3,071 research outputs found
The GREAT triggerless total data readout method
Recoil decay tagging (RDT) is a very powerful method for the spectroscopy of exotic nuclei. RDT is a delayed coincidence technique between detectors usually at the target position and at the focal plane of a spectrometer. Such measurements are often limited by dead time. This paper describes a novel triggerless data acquisition method, which is being developed for the Gamma Recoil Electron Alpha Tagging (GREAT) spectrometer, that overcomes this limitation by virtually eliminating dead time. Our solution is a total data readout (TDR) method where all channels run independently and are associated in software to reconstruct events. The TDR method allows all the data from both target position and focal plane to be collected with practically no dead-time losses. Each data word is associated with a timestamp generated from a global 100-MHz clock. Events are then reconstructed in real time in the event builder using temporal and spatial associations defined by the physics of the experimen
Regular Consumption of a Flavanol-rich Chocolate can Improve Oxidant Stress in Young Soccer Players
The consumption of a diet rich in certain flavonoids, including the flavanol
sub-class, has been associated with a reduced risk for vascular disease. We
evaluated the effects of the regular consumption (14 d) of a flavanol-containing
milk chocolate (FCMC) or cocoa butter chocolate (CBC) on variables related to
vascular disease risk, oxidative stress and physical activity. Twenty-eight free-living,
young (18–20 years old) male soccer players consumed daily 105 g of FCMC
(168 mg of flavanols) or CBC (<5 mg of flavanols), as part of their normal diet.
The consumption of FCMC was significantly associated with a decrease in diastolic
blood pressure (-5 mm Hg), mean blood pressure (-5 mm Hg), plasma cholesterol
(-11%), LDL-cholesterol (-15%), malondialdehyde (-12%), urate (-11%) and lactate
dehydrogenase (LDH) activity (-11%), and an increase in vitamin E/cholesterol
(+12%). No relevant changes in these variables were associated with CBC
consumption. No changes in the plasma levels of (-)-epicatechin were observed
following analysis of fasting blood samples. In conclusion, FCMC consumption was
associated with changes in several variables often associated with cardiovascular
health and oxidant stress. The presence of significant quantities of
flavanols in FCMC is likely to have been one of the contributing factors to these results
New apparatus for DTA at 2000 bar: thermodynamic studies on Au, Ag, Al and HTSC oxides
A new DTA (Differential Thermal Analysis) device was designed and installed
in a Hot Isostatic Pressure (HIP) furnace in order to perform high-pressure
thermodynamic investigations up to 2 kbar and 1200C. Thermal analysis can be
carried out in inert or oxidising atmosphere up to p(O2) = 400 bar. The
calibration of the DTA apparatus under pressure was successfully performed
using the melting temperature (Tm) of pure metals (Au, Ag and Al) as standard
calibration references. The thermal properties of these metals have been
studied under pressure. The values of DV (volume variation between liquid and
solid at Tm), ROsm (density of the solid at Tm) and ALPHAm (linear thermal
expansion coefficient at Tm) have been extracted. A very good agreement was
found with the existing literature and new data were added. This HP-DTA
apparatus is very useful for studying the thermodynamics of those systems where
one or more volatile elements are present, such as high TC superconducting
oxides. DTA measurements have been performed on Bi,Pb(2223) tapes up to 2 kbar
under reduced oxygen partial pressure (p(O2) = 0.07 bar). The reaction leading
to the formation of the 2223 phase was found to occur at higher temperatures
when applying pressure: the reaction DTA peak shifted by 49C at 2 kbar compared
to the reaction at 1 bar. This temperature shift is due to the higher stability
of the Pb-rich precursor phases under pressure, as the high isostatic pressure
prevents Pb from evaporating.Comment: 6 figures, 3 tables, Thermodynamics, Thermal property, Bi-2223,
fundamental valu
Calculating all elements of minimal index in the infinite parametric family of simplest quartic fields
summary:It is a classical problem in algebraic number theory to decide if a number field is monogeneous, that is if it admits power integral bases. It is especially interesting to consider this question in an infinite parametric family of number fields. In this paper we consider the infinite parametric family of simplest quartic fields generated by a root of the polynomial , assuming that , and has no odd square factors. In addition to generators of power integral bases we also calculate the minimal index and all elements of minimal index in all fields in this family
An Eccentric Binary Millisecond Pulsar in the Galactic Plane
Binary pulsar systems are superb probes of stellar and binary evolution and
the physics of extreme environments. In a survey with the Arecibo telescope, we
have found PSR J1903+0327, a radio pulsar with a rotational period of 2.15 ms
in a highly eccentric (e = 0.44) 95-day orbit around a solar mass companion.
Infrared observations identify a possible main-sequence companion star.
Conventional binary stellar evolution models predict neither large orbital
eccentricities nor main-sequence companions around millisecond pulsars.
Alternative formation scenarios involve recycling a neutron star in a globular
cluster then ejecting it into the Galactic disk or membership in a hierarchical
triple system. A relativistic analysis of timing observations of the pulsar
finds its mass to be 1.74+/-0.04 Msun, an unusually high value.Comment: 28 pages, 4 figures inc Supplementary On-Line Material. Accepted for
publication in Science, published on Science Express: 10.1126/science.115758
Sensitive Search for a Permanent Muon Electric Dipole Moment
We are proposing a new method to carry out a dedicated search for a permanent
electric dipole moment (EDM) of the muon with a sensitivity at a level of
10^{-24} e cm. The experimental design exploits the strong motional electric
field sensed by relativistic particles in a magnetic storage ring. As a key
feature, a novel technique has been invented in which the g-2 precession is
compensated with radial electric field. This technique will benefit greatly
when the intense muon sources advocated by the developers of the muon storage
rings and the muon colliders become available.Comment: 16 pages, 3 figures. Submitted for publication in Proceedings of the
International Workshop on High Intensity Muon Sources (HIMUS99), KEK, Japan,
December 1-4 199
Analysis of the pattern of suprahyoid muscle activity during pharyngeal swallowing of foods by healthy young subjects
We previously developed the TP technique to discriminate between the activity patterns of skeletal muscles. In this study we aim to identify the TP value(s) that can be used to sensitively evaluate the activity patterns of the suprahyoid (SH) muscles during swallowing. We also analyse the effect of food textural properties on the activity patterns of the SH muscle during oral and pharyngeal swallowing. Three test foods consisting of 3%, 6% and 9% of a thickening agent, Mousse-up (MU) were prepared. Their textural properties differed significantly. Swallowing of 9% MU involved a significantly longer average duration than 3% MU. The average T50 value for 6% MU was significantly larger than that for 3% MU. However, the average T20 and T80 values of the test foods did not differ. Thus, the T50 value is particularly suitable for evaluating SH muscle swallowing patterns. Moreover, test foods that vary in their textural properties elicit different durations and patterns of SH muscle activity
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