On the reduction of 4-oxo-4h-benzopyran-3-carbaldehydes : global and local electrophilicity patterns

The theoretical global and local electrophilicity patterns of substituted and chelated 4-oxo-4H-benzopyran-3-carbaldehydes (formylchromones) have been evaluated using the electrophilicity index proposed by Parr et al [J. Am. Chem. Soc. 1999, 121, 1922]. The complexation of formylchromones with aluminum predicts a strong electrophilic character of these compounds against nucleophiles. Local response at the active sites may also be assessed in terms of a global contribution described by the global electrophilicity, and a local contribution described by the variations in electrophilic Fukui function at those sites. The highest local electrophilicity is found at the formyl group of the chelated formylchromones, in spite of that, the highest positive charge is located on the pyrone carbonyl group. This result is consistent with the experimental observed reactivity displayed by 4-oxo-4H-benzopyran-3-carbaldehydes in the presence of 2-propanol and alumina

Value stream analysis in military logistics: The improvement in order processing procedure

Military logistics is a complex process where response times, demand uncertainty, wide variety of material references, and cost-effectiveness are decisive for combat capability. The demanding flexibility can only be achieved by improving supply chain management (SCM) to minimize lead times. To cope with these requirements, lean thinking can be extended to military organizations. This research justifies and proposes the use of lean methodologies to improve logistics processes with the case study of a military unit. In particular, the article presents the results obtained using value stream mapping (VSM) and value stream design (VSD) tools to improve the order processing lead time of spare items. The procedure starts with an order generation from a military unit that requests the material and ends before transportation to the final destination. The whole project was structured, considering the define-measure-analyze-improve-control (DMAIC) problem-solving methodology. The results show that the future state map might increase added-value activities from 44% to 70%. After implementation, it was demonstrated that the methodology applied reduced the lead-time average and deviation up to 69.6% and 61.9%, respectively

A comprehensive asteroseismic modelling of the high-amplitude delta Scuti star RV Arietis

We present a comprehensive asteroseismic study of the double-mode high-amplitude delta Scuti star HD 187642 (RV Arietis). The modelling includes some of the most recent techniques: 1) effects of rotation on both equilibrium models and adiabatic oscillation spectrum, 2) non-adiabatic study of radial and non-radial modes, 3) relationship between the fundamental radial mode and the first overtone in the framework of Petersen diagrams. The analysis reveals that two of the observed frequencies are very probably identified as the fundamental and first overtone radial modes. Analysis of the colour index variations, together with theoretical non-adiabatic calculations, points to models in the range of [7065,7245] K in effective temperature and of [1190, 1270] Myr in stellar age. These values were found to be compatible with those obtained using the three other asteroseismic techniques.Comment: accepted for publication in A&

Growth-promoting effects of sustained swimming in fingerlings of gilthead sea bream (Sparus aurata L.)

Fish growth is strongly influenced by environmental and nutritional factors and changing culture conditions can help optimize it. The importance of early-life experience on the muscle phenotype later in life is well known. Here, we study the effects of 5 weeks of moderate and sustained swimming activity (5 BL s) in gilthead sea bream during early development. We analysed growth and body indexes, plasma IGF-I and GH levels, feed conversion, composition [proximate and isotopic (N/C)] and metabolic key enzymes (COX, CS, LDH, HOAD, HK, ALAT, ASAT) of white muscle. Moderate and continuous exercise in fingerlings of gilthead sea bream increased plasma IGF-I, whereas it reduced plasma GH. Under these conditions, growth rate improved without any modification to feed intake through an increase in muscle mass and a reduction in mesenteric fat deposits. There were no changes in the content and turnover of muscle proteins and lipid reserves. Glycogen stores were maintained, but glycogen turnover was higher in white muscle of exercised fish. A lower LDH/CS ratio demonstrated an improvement in the aerobic capacity of white muscle, while a reduction in the COX/CS ratio possibly indicated a functional adaptation of mitochondria to adjust to the tissue-specific energy demand and metabolic fuel availability in exercised fish. We discuss the synergistic effects of dietary nutrients and sustained exercise on the different mitochondrial responses.A.M.C and E.J.V. are supported by a predoctoral fellowship from the “Ministerio de Ciencia e Innovación” (MICINN) and A.M.P. by a fellowship from the University of Barcelona (APIF-2012). This study was supported by the projects from the MICINN AGL2012-39768, and the “Xarxa de Refèrencia d’R+D+I en Aqüicultura” and the SGR2009-00402 from the “Generalitat de Catalunya”.Peer Reviewe

Microwave-assisted solution synthesis, microwave sintering and magnetic properties of cobalt ferrite

[EN] A simple, soft, and fast microwave-assisted hydrothermal method was used for the preparation of nanocrystalline cobalt ferrite powders from commercially-available Fe(NO3)(3)center dot 9H(2)O, Co(NO3)(2)center dot 6H(2)O, ammonium hydroxide, and tetrapropylammonium hydroxide (TPAH). The synthesis was conducted in a sealed-vessel microwave reactor specifically designed for synthetic applications, and the resulting products were characterized by XRD, FE-SEM, TEM, and HR-TEM. After a systematic study of the influence of the microwave variables (temperature, reaction time and nature of the bases), highly crystalline CoFe2O4 nanoparticles with a high uniformity in morphology and size, were directly obtained by heating at 130 degrees C for 20 min using the base TPAH. Dense ceramics of cobalt ferrite were prepared by non-conventional, microwave sintering of synthesized nanopowders at temperatures of 850-900 degrees C. The magnetic properties of both the nanopowders and the sintered specimens were determined in order to establish their feasibility as a permanent magnet.This work has been carried out with financial support from the Spanish Ministry of Economy, Industry and Competitiveness (MINECO) and CSIC through the Projects MAT2015-67586-C3-R and NANOMIND, respectively. A. Borrell acknowledges MINECO for a Juan de la Cierva contract (IJCI-2014-19839).Fariñas, JC.; Moreno, R.; Pérez, A.; García, MA.; García-Hernández, M.; Salvador Moya, MD.; Borrell Tomás, MA. (2018). Microwave-assisted solution synthesis, microwave sintering and magnetic properties of cobalt ferrite. Journal of the European Ceramic Society. 38(5):2360-2368. https://doi.org/10.1016/j.jeurceramsoc.2017.12.052S2360236838

Seismology of beta Cephei stars: differentially-rotating models for interpreting the oscillation spectrum of nu-Eridani

A method for the asteroseismic analysis of beta Cephei stars is presented and applied to the star nu Eridani. The method is based on the analysis of rotational splittings, and their asymmetries using differentially-rotating asteroseismic models. Models with masses around 7.13 M_sun, and ages around 14.9 Myr, were found to fit better 10 of the 14 observed frequencies, which were identified as the fundamental radial mode and the three L=1 triplets g, p, and p. The splittings and aymmetries found for these modes recover those provided in the literature, except for p. For this last mode, all its non-axysimmetric components are predicted by the models. Moreover, opposite signs of the observed and predicted splitting asymmetries are found. If identification is confirmed, this can be a very interesting source of information about the internal rotation profile, in particular in the outer regions of the star. In general, the seismic models which include a description for shellular rotation yield slightly better results as compared with those given by uniformly-rotating models. Furthermore, we show that asymmetries are quite dependent on the overshooting of the convective core, which make the present technique suitable for testing the theories describing the angular momentum redistribution and chemical mixing due to rotationally-induced turbulence.Comment: 11 pages, 9 figures, 8 tables. ApJ (in press

Sistema de gestión de energía para microrredes basado en control predictivo

En este artículo se presenta un sistema de gestión de energía para microrredes a partir de un control Predictivo basado en Modelos (MPC), el cual tiene como tarea la optimización de las operaciones de una microrred, al tiempo que cumple una serie de restricciones de funcionamiento. Para ello, el problema ha sido formulado empleando Programación Lineal Entera-Mixta (MILP), la cual ha sido resuelta de manera eficiente. Se han estudiado diferentes escenarios, comparando el MPC con una estrategia fija y se han calculado costes de funcionamiento e inversión, mostrando finalmente los resultados.Los autores quieren agradecer a la Universitat Jaume I y a la Generalitat Valenciana el apoyo recibido y materializado en los proyectos P11B2013-34 y GV/2014/117 respectivamente

Control de la tensión del bus de continua de un filtro activo mediante un convertidor DC-DC

En este artículo se presentan los resultados experimentales obtenidos mediante un sistema compensador generador trabajando de forma aislada de la red eléctrica. Para analizar el funcionamiento del sistema se ha desarrollado un prototipo de un convertidor DC-DC bidireccional el cual permite adaptar el valor de la tensión de las baterías conectadas a su entrada con la tensión del bus de continua a la entrada del filtro activo. Para el control del convertidor DC-DC se ha utilizado un control por realimentación del estado diseñado mediante algoritmos genéticos, y en el caso del filtro activo se ha utilizado un control proporcional con prealimentación. Los resultados experimentales obtenidos muestran el correcto funcionamiento del sistema tanto en estado estacionario, como en régimen transitorio.Los autores quieren agradecer a la Universitat Jaume I y a la Generalitat Valenciana el apoyo recibido y materializado en los proyectos P11B2013-34 y GV/2014/117 respectivamente

The pulsating hot subdwarf Balloon 090100001: results of the 2005 multisite campaign

We present the results of a multisite photometric campaign on the pulsating sdB star Balloon 090100001. The star is one of the two known hybrid hot subdwarfs with both long- and short-period oscillations. The campaign involved eight telescopes with three obtaining UBVR data, four B-band data, and one Stromgren uvby photometry. The campaign covered 48 nights, providing a temporal resolution of 0.36microHz with a detection threshold of about 0.2mmag in B-filter data. Balloon 090100001 has the richest pulsation spectrum of any known pulsating subdwarf B star and our analysis detected 114 frequencies including 97 independent and 17 combination ones. The strongest mode (f_1) in the 2.8mHz region is most likely radial while the remaining ones in this region form two nearly symmetric multiplets: a triplet and quintuplet, attributed to rotationally split \ell=1 and 2 modes, respectively. We find clear increases of splitting in both multiplets between the 2004 and 2005 observing campaigns, amounting to 15% on average. The observed splittings imply that the rotational rate in Bal09 depends on stellar latitude and is the fastest on the equator. We use a small grid of models to constrain the main mode (f_1), which most likely represents the radial fundamental pulsation. The groups of p-mode frequencies appear to lie in the vicinity of consecutive radial overtones, up to the third one. Despite the large number of g-mode frequencies observed, we failed to identify them, most likely because of the disruption of asymptotic behaviour by mode trapping. The observed frequencies were not, however, fully exploited in terms of seismic analysis which should be done in the future with a larger grid of reliable evolutionary models of hot subdwarfs.Comment: accepted for publication in MNRA

The Frequency Ratio Method for the seismic modelling of gamma Doradus stars. II The role of rotation

The effect of rotation on the Frequency Ratio Method (Moya et al. 2005) is examined. Its applicability to observed frequencies of rotating gamma Doradus stars is discussed taking into account the following aspects: the use of a perturbative approach to compute adiabatic oscillation frequencies; the effect of rotation on the observational Brunt-Vaisala integral determination and finally, the problem of disentangling multiplet-like structures from frequency patterns due to the period spacing expected for high-order gravity modes in asymptotic regime. This analysis reveals that the FRM produces reliable results for objects with rotational velocities up to 70 kms/s, for which the FRM intrinsic error increases one order of magnitude with respect to the typical FRM errors given in Moya et al. (2005). Our computations suggest that, given the spherical degree "l" identification, the FRM may be discriminating for m = 0 modes, in the sense that the method avoids any misinterpretation induced by the presence of rotationally split multiplet-like structures, which reinforces the robustness of the method. However, if "l" is unknown, such discrimination is not ensured. In order to check the FRM in presence of slow-moderate rotation, we have applied it to the three observed frequencies of the slowly rotating (vsini = 29 km/s) gamma Doradus star HD48501.Comment: A&A, in pres