Production of renewable fuel and value-added bioproducts using pineapple leaves in Costa Rica

Pineapple, Ananas comosus, is one of the most important cash crops in Costa Rica with more than 44,500 ha of plantation. The pineapple industry contributes approximately 1.7% of the gross domestic product (GDP) of Costa Rica. Pineapple cultivation generates a large amount of plant residues (250 metric tons per hectare of wet plant residues mainly leaves). Current practices of the field residue handing include direct burning, in situ decomposition and removal of residue before planting, which are neither economically sound nor environmentally friendly. New approaches are urgently needed to utilize the residues and improve sustainability of pineapple production in Costa Rica. This study developed a simple, efficient process to convert the pineapple plant leaves into bioethanol, spent yeast proteins, and fibrous material (pulp). The residue was first treated by a mechanical extruder to generate juice and fibrous material. The juice was fermented by a yeast, Kluyveromyces marxianus, to produce ethanol and spent yeast proteins. Under the selected process conditions, the plant leaves (125 tons fresh weight per year) from 1 ha can generate 2.1 tons of bio-ethanol, 1.55 tons of spent yeast biomass, and 11.65 tons of dry fibrous material. The mass and energy balance analysis concluded that using the studied process, the pineapple plant leaves from 44,500 ha of pineapple plantation in Costa Rica can produce 93,043, 68,975, and 518,425 tons of bioethanol, spent yeast, and fibrous material per year, respectively. The amount of bioethanol is able to replace approximately 8.51% of transportation fossil fuel consumption in Costa Rica.Michigan State University/[]/MSU/Estados UnidosNational Natural Science Foundation of China/[31701533]/NSFC/ChinaProgram of Study Abroad for Young Scholars/[gxgwfx 2018036]//Estados UnidosUCR::Vicerrectoría de Docencia::Ingeniería::Facultad de Ingeniería::Escuela de Ingeniería de Biosistema

Chemodynamics of the Milky Way. I. The first year of APOGEE data

We investigate the chemo-kinematic properties of the Milky Way disc by exploring the first year of data from the Apache Point Observatory Galactic Evolution Experiment (APOGEE), and compare our results to smaller optical high-resolution samples in the literature, as well as results from lower resolution surveys such as GCS, SEGUE and RAVE. We start by selecting a high-quality sample in terms of chemistry (____sim 20.000 stars) and, after computing distances and orbital parameters for this sample, we employ a number of useful subsets to formulate constraints on Galactic chemical and chemodynamical evolution processes in the Solar neighbourhood and beyond (e.g., metallicity distributions -- MDFs, [____alpha/Fe] vs. [Fe/H] diagrams, and abundance gradients). Our red giant sample spans distances as large as 10 kpc from the Sun. We find remarkable agreement between the recently published local (d $<$ 100 pc) high-resolution high-S/N HARPS sample and our local HQ sample (d $<$ 1 kpc). The local MDF peaks slightly below solar metallicity, and exhibits an extended tail towards [Fe/H] $= -$1, whereas a sharper cut-off is seen at larger metallicities. The APOGEE data also confirm the existence of a gap in the [____alpha/Fe] vs. [Fe/H] abundance diagram. When expanding our sample to cover three different Galactocentric distance bins, we find the high-[____alpha/Fe] stars to be rare towards the outer zones, as previously suggested in the literature. For the gradients in [Fe/H] and [____alpha/Fe], measured over a range of 6 $<$ R $<$ 11 kpc in Galactocentric distance, we find a good agreement with the gradients traced by the GCS and RAVE dwarf samples. For stars with 1.5 $<$ z $<$ 3 kpc, we find a positive metallicity gradient and a negative gradient in [____alpha/Fe]

Implementación de Flippedclassroom (aula invertida) en la transformación de las prácticas pedagógicas de los docentes en el bachillerato de la Escuela Tecnológica Instituto Técnico Central.

Los maestros planean, desarrollan y evalúan sus contenidos programáticos, de los espacios académicos cumpliendo con las directrices establecidas por el Ministerio de Educación Nacional y basados en su experiencia personal y tradicional; sin embargo, en algunos casos las clases pueden hacerse tediosas y de cuestionable calidad convirtiéndose en un espacio de reproducción de contenidos, que no motiva a los estudiantes en su proceso de enseñanza y aprendizaje; de allí que se hace necesario transformar el paradigma de la clase tradicional, incorporando las TIC al quehacer educativo, y proponer unas mejores prácticas educativas de los docentes. La presente investigación está fundamentada en las corrientes pedagógicas del constructivismo y el aprendizaje colaborativo según y Vigotsky y Johnson, D. W., & Johnson, R. T. El proyecto de investigación se propone la implementación del Flipped Classroom para la trasformación de las prácticas pedagógicas de los docentes, del bachillerato de la Escuela Tecnológica Instituto Técnico Central. Para el desarrollo de la investigación se optará por una metodología mixta según la conceptualización que de ésta hace Hernández, Fernández, &, (2008), y la define como el “conjunto de procesos sistemáticos, empíricos y críticos de investigación e implican la recolección y el análisis de datos cuantitativos y cualitativos, así como su integración y discusión conjunta. Por otro lado, el enfoque seleccionado para la investigación es de tipo descriptivo por cuanto se desarrollarán procesos enfocados en las prácticas pedagógicas utilizadas por los docentes en las aulas de clase, y se acudirá a técnicas específicas en la recolección de información, como la técnica de grupos focales entre otros. Se utilizará, además el diseño cuasi experimental con la aplicación de un pretest- postest con grupo de control, a fin de realizar un análisis comparativo entre los grupos seleccionados del grado sexto de secundaria. Esta investigación es de mucha importancia ya que aporta elementos valiosos a la construcción de nuevas didácticas, metodologías para los docentes, y que, si se utiliza de manera correcta, podrá transformar la práctica educativa haciendo de los estudiantes el centro de los aprendizajes, y por consiguiente se reflejarán excelentes resultados en el desempeño escolar.Tecnología Educativa y Filosofía de la Educación

Ecological Specialization of Two Photobiont- Specific Maritime Cyanolichen Species of the Genus Lichina

22 páginas, 4 tablas, 4 figurasAll fungi in the class Lichinomycetes are lichen-forming and exclusively associate with cyanobacteria. Two closely related maritime species of the genus Lichina (L. confinis and L. pygmaea) show similar distribution ranges in the Northeast Atlantic, commonly co-occurring at the same rocky shores but occupying different littoral zones. By means of 16S rRNA and phycocyanin operon markers we studied a) the phylogenetic relationships of cyanobionts associated with these species, b) the match of divergence times between both symbionts, and c) whether Lichina species differ in photobiont association and in how geography and ecology affect selectivity. The cyanobionts studied are closely related to both marine and freshwater strains of the genus Rivularia.We found evidence of a high specificity to particular cyanobiont lineages in both species: Lichina pygmaea and L. confinis incorporate specific lineages of Rivularia that do not overlap at the haplotype nor the OTU levels. Dating divergences of the fungal and cyanobacterial partners revealed an asynchronous origin of both lineages. Within each fungal species, selectivity varied across the studied area, influenced by environmental conditions (both atmospheric and marine), although patterns were highly correlated between both lichen taxa. Ecological speciation due to the differential association of photobionts to each littoral zone is suspected to have occurred in marine Lichina.Both ROA (BES-2013-066105) and SPO (CTM2012-38222-C02-02) were supported in the form of salary by grants from the Spanish Ministry of Economy and Competitiveness.Peer reviewe

Catalyst design for natural-gas upgrading through oxybromination chemistry

ISSN:1755-4349ISSN:1755-433