Thermal History of Solid 4He Under Oscillation (2007)
Clark, A. C., Maynard, J. D., Chan, M. H. W.
We have studied the thermal history of the resonant frequency of a torsional oscillator containing solid 4He. We find that the magnitude of the frequency shift that occurs below 100 mK is multivalued...
The effect of 3He impurities on the nonclassical response to oscillation of solid 4He (2007)
Kim, E., Xia, J. S., West, J. T., Lin, X., Clark, A. C., Chan, M. H. W.
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...
Nonclassical Rotational Inertia in Single Crystal Helium (2007)
Clark, A. C., West, J. T., Chan, M. H. W.
It has been proposed that the observed nonclassical rotational inertia (NCRI) in solid helium results from the superflow of thin liquid films along interconnected grain boundaries within the sample....
Search for Superfluidity in Solid Hydrogen (2006)
Clark, A. C., Lin, X., Chan, M. H. W.
A torsional oscillator study of solid para-hydrogen has been carried out down to 20 mK in search for evidence of superfluidity. This work was inspired by the observation of the supersolid phase in...
Acute acquired comitant esotropia.
Clark, A C, Nelson, L B, Simon, J W, Wagner, R, Rubin, S E
Acute acquired comitant esotropia has been used to describe a dramatic onset of a relatively large angle of esotropia with diplopia and minimal refractive error. We describe six children aged 5 to 11...
Clark, A. C., Karon, B. S., Frieden, C.
Previous investigation has shown that at 22 degrees C and in the presence of the chaperonin GroEL, the slowest step in the refolding of Escherichia coli dihydrofolate reductase (EcDHFR) reflects...