Role of Transition Metals in UV-B-Induced Damage to Bacteria

2013 ◽  
Vol 89 (3) ◽  
pp. 640-648 ◽  
Author(s):  
Ana L. Santos ◽  
Newton C.M. Gomes ◽  
Isabel Henriques ◽  
Adelaide Almeida ◽  
António Correia ◽  
...  
Keyword(s):  
Transition Metals

Ion chemistry of transition metals in hydrocarbon flames. II. Cations of Sc, Ti, V, Cr, and Mn

1988 ◽  
Vol 66 (9) ◽  
pp. 2219-2228 ◽  
Author(s):  
John M. Goodings ◽  
Quang Tran ◽  
Nicholas S. Karellas
Keyword(s):  
Transition Metals ◽  
Metal Atom ◽  
Chemical Ionization ◽  
Metallic Ions ◽  
Ion Chemistry ◽  
Hydrocarbon Flames ◽  
Basic Series ◽  
First Time ◽  
Isomeric Structures

The same fuel-rich, premixed, conical, methane–oxygen flame at 2200 K and atmospheric pressure used for studies of Fe, Co, Ni, Cu, and Zn in Part I (1) is doped with the same concentration (~1 ppm) of Sc, Ti, V, Cr, and Mn to complete the first row of ten transition metals. Metallic ions of these metals and their compounds formed by chemical ionization reactions with H3O+ are observed by sampling the flame through a nozzle into a quadrupole mass spectrometer. Concentration profiles of individual and total cations are measured as a function of distance along the flame axis, and also mass spectra at a fixed point in the burnt gas. If A is the metal atom, the observed ions can be represented by four hydrate series including (a) A+•nH2O, (b) AOH+•nH2O, (c) AO+•nH2O, and (d) AO2H+•nH2O with n = 0–3 or 4, giving a maximum of four ligands around the metal atom. However, alternative isomeric structures are possible for each of the four basic series (e.g. AO+•2H2O ~ A(OH)2+•H2O ~ A(OH)3H+). The ions observed with Cr and Mn, in common with those of Fe, Co, Ni, and Cu, strongly favour series (a). On the other hand, Sc is completely different; the ions of series (c) are dominant. All four series are observed with each of Ti and V. Series (b) dominates for Ti and series (c) for V; ions from series (d) were observed for the first time. The ion chemistry of these metals is discussed in detail with emphasis on the probable chemical ionization reactions responsible for metallic ion formation. The pre-eminent role of proton transfer processes is apparent.

Room temperature p-orbital magnetism in carbon chains and the role of group IV, V, VI, and VII dopants

Nanoscale ◽  
2018 ◽  
Vol 10 (23) ◽  
pp. 11186-11195 ◽  
Author(s):  
C. H. Wong ◽  
E. A. Buntov ◽  
A. F. Zatsepin ◽  
J. Lyu ◽  
R. Lortz ◽  
...  
Keyword(s):  
Rare Earth ◽  
Transition Metals ◽  
Room Temperature ◽  
Group Iv ◽  
Rare Earth Ions ◽  
Next Generation ◽  
Spintronic Devices ◽  
Carbon Chains ◽  
Orbital Magnetism

The study of magnetism without the involvement of transition metals or rare earth ions is considered the key to the fabrication of next-generation spintronic devices.

Ti and Zr Transition Metals Effect in the D03 Fe3Al by Ab Initio Study Approach

2014 ◽  
Vol 783-786 ◽  
pp. 1640-1645
Author(s):  
Jean Marc Raulot ◽  
S. Chentouf ◽  
T. Grosdidier ◽  
Hafid Aourag
Keyword(s):  
Molecular Dynamics ◽  
Transition Metals ◽  
Ab Initio ◽  
Density Functional ◽  
Ab Initio Molecular Dynamics ◽  
Effect Of Temperature ◽  
Site Preference ◽  
Functional Theory ◽  
Study Approach

The effect of the Ti and Zr transition metals on the D03-Fe3Al intermetallic compounds has been investigated by means of ab initio Pseudo Potentials numerical simulations based on Density Functional Theory. Two main issues will be addressed the understanding of the role of these two transition metals in terms of stability of the bulk at the light of their site preference in the D03-Fe3Al structure the behaviour of Ti and Zr transition metals in the sigma 5 (310) [001] grain boundary and their effect on the structural stability of this interface. An important issue when studying these aspects is to take into accounts the effect of temperature. This requires a molecular dynamics treatment of the atoms in the supercell. The technique known as ab initio molecular dynamics (AIMD) solves these problems by combining ‘on the fly’ electronic structure calculations with finite temperature dynamics. Thus, our study was conducted both using the conventional static ab initio calculations (0K) as well as by taking into account the effect of temperature (Ab Initio Molecular Dynamics).

scholarly journals Spontaneous atomic ordering and magnetism in epitaxially stabilized double-perovskites

2012 ◽  
Vol 1454 ◽  
pp. 3-13
Author(s):  
Akira Ohtomo ◽  
Suvankar Chakraverty ◽  
Hisanori Mashiko ◽  
Takayoshi Oshima ◽  
Masashi Kawasaki
Keyword(s):  
Magnetic Properties ◽  
Transition Metals ◽  
Double Perovskite ◽  
Perovskite Oxides ◽  
Epitaxial Films ◽  
Atomic Ordering ◽  
Magnetic Ground State ◽  
Half Metallic ◽  
Optical Band Gaps

ABSTRACTWe report on the atomic ordering of B-site transition-metals and magnetic properties in double-perovskite oxides, La2CrFeO6 (LCFO) and La2VMnO6 (LVMO), which have never been reported to exist in ordered forms. These double-perovskite oxides are particularly interesting because of possible ferromagnetism (expected from the Kanamori-Goodenough rule for LCFO) and half-metallic antiferromagnetism (predicted for LVMO). Using pulsed-laser deposition technique with single solid-solution targets, we have prepared epitaxial films in ordered forms. Despite similar ionic characters of constituent transition-metals in each compound, the maximum B-site order attained was surprisingly high, ∼90% for LCFO and ∼80% for LVMO, suggesting a significant role of epitaxial stabilization in the spontaneous ordering process. Magnetization and valence state characterizations revealed that the magnetic ground state of both compounds was coincidently ferrimagnetic with saturation magnetization of ∼2μBper formula unit, unlike those predicted theoretically. In addition, they were found to be insulating with optical band-gaps of 1.6 eV and 0.9 eV for LCFO and LVMO, respectively. Our results present a wide opportunity to explore novel magnetic properties of binary transition-metal perovskites upon epitaxial stabilization of the ordered phase.

scholarly journals Monolayer Nitrides Doped with Transition Metals as Efficient Catalysts for Water Oxidation: The Singular Role of Nickel

2019 ◽  
Vol 123 (43) ◽  
pp. 26289-26298 ◽  
Author(s):  
Qiuhua Liang ◽  
Geert Brocks ◽  
Xueqing Zhang ◽  
Anja Bieberle-Hütter
Keyword(s):  
Transition Metals ◽  
Water Oxidation

The role of the [CpM(CO)2]− chromophore in the optical properties of the [Cp2ThMCp(CO)2]+ complexes, where M = Fe, Ru and Os. A theoretical view

2015 ◽  
Vol 44 (46) ◽  
pp. 20004-20010 ◽  
Author(s):  
Plinio Cantero-López ◽  
Laura Le Bras ◽  
Dayán Páez-Hernández ◽  
Ramiro Arratia-Pérez
Keyword(s):  
Optical Properties ◽  
Transition Metals ◽  
Tddft Calculations ◽  
Theoretical View

SO-TDDFT calculations shows that transition metals sensitize the emission of Th ion in the present unsupported complexes.

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