Browsing Facultad de Ciencias Exactas y Naturales by Title
Now showing items 1863-1882 of 2680
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New advances in the method validation, extraction methods and measurement uncertainty for the determination of water-soluble hexavalent chromium in hydraulic cemen
(Elsevier, 2021)The quantification of Cr (VI) in the cement matrix is highly important, given the possibility of suffering illnesses including dermatitis, induced nasal carcinoma, and DNA damage produced by inhalation of and/or direct ... -
New advances in the method validation, extraction methods and measurement uncertainty for the determination of water-soluble hexavalent chromium in hydraulic cement
(Elsevier Ltd, 2021-04-20)The quantification of Cr (VI) in the cement matrix is highly important, given the possibility of suffering illnesses including dermatitis, induced nasal carcinoma, and DNA damage produced by inhalation of and/or direct ... -
New Botanical Anxiolytics for Use in Companion Animals and Humans
(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 ... -
New records of historical tsunamis obtained from Costa Rican newspapers
(American Geophysical Union, 2020-12-14)Costa Rica has few records of historical tsunamis, due to traditionally low populated coasts and moderate tsunami potential, among other reasons. As part of the writing of the first tsunami catalog of Costa Rica, the authors ... -
New records of Pteris (Pteridaceae) from the Neotropics
(Universidad Nacional (Costa Rica), 2014)As a result of studies on neotropical Pteris L., we report new records of Pteris albertiae and P. longifoliafrom Costa Rica; P. longipetiolulata from Costa Rica, Panama, Peru, Bolivia, and Venezuela; and P. muricatopedatafrom ... -
New records of snipe eels (Anguilliformes: Nemichthyidae) from the Pacific coast of lower Central America
(Marine Biodiversity Records vol.9 no.1 1-6 2016, 2016)Background: New records of occurrence of two snipe eels (Avocettina bowersii and Nemichthys scolopaceus), poorly known for the Pacific coast of Costa Rica and Panama are herein reported. Results: Specimens, 45 in total (28 ... -
New records, validated name, and redefinition in Azolla (Salviniaceae, Pteridophyta) from Costa Rica
(Universidad de Antioquia (Colombia), 2024)In studies of herbarium specimens and living material, we observed that several species in the genus Azolla Lam. are present in different wetlands of Costa Rica, which instigated the search for applicable names of each ... -
New sighting of seagrasses in the Eastern Tropical Pacific (Bahía Potrero, Costa Rica)
(Elsevier B.V., 2018-07-22)Seagrass meadows provide a multitude of ecosystem services, yet they are currently threatened and declining worldwide due to anthropogenic impacts. Current knowledge of seagrass presence in the Eastern Tropical Pacific ... -
New species and records of Cloeodes Traver, 1938 (Ephemeroptera, Baetidae) from Costa Rica
(Pensoft (Bulgaria), 2020)The nymph of Cloeodes danta sp. nov. is described from male and female nymphs collected from highland streams in the Caribbean Slope of the Costa Rica Central Volcanic Mountain Range. Adults are unknown. In addition, C. ... -
New species of Potamocoris Hungerford (Heteroptera, Potamocoridae) from Costa Rica and a key to the species
(Magnolia Press, 2014-11)A new potamocorid species, Potamocoris sitesi NEW SPECIES, with its two wing morphs (coleopteroid and macropterous) are described from Costa Rica. Descriptions are supported with photographs and illustrations. Parameres ... -
Nitrate Contamination and Temporal Trends in Volcanic Barva and Colima Aquifers (1988-2018), in an urban and agriculture-dominated region, Costa Rica
(Universidad Nacional (Costa Rica), 2019)In the Great Metropolitan Area (GAM) of Costa Rica, 65% of the population, equivalent to 1.7 million people, is supplied by the most important volcanic aquifers in the country: Barva, phreatic and the most superficial, ... -
Nitrate contamination and temporal trends in volcanic Barva and Colima aquifers (1988-2018), in an urban and agriculture-dominated region, Costa Rica
(Universidad Nacional (Costa Rica), 2019-09)In the great metropolitan area (GAM) of Costa Rica, 65% of the population, equivalent to 1.7 million people, is supplied by the most important volcanic aquifers in the country: Barva, phreatic and the most superficial, ... -
Nitrate Legacy in a Tropical and Complex Fractured Volcanic Aquifer System
(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 ... -
Nitrogen budget and fluxes in Colossoma macropomum ponds
(Blackwell Publishing Ltd., 2005-07-01)This study quanti¢ed the accumulation of nitrogen (N) in the water column, sediments, ¢sh and seepage water during a production cycle of Colossoma macropomum. By combining estimates of the deposition rates of uneaten feed, ... -
Nitrogen transformations and fluxes in fish ponds: a modelling approach
(Wageningen University, 2001-04-18)Nitrogen is a key element in aquatic environments, and in Aquaculture it is an important pond management variable. In current aquaculture research two important goals are to maintain the water quality within the system, ... -
Nitrógeno y fósforo en el efluente de un proceso de una industria productora de concentrados para bebidas. Viabilidad de la introducción de procesos de minimización
(Universidad Nacional (Costa Rica), 2009)La industria en la que se realizó el proyecto se dedica a la elaboración de concentrados para base de bebidas; cuenta con cuatro diferentes procesos productivos que se dividen en: elaboración para base de bebidas líquidas ... -
Nivel de desarrollo de las competencias científicas en estudiantes de secundaria de (Mendoza) Argentina y (San José) Costa Rica
(Organización de Estados Iberoamericanos, 2011)Una de las premisas que se maneja con más fuerza en la actualidad es que la sociedad organiza los procesos educativos formales con el propósito de integrar a todos sus miembros en la construcción de la tradición ... -
Noción y práctica pedagógica sobre competencias de pensamiento científico en docentes de Física, Química y Biología de la carrera de Enseñanza de las Ciencias de la UNA
(Universidad Nacional (Costa Rica), 2017-04)Esta investigación tuvo como propósito principal analizar la noción y práctica pedagógica del profesorado de Física, Química y Biología de la carrera de Enseñanza de las Ciencias de la UNA sobre competencias de pensamiento ... -
Nonirritant and Cytocompatible Tinospora cordifolia Nanoparticles for Topical Antioxidant Treatments
(Hindawi (Egipto), 2020)Tinospora cordifolia extract contains antioxidants such as polyphenols, and thus, it has been used as a natural phytochemical antioxidant therapeutic agent. Many of these compounds are insoluble or only partially soluble ... -
Norops biporcatus (Wiegmann, 1834). Color change during foraging
(Eagle Mountain Publishing (Estados Unidos), 2017-03)Reptiles use body colors for many purposes: camouflage, warning predators, mate choice, and thermoregulation, among others (Cooper and Greenberg, 1992). The body color of anoles results from a combination of three pigments ...