Listar Ciencias básicas por título
Mostrando ítems 1048-1067 de 3121
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Elaboración de un lubricante potencialmente biodegradable de uso industrial a partir de quitosano, aceite de ricino y aditivos antioxidantes de origen natural
(2023-09-07)En la actualidad, la tecnología de los lubricantes se enfoca hacia la protección del medio ambiente. Sin embargo, la mayoría de los actuales lubricantes de uso industrial están conformados por aceites minerales como matriz ... -
Elasmobranch bycatch associated with the shrimp trawl fishery off the Pacific coast of Costa Rica, Central America
(2015)Demersal sharks and rays are common yet vulnerable components of the bycatch in tropical bottom-trawl fisheries. Little is known about the elasmobranch assemblages associated with most of these fisheries, particularly ... -
Electric-field control of single-molecule tautomerization
(2020)The electric field is an important parameter to vary in a single-molecule experiment, because it can directly affect the charge distribution around the molecule. Yet, performing such an experiment with a well-defined ... -
Electroactive copper (II) bimetallic self-assembled multilayers on Si (100)
(2012)Silicon (100) surfaces were modified by reacting 4-aminopyridine and Si–Cl bond. These surfaces were further used for tethering copper bimetallic complexes and growing monolayers and multilayers by changing the axial ... -
Electrochemical biosensor for quantitative determination of fentanyl based on immobilized cytochrome c on multi-walled carbon nanotubes modified screen-printed carbon electrodes
(2022)Fentanyl is a powerful synthetic opioid used to treat severe pain. New administration routes toward its illegal consumption for recreational purposes pose a growing threat to public health, either due to misuse or abuse ... -
Electrochemical determination of novel psychoactive substances by differential pulse voltammetry using a microcell for boron-doped diamond electrode and screen-printed electrodes based on carbon and platinum
(2021)25B-NBOMe, benzylpiperazine (BZP), 1-(3-chlorophenyl)piperazine (mCPP), and N,N-dimethyltryptamine (DMT) are potent hallucinogenic and stimulant drugs which have emerged as novel psychoactive substances (NPS). The ... -
Electronic structure of silicon-based nanostructures
(2007-08-30)We have developed a unifying tight-binding Hamiltonian that can account for the electronic properties of recently proposed Si-based nanostructures, namely, Si graphene-like sheets and Si nanotubes. We considered the sp3s∗ ... -
Elevational and seasonal patterns of plant pollinator networks in two highland tropical ecosystems in Costa Rica
(2024-01-11)Many plant species in high montane ecosystems rely on animal pollination for sexual repro- duction, however, our understanding of plant-pollinator interactions in tropical montane hab- itats is still limited. We compared ... -
Elimination of quantifiers of a theory of real closed rings.
(2022-10-09)Let T* be the theory of lattice-ordered subrings, without minimal (non zero) idempontents, convex in von Neumann regular real closed rings that are divisible-proyectable and sc-regular. In this paper, a local divisibility ... -
Elliot Coen Paris: Pionero de la meteorología en Costa Rica
(1998)Ingeniero Naval de profesión, pero naturalista por vocación y dedicación a sus actividades profesionales. Elliot Coen París realizó una notable labor, tanto en la Universidad de Costa Rica como en el Servicio Meteorológico ... -
Elliott Coen París (1921-1997): Naturalista y forjador de la meteorología moderna en Costa Rica
(1997)Este artículo ofrece un esbozo de varios aspectos de la vida personal, académica y profesional de "Don Elliott" como justo, aunque tal vez incompleto reconocimiento, a la labor desarrollada en las instituciones con las que ... -
Empirical evidence for multiple costs of begging in poison frog tadpoles
(2018)In recent decades, theoretical and empirical work has investigated the relative roles of costs and benefits in inhibiting excessive displays of begging to parents. Whether costs are important in maintaining reliability of ... -
Empleo de técnicas y materiales biológicos en la búsqueda de productos activos contra la malaria
(2001)Se describen los métodos empleados en el estudio del efecto de extractos de insectos preparados en el Instituto Nacional de Biodiversidad de Costa Rica, sobre un tipo de malaria murina producida por el Plasmodium bergheim. ... -
En busca de Karl Hoffmann
(2006)Se comenta y analiza el libro biográfico escrito por Luko Hilje "Karl Hoffmann: naturalista, médico y héroe nacional" (Heredia, Costa Rica: INBio, 2006). -
Energy exchange between atoms with a quartz crystal μ-balance
(2018)We propose an experimental method to fully characterize the energy exchange of particles during the physical vapor deposition (PVD) process of thin surface layers. Our approach is based on the careful observation of ... -
Energy flow structure and role of keystone groups in shallow water environments in Isla del Coco, Costa Rica, Eastern Tropical Pacific
(2019)Isla del Coco (Costa Rica) forms part of the five oceanic islands of the Eastern Tropical Pacific and is well known for its high biodiversity and great endemism. While several marine biological and oceanographical surveys ... -
Enfoques y redes en las políticas públicas de Ciencia y Tecnología en Costa Rica
(2009)Este artículo pretende ser un aporte a la discusión en relación con los enfoques más comunes acerca del diseño, formulación y gestión de las políticas públicas de Ciencia y Tecnología. Asimismo, procura explorar las redes ... -
Enjambres sísmicos en la placa Caribe y la microplaca de Panamá disparados por el terremoto de Nicoya (7,6 Mw) del 5 de septiembre del 2012
(2014)La sismicidad disparada remotamente que ocurre a distancias superiores a 1-2 veces la longitud de la falla, parece ser un fenómeno frecuente que se ha presentado en Costa Rica luego de sismos de magnitud mayor a 7,0 Mw ...