Search results for "bama"
showing 10 items of 304 documents
Reacciones de CO2 con nucleófilos carbonado y nitrogenados: aplicaciones en síntesis
2015
Las reacciones de carboxilación de nucleófilos carbonados y nitrogenados, así como de descarboxilación de los productos presentan una notable complejidad mecanística que sigue siendo objeto de discusión actualmente. El objetivo general del presente estudio plantea la exploración de estas reacciones y su eventual aplicación en síntesis. En el primer capítulo se describen las reacciones de carboxilación de aniones enolato y la química de los β-cetocarboxilatos alcalinos correspondientes en el contexto de su aplicación en reacciones de alquilación monoselectiva. Los resultados muestran el impacto de la agregación y los equilibrios ácido-base sobre la evolución de los intermedios de reacción, y…
Kako budući stručnjaci u sportu, tjelovježbi i tjelesnome odgoju percipiraju tjelesni izgled pretile djece
2010
Anti-fat bias has been previously identified amongst practising obesity health care specialists, physical education (PE) teachers and students of exercise science and PE in samples in the USA and New Zealand. The present research investigated the perceptions of the physical self of ‘fat’ versus ‘normal-weight’ children held by 167 students studying sport exercise and PE related programmes in higher education in England. Onesample t-tests identified that the sample held negative perceptions towards ‘fat’ children (identified by subscale mean scores that were significantly different from the subscale mean of 2.5 that would identify equivocal perception between ‘fat’ and ‘normal-weight’ childr…
CCDC 831123: Experimental Crystal Structure Determination
2011
Related Article: E.Nauha, E.Kolehmainen, M.Nissinen|2011|CrystEngComm|13|6531|doi:10.1039/c1ce05730h
CCDC 157255: Experimental Crystal Structure Determination
2002
Related Article: G.Barone, T.Chaplin, T.G.Hibbert, A.T.Kana, M.F.Mahon, K.C.Molloy, I.D.Worsley, I.P.Parkin, L.S.Price|2002|J.Chem.Soc.,Dalton Trans.||1085|doi:10.1039/b108509n
Transboundary Movements of Hazardous Wastes in International Law: The Special Case of the Mediterranean Area
1997
AbstractSince the early 1980s different organisations have tried to enact international instruments to control international waste trade. The Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal was adopted in 1989 under the auspices of UNEP in order to protect human health and the environment against the adverse effects which may result from the management of waste involved in transboundary movements of hazardous waste and its disposal. The Basel Convention has evolved significantly in eight years-whereas only 35 states and the EC signed the Convention at the time of its adoption, more than 113 states have ratified it as to August 1997. Several …
Chromatography of metal chelates
1973
The chromatographic behavior of metal bis(ethoxyethyl)dithiocarbamate was investigated. The chelates of 14 elements (V, Cr, Co, Ni, Cu, Zn, Se, Mo, Cd, Te, Hg, Tl, Pb and Bi) could be preconcentrated from water with an on-line system and were shown to be suitable for C18-reversed-phase liquid chromatography. A quaternary solvent mixture with admixture of a surfactant was used as eluent, UV-detection was performed at 254 nm. Thermostating the column to 40° C resulted in a significant increase in chromatographic resolution and in a decrease of analysis time. The recovery of the chelates from the aqueous solutions as well as reproducibility of the results are very sensitive to pH changes.
Synthesis and structural studies on Ni(II) dithiocarbamates : Exploring intramolecular Ni···H-C interactions
2017
Abstract Five new Ni(II) dithiocarbamates with NiS4, NiS2PN and NiS2PCl coordination spheres, viz. [Ni(bupmbzdtc)2] (1), [Ni(bupmbzdtc)(PPh3)(NCS)] (2), [Ni(bupmbzdtc)(PPh3)Cl] (3), [Ni(4-dpmpzdtc)(PPh3)Cl] (4) and [Ni(pbbzbudtc)(PPh3)(NCS)] (5), where bupmbzdtc = N-butyl(p-methylbenzyl)dithiocarbamato anion, 4-dpmpzdtc = 4-(diphenylmethyl)piperazinecarbodithioato anion, pbbzbudtc = N-(p-bromobenzyl)butyl-dithiocarbamato anion and PPh3 = triphenylphosphine, were synthesized and characterized by UV, IR, NMR and single crystal X-ray diffraction methods. Spectral results suggest a square planar geometry around the Ni(II) metal center for all the synthesized complexes. Single crystal X-ray stru…
Analysis of carbamate pesticides and their metabolites in water by solid phase extraction and liquid chromatography: A review
2001
Carbamates are an important, broad class of pesticides that are used extensively as insecticides, fungicides, and herbicides. Sensitive, economical, fast, and environmental friendly procedures are constantly developed to investigate their residues in water samples. The state of the art in methods based on solid phase extraction (SPE) and liquid chromatographic determination are examined here. SPE is presently the most extended method for preconcentration of carbamate pesticide residues and their transformation products from water samples. Advantages and limitations of alkyl bonded-silica, and polymeric sorbents, carbon, and mixed-phases in off-line and on-line procedures are discussed. Beca…
Differential reactivity of fluorinated homopropargylic amino esters vs gold(I) salts. The role of the nitrogen protecting group
2015
The reaction of several homopropargyl amino esters 4, bearing aromatic substituents and a benzyl group as nitrogen substituents, with gold(I) salts gave rise to fluorinated quinolines 6 in a tandem hydroarylation-isomerization process. On the other hand, homopropargyl amino esters 7 containing a carbamate group underwent the carbonyl addition over the triple bond in the presence of gold(I) salts, rendering fluorinated oxazines 8. The use of chiral sulfoxides allowed us to develop the asymmetric version of this protocol. This two processes complete the differential reactivity showed by these types of susbtrates, depending on the nature of the nitrogen protecting group. (C) 2014 Elsevier B.V.…
Carbamate Linker Strategy in Solid-Phase Synthesis of Amino-Functionalized Glycoconjugates for Attachment to Solid Surfaces and Investigation of Prot…
2009
Amino-functionalized serine-based galactose and glucose neoglycolipids were prepared by solid-phase synthesis using a carbamate strategy for anchoring amino functionalities to a (2-fluoro-4-hydroxy ...