Hot carrier and hot phonon coupling during ultrafast relaxation of photoexcited electrons in graphene

We study, by means of a Monte Carlo simulator, the hot phonon effect on the relaxation dynamics in photoexcited graphene and its quantitative impact as compared to considering an equilibrium phonon distribution. Our multi-particle approach indicates that neglecting the hot phonon effect significantly underestimates the relaxation times in photoexcited graphene. The hot phonon effect is more important for a higher energy of the excitation pulse and photocarrier densities between $1$ and $3\times 10^{12} \mathrm{~cm}^{-2}$. Acoustic intervalley phonons play a non-negligible role, and emitted phonons with wavelengths limited up by a maximum (determined by the carrier concentration) induce a slower carrier cooling rate. Intrinsic phonon heating is damped in graphene on a substrate due to additional cooling pathways, with the hot phonon effect showing a strong inverse dependence with the carrier density.Comment: 12 pages, 5 figure

Research activities on turbot industrial procedures in Spain

This technical report deals with the evolution during the last decade of the research activities of the governmental institutions working on the development of turbot (Scophthalmus maximus L.) culture. The Instituto Español de Oceanografía (Santander and Vigo), the CSIC (Vigo and Castellón), the Xunta de Galicia (Villajuán and Couso) and The University of Santiago are the institutions analyzed. A general review of the different projects on turbot farming is given, including those with grants from the institutions and from the CICYT (Comite Interministerial de Ciencia y Tecnología), C.D.T.I (Centro de Desarrollo Tecnologico e Industrial) and the EC (European Community). Finally, an analysis is given of the present situation and bottlenecks to development are highlighted. leading to priorities for future research.Versión del edito

Culture viability of Sardine pilchardus (Fish, teleost): Preliminary results of growth in captivity up to 18 months

Larvae of Sardina pilchardus were obtained in captivity from fertilized eggs captured in the wild and grown in a 10000-L tank. Isochrysis galbana, Artemia franciscana nauplii and live zooplankton were used as prey during the first two weeks; afterwards, the animals were fed on Artemia metanauplii enriched with Isochrysis galbana. A dry feed (Gemma 0.4 and 0.8) from Skretting S.A. (Burgos, España) was supplied from the 3rd to the 18th month. The total length reached by sardines at one year of life was 162.02±9.49 mm, corresponding to a wet weight of 36.12±10.82 g. Total length of the last survivor individual at 18 months was 182.37 mm. An 18-month experiment of sardine culture is described for the first time, and the growth data reported can help to determine its potential as a candidate for marine aquaculture.Publicado

Release experiments with Octopus vulgaris Cuvier, 1797 in Galicia, NW Spain. First results on recapture rate, distribution and growth.

This paper describes the release experiments carried out with 465 octopus (Octopus vulgaris Cuvier, 1797) with an average weight ranging from 703 to 986 g in three different areas in the Ría of Vigo, Galicia, NW Spain. Thirty-seven individuals were recaptured by fishermen, representing a total recapture rate of 7.9 %. Among these, 80.5 % remained within 5 km of the release point, showing a sedentary behavior. The specific growth rate (SGR) in weight was 0.00902 ± 0.00468; there was not a significant difference between males and females. The exponential growth curve is the best fitting theoretical model. Life expectancy in Ría de Vigo waters was estimated at 18 months for males, and 16 months for females. Throughout the recapture process, males were predominant over females, giving a sex ratio of 1.83:1. Data reported in this paper on recapture rate, sedentary behavior and instantaneous growth rate can be used as reference for future stocking programs in Galicia

Culture viability of Sarddina pilchardus: preliminary results of growth in captivity

Larvae of Sardina pilchardus were obtained in captivity from fertilized eggs captured in the wild, and grown in a 10 000 L tank. Isochrysis galbana , Artemia franciscana nauplii and live zooplankton were used as prey during the first two weeks; afterwards, anim als were fed on artemia metanauplius enriched with Isochrysis galbana . A dry feed (Gemma 0.4 and 0.8) from SKRETTING S.A. (Burgos, España) was supplied from the third to 18th month. The total length reached by sardines at one year of life was 162.02 ± 9. 49 mm, corresponding to a wet weight of 36.12 ± 10.82 g. Total length at 18 months was 182.37 mm. A long experiment (18 ‐ month) of sardine culture is described for the first time, and growth data reported can contribute to determine its potential interest as a candidate for marine aquacultur

Innovative concepts of Integrated Solar Combined Cycles (ISCC) using a Solid Oxide Fuel Cell (SOFC)

Concentrating Solar Power (CSP) is one of the most promising ways for electricity production of the upcoming years with high penetration of intermittent renewable energy sources such as wind and solar-photovoltaics. This is due to the fact that CSP when coupled to Thermal Energy Storage (TES) system enables large, inexpensive and flexible energy dispatch, which contributes to energy grid stabilization. At the same time, TES allows for steady operation of the power block by reducing undesirable fluctuations due to weather transient conditions and increasing the number of hours that the power block operates at design conditions 1. Despite the abovementioned advantages of CSP systems, a step further is needed for increase overall system efficiency and decrease CO2 emissions. Several studies have been performed considering high efficiency plant layouts such as combined cycle. For the latter, several works have been investigated about solar integration of combined cycle using parabolic trough and solar tower technologies. In both cases, solar energy was used for water/steam preheating and evaporation steps of the Rankine cycle in combination with the exhaust gases of fossil-fuel gas turbine engine. However, no research has been performed considering ISCC coupled with a Solid Oxide Fuel Cell (SOFC). In this research, two innovative layouts of ISCC power plants will be analyzed. First considers a ISCC based on solar tower and second a ISCC with a parabolic trough collector field coupled to the Heat Recovery Steam Generator (HRSG). The objective of this research is analyze the energy behavior of both layouts, selecting the best ISCC scheme to be coupled with a SOFC. The simulations will be performed using Thermoflex software. In both layouts, a SOFC is introduced before the combustion chamber at the topping cycle, and a Rankine cycle (bottoming cycle) with 2 pressures is considered.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Experiences in teaching Hydrogen Technologies in the framework of the International Campus of Excellence Andalucia TECH

The increasing importance of hydrogen technologies is demanding prepared professionals in the numerous topics related to this energy vector. Apart from some basic and advanced courses given by actual experts in these topics, universities must play an important role in the general formation of future professionals. In this way, the International Campus of Excellence (ICE) Andalucía TECH has created several degrees taught jointly by its participating universities of Seville (US) and Málaga (UMA). Among those degrees, Energy Engineering is the best suited to the field of this conference because this degree provide future engineers with specialized training in energy generation, transformation and management. In relation to hydrogen technologies this degree includes a cross sectional optional unit named Hydrogen Based Systems (4.5 ECTS/112.5 h), which is placed in the last term of the fourth year and sharing space with work placement and mobility courses. This paper will present some author’s experiences as teachers of that unit during its short history of only three years. In spite of being a joint degree, which is coordinated between both universities (US and UMA) trying to give similar contents, it is interesting to highlight the differential experiences coming from the teachers of both universities in relation to the teaching methodologies and academic results.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Effect of light and temperature on the development of turbot eggs

Different experiments were done to determine the effeets of light and temperature on the embryonie development of turbot eggs (Seophthalmus maximus L.) obtained in eaptivity. No signifieant differen~es have from fertilization to hC'tehing in the been found between time elapsed trials earried out wi th 24 hours of light and those done in dark eonditions,therefore light is not a determining faetor in the embryonie development of turbot eggs. The relation between temperature and time needed to reaeh eaeh embryonie stage, shows a elear inverse relationship. The exponential-potential equation whieh relates temperature and the age of the eggs, defined as the time in hours elapsed sinee fertilization, is: Y = 27.64 . e -0.11 T + 0.05 i . 1.21 1 r = 0.9904 paper also provides for eaeh experimental From the applieation of this equation, this th~ development eurves for eaeh embryonie stage temperature (in the range 10 QC to 20 QC)