Search results for "mangaani"
showing 9 items of 9 documents
Successive alkalinity producing system for the treatment of acid sulphate soil runoff: preliminary results of a field trial
2005
A successive alkalinity producing system (SAPS) has been investigated as a potential passive treatment option for acid, metal containing runoff from acid sulphate soil. A pilot-scale system was installed at an agricultural land site in Rintala embankment area in mid-western Finland. The experimental layout consists of three parallel treatment units: two different SAPS cells and one limestone-filled cell for comparison of performance. The SAPS cells are composed of a bottom layer of limestone and a top layer of compost supplemented with sand. One of the SAPS cells contains sulphate-rich, waste gypsum mixed with the compost layer in order to enhance the metal reduction by sulphate reducing-ba…
Changes in nuclear structure along the Mn isotopic chain studied via charge radii
2016
The hyperfine spectra of $^{51,53-64}$Mn were measured in two experimental runs using collinear laser spectroscopy at ISOLDE, CERN. Laser spectroscopy was performed on the atomic $3d^5\ 4s^2\ ^{6}\text{S}_{5/2}\rightarrow 3d^5\ 4s4p\ ^{6}\text{P}_{3/2}$ and ionic $3d^5\ 4s\ ^{5}\text{S}_2 \rightarrow 3d^5\ 4p\ ^{5}\text{P}_3$ transitions, yielding two sets of isotope shifts. The mass and field shift factors for both transitions have been calculated in the multiconfiguration Dirac-Fock framework and were combined with a King plot analysis in order to obtain a consistent set of mean-square charge radii which, together with earlier work on neutron-deficient Mn, allow the study of nuclear struc…
Evidence for Increased neutron and proton excitations between 51−63 Mn
2015
The hyperfine structures of the odd-even 51−63Mnatoms (N=26 −38) were measured using bunched beam collinear laser spectroscopy at ISOLDE, CERN. The extracted spins and magnetic dipole moments have been compared to large-scale shell-model calculations using different model spaces and effective interactions. In the case of 61,63Mn, the results show the increasing importance of neutron excitations across the N=40subshell closure, and of proton excitations across the Z=28shell gap. These measurements provide the first direct proof that proton and neutron excitations across shell gaps are playing an important role in the ground state wave functions of the neutron-rich Mn isotopes. publisher: Els…
COLLINEAR LASER SPECTROSCOPY ON NEUTRON-RICH Mn ISOTOPES APPROACHING N = 40
2015
We have studied 51,53−64Mn (Z=25) via bunched-beam collinear laser spectroscopy at ISOLDE, CERN. Model-independent information on the ground- and isomeric state spins, as well as their g-factors is obtained from the measured hyperfine spectra. The spins are essential for further establishing the level schemes in the mass region, while the g-factors reveal the changing ground state wave functions in the Mn chain approaching N=40. ispartof: pages:699-702 ispartof: Acta Physica Polonica B vol:46 issue:3 pages:699-702 ispartof: location:Zakopane, Poland status: published
Metallimalmikaivosten vesistövaikutukset : esimerkkinä Talvivaaran kaivoksen sulfaatti-, natrium- ja mangaanipäästöt
2013
Mining industry is expanding in Finland and it is expected to become a forerunner in taking environmental issues into account in its processes. Mines often lower the water quality of their surrounding waters and this may lead to salinization and eutrophication for instance. Salinization may be due to dissolved ions in the wastewater, like sulphate and sodium, and may cause the artificial stratification of a lake. Sulphate can also prevent the natural circulation of iron in the sediments, which favors the release of phosphorus and could lead to eutrophication. All impacts cannot be assessed in advance and not enough studies have been made concerning these substances. The Talvivaara mine in S…
Computational studies of chemical looping combustion materials and CO₂ activating surfaces
2016
Spins and magnetic moments of 58;60;62;64Mn ground states and isomers
2015
The odd-odd 54;56;58;60;62;64Mn isotopes (Z = 25) were studied using bunched-beam collinear laser spectroscopy at ISOLDE, CERN. From the measured hyperfine spectra the spins and magnetic moments of Mn isotopes up to N = 39 were extracted. The previous tentative ground state spin assignments of 58;60;62;64Mn are now firmly determined to be I = 1 along with an I = 4 assignment for the isomeric states in 58;60;62Mn. The I = 1 magnetic moments show a decreasing trend with increasing neutron number while the I = 4 moments remain quite constant between N = 33 and N = 37. The results are compared to large-scale shell-model calculations using the GXPF1A and LNPS effective interactions. The excellen…