Parabolic trough collectors. Fundamentals of heat transfer applied to solar thermal energy.

Solar thermal energy has undergone major development in recent years. The most widely used technologies are central receiver solar towers and parabolic trough collectors (PTC)[1]. The latter technology has great advantages due to its higher optical and thermal efficiency, but, despite being a well-proven technique, it presents certain problems inherent to the manufacturing and durability of some critical elements in the system. They are generally composed of an absorber tube surrounded by a glass cover and in the intermediate space, a vacuum is created to minimize thermal losses by convection[2]. The absorber tube is located at the focal line of a parabolic mirror that concentrates sun’s rays. To predict the thermal behavior of this type of system, ray-tracing techniques are used to determine the thermal load and accurate correlations are also needed to calculate the convective heat transfer. Also, the original design shows some problems such as the selective coating applied on the absorber surface, whose thermal performance decays with time. Besides, the metal-glass welding are also a significant weak spot, which due to the thermal expansion can cause the partial or total loss of the vacuum in the aforementioned annulus. In this work we present the results of the modeling of this type of systems in different working configurations, as well as a new design proposal to improve the thermal transfer in this type of systems.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Influence of the Slaughter Method on the Hygienic Quality of Beef Cattle Meat and Animal Welfare Biomarkers

The main objective of this research was to carry out a comparative study between different types of slaughter in beef cattle with and without stunning. In addition, the hygienic quality of the obtained meat was determined through microbiological analysis and the animal welfare at the time of slaughtering was assessed by means of physiological parameters. A total of 52 blood samples collected at the slaughterhouse during slaughter (10 for each type of slaughter: regular, halal, and halal with stunning; 10 at the time of resting; and 12 from rotating box slaughter) were analysed for physiological parameters indicating animal welfare status, namely, glucose, cortisol, lactate dehydrogenase (LDH) and creatine kinase (CK). In addition, the meat from 30 of the above animals was analysed for aerobic mesophilic bacteria, enterobacteria and coliforms. Moreover, a radiological study of the possible skull damage due to the non-penetrative captive bolt used at the time of stunning in the halal rite slaughter was carried out. A significance difference (p < 0.05) in the microbiological counts per type of slaughter was observed. It was proven that the amounts of glucose, LDH, CK, and cortisol in plasma were influenced (p < 0.05) by the type of slaughter. The halal rite slaughter using stunning with a non-penetrative captive bolt resulted in the best hygienic quality of meat and obtained the lowest values for all animal welfare biomarkers

Effect of the support composition on the vapor-phase hydrogenation of crotonaldehyde over Pt/CexZr1-xO2 catalysts

Vapor-phase hydrogenation of toluene and selective hydrogenation of crotonaldehyde (2-butenal) have been performed at 333 K over Cl-free Pt/ZrO2 and Pt/CexZr1−xO2 catalysts (0.2⩽x⩽0.8) after reduction under H2 at low (473 K) and high (773 K) temperatures. The catalysts were characterized by X-ray diffraction, Raman spectroscopy, temperature-programmed reduction, and X-ray photoelectron spectroscopy after each reduction treatment. An important effect of the support composition on the catalytic activity was observed for both reactions. The catalytic behavior of Pt in the two test reactions studied was strongly dependent on the support composition and on the reduction temperature. For toluene hydrogenation, after reduction at 473 K, catalytic activity was higher for catalysts with no or low ceria content. Furthermore, whereas the increase in the reduction temperature hardly modified the activity of Pt/ZrO2, it strongly deactivated the catalysts with high cerium content in the support. For crotonaldehyde hydrogenation, on the other hand, increased reduction temperature produced a general increase in activity (except for the catalyst with the highest cerium content), along with an increase in selectivity toward the hydrogenation of the carbonyl bond to yield crotyl alcohol. The results are explained on the basis of the effect of partial reduction of Ce(IV) in the support

Zn-modified MCM-41 as support for Pt catalysts

The effect of Zn location and reduction temperature have been studied on pure and Zn-modified MCM-41 supported Pt catalysts. Experimental results show that incorporation of Zn into the siliceous framework of the MCM-41 material introduces structural oxidized Zn centres with a high stability towards a reduction treatment even at high temperatures. XP spectra confirm the high stability of these Zn species although, at the highest reduction temperature (723 K), a high mobility of the doping cations from structural positions to the inner wall of the mesopores is observed. Catalytic studies in the chemoselective hydrogenation of crotonaldehyde show that the presence of Zn produces an important decrease in the catalytic activity of the Pt nanoparticles, in accordance with Pt dispersion measurements. However, the presence of Zn improves the selectivity towards the formation of crotyl alcohol. Compared with a conventional impregnated PtZn/MCM-41 catalyst, structural Zn centres in the doped Pt/ZnMCM-41 catalysts exhibit a higher polarizing/activation of the carbonyl double bond giving rise to a higher yield to crotyl alcohol, the product of interest. Additionally, these Zn-modified MCM-41-based Pt catalysts show an excellent behaviour in an important industrial reaction such as the dehydrogenation of iso-butane to iso-butene, with a selectivity of 100%, which remains stable with time on stream.Es la versión preprint del artículo. Se puede consultar la versión final en https://doi.org/10.1016/j.apcata.2008.08.02

Control of trace metal distribution and variability in an interdunal wetland

Trace elements are serious pollutants in the natural environment and are of increasing concern due to the adverse effects at global scale. To refine the current understanding of trace metal distribution and variability in natural environments, concentrations of dissolved trace metals (Ag, Al, As, B, Ba, Be, Co, Cr, Cd, Cu, Fe, Hg, Mo, Ni, Pb, Sb, Se, Th,Tl, U, V, Mn, Zn), major ions, inorganic nutrients (NO3, PO4), TOC and stable isotopes of water were determined in water samples from rainwater, seven piezometers and a pond in the coastal Doñana wetland during four sampling campaigns between 2017 and 2019. Results show clear evaporation signatures of stable isotopes in the pond but not in the groundwater. Hydrochemical analyses yield significant, systematic changes in groundwater trace metal and nutrient composition along the flowpath from the dune belt to the pond, controlled by organic matter in the sediments. Whereas major ions reached maximum concentrations in the pond due to evapoconcentration, most trace metals showed highest concentrations at sites with lower redox levels, except for B, As and U, which showed very high concentrations in the pond. Cu, Zn, Ni, Sb and Tl yielded higher median concentrations in rainwater than in most of the groundwater points and in case of Cu and Zn higher even than in surface water which points to an atmospheric input source of these elements. Temporal variability of trace metals was related to lower hydraulic heads after an elongated dry period which led to lower redox levels and higher concentrations of most of the trace elements whereas major ions showed more constant concentration levels. This is of special concern regarding climate change and the predicted higher frequency of prolonged dry periods, which could modify the natural hydrochemical patterns in undisturbed wetlands systemsThis work has been financed by the CLIGRO Project (MICINN, CGL2016-77473-C3-1-R) of the Spanish National Plan for Scientific and Technical Research and Innovation. The infrastructure has been cofinanced by European Research Funds (SE Scientific Infrastructures and Techniques and Equipment 388 2013, IGME13-1E-2113). We are especially grateful for the technical support of Lidia Molano Leno and Daniel Jesus Martinez Suárez. The contracts of Lidia Molano Leno (PEJ-2014-A-68763) and Daniel Jesus Martinez Suárez (PTA2014-09579-I) were financed by the Ministry of Economy, Industry and Competitiveness of Spain (MINECO) and co-financed by the European Investment Bank (EIB) and the European Social Fund (ESF). The contract of Carmen Serrano Hidalgo was funded by the Industrial PhD grant supported by the Autonomous Region of Madrid, Spain (IND2018/AMB-9553). This work is also a contribution to the Andalusian research groups RNM-308 (Group of Hydrogeology) and RNM-126 (Group of water resources), the Lower Guadalquivir Basin convention between the CN IGME CSIC and Confederación Hidrológica del Guadalquivir (CHG) as well as the convention between Pablo de Olavide University and the Guadalquivir River Basin Board (Hydrological monitoring and modeling in Doñana temporary ponds

Development of Clay Plasters Containing Thermoregulating Microcapsules for Indoor Walls

This work shows the technical feasibility of incorporating phase change materials (PCMs) into clay plastering mortars to improve the thermal properties of the building envelopes. Due to the absence of regulated and internationally agreed-upon norms for clay mortars containing thermoregulating microcapsules (MPCMs), two tests following UNE-EN-998-1:2010 and UNE-EN-1015, were designed to provide the greatest similarity to its final application. Three different dosages 5, 10, and 15 wt% of MPCM relative to the dried mortar weight were used. Fresh mortars were physically characterized to determine its consistency, apparent density, period of workability and open time, and occluded air content. Physical and mechanical characteristics were determined for hardened mortar. The thermal characteristics of the specimens were analysed by using a differential scanning calorimetry, obtaining their apparent specific heat capacities and the enthalpy curves. Building simulation software is a fundamental tool for designing buildings with almost zero energy consumption. In this study, three identical architectural models were simulated. The reference building had inner coatings of clay-based mortar, mortar with 15% added material, and a conventional gypsum mortar. These buildings were subjected to the same exposure and radiation conditions, which allowed the result to be compared to evaluate the effect of incorporating the PCM

FUNCIONALIDAD DE LA FAMILIA Y SU INCIDENCIA EN EL RENDIMIENTO ACADÉMICO EN ADOLESCENTES

Nowadays, some studies show that the academicals performance is affected not only for any factors; taking account the family environment could be a determinate aspect in the success and failure in the school. For this reason, the researching has an objective to determine how the family´s functionality inside in the academicals performance at first to third baccalaureate students in the Academic Educative Unit. The informative data was obtained to a purposive sample of three hundred people, whom twenty four were teachers, one hundred fifty six were students and one hundred twenty were family parents. To reach this objective, first able a theoretical review, after that a field development were done through questionnaires. The main results show to the families don´t interchange enough opinions in the educative institution, in some of the cases they don’t participate in the teaching- learning process in the educative unit. In addition it is checked, in some family environment, there is the lack of dialogue between parents it has influence in the academicals development. As a conclusion the communicative element in the familiar and inter-institutional levels, is the most relevant problem. On the basis of the results obtained, is designed a proposal for five levels, with the purpose to improve the communication among parents, teachers and students.&nbsp; En la actualidad numerosos estudios revelan que&nbsp;el rendimiento académico no sólo se ve afectado por diversos factores en el centro educativo, demostrando que el entorno familiar puede ser determinante para el éxito o el fracaso escolar. Por este motivo, la presente investigación pretende determinar&nbsp;cómo incide la&nbsp;funcionalidad familiar en el rendimiento académico en los estudiantes de primer a tercer año de bachillerato. Los datos se obtienen a partir de una muestra intencional de trescientas personas, de las cuales veinticuatro&nbsp;fueron docentes, ciento cincuenta y seis estudiantes y ciento veinte familiares. El estudio se lleva a cabo en una institución educativa que comprende educación primaria, secundaria y bachillerato del Cantón Latacunga (Ecuador). Para lograr este objetivo, se realiza en primer lugar una revisión teórica y posteriormente, se lleva a cabo la investigación de campo a través de la aplicación de tres cuestionarios.&nbsp;Los principales resultados muestran que las familias no interaccionan lo suficiente con la institución educativa y en muchos casos no son coparticipes del proceso educativo de sus hijos. Se comprueba además que, en muchos contextos familiares, existe ausencia de diálogo entre padres e hijos lo cual puede influir en el rendimiento académico de los estudiantes. Se concluye que el elemento comunicativo a nivel intrafamiliar e interinstitucional es uno de los problemas más destacables e influyentes en el rendimiento académico de los estudiante

Parallel Online Time Warping for Real-Time Audio-to-Score Alignment in Multi-core Systems

[EN] The Audio-to-Score framework consists of two separate stages: pre- processing and alignment. The alignment is commonly solved through offline Dynamic Time Warping (DTW), which is a method to find the path over the distortion matrix with the minimum cost to determine the relation between the performance and the musical score times. In this work we propose a par- allel online DTW solution based on a client-server architecture. The current version of the application has been implemented for multi-core architectures (x86, x64 and ARM), thus covering either powerful systems or mobile devices. An extensive experimentation has been conducted in order to validate the software. The experiments also show that our framework allows to achieve a good score alignment within the real-time window by using parallel computing techniques.This work has been partially supported by Spanish Ministry of Science and Innovation and FEDER under Projects TEC2012-38142-C04-01, TEC2012-38142-C04-03, TEC2012-38142-C04-04, TEC2015-67387-C4-1-R, TEC2015-67387-C4-3-R, TEC2015-67387-C4-4-R, the European Union FEDER (CAPAP-H5 network TIN2014-53522-REDT), and the Generalitat Valenciana under Grant PROMETEOII/2014/003.Alonso-Jordá, P.; Cortina, R.; Rodríguez-Serrano, F.; Vera-Candeas, P.; Alonso-González, M.; Ranilla, J. (2017). Parallel Online Time Warping for Real-Time Audio-to-Score Alignment in Multi-core Systems. The Journal of Supercomputing. 73(1):126-138. https://doi.org/10.1007/s11227-016-1647-5S126138731Joder C, Essid S, Richard G (2011) A conditional random field framework for robust and scalable audio-to-score matching. 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In: Proceedings of the international computer music conference (ICMC), pp 129–132Simon I, Morris D, Basu S (2008) MySong: automatic accompaniment generation for vocal melodies. In: Proceedings of the SIGCHI conference on human factors in computing systems. ACM, New York, pp 725–734Rodriguez-Serrano FJ, Duan Z, Vera-Candeas P, Pardo B, Carabias-Orti JJ (2015) Online score-informed source separation with adaptive instrument models. J New Music Res Lond 44(2):83–96Arzt A, Widmer G, Dixon S (2008) Automatic page turning for musicians via real-time machine listening. In: Proceedings of the 18th European conference on artificial intelligence. IOS Press, Amsterdam, pp 241–245Carabias-Orti JJ, Rodriguez-Serrano FJ, Vera-Candeas P, Canadas-Quesada FJ, Ruiz-Reyes N (2015) An audio to score alignment framework using spectral factorization and dynamic time warping. In: 16th International Society for music information retrieval conference, pp 742–748Rodríguez-Serrano FJ, Menéndez-Canal J, Vidal A, Cañadas-Quesada FJ, Cortina R (2015) A DTW based score following method for score-informed sound source separation. In: Proceedings of the 12th sound and music computing conference 2015 (SMC-15), Ireland, pp 491–496Carabias-Ortí JJ, Rodríguez-Serrano FJ, Vera-Candeas P, Cañadas-Quesada FJ, Ruíz-Reyes N (2013) Constrained non-negative sparse coding using learnt instrument templates for realtime music transcription. Eng Appl Artif Intell 26(7):1671–1680Raphael C (2006) Aligning music audio with symbolic scores using a hybrid graphical model. Mach Learn 65:389–409Schreck-Ensemble (2001–2004) ComParser 1.42. http://home.hku.nl/~pieter.suurmond/SOFT/CMP/doc/cmp.html . Accessed Sept 2015Itakura F (1975) Minimum prediction residual principle applied to speech recognition. 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Hydrogenation of α, β unsaturated aldehydes over polycrystalline, (111) and (100) preferentially oriented Pt nanoparticles supported on carbon

The influence of the shape/surface structure of Pt nanoparticles on the selective hydrogenation of crotonaldehyde and cinnamaldehyde has been studied. (111) and (100) preferentially oriented Pt nanoparticles (10 nm) as well as polyoriented Pt nanoparticles (3 nm) were synthesized, characterized (by TEM, cyclic voltammetry and adsorption microcalorimetry) and their catalytic properties evaluated. TEM analysis provided information about the size and shape of the Pt nanoparticles, whereas cyclic voltammetry allowed gaining qualitative and quantitative information about their surface structure. Thus, small Pt nanoparticles ( ) were revealed to have a polyoriented surface, containing high ratio of corner and edges atoms to terrace atoms, whereas large Pt nanoparticles ( ) were shown to have larger Pt domains with (100) and (111) surface structures. Microcalorimetric results for CO adsorption showed higher values of initial heat for polyoriented Pt/C compared to preferentially oriented samples, thus accounting for a higher amount of highly unsaturated surface platinum atoms for Pt/C, in agreement with cyclic voltammetry. The catalytic performances of the samples showed a strong structure-sensitive character for both reactions, with TOF values following the trend Pt(100)/C > Pt(111)/C > Pt/C. Moreover, Pt(111)/C showed higher selectivities to unsaturated alcohol than Pt(100)/C and Pt/C samples.Es la versión prepritn del artículo. Se puede consultar la versión final en https://doi.org/10.1016/j.jcat.2007.10.01

Early Science with the Large Millimetre Telescope: Molecules in the Extreme Outflow of a proto-Planetary Nebula

Extremely high velocity emission likely related to jets is known to occur in some proto-Planetary Nebulae. However, the molecular complexity of this kinematic component is largely unknown. We observed the known extreme outflow from the proto-Planetary Nebula IRAS 16342-3814, a prototype water fountain, in the full frequency range from 73 to 111 GHz with the RSR receiver on the Large Millimetre Telescope. We detected the molecules SiO, HCN, SO, and $^{13}$CO. All molecular transitions, with the exception of the latter are detected for the first time in this source, and all present emission with velocities up to a few hundred km s$^{-1}$. IRAS 16342-3814 is therefore the only source of this kind presenting extreme outflow activity simultaneously in all these molecules, with SO and SiO emission showing the highest velocities found of these species in proto-Planetary Nebulae. To be confirmed is a tentative weak SO component with a FWHM $\sim$ 700 km s$^{-1}$. The extreme outflow gas consists of dense gas (n$_{\rm H_2} >$ 10$^{4.8}$--10$^{5.7}$ cm$^{-3}$), with a mass larger than $\sim$ 0.02--0.15 M$_{\odot}$. The relatively high abundances of SiO and SO may be an indication of an oxygen-rich extreme high velocity gas.Comment: Accepted for publication in Monthly Notices of the Royal Astronomical Society Letter