470 research outputs found
Influence of the electric energy non-regulated market in the intensive aquaculture plants associated to cooling effluents
En este trabajo se analiza el efecto que la liberalización del mercado eléctrico tiene
sobre la variación de los regímenes de temperatura del agua en plantas de acuicultura
intensiva que aprovechan los efluentes de refrigeración de centrales generadoras de electricidad.
Para ello se han utilizado datos de una instalación dedicada al engorde de anguilas
europeas, la cual toma el agua caliente del efluente de refrigeración de la Central Térmica
de Puente Nuevo (Córdoba). Los resultados indican que la liberalización del
mercado del sector eléctrico tiene una influencia significativa sobre la forma y cantidad
de energía generada por la Central Térmica, y por consiguiente sobre el régimen termal
del efluente de refrigeración. Los niveles de temperatura en el interior de la instalación
son dependientes asimismo de la temperatura del agua en el efluente de refrigeración,
estimándose la disminución de los índices de crecimiento debidos a este factor en un 5%.In this paper, the effect of the electric energy non-regulated market in the water
thermal regimes variation of intensive fishfarms that use the heated water for cooling of
power plants is analysed. This way, data of aneel intensive rearing system was used. In
this fishfarm the heated water is drawn from the cooling effluent of the Puente Nuevo
power plant (Córdoba). The results show that the non-regulated market has a significant effect on the form and amount of generated energy and the thermal regime of the cooling
effluent. The temperature levels in the fishfarm depend of the water temperature of
cooling effluent, being estimated the decrease of the growth index in 5%
Indigenous peoples, exclusion and precarious work: Design of strategies to address poverty in indigenous and peasant populations in Ecuador through the SWOT-AHP Methodology
[EN] This research analysed the options that, following decent employment and the social economy,
can allow the human development of poor, excluded and vulnerable indigenous populations
in Ecuador. A set of strategies were developed which can be implemented by public authorities
and by community organisations. They were designed from two types of expert consultations:
the Delphi method and the analysis of Strengths,Weaknesses, Opportunities and Threats (SWOT)
combined with Analytic Hierarchy Process method (AHP) for hierarchizing the criteria collected and
obtaining strategies. The proposed strategies are as follows: adopting appropriate legal frameworks,
respecting peoples’ rights, better distribution of public resources, implementing monitoring systems,
developing solidarity markets and recognizing the participation of the poor as a subject of rights.
This investigation revealed differences between the state, which identifies the poor with monetary
indicators, and the indigenous peoples, who see it as the lack of community links, by conceiving
the poor as a beneficiary of official assistance, despite the fact that a strong community and peasant
organisation could be used. The value of an economy based on reciprocity and confidence was also
recognized, identifying niches of production and consumption to create partnerships and ensure the
participation of indigenous peoples in decision-making areas.S
Wide-bandgap InAs/InGaP quantum-dot intermediate band solar cells
Current prototypes of quantum-dot intermediate band solar cells suffer from voltage reduction due to the existence
of carrier thermal escape. An enlarged sub-bandgap EL would
not only minimize this problem, but would also lead to a bandgap distribution that exploits more efficiently the solar spectrum. In this work we demonstrate InAs/InGaP QD-IBSC prototypes with the following bandgap distribution: EG = 1.88 eV, EH = 1.26 eV and EL > 0.4 eV. We have measured, for the first time in this material, both the interband and intraband transitions by means of photocurrent experiments. The activation energy of the carrier thermal escape in our devices has also been measured. It is found that its value, compared to InAs/GaAs-based prototypes, does not follow the increase in EL. The benefits of using thin AlGaAs barriers before and after the quantum-dot layers are analyzed
A detailed analysis of the Gl 486 planetary system
Context. The Gl 486 system consists of a very nearby, relatively bright, weakly active M3.5 V star at just 8 pc with a warm transiting rocky planet of about 1.3 R-circle plus and 3.0 M-circle plus. It is ideal for both transmission and emission spectroscopy and for testing interior models of telluric planets. Aims. To prepare for future studies, we aim to thoroughly characterise the planetary system with new accurate and precise data collected with state-of-the-art photometers from space and spectrometers and interferometers from the ground. Methods. We collected light curves of seven new transits observed with the CHEOPS space mission and new radial velocities obtained with MAROON-X at the 8.1 m Gemini North telescope and CARMENES at the 3.5 m Calar Alto telescope, together with previously published spectroscopic and photometric data from the two spectrographs and TESS. We also performed near-infrared interferometric observations with the CHARA Array and new photometric monitoring with a suite of smaller telescopes (AstroLAB, LCOGT, OSN, TJO). This extraordinary and rich data set was the input for our comprehensive analysis. Results. From interferometry, we measure a limb-darkened disc angular size of the star Gl 486 at theta(LDD) = 0.390 +/- 0.018 mas. Together with a corrected Gaia EDR3 parallax, we obtain a stellar radius R-* = 0.339 +/- 0.015 R-circle plus. We also measure a stellar rotation period at P-rot = 49.9 +/- 5.5 days, an upper limit to its XUV (5-920 A) flux informed by new Hubble/STIS data, and, for the first time, a variety of element abundances (Fe, Mg, Si, V, Sr, Zr, Rb) and C/O ratio. Moreover, we imposed restrictive constraints on the presence of additional components, either stellar or sub-stellar, in the system. With the input stellar parameters and the radial-velocity and transit data, we determine the radius and mass of the planet Gl 486 b at R-p = 1.343(-0.062)(+0.063) R-circle plus and M-p = 3.00(-0.12)(+0.13) M-circle plus, with relative uncertainties of the planet radius and mass of 4.7% and 4.2%, respectively. From the planet parameters and the stellar element abundances, we infer the most probable models of planet internal structure and composition, which are consistent with a relatively small metallic core with respect to the Earth, a deep silicate mantle, and a thin volatile upper layer. With all these ingredients, we outline prospects for Gl 486 b atmospheric studies, especially with forthcoming James Webb Space Telescope (Webb) observations.The David & Lucile Packard FoundationHeising-Simons FoundationGemini ObservatoryUniversity of ChicagoMax Planck SocietyConsejo Superior de Investigaciones Cientificas (CSIC)Spanish GovernmentEuropean Commission FICTS-2011-02
ICTS-2017-07-CAHA-4
CAHA16-CE-3978German Research Foundation (DFG) FOR2544National Science Foundation (NSF) AST-1636624
AST-2034336
2108465
DGE 1746045European Research Council (ERC) 639889National Aeronautics & Space Administration (NASA) XRP NNX16AD43GNational Science Foundation (NSF) AST 1909165Wise Observatory, Tel-Aviv University, Israel TAU2021A-015Agencia Estatal de Investigacion of the Ministerio de Ciencia, Innovacion y Universidades and the ERDF PID2019-109522GB-C5[1:4]
PID2019-107061GBC64
PID2019-110689RB-100
PGC2018-095317-B-C21
PGC2018-102108-BI00Centre of Excellence "Severo Ochoa" CEX2019-000920-SCentre of Excellence "Maria de Maeztu" CEX2019-000920-SInstituto de Astrofisica de Andalucia SEV-2017-0709Centro de Astrobiologia MDM2017-0737German Research Foundation (DFG)European Commission FOR2544 (KU 3625/2-1)Germany's Excellence Strategy to the Excellence Cluster ORIGINS EXC-2094 -390783311European Research Council (ERC)European Commission 639889Bulgarian National Science Fund through VIHREN-2021 KP-06-DB/5Schweizerischer Nationalfonds zur Forderung der wissenschaftlichen Forschung/Fonds national suisse de la recherche scientifique PZ00P2_174028United Kingdom Science Technology and Facilities Council 630008203Princeton UniversityUniversidad La Laguna through the Margarita Salas Fellowship from the Spanish Ministerio de UniversidadesEU Next Generation funds UNI/551/2021Generalitat de Catalunya (CERCA programme
IoT Smart Parking System Based on the Visual-Aided Smart Vehicle Presence Sensor: SPIN-V
Humanity is currently experiencing one of the short periods of transition thanks to novel sensing solutions for smart cities that bring the future to today. Overpopulation of cities demands the development of solid strategic plannings that uses infrastructure, innovation, and technology to adapt to rapid changes. To improve mobility in cities with a larger and larger vehicle fleet, a novel sensing solution that is the cornerstone of a smart parking system, the smart vehicular presence sensor (SPIN-V, in its Spanish abbreviation), is presented. The SPIN-V is composed of a small single-board computer, distance sensor, camera, LED indicator, buzzer, and battery and devoted to obtain the status of a parking space. This smart mobility project involves three main elements, namely the SPIN-V, a mobile application, and a monitoring center, working together to monitor, control, process, and display the parking space information in real-time to the drivers. In addition, the design and implementation of the three elements of the complete architecture are presented.ITESO, A.C
Synthesis and Antiproliferative Activity of Sulfa-Michael Adducts and Thiochromenes Derived from Carbohydrates
The Michael addition reactions of carbohydrate-derived nitroalkenes with ethyl thioglycolate and 2-mercaptobenzyl alcohol were studied. Reactions were conducted under mild, solvent-free conditions with DABCO as a catalyst, affording the corresponding adducts in good yields. Furthermore, compounds resulting from the addition with 2-mercaptobenzyl alcohol were used as starting materials for the synthesis of chiral 3-nitro-2H-thiochromenes. For some of the compounds synthesized herein, the antioxidant and antiproliferative activities against a panel of human solid tumor cell lines were assayed and compared with those of carbohydrate-nitroalkene substrates.Junta de Extremadura GR15022Unión Europea FP7-REGPOT-2012-CT2012-31637-IMBRAI
Room temperature photo-response of titanium supersaturated silicon at energies over the bandgap
Silicon samples were implanted with high Ti doses and subsequently processed with the pulsed-laser melting technique. The electronic transport properties in the 15–300 K range and the room temperature spectral photoresponse at energies over the bandgap were measured. Samples with Ti concentration below the insulator-metal (I-M) transition limit showed a progressive reduction of the carrier lifetime in the implanted layer as Ti dose is increased. However, when the Ti concentration exceeded this limit, an extraordinary recovery of the photoresponse was measured. This result supports the theory of intermediate band materials and is of utmost relevance for photovoltaic cells and Si-based detectors
Demonstration of the operation principles of intermediate band solar cells at room temperature
In this work we report, for the first time at room temperature, experimental results that prove, simultaneously in the same device, the two main physical principles involved in the operation of intermediate band solar cells: (1) the production of sub-bandgap photocurrent by two optical transitions through the intermediate band; (2) the generation of an output voltage which is not limited by the photon energy absorption threshold. These principles, which had always required cryogenic temperatures to be evidenced all together, are now demonstrated at room temperature on an intermediate band solar cell based on InAs quantum dots with Al0.3Ga0.7As barriers
XMM-Newton detection of the supernova remnant G304.6+0.1 (Kes 17)
Aims. We report the first detailed X-ray study of the supernova remnant (SNR)
G304.6+0.1, achieved with the XMM-Newton mission. Methods. The powerful imaging
capability of XMM-Newton was used to study the X-ray characteristics of the
remnant at different energy ranges. The X-ray morphology and spectral
properties were analyzed. In addittion, radio and mid-infrared data obtained
with the Molonglo Observatory Synthesis Telescope and the Spitzer Space
Telescope were used to study the association with the detected X-ray emission
and to understand the structure of the SNR at differents wavelengths. Results.
The SNR shows an extended and arc-like internal structure in the X-ray band
with out a compact point-like source inside the remnant. We find a high column
density of NH in the range 2.5-3.5x1022 cm-2, which supports a relatively
distant location (d 9.7 kpc). The X-ray spectrum exhibits at least three
emission lines, indicating that the X-ray emission has a thin thermal plasma
origin, although a non-thermal contribution cannot be discarded. The spectra of
three different regions (north, center and south) are well represented by a
combination of a non-equilibrium ionization (PSHOCK) and a power-law (PL)
model. The mid-infrared observations show a bright filamentary structure along
the north-south direction coincident with the NW radio shell. This suggests
that Kes 17 is propagating in a non-uniform environment with high density and
that the shock front is interacting with several adjacent massive molecular
clouds. The good correspondence of radio and mid-infrared emissions suggests
that the filamentary features are caused by shock compression. The X-ray
characteristics and well-known radio parameters indicate that G304.6+0.1 is a
middle-aged SNR (2.8-6.4)x104 yr old and a new member of the recently proposed
group of mixed-morphology SNRs.Comment: 5 pages, 2 figures; Accepted for publication in Astronomy &
Astrophysic
Sub-bandgap external quantum efficiency in Ti implanted Si heterojunction with intrinsic thin layer cells
In this work we present the manufacturing processes and results obtained from the characterization of heterojunction with intrinsic thin layer solar cells that include a heavily Ti ion implanted Si absorbing layer. The cells exhibit external circuit photocurrent at photon energies well below the Si bandgap. We discuss the origin of this below-bandgap photocurrent and the modifications in the hydrogenated amorphous intrinsic Si layer thickness to increase the open-circuit voltage. © 2013 The Japan Society of Applied Physics.This work has been supported by the Regional Government of Comunidad de Madrid within the project NUMANCIA II (S-2009/ENE-1477). J. Olea and D. Pastor would like to acknowledge a Juan de la Cierva fellowship from the Spanish Science Ministry (JCI-2011-10402, JCI-2011-11471). E. Antolín acknowledges a Marie Curie Fellowship from the European Commission (Project Siracusa, Grant PIEF-GA-2011-302489.S-2009/ENE-1477/NUMANCIA-IIPeer Reviewe
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