Flash Hydrolysis of Microalgae Biomass for Biofuels Intermediates Production, Protein Extraction, and Nutrients Recycle

Microalgae have shown much higher growth rates and productivity when compared to conventional agricultural crops, aquatic plants and tree species, requiring much less land area than other biodiesel feedstock. To harness that potential the hydrothermal liquefaction of algae biomass was studied and a new process called Flash Hydrolysis was developed to use water under subcritical conditions, this process capitalizes on the difference in reaction kinetics of algae polymeric components and fractionates proteins in liquid phase in seconds of residence time. The main objectives for this study are: Analyze the effect of temperature in FH process to maximize the extraction of protein from the microalgae biomass and its recovery as soluble peptides and free amino acids (Chapter 2). To obtain enough experimental data to fit in a mathematical model for a kinetics study of protein and arginine solubilization via Flash Hydrolysis (rates constant k, reaction order and activation energy Ea) and characterize both liquid and solid products collected after Flash Hydrolysis (Chapter 3). Evaluate the possibility of recycle the extracted nutrients in the aqueous phase products after FH to grow more algae and close the loop in a continuous production system (Chapter 4). In Chapter 2 all the experiments were conducted using flocculated Scenedesmus sp. cultivated in the laboratory using photobioreactors. The effect of temperature and residence time on protein hydrolysis to water-soluble fractions (algal hydrolyzate) and yield of lipid-rich solids (biofuels intermediate) was studied using a lab-scale continuous flow reactor. More than 60 wt% of the total nitrogen content (dry basis) in Scenedesmus sp. was extracted within 10 s of residence time above 240 °C. The ion chromatography and NMR spectra of the algal hydrolyzate showed that the extracted proteins were present both as free amino acids and peptides. The carbon content of biofuels intermediate increased up to 66 wt% making it lipid- and energy-dense feedstock suitable for biofuels production. The scanning electron microscope image of biofuels intermediate indicated that the solids were globular and smaller in size as compared to the untreated microalgae. In Chapter 3 a new set of Flash Hydrolysis experiments were conducted at two different temperatures (240 and 280°C) and three residence times (6, 9 and 12 seconds) to understand the kinetics of algae proteins hydrolysis to water-soluble peptides and arginine. The proteins-rich microalgae Scenedesmus sp. with an average composition of 55% proteins, 18% lipids, and 20% carbohydrates was used as feedstock. After Flash Hydrolysis both liquid and solid products were collected and the soluble peptides and arginine contents were analyzed in the liquid fraction, as well as the content of remaining proteinaceous material in the solids. The experiments at 280 °C and 9 s residence time was the optimum process conditions for soluble-peptides yield (63.7%) whereas the maximum arginine yield (54.4%) was achieved at 280 °C and 12 s of residence time. The protein solubilization to soluble peptides fitted second order reaction kinetics, while for arginine was zeroth order and the activation energy was calculated to be 40.7 and 53.6 KJ/mol, respectively. The results of the study suggest that the Flash Hydrolysis can be an environmentally benign method to hydrolyze proteins from microalgae for producing valuable co-products such as arginine and water soluble peptides along with lipid-rich solids (biofuels intermediate) as a feedstock for biofuels production. Flash hydrolysis (FH) of microalgae biomass is a promising conversion and extraction method capable of solubilize more than 60% of the protein and recover it in the hydrolyzate (aqueous phase) as organic nitrogen (mix of ammonia, amino acids and soluble peptides). In a similar way almost 100% of the organic phosphorus from the microalgae biomass is recovered as soluble phosphates. In Chapter 4 the evaluation and potential use of the hydrolyzate obtained after FH as a source of nutrients for continuous microalgae production was demonstrated in laboratory conditions. The hydrolyzate contains a combination of nitrogen species that include soluble ammonia and peptides. This two organic nitrogen species are available for the algae to use as nitrogen source an support its growth in levels comparable to those obtained pure culture media (AM-14). Besides nitrogen, soluble phosphorus is recovered after Flash hydrolysis and its present mostly as orthophosphate. The amount of P supplemented by the hydrolyzate was taken by the algae almost completely in a similar way as it could metabolize the P provided by the culture media. The recycle of nitrogen and phosphorus would reduce the initial requirement of those nutrients in the balanced media used to grow algae and will reflect in a reduction in the total production cost

A Gravity Approach to Assess the Effects of Association Agreements on Euromediterranean Trade of Fruits and Vegetables

The paper is intended to draw on a gravity methodology to assess the impact of EuroMediterranean Association Agreement on Fruit and Vegetable trade from Mediterranean Partner Countries (MPC) to the EU. The Association Agreements appear to be significant as an explanatory of both fruit and vegetables’ trade flows to the EU. However, while the impact of such arrangements has contributed to boost MPC’s horticultural exports, it has not been sufficient to compensate the export loss related to the nature of MPCs as third countries. MPCs may have obtained gains from the EuroMed Agrements but the Barcelona process is still far to achieve its initial goals, at least concerning crucial products for the MPCs’ export strategy. The presented approach supplies a method to monitor future developments in the EuroMediterranean process.agricultural trade; Euro-Mediterranean agreements; fruit and vegetables

Identificación de zonas aptas para la recuperación del bosque de alta montaña del Estado de México

Se analizó el grado de aptitud ambiental y calidad de sitio para la recuperación del bosque de alta montaña del Estado de México, así como las características físico-químicas del suelo. Para el primer caso, se consideraron variables ambientales empleadas en otros trabajos de investigación. Sin embargo los rangos de aptitud fueron establecidos a partir de la revisión de literatura, así como a partir de una serie de puntos ubicados en el bosque de Pinus hartwegii Lindley. Para el segundo caso, se instalaron 42 parcelas de muestreo en las que se levantó información de calidad de sitio e información dasonómica. En ambos casos, los datos se analizaron a partir de técnicas de Evaluación Multicriterio y Sistemas de Información Geográfica; mientras que las características físico-químicas del suelo fueron evaluadas a partir de 21 sitios de muestreo: 7 en bosque denso, 7 en semidenso y 7 en fragmentado. Los resultados muestran que ambientalmente, las mejores zonas para la recuperación del bosque de alta montaña del Estado de México se localizan en el Parque Nacional Nevado de Toluca y en el Parque Nacional Izta-Popo Zoquiapan, ya que del total de la superficie con un nivel muy alto de adecuación (4235 ha), el 23% corresponde al primer caso y el 20% al segundo. En contra parte, la Sierra de las Cruces solo ocupa el 16%, y es también en esta zona donde se localizan las áreas con el nivel muy bajo de aptitud, ya que de 4672 ha, el 30% se localiza en esta zona. Estas condiciones ambientales pueden estar favoreciendo que las especies forestales se estén adaptando a condiciones cada vez más extremas, principalmente en las zonas de mayor altitud. Por otra parte, las mejores condiciones de calidad de sitio se localizan en la Sierra de las Cruces, sin embargo, estadísticamente las tres zonas no mostraron diferencias significativas (p> 0.05), lo que hace pensar que la calidad de sitio no sólo depende de las condiciones dasonómicas sino también de las condiciones ambientales. Ante esto, analizando la relación entre el grado de aptitud ambiental y el de calidad de sitio, se identificó que sólo un sitio cumple con un grado alto de aptitud para la recuperación del bosque y se localiza en la Sierra de las Cruces, cabe recalcar que se trata de una relación a nivel de punto de muestreo. Por otra parte, el análisis físico-químico del suelo de la alta montaña muestra que la mayor disponibilidad de nutrientes en el suelo se presenta en los primeros 30 cm de profundidad. Esta diferencia en la concentración de nutrientes puede estar influenciada por la densidad del bosque y los incendios forestales, ya que los resultados muestran que a mayor número de incendios y mayor densidad del bosque, la disponibilidad de materia orgánica, fósforo, Ca2+, N y pH se incrementa, y el resto de los nutrientes del suelo mostró un comportamiento heterogéneo. Por esto, el estudio sugiere que para la recuperación de los bosques de la alta montaña se consideren principalmente variables de calidad de sitio y que estas sean interrelacionadas con las variables ambientales para así lograr un mayor grado de éxito de la regeneración o reforestación en el Estad

Estradiol activates PI3K/Akt/GSK3 pathway under chronic neurodegenerative conditions triggered by perinatal asphyxia

Perinatal asphyxia (PA) remains as one of the most important causes of short-term mortality, psychiatric and neurological disorders in children, without an effective treatment. In previous studies we have observed that the expression of different neurodegenerative markers increases in CA1 hippocampal area of 4-months-old male rats born by cesarean section and exposed for 19 min to PA. We have also shown that a late treatment with 17β estradiol (daily dose of 250 μg/kg for 3 days) was able to revert the brain alterations observed in those animals. Based on these previous results, the main aim of the present study was to explore the mechanism by which the estrogenic treatment is involved in the reversion of the chronic neurodegenerative conditions induced by PA. We demonstrated that estradiol treatment of adult PA exposed animals induced an increase in estrogen receptor (ER) a and insulin-like growth factor receptor (IGF-1R) protein levels, an activation of the phosphatidylinositol 3-kinase/Akt/glycogen synthase kinase 3 beta/β-catenin signaling pathway and an increase in Bcl-2/Bax ratio in the hippocampus in comparison to PA exposed animals treated with vehicle. Taking together, our data suggest that the interaction between ERa and IGF-IR, with the subsequent downstream activation, underlies the beneficial effects of estradiol observed in late treatment of PA.Fil: Saraceno, Gustavo Ezequiel. Universite de Bordeaux; Francia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; ArgentinaFil: Bellini, Maria Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner"; ArgentinaFil: Garcia Segura, Luis Miguel. Consejo Superior de Investigaciones Científicas; España. Instituto de Salud Carlos III; EspañaFil: Capani, Francisco. Universidad Autónoma de Chile; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; Argentin

Provision of Ancillary Services by Wind Power Generators

The current and future power systems foresee very deep penetration of renewable power plants into the generation mix, which will make the provision of ancillary services by renewables an ultimate necessity. This would be further emphasised when green power stations replace conventional power plants that rely on fossil fuels. In this context, many control methodologies could be applied to the controllers of the green generators to enable the provision of these services, mainly frequency support and voltage regulation. Most of the available models (i.e. in power system simulators) do not include such supplementary controls to provide ancillary services. Hence, this chapter exploits key examples of these controllers that proved to be efficient and widely accepted. In addition, this chapter considers their integration into the conventional controls of green generators, where the focus is on wind energy

Encouraging Willingness to Contribute, City Fortifications and their Conservation in the Mediterranean

[EN] City fortifications are a defining feature of many cities and their communities in the Mediterranean. They clearly delineate boundaries, provide circulations paths and encourage visitation. However, they are expensive to conserve and maintain. A visitor or user fee is one available option that can simultaneously generate revenue for conservation while restricting access to vulnerable areas. Willingness to Pay is a term reflecting of the maximum amount that a visitor thinks an entry fee is worth. When combined with an Optimal Pricing Policy and Price Discrimination to segment visitors into those willing to pay more, profits can be maximized. Obtaining the optimal price and thus maximum profit is especially important for extensive, expensive and difficult to conserve cultural heritage sites such as city wall fortifications. Wall fortifications cannot usually be adapted to other selfsustainable financial (or even semi-sustainable) uses beyond visitation; thus funding options to offset costs for maintenance, conservation and management are limited. However, this is a sensitive subject given the cultural, scientific and educational values of such places. Fortifications belong to the public and should be easily available for their enjoyment, recreation and educational understanding of history. Given this contradiction it is extremely difficult to achieve a balance between seeking maximum profit while providing access. Therefore this paper explores an alternative – encouraging a Willingness to Contribute. Visitors are often willing to contribute or pay more especially if they know a percentage of their fee funds upkeep. The paper describes research into access prices and strategies (or lack thereof) to extract willing contributions at fortified cities throughout the Mediterranean including Famagusta, Rhodes, Dubrovnik, Valletta, Ávila, Jerusalem, Pamplona, Carcassonne, Elvas, Lucca and Acre.Eppich, R.; Garcia Grinda, JL. (2015). Encouraging Willingness to Contribute, City Fortifications and their Conservation in the Mediterranean. En Defensive architecture of the mediterranean: XV to XVIII centuries. Vol. I. Editorial Universitat Politècnica de València. 357-364. https://doi.org/10.4995/FORTMED2015.2015.1745OCS35736