12,146 research outputs found
Recommendations for a wind profiling network to support Space Shuttle launches
The feasibility is examined of a network of clear air radar wind profilers to forecast wind conditions before Space Shuttle launches during winter. Currently, winds are measured only in the vicinity of the shuttle launch site and wind loads on the launch vehicle are estimated using these measurements. Wind conditions upstream of the Cape are not monitored. Since large changes in the wind shear profile can be associated with weather systems moving over the Cape, it may be possible to improve wind forecasts over the launch site if wind measurements are made upstream. A radar wind profiling system is in use at the Space Shuttle launch site. This system can monitor the wind profile continuously. The existing profiler could be combined with a number of radars located upstream of the launch site. Thus, continuous wind measurements would be available upstream and at the Cape. NASA-Marshall representatives have set the requirements for radar wind profiling network. The minimum vertical resolution of the network must be set so that the wind shears over the depths greater than or = 1 km will be detected. The network should allow scientists and engineers to predict the wind profile over the Cape 6 hours before a Space Shuttle launch
Accuracy of urinary human papillomavirus testing for presence of cervical HPV: systematic review and meta-analysis
This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 3.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/3.0/.Funding: This study did not receive any fundin
URINARY TESTING FOR HPV Authors' reply to Vorsters and colleagues
This is the peer reviewed published version of the following article: URINARY TESTING FOR HPV Authors' reply to Vorsters and colleagues, which has been published in final form at 10.1136/bmj.g6253. This article may be used for non-commercial purposes in accordance with BMJ's Terms and Conditions for Self-Archiving.
This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/ by/4.0
Rhodium and copper 6-methylpicolinate complexes. Structural diversity and supramolecular interaction study
Seven new coordination compounds with 6-methylpicolinic acid (6-HMepic) and rhodium(III) or copper(II) of formula [Rh(6-Mepic)3] (1), [Rh(6-Mepic)2(H2O)Cl] (2), [Rh(6-HMepic)(6-Mepic)Cl2]·3.5(H2O) (3), [Cu(6-Mepic)2(H2O)]·H2O (4), [Cu(6-Mepic)2]n, (5), [Cu(6-Mepic)(6-HMepic)I] (6) and [Cu(6-Mepic)(6-HMepic)Cl] (7) have been obtained. Their syntheses have been rationalized, and their structural and supramolecular characteristics have been studied and compared with other similar rhodium and copper picolinate complexes previously reported, in order to stablish structural correlations and analogies. The electrical properties of coordination polymer [Cu(6-Mepic)2]n (5) have been also analyzed and it has been found that it shows a moderated electrical transport along the chain.We thank the financial support from the Spanish Ministerio de Economía y Competitividad (MAT2013-46502-C2-2P and MAT2013-46753-C2-1P). Also the scientific computing center (CCC) of the Autonoma University of Madrid for their tim
Verlinde's emergent gravity in an dimensional, non-additive Tsallis' scenario
This paper brings together four distinct but very important physical notions:
1) Entropic force, 2) Entropy-along-a-curve, 3) Tsallis' q-statistics, and 4)
Emergent gravitation. We investigate the non additive, classical (Tsallis')
q-statistical mechanics of a phase-space curve in dimensions (3 dimensions,
in particular). We focus attention on an entropic force mechanism that yields a
simple realization of it, being able to mimic interesting effects such as
confinement, hard core, and asymptotic freedom, typical of high energy physicsComment: 19 pqges. 2 figures. Title has changed. Text has changed
significantl
Polydispersity Effects in the Dynamics and Stability of Bubbling Flows
The occurrence of swarms of small bubbles in a variety of industrial systems
enhances their performance. However, the effects that size polydispersity may
produce on the stability of kinematic waves, the gain factor, mean bubble
velocity, kinematic and dynamic wave velocities is, to our knowledge, not yet
well established. We found that size polydispersity enhances the stability of a
bubble column by a factor of about 23% as a function of frequency and for a
particular type of bubble column. In this way our model predicts effects that
might be verified experimentally but this, however, remain to be assessed. Our
results reinforce the point of view advocated in this work in the sense that a
description of a bubble column based on the concept of randomness of a bubble
cloud and average properties of the fluid motion, may be a useful approach that
has not been exploited in engineering systems.Comment: 11 pages, 2 figures, presented at the 3rd NEXT-SigmaPhi International
Conference, 13-18 August, 2005, Kolymbari, Cret
On the critical end point in a two-flavor linear sigma model coupled to quarks
We use the linear sigma model coupled to quarks to explore the location of
the phase transition lines in the QCD phase diagram from the point of view of
chiral symmetry restoration at high temperature and baryon chemical potential.
We compute analytically the effective potential in the high- and
low-temperature approximations up to sixth order, including the contribution of
the ring diagrams to account for the plasma screening properties. We determine
the model parameters, namely, the couplings and mass-parameter, from conditions
valid at the first order phase transition at vanishing temperature and, using
the Hagedorn limiting temperature concept applied to finite baryon density, for
a critical baryochemical potential of order of the nucleon mass. We show that
when using the set of parameters thus determined, the second order phase
transition line (our proxy for the crossover transition) that starts at finite
temperature and zero baryon chemical potential converges to the line of first
order phase transitions that starts at zero temperature and finite baryon
chemical potential to determine the critical end point to lie in the region
5.02<\mu_B^{\mbox{CEP}}/T_c<5.18, 0.14, where
is the critical transition temperature at zero baryon chemical potential.Comment: 11 pages, 3 figures, discussion extended, explicit calculations
included in appendices and version accepted for publication in EPJ
- …
