83,170 research outputs found
On the nature of the phase transitions in two-dimensional type II superconductors
We have simulated the thermodynamics of vortices in a thin film of a type-II
superconductor. We make the lowest Landau level approximation, and use
quasi-periodic boundary conditions. Our work is consistent with the results of
previous simulations where evidence was found for an apparent first order
transition between the vortex liquid state and the vortex crystal state. We
show, however, that these results are just an artifact of studying systems
which are too small. There are substantial difficulties in simulating larger
systems using traditional approaches. By means of the optimal energy diffusion
algorithm we have been able to study systems containing up to about one
thousand vortices, and for these larger systems the evidence for a first order
transition disappears. By studying both crystalline and hexatic order, we show
that the KTHNY scenario seems to apply, where melting from the crystal is first
to the hexatic liquid state and next to the normal vortex liquid, in both cases
via a continuous transition.Comment: 26 pages, 26 composite figures. Pre-proof versio
Microwave radiometer-scatterometer measurements
There are no author-identified significant results in this report
Development of a lithium secondary battery separator
A nonporous membrane based on the polymerization of 2,3-dihydrofuran followed by crosslinking in situ was prepared. The material is compatible with rechargeable Li battery components and, when swollen with an appropriate solvent such as tetrahydrofuran, exhibits separator resistance and Li transport equivalent to Celgard
Common drive unit
The Common Drive Unit (CDU) is a high reliability rotary actuator with many versatile applications in mechanism designs. The CDU incorporates a set of redundant motor-brake assemblies driving a single output shaft through differential. Tachometers provide speed information in the AC version. Operation of both motors, as compared to the operation of one motor, will yield the same output torque with twice the output speed
The ultraviolet excess of quasars 3: The highly polarized quasars PKS 0736+017 and PKS 1510-089
Ultraviolet/optical/infrared spectrophotometry of the highly-polarized quasars (HPQ's) PKS 0736+017 and PKS 1510-089 is analyzed. A blazar continuum component like that in BL Lac objects (e.g. with violent variability, high polarization, and a steep power-law shape) contributes about half the visual light of 1510-089, and at least three-quarters of that in 0736+017. The remaining light has the same spectrum as normal (low-polarization) quasars, including an ultraviolet excess or blue bump, which is easily detected in the IUE spectra of 1510-089, and weakly detected in 0736+017. The line fluxes do vary, but not as much as the continuum. The ratios of the broad emission lines, and the Balmer continuum are normal in both quasars
Investigation of thermionic energy conversion final report, 9 jul. - 9 sep. 1962
Refractory ceramic oxide for thermionic diode
Next-to-Leading Order Shear Viscosity in lambda phi^4 Theory
We show that the shear viscosity of lambda phi^4 theory is sensitive at
next-to-leading order to soft physics, which gives rise to subleading
corrections suppressed by only a half power of the coupling, eta = [3033.54 +
1548.3 m_{th}/T] N T^3]/[ (N+2)/3 lambda^2], with m^2_th=(N+2)/72 lambda T^2.
The series appears to converge about as well (or badly) as the series for the
pressure.Comment: 4 pages, 1 figure. Typos fixed, tiny change in discussio
- …