The application of ultrasonic NDT techniques in tribology

The use of ultrasonic reflection is emerging as a technique for studying tribological contacts. Ultrasonic waves can be transmitted non-destructively through machine components and their behaviour at an interface describes the characteristics of that contact. This paper is a review of the current state of understanding of the mechanisms of ultrasonic reflection at interfaces, and how this has been used to investigate the processes of dry rough surface contact and lubricated contact. The review extends to cover how ultrasound has been used to study the tribological function of certain engineering machine elements

Fundamental Movement Skills of Preschool Children in Northwest England

Summary. - This cross-sectional study examined fundamental movement skill competency among deprived preschool children in Northwest England and explored sex differences. A total of 168 preschool children (age 3-5 years) were included in the study. Twelve skills were assessed using the Children’s Activity and Movement in Preschool Motor Skills Protocol and video analysis. Sex differences were explored using independent t-tests, Mann-Whitney U-test and Chi Square analysis at the subtest, skill and component levels, respectively. Overall competence was found to be low amongst both sexes, although it was higher for locomotor skills than for object-control skills. Similar patterns were observed at the component level. Boys had significantly better object-control skills than girls, with greater competence observed for the kick and overarm throw, whilst girls were more competent at the run, hop and gallop. The findings of low competency suggest that developmentally-appropriate interventions should be implemented in preschool settings to promote movement skills, with targeted activities for boys and girls

Fundamental Movement Skills in relation to weekday and weekend physical activity in preschool children

OBJECTIVES: To examine associations between fundamental movement skills and weekday and weekend physical activity among preschool children living in deprived communities. DESIGN: Cross-sectional observation study. METHODS: Six locomotor skills and 6 object-control skills were video-assessed using The Children's Activity and Movement in Preschool Study Motor Skills Protocol. Physical activity was measured via hip-mounted accelerometry. A total of 99 children (53% boys) aged 3-5 years (M 4.6, SD 0.5) completed all assessments. Multilevel mixed regression models were used to examine associations between fundamental movement skills and physical activity. Models were adjusted for clustering, age, sex, standardised body mass index and accelerometer wear time. RESULTS: Boys were more active than girls and had higher object-control skill competency. Total skill score was positively associated with weekend moderate-to-vigorous physical activity (p=0.034) but not weekday physical activity categories (p>0.05). When subdomains of skills were examined, object-control skills was positively associated with light physical activity on weekdays (p=0.008) and with light (p=0.033), moderate-to-vigorous (p=0.028) and light- and moderate-to-vigorous (p=0.008) physical activity at weekends. Locomotor skill competency was positively associated with moderate-to-vigorous physical activity on weekdays (p=0.016) and light physical activity during the weekend (p=0.035). CONCLUSIONS: The findings suggest that developing competence in both locomotor and object-control skills may be an important element in promoting an active lifestyle in young children during weekdays and at weekends

Decline in Physical Fitness From Childhood to Adulthood Associated With Increased Obesity and Insulin Resistance in Adults

To examine how fitness in both childhood and adulthood is associated with adult obesity and insulin resistance. A prospective cohort study set in Australia in 2004-2006 followed up a cohort of 647 adults who had participated in the Australian Schools Health and Fitness Survey in 1985 and who had undergone anthropometry and cardiorespiratory fitness assessment during the survey. Outcome measures were insulin resistance and obesity, defined as a homeostasis model assessment index above the 75th sex-specific percentile and BMI &ge;30 kg/m^sup 2^, respectively. Lower levels of child cardiorespiratory fitness were associated with increased odds of adult obesity (adjusted odds ratio [OR] per unit decrease 3.0 [95% CI 1.6- 5.6]) and insulin resistance (1.7 [1.1-2.6]). A decline in fitness level between childhood and adulthood was associated with increased obesity (4.5 [2.6-7.7]) and insulin resistance (2.1 [1.5- 2.9]) per unit decline. A decline in fitness from childhood to adulthood, and by inference a decline in physical activity, is associated with obesity and insulin resistance in adulthood. Programs aimed at maintaining high childhood physical activity levels into adulthood may have potential for reducing the burden of obesity and type 2 diabetes in adults.<br /

Simple incentives and group dependence for successful payments for ecosystem services programs: evidence from an experimental game in rural Lao PDR

In this paper, we use a new game-based tool to evaluate the immediate and longer-term behavioral change potential of three different payment for environmental services (PES) delivery mechanisms: direct payments for individual performance, direct payments for group performance and insurance. Results from four rural shifting-cultivation dependent communities in Lao PDR suggest that easily understood group-oriented incentives yield the greatest immediate resource-use reduction and experience less free-riding. Group-based incentives may succeed because they motivate participants to communicate about strategies and coordinate their actions and are perceived as fair. No incentive had a lasting effect after it ceased, but neither did any crowd out the participants’ baseline behavior. Temporary reductions in resource dependence may provide a buffer for development of new livelihoods and longer-term change. Games like the one developed here can help policymakers appropriately target environmental incentive programs to local contexts and teach program participants how incentive schemes work

Consumer credit in comparative perspective

We review the literature in sociology and related fields on the fast global growth of consumer credit and debt and the possible explanations for this expansion. We describe the ways people interact with the strongly segmented consumer credit system around the world—more specifically, the way they access credit and the way they are held accountable for their debt. We then report on research on two areas in which consumer credit is consequential: its effects on social relations and on physical and mental health. Throughout the article, we point out national variations and discuss explanations for these differences. We conclude with a brief discussion of the future tasks and challenges of comparative research on consumer credit.Accepted manuscrip

In-situ measurement of journal bearing lubricant viscosity by means of a novel ultrasonic measurement technique using matching layer

An ultrasonic viscometer was used to measure the circumferential viscosity variation in a journal bearing non-invasively. This sensing technique is based on the reflection of a shear wave at a solid-liquid boundary that depends on the viscosity of the liquid and the acoustic properties of the solid. Very little ultrasonic energy can propagate into the oil at a metal-oil interface because the acoustic mismatch is significant. Interleaving a matching layer between the metal and the lubricant enables accurate ultrasonic viscosity measurements [1] Schirru, M., Mills, R., Dwyer-Joyce, R., Smith, O., and Sutton, M. (2015). Viscosity Measurement in a Lubricant Film Using an Ultrasonically Resonating Matching Layer. Tribology Letters, 60(3) pp. 1–11. [CrossRef], [Web of Science ®] . This technique has been used to build a miniaturized ultrasonic viscometer that is accommodated inside a journal to obtain the circumferential viscosity profile. Four viscosity regions are identified due to the variations in the localized temperatures and loads. The results are compared with the isothermal solution of the Reynolds equations for hydrodynamic lubricated bearings. The ultrasonic viscometer locates the angle at which the maximum load occurs and the length of the loaded contact with good accuracy. Finally, the viscosity results are used to estimate the frictional power losses. It is shown that over 70% of the total losses in the journal bearing occur in the region where the load is maximum

Toll-like Receptor 3 L412F Polymorphism Promotes a Persistent Clinical Phenotype in Pulmonary Sarcoidosis

Background: Sarcoidosis is a multisystemic disorder of unknown etiology, characterised by the presence of non-caseating granulomas in target organs. In ninety percent of cases, there is thoracic involvement. Fifty to seventy percent of pulmonary sarcoidosis patients will experience acute, self-limiting disease. For the subgroup of patients who develop persistent disease, no targeted therapy is currently available. Aim: To investigate the potential of the single nucleotide polymorphism (SNP), Toll-like receptor 3 Leu412Phe (TLR3 L412F; rs3775291), as a causative factor in the development of, and in disease persistence in pulmonary sarcoidosis. To investigate the functionality of TLR3 L412F in vitro in primary human lung fibroblasts from pulmonary sarcoidosis patients. Methods: Cohorts of Irish sarcoidosis patients (n=228), healthy Irish controls (n = 263) and a secondary cohort of American sarcoidosis patients (n=123) were genotyped for TLR3 L412F. Additionally, the effect of TLR3 L412F in primary lung fibroblasts from pulmonary sarcoidosis patients was quantitated following TLR3 activation in the context of cytokine and type I interferon production, TLR3 expression, and apoptotic- and fibroproliferative-responses. Results: We report a significant association between TLR3 L412F and persistent clinical disease in two cohorts of Irish and American Caucasians with pulmonary sarcoidosis. Furthermore, activation of TLR3 in primary lung fibroblasts from 412F-homozygous pulmonary sarcoidosis patients resulted in reduced IFN-â and TLR3 expression, reduced apoptosis- and dysregulated fibroproliferative-responses compared with TLR3 wild-type patients. Conclusions: This study identifies defective TLR3 function as a previously unidentified factor in persistent clinical disease in pulmonary sarcoidosis and reveals TLR3 L412F as a candidate biomarker

A comparative study of ultrasonic direct contact, immersion, and layer resonance methods for assessment of enamel thickness in teeth

Wear of dental enamel is a growing problem, but is clinically difficult to diagnose and monitor. An accurate and easy-to-use non-destructive method for the measurement of enamel thickness would be useful for early diagnosis of enamel loss and for monitoring progression. Ultrasound has been identified by several researchers as a potential tool suitable for enamel thickness measurement. However, in vitro studies have shown that while the method is feasible, it suffers from wide variability. The methods proposed to date rely on the measurement of the time of flight of an ultrasonic pulse through the enamel layer. This requires the operator to locate the enamel-dentine junction. In this work, three methods are evaluated to try to reduce this variability and to investigate some practicalities of the approach. Time-of-flight methods using both contact and immersion transducers were used. Immersion transducers gave the most accurate results, within 10-15 per cent of values deduced from tooth sections, but would be harder to arrange for in vivo measurements. Preliminary studies have also shown that it is possible to achieve a resonance in the enamel layer and to measure thickness that way. While this approach needs further experimental refinement, it has the potential to be used for much thinner enamel layer thicknesses