255 research outputs found
The comparative osteology of the skulls of three species of Paralichthys, family Bothidae
This study was undertaken to determine if there were osteological variations in the skulls of young summer flounders, Paralichthys dentatus (Linaeus), southern flounders, Paralichthys lethostigma Jordan and Gilbert and - gulf flounders, Paralichthys albigutta Jordan and Gilbert that could be used as bases of species separation. As two of the species (dentatus and lethostigma) are of considerable economic importance, it would be of substantial value to establish skeletal characters that would help identify the young and. subsequently aid in determining their particular habitats where they occur in the same area.The three are closely related and difficult to recognize unless the pigment pattern is developed separated them primarily by gill raker, anal ray and dorsal ray counts or by correlation of these and considered them to be well defined species acknowledged only two of the three species. They easily separated denaus by numbers of gill rakers, anal rays and dorsal rays; however, they were unable to distinguish lethostigma from z.albigutta and grouped them into a single species, E·albigutta
Structurally integrated joint torque sensors in an assistive upper limb exoskeleton
This paper describes the design process of a torque sensor, which is structurally integrated into the kinematic chain of an assistive upper limb exoskeleton to measure user interaction. Two different approaches of torque sensor integration are discussed regarding the nominal torque loads on each joint and applied transverse stresses. The final sensor concept consists of an aluminum spoke wheel deformation element with four strain gauges connected to a Wheatstone bridge. It is mounted between the motor casing and gear drive of each joint to measure the torque of the actuator and user. A sensor electronics board including signal processing and an EtherCAT interface is integrated in each joint. The torque sensor shows linear transmission characteristics for 0.4 Nm nominal rated torque with a linear error of 0.51 % and a hysteresis error of 0.53 %
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