Modelling titration curves of mixed materials with variable and permanent surface charge: application

3 pages, 1 figure, 2 references. Congreso celebrado del 7-10, septiembre, 1987, Sevilla, España. EUROCLAY'87.Two well-known materials, lepidocrocite (specilic sur-face area 115 m2g-1) and montmorillonite (internal surface are a 700 m2g-1), can be useful to test the mathematical model described in the preceding communication. With thispurpose, acid and base titration curves of both minerals and of mixtures containing 80% (w/w) of lepidocrocite (sample LM) and 80% montmorillonite (sample ML) were obtained at three ionic strengths (0.01, 0.1 and 1 M NaCl). The amounts of titrant consumed by the suspensions at each pH were corrected for the amount consumed by the corresponding solution at the same pH. The resulting graphs are shown in next page. Dashed lines will be explained later.Peer reviewe

Conflicto y violencia en las Sierras de Córdoba durante el período prehispánico : una discusión basada en información arqueológica y etnohistórica

Fil: Díaz, Iván. Fil: Barrientos, Gustavo. División Antropología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Pastor, Sebastián

Influence of inorganic amendments on trace metal extractable contents in urban soils

2 páginas, 1 tabla y 2 referencias. Poster contributions- SO-62 presentado en el VIII International symposium on analytical methodology in the environmental field. XIII Reunión de la Sociedad española de química analítica, VIII ISAMEF/SEQA 2003. University of A Coruña October 21-24, 2003.Urban soils in medium size and big cities, have shown in many cases (Madrid et al. 2002) high contents of some trace metals, for example lead, copper, or zinc, due to traffic, industry, etc (Bullock and Gregory, 1991). The presence of these metals at high concentrations in the soils of green areas, mainly recreational areas, is a potential source of dangerous elements for human health. For that reason, the availability of these contaminant elements is an essential control parameter, because it is related to plant uptake, and to their transfer to humans via suspended dust or by direct contact, specially by small childrens. The addition of amendments to the soil is a reasonable technique to reduce the availability of trace metals. The relationship between trace metals and different inorganic amendments was studiedXunta de Galicia: Consellería de Medio Ambiente. Dirección Xeral do Centro de Desenvolvemento Sostible. Xunta de Galicia: Consellería de Innovación, de Industria e Comercio. Dirección Xeral de Investigación e Desenvolvemento. Xunta de Galicia: Consellería de Educación e Ordenación Universitaria. Dirección Xeral de Universidades. Ministerio de Ciencia y Tecnología. Dirección General de Investigación. Excma. Diputación Provincial de A Coruña. Excmo. Ayuntamiento de A Coruña REPSOL, YPF, ENDESA GENERACIÓN, SIR, ENCE, GAIRESA, UNIÓN FENOSA, TIRME.Peer reviewe

Modelamiento del calentamiento de probetas cilíndricas en un horno de inducción mediante el uso de diferencias finitas

95 p.El objetivo de esta memoria es modelar el calentamiento de piezas cilíndricas en un horno de inducción electromagnética que se encuentra en el laboratorio de electrónica de la Universidad de Talca, mediante el uso del método de las diferencias finitas regresivas, por lo cual, se escribirá un código para tal fin. Para obtener un parámetro de comparación del código, se crearan dos modelos: uno teórico-computacional (ANSOFT MAXWELL) y otro experimental-práctico, en el cual se analizaran la distribución de temperaturas durante el tiempo y se comparara con los datos calculados mediante el código FDM. El error en las mediciones es de un 10% Palabras clave: Método diferencias finitas, Transferencia de calor, Hornos de inducción, ANSYS, Electromagnetismo, Inducción electromagnética/ ABSTRACT: The subject of this thesis is modelling the heating in cylindrical probes in an electromagnetic induction oven that is on the electronic laboratory of the University of Talca, using the backward finite difference method. In this thesis will be write a code for modelling this. For comparing the code, we create two models, the first one is a theoric-computational (ANSOFT MAXWELL) and the second one is a practice-experimental, where the temperatures will be analized and comparated across the time with the FDM code. The error of the temperatures is around 10%. Keywords : Finite difference method, heat transfer, induction oven, ANSYS, electromagnetism, electromagnetic inductio

An effective lagrangian description of charged Higgs decays H^+ -> Wg, WZ and Wh

Charged Higgs decays are discussed within an effective lagrangian extension of the two-higgs doublet model, assuming new physics appearing in the Higgs sector of this model. Low energy constrains are used to imposse bounds on certain dimension -six operators that describe the modified charged Higgs interactions. These bounds are used then to study the decays H^+ -> Wg, WZ and Wh, which can have branching ratios of order 10^-5, 10^-1 and O(1), respectively; thse modes are thus sensitive probes of the symmetries of the Higgs sector that could be tested at future colliders.Comment: 15 pages, 3 figure

Anthropometric Characteristics, Body Composition and Somatotype in Elite Junior ITF Tennis Players from South America

Indexación: Scopus; Scielo.El objetivo de este estudio fue determinar las características antropométricas, composición corporal y somatotipo en tenistas varones elite juniors sudamericanos de la Federación Internacional de Tenis. Participaron 25 jugadores de 17,04 ± 1,05 años. La composición corporal se evaluó con el perfil restringido de 25 variables propuesto por Kerr en base al método pentacompartimental, el cual fracciona el cuerpo en 5 componentes (tejidos: muscular, adiposo, óseo, residual, y piel). El somatotipo se identificó con el método de Heath y Carter. Para la evaluación se utilizaron las normas propuestas por La Sociedad Internacional para el Avance de la Cineantropometría (ISAK) y el Grupo Español de Cineantropometría (GREC). El porcentaje de tejido muscular fue de 47,65 ± 2,83 %, tejido adiposo de 23,23 ± 3,56 %, y tejido óseo de 11,79 ± 1,56 % con un índice músculoóseo(IMO) de 4,09 ± 0,50. En cuanto al somatotipo se apreció una clasificación de tipo mesomorfo balanceado con valores de 2,5 ± 0,81 de endomorfia, 4,9 ± 0,66 de mesomorfia, y 2,7 ± 0,96 de ectomorfia. El grupo de tenistas presentó un predominio del componente mesomorfia con un equilibrio entre los componentes endomorfia y ectomorfia con características de composición corporal similares a las encontradas en la literatura. El presente estudio entrega datos referenciales sobre las características antropométricas en tenistas sudamericanos nivel elite categoría junior.The objective of the study was to determine the anthropometric characteristics, body composition and somatotype in male elite junior tennis players from the International Tennis Federation (ITF). Twenty five players of 17.04 ± 1.05 years participated. The body composition was evaluated with the restricted profile of 25 variables proposed by Kerr based on the pent compartmental method, which divided the body into 5 components (tissues: muscle, adipose, bone, residual, and skin). The somatotype was identified with the Heath and Carter method. For the evaluation, the norms proposed by the International Society for the Advancement of Cineanthropometry (ISAK) and the Spanish Group of Cineanthropometry (GREC) were used. The percentage of muscle tissue was 47.65 ± 2.83 %, adipose tissue of 23.23 ± 3.56 %, and bone tissue of 11.79 ± 1.56 % with a muscle-osseous index (IMO) of 4.09 ± 0.50. Regarding somatotype, a balanced mesomorphic classification was observed with values of 2.5 ± 0.81 of endomorphy, 4.9 ± 0.66 of mesomorphy, and 2.7 ± 0.96 of ectomorphy. The group of tennis players presented a predominance of the mesomorphy component with a balance between the components endomorphy and ectomorphy with characteristics of body composition similar to those found in the literature. The present study provides referential data on the anthropometric characteristics in South American tennis players elite junior category.https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0717-95022018000301095&lng=en&nrm=iso&tlng=e

Niños, niñas y adolescentes en situación de calle : vínculos y relaciones al interior del grupo de la Caleta del Río Mapocho, una investigación cualitativa .

Tesis (Trabajo Social)RESÚMEN: La presente investigación tiene como principal objetivo conocer y analizar los vínculos que se generan al interior del grupo de niños, niñas y adolescentes en situación de calle que habitan la caleta del Río Mapocho, a partir de sus propios relatos. Esta investigación se realizó en la Escuela Refugio de Artes y Oficios de la Fundación Abrazarte, la cual reside a un grupo de adolescentes que durante un largo período de tiempo estuvieron en situación de calle, habitando las caletas del río Mapocho. La investigación se lleva a cabo a través de un enfoque metodológico cualitativo que nos permitió insertarnos en la temática desde una mayor comprensión del fenómeno, a partir de nuestras técnicas de recolección de información: la observación participante y la entrevista semiestructurada, de la cuál pudimos recoger los relatos. Los principales hallazgos de esta investigación dan cuenta del significado de familia que le otorgan a los vínculos al interior del grupo los niños, niñas y adolescentes en situación de calle, habitantes de la caleta del río Mapocho

Linking changes in radial profiles of sap flux density with the response of water vapour exchange to water deficit

8 páginas, 5 figuras, 1 tabla, 19 referencias.-- IX International Workshop on Sap Flow, celebrado del 4-7 de junio 2013, en Gante, Bélgica.Knowledge of temporal variations in radial profiles of sap flux density (Js) and its relation to canopy water vapour exchange would help to improve our understanding of plant water relations. In this study we aimed to test if there is a consistent radial profile of Js in olive trees under optimal soil water availability and severe water stress conditions. Furthermore, if the radial profile of Js is not consistent through time we aimed to assess whether this radial variability can be explained through differential water exchange response to evaporative demand (D) of sun-exposed, new foliage and shade, old foliage. We measured sap flux density in the trunk of 6-year-old olive trees under two different irrigation treatments: a full irrigation treatment and a treatment replacing 30% of the of irrigation needs. We related the hourly radial profiles characterized with the Beta probability distribution function with independent water vapour exchange measurements at different exposures in the tree canopy (sun-exposed, young foliage and shade, old foliage). Results showed that under well irrigated conditions the shape of the radial profile of Js hardly varied, but under water deficit situations most of the sap appears to be conducted deeper into the sapwood and Js is also more variable throughout the sapwood. Accordingly, results demonstrated that in shade, old foliage water vapour exchange varied less than in sun-exposed new foliage. As a result, in days under severe water deficit, the contribution of shade old foliage to the whole tree transpiration was greater. Radial profile changes and canopy measurements were found to respond in a similar way to D. During conditions of low D and soil water deficit it was observed a greater contribution of the inner xylem to total stem flow and shade, old leaves to canopy gas exchange.Peer reviewe

Reviewing the Composition of Vaginal Microbiota: Inclusion of Nutrition and Probiotic Factors in the Maintenance of Eubiosis

The vaginal microbiota has importance in preserving vaginal health and defending the host against disease. The advent of new molecular techniques and computer science has allowed researchers to discover microbial composition in depth and associate the structure of vaginal microbial communities. There is a consensus that vaginal flora is grouped into a restricted number of communities, although the structure of the community is constantly changing. Certain Community-State Types (CSTs) are more associated with poor reproductive outcomes and sexually transmitted diseases (STDs) meanwhile, CSTs dominated by Lactobacillus species—particularly Lactobacillus crispatus—are more related to vaginal health. In this work, we have reviewed how modifiable and non-modifiable factors may affect normal vaginal microbiota homeostasis—including sexual behavior, race or ethnicity, and hygiene. Special interest has been given to how the use of probiotics, diet intake, and use of hormone replacement therapies (HRTs) can potentially impact vaginal microbiota composition

UNDERSTOREY CHANGES COMPOSITION AFTER TEMPERATE KELP FOREST COLLAPSE BUT KEEPS RICHNESS AND DIVERSITY

Kelps are foundation species that provide important ecosystem services in temperate rocky shores worldwide. Similarly to terrestrial forests, healthy kelp forests are structurally complex as they are often arranged as patches composed by a multi-layered understorey of algae aggregations with different canopy adaptations. Over the last decades, several studies have reported a global kelp forest degradation, turning seascapes dominated by complex forest into structurally simpler mats of low-laying seaweeds. In NW Spain, golden kelp (Laminaria ochroleuca) canopy forests have recently receded within the limits of a MPA. This paradoxical loss inside a MPA allowed us to investigate the consequences of kelp forest collapse for other members of the biotic community, using nearby healthy kelp forest outside the MPA as a control. To assess these changes, four degraded sites within the MPA and four healthy kelp forest in nearby areas were sampled year round to assess the seasonal dynamics of understorey algae. Healthy and degraded kelp reefs had significantly different understorey assemblage compositions. However, unlike our expectations, these differences had little to none impact on the richness and diversity of the understorey assemblage. Moreover, understory differences were only perceptible when the assemblages were compared at the lowest taxonomic resolution (species). Unlike other studies, comparisons based on functional groups (canopy, sub-canopy, turf and crust) failed to detect any significant difference between healthy and degraded kelp forest