3,732 research outputs found
Debris cover and surface melt at a temperate maritime alpine glacier: Franz Josef Glacier, New Zealand
Melt rates on glaciers are strongly influenced by the presence of supraglacial debris, which can either enhance or reduce ablation relative to bare ice. Most recently, Franz Josef Glacier has entered into a phase of strong retreat and downwasting, with the increasing emergence of debris on the surface in the ablation zone. Previously at Franz Josef Glacier, melt has only been measured on bare ice. During February 2012, a network of 11 ablation stakes was drilled into locations of varying supraglacial debris thickness on the lower glacier. Mean ablation rates over 9 days varied over the range 1.2â10.1 cm dâ1, and were closely related to debris thickness. Concomitant observations of air temperature allowed the application of a degree-day approach to the calculation of melt rates, with air temperature providing a strong indicator of melt. Degree-day factors (d f) varied over the range 1.1â8.1 mm dâ1 °Câ1 (mean of 4.4 mm dâ1 °Câ1), comparable with rates reported in other studies. Mapping of the current debris cover revealed 0.7 km2 of the 4.9 km2 ablation zone surface was debris-covered, with thicknesses ranging 1â50 cm. Based on measured debris thicknesses and d f, ablation on debris-covered areas of the glacier is reduced by a total of 41% which equates to a 6% reduction in melt overall across the entire ablation zone. This study highlights the usefulness of a short-term survey to gather representative ablation data, consistent with numerous overseas ablation studies on debris-covered glaciers
Orbital operations study. Volume 2: Interfacing activities analysis. Part 2: Structural and mechanical group
The activities of the structural and mechanical activity group of the orbital operations study project are discussed. Element interfaces, alternate approaches, design concepts, operational procedures, functional requirements, design influences, and approach selection are presented. The following areas are considered: (1) mating, (2) orbital assembly, (3) separation, EOS payload deployment, and EOS payload retraction
Orbital operations study. Appendix B: Operational procedures
Operational procedures for each alternate approach for each interfacing activity of the orbital operations study are presented. The applicability of the procedures to interfacing element pairs is identified
Small cell carcinoma of the cervix: a retrospective analysis of characteristics important in outcomes
To assess clinical characteristics and treatment modalities in patients with small cell carcinoma of the cervix and the effect this has on overall (OS) and recurrence free survival (RFS)
Superficial versus deep lymph node dissection in early stage vulvar carcinoma
Our primary objective was to evaluate the difference in overall survival, recurrence rate, and post-operative morbidity related to superficial versus deep inguinal lymphadenectomy in squamous cell carcinoma of the vulva
Off-Equilibrium Dynamics in Finite-Dimensional Spin Glass Models
The low temperature dynamics of the two- and three-dimensional Ising spin
glass model with Gaussian couplings is investigated via extensive Monte Carlo
simulations. We find an algebraic decay of the remanent magnetization. For the
autocorrelation function a typical
aging scenario with a scaling is established. Investigating spatial
correlations we find an algebraic growth law of
the average domain size. The spatial correlation function scales with . The sensitivity of the
correlations in the spin glass phase with respect to temperature changes is
examined by calculating a time dependent overlap length. In the two dimensional
model we examine domain growth with a new method: First we determine the exact
ground states of the various samples (of system sizes up to )
and then we calculate the correlations between this state and the states
generated during a Monte Carlo simulation.Comment: 38 pages, RevTeX, 14 postscript figure
Multimodal perioperative pain protocol for Gynecologic Oncology laparotomy reduces length of hospital stay
Our primary objective was to evaluate the impact of a multimodal perioperative pain regimen on length of hospital stay for patients undergoing laparotomy with a gynecologic oncologist
Classical limit in terms of symbolic dynamics for the quantum baker's map
We derive a simple closed form for the matrix elements of the quantum baker's
map that shows that the map is an approximate shift in a symbolic
representation based on discrete phase space. We use this result to give a
formal proof that the quantum baker's map approaches a classical Bernoulli
shift in the limit of a small effective Plank's constant.Comment: 12 pages, LaTex, typos correcte
"After my husband's circumcision, I know that I am safe from diseases": Women's Attitudes and Risk Perceptions Towards Male Circumcision in Iringa, Tanzania.
While male circumcision reduces the risk of female-to-male HIV transmission and certain sexually transmitted infections (STIs), there is little evidence that circumcision provides women with direct protection against HIV. This study used qualitative methods to assess women's perceptions of male circumcision in Iringa, Tanzania. Women in this study had strong preferences for circumcised men because of the low risk perception of HIV with circumcised men, social norms favoring circumcised men, and perceived increased sexual desirability of circumcised men. The health benefits of male circumcision were generally overstated; many respondents falsely believed that women are also directly protected against HIV and that the risk of all STIs is greatly reduced or eliminated in circumcised men. Efforts to engage women about the risks and limitations of male circumcision, in addition to the benefits, should be expanded so that women can accurately assess their risk of HIV or STIs during sexual intercourse with circumcised men
The efficient low-mass Seyfert MCG-05-23-016
The Seyfert 1.9 galaxy MCG-05-23-016 has been shown to exhibit a complex
X-ray spectrum. This source has moderate X-ray luminosity, hosts a comparably
low-mass black hole, but accretes at a high Eddington rate, and allows us to
study a super massive black hole in an early stage. Three observations of the
INTEGRAL satellite simultaneous with pointed Swift/XRT observations performed
from December 2006 to June 2007 are used in combination with public data from
the INTEGRAL archive to study the variability of the hard X-ray components and
to generate a high-quality spectrum from 1 to 150 keV. The AGN shows little
variability in the hard X-ray spectrum, with some indication of a variation in
the high-energy cut-off energy ranging from 50 keV to >>100 keV, with an
electron plasma temperature in the 10 - 90 keV range. The reflection component
is not evident and, if present, the reflected fraction can be constrained to R
< 0.3 for the combined data set. Comparison to previous observations shows that
the reflection component has to be variable. No variability in the UV and
optical range is observed on a time scale of 1.5 years. The hard X-ray spectrum
of MCG-05-23-016 appears to be stable with the luminosity and underlying power
law varying moderately and the optical/UV flux staying constant. The spectral
energy distribution appears to be similar to that of Galactic black hole
systems, e.g. XTE 1118+480 in the low state. The AGN exhibits a remarkably high
Eddington ratio of L(bol)/L(Edd)> 0.8 (or L(bol)/L(Edd) > 0.1, if we consider a
higher mass of the central engine) and, at the same time, a low cut-off energy
around 70 keV. Objects like MCG-05-23-016 might indicate the early stages of
super massive black holes, in which a strong accretion flow feeds the central
engine.Comment: 8 pages, 5 figures, accepted for publication in A&
- âŠ