Search results for "SSB"
showing 10 items of 537 documents
Structural investigations on diorgano- and triorganotin(IV) derivatives of [meso-tetra(4-sulfonatophenyl)porphine]metal chlorides.
2006
Abstract Several new complexes of organotin(IV) moieties with MCln[meso-tetra(4-sulfonatophenyl)porphine], (R2Sn)2MCln[meso-tetra(4-sulfonatophenyl)-porphinate]s and (R3Sn)4MCln [meso-tetra(4-sulfonatophenyl)porphinate]s, [M = Fe(III), Mn(III): n = 1, R = Me, n-Bu; Ph; M = Sn(IV): n = 2, R = Me, n-Bu] have been synthesized and their solid state configuration investigated by infrared (IR) and Mossbauer spectroscopy, and by 1H and 13C NMR in D2O. The electron density on the metal ion coordinated inside the porphyrin ring is not influenced by the organotin(IV) moieties bonded to the oxygen atoms of the side chain sulfonatophenyl groups, as it has been inferred on the basis of Mossbauer spectro…
PERANAN GELOMBANG PANJANG TERHADAP SIRKULASI ARUS GLOBAL
2008
The global surface current system forms a large scala current circulation pattern known as gyra, which occurs in the Pasific, Hindia, and Atlantic oceans. At the nothern equator, the gyra circulation is counterclockwise, while it is anti counterclockwise at the southern equator. The trade wind crossing the Equatorial ocean causes a different slope and influences the slope form. The response of the sea level slope can be only described by the sea level pertubation concept that the disturbance moves as pulse wave which travel alongside equatorial ocean. The effects of the Rossby and Kelvin waves propagation on the ocean circulation depend on the lattitude. At the middle and high lattitudes, t…
The miniaturised Mössbauer spectrometer MIMOS IIA: Increased sensitivity and new capability for elemental analysis
2010
The Miniaturised Mossbauer Spectrometers MIMOS II on board the two Mars Exploration Rovers (MER) have now been collecting valuable scientific data for more than five years. Mossbauer Spectrometers are part of two future missions: Phobos Grunt (Russian Space Agency) and a joint ESA—NASA Rover in 2018. The new advanced MIMOS IIA instrument described in this paper uses Silicon Drift Detectors (SDD) allowing also X-ray fluorescence chemical analysis (XRF) simultaneously to Mossbauer acquisitions. This paper highlights the features and technological improvements of the new spectrometer MIMOS IIA.
Hybrid Molecular Magnets Obtained by Insertion of Decamethylmetallocenium Cations into Layered, Bimetallic Oxalate Complexes: [ZIIICp*2][MIIMIII(ox)3…
2000
A new series of hybrid organometallic - inorganic layered magnets with the formula [Z(III)Cp*2][M(II)M(III)(ox)3] (Z(III) = Co, Fe; M(III) = Cr, Fe; M(II) = Mn, Fe, Co, Cu, Zn; ox = oxalate; Cp* = pentamethylcyclopentadienyl) has been prepared. All of these compounds are isostructural and crystallize in the monoclinic space group C2/m, as found by X-ray structure analysis. Their structure consists of an eclipsed stacking of the bimetallic oxalate-based extended layers separated by layers of organometallic cations. These salts show spontaneous magnetization below To, which corresponds to the presence of ferro-, ferri-, or canted antiferromagnetism. Compounds in which the paramagnetic deca-me…
The structure and dynamics of Cl-substituted tetraphenyl- and tetrabenzyl-tin(IV)
1999
Abstract The crystal and molecular structure of (o-ClC6H4CH2)4Sn has been determined by X-ray crystallography. Tin is in a slightly distorted environment. The molecular dynamics of (p-ClC6H4)4Sn, (o-ClC6H4)4Sn and (o-ClC6H4CH2)4Sn have been investigated by variable temperature 119Sn Mossbauer spectroscopy (VTMS). A Debye-solid behaviour has been detected for (p-ClC6H4)4Sn, where, on the other hand, no influence by hydrogen–chlorine interaction on the magnitude of the dynamics data and functions seems to occur. For the o-Cl-substituted derivatives, a non-Debye-solid character could be advanced.
The interaction of S,N-coordinated dimethyltin(IV) derivatives with deoxyribonucleic acid: Structure and dynamics by119Sn mössbauer spectroscopy
1999
Complexes Me2SnCl(SPy) and Me2SnCl(SPym) (HSPy = 2-mercaptopyridine; HSPym = 2-mercaptopyrimidine), from ethanol solutions, interact with aqueous calf-thymus DNA yielding condensed phases with probable Me2Sn(SPy,-SPym) (DNA monomer) stoichiometries of 1:1; the condensation of DNA is inferred originated from electrostatic bonding between complex cations Me2Sn(SPy,SPym)+ and the phosphate oxygen of the phosphodiester groups. Octahedral-or trigonal-bipyramidal tin environments are inferred from the point-charge model treatment of the 119Sn Mössbauer parameter nuclear quadrupole splitting, considering the bonding by S and N, or only S donor atoms from the ligand, as well as possible coordinatio…
The influence of crossbite in early development of mandibular bone asymmetries in paediatric patients
2017
BACKGROUND All authors agree that posterior crossbite is a malocclusion that affects mandibular growth and may lead to skeletal asymmetry but there are few data on which age these modifications are easily quantifiable. MATERIAL AND METHODS For this study, the researchers used x-ray records of 217 children between 6 and 9 years of age, in the mixed dentition stage and with unilateral posterior crossbite. All the horizontal variables were traced and evaluated by the principal researcher, using the tpsDig version 2 computer program. Subsequently, a descriptive and statistical analysis was carried out, using the SPSS 17.0 for Windows program. RESULTS AND DISCUSSION After analysing the vertical …
Mechanical properties of the NiTi Memoria Leaf Spring Activated Expander (NiTi MLSAE) for maxillary transverse discrepancy correction: An in-vitro st…
2020
Background To determine the mechanical properties of the NiTi Memoria® Leaf Spring Activated Expander (NiTi MLSAE) in two forms, unaltered (unbent) and altered (bent) to mimic clinical use. Material and Methods This in-vitro pilot study was conducted using eight NiTi MLSAE expanders (American Tooth Industries, Oxnard, California) representing four force magnitudes: 10mm 500g, 10mm 900g, 6mm 450g and 6mm 900g models. Two experiments were performed: the first tested the expanders in their unbent form and the second tested them after they were bent by one experienced technician. All expanders were adapted to a standard three dimensional printed maxillary study model. A Dillion Quantrol 500N (1…
Study of the influence of crossbite on the size of the apical area in a child population by analyzing panoramic X-ray
2018
The apical area is the space in the maxillary bones that contains teeth during formation and is subsequently occupied by the apices of the permanent teeth. Its dimensions are easy to perceive and determine by observing a panoramic X-ray. Our objective was to analyze the influence of crossbite on the size of the anterior and mesial apical area in Caucasian children. Based on the ortopantomograph of 353 patients in mixed dentition and crossbite, the sizes of the apical areas of the four hemiarches were studied using the Tps Dig Version 2® computer program. These data were subjected to statistical analysis using the SPSS 22.0 for Windows program and applying the methods of descriptive statisti…
In situ Mössbauer spectroscopy: Evidence for green rust (fougerite) in a gleysol and its mineralogical transformations with time and depth
2005
Abstract A miniaturized Mossbauer spectrometer, adapted to the Earth’s conditions from the instrument developed for Mars space missions, has been used for the first time to study in situ variations with depth and transformations with time of iron minerals in a gleysol. The instrument is set into a PVC tube and can be moved up and down precisely (±1 mm) at the desired depth. Mossbauer spectra were obtained from 15 to 106 cm depth and repeated exactly at the same point at different times to follow mineralogical transformations with time. X-ray diffraction (XRD) and selective extraction techniques were performed on soil samples. The piezometric level of the water table was measured and the com…