University of New Brunswick

About: University of New Brunswick is a education organization based out in Fredericton, New Brunswick, Canada. It is known for research contribution in the topics: Population & Context (language use). The organization has 10498 authors who have published 20654 publications receiving 474448 citations.

On microstructure and mechanical properties of additively manufactured AlSi10Mg_200C using recycled powder

Abstract: Additive manufacturing of reactive metals has opened door to consider using metal 3D printing to manufacture aluminum alloys for different applications from automotive and aerospace to defense. However, one of the major milestones of adopting the technology is still the high price of metal powder in comparison to casting methods. Using recycled powder to additively manufacture parts can be considered one way to decrease the final price in this technology. In the present paper, the microstructural evolution and mechanical properties of the DMLS-AlSi10Mg_200C alloy manufactured by recycled powder were investigated. As the first step of this research, the powder characteristics, i.e. morphology, average particle size, microstructure and composition, of virgin, condensate and recycled AlSi10Mg powder were studied. It was inferred that virgin and recycled powders had comparable powder characteristics, which are very different in comparison to the condensate powder. In the second step of this research, microstructural and mechanical characterization of the as-built DMLS-AlSi10Mg_200C alloy using recycled powder revealed that elongation of horizontally built DMLS-AlSi10Mg_200C was higher compared to that of vertically built. In addition, the fracture surfaces of vertically and horizontally built samples were investigated and possible fracture modes discussed. It is confirmed that, the microstructure and mechanical behavior of the as-built as-built DMLS-AlSi10Mg_200C manufactured by recycled powder were similar to that of virgin powder.

Inheritance of numbers of lateral plates and gill rakers in Gasterosteus aculeatus

Abstract: Heritabilities for lateral plates in Gasterosteus are 0·50 ± 0·043 at 21° C. and 0·83 ± 0·033 at 16° C. for Lake Wapato stocks, and 0·84 ± 0·039 at 21° C. for five other populations. The estimate for gill rakers from Lake Wapato is 0·58 ± 0·056 at 21° C. In general, the two sexes of offspring do not differ in heritabilities; maternal effects apparently are not present. There is evidence that the asymmetry of plates has a large genetic component. The heritability is estimated at 0·63 ± 0·16. Sex ratio varies widely among laboratory-reared families and there is a significant excess of females in the field. No effects of temperature or density on sex ratio were found.

A Real-Time Pattern Recognition Based Myoelectric Control Usability Study Implemented in a Virtual Environment

Abstract: Pattern recognition based myoelectric control systems have been well researched; however very few systems have been implemented in a clinical environment. Although classification accuracy or classification error is the metric most often reported to describe how well these control systems perform, very little work research has been conducted to relate this measure to the usability of the system. This work presents a virtual clothespin usability test to assess the performance of pattern recognition based myoelectric control systems. The results suggest that users can complete the virtual task in reasonable time frames when using systems with high classification accuracies. Additionally, results indicate that a clinically-supported classifier training approach (inclusion of the transient potion of contraction signals) may reduce classification accuracy but increase real-time performance.

Nonmigrating diurnal tides in the thermosphere

Abstract: [1] Horizontal wind measurements from the HRDI and WINDII instruments on the Upper Atmosphere Research Satellite are analyzed to reveal the most prominent nonmigrating diurnal tidal components at 95 km: the eastward propagating diurnal tide with zonal wave number s = 3 (DE3), the standing (s = 0) diurnal oscillation (D0), and the westward propagating diurnal tide with s = 2 (DW2). The strongest DE3 occurs primarily during Northern Hemisphere summer/fall with maximum eastward winds near the equator of order 15 ms−1 and is a vertical extension of the s = 3 Kelvin wave. The first antisymmetric mode of DE3 dominates during October–April, with maximum meridional winds near the equator of order 8 ms−1. D0 exists during nearly all months and is nonsymmetric about the equator with maximum northward wind amplitudes in the Southern Hemisphere of order 7–10 ms−1. DW2 closely resembles the first symmetric propagating mode from classical tidal theory, with maximum northward wind amplitudes of order 10–12 ms−1 during September through February. The combination of DE3, D0, and DW2 with DW1 gives rise to significant longitude variations in the diurnal tide between ±40° latitude. Forcing in the Global Scale Wave Model (GSWM) is calibrated according to the above observations, thus enabling global estimates of nonmigrating tidal temperatures and other fields. For instance, it is estimated that the temperature and eastward wind perturbations associated with DE3 may be as large as 20K and 35 ms−1 at 145 km and 115 km, respectively, over the equatorial region during July.