1000 resultados para Psicología aplicada


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Peer-reviewed

Relevância:

20.00% 20.00%

Publicador:

Resumo:

extracts of the regional plants Annona squamosa and Annona muricata were analysed by silica gel thin-layer chromatography using adequate systems of solvents and spray reagents. Carbohydrates, amino acids, alkaloids, flavonoids and terpenoids were detected in both species. These data agree with those on the literature about phytochemistry of the Annonaceae.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Catalan has drawn considerable attention given its impressive institutional support and increased usage since the restoration of the Generalitat of Catalonia. We report a study on 112 Catalan-speaking students who were administered the"subjective vitality questionnaire". Results show (and these are compared with reports 20 years ago) that it continues to gain momentum and status, even with the International stature of Spanish. The theoretical and pragmatic significance of these findings are discussed in terms of vitality"s role in shaping Language choices (Catalan vs. Castilian) in everyday communication as well as the societal level in forging Language policies for communicating in Catalan in business, political, educational, and media arenas

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In the selective reduction procedure proposed by Magos SnCl2 was used as reductant for inorganic mercury while total mercury was determined after reduction with a mixture of SnCl2 and CdCl2. The difference between total mercury and inorganic mercury determines the content of organic mercury. The procedure of the present work differs of Magos in that the mercury vapour is carried to the absorption cell after magnetic stirring of the solution in the reaction flask; in the Magos procedure, mercury vapour is carried by bubbling the gas in to the solution. In contrast to the Magos procedure this slight modification overcame the necessity of at calibration by analyte addition, saving time and gainning accuracy.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The solution fluorescence of N-alkyl-2,3-naphthalimides (1-4) in polar protic and aprotic solvents was compared to the emission from solid samples resulting from the imide complexation with b-cyclodextrin or adsorption on the surface of microcrystalline cellulose. Solid samples of the inclusion complex 2,3-naphthalimides/b-cyclodextrin show maximum for fluorescence emission significantly different to the observed in methanolic solution. Beside this, a clear effect on the alkyl chain length could be observed for these samples which is probably due to differences in probe location inside the cyclodextrin cavity. The constancy for fluorescence quantum yield and fluorescence lifetime for the imides 1 - 4 adsorbed on microcrystalline cellulose suggests that, independently of the polarity of the solvent used for sample preparation, the probe is preferentially located on the cellulose surface. An increase of fluorescence quantum yield and fluorescence lifetime for solid samples, when compared to the values obtained in solution for the different solvents employed in this study (acetonitrile, methanol and water), is fully in accordance with a decrease of the probe mobility due to inclusion in b-cyclodextrin or to adsorption on cellulose.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The data analyzed in this work were generated following the methodology developed by Molina et al.(J. Electroanal. Chem., 1979) for the calibration of a potentiometric system of measurement of hydrogen-ion concentrations resulting from neutralizations, at 25 ºC, of acidic or alkaline solutions at constant ionic strength (0.1 mol.l-1) held with NaClO4. The observed data present a serious deviation in relation to the mathematical model derived from the Nernst equation, for pH values ranging from 3 to 11, where pH=-log[H+]. We show that the minimization of the sum of the absolute values of the residuals gives estimates that are not influenced by outlying values.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

En aquest projecte s’ha creat una aplicació d’ús mèdic que permet veure l’eficàcia dels tractament aplicats a pacient que pateixen de dismenorrea. Aquesta aplicació està dissenyada per a ser utilitzada per a dos tipus d’usuaris, el pacient que és l’encarregat d’introduir la informació sobre els seus símptomes en els moments que aquests apareixen, i l’investigador que analitza aquesta informació per a avaluar els tractaments utilitzats. L’aplicació consta d’un entorn amigable que facilita l’ús per part dels usuaris. La seva interfície web permet a l’investigador visualitzar les dades i exportar-les per a ser utilitzades en aplicacions estadístiques, i per altra banda, també ofereix la possibilitat al pacient de fer un seguiment de l’evolució dels seus símptomes a través de gràfiques.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper describes an experimental design technique, known as variables search, developed to expose the critical variables and screen out the irrelevant ones. It is easy to learn and use and clearly dissociates the main and interactions effects from each other. An example of air separation process by pressure swing adsorption was used to demonstrate how the variables search technique works. The phases of identification of the critical variables is shown, step by step,.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Peer-reviewed

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The study of the reactions of organometallic complexes with the surfaces of inorganic oxides, zeolites and metals constitutes the basis of Surface Organometallic Chemistry (SOMC). The basic rules of organometallic chemistry are often valid when applied to surfaces and well-defined surface organometallic complexes can be obtained. These complexes can be used as heterogeneous catalysts or, by controlled reactions, can be transformed in other species useful for a given catalytic reaction. In some cases, these catalysts exhibit higher activity and/or selectivity than their analogous molecular complexes.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Although electrospray ionization mass spectrometry (ES-MS) has been extensively applied to study organic and biochemical species, it is also specially suitable to study inorganic and organo-metallic species. Such species, even those that are low-volatile or thermo-unstable, can be easily ionized or simply transferred from liquid to gas phase by electrospray. However, chemical transformations frequently occur during the process. This paper discusses the fundamental aspects of electrospray ionization as well as its analytical applicability to inorganic and organo-metallic species in order to spread the technique and make its characteristics more familiar to potential users.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

La jubilación y la vejez implican la necesidad de una reorganización de los roles sociales, personales y familiares, y una adaptación al nuevo estatus social. Es una etapa crítica en la que puede aparecer un deterioro de la autoestima y el incremento del aislamiento social. Por ello, los objetivos de la presente intervención son incrementar la autoestima y disminuir el aislamiento social en el mayor jubilado.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Calculations based on density functional theory at the B3LYP hybrid functional level applied to periodic models have been performed to characterize the structural and electronic properties of PbTiO3. Two different slab terminations (PbO and TiO2) have been considered to obtain and discuss the results of band structure, density of states, charge distribution on bulk and surface relaxation. It is observed that the relaxation processes are most prominent for the Ti and Pb surface atoms. The electron density maps confirm the partial covalent character of the Ti-O bonds. The calculated optical band gap and other results are in agreement with experimental data.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Plant extracts are usually complex mixtures which contain several molecules of different sizes with varied functional groups. Such extracts are a challenge to the chemist of natural products. Ion exchange chromatography in non-aqueous medium, used for separation of basic or acidic fractions from plant extracts, is an important unit operation in preparative scale separations. Anionic macroporous resin in non-aqueous medium was used with success in this study for separation of the acid fraction of Copaifera multijuga (Copaiba oil), rich in labdanic diterpenes and for the methanolic extract of Croton cajucara (acetyl aleuritoric acid).