141 research outputs found
Unusual, basin-scale, fluidârock interaction in the Palaeoproterozoic Onega basin from Fennoscandia : Preservation in calcite ÎŽ18O of an ancient high geothermal gradient
Acknowledgements We acknowledge financial support from ICDP for the drilling programme. AEF, ATB and ARP thank NERC for financial support through NE/G00398X/1. VAM thanks the Norwegian Research Council for financial support through 191530/V30. We are grateful for sample preparation and analyses to all the personnel at NGU lab. At SUERC we enjoyed exceptional analytical support from Julie Dougans. Anonymous reviewers and the editor provided comments that improved the final manuscript.Peer reviewedPostprin
Differential cross sections for muonic atom scattering from hydrogenic molecules
The differential cross sections for low-energy muonic hydrogen atom
scattering from hydrogenic molecules are directly expressed by the
corresponding amplitudes for muonic atom scattering from hydrogen-isotope
nuclei. The energy and angular dependence of these three-body amplitudes is
thus taken naturally into account in scattering from molecules, without
involving any pseudopotentials. Effects of the internal motion of nuclei inside
the target molecules are included for every initial rotational-vibrational
state. These effects are very significant as the considered three-body
amplitudes often vary strongly within the energy interval eV.
The differential cross sections, calculated using the presented method, have
been successfully used for planning and interpreting many experiments in
low-energy muon physics. Studies of nuclear capture in and the
measurement of the Lamb shift in atoms created in H gaseous targets
are recent examples.Comment: 21 pages, 13 figures, submitted to Phys. Rev.
Petrography and geochemistry of carbonate rocks of the Paleoproterozoic Zaonega Formation, Russia : Documentation of C-13-depleted non-primary calcite
The Norwegian Research Council grant 191530/V30 to V.A. Melezhik fully funded the work of AEC, VAM and AL. ATB was supported by NERC grant NE/G00398X/1 to AEF and ARP. We are grateful for sample preparation and analyses to all the personnel at NGU lab. We appreciate the work on carbon and oxygen isotope analyses by Julie Dougans and Chris Taylor. Bojan OtoniÄar organized and helped with the CL work at the Karst Research Institute at Postojna. Arrangement of TOC, IC, and TC analyses at University of MĂŒnster is acknowledged to Harald Strauss.Peer reviewedPostprin
Travertine precipitation in the Paleoproterozoic KuetsjÀrvi Sedimentary Formation, Pechenga Greenstone Belt, NE Fennoscandian Shield
PES was supported by VÀisÀlÀ Foundation (Finnish Academy of Science and Letters) and the Finnish Doctoral Program in Geology. ATB was supported by NERC grant NE/G00398X/1. VAM was supported by NFR grant 191530/V30 (projects 331000 and 802795). This is a contribution (paper) # 18 to the ICDP FAR-DEEP project.Peer reviewedPublisher PD
Multi-Channel Atomic Scattering and Confinement-Induced Resonances in Waveguides
We develop a grid method for multi-channel scattering of atoms in a waveguide
with harmonic confinement. This approach is employed to extensively analyze the
transverse excitations and deexcitations as well as resonant scattering
processes. Collisions of identical bosonic and fermionic as well as
distinguishable atoms in harmonic traps with a single frequency
permitting the center-of-mass (c.m.) separation are explored in depth. In the
zero-energy limit and single mode regime we reproduce the well-known
confinement-induced resonances (CIRs) for bosonic, fermionic and heteronuclear
collisions. In case of the multi-mode regime up to four open transverse
channels are considered. Previously obtained analytical results are extended
significantly here. Series of Feshbach resonances in the transmission behaviour
are identified and analyzed. The behaviour of the transmission with varying
energy and scattering lengths is discussed in detail. The dual CIR leading to a
complete quantum suppression of atomic scattering is revealed in multi-channel
scattering processes. Possible applications include, e.g., cold and ultracold
atom-atom collisions in atomic waveguides and electron-impurity scattering in
quantum wires.Comment: 35 pages, 18 figure
Fabrication and Characterization of Anionic Exchange Membranes Based on Chitosan/Poly (Vinyl) Alcohol and Chitosan/Chondroitin Doped with an Amino Cumulene Derivative and Carbon Nanotubes
Anionic exchange membranes mainly based on mixed matrix membranes (MMM) via the crosslinking of either chitosan (CHT) with poly (vinyl alcohol) (CHT : PVA) or CHT with chondroitin sulfate (CHT : CS) in a 50 : 50 wt% were synthesized. The doping of CHT, CHT : PVA and CHT : CS membranes with either the dispersant agent aminocumulene derivative (named AC, coming from the polycondensation of hexamethylenetetramine in an anhydrous acid medium) or with the carbonaceous inch made of multi-walled carbon nanotubes (CNT) dispersed by using AC to perform (AC/CNT) were characterized by the exploration of the topology by scanning electron microscopy, the determination of water uptake, and the analysis of X-ray diffraction spectroscopy together with the measurement of the anionic conductivity by using electrochemical impedance spectroscopy. Results revealed that the modification of the MMMs with the above inorganic carbonaceous fillers, i.e. AC or AC/CNT, improved remarkably the OHâ conductivity for all membranes. The modified CHT:CS blend membranes exhibited the highest ionic conductivities of the series. Water uptake increased for the modified CHT and CHT : PVA membranes, whereas a remarkable reduction of water uptake for the CHT : CS based membranes took place. The best membranes in terms of anionic conductivity were correlated with crystallinity and water uptake.The research was carried out at the expense of a grant from the Russian Science Foundation (project No. 15-13-10038). AG acknowledges the Presidential fellowship programme of the Ministry of Education and Science of the Russian Federation. Also LGC and JI are grateful to the Spanish MINECO through the project CTQ2016-76231-C2-2-R
Wave packet evolution approach to ionization of hydrogen molecular ion by fast electrons
The multiply differential cross section of the ionization of hydrogen
molecular ion by fast electron impact is calculated by a direct approach, which
involves the reduction of the initial 6D Schr\"{o}dinger equation to a 3D
evolution problem followed by the modeling of the wave packet dynamics. This
approach avoids the use of stationary Coulomb two-centre functions of the
continuous spectrum of the ejected electron which demands cumbersome
calculations. The results obtained, after verification of the procedure in the
case atomic hydrogen, reveal interesting mechanisms in the case of small
scattering angles.Comment: 7 pages, 8 Postscript figure
The District Heating in the Context of the Active Consumers Development in Smart Energy Systems
The paper defines the main factors of the smart energy systems that influence on the district heating. Noted increase in the regulatory impact of electric energy system on the district heating and increase in roles of the distribution and consumption of thermal energy. Urban population and other consumers of energy become equal partners of the utilities and acquire the status of "active" consumers. The heating supply companies need to develop a new model of management of heating regimes with dynamic synchronization with energy system and "active" consumers. One of the most important conditions of the achievement of the cost reduction, reliability and quality increase in community facilities is active consumer's behavior
Hydrogen and Helium Atoms and Molecules in an Intense Magnetic Field
We calculate the atomic structure of hydrogen and helium, atoms and molecules
in an intense magnetic field, analytically and numerically with a judiciously
chosen basis.Comment: 16 pages, 5 figures, to appear in Phys. Rev.
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