154 research outputs found
Characterizing a CCD detector for astronomical purposes: OAUNI Project
This work verifies the instrumental characteristics of the CCD detector which
is part of the UNI astronomical observatory. We measured the linearity of the
CCD detector of the SBIG STXL6303E camera, along with the associated gain and
readout noise. The linear response to the incident light of the detector is
extremely linear (R2 =99.99%), its effective gain is 1.65 +/- 0.01 e-/ADU and
its readout noise is 12.2 e-. These values are in agreement with the
manufacturer. We confirm that this detector is extremely precise to make
measurements for astronomical purposes.Comment: 6 pages, 8 figures, Published by TECNIA (UNI
SUPRESIVIDAD DEL COMPOST DE ORUJO DE VID FRENTE A MICOSIS EDÁFICAS DE PLÁNTULAS DE HORTALIZAS
Suppression of soil-borne diseases of horticultural crops by compost has been attributed to
the activities of antagonistic microorganisms. A great diversity of biological control agents naturally colonize compost. This is especially true for biological control agents effective against the soilborne Oomycete pathogens. The purpose of this research was to determine the suppressive capacity of grape marc compost against Fusarium oxysporum f. sp. radicis-cucumerinum, Rhizoctonia solani, Pythium aphanidermatum and Phytophthora parasitica. Previously, antagonist in vitro assay were performed with 432 microbial morphologies isolated from grape marc compost. Seven microorganisms were selected for further bioassay with radish-Rhizoctonia solani, melon-Fusarium oxysporum f. sp. radicis-cucumerinum, and tomato-Phytophthora parasitica and two microorganisms for cucumber-Pythium aphanidermatum. Those experiments indicate, that grape marc compost reduce the severity of Pythium dumping-off on cucumber, but do not reduce the severity of Phytophthora root rot on tomato, Fusarium oxysporum f. sp. radicis-cucumerinum on melon and Rhizoctonia solani on radish. The enrichment of compost or vermiculite with the selected microbes for compost do not improved the suppressive effects.La supresión de enfermedades producidas por patógenos del suelo mediante compost en los cultivos hortícolas se ha atribuido muy especialmente a la actividad antagonista de los microorganismos. Una gran diversidad de agentes de control biológico colonizan naturalmente el compost. Esto es especialmente importante para el control de oomicetos patógenos del suelo. El propósito de este trabajo fue determinar la capacidad supresora del compost de orujo de vid frente a Fusarium oxysporum f. sp. radicis-cucumerinum, Rhizoctonia solani, Pythium aphanidermatum y Phytophthora nicotianae var. parasitica (P. parasitica). Previamente, se realizaron ensayos de antagonismo in vitro con 432 microorganismos obtenidos del compost de orujo de vid. Siete microorganismos fueron seleccionados para el enriquecimiento del compost para el bioensayo Rhizoctonia solani en rábano, Fusarium oxysporum f. sp. radicis-cucumerinum en melón, Phytophthora parasitica en tomate y dos para Pythium aphanidermatum en pepino. Estos experimentos indican que el compost de orujo de vid reduce la severidad de la enfermedad causado por Pythium, pero no se produce supresión ni disminución de la severidad de la enfermedad causada por los hongos fi topatógenos Rhizoctonia solani, Fusarium oxysporum f. sp. radicis-cucumerinum y Phytophthora parasitica. El enriquecimiento del compost o vermiculita con los microorganismos seleccionados no incrementa el efecto supresor
Social Commerce as a Driver to Enhance Trust and Intention to Use Cryptocurrencies for Electronic Payments
The deployment of cryptocurrencies in e-commerce has reached a significant number of transactions and continuous increases in monetary circulation; nevertheless, they face two impediments: a lack of awareness of the technological utility, and a lack of trust among consumers. E-commerce carried out through social networks expands its application to a new paradigm called social commerce. Social commerce uses the content generated within social networks to attract new consumers and influence their behavior. The objective of this paper is to analyze the role played by social media in increasing trust and intention to use cryptocurrencies in making electronic payments. It develops a model that combines constructs from social support theory, social commerce, and the technology acceptance model. This model is evaluated using the partial least square analysis. The obtained results show that social commerce increases the trust and intention to use cryptocurrencies. However, mutual support among participants does not generate sufficient trust to adequately promote the perceived usefulness of cryptocurrencies. This research provides a practical tool for analyzing how collaborative relationships that emerge in social media can influence or enhance the adoption of a new technology in terms of perceived trust and usefulness. Furthermore, it provides a significant contribution to consumer behavior research by applying the social support theory to the adoption of new information technologies. These theoretical and practical contributions are detailed in the final section of the paper.This work was supported in part by the Spanish Research Agency (AEI) and in part by the European Regional Development Fund (FEDER) through project CloudDriver4Industry under Grant TIN2017-89266-R
VINAZAS Y HONGOS DEL SUELO
The purpose of this research was to study the biocidal effect of three agroindustrial subproducts, concretely sugar beet, sugar cane and wine vinasse. Two tests were carried out. The first centred on studying the action of the three agroindustrial subproducts in vitro. In dilutions at initial doses of 1%, 3% and 5%, their performance against six phytopathogenic fungi was analyzed: Fusarium oxysporum f.sp. melonis race 0 and 1, F. oxysporum f.sp. radicis-cucumerinum, Sclerotinia sclerotiorum, Pythium aphanidermatum and Phytophthora parasitica. Next, the antagonistic capacity of the solutions assayed in vitro was tested in soil, studying the incidence of the subproducts on the Fusarium populations in these soils.
Results from in vitro testing determined that wine vinasse is what shows a 100% capacity to suppress fungal growth with concentrations that are not very high, between 5% and 7% for Fusarium oxysporum f.sp. melonis race 0 and 1, S. sclerotiorum, P. aphanidermatum and P. parasitica and 10-15% for Fusarium oxysporum f.sp. radicis-cucumerinum. On the other hand, sugar cane vinasse produced an increase at high concentrations and sugar beet vinasse showed an approximate 100% suppressor effect on fungal growth for only some of the phytopathogens tested: S. sclerotiorum (15%), P. aphanidermatum (7%), P. parasitica (15%) and Fusarium oxysporum f.sp. radiciscucumerinum (15%).
In the soil samples analyzed none of the three vinasse extracts decreased fusaric microbiota, producing an increase in the three samples tested. This would implicitly convey an improvement
in soil quality by producing a potential increase in bacterial and fungal microbiota. El propósito de este trabajo fue estudiar el efecto biocida de tres subproductos agroindustriales, concretamente de la vinaza de remolacha, la vinaza de caña de azúcar y la vinaza de vino. Se
realizaron dos estudios, el primero se centró en estudiar in vitro la acción de los tres subproductos agroindustriales analizando su comportamiento en diluciones a las dosis iniciales del 1%, 3% y 5% frente a seis hongos fitopatógenos: Fusarium oxysporum f.sp. melonis raza 0 y 1, F. oxysporum f.sp. radicis-cucumerinum, Sclerotinia sclerotiorum, Pythium aphanidermatum y Phytophthora parasitica. Posteriormente, se estudió la capacidad antagonista de las disoluciones ensayadas in vitro, sobre suelos, estudiando la incidencia de los subproductos mencionados sobre las poblaciones fusáricas presentes en dichos suelos.
Los resultados obtenidos para los ensayos realizados in vitro determinan que la vinaza de vino es la que presenta una capacidad de supresión del crecimiento fúngico del 100% a concentraciones no muy elevadas, entre el 5% y 7% para Fusarium oxysporum f.sp. melonis raza 0 y 1, S. sclerotiorum, P. aphanidermatum y P. parasitica y al 10-15% para Fusarium oxysporum f.sp. radicis-cucumerinum. Por el contrario, la vinaza de caña de azúcar produce un incremento a altas concentraciones y la vinaza de remolacha presenta efecto supresor del crecimiento fúngico aproximadamente del 100% sólo para algunos de los fi topatógenos ensayados: S. sclerotiorum (15%), P. aphanidermatum (7%), P. parasitica (15%) y Fusarium oxysporum f.sp. radicis-cucumerinum (15%).
En las muestras de suelo analizadas ninguno de los tres extractos de vinaza consigue disminuir la microbiota fusárica, produciendo un incremento en las tres muestras ensayadas, lo que podría llevar implícito una mejora en la calidad de los suelos al producirse un posible incremento en la microbiota bacteriana y fúngica de los mismos
Exploration of copper oxide nanoneedle electrosynthesis applied in the degradation of methylene blue
In this study, we report a low cost, fast and unexplored electrochemical synthesis strategy of copper oxide nanoneedles films as well as their morphological and chemical characterization. The nanostructured films were prepared using electrochemical anodization in alkaline electrolyte solutions of ethylene glycol, water and fluoride ions. The film morphology shows nanoneedle-shaped structures, with lengths up to 1–2 µm; meanwhile, high-resolution X-ray photoelectron spectroscopy (HRXPS) and spectroscopy Raman analyses indicate that a mixture of Cu(II) and Cu(I) oxides, or only Cu(I) oxide, is obtained as the percentage of water in the electrolyte solution decreases. A preliminary study was also carried out for the photocatalytic degradation of the methylene blue (MB) dye under irradiation with simulated sunlight in the presence of the nanoneedles obtained, presenting a maximum degradation value of 88% of MB and, thus, demonstrating the potential characteristics of the material investigated in the degradation of organic dyes.Fil: Oyarzún, Diego P.. Universidad de Atacama.; ChileFil: Tello, Alejandra. Universidad de Atacama.; ChileFil: Sánchez, Julio. Universidad de Santiago de Chile; ChileFil: Boulett, Andrés. Universidad de Santiago de Chile; ChileFil: Linarez Pérez, Omar Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Martin-Trasanco, Rudy. Universidad Tecnologica Metropolitana; ChileFil: Pizarro, Guadalupe Del C.. Universidad Tecnologica Metropolitana; ChileFil: Flores, Marcos. Universidad de Chile; ChileFil: Zúñiga, César. Universidad de Las Américas.; Ecuado
The Management of Agriculture Plastic Waste in the Framework of Circular Economy. Case of the Almeria Greenhouse (Spain)
In recent decades, ecosystems have suffered diverse environmental impacts caused by anthropogenic activities, including the dumping of plastic waste. This situation has prompted the European Union to introduce a new policy based on the circular economy. In this study, the present state and future perspectives on the generation and treatment of plastic waste in the intensive agriculture of Almeria (Spain) are analyzed. This activity generates 1503.6 kg·ha−1·year−1, on average, of plastic waste with an approximate treatment cost of 0.25 €/kg. The present study shows that the volume of plastic waste from intensive agriculture in Almeria is constantly increasing (48,948.2 tons in 2020/21) and it is suggested that the current management system does not meet the needs of the sector. Although it presents great opportunities for improvement under the framework of the circular economy. Furthermore, this work reports a direct relationship between the price of the raw materials needed for the production of plastic and the volume of recycled plastics. For this reason, it would be advisable for the administration to consider the implementation of a tax rebate system for the sector and specifically when the petroleum derivatives used to manufacture plastic are less expensive, and the recycling option is not so attractive
Biodisinfection as a Profitable Fertilization Method for Horticultural Crops in the Framework of the Circular Economy
Intensive agriculture has resulted in various environmental impacts that affect ecosystems. In some cases, the application of conventional fertilizers has deteriorated water quality, which includes the marine environment. For this reason, institutions have designed various strategies based on the principles of the circular economy and the bioeconomy. Both of these dynamics aim to reduce excessive fertilization and to inhibit the negative externalities it generates. In our work, a field trial is presented in which a 100% reduction in conventional inorganic fertilizers has been evaluated through a production methodology based on fertilization with reused plant debris in combination with other organic compounds. Based on one tomato crop, the profitability of this production technique has been analyzed in comparison with other conventional vegetable production techniques. The productivity and economic yield of the alternative crop was similar to that of the conventional crop, with a 37.2% decrease in water consumption. The reuse of biomass reduced production costs by 4.8%, while the addition of other organic amendments increased them by up to 22%. The results of our trial show that farms are more sustainable and more profitable from a circular point of view when using these strategies
Plan de negocios para una empresa de intermediaci?n de comida casera a trav?s de una plataforma virtual en la ciudad de Trujillo
Ruta Casera tiene como objetivo la intermediaci?n entre personas que gustan cocinar en casa con comensales que buscan una opci?n de alimentaci?n casera. El plan de negocio propone establecer una intermediaci?n entre emprendedores y consumidores, en la que podr? acceder a esta plataforma virtual para seleccionar, comprar y pagar los platos de su pedido desde su tel?fono inteligente. Es as?, que el objetivo del presente plan de negocios es evaluar la viabilidad comercial, operativa y econ?mica para instalar el servicio de intermediaci?n entre emprendedores y consumidores
Fundación de Investigaciones Arqueológicas Nacionales, Informes preliminares:
Arqueología de San Agustín, Investigaciónes en la Mesita CEl yacimiento arqueológico "Mesita C", conocido con este nombre desde los albores del presente siglo, forma parte del área del Parque Arqueológico de San Agustín. El sitio se localiza aproximadamente a 800 metros al sur del edificio de Museo y Administración, en el borde del peniplano que cae al occidente en fuerte desnivel hacia la quebrada de Lavapatas, donde se encuentra ese extraordinario monumento labrado en la roca que es la "Fuente de Lavapatas". La vía peatonal que conduce a este lugar, atraviesa el sitio de que tratamos.Estudio Geológico de San Agustín (Huila)El estudio geológico de San Agustin se realizó con el propósito de aumentar la información sobre esta importante región arqueológica. Se buscó analizar la composición y el origen de las rocas en que fueron labradas las estatuas, la fuente ceremonial de Lavapatas y los utensilios para estas labores. También se elaboró un mapa geológico con escala 1:25.000 que cubre una extensión de cien kilómetros cuadrados, teniendo como centro el pueblo de San Agustin, complementado con fotografias aéreas.Fundación de Investigaciones Arqueológicas Nacionales, Informes preliminares:Etnohistoria del bajo Caquetá – Putumayo (s. XVI – XVII – XVIII – XIX)El cuadro histórico del Bajo Caquetá-Putumayo es, supuestamente, bastante sencillo: la región estaría habitada, a finales del siglo pasado, por numerosas etnias, marginadas completamente del proceso "civilizador": la situación se habría visto alterada, únicamente, por las redadas portuguesas en búsqueda de esclavos indígenas. La invasión cauchera, iniciada en los últimos lustros del siglo pasado, habría violentado, por primera vez, el orden tradicional del indio, con las consecuencias de etnocidio denunciadas por J. E. Rivera
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