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Study on the Maintenance Costs of Military Helicopters by Using ABC Costing
According to information provided by the Colombian Air Force and to investigations on helicopter maintenance, it is possible to highlight control and activity classification mechanisms. This is developed when incorporating ... -
Synthesis of ZnS thin films by CBD for use as buffer layer in solar cells based on Cu2SnZnS4
ZnS thin films were deposited by CBD (chemical bath deposition) method using a solution containing thiourea and zinc acetate as sources of S and Zn and ammonium citrate as complexing agent. The samples were grown on soda ... -
The effects of temperature on the structure and morphology of (Ti,Al)N coatings
(Ti,Al)N films were grown on a susbtrate of stainless steel by means PAPVD by controlled pulsed cathodic arc technique usinga target of TiAl (50/50 % atomic) in an Ar + N atmosphere. The coatings were deposited at different ... -
Toxicidad aguda de una formulación comercial de glifosato sobre Poecilla reticulata (pisces:poecilidae) en condiciones de laboratorio
El glifosato es un herbicida ampliamente usado en Colombiatanto en actividades agrícolas como para la erradicación de cultivosilícitos. La deriva por viento en aspersiones aéreas y la lixiviación deeste producto pueden ... -
Una nota sobre la transformada de Fourier en espacios de Hölder
En este artículo, se estudia la acotación de la transformada periódica de Fourier desde espacios de Lebesgue a Espacios Hölder. Par- ticularmente, se generaliza un resultado clásico de Bernstein. -
Use of personalized academic text in Politécnico Grancolombiano
The assignment of personalized academic tests, aside from contributing to the eradication of fraud and plagiarism, make possible a better classroom climate. In this article we review some tools used to generate multiple ... -
XPS study for CZTS thin films growth by PVD co-evaporation method
This study shows the preparation of different Cu2ZnSnS4 thin films, following the co-evaporation route of metals (Cu, Sn and Zn Zn) in sulfur atmosphere, in three steps sulfide formation. The best results were acquired by ...