3,176 research outputs found
Transonic Flutter Investigation of Models of the All-movable Horizontal Tail of a Fighter Airplane
Full-scale Investigation of Boundary-layer Control by Suction Through Leading-edge Slots on a Wing-fuselage Configuration Having 47.5 Degree Leading-edge Sweep with and Without Flaps
Low-speed investigation of leading-edge and trailing-edge flaps on a 47.5 degree sweptback wing of aspect ratio 3.4 at a Reynolds number of 4.4 x 10(exp 6)
Low-speed Investigation of the Effect of Several Flap and Spoiler Ailerons on the Lateral Characteristics of a 47.5 Degree Sweptback-wing-fuselage Combination at a Reynolds Number of 4.4. x 10(6)
Convex hull estimation of mammalian body segment parameters
Obtaining accurate values for body segment parameters (BSPs) is fundamental in many biomechanical studies, particularly for gait analysis. Convex hulling, where the smallest-possible convex object that surrounds a set of points is calculated, has been suggested as an effective and time-efficient method to estimate these parameters in extinct animals, where soft tissues are rarely preserved. We investigated the effectiveness of convex hull BSP estimation in a range of extant mammals, to inform the potential future usage of this technique with extinct taxa. Computed tomography scans of both the skeleton and skin of every species investigated were virtually segmented. BSPs (the mass, position of the centre of mass and inertial tensors of each segment) were calculated from the resultant soft tissue segments, while the bone segments were used as the basis for convex hull reconstructions. We performed phylogenetic generalized least squares and ordinary least squares regressions to compare the BSPs calculated from soft tissue segments with those estimated using convex hulls, finding consistent predictive relationships for each body segment. The resultant regression equations can, therefore, be used with confidence in future volumetric reconstruction and biomechanical analyses of mammals, in both extinct and extant species where such data may not be available
Flutter characteristics at transonic speeds of a 45 degree sweptback wing with and without inboard modifications at the leading and trailing edges
An experimental investigation of the transonic-flow-generation and shock-wave-reflection characteristics of a two-dimensional wind tunnel with 17-percent-open perforated walls
An Experimental Investigation of the Transonic-flow-generation and Shock-wave-reflection Characteristics of a Two-dimensional Wind Tunnel with 24-percent-open, Deep, Multislotted Walls
An Experimental Study of Porosity Characteristics of Perforated Materials in Normal and Parallel Flow
Getting its feet on the ground : elucidating Paralouatta's semi-terrestriality using the virtual morpho-functional toolbox
Altres ajuts: CERCA Programme/Generalitat de CatalunyaCurrently, there are no living platyrrhine primates inhabiting the main Caribbean islands. Nevertheless, the fossil record of this area has provided outstanding findings of different New World monkeys that were part of a diverse radiation exhibiting remarkably unusual morphologies. Among these, the Cuban genus Paralouatta corresponds to one of the most enigmatic primates ever found in the Greater Antilles. Some researchers have argued that Paralouatta's post-cranium shows evidence of semi-terrestriality, a locomotor adaptation that is unusual, if not unique, in platyrrhine evolutionary history. Whether or not Paralouatta was truly semi-terrestrial remains uncertain, however, due to a lack of more sophisticated functional analyses on its morphology. Using novel virtual morpho-functional techniques on a comparative sample of 3D talar models belonging to diverse primate species representing three substrate preferences, this study aims to further evaluate whether Paralouatta was a semi-terrestrial genus or not. Geometric morphometrics and finite element analysis were used to empirically assess shape and biomechanical performance, respectively, and then several machine-learning (ML) classification algorithms were trained using both morphometric and biomechanical data to elucidate the substrate preference of the fossils. The ML algorithms categorized the Paralouatta specimens as either arboreal or as species commonly active on both ground and in trees. These mixed results are suggestive of some level of semi-terrestriality, thus representing the only known example of this locomotor behavior in platyrrhine evolutionary history
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