In Vitro Propagation of Sugarcane for Certified Seed Production

Micropropagation of sugarcane is important to obtain pathogen-free plants, genetically homogeneous and invigorate. The micropropagation procedure is divided into stages for the sake of better understanding. Micropropagation for large-scale sugarcane production using a temporary immersion system (TIS) is described. In addition, the aim of this chapter is to report, from the laboratory to the field, the best way to establish and use basic seed (primary seed), semicommercial seed (foundation or secondary seed) and commercial seed production. In conclusion, commercial sugarcane micropropagation enables the massive multiplication of plants to obtain certified vitroplants and increase the sugarcane and sugar productivity per unit area

“Nanopartículas de Hierro con Tamaño Controlado Depositadas sobre Clinoptilolita por la Técnica de Electroless Plating Method- Coprecipitación: Síntesis y Caracterización”

En el presente trabajo se ha abordado el estudio de la concentración de HCl sobre la activación con SnCl2 de una Zeolita sintetica tipo A de Sodio, que denominaremos Clinoptilolita (CLT), para la depositación en su superficie de óxidos de hierro de tamaño nanomaetrico mediante una técnica conjunta de Electroless Plating Method-Coprecipitación. La razón de utilizar una zeolita como sustrato surge de querer aprovechar sus dimensiones para obtener depósitos de tamaño nanométrico, esto con el fin de que el sustrato sea evaluado a futuro como un material compuesto que presente propiedades magnéticas, de catálisis heterogénea, conducción térmica o de reforzamiento mecánico, esta ultima si se le llegase a utilizar como carga en polímeros

¿Qué se entiende por calidad en la educación?

Durante el Seminario Internacional “Factores Asociados a la Calidad de la Educación: una Cuestión de Derechos”, que fue organizado por el IDEP y realizado en el Auditorio de COMPENSAR en Bogotá durante los días 7 y 8 de septiembre, participaron especialistas de varios países y cientos de docentes provenientes de la capital y de diferentes regiones del país

Soil and water pollution in a banana production region in tropical Mexico

The effects of abundant Mancozeb (Mn, Zn— bisdithiocarbamate) applications (2.5 kg ha-1week-1 for 10 years) on soil and surface-, subsurface- and groundwater pollution were monitored in a banana production region of tropical Mexico. In soils, severe manganese accumulation was observed, wheras the main metabolite ethylenethiourea was near the detection limit. Surface and subsurface water was highly polluted with ethylenethiourea, the main metabolite of Mancozeb (22.5 and 4.3 lg L-1, respectively), but not with manganese. In deep ground water, no ethylenethiourea was detected. The level of pollution in the region presents a worrisome risk for aquatic life and for human health

Production of biogas with high calorific value from wastewater via hydrogen assisted anaerobic digestion

Anaerobic digestion is a well-known technology for wastewater treatment and biogas production. This process has been used all over the world for treating a wide range of waste and wastewater streams with biogas being one of its most valuable products. However, there are still a few challenges with this technology such as low methane content of the biogas. In general, the biogas primarily contains about 60% of methane and 40% of CO2. The CO2 content of the biogas lowers the calorific value of this valuable and renewable gas and limits its industrial applications. Therefore, biogas upgrading mechanisms have been studied to remove CO2 and other unwanted gases from the biogas. Biogas upgrading has gained attention particularly because many countries are moving towards renewable fuel production. Upgraded biogas can be an appealing substitute for natural gas. Hydrogen-assisted biological biogas upgrading has been explored to convert CO2 to methane gas with the help of CO2-consuming hydrogenotrophic methanogens. These microorganisms use hydrogen and CO2 and produce methane gas as the results of their biological activities. However, hydrogen gas can take other pathways in mixed culture systems such as anaerobic digesters where volatile fatty acids are produced as a result of biological reaction of CO2 and H2. In this context, the aim of this study was to identify the H2 injection rate required to increase the methane content in the biogas. The results demonstrated a positive effect of hydrogen addition on biogas upgrading. The methane content of the biogas in H2-assisted anaerobic digestion (70%) was higher than that of conventional anaerobic digestion (45%). The results showed that after acclimation of anaerobic microorganisms to the added hydrogen, hydrogen gas uptake and sequestration of CO2 occurred which resulted in the production of high quality biogas

Carpark pollutant yields from first flush stormwater runoff

Stormwater runoff from carparks should be treated to remove pollutants before they enter urban waterways; however, differences in traffic characteristics and surrounding land use activities can result in varying first flush pollutant types and concentrations requiring specific treatment approaches. An understanding of potential variations in first flush pollutant characteristics from carparks is necessary to design adequate treatment systems. Stormwater runoff from over 20 runoff events in three different carparks (university, hospital and industrial) in Christchurch, New Zealand were thus analyzed for Total Suspended Solids (TSS) and heavy metals (Zn, Cu and Pb) over a year. Pollutant concentrations were found to vary across the carparks, which were largely driven by land use activities such as traffic count, size of the vehicles, and surrounding topography. Mean concentrations of heavy metals (both dissolved and particulate) and TSS were significantly higher in the industrial carpark than in the other two urban carparks, which had statistically similar mean pollutant concentrations. Specific ratios of metal species (Zn:Cu, and Zn:Pb) were relatively high for the industrial carpark, indicating a greater contribution from the wear and tear of large commercial vehicles. TSS and total Zn wash-off concentrations from the hospital carpark when it was non-operational (passive) were found to be significantly lower than the hospital carpark when it was operational (active), confirming that pollutant concentrations increase with vehicular activity. Rainfall characteristics such as antecedent dry days and rain intensity and duration were found to only have a low positive correlation to pollutant concentrations for all carparks. The findings from this study highlight the importance of considering carpark characteristics in the implementation of on-site stormwater treatment systems

Anaerobic pond treatment of pig farm effluent in New Zealand: exploring opportunities for enhanced performance

The objective of this project is to explore ways to enhance the performance of covered anaerobic ponds to increase methane production, reduce odour emission, and improve digestate quality. The methane production and effluent quality of pond systems on two pig farms will be characterised and compared. One farm uses a fat-rich dairy by-product in the pig feed and reports anaerobic pond issues, while the other farm does not use the fat-rich dairy by-product and reports no issues

Influence of groundwater condition on nutrient dynamics in urban waterways

Excess nutrients in waterways contribute to eutrophication and decrease aquatic ecosystem health, a problem affecting both rural and urban catchments. In order to address excess nutrient problems in urban waterways, authorities have been developing strategies to mitigate impacts by using in-channel and landbased stormwater treatment to remove pollutants via settling and other physical, chemical and/or biological processes. However, little is known about how pollutants are transported and transformed in urban in-channel systems under the influence of different groundwater conditions. Therefore, this research aims to understand nutrient dynamics (nitrogen and phosphorus) in waterway channels under the influence of seepage, neutral, and drainage conditions. It was hypothesized that groundwater and bed material characteristics affect the concentration and form of surface pollutants, as well as their mobility. This understanding could help guide stream management decisions

Diagnóstico del cultivo de tomate en la zona metropolitana de Bucaramanga

El tomate es una hortaliza de gran demanda en el área metropolitana de Bucaramanga, para consumo fresco, como condimento y en forma de salsa. El presente estudio se adelantó con el propósito de conocer la problemática del cultivo de tomate respecto a la utilización de agroquímicos, mano de obra y fotosanidad, en los cultivos establecidos en el área de influencia de Bucaramanga en el año de 1987. Para la realización de este trabajo se encuestaron 25 agricultores ubicados en 14 veredas de vocación tomatera de los municipios de Bucaramanga, Floridablenca, Piedecuesta, Girón y Cepitá. Los resultados más importantes de la investigación fueron: la mayoría de los agricultores manejan inadecuadamente el cultivo en cuanto a labores culturales básicas. El control de plagas y enfermedades lo hacen por calendario, notándose un total desconocimiento de los sistemas de manejo integrado de plagas y enfermedades que tan excelentes resultados ha producido en otras zonas de cultivo como los del Valle del Cauca. Se encontró igualmente que no se destruyen los residuos de cosecha no se practica la rotación de cultivos de manera significativa. Hay uso indiscriminado y deficiente aplicación de plaguicidas con lo cual se incrementan los costos de producción y se contamina el producto cosechado, el cultivador y el ambiente. Los problemas fitosanitarios relevantes detectados en la fecha, lo constituyen los nemátodos, el barrenador del fruto (Neoleucinodes elegantalis), la virosis y la gota, La rentabilidad del cultivo es baja, el crédito insuficiente e inoportuno y no se cuenta con asistencia técnicaTomate-Solanum lycopersicu