Artículos de revista: Envíos recientes
Mostrando ítems 821-840 de 872
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Maderas neógenas de Cerro Pampa, Catamarca, Argentina
(Museo Argentino de Ciencias Naturales Bernardino Rivadavia, 2018)Por primera vez se da a conocer el registro de maderas angiospérmicas de Fabaceae de la localidad de Cerro Pampa (Catamarca). Estratigráficamente proceden de los sedimentos de la Formación Chiquimil que pertenece al Grupo ... -
Analytical method for the determination of surfactants with fluorescent activity, present in liquid effluents from textile industries, by HPLC fluorescence
(Science Domain International, 2017)In textile industries effluents we can be found surfactants of various characteristics, alkalis, and sulfides partially or totally hydrolyzed dyes, among other things, which are used as dyeing material. This study aims to ... -
Multielemental composition and nutritional value of "dumosa" (Ilex dumosa), "yerba mate" (I. paraguariensis) and their commercial mixture in different forms of use
(Universidad Nacional de Cuyo. Centro Coordinador de Ediciones Académicas, 2016)The multielement composition and nutritional value of "dumosa" (Ilex dumosa) (ID), "yerba mate" (I. paraguariensis) (IP) and their commercial 70:30 mixture (ID:IP, w/w) in crude drug, brewed mate and tea-bag-like infusion ... -
Multiway calibration strategy with chromatographic data exploiting the second order advantage for quantitation of three antidiabetic and three antihypertensive drugs in serum samples
(Elsevier, 2018)This paper proposes a multiway calibration strategy implementing the modeling with MCR-ALS and U-PLS/RBL of second-order chromatographic data for quantitation of six analytes: gliclazide, glibenclamide, glimepiride, atenolol, ... -
Chemometric optimization and validation of a novel dispersive liquid liquid microextraction HPLC method for gliclazide, glibenclamide and glimepiride quantitation in serum samples
(Elsevier, 2016)A dispersive liquid–liquid micro extraction (DLLME) liquid chromatographic method that allows extraction and separation of gliclazide, glibenclamide and glimepiride from serum was developed and optimized with the use of ... -
Siraty, una nueva localidad fosilífera con maderas y estípites de la formación Tacuary (pérmico superior), Paraguay
(Museo Argentino de Ciencias Naturales Bernardino Rivadavia, 2018)Se describen maderas y estípites silicificados provenientes de Siraty, una nueva localidad fosilífera de la Formación Tacuary (Pérmico superior), Paraguay. Se identificó Tuvichapteris solmsi Herbst (Marattiales) y los ... -
New gymnosperm wood fossils, a seed ovule structure, and a new generic affinity to cedroxylon canoasense rau from the permian and triassic jurassic of southern Brazil
(Sociedad Brasileira de Pleontología, 2018)Two new species of gymnosperm wood from the Triassic–Jurassic of Brazil are here described [Lobatoxylon kaokense Kräusel and Chapmanoxylon jamuriense (Maheswari) Pant & Singh], and a new age and generic a nity are proposed ... -
Buckya austroamericana nov. gen. et sp. (Bennettitales) from the upper triassic Laguna Colorada formation (El Tranquilo Group), Santa Cruz province, Argentina
(Universidad Nacional de Tucumán. Instituto Superior de Correlación Geológica, 2016)Siraty, a new fossiliferous locality with woods and stipes of the Tacuary Formation (upper Permian), Paraguay. Silicified fossil woods and arborescent stems from Siraty, a new fossiliferous locality of the Tacuary Formation ... -
Multicenter (FX)n/NH3 halogen bonds (X = Cl, Br and n = 1–5). QTAIM descriptors of the strength of the X…N interaction
(Molecular Diversity Preservation International, 2017)In the present work an in depth deep electronic study of multicenter XBs (FX)n/NH3 (X = Cl, Br and n = 1–5) is conducted. The ways in which X X lateral contacts affect the electrostatic or covalent nature of the X N ... -
Simultaneous occurrence of quadruple lewis acid–base interactions between selenium atoms in selenocarbonyl dimers
(Wiley VCH Verlag, 2017)High-level quantum chemical calculations are performed to investigate C=Se···Se=C interactions. Bounded structures are found with binding energies between @4 and @7 kJmol@1. An energy decomposition analysis shows that ... -
Is σ-hole an electronic exchange channel in YX⋯CO interactions?
(Elsevier Science, 2018)A theoretical study of linear YX⋯CO complexes (in which YX are diatomic interhalogens or hydrogen halide) has been performed to high-level quantum chemical calculations. Calculations show that at the equilibrium geometry, the ... -
Lewis acid-base behavior of hypervalent halogen fluorides in gas phase
(Springer, 2017)Theoretical studies on Lewis acid-base behavior of hypervalent halogen fluorides, F3X and F5X (X = Cl, Br, I) have been instrumental in guiding this work. We have also examined whether the hole-lump concept explains the ... -
A theoretical study of the strong interactions between carbón dioxide and OH+ and NH2+ products resulting from protonation of 1,2-dioxirane-3-one and 1,2-oxaziridine-3-one, respectively
(Springer, 2016)In this work, we investigate the nature of the O– O and O–N interactions in protonated 1,2-dioxirane-3-one derivatives and protonated 1,2-oxaziridine-3-one derivatives, respectively. The quantum theory of atoms in molecules ... -
Naturaleza de las interacciones Mδ+⋯δ+C-Oδ- en carbonilos metálicos : un estudio basado en la topología de la densidad de carga electrónica y su función laplaciana
(Sociedade Brasileira de Química, 2016)nature of the metal–ligand interactions, in the [Ti(CO)6]2-, [V(CO)6]-, [Cr(CO)6], [Mn(CO)6]+, [Fe(CO)6]2+ and [Co(CO)6]3+ complexes has been studied by means of topological analyses of the electron charge density, using ... -
Intermolecular perturbation in the self‑assembly of melamine
(Springer, 2016)A theoretical study has been conducted on a set of supramolecular complexes based on 1,3,5-triazine-2,4,6- triamine, or melamine (M), with cyanuric acid (CA), trithiocyanuric acid (TCA), and two mono-substituted ... -
Halogen bonding. The role of the polarizability of the electron-pair donor
(Royal Society of Chemistry, 2016)The nature of F–Br X–R interactions (with X = F, Cl, Br, I and R = –H, –F) has been investigated through theoretical calculation of molecular potential electrostatic (MEP), molecular polarizability, atoms in molecules ... -
Prodromus sinsistemático de la República Argentina y una breve introducción a los estudios fitosociológicos
(Sociedad Argentina de Botánica, 2016)Se presenta el Prodromus de la vegetación de Argentina, que constituye la primera versión del sinsistema nacional detallado hasta nivel de asociación y subasociación. Se describen las 57 clases de vegetación hasta ahora ... -
What is the enthalpy of formation of pyrazine-2-carboxylic acid?
(Elsevier, 2016)There are two contemporary conflicting, indeed, incompatible determinations of measurements of the enthalpies of combustion and of formation of pyrazine-2-carboxylic acid in the literature, ( 2268.0 ± 0.9 and 271.2 ± ... -
Theoretical characterization of the chemical bonds of some three-membered ring compounds through QTAIM theory
(Springer, 2015)In this paper, we investigate the nature of the carbonyl and the intraring C–C, C–N, C–O, N–N, O–O and N–O bonds of cyclopropanone and the following cyclopropanone derivatives: aziridine-2-one (1); oxirane-2-one (2); ... -
Protonated heterocyclic derivatives of cyclopropane and cyclopropanone : classical species, alternate sites, and ring fragmentation
(Canadian Science Publishing, 2015)A computational study has been performed for protonated oxygen- or nitrogen-containing heterocyclic derivatives of cyclopropane and cyclopropanone. We have searched for the most stable conformations of the protonated ...
