1,721,025 research outputs found
In-depth study from gluten/PCL-based food packaging films obtained under reactive extrusion conditions using chrome octanoate as a potential food grade catalyst
No full textSingle-use food packaging derived from petroleum is causing serious environmental problems, and food hydrocolloids have been suggested as raw materials to replace these non-biodegradable materials. However, food hydrocolloid-based food packaging materials have some challenges that must be overcome to achieve their manufacture on a large scale. Keeping this in view, three thermoplastic gluten (TPG)-based film systems were developed in this study under reactive extrusion (REx) conditions followed by thermo-molding: TPG, TPG/poly(ε-caprolactone) (PCL) and TPG/PCL plus chrome octanoate as a potential food grade catalyst (TPG/PCL + Cat). An in-depth analysis in terms of the structural, thermal, crystalline, physicochemical, microstructural, rheological, mechanical and environmental properties was carried out here. The films prepared from the TPG/PCL blend showed a clear phase separation: a TPG-rich phase (hard section) and another PCL-rich phase (soft section). Despite this, mechanical compatibility was observed in these systems. In addition, TPG/PCL and TPG/PCL + Cat films were recommended as potential shape memory food packaging materials. In particular, the addition of the Cat caused the crosslinking of the TPG and PCL chains via Schiff's base reactions, resulting in a more hydrophobic material, which showed to be kinetically less biodegradable than the other developed film systems. It should be noted, however, that all the materials were biodegradable after 90 days under vegetable compost conditions, as well as none of them proved to be ecotoxic. All the materials manufactured in this study can thus be well named as compostable materials.Fil: Gutiérrez Carmona, Tomy José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Mendieta, Julieta Renee. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Ortega Toro, Rodrigo. Universidad de Cartagena.; Colombi
Recubrimientos comestibles a base de almidón con potencial aplicación en conservación de frutas
Full text linkEste documento presenta un diagnóstico de los avances en los recubrimientos comestibles de una base de almidón con la aplicación potencial de conservación de frutas y hortalizas.This document presents a diagnosis of the advances in the edible coatings of a starch base with the potential application of conservation of fruits and vegetables
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
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
Desarrollo de películas bicapa a base de almidón termoplástico (TPS) y polímeros hidrofóbicos con sorbato de potasio como agente interfacial
Full text linkSe obtuvieron películas bicapa que consistían en una capa de PCL, PLA (amorfo) y PLA (Semicristalino) polímeros biodegradables y por otro lado, PP-y-Ma que constituye a un polímero no biodegradable. Estas fueron ensambladas a una capa de almidón termoplástico (TPS) de maíz o yuca, los materiales se obtuvieron mediante moldeo por compresión con y sin incorporación de sorbato de potasio en la interfaz. Antes de la compresión, se humedeció la capa del almidón con una solución acuosa de sorbato de potasio (1% w/v) para plastificarlas y favorecer su adhesión por los enlaces que puede conformar con los polímeros y los almidones. Todas las películas bicapa con Sorbato de potasio, tienen interacciones significativas en las longitudes de onda (C=O), (C-O-C) y (-OH), evidenciando la presencia del aditivo. También podemos resaltar que unos de los resultados significativa en la prueba de FT-IR son las monocapas de almidón con 5% de de los polímeros, por qué mostraron Interacciones de los dos componentes mezclados. Para la prueba SEM, se encontró que las películas de 5% de PCL en almidón de maíz y 5% de PP-y-Ma en almidón de yuca formaron bicapas con PCL y PP-y-Ma tuvieron la mejor adhesión interfacial. Todas las bicapas mejoraron sus propiedades de transición al vapor de agua, solubilidad en agua y adsorción de agua pero en especial las que en su formulación contenían almidón de maíz. Las propiedades de biodegradación (producción de CO2 y mineralización) fueron mejores para las películas de almidón termoplástico de maíz o yuca con contenido de 5% de cada polímero comparadas con las películas bicapa, debido a la barrera física ofrecida por la película del polímero al TPS.Bilayer films were obtained consisting in a layer of PCL, PLA (amorphous) and PLA (Semi-crystalline) biodegradable polymers and on the other hand, PP-y-Ma that constitutes a non-biodegradable polymer
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. These were assembled to a layer of thermoplastic starch (TPS) of corn or cassava, the materials were obtained by compression molding with and without incorporation of potassium sorbate at the interface. Before the compression, the layer of the starch was moistened with an aqueous solution of potassium sorbate (1% w/v) to plasticize them and to favor their adhesion by the bonds that can conform with the polymers and the starch. All bilayer films with potassium sorbate, have significant interactions in the wavelengths (C = O), (C-O-C) and (-OH), evidencing the presence of the additive. We can also highlight that one of the significant results in the FT-IR test are the starch monolayers with 5% of the polymers, why they showed Interactions of the two components mixed. For the SEM test, it was found that films of 5% PCL in corn starch and 5% PP-y-Ma in cassava starch formed bilayers with pure PCL and PP-y-Ma had the best interfacial adhesion. On the other hand, all bilayers improved their properties of transition in steam, water solubility and water adsorption but especially those in their formulation containing corn starch. The biodegradation properties (CO2 production and mineralization) were better for corn or cassava thermoplastic starch films with 5% content of each polymer compared to bilayer films, due to the physical barrier offered by the polymer film to TPS.Ingeniero Químic
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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