Combination of synergic enzymes and ultrasounds as an effective Pretreatment Process to Break Microalgal Cell Wall and Enhance Algal Oil Extraction

Microalgal biomass is a sustainable source of bioactive lipids with omega-3 fatty acids. The efficient extraction of neutral and polar lipids from microalgae requires alternative extraction methods, frequently combined with biomass pretreatment. In this work, a combined ultrasound and enzymatic process using commercial enzymes Viscozyme, Celluclast, and Alcalase was optimized as a pretreatment method for Nannochloropsis gaditana, where the Folch method was used for lipid extraction. Significant differences were observed among the used enzymatic pretreatments, combined with ultrasound bath or probe-type sonication. To further optimize this method, ranges of temperatures (35, 45, and 55 °C) and pH (4, 5, and 8) were tested, and enzymes were combined at the best conditions. Subsequently, simultaneous use of three hydrolytic enzymes rendered oil yields of nearly 29%, showing a synergic effect. To compare enzymatic pretreatments, neutral and polar lipids distribution of Nannochloropsis was determined by HPLC–ELSD. The highest polar lipids content was achieved employing ultrasound-assisted enzymatic pretreatment (55 °C and 6 h), whereas the highest glycolipid (44.54%) and PE (2.91%) contents were achieved using Viscozyme versus other enzymes. The method was applied to other microalgae showing the potential of the optimized process as a practical alternative to produce valuable lipids for nutraceutical applications

Spontaneous light emission in complex nanostructures

The spontaneous emission of an excited atom surrounded by different materials is studied in the framework of a semiclassical approach, where the transition dipole moment acts as the source of the emission field. The emission in the presence of semiinfinite media, metallic nanorings, spheres, gratings, and other complex geometries is investigated. Strong emission enhancement effects are obtained in some of these geometries associated to the excitation of plasmons (e.g., in nanorings or spheres). Furthermore, the emission is shown to take place only along narrow angular distributions when the atom is located inside a low-index dielectric and near its planar surface, or when metallic nanogratings are employed at certain resonant wave lengths. In particular, axially symmetric gratings made of real silver metal are considered, and both emission rate enhancement and focused far-field emission are achieved simultaneously when the grating is decorated with further nanostructures.This work has been supported in part by the Basque Departamento de Educacion, Universidades e Investigacion, the University of the Basque Country UPV/EHU (Contract No. 00206.215-13639/2001) and the Spanish Ministerio de Ciencia y Tecnologia (Contract No. MAT2001-0946).Peer reviewe

Electrical generator's manufacturing through recycled materials for self-consumption

The reduction of the useful life of some technologies for various reasons currently generates a large amount of electronic waste whose main destination is landfills located in underdeveloped countries. On the other hand, the lack of availability of electrical energy can encourage the use of other less efficient means of generation with a greater environmental impact. To overcome these problems, it is proposed to recover certain wastes in the manufacture of small wind turbines for use in the construction of these countries. This article provides a practical example of the design of the electric machine and its performance in building with the positive social, economic and environmental impact of the regions involved

A Combined Use of GPR Data With Historical Archives for Identifying Pavement Construction Periods of Valencian Silos (16th Century, Spain)

© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper describes the combined use of ground penetrating radar (GPR) data with historical archives performed in the silo-yard of Valencia (Spain) to identify and map various pavement construction periods. The Valencian silos were constructed to house the underground grain storage of Valencia City. This architectural complex is composed of three buildings and a big square (silo-yard), under which 41 silos are placed. The construction of the silo-yard pavement extended for two centuries (16 18th century) following different construction systems. Historical archives confirmed seven pavement construction periods. However, archive data provided scant information on pavement layers and the construction periods. A GPR survey was carried out for pinpointing the seven pavement construction periods. A GSSI SIR-3000 equipment with a 400-MHz frequency antenna was used for collecting 1 × 1 m grid −141 profiles across the square (5110 m2), reaching 1.5-m depth. In addition, a GPS survey was performed specifically for surface mapping the silo-yard in detail. The combined use of the GPR data (2-D reflection profiles, spectra, and amplitude slice maps) with the historical archives allowed identifying and delineating the different pavement construction periods on the silo-yard map in terms of materials and thicknesses. These results demonstrate GPR is a noninvasive and nondestructive technique for mapping soils and near surface horizons. Additionally, the combined use of the GPR data with the historical documentation makes this technique even more efficient for the comprehension of shallow ground layers, especially in cultural heritage studies.This work was supported by the Valencian Government under Grant ACIF/2011/032. This paper was presented in part at the 15th Annual International Conference on Ground Penetration Radar GPR 2014, Square Brussels Meeting Centre, Brussels, Belgium, June 30-July 4, 2014.Valls Ayuso, A.; García García, F.; Ramírez Blanco, MJ.; Benlloch Marco, J. (2015). A Combined Use of GPR Data With Historical Archives for Identifying Pavement Construction Periods of Valencian Silos (16th Century, Spain). IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. 9:1-10. https://doi.org/10.1109/JSTARS.2015.2466192S110

Understanding subterranean grain storage heritage in the Mediterranean region: The Valencian silos (Spain)

Underground space has widely been used through history, provided either by natural or by dug cavities that were used as storage for farming production. In particular, cereals has constantly been present in the Mediterranean cultures. Their preservation was crucial in the Mediterranean grain trade for local and urban growth. The main goal of this multidisciplinary study is to analyse the typological and architectural characteristics of underground Mediterranean granary structures. It also discusses the excavation process for building a silo, focusing in a study of the Valencian silos at the Spanish Mediterraean shore. The Valencian silo-yard was essential for the socio-economic city development in the 16th century. this is the first research performed on this subterranean ensemble, by searching through historical documents and using a non-destructive technique (NDT) as Ground Penetrating Radar (SIR-3000, GSI) with 100 MHZ and 400 MHZ antennae. The composition soil was obtained for hydrogeological characteristics by goetechnical tests. Besides, laser scanner and GPS surveys were carried out for mapping the silo-yard in detail. Since the Valencian silos are a relevant example of subterranean engineering storage, we were able to carry out a comparative study of significant Mediterranean silos (from Algeria, Italy, Jordan, Malta and Turkey) by reviewing documentation. As a result, these underground spaces share numerous features, as type of terrain, excavation process, geographic location, morphology, dimensions, sealing system, usage, etc. These similar features illustrate that a subterranean grain storage stereotype is present in the Mediterranean región heritage.The authors would like to thank Valencia and Burjassot city councils for letting us carry out this research of the Valencian silos, as well as to the Historical Archive of Valencia for the attention and helpful suggestions. We would like to show our gratitude to the people who have collaborated with diverse information, as the author Mr. Miret and the manager of Events & Customer Care in Malta Tourism Authority, Mr. Morana. Also we would like to express our appreciation to the Valencian Government, which through a pre-doctoral grant has funded this research (ACIF/2011/032).Valls Ayuso, A.; García García, F.; Ramírez Blanco, MJ.; Benlloch Marco, J. (2015). Understanding subterranean grain storage heritage in the Mediterranean region: The Valencian silos (Spain). Tunnelling and Underground Space Technology. 50:178-188. https://doi.org/10.1016/j.tust.2015.07.003S1781885

Early Stages of the Fablab Movement: A New Path for an Open Innovation Model

FabLabs, also known as digital fabrication laboratories, are a groundbreaking phenomenon that is contributing to the democratization of innovation and technology. Despite their potential influence, this emerging area has received little attention in the literature. This paper examines the initial stages of the FabLab movement using a mixed-sequential exploratory methodology. Qualitative methodologies were employed to identify relevant dimensions and establish research hypotheses, while quantitative methodologies were used to evaluate and validate these hypotheses and generate a predictive model for the innovation process through binary logistic regression. The information obtained through the participation of 124 laboratories in the online FabLab Global Survey was used. The results indicate that collaborations with large companies and a majority focus on research in FabLab projects promote the development of innovative projects compared to those laboratories affiliated with educational institutions or primarily used by students

Escuela y fracaso: cambiar el color del cristal con que se mira

En el presente artículo pretendemos, por un lado, poner de manifiesto algunas cuestiones sobre la complejidad del fenómeno del fracaso escolar –justificando la pertinencia y relevancia de la tarea en el hecho de que basta con revisar los datos de la Unión Europea para encontrar un importante porcentaje de jóvenes que no alcanzan la formación básica– y, por otro, estudiar sus repercusiones tanto personales como sociales, además de señalar algunas vías que ayuden a solucionar esta cuestión. Consideramos fundamental abordar esta problemática partiendo de un análisis realista y contextualizado con el objetivo de proponer no solo acciones preventivas sino también paliativas. Para ello es necesario que todos los agentes sociales asuman su parte de responsabilidad, necesidad de reflexión y cambio y no, como suele suceder, responsabilizar únicamente a uno de los actores involucrados. En los centros escolares es necesaria la innovación en los procedimientos, rescatando actividades que despierten el interés del alumnado. Es necesario que la familia, además de implicarse más profundamente en el proceso educativo de sus hijos, realice un esfuerzo para establecer y mantener normas y límites precisos que permitan a sus hijos asumir responsabilidades y conocer las consecuencias de su no asunción. Por último, los jóvenes no ven los problemas, principalmente laborales, que les acarrea esta situación pues pese a encontrar trabajos, la naturaleza de los mismos no les va a permitir seguir un itinerario cualificador. Existen estrategias que están dando buenos resultados pero es imprescindible que, si se opta por acciones extraordinarias al sistema educativo, estas se lleven a cabo bajo los principios de la educación permanente

Aplicación de tecnología NIR portátil a la estimación el parcela de la concentración de azúcares en uva

During the 2008 growing season field tests have been carried out on three varieties of wine grape. Over 2500 samples of wine grape berries were scanned with a portable and commercial near infrared (NIR) spectrometer and subsequently processed to determine °Brix using a digital refractometer. The main objectives of this research are to evalúate the potential of a portable NIR equipment to measure the changes in soluble solid contents of grapes during the pre-harvest period, and to establish calibration model for soluble solid contení (°Brix) in grapes, in order to provide a non destructive tool for determining optimal harvest date. A first calibration model has been constructed based on data of three varieties with a R2 of 0.81

Las matemáticas empresariales en el marco de cualificaciones del Espacio Europeo de Educación Superior (QF-EHEA)

Haremos comparaciones entre las metodologías docentes de las asignaturas de Matemáticas Empresariales impartidas en las principales universidades europeas, proponiendo medidas para la mejora de la calidad de estas asignaturas en nuestra universidad

Stability comparison of dimensionality reduction techniques attending to data and parameter variations

The analysis of the big volumes of data requires efficient and robust dimension reduction techniques to represent data into lower-dimensional spaces, which ease human understanding. This paper presents a study of the stability, robustness and performance of some of these dimension reduction algorithms with respect to algorithm and data parameters, which usually have a major influence in the resulting embeddings. This analysis includes the performance of a large panel of techniques on both artificial and real datasets, focusing on the geometrical variations experimented when changing different parameters. The results are presented by identifying the visual weaknesses of each technique, providing some suitable data-processing tasks to enhance the stabilit