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On the boundary layer structure of differentially heated cavity flow in a stably stratified porous medium
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On the boundary-layer structure of high-Prandtl-number horizontal convection
Stirling cycle cryogenic cooler
A long lifetime Stirling cycle cryogenic cooler particularly adapted for space applications is described. It consists of a compressor section centrally aligned end to end with an expansion section, and respectively includes a reciprocating compressor piston and displacer radially suspended in interconnecting cylindrical housings by active magnetic bearings and has adjacent reduced clearance regions so as to be in noncontacting relationship therewith and wherein one or more of these regions operate as clearance seals. The piston and displacer are reciprocated in their housings by linear drive motors to vary the volume of respectively adjacent compression and expansion spaces which contain a gaseous working fluid and a thermal regenerator to effect Stirling cycle cryogenic cooling
Hysteresis and competition between disorder and crystallization in sheared and vibrated granular flow
Experiments on spherical particles in a 3D Couette cell vibrated from below
and sheared from above show a hysteretic freezing/melting transition. Under
sufficient vibration a crystallized state is observed, which can be melted by
sufficient shear. The critical line for this transition coincides with equal
kinetic energies for vibration and shear. The force distribution is
double-peaked in the crystalline state and single-peaked with an approximately
exponential tail in the disordered state. A linear relation between pressure
and volume () exists for a continuum of partially and/or
intermittently melted states over a range of parameters
Instabilities in droplets spreading on gels
We report a novel surface-tension driven instability observed for droplets
spreading on a compliant substrate. When a droplet is released on the surface
of an agar gel, it forms arms/cracks when the ratio of surface tension gradient
to gel strength is sufficiently large. We explore a range of gel strengths and
droplet surface tensions and find that the onset of the instability and the
number of arms depend on the ratio of surface tension to gel strength. However,
the arm length grows with an apparently universal law L ~ t^{3/4}
Hysterectomy, endometrial ablation, and levonorgestrel releasing intrauterine system (Mirena) for treatment of heavy menstrual bleeding : cost effectiveness analysis
Peer reviewedPublisher PD
A Multicenter, Prospective, Randomized, Contralateral Study of Tissue Liquefaction Liposuction vs Suction-Assisted Liposuction
Tissue liquefaction liposuction (TLL) deploys a novel energy source utilizing a stream of warmed, low-pressurized, and pulsed saline to extract fat tissue.
Objectives:
Compare TLL to suction-assisted liposuction (SAL) to determine which device is more efficient for surgeons and provides better recovery for patients.
Methods:
Thirty-one adult female patients were followed prospectively in a contralateral study design comparing differences in bruising, swelling, tenderness, and incision appearance ratings between TLL and SAL procedures. Surgical efficiency and appearance of the lipoaspirate were also compared.
Results:
All 31 patients successfully completed the study. For TLL and SAL procedures, the average volumes of infusion (1.242 vs 1.276 L) and aspirated supernatant fat (704 vs 649 mL) were statistically similar. TLL median fat extraction rate was faster than SAL (35.6 vs 25 mL/min; P < 0.0001), and stroke rate was reduced in TLL vs SAL procedures (48 vs 120 strokes/min; P < 0.0001), and both were statistically significant. The mean total scores for bruising, swelling, treatment site tenderness, and incision appearance were lower, indicating improved patient recovery on the TLL side.
Conclusions:
TLL and SAL techniques produced comparable volume of fat aspirate. TLL demonstrated a 42% faster fat extraction rate and a 68% reduction in arm movements needed to complete the procedure compared to SAL, both of these differences are statistically significant. The TLL side was noted to have reduced bruising and swelling and improved incision site appearance with less tenderness compared to the SAL side
Hysterectomy, endometrial destruction, and levonorgestrel releasing intrauterine system (Mirena) for heavy menstrual bleeding : systematic review and meta-analysis of data from individual patients
Peer reviewedPublisher PD
Statistical properties of stock order books: empirical results and models
We investigate several statistical properties of the order book of three
liquid stocks of the Paris Bourse. The results are to a large degree
independent of the stock studied. The most interesting features concern (i) the
statistics of incoming limit order prices, which follows a power-law around the
current price with a diverging mean; and (ii) the humped shape of the average
order book, which can be quantitatively reproduced using a `zero intelligence'
numerical model, and qualitatively predicted using a simple approximation.Comment: Revised version, 10 pages, 4 .eps figures. to appear in Quantitative
Financ
Burst avalanches in solvable models of fibrous materials
We review limiting models for fracture in bundles of fibers, with
statistically distributed thresholds for breakdown of individual fibers. During
the breakdown process, avalanches consisting of simultaneous rupture of several
fibers occur, and the distribution of the magnitude of
such avalanches is the central characteristics in our analysis. For a bundle of
parallel fibers two limiting models of load sharing are studied and contrasted:
the global model in which the load carried by a bursting fiber is equally
distributed among the surviving members, and the local model in which the
nearest surviving neighbors take up the load. For the global model we
investigate in particular the conditions on the threshold distribution which
would lead to anomalous behavior, i.e. deviations from the asymptotics
, known to be the generic behavior. For the local
model no universal power-law asymptotics exists, but we show for a particular
threshold distribution how the avalanche distribution can nevertheless be
explicitly calculated in the large-bundle limit.Comment: 28 pages, RevTeX, 3 Postscript figure
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