1,721,402 research outputs found
Effect of Cross-Linking Agent on Mechanical and Permeation Properties of Criolla Orange Pectin
Full text linkPectin from orange peel was extracted and cross-linked, applying different cross-linking agents to visualize any effect on its mechanical and permeation properties. Calcium chloride (II) and iron chloride (III) were the cross-linking agents. Besides, commercial pectin was also used to compare its properties with neat orange pectin. Tensile testing showed mechanical stiffness of the orange pectin matrix in the presence of cross-linking agents. Calcium ions better cross-linked the polymer matrix as shown by their highest tensile strength and elastic modulus, with moderate elongation at break. Iron ions showed a weaker cross-linking effect on the pectin matrix, improving the elastic modulus but retaining almost the same tension strength. Lower elongation at break concerning neat orange pectin was observed for cross-linked samples. Water uptake (WU) and water vapor permeation (WVP) of cross-linked samples had lower values than those of neat orange pectin. However, these results are still high compared with synthetic polymers. Finally, gas permeation assays were performed using N2, O2 and CO2 gases, according to exchangeable gases in fresh fruits and vegetable packaging. Results showed a conveniently modified atmosphere effect by avoiding CO2 permeation and stabilizing N2 and O2 selectivity.Fil: Garcia, Maria Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Masuelli, Martin Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentin
Electrokinetic study of bovine serum albumin in aqueous solution: Electroviscosity
No full textThe electrokinetic of bovine serum albumin (BSA) in water is scarcely studied, and the experimental measurements are narrowly reported. Intrinsic viscosity data are very useful in assessing the interaction between the solute and solvent. This work discussed how a simple calculation of the intrinsic viscosity of BSA in aqueous solution could evaluate any electrokinetic effect. The intrinsic viscosity is determined according to the Huggins method. Furthermore, this work proposes electrokinetic study as an indicator of the protein degree of affinity with ions/water, and their implications in conformational changes.Fil: Lazo Delgado, Lismet. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Cátedra de Química Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Gassmann, Jesica Cristina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Cátedra de Química Física; ArgentinaFil: Masuelli, Martin Alberto. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Cátedra de Química Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentin
Biopackaging: Tara Gum Films
No full textIn this work, we prepared and characterized water insoluble crosslinked Tara gum films. Tara gum (TG) is a polysaccharide extracted from the endosperm of Caesalpinia spinosa seeds with a performance of 12% wt. TG films were evaluated as barrier material for agricultural and food industries. The films were modified in order to improve water resistance by using glutaraldehyde (Glu) as crosslinker. The crosslinking process consisted on placing the TG films in a bath containing Glu in an acidic medium for a period of 12 and 24 hours (TG-12 and TG-24) at 25ºC. Film properties were structurally studied through XRD, TGA and SEM images and operationally evaluated by measuring water vapor permeability (WVP), gas permeation and mechanical properties. WVP values decreased with increasing crosslinking time. This is due to crosslinking hinders the diffusion of vapor molecules through the polymer matrix. Gas permeability tests showed permeabilities in the order CO2>> N2> O2. Mechanical tests indicated an increase in the elastic modulus of the film with increasing crosslinking time; this effect is due to the loss of flexibility of the crosslinked polymeric matrix.Fil: Masuelli, Martin Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Garcia, Maria Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentin
Transformaciones territoriales y producción vitícola en el oasis norte de Mendoza : una mirada desde los productores
Full text linkLas trasformaciones de los territorios rurales ocurridas en los últimos años como consecuencia de los cambios globales de la economía, el clima y el tipo de hábitat humano tienen marcada influencia en la producción agropecuaria. Los grados de éxito o fracaso con que se resuelvan los conflictos ocasionados en el territorio por estos procesos de transformación, pueden influir en la permanencia y desarrollo de las actividades productivas, el bienestar de la población y la sustentabilidad ambiental. El presente libro es el resultado de una investigación realizada desde un equipo interdisciplinario e interinstitucional enmarcado en el proyecto denominado “Análisis del capital social de los productores vitícolas del Oasis Norte de la provincia de Mendoza: impacto sobre el territorio y el ordenamiento territorial” (INTA - Asociación ad hoc IDi de la Corporación Vitivinícola Argentina)EEA MendozaFil: Dalmasso, Catterina. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro Regional Mendoza-San Juan; ArgentinaFil: Lettelier, Dolores. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; ArgentinaFil: Bres, Emilce. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Silva, Jorge Horacio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Silva Jorge Horacio. Universidad Juan Agustín Maza; ArgentinaFil: Gudiño, José Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Del Barrio, Lucia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Van den Bosch, Maria Eugenia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Perez, Martin Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentin
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Clasificación de coberturas de suelo de la cuenca del río Tunuyán superior
Full text linkEste trabajo presenta la Clasificación de coberturas de suelo en el oasis irrigado del río Tunuyán superior, resultado de la primera etapa del Convenio de Cooperación Técnica entre el Instituto Nacional de Tecnología Agropecuaria (INTA), el Departamento General de Irrigación (DGI) y la Fundación Instituto de Desarrollo Rural (IDR).EEA MendozaFil: Perez, Martin Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentina. Universidad Nacional de Cuyo. Facultad de Filosofía y Letras; ArgentinaFil: Bacaro, Alejandrina. Mendoza (provincia). Departamento General de Irrigación; Argentin
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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