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This research evaluates achira starch modification via gamma radiation, chemical modification and the subsequent adhesives formulation. Native starch was irradiated using a linear accelerator; the mean dose rate used was 19.5 kGy/min at ambient temperature and normal pressure. The chemical modification of irradiated starch consisted of a hydrolysis process, followed by the obtention of carbamates from the hydrolyzed starch with urea, sulphuric acid and ethanol. In order to prepare adhesives; native, modified and dual-modified starches were tested in different proportions with a polyvinyl alcohol (PVA) solution. Fourier Transformed Infrared Spectroscopy (FTIR) analysis showed all modified starches had a lower intensity in the band between 1100 and 900 cm-1 due to the damage in the glycosidic bonds. Only single modified starches evidenced a characteristic band at 1715 cm-1, which corresponds to the group carbonyl (C=O) of carbamates. The viscosity of native starch adhesives increased with the starch-PVA, unlike, single and dual-modified starch adhesives. The shear bond strength did not change significantly in the adhesives formulated either with starch modified by urea or electron beam irradiation. The combination of hydrolysis with gamma radiation caused strong damage in the starch structure. However, despite the molecular destruction of polysaccharide, the adhesion capacity for non-irradiated starches is similar in all cases.

Resumen Las fuentes naturales con alto contenido de color y baja turbiedad, características de una fuente superficial de páramo, pueden limitar el proceso de una planta potabilizadora, ya que se genera una baja velocidad de sedimentación de los flóculos formados en el proceso de coagulación. El objetivo de este documento es presentar el resultado de la investigación realizada al comparar la sedimentación producida por la combinación de cloruro férrico (FeCl3) e hidroxicloruro de aluminio (PAC), usados como coagulante primario y auxiliar de coagulación, respectivamente, versus PAC como coagulante primario. El estudio se desarrolló a escala de laboratorio utilizando pruebas de jarras y un agua natural con las características previamente mencionadas. Para cada opción de tratamiento se determinaron las curvas de sedimentación y se ajustaron a regresiones lineales, las cuales fueron comparadas estadísticamente. Asimismo, para cada curva, se estableció la eficiencia y la turbiedad teórica para tres velocidades de sedimentación: 1.3 cm/s, 0.9 cm/s y 0.6 cm/s. Los resultados indicaron que los dos procesos eran diferentes (p=0.000) y que el uso de FeCl3+PAC genera mayores velocidades de sedimentación de las partículas floculentas y menores turbiedades residuales teóricas, lo que permite mejorar la eficiencia del proceso de sedimentación. El estudio concluyó que el uso de FeCl3 en combinación con PAC representa una mejor opción técnica en comparación con el PAC como coagulante primario, ya que además de permitir la optimización del proceso de sedimentación, podría ayudar a aumentar la filtración y reducir el consumo de agua de lavado de filtros. Abstract Highly colored low turbidity water, which is characteristic of high mountain sources, can limit the process of water treatment plants because it generates a low sedimentation rate of the flocs formed in the coagulation process. This article compares the sedimentation produced by the combination of ferric chloride (FeCl3) and polyaluminium chloride (PAC) used as primary coagulant and coagulation auxiliary, respectively, versus PAC as primary coagulant. This study was conducted at laboratory level using jar tests and natural water with the aforementioned characteristics. The sedimentation curves of each treatment option were determined and adjusted to linear regressions, which were statistically compared. For each curve, efficiency and theoretical turbidity were determined using three sedimentation rates: 1.3 cm/s, 0.9 cm/s, and 0.6 cm/s. The results indicate that the two processes were different (p=0.000), and the use of FeCl3+PAC generated higher sedimentation rates and lower theoretical residual turbidities, which improves the efficiency of the sedimentation process. In conclusion, the use of FeCl3 in combination with PAC represents a better technical option than PAC as primary coagulant because, in addition to optimizing the sedimentation process, it could help to increase the filtration run and reduce the consumption of water for filter washing.

Brominated flame retardants (BFRs) have attracted increasing attention in recent decades because of their persistence, distribution, bioaccumulation, and biotoxicity in the environment. In the present study, the levels and distribution of polybrominated diphenyl ethers (PBDEs) and polybrominated biphenyl (PBBs) in twenty-four samples of twelve fish species collected from the Three Gorges Reservoir (TGR) were analyzed. The results indicated that ∑PBDE concentrations in fish muscle ranged from 22.62 pg g -1 by wet weight (ww) (yellowcheek carp) to 217.75 pg g -1 ww (yellow catfish). BDE47 and BDE209 were the most predominant congeners, with their sum accounted for 23.62–68.16% of ∑PBDEs. ∑PBB concentrations ranged from 27.83 pg g -1 ww (silver carp) to 155.75 pg g -1 ww (topmouth culter); BB49 and BB209 were detected in all samples, with concentrations ranging from 4.62 to 47.10 pg g -1 ww and 1.29 to 80.95 pg g -1 ww, respectively. There are no significant correlations between the BFRs levels and fish length (or weight) in these samples. Compared to other areas, the level of BFRs in edible fishes from TGR was low.

[EN] This article describes the forward and inverse kinematic model of position of the Hex-piderix robot, taking on account current attitude. Also three strategies to get terrain adaptability to the robot, guaranty statically stability are presented: constant orientation of the thorax, geometric strategy and emergency strategy. The designing of the adaptability strategies are considered geometric parameters and the weight of each of its components; both direct and inverse kinematics in position is essential for the robot could redirect. Statically stable is evaluated by using Normalized Energy Stability Margin. Adaptability strategies were simulated in MatLab and experimentally validated by using LabView., [ES] Este artículo presenta la cinemática directa e inversa en posición de un robot caminante hexápodo, tomando en cuenta la pose del tórax. También se presentan tres estrategias de adaptabilidad al terreno que garantizan la estabilidad: orientación constante del tórax, estrategia geométrica y estrategia de emergencia. El diseño de las estrategias de adaptabilidad considera los parámetros geométricos y el peso de todos los elementos. La cinemática directa e inversa es esencial para redireccionar la postura del robot caminante. La estabilidad de las estrategias es evaluada con el margen normalizado de estabilidad energético (NESM). Las estrategias fueron simuladas en software especializado y se validaron experimentalmente.

Time Resolved Raman spectroelectrochemistry (TR-Raman-SEC) has been used for the first time to obtain two different Raman spectra of one single analyte in the same experiment. This double detection has been accomplished thanks to the use of electrochemical surface enhanced Raman scattering (EC-SERS) and electrochemical surface oxidation enhanced Raman scattering (EC-SOERS) in the same experiment. These two Raman enhancement phenomena can provide a broad insight into the interaction between analyte and substrate surface when they are combined. To prove the possibilities of this methodology, a Raman spectroelectrochemistry study of uracil (U) and 5-fluorouracil (5-FU), two analytes with relevance in medicine and biochemistry, have been performed. Density functional theory (DFT) calculations has been carried out to shed more light on the interaction of these molecules with silver substrates in acidic media., Ministerio de Economía, y Competitividad (Grant CTQ2017–83935-R-AEI/FEDERUE), Junta de Castilla y León (Grant BU297P18, Grant BU087G19, and Grant BU263P18) and Ministerio de Ciencia, Innovación y Universidades (Grant RED2018–102412-T and Grant PID2019–111215RB-I00). W. Ch. thanks JCyL for his postdoctoral fellowship (Grant BU297P18). S.H. thanks JCyL and European Social Fund for her predoctoral fellowship. M.P-E. thanks JCyL, the European Social Fund and the Youth Employment initiative and JCyL and European Social Fund for his predoctoral fellowship. This research has made use of the high-performance computing resources of the Castilla y León Supercomputing Center (SCAYLE, https://www.scayle.es), financed by FEDER (Fondo Europeo de Desarrollo Regional). Jorge Gonzalez is acknowledged for his help in the laboratory whose contract was founded by JCyL, the European Social Fund and the Youth Employment Initiative.

Queremos expresar nuestro más profundo agradecimiento a D. Marcelo Castro, director del Conjunto Arqueológico de Cástulo, y a D. Juan F. Murillo, director de la Oficina de Arqueología de la Gerencia de Urbanismo del Ayuntamiento de Córdoba. Este trabajo ha sido financiado por la Agencia Estatal de Investigación, en el marco del Proyecto de Investigación de referencia PID2019-105706GB-I00 “Estudios de materiales y técnica de ejecución, ensayos de tratamientos de conservación-restauración y aplicaciones 3D de elementos decorativos del Patrimonio Cultural”., Para el estudio de una pintura mural arqueológica resulta de gran importancia el análisis de su soporte, esto es, del mortero. En este artículo se muestra la metodología seguida para el estudio comparativo de morteros procedentes de diversos ejemplos de pintura mural cuya cronología comprende desde época romana hasta época califal. Para su examen se ha llevado a cabo un análisis visual y una toma de muestra; las muestras seleccionadas han sido estudiadas con diferentes técnicas instrumentales: microscopía estereoscópica, microscopía óptica, microscopía electrónica de barrido (SEM-EDX) y difracción de rayos X. Además, dada la similitud de los resultados obtenidos en estos primeros análisis, se procedió también a la realización de un estudio para establecer la distribución granulométrica y la relación entre aglomerante y árido. Todo ello ha permitido la caracterización de los diferentes estratos de mortero así como establecer diferencias y semejanzas entre los morteros pertenecientes a las distintas cronologías., In the study of an archaeological wall painting, the analyze of its support, the mortar, has a great importance. In this paper, the methodology followed for the comparative study of mortars from various examples of wall painting whose chronology ranges from roman to caliphate times is shown. For the examination of the mortars a visual analysis and a sampling have been carried out; the selected samples have been studied with different instrumental methods: stereoscopic microscopy, optical microscopy, scanning electron microscopy (SEM-EDX) and X-ray diffraction. In addition, because of the similarity of the results obtained in these first analyses, a study was also carried out to establish the distribution of the aggregate and the relationship between binder and aggregate. All this has allowed the characterization of the different layers of mortar as well as establishing differences and similarities between the mortars belonging to the different chronologies., Para o estudo de uma pintura mural arqueológica é importante a análise do seu suporte, a argamassa. Este artigo dá a conhecer a metodologia seguida para o estudo comparativo de argamassas de vários exemplos de pintura mural, cuja cronologia vai da época romana à época do califado. Foi realizada uma análise visual e recolha de amostras; as amostras selecionadas foram estudadas com diferentes técnicas instrumentais: microscopia estereoscópica, microscopia ótica, microscopia eletrónica de varrimento (SEM-EDX) e difração de raios X. Além disso, dada a similaridade dos resultados obtidos nestas primeiras análises, procedeu-se também à realização de um estudo para estabelecer a distribuição do tamanho das partículas e a relação entre o aglutinante e o agregado. Tudo isto permitiu caracterizar as diferentes camadas de argamassa bem como estabelecer diferenças e semelhanças entre as argamassas pertencentes às diferentes cronologias., Agencia Estatal de Investigación (PID2019-105706GB-I00)

Digital, Thermochemical conversion by gasification process is one of the most relevant technologies for energy recovery from solid fuel, with an energy conversion efficiency better than other alternatives like combustion and pyrolysis. Nevertheless, the most common technology used in the last decades for thermochemical conversion of solid fuel through gasification process, such as coal, agriculture residues or biomass residues are the fluidized bed or bubbling fluidized bed system. For these gasification technologies, an inert bed material is fed into reactor to improve the homogenization of the particles mixture and increase the heat transfer between solid fuel particles and the bed material. The fluidized bed reactors usually operate at isothermal bed temperatures in the range of 700–1000 °C, providing a suitable contact between solid and gas phases. In this way, chemical reactions with high conversion yield, as well as an intense circulation and mixing of the solid particles are encouraged. Moreover, a high gasification temperature favours carbon conversion efficiency, increasing the syngas production and energy performance of the gasifier. However, the risk of eutectic mixtures formation and its subsequent melting process are increased, and hence the probability of bed agglomeration and the system collapse could be increased, mainly when alkali and alkaline earth metals-rich biomasses are considered. Generally, bed agglomeration occurs when biomass-derived ash reacts with bed material, and the lower melting temperature of ash components promotes the formation of highly viscous layers, which encourages the progressive agglomerates creation, and consequently, the bed collapse and system de-fluidization. Taking into account the relevance of this topic to ensure the normal gasification process operating, this paper provides several aspects about bed agglomeration, mostly for biomass gasification systems. In this way, chemistry and mechanism of bed agglomeration, as well as, some methods for in-situ detection and prediction of the bed agglomeration phenomenon are reviewed and discussed., Ingeniería Ambiental

[EN] Architecture made in concrete has been revealing its own characteristics due to the qualities of the material and its unique place in construction, which has been quite clear throughout history, even above the styles, dominating theories or current design concerns. This possible independence places it in a different sphere, that should be approached from its material reality, as a method that contributes new information, knowledge, and design possibilities. This paper deals with laying the foundations for this new approach where the material wants to be aware if its own potential so that the architectural projects can benefit from it. Due to its ability to change, it is difficult to understand the nature of concrete: it could be strictly humble, be the central focus or a mix of both; yet we consider it to be another fact to develop the ideal and although production disguises and disperses it, in essence it helps to strengthen this final desire. The aim is to establish an extracted ideal of its extensive qualities. To do this, a temporal process is identified, not chronological but deductive, where each line of reasoning is supported by the previous one in order to reach the final thesis, the origin of new research., [ES] La arquitectura de hormigón ha ido desvelando características propias debido a las cualidades del material y su singular puesta en obra, que han quedado más o menos patentes a lo largo de la historia, por encima incluso de los estilos, teorías dominantes o inquietudes proyectuales del momento. Esa posible independencia las sitúa en una órbita distinta, que debe ser mirada desde su realidad material, como método que aporte nuevos datos, conocimientos y posibilidades proyectuales. Este escrito trata de sentar las bases para esa nueva mirada, donde el material quiere ser consciente de su potencial para que el proyecto de arquitectura se pueda beneficiar de ellas. Por su capacidad mutante es difícil abarcar la naturaleza del hormigón: puede ser plenamente servil, plenamente protagonista o una mezcla; pero consideramos que es otro dato más para definir la formación del ideal, y aunque mucha producción lo camufle y lo disperse, en el fondo, ayuda a reforzar más claramente ese deseo final. La intención es establecer un ideal entresacado de sus más amplias cualidades. Para ello se establece un proceso temporal, no cronológico sino deductivo, donde cada tiempo argumental se apoya en el anterior para llegar a la tesis final, origen de nuevas investigaciones.

It is no doubt Isoniazid is a powerful tuberculosis drug, but it might give rise to Vitamin B6 (Pyridoxine) deficiency. In this case, a usual treatment is the combined administration of Isoniazid and Pyridoxine. An easy-to-conduct procedure based on Micellar Liquid Chromatography has been developed to quantify Isoniazid and Pyridoxine in plasma from Tuberculosis patients. The sample was diluted in mobile phase, filtered and directly injected, thus avoiding extraction or purification steps. Both drugs were adequately resolved from the matrix and endogenous compounds using a mobile phase made up of 0.15 M sodium dodecyl sulfate – 8%(v/v) 1-butanol – 0.01 M phosphate buffer at pH 3, running at 1 mL/min through a C18 column at 25 °C, in less than 8 min. Detection was carried out by UV-Absorbance at 265 nm. This innovative analytical method was validated following the Food and Drug Administration Bioanalytical Method Validation Guidance for Industry (2018) with satisfactory results. The response of the drugs was linear in the range 0.1 to 15 mg/L, with r2 > 0.9990 for both compounds. Trueness and precision were 89.2–102.3% and

Inúmeros estudos são realizados todos os anos no intuito de descobrir formas inovadoras de elaborar têxteis para o conforto, segurança e, muitas vezes, que representem as ideologias do consumidor. No entanto, devido à problemática da indústria têxtil relacionada à degradação ambiental, pesquisadores têm realizado estudos acerca de materiais e processos que sejam mais sustentáveis. Portanto, o presente artigo propõe uma revisão bibliográfica de caráter analítico, em quatro bases de dados “Scopus”, “Science Direct” e “Proquest”, sobre materiais e processos mais sustentáveis utilizados no setor de têxteis entre os períodos de 2015 e 2020. Os resultados mostram 38 artigos sobre alternativas sustentáveis de materiais e processos para o mercado atual, bem como sobre pesquisas em andamento sobre novas possibilidades de têxteis nos campos da engenharia, biotecnologia, design, entre outros.

Silk refers to a family of natural fibers spun by several species of invertebrates such as spiders and silkworms. In particular, silkworm silk, the silk spun by Bombyx mori larvae, has been primarily used in the textile industry and in clinical settings as a main component of sutures for tissue repairing and wound ligation. The biocompatibility, remarkable mechanical performance, controllable degradation, and the possibility of producing silk-based materials in several formats, have laid the basic principles that have triggered and extended the use of this material in regenerative medicine. The field of neural soft tissue engineering is not an exception, as it has taken advantage of the properties of silk to promote neuronal growth and nerve guidance. In addition, silk has notable intrinsic properties and the by-products derived from its degradation show anti-inflammatory and antioxidant properties. Finally, this material can be employed for the controlled release of factors and drugs, as well as for the encapsulation and implantation of exogenous stem and progenitor cells with therapeutic capacity. In this article, we review the state of the art on manufacturing methodologies and properties of fiber-based and non-fiber-based formats, as well as the application of silk-based biomaterials to neuroprotect and regenerate the damaged nervous system. We review previous studies that strategically have used silk to enhance therapeutics dealing with highly prevalent central and peripheral disorders such as stroke, Alzheimer’s disease, Parkinson’s disease, and peripheral trauma. Finally, we discuss previous research focused on the modification of this biomaterial, through biofunctionalization techniques and/or the creation of novel composite formulations, that aim to transform silk, beyond its natural performance, into more efficient silk-based-polymers towards the clinical arena of neuroprotection and regeneration in nervous system diseases.

This research evaluates the effect of falling film vacuum evaporation on the characteristics of clarified acid bovine milk whey. The clarified acid whey was obtained by microfiltration (ceramic membranes, 0.2 µm cut-off, ∆TMP: 2 bar) and concentrated by a falling film evaporator. The clarified whey composition was mainly protein (0.32 ± 0.06% w/w), ashes (0.56 ± 0.08% w/w), soluble solids (5 ± 1% w/w), and turbidity (16 ± 5 NTU). During the concentration step, the number of cycles changed notoriously for each volume reduction factor (VRF), being four the highest value achieved, with an average number of cycles of 18. The characteristics of concentrates were not affected by differences in the number of cycles, increasing proportionally with the VRF; it could be noticed in the final content that protein, ashes, and °Bx increased linearly around 3.5 times the initial composition. However, turbidity was different for each VRF because of heat treatment during the concentration stage (above 60°C). A thermal treatment step after ricotta preparation would be advisable to remove the remaining protein. Tukey’s test was carried out at a 95% CI, revealing statistical differences among means; therefore, there was a change in the characteristics of the final concentrated whey. Regarding color (absorbance), there were no considerable changes during the concentration process. Resumen Se evaluó el efecto de la evaporación de película descendente al vacío en las características de lactosueros ácidos previamente clarificados mediante microfiltración (membranas cerámicas, umbral de corte: 0,2 µm y ∆PTM: 2 bar). La composición del lactosuero inicial fue proteína 0,32 ± 0,06% p/p, cenizas 0,56 ± 0,08% p/p, sólidos solubles 5 ± 1% p/p (°Bx) y turbidez 16 ± 5 NTU. Durante la etapa de concentración, el número de ciclos cambió de forma notoria para cada factor de reducción de volumen (FRV), cuyo valor máximo fue de 4 con un promedio de 18 ciclos por lote. Las características de los concentrados no se vieron afectadas por las diferencias en el número de ciclos, los cuales aumentaron en proporción al FRV. Esto pudo evidenciarse en la composición de proteína, cenizas y °Bx, que incrementaron su valor de forma lineal cerca de 3,5 veces más con respecto a la composición inicial. Sin embargo, la turbidez fue diferente debido al tratamiento térmico durante la etapa de concentración (por encima de 60°C), por lo que es conveniente llevar a cabo una etapa de tratamiento térmico después de la elaboración del queso ricota para remover la proteína remanente. La prueba de Tukey con nivel de confianza del 95% confirmó que hubo cambios en la composición del lactosuero final concentrado. No se evidenciaron cambios en el color (absorbancia) durante el proceso de concentración.

The development of drug carriers based in lipid nanoparticles (LNPs) aims toward the synthesis of non-toxic multifunctional nanovehicles that can bypass the immune system and allow specific site targeting, controlled release and complete degradation of the carrier components. Among label free techniques, Surface Plasmon Resonance (SPR) biosensing is a versatile tool to study LNPs in the field of nanotherapeutics research. SPR, widely used for the analysis of molecular interactions, is based on the immobilization of one of the interacting partners to the sensor surface, which can be easily achieved in the case of LNPs by hydrophobic attachment onto commercial lipid- capture sensor chips. In the last years SPR technology has emerged as an interesting strategy for studying molecular aspects of drug delivery that determines the efficacy of the nanotherapeutical such as LNPs' interactions with biological targets, with serum proteins and with tumor extracelullar matrix. Moreover, SPR has contributed to the obtention and characterization of LNPs, gathering information about the interplay between components of the formulations, their response to organic molecules and, more recently, the quantification and molecular characterization of exosomes. By the combination of available sensor platforms, assay quickness and straight forward platform adaptation for new carrier systems, SPR is becoming a high throughput technique for LNPs' characterization and analysis., Facultad de Ciencias Exactas, Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas

Producción Científica, The development of techniques for fabricating vascular wall models will foster the development of preventive and therapeutic therapies for treating cardiovascular diseases. However, the physical and biological complexity of vascular tissue represents a major challenge, especially for the design and the production of off-the-shelf biomimetic vascular replicas. Herein, we report the development of a biocasting technique that can be used to replicate the tunica adventitia and the external elastic lamina of the vascular wall. Type I collagen embedded with neonatal human dermal fibroblast (HDFn) and an elastic click crosslinkable, cell-adhesive and protease-sensitive elastin-like recombinamer (ELR) hydrogel were investigated as readily accessible and tunable layers to the envisaged model. Mechanical characterization confirmed that the viscous and elastic attributes predominated in the collagen and ELR layers, respectively. In vitro maturation confirmed that the collagen and ELR provided a favorable environment for the HDFn viability, while histology revealed the wavy and homogenous morphology of the ELR and collagen layer respectively, the cell polarization towards the cell-attachment sites encoded on the ELR, and the enhanced expression of glycosaminoglycan-rich extracellular matrix and differentiation of the embedded HDFn into myofibroblasts. As a complementary assay, 30% by weight of the collagen layer was substituted with the ELR. This model proved the possibility to tune the composition and confirm the versatile character of the technology developed, while revealing no significant differences with respect to the original construct. On-demand modification of the model dimensions, number and composition of the layers, as well as the type and density of the seeded cells, can be further envisioned, thus suggesting that this bi-layered model may be a promising platform for the fabrication of biomimetic vascular wall models., The authors are grateful for funding from the Spanish Government (PID2019-110709RB-100, RTI2018-096320-B-C22, FPU15-00448 and EST18/00068), the Junta de Castilla y León (VA317P18, Infrared2018-UVA06), the Interreg V A España Portugal POCTEP (0624_2IQBIONEURO_6_E), the Centro en Red de Medicina Regenerativa y Terapia Celular de Castilla y León, the Natural Sciences and Engineering Research Council of Canada (NSERC), the NSERC Create Program in Regenerative Medicine, the Canadian Foundation for the Innovation and the Fonds de Recherche du Québec (Nature et Technologies, and Santé).

Hoy en día la industria manufacturera tiene que hacer frente a cambios paradigmáticos de producción, donde la personalización en masa son pilares fundamentales para adaptarse a la demanda cambiante del mercado. La tecnología actual brinda las herramientas necesarias que, al integrarse con las habilidades humanas, da paso a las Smart Industry entrando así a un entorno de revolución industrial 4.0. En el presente trabajo se propone el diseño de una interfaz Digital Twin que apoya la actividad de supervisión del brazo robótico UR3 mientras este realiza el marcado para corte de superficies en el contexto de producción flexible. La interfaz se logra a través de una interacción Humano-Computador Máquina (HCMI) mientras que la autoadaptación a la producción y cambios ambientales se consigue mediante un algoritmo cut and packing y una cámara adaptada al robot respectivamente. La interfaz se implementa y valida mediante un estudio de caso de laboratorio virtual en el que se observa que el Digital Twin replica el movimiento del robot con un tiempo de latencia insignificante. Nowadays manufacturing industry is facing paradigm production changes, where mass customization is a fundamental pillar in adapting to changing market demands. Today's technology provides the necessary tools that, when integrated with human skills, give way to the Smart Industry thus entering an environment of industrial revolution 4.0. This paper proposes the design of a Digital Twin interface that supports the monitoring activity of the UR3 robotic arm while it performs the marking for surface cutting in the context of flexible production. The interface is achieved through a HumanComputer-Machine interaction (HCMI), while the self-adaptation to production and environmental changes is achieved through a cut and packing algorithm and a camera adapted to the robot respectively. The interface is implemented and validated through a virtual laboratory case study in which it is observed that the Digital Twin replicates the movement of the robot with a negligible latency time.

RESUMEN La sericina es una proteína globular que se obtiene a partir de los capullos del gusano de seda Bombyx mori y tiene aplicaciones en la industria farmacéutica, alimentaria y cosmética. El objetivo de este trabajo fue determinar la estabilidad e irritabilidad dérmica y oftálmica del hidrolizado de sericina (líquido). 3 lotes producidos a escala piloto se almacenaron en frascos de polietileno de alta densidad en diferentes condiciones de temperatura: 40±2 °C por 6 meses y temperatura hasta los 30 °C durante 18 meses. Se hizo una evaluación fisicoquímica y microbiológica a tiempo inicial y 1, 2, 3, 6 meses (acelerada) y 3, 6, 9, 12, 18 meses (anaquel). Se llevaron a cabo los estudios toxicológicos correspondientes a productos con fines cosméticos. Se constató que las características organolépticas, densidad, el pH, la concentración de proteínas y la identidad de los lotes en las dos condiciones de temperaturas y no hubo variación significativa en el tiempo del estudio. Se definió el tiempo de vida útil del producto en 18 meses. Se concluyó que el hidrolizado de sericina en frascos de polietileno de alta densidad es estable a temperaturas hasta 30 °C durante 18 meses y no clasificó como irritante dérmico, ni oftálmico. SUMMARY Sericin is a globular protein that is obtained from the cocoons of the Bombyx mori silkworm and has applications in the pharmaceutical, food and cosmetic industries. The objective of this work was to determine the stability and dermal and ophthalmic irritability of the sericine hydrolyzate (liquid). 3 batches produced on a pilot scale were stored in high density polyethylene bottles under different temperature conditions: 40 ± 2 °C for 6 months and temperature up to 30 °C for 18 months. A physical-chemical and microbiological evaluation was performed at initial time and 1, 2, 3, 6 months (accelerated) and 3, 6, 9, 12, 18 months (shelf). Toxicological studies corresponding to products for cosmetic purposes were performed. It was found that the organoleptic characteristics, density, pH, protein concentration and the identity of the lots in the two temperature conditions, there was no significant variation in the study time. The shelf life of the product was defined in 18 months. It was concluded that the sericin hydrolyzate in high density polyethylene bottles is stable at temperatures up to 30 °C for 18 months and this product did not classify as dermal or ophthalmic irritant.

There is a great concern about the indoor microbial colonization especially in places that should have high standards of environmental hygiene. Besides, due it shortened the useful life of the coating by discoloration and degradation. Currently this is a problem that must be solved in an innovative and eco-friendly way. In this sense, the aim of the work was to develop a green waterborne paint formulated with microcapsules containing es- sentials oil as biocide agent. This novel hygienic coating would be applied as to protect indoor surfaces from fungi. The microcapsules were synthesized by interfacial polymerization. Melamine-formaldehyde (MF) resin was used for the microcapsule shell wall, and Lavandin and Tea Tree essential oils (EOs) as core materials. The synthesized microcapsules were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and particle size analysis. Preparation of acrylic waterborne paint was performed and the micro- capsules MF-EOs were dispersed into the original paint just before application on commercial gypsum boards. The stability of the MF-EOs in the paint was successfully achieved. Two control paints were used, one containing EOs in free form and other without biocide. The effectiveness of the microcapsules into paint film against spore suspension of Aspergillus fumigatus was evaluated by seeding the fungus on the painted surface. The fungal growth was evaluated according to ASTM D5590 standard specification. The score obtained from MF-Lavandin paint indicates just a trace growth onto the painted surface (, Centro de Investigación y Desarrollo en Tecnología de Pinturas, Facultad de Ciencias Exactas, Facultad de Ingeniería

This manuscript presents the development of a low-pressure extrinsic Fabry-Perot fiber optic sensor based on a thin polyester film, using a phase signal analysis. The proposed interferometer is controlled by the simple contact interaction between the polymer membrane and a multimode fiber optic tip. The created cavity was uniformly stressed by applying a pressure varying from 0 to 2 psi. A finite element analysis was performed for these parameters. The stress applied to the membrane was below the yielding point. Thus, a linear study could be performed. The wavelength spectra exhibited a blue shift with a sensitivity of around 10.5 nm/psi. Although the interference spectra presented crosstalk measurements and required an initial set-point calibration, these effects were overcome by examining the spatial frequency components’ phase analysis. The sensors offered a high sensitivity, close to 3.5 rad/psi. Ultimately, this sensor is a high sensitivity and versatile alternative for low-pressure detection.

RESUMEN El fácil acceso y preparación de bebidas a base de Hibiscus sabdariffa L. representa una alternativa en el tratamiento de enfermedades crónicas y degenerativas. El estudio tuvo como objetivo comparar la contracción de fenoles totales y flavonoides en cálices de Hibiscus sabdariffa L., de una marca comercial y otra sin permiso sanitario. Para la determinación de fenoles totales se utilizó el método de Folin-Ciocalteu y método colorimétrico de Marinova para flavonoides. Se encontró una diferencia estadísticamente significativa (p

[ES] La destilación por membranas es un proceso de separación impulsado térmicamente en fase de investigación. Esta tecnología destaca principalmente por la simplicidad del proceso y su baja temperatura de operación, lo que permite que pueda ser alimentada con energía solar de media-baja temperatura. Así, la destilación por membranas se ha convertido en una solución prometedora, eficiente y sostenible para desarrollar plantas de desalación de pequeño o mediano tamaño en lugares aislados con buenas condiciones de radiación. No obstante, para que esta tecnología pueda llegar a ser implementada a escala industrial se debe seguir investigando y mejorando aspectos relacionados tanto con el diseño de las membranas y de los módulos como con la propia operación de estos. En relación con la operación, el desarrollo de modelos y técnicas de control cobran un papel fundamental. En este trabajo se presenta una revisión de las técnicas de control y modelado aplicadas en este campo, describiendo las principales metodologías empleadas y los retos futuros que quedan por abordar, incluyendo además un ejemplo ilustrativo., [EN] Membrane distillation is a termally-driven separation process under investigation. This technology stands out for the simplicity of the process and for its low operating temperature, which allows it to be combined with low grade solar energy. Thus, membrane distillation has become a promising, effcient and sustainable solution for the development of small-medium stand-alone desalination facilities to be implemented in offgrids areas with good irradiance conditions. However, in order to develop this technology on an industrial scale, research must continue to improve aspects related to both the design of membranes and modules and their operation. Regarding the operation, the development of models and control techniques play a fundamental role. This paper presents a review of the control and modeling techniques applied in this field, describing the main methodologies employed and the future challenges to be addressed, also including an illustrative example., Este trabajo ha sido financiado con el Proyecto I+D+i del Plan Nacional DPI2017-85007-R del Ministerio de Ciencia, Innovacion y Universidades y Fondos FEDER. Juan D. Gil quiere ´ agradecer al Plan Propio de Investigacion y Transferencia de la ´ Universidad de Almer´ıa por la financiacion de su contrato pre- ´ doctoral.

RESUMEN La determinación de la tenacidad a la fractura en materiales compuestos híbridos, laminados fibra-metal, FML (Fiber Metal Laminates) resulta muy importante para poder realizar un análisis de integridad estructural que permita estimar la tolerancia al daño y la resistencia remanente del material frente a la propagación de una fisura. Dicha evaluación debe realizarse tanto en estructuras aeronáuticas como navales que utilizan compuestos FML del tipo CARALL (CArbon Reinforced Aluminum Laminates). En este trabajo se presenta la determinación experimental de la tenacidad a la fractura en términos de los parámetros J y CTOD utilizando probetas compactas C(T) en dos tipos de material compuesto laminado con láminas de aluminio 6061-T0 en un caso y láminas de aluminio 1050 en otro y fibras de carbono NCT-301, embebidas en resina epoxi, para ambos materiales. Los resultados indican que la adaptación de las técnicas de ensayo de tenacidad a la fractura elasto-plástica, aplicando la norma ASTM E1820, son aceptables para la determinación de la tenacidad a la fractura J en compuestos del tipo CARALL. Dicha caracterización es necesaria para el desarrollo de un programa de evaluación de daño tolerable tanto a nivel de diseño como para un análisis de significación de defectos a partir de resultados de ensayos no destructivos sobre este tipo de materiales compuestos. ABSTRACT The determination of fracture toughness in hybrid composite materials, fiber-metal laminates(FML) is very important in order to make a structural integrity analysis that allows estimating damage tolerance and the remaining strength of the material against crack propagation. This evaluation should be carried out in both aeronautical and naval structures that use FML composites, CARALL type (CArbon Reinforced Aluminum Laminates). This paper presents the experimental determination of fracture toughness in terms of parameters J and CTOD using compact C (T) specimens in two types of composite material laminated with 6061-T0 aluminum sheets in one case and sheets 1050 aluminum in another and carbon fibers NCT-301, embedded in epoxy resin, for both materials. The results indicate that the use of the elasto-plastic fracture toughness test techniques, applying ASTM E1820, are acceptable for the determination of the fracture toughness J in CARALL type materials. Such characterization is necessary for the development of a tolerable damage assessment program both at the design level and for a defect significance analysis based on the results of non-destructive tests on this type of composite materials.

Electrochemical Surface Oxidation Enhanced Raman Scattering (EC-SOERS) is an interesting and promising phenomenon capable of amplifying the Raman signal in a similar way to Surface Enhanced Raman Scattering (SERS), but EC-SOERS takes place during the oxidation of a silver substrate. This phenomenon was originally described for specific electrolytic conditions in which a small amount of chloride in acidic medium was mandatory to obtain a substantial enhancement. Herein, we demonstrate that EC-SOERS can be also observed in presence of KBr, showing a potential-dependent behavior. Moreover, in this work a novel approach to reach chemical selectivity during time resolved Raman spectroelectrochemistry (TR-Raman-SEC) experiments is proposed. This new approach is based on the effect of the electrolytic medium on the structures that are formed on the electrode surface. SEM studies were carried out to study the origin of this selectivity. Although SEM images reveal clear differences between the structures of silver halides formed on the electrode surface during the oxidation of the substrate, the absence of EC-SOERS effect at open circuit potential hinders the identification of the actual structures responsible for the phenomenon., Ministerio de Economía y Competitividad (Grants CTQ2017-83935-R-AEI/FEDERUE), Junta de Castilla y León (BU297P18) and Ministerio de Ciencia, Innovación y Universidades (RED2018-102412-T)

In the quest for searching for new redox-flow battery chemistries, cycling stability must be carefully evaluated since it is one of the most important parameters of new active species. However, it is challenging to elucidate the intrinsic stability during operation of a redox flow battery. The symmetrical flow battery cell is a powerful tool that helps to unambiguously determine the cycling stability. Herein, trustworthiness of this technique is critically re-evaluated. Potassium ferrocyanide in alkaline media is used as a case study since i) it is the best performing species for the catholyte of alkaline flow batteries in terms of reversibility, solubility, costs and environmental compatibility and ii) the cycling stability of this species is still under strong debate. Potassium ferrocyanide is found to be stable at pH 14 upon electrochemical cycling when the oxygen evolution reaction is prevented, which should encourage researchers to resume the use of this species. The results also reveal that care should be taken when interpreting results from this powerful technique to avoid misleading conclusions., Spanish Government (MINECO) through the Research Challenges Programme (Grant RTI2018-099228-A-I00) as well as the Comunidad de Madrid through the Talent Attraction Programme (2017-T1/AMB-5190). A. M.-C. thanks Ministerio de Ciencia, Innovación y Universidades and MINECO for the financial support (CTQ2017-87231-P and RYC-2017-22700). E.V. thanks the MINECO for the financial support (RYC2018-026086-I)

Resumen Los aptámeros son secuencias de ADN o ARN de cadena sencilla que adoptan la forma de estructuras tridimensionales únicas, lo cual les permite reconocer un blanco específico con gran afinidad. Sus usos potenciales abarcan, entre otros, el diagnóstico de enfermedades, el desarrollo de nuevos agentes terapéuticos, la detección de riesgos alimentarios, la producción de biosensores, la detección de toxinas, el transporte de fármacos en el organismo y la señalización de nanopartículas. El pegaptanib es el único aptámero aprobado para uso comercial por la Food and Drug Administration (FDA). Otros aptámeros para el tratamiento de enfermedades están en la fase clínica de desarrollo. En parasitología, se destacan los estudios que se vienen realizando en Leishmania spp., con la obtención de aptámeros que reconocen la proteína de unión a poliA (LiPABP) y que pueden tener potencial utilidad en la investigación, el diagnóstico y el tratamiento de la leishmaniasis. En cuanto a la malaria, se han obtenido aptámeros que permiten identificar eritrocitos infectados e inhiben la formación de rosetas, y otros que prometen ser alternativas para el diagnóstico al detectar de forma específica la proteína lactato deshidrogenasa (PfLDH). Para Cryptosporidium parvuum se han seleccionado aptámeros que detectan ooquistes a partir de alimentos o aguas contaminadas. Para Entamoeba histolytica se han aislado dos aptámeros llamados C4 y C5, que inhiben la proliferación in vitro de los trofozoítos y tienen potencial terapéutico. Los aptámeros contra Trypanosoma cruzi inhiben la invasión de células LLC-MK2 (de riñón de mono) en un 50 a 70 % y aquellos contra T. brucei transportan moléculas tóxicas al lisosoma parasitario como una novedosa estrategia terapéutica. Los datos recopilados en esta revisión destacan los aptámeros como una alternativa para la investigación, el diagnóstico y el tratamiento contra parásitos de interés nacional. Abstract Aptamers are single-stranded DNA or RNA sequences that adopt unique three-dimensional structures that allow them to recognize a specific target with high affinity. They can potentially be used for the diagnosis of diseases, as new therapeutic agents, for the detection of food risks, as biosensors, for the detection of toxins, and as drug carriers and nanoparticle markers, among other applications. To date, an aptamer called pegaptanib is the only aptamer approved by the Food and Drug Administration (FDA) for commercial use. Other aptamers are in different clinical stages of development for the treatment of different diseases. In parasitology, investigations carried out with parasites such as Leishmania spp. allowed the acquisition of aptamers that recognize the polyA-binding protein LiPABP and may have potential applications in research and diagnosis and even as therapeutic agents. Regarding malaria, aptamers have been obtained that allow the identification of infected erythrocytes or inhibit the formation of rosettes, along with those that provide promising alternatives for diagnosis by specifically detecting the protein lactate dehydrogenase (PfLDH). In Cryptosporidium parvum allow the detection of oocysts in contaminated food or water. In Entamoeba histolytica, two aptamers called C4 and C5, which inhibit the proliferation of trophozoites in vitro and have potential use as therapeutic agents, have been isolated. Aptamers obtained against Trypanosoma cruzi inhibit the invasion of LLC-MK2 (from monkey kidney) cells by 50-70%, and in T. brucei, aptamers with the potential to transport toxic molecules to the parasitic lysosome were identified as a novel therapeutic strategy. The data collected in this review highlight aptamers as a novel alternative in the research, diagnosis, and treatment of parasites of national interest.

The phenomena of climatic variability such as El Niño affect the expansion planning of electricity supply systems with hydroelectric power plants due to the uncertainty presented in the variables of rainfall patterns, temperature, wind, solar radiation changes, among others. The El Niño affects the electricity generation in Colombia, Venezuela and northwestern Brazil due to severe droughts that reduce water flows in rivers and water volume in dams. While in Peru, Paraguay, Bolivia, Uruguay, Argentina and southern Brazil, causes heavy rains that lead to an increase in reservoirs. Recent findings provide sufficient evidence on how climate change modifies the patterns of duration, frequency and intensity of El Niño and therefore will introduce additional uncertainties to the expansion planning of electricity generation systems in countries that uses predominantly hydroelectric power. The vulnerability of electricity supply systems with a significant participation of hydroelectric power plants in Colombia, Brazil, Ecuador, Peru, Panama, Canada, Norway, Costa Rica and New Zealand is associated with fluctuations in the availability of water resources. This document aims to analyze the current plans for the expansion of electric power generation systems by the aforementioned countries in the context of climate change in medium and long term. Additionally, this document provides a detailed analysis of the situation of electricity supply systems in Colombia.Keywords: El Niño phenomenon, Vulnerability, Colombia, Water Resource. Development Planning.JEL Classifications: L94, O20, Q4DOI: https://doi.org/10.32479/ijeep.9813

The present work shows the outcomes from a first experimental analysis that aimed to find a support fabric with the functional features of Tetex TR (a polyester fabric), which, currently, is no longer produced. The study is divided in different stages: on the one hand, four different fabrics were selected and tested by a visual exam under a microscope in order to determine their main structural features; on the other hand, several mock-ups were prepared to compare and evaluate the mechanical behavior, chemical stability and reversibility of the fabrics, before and after an artificial ageing process. The results show the possibility of replacing Tetex TRsome of the tested fabrics for local interventions on textile support, introducing new accessible and affordable materials into the field of canvas painting restoration. History Received: 2018-10-20Revised: 2019-2-18Accepted: 2019-3-13Online: 2019-3-18Publication: 2020-7-31, El presente trabajo recoge los resultados obtenidos en un primer análisis experimental planteado con la finalidad de encontrar un tejido de refuerzo con las características funcionales del Tetex TR (un tejido de poliéster), material que actualmente se encuentra fuera del mercado. El estudio se ha dividido en varios puntos: por un lado, se han seleccionado cuatro tipos diferentes de tejidos que han sido sometidos a un examen visual bajo microscopio para determinar sus principales aspectos estructurales; por otro, se ha preparado una serie de maquetas sobre las que poder comparar y evaluar el comportamiento mecánico, la estabilidad química y la reversibilidad de los tejidos, antes y después de sometidos a un proceso de envejecimiento artificial. Los resultados alcanzados muestran las posibilidades que ofrecen algunos de los tejidos testados como posibles sustitutos del Tetex TR en intervenciones locales del soporte textil, incorporando así materiales nuevos, accesibles y económicos al ámbito de la restauración de pintura de caballete., O presente trabalho reúne os resultados obtido numa primeira análise experimental realizada com a finalidade de encontrar um tecido de reforço com as características funcionais do Tetex TR (um tecido de poliéster), material que atualmente se encontra fora do mercado. O estudo foi dividido em várias partes: por um lado, selecionaram-se quatro tipos diferentes de tecidos que foram submetidos a um exame visual no microscópio para determinar os seus principais aspetos estruturais; por outro, preparou-se uma série de maquetas para poder comparar e avaliar o comportamento mecânico, a estabilidade química e a reversibilidade dos tecidos, antes e depois de serem submetidos a um processo de envelhecimento artificial. Os resultados alcançados mostram as possibilidades que oferecem alguns dos tecidos testados como possíveis substitutos do Tetex TR em intervenções locais do suporte têxtil, introduzindo, assim, materiais novos, acessíveis e económicos no restauro de pintura de cavalete. Recebido: 2018-10-20Revisto: 2019-2-18Aceite: 2019-3-13Online: 2019-3-18Publicação: 2020-7-31

Resumen: La determinación de los parámetros eléctricos y funcionales para aplicación de soldadura requiere realizar pruebas preliminares tanto en la industria como en la investigación. Sin embargo, este proceso resulta ser muy costoso, lento y, para objeto de investigación, de baja confiabilidad, por tal motivo, el desarrollo de una metodología de experimentación que permita obtener adecuadamente dichos parámetros es muy importante. El presente trabajo muestra el análisis estadístico para la aplicación de soldadura de arco metálico con electrodo de tungsteno y gas inerte (GTAW) utilizada para determinar la velocidad de avance de la antorcha y la corriente de soldadura óptimos para lograr soldadura libre de defectos. Con los resultados obtenidos en el diagrama causa-efecto (Ishikawa) se permite la interpretación efectiva de la causa raíz de los defectos, reduciendo el número de experimentos, posteriormente el diagrama de árbol da pauta para definir la matriz experimental. La validación de la experimentación se hace con el diseño de experimento factorial completo, la efectividad proporcionada por el cálculo del coeficiente de determinación, también conocido como nivel de correlación, de 94,24% en penetración del cordón y 85,03% en ancho del cordón. La gráfica de residuales y valores predichos valida la distribución del error en las probetas. Abstract: Electrical and functional parameters determination for welding application requires preliminary tests in industry and research fields. However, this process turns out to be very expensive, slow and, for research purposes, with low reliability. Thus, the development of a statistical analysis that allows obtaining these parameters properly is very important. The present work shows and experimental methodology to apply the metal arc welding with tungsten electrode and inert gas (GTAW), used to determine the optimum torch speed and current level to achieve defect-free welding. With the results obtained in the cause-effect diagram (Ishikawa), the effective interpretation of the root cause of the defects is allowed, reducing the number of experiments, then the tree diagram gives guidelines to define the experimental matrix. The validation of the experimentation is performed by designing a complete factorial experiment, the effectiveness provided by coefficient of determination estimation or correlation level known is 94.24% in cord penetration and 85.03% in cord width. Residuals and predicted values graph are used to validate the specimens error distribution.

RESUMEN En el presente trabajo se realiza la caracterización del comportamiento ante el desgaste por deslizamiento en seco de un acero inoxidable súper dúplex. Los ensayos fueron desarrollados en un tribómetro tipo bola sobre anillo. Como material del anillo se empleó el acero inoxidable dúplex tipo SAF 2507 sin tratamiento térmico y como material para la bola se usó el acero AISI 52100. Los ensayos se realizaron sin lubricante en condiciones de ambiente (aire), temperatura y humedad estándar de laboratorio. Los parámetros seleccionados, a fin de estudiar sus efectos en el coeficiente desgaste por deslizamiento, fueron: velocidad de deslizamiento (0,9 m/s y 2 m/s), carga normal (9 N, 19 N y 29 N) y distancias de deslizamiento (500 m, 1000 m y 2000 m). Se empleó un diseño experimental de Taguchi con nueve tratamientos y dos réplicas. En la caracterización del acero SAF 2507 se obtuvo valores del coeficiente de desgaste en el intervalo desde 0,19588 x 1012 m2/N hasta 0,72381 x 1012 m2/N, para las condiciones evaluadas. El factor que más afecta el coeficiente de desgaste es la velocidad de deslizamiento. El mecanismo de desgaste identificado para el SAF 2507 es de adhesión y delaminación de alta velocidad. ABSTRACT In this paper the characterization of the behavior during dry sliding wear of a super duplex stainless steel was performed. The tests were developed in a ball on ring tribometer type. As material of the ring is used the duplex stainless steel type SAF 2507 without heat treatment and as material for the ball is used the steel AISI 52100. Tests were conducted without lubrication in ambient conditions (air), temperature and humidity laboratory standard was used. The parameters selected in order to study its effects on sliding wear coefficient were: sliding speed (0.9 m/s and 2 m/s), normal load (9 N, 19 N and 29 N) and distances slip (500 m, 1000 m and 2000 m). Taguchi experimental design with nine treatments and two replicates was used. In the characterization of steel SAF 2507 wear coefficient values was obtained in the range from 0.19588 x 10-12 m2/N to 0.72381 x 10-12 m2/N, for the conditions tested. The factor that most affects the wear coefficient is the sliding velocity. The wear mechanism identified for the SAF 2507 was adhesion and high speed delamination.

Resumen La síntesis de películas delgadas por pulverización catódica o sputtering requiere la utilización de blancos o targets, que actúan como los materiales a partir de los cuales se elaboran los recubrimientos. Este trabajo está enfocado en la implementación del proceso de proyección térmica por plasma atmosférico para la fabricación de blancos de TiO2, que posteriormente puedan emplearse en la deposición de recubrimientos de TiO2 por magnetrón sputtering. Se partió de tres polvos de TiO2 comerciales de la marca Oerlikon Metco, los cuales fueron proyectados mediante diferentes parámetros de proyección para evaluar su efecto en la microestructura (porcentaje de poros y grietas en sección transversal) de los blancos de TiO2 obtenidos. Los blancos fueron caracterizados por microscopía electrónica de barrido y procesamiento de imágenes y utilizados en algunas pruebas de deposición sputtering para estimar la tasa de deposición. Los resultados permitieron identificar las variables que tienen un efecto más significativo sobre la microestructura de los blancos. En orden decreciente a la magnitud del efecto, estas variables son: la relación de gases generadores de plasma, la distancia de proyección, el flujo del gas de arrastre, la corriente en el arco eléctrico y la distribución de tamaños de partícula de la materia prima. Los porcentajes de defectos microestructurales encontrados durante la ejecución de las pruebas variaron entre 0.41 ± 0.30 % y 6.80 ± 2.03 %, rango que demuestra la importancia que puede llegar a tener el control de los parámetros de proyección en la fabricación de blancos mediante esta técnica. Abstract The synthesis of thin films by sputtering requires the use of targets, which act as materials from which the coatings are made. This work is focused on the implementation of Atmospheric Plasma Spray (APS) for manufacturing TiO2 targets that can later be used in the deposition of TiO2 coatings by magnetron sputtering. Three commercial TiO2 powders, produced by Oerlikon Metco, were sprayed using different spray parameters to evaluate their effect on the microstructure (percentage of pores and cracks on the cross section) of the obtained TiO2 targets. The targets were characterized by Scanning Electron Microscopy (SEM) and image processing and used in sputtering deposition tests to estimate the deposition rate. The results enabled us to identify the variables with the most significant effect on the targets’ microstructure (in a decreasing order in terms of magnitude of the effect): ratio of plasma generating gases, stand-off distance, carrier gas flow rate, current in the electric arc, and particle size distribution of the raw material. The percentages of microstructural defects found during the tests ranged between 0.41 ± 0.30 % and 6.80 ± 2.03 %, which demonstrates the importance of controlling spray parameters in the manufacture of targets by this technique.

RESUMEN La posibilidad de usar el oxihidróxido del cobalto en la detección electroquímica de la gabapentina ha sido evaluada, y se sugirió un mecanismo del desempeño del analito y del modificador. Este fue desarrollado y analizado (mediante la teoría de estabilidad lineal y análisis de bifurcaciones) un modelo matemático basado en este mecanismo. La evaluación teórica confirma que el oxihidróxido de cobalto puede ser un modificador eficiente para la detección de la gabapentina, a pesar de la hibridez de su mecanismo de oxidación. La posibilidad y las causas de los comportamientos oscilatorio y monotónico también han sido investigadas. SUMMARY The possibility for the use of cobalt (III) oxyhydroxide in gabapentine electrochemical determination has been evaluated. A mechanism for analyte and modifier function has been suggested. A mathematical model based in this mechanism has been developed and analyzed (by means of linear stability theory and bifurcation analysis). The theoretical evaluation confirms that the cobalt (III) oxyhydroxide may be an efficient modifier for gabapentine electrochemical determination, despite of the hybridity of its oxidation mechanism. The possibility and the causes for oscillatory and monotonic instabilities have also been investigated.

A lo largo del presente artículo demostraremos cómo Unamuno, en torno a los años 1912 y 1913, realiza una profunda reflexión poética que le lleva a borrar fronteras genéricas entre la prosa y la poesía. Gracias a los manuscritos de trabajo analizados mediante la metodología de la crítica genética, comprobaremos cómo pone en práctica esta reflexión teórica iniciando la redacción de un poemario en prosa. Asimismo, los apuntes autógrafos del prólogo que planeó para dicho volumen de versos se revelan de suma importancia, pues evidencian que Unamuno concibió el poema como un organismo, para cuya composición intentó desarrollar una secuencia rítmica basada en números impares. Será el endecasílabo el metro al que otorgue un lugar privilegiado dentro de su poética, y llegará a considerarlo como el auténtico «verso orgánico». Throughout this article, we will discuss how Unamuno made a profound poetic reflection; around 1912 and 1913, he eliminated the generic boundaries between prose and poetry. Applying the methodology of genetic criticism to the analysis of the drafts reveals that don Miguel implemented his theoretical reflection by writing a poetic book in prose form. Furthermore, the autograph notes provided in the prologue revealed themselves important. They demonstrated how Unamuno conceived poems as an organism and developed a rhythmic sequence based on odd numbers for his composition. He introduced the hendecasyllable in his poems, which would forever be considered the real “organic verse”. info:eu-repo/semantics/publishedVersion

According to Italian historiography, the term modernization refers to the transformation of Italian society between 1950 and the late 1960s. This study aims to analyse those years by adopting the specific framework defined by the action of State institutions, trying to clarify which contribution was given by the «State» to the modernization processes. The analysis starts from the period of political and institutional transition between Fascism and democracy, focusing the pivotal role played by Democrazia Cristiana (DC) to drive, and even delay, institutional and socio-economic transformations. It has been devoted some space to the «conquest of the State» by DC, enlighting the increasing connection between the DC political elites and State elites. During the Sixties, DC gained almost a complete control on the State apparatus, while the modernization was happening «out of the State». 1968 could be seen as a watershed in the history of the Italian Republic also by the State institutions’ point of view because of the regionalisation reform, but the regions would only be able to exercise their powers just from 1977, while the political system went on to be dominated by clientelism and restricted power-ful circles both on central and local level. Modernization would continue to be a deeply foreign enterprise for the Italian State. Only part of the private economy and some of the semi-public bodies would engage in it.

En este trabajo se sintetizo una zeolita tipo faujasita a partir de aluminio y silica gel, por el metodo sol-gel. Dicho procedimiento se realizo por medio de espectroscopia de infrarrojo (FTIR por su nombre en ingles), difraccion de rayos X (XRD por su nombre en ingles), analisis termogravimetrico (TGA por su nombre en ingles) y microscopia de electronica de barrido (SEM por su nombre en ingles). Se identifico el material sintetizado como zeolita tipo faujasita X. Se evaluo la capacidad de remocion de materia organica, nitrogeno amoniacal, dureza y metales pesados (Fe, Cu, Zn, Pb) utilizando aguas residuales municipales (ARM) y agua sintetica. La afinidad de la zeolita tipo faujasita X, por los iones metalicos estudiados presenta el siguiente comportamiento: Zn 2+ > Cu 2+ > Pb 2+ > Fe 3+ en ARM, con alta concentracion de materia organica. Se observo que la dosis de zeolita, el tipo de ion, la concentracion de las especies cationicas y el tamano del cation hidratado fueron factores determinantes en el proceso de adsorcion. Se obtuvo una mayor capacidad de adsorcion de la zeolita para iones de Ca 2+ y Mg 2+ (dureza), y nitrogeno amoniacal en ARM. La sencillez del proceso y la efectividad conseguida por la zeolita para la remocion de distintos iones con porcentajes de remocion mayores al 70%, la convierten en una alternativa viable como adsorbente de iones metalicos, dureza y nitrogeno amoniacal en ARM. Lo anterior conduce a la posibilidad de implementar columnas de adsorcion a gran escala para el tratamiento de ARM.

La producción de plásticos a nivel mundial presenta cifras abrumadoras debido a que tienen aplicaciones en diferentes campos, desde la medicina hasta la industria de empaques. Uno de los problemas radica en que la materia prima para preparar esos plásticos proviene de fuentes fósiles, los principales responsables de las emisiones de dióxido de carbono a la atmósfera y después de usar esos materiales se desechan y tardan varios años en descomponerse. Otro problema está enfocado hacia la agricultura e incluye los procesos que generan desechos orgánicos como la industria azucarera y del café, que pueden contaminar el medio ambiente sin tratamiento adecuado. Cada vez cobra más importancia reemplazar los plásticos convencionales por biomateriales cuyos sustratos de partida provengan de fuentes renovables, que sean biodegradables y que puedan tener aplicaciones similares a los materiales convencionales. Por ello, en este artículo se destacan los últimos avances en el área de los materiales a partir de recursos renovables, en especial de los polímeros biobasados, de su biodegradabilidad y sus aplicaciones, para generar curiosidad y propiciar la búsqueda de alternativas de aprovechamiento de las fuentes renovables en la obtención de nuevos biopolímeros

Vazquez, M., Gutierrez, R., Perez, J. J., Escobar, A., Rivera, J. G., & Vega, S. (septiembre-octubre, 2017). Presencia de ftalatos en agua embotellada comercializada en la ciudad de Mexico y su migracion durante el almacenamiento a diferentes temperaturas. Tecnologia y Ciencias del Agua , 8 (5), 91-103. El objetivo de este estudio fue investigar la presencia de ftalatos en cuatro marcas de agua embotellada y evaluar el efecto de la temperatura en la migracion a traves del tiempo. Se realizo un muestreo durante seis meses de cuatro marcas comercializadas en la Ciudad de Mexico, para determinar el contenido de esteres de ftalatos por cromatografia liquida de alta resolucion (HPLC, por sus siglas en ingles) y se evaluo la migracion de los esteres de ftalato en el agua a partir de sus envases plasticos (1.5 l) a distintas temperaturas (8+2 °C; 22-25 °C; y 35±1 °C) durante 70 dias. En las cuatro marcas de agua embotellada se identificaron el ftalato de dibutilo (DBP, por sus siglas en ingles), ftalato de benzil butilo (BBP, por sus siglas en ingles) y ftalato de di-(2-etil-hexilo) (DEHP, por sus siglas en ingles), con una frecuencia de 54, 25 y 96%, respectivamente. En la marca 1, dos muestras sobrepasaron el limite permisible para este compuesto (6 ig l-1); mientras en los ftalatos DBP y BBP, sus valores se encuentran por debajo del limite umbral establecido por la Agencia de Proteccion del Medio Ambiente de Estados Unidos de 455 y 100 ig l-1, respectivamente. El DEHP fue el mas abundante en las muestras investigadas. Se observo un incremento de DEHP a los 70 dias, alcanzando la saturacion en todos los tratamientos evaluados. Estos resultados alertan a las instancias reguladoras de la necesidad de contar con programas de monitoreo para el DEHP y otros ftalatos que se han relacionado de forma directa con enfermedades endocrinas a nivel global.

En el presente estudio procuraremos determinar los dos ejes de la ética unamuniana, que, al estar vinculados con el dualismo antropológico “yo-íntimo” y “yo-público”, podríamos condensar en los conceptos de “bondad” y “obra”. Unamuno, en cuanto heredero del romanticismo y del existencialismo, consideró que lo fundamental, en términos axiológicos, era que los individuos aprendiesen a “ser buenos” y no a “hacer [meramente] el bien”, ya que solo a través de la pureza del sentir, es decir, de la “bondad ética”, el “sujeto moral” podría constituirse como una “persona” a través de sus “obras”. En este aspecto, la relación de la ética unamuniana con los “oficios” es decisiva, ya que cada “individuo” a través de su “profesión” está llamado a formar su “persona”., In this study, we seek to determine the two axes of Unamunian ethics, which are linked to the "I-intimate" and "I-public" anthropological dualism, and which could be condensed into the concepts of "goodness" and "work." Unamuno, as heir to romanticism and existentialism, considered that what was fundamental, in axiological terms, was for individuals to learn to "be good" and not to " [merely] do good," because only through the purity of feeling, that is, of "ethical goodness", the "moral subject" could become a "person" through his "works". In this regard, the relation of Unamunian ethics to "occupations" is decisive, since each "individual" through his "profession" is bound to mold his "being".

During the first half of the reign of the Emperor Carlos V the Order of Santiago contributed, so much of passive as active form, to the rescue of captive Christians retained in the north of Africa; for this intention it relied on a bottom of eventual income that it tried to attend to his obligations as redeeming institution, since it receives documents specially in 1525 and 1535.

Context: In advanced ultralow-power devices, it is necessary to use the accuracy extraction procedures of the MOSFET threshold voltage to fully characterize the devices. These procedures are based in the measurement of the Tran-conductance efficiency (gm/ID) and its first derivative in function of the voltage gate source (d(gm/ID)/dVGS). In order to increase their independency respect to the non-zero drain source voltage (VDS ≠0) it is used a process to correct the error. Theoretically, VDS should be 0 V; however, the VDS is grater than 10 mV in the experimental setup in order to avoid electrical noise, but less than a certain maximum value for allowing the MOSFET operation in the linear region of the weak inversion. Objective: To compare the extraction procedure proposed by (MC Schneider et al., 2006) and the method proposed by (Rudenko et al., 2011) with a generic, controlled and coherent test scenario. Method: This paper proposes a test scenario based on the Advanced Compact MOSFET model (ACM) of a long channel MOSFET made in a standard 0.35 mm CMOS process, implemented numerically in MATLABâ. The concept of Power Error Correction (PEC) was used to compare the two processes numerically; it quantifies the sensitivity of the extraction process to the effect by the non-zero voltage value of the VDS in the experimental setup (i.e., NZ-DS effect). Results: The error correction procedure proposed by (Siebel et al., 2012, Schneider et al., 2006) estimates the NZ-DS effect better than the procedure proposed by (Rudenko et al., 2011), considering the average, maximum and minimum PEC obtained for both extraction methodologies for a long channel MOSFET fabricated in a standard CMOS process of 0.35 μm, when the VDS is less than 50 mV. Conclusions: The Vth extraction procedure proposed by (MC Schneider et al., 2006) is more robust than the method proposed by (Rudenko et al., 2011) regarding the NZ-DS effect. Resumen Contexto: En los dispositivos de ultrabaja potencia son necesarios procedimientos precisos de extracción de voltaje de umbral del MOSFET. Estos se basan en la medición de la eficiencia de la transconductancia (gm/ID) y su primera derivada respecto al voltaje puerta-fuente (d(gm/ID)/ dVGS). Para aumentar en algunas decenas de mV la precisión del voltaje de umbral extraído, se recurre a un proceso de corrección de errores que disminuye la influencia del voltaje dreno-fuente (VDS) que teóricamente debería ser 0 V. Típicamente, en el montaje experimental, el VDS es mayor a 10 mV con el fin de evitar el ruido eléctrico, pero menor a un cierto valor máximo con el fin de permitir que el MOSFET siempre opere en su región lineal. Objetivo: Comparar el procedimiento de extracción propuesto por Schneider et al. (2006) y el método propuesto por Rudenko et al. (2011) con un escenario de prueba genérico, controlado y coherente. Método: Se implementó un escenario de prueba en el softwareMatlab® para un MOSFET de canal largo fabricado en un proceso estándar CMOS de 0,35 mm, usando el modelo Advanced Compact MOSFET (ACM). Para comparar los dos procesos de extracción se tomó el concepto de potencia de corrección del error (PEC), el valor de este cuantifica la sensibilidad del proceso de extracción con respecto al valor no 0V del VDS usado experimentalmente (i.e., efecto NZ-DS). Resultados: Considerando el promedio, el máximo y el mínimo PEC obtenido para ambas metodologías de extracción, el procedimiento de corrección de errores propuesto en Siebel, Schneider y Galup (2012) y Schneider et al. (2006) estima el efecto NZ-DS mejor que el procedimiento propuesto en Rudenko et al. (2011) para un MOSFET de canal largo fabricado en un proceso estándar CMOS de 0,35 μm, cuando el VDS es inferior a 50 mV. Conclusiones: El procedimiento de extracción de Vth propuesto por Schneider et al. (2006) es más robusto que el sugerido en Rudenko et al. (2011) con respecto al efecto NZ-DS.

Perovskite-like materials which include magnetic elements have relevance due to the technological perspectives in the spintronics industry. In this work, the magnetic, structural and electronic properties of the Ba2CoMoO6 double perovskite are investigated. Calculations are carried out through the Full-Potential Linear Augmented Plane Wave method within the framework of the Density Functional Theory with exchange and correlation effects in the Generalized Gradient and Local Density approximations, including spin polarization. From the minimization of energy as a function of volume using the Murnaghan’s state equation the equilibrium lattice parameter and cohesive properties of this compound were obtained. The study of the electronic structure was based in the analysis of the electronic density of states, and the band structure, showing that this compound evidences a conductive character for a spin channel and insulation for the other, and presents an integer value for the effective magnetic moment (3.0 μB), which allows it to be classified as a half-metallic material. The effects of pressure and temperature on thermophysical properties such as specific heat, Debye temperature, coefficient of thermal expansion and the Grüneisen parameter were calculated and analyzed from the state equation of the system. The obtained results reveal that, in the low temperature regime, the specific heat at constant volume and pressure presents an analogous behavior to each other, with a tendency to the limit of Dulong-Petit typical of the structures of cubic perovskite type, showing a value of 246.3 J/mol.K at constant volume and slightly higher values at constant pressure. The dependence of the coefficient of thermal expansion, the temperature of Debye and the Grüneisen parameter with the increase in temperature is discussed in relation to other perovskite-like materials. Los materiales de tipo perovskita que incluyen elementos magnéticos tienen relevancia debido a las perspectivas tecnológicas en la industria de la espintrónica. En este trabajo se efectúa un estudio exhaustivo de las propiedades magnéticas, estructurales y electrónicas de la perovskita doble Ba2CoMoO6. Los cálculos se realizan a través del método de ondas planas aumentadas y linealizadas dentro del marco de la teoría del funcional de la densidad con efectos de intercambio y correlación en las aproximaciones del gradiente generalizado y de densidad local, incluyendo polarización de espín. A partir de la minimización de la energía en función del volumen, utilizando la ecuación de estado de Murnaghan, se obtuvieron el parámetro de red de equilibrio y las propiedades cohesivas de este compuesto. El estudio de la estructura electrónica se basó en el análisis de la densidad electrónica de estados y la estructura de bandas, mostrando que este compuesto evidencia un carácter conductor para un canal de espín y aislante para el otro, presentando un valor entero para el momento magnético efectivo (3.0 μB), que permite clasificarlo como un material espín-metálico. Los efectos de la presión y la temperatura sobre las propiedades termofísicas, como el calor específico, la temperatura de Debye, el coeficiente de expansión térmica y el parámetro Grüneisen, se calcularon y analizaron a partir de la ecuación de estado del sistema. Los resultados obtenidos revelan que, en el régimen de baja temperatura, el calor específico a volumen y presión constantes presenta un comportamiento análogo entre sí, con una tendencia al límite de Dulong-Petit típico de las estructuras de tipo perovskita cúbica, mostrando un valor de 246.3 J/mol.K a volumen constante y valores ligeramente más altos a presión constante. La dependencia del coeficiente de expansión térmica, la temperatura de Debye y el parámetro Grüneisen con el aumento de temperatura se discute en relación con otros materiales de tipo perovskita. Fil: Deluque Toro, Crispulo Enrique. Universidad del Magdalena; Colombia Fil: Gil Rebaza, Arles Víctor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería. Departamento de Electrotecnia. Grupo de Estudio de Materiales y Dispositivos Electrónicos; Argentina Fil: Villa Hernández, Jorge I.. Universidad Nacional de Colombia; Colombia Fil: Landinez Téllez, David A.. Universidad Nacional de Colombia; Colombia Fil: Roa Rojas, Jairo. Universidad Nacional de Colombia; Colombia

International audience; The generalized extreme value distribution (GEVD) was used to model extreme rainfall events in Central America for a period of 30 years, beginning in 1971. Data consisted of daily rainfall records of 103 meteorological stations located throughout the isthmus. Central America was divided into 3 regions: Pacific, Caribbean and an intermediate zone. A bootstrap hypothesis test was used to compare the parameters of location, scale and form of the 3 regions. The results of the study showed significant differences between the 3 regions, mainly in terms of location and scale parameters.; Se utilizó la distribución de valor extremo generalizada (DVEG) para modelar los eventos de lluvia extrema en América Central, durante 30 años, a partir de 1971. Los datos consistieron en registros de precipitaciones diarias en 103 estaciones meteorológicas localizadas en todo el istmo. El área de América Central se dividió en 3 regiones: el Pacífico, el Caribe y la zona intermedia. Con el objetivo de comparar los parámetros de ubicación, escala y forma de la DVEG de esas 3 localidades, se utilizó la prueba de hipótesis Bootstrap. Los resultados del estudio muestran diferencias significativas, especialmente en los parámetros de ubicación y escala entre las 3 regiones.; A distribuição generalizada de valores extremos (DVEG) foi utilizada para modelar os eventos de precipitação máxima na América Central durante 30 anos, a partir de 1971. Os dados consistiram em registros de precipitações diárias em 103 estações meteorológicas localizadas ao longo do istmo. A área da América Central foi dividida em 3 regiões: o Pacífico, o Caribe e a zona intermediária. A fim de comparar os parâmetros de localização, escala e forma da DVEG desses 3 locais, foram utilizados os testes de hipóteses de Bootstrap. Os resultados do estudo mostram diferenças significativas, especialmente nos parâmetros de localização e escala entre as 3 regiões.

Resumen Se investigó la remoción de plomo de soluciones acuosas por biomasa de los cladodios de la tuna (BCT), una especie abundante en la sierra peruana. Las propiedades físicas y químicas de la BCT se determinaron por técnicas de FTIR y SEM/ EDX. El análisis FTIR confirmó la presencia de grupos -OH, CO-C, C=O y -NH2, los cuales interactuarían con el metal. La micrografía SEM reveló que la morfología superficial de la BCT tiene porosidad adecuada para la biosorción. En un sistema discontinuo se obtuvo la más alta capacidad de biosorción (qe) con una relación masa BCT/volumen de 4 g/L, pH 4,5 y tiempo de contacto de 1 h. La biosorción siguió un modelo cinético de pseudo-segundo orden y el proceso de difusión intraparticular fue el factor principal de control de la velocidad. Los datos en el equilibrio fueron correlacionados con cinco modelos (Langmuir, Freundlich, Temkin, D-R y Redlich-Peterson) y se ajustaron mejor al modelo de Langmuir, lo que indica que el proceso se realiza en centros activos energéticamente homogéneos, el valor de qe máxima fue 50,25 mg/g. Los resultados obtenidos demuestran que la BCT puede ser usada como biosorbente eficiente para el tratamiento de aguas contaminadas con Pb (II). Abstract The removal of lead from aqueous solutions by the biomass of prickly pear cladodes (BCT), a species found in abundance in the Sierra region in Peru, was investigated. The physical and chemical properties of BCT were determined by FTIR and SEM/EDX techniques. The FTIR analysis confirmed the presence of -OH, C-O-C, C=O and -NH2 groups which would interact with the metal. The SEM micrograph revealed that the surface morphology of the BCT shows adequate porosity for biosorption. In a discontinuous system, the highest biosorption capacity (qe) was obtained with a BCT mass/volume ratio of 4 g/L, pH 4.5 and 1 h of contact time. Biosorption followed a pseudo-second order kinetic model and the intraparticle diffusion process was the main factor controlling speed. Data at equilibrium were correlated using five models (Langmuir, Freundlich, Temkin, DR, and Redlich-Peterson) and were better fitted to the Langmuir model, which would indicate that the process is carried out in energetically homogeneous active centers, the value of qe maximum was 50.25 mg/g. The results obtained demonstrate that BCT can be used as an efficient biosorbent for the treatment of waters contaminated with Pb (II). Resumo Investigou-se a remoção de chumbo de soluções aquosas pela biomassa de cladódios de pera espinhosa (BCT), espécie encontrada em abundância na região da Sierra, no Peru, e as propriedades físicas e químicas do BCT foram determinadas por técnicas de FTIR y SEM/EDX. A análise por FTIR confirma a presença dos grupos -OH, C-O-C, C=O e -NH2 que interagem com o metal; a micrografia SEM revela que a morfologia da superfície do BCT mostra porosidade adequada para biossorção. Em um sistema descontínuo, a maior capacidade de biossorção (qe) foi obtida com uma relação massa/volume de BCT de 4 g/L, pH 4,5 e tempo de contato 1 h. A biossorção seguiu um modelo cinético de pseudo-segunda ordem e o processo de difusão intrapartículas foi o principal fator de controle da velocidade. Os dados em equilíbrio foram correlacionados usando cinco modelos (Langmuir, Freundlich, Temkin, DR e Redlich-Peterson) e foram melhor ajustados ao modelo de Langmuir, o que indicaria que o processo é realizado em centros ativos energeticamente homogêneos, o valor de qe o máximo foi de 50,25 mg/g. Os resultados obtidos demonstram que o BCT pode ser usado como um biossorvente eficiente para o tratamento de águas contaminadas com Pb (II).

RESUMEN Los electrodos selectivos de iones (ISEs) con membranas de vidrios calcogenuros son sensores capaces de detectar iones de metales pesados en soluciones electrolíticas. Su uso in-situ y repetido plantea grandes desafíos a la selección del material para encapsular la membrana sensible. La falla en el encapsulado inutiliza al sensor, que debe ser descartado. Sin embargo, no existe hasta ahora estudios reportados sobre este componente crítico de los sensores. El material encapsulante debe aislar al contacto eléctrico de la solución circundante, tener un bajo nivel de absorción de la solución y de los iones en solución, así como mantener sus propiedades invariables por largos períodos de tiempo. Los requisitos del material dependerán también de la geometría de la membrana, ya sea en bulk o en forma de película delgada. Con el fin de facilitar nuevas investigaciones en la temática de los ISEs, estudiamos cinco materiales encapsulantes disponibles comercialmente en la región latinoamericana (Poxipol transparente, Vaicel, Wilpox APV 3C, Wilpox Doming P-5 y Araldite CY-248 + HY-956). Analizamos los requisitos de estabilidad y confiabilidad evaluando las siguientes propiedades: viscosidad, tiempo de curado, dureza, calidad superficial, formación de burbujas, respuesta al pulido mecánico, reacción con pintura de Ag, efecto del agua y de soluciones de limpieza y almacenamiento. Encontramos que, tomando los cuidados necesarios, las resinas epoxi Wilpox APV 3C y Araldite CY-248 + HY-956 son las más idóneas para encapsular membranas de vidrios calcogenuros en bulk, mientras que la resina epoxi Wilpox APV 3C y la resina acrílica Vaicel resultan ser las mejores candidatas para el caso de las membranas en forma de película delgada. ABSTRACT Ion-selective electrodes (ISEs) built with chalcogenide glass membranes are sensors capable of detecting heavy metal ions in electrolytic solutions. Using ISEs in-situ and repeatedly can be challenging not only to the sensitive membrane, but to the material used to encapsulate the electrical contact between the membrane and the metallic wire. If the encapsulation fails, the sensor must be discarded. Despite how critical these issues are on this sensor component, no studies on the requirements and selection of the encapsulation material have been reported so far. This material must isolate the electrical contact of the surrounding solution, have a low level of absorption of the solution and the ions in the solution, as well as keep its properties stable in the long-term. The material requirements will also depend on the geometry of the membrane, either bulk or thin film. To stimulate further research and development in the field of ISEs, we investigated five encapsulating materials commercially available in the Latin American region (transparent Poxipol, Vaicel, Wilpox APV 3C, Wilpox Doming P-5 and Araldite CY-248 + HY-956). We analyzed the encapsulation requirements to enable stable and reliable ISEs by evaluating the following properties: viscosity, curing time, hardness, surface quality, formation of bubbles, effect of mechanical polishing, reaction to Ag paint, effect of water, and cleaning and storage solutions. We found that, under the proper conditions, Wilpox APV 3C and Araldite CY-248 + HY-956 epoxy resins are the most suitable materials to encapsulate bulk chalcogenide glass membranes, while Wilpox APV 3C epoxy resin and Vaicel acrylic resin turn out to be the best candidates for thin film membranes.

[ES]: El transporte de cloruro en el hormigón por difusión es un problema extensamente estudiado para determinar la vida útil de las estructuras en ambientes marinos. Sin embargo, cuando el hormigón se encuentra fisurado no existe un procedimiento que permita calcular el transporte de los cloruros. Los Códigos limitan el ancho de las fisuras según el tipo de ambiente de exposición. En este trabajo se estudia la relación del ancho de fisura con el coeficiente de difusión y se estima el periodo de iniciación de la corrosión por cloruros en hormigones fisurados. Se ha obtenido una ley que permite predecir la variación del tiempo de iniciación de la corrosión en función del ancho de la fisura., [EN]: The transport of chloride in concrete by diffusion is a problem widely studied to determine the service-life of structures in marine environments. However, there is no procedure to calculate the chlorides transport when the concrete is cracked. The standards limit the width of the cracks according to the type of exposure environment. In this paper, the relation of the crack width with the diffusion coefficient is studied and the initiation time of chloride-induced corrosion in fissured concrete is estimated. A law has been obtained that allows to predict the variation of the corrosion initiation time according to the width of the crack.

The use of recycled PET (rPET) in long-term applications, such as composites, may provide an environmentally friendly solution for PET wastes. Main problem to overcome to use rPET in composites is its high viscosity which compromises the impregnation with the fibers during the consolidation process. As it is well known, PET undergoes thermo-mechanical and hydrolytic degradation during its mechanical recycling decreasing its viscosity and causing a loss of mechanical properties. For this reason, this paper takes into consideration a rheological modification during mechanical recycling to achieve the necessary fluidity for composites while maintaining the mechanical properties. Rheological modification was carried out by physical and chemical methods. Physical method was realized through blending with virgin PET (vPET) of low melt viscosity. Chemical method was performed on rPET, vPET and its blends by reactive extrusion. The effect of rheological modifications on the final thermal and mechanical properties was studied. Main results showed that both methods are able to decrease the viscosity without compromising mechanical properties. In addition, the chemical method during the reactive extrusion provided higher Elastic Modulus values., Ministerio de Economía, industria y Competitividad (Project MAT2017-85101-C2-1-R), Junta de Castilla y León-Instituto para la Competitividad Empresarial de Castilla y León (projects VA071G18 and CCTT2/18/VA/0002), Ministerio de Ciencia, Innovación y Universidades (project PTQ-16-0844)

Producción Científica, Due to the high number of reachable conductance levels in resistive switching devices, they are good candidates to implement artificial synaptic devices. In this work, we have studied the control of the intermediate conductance levels in HfO2-based MIM capacitors using current pulses. The set transition can be controlled in a linear way using this kind of signal. The potentiation characteristic is not affected by the pulse length due to the filament formation takes place in very short times. This behavior does not allow using identical pulses to obtain the potentiation characteristic. The transient response of the devices when applying current pulses showed the filament formation is characterized by a peak in the voltage transient signal. No depression characteristic can be obtained using current signals due to the abrupt reset transition. However, the depression characteristic can be obtained using voltage pulses, so combining both signals should allow control the synaptic weight in an appropriate way.

Las aleaciones Ti-β se han vuelto altamente demandadas en la industria, por sus buenas características físicas y químicas. En el presente trabajo, se sintetizó una aleación Ti-13Ta-3Sn (%at) por aleado mecánico con tiempos entre 2 y 100h. Las aleaciones se caracterizaron por difracción de rayos X (DRX) y los patrones se analizaron por el método Rietveld con el software MAUD. Se caracterizaron los cambios microestructurales y la evolución de las fases Ti-α y Ti-β. Se identificó la presencia una nueva fase metaestable fcc y la síntesis de una aleación con un 79,80% en peso de fase Ti-β, ambas con tamaño de cristalita nanométrico. The Ti-β alloys have become highly demanded in industry, due to their good physical and chemical characteristics. In the present work, a Ti-13Ta-3Sn (%at) alloy was synthesized using mechanical alloying (MA) between the times of 2 and 100h. The alloys were characterized by X-ray diffraction (XRD) and analyzed by the Rietveld method with the MAUD software. The microstructural changes and the evolution of the Ti-α and Ti-β phases were characterized. Identifying the presence of a new metastable fcc phase and the synthesis of an alloy with 79.80%wt of Ti-β phase, both alloys with nanometric crystallite size. Los autores agradecen al apoyo de FONDECYT 1161444, FONDECYT 1190797, FONDEQUIP EQM 140095 y al Programa de Incentivos a la Iniciación Científica (PIIC) de la USM.

Complex recombinant biomaterials that merge the self-assembling properties of different (poly)peptides provide a powerful tool for the achievement of specific structures, such as hydrogel networks, by tuning the thermodynamics and kinetics of the system through a tailored molecular design. In this work, elastin-like (EL) and silk-like (SL) polypeptides are combined to obtain a silk-elastin-like recombinamer (SELR) with dual selfassembly. First, EL domains force the molecule to undergo a phase transition above a precise temperature, which is driven by entropy and occurs very fast. Then, SL motifs interact through the slow formation of β-sheets, stabilized by H-bonds, creating an energy barrier that opposes phase separation. Both events lead to the development of a dynamic microstructure that evolves over time (until a pore size of 49.9 ± 12.7 µm) and to a delayed hydrogel formation (obtained after 2.6 h). Eventually, the network is arrested due to an increase in β-sheet secondary structures (up to 71.8 ± 0.8%) within SL motifs. This gives a high bond strength that prevents the complete segregation of the SELR from water, which results in a fixed metastable microarchitecture. These porous hydrogels are preliminarily tested as biomimetic niches for the isolation of cells in 3D cultures., Este trabajo forma parte de los proyectos de investigación MAT2016-78903-R, MAT2016-79435-R, RTI2018-096320-B-C22 y DTS19/00162 del Ministerio de Ciencia e Innovación, del proyecto VA317P18 de la Junta de Castilla y León, del proyecto 0624_2IQBIONEURO_6_E del programa Interreg V A España Portugal POCTEP y del Centro en Red de Medicina Regenerativa y Terapia Celular de Castilla y León

Producción Científica, Natural polymers are commonly used as scaffolds for vascular tissue engineering. The recognized biological properties of this class of materials are often counterbalanced by their low mechanical performance. In this work, recombinant elastin-like polypeptides (or elastin-like recombinamers, ELRs) were mixed with collagen gel and cells to produce cellularized tubular constructs in an attempt to recapitulate the mechanical behavior of the vascular extracellular matrix (ECM). The presence of the elastic protein influenced cell-mediated remodeling evaluated in terms of construct compaction, cell proliferation and ECM (collagen, elastin and fibrillin-1) gene expression. The partial substitution of collagen with ELR and the observed differences in cellular behavior synergistically contributed to the superior viscoelastic properties of the constructs containing 30% ELR and 70% of collagen (in mass). This led to the improvement of 40% in the initial elastic modulus, 50% in the equilibrium elastic modulus, and 37% in the tensile strength at break without compromising the strain at break, when compared to a pure collagen scaffold. Suggestions for future research include modifications in the crosslinking technology, ELR composition, polymer concentration, cell seeding density and dynamic stimulation, which have the potential to further improve the mechanical performance of the constructs towards physiological values., Este trabajo forma parte de los proyectos de investigación MAT2016-78903-R, RTI2018-096320-B-C22 y FPU15-00448 del Ministerio de Ciencia e Innovación, del proyecto VA317P18 de la Junta de Castilla y León, del proyecto 0624_2IQBIONEURO_6_E del programa Interreg V A España Portugal POCTEP y del Centro en Red de Medicina Regenerativa y Terapia Celular de Castilla y León

El procesamiento de fibroina de seda (SF) por medio de la tecnica de electrohilatura ha abierto un amplio campo de posibilidades para generar membranas fibrilares a escala micro y nanometrica, que aunados a las propiedades de biocompatibilidad y destacadas propiedades mecanicas de esta proteina, potencian su uso en diversas aplicaciones ingenieriles y biomedicas. Los procesos de electrohilatura se encuentran sujetos a una gran cantidad de variables y a las interacciones entre ellas, lo cual a su vez repercute en las propiedades morfologicas del material obtenido. En el presente trabajo se empleo SF proveniente de residuos sericolas colombianos, disuelta en acido formico (AF) al 10% w/w, se estudiaron dos condiciones de campo electrico (R=1 y 2 kV/cm) a tres distancias (8, 10 y 12 cm), y bajo dos condiciones de flujo (0,05 y 0.1 mL/h). Las membranas fibrosas obtenidas fueron caracterizadas por microscopia electronica de barrido (SEM), las imagenes se analizaron con el software ImajeJ para establecer presencia de defectos tipo beads, sus diametros y distribuciones. Se encontro que el campo electrico menor R=1 disminuyo la aparicion de defectos. Se realizo un analisis de varianza (ANOVA) bajo dicha condicion y se hizo la comparacion de medias usando la prueba Tukey (P

Resumen Los biosensores electroquímicos son herramientas analíticas de rápida y confiable respuesta que han adquirido especial interés en los últimos años gracias a la posibilidad de integrar biomoléculas con electrodos hechos a base de materiales nanométricos. En este trabajo se desarrolló un biosensor electroquímico para detección de peróxido de hidrógeno (H2O2) usando peroxidasa de pasto Guinea (PPG) inmovilizada sobre electrodos serigrafiados de puntos cuánticos (ESPC). La PPG fue aislada y parcialmente purificada a partir de hojas de pasto Guinea con una actividad específica de 602 U mg-1. Posteriormente, la PPG fue inmovilizada sobre la superficie del ESPC mediante adsorción física y el estudio del comportamiento electroquímico fue llevado a cabo mediante voltamperometría cíclica y cronoamperometría. La PPG reveló una pareja bien definida de señales redox a 17 mV/-141 mV correspondientes al proceso redox del grupo hemo (Fe2+/Fe3+) de las peroxidasas. La reducción bioelectrocatalítica del peróxido de hidrógeno se observó a un potencial redox de -645 mV vs Ag. Este proceso fue controlado por difusión de las especies en la superficie del electrodo en un rango de velocidad de barrido lineal de 50-500 mV/s. La cronoamperometría permitió la construcción de curvas de calibración entre la corriente de reducción y la concentración del H2O2 para la determinación de parámetros analíticos como sensibilidad, rango lineal y nivel mínimo de detección. El desarrollo de este biosensor amperométrico se convierte en un paso preliminar para la construcción de un dispositivo portátil y de respuesta rápida para el análisis de H2O2 en muestras de interés ambiental y biomédico. Abstract Electrochemical biosensors are analytical tools of fast and reliable response that have acquired interest in the last years due to the possibility of integrating biomolecules and electrodes made of nanometric materials. In this study, an electrochemical biosensor to detect hydrogen peroxide (H2O2) based on Guinea Grass peroxidase (GGP) immobilized on screen-printed quantum dots electrodes (SPQDE) was developed. GGP was partially purified from Guinea grass leaves having a specific activity of 602 U mg-1. Then, GGP was immobilized by physical adsorption on the surface on SPQDE and the electrochemical behavior was carried out through cyclic voltammetry and chronoamperometry techniques. GGP revealed a well-defined pair of redox signals at 17 mV/-141 mV corresponding to the redox process of the heme group (Fe2+/Fe3+) of peroxidases. The bioelectrocatalytic reduction of H2O2 has a redox potential of -645 mV vs Ag. This process was controlled by the diffusion of the species on the electrode surface using a scan rate range of 50-500 mV s. Chronoamperometry studies allow us the construction of calibration curves of reduction current vs H2O2 concentration for the determination of analytical parameters such as sensitivity, linear range and minimum detection level. The development of this amperometric biosensor becomes a preliminary step for the construction of a portable and rapid response device for the analysis of H2O2 in samples of environmental and biomedical interest. Resumo Os biossensores eletroquímicos são ferramentas analíticas de resposta rápida e confiável que adquiriram interesse especial nos últimos anos, graças à possibilidade de integrar biomoléculas com eletrodos feitos de materiais nanométricos. Neste trabalho, um biossensor eletroquímico foi desenvolvido para a detecção de peróxido de hidrogênio (H2O2) usando peroxidase do capim-da-Guiné (PPG) imobilizada em eletrodos serigráficos de pontos quânticos (ESPC) serigrafados. O PPG foi isolado e parcialmente purificado a partir de folhas de capim-da-Guiné com atividade específica de 602 U mg-1. Posteriormente, o PPG foi imobilizado na superfície do ESPC por adsorção física e estudo do comportamento eletroquímico foi realizado por voltametria cíclica e cronoamperometria. O PPG revelou um par bem definido de sinais redox em 17 mV/-141 mV correspondente ao processo redox do grupo heme (Fe2+/Fe3+) de peroxidases. A redução bioeletrocatalítica do H2O2 foi observada com um potencial redox de -645 mV vs. Ag. Esse processo foi controlado pela difusão das espécies na superfície do eletrodo em uma faixa de velocidade de varredura linear de 50-500 mV/s. A cronoamperometria permitiu a construção de curvas de calibração entre a corrente de redução e a concentração de H2O2 para a determinação de parâmetros analíticos como sensibilidade, faixa linear e nível mínimo de detecção. O desenvolvimento deste biossensor amperométrico torna-se uma etapa preliminar para a construção de um dispositivo portátil e de resposta rápida para a análise de H2O2 em amostras de interesse ambiental e biomédico.