27 research outputs found

    Behavior of fluids in the vicinity of the critical point

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    Fluid behavior in vicinity of critical poin

    PVF2 Transducers for NDT

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    We have investigated the spatial dependence of the longitudinal piezoelectric stress constant e of PVF2. Experiments were performed on a series of no.minally identical brass-backed PVF2 longitudinal wave transducers in water using commercial PVF2 film. Computer programs were designed to predict the performance of the transducers as a function of ezz (Z) , the thickness mode piezoelectric stress constant as a function of position Z through the thickness of the film. Our experiments indicate that the coupling coefficient is uniform across the film thickness. These computer programs were also used to model the insertion loss and bandwidth performance of the transducers. High voltage pulses were applied to PVF2 transducers to determine the region of linearity and to find the maximum nondestructive voltage that can be used. Transducers of this type were also made using PVF films fabricated in the Stanford Center for Materials Research using commercial resin, and found to pertorm as well as transducers using commercial film. Transducers of the above kind have also been used as bulk wave sources in wedge transducer assemblies for the production of surface acoustic waves on ceramic plates, and initial observations of reflections from surface cracks have been made

    Laboratory Equipment Type Fiber Optic Refractometer

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    Using fiber optics and micro optics technologies we designed aninnovative fiber optic index of refraction transducer that has uniqueproperties. On the base of this transducer a laboratory equipment typefiber optic refractometer was developed for liquid index of refractionmeasurements. Such refractometer may be used for medical,pharmaceutical, industrial fluid, petrochemical, plastic, food, andbeverage industry applications. For example, it may be used formeasuring the concentrations of aqueous solutions: as the concentrationor density of a solute increase, the refractive index increasesproportionately. The paper describes development work related to designof laboratory type fiber optic refractometer and describes experimentsto evaluation of its basic properties

    PVF2 Transducers for NDT

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    We have investigated the spatial dependence of the longitudinal piezoelectric stress constant e of PVF2. Experiments were performed on a series of no.minally identical brass-backed PVF2 longitudinal wave transducers in water using commercial PVF2 film. Computer programs were designed to predict the performance of the transducers as a function of ezz (Z) , the thickness mode piezoelectric stress constant as a function of position Z through the thickness of the film. Our experiments indicate that the coupling coefficient is uniform across the film thickness. These computer programs were also used to model the insertion loss and bandwidth performance of the transducers. High voltage pulses were applied to PVF2 transducers to determine the region of linearity and to find the maximum nondestructive voltage that can be used. Transducers of this type were also made using PVF films fabricated in the Stanford Center for Materials Research using commercial resin, and found to pertorm as well as transducers using commercial film. Transducers of the above kind have also been used as bulk wave sources in wedge transducer assemblies for the production of surface acoustic waves on ceramic plates, and initial observations of reflections from surface cracks have been made.</p

    Cross-Sectional Analysis of the 1039 U.S. Physicians Reported to the National Practitioner Data Bank for Sexual Misconduct, 2003-2013.

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    Little information exists on U.S. physicians who have been disciplined with licensure or restriction-of-clinical-privileges actions or have had malpractice payments because of sexual misconduct. Our objectives were to: (1) determine the number of these physicians and compare their age groups' distribution with that of the general U.S. physician population; (2) compare the type of disciplinary actions taken against these physicians with actions taken against physicians disciplined for other offenses; (3) compare the characteristics and type of injury among victims of these physicians with those of victims in reports for physicians with other offenses in malpractice-payment reports; and (4) determine the percentages of physicians with clinical-privileges or malpractice-payment reports due to sexual misconduct who were not disciplined by medical boards.We conducted a cross-sectional analysis of physician reports submitted to the National Practitioner Data Bank (NPDB) from January 1, 2003, through September 30, 2013. A total of 1039 physicians had ≥ 1 sexual-misconduct-related reports. The majority (75.6%) had only licensure reports, and 90.1% were 40 or older. For victims in malpractice-payment reports, 87.4% were female, and "emotional injury only" was the predominant type of injury. We found a higher percentage of serious licensure actions and clinical-privileges revocations in sexual-misconduct-related reports than in reports for other offenses (89.0% vs 68.1%, P = < .001, and 29.3% vs 18.8%, P = .002, respectively). Seventy percent of the physicians with a clinical-privileges or malpractice-payment report due to sexual misconduct were not disciplined by medical boards for this problem.A small number of physicians were reported to the NPDB because of sexual misconduct. It is concerning that a majority of the physicians with a clinical-privileges action or malpractice-payment report due to sexual misconduct were not disciplined by medical boards for this unethical behavior

    PVF2 Transducers for NDT

    No full text
    We have investigated the spatial dependence of the longitudinal piezoelectric stress constant e of PVF2. Experiments were performed on a series of no.minally identical brass-backed PVF2 longitudinal wave transducers in water using commercial PVF2 film. Computer programs were designed to predict the performance of the transducers as a function of ezz (Z) , the thickness mode piezoelectric stress constant as a function of position Z through the thickness of the film. Our experiments indicate that the coupling coefficient is uniform across the film thickness. These computer programs were also used to model the insertion loss and bandwidth performance of the transducers. High voltage pulses were applied to PVF2 transducers to determine the region of linearity and to find the maximum nondestructive voltage that can be used. Transducers of this type were also made using PVF films fabricated in the Stanford Center for Materials Research using commercial resin, and found to pertorm as well as transducers using commercial film. Transducers of the above kind have also been used as bulk wave sources in wedge transducer assemblies for the production of surface acoustic waves on ceramic plates, and initial observations of reflections from surface cracks have been made.</p

    Fiber optic gradient hydrophone

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