Percolation model for structural phase transitions in Li1−x_{1-x}Hx_xIO3_3 mixed crystals

A percolation model is proposed to explain the structural phase transitions found in Li$_{1-x}$H$_x$IO$_3$ mixed crystals as a function of the concentration parameter $x$. The percolation thresholds are obtained from Monte Carlo simulations on the specific lattices occupied by lithium atoms and hydrogen bonds. The theoretical results strongly suggest that percolating lithium vacancies and hydrogen bonds are indeed responsible for the solid solution observed in the experimental range $0.22 < x < 0.36$.Comment: 4 pages, 2 figure

Fitting the integrated Spectral Energy Distributions of Galaxies

Fitting the spectral energy distributions (SEDs) of galaxies is an almost universally used technique that has matured significantly in the last decade. Model predictions and fitting procedures have improved significantly over this time, attempting to keep up with the vastly increased volume and quality of available data. We review here the field of SED fitting, describing the modelling of ultraviolet to infrared galaxy SEDs, the creation of multiwavelength data sets, and the methods used to fit model SEDs to observed galaxy data sets. We touch upon the achievements and challenges in the major ingredients of SED fitting, with a special emphasis on describing the interplay between the quality of the available data, the quality of the available models, and the best fitting technique to use in order to obtain a realistic measurement as well as realistic uncertainties. We conclude that SED fitting can be used effectively to derive a range of physical properties of galaxies, such as redshift, stellar masses, star formation rates, dust masses, and metallicities, with care taken not to over-interpret the available data. Yet there still exist many issues such as estimating the age of the oldest stars in a galaxy, finer details ofdust properties and dust-star geometry, and the influences of poorly understood, luminous stellar types and phases. The challenge for the coming years will be to improve both the models and the observational data sets to resolve these uncertainties. The present review will be made available on an interactive, moderated web page (sedfitting.org), where the community can access and change the text. The intention is to expand the text and keep it up to date over the coming years.Comment: 54 pages, 26 figures, Accepted for publication in Astrophysics & Space Scienc

Measurement of the top quark-pair production cross section with ATLAS in pp collisions at \sqrt{s}=7\TeV

A measurement of the production cross-section for top quark pairs(\ttbar) in $pp$ collisions at \sqrt{s}=7 \TeV is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two different topologies: single lepton (electron $e$ or muon $\mu$) with large missing transverse energy and at least four jets, and dilepton ($ee$, $\mu\mu$ or $e\mu$) with large missing transverse energy and at least two jets. In a data sample of 2.9 pb-1, 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding expected backgrounds from non-\ttbar Standard Model processes are estimated using data-driven methods and determined to be $12.2 \pm 3.9$ events and $2.5 \pm 0.6$ events, respectively. The kinematic properties of the selected events are consistent with SM \ttbar production. The inclusive top quark pair production cross-section is measured to be \sigmattbar=145 \pm 31 ^{+42}_{-27} pb where the first uncertainty is statistical and the second systematic. The measurement agrees with perturbative QCD calculations.Comment: 30 pages plus author list (50 pages total), 9 figures, 11 tables, CERN-PH number and final journal adde

Inclusive search for same-sign dilepton signatures in pp collisions at root s=7 TeV with the ATLAS detector

An inclusive search is presented for new physics in events with two isolated leptons (e or mu) having the same electric charge. The data are selected from events collected from p p collisions at root s = 7 TeV by the ATLAS detector and correspond to an integrated luminosity of 34 pb(-1). The spectra in dilepton invariant mass, missing transverse momentum and jet multiplicity are presented and compared to Standard Model predictions. In this event sample, no evidence is found for contributions beyond those of the Standard Model. Limits are set on the cross-section in a fiducial region for new sources of same-sign high-mass dilepton events in the ee, e mu and mu mu channels. Four models predicting same-sign dilepton signals are constrained: two descriptions of Majorana neutrinos, a cascade topology similar to supersymmetry or universal extra dimensions, and fourth generation d-type quarks. Assuming a new physics scale of 1 TeV, Majorana neutrinos produced by an effective operator V with masses below 460 GeV are excluded at 95% confidence level. A lower limit of 290 GeV is set at 95% confidence level on the mass of fourth generation d-type quarks

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

Montagem De Comunidades: Conceitos, Domínio E Estrutura Teórica

Community assembly refers to any ecological process that operates to select species from a regional pool and put them together in local communities. Initially, Diamond (1975) proposed a community assembly model based on rules explaining the checkerboard distribution of co-occurring bird species in New Guinea archipelago. By that time, the assembly rules proposed interspecific competition as the only plausible explanation for the patterns observed. However, the lack of testable predictions, inappropriate statistical analyses and, mainly, the absence of alternative hypotheses have represented an obstacle for the theory development. With the introduction of phylogenetic/functional analyses in community studies, a meaningful increase of published papers on community assembly has been noticed, mainly due to the development of models providing more predictive power to assembly processes. Hence, we decided to elaborate a critical review about the conceptual progress in the community assembly theory. We point out that a) the community assembly theory has enhanced its predictive power when it became to be associated with solid statistics; b) the hypothesis test by null models has been reinforced as a consistent data analysis method applied in many studies; and c) the neutral theory has been used as a satisfactory alternative to the coexistence hypothesis by deterministic niche-based processes. However, the community assembly theory is not fully mature yet but has a high potential of near-future development, mainly through the consolidation of its conceptual base. We hope that our review can help in this development by systematizing the community assembly theory and clarifying some misunderstood and/or so-far poorly applied concepts. © 2016, Universidade Federal do Rio de Janeiro (UFRJ). All rights reserved.20111

Measurement of inclusive two-particle angular correlations in pp collisions with the ATLAS detector at the LHC

We present a measurement of two-particle angular correlations in proton- proton collisions at s√=900 GeV and 7 TeV. The collision events were collected during 2009 and 2010 with the ATLAS detector at the Large Hadron Collider using a single-arm minimum bias trigger. Correlations are measured for charged particles produced in the kinematic range of transverse momentum p T  > 100 MeV and pseudorapidity |η| < 2.5. A complex structure in pseudorapidity and azimuth is observed at both collision energies. Results are compared to pythia 8 and herwig++ as well as to the AMBT2B, DW and Perugia 2011 tunes of pythia 6. The data are not satisfactorily described by any of these models

Towards a novel combined lung and kidney support device – effect of utilizing hemodialysis membranes outside-in on solute clearance and filtration efficiency in full blood

Objectives: A novel artificial lung with integrated kidney support is being developed (RenOx) combining oxygenation and hemodialysis fibers utilized outside-in (blood flow outside the fibers). In a previous study, we indicated that 25% of gas exchange fibers in our oxygenator could be replaced by dialysis fibers maintaining sufficient pulmonary support. However, the effect of utilizing dialysis fibers outside-in on renal support is unknown. Thus, this study evaluates the efficiency of commercial dialyzer membranes utilized outside-in compared to traditional inside-out mode regarding solute clearance during continuous renal replacement therapy (CRRT), and ultrafiltration coefficient.Methods: The performance of commercial dialyzers utilized outside-in and inside-out was compared during in-vitro blood tests adapting the ISO8637:2016. Clearance of urea and creatinine was measured during continuous hemodialysis with a blood flow of 150 mL/min and dialysate flow of 30 mL/min or 50 mL/min, and during continuous hemofiltration with ultrafiltration of 20 mL/min. Filtration efficiency was evaluated in terms of ultrafiltration coefficient.Results: Clearance of urea and creatinine during continuous hemodialysis and hemofiltration were not significantly different between dialyzers utilized outside-in and inside-out (p &gt;0.2), except for tests with dialysate flow of 50 mL/min, where outside-in fibers achieved higher urea clearance. The ultrafiltration coefficient of dialyzers utilized outside-in (11.7 mL/h/mmHg) was 4 times smaller than the one obtained for inside-out dialyzers. However, required fluid removal could be achieved by managing pressures in the system.Conclusions: We showed that hemodialyzers utilized outside-in achieved similar small solute clearance dose as traditional dialyzers, sufficient to provide a required CRRT dose of 20–25 mL/kgpatient/h assuming the treatment of a hypothetical 80 kgpatient. Sufficient fluid removal could be provided by controlling system pressures. We consider this a step towards the development of the RenOx device

Water use in the São Francisco River basin, Brazil: an interregional input-output analysis

The planning and management of water resources aiming to a sustainable development must necessary pass through a series of studies that will reveal the interrelations and links among economic activities, and if one is considering that there is a set regions involved in the process, the direct and indirect regional interdependencies. Increasing demands of water-use for industrial, agricultural and urban sectors may became very competitive and can result in conflicts among multiple users. In the case of the São Francisco River Basin, Brazil, consisting of a wide-range five states - most of them having drought problems - the water in the basin plays an essential role and any activity in this area has to consider the effects of the water use in the intersectoral and interregional economic relations. Considering the three main states in the basin - Minas Gerais, Bahia and Pernambuco - an interregional input-output system for the economy and for the water flows was constructed by the authors. The above interregional system is then used to analyze the interregional and intersectoral dependencies among the states and the economic activities on the São Francisco river basin area and their relations with the use of water

Water use in the São Francisco River basin, Brazil: an interregional input-output analysis

The planning and management of water resources aiming to a sustainable development must necessary pass through a series of studies that will reveal the interrelations and links among economic activities, and if one is considering that there is a set regions involved in the process, the direct and indirect regional interdependencies. Increasing demands of water-use for industrial, agricultural and urban sectors may became very competitive and can result in conflicts among multiple users. In the case of the São Francisco River Basin, Brazil, consisting of a wide-range five states - most of them having drought problems - the water in the basin plays an essential role and any activity in this area has to consider the effects of the water use in the intersectoral and interregional economic relations. Considering the three main states in the basin - Minas Gerais, Bahia and Pernambuco - an interregional input-output system for the economy and for the water flows was constructed by the authors. The above interregional system is then used to analyze the interregional and intersectoral dependencies among the states and the economic activities on the São Francisco river basin area and their relations with the use of water