11,175 research outputs found
Resolving parameter degeneracies in long-baseline experiments by atmospheric neutrino data
In this work we show that the physics reach of a long-baseline (LBL) neutrino
oscillation experiment based on a superbeam and a megaton water Cherenkov
detector can be significantly increased if the LBL data are combined with data
from atmospheric neutrinos (ATM) provided by the same detector. ATM data are
sensitive to the octant of and to the type of the neutrino mass
hierarchy, mainly through three-flavor effects in e-like events. This allows to
resolve the so-called - and sign()-parameter
degeneracies in LBL data. As a consequence it becomes possible to distinguish
the normal from the inverted neutrino mass ordering at CL from a
combined LBL+ATM analysis if . The potential
to identify the true values of and the CP-phase
is significantly increased through the lifting of the
degeneracies. These claims are supported by a detailed simulation of the T2K
(phase II) LBL experiment combined with a full three-flavor analysis of ATM
data in the HyperKamiokande detector.Comment: 25 pages, 10 figure
Self-healing of dense asphalt concrete by two different approaches: electromagnetic induction and infrared radiation
Self-healing of cracks in asphalt mixtures is a phenomenon that can be accelerated by reducing the viscosity of bitumen as it increases the capillarity flow through the cracks. One method to achieve this is by increasing temperature, which also produces a thermal expansion that contributes to the circulation of the bitumen through cracks. In the present paper, the healing performance of asphalt mixture heated using infrared heating to simulate the natural solar radiation, and induction heating, a new method to increase the temperature of asphalt pavements, were compared in terms of time and healing temperature. Healing was defined as the relationship between the 3-point bending strength of an asphalt beam before and after healing. The results show that both methods reach similar and satisfactory healing ratios at around 90 %. However, induction heating is more energy efficient because the effect is concentrated on the binder, instead of heating the whole mix. This can be translated into much shorter heating times to reach the same healing level. Finally, an optimum radiation energy was found, after which higher amounts of infrared radiation damage the properties of the healed material
Proper motions of the HH1 jet
We describe a new method for determining proper motions of extended objects,
and a pipeline developed for the application of this method. We then apply this
method to an analysis of four epochs of [S~II] HST images of the HH~1 jet
(covering a period of ~yr).
We determine the proper motions of the knots along the jet, and make a
reconstruction of the past ejection velocity time-variability (assuming
ballistic knot motions). This reconstruction shows an "acceleration" of the
ejection velocities of the jet knots, with higher velocities at more recent
times. This acceleration will result in an eventual merging of the knots in
~yr and at a distance of from the outflow source, close to
the present-day position of HH~1.Comment: 12 pages, 8 figure
A Comparison of Morphological, Jump, and Sprint Kinematic Asymmetries in Division I Track and Field Athletes
International Journal of Exercise Science 16(1): 1306-1319, 2023. Inter-limb asymmetries are the difference in performance in one limb with respect to the other. Running events in track and field are considered symmetrical while jumping and throwing events are considered asymmetrical. It is unknown if competing in these different events result in differences in inter-limb asymmetries, thus, this study compared the magnitude of jump, sprint, and morphological asymmetries in track and field athletes who compete in symmetrical and asymmetrical events. Forty-six Division I track and field athletes performed a series of vertical jumps (VJ) and broad jumps (BJ) with force platforms measuring peak force of each limb, and 30-meter fly sprints with kinematics (step length (SL), flight time (FT), and contact time (CT)) recorded during the sprints. Additionally, thirty-eight of these subjects underwent body composition analysis via dual x-ray absorptiometry to determine morphological asymmetries. Asymmetries were calculated using the symmetry index and the asymmetry measures were compared between sprinters, distance runners, throwers, and jumpers utilizing a one-way analysis of variance or Kruskal-Wallis tests with post-hoc comparisons as necessary. There were no differences in VJ, BJ, and sprint kinematic asymmetries found between groups but there were differences in leg fat mass asymmetries (H(3)=8.259, p=0.041, eta2= 0.101) as well as arm lean mass (H(3)=9.404, p=0.024, eta2=0.152), fat mass (H(3)=17.822,
Carbon-fiber tips for scanning probe microscopes and molecular electronics experiments
We fabricate and characterize carbon-fiber tips for their use in combined
scanning tunneling and force microscopy based on piezoelectric quartz tuning
fork force sensors. An electrochemical fabrication procedure to etch the tips
is used to yield reproducible sub-100-nm apex. We also study electron transport
through single-molecule junctions formed by a single octanethiol molecule
bonded by the thiol anchoring group to a gold electrode and linked to a carbon
tip by the methyl group. We observe the presence of conductance plateaus during
the stretching of the molecular bridge, which is the signature of the formation
of a molecular junction.Comment: Conference Proceeding (Trends in NanoTechnology 2011, Tenerife
SPAIN); Nanoscale Research Letters, (2012) 7:25
Strength, jumping, and change of direction speed asymmetries are not associated with athletic performance in elite academy soccer players
The aims of the present study were twofold: 1) to measure inter-limb asymmetries from a battery of fitness tests in youth soccer players and, 2) determine the association between asymmetry and measures of athletic performance. Sixteen elite youth soccer players (14.7 ± 0.2 years) performed a single leg Abalakov test (ABK), change of direction (COD) test over 10 m (5 + 5) and 20 m (10 + 10), and an iso-inertial power test. Subjects also performed 10 m, 20 m and 30 m sprints and a bilateral countermovement jump (CMJ), which were correlated with all ABK, COD and iso-inertial asymmetry scores. A one-way repeated measures ANOVA showed significant differences between inter-limb asymmetry scores across multiple tests (p 0.05) between the different inter-limb asymmetry scores, and between asymmetry scores and athletic performance. These findings show the test-specific nature of asymmetries in youth soccer players, with the iso-inertial power test being the most sensitive in detecting asymmetry. Moreover, the results obtained suggest that inherent asymmetry in young soccer players did not negatively impact their performance
Definition of tailor made cutting tools for machining of complex surfaces based on final surface shape
In this work a design methodology to define the best geometry of cutting tool for complex surfaces is defined, being based on the final part surface geometry. The manufacture of components with tailor made shaped tools, based on algorithm calculation and adapted to the geometry of the final piece surface, reduces manufacturing time and maintains piece quality in comparison with traditional cutting tools. Cutting tools are usually cylindrical (end mills) or ball-end mills. With mathematical algorithms can be defined diamond & CBN electroplated form tools, multi-tooth endmills, abrasive grinding tools and so on. The approach here presented can enable the production of tools for manufacturing process such as Super Abrasive Machining (SAM) and Flank milling strategies. Comparison between standard tools and traditional machining processes versus custom-shaped tools was studied in terms of process time. Final applications are numerous, such as, integral blade rotors, spiral bevel gears, blisks and impellers, complex screws, and others
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