Coatings decrease metal fatigue failure

Metal test specimens were coated with suitable materials to limit the rate of attack of fresh metal surfaces by the atmosphere. The fatigue properties of coated metals were superior to those which were uncoated and approached the properties observable in vacuum

Mental health clients confirm the value of occupation in building competence and self-identity

Engagement in occupation is proposed to enhance health and wellbeing. To date, few studies have demonstrated this in relation to people with mental health problems. This study aimed to evaluate occupational therapy’s beliefs in the restorative powers of occupation from the perspective of people with enduring mental health problems living in the community. Qualitative research methods were used in two mental health day service settings: a workshop, where woodwork was provided as a medium for creative therapy, and a drop-in facility. Participant observation was undertaken over 10 sessions and, during six in-depth interviews, the clients were asked about their occupational experiences and whether they had perceived any benefits from engagement in occupation. Content and inductive analysis as well as concept mapping of the data resulted in emergent themes and subthemes. Occupation was identified both as a means for building competence through the acquisition of skills, coping with challenges and achieving success and as a medium for developing self-identity through the drive to create, feelings of usefulness and engendering a sense of self. These themes help to support the need for an increase in the provision of meaningful occupation for people with enduring mental health problems. However, further research is required to develop and corroborate the findings

Effects of moisture on torsion and flexure properties of graphite-epoxy composites

The effects of moisture and temperature on unidirectional and multi-ply laminates of T300/934 and AS/3501 graphite-epoxy systems were investigated. Properties studied were static flexure strength, and flexure and torsion fatigue strengths at room temperature and at 74 C. Specimens with increased moisture content showed a reduced static flexure strength; water as the test environment had only a negligible influence. In flexure fatigue and torsion fatigue, the water environment caused somewhat reduced fatigue strengths at room temperature and significantly greater degradation in 74 C water. The failure mode in all cases was interlaminar delamination

Simple torsion test for shear moduli determination of orthotropic composites

By means of torsion tests performed on test specimens of the same material having a minimum of two different cross sections (flat sheet of different widths), the effective in-plane (G13) and out-of-plane (G23) shear moduli were determined for two composite materials of uniaxial and angleply fiber orientations. Test specimens were 16 plies (nominal 2 mm) thick, 100 mm in length, and in widths of 6.3, 9.5, 12.5, and 15.8 mm. Torsion tests were run under controlled deflection (constant angle of twist) using an electrohydraulic servocontrolled test system. In-plane and out-of-plane shear moduli were calculated from an equation derived in the theory of elasticity which relates applied torque, the torsional angle of twist, the specimen width/thickness ratio, and the ratio of the two shear moduli G13/G23. Results demonstrate that torsional shear moduli, G23 as well as G13, can be determined by simple torsion tests of flat specimens of rectangular cross section. Neither the uniaxial nor angleply composite material were transversely isotropic

Cargo throughput and survivability trade-offs in force sustainment operations

Force sustainment requires an optimum supply of resources to maintain and project power in an area. With sustainment reaching ever farther from the origin of supplies, commanders find an increasing exposure of their logistic trains to risk. To mitigate the increased risk from hostile forces, the survivability of supply vehicles must be considered in force sustainment operations to accurately capture a true throughput projection. Development of an optimum throughput plan for littoral sustainment will reduce overall risk to supplies and maximize throughput to the war-fighter. The research conducted focused on maximizing throughput considering the size, quantity, and risk to the cargo vehicles traversing the littoral arena. The major risk component studied is comprised primarily of littoral mines, though this risk is comparable to many other survivability situations. Use of data collected from computer modeling programs are used to compute and maximize throughput.http://archive.org/details/cargothroughputn109454008US Navy (USN) author.Approved for public release; distribution is unlimited