Model Calculation of Electron-Phonon Couplings in a Dimer with a Non-Degenerate Orbital

We evaluate all the electron-phonon couplings derived from the one-body electronic interactions, in both the adiabatic and extreme non-adiabatic limit, for a dimer with a non-degenerate orbital built from atomic wave functions of Gaussian shape. We find largely different values of the coupling parameters in the two cases, as well as different expressions of the corresponding terms in the Hamiltonian.Comment: 5 postscript figure

Integration of Dirac-Jacobi structures

We study precontact groupoids whose infinitesimal counterparts are Dirac-Jacobi structures. These geometric objects generalize contact groupoids. We also explain the relationship between precontact groupoids and homogeneous presymplectic groupoids. Finally, we present some examples of precontact groupoids.Comment: 10 pages. Brief changes in the introduction. References update

Glassy magnetic phase driven by short range charge and magnetic ordering in nanocrystalline La1/3_{1/3}Sr2/3_{2/3}FeO3−δ_{3-\delta}: Magnetization, Mossbauer, and polarised neutron studies

The charge ordered La$_{1/3}$Sr$_{2/3}$FeO$_{3-\delta}$ (LSFO) in bulk and nanocrystalline forms are investigated using ac and dc magnetization, M\"{o}ssbauer, and polarised neutron studies. A complex scenario of short range charge and magnetic ordering is realized from the polarised neutron studies in nanocrystalline specimen. This short range ordering does not involve any change in spin state and modification in the charge disproportion between Fe$^{3+}$ and Fe$^{5+}$ compared to bulk counterpart as evident in the M\"{o}ssbauer results. The refinement of magnetic diffraction peaks provides magnetic moments of Fe$^{3+}$ and Fe$^{5+}$ are about 3.15$\mu_B$ and 1.57$\mu_B$ for bulk, and 2.7$\mu_B$ and 0.53$\mu_B$ for nanocrystalline specimen, respectively. The destabilization of charge ordering leads to magnetic phase separation, giving rise to the robust exchange bias (EB) effect. Strikingly, EB field at 5 K attains a value as high as 4.4 kOe for average size $\sim$ 70 nm, which is zero for the bulk counterpart. A strong frequency dependence of ac susceptibility reveals cluster-glass like transition around $\sim$ 65 K, below which EB appears. Overall results propose that finite size effect directs the complex glassy magnetic behavior driven by unconventional short range charge and magnetic ordering, and magnetic phase separation appears in nanocrystalline LSFO.Comment: 10 pages, 9 figures. Fig. 1 available upon request or in http://www.ffn.ub.es/oscar/Articles.html. Accepted in Phys. Rev.

Self-T-Dual Brane Cosmology and the Cosmological Constant Problem

We consider a codimension-one brane embedded in a gravity-dilaton bulk action, whose symmetries are compatible with T-duality along the space-like directions parallel to the brane, and the bulk time-like direction. The equations of motions in the string frame allow for a smooth background obtained by the union of two symmetric patches of AdS space. The Poincar\'{e} invariance of the solution appears to hold independently of the value of the brane vacuum energy, through a self-tuning property of the dilaton ground state. Moreover, the effective cosmology displays a bounce, at which the scale factor does not shrink to zero. Finally, by exploiting the T-duality symmetry, we show how to construct an ever-expanding Universe, along the lines of the Pre-Big Bang scenario.Comment: Minor corrections, comments & references added. Accepted for publicatio

Heterogeneous electro-Fenton treatment: preparation, characterization and performance in groundwater pesticide removal

In this work the preparation, characterization and performance of Y-zeolite as catalyst for electro-Fenton treatment of pesticides was carried out. Initially iron supported Y-zeolite (Fe-Y) was prepared and evaluated for the degradation of imidacloprid and chlorpyrifos. Kinetics studies determined that the pesticides removal followed a pseudo-first-order kinetic model. However, the reusability of this catalyst was not appropriated and to enhance its recyclability, Fe-Y catalyst was embedded in alginate (Al-Fe-Y). The new catalyst showed similar degradation efficiency; and the recyclability was improved. This study demonstrated that Al-Fe-Y could be efficiently used to remove commonly pesticides, imidacloprid and chlorpyrifos, of aqueous medium.This work has been supported by the Xunta de Galicia (EM2012/083). The authors are thankful to the Ramón y Cajal programme for Marta Pazos’ financial support and to C.A.C.T.I. from Vigo University for providing access to their Electron Microscopy Service

Анализ рисков для здоровья населения питьевой воды, обеззараженной диоксидом хлора (обзор литературы и собственных исследований)

Проаналізовано данні літератури і особистих досліджень щодо безпечності питної води, знезараженої диоксидом хлору. Показана відсутність самостійних досліджень щодо вивчення впливу диоксиду хлору і хлориту на біохімічні константи сироватки крові і активність ферментів. Вказано, що ці показники є у більшій мірі інформативними, ніж традиційні (число еритроцитів, рівень гемоглобіну) як тест-реакції на можливу окислювальну деструкцію під впливом диоксиду хлору і хлорит-аніону.The given literatures and own researches about safety of the potable water disinfected of chlorine dioxide are analyzed. Absence of independent researches of chlorine dioxide and chlorite influence on biochemical constants of blood whey and levels of enzymes activity ascertained. It is specified, that these parameters are in the greater degree informative, rather than traditional (erythrocyte number, level of hemoglobin) as tests - reactions on possible oxidizing destruction under influence of chlorine dioxide and chlorite anion

Star Forming Objects in the Tidal Tails of Compact Groups

A search for star forming objects belonging to tidal tails has been carried out in a sample of deep Halpha images of 16 compact groups of galaxies. A total of 36 objects with Halpha luminosity larger than 10^38 erg s-1 have been detected in five groups. The fraction of the total Halpha luminosity of their respective parent galaxies shown by the tidal objects is always below 5% except for the tidal features of HCG95, whose Halpha luminosity amounts to 65% of the total luminosity. Out of this 36 objects, 9 star forming tidal dwarf galaxy candidates have been finally identified on the basis of their projected distances to the nuclei of the parent galaxies and their total Halpha luminosities. Overall, the observed properties of the candidates resemble those previously reported for the so-called tidal dwarf galaxies.Comment: 5 gif figures. Accepted for publication in Astrophysical Journa

In vivo staging of frontotemporal lobar degeneration TDP-43 type C pathology

Background: TDP-43 type C is one of the pathological forms of frontotemporal lobar degeneration (FTLD) and mainly associated clinically with the semantic variant of primary progressive aphasia (svPPA). We aimed to define in vivo the sequential pattern of neuroanatomical involvement in a cohort of patients with FTLD-TDP type C pathology. Methods: We extracted the volumes of a set of cortical and subcortical regions from MRI scans of 19 patients with post mortem confirmed TDP-43 type C pathology (all with left hemisphere-predominant atrophy at baseline). In the initial development phase, we used w-scores computed from 81 cognitively normal controls to define a set of sequential stages of neuroanatomical involvement within the FTLD-TDP type C cohort where a w-score of < − 1.65 was considered abnormal. In a subsequent validation phase, we used 31 follow-up scans from 14 of the 19 patients in the same cohort to confirm the staging model. Results: Four sequential stages were identified in the initial development phase. Stage 1 was defined by atrophy in the left amygdala, medial temporal cortex, temporal pole, lateral temporal cortex and right medial temporal cortex; Stage 2 by atrophy in the left supratemporal cortex; Stage 3 by atrophy in the right anterior insula; and Stage 4 by atrophy in the right accumbens. In the validation phase, calculation of w-scores in the longitudinal scans confirmed the staging system, with all patients either staying in the same stage or progressing to a later stage at follow-up. Conclusion: In vivo imaging is able to detect distinct stages of neuroanatomical involvement in FTLD-TDP type C pathology. Using an imaging-derived staging system allows a more refined stratification of patients with svPPA during life