260 research outputs found
High--Resolution 3D Simulations of Relativistic Jets
We have performed high-resolution 3D simulations of relativistic jets with
beam flow Lorentz factors up to 7, a spatial resolution of 8 cells per beam
radius, and for up to 75 normalized time units to study the morphology and
dynamics of 3D relativistic jets. Our simulations show that the coherent fast
backflows found in axisymmetric models are not present in 3D models. We further
find that when the jet is exposed to non-axisymmetric perturbations, (i) it
does not display the strong perturbations found for 3D classical hydrodynamic
and MHD jets (at least during the period of time covered by our simulations),
and (ii) it does propagate according to the 1D estimate. Small 3D effects in
the relativistic beam give rise to a lumpy distribution of apparent speeds like
that observed in M87. The beam is surrounded by a boundary layer of high
specific internal energy. The properties of this layer are briefly discussed.Comment: 15 pages, 4 figures. Accepted to be publish in the ApJ Letters.
Tar+gzip documen
Basketball game-related statistics that discriminate between teams season-long success
The aim of the present study was to identify the game-related statistics that discriminate between season-long successful and unsuccessful basketball teams participating in the Spanish Basketball League (LEB1). The sample included all 145 average records per season from the 870 games played between the 2000-2001 and the 2005-2006 regular seasons. The following game-related statistics were gathered from the official box scores of the Spanish Basketball Federation: 2- and 3-point field-goal attempts (both successful and unsuccessful), free-throws (both successful and unsuccessful), defensive and offensive rebounds, assists, steals, turnovers, blocks (both made and received), and fouls (both committed and received). To control for season variability, all results were normalized to minutes played each season and then converted to z-scores. The results allowed discrimination between best and worst teams' performances through the following game-related statistics: assists (SC=0.47), steals (SC=0.34), and blocks (SC=0.30). The function obtained correctly classified 82.4% of the cases. In conclusion, season-long performance may be supported by players' and teams' passing skills and defensive preparation
Primera encuesta de "Nuestro cinema"
Casinos Guillén, A.; Marinel·lo Roca, R.; Gómez Ibáñez, J. (1932). Primera encuesta de "Nuestro cinema". Nuestro cinema. (6):161-167. http://hdl.handle.net/10251/42816.Importación Masiva161167
3D Simulations of Relativistic Precessing Jets Probing the Structure of Superluminal Sources
We present the results of a three-dimensional, relativistic, hydrodynamic
simulation of a precessing jet into which a compact blob of matter is injected.
A comparison of synthetic radio maps computed from the hydrodynamic model,
taking into account the appropriate light travel time delays, with those
obtained from observations of actual superluminal sources shows that the
variability of the jet emission is the result of a complex combination of phase
motions, viewing angle selection effects, and non-linear interactions between
perturbations and the underlying jet and/or the external medium. These results
question the hydrodynamic properties inferred from observed apparent motions
and radio structures, and reveal that shock-in-jet models may be overly
simplistic.Comment: Accepted for publication in ApJL. 4 pages, 5 figures (4 in color
Comparación analítica de dos consolidantes comerciales aplicados en areniscas eocenas de monumentos de los siglos XVI y XIX en San Sebastián (norte de España)
The conservation of buildings in the Basque Country made of Eocene sandstone is somewhat problematical, because this type of rock is relatively unstable. This instability is due to the variable content of carbonate cement (0-28%) and the presence of K-feldspar grains (1-13%) which appear to have been dissolved by both diagenetic and environmental processes. We have compared the results of the application of two commercial consolidating products: Sicof SM 296 (product A) and Consistone FS-hA (product B), both ethylsilicates, on Eocene sandstones of the Oquendo Admiral House (16th century) and the Gipuzkoa Provincial Government Palace (19th century), which are both located in the city of San Sebastián (Province of Gipuzkoa, Basque Country, Northern Spain). On the basis of different chemical and physical laboratory tests, together with Scanning Electron Microscopy (SEM) analysis, product A seems to be more efficient in consolidating such Eocene sandstone materials, since it penetrates into the first 8 mm of the rock, occupies very homogeneously even the smallest pore spaces and leaves a certain degree of remaining porosity which allows ventilation of the rock. In contrast, product B seems to be more appropriate for larger pore-sized rocks, because it only penetrates into the first 3 mm of the Eocene sandstone samples due to the thin pores of the matter. Our results demonstrate that the suitability of a commercial product depends not only on its own chemical composition, but also on the textural and lithological features of the rock material upon which it is to be applied.La conservación de los edificios del País Vasco construidos con areniscas del Eoceno es problemática porque este tipo de roca es relativamente inestable debido a su contenido variable en cemento carbonatado (0-28%) y a la presencia de granos de feldespato potásico (1-13%) disueltos tanto por procesos diagenéticos como ambientales. Hemos aplicado dos consolidantes comerciales: Sicof SM 296 (producto A) y Consistone FS+A (producto B), ambos silicatos de etilo, sobre las areniscas de la Casa del Almirante Oquendo (siglo XVI) y el Palacio de la Diputación Foral de Gipuzkoa (siglo XIX), ambos edificios en San Sebastián (País Vasco, norte de España). Los diferentes ensayos físicos y químicos junto con las observaciones al microscopio electrónico de barrido (SEM) revelan que el producto A es más eficiente para la consolidación de este tipo de areniscas, dado que penetra los primeros 8 mm de la roca, ocupa muy regularmente incluso los poros más pequeños y deja un cierto grado de porosidad remanente que permite la aireación de la roca. Por el contrario, el producto B parece más adecuado para rocas con mayor tamaño de poro, dado que sólo penetra los primeros 3 mm. Con ello, queda claro que la eficiencia de un consolidante comercial depende no sólo de su composición química, sino, en gran medida, de las características texturales y litológicas de la roca sobre la que se va a aplicar
"The trauma of competition": the entry of Air Products Inc. into the industrial gases business in Britain and continental Europe 1947-1970
The British Oxygen Company (BOC) had a virtual monopoly on the supply of industrial gases (e.g. oxygen and acetylene) on the British market through the 1950s, when it was finally challenged by an American-based company, Air Products. Air Products Limited (APL) was able to undercut BOCs position, overcoming high barriers to entry to gain significant market share in this sector, which shares some features of network industries. Factors in this success included conditions imposed by the Board of Trade, APL’s innovations, BOC’s slow response, and favourable market conditions. APL’s success had implications for the internationalisation of the industrial gases industry
U(1) textures and Lepton Flavor Violation
U(1) family symmetries have led to successful predictions of the fermion mass
spectrum and the mixing angles of the hadronic sector. In the context of the
supersymmetric unified theories, they further imply a non-trivial mass
structure for the scalar partners, giving rise to new sources of flavor
violation. In the present work, lepton flavor non-conserving processes are
examined in the context of the minimal supersymmetric standard model augmented
by a U(1)-family symmetry. We calculate the mixing effects on the \mu-> e\gamma
and \tau -> \mu\gamma rare decays. All supersymmetric scalar masses involved in
the processes are determined at low energies using two loop renormalization
group analysis and threshold corrections. Further, various novel effects are
considered and found to have important impact on the branching ratios. Thus, a
rather interesting result is that when the see-saw mechanism is applied in the
(12 X 12)-sneutrino mass matrix, the mixing effects of the Dirac matrix in the
effective light sneutrino sector are canceled at first order. In this class of
models and for the case that soft term mixing is already present at the GUT
scale, tau -> \mu \gamma decays are mostly expected to arise at rates
significantly smaller than the current experimental limits. On the other hand,
the \mu \ra e \gamma rare decays impose important bounds on the model
parameters, particularly on the supersymmetric scalar mass spectrum. In the
absence of soft term mixing at high energies, the predicted branching ratios
for rare decays are, as expected, well below the experimental bounds.Comment: 24p, 10 figures, version to appear in Phys. Rev.
B -> X_s gamma in Supersymmetry with Explicit CP Violation
We discuss B -> X_s gamma decay in both constrained and unconstrained
supersymmetric models with explicit CP violation within the minimal flavor
violation scheme by including tan(beta) -enhanced large contributions beyond
the leading order. In this analysis, we take into account the relevant
cosmological and collider bounds, as well as electric dipole moment
constraints. In the unconstrained model, there are portions of the parameter
space yielding a large CP asymmetry at leading order (LO). In these regions, we
find that the CP phases satisfy certain sum rules, e.g., the sum of the phases
of the \mu parameter and the stop trilinear coupling centralize around \pi with
a width determined by the experimental bounds. In addition, at large values of
tan(beta), the sign of the CP asymmetry tracks the sign of the gluino mass, and
the CP asymmetry is significantly larger than the LO prediction. In the
constrained minimal supersymmetric standard model based on minimal
supergravity, we find that the decay rate is sensitive to the phase of the
universal trilinear coupling. This sensitivity decreases at large values of the
universal gauino mass. We also show that for a given set of the mass
parameters, there exists a threshold value of the phase of the universal
trilinear coupling which grows with tan(beta) and beyond which the experimental
bounds are satisfied. In both supersymmetric scenarios, the allowed ranges of
the CP phases are wide enough to have phenomenological consequences.Comment: 25 pages, 11 figures. Added references, made minor changes in the
text; journal versio
Direct Detection of Dark Matter in the MSSM with Non-Universal Higgs Masses
We calculate dark matter scattering rates in the minimal supersymmetric
extension of the Standard Model (MSSM), allowing the soft
supersymmetry-breaking masses of the Higgs multiplets, m_{1,2}, to be
non-universal (NUHM). Compared with the constrained MSSM (CMSSM) in which
m_{1,2} are required to be equal to the soft supersymmetry-breaking masses m_0
of the squark and slepton masses, we find that the elastic scattering cross
sections may be up to two orders of magnitude larger than values in the CMSSM
for similar LSP masses. We find the following preferred ranges for the
spin-independent cross section: 10^{-6} pb \ga \sigma_{SI} \ga 10^{-10} pb, and
for the spin-dependent cross section: 10^{-3} pb \ga \sigma_{SD}, with the
lower bound on \sigma_{SI} dependent on using the putative constraint from the
muon anomalous magnetic moment. We stress the importance of incorporating
accelerator and dark matter constraints in restricting the NUHM parameter
space, and also of requiring that no undesirable vacuum appear below the GUT
scale. In particular, values of the spin-independent cross section another
order of magnitude larger would appear to be allowed, for small \tan \beta, if
the GUT vacuum stability requirement were relaxed, and much lower cross-section
values would be permitted if the muon anomalous magnetic moment constraint were
dropped.Comment: 30 pages LaTeX, 40 eps figure
Clinical Validation of a 3-Dimensional Ultrafast Cardiac Magnetic Resonance Protocol Including Single Breath-Hold 3-Dimensional Sequences
Objectives: This study sought to clinically validate a novel 3-dimensional (3D) ultrafast cardiac magnetic resonance (CMR) protocol including cine (anatomy and function) and late gadolinium enhancement (LGE), each in a single breath-hold.
Background: CMR is the reference tool for cardiac imaging but is time-consuming.
Methods: A protocol comprising isotropic 3D cine (Enhanced sensitivity encoding [SENSE] by Static Outer volume Subtraction [ESSOS]) and isotropic 3D LGE sequences was compared with a standard cine+LGE protocol in a prospective study of 107 patients (age 58 ± 11 years; 24% female). Left ventricular (LV) mass, volumes, and LV and right ventricular (RV) ejection fraction (LVEF, RVEF) were assessed by 3D ESSOS and 2D cine CMR. LGE (% LV) was assessed using 3D and 2D sequences.
Results: Three-dimensional and LGE acquisitions lasted 24 and 22 s, respectively. Three-dimensional and LGE images were of good quality and allowed quantification in all cases. Mean LVEF by 3D and 2D CMR were 51 ± 12% and 52 ± 12%, respectively, with excellent intermethod agreement (intraclass correlation coefficient [ICC]: 0.96; 95% confidence interval [CI]: 0.94 to 0.97) and insignificant bias. Mean RVEF 3D and 2D CMR were 60.4 ± 5.4% and 59.7 ± 5.2%, respectively, with acceptable intermethod agreement (ICC: 0.73; 95% CI: 0.63 to 0.81) and insignificant bias. Both 2D and 3D LGE showed excellent agreement, and intraobserver and interobserver agreement were excellent for 3D LGE.
Conclusions: ESSOS single breath-hold 3D CMR allows accurate assessment of heart anatomy and function. Combining ESSOS with 3D LGE allows complete cardiac examination in less than 1 min of acquisition time. This protocol expands the indication for CMR, reduces costs, and increases patient comfort. (J Am Coll Cardiol Img 2021;14:1742–1754)Funding included Instituto de Salud Carlos III (ISCIII) and the
European Regional Development Fund (ERDF) Grants DTS17/00136 to
Dr. Ibáñez and PI19/01704 to Dr. Fernandez-Jimenez; Spanish Society
of Cardiology Translational Research Grant 2016 to Dr. Ibáñez;
European Research Council ERC-CoG 819775-MATRIX to Dr. Ibáñez;
Comunidad de Madrid S2017/BMD-3867-RENIM-CM to Drs. Desco
and Ibáñez; and Ministerio de Ciencia e Innovación (MICINN)
RETOS2019-107332RB-I00 to Dr. Ibáñez. Dr. Fernandez-Jimenez received funding from the European Union Horizon 2020 research and innovation programme under Marie Sklodowska-Curie Hrant
Agreement No. 707642. The CNIC is supported by the ISCIII, the
MICINN, and the Pro CNIC Foundation. Drs. Fernandez-Jimenez,
Nothnagel, Fuster, Ibáñez, and Javier Sánchez-González are inventors
of a joint patent (Philips/CNIC) for the new cine imaging
method here described and validated/protected under the IP
#2014P00960EP. Drs. Nothnagel, Kouwenhoven, Clemence, and
Javier Sánchez-González are Philips employees. All other authors
have reported that they have no relationships relevant to the contents
of this paper to disclose
- …