20,229 research outputs found

    Magnetization transfer MRI measurements of cervical spinal cord abnormalities in patients with neuromyelitis optica

    Get PDF
    Poster Presentation - Advanced Imaging of Spine: no. 4230postprintThe Joint Annual Meeting of ISMRM-ESMRMB 2010, Stockholm, Sweden, 1-7 May 2010

    Quantitative assessment of the cervical spinal cord damage in neuromyelitis optica using diffusion tensor imaging at 3T

    Get PDF
    postprintThe Joint Annual Meeting of ISMRM-ESMRMB 2010, Stockholm, Sweden, 1-7 May 2010

    Low Pressure Ethenolysis of Renewable Methyl Oleate in a Microchemical System

    Get PDF
    A microchemical system for ethenolysis of renewable methyl oleate was developed, in which the dual-phase, microfluidic design enabled efficient diffusion of ethylene gas into liquid methyl oleate through an increased contact area. The increased mass transfer of ethylene favored the formation of desired commodity chemicals with significantly suppressed homometathesis when compared to the bulk system. In addition to higher selectivity and conversion, this system also provides the typical advantages of a microchemical system, including the possibility of convenient scale-up

    The effect of 3He impurities on the nonclassical response to oscillation of solid 4He

    Full text link
    We have investigated the influence of impurities on the possible supersolid transition by systematically enriching isotopically-pure 4He (< 1 ppb of 3He) with 3He. The onset of nonclassical rotational inertia is broadened and shifts monotonically to higher temperature with increasing 3He concentration, suggesting that the phenomenon is correlated to the condensation of 3He atoms onto the dislocation network in solid 4He.Comment: 4 page

    Absence of supersolidity in solid helium in porous Vycor glass

    Full text link
    In 2004, Kim and Chan (KC) carried out torsional oscillator (TO) measurements of solid helium confined in porous Vycor glass and found an abrupt drop in the resonant period below 200 mK. The period drop was interpreted as probable experimental evidence of nonclassical rotational inertia (NCRI). This experiment sparked considerable activities in the studies of superfluidity in solid helium. More recent ultrasound and TO studies, however, found evidence that shear modulus stiffening is responsible for at least a fraction of the period drop found in bulk solid helium samples. The experimental configuration of KC makes it unavoidable to have a small amount of bulk solid inside the torsion cell containing the Vycor disc. We report here the results of a new helium in Vycor experiment with a design that is completely free from any bulk solid shear modulus stiffening effect. We found no measureable period drop that can be attributed to NCRI
    • …
    corecore