814 research outputs found
Dynamics of the Free Surface of a Conducting Liquid in a Near-Critical Electric Field
Near-critical behavior of the free surface of an ideally conducting liquid in
an external electric field is considered. Based on an analysis of three-wave
processes using the method of integral estimations, sufficient criteria for
hard instability of a planar surface are formulated. It is shown that the
higher-order nonlinearities do not saturate the instability, for which reason
the growth of disturbances has an explosive character.Comment: 19 page
Experimental characterization of anomalous strong scattering of mm-waves in TEXTOR plasmas with rotating islands
Anomalous scattering of high power millimetre waves from gyrotrons at 140 and 110 GHz is investigated for plasma with rotating islands at TEXTOR. The magnetic field and plasma density influence the spectral content of the scattered waves and their power levels significantly. Anomalous strong scattering occurs in two density regimes, one at low densities and one at high densities, that also depend on the magnetic field. The two regimes are separated by a quiescent regime without anomalous scattering. Investigations suggest that scattering in the high-density regime is generated at the low-field side intersection of the gyrotron beam and the island position. The transition from the quiescent regime to the high-density regime occurs when the gyrotron frequency is twice the upper hybrid frequency at this position. There is some evidence that the scattering in the low-density regime is generated near the plasma centre. Under this assumption all the observed scattering is generated when the gyrotron frequency is near or below twice the upper hybrid frequency
Hybrid interventions on aorto-iliac segment and arteries of lower limbs
Department of Vascular Surgery, Department of Endovascular Surgery, Mariinsky Hospital, Saint Petersburg, Russia, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și
al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaIntroduction: Current progress in endovascular methods and techniques makes possible its effective combination with open surgical
procedures.
Material and methods: The following hybrid procedures were performed in our department: 34 interventions on aorto-iliac segment
(iliac arteries stenting combined with reconstruction of deep femoral artery – 16 cases, loop-endarterectomy from external iliac artery
combined with iliac arteries stenting – 18 cases); 25 interventions on femoral-popliteal segment (loop-endarterectomy from superficial
femoral artery – 15 cases, iliac stenting combined with loop-endarterectomy from superficial femoral artery – 7 cases, above-knee
femoral-popliteal bypass combined with popliteal artery stenting – 3 cases); and 21 interventions on popliteal-tibial segment (loopendarterectomy from popliteal artery with angioplasty of tibial arteries – 8 cases, femoral-peroneal bypass combined with angioplasty
of tibial arteries – 13 cases). Completion angiography was routinely performed in all patients for quality control of revascularization.
Chronic ischemia grade II Fontaine was diagnosed preoperatively in 19 (23,75%) patients, grade III - in 40 (50%) and grade IV – in
21 (26,25%) patients.
Results: Complete regression of ischemic pain, initial signs of healing of superficial defects of soft tissues as well as primary healing
of wounds after debridement of necrotic lesions were observed in the postoperative period. Mean duration of hospital stay was 7 days.
Conclusion: Thus, implementation of hybrid procedures contributes to the reduction of the volume of open vascular reconstructions.
Hybrid interventions represent the optimal approach for treatment of occlusive lesions of aorto-iliac segment and arteries of lower
limbs
Plasma Level’s of Neuregulin-1 in Healthy People
Aim. To determine the median levels of neuregulin-1 (NRG-1; endothelium-derived growth factor and the natural agonist of the ERBB3 and ERBB4 receptors) NRG-1 in healthy volunteers and to study the associations of NRG-1 levels with gender and age.Material and Methods. Ninety seven healthy participants were enrolled (median age of 44 [32-54], men 45 men [46.4%]). The following age groups were identified: 20-29 y.о. (n=20, men – 50.0%), 30-39 y.о. (n=21, men – 52.4%), 40-49 y.о. (n=22, men – 45.5%), 50-59 y.о. (n=22, men – 36.4%); 60-69 y.о. (n=12, men – 50.0%). Peripheral blood samples were collected at the time of enrolment, standard laboratory tests were performed, and NRG-1 levels were determined in the plasma samples by ELISA.Results. In the cohort of 97 healthy participants the median value of NRG-1 was 0.3 [0.121-2.24] ng/ml. NRG-1 levels did not differ significantly between men and women (p=0.145), indicating that NRG-1 levels are not influenced by gender. The levels of NRG-1 were similar in the different age groups: age 20-29 years=0.26 [0.17-0.37] ng/ml; age 30-39=0.24 [0.1-0.39] ng/ml; age 40-49=0.31 [0.19-1.15] ng/ml; age 50-59=0.37 [0.19-1.0] ng/ml; age 60-69=0.4 [0.13-0.81] ng/ml. Correlation analysis between NRG-1 levels and route blood measurements (haemoglobin, lipids, glucose, creatinine, and uretic acid) did not show significant associations.Conclusions. In this study, the median value of NRG-1 plasma levels were determined. The results of the study show that age and gender had no influence on NRG-1 values
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Spectroscopy of geo-neutrinos from 2056 days of Borexino data
We report an improved geo-neutrino measurement with Borexino from 2056 days
of data taking. The present exposure is
protonyr. Assuming a chondritic Th/U mass ratio of 3.9, we obtain geo-neutrino events. The null
observation of geo-neutrinos with Borexino alone has a probability of (5.9). A geo-neutrino signal from the mantle is
obtained at 98\% C.L. The radiogenic heat production for U and Th from the
present best-fit result is restricted to the range 23-36 TW, taking into
account the uncertainty on the distribution of heat producing elements inside
the Earth.Comment: 4 pages, 4 figure
The LBNO long-baseline oscillation sensitivities with two conventional neutrino beams at different baselines
The proposed Long Baseline Neutrino Observatory (LBNO) initially consists of
kton liquid double phase TPC complemented by a magnetised iron
calorimeter, to be installed at the Pyh\"asalmi mine, at a distance of 2300 km
from CERN. The conventional neutrino beam is produced by 400 GeV protons
accelerated at the SPS accelerator delivering 700 kW of power. The long
baseline provides a unique opportunity to study neutrino flavour oscillations
over their 1st and 2nd oscillation maxima exploring the behaviour, and
distinguishing effects arising from and matter. In this paper we
show how this comprehensive physics case can be further enhanced and
complemented if a neutrino beam produced at the Protvino IHEP accelerator
complex, at a distance of 1160 km, and with modest power of 450 kW is aimed
towards the same far detectors. We show that the coupling of two independent
sub-MW conventional neutrino and antineutrino beams at different baselines from
CERN and Protvino will allow to measure CP violation in the leptonic sector at
a confidence level of at least for 50\% of the true values of
with a 20 kton detector. With a far detector of 70 kton, the
combination allows a sensitivity for 75\% of the true values of
after 10 years of running. Running two independent neutrino
beams, each at a power below 1 MW, is more within today's state of the art than
the long-term operation of a new single high-energy multi-MW facility, which
has several technical challenges and will likely require a learning curve.Comment: 21 pages, 12 figure
Synchronization of the Distributed Readout Frontend Electronics of the Baby MIND Detector
Baby MIND is a new downstream muon range detector for the WGASCI experiment. This article discusses the distributed readout system and its timing requirements. The paper presents the design of the synchronization subsystem and the results of its test
Measurement of neutrino flux from the primary proton--proton fusion process in the Sun with Borexino detector
Neutrino produced in a chain of nuclear reactions in the Sun starting from
the fusion of two protons, for the first time has been detected in a real-time
detector in spectrometric mode. The unique properties of the Borexino detector
provided an oppurtunity to disentangle pp-neutrino spectrum from the background
components. A comparison of the total neutrino flux from the Sun with Solar
luminosity in photons provides a test of the stability of the Sun on the
10 years time scale, and sets a strong limit on the power production in
the unknown energy sources in the Sun of no more than 4\% of the total energy
production at 90\% C.L.Comment: 15 pages, 2 tables, 3 figure
Recent Borexino results and prospects for the near future
The Borexino experiment, located in the Gran Sasso National Laboratory, is an
organic liquid scintillator detector conceived for the real time spectroscopy
of low energy solar neutrinos. The data taking campaign phase I (2007 - 2010)
has allowed the first independent measurements of 7Be, 8B and pep fluxes as
well as the first measurement of anti-neutrinos from the earth. After a
purification of the scintillator, Borexino is now in phase II since 2011. We
review here the recent results achieved during 2013, concerning the seasonal
modulation in the 7Be signal, the study of cosmogenic backgrounds and the
updated measurement of geo-neutrinos. We also review the upcoming measurements
from phase II data (pp, pep, CNO) and the project SOX devoted to the study of
sterile neutrinos via the use of a 51Cr neutrino source and a 144Ce-144Pr
antineutrino source placed in close proximity of the active material.Comment: 8 pages, 11 figures. To be published as proceedings of Rencontres de
Moriond EW 201
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Solar neutrino with Borexino: results and perspectives
Borexino is a unique detector able to perform measurement of solar neutrinos
fluxes in the energy region around 1 MeV or below due to its low level of
radioactive background. It was constructed at the LNGS underground laboratory
with a goal of solar Be neutrino flux measurement with 5\% precision. The
goal has been successfully achieved marking the end of the first stage of the
experiment. A number of other important measurements of solar neutrino fluxes
have been performed during the first stage. Recently the collaboration
conducted successful liquid scintillator repurification campaign aiming to
reduce main contaminants in the sub-MeV energy range. With the new levels of
radiopurity Borexino can improve existing and challenge a number of new
measurements including: improvement of the results on the Solar and terrestrial
neutrino fluxes measurements; measurement of pp and CNO solar neutrino fluxes;
search for non-standard interactions of neutrino; study of the neutrino
oscillations on the short baseline with an artificial neutrino source (search
for sterile neutrino) in context of SOX project.Comment: 15 pages, 4 figure
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