41 research outputs found
Viscosity Measurement with Laser Ultrasonics
Get PDFIn the previous year, results were presented in which the viscosity of calibration liquids were determined by measuring the reflection coefficient of laser generated shear waves. [1] The shear waves were launched with a pulsed Nd: YAG laser into an aluminum wedge and detected using a piezoelectric transducer. This year results are presented from a totally noncontact system, generating the shear waves with a pulsed laser and detecting the reflected shear waves with a laser interferometer. The design of the wedge was modified so that the shear waves are incident to the solid-liquid interface at nearly normal incidence. They reflect off this interface and are incident on the surface of detection at greater than the critical angle. This allows for the largest possible out-of-plane displacement, which can then be detected with the interferometer. This type of arrangement has been used with both aluminum and graphite wedges
Is deep venous thrombosis a common complication in patients treated with Ilizarov external fixator?
Get PDFBackground: Determining the incidence of deep venous thrombosis (DVT), a prospective study, in patients treated with Ilizarov external fixators for lower extremity fractures, fracture non unions or deformity correction.Methods: A Prospective, observational and cross sectional study. 49 Patients with complex lower extremity injuries, deformities and non-union of fractures were treated with Ilizarov external fixator application, were assessed clinically and radiological (Venous Doppler) at regular intervals- 6 days post-surgery then at 6 weeks, 12 weeks and between 4 to 6 months post-operative. None were given chemoprophylaxis for the prevention of DVT and everyone were assessed pre operatively with a questionnaire and wells criteria was taken for assessment of high risk for developing venous thrombosis. There were 41 men and 8 women, 85.75% of the study group is of age 30 to 60 years.Results: Only 1 of 49 patients developed radiological evident DVT within 6 days of surgery. Patients who underwent application of Ilizarov external fixator electively for deformity correction, osteomyelitis and non-union showed no clinical or radiological evident signs of DVT.Conclusions: The incidence of DVT and PTE is minimal when patients without chemoprophylaxis underwent lower limb Ilizarov external fixator application for acute trauma and electively for deformity correction, treatment of non-union and osteomyelitis. However further comparative and randomized studies need to be done to confirm our results
