Gallium nanoparticles colloids synthesis for UV bio-optical sensors

F. Nucciarelli, I. Bravo, L. Vázquez, E. Lorenzo, J. L. Pau, "Gallium nanoparticles colloids synthesis for UV bio-optical sensors", SPIE Optics + Optoelectronics Proc. SPIE 10231 (16 May 2017) Copyright 2017 Society of Photo Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited. Proceedings of the Optical Sensors Conference (Prague, Czech Republic) doi: https://doi.org/10.1117/12.2265883A new method for the synthesis of colloidal gallium nanoparticles (Ga NPs) based on the thermal evaporation of Ga on an expendable aluminum zinc oxide (AZO) layer is presented here. The growth of AZO layers was investigated on different substrates at room temperature and 300 °C. By means of physical evaporation process, nanoparticles were deposited with a distribution ranging from 10 nm to 80 nm in diameter. A study of their endurance in acidic environment was carried out in order to assure the NPs shape and size stability during the etching process. Smaller particles start to disappear between 1h and 2h immersion time in a pH=1 solution, while bigger particles reduce their dimension. The NPs were dispersed in tetrahydrofuran (THF) organic solvent and optically characterized, showing strong UV absorption with a band centered at 280 nm. The colloids size distribution of as-evaporated samples was compared with the distribution obtained in droplets of the solution after drop-casting. By Dipole Discrete Approximation simulations, a close relationship between the UV absorption and the NPs with diameter smaller than ∼40 nm was found. Because of the gallium oxide (Ga1-xOx) outer shell that surrounds the Ga NPs, an enhancement of their hydrophobicity occurs. Hence, the low agglomeration state between NPs in tetrahydrofuran allows to obtain narrow absorption band in the optical spectrumWe are also grateful to the international PROMIS project, framed in the Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 641899. This research is supported by the MINECO (CTQ2014-53334-C2-2-R and MAT2016-80394-R) and Comunidad de Madrid (NANOAVANSES ref. S2013/MIT-3029) Projec

Triple bottom line and sustainable performance measurement in industrial companies

Purpose – The purpose of this paper is to propose a minimum set of indicators to be measured by industrial companies to represent the triple bottom line (TBL) approach. Design/methodology/approach – The research is both descriptive and quantitative. Three hypotheses establish associations among the degrees of use of TBL indicators and their different degrees of use in firms. The authors used confirmatory factor analysis (CFA) to validate the scale and structural equation modelling to represent the final measurement model. The survey gathered 149 industrial companies. Findings – The results pointed out that there are positive associations among the degree of use of environmental indicators and social indicators, economic, environmental and social indicators have different degrees of use in firms, a positive association between the degree of use of environmental and social indicators and the use of economic indicators was not confirmed. The findings suggest how to measure sustainable performance for industrial companies and highlight the differences in the degree of use for the three dimensions of TBL. Research limitations/implications – The limitations refer to the non-probabilistic sample, applied in a specific context, industrial companies. Practical implications – This set of indicators is intended to be used by industrial companies as a reliable instrument to sustainable performance assessment of the current stage of the TBL deployment and provide alternative approaches to address specific issues related to the environmental, social and economic sustainability. Social implications – The results offer tangible results for measuring and reporting firm’s social and environmental performance. Originality/value – This paper intends to offer an integrated and consistent way of measuring sustainability in industrial companies

NADH Oxidation onto Different Carbon-Based Sensors: Effect of Structure and Surface-Oxygenated Groups

Different carbon-based materials have been compared for the development of NADH sensors: glassy carbon electrodes (GCE), multiwalled carbon nanotubes (MWCNT), and carbon black (CB). The GCE and MWCNT has been subjected to oxidative pretreatment to study the influence of oxidative groups for NADH oxidation. The materials had been characterized by FT-IR to identify the surface composition. The response of bare (GC) and GC/modified electrodes toward potassium ferricyanide have been employed to obtain information about the electroactive area and electron transfer rate. Studies of NAD+/NADH redox behavior showed that MWCNT and GCE exhibit high degree of passivation while CB shows no fouling effects. Catalytic effect of surface-oxygenated groups was also proved for GCE and MWCNT, and both, O-GCE and O-MWCNT, exhibited a lower oxidation overpotential compared to the respective untreated materials. Chronoamperometric quantification showed a linear dependence between 2–18 μmol·L−1 and a detection limits of 6.2 μmol·L−1 (GCE), 5.4 μmol·L−1 (O-GCE), 3.2 μmol·L−1 (GCE/CB), 9.6 μmol·L−1 (GCE/MWCNT), and 4.9 μmol·L−1 (GCE/O-MWCNT) were obtained. The analytical performances suggest that a careful choice of the material for NADH sensing is necessary depending on the sensor application

Triple bottom line and sustainable performance measurement in industrial companies

Purpose - The purpose of this paper is to propose a minimum set of indicators to be measured by industrial companies to represent the triple bottom line (TBL) approach. Design/methodology/approach - The research is both descriptive and quantitative. Three hypotheses establish associations among the degrees of use of TBL indicators and their different degrees of use in firms. The authors used confirmatory factor analysis (CFA) to validate the scale and structural equation modelling to represent the final measurement model. The survey gathered 149 industrial companies. Findings - The results pointed out that there are positive associations among the degree of use of environmental indicators and social indicators, economic, environmental and social indicators have different degrees of use in firms, a positive association between the degree of use of environmental and social indicators and the use of economic indicators was not confirmed. The findings suggest how to measure sustainable performance for industrial companies and highlight the differences in the degree of use for the three dimensions of TBL. Research limitations/implications - The limitations refer to the non-probabilistic sample, applied in a specific context, industrial companies. Practical implications - This set of indicators is intended to be used by industrial companies as a reliable instrument to sustainable performance assessment of the current stage of the TBL deployment and provide alternative approaches to address specific issues related to the environmental, social and economic sustainability. Social implications - The results offer tangible results for measuring and reporting firm’s social and environmental performance. Originality/value - This paper intends to offer an integrated and consistent way of measuring sustainability in industrial companies

Estrategias de codificación de información empleadas por docentes Mexicanos en procesos de formación

Las Estrategias de Codificación de Información refieren al conjunto de procedimientos que conectan los conocimientos previos, integrándolos en estructuras de significado más amplias y transportándolos a la memoria de largo plazo (Pizano, 2012). En el presente estudio se planteó como objetivo general establecer un perfil descriptivo que contemple las Estrategias de Codificación de Información que emplean los Docentes que estudian el Posgrado en el Centro de Actualización del Magisterio (CAM). En una segunda etapa, se ampliará dicho perfil con base en los resultados obtenidos con otros estudiantes que cursan distintos programas en el resto de las Instituciones Formadoras de Docentes en el estado de Durango, México. Para el logro del objetivo citado, se realizó un estudio exploratorio, descriptivo-correlacional, transversal y no experimental. La recolección de información se efectuó mediante la Escala de Estrategias de Aprendizaje ACRA, que fue aplicada a 67 estudiantes que durante el mes de octubre de 2016 cursaban la Maestría en Educación, Campo Intervención Didáctica (MECID), en alguna sede del CAM. Los principales resultados obtenidos muestran que los encuestados presentan un nivel medio de frecuencia de empleo de Estrategias de Codificación de Información (66%) y que la variable Género tiene un efecto modulador

Espacio de desarrollo de rampas tecnológicas para mejora de la accesibilidad e inclusión

En este trabajo se describen las actividades y desarrollos tecnológicos que surgen con la premisa de fortalecer los mecanismos que vinculan la Universidad con el medio, definiendo nuevas y mejores estrategias de extensión relacionadas con temáticas que se consideran de interés para la sociedad. Se busca promover la interacción teniendo en cuenta la complejidad, diversidad, actores y demandas de una parte muy sensible de la sociedad tal la determinada por Necesidades Educativas Especiales (NEE) y problemas derivados de diferentes discapacidades.Facultad de Ingenierí

Caracterización agronómica, calidad industrial y nutricional de maíz para el trópico mexicano

Caracterización agronómica, calidad industrial y nutricional de maíz para el trópico mexicano. El objetivo de este trabajo fue determinar el valor agronómico y nutricional de varie dades e híbridos de maíz en Veracruz, México, durante el ciclo primavera verano 2006. Se validaron híbridos y varie dades de maíz normal y con alta calidad de proteína en Cotaxtla, Mata de Agua, Tlalixcoyan, Ignacio de la Llave, Martínez de la Torre y Rodríguez Clara, en Veracruz, México. Se utilizó un diseño de bloques completos al azar con dos repe ticiones y parcelas de ocho surcos de 25 m de largo con una densidad de 62 500 semillas/ha. Del análisis de varianza combinado, se encontró diferencia altamente significativa para Ge notip os (G), Localidades (L) y la interacción GxL. Los genotip os sobresalie ntes, por su rendimie nto de grano y otras características agronómicas fueron HQ4, H-520, HQ3 y HQ1 con 5,42; 5,38; 5,13 y 5,06 t/ha, respectivamente. Los híbridos con mejor valor nutricional de grano blanco fueron HQ1, HQ3 y HQ4, y la varie dad V-556AC , de grano amarillo, calidad basada en características físicas, químicas, de nixtamal, la masa y las tortillas, así como los aminoácidos lisina y trip tofano, en endospermo, grano entero y tortillas. Estos maíces cumplen con las especificaciones de la norma mexicana para maíces destinados al proceso de nixtamalización. El HQ1 produjo las mejores tortillas, y el híbrido HQ4, se consideró apropiado para la industria de la harina nixtamalizada

Polimerización del acrilato de butilo en solución y la caracterización de sus propiedades fisicoquímicas

Se propuso una metodología y formulación para la síntesis del acrilato de butilo vía polimerización en solución a temperaturas menores a 100°C, así como la evaluación de sus propiedades fisicoquímicas resultantes, tales como un buen control de la masa molecular y la predicción de la temperatura de transición vítrea (Tg). Las muestras polimerizadas se caracterizaron por diferentes técnicas como FTIR, cromatografía por exclusión de tamaños (CET) y calorimetría diferencia de barrido (DSC). Se propuso el uso del AIBN y el peróxido de benzoílo como iniciadores, se hizo uso del n-dodecanotiol como agente de transferencia para controlar su masa molecular. Con los resultados obtenidos se hace factible escalar el proceso para aplicaciones en la industria del petróleo o de los adhesivos.A methodology and formulation was proposed for the synthesis of the n-butyl acrylate via solution polymerization at temperatures below 100°C, as well as the evaluation of its resulting physicochemical properties, such as well control of molecular weight and the prediction of glass transition temperature (Tg). The polymerized samples were characterized by different techniques such as FTIR, size exclusion chromatography (CET) and differential scanning calorimetry (DSC). The use of AIBN and benzoyl peroxide as initiators was proposed, using n-dodecanethiol as a transfer agent in order to control their molecular weight. With the results obtained it becomes feasible to scale the process for applications in the petroleum industry or adhesives

A Simple Method to Measure Renal Function in Swine by the Plasma Clearance of Iohexol

There is no simple method to measure glomerular filtration rate (GFR) in swine, an established model for studying renal disease. We developed a protocol to measure GFR in conscious swine by using the plasma clearance of iohexol. We used two groups, test and validation, with eight animals each. Ten milliliters of iohexol (6.47 g) was injected into the marginal auricular vein and blood samples (3 mL) were collected from the orbital sinus at different points after injection. GFR was determined using two models: two-compartment (CL2: all samples) and one-compartment (CL1: the last six samples). In the test group, CL1 overestimated CL2 by ~30%: CL2 = 245 ± 93 and CL1 = 308 ± 123 mL/min. This error was corrected by a first-order polynomial quadratic equation to CL1, which was considered the simplified method: SM = −47.909 + (1.176xCL1) − (0.00063968xCL12). The SM showed narrow limits of agreement with CL2, a concordance correlation of 0.97, and a total deviation index of 14.73%. Similar results were obtained for the validation group. This protocol is reliable, reproducible, can be performed in conscious animals, uses a single dose of the marker, and requires a reduced number of samples, and avoids urine collection. Finally, it presents a significant improvement in animal welfare conditions and handling necessities in experimental trials