No abstract available

[en] The core level binding energies and valence band spectra of MnS, MnSe, and MnTe have been examined by X-ray photoelectron spectroscopy. The results demonstrate that the compounds are substantially more ionic in character than related transition metal compounds, and that the compounds lack significant metal-metal interactions, accounting for the nontypical nature of the compounds as transition metal chalcides

[en] Low-temperature nuclear orientation experiments on radioactive ⁵⁶Mn ions implanted into insulating, antiferromagnetic crystals of MnCl₂·4H₂O and CoCl₂·6H₂O are reported. In MnCl₂·4H₂O, comparison of the γ-ray anisotropy of the ⁵⁶Mn nuclei with that of ⁵⁴Mn, doped into the sample during growth, showed that both the ⁵⁶Mn and ⁵⁴Mn spins felt a very similar hyperfine field. The site occupancy factor in a simple, two-site model was deduced to be 0.96_-0.07^+0.04. In CoCl₂·6H₂O, the average hyperfine field for the implanted ⁵⁶Mn was significantly less than that for ⁵⁴Mn and corresponded to f=0.53±0.10

[en] Exposure of the manganese pentacarbonyl halides [Mn(C0)₅X](X = Cl,Br or I), to ⁶⁰Co γ-rays at 77K gives an S = 1/2 centre having a g ca. 2 and a large hyperfine coupling to ⁵⁵Mn and the halogen nuclei. The results are interpreted in terms of electron addition into a sigma* orbital involving mainly the metal dsub(z)2 and halide psub(z) orbitals. A second centre having two apparent g values in the g = 6 region is also formed for all the three complexes. These again exhibit hyperfine coupling to ⁵⁵M and to the halogen nuclei. Various structures are considered, and it is concluded that the most reasonable are cations formed by loss of an electron and one or more carbonyl groups with unpairing of the remaining electrons to to give S = 5/2. (author)

[en] A method for the sorting of manganese ore in particulate form according to the manganese content of the particles including the steps of irradiating the ore with neutrons to induce the reaction Mn (n, Gamma) ⁵⁶Mn; detecting the gamma rays emitted by the ⁵⁶Mn; and using the information so obtained to sort paricles of relatively high manganese content from particles of relatively low manganese content is discussed

[en] Highlights: • MOB mediate enhanced BPA degradation at low (μM range) Mn(II) concentrations. • MOB contribute to BPA degradation, but organism-specific differences exist. • Mn flux determines efficacy of coupled biotic-abiotic BPA degradation. • Oxic-anoxic interfaces are hotspot barriers for BPA degradation. • The BMAD process, both natural and engineered, promises sustainable attenuation of BPA. Bisphenol A (BPA), a chemical of environmental concern, is recalcitrant under anoxic conditions, but is susceptible to oxidative degradation by manganese(IV)-oxide (MnO₂). Microbial Mn(II)-oxidation generates MnO_2-bio; however, BPA degradation in cultures of Mn(II)-oxidizing bacteria has not been explored. We assessed MnO_2-bio-mediated BPA degradation using three Mn(II)-oxidizing bacteria, Roseobacter sp. AzwK-3b, Erythrobacter sp. SD-21, and Pseudomonas putida GB-1. In cultures of all three strains, enhanced BPA degradation was evident in the presence of Mn(II) compared to replicate incubations without Mn(II), suggesting MnO_2-bio mediated BPA degradation. Increased Mn(II) concentrations up to 100 µM resulted in more MnO_2-bio formation but the highest BPA degradation rates were observed with 10 µM Mn(II). Compared to abiotic BPA degradation with 10 μM synthetic MnO₂, live cultures of strain GB-1 amended with 10 μM Mn(II) consumed 9-fold more BPA at about 5-fold higher rates. Growth of strain AzwK-3b was sensitive to BPA and the organism showed increased tolerance against BPA in the presence of Mn(II), suggesting MnO_2-bio alleviated the inhibition by mediating BPA degradation. The findings demonstrate that Mn(II)-oxidizing bacteria contribute to BPA degradation but organism-specific differences exist, and for biologically-mediated-abiotic-degradation (BMAD), Mn-flux, rather than the absolute amount of MnO_2-bio, is the key determinant for oxidation activity.

No abstract available

[en] The AMS facility at China Institute of Atomic Energy has been equipped with a ΔE-Q3D detection system for the measurements of ⁵³Mn. While the sample material of MnO₂ and the extraction ions of MnO⁻ were used previously in AMS measurement of ⁵³Mn with fairly good results, a method has recently been developed with the extraction of MnF⁻ from ion source using MnF₂ and MnO₂ + PbF₂ as sample materials. As a result, a sensitivity of 10⁻¹⁴ (⁵³Mn/Mn) has been achieved. Compared with the original MnO⁻/MnO₂ approach, the method of MnF⁻ extraction, combined with ΔE-Q3D detection technique, demonstrated an improved sensitivity for AMS measurement of ⁵³Mn.

[en] Complete text of publication follows. Complete text of publication follows. The crystal structures of the ^α and ^β allotropes of manganese, are among the most complicated found in nature, with the ^α-Mn unit cell containing 58 Mn atoms shared between four crystallographically inequivalent sites, and the ^β-Mn unit cell containing 20 Mn atoms shared between two sites. A comprehensive neutron diffraction study of the alloys, ^α-MnT where T = Al, Cr, V, Co and Fe, and ^β-MnT where T = Al, In, Sn, Co and Fe has been carried out in order to determine their impurity site occupancies and lattice expansion properties. In the case of the ^β-MnT alloys, we find that Al, In and Sn preferentially occupy the site II ^β-Mn sublattice, while Fe and Co prefer site I, confirming most of the previous studies. For the ^α-MnT alloys, we find that Al and V display a strong preference for the site I ^α-Mn sublattice, while Fe and Co occupy sites III and IV. No site preference is observed in dilute ^α-MnCr. Large ionic radii non-TM impurities produce significant lattice expansion; 0.9%/at% In, 0.8%/at% Sn and 0.05%/at% Al, while TM impurities leave the ^β-Mn lattice constant virtually unchanged; 0.009%/at% Co and 0.01%/at% Fe. The preferential occupancies of these impurities are discussed in terms of their effect on the magnetic ground states of these alloys. (author)

No abstract available