| 201. |
- Tengborn, Elisabeth, 1978, et al.
(författare)
-
The 8Li + 2H reaction studied in inverse kinematics at 3.15 MeV/nucleon using the REX-ISOLDE post-accelerator
- 2011
-
Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 84:6, s. 064616-
-
Tidskriftsartikel (refereegranskat)abstract
- The reaction 8Li + 2H has been studied in inverse kinematics at the incident energy of 3.15 MeV/nucleon, using the REX-ISOLDE post-accelerator. The reaction channels corresponding to (d,p), (d,d), and (d,t) reactions populating ground states and low-lying excited states in 7–9Li have been identified and the related angular distributions extracted and compared with coupled-channels, distorted-wave Born approximation (DWBA), and coupled-reaction-channels calculations. For the inelastic and (d,t) channels we find that higher order effects are very important and hence one needs to go beyond the simple DWBA to extract reliable structure information from these processes.
|
|
| 202. |
- Utko, P., et al.
(författare)
-
Coupling between electronic and vibrational excitations in carbon nanotubes filled with C(60) fullerenes
- 2011
-
Ingår i: Acta Physica Polonica A. - 0587-4246. ; 120:5, s. 839-841
-
Tidskriftsartikel (refereegranskat)abstract
- We investigate the low-temperature electron transport through C60 peapods, which are carbon nanotubes encapsulating C60 fullerenes. We find that the temperature dependence of the Coulomb blockade oscillations in peapod quantum dots deviates from conventional Breit–Wigner behavior, showing signatures of the Franck–Condon blockade of conductance. This indicates the presence of a coupling between electronic states and vibrational excitations. Unlike for suspended empty nanotubes, these are not intrinsic vibrational modes of the tube but mechanical vibrations of the encapsulated fullerenes that affect the electronic transport. Fullerene peapods thus emerge as a new class of nanoelectromechanical systems.
|
|
| 203. |
|
|
| 204. |
- van Caspell, Willem E., et al.
(författare)
-
Implementation and evaluation of updated photolysis rates in the EMEP MSC-W chemical transport model using Cloud-J v7.3e
- 2023
-
Ingår i: Geoscientific Model Development. - 1991-959X .- 1991-9603. ; 16:24, s. 7433-7459
-
Tidskriftsartikel (refereegranskat)abstract
- The present work describes the implementation of the state of the art Cloud-J v7.3 photolysis rate calculation code in the EMEP MSC-W chemistry-transport model. Cloud-J calculates photolysis rates and accounts for cloud and aerosol optical properties at model run time, replacing the old system based on tabulated values. The performance of Cloud-J is evaluated against aerial photolysis rate observations made over the Pacific Ocean and against surface observations from three measurement sites in Europe. Numerical experiments are performed to investigate the sensitivity of the calculated photolysis rates to the spatial and temporal model resolution, input meteorology model, simulated ozone column, and cloud effect parameterization. These experiments indicate that the calculated photolysis rates are most sensitive to the choice of input meteorology model and cloud effect parameterization while also showing that surface ozone photolysis rates can vary by up to 20 % due to daily variations in total ozone column. Further analysis investigates the impact of Cloud-J on the oxidizing capacity of the troposphere, aerosol–photolysis interactions, and surface air quality predictions. Results find that the annual mean mass-weighted tropospheric hydroxyl concentration is increased by 26 %, while the photolytic impact of aerosols is mostly limited to large tropical biomass-burning regions. Overall, Cloud-J represents a major improvement over the tabulated system, leading to improved model performance for predicting carbon monoxide and daily maximum ozone surface concentrations.
|
|
| 205. |
- Viñals, S., et al.
(författare)
-
The experiments to determine the electron capture and β-decay of 8B into the highly excited states of 8Be
- 2020
-
Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 1643:1
-
Konferensbidrag (refereegranskat)abstract
- The main goal of this work is to study the structure of the highest energy states in 8Be populated following the β+-decay and the electron capture (EC) of 8B. With this aim, two experiments were performed at ISOLDE-CERN in 2017 and 2018. The first experiment had the aim to resolve the 2+ doublet at 16.6 and 16.9 MeV, in order to study their isospin mixing. The second experiment aimed to determine a value or give an experimental upper limit to the branching ratio of the exotic EC-p decay. In this paper, we present the experimental setups and we discuss the analysis and present the preliminary results obtained so far.
|
|
| 206. |
- Viñals, S., et al.
(författare)
-
The most accurate determination of the 8 B half-life
- 2020
-
Ingår i: Acta Physica Polonica, Series B.. - 1509-5770 .- 0587-4254. ; 51:3, s. 717-723
-
Tidskriftsartikel (refereegranskat)abstract
- Beta decay is a primary source of information of the structure of a nucleus. An accurate measurement of the half-life of a nucleus is essential for the proper determination of the reduced Gammow-Teller transition probability B(GT). In this work, we present an experiment using a compact set-up of Si-telescope detectors to measure the half-life of the 8B nucleus. Three independent measurements have been analysed, obtaining the values 771.9(17) ms, 773.9(18) ms, and 770.9(27) ms. The value of the half-life obtained as the weighted averaged with the previous published measures is 771.17(94) ms which is a factor 3.2 of improvement in the uncertainty of the half-life.
|
|
| 207. |
- Wamers, F., et al.
(författare)
-
First Observation of the Unbound Nucleus Ne-15
- 2014
-
Ingår i: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 112:13
-
Tidskriftsartikel (refereegranskat)abstract
- We report on the first observation of the unbound proton-rich nucleus Ne-15. Its ground state and first excited state were populated in two-neutron knockout reactions from a beam of 500 MeV/u Ne-17. The Ne-15 ground state is found to be unbound by 2.522(66) MeV. The decay proceeds directly to O-13 with simultaneous two-proton emission. No evidence for sequential decay via the energetically allowed 2(-) and 1(-) states in F-14 is observed. The Ne-15 ground state is shown to have a strong configuration with two protons in the (sd) shell around O-13 with a 63(5)% (1s(1/2))(2) component.
|
|
| 208. |
- Wollmer, P, et al.
(författare)
-
Measurement of pulmonary density by means of X-ray computerized tomography. Relation to pulmonary mechanics in normal subjects
- 1986
-
Ingår i: Chest. - : Elsevier BV. - 0012-3692. ; 90:3, s. 91-387
-
Tidskriftsartikel (refereegranskat)abstract
- We examined the relationship between pulmonary density, measured with computerized tomography, and pulmonary mechanics (static pulmonary volume; pulmonary resistance) in 39 normal subjects (20 nonsmokers and 19 smokers). Pulmonary density decreased with increasing static elastic recoil pressure, and smokers consistently showed higher pulmonary density than nonsmokers. Pulmonary density, measured at full inspiration, correlated inversely with total lung capacity. Pulmonary density showed a ventrodorsal gradient, which was greater at low elastic recoil pressure than at high recoil pressure. The study shows that pulmonary density is related to the mechanical properties of the lung in normal subjects. Increased pulmonary density appears to be a sensitive indicator of pulmonary damage induced by smoking. Further studies of the relationship between pulmonary density and pulmonary mechanics in disease seem warranted.
|
|
| 209. |
- Wollmer, Per, et al.
(författare)
-
Relation between lung function, exercise capacity, and exposure to asbestos cement
- 1987
-
Ingår i: British Journal of Industrial Medicine. - 0007-1072. ; 44:8, s. 542-549
-
Tidskriftsartikel (refereegranskat)abstract
- A group of 137 male workers with known exposure (mean 20 fibre years per millilitre) to asbestos cement who had symptoms or signs of pulmonary disease was studied together with a reference group of 49 healthy industrial workers with no exposure to asbestos. Lung function measurements were made at rest and during exercise. Evidence of lung fibrosis was found as well as of obstructive airways disease in the exposed group compared with the reference group. Asbestos cement exposure was related to variables reflecting lung fibrosis but not to variables reflecting airflow obstruction. Smoking was related to variables reflecting obstructive lung disease. Exercise capacity was reduced in the exposed workers and was related to smoking and to lung function variables, reflecting obstructive airways disease. There was no significant correlation between exercise capacity and exposure to asbestos cement.
|
|
| 210. |
- Zinser, M., et al.
(författare)
-
Invariant-mass spectroscopy of Li-10 and Li-11
- 1997
-
Ingår i: Nuclear Physics A. - 0375-9474. ; 619:1-2, s. 151-176
-
Tidskriftsartikel (refereegranskat)abstract
- Break-up of secondary Li-11 ion beams (280 MeV/nucleon) on C and Pb targets into Li-9 and neutrons is studied experimentally. Cross sections and neutron multiplicity distributions are obtained, characterizing different reaction mechanisms. Invariant-mass spectroscopy for Li-11 and Li-10 is performed. The E1 strength distribution, deduced from electromagnetic excitation of Li-11 up to an excitation energy of 4 MeV comprises similar to 8% of the Thomas-Reiche-Kuhn energy-weighted sumrule strength. Two low-lying resonance-like structures are observed for Li-10 at decay energies of 0.21(5) and 0.62(10) MeV, the former one carrying 26(10)% of the strength and likely to be associated with an s-wave neutron decay. A strong di-neutron correlation in Li-11 can be discarded. Calculations in a quasi-particle RPA approach are compared with the experimental results for Li-10 and Li-11. (C) 1997 Elsevier Science B.V.
|
|
