Jade L Williams

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Individual trabeculae, rodlike in form, were excised from bovine femora and tested in tension to obtain stress-strain plots. Tensile grips were constructed to permit such small specimens to be tested and to avoid slippage during the test. Data were collected for 38 specimens. The results of these tests show that rodlike trabeculae obtained from the femora(More)
2.36 cm diameter cores of trabecular bone (n = 22), oriented in the mediolateral direction, were obtained from fresh-frozen calcanei of 16 cadavers ranging in age from 32 to 89 yr. The cores were defatted and tested to determine values for permeability along the cylinder axis. Permeability values (0.4-11 x 10(-9)m2) were found to be strongly correlated with(More)
An ultrasonic pulse-transit time technique is used to determine the nine orthotropic engineering constants of 32 cement-cancellous bone composites as a function of volume fractions of bone ranging from 0.0 to 0.4. The composites are manufactured using well-aligned bovine cancellous bone from the proximal end of the tibia and low viscosity bone cement.(More)
An investigation has been made of the source and magnitude of anisotropic material properties of cancellous bone in the proximal epiphysis of the human tibia. Results are reported for stiffness measurements made in three orthogonal directions on 21 cubes of cancellous bone before testing to failure along one of the three principal axes. The structure is(More)
A three-dimensional analytical model of the cervical spine is described. The cervical vertebrae and the head are modeled as rigid bodies which are interconnected by deformable elements representing the intervertebral disks, facet joints, ligaments and muscles. A special pentahedral continuum element for representing the articular facets is described which(More)
The study investigates the optimal interference screw dimensions required to secure a tendon graft in a bone tunnel. A standard 8 mm pig flexor-tendon graft was inserted into a standard open-ended 8 mm bone tunnel of a porcine distal femur and secured using either 7 mm, 8 mm or 9 mm diameter metal interference screws (Arthrex Inc, Naples, FL). The construct(More)
A device is described which is designed to bring about uniform and equi-biaxial strains of 0.04-0.4% on a circular elastomeric sheet upon which cells are grown in a monolayer. Strain measurements at six different radii of the well provide evidence of the uniformity of the strain field over the 2.54 cm diameter of the well with a mean strain of 0.15% and a(More)
Understanding how comets work--what drives their activity--is crucial to the use of comets in studying the early solar system. EPOXI (Extrasolar Planet Observation and Deep Impact Extended Investigation) flew past comet 103P/Hartley 2, one with an unusually small but very active nucleus, taking both images and spectra. Unlike large, relatively inactive(More)