Determination of lead traces in honey using a fluorimetric method

Heavy traces metals may be present in honey being their detection very important for the quality control and it also serves as an indicator of environmental pollution. A new methodology for lead traces determination has been developed based on the quenching effect of the metal on fluorescent emission of 8-hydroxyquinoline and o-phenanthroline at λem = 360 nm (λexc = 250 nm). Experimental variables that influence on fluorimetric sensitivity were optimized by uni-variation assays. The calibration graph using zeroth order regression was linear from 0.105 μg L-1 to 51.8 μg L-1, with correlation coefficient better than 0.998. Under the optimal conditions, the limits of detection and quantification were of 0.035 μg L−1 and 0.105μg L−1, respectively. The trueness of the methodology was assessed trough parallel samples analysis by ICP-MS. The proposed method showed good sensitivity, adequate selectivity with good tolerance to foreign ions, and was applied to the determination of lead trace amounts in honey from San Luis city (Argentina) with satisfactory results.Fil: Talio, María Carolina. 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: Muñoz, Vanesa Alejandra. 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: Acosta, Mariano. 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: Fernandez, Liliana Patricia. 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

New Analytical Methodology for Sb(III) Traces Quantification as Emergent Contaminant in Drinks Packaged PET Samples by Solid Surface Fluorescence

Emerging contaminants constitute a set of substances that are released into the environment for which regulations are currently not established for their environmental monitoring, being antimony one of them. A new methodology for Sb(III) traces monitoring by solid surface fluorescence is proposed. The metal was complexed with alizarine (Az) as fluorosphore reagent in alcaline medium in presence of the bile salt sodium cholate. To isolate the analyte of matrix constituents, a preconcentration/separation strategy on filter paper was introduced prior to determination step. The solid surface fluorescence was measured λem = 450 nm and λexc = 363 nm using a solid sampler holder. Under optimal conditions, the limits of detection and quantification of proposed methodology were 0.08 and 0.24 μg·L-1, respectively, showing a linear range from 0.24 to 304.4 μg·L-1 with good sensitivity and adequate selectivity. It was applied to the Sb(III) traces determination present in drinking water and beverages samples packaged in polyethylene terephthalate (PET) bottles widely consumed in Argentina. The combination of a preconcentration step on common filter paper and the inherent sensitivity of photoluminescent methods have permitted to achieve sensitivity similar to atomic spectroscopies using a lower price instrument typical in control laboratories. Precision and accuracy were tested with excellent agreement. Results were truenessed by ETAAS with satisfactory concordance.Fil: Talio, María Carolina. 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: Feresin, Valentina. Universidad Nacional de San Luis; ArgentinaFil: Muñoz, Vanesa Alejandra. 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: Acosta, Mariano. 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: Fernandez, Liliana Patricia. 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

Using virtual learning environments in bricolage mode for orchestrating learning situations across physical and virtual spaces

Producción CientíficaTeachers usually implement their pedagogical ideas in Virtual Learning Environments (VLEs) in a continuous refinement approach also known as “bricolage”. Recently, different proposals have enabled the ubiquitous access to VLEs, thus extending the bricolage mode of operation to other learning spaces. However, such proposals tend to present several limitations for teachers to orchestrate learning situations conducted across different physical and virtual spaces. This paper presents an evaluation study that involved the across-spaces usage of Moodle in bricolage mode and learning buckets (configurable containers of learning artifacts) in multiple learning situations spanning five months in a course on Physical Education in the Natural Environment for pre-service teachers. The study followed a responsive evaluation model, in which we conducted an anticipatory data reduction using an existing orchestration framework (called “5 + 3 aspects”) for structuring data gathering and analysis. The results showed that learning buckets helped the teachers in the multiple aspects of orchestration, overcoming the limitations of alternative approaches in some specific orchestration aspects: helping the involved teachers to connect different physical and physical spaces, while supporting technologies and activities of their everyday practice, and transferring part of the orchestration load from teachers to students. The results also suggested lines of future improvement, including the awareness of outdoor activities.Ministerio de Economía, Industria y Competitividad (Project TIN2011-28308-C03-02 and TIN2014-53199-C3-2-R)Junta de Castilla y León (programa de apoyo a proyectos de investigación - Ref. VA277U14 and VA082U16

Game of Blazons: Helping teachers conduct learning situations that integrate web tools and multiple types of augmented reality

Producción CientíficaSeveral studies have explored how to help teachers carry out learning situations involving Augmented Reality (AR), a technology that has shown different affordances for learning. However, these proposals tend to rely on specific types of AR, focus on particular types of spaces, and are generally disconnected from other technologies widely used in education, such as VLEs or Web 2.0 tools. These constraints limit the possible range of activities that can be conducted and their integration into the existing classroom practice. GLUEPS-AR is a system that can help overcome these limitations, aiding teachers in the creation and enactment of learning situations that may combine multiple types of AR with other common web tools. This paper presents an evaluation study conducted on Game of Blazons, a learning situation carried out by two university teachers using GLUEPS-AR, and framed within two days of outdoor activities in a village in Spain. The evaluation showed that GLUEPS-AR provided an affordable support to the participant teachers to integrate several activities that made use of multiple types of AR, common web tools and augmented paper, into a unique learning situation.Ministerio de Economía, Industria y Competitividad (Projects TIN2011-28308-C03-02 and TIN2014-53199-C3-2-R)Junta de Castilla y León (programa de apoyo a proyectos de investigación - Ref. VA082U16

Monitoring for awareness and reflection in ubiquitous learning environments

Producción CientíficaDespite the educational affordances that ubiquitous learning has shown, it is still hampered by several orchestration difficulties. One of these difficulties is that teachers lose awareness of what the students perform across the multiple technologies and spaces involved. Monitoring can help in such awareness, and it has been highly explored in face-to-face and blended learning. Nevertheless, in ubiquitous learning environments monitoring has been usually limited to activities taking place in a specific type of space (e.g., outdoors). In this paper we propose a monitoring system for ubiquitous learning, which was evaluated in three authentic studies, supporting the participants in the affordable monitoring of learning situations involving web, augmented-physical, and 3D virtual world spaces. The work carried out also helped identify a set of guidelines, which are expected to be useful for researchers and technology developers aiming to provide participants’ support in ubiquitous learning environments

The orientation of galaxy pairs with filamentary structures: Dependence on morphology

Aims. With the aim of performing an analysis of the orientations of galaxy pair systems with respect to the underlying large-scale structure, we study the alignment between the axis connecting the pair galaxies and the host cosmic filament where the pair resides. In addition, we analyze the dependence of the amplitude of the alignment on the morphology of pair members as well as filament properties. Methods. We build a galaxy pair catalog requiring rp < 100 h-1 kpc and ΔV < 500 km s-1 within redshift z < 0.1 from the Sloan Digital Sky Survey (SDSS). We divided the galaxy pair catalog taking into account the morphological classification by defining three pair categories composed by elliptical-elliptical (E-E), elliptical-spiral (E-S) and spiral-spiral (S-S) galaxies. We use a previously defined catalog of filaments obtained from SDSS and we select pairs located closer than 1 h-1 Mpc to the filament spine, which are considered as members of filaments. For these pairs, we calculate the relative angle between the axis connecting each galaxy, and the direction defined by the spine of the parent filament. Results. We find a statistically significant alignment signal between the pair axes and the spine of the host filaments consistent with a relative excess of ∼15% aligned pairs. We obtain that pairs composed by elliptical galaxies exhibit a stronger alignment, showing a higher alignment signal for pairs closer than 200 h-1 kpc to the filament spine. In addition, we find that the aligned pairs are associated with luminous host filaments populated with a high fraction of elliptical galaxies. The findings of this work show that large-scale structures play a fundamental role in driving galactic anisotropic accretion as induced by galaxy pairs exhibiting a preferred alignment along the filament direction.Fil: Mesa, Valeria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Duplancic Videla, Maria Fernanda. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Alonso Giraldes, Maria Sol. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Muñoz Jofré, Maria Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Coldwell Lloveras, Georgina Vanesa. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Garcia Lambas, Diego Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentin

Oregano Essential Oil Interactions with Photogenerated Singlet Molecular Oxygen

Essential oils are a mixture of volatile compounds, products of the secondary metabolism of plants. Once extracted, they can be deteriorated losing their organoleptic and therapeutic properties due to various environmental factors, being light exposure in aerobic conditions the main cause. In this work, the oregano essential oil extraction and characterization from Origanum vulgare plants grown in the experimental field of the FTU-UNSL and its photodegradation in MeOH:H2O 60:40 v/v solvent were studied. Characterization by EIMS and NIST Mass Spectrometry indicates the main compounds of oregano essential oil, quantified in the extracted oil by GC-MS, are carvacrol (7.14%) and thymol (47.37%). Degradation of essential oil and its two major components can be caused by reactive oxygen species photogenerated from endogenous sensitizers as riboflavin. Our results suggest degradation occurs involving singlet molecular oxygen. Interaction of carvacrol and thymol with singlet oxygen is mainly a physical process, while essential oil has an important reactive component, which indicates there might be other constituents which could contribute to reactive photoprotection. The effect of simultaneous presence of oregano essential oil and tryptophan amino acid—used as a photooxidizable model under riboflavin-photosensitizing conditions—was studied in order to evaluate the possible photoprotection exerted by the essential oil.Fil: Dimarco Palencia, Frida Claudia Daniela. 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: Muñoz, Vanesa Alejandra. 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: Posadaz, Ariana C.. Universidad Nacional de San Luis. Facultad de Turismo y Urbanismo; ArgentinaFil: Cifuente, Diego Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Miskoski, Sandra. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Ferrari, Gabriela Verónica. 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: García, Norman Alberto. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Montaña, Maria Paulina. 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

The employment of a removable chitosan-derivatized polymeric sensitizer in the photooxidation of polyhydroxylated water-pollutants

The known O2(1g)-sensitizer system Chitosan bounded Rose Bengal (CH-RB), with Rose Bengal (RB) immobilized by irreversible covalent bonding to the polymer Chitosan (CH), soluble in aquous acidic medium, was employed in the photodegradation of three tri-hydroxy benzene water-contaminants (THBs). The system sensitizes the O2(1g)-mediated photodegradation of THBs by a process kinetically favored, as compared to that employing free RB dissolved in the same solvent. Additionally the free xanthene dye, degradable by O2(1g) through self-sensitization upon prolonged light-exposure, is considerably protected when bonded to CH-polymer. The polymeric sensitizer, totally insoluble in neutral medium, can be removed from the solution after the photodegradative cycle by precipitation through a simple pH change. This fact constitutes an interesting aspect in the context of photoremediation of confined polluted waters. In other words, the sensitizing system could be useful for avoiding to dissolve dyestuffs in the polluted waters, in order to act as conventional sunlight-absorbing dye-sensitizers. In parallel the interaction CH - O2(1g) in acidic solution was evaluated. The polymer quenches the oxidative species with a rate constant 2.4x108 M-1s-1 being the process mostly attributable to a physical interaction. This fact promotes the photoprotection of the bonded dye in the CH-RB polymer.Fil: Ferrari, Gabriela Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Andrada, María Elisa. Universidad Nacional de Rio Cuarto; ArgentinaFil: Natera, Jose Eduardo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Muñoz, Vanesa Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Montaña, Maria Paulina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Gambetta, Carolina. Universidad Nacional de Rio Cuarto; ArgentinaFil: Boiero, María Laura. Universidad Tecnologica Nacional. Facultad Regional Villa Maria; ArgentinaFil: Montenegro, Mariana Angélica. Universidad Tecnologica Nacional. Facultad Regional Villa Maria; Argentina. Universidad Nacional de Villa Maria; ArgentinaFil: Massad, Walter Alfredo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Garcia, Norman Andino. Universidad Nacional de Rio Cuarto; Argentin

Experiencias de una Viaje: Estudiantes proyecto: "Patrimonio y nueva Cultura Industrial"

Este artículo es un relato del viaje que realizó un grupo de estudiantes de 9º semestre de la Facultad de Arquitectura de la Universidad Santo Tomás seccional Tunja, auxiliares del proyecto de investigación Patrimonio ynueva cultura industrial, por los departamentos de Santander y Antioquia, con motivo de la visita de arquitectos alemanes del INIK, Institut für neue Industriekultur de Alemania, a Colombia, con el fin de observar directamente la presencia de Alemania en la cultura industrial colombiana. A manera de diario, se relatan las experiencias del viaje y los hallazgos, ilustrando así las vivencias del grupo, las cuales son base para la continuación de la investigación

Diagnóstico del manejo de los efluentes porcinos generados en la provincia de Córdoba

La intensificación de la producción porcina genera grandes volúmenes de efluentes que deben ser manejados adecuadamente. Su acumulación y aplicaciones no controladas al suelo pueden provocar impactos negativos en el ambiente. Este trabajo se planteó como objetivo estimar la generación de efluente porcino en la provincia de Córdoba y diagnosticar actuales prácticas de manejo en el departamento de Marcos Juárez. Las estimaciones realizadas evidencian que el potencial de generación de efluente porcino en la provincia es de 811911 m3 año-1, los cuales aportan 2517 toneladas N año-1. Esta generación se concentra en los departamentos sur-sureste, ligados a la mayor existencia animal. A su vez, el departamento Marcos Juárez genera 119378 m3 año-1 de efluente porcino. De este volumen generado un 61% fue almacenado en sistemas impermeabilizados, 51% fue sometido a sistemas de tratamiento y un 68% fue aplicado al suelo. Sin embargo, al evaluar el porcentaje de productores que llevaron a cabo estas prácticas, se evidenció que estos fueron minoría, pero con mayor número de animales.Pig production intensification generates large volume of the slurry that must be managed properly. Their accumulation and uncontrolled applications on the soil can cause negative impacts on the environment. The aims of this article were estimated pig slurry generation in Córdoba Province, Argentina and diagnose farm pig slurry management in Marcos Juarez department. The potential generation of pig slurry in Córdoba Province is 811911 m3 year-1, which 2517 tons N year-1, concentrated in the south-southeast departments in Córdoba. The Marcos Juárez department generated 119378 m3 year-1 of pig slurry. Of this generated volume, 61% was stored in waterproofed systems, 51% was subjected to treatment systems and 68% was applied to the soil. However, when evaluating the percentage of pig farmers who carried out these practices, it was evident that they were a minority but with a greater number of animals.publishedVersionFil: Pegoraro, Vanesa Romina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Marcos Juárez; Argentina.Fil: Cazorla, Cristian Román. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Marcos Juárez; Argentina.Fil: Masino, Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Marcos Juárez; Argentina.Fil: Alladio, Matías. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Marcos Juárez; Argentina.Fil: Cottura, Germán Andrés. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Marcos Juárez; Argentina.Fil: Bachmeier, Omar Antonio. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Hang, Susana Beatriz. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Muñoz, Sebastián Andrés. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Marcos Juárez; Argentina.Fil: Zubillaga, Marta Susana. Universidad de Buenos Aires (UBA). Facultad de Agronomía; Argentina