Browsing by Author "Contreras, D."
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- ItemBiOI. microspheres for photocatalytic degradation of gallic acid(2016) Mera, A.; Contreras, D.; Escalona, Néstor; Mansilla, H.
- ItemCorrigendum: Selective photocatalytic conversion of guaiacol using g-C3N4 metal free nanosheets photocatalyst to add-value products (vol 421, 113513, 2021)(ELSEVIER SCIENCE SA, 2022) Rojas, S. D.; Espinoza Villalobos, N.; Salazar, R.; Escalona, N.; Contreras, D.; Melin, V.; Laguna Bercero, M. A.; Sanchez Arenillas, M.; Vergara, E.; Caceres Jensen, L.; Rodriguez Becerra, J.; Barrientos, L.© 2021 Elsevier B.V.The authors regret that in the above article, affiliation c is mistaken. Therefore, afiliation c should be: c Departamento de Química de los materiales, Laboratorio de electroquímica Medio ambiental, LEQMA, Universidad de Santiago de Chile, Avenida Libertador Bernardo O'Higgins 3363, Estación Central, Santiago 9170376, Chile The authors would like to apologize for any inconvenience caused.
- ItemLa diversidad florística del humedal "Ciénagas del name" (región del Maule) comparada con otros humedales costeros de Chile central(2014) Ramírez García, Carlos; Fariña Rivas, José Miguel; Contreras, D.; Camano, A.; Martin, C.; Molina, M.; Moraga, P.; Vidal, O.; Perez, Y.
- ItemEffectiveness of Different Kidney Exchange Mechanisms to Improve Living Donor Transplantation in Chile(ELSEVIER SCIENCE INC, 2011) Dominguez, J.; Harrison, R.; Contreras, D.Introduction. Chile has a low cadaveric organ donation rate; at the same time, living donor transplantation activity is also low. The purpose of this study was to analyze the impact on the number and quality of transplants using various mechanisms for kidney exchange from living donors to patients on Chile's waiting list.
- ItemMicrostructure, vibrational and visible emission properties of low frequency ultrasound (42 kHz) assisted ZnO nanostructures(2016) Pandiyarajan, T.; Mangalaraja, R.; Karthikeyan, B.; Sepulveda, S.; Mansilla, H.; Contreras, D.; Escalona, Néstor; Gracia, M.
- ItemOpiniones sobre terapias complementarias por parte de los estudiantes de medicina de la Pontificia Universidad Católica de Chile. Año 2014(2015) Contreras, D.; Alamos, M.; Chang, M.; Bedregal, Paula
- ItemSelective oxofunctionalization of cyclohexene over titanium dioxide‐based and bismuth oxyhalide photocatalysts by visible light irradiation(2020) Henríquez, A.; Mansilla, H. D.; Martínez de la Cruz, A.; Cornejo Ponce, L.; Schott Verdugo, Eduardo Enrique; Contreras, D.
- ItemSelective photocatalytic conversion of guaiacol using g-C3N4 metal free nanosheets photocatalyst to add-value products(ELSEVIER SCIENCE SA, 2021) Rojas de la Fuente, Susana Dennis; Espinoza Villalobos, Nicole Margarita; Salazar, R.; Escalona, Néstor; Contreras, D.; Melin, V; Laguna Bercero, M. A.; Sanchez Arenillas, M.; Vergara, E.; Caceres Jensen, L.; Rodríguez Becerra, J.; Barrientos, LorenaValorization of lignin into high valuable chemical is a critical challenge. Its availability is a key factor for the development of viable lignocellulosic processes to replace fossil derived compounds. In this work, new insights on the high photocatalytic conversion of guaiacol (82%) as a lignin model compound was achieved, also, high selectivity to p-benzoquinone (59%), catechol (27%), and pyrogallol (6%) was obtained using metal-free pyrolyzed g-C3N4 under visible light irradiation. To highlight the new insights, experimental parameters were modified to control the reaction mechanism to increase selectivity and photo-conversion. g-C3N4 photocatalyst was synthesized through urea calcination at 550 degrees C and the photocatalytic performance was assessed in terms of pyrolysis time, where higher time resulted in better photocatalytic activity. This effect was attributed to smaller structures and therefore better quantum confinement of the charges. The oxidation was promoted by OH radicals, which were detected through EPR operando mode and the addition of radical scavengers. A reaction pathway was proposed, in which the OH attacks guaiacol through a methoxy group. The photocatalytic reaction can be tuned using external oxidant agents such as O-2 and/or H2O2 to promote certain radical formation, enhancing conversion rates and promoting selectivity for a specific product, where yield shifting from p-benzoquinone to pyrogallol was experimentally observed.