Design of an autonomous Lunar construction utility vehicle

In order to prepare a site for a manned lunar base, an autonomously operated construction vehicle is necessary. A Lunar Construction Utility Vehicle (LCUV), which utilizes interchangeable construction implements, was designed conceptually. Some elements of the machine were studied in greater detail. Design of an elastic loop track system has advanced to the testing stage. A standard coupling device was designed to insure a proper connection between the different construction tools and the LCUV. Autonomous control of the track drive motors was simulated successfully through the use of a joystick and computer interface. A study of hydrogen-oxygen fuel cells has produced estimates of reactant and product size requirements and identified multi-layer insulation techniques. Research on a 100 kW heat rejection system has determined that it is necessary to house a radiator panel on a utility trailer. The impact of a 720 hr use cycle has produced a very large logistical support lien which requires further study

Shear wave generation using a spiral electromagnetic acoustic transducer

A spiral electromagnetic acoustic transducer (EMAT) is efficient in eddy current generation and has been used for surface defect inspection using Rayleigh waves or thickness gauging based on plane waves in echo mode. Measured and calculated particle velocities and directivities are presented. It is found that the shear wave is not predominantly a plane wave. It has zero amplitude on the axis of the generation EMAT and has maximum amplitude at the critical angle. The shear wave could be used in the steel industry for both internal and surface defect inspections together with Rayleigh wave

Study on impact of robotic-assisted orthopaedic industrial noise (SIREN)

Acknowledgements We would like to thank Mr Patrick Ashcroft for his contribution to this study, especially with the provision of the recording equipment used in this study. Funding The author(s) received no financial support for the research, authorship, and/or publication of this article.Peer reviewe

Nondestructive testing of high strength conductors for high field pulsed magnets

High field pulsed magnets at the NHMFL use high strength conductor wires up to 90% of their ultimate tensile strength. Therefore it is very important to ensure that the wires are free of flaws. It is known that in the conductors cold drawing process, internal chevron crack could occur due to unsuitable drawing die schedule or inadequate lubrication. These internal cracks occurs infrequently along the wire, so tensile tests of short samples cut from the ends of a long length conductor often miss the problem. In addition, small inclusions on the wire surface can compromise wires fatigue properties. In this paper, we present results of our non-destructive testing (NDT) inspection of Glidcop AL60 wires using eddy current testing (ECT), ultrasonic testing (UT) and x-ray radiography (2D and 3D). Chevron cracks were found in some AL60 conductors by all three NDT techniques. Surface inclusions were found by ECT. We have developed a long length ECT wire inspection capability.Comment: 4 pages, 9 figure

Hereditary dentine disorders: dentinogenesis imperfecta and dentine dysplasia

The hereditary dentine disorders, dentinogenesis imperfecta (DGI) and dentine dysplasia (DD), comprise a group of autosomal dominant genetic conditions characterised by abnormal dentine structure affecting either the primary or both the primary and secondary dentitions. DGI is reported to have an incidence of 1 in 6,000 to 1 in 8,000, whereas that of DD type 1 is 1 in 100,000. Clinically, the teeth are discoloured and show structural defects such as bulbous crowns and small pulp chambers radiographically. The underlying defect of mineralisation often results in shearing of the overlying enamel leaving exposed weakened dentine which is prone to wear

The effect of a 12 week core training regimen on electromyographic activation in national-level junior swimmers

Knowledge of muscle activation during core training exercises over the duration of a training program would enhance our understanding of the physiological responses to training. The purpose of this study was to quantify the effect of a 12-week core training regimen on neuromuscular activation in swimmers. Ten national-level junior swimmers performed a core exercise regimen three times a week over a 12-week training period. Surface electromyographic (EMG) measurements from 6 core muscles were taken pre- (0 weeks), mid- (6 weeks) and post training (12 weeks). Analysis was carried out on the EMG activity during maximal voluntary isometric contractions (MVCs) and on the normalized and non-normalized EMG values during the core exercises. MVC EMG activity increased with the intervention in all muscles. The magnitudes of changes in MVC EMG activity were greater during the initial phase (effect sizes - standardized mean differences 0.32 to 1.01) compared to the second phase (effect sizes -0.20 to 1.04). Substantial reductions were observed in the normalized EMG data, with these effects being greater during the initial phase (effect sizes -1.54 to -0.28) compared to the second phase (effects sizes -1.12 to -0.22). There were also substantial reductions in non-normalized absolute EMG activity in both the initial (effect sizes -2.73 to -0.27) and second (effects sizes -1.27 to -0.20) phases. Over the 12 week training program substantial neuromuscular adaptations occurred in the core muscles; activation during the core exercises reduced, whilst activation during the MVCs increased. These adaptations are indicative of improvements in neuromuscular strength and efficiency. Changes in EMG data provide objective measures of neuromuscular adaptation which can inform future iterations of training regimens for athletic populations