Análisis bibliométrico de las publicaciones científicas españolas en la categoría Construction & Building Technology de la base de datos Web of Science (1997-2008)

En este trabajo se analizan las publicaciones procedentes de instituciones españolas recogidas en las revistas de la categoría Construction & Building Technology de la base de datos Web of Science para el periodo 1997-2008. El número de revistas incluidas es de 35 y el número de artículos publicados ha sido de 760 (Article o Review). Se ha realizado una evaluación bibliométrica con dos nuevos parámetros: Factor de Impacto Ponderado y Factor de Impacto Relativo; asimismo se incluyen el número de citas y el número de documentos a nivel institucional. Entre los centros con una mayor producción científica destaca, como era de prever, el Instituto de Ciencias de la Construcción Eduardo Torroja (CSIC), mientras que atendiendo al Factor de Impacto Ponderado ocupa el primer lugar la Universidad de Vigo. Por otro lado, sólo dos revistas Cement and Concrete Research y Materiales de Construcción aglutinan el 45.26% de toda la producción científica española, con 172 trabajos cada una de ellas. En cuanto a la colaboración internacional, destacan países como Inglaterra, México, Estados Unidos, Italia, Argentina y Franci

Wideband magnetic losses and their interpretation in HGO steel sheets

The magnetic properties of high-permeability grain-oriented (HGO) Fe-Si sheets have been investigated in the frequency range 1 Hz-10 kHz, with attention devoted to the role of thickness on the behavior of the magnetic losses and the phenomenology of skin effect. The study is focused on the wideband response of 0.174 mm and 0.289 mm thick sheets, comparatively tested at peak polarization values ranging between 0.25 T and 1.7 T. The experiments associate fluxmetric measurements with direct Kerr observations of the dynamics of the domain walls. A picture of the magnetization process comes to light, where the dynamics of the flux reversal takes hold under increasing frequencies through the motion of increasingly bowed 180 degrees walls, eventually merging at the sheet surface for a fraction of the semi-period. This effect can be consistently predicted, starting from the Kerrbased knowledge of the equilibrium wall spacing, by the numerical modeling of the motion of an extended array of 180 degrees domain walls, subjected to the balanced action of the applied and eddy current fields, and the elastic reaction of the bowed walls. This model can be incorporated into the general concept of loss separation, by calculating the classical loss component through the solution of the Maxwell's diffusion equation under a magnetic constitutive law identified with the normal DC curve. The numerical domain wall model and the loss decomposition consistently predict that the excess loss component, playing a major role in these grain-oriented materials at power frequencies, tends to disappear in the upper induction-frequency corner

Inhomogeneous vacuum energy

Vacuum energy remains the simplest model of dark energy which could drive the accelerated expansion of the Universe without necessarily introducing any new degrees of freedom. Inhomogeneous vacuum energy is necessarily interacting in general relativity. Although the four-velocity of vacuum energy is undefined, an interacting vacuum has an energy transfer and the vacuum energy defines a particular foliation of spacetime with spatially homogeneous vacuum energy in cosmological solutions. It is possible to give a consistent description of vacuum dynamics and in particular the relativistic equations of motion for inhomogeneous perturbations given a covariant prescription for the vacuum energy, or equivalently the energy transfer four-vector, and we construct gauge-invariant vacuum perturbations. We show that any dark energy cosmology can be decomposed into an interacting vacuum+matter cosmology whose inhomogeneous perturbations obey simple first-order equations.Comment: 8 pages; v2 clarified discussion of Chaplygin gas model, references adde

Hipodoncia: utilidad de hallazgos dentales en la determinación de patologías y parentesco en poblaciones antiguas. Estudio de dos casos en la necrópolis oriental de Carthago Spartaria

The use of forensic techniques when studying partial or badly-conserved human remains is very important when we want to determine age, sex, and race, as well as parental relation between two or more individuals. Of these techniques, some of the simplest but most reliable are those related to the dental studies of the retrieved remains. Finding dental anomalies may give useful information about diseases suffered by the individual (congenital or infecto-contagious) and possible family relation between several individuals. This study describes several cases of dental agenesia (absence of teeth caused by lack of formation of these teeth) found in populations living during the fi fth to seventh centuries (a.D.), retrieved in the oriental necropolis of Carthago Spartaria, in the neighborhood of the present University (Cartagena, Murcia).La utilización de técnicas forenses a la hora de estudiar restos humanos parciales o en mal estado de conservación son muy importantes cuando queremos determinar la edad, sexo y raza, así como el parentesco entre dos o más individuos. De estas técnicas, algunas de las más sencillas pero de resultados bastante fi ables son aquellas relacionadas con el estudio dental de los restos encontrados. El hallazgo de anomalías dentarias puede facilitar información acerca de enfermedades padecidas por el individuo (tanto infectocontagiosas como congénitas) y de posibles relaciones familiares entre varios individuos. El presente estudio describe varios casos de agenesias dentales (ausencia dental debida a la falta de formación de algún diente) encontradas en una población de los siglos V-VII d.C., recuperados en la necrópolis oriental de Carthago Spartaria, en la zona del actual Barrio Universitario. (Cartagena, Murcia

Exploring diversity and distribution of demersal fish species from the Northern Alboran Sea and Gulf of Vera (Western Mediterranean Sea)

The Alboran Sea is a transition region between the Mediterranean basin and the Atlantic Ocean containing a mix of Mediterranean and Atlantic species. The Strait of Gibraltar, at the west end of the Alboran Sea, connects the Mediterranean with the Atlantic Ocean. The Gulf of Vera also occupies a strategic location in the Western Mediterranean, representing a transition zone between the Alboran Sea and the rest of the basins with a more distinctive Mediterranean character. The Alboran Sea is one of the most productive areas of the Mediterranean, in contrast to the Gulf of Vera that displays a more oligotrophic character. Despite of the interest of the study area the information about the distribution of demersal fishes is scarce. In the present study, the main aim is to analyse diversity and distribution of demersal fish species of circalittoral and bathyal soft bottoms of the Alboran Sea (with a higher Atlantic influence and primary production) and the Gulf of Vera (with a higher Mediterranean influence and lower primary production). Sampling was carried out in the scientific trawl survey MEDITS (International bottom trawl survey in the Mediterranean) between 30 and 800 m depth. All samples were taken from Estepona and Cabo de Palos between 1994-2015 in the Alboran Sea and between 1995-2008 and 2014-2015 in the Gulf of Vera. (Figure 1). A total of 818 samples (687 from Alboran and 131 from Vera) were considered for this study. For each haul, the abundance and weight of individuals per fish species were standardised to 1 hour towing in order to calculate both species abundance (number of individuals per 1 hour towing) (ind•h−1) and biomass (g•h−1). In order to identify fish assemblages, ordination and classification multivariate methods using fish species abundance and biomass per haul matrices were applied. Prior to analyses, all data were logarithmically transformed using log(x + 1) to minimise the weighting of extreme abundance or biomass values of certain species. An analysis of similarities (ANOSIM) was carried out for statistical comparisons of groups of samples according to the different factors considered (depth, Alboran vs. Vera). Species rarefaction curves were used to compare the species richness values of each fish assemblage. In addition, for each group, Shannon-Wiener (H’) and Taxonomic distinctness (Δ*) diversity indices were calculated. For comparisons of the mean values of the considered variables (abundance, biomass and diversity indices) across the identified assemblages and years, we used a non-parametric Kruskal–Wallis test. A total of 231 fish species have been identified considering all samples, with 215 spp. collected from Alboran (3 classes, 25 orders and 75 families) and 160 spp.. from Vera (2 classes, 21 orders and 67 families), probably because the number of samples in the latter were lower. The number of occasional species, considering those that were captured only in 1 or 2 samples, were 56 in Alboran and 44 in Vera. The multivariate analyses (nMDS) indicated that depth is the main factor that determines the distribution of species in both areas, with four groups of samples displaying significant differences between them (ANOSIM-Alboran: R=0.85, p=0.001; ANOSIM-Vera: R=0.81, p=0.001). These groups were similar in both areas: Inner continental shelf (30-100 m), Outer continental shelf (101-200 m), Upper continental slope (201-500 m) and Middle continental slope (501-800 m) (Figures 2 and 3). Regarding the faunistic comparison between Alboran and Vera, the most acute differences were found between those samples from the Middle continental slope. These differences were evident for abundance (ANOSIM: R=0.81, p=0.001), biomass (ANOSIM: R=0.78, p=0.001) and species composition (presence-absence data) (ANOSIM: R=0.61, p=0.001). The trends for species rarefaction curves with depth was similar in both areas, with similar curves for the Inner and Outer continental shelf , a decrease of the species number for the Upper slope and finally the lowest number of species for the Middle slope. Likewise, the mean values of abundance, Shannon and Taxonomic indices also showed a similar pattern in both areas. Mean abundances differed significantly between assemblages increasing from the Inner shelf to Outer shelf and decreasing abruptly to the Upper and Lower slope (.minimum values). The Shannon diversity index showed significant differences in Alboran, but not in Vera, with minima in the Outer shelf in both areas. The taxonomic index also displayed significant differences in Alboran and Vera, with low values in the Inner shelf that increased abruptly to the Outer shelf and Upper slope, with a further acute increase in the Middle slope. Unlike for the other indexes, trends for mean the biomass values with depth were different in both areas. In Alboran biomass decreased from the Inner shelf to the Upper slope and increased to the Middle slope. Nevertheless, in Vera the biomass decreased with depth, with significant differences. In two sectors were evident significant differences. Regarding the interannual changes, the differences between years in Alboran were significant respect to species richness, abundance, biomass and Shannon diversity index. No clear increase or decrease trend was detected interannually. Unlike Alboran, in Vera, no significant interannual differences were detected. In conclusion: 1) Four main fish assemblages were detected on the continental shelf and slope in both areas that seem to be strongly linked to the depth gradient. 2) The middle slope showed the higher differences between both areas for abundance, biomass and presence-abundance data. 3) The species rarefaction curves, abundance, Shannon and Taxonomic diversity indices showed similar patterns with depth in both areas. Biomass index showed a different pattern, with maximum values in the Middle slope in Alboran and minimum ones in Vera

Collapses and explosions in self-gravitating systems

Collapse and reverse to collapse explosion transition in self-gravitating systems are studied by molecular dynamics simulations. A microcanonical ensemble of point particles confined to a spherical box is considered; the particles interact via an attractive soft Coulomb potential. It is observed that the collapse in the particle system indeed takes place when the energy of the uniform state is put near or below the metastability-instability threshold (collapse energy), predicted by the mean-field theory. Similarly, the explosion in the particle system occurs when the energy of the core-halo state is increased above the explosion energy, where according to the mean field predictions the core-halo state becomes unstable. For a system consisting of 125 -- 500 particles, the collapse takes about $10^5$ single particle crossing times to complete, while a typical explosion is by an order of magnitude faster. A finite lifetime of metastable states is observed. It is also found that the mean-field description of the uniform and the core-halo states is exact within the statistical uncertainty of the molecular dynamics data.Comment: 9 pages, 14 figure

Physics of dark energy particles

We consider the astrophysical and cosmological implications of the existence of a minimum density and mass due to the presence of the cosmological constant. If there is a minimum length in nature, then there is an absolute minimum mass corresponding to a hypothetical particle with radius of the order of the Planck length. On the other hand, quantum mechanical considerations suggest a different minimum mass. These particles associated with the dark energy can be interpreted as the ``quanta'' of the cosmological constant. We study the possibility that these particles can form stable stellar-type configurations through gravitational condensation, and their Jeans and Chandrasekhar masses are estimated. From the requirement of the energetic stability of the minimum density configuration on a macroscopic scale one obtains a mass of the order of 10^55 g, of the same order of magnitude as the mass of the universe. This mass can also be interpreted as the Jeans mass of the dark energy fluid. Furthermore we present a representation of the cosmological constant and of the total mass of the universe in terms of `classical' fundamental constants.Comment: 10 pages, no figures; typos corrected, 4 references added; 1 reference added; reference added; entirely revised version, contains new parts, now 14 page

ERP evidence suggests executive dysfunction in ecstasy polydrug users

Background: Deficits in executive functions such as access to semantic/long-term memory have been shown in ecstasy users in previous research. Equally, there have been many reports of equivocal findings in this area. The current study sought to further investigate behavioural and electro-physiological measures of this executive function in ecstasy users. Method: Twenty ecstasy–polydrug users, 20 non-ecstasy–polydrug users and 20 drug-naïve controls were recruited. Participants completed background questionnaires about their drug use, sleep quality, fluid intelligence and mood state. Each individual also completed a semantic retrieval task whilst 64 channel Electroencephalography (EEG) measures were recorded. Results: Analysis of Variance (ANOVA) revealed no between-group differences in behavioural performance on the task. Mixed ANOVA on event-related potential (ERP) components P2, N2 and P3 revealed significant between-group differences in the N2 component. Subsequent exploratory univariate ANOVAs on the N2 component revealed marginally significant between-group differences, generally showing greater negativity at occipito-parietal electrodes in ecstasy users compared to drug-naïve controls. Despite absence of behavioural differences, differences in N2 magnitude are evidence of abnormal executive functioning in ecstasy–polydrug users