Escuela de Química: Recent submissions

Now showing items 21-40 of 446

    • Analysis of Benzene Exposure Levels on Commuters Traveling within the Metropolitan Area of Costa Rica 

      Villalobos-Gonzalez, Wendy; Esquivel-Hernández, Germain; Sanchez-Murillo, Ricardo; Corrales-Salazar, José Leonardo; Valdés-González, Juan (Scientific Research Publishing (China), 2015)
      This study reports the benzene exposure levels of commuters traveling within the metropolitan area of Costa Rica using personal cars, buses, and urban trains. 47 in-vehicle samples were collected in the 2014 wet season ...

    • Near Surface Carbon Dioxide and Methane in Urban Areas of Costa Rica 

      Esquivel-Hernández, Germain; Villalobos-Forbes, Mario; Sanchez-Murillo, Ricardo; Birkel, Christian; Valdés-González, Juan; Boll, Jan (Scientific Research Publishing (China), 2015)
      Little information is available for Central America regarding methane and carbon dioxide mixing ratios in urban areas. This work reports a representative spatial and seasonal study of near surface carbon dioxide and ...

    • Variación Espacial de la Composición de 222RN en los Acuíferos Barva y Colima Superior, Costa Rica 

      Sanchez-Murillo, Ricardo; Delgado, Miguel; Espinach, Diego; Lobo, Marcela; Madrigal, Fabián; Morera, Adolfo; Rojas, Karla; Saénz, Wendy; Ugalde, Susana; Umaña, Brayan; Pérez-Salazar, Roy; Mora, José; Esquivel-Hernández, Germain; Birkel, Christian; Ulloa, Franz; Rojas, Luis D.; Alvarado, Guillermo E. (Universidad de Costa Rica (Costa Rica), 2016)
      Radon (222Rn) is a useful natural-occurring tracer to elucidate groundwater to surface water connectivity with important implications for human health. This study presents the first spatial distribution of 222Rn in ...

    • Hydroclimatic and ecohydrological resistance/resilience conditions across tropical biomes of Costa Rica 

      Esquivel-Hernández, Germain; Sanchez-Murillo, Ricardo; Birkel, Christian; Good, Stephen P.; Boll, Jan (John Wiley & Sons (Estados Unidos), 2017)
      Water resources management in the tropics is challenged by climate variability and unregulated land use change and their impacts on the complex interactions between vegetation, soil, and atmosphere. This study focuses ...

    • Análisis de vapor de agua precipitable sobre Costa Rica: una comparación entre diferentes técnicas de análisis basadas en GPS, sondeo atmosférico y productos satelitales MODIS 

      Campos-Arias, Polleth; Esquivel-Hernández, Germain; Valverde-Calderón, Jose Francisco; Rodríguez-Rosales, Stephanie; Moya-Zamora, Jorge; Sanchez-Murillo, Ricardo; Boll, Jan (Universidad Nacional (Costa Rica), 2019)
      La cuantificación del vapor de agua en regiones tropicales como América Central es necesaria para estimar la influencia del cambio climático en su distribución y la formación de precipitaciones. Este trabajo analiza las ...

    • Análisis hidroclimático en condiciones no estacionarias utilizando el marco teórico de Budyko: el caso del páramo de Costa Rica 

      Esquivel-Hernández, Germain; Sanchez-Murillo, Ricardo (Universidad Nacional (Costa Rica), 2019)
      La gestión del recurso hídrico en los trópicos se ha visto recientemente desafiada por la variabilidad del clima y los cambios no controlados en el uso de la tierra y sus impactos en las complejas interacciones entre la ...

    • Data Descriptor: Daily observations of stable isotope ratios of rainfall in the tropics 

      Munksgaard, Niels; Kurita, Naoyuki; Sánchez-Murillo, Ricardo; Ahmed, Nasir; Araguas, Luis; Balachew, Dagnachew L.; Bird, Michael; Chakraborty, Supriyo; Kien Chinh, Nguyen; Cobb, Kim M.; Ellis, Shelby A.; Esquivel-Hernández, Germain; Ganyaglo, Samuel Y.; Gao, Jing; Gastmans, Didier; Kaseke, Kudzai Farai; Kebede, Seifu; Morales, Marcelo R.; Müller, Moritz; Chee Poh, Seng; dos Santos, Vinícius; Shaoneng, He; Wang, Lixin; Yacobaccio, Hugo; Zwart, Costijn (Springer Nature (Alemania), 2019)
      We present precipitation isotope data (δ2H and δ18O values) from 19 stations across the tropics collected from 2012 to 2017 under the Coordinated Research Project F31004 sponsored by the International Atomic Energy Agency. ...

    • Isotopic composition and major ion concentrations of national and international bottled waters in Costa Rica 

      Sanchez-Murillo, Ricardo; Esquivel-Hernández, Germain; Birkel, Christian; Ortega, Lucía (Elsevier (Países Bajos), 2021)
      Global bottled water consumption has largely increased (14.35 billion gallons in 2020) [1], [2], [3], [4], [5] during the last decade since consumers are demanding healthier and safer forms of rehydration. Bottled water ...

    • Exploring Dissolved Organic Carbon Variations in a High Elevation Tropical Peatland Ecosystem: Cerro de la Muerte, Costa Rica 

      Sanchez-Murillo, Ricardo; Gastezzi-Arias, Paola; Sánchez-Gutiérrez, Rolando; Esquivel-Hernández, Germain; Pérez-Salazar, Roy; Poca, María (Frontiers Media (Suiza), 2022-01)
      Tropical peatlands are distributed mainly in coastal lowlands; however high elevation regions exhibit a large prevalence of small and fragmented peatlands that are mostly understudied. Artificial drainage of peatlands to ...

    • Hydrometeorological Factors Controlling the Stable Isotopic Composition of Precipitation in the Highlands of South Ecuador 

      Zhiña, Dario; Mosquera, Giovanny M.; Esquivel-Hernández, Germain; Córdova, Mario; Sanchez-Murillo, Ricardo; Orellana-Alvear, Johanna; Crespo, Patricio (American Meteorological Society (Estados Unidos), 2022-07)
      Knowledge about precipitation generation remains limited in the tropical Andes due to the lack of water stable isotope (WSI) data. Therefore, we investigated the key factors controlling the isotopic composition of precipitation ...

    • Water stable isotopes reveal the hydrological response of Costa Rican glacial lakes to climate variability 

      Esquivel-Hernández, Germain; Quesada-Román, Adolfo; Sanchez-Murillo, Ricardo; Vargas-Salazar, Enzo; Quesada-Román, Adolfo (Elsevier (Países Bajos), 2022)
      Los lagos generalmente se consideran una fuente de información clave para comprender el paleoclima. Aquí usamos estable. Isótopos de agua (δ2H y δ18O) en un lago glacial tropical de gran altitud para informar sobre la ...

    • Dry season plant water sourcing in contrasting tropical ecosystems of Costa Rica 

      Sánchez-Murillo, Ricardo; Todini-Zicavo, Diego; Poca, María; Birkel, Christian; Esquivel-Hernández, Germain; Chavarría, María Marta; Zuecco, Giulia; Penna, Daniele (John Wiley & Sons (Estados Unidos), 2023)
      Tracer-aided studies to understand plant water uptake sources and dynamics in tropical ecosystems are limited. Here, we report the analysis of dry season source water uptake patterns of five unique ecosystems of Costa ...

    • Exploring the acid neutralizing effect in rainwater collected at a tropical urban area: Central Valley, Costa Rica 

      Esquivel-Hernández, Germain; Sanchez-Murillo, Ricardo; Villalobos Córdoba, Diego; Monteiro, Lucilena Rebelo; Villalobos Forbes, Mario; Sánchez-Gutiérrez, Rolando; Cotrim, Marycel; Matiatos, Ioannis (Elsevier (Países Bajos), 2023)
      We report on the chemical and the carbon isotopic composition of dissolved inorganic carbon (DIC) of rainwater collected between May and October 2020 in the Central Valley, Costa Rica. Precipitation samples were ...

    • Frontiers in páramo water resources research: A multidisciplinary assessment 

      Mosquera, Giovanny M.; Hofstede, Robert; Bremer, Leah L.; Asbjornsen, Heidi; Carabajo-Hidalgo, Aldemar; Célleri, Rolando; Crespo, Patricio; Esquivel-Hernández, Germain; Feyen, Jan; Manosalvas, Rossana; Marín, Franklin; Mena-Vásconez, Patricio; Montenegro-Díaz, Paola Fernanda; Ochoa-Sánchez, Ana; Pesántez, Juan; Riveros-Iregui, Diego; Suárez, Esteban (Elsevier (Países Bajos), 2023)
      Interdisciplinary knowledge is necessary to achieve sustainable management of natural resources. However, research is still often developed in an exclusively disciplinary manner, hampering the capacity to holistically ...

    • Nitrate Legacy in a Tropical and Complex Fractured Volcanic Aquifer System 

      Sánchez-Gutiérrez, Rolando; Sanchez-Murillo, Ricardo; Esquivel-Hernández, Germain; Birkel, Christian; Boll, J.; Rojas-Jiménez, L. D.; Castro-Chacón, L. (John Wiley & Sons (Estados Unidos), 2023)
      Nitrate legacy is affecting groundwater sources across the tropics. This study describes isotopic and ionic spatial trends across a tropical, fractured, volcanic multi-aquifer system in central Costa Rica in relation to ...

    • ENSO sentinels in the Americas' humid tropics: We need combined hydrometric and isotopic monitoring for improved El Niño and La Niña impact prediction 

      Sánchez-Murillo, Ricardo; Birkel, Christian; Boll, J.; Esquivel-Hernández, Germain; Rojas-Jiménez, L. D.; Castro-Chacón, L.; Durán-Quesada, Ana María ; Voarintsoa, Ny Riavo; Dee, Sylvia; Winguth, Arne (John Wiley & Sons (Estados Unidos), 2023)
      This Scientific Briefing presents results from a nearly 10-year hydrometric and isotope monitoring network across north-central Costa Rica, a region known as a headwater-dependent system. This monitoring system has ...

    • Aprendizaje activo, “nueva” metodología aplicada en secundaria para la enseñanza de la química ¿Solución para cambiar el paradigma? 

      Carballo Arce, Ana Francis (Universidad Nacional (Costa Rica), 2019-06)
      Debido a los desafíos que enfrenta la educación científica actualmente y la gran importancia que esta tiene pata el progreso del país, es que el Ministerio de Educación Publica (MEP) ha venido haciendo esfuerzos múltiples ...

    • New Botanical Anxiolytics for Use in Companion Animals and Humans 

      Liu, Rui; Ahmed, Fida; Cayer, Christian; Mullally, Martha; Carballo Arce, Ana Francis; Otarola Rojas, Marco; Garcia, Mario; Baker, John; Masic, Aleksandar; Sanchez, Pablo E.; Poveda, Luis; Merali, Zul; Durst, Tony; Arnason, John T. (Springer (Alemania), 2017-11)
      As part of our ongoing research into botanical therapies for anxiety disorders, the neotropical vine Souroubea sympetala was chosen for study as a phytochemical discovery strategy focusing on rare Central American plant ...

    • Saneamiento de aguas residuales mediante humedales artificiales en el Museo de Cultura Popular de la Universidad Nacional 

      Alfaro, Carolina; Pérez, Roy; Solano, Mayela (Universidad Nacional (Costa Rica), 2013-06)
      El cumplimiento de los Objetivos de Desarrollo del Milenio en términos de acceso sostenible al saneamiento requiere incrementar el desarrollo de programas de investigación que promuevan opciones tecnológicas simples y de ...

    • Polypropylene Composites Reinforced with Lignocellulose Nanocrystals of Corncob: Thermal and Mechanical Properties 

      Santos-Ventura, Edgar Mauricio; Escalante-Álvarez, Marcos Alfredo; González-Nuñez, Rubén; ESQUIVEL, MARIANELLY; Sulbaran Rangel, Belkis (Universidad Nacional (Costa Rica), 2024-03-29)
      Composites based on recycled polypropylene (PP) reinforced with cellulose nanocrystals whit lignin corncob were prepared. The effect of the ratio composites prepared via a compression molding process on the mechanical and ...