296 research outputs found

    Quantitative analysis and processing of surfaces and profiles from profilometry images

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    Surface metrology is concerned with inspecting morphological parameters of a surfaces or profiles, by using contact or non-contact profilometers. The following abstract describes the development of a software in Python environment that implements various processing methods on images from optical and stylus profilometers. In particular, the program focusses on image pre-processing and determination of dimensional parameters for 2D areas and 1D profiles. It is worth mentioning that many open and closed source programs are already distributed, but they do not provide a sufficient automatization in the image processing, often requiring the user to repeat the same steps for each image to obtain the expected results. The program has been initially developed within the framework of the EMPIR 20IND07 TracOptic project for the processing of a batch of topographies on RS-M and RS-N linear step samples, in order to compensate for the lack of automation for the calculation of height parameters. The developed program is designed to be modular and scalable for expanding the processing capabilities

    Effects of enzymatic modification of soybean protein on the pasting and rheological profile of starch–protein systems

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    ABSTRACT Reformulation of traditional food systems to introduce new ingredients may change their structure and perceived texture. Interactions between proteins and starch during processing can markedly influence starch gel network structure and rheological profile. The present work aimed to study the effects of soybean protein and the products of enzymatic modification on the pasting and rheological profile of corn and cassava starch. The behaviour of those protein enriched gels during storage was also assessed. Soybean protein isolate (SPI) was incubated with endopeptidase (AL) or food grade microbial transglutaminase (TG). Pasting and rheological behaviour, water retention capacity and structure of protein-and hydrolysed protein-starch gels were analyzed. Protein incorporation increased the viscosity of starch suspension during and after heating. SPImodified proteins increased peak viscosity. Only the structural modifications brought by TG on SPI increased the final viscosity during starch pasting and the storage modulus (G′). This modulus (G′) of the gelled systems decreased with the addition of AL-treated protein isolate. Light and fluorescence microscopy showed that SPI formed a continuous phase, like a network, in the gelled system. Different network structures and rheological properties can be obtained when SPI are modified by protease and transglutaminase enzymes, which may be very useful for designing new food products

    Differential salt-stress response during germination and vegetative growth in in vitro selected somaclonal mutants of Cenchrus ciliaris L.

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    Four somaclonal mutants (S1, S4, S6 and M10) and their parental Cenchrus ciliaris L. cultivar Biloela were characterized under salinity conditions at germination and vegetative growth stages. Seeds of all somaclonal mutants had higher germination percentages than cv. Biloela seeds in the control and salt treatments. At 150 mM, germination was significantly higher in M10, S6 and S4 (72.3%, 66.3% and 61.8%, respectively) than in cv. Biloela (35.5%). Mutants grown under salinity along with cv. Biloela for 35 days had a different relative growth rate. S6 had the highest growth rate, indicating its potential tolerance to salt stress, whereas M10 was the most sensitive, with Bi, S4 and S1 being intermediate tolerant genotypes. Catalase enzyme activity (CAT) in M10 decreased in response to salt stress and was significantly associated with malondialdehide content, suggesting salt injury, whereas higher levels of CAT activity in S6 during salt stress were associated with increased salinity tolerance. The present results indicate that somaclonal variation and in vitro mutagenesis offer an effective tool for improvement of C. ciliaris because the somaclonal mutants showed differential tolerance to salt stress with respect to their parental and could be a better choice for use in a breeding program.Fil: Lopez Colomba, Eliana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Fisiología y Recursos Geneticos Vegetales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tommasino, E.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Fisiología y Recursos Geneticos Vegetales; ArgentinaFil: Luna, Celina Mercedes. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Fisiología y Recursos Geneticos Vegetales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Griffa, Sabrina Mariana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Fisiología y Recursos Geneticos Vegetales; ArgentinaFil: Carloni, Edgardo José. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Fisiología y Recursos Geneticos Vegetales; ArgentinaFil: Ribotta, Andrea Noemí. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Fisiología y Recursos Geneticos Vegetales; ArgentinaFil: Quiroga, M.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Fisiología y Recursos Geneticos Vegetales; ArgentinaFil: Grunberg, Karina Alejandra. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Fisiología y Recursos Geneticos Vegetales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    El rol del control personal en la función paliativa de la justificación del sistema entre la población indígena y no indígena de estudiantes peruanos

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    Indexación: Scopus.In this article we propose a mediation model for the association between system justification and psychological well-being (i.e., the palliative function of ideology), based on system justification theory and compensatory control theory. Specifically, we argue that endorsing system-justifying beliefs leads to increased perceived personal control, which in turn predicts higher well-being. We used a convenience sample of students from two Peruvian universities. The results showed that system justification was related to general psychological well-being and personal control. In addition, indigenous students rated lower on system justification, general psychological well-being, self-esteem and personal control. Next, we found that the association between system justification and general psychological well-being was stronger among indigenous students, and this relationship was partially mediated by personal control. In addition, we showed that the mediation model is moderated by ethnicity, so that personal control is a mediator only among non-indigenous participants. We conclude that personal control is a mechanism involved in the palliative function of ideology among this group. Finally, we discuss possible explanations for the mechanisms involved in the palliative function of ideology among low-status individuals. © 2018, © 2018 Fundacion Infancia y Aprendizaje.En este artículo se propone un modelo de mediación de las relaciones entre la justificación del sistema y el bienestar psicológico (i.e., la función paliativa de la ideología) basado en las teorías de la justificación del sistema y del control compensatorio. En concreto, se propone que la adopción de creencias justificativas del sistema produce un aumento del control personal percibido que, a su vez, predice niveles más elevados de bienestar. En este estudio se utilizó una muestra por conveniencia de estudiantes provenientes de dos universidades peruanas. Los resultados muestran que la justificación del sistema está relacionada con el bienestar psicológico general y con el control personal. Además, los estudiantes indígenas mostraron niveles más reducidos de justificación del sistema, bienestar psicológico general, autoestima y control personal. También se observó que la relación entre la justificación del sistema y el bienestar psicológico general era más fuerte entre los estudiantes indígenas y que el control personal mediaba parcialmente en esta relación. Asimismo, mostramos que la etnicidad es un factor moderador del modelo de mediación, por lo que el control personal es un mediador únicamente entre los participantes no indígenas. El estudio concluye que el control personal es un mecanismo que interviene en la función paliativa de la ideología en este grupo. Por último, se discuten posibles explicaciones de los mecanismos implicados en la función paliativa de la ideología entre individuos de estatus social bajo.https://www.tandfonline.com/doi/full/10.1080/02134748.2018.153765

    Efecto de los parámetros del proceso de extracción por prensado sobre el rendimiento y la calidad de aceite de Pistacho

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    Pistachio nuts have high economical and nutritional value, mostly due to their elevated oil con­tent (50%), which is composed mainly of oleic and linoleic fatty acids. Box-Behnken experimental designs were performed to optimize the oil extraction by response surface analysis. The independent variables measured were seed moisture content (SMC), restriction die (RD), screw press speed (PS) and pressing temperature (PT), while the response variables considered were oil recovery (OR), fine solid contents in the oil (FSC), oil remain­ing in the cake (OC) and parameters related to oil quality (free fatty acid composition (FFAC, mg KOH/g oil), peroxide value (PV, meq O2/kg oil), K232, K270 and pigment contents, mg/kg oil). Given that the chemical quality of pistachio nut oil pressed under different conditions was not affected, the process response was optimized in order to maximize OR under two pressing temperatures. Therefore, at 75 °C, pistachio oil extraction showed a maximum OR (79.61 g/100 g oil) at 8% SMC, 4 mm RD and 20 rpm SP; while, under cold-pressed conditions, the maximum OR (65.97 g/100 g oil) was achieved at 10% SMC, 4mm RD and 20 rpm SP. It is important to highlight that OR values were higher than the results reported previously and the chemical quality parameters from both oils were in the range of Codex standards for virgin (non-refined) oils (FFAC < 0.31 and PV < 0.33).Los frutos de pistacho son altamente nutritivos, principalmente debido a su contenido de aceite (50%), compuesto principalmente por ácidos grasos mono y di-insaturados. Con la finalidad de conocer las condiciones de proceso adecuadas que permitan maximizar la cantidad de aceite extraído preservando la calidad química del mismo se utilizaron dos diseños experimentales de Box-Behnken. Las variables independientes analizadas fueron la humedad de la semilla (HS), el diámetro de reducción (DR), la velocidad y temperatura de prensado (VP y TP, respectivamente), mientras que las variables de respuesta fueron el rendimiento en aceite (RA), el contenido de sólidos finos en el aceite (CFA), el aceite remanente en torta (AT) y parámetros relacionados con la calidad (composición en ácidos grasos libres (CAGL, mg KOH/g aceite), índice de peróxido (IP, meqO2/kg aceite), K232, K270 y pigmentos (mg/kg aceite)). La calidad química de los aceites obtenidos no mostró daño oxidativo y/o hidrolítico significativo bajo las diferentes condiciones del proceso (IP< 0.33 y CAGL< 0.31, respectivamente), por lo tanto, la respuesta se optimizó para maximizar RA a dos TP, 75 y 40 °C. El rendimiento en aceite se maximizó ajustando HS (8% ó 10% b.h.), DR (4 mm), VP (20 rpm) a ambas temperaturas, alcanzando extracciones de aceite de 79.61% y 65.97%, respectivament

    Efecto de distintos oxidantes sobre la calidad de panes elaborados por el método tradicional argentino

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    La metodología de panificación tradicional argentina se destaca por utilizar escasa levadura y realizar fermentaciones muy largas, utilizando como oxidante bromato de potasio. Con la prohibición del uso de bromato desde el año 1998,cobró importancia el análisis de la acción de distintos oxidantes en estos procesos.En el presente trabajo se estudió la acción de 5 oxidantes sobre la retención de gases, el volumen de pan, las propiedades reológicas, la estructura de la miga y las interacciones entre proteínas. Los resultados de las electroforesis muestran que los oxidantes favorecen la formación de agregados proteicos, lo que estaría indicando el establecimiento de puentes disulfuro a partir de grupos sulfhidrilo. También se observa que ninguno de los aditivos en estudio puede suplantar por sí solo al bromato de potasio en este tipo de panificación, siendo la azodicarbonamida el oxidante que tiene el comportamiento más simila

    Morphological evaluation of buffelgrass cultivar “Lucero INTA-PEMAN” in drought conditions

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    In searching for new cultivars that are better adapted to edapho-climatic constraints existing in northwestern Argentina, mainly drought and salinity stress, a hybrid of buffelgrass (Cenchrus ciliaris L.) named Lucero INTA PEMAN was obtained by controlled crosses at the Instituto de Fitopatología y Fisiología Vegetal, INTA. The objective was to morphologically evaluate and compare Cenchrus ciliaris cv Lucero with Texas-4464, Biloela and Molopo cultivars in Dean Funes (North of the Province of Córdoba, Argentina) under drought field conditions using a randomized complete block design with three replications in two crop cycles (2006/2007 and 2007/2008) considering one-year plant and re-growth as ontogenic stages of the plant, respectively. Thirteen morphological characters were analyzed by ANOVA and DGC testing (p <0.05). Although most of the thirteen morphological characters evaluated showed decreased re-growth over one-year plants, Lucero was least affected by low water availability, showed highest values for seed production components in both ontogenic stages and was superior to Texas-4464 in biomass production characters and to Biloela and Molopo cultivars in most of them. Lucero showed a promising and considerable forage value for drought-affected regions, such as northwestern Argentina

    Morphological stabilization and KPZ scaling by electrochemically induced co-deposition of nanostructured NiW alloy films

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    We have assessed the stabilizing role that induced co-deposition has in the growth of nanostructured NiW alloy films by electrodeposition on polished steel substrates, under pulsed galvanostatic conditions. We have compared the kinetic roughening properties of NiW films with those of Ni films deposited under the same conditions, as assessed by Atomic Force Microscopy. The surface morphologies of both systems are super-rough at short times, but differ at long times: while a cauliflower-like structure dominates for Ni, the surfaces of NiW films display a nodular morphology consistent with more stable, conformal growth, whose height fluctuations are in the Kardar-ParisiZhang universality class of rough two-dimensional interfaces. These differences are explained by the mechanisms controlling surface growth in each case: mass transport through the electrolyte (Ni) and attachment of the incoming species to the growing interface (NiW). Thus, the long-time conformal growth regime is characteristic of electrochemical induced co-deposition under current conditions in which surface kinetics is hindered due to a complex reaction mechanism. These results agree with a theoretical model of surface growth in diffusion-limited systems, in which the key parameter is the relative importance of mass transport with respect to the kinetics of the attachment reaction.We acknowledge financial support from ANPCyT (PICT 2012-1808), CONICET (PIP 0671) and Universidad Nacional de La Plata (11X760) as well as from MINECO/FEDER (Spain/UE) Grants MAT2014-54231-C4-1-P, FIS2015-66020-C2-1-P and MAT2014-52405-C2-2-R, as well as by Comunidad Autónoma de Madrid (Spain) Grant NANOAVANSENS S2013/MIT-3029. M.E.V. is member of the research career of CICPB

    The electrochemistry of nanostructured Ni–W alloys

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    This work reports on the features that Ni–W nanostructured alloys, electrodeposited on carbon steel by different current pulse programs, may present depending on their surface morphology and surface composition. The Ni–W nanostructured coating, with a cauliflower structure, lack of fragility, and high WO3/W surface composition ratio, is a stable electrode to catalyze hydrogen evolution reaction, exceeding bulk and electrodeposited Ni catalytic activity. Also, the nanostructured alloys must have a low WO3/W surface composition ratio for Ni and its oxides to provide protection and improve corrosion resistance in sulfate media.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada
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