Cool dwarfs in wide multiple systems. Paper 6: A curious quintuple system of a compact Sun-like triple and a close pair of an M dwarf and a very cool white dwarf at a wide separation

The system WDS 16329+0315 is an old, nearby quintuple physical system in the thick Galactic disc formed by a close-resolved, triple primary of solar metallicity, namely HD 149162, and a very wide, common proper motion, secondary pair, formed by the mid-M dwarf G-17-23 and the white dwarf LSPM J1633+0311S. We present an exhaustive astrometric and photometric data compilation of the system, including Gaia DR2 parallaxes and proper motions, and the first analysis of the nature of the faintest component. LSPM J1633+0311S (HD 149162 C) is a very cool white dwarf with an effective temperature of only about 5500 K, near the coolest end of the grid of theoretical models.Comment: The Observatory, in press, to appear in December 201

Microestructura y resistencia a la corrosión de nitruros de cromo obtenidos por nitruración gaseosa al vacío de cromo electrolítico depositado sobre acero AISI H13.

En este artículo se caracteriza la microestructura y se evalúa la resistencia a la corrosión de nitruros de cromo obtenidos a partir de un tratamiento dúplex constituido por un recubrimiento electrolítico de cromo aplicado sobre un acero AISIH13 combinado posteriormente a un proceso de nitruración gaseosa, mediante un tratamiento termoquímico al vacío, utilizando NH3 como gas precursor de nitrógeno. Este tipo de tratamientos dúplex permite combinar las ventajas de tratamientos individuales y con este efecto sinérgico, obtener compuestos tipo CrxN en forma más económica que los producidos tradicionalmente de deposición física en fase de vapor (PVD). Los resultados obtenidos mediante difracción de rayos-X (XRD) indican una transformación superficial y subsuperficial del recubrimiento electrolítico de cromo con formación de fases CrN y Cr2N. Así mismo, los ensayos de polarización potenciodinámica indican un incremento en la resistencia a la corrosión de este tipo de compuestos en comparación con los obtenidos con cromo duro electrolítico.

Electrodialytic separation of Cu(II) and As(V) in acidic electrolytes

[ES]Se investigó el uso de la electrodiálisis para separar cobre y arsénico desde soluciones ácidas a temperatura ambiente. Se estudió el efecto de la densidad de corriente y grado de acidez del electrolito en la separación a través de experimentos en celda batch de 5 compartimientos durante 3 h. Los parámetros cinéticos indican que la velocidad de transporte de Cu(II) fue de 0,75 mol/h/m2 y de As(V) fue de 0,002 mol/h/m2 a una densidad de corriente de 225 A/m2. Se logró obtener una eficiente separación de Cu(II) y As(V), con la generación de una solución concentrada de cobre sin presencia de arsénico, lo cual fue independiente del grado de acidez de la operación y de la densidad de corriente. El efecto de la distribución de las especies iónicas de As(V) con el pH también se discute.[EN]The separation of copper and arsenic from acidic electrolytes by electrodialysis was investigated at room temperature. The effect of current density and pH was studied in a batch cell during 3 hours. The kinetic parameters showed that Cu(II) transport rate was 0.75 mol/m2/h and the As(V) transport rate was 0.002 mol/m2/h. An efficient separation between Cu(II) and As(V) was achieved; generating a concentrated solution of copper with no arsenic, which was obtained independently of the electrolyte acidity and current density used. The effect of the arsenic speciation with pH is discussed as well.Peer reviewe

A Finite Element‑Based Methodology for the Thermo‑mechanical Analysis of Early Age Behavior in Concrete Structures

This paper presents a general procedure based on fracture mechanics models in order to analyze the level of cracking and structural safety in reinforced concrete elements at early ages, depending on the stripping time. Our procedure involves the development of a thermo-mechanical numerical model based on the finite element method that accounts for the change in the mechanical properties of concrete with time. Moreover, fracture mechanisms are analyzed by means of a material damage model, which is characterized via specific experimental results obtained for standard specimens and notched beams under three-point bending testing. The loading conditions are both thermal and mechanical, and are obtained from the hydration process for a given concrete dosage. The presented methodology allows for the determination of the optimal stripping time, whereas it helps assessing the analysis of the cracking and the stress states of the elements under consideration. A practical application, namely the analysis of a retaining wall, is used to validate our methodology, showing its suitability in engineering practice.Ministerio de Economía y Competitividad BIA2016-75431-

Supercritical fluid extraction: Recent advances and applications

17 páginas, 2 figuras, 5 tablas.Among the different extraction techniques used at analytical and preparative scale, supercritical fluid extraction (SFE) is one of the most used. This review covers the most recent developments of SFE in different fields, such as food science, natural products, by-product recovery, pharmaceutical and environmental sciences, during the period 2007–2009. The revision is focused on the most recent advances and applications in the different areas; among them, it is remarkable the strong impact of SFE to extract high value compounds from food and natural products but also its increasing importance in areas such as heavy metals recovery, enantiomeric resolution or drug delivery systems.M. H. would like to thank MEC for his Juan de la Cierva contract. This work was supported by an AGL2008-05108-C03-01 (Ministerio de Educacion y Ciencia) and CSD2007-00063 FUN-C-FOOD (Programa CONSOLIDER-INGENIO 2010) projects.Peer reviewe

Use of compressed fluids for sample preparation: Food applications

This review attempts to provide an updated overview (including works published till June 2006) on the latest applications of compressed fluids as sample preparation techniques for food analysis. After a general review of the principles of supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE; also called accelerated solvent extraction, ASE or subcritical water extraction, SWE, when water is employed as extraction solvent), the principal applications of such techniques in the mentioned fields of food and natural products are described, discussing their main advantages and drawbacks.This work has been financed by Spanish Ministry of Education (Project AGL2005-06726-C04-01/02 and Project AGL2005-05320-C02-01) and Comunidad Autónoma de Madrid (S-0505/AGR/000153) projects. JAM and MH thank the Spanish Ministry of Education for a grant.Peer reviewe

Risk screening for exposure to groundwater pollution in a wastewater irrigation district of the Mexico City region.

Untreated wastewater from the Mexico City basin has been used for decades to irrigate cropland in the Mezquital Valley, State of Hidalgo, Mexico. Excess irrigation water recharges the near-surface aquifer that is used as a domestic water supply source. We assessed the groundwater quality of three key groundwater sources of domestic water by analyzing for 24 trace metals, 67 target base/neutral/acid (BNA) organic compounds, nontarget BNA organics, 23 chlorinated pesticides, 20 polychlorinated biphenyls, and nitrate, as well as microbiological contaminants--coliforms, Vibrio cholerae, and Salmonella. Study participants answered a questionnaire that estimated ingestion and dermal exposure to groundwater; 10% of the sample reported frequent diarrhea and 9% reported persistent skin irritations. Detection of V. cholerae non-01 in surface waters at all sites suggested a potential risk (surrogate indicator present) of diarrheal disease for canal and river bathers by accidental ingestion, as well as potential Vibrio contamination of near-surface groundwater and potential cholera risk, magnified by lapses in disinfection. High total coliform levels in surface water and lower levels in groundwater at all sites indicated fecal contamination and a potential risk of gastrointestinal disease in populations exposed to inadequately disinfected groundwater. Using chemical criteria, no significant risk from ingestion or dermal contact was identified at the method detection limits at any site, except from nitrate exposure: infants and young children are at risk from methemoglobinemia at all sites. Results suggest that pathogen risk interventions are a priority, whereas nitrate risk needs further characterization to determine if formal treatment is needed. The risks exist inside and outside the irrigation district. The method was highly cost-effective

Analysis of the main passive soft tissues associated with adult acquired flatfoot deformity development: A computational modeling approach

Adult acquired flatfoot deformity (AAFD) is a pathology with a wide range of treatment options. Physicians decide the best treatment based on their experience, so the process is entirely subjective. A better understanding of soft tissue stress and its contribution in supporting the plantar arch could help to guide the clinical decision. Traditional experimental trials cannot consistently evaluate the contribution of each tissue. Therefore, in this research a 3-Dimensional FE foot model was reconstructed from a normal patient in order to measure the stress of the passive stabilizers of the arch, and its variation in different scenarios related with intermediate stages of AAFD development. All bones, the plantar fascia (PF), cartilages, plantar ligaments and the spring ligament (SL) were included, respecting their anatomical distribution and biomechanical characteristics. An AAFD evaluation scenario was simulated. The relative contribution of each tissue was obtained comparing each result with a normal case. The results show that PF is the main tissue that prevents the arch elongation, while SL mainly reduces the foot pronation. Long and short plantar ligaments play a secondary role in this process. The stress increment on both PF and SL when one of two fails suggests that these tissues complement each other. These findings support the theory that regards the tibialis posterior tendon as a secondary actor in the arch maintenance, compared with the PF and the SL, because this tendon is overstretched by the hindfoot pronation around the talonavicular joint. This approach could help to improve the understanding of AAFD

Curiosity driven search: When is relevance irrelevant?

Classical information search behaviour models based on work-task scenarios fail to explain common leisure search scenarios motivated by a hedonistic need rather than a defined information need. This paper presents work into such unstructured search driven by curiosity. In order to explore this hedonistic catalyst, a social media search application was designed in which the search experience is triggered by the user's spatio-temporal context during their exploration rather than query-response based information retrieval. We report a study with real users and a simulated casual-leisure search task where results indicated that relevance is not relevant for some searches