Singular kernels, multiscale decomposition of microstructure, and dislocation models

We consider a model for dislocations in crystals introduced by Koslowski, Cuiti\~no and Ortiz, which includes elastic interactions via a singular kernel behaving as the $H^{1/2}$ norm of the slip. We obtain a sharp-interface limit of the model within the framework of $\Gamma$-convergence. From an analytical point of view, our functional is a vector-valued generalization of the one studied by Alberti, Bouchitt\'e and Seppecher to which their rearrangement argument no longer applies. Instead we show that the microstructure must be approximately one-dimensional on most length scales and exploit this property to derive a sharp lower bound

Characterization of organic compounds from biosolids of Buenos Aires city

143-152The use of biosolids as a source of organic matter improves the physical and chemical properties of agricultural soils, resulting in an increase in crop yields. In previous studies, between 29-45 percent of sludge-borne carbon was recalcitrant a year after land application of biosolids from Buenos Aires City. Although high concentrations of some persistent organic pollutants have been worldwide reported to be present in this waste, this study has not been addressed in Argentina until now. Therefore, our aim was to characterize the organic compounds in Buenos Aires City's biosolids. Different extracting solvents were evaluated for ultrasound-assisted extraction (UAE). Results indicated that the combination of hexane: acetone (3:2, v/v) showed the highest extractability, allowing the identification of a wide range of organic compounds, without a clean-up or a pre-concentration step. The organic compounds mainly consisted of fatty acids, n-alkanes and steroids, with concentrations of persistent organic pollutants below detection limits. We conclude that the recalcitrant organic fraction reported in previous research is mainly due to the presence of stable sterols

Dynamics of trace metal sorption by an ion-exchange chelating resin described by a mixed intraparticle/film diffusion transport model. The Cd/Chelex case

The time-evolution of Cd2+ ion sorption by Chelex 100 resin was studied in batch experiments as a function of time, pH, ionic strength, stirring rate, mass of resin and initial metal ion concentration. In the experimental conditions, the amount of resin sites are in excess with respect to the amount of metal ion, leading to extensive depletion of metal in bulk solution when equilibrium is reached. The data were described using a mixed control mass transport model in finite volume conditions (MCM) that includes explicitly both intraparticle and film diffusion steps. Exact numerical computations and a new approximate analytical expression of this model are reported here. MCM successfully predicts the influence of pH and ionic strength on the experimental Cd(II)/Chelex kinetic profiles (which cannot be justified by a pure film diffusion controlled mechanism) with a minimum number of fitting parameters. The overall diffusion coefficient inside the resin was modelled in terms of the Donnan factor and the resin/cation binding stability constant. The values of the latter coefficient as a function of pH and ionic strength were estimated from the Gibbs-Donnan model. Even though MCM is numerically more involved than models exclusively restricted to film or intraparticle diffusion control, it proves to be accurate in a wider range of values of the mass transfer Biot number and solution/resin metal ratios.The authors gratefully acknowledge support for this research from the Spanish Ministry MINECO (Projects CTM2013-48967 and CTM2016-78798) and by the “Comissionat d'Universitats i Recerca de la Generalitat de Catalunya” (2014SGR1132). FQ acknowledges a grant from AGAUR

A simple abstraction of arrays and maps by program translation

We present an approach for the static analysis of programs handling arrays, with a Galois connection between the semantics of the array program and semantics of purely scalar operations. The simplest way to implement it is by automatic, syntactic transformation of the array program into a scalar program followed analysis of the scalar program with any static analysis technique (abstract interpretation, acceleration, predicate abstraction,.. .). The scalars invariants thus obtained are translated back onto the original program as universally quantified array invariants. We illustrate our approach on a variety of examples, leading to the " Dutch flag " algorithm

Control of Fusarium head blight and accumulation of deoxynivalenol in durum wheat grain, semolina and bran

To verify the effects of E.B.I. fungicides on Fusarium head blight and to determine the deoxynivalenol (DON) content in grain, semolina and bran, three separate trials were carried out in fields near Bologna (Italy) on susceptible durum wheat varieties artificially inoculated with F. graminearum and F. culmorum, responsible of this disease. Treatments with bromuconazole, prochloraz, tebuconazole applied in the field had significantly reduced the FHB disease incidence and severity by 56% and 73% respectively and the numbers of kernels infected by F. graminearum and F. culmorum by 66.6%. These products reduced also DON content in kernels, semolina and bran, compared to the non treated samples. The correlation (r) between DON and the incidence of F. graminearum and F. culmorum infected kernels was in the Original Sample (OS) 0.90

Catalysis in non--local quantum operations

We show how entanglement can be used, without being consumed, to accomplish unitary operations that could not be performed with out it. When applied to infinitesimal transformations our method makes equivalent, in the sense of Hamiltonian simulation, a whole class of otherwise inequivalent two-qubit interactions. The new catalysis effect also implies the asymptotic equivalence of all such interactions.Comment: 4 pages, revte

Unusual PLS application for Pd(ii) sensing in extremely acidic solutions

An economic and extremely selective device for Pd(ii) determination in very acidic solutions, TazoC-Mar@ is presented. The sensor was prepared via an ion exchange technique of an azoic ligand, (2-(tetrazolylazo)-1,8 dihydroxy naphthalene-3,6,-disulphonic acid), named TazoC, on a Macroporous Strong Anion Exchange Resin, namely Marathon® (Dow Chemical-USA). The TazoC-Mar@ rapidly forms complexes with palladium(ii) ions, which give an intense blue colour to the solid phase, even at low pH. The reaction is highly selective and no other metal ions react with the device at this pH. Moreover, the quantification of Pd(ii) is reliable when applying partial least squares regression (PLS) to relate the signal to the metal ion concentration. The regression model gives a good fit and correct predictions of Pd(ii) concentrations in unknown samples. The method presented here is highly sensitive with an LOD and LOQ equal to 0.2 nM and 0.5 nM, respectively

Evaluation of Fresh Groundwater Lens Volume and Its Possible Use in Nauru Island

A proper management of fresh groundwater lenses in small islands is required in order to avoid or at least limit uncontrolled saltwater intrusion and guarantee the availability of the resource even during drought occurrences. An accurate estimation of the freshwater volume stored in the subsoil is a key step in the water management decision process. This study focused on understanding the hydrogeological system behaviour and on assessing the sustainable use of the groundwater resource in Nauru Atoll Island (Pacific Ocean). A first phase, concerning the hydrogeological characterization of the island, highlighted the occurrence of few drought-resilient freshwater lenses along the seashore. The second part of the study focused on the characterization of a freshwater lens found in the northern coastal area and identified such area as the most suitable for the development of groundwater infrastructures for water withdrawal. The characterization activities allowed quantifying the freshwater lens thickness and volume in order to assess the capability to satisfy the population water demand. A geo-electrical tomography survey was carried out, and a 3D density-dependent numerical model was implemented in SEAWAT. The model results demonstrated that in small islands freshwater can unexpectedly accumulate underground right along the seashore and not in the centre of the island as is commonly believed. Furthermore, the model can constitute a useful tool to manage the groundwater resources and would allow the design of sustainable groundwater exploitation systems, avoiding saltwater intrusion worsening

La Técnica de Rejilla como Instrumento de Evaluación y Formulación de Hipótesis Clínicas

El presente artículo se inicia con una presentación de la Técnica de Rejilla (TR), enmarcada en el contexto de la Teoría de los Constructos Personales (TCP). A continuación, se expone la aplicación de la TR al caso de Ana diagnosticada por trastorno depresivo mayor, bulimia nerviosa y trastorno de personalidad por evitación, además de presentar otros síntomas variados. Se eligió este caso por su complejidad clínica y por la manera en que se ven reflejados los síntomas de la paciente en su estructura cognitiva, puesta de manifiesto por la TR. A pesar de que Ana pidió ayuda por iniciativa propia, en las sesiones se muestra reticente a hablar de sí misma, por lo que la TR resultó ser un buen medio de aproximación a la visión del mundo de la cliente, y un instrumento útil para formular hipótesis clínicas