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Barrera-Garcia V.D.,University of Burgundy | Barrera-Garcia V.D.,University of Tourism of Costa Rica | Chassagne D.,University of Burgundy | Paulin C.,University of Burgundy | And 5 more authors.
Langmuir | Year: 2011

Lignin is considered to be responsible for a selective sorption of phenolic compounds on wood. In order to investigate the mechanisms involved, two similar guaiacol compounds-only differeing by the nature of the para side chain-were adsorbed on oak wood extracted lignin. Vapor sorption-desorption isotherms indicated that about 3.5 wt % of 4-vinylguaiacol is adsorbed near saturation whereas it is only 0.8% for 4-ethylguaiacol. For both compounds, the isotherms displayed a hysteresis though significantly greater for 4-vinylguaiacol. Analyses of the hydroxyl stretching region of FTIR spectra of the lignin/4-ethylguaiacol and lignin/4-vinylguaiacol complexes indicated that physisorption via hydrogen bonds occurs for both sorbates with lignin phenolic hydroxyl groups but which would be more condensed for the former than for the latter. According to NMR spectra, these phenolic hydroxyl groups correspond to non-etherified guaiacyl subunits. In contrast with other para substituents, the conjugated vinyl bond favors not only physisorption but also chemisorption as witnessed by the fact that upon desorption in the vapor phase, even after pumping under dynamic vacuum for several days, about 1 wt % of 4-vinylguaiacol remains adsorbed onto lignin. © 2011 American Chemical Society.


D'Ambrosio G.T.,University of Tourism of Costa Rica | Bohn V.Y.,University of Tourism of Costa Rica | Piccolo M.C.,CONICET
Cuadernos Geograficos | Year: 2013

The rainfall variability and drought effects in the Paso de las Piedras Dam and farming were analyzed in the western pampean region (Argentina) for the 2008-2009 years. The methodology includes the Standardized Precipitation Index application, the satellite image processing and the production yields analysis of four crops of the region. The Standardized Precipitation Index was showed meteorological drought in the 2008 and 2009 years. The production of yields has decreased between 25 and 65% during 2009 compared to previous years. The dam area has decreased 52% in 2009, in relation with wet periods.


Bohn V.Y.,University of Tourism of Costa Rica | Piccolo M.C.,CONICET | Perillo G.M.E.,CONICET
Estudios Geograficos | Year: 2013

The aim of this study was to evaluate the correlation between field sensors and sate - llite images in the bio-optical characterization of Lake Chasicó (Argentina) during the February-April 2010 period. The morphometric parameters of the body of water were obtained from in situ measurements and satellite data processing. The sensors that were used allowed spectral signatures to be acquired and then surface water characteristics were detected: turbidity, chlorophyll-a and depth variations. Results obtained from the morphometric analysis included that the lake surpassed the 50 km2 extension and showed a sub-rectangular elongated shape. The chlorophyll-a spatial distri - bution in the lake was modeled from the satellite image processing, in situ chlorophyll-a data and the Normalized Difference Vegetation Index (NDVI) calculation. 53.2 % of its area showed a chlorophyll-a range between 5 and 10 g/l. Therefore, the body of water was characterized as a mesotrophic lake, during the studied period.


Diaz-Bandera D.,National Autonomous University of Mexico | Villanueva-Carvajal A.,National Autonomous University of Mexico | Dublan-Garcia O.,National Autonomous University of Mexico | Quintero-Salazar B.,University of Tourism of Costa Rica | Dominguez-Lopez A.,National Autonomous University of Mexico
International Journal of Food Science and Technology | Year: 2013

Summary: Gelatin beads containing a concentrated extract of Roselle (Hibiscus sabdariffa L.) calyx rich in polyphenolic compounds were coated with sodium alginate and ionotropically gelled using CaCl2. Single-coated beads and double-coated beads were obtained by this technique, and the release pattern of the loaded extract was evaluated. As a result, release pattern of these compounds fits properly to a first-order Weibull distribution equation. The release rate constant decreased linearly with the number of alginate coats and with the increase in immersion time in CaCl2 and the Lag period increased significantly with the number of alginate coats. The release of H. sabdariffa's polyphenols can be well controlled manipulating the number of alginate coats and the immersion time in a CaCl2 solution, allowing not only to control the gastrointestinal segment where they could be released but also to control the release rate with the certainty that the initial concentration will be completely released showing a highly significant antioxidant activity as well. © 2013 The Authors. International Journal of Food Science and Technology © 2013 Institute of Food Science and Technology.


Diaz-Bandera D.,National Autonomous University of Mexico | Villanueva-Carvajal A.,National Autonomous University of Mexico | Dublan-Garcia O.,National Autonomous University of Mexico | Quintero-Salazar B.,University of Tourism of Costa Rica | Dominguez-Lopez A.,National Autonomous University of Mexico
LWT - Food Science and Technology | Year: 2015

The aim of this study was to investigate the effect of different carriers (maltodextrin, pectin, gelatin, carboxymethyl cellulose, whey protein, carrageenan and gum arabic) on the release kinetics and dissolution of Roselle's extract obtained through a spray drying process. Aqueous solutions at different concentrations of carrier and extract were prepared. The particles obtained exhibited nearly monomodal or bimodal size distribution, indicating two predominant sizes. The frequency distribution of the mean size of the powders behaved, significantly, like a normal distribution. Throughout the dissolution test, all the particles obtained followed a Weibull-First Order kinetic model. Pectin retained the highest amount of polyphenols after the drying process (98.20 mg GAE/100 mg GAE of roselle concentrate) and released the highest amount of phenolic compounds (79.48 mg GAE/100 mg GAE in the particles) during a longer time. Pectin particles obtained (9 mm as mean size) were significantly homogeneous (93.45 g/100 g powder), being the most suitable carrier of Roselle's phenolic compounds compared to the other carriers used. Estimated dissolution times, by means of the dissolution equation proposed, were compared to experimental results and proved to be more reliable than the regularly used observation method. © 2015 Elsevier Ltd.


The study area includes Ernesto Tornquist Provincial Park located in the area of Sierra de La Ventana (Buenos Aires). The aim of this work is to develop a methodology for defining and calculating fire-affected areas, based on visual and digital analysis of satellite imagery (pre and a post fire) using an image processor and the construction of thematic maps, using GIS. We propose the application of two spectral indices, one for vegetation and another for burned areas, and two supervised classifications. Results demonstrated that the Burned Area Index is the technique that provides the best results, allowing the delimitation and calculation of burned areas as well as the discrimination of islands of vegetation not affected by fire within the burned area. Moreover, it was established that the vegetation affected by the fire corresponded to conifers and native grasslands.


Hruleva M.,University of Tourism of Costa Rica | Romero A.B.,Autonomous University of Barcelona | Valiente G.C.,Autonomous University of Barcelona
Cuadernos de Turismo | Year: 2013

This article analyzes the possibilities for development of pilgrimage travel and religious tourism in the monasteries of The Holy Mount of Sofia (Bulgaria). The pilgrimage is described as a specific tourist product and we explained the importance of the strategic planning as a tool to diversify the offer of any tourist destination. In the study, it is also described the religious environment of The Holy Mount and its main characteristics as a pilgrimage center. We analyze the strategy, the market and the tourist offer in Bulgaria of the city of Sofia, mainly based on the cultural and business segment. Finally, statistical data are measured to evaluate the potential of Holy Mount of Sofia as a tourist destination, to design proposals and to face some challenges ahead.


University of Tourism of Costa Rica | Entity website

La carrera universitaria en Administracin Hotelera est diseada para suplir los profesionales que requieren la moderna industria de la hospitalidad, con altsima calidad tcnica y con los estndares internacionales que exigen las buenas prcticas hoteleras y el desarrollo sostenible. Nuestros programas de estudio permiten desarrollar la capacidad en la toma de decisiones en situaciones de gran presin, de liderazgo y trabajo en equipo, y de mejoramiento continuo para el logro de la eficiencia y la eficacia ...


University of Tourism of Costa Rica | Entity website

Aprobada por el Consejo Nacional de Enseanza Superior (CONESUP) en el Acta de la sesin 627-2009, celebrada el 13 de mayo 2009, Exp N1924-8. La Universidad del Turismo (UTUR) ofrece la carrera de Bachillerato en Gestin del Turismo Ecolgico, con el fin de responder a las expectativas del Turismo Sostenible y a las necesidades del mercado laboral de este sector ...


University of Tourism of Costa Rica | Entity website

El acelerado desarrollo turstico de Costa Rica, dio base a la iniciativa de fundar una institucin especializada en la formacin de talento humano, altamente calificado, para atender las demandas de la industria de la hospitalidad y el turismo ecolgico. Mediante un estudio de necesidades de profesionales en la industria turstica costarricense y un proceso de seleccin de cuerpo docente, se cumpli con los trmites necesarios para su debida inscripcin y reconocimiento ...

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