| 1. |
- Charity, R. J., et al.
(author)
-
Two-proton decay of the 6Be ground state and the double isobaric analog of 11Li
- 2013
-
In: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 420:1
-
Conference paper (peer-reviewed)abstract
- Two-proton decay is discussed in a number of light isobaric multiplets. For the lightest two-proton emitter, 6Be, the momentum correlations between the three decay products were measured and found to be consistent with quantum-mechanical three-cluster-model calculations. Two-proton decay was also found for two members of the A=8 and A=11 quintets. Finally, a third member of the A=11 sextet, the double isobaric analog of the halo nucleus 11Li in 11B was observed by its two-proton decay.
|
|
| 2. |
- Egorova, I. A., et al.
(author)
-
Democratic Decay of Be-6 Exposed by Correlations
- 2012
-
In: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 109:20
-
Journal article (peer-reviewed)abstract
- The interaction of an E/A = 70-MeV Be-7 beam with a Be target was used to populate levels in Be-6 following neutron knockout reactions. The three-body decay of the ground and first excited states into the alpha + p + p exit channel were detected in the High Resolution Array. Precise three-body correlations extracted from the experimental data allowed us to obtain insight into the mechanism of the three-body democratic decay. The correlation data are in good agreement with a three-cluster-model calculation and thus validate this theoretical approach over a broad energy range.
|
|
| 3. |
- Grigorenko, L. V., et al.
(author)
-
Complete correlation studies of two-proton decays: Be-6 and Fe-45
- 2009
-
In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 677:1-2, s. 30-35
-
Journal article (peer-reviewed)abstract
- The complete three-body correlation pictures are experimentally reconstructed for the two-proton decays of the Be-6 and (45)e ground states. We are able to see qualitative similarities and differences between these decays. They demonstrate very good agreement with the predictions of a theoretical three-body cluster model. Validity of the theoretical methods for treatment of the three-body Coulombic decays of this class is thus established by the broad range of lifetimes and nuclear masses spanned by these cases. Implementations for decay dynamics and nuclear structure of 2p emitters are discussed. (C) 2009 Elsevier B.V. All rights reserved.
|
|
| 4. |
- Felipe, T., et al.
(author)
-
Three-dimensional structure of a sunspot light bridge
- 2016
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 596
-
Journal article (peer-reviewed)abstract
- Context. Active regions are the most prominent manifestations of solar magnetic fields; their generation and dissipation are fundamental problems in solar physics. Light bridges are commonly present during sunspot decay, but a comprehensive picture of their role in the removal of the photospheric magnetic field is still lacking. Aims. We study the three-dimensional configuration of a sunspot, and in particular, its light bridge, during one of the last stages of its decay. Methods. We present the magnetic and thermodynamical stratification inferred from full Stokes inversions of the photospheric Si I 10 827 angstrom and Ca I 10 839 angstrom lines obtained with the GREGOR Infrared Spectrograph of the GREGOR telescope at the Observatorio del Teide, Tenerife, Spain. The analysis is complemented by a study of continuum images covering the disk passage of the active region, which are provided by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory. Results. The sunspot shows a light bridge with penumbral continuum intensity that separates the central umbra from a smaller umbra. We find that in this region the magnetic field lines form a canopy with lower magnetic field strength in the inner part. The photospheric light bridge is dominated by gas pressure (high-beta), as opposed to the surrounding umbra, where the magnetic pressure is higher. A convective flow is observed in the light bridge. This flow is able to bend the magnetic field lines and to produce field reversals. The field lines merge above the light bridge and become as vertical and strong as in the surrounding umbra. We conclude that this occurs because two highly magnetized regions approach each other during the sunspot evolution.
|
|
| 5. |
- Elekes, Z., et al.
(author)
-
Shape coexistence in 66Se
- 2023
-
In: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 844
-
Journal article (peer-reviewed)abstract
- The nuclear structure of 66Se, nucleus beyond the N=Z line on the proton-rich side of the valley of stability, was investigated by the neutron knock-out reaction 67Se(12C,X)66Se using a 12C target. The analysis of the singles spectrum of the γ-rays emitted during the de-excitation of the populated low-lying excited states revealed two previously detected (927(4) keV, 1460(32) keV) and three new (744(6) keV, 1210(17) keV, 1661(23) keV) transitions. The 744-keV, the 1210-keV, and the 1460-keV transitions were found to be in coincidence with the one at 927 keV. The spectrum coincident with the 927-keV transition showed a further possible transition at 299(35) keV, which was obscured by significant atomic background in the singles spectrum. This transition might correspond to a peak previously reported at 273(5) keV that could not be assigned to 66Se unambiguously. Based on a comparison of the experimental data to theoretical calculations, four new excited states are proposed which suggest that 66Se exhibits shape coexistence.
|
|
| 6. |
- Joshi, Jayant, et al.
(author)
-
Upper chromospheric magnetic field of a sunspot penumbra : observations of fine structure
- 2016
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 596
-
Journal article (peer-reviewed)abstract
- Aims. The fine-structure of the magnetic field in a sunspot penumbra in the upper chromosphere is to be explored and compared to that in the photosphere. Methods. Spectropolarimetric observations with high spatial resolution were recorded with the 1.5-m GREGOR telescope using the GREGOR Infrared Spectrograph (GRIS). The observed spectral domain includes the upper chromospheric Hei triplet at 10 830 angstrom and the photospheric Si I 10 827.1 angstrom and Ca I 10 833.4 angstrom spectral lines. The upper chromospheric magnetic field is obtained by inverting the Hei triplet assuming a Milne-Eddington-type model atmosphere. A height-dependent inversion was applied to the Si I 10 827.1 angstrom and Ca I 10 833.4 angstrom lines to obtain the photospheric magnetic field. Results. We find that the inclination of the magnetic field varies in the azimuthal direction in the photosphere and in the upper chromosphere. The chromospheric variations coincide remarkably well with the variations in the inclination of the photospheric field and resemble the well-known spine and interspine structure in the photospheric layers of penumbrae. The typical peak-to-peak variations in the inclination of the magnetic field in the upper chromosphere are found to be 10 degrees-15 degrees, which is roughly half the variation in the photosphere. In contrast, the magnetic field strength of the observed penumbra does not vary on small spatial scales in the upper chromosphere. Conclusions. Thanks to the high spatial resolution of the observations that is possible with the GREGOR telescope at 1.08 microns, we find that the prominent small-scale fluctuations in the magnetic field inclination, which are a salient part of the property of sunspot penumbral photospheres, also persist in the chromosphere, although at somewhat reduced amplitudes. Such a complex magnetic configuration may facilitate penumbral chromospheric dynamic phenomena, such as penumbral micro-jets or transient bright dots.
|
|
| 7. |
- Brown, K. W., et al.
(author)
-
Observation of Long-Range Three-Body Coulomb Effects in the Decay of Ne-16
- 2014
-
In: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 113:23, s. Art. no. 232501-
-
Journal article (peer-reviewed)abstract
- The interaction of an E/A = 57.6-MeV Ne-17 beam with a Be target is used to populate levels in Ne-16 following neutron knockout reactions. The decay of 16Ne states into the three-body O-14 + p + p continuum is observed in the High Resolution Array (HiRA). For the first time for a 2p emitter, correlations between the momenta of the three decay products are measured with sufficient resolution and statistics to allow for an unambiguous demonstration of their dependence on the long-range nature of the Coulomb interaction. Contrary to previous measurements, our measured limit Gamma
|
|
| 8. |
- Grigorenko, L. V., et al.
(author)
-
Three-body decay of Be-6
- 2009
-
In: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 80:3
-
Journal article (peer-reviewed)abstract
- Three-body correlations for the ground-state decay of the lightest two-proton emitter Be-6 are studied both theoretically and experimentally. Theoretical studies are performed in a three-body hyperspherical-harmonics cluster model. In the experimental studies, the ground state of Be-6 was formed following the alpha decay of a C-10 beam inelastically excited through interactions with Be and C targets. Excellent agreement between theory and experiment is obtained demonstrating the existence of complicated correlation patterns that can elucidate the structure of Be-6 and, possibly, of the A = 6 isobars.
|
|
| 9. |
- Sobotka, Kristina, et al.
(author)
-
Single Sustained Inflation followed by Ventilation Leads to Rapid Cardiorespiratory Recovery but Causes Cerebral Vascular Leakage in Asphyxiated Near-Term Lambs
- 2016
-
In: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 11:1
-
Journal article (peer-reviewed)abstract
- Background A sustained inflation (SI) rapidly restores cardiac function in asphyxic, bradycardic newborns but its effects on cerebral haemodynamics and brain injury are unknown. We determined the effect of different SI strategies on carotid blood flow (CaBF) and cerebral vascular integrity in asphyxiated near-term lambs. Lambs were instrumented and delivered at 139 +/- 2 d gestation and asphyxia was induced by delaying ventilation onset. Lambs were randomised to receive 5 consecutive 3 s SI (multiple SI; n = 6), a single 30 s SI (single SI; n = 6) or conventional ventilation (no SI; n = 6). Ventilation continued for 30 min in all lambs while CaBF and respiratory function parameters were recorded. Brains were assessed for gross histopathology and vascular leakage. CaBF increased more rapidly and to a greater extent during a single SI (p = 0.01), which then decreased below both other groups by 10 min, due to a higher cerebral oxygen delivery (p = 0.01). Blood brain barrier disruption was increased in single SI lambs as indicated by increased numbers of blood vessel profiles with plasma protein extravasation (p = 0.001) in the cerebral cortex. There were no differences in CaBF or cerebral oxygen delivery between the multiple SI and no SI lambs. Ventilation with an initial single 30 s SI improves circulatory recovery, but is associated with greater disruption of blood brain barrier function, which may exacerbate brain injury suffered by asphyxiated newborns. This injury may occur as a direct result of the initial SI or to the higher tidal volumes delivered during subsequent ventilation.
|
|
| 10. |
- Sobotka, L., et al.
(author)
-
ESPEN Guidelines on Parenteral Nutrition : Geriatrics
- 2009
-
In: Clinical Nutrition. - : Elsevier BV. - 0261-5614 .- 1532-1983. ; 28:4, s. 461-466
-
Journal article (peer-reviewed)abstract
- Older subjects are at increased risk of partial or complete loss of independence due to acute and/or chronic disease and often of concomitant protein caloric malnutrition. Nutritional care and support should be an indispensable part of their management. Enteral nutrition is always the first choice for nutrition support. However, when patients cannot meet their nutritional requirements adequately via the enteral route, parenteral nutrition (PN) is indicated. PN is a safe and effective therapeutic procedure and age per se is not a reason to exclude patients from this treatment. The use of PN should always be balanced against a realistic chance of improvement in the general condition of the patient. Lower glucose tolerance, electrolyte and micronutrient deficiencies and lower fluid tolerance should be assumed in older patients treated by PN. Parenteral nutrition can be administered either via peripheral or central veins. Subcutaneous administration is also a possible solution for basic hydration of moderately dehydrated subjects. In the terminal, demented or dying patient the use of PN or hydration should only be given in accordance with other palliative treatments.
|
|
