124 research outputs found
Conversion of Lignin to Heat and Power, Chemicals or Fuels into the Transition Energy Strategy
Energy transition toward low carbon, high sustainable and efficient generation and distribution systems will change the supply matrix of the world and create new opportunities but challenges still remain. Energy generation from biomass, or bioenergy, is one of such renewable sources and its use might be generalized in the following years. Bioenergy is a very promising strategy to provide energy not only for mobility but also for onsite places for heat and power generation. Besides, bioenergy differentiates from other renewable energies that biomass may be the source of a myriad of molecules enabling the bio-based economy and allowing the replacement in an extent of solvents, petrochemicals, and polymers produced by the petroleum industry. Biomass is generally composed of some large polymers found in nature such as cellulose, hemicellulose, proteins, starch, chitin, and lignin. The latter is a complex phenylpropanoid biopolymer conferring mechanical strength to plant cell walls and one of major spread in nature along with cellulose and chitin. Lignin has a plenty of potential uses in modern bio-based economy, from conventional paper industry uses to more challenging conversion to useful chemicals, materials, and clean biofuels. This chapter undertakes a rapid overview on lignin applications in order to describe the basis of a lignin-based economy
Estimation of pre-exercise hydration status of Mexican college athletes
INTRODUCTION: The state of hydration is a very important aspect for athletes and coaches. According to NATA and ACSM athletes must be educated to maintain a good state of hydration and thus obtain better results. PURPOSE: To determine the state of hydration, before the sport practice of athletes (males) that belong to representative sports. METHODS: Seventy-five males college athletes, physically active and apparently healthy, were voluntarily recruited. They had an average height of 174.8 ± 7.4cm, weight 87.2 ± 24.0kg and age 21.3 ± 2.4 years. The athletes attended the study on a single spontaneous occasion, prior to the training session. Were given a questionnaire of hydration habits and a urine container (to collect a urine sample of their own). The urine gravity (UG) was determined by a urinary refractometer (ATAGO, Master-Sur/Na). RESULTS: Athletes had a urine gravity of 1.024 ± 0.006UG, finding maximum values up to 1.033 UG. Only 2.6% of the study population was well hydrated (1.030UG), which means a loss of fluid of 2%, 4% and more than 5% of total body weight for hypohydration conditions. Athletes mentioned that during and one hour after exercise they drink 762.3 ± 560.2mL and 644.4 ± 362.2mL respectively, either water or isotonic drink. However, these liquid volume did not compensated the water deficiency with which they begin the practice of the exercise. CONCLUSION: Before the training, 97.4% of the subjects presented different level of hypohydration, including very severe hypohydration state. The fluid ingested after the training session did not disappear the hydration deficiency with which they begin the exercise
Análisis de los Factores metodológicos que inciden en el desarrollo de habilidades y destrezas en la Lectura y Escritura durante el proceso de enseñanza y aprendizaje en los estudiantes del tercer grado del turno Matutino de la Escuela Pública Rodolfo Schear del Municipio de San Rafael del Sur, Departamento de Managua en el primer semestre de año 2014
El presente trabajo tiene como propósito valora los factores metodológicos que inciden en el desarrollo de habilidades y destrezas de la lectura y escritura durante el proceso de enseñanzay aprendizaje en los estudiantes, del tercer grado de la escuela Pública Rodolfo Schear, del Municipio San Rafael del Sur, Departamento de Managua, en el primer semestre del 2014. Esta investigación permitió identificar primeramente los factores metodológicos que inciden en el aula de clase, luego conocer las habilidades y destrezas en la lectura y escritura de los estudiantes e identificar el proceso de enseñanza y aprendizaje. Para obtener los datos y la información necesaria para el análisis se utilizaron instrumentos tales como: la observación al aula de clase, la entrevista a la docente y a la directora y una encuesta dirigida a los estudiantes también un grupo focal dirigido a los padres de familia. Los resultados se triangularon y la mayor debilidad se encontró en la docente ya que ésta no utiliza una metodología apropiada en la lectura y la escritura, básicamente la maestra solamente utiliza la pizarra y el dictado. Palabras Claves: Factores en la lectura y escritura
Reincidencia y Habitualidad en Procesos Penales a Consecuencia de la Ley 30076
El objetivo de la presente investigación fue: Determinar las condiciones que
harían conveniente la incorporación de las figuras jurídica de reincidencia y
habitualidad delictiva, como presupuesto material, como causas que eximan o
atenúan responsabilidad Penal a consecuencia de la ley 30076, para que el juez
pueda dictar el mandato de pena privativa de la libertad.
En cuanto a la metodología el estudio fue de enfoque cualitativo, donde se
analizó el fenómeno a investigar sin alterar su medio donde se desarrolla, y de
diseño fenómeno lógico, pues según Salgado (2007), estos diseños se enfocan
en las experiencias individuales subjetivas de los participantes ya que, las
percepciones de los sujetos evidencian para él la existencia del mundo, no como
lo piensa, sino como lo vive.
Los resultados determinan que con las modificaciones realizadas en virtud
de la Le y las modificaciones realizadas en virtud de la Ley 30076, los artículos
46ºB 46ºC del Código Penal referidos la reincidencia y habitualidad,
respectivamente, evidencian en el tratamiento de las faltas, una limitación del
acceso a beneficios penitenciarios u otras, se enmarcan en un proceso de
endurecimiento del sistema penal, el mismo que parte de un Derecho altamente
punitivo
Analizar de forma comparativa diferentes tipos de cubeta para la obtención de modelos de yeso tipo IV más precisos, realizados en los laboratorios de la UAM en febrero - marzo 2017
Tesis(Cirujano Dentista)--Universidad Americana, Managua, 2017Existe una gran cantidad de estudios los cuales se han encargado de evaluar la estabilidad dimensional y precisión de distintos materiales utilizados para la toma de impresión, estos evalúan, como diversos factores producen cambios o alteraciones en la calidad de los modelos definitivos. Nuestro estudio consiste en evaluar uno de esos factores, el tipo de cubeta para impresión definitiva
Deterioration of the Gαo Vomeronasal Pathway in Sexually Dimorphic Mammals
In mammals, social and sexual behaviours are largely mediated by the vomeronasal system (VNS). The accessory olfactory bulb (AOB) is the first synaptic locus of the VNS and ranges from very large in Caviomorph rodents, small in carnivores and ungulates, to its complete absence in apes, elephants, most bats and aquatic species. Two pathways have been described in the VNS of mammals. In mice, vomeronasal neurons expressing Gαi2 protein project to the rostral portion of the AOB and respond mostly to small volatile molecules, whereas neurons expressing Gαo project to the caudal AOB and respond mostly to large non-volatile molecules. However, the Gαo-expressing pathway is absent in several species (horses, dogs, musk shrews, goats and marmosets) but no hypotheses have been proposed to date to explain the loss of that pathway. We noted that the species that lost the Gαo pathway belong to Laurasiatheria and Primates lineages, both clades with ubiquitous sexual dimorphisms across species. To assess whether similar events of Gαo pathway loss could have occurred convergently in dimorphic species we studied G-protein expression in the AOB of two species that independently evolved sexually dimorphic traits: the California ground squirrel Spermophilus beecheyi (Rodentia; Sciurognathi) and the cape hyrax Procavia capensis (Afrotheria; Hyracoidea). We found that both species show uniform expression of Gαi2-protein throughout AOB glomeruli, while Gαo expression is restricted to main olfactory glomeruli only. Our results suggest that the degeneration of the Gαo-expressing vomeronasal pathway has occurred independently at least four times in Eutheria, possibly related to the emergence of sexual dimorphisms and the ability of detecting the gender of conspecifics at distance
Sugarcane Bagasse Valorization Strategies for Bioethanol and Energy Production
The use of sugarcane bagasse pith as solid substrate for fungi and microbial growth is well known, as well as a source of microorganisms that can be isolated from it. Pith has also been used as a bulking agent for soil bioremediation. More recently, bagasse pith has been used for bioethanol production involving pretreatment and hydrolysis followed by fermentation and dehydration. However, little is reported about biomass valorization for the development of environmentally sound and innovative strategies to process sugarcane bagasse from sugar mills. Incineration of sugarcane bagasse pith is a very common and mature technology for waste disposal and generation of electrical and thermal energy. However, this approach may not be satisfactory in organic waste management due to pollutant emissions, economic and labor costs, loss of energy, and bad odor. In addition, no valuable product is generated from its decomposition process. Instead of incineration, recent research has focused on its utilization as biofuel source. In this chapter, the use of sugarcane bagasse pith as a waste material for incineration versus biomass to produce bioethanol is discussed in terms of energy ratio and emissions, in addition to elucidate the potential of sugarcane bagasse valorization for a more sustainable society
Characterization, stability and solubility of co-amorphous systems of glibenclamide and L-arginine at different pH
Purpose: To investigate the stability and solubility of co-amorphous systems of glibenclamide (GBC) with L-arginine (L-Arg) at different pH values.
Methods: Three co-amorphous solids of GBC and L-Arg were obtained by fast solvent evaporation using 2:1, 1:1 and 1:2 stoichiometries. All co-amorphous systems were characterized by XRPD, FTIR, RAMAN and NMR-solid state as well as thermal techniques such as DSC and TGA. The stability of coamorphous systems was evaluated by indicative stability and stability in relevant physiological media was measured at different pH values.
Results: The chemical characterization suggest that there was no proton transference between L-Arg and GBC indicative of co-amorphous solids. Stability studies showed that all the co-amorphous solids are unstable under humid conditions and only the co-amorphous system of GBC: L-Arg 1:2 was stable in all the pH values tested. Solubility studies at different pH values showed that the co-amorphous GBC: L-Arg 1:1 and 1:2, showed increasing solubility values even at pH < 7 (0.6468 mg/mL at pH 1.2 for coamorphous GBC: L-Arg 1:2 at the first hour) where free GBC was not soluble.
Conclusion: Co-amorphous systems of GBC and L-Arg, is an interesting strategy to increase the solubility of poorly-soluble drugs at acidic pH values
Keywords: Co-amorphous; Glibenclamide; L-Arginine; Solubility; Stabilit
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