Search results for "Spectroscopy"
showing 10 items of 10293 documents
Probing the nature of particle–core couplings in 49Ca with γ spectroscopy and heavy-ion transfer reactions
2011
Neutron rich nuclei around 48Ca have been measured with the CLARA–PRISMA setup, making use of 48Ca on 64Ni binary reactions, at 5.9 MeV/A. Angular distributions of γ rays give evidence, in several transfer channels, for a large spin alignment (≈70%) perpendicular to the reaction plane, making it possible to firmly establish spin and parities of the excited states. In the case of 49Ca, states arising from different types of particle–core couplings are, for the first time, unambiguously identified on basis of angular distribution, polarization and lifetime measurements. Shell model and particle–vibration coupling calculations are used to pin down the nature of the states. Evidence is found fo…
Measurements of relative line strengths in N I multiplets for transition arrays 3s–np (n=3, 4, 5)
2008
Abstract Applying the emission method, intensities of 60 spectral lines of neutral nitrogen (N I) belonging to 15 multiplets originating from 3s–np (n=3, 4, 5) transition arrays have been measured. A wall-stabilized arc, operated at atmospheric pressure in helium with some admixture of nitrogen was applied as the excitation source. From measured line intensities, relative line strengths within multiplets have been evaluated. For transitions with Δn=1 and 2, significantly larger discrepancies from LS coupling results are found if compared to transitions 3s–3p (Δn=0). The measured relative line strengths within 3s–3p multiplets are compared with older measurements, recent calculations and wit…
Experimental tests of the spectroscopic coupling for neutral oxygen
2008
Abstract The radiation emitted from a high-current wall-stabilized arc operated in helium with some admixture of CO 2 has been studied. Intensities of fine structure components for 10 multiplets of neutral oxygen (O I) have been determined applying the emission method. On the basis of measured line intensities relative line strengths within each studied multiplet have been obtained. The results are compared with data resulting from the LS-coupling scheme and with other theoretical as well as experimental results available in literature.
Computational investigation and experimental considerations for the classical implementation of a full adder on SO2 by optical pump-probe schemes
2008
International audience; Following the scheme recently proposed by Remacle and Levine Phys. Rev. A 73, 033820 2006 , we investigate the concrete implementation of a classical full adder on two electronic states X˜ 1A1 and C ˜ 1B2 of the SO2 molecule by optical pump-probe laser pulses using intuitive and counterintuitive stimulated Raman adiabatic passage excitation schemes. The resources needed for providing the inputs and reading out are discussed, as well as the conditions for achieving robustness in both the intuitive and counterintuitive pump-dump sequences. The fidelity of the scheme is analyzed with respect to experimental noise and two kinds of perturbations: The coupling to the neigh…
Inelastic and quasi-elastic light scattering in (NaCN)1?x(KCN)x quadrupolar glasses
1990
The elastic constantsc11 andc44, and the attenuation of longitudinal phonons along (100)-direction in (NaCN)1−x(KCN)x mixed crystals have been determined by brillouin spectroscopy in the temperature range fromT=10K−300K. Minima inc44 (T) which determine the freezing tempratureTF in these orientational glasses appear at lower temperatures compared to neutron scattering results. The coupling of molecular reorientations to longitudinal phonons in NaCN-rich smaples shows up in dispersion effects inc11 (T) and the appearence of a dynamical central peak nearTF.
Line mixing in the stimulated Raman spectrum of the ν1 band of SiH4 at 0.4–1.0 bar
1993
The stimulated Raman spectrum of the ν1 band of SiH4 has been recorded at 0.4 and 1.0 bar pressures and room temperature. Line mixing of the fine structure components of this spectrum was taken into account in a calculated profile by considering coupling between the main transitions and using a simple model (strong collision model, SCM) for the relaxation matrix.
Surfactant-based enrichment of rare earth elements from NdFeB magnet e-waste: Optimisation of cloud formation and rare earths extraction
2023
Appropriate waste and resource management are essential for a sustainable circular economy with reduced environmental impact. With critical resources, e-waste may serve as indirect raw material. For example, with NdFeB permanent magnets, Neodymium (Nd) and the co-present Dysprosium (Dy) are critical rare earth elements (REEs). However, there exists no economically viable technology for recycling them from electronic waste (e-waste). Here, a method is presented based on cloud point extraction (CPE). The work involves basic complexation chemistry in a cloud medium with pure REE salts, as well as, with real NdFeB-magnets (nearly 28% REE content by weight) from an old hard disk drive (5.2 g mag…
Effects of high-pressure on the structural, vibrational, and electronic properties of monazite-type PbCrO4
2012
We have performed an experimental study of the crystal structure, lattice dynamics, and optical properties of PbCrO 4 (the mineral crocoite) at ambient and high pressures. In particular, the crystal structure, Raman-active phonons, and electronic band gap have been accurately determined. X-ray-diffraction, Raman, and optical absorption experiments have allowed us also to completely characterize two pressure-induced structural phase transitions. The first transition is from a monoclinic structure to another monoclinic structure. It maintains the symmetry of the crystal but has important consequences in the physical properties; among others, a band-gap collapse is induced. The second one invo…
Removal of Escherichia coli from Saturated Sand Columns Supplemented with Hydrochar Produced from Maize
2014
Despite numerous studies on hydrochar use, its application in water treatment for pathogen removal remains unexplored. In this study, we evaluated the efficiency of hydrochar produced from crop residue of maize for water treatment by determining Escherchia coli breakthrough from sand columns supplemented with hydrochar. To enhance the adsorptive capacity, raw hydrochar was activated by 1 mol L⁻¹ KOH at room temperature. The experiments conducted in a 10-cm sand bed with 1.5% (w/w) activated and raw hydrochar supplements, not activated by KOH, showed 93 and 72% of E. coli removal efficiencies, respectively. Activation of KOH not only enhanced the E. coli removal but also increased the streng…
Global and time-resolved monitoring of crop photosynthesis with chlorophyll fluorescence
2014
Guanter, Luis et al.