4 research outputs found

    Development of a pulsed eddy current instrument for corrosion detection

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    The pulsed eddy current technique has been under development at Iowa State University since 199:3 under the supervision of Mr. John Moulder. It has shown much promise for detecting corrosion and cracks in multi-layered aircraft structures, and has elicited strong interest from the aviation community. The Pulsed Eddy Current Group at the Center for Nondestructive Evaluation, ISU, has built an instrument which utilizes the theory behind pulsed eddy currents and transforms it into a practical field instrument

    Time-Gating of Pulsed Eddy Current Signals for Defect Characterization and Discrimination in Aircraft Lap-Joints

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    Pulsed eddy current (PEC) nondestructive testing differs from conventional eddy current techniques in that the probe coil is excited by a pulse, rather than continuous excitation at a single frequency. Reviews of early work on pulsed eddy currents are given by Waidelich1 and by Renkin.2 Pulsed excitation causes the propagation of a highly attenuated traveling wave, which is governed by the diffusion equation.3 The diffusive propagation of the eddy current pulse results in spatial broadening and a delay, or travel time, proportional to the square of the distance traveled. It was realized in early work on pulsed eddy current systems that this time dependence offered certain advantages over conventional eddy currents.4 In the current study we demonstrate the ability of a prototype pulsed eddy current instrument, described elsewhere,5,6 to take advantage of this time dependence to discriminate flaws from such interfering signals as probe liftoff, air gaps, and fasteners

    Computed Tomography- and Radiography-Based Morphometric Analysis of the Lateral Mass of the Subaxial Cervical Spine in the Indian Population

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    Study DesignThis was a double-blinded cross-sectional study, which obtained no financial support for the research.PurposeTo obtain a detailed morphometry of the lateral mass of the subaxial cervical spine.Overview of LiteratureThe literature offers little data on the dimensions of the lateral mass of the subaxial cervical spine.MethodsWe assessed axial, sagittal, and coronal computed tomography (CT) cuts and anteroposterior and lateral X-rays of the lateral mass of the subaxial cervical spine of 104 patients (2,080 lateral masses) who presented to a tertiary care public hospital (King Edward Memorial Hospital, Mumbai) in a metropolitan city in India.ResultsFor a majority of the parameters, males and females significantly differed at all levels (p<0.05). Females consistently required higher (p<0.05) minimum lateral angulation and lateral angulation. While the minimum lateral angulation followed the order of C5<C4<C6<C3, the lateral angulation followed the order of C3<C5<C4<C6. The lateral mass becomes longer and narrower from C3 to C7. In axial cuts, the dimensions increased from C3 to C6. The sagittal cut thickness and diagonal length increased and the sagittal cut height decreased from C3 to C7. The sagittal cut height was consistently lower in the Indian population at all levels, especially at the C7 level, as compared with the Western population, thereby questioning the acceptance of a 3.5-mm lateral mass screw. A good correlation exists between X-ray- and CT-based assessments of the lateral mass.ConclusionsLarger lateral angulation is required for Indian patients, especially females. The screw length can be effectively calculated by analyzing the lateral X-ray. A CT scan should be reserved for specific indications, and a caution must be exercised while inserting C7 lateral mass screws

    A phase-I, open label clinical trial to assess the safety &amp; tolerability of qHPV vaccine manufactured by Serum Institute of India Pvt. Ltd. in adults

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    Background: This first in human study was designed as an open label clinical trial to assess safety and tolerability of Serum Institute of India Pvt. Ltd. (SIIPL) quadrivalent HPV (qHPV) vaccine. Methods: A total of 48 healthy male and female (24 each) adult volunteers were administered a 0.5 ml single dose of SIIPL qHPV vaccine intramuscularly, and were followed for one month for safety outcomes viz., immediate, solicited, unsolicited and serious adverse events. Results: 47 subjects completed the study in compliance with protocol. One subject had pain immediately after immunization which was recovered without treatment. None of the participants experienced any other local or systemic solicited AEs and serious AE. Conclusion: qHPV vaccine manufactured by SIIPL was found to be safe and well tolerable in adults. Further clinical development should continue to assess safety and immunogenicity, in the target population following recommended 2 and 3-dose schedule.Clinical Trial Registration – CTRI/2017/02/007785
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