The Effect Of Pitting Corrosion On The Position Of Aircraft Structural Failures

Corrosion has been shown over the last decade to significantly reduce the structural integrity of aircraft as they age. Previous work at DSTO has shown that pitting and exfoliation corrosion are particularly deleterious to aircraft structural integrity. In addition to reducing fatigue endurance, pitting also increases the surface area of the component over which fatigue failures can occur. This paper reports the results of a Monte-Carlo model of this phenomenon, which has been labelled 'corrosion criticality'. This model concentrates on the effect of the pit spatial density and position on the endurance of a fatigue coupon designed to mimic a simple aircraft component. The study's results show that pitting increases the area of the coupon over which failures can occur

The measurement of reflective function in adolescents with and without borderline traits

Reflective function refers to the capacity to reflect on the mind of self and others in the context of the attachment relationship. Reflective function (and its conceptual neighbor, mentalizing) has been shown to be an important correlate of a variety of disorders, including borderline personality disorder (BPD). The current study examined the construct validity of the Reflective Function Questionnaire for Youths (RFQY) in an inpatient sample of adolescents. Adequate internal consistency was established for the RFQY. Significant positive associations with an interview-based measure of reflective function and an experimental-based assessment of mentalization were found for the RFQY. Strong negative relations with BPD features were found and adolescent patients who scored above clinical cut-off for BPD symptoms demonstrated significantly poorer reflective function compared to patients without the disorder. These findings provide preliminary support for the notion that reflective function can be validly and reliably assessed in adolescent populations

The Reliability of a Rotational Power Assessment of the Core

Context: Most athletic upper-body power generation involveshigh levels of neuromuscular activation/coordination of a rotationalnature. Therefore, it is important to assess athletic ability thatreplicates the rotational activity of athletes. However, a paucity ofresearch currently measures rotational power of the core.Objective: Establish inter-day reliability of chop and lift mean poweroutput via a linear position transducer on rotational reliant powerathletes.Design: Controlled laboratory study.Setting: Professional cricket training facilities.Population: Eight male professional cricket players (age= 23±3.38years, height= 186±10.06 cm, mass= 89.71± 8.12 kg) with aresistance (>2 years) training background volunteered to participatein the study.Intervention: A linear position transducer was attached to theweight stack of a cable pulley system to determine the peak poweroutputs associated with a chop and lift movement. Assessmentoccurred on three occasions separated by at least seven days.Asymmetry, intraclass correlation coefficients (ICCs) and coefficientof variations (CV) were calculated and used to quantify the absoluteand relative consistency of the testing procedures.Results: The mean peak power outputs for chop and lift rangedfrom 404 - 494W and 277-314W respectively, the power outputsdiffering minimally (2.7-6.3%) between the left and right sides.Coefficients of variation of 7.4% - 19% were reported, with intraclass correlation coefficients of 0.54 - 0.94 observed betweentesting occasions.Conclusion: Mean muscular power output associated with the liftassessment reported greatest reliability in well trained athletes.The asymmetry between sides was relatively small suggestingbalanced multi-planar trunk development in the current throwingathletes. Equipment limitations (load related), training status andvariable selection (mean or peak power) need to be consideredprior to rotational assessment of the core.It is recommended that the lift movement is utilized in rotationalpower assessments, or that greater familiarization is undertakenwhen administering the chop assessment.KeywordsCore; Trunk; Assessment; Anaerobic; Transverse plan

The Effectiveness Of Repairing Fatigue Damaged 7050 Aluminium Alloy Using Shot Peening

Shot peening is an effective life extension surface treatment process. In this study, experiments were performed to investigate whether shot peening could be used to recover the fatigue resistance of aluminium alloy 7050 that has experienced prior fatigue damage. The results showed that shot peening may be used for restoring the original fatigue life of the material, but the effectiveness strongly depends on the amount of prior damage (e.g. the crack depth of any cracks that have already formed) in the material. A numerical model was established and the effect of residual stress was incorporated into the model. The prediction by the model agreed well with the experimental results in terms of trend

Improving the economic value of photographic screening for optical coherence tomography-detectable macular oedema : a prospective, multicentre, UK study

Peer reviewedPublisher PD