ALBERT

Description: Author(s): Juan J. Omiste and Rosario González-Férez We present a theoretical study of the rotational dynamics of asymmetric-top molecules in an electric field and a parallel nonresonant linearly polarized laser pulse. The time-dependent Schrödinger equation is solved within the rigid rotor approximation. Using the benzonitrile molecule as a prototype... [Phys. Rev. A 88, 033416] Published Tue Sep 17, 2013

Description: Author(s): Aharon Brodutch, Animesh Datta, Kavan Modi, Ángel Rivas, and César A. Rodríguez-Rosario The description of the dynamics of a system that may be correlated with its environment is only meaningful within the context of a specific framework. Different frameworks rely upon different assumptions about the initial system-environment state. We reexamine the connections between complete positi... [Phys. Rev. A 87, 042301] Published Mon Apr 01, 2013

Description: Author(s): Benjamin Aaronson, Rosario Lo Franco, and Gerardo Adesso We show that the phenomenon of frozen discord, exhibited by specific classes of two-qubit states under local nondissipative decoherent evolutions, is a common feature of all known bona fide measures of general quantum correlations. All those measures, despite inducing typically inequivalent ordering... [Phys. Rev. A 88, 012120] Published Mon Jul 22, 2013

Description: Author(s): Nicolas Didier, Marco Gibertini, Ali G. Moghaddam, Jürgen König, and Rosario Fazio Charge transport through a small topological superconducting island in contact with a normal and a superconducting electrode occurs through a cycle that involves coherent oscillations of Cooper pairs and tunneling in/out the normal electrode through a Majorana bound state, the Josephson-Majorana cyc... [Phys. Rev. B 88, 024512] Published Wed Jul 24, 2013

Description: The groundwater hydrochemical behaviour of the Langueyú creek basin (Argentina) has been evaluated through a systematic survey, followed by application of hydrological and chemometric multivariate techniques. Ten physicochemical parameters were determined in groundwater samples collected from 26 wells during 4 sampling campaigns (June, 2010; October, 2010; February, 2011 and June, 2011), originating a tridimensional experimental dataset X . Univariate statistical and graphical hydrochemical tools (contour maps and Piper diagrams) applied to individual campaigns, allowed to reach some preliminary conclusions. However, a best visualization of the aquifer behaviour was achieved by applying Principal Component Analysis (MA-PCA) and N-way PCA procedures, PARAFAC and Tucker3. Results were consistent with two-term models, being Tucker3 [2 2 1] the most adequate, explaining a large amount of the dataset variance (50.7 %) with a low complexity. The first Tucker3 [1 1 1] interaction (38.2% of variance) is related with (i) calcium/magnesium vs. sodium/potassium ion exchange processes; (ii) an increase of ionic concentration and (iii) a decrease of nitrate pollution, all processes along the direction of the groundwater flow. The second [2 2 1] interaction (12.5% of variance), accounts for the predominant role played by conductivity, bicarbonate and magnesium in the dataset. The seasonal variations are closely related to concentration/dilution phenomena originated by the variations of the phreatic levels, although this point will require additional sampling to establish a definitive hydrochemical model. This article is protected by copyright. All rights reserved.

Description: Author(s): Giuseppe Buccheri, Stefano Marmi, and Rosario N. Mantegna We investigate the dynamics of correlations present between pairs of industry indices of U.S. stocks traded in U.S. markets by studying correlation-based networks and spectral properties of the correlation matrix. The study is performed by using 49 industry index time series computed by K. French an... [Phys. Rev. E 88, 012806] Published Mon Jul 08, 2013

Description: Syntheses for 2-[1-(diarylphosphinoyl)-1-(pyridin-2-yl)methyl]pyridines, ( 8a, b ), and 2-[1-(diarylphosphinoyl)-1,1-bis(methylpyridin-2yl)methyl]pyridines, ( 11a, b ), (Ar = C 6 H 5 and 2-CF 3 C 6 H 4 ), based on substitution of 2-methylpyridine fragments onto the exo methylene carbon atom of 2-[(diaryl)phosphinoylmethyl]pyridine platforms, are described. N-oxidations of 8a, b and 11a, b produced the 2-[1-(diarylphosphinoyl)-1-(1-oxy-pyridin-2yl)methyl]pyridine N -oxides ( 5a, b ) and the 2-[1-(diarylphosphinoyl)-1,1-bis(1-oxy-methylpyridin-2-yl)methyl]pyridines ( 6a, b ), respectively. The “short-arm“ pyridine fragment of 11a, b resists N-oxidation, and the fully oxidized molecules, 2-[1-(diarylphosphinoyl)-1,1-bis(1-oxy-methylpyridin-2-yl)methyl]pyridine N -oxides ( 7a, b ) were not isolated. Molecular mechanics calculations for gas phase 1:1 ligand/lanthanide complexes indicated that 5a should accommodate a tridentate NO(meNO)PO coordination mode with minimal steric strain. In contrast, 7a cannot form tetradentate NO(meNO) 2 PO chelates; however, tridentate binding should be accessible with minimal ligand strain. Coordination complexes of 8a, b , 5a, b , 6a, b and 11a, b with Ln(NO 3 ) 3 salts were isolated and a X-ray crystal structure for [Er( 8a )(NO 3 ) 3 (MeOH) 2 ]·CH 2 Cl 2 , revealed a monodentate Er–O=P interaction. On the other hand, complexes formed by a more symmetrical trifunctional phenylphosphino-bis-2-methylpyridine N, N, P-trioxide ligand, (meNO) 2 PO* , {La[( meNO) 2 PO* )](OTf) 2 (MeOH) 3 (H 2 O) + }(OTf – ) and {Pr[ (meNO) 2 PO* )](OTf)(MeOH) 4 + }(OTf – ) 2 , realized a tridentate coordination mode. Solvent extraction behaviors for Eu III and Am III in nitric acid solutions using 5a, b , 6a, b , Ph 3 PO and the parent bifunctional ligand 2-[(diphenylphosphanyl)methyl]pyridine N, P-dioxide ( 3a ) in 1, 2-dichloroethane were assessed, and 5a, b and 6a, b were found to behave more like Ph 3 PO than 3a .

Description: Questions Are species from different biogeographic groups (mediterranean, alpine and endemic) filtered in different ways by altitude and topography in alpine plant communities? What is the relative performance of these environmental factors at predicting the species diversity of the communities as a whole and of the geographic species groups? Location Picos de Europa, Cantabrian Range (Spain). Methods We sampled the presence and cover of vascular plants in 5-m radius plots on alpine grasslands between 1900 and 2500 m a.s.l. Five GIS-based terrain variables at 15 m × 15 m were used to model species richness and cover per plot using generalized and linear models, and the variation in species composition with redundancy analysis. The same analyses were repeated for the whole data set and for subsets of species from alpine, mediterranean and endemic distributions. Results The influence of altitude and topography on species richness, cover and composition differed for the whole data set and for the geographic species groups. Altitude was the main variable affecting floristic diversity in the communities as a whole, but the separate species groups were more influenced by slope, topographic wetness index and solar radiation. Richness and cover of mediterranean species showed the strongest relationships with topography. Alpine and endemic species showed relationships with topography for species cover and composition, but not for species richness. Conclusions In alpine landscapes, biogeographic deconstruction of the species pool can provide a better understanding of the influence of altitude and topography on local communities than analysis of the entire community alone. Furthermore, the strong influence of local topography on species groups improves our understanding of how alpine species will respond to climate change. We studied the influence of high-resolution altitudinal and topographic variables on species groups with different biogeographic history. Diversity estimates of the geographic groups showed remarkable differences in the relationships with temperature-related factors that were neglected when using data for the whole community. This procedure provides a better understanding of the influence of topography in species assemblages of alpine communities.

Description: Using Herschel data from the deepest SPIRE and PACS surveys (HerMES and PEP) in COSMOS, GOODS-S and GOODS-N, we examine the dust properties of infrared (IR)-luminous ( L IR  〉 10 10  L ) galaxies at 0.1 〈 z  〈 2 and determine how these evolve with cosmic time. The unique angle of this work is the rigorous analysis of survey selection effects, making this the first study of the star-formation-dominated, IR-luminous population within a framework almost entirely free of selection biases. We find that IR-luminous galaxies have spectral energy distributions (SEDs) with broad far-IR peaks characterized by cool/extended dust emission and average dust temperatures in the 25–45 K range. Hot ( T  〉 45 K) SEDs and cold ( T  〈 25 K), cirrus-dominated SEDs are rare, with most sources being within the range occupied by warm starbursts such as M82 and cool spirals such as M51. We observe a luminosity–temperature ( L - T ) relation, where the average dust temperature of log [ L IR /L ] ~ 12.5 galaxies is about 10 K higher than that of their log [ L IR /L ] ~ 10.5 counterparts. However, although the increased dust heating in more luminous systems is the driving factor behind the L - T relation, the increase in dust mass and/or starburst size with luminosity plays a dominant role in shaping it. Our results show that the dust conditions in IR-luminous sources evolve with cosmic time: at high redshift, dust temperatures are on average up to 10 K lower than what is measured locally ( z 0.1). This is manifested as a flattening of the L - T relation, suggesting that (ultra)luminous infrared galaxies [(U)LIRGs] in the early Universe are typically characterized by a more extended dust distribution and/or higher dust masses than local equivalent sources. Interestingly, the evolution in dust temperature is luminosity dependent, with the fraction of LIRGs with T  〈 35 K showing a two-fold increase from z  ~ 0 to z  ~ 2, whereas that of ULIRGs with T  〈 35 K shows a six-fold increase. Our results suggest a greater diversity in the IR-luminous population at high redshift, particularly for ULIRGs.

Description: The transformation process of clay minerals into pozzolanic products for use as active additives in cement matrixes has been closely studied by both the scientific community and the cement industry. Sourcing these additions from recycled waste products is widely prioritized in environmental policies, because of their associated environmental benefits. This article reports an exhaustive analysis of slate waste in Spain, for its eventual use as an alternative source of pozzolans, based on activated phyllosilicates. The analysis examines the effect of activation conditions on mineralogy and the formation and evolution of the hydrated phases that form during the pozzolanic reaction at 28 days. The results show good pozzolanic activity in the starting slate wastes activated between 800°C and 1100°C of temperature for 2 h of retention, on which basis 1000°C and 2 h were recommended as the more suitable activation conditions for these activated slate wastes (ASW), as total destruction of all phyllosilicates is ensured under those conditions. The hydrated phases formed during the pozzolanic reaction in the ASW/ Ca (\ OH ) 2 system were calcium silicate hydrate gels (CSH), randomly interstratified chlorite (Cl) /smectite with variables containing chlorite/smectite ratios 30% chlorite, 40% chlorite, 50% chlorite, 60% chlorite, respectively, and monosulfoaluminate ( C 3 A · SO 4 Ca ·12 H 2 O ) directly related to the activation process used in this article. All of these findings support the viability of slate waste for use as a pozzolanic addition.