Search results for " Structure"
showing 10 items of 25475 documents
A large ameloblastic fibro-odontoma of the right mandible
2007
The ameloblastic fibro-odontoma is a rare mixed odontogenic tumor. It occurs predominantly in children and young adults with no sex predilection and locates most often in the posterior segment of the mandible. A painless swelling is the most common clinical sign. Radiologically, ameloblastic fibro-odontoma shows a circumscribed radiolucency, which contains radio-opaque foci of various sizes and shapes. Histological examination reveals a fibrous soft tissue, islands of odontogenic epithelium and a disordered mixture of dental tissues. The tumor produces enamel or enamel matrix, dentin and cementum. The treatment of ameloblastic fibro-odontomas usually consists of enucleation or surgical cure…
R&D with spillovers: Monopoly versus noncooperative and cooperative duopoly.
2011
This paper compares industry profit and R&D propensity for a duopoly conducting either noncooperative or cooperative R&D and a monopoly, using two different basic models of strategic R&D. One postulates spillovers in R&D inputs and predicts that equilibrium joint profit and R&D levels are always larger under monopoly. The other postulates spillovers in R&D outputs and sometimes predicts that joint profit and R&D levels are larger under either of the alternative scenarios. In addition, unlike input spillovers, spillovers in R&D outputs sometimes exert a positive effect on both effective and private noncooperative R&D levels.
Characterization of rhenium oxide films and their application to liquid crystal cells
2009
Rhenium trioxide exhibits high electronic conductivity, while its open cubic crystal structure allows an appreciable hydrogen intercalation, generating disordered solid phases, with protonic conductivity. Rhenium oxide thin films have been obtained by thermal evaporation of ReO3 powders on different substrates, maintained at different temperatures, and also by reactive magnetron sputtering of a Re metallic target. A comparative investigation has been carried out on these films, by using micro-Raman spectroscopy and x-ray diffraction. Two basic types of solid phases appear to grow in the films: a red metallic HxReO3 compound, with distorted perovskite structures, like in the bulk material, a…
Conception de documents numériques : Parcours méthodologique
2009
There is a strong social demand for studies of digital document. Yet our models of society and education are struggling to integrate issues related to these types of documents. However, the subject is less than half a century old, and so it is hardly surprising that the writing and training practices are just being developed. Like the book, the digital document involves many different skills and techniques in its development. The list of jobs tends to grow steadily: ergonomists, referencing specialists, information architects, programmers, designers, integrators ... It is therefore difficult to have a global view on all this know-how and the related methodologies. This special edition seeks…
Structure/Structuralism
2020
The first issue of Word, the Journal of the Linguistic Circle of New York, published in April 1945 by Roman Jakobson and André Martinet, both exiles living in the USA, features one of the first articles by Claude Lévi-Strauss (1958) (L’analyse structurale en linguistique et en anthropologie) and the last essay by Ernst Cassirer (2002) (Structuralism in Modern Linguistics), who died a few weeks before its publi cation. This is the official birth of structuralism, a term seemingly coined by the author of Philosophie der symbolischen Formen in his posthumous essay with its testimonial quality.
On the mechanism of radiation synthesis of nanogels
2016
Radiation-engineered poly(N-vinyl pyrrolidone) nanogels are very interesting biocompatible nanocarriers for i.v. administration of therapeutics and contrast agents for bioimaging among other applications. Nanogels are usually produced upon irradiation of dilute aqueous polymer solutions. Under these conditions, the polymer radicals formed primarily react via intramolecular radical-radical combination forming intramolecular crosslinks. The manufacturing process is fast and effective and grants excellent control of particle size and simultaneous sterilization of the formed nanogels. Interestingly, primary amino groups and carboxyl groups, useful for (bio)conjugation, are also formed in a dose…
Crystal structure and Hirshfeld surface analysis of [N(CH3)4][2,2′-Fe(1,7-closo-C2B9H11)2]
2017
Abstract This work investigates the meta -ferrabis(dicarbollide) anion that was isolated as salt of tetramethylammonium. The structure of the obtained crystal consisted of discrete [2,2′-Fe(1,7- closo -C 2 B 9 H 11 ) 2 ] − anions and disordered [N(CH 3 ) 4 ] + cations. The anion had a considerable chemical stability ensured by ionic and Van der Waals interactions. Thus, Hirshfeld surfaces and fingerprint plot were used to visualize, explore, and quantify intermolecular interactions in the crystal lattice of the title compound. This investigation proved that close contacts were dominated by H⋯H interactions.
Ekskurs VIII. Powołania Ezechiela na stróża Izraela Ez 3,16-21 oraz Ez 33,1-20 w świetle retoryki hebrajskiej
2020
Kontekstem badań była konstatacja, że wielu komentatorów różnie określa strukturę opisywanych fragmentów Księgi Ezechiela. Czytelnik może odnieść wrażenie, że jest to zrobione na wyczucie, a wyczucie nie jest metodą naukową. Dlatego celem przeprowadzonych badań było opracowanie struktury tekstu przy pomocy naukowych metod. Wykorzystano metodę retoryki hebrajskiej, którą opracował Roland Meynet. Uzyskano wyniki: Ez 3,16-21: A, A’, B, B’ lub A, B, A’, B’; Ez 33,1-20: A, B, B’, A’; Ez 33,2-6: A, B, C, D, E, F, G, H, I, H’, G’, F’, E’, D’, C’, B’, A’; Ez 33,7-20: A, B, C, D, E, F, E’, D’, C’, B’, A’. Żeby można było sformułować naukowe, ogólne konstatacje na temat Księgi Ezechiela potrzebny jes…
Classical and reverse substituent effects in meta- and para-substituted nitrobenzene derivatives
2017
Electron-accepting properties of the nitro group were studied in a series of meta- and para-X-substituted nitrobenzene derivatives (X = NMe2, NH2, OH, OMe, CH3, H, F, Cl, CF3, CN, CHO, COMe, CONH2, COOH, COCl, NO2, NO). For this purpose Hammett-like approaches were applied based on quantum chemistry modeling; the B3LYP/6-311++ G(d,p) method was used. The substituent effect (SE) was characterized by the mutually interrelated descriptors: the charge of the substituent active region, cSAR(X), and substituent effect stabilization energy, SESE, as well as substituent constants, σ. Classical SE is realized by dependences of the structural parameters of the nitro group (ONO angle and NO bond lengt…
Titanocene Selenide Sulfides Revisited: Formation, Stabilities, and NMR Spectroscopic Properties
2019
[TiCp2S5] (phase A), [TiCp2Se5] (phase F), and five solid solutions of mixed titanocene selenide sulfides [TiCp2SexS5−x] (Cp = C5H5−) with the initial Se:S ranging from 1:4 to 4:1 (phases B–E) were prepared by reduction of elemental sulfur or selenium or their mixtures by lithium triethylhydridoborate in thf followed by the treatment with titanocene dichloride [TiCp2Cl2]. Their 77Se and 13C NMR spectra were recorded from the CS2 solution. The definite assignment of the 77Se NMR spectra was based on the PBE0/def2-TZVPP calculations of the 77Se chemical shifts and is supported by 13C NMR spectra of the samples. The following complexes in varying ratios were identified in the CS2 solutions of …