Ponencia presentada en: 16th European Meeting on Supercritical Fluids, 25 a 28 de abril de 2017, Lisboa ; The quality of cloudy apple juice seems to be better than the clarified juice due to the loss of phenolic compounds during processing. Enzymatic browning and cloud stability are the main problems in processing and storage of the juice. In this work, HPCD is proposed as an alternative to the traditional heat treatments that can degrade the quality of the juice. Polyphenol oxidase (PPO) and pectin methylesterase (PME) inactivation by HPCD were determined for both enzymes. The effect of stirring speed on PPO inactivation was studied; obtaining that at higher speed inactivation was also higher. Other quality parameters in the juice were also determined after HPCD treatment, such as particle size distribution, colour, turbidity and total phenolic compounds. ; (MINECO) and the European Regional Development Fund (ERDF) for financial support of project CTQ2015-64396-R and AEI's contract. R. Melgosa acknowledges MINECO for a grant (BES-2013-063937). ; Spanish Government (MINECO) and the European Regional Development Fund (ERDF) for financial support of project CTQ2015-64396-R and AEI's contract. R. Melgosa acknowledges MINECO for a grant (BES-2013-063937)
Modificación de electrodos de carbono con óxido de grafeno para la mejora del rendimiento en sistemas bioelectroquímicos. This research was supported by the regional government 'Junta de Castilla y León, Consejería de Educación', project reference: LE060U16, co-financed by FEDER funds
Resumen del póster presentado en Symposium on Renewable Energy and Products from Biomass and Waste, CIUDEN (Cubillos de Sil, León, Spain), 12-13 May 2015 ; Thermochemical conversion pathways of biomass for the production of primary energy by direct combustion, as well as other thermal processes, have a remarkable drawback among others: tar formation. In the present work, a detailed study of the reforming of syngas produced in the decomposition of Posidonia oceanica is done. The effect of the presence of different amounts of dolomite is analysed. Gasification of the species is done in the presence of sub-stoichiometric air, analyzing the produced gases. Also pyrolysis is studied, in nitrogen atmosphere, and gasification in the presence of air, oxygen and different amounts of steam. A discussion on formation and destruction of tars is done. Furthermore, the effect of the heating rate in the decomposition and the residence time of the evolved gases are discussed. Syngas with ratio H2/CO from 0.3 to ca. 3 can be obtained from this interesting material. It can be concluded that: 1) The presence of increasing percentages of water vapor in the reaction gases in the presence of dolomite increases the ratio H2/CO and decreases the NCV of the gas for all reaction atmospheres and residence times; 2) The highest values of the ratio H2/CO and less NCV are obtained for combustion in sub-stoichiometric air and low residence time; 3) The possible use of syngas goes from heat engines use with internal and external combustion to the processing fluid for obtaining biofuels, methanol, ammonia, synthetic natural gas and hydrogen; 4) If atmospheres are used with an amount of oxygen, it would be necessary a post-treatment aimed to remove the oxygen gas. Marine species (microalgae) are usually studied with the aim of cultivate them for gas or oil production, but in this work we draw attention to the possibility of using a natural resource with a very small impact in the ecosystem. ; Authors kindly wish to thank the Ministry of Economy and Competitiveness (Spain): CTQ2013-41006-R and Valencian Community Government (Spain): PROMETEOII/2014/007 for provided support of this work. The author M.E. Iñiguez also thanks the Ministry of Economy and Competitiveness (Spain), for a Ph.D. grant (contract grant number BES-2014-069473).
En el trabajo se exponen los resultados de una investigación realizada en el marco del proyecto: Estudio de la preparación inicial para el aprendizaje de la Física y la Química de los estudiantes que ingresan a las carreras de Ingeniería en Agronomía y Licenciatura en Educación Química y Física, cuyo objetivo consiste en diagnosticar las estrategias de aprendizaje. El producto final es un instrumento con 36 ítems que evalúa las estrategias cognitivas, de apoyo y metacognitivas que utilizan los estudiantes. Para la elaboración de dicho instrumento se aplicó una metodología de trabajo que implica la definición e identificación de las variables que se desean medir y la determinación de ítems e indicadores de cada una de esas variables.
El objetivo del presente trabajo fue diseñar una estrategia didáctica para la divulgación científica de las sustancias constituyentes de las bebidas energizantes y sus efectos en los consumidores. La población a la que se dirigió la estrategia, son jóvenes de los grados noveno a once de diferentes instituciones educativas tanto públicas como privadas del municipio de Mosquera. La metodología empleada para cumplir con el objetivo propuesto partió, en primer lugar, con la aplicación de una prueba diagnóstica (encuesta) la cual permitió recopilar información del conocimiento que tienen los jóvenes, de las instituciones educativas en las que se elaboró el trabajo, acerca de las bebidas energizantes. En segundo lugar, en cada institución educativa se realizó una conferencia, para efectuar una divulgación sobre los constituyentes de estas bebidas y los efectos adversos asociados a un consumo excesivo. De igual manera se invitó a conocer un objeto de aprendizaje (OA) virtual desarrollado en el presente trabajo, el cual está disponible en internet de forma gratuita en el enlace http://lemarsilva.wix.com/energizante. En este sitio se brinda información detallada acerca de estas bebidas, sus restricciones y la legislación vigente en nuestro país. Además, se incluye una encuesta que permite evaluar la nueva perspectiva de los estudiantes después de conocer la información presentada. De los datos recopilados se encontró que de 412 estudiantes encuestados, el 84% de ellos han ingerido bebidas energizantes. Estos resultados nos invitan a reflexionar acerca de la importancia de generar estrategias que conlleven a un consumo racional y controlado de las bebidas energizantes en nuestro país. ; Abstract The objective of this project was to design a didactic strategy for scientific publication of the constituent substances of energy drinks and their effects on consumers. The populations of that strategy are young people from ninth to eleven grades of different public and private schools in Mosquera town. The methodology used to achieve the proposed objective, began, first, with the application of a diagnostic test (survey) which allowed to collect information about the knowledge that young people who study at the schools where this work was placed, have about energy drinks. Second, in each school a conference was held, to make a disclosure about the constituents of these drinks and adverse effects associated with excessive consumption. In the same way, they were invited to meet a virtual learning object (LO) developed in this paper, which is available online for free at the link http://lemarsilva.wix.com/energizante. This website gives information about these drinks, restrictions and legislation in our country it provides. In addition, there is a survey which assesses the new perspective of the students after learning the information presented. From the data collected was found that of 412 students surveyed, 84% of them have consumed energy drinks. These results invite us to reflect on the importance of creating strategies that lead to a controlled and rational consumption of energy drinks in our country. ; Maestría
The need to increase the recovery rates of recyclables from households, reducing at the same time the collection costs, has favored the spreading of commingled collection systems. This study presents a thorough analysis of the quality of a secondary source of recovered paper of a Spanish newsprint mill, imported from the United Kingdom, where these systems are widely practiced. The results show that the quality of recovered paper from commingled systems is very far from the quality obtained with selective systems: the unusable material content vary from 1% to 29% (11.9% on average) compared to less than 1%. Larger materials recovery facilities (MRF), less oversaturated and with advanced sorting techniques, have demonstrated to be able to render better qualities, the unusable material content varying from 0.3% to 16.6% (8.1% on average). However, the quality is still far from contamination levels typically found with selective systems, especially in terms of non-paper components. This fact limits significantly the use of this recovered paper for graphic paper production where the major potential for an extended use of recovered paper in papermaking lies. Furthermore, there is a discussion on the cost efficiency of these systems and how the legislation and private or public initiatives are affecting the spreading of these systems, especially in the United States and the United Kingdom.
RESUMEN: En el año 2003, la Facultad de Ingeniería de la Universidad de Antioquia cumple 60 años de su más reciente fundación; esto es así porque la Facultad fue la primera escuela de ingeniería de Colombia y tiene una larga historia que se remonta hasta la época de la guerra de independencia. En efecto, a fines de agosto de 1814 se inauguró en Medellín la primera Escuela Colombiana de Ingenieros Militares, bajo la dirección del "coronel injeniero jeneral" Francisco José de Caldas, que funcionó hasta el 25 de septiembre de 1815. Así pues, la evolución de la Facultad es larga y merece conocerse y guardar memoria de ella; de ahí el pretexto de esta conmemoración para presentar brevemente esta historia de una entidad que ahora entra a su tercer siglo de existencia. En esta segunda entrega se hace un recuento desde el decenio de 1980 hasta el futuro. Palabras clave: Universidad de Antioquia, Facultad de Ingeniería, Facultad de Ingeniería Química, Escuela de Ciencias Químicas, Escuela de Minería, Academia de Ingenieros Militares, Francisco José de Caldas. ; ABSTRACT: In the year 2003, the College of Engineering of the University of Antioquia arrives to 60 years from its more recent foundation; this is so, because this College was the first School of Engineering in Colombia and really has a long history that goes back to the Independence times. In fact, at the end of August, 1814, in Medellín, the first Colombian Academy of Military Engineers was inaugurated, under the guidance of "coronel injeniero general", Francisco José de Caldas, and functioned up to September 25, 1815. So, the evolution of our College is quite long and deserves to be related and kept in the common memory. For that reason, this anniversary is a good excuse for briefly present this history of an entity that now enters its third century of existence. In this second issue an account is done from the 1980 decade up to the future. Keywords: Universidad de Antioquia, Facultad de Ingeniería, Facultad de Ingeniería Química, Escuela de Ciencias Químicas, Escuela de Minería, Academia de Ingenieros Militares, Francisco José de Caldas.
[EN] This work presents a solid-state ionic-based device to selectively detect C2H4 in car exhaust gases. The sensor consists of 8YSZ as the electrolyte and two electrodes: Fe0.7Cr1.3O3/8YSZ and LSM/8YSZ. The main aim of this work is to optimize the catalytic behavior of the working electrode to C2H4 and reduce cross-sensitivity toward CO and H2O. Several catalyst nanoparticles were infiltrated to tailor C2H4 adsorption and electrochemical oxidation properties while diminishing adsorption and conversion of other gas components such as CO. The infiltrated metal catalysts were selected, taking into account both adsorption and redox properties. Infiltration of Ti or Al, followed by a second infiltration of Ni, enabled the selective detection of C2H4 with low cross-sensitivity toward CO and H2O in a moist gas environment. Further insight into potentiometric C2H4 sensing is achieved by electrochemical impedance analysis of the electrodes activated with bifunctional catalysts. ; FundingFunding from the Spanish Government (Grants FPU13/03478, AP-2003-03478, and RTI2018-102161) is kindly acknowledged. ; Toldrá-Reig, F.; Serra Alfaro, JM. (2021). Potentiometric C2H4-Selective Detection on Solid-State Sensors Activated with Bifunctional Catalytic Nanoparticles. Chemosensors. 9(10):1-14. https://doi.org/10.3390/chemosensors9100274 ; S ; 1 ; 14 ; 9 ; 10
The thermal degradation of flexible polyurethane foam has been studied under different conditions by thermogravimetric analysis (TG), thermogravimetric analysis-infrared spectrometry (TG-IR) and thermogravimetric analysis-mass spectrometry (TG-MS). For the kinetic study, dynamic and dynamic+isothermal runs were performed at different heating rates (5, 10 and 20 °C min−1) in three different atmospheres (N2, N2:O2 4:1 and N2:O2 9:1). Two reaction models were obtained, one for the pyrolysis and another for the combustion degradation (N2:O2 4:1 and N2:O2 9:1), simultaneously correlating the experimental data from the dynamic and dynamic+isothermal runs at different heating rates. The pyrolytic model considered consisted of two consecutive reactions with activation energies of 142 and 217.5 kJ mol−1 and reaction orders of 0.805 and 1.246. Nevertheless, to simulate the experimental data from the combustion runs, three consecutive reactions were employed with activation energies of 237.9, 103.5 and 120.1 kJ mol−1, and reaction orders of 2.003, 0.778 and 1.025. From the characterization of the sample employing TG-IR and TG-MS, the results obtained showed that the FPUF, under an inert atmosphere, started the decomposition breaking the urethane bond to produce long chains of ethers which were degraded immediately in the next step. However, under an oxidative atmosphere, at the first step not only the urethane bonds were broken but also some ether polyols started their degradation which finished at the second step producing a char that was degraded at the last stage. ; The authors thank the Spanish Ministry of Education Culture and Sport and the research projects CTQ2013-41006 from the Spanish Ministry of Economy and Competitiveness and PROMETEOII/2014/007 from the Valencian Community Government for the support provided.
In the present work, a very detailed study of the reforming of syngas produced in the decomposition of Posidonia oceanica is done. The effect of the presence of different amounts of dolomite is analyzed. Also pyrolysis is studied, in nitrogen atmosphere, and gasification in the presence of air, oxygen and different amounts of steam. A detailed discussion on formation and destruction of tars is done. Furthermore, the effect of the heating rate in the decomposition and the residence time of the evolved gases are discussed. Syngas with ratio H2/CO from 0.3 to ca. 3 can be obtained from this interesting material. Marine species (microalgae) are usually studied with the aim of cultivating them for gas or oil production, but in this paper we draw attention to the possibility of using a natural resource with a very small impact in the ecosystem. ; Support for this work was provided by the CTQ2013-41006-R project from the Ministry of Education and Science (Spain) and the PROMETEOII/2014/007 project from the Valencian Community Government (Spain).
The closure of water circuits within pulp and paper mills has resulted in a higher contamination load of the final mill effluent, which must consequently be further treated in many cases to meet the standards imposed by the legislation in force. Different treatment strategies based on advanced oxidation processes (ozonation and TiO2-photocatalysis), and their combination with biological treatment (MBR), are herein assessed for effluents of a recycled paper mill and a kraft pulp mill. Ozone treatment achieved the highest efficiency of all. The consumption of 2.4 g O3 L−1 resulted in about a 60% COD reduction treating the effluent from the kraft pulp mill at an initial pH = 7; although it only reached about a 35% COD removal for the effluent of the recycled paper mill. Otherwise, photocatalysis achieved about a 20–30% reduction of the COD for both type of effluents. In addition, the effluent from the recycled paper mill showed a higher biodegradability, so combinations of these AOPs with biological treatment were tested. As a result, photocatalysis did not report any significant COD reduction improvement whether being performed as pre- or post-treatment of the biological process; whereas the use of ozonation as post-biological treatment enhanced COD removal a further 10%, summing up a total 90% reduction of the COD for the combined treatment, as well as it also supposed an increase of the presence of volatile fatty acids, which might ultimately enable the resultant wastewater to be recirculated back to further biological treatment.
The authors thank the research project CTQ2008-05520 from the Spanish Ministry of Education and Science and PROMETEO/2009/043/FEDER from the Valencian Community Government (Spain) for the support provided.
According to current environmental legislation concerned with water scarcity, paper industry is being forced to adopt a zero liquid effluent policy. In consequence, reverse osmosis (RO) systems are being assessed as the final step of effluent treatment trains aiming to recover final wastewater and reuse it as process water. One of the most important drawbacks of these treatments is the production of a retentated stream, which is usually highly loaded with biorecalcitrant organic matter and inorganics; and this effluent must meet current legislation stringent constraints before being ultimately disposed. The treatment of biorefractory RO retentate from a paper mill by several promising advanced oxidation processes (AOPs) – conventional Fenton, photo-Fenton and photocatalysis – was optimized considering the effect and interaction of reaction parameters; particularly using response surface methodology (RSM) when appropriate (Fenton processes). The economical cost of these treatments was also comparatively assessed. Photo-Fenton process was able to totally remove the COD of the retentate, and resulted even operatively cheaper at high COD removal levels than conventional Fenton, which achieved an 80% reduction of the COD at best. In addition, although these optimal results were produced at pH = 2.8, it was also tested that Fenton processes are able to achieve good COD reduction efficiencies (>60%) without adjusting the initial pH value, provided the natural pH of this wastewater was close to neutral. Finally, although TiO2-photocatalysis showed the least efficient and most expensive figures, it improved the biodegradability of the retentate, so its combination with a final biological step almost achieved the total removal of the COD.
El ámbito tecnológico y económico cambiante de nuestro tiempo incorpora la filosofía de la calidad como una de las herramientas que inexorablemente conduce a una visión reformadora del individuo. Por lo cual los conceptos de calidad están siendo tornados en cuenta en los círculos sociales. políticos y empresariales. dejando de lado planteamientos meramente circunstanciales y superficiales ya que al ser consideradas una exigencia más que un deseo se tiende a asumirla obligatoriamente. Cabe mencionar que el éxito de la cultura de la calidad dará sus resultados en la medida que se incorporen en la sociedad también los principios de calidad moral. ética y justicia. Con estas palabras se inicia la exposición sobre la actividad profesional en el Laboratorio Antenor Rizo Patrón Lequerica (ARPL) Tecnología Industrial S. A. Esta empresa orienta su labor principalmente hacia el campo de la Industria del Cemento y tiene como objetivo central elaborar informes de los Análisis Químicos, Ensayos Físicos y Mecánicos efectuados sobre materias primas (calizas y crudos), productos intermedios (clinker), producto final (cemento) y materiales relacionados de las Fábricas de Cemento Lima S. A. y Cemento Andino S. A. Los resultados de los Análisis y Ensayos son rigurosamente desarrollados teniendo presente el Sistema de Aseguramiento de la Calidad en concordancia con los lineamientos básicos de las Guías: ^INDECOPI, Normas Itintec, Guías ISO/IEC. Cabe destacar la importancia de la Química Clásica como plataforma de soporte básico del análisis químico instrumental, que sustenta la base de datos para elaborar las diferentes curvas o correlaciones de los diferentes materiales (calizas, crudos, arcillas, arenas, minerales de hierro, puzolanas, cemento y clinker, yeso). El análisis químico instrumental se realiza con equipos analíticos que en la mayoría de los casos incorpora tecnología de punta y que califican con las respectivas normas de análisis. Hoy la planta de cemento es una industria de gran dinamismo, que implementa constantemente nuevas tecnologías. La búsqueda de eficiencia, calidad y reducción en el consumo de energía supone desde luego una mejora continua de la planta de cemento a través de nuevos equipos tales como separadores de alta eficiencia, chancadoras de rodillos, molinos de rodillo, modificaciones de los ciclones precalentadores, como del enfriador. Además, grandes esfuerzos están siendo orientados hacia la automatización. Varias plantas están introduciendo sistemas de control expertos, los cuales permiten reducir el consumo de combustible, incrementar la vida del refractario y facilitan el quemado del crudo. Una buena calidad de cemento requiere un clinker con un alto contenido de silicato tricálcico (C3S) y baja cal libre. Esta condición es alcanzada entre otras variables con una mezcla cruda con valores de saturación de cal alto y módulo de sílice ambos constantes. Los resultados generados por el laboratorio analítico constituyen hoy parte de la información técnica tan necesaria sobre todo para efectos de competitividad en el mercado. Si la información en general se considera como un cuarto poder de la sociedad además de los poderes legislativo, ejecutivo. y judicial. la información técnica bien puede considerarse como un cuarto pilar de la economía moderna. además del capital. trabajo y materias primas. De esta manera la calidad ele la información generada es un objetivo prioritario de la química analítica ele hoy y mañana. En ese sentido ARPL evalúa la calidad externa analizando productos elaborados o para monitorizar los procesos productivos de las plantas de cemento, así como también la calidad interna en sus resultados generados. El control de calidad. por ser un conjunto de acciones. planificadas y ejecutadas para proporcionar una información analítica con un nivel definido de calidad (exactitud y representatividad) que satisfaga los requisitos impuestos por las normas, tanto ITINTEC como ASTM, es una parte activa de los sistemas de garantía de calidad y este sujeto a su contraste mediante los sistemas de Evaluación de la calidad. Con la finalidad de que el Laboratorio ARPL Tecnología Industrial S. A. sea reconocido como una institución competente dentro del campo del Análisis químico, físico y mecánico en sus diferentes áreas, se sometió a una Auditoría, condición necesaria para acreditar que sus análisis se realizan con métodos validados. equipos calificados, procedimientos documentados, con estándares trazables, e instrumentos calibrados de acuerdo con nuestro sistema de aseguramiento de la calidad, obteniéndose con éxito el mencionado certificado en el año 1995. ; Trabajo de suficiencia profesional
A further closure of the water circuit in paper mills with a relative high optimization of their water network is limited by the increase of contamination in the water and runnability problems of the paper machine. Therefore, new strategies for saving water must be focussed on the treatment of final effluents of the paper mill, aiming to obtain high quality water that may replace fresh water use in some applications. An appropriate treatment train performed at pilot scale,consisting on a previous clarification stage followed by anaerobic and aerobic treatments,ultrafiltration, and reverse osmosis, made possible producing the highest water quality from the final effluent of the mill. Anaerobic pre-treatment showed very good performance assisting the aerobic stage on removing organics and sulphates, besides it produced enough biogas for being considered as cost-effective. Permeate recovery depended on the silica content of the paper mill effluent, and it was limited to a 50–60%. The reject of the membranes fully met the legislation requirements imposed to effluents arriving to municipal wastewater treatment plants.
