1,598 research outputs found
Cherenkov and Scintillation Light Separation in Organic Liquid Scintillators
The CHErenkov / Scintillation Separation experiment (CHESS) has been used to
demonstrate the separation of Cherenkov and scintillation light in both linear
alkylbenzene (LAB) and LAB with 2g/L of PPO as a fluor (LAB/PPO). This is the
first such demonstration for the more challenging LAB/PPO cocktail and improves
on previous results for LAB. A time resolution of 338 +/- 12 ps FWHM results in
an efficiency for identifying Cherenkov photons in LAB/PPO of 70 +/- 3% and 63
+/- 8% for time- and charge-based separation, respectively, with scintillation
contamination of 36 +/- 5% and 38 +/- 4%. LAB/PPO data is consistent with a
rise time of 0.75 +/- 0.25 ns
Structural Characterization and Numerical Modeling of Historic Quincha Walls
Quincha is a construction technique found in upper stories of many historic residential buildings on the coast of Peru, consisting of a timber frame with a woven cane and mud infill. This article presents the methodology for the development of a numerical model of the quincha system. The quincha walls have been subdivided into three components, the timber frame, bracing, and infill, and the modeling of each component is calibrated separately using experimental and analytical techniques. The resulting numerical model is found to successfully reproduce the behaviour of test specimens. The developed model can be used to assess the global seismic behavior of historic buildings containing quincha of varying geometries. This is demonstrated by modeling a portion of one of the facades of a well-known casona in Lima, Hotel el Comercio
Is there something of the MCT in orientationally disordered crystals ?
Molecular Dynamics simulations have been performed on the orientationally
disordered crystal chloroadamantane: a model system where dynamics are almost
completely controlled by rotations. A critical temperature T_c = 225 K as
predicted by the Mode Coupling Theory can be clearly determined both in the
alpha and beta dynamical regimes. This investigation also shows the existence
of a second remarkable dynamical crossover at the temperature T_x > T_c
consistent with a previous NMR and MD study [1]. This allows us to confirm
clearly the existence of a 'landscape-influenced' regime occurring in the
temperature range [T_c-T_x] as recently proposed [2,3].Comment: 4 pages, 5 figures, REVTEX
Human papillomavirus-16/18 AS04-adjuvanted cervical cancer vaccine: Immunogenicity and safety in healthy Chinese women from Hong Kong
Objective To assess the immunogenicity and safety of human papillomavirus-16/18 AS04-adjuvanted cervical cancer vaccine in Chinese women aged 18 to 35 years enrolled from Hong Kong. Design Double-blind, randomised controlled trial with vaccine and placebo groups. Setting Single-centre study in Hong Kong. Participants Three hundred women enrolled (150 per group) between March 2006 and June 2007. Interventions Subjects received three doses of human papillomavirus-16/18 vaccine or placebo (aluminium hydroxide), administered intramuscularly at 0, 1, and 6 months. Main outcome measures Human papillomavirus-16/18 seroconversion rates and geometric mean titres at month 7 (in human papillomavirus-16/18 recipients); reactogenicity and safety (in all subjects). Results A total of 294 women completed the study (148 in the vaccine group, 146 in placebo group). All initially seronegative subjects in the vaccine group had seroconverted for human papillomavirus-16/18 antibodies by month 7. Anti-human papillomavirus-16 and anti-human papillomavirus-18 antibody geometric mean titres were 10 422 (95% confidence interval, 8730-12 442) EL.U/mL and 4649 (3975-5437) EL.U/mL, respectively. High compliance (99% in both groups) was observed for the three-vaccination course. The frequencies of local injection site reactions were higher in the vaccine than placebo group; pain being the most common symptom in both groups. Regarding solicited symptoms, fatigue and myalgia were the most frequent in both groups. Five serious adverse events (four in vaccine group, one in placebo group) were reported, but all were considered unrelated to the vaccinations. Conclusion The human papillomavirus-16/18 AS04-adjuvanted vaccine was highly immunogenic, safe, and generally well tolerated in Chinese women from Hong Kong.published_or_final_versio
A low density of 0.8 g/cc for the Trojan binary asteroid 617 Patroclus
The Trojan population consists of two swarms of asteroids following the same
orbit as Jupiter and located at the L4 and L5 Lagrange points of the
Jupiter-Sun system (leading and following Jupiter by 60 degrees). The asteroid
617 Patroclus is the only known binary Trojan (Merline et al. 2001). The orbit
of this double system was hitherto unknown. Here we report that the components,
separated by 680 km, move around the system centre of mass, describing roughly
a circular orbit. Using the orbital parameters, combined with thermal
measurements to estimate the size of the components, we derive a very low
density of 0.8 g/cc. The components of Patroclus are therefore very porous or
composed mostly of water ice, suggesting that they could have been formed in
the outer part of the solar system.Comment: 10 pages, 3 figures, 1 tabl
Main Belt Binary Asteroidal Systems With Eccentric Mutual Orbits
Using 8m-10m class telescopes and their Adaptive Optics (AO) systems, we
conducted a long-term adaptive optics campaign initiated in 2003 focusing on
four binary asteroid systems: (130) Elektra, (283) Emma, (379) Huenna, and
(3749) Balam. The analysis of these data confirms the presence of their
asteroidal satellite. We did not detect any additional satellite around these
systems even though we have the capability of detecting a loosely-bound
fragment (located at 1/4 x RHill) ~40 times smaller in diameter than the
primary. The orbits derived for their satellites display significant
eccentricity, ranging from 0.1 to 0.9, suggesting a different origin. Based on
AO size estimate, we show that (130) Elektra and (283) Emma, G-type and P-type
asteroids respectively, have a significant porosity (30-60% considering CI-CO
meteorites as analogs) and their satellite's eccentricities (e~0.1) are
possibly due to excitation by tidal effects. (379) Huenna and (3749) Balam, two
loosely bound binary systems, are most likely formed by mutual capture. (3749)
Balam's possible high bulk density is similar to (433) Eros, another S-type
asteroid, and should be poorly fractured as well. (379) Huenna seems to display
both characteristics: the moonlet orbits far away from the primary in term of
stability (20% x RHill), but the primary's porosity is significant (30-60%).Comment: 60 pages, 7 tables, 4 figures, in press to Icaru
- …