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Mostrando ítems 71-77 de 77
Historia del campo geomagnético de Costa Rica
Historia del campo geomagnético de Costa Rica
(2011-02-15)
The study of the geomagnetic field began with the publication of the book De Magnete (1600) of Sir William Gilbert (1504-1603). By influence of Sir Edmund Halley the British Marine is obligated to make measurements of the ...
Polymers of unidimentional coordination [M(sac)2(H2O)(pyz)]n, (M= Ni2+, Cu2+ and Zn2+, sac =saccharinate, pyz= pyrazine), spectroscopy and magnetic properties
(2011-07-18)
Coordination polymers have been prepared by the hydrothermal reaction of M2+saccharinates (M = Ni, Cu and Zn) and pyrazine, pyz, in a ratio 1:1. The complexes of formula [M(sac)2(H2O)2pyz]n, M = Ni2+ and Zn2+ and ...
Estudio de una definición no aritmética de finitud conjuntista
(1987)
Intuitivamente, un conjunto es finito si termina quedando vacío al extraerle elementos de uno en uno. El propósito de este trabajo es formalizar esta noción de finitud conjuntista y discutir algunas propiedades que se ...
Emisiones antropogénicas de compuestos tóxicos para el aire en el Gran Área Metropolitana de Costa Rica en el 2007
Emisiones antropogénicas de compuestos tóxicos para el aire en el Gran Área Metropolitana de Costa Rica en el 2007
(2015-06-17)
The Emissions Inventory Toxic Air Compounds for the Greater Metropolitan Area in 2007 is framed within the air quality policy in Costa Rica. The main toxic anthropogenic contaminants were toluene, methanol, xylenes, ...
Modelización directa y comparación de los principales dispositivos geoeléctricos
(2009-04-29)
With the purpose of comparing the main geolectrics arrays used for the realization of vertical electrical sounding, a direct simulation is presented, considering two geologic models. The investigation depth, precision in ...
Lignanos de Zanthoxylum acuminatum
(2009-01-13)
From the aerial parts of Zanthoxylum acuminatum (Rutaceae) collected in Upala, Alajuela, Costa Rica were isolated the known lignans hinokinin, (+)-asarinin, (+)- piperitol, (+)-kobusin, and epi-kobusin. In addition to the ...
Soluciones interiores exactas a las ecuaciones de Einstein para un líquido ideal con simetría axial
(2011-07-18)
Exact interior solutions of Einstein equations were obtained, using the ideal fluid model with axial symmetry (Weyl-Lewis-Papapetrou or Weyl-Papapetrou).