Recuperación de energía del aire de salida de los extractores en invernaderos

CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMEN: El uso de los extractores axiales en invernaderos para el control de temperatura y renovación de volumen de aire permite la recuperación de la energía eólica residual, esto representa una fuente constante de producción de energía limpia, y reducción de los costos de producción al bajar los costos de consumo de energía. El objetivo de este trabajo fue diseñar, construir y evaluar un sistema de recuperación de energía eólica residual en los invernaderos. Este sistema consiste en una turbina eólica colocada a una distancia óptima, un cono en la descarga de aire y un mecanismo para modificar el ángulo de aspas de la turbina eólica. Se analizó el balance de energía del sistema, midiendo los principales parámetros de energía, tales como: voltaje, amperaje, velocidad del aire y velocidad angular de los rotores. Las pruebas con la turbina eólica se realizaron en el sistema extractor de aire de un invernadero, sin cono y con cono. La implementación del sistema propuesto permitió recuperar la energía eléctrica del motor. Con el cono instalado, la energía eléctrica recuperada se incrementó en comparación que con el sistema de recuperación sin cono.ABSTRACT: The use of axial extractors in greenhouses for temperature control and air volume renewal allows the recovery of residual wind energy, this represents a constant source of clean energy production, and reduction of production costs by lowering energy consumption costs. The objective of this work was to design, build and evaluate a wind energy recovery system in greenhouses. This system consists of a wind turbine placed at an optimal distance, an air discharge cone and a mechanism to modify the angle of the wind turbine blades. The energy balance of the system was analyzed, measuring the main energy parameters, such as: voltage, amperage, air speed and angular velocity of the rotors. The tests with the wind turbine were carried out in the air extraction system of a greenhouse, without cone and with cone. The implementation of the proposed system allowed the recovery of electrical energy from the engine. With the cone installed, the electrical energy recovered was increased compared to the recovery system without cone.info:eu-repo/semantics/publishedVersio

Modified f(G) gravity models with curvature-matter coupling

A modified f(G) gravity model with coupling between matter and geometry is proposed, which is described by the product of the Lagrange density of the matter and an arbitrary function of the Gauss-Bonnet term. The field equations and the equations of motion corresponding to this model show the non-conservation of the energy-momentum tensor, the presence of an extra-force acting on test particles and the non-geodesic motion. Moreover, the energy conditions and the stability criterion at de Sitter point in the modified f(G) gravity models with curvature-matter coupling are derived, which can degenerate to the well-known energy conditions in general relativity. Furthermore, in order to get some insight on the meaning of these energy conditions, we apply them to the specific models of f(G) gravity and the corresponding constraints on the models are given. In addition, the conditions and the candidate for late-time cosmic accelerated expansion in the modified f(G) gravity are studied by means of conditions of power-law expansion and the equation of state of matter less than -1/ 3 .Comment: 13 pages, 4 figure

Stimuli-responsive hydrogels synthesis using free radical and RAFT polymerization

Temperature and pH stimuli-responsive hydrogel particles were synthesized using inverse-suspension polymerization in batch stirred reactor. Different water soluble co-monomers were present in the initial mixture (e.g. N-isopropylacrylamide and acrylic acid) as well as crosslinkers with different functionalities. Different operating conditions such as polymerization temperature, monomers dilution, neutralization and the initial ratios of co-monomers and monomers/crosslinker were also tried. Hydrogel particles were produced considering classical free-radical polymerization (FRP) and also RAFT polymerization. Commercially available RAFT agents 4-cyano-4-phenylcarbonothioylthio-pentanoic acid (CPA), 2-(dodecylthiocarbonothioylthio)-2-methylpropionic acid (DDMAT) and cyanomethyl dodecyl trithiocarbonate (CDT) were alternatively used. Sampling at different polymerization times allowed the study of the kinetics of polymerization through the analysis by SEC of the soluble phase. A tetra-detector array with simultaneous detection of refractive index, light scattering, intrinsic viscosity and ultra-violet signals was used in these studies. Usefulness of in-line FTIR-ATR monitoring to study the building process of such networks was also assessed. The performance of hydrogel beads was studied through drug delivery tests triggered by changes in the environmental temperature and pH. This research aims to contribute for the elucidation of the connection between the synthesis conditions, molecular architecture and properties/performance of such advanced materials.FCT and FSE (Programa Operacional Potencial Humano/POPH) through the PhD scholarship SFRH/BD/76587/2011. FCT through researcher scholarship in the framework of the project PTDC/EQU-EQU/098150/2008 (Ministry of Science and Technology of Portugal/Program COMPETE - QCA III/ European Community/FEDER). Marie Curie Initial Training Network “Nanopoly” (Project: ITN-GA-2009-238700) program SAESCTN - PIIC&DT/1/2011, Programa Operacional Regional do Norte (ON.2), contract NORTE-07-0124-FEDER-000014 (RL2_P3 Polymer Reaction Engineering).FCT through researcher scholarship in the framework of the project PTDC/EQU-EQU/098150/2008 (Ministry of Science and Technology of Portugal/Program COMPETE - QCA III/ European Community/FEDER

The impact of deep-sea fisheries and implementation of the UNGA Resolutions 61/105 and 64/72. Report of an international scientific workshop

The scientific workshop to review fisheries management, held in Lisbon in May 2011, brought together 22 scientists and fisheries experts from around the world to consider the United Nations General Assembly (UNGA) resolutions on high seas bottom fisheries: what progress has been made and what the outstanding issues are. This report summarises the workshop conclusions, identifying examples of good practice and making recommendations in areas where it was agreed that the current management measures fall short of their target

Distinct incubation for homologous in vitro spermatozoa binding on swine oocytes subjected to different storage conditions

AbstractThe sperm in vitro binding assay in homologous oocytes can be used to estimate the boar fertility potential, but its usefulness may be limited by laboratorial structure and oocytes availability. This study aimed at determining the effect of distinct methods of oocytes conditioning and incubation media for the in vitro penetration (IVP) test. Oocytes used in the IVP test were: fresh and conditioned in PBS (T1); cooled and conditioned in PBS at 5°C for 48h (T2); or stored in ovaries frozen at −20°C (T3). For each treatment, two incubation media were tested at 39°C for 6h: modified TRIS buffer medium (mTBM); or Beltsville Thawing Solution (BTS) extender. The responses of interest were: IVP and polyspermy rates; and the number of penetrating spermatozoa per oocyte. All responses observed with incubation in BTS were inferior to those observed with incubation in mTBM (P<0.0001). When incubation was done in mTBM, none of the responses differed across treatments (P>0.05). However, when incubation was in BTS, all the three responses were superior for T1 than for T2 and T3 (P<0.05). Thus, the IVP test may be conducted with ovaries either cooled or recovered from frozen ovaries with results similar to those observed with fresh oocytes, if incubation is done in mTBM

Light-confining nanoporous anodic alumina microcavities by apodized stepwise pulse anodization

This study presents an innovative approach to fabricate nanoporous anodic alumina optical microcavities (NAA-μCVs) with enhanced quality factor and versatile optical properties. An apodization strategy using a logarithmic negative function is applied to a stepwise pulse anodization process in order to engineer the effective medium of NAA so that it confines light efficiently. The architecture of these light-trapping photonic crystals is composed of two highly reflecting mirrors with an asymmetrically apodized effective medium. Various anodization parameters such as the anodization time, anodization period, current density offset, and pore-widening time are systematically modified to assess their effect on the optical properties of NAA-μCVs in terms of the quality factor and position of the resonance band. We demonstrate that this fabrication approach enables the generation of NAA-μCVs with a high quality factor (∼113) and well-resolved and tunable resonance bands across the spectral regions, from UV to near-IR, through manipulation of the anodization parameters. These results represent a comprehensive rationale for the development of high-quality NAA-μCVs with enhanced light-confining capabilities, providing new opportunities for further fundamental and applied research across a broad range of fields and disciplines such as photonics and optical sensing.Cheryl Suwen Law, Yee Lim, Raeanne M. Macalincag, Andrew D. Abell, and Abel Santo

Metabolic oscillations on the circadian time scale in <i>Drosophila</i> cells lacking clock genes.

Circadian rhythms are cell-autonomous biological oscillations with a period of about 24 h. Current models propose that transcriptional feedback loops are the primary mechanism for the generation of circadian oscillations. Within this framework, &lt;i&gt;Drosophila&lt;/i&gt; S2 cells are regarded as "non-rhythmic" cells, as they do not express several canonical circadian components. Using an unbiased multi-omics approach, we made the surprising discovery that &lt;i&gt;Drosophila&lt;/i&gt; S2 cells do in fact display widespread daily rhythms. Transcriptomics and proteomics analyses revealed that hundreds of genes and their products, and in particular metabolic enzymes, are rhythmically expressed in a 24-h cycle. Metabolomics analyses extended these findings and demonstrate that central carbon metabolism and amino acid metabolism are core metabolic pathways driven by protein rhythms. We thus demonstrate that 24-h metabolic oscillations, coupled to gene and protein cycles, take place in nucleated cells without the contribution of any known circadian regulators. These results therefore suggest a reconsideration of existing models of the clockwork in &lt;i&gt;Drosophila&lt;/i&gt; and other eukaryotic systems