1,798 research outputs found
Quasi-Simultaneous Two Band Optical Micro-Variability of Luminous Radio-Quiet QSOs
We report the first results of quasi-simultaneous two passband optical
monitoring of six quasi-stellar objects to search for micro-variability. We
carried out photometric monitoring of these sources in an alternating sequence
of R and V passbands, for five radio-quiet quasi-stellar objects (RQQSOs),
0748+291, 0824+098, 0832+251, 1101+319, 1225+317 and one radio-loud
quasi-stellar object (RLQSO), 1410+429. No micro-variability was detected in
any of the RQQSOs, but convincing micro-variability was detected in the RLQSO
on two successive nights it was observed. Using the compiled data of optical
micro-variability of RQQSOs till date, we got the duty cycle for
micro-variability in RQQSOs is 10%. The present investigation indicates
that micro-variability is not a persistent property of RQQSOs but an occasional
incident.Comment: 22 pages, 3 tables, 6 figures; Accepted for publication to New
Astronom
Results from the Blazar Monitoring Campaign at the Whipple 10m Gamma-ray Telescope
In September 2005, the observing program of the Whipple 10 m gamma-ray
telescope was redefined to be dedicated almost exclusively to AGN monitoring.
Since then the five Northern Hemisphere blazars that had already been detected
at Whipple are monitored routinely each night that they are visible. Thanks to
the efforts of a large number of multiwavelength collaborators, the first year
of this program has been very successful. We report here on the analysis of
Markarian 421 observations taken from November, 2005 to May, 2006 in the
gamma-ray, X-ray, optical and radio bands.Comment: 4 pages; contribution to the 30th International Cosmic Ray
Conference, Merida, Mexico, July 200
Minilaparoscopic Versus Open Pyeloplasty in Children Less Than 1 Year
Purpose:
The aim of this study is to compare minilaparoscopic (MLS) and open pyeloplasty (OP) in children <1 year in terms of intra- and perioperative outcomes and esthetic results.
Materials and Methods:
Patients <1 year of age, with prenatal hydronephrosis, who underwent Anderson-Hynes pyeloplasty for monolateral ureteropelvic junction obstruction (UPJO) at our center from January 2016 to August 2017 were enrolled in the study. Outcomes evaluated were as follows: operative time, length of hospital stay, and postoperative pain anterior-posterior pelvic diameter (APD) reduction. The Vancouver Scar Scale (VSS) was utilized to evaluate esthetic results. Mean follow-up was 26.5 months.
Results:
Eighteen patients (11M, 7F) of mean age 8.1 months (range 4-12) and mean weight 8.5 kg (range 7-10) underwent Anderson-Hynes pyeloplasty in the study period. Nine of eighteen underwent OP, and 9/18 underwent MLS. Mean operative time was 167 minutes for MLS versus 153 minutes for OP (P = .14). Mean hospital stay was 3.9 days for MLS versus 5.3 days for OP (P = .11). Mean APD reduction was 13.6 mm for MLS and 16.5 mm for OP procedures (P = .63). Mean VSS score was 1.3 for VLS versus 3.4 for OP (P = .04).
Conclusions:
MLS pyeloplasty is feasible and safe, and reported equivalent results as open procedure for management of UPJO also in toddlers and infants. We found that the only significant difference between the two approaches in children <1 year was represented by the esthetic outcome in the short follow-up period
Current-voltage scaling of a Josephson-junction array at irrational frustration
Numerical simulations of the current-voltage characteristics of an ordered
two-dimensional Josephson junction array at an irrational flux quantum per
plaquette are presented. The results are consistent with an scaling analysis
which assumes a zero temperature vortex glass transition. The thermal
correlation length exponent characterizing this transition is found to be
significantly different from the corresponding value for vortex-glass models in
disordered two-dimensional superconductors. This leads to a current scale where
nonlinearities appear in the current-voltage characteristics decreasing with
temperature roughly as in contrast with the behavior expected
for disordered models.Comment: RevTex 3.0, 12 pages with Latex figures, to appear in Phys. Rev. B
54, Rapid. Com
Emergence of a confined state in a weakly bent wire
In this paper we use a simple straightforward technique to investigate the
emergence of a bound state in a weakly bent wire. We show that the bend behaves
like an infinitely shallow potential well, and in the limit of small bending
angle and low energy the bend can be presented by a simple 1D delta function
potential.Comment: 4 pages, 3 Postscript figures (uses Revtex); added references and
rewritte
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