Effect of LSP treatment on the surface topography, friction and wear of Al2024 alloy

OUTLINE: •Introduction •Experimental Setup • Experimental Procedure • Experimental Results - Surface Roughness - Residual Stresses - Friction - Wear - EDX •Conclusions

The wagon wheel illusion in movies and reality.

Wheels turning in the movies or in other forms of stroboscopic presentation often appear to be rotating backward. Remarkably, a similar illusion is also seen in continuous light. The occurrence of this perception in the absence of intermittent illumination suggests that we normally see motion, as in movies, by processing a series of visual episodes.

Resistência à abrasão de aço Hadfield para britadores: efeito do tamanho do abrasivo e do pH do meio.

Neste trabalho, foi investigado o efeito do tamanho do abrasivo e do pH do meio na resistência ao desgaste abrasivo do aço H-13 com matriz martensítica e do aço Hadfield com matriz austenítica. Ensaios de abrasão foram realizados utilizando o equipamento roda de borracha a úmido, variando o tamanho do abrasivo entre 0,15 e 2,40 mm e o pH do meio entre 5,5 e 12,8. As microestruturas dos materiais estudados foram analisadas utilizando microscopia óptica, as superfícies de desgaste e as partículas de desgaste foram analisadas em microscópio eletrônico de varredura. A macrodureza e a microdureza, antes e após os ensaios, foram obtidas utilizando durômetro Vickers. A topografia da região central da superfície de desgaste foi obtida utilizando Perfilometria 3D, visando obter valores de profundidade de penetração do abrasivo. Os resultados mostraram que o aço Hadfield é mais resistente do que o aço H-13 em todos os valores de pH e tamanhos de abrasivo utilizados. Para os dois materiais, a perda de massa aumenta linearmente até um tamanho crítico de abrasivo (TCA) e, após este, a mesma continua a aumentar, mas com uma intensidade menor. Para os dois materiais e para todos os tamanhos de abrasivo, o aumento do pH do meio resultou em menores perdas de massa, sendo este efeito maior para os dois menores tamanhos de abrasivo. Para maiores valores de pH, foram observadas menores profundidades de penetração do abrasivo. A microdureza da superfície de desgaste do aço H-13 sofreu um pequeno aumento com o aumento do tamanho do abrasivo enquanto que para o aço Hadfield esse aumento foi mais intenso. A análise das partículas de desgaste mostraram que, para todas as condições ensaiadas, os debris do aço H-13 tinham duas morfologias, contínuas e descontínuas enquanto que os cavacos do aço Hadfield foram sempre descontínuos. Para os dois materiais, foram observados dois micromecanismos de desgaste, sendo eles microcorte e microsulcamento. Por fim, os resultados apresentados neste trabalho sugerem que a análise de desempenho do aço Hadfield em serviço deve considerar o pH do meio bem como a granulometria do abrasivo em contato.

First molar size and wear within and among modern hunter-gatherers and agricultural populations

Apart from reflecting modern human dental variation, differences in dental size among populations provide a means for studying continuous evolutionary processes and their mechanisms. Dental wear, on the other hand, has been widely used to infer dietary adaptations and variability among or within diverse ancient human populations. Few such studies have focused on modern foragers and farmers, however, and diverse methods have been used. This research aimed to apply a single, standardized, and systematic quantitative procedure to measure dental size and dentin exposure in order to analyze differences among several hunter-gatherer and agricultural populations from various environments and geographic origins. In particular, we focused on sexual dimorphism and intergroup differences in the upper and lower first molars. Results indicated no sexual dimorphism in molar size and wear within the studied populations. Despite the great ethnographic variation in subsistence strategies among these populations, our findings suggest that differences in sexual division of labor do not affect dietary wear patterns.

Girls' and juniors' ready-to-wear

by Fredonia Jane Ringo ...

A success story for the EU and seasonal workers’ rights without reinventing the wheel. EPC Policy Brief, 28 March 2014

Despite the economic crisis with resulting high unemployment, EU economies face vacancies across the skill spectrum. At the low end there is a structural need when it comes to seasonal work. The Seasonal Workers Directive was launched at the same time as the Inter-Corporate Transferees (ICTs) Directive in 2010 – as part of the Commission’s 2005 Policy Plan on Legal Migration – and initially appeared to be more troublesome, with the stigma of ‘migrants stealing local jobs’ haunting it. However, without the provisions for intra-EU mobility that have plagued the ICTs Directive, the Seasonal Workers Directive became less problematic despite the fact that seasonal workers are more numerous than intra-corporate transferees. This Policy Brief looks at how negotiating parties ensured a focus not only on the needs of the European labour market, but also saw an opportunity to bring added value to seasonal workers’ rights, through equal treatment to EU nationals. It assesses the final outcome of three and a half years of intra-EU negotiation, looking at the rights gained for seasonal migrants, the level of harmonization achieved, and the future of migration policy with the strategic guidelines for the area of freedom, security and justice in mind.

Correlation between ultrasonic nondestructive inspection and wheel test of 34 retreaded tires. Interim report.

National Highway Traffic Safety Administration, Office of Research and Development, Washington, D.C.

Development of car/trailer handling and braking standards. Volume II: technical report for Phase I - rear wheel drive tow cars. Final report.

National Highway Traffic Safety Administration, Office of Passenger Vehicle Research, Washington, D.C.

Steering wheel oscillations and vertical movement in 30 mph barrier impacts. Technical report.

Mode of access: Internet.

Canning preserving, and jelly making made easy by using a "Wear-Ever" Aluminum Roaster and a "Wear-Ever" Preserving Kettle.

Promotional literature for "'Wear-Ever' Aluminum Utensils."