{all} transport coefficients. In the overdoped regime our results reduce to those of standard fluctuation theories ($T^*\approx T_c$). Semi-quantitative agreement with Nernst, ac conductivity and diamagnetic measurements is quite reasonable.Comment: 9 pages, 4 figures; Title, abstract and contents modified, new references added, figures changed, one more figure added; to be published on PR