Functionalization of hydroxyapatite scaffolds with ZnO

This paper analyzes the effectiveness of a new method for treating the surface of bioceramics scaffolds intended for bone substitutes (SO). This employs hydroxyapatite (Ca5(PO4)3(OH), HA) obtained from the chemical treatment (weak acid) and pyrolysis (at 900°C) of fresh bovine bone. The inorganic matrix is formed by an interconnected pore structure and hydrophilic, very similar to the human cancellous bone, which is used in reconstructive surgery. The SO biologic response can be improved by surface modification with Zn, element known for its antibacterial action. The Zn fixing in HA is frequently performed by chemicalsynthesis processes, where Zn2 +, Ca2 + and PO43- ions co-precipitation processes take place. The proposed method begins with the chemical treatment of the HA with an aqueous solution of phosphoric acid (30 wt. %). These scaffolds are submerged (under vacuum) in a dispersion of ZnO in an alcohol-glycerin solution, which allows relatively uniform distribution of oxide on the porous medium, when it is dried. The Zn chemical bonding on HA surface is accomplished by sintering (900 to 1100°C). This promotes a solid state reaction, which leads to the formation of Zn phosphates (in hydrated and non-hydrated forms), according to the analysis of X-ray diffraction, energy spectroscopy and electron microscopy observation. This process is of simpleimplementation and it would allow SO functionalization with other therapeutic agents of interest, represented by different ions.Fil: Martinez, Cristian. Universidad de Buenos Aires. Facultad de Ingeniería; Argentina. Universidad Nacional de Cuyo. Facultad de Odontologia; ArgentinaFil: Gilabert, Ulises Eduardo. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Garrido, Liliana Beatriz. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; ArgentinaFil: Rosenbusch, Mariana Lidia. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes. Gerencia de Investigación y Aplicaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ozols, Andres. Universidad de Buenos Aires. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

A novel on-line preconcentration method for trace molybdenum determination by USN-ICP OES with biosorption on immobilized yeasts

A new system for on-line preconcentration of molybdenum by sorption on a minicolumn associated to inductively coupled plasma - optical emission spectrometry with ultrasonic nebulization was studied. It is based on the sorption of molybdenum on a column packed with immobilized baker's yeasts on controlled pore glass without further complexing reagent. The molybdenum preconcentrated by biosorption was subsequently eluted with hydrochloric acid. Considering a sample flow rate of 5.0 mL min- 1, 10 mL of sample was preconcentrated in 2 min achieving a sensitive total enhancement factor of 480-fold, and the detection limit (3 s) obtained was 21 ng L- 1. Additionally, the calculated precisions expressed as percent relative standard deviation (RSD%) was 1.9%. Satisfactory results were obtained for the determination of molybdenum in standard reference material NIST 1643e Trace Elements in Water and real water samples.Fil: Gil, Raul Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Pasini Cabello, Sergio David. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química. Área de Química Analítica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Takara, Eduardo Andres. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química. Área de Química Analítica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Smichowski, Patricia Nora. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Olsina, Roberto Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Martinez, Luis Dante. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentin

Proposal of a New Porous Concrete Dosage Methodology for Pavements

Although porous concrete pavement design methods are mainly focused on maintaining high permeability rates in order to improve their ability to manage stormwater runoff, the mixture strength is paramount for its durability and service life. This paper proposes a new mixture design method for porous concrete, named PCD (porous concrete design), derived from the ACI 522R-10 and ACI 211.3R-02 standards. The aim is to improve mechanical strength in porous concrete mixtures, while ensuring enough permeability for its use in urban roads. With PCD methodology it is possible to obtain mechanical strengths 30% higher than those produced with ACI methodologies, while maintaining permeability rates close to 2 cm/s, lower than those obtained with ACI methods but still enough to manage extreme storm events. Finally, with the analytical Hierarchy Process (AHP) multi-criteria decision-making methodology and also bearing in mind safety variables, the best porous concrete mixtures are the ones produced with PCD methodology.This research was funded by the Spanish Ministry of Economy and Competitiveness and the European Union (ERDF) through the project SUPRIS.SUReS (Ref. BIA2015-65240-C2-1-R)

Design of the electric propulsion system for dumper trucks

This article designs a high-efficiency electric propulsion system for industrial trucks, such as dumper trucks. This design proposes using an alternative energy storage system of green H2 hydrogen to reduce emissions. This design determines the propulsion systems' technical and power requirements, starting with each vehicle's driving and duty cycles. For this analysis, a longitudinal dynamic model is created, with which the behavior of the energy conversion chain of the propulsion system is established. The evolutionary methodology analyzes the dynamic forces of vehicle interaction to size the propulsion system's components and the storage system. Using green H2 as fuel allows an energy yield three times higher than diesel. In addition, using this green hydrogen prevents the emission of 264,172 kg of CO₂, which the dumper emits when consuming 1,000 daily gallons of diesel within its working day

Soil biologic crusts restoration: past, present and future

El presente trabajo resume los aspectos más importantes sobre la restauración de costras biológicas del suelo (CBs), incluyendo los factores más determinantes en el éxito de una restauración, los aspectos a tener en cuenta para seleccionar especies y las técnicas más empleadas, con el fin de servir como base para quienes desean llevar a cabo proyectos de recuperación de CBs. Se propone una serie de pasos con sus recomendaciones de acuerdo al área y condiciones a restaurar, donde se destaca la importancia de la identificación del sitio a cosechar, la colecta, el almacenamiento y la inoculación en laboratorio o en campo. Finalmente se enumeran las técnicas de enriquecimiento y estabilización más usadas en los procesos de restauración de CBs. Cada aspecto considerado está avalado por múltiples experiencias con resultados ampliamente probados. En el momento de seleccionar las estrategias más adecuadas pueden surgir imposibilidades económicas que llevarán por otra vía. Independientemente de las estrategias abordadas, el camino seleccionado será el que asegure el mejor éxito posible en la restauración.This work summarizes the most important aspects of restoration in biological soil crusts (BSC), including the most determining factors in the success of a restoration, the aspects to take into account to select species and the techniques most used in their restoration, in order to serve as base for those who wish to carry out BSC´s restoration projects. A series of steps with their recommendations according to the area and conditions to be restored are proposed, where the importance of identifying the site to be harvested, the collection, storage and inoculation in the laboratory or in the field are highlighted. Finally, the enrichment and stabilization techniques most used in the restoration process of BSC are listed. Each aspect considered is supported by multiple experiences with widely proven results. At the moment of selecting the most appropriate strategies can emerge economic impossibilities that will lead for another path. Regardless of the strategies addressed, the selected path will be the one that ensures the best possible success in restoration.Fil: Navas Romero, Ana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas. Grupo Vinculado Instituto de Ingeniería Química | Universidad Nacional del Comahue. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas. Grupo Vinculado Instituto de Ingeniería Química; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Ingeniería Química; ArgentinaFil: Martinez Carretero, Eduardo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Herrera Moratta, Mario Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentin

Incorporación de cultivos de cobertura previos a soja en el sudeste bonaerense

En la zona del sudeste bonaerense existe escasa información sobre las eventuales ventajas de la incorporación de los CC en los planteos productivos actuales, la cual sería de suma utilidad para evaluar la factibilidad de dicha alternativa. El objetivo de este trabajo fue determinar la acumulación de biomasa aérea, C y N en CC con y sin fertilización con N y evaluar el efecto de su incorporación sobre el rendimiento del cultivo de soja, en un suelo Argiudol Típico de Balcarce (Buenos Aires, Argentina).Fil: Martinez, Juan Pablo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce. Unidad Integrada. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Barbieri, Pablo Andres. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce. Unidad Integrada. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sainz Rozas, Hernan Rene. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce. Unidad Integrada. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Echeverria, Hernan Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce. Unidad Integrada. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentin

Dry matter estimation and partitioning of assimilates in dominant shrubs with two different morphologies from the High Central Andes of San Juan, Argentina

Background and aims: High mountain shrubs play a key role in the maintenance and functioning of ecosystem processes. Nevertheless, studies to understand their morphology and dry matter partitioning are scarce. The goal of this study is to quantify dry matter partitioning and study the morphology for Senecio oreophyton and Baccharis tola ssp. tola in the Central Andes, Argentina. Additionally, allometric equations are proposed. M&M: The work was done in the Austral Puna, province of San Juan. A total of 60 S. oreophyton and B. tola plants were selected. Biometric variables were measured in each specimen to estimate dry matter. The lateral and top view of each specimen were photographed to determine shrub morphology. Each specimen was harvested and differentiated in stem, leaves and roots. Results: The geometric shape of S. oreophyton was similar to an inverted cone and B. tola was similar to a hemisphere shape. In both shrubs, aboveground dry matter was higher than the belowground dry matter. In B. tola, similar proportions of dry matter assigned to the stem and leaves were found. Allometric equations were established for each component from direct field measurements. Conclusions: The dry matter partitioning found for both shrubs would indicate that it is strongly associated with the morphology of the plant, and its strategy for surviving under harsh conditions. This is a contribution to improve the knowledge about morphological characteristics of woody shrubs and their environmental interactions for conservation and management in highlands.Fil: Herrera Moratta, Mario Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Navas Romero, Ana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Vento, Barbara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Martinez Carretero, Eduardo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentin

Modelado de la sismicidad en Colombia a partir de características de la litosfera terrestre

En el presente artículo se realizó la estimación de modelos del proceso de Poisson no homogéneo, aso- ciado al patrón de sismos en Colombia utilizando covariables descriptivas de la litosfera terrestre tales como la altitud del terreno, anomalías magnéticas e isostáticas, y mediciones de distancia a estructu- ras geológicas tales como fallas, bordes de placa y volcanes. En este estudio se confirmó que los sismos tienden a ocurrir en las cercanías a determinadas es- tructuras geológicas, en zonas con importantes ano- malías gravimétricas, tanto positivas como negativas, y en zonas con valores específicos de anomalías magnéticas y de altitud.

Honokiol and Magnolol as Renewable Resources for the Synthesis of Polymers Towards Biomedical and Engineering Applications

This dissertation has focused on the design, synthesis, and characterization of novel polymers derived from the renewable resources honokiol and magnolol. These natural products – isolated from magnolia officinalis – are highly functional and, thus, amenable to a broad range of synthetic organic transformations. The transformations explored in this work have yielded diverse monomers and, subsequently, polymer types which have included polycarbonates, thermosets, and olefin-based polymers that were studied for potential engineering or biomedical materials. A guiding theme in the development of polymers from honokiol and magnolol has been to control and vary the final polymer properties through the monomer design and polymerization chemistry. This work has used scalable syntheses, well-known chemistries, and, as the first examples of polymers synthesized from these natural products, it has laid the foundation to further explore material applications and new polymers based on honokiol and magnolol. Poly(honokiol carbonate) (PHC) was synthesized in one step from honokiol using step-growth polycondensation techniques. Synthetic conditions were screened to yield polymers of varying molecular weight and the resulting polymers were studied in their thermomechanical and biological properties. PHC shares comparable thermomechanical properties with established engineering materials, both renewable- and petroleum-based, with which it was compared. Additionally, PHC serves as a good substrate for cell growth over an extended period of time. In an effort to take advantage of both the phenolic and alkenyl functionalities of magnolol, thermoset syntheses via thiol-ene chemistry were performed directly from magnolol and with a library of magnolol-based monomers. The thermomechanical and hydrolytic degradation properties were controlled via monomer design in order to leverage beneficial biological effects, namely radical scavenging, in future biomedical applications. Degradation products and model compound studies showed antioxidant behavior similar to what has been observed for the natural product, magnolol. A similar approach in controlling polymer properties through monomer design was realized in the synthesis of olefin-based polymers from magnolol through acyclic diene metathesis (ADMET) chemistry. Magnolol is an alkene-containing natural product and, as such, avoids the necessity to install alkene moieties that other renewable resources often require before metathesis chemistry. The rigid polymers displayed a wide range of glass transition temperatures (Tvg) up to 180 °C after the initial polymerization. Additionally, several strategies were employed for post-polymerization modification and further tuning of the thermomechanical and physical properties