Search results for "visual_art"
showing 10 items of 2987 documents
Cytotoxicity investigations of plasma sprayed calcium phosphate coatings
1994
One potential alternative material to replace hydroxyapatite (HAp) as a coating material for plasma-sprayed coatings on implants for hip replacement is fluorapatite (FAp). FAp has advantages over HAp regarding the capability of being chemically stable during the coating process. This leads to surface coatings containing high apatite rates with a mechanical stability (bond strength, microhardness) comparable to HAp. From the technical point of view the production of FAp coatings is well investigated, although studies on biocompatibility of FAp coatings are fewer. This paper reports the production of HAp and FAp coatings with varying solubilities by plasma spraying and their in vitro cytotoxi…
Winter male plumage coloration correlates with breeding status in a cooperative breeding species
2007
The function of colored ornaments is usually related to the signaling of individual quality in intra- and intersexual interactions. In cooperative breeding species, where only a fraction of the male population access the breeding status and the other fraction has the option to help breeding pairs, colored traits might provide the females with a reliable information on the quality of potential mate. Males of the cooperative breeding azure-winged magpies (Cyanopica cyanus) display conspicuous blue plumage coloration. Here we explored the role played by structural blue coloration of males and the probability of becoming a breeder or a helper. Birds were trapped during 4 consecutive years, and …
The first copper(I)-olefin complexes bearing a 1,3,4-oxadiazole core: Alternating-current electrochemical crystallization, X-ray experiment and DFT s…
2017
By means of alternating-current electrochemical technique, four new π-complexes, namely [Cu2(C11H10N2OS)2Br1.91Cl0.09] (1), [Cu(C11H10N2OS)NO3] (2), [Cu2(C11H10N2OS)2(H2O)2](BF4)2 (3) and [Cu2(C11H10N2OS)2(H2O)2](ClO4)2 (4), were obtained using copper(II) salts and the 2-(allylthio)-5-phenyl-1,3,4-oxadiazole (C11H10N2OS) ligand. The metal and halogen centers in 1 form Cu2X2 dimers; the N-atom from the oxadiazole ring and the Cdouble bond; length as m-dashC bond of the allyl group from the same ligand complete the copper coordination environment, giving [Cu(C11H10N2OS)X]2 isolated fragments. The ligand plays the same chelating role in 2, whereas the O (NO3) atom occupies the third position i…
Double-CO32− Centered [CoII5] Wheel and Modeling of Its Magnetic Properties
2010
A high-spin Co(II) cluster with a rare pentagonal molecular structure and formula [Co(5)(CO(3))(2)(bpp)(5)]ClO(4) (1; Hbpp is 2,6-bis(phenyliminomethyl)-4-methylphenolate) has been synthesized and characterized by single-crystal X-ray diffraction. This topology arises from fusing five [Co(2)(bpp)] moieties in a cyclic manner around two CO(3)(2-) central ligands, resulting in propeller-like configuration. The irregular coordination of the carbonate ions to the metal centers results in a combination of coordination numbers (CNs) of the Co(II) ions of five and six. The bulk magnetization of this complicated magnetically exchanged system has been modeled successfully by employing a matrix diago…
Ruthenium(II) carbonyl compounds with the 4′-chloro-2,2′:6′,2′′-terpyridine ligand
2017
The RuII atoms in the crystal structures of two new potential catalyst precursors, [Ru(Tpy-Cl)(CO)2Cl][Ru(CO)3Cl3] and [Ru(Tpy-Cl)(CO)2Cl2] (Tpy-Cl = 4′-chloro 2,2′:6′,2′′-terpyridine-κ3 N), exhibit distorted octahedral coordination spheres.
Crystal structure of chlorido(2-{1-[2-(4-chlorophenyl)hydrazin-1-ylidene-κN]ethyl}pyridine-κN)(η5-pentamethylcyclopentadienyl)rhodium(III) chloride
2015
The title compound, [Rh(η5-C5Me5)Cl(C13H12ClN3)]Cl, is chiral at the metal and crystallizes as a racemate. Upon coordination, the hydrazinylidenepyridine ligand is non-planar, an angle of 54.42 (7)° being observed between the pyridine ring and the aromatic ring of the [2-(4-chlorophenyl)hydrazin-1-ylidene]ethyl group.
Three phenanthroline-metal complexes with topologically similar but geometrically different conformations.
2016
Two out of the three very similar complexes described present twofold symmetry but not the third one, probably by way of a strong intramolecular C—H⋯O hydrogen bond disrupting the symmetry, a fact which is analysed in detail.
Crystal structure of bis[2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole-κ2N2,N3]bis(thiocyanato-κS)copper(II)
2016
The structure of the title compound is similar to that of the related complexes [Co(C12H8N4S)2(N3)2] and [Ni(C12H8N4S)2(N3)2] in which the azide ion is substituted by the thiocyanate group. The CuN4S2 octahedron is more distorted than the CoN6 and NiN6 octahedra.
Crystal structure of chlorido(2-{[2-(4-chlorophenyl)hydrazin-1-ylidene-κN1](phenyl)methyl}pyridine-κN)(η5-pentamethylcyclopentadienyl)iridium(III) te…
2015
The title compound, [Ir(η5-C5Me5)Cl(C18H14ClN3)]B(C6H5)4, is chiral at the metal center and crystallizes as a racemate. In the cation, the hydrazinylidenepyridine ligand isN,N-coordinated through theN-pyridyl andN-hydrazinylidene groups forming a five-membered metallacycle. An intramolecular C—H...Cl hydrogen bond is observed. In the crystal, centrosymmetrically-related cations are connected by C—Cl...π interactions, forming a dimeric structure. The crystal packing is further stabilized by weak interionic C—H...π interactions.
Quantitation of Metal Ions in Archaeological Glass by Abrasive Stripping Square-Wave Voltammetry Using Graphite/Polyester Composite Electrodes
2003
A method for identifying Co, Cu, Sb, Sn, Fe, Zn, and Zr pigments in glasses using square-wave voltammetry as the detection mode is described. It is based on the abrasive attachment of glass microsamples to graphite/polyester composite electrodes. Sample amounts less than 1 μg are used allowing for the study of archaeological samples. In all cases well-defined anodic stripping peaks corresponding to the oxidation of metal deposits generated at potentials ranging from −0.6 to −1.6 V (vs. SCE) are obtained. This response is in agreement with that displayed by the corresponding metal oxides. Quantitative estimates of the relative population of metal ions in glasses are obtained from peak area m…