Thermomagnetic detection of recrystallization in FeCoNbBCu nanocrystalline alloys

The recrystallization process in FeCoNbBCu nanocrystallinealloys is evidenced from thermomagnetic results as a significant decrease in magnetization at the second crystallization stage. The lowering in the volume fraction of α-FeCo crystals indicates that some of these crystals contribute to the boride phases formed. Electron microscopy images reveal that the final microstructure consists of large crystals (∼500 nm) of a fcc (FeCo)23B6(FeCo)23B6 phase and small crystals (∼20 nm) of bcc α-FeCo and of some boride phases as such (FeCo)2B

The cosmic evolution of the spatially-resolved star formation rate and stellar mass of the CALIFA survey

We investigate the cosmic evolution of the absolute and specific star formation rate (SFR, sSFR) of galaxies as derived from a spatially-resolved study of the stellar populations in a set of 366 nearby galaxies from the CALIFA survey. The analysis combines GALEX and SDSS images with the 4000 break, H_beta, and [MgFe] indices measured from the datacubes, to constrain parametric models for the SFH, which are then used to study the cosmic evolution of the star formation rate density (SFRD), the sSFR, the main sequence of star formation (MSSF), and the stellar mass density (SMD). A delayed-tau model, provides the best results, in good agreement with those obtained from cosmological surveys. Our main results from this model are: a) The time since the onset of the star formation is larger in the inner regions than in the outer ones, while tau is similar or smaller in the inner than in the outer regions. b) The sSFR declines rapidly as the Universe evolves, and faster for early than for late type galaxies, and for the inner than for the outer regions of galaxies. c) SFRD and SMD agree well with results from cosmological surveys. At z< 0.5, most star formation takes place in the outer regions of late spiral galaxies, while at z>2 the inner regions of the progenitors of the current E and S0 are the major contributors to SFRD. d) The inner regions of galaxies are the major contributor to SMD at z> 0.5, growing their mass faster than the outer regions, with a lookback time at 50% SMD of 9 and 6 Gyr for the inner and outer regions. e) The MSSF follows a power-law at high redshift, with the slope evolving with time, but always being sub-linear. f) In agreement with galaxy surveys at different redshifts, the average SFH of CALIFA galaxies indicates that galaxies grow their mass mainly in a mode that is well represented by a delayed-tau model, with the peak at z~2 and an e-folding time of 3.9 Gyr.Comment: 23 pages, 16 figures, 6 tables, accepted for publication in Astronomy & Astrophysics. *Abridged abstract

Results of the 2004 Spanish Experimental Fishing in NAFO Subarea 1

An experimental fishing was carried out with three bottom trawlers commercial Spanish vessels from July to December of the year 2004 in the Subarea 1. The main objective of the experimental fishing was to search for cephalopods species concentrations inside the territorial waters of Greenland. During the experimental fishing a scientific observer stayed on board each vessel to collect effort data, catches and yields by haul and Division. The observers carried out length distribution samplings of the following species: Reinhardtius hippoglossoides, Pandalus borealis, Gadus morhua, Sebastes spp., Hippoglossoides platessoides and Macrourus berglax. Biological samplings of R. hippoglossoides, P. borealis, H. platessoides, G. morhua and M. berglax were also carried out. Otoliths of Greenland halibut (1 356) and Atlantic cod (739) were collected for age determination. Greenland halibut was the main species caught and the cephalopods, target species, have not been found in the experimental fishing

Effect of the particle size and solids volume fraction on the thermal degradation behaviour of Invar 36 feedstocks

Degradation kinetics and the thermal stability of Invar 36 powder injection moulding feedstocks (PIM) based on cellulose acetate butyrate (CAB) and polyethylene glycol (PEG) binders were investigated using simultaneous thermogravimetric analysis (STA) and differential scanning calorimetry (DSC). The initial decomposition temperature (IDT) and the integral procedure decomposition temperature (IPDT) were used to analyse the thermal stability of the binder system as a function of the solid loading content and powder particle size. The degradation kinetics was studied, and the process apparent activation energies were assessed using isoconversional methods. All the methodologies revealed changes in the thermal degradation behaviours of the feedstocks for solid loadings that were previously determined to correspond to optimal solid loadings using other experimental procedures. The studies also contrast previous similar findings with a ceramic powder. Therefore these results strengthen the proposal of thermodynamic degradation studies of feedstocks as an alternative or complementary technique to determine optimal solid loading contents in metal injection moulding (MIM).The authors a wish to thank GUZMÁN GLOBAL S.L. and MIM TECH ALFA for their collaboration on the ECOPIM project (ref. IPT 2011 0931 20000) that was funded by the Spanish Ministry of the Economy and Competitiveness. Furthermore, the authors would like to acknowledge the strong support from the ESTRUMAT projects (ref. S2009/MAT 1585), which were funded by the CAM Consejería Educación Dir. Gral. Universidades e Investigación, and from the COMETAS project (ref. MAT2009/14448 C02 02), which was funded by the Spanish Ministry of the Economy and Compet itiveness. J.P.F. B. acknowledges support from “Marie Curie” Amarout Europe Program

Light-activated electroforming in ITO/ZnO/p-Si resistive switching devices

We report on light-activated electroforming of ZnO/p-Si heterojunction memristors with transparent indium tin oxide as the top electrode. Light-generated electron-hole pairs in the p-type substrate are separated by the external electric field and electrons are injected into the active ZnO layer. The additional application of voltage pulses allows achieving different resistance states that end up in the realization of the low resistance state (LRS). This process requires much less voltage compared to dark conditions, thus avoiding undesired current overshoots and achieving a self-compliant device. The transport mechanisms governing each resistance state are studied and discussed. An evolution from an electrode-limited to a space charge-limited transport is observed along the electroforming process before reaching the LRS, which is ascribed to the progressive formation of conductive paths that consequently induce the growth of conductive nanofilaments through the ZnO layer. This work was financially supported by the Spanish Ministry of Economy and Competitiveness (Project Nos. TEC2012-38540-C02-01 and TEC2016-76849-C2-1-R). O.B. also acknowledges the subprogram "Ayudas para Contratos Predoctorales para la Formación de-Doctores" from the Spanish Ministry of Economy and Competitiveness for economical support. J.L.F. acknowledges the subprogram "Ayudas para la Formación de Profesorado Universitario" (No. FPU16/06257) from the Spanish Ministry of Education, Culture and Sports for economical support. X.P., C.L., and C.G. are grateful to C. Frilay for his expertise in the maintenance of the sputtering setup used for the growth of the ZnO films

Processing and mechanical properties of novel biodegradable poly-lactic acid/Zn 3D printed scaffolds for application in tissue regeneration

The feasibility to manufacture scaffolds of poly-lactic acid reinforced with Zn particles by fused filament fabrication is demonstrated for the first time. Filaments of 2.85 mm in diameter of PLA reinforced with different weight fractions of $\mu$m-sized Zn - 1 wt. \% Mg alloy particles (in the range 3.5 to 17.5 wt. \%) were manufactured by a double extrusion in method in which standard extrusion is followed by a precision extrusion in a filament-maker machine. Filaments with constant diameter, negligible porosity and a homogeneous reinforcement distribution were obtained for Zn weight fractions of up to 10.5\%. It was found that the presence of Zn particles led to limited changes in the physico-chemical properties of the PLA that did not affect the window temperature for 3D printing nor the melt flow index. Thus, porous scaffolds could be manufactured by fused filament fabrication at 190\textdegree C with poly-lactic acid/Zn composites containing 3.5 and 7 wt. \% of Zn and at 170\textdegree C when the Zn content was 10.5 wt. \% with excellent dimensional accuracy and mechanical properties

Concept of finite limit of a function at a point: meanings and specific terms

In this paper, we present some results of an exploratory study performed with students aged 16-17. We investigate the different uses that these students make of terms such as ‘to approach’, ‘to tend’, ‘to reach’, ‘to exceed’ and ‘limit’ that describe the basic notions related to the concept of the finite limit of a function at a point. We use the interpretive framework of conceptual analysis to infer the meanings that students associate with these specific terms in connection with the effective use of terms in their answers.This study was performed with aid and financing from Fellowship FPU AP2010-0906 (MEC-FEDER), Projects EDU2009-11337 and EDU2012-33030 of the National Plan for R&D&R (MICIN), Subprogram EDUC and Group FQM-193 of the 3rd Andalusian Research Plan (PAIDI).This chapter is derived in part from an article published in International Journal of Mathematical Education in Science and Technology 05 Jul 2013, available online: http://www.tandfonline.com/10.1080/0020739X.2013.80588

VdBH 222: a starburst cluster in the inner Milky Way

Context. It has been suggested that the compact open cluster VdBH 222 is a young massive distant object.Aims. We set out to characterise VdBH 222 using a comprehensive set of multi-wavelength observations.Methods.We obtained multi-band optical (UBVR) and near-infrared (JHKS) photometry of the cluster field, as well as multi-object and long-slit optical spectroscopy for a large sample of stars in the field. We applied classical photometric analysis, as well as more sophisticated methods using the CHORIZOS code, to determine the reddening to the cluster. We then plotted dereddened HR diagrams and determined cluster parameters via isochrone fitting.Results. We have identified a large population of luminous supergiants confirmed as cluster members via radial velocity measurements. We find nine red supergiants (plus one other candidate) and two yellow supergiants. We also identify a large population of OB stars. Ten of them are bright enough to be blue supergiants. The cluster lies behind ≈7.5 mag of extinction for the preferred value of RV = 2.9. Isochrone fitting allows for a narrow range of ages between 12 and 16 Ma. The cluster radial velocity is compatible with distances of ~6 and ~10 kpc. The shorter distance is inconsistent with the age range and Galactic structure. The longer distance implies an age ≈ 12 Ma and a location not far from the position where some Galactic models place the far end of the Galactic bar.Conclusions. VdBH 222 is a young massive cluster with a likely mass >20 000 M⊙. Its population of massive evolved stars is comparable to that of large associations, such as Per OB1. Its location in the inner Galaxy, presumably close to the end of the Galactic bar, adds to the increasing evidence for vigorous star formation in the inner regions of the Milky Way

What Does It Drive the Relationship Between Suicides and Economic Conditions? New Evidence from Spain

In this paper we analyse suicides across the 17 Spanish regions over the period 2002?2013. In doing so, we estimate count panel data models considering gender differences taking into account before and during economic crisis periods. A range of aggregate socioeconomic regional-level factors have been considered. Our empirical results show that: (1) a socioeconomic urban?rural suicide differentials exist, (2) there exists a Mediterranean suicide pattern; and (3) unemployment levels have a marked importance during the crisis period. The results of this study may have usefulness for suicide prevention in Spain