Design and Synthesis of N-Doped Carbons as Efficient Metal-Free Catalysts in the Hydrogenation of 1-Chloro-4-Nitrobenzene

Metal-free catalysts based on nitrogen-doped porous carbons were designed and synthesized from mixtures of melamine as nitrogen and carbon sources and calcium citrate as carbon source and porogen system. Considering the physicochemical and textural properties of the prepared carbons, a melamine/citrate ratio of 2:1 was selected to study the effect of the pyrolysis temperature. It was observed that a minimum pyrolysis temperature of 750 ◦C is required to obtain a carbonaceous structure. However, although there is a decrease in the nitrogen amount at higher pyrolysis temperatures, a gradual development of the porosity is produced from 750 ◦C to 850 ◦C. Above that temperature, a deterioration of the carbon porous structure is produced. All the prepared carbon materials, with no need for a further activation treatment, were active in the hydrogenation reaction of 1-chloro-4-nitrobenzene. A full degree of conversion was reached with the most active catalysts obtained from 2:1 melamine/citrate mixtures pyrolyzed at 850 ◦C and 900 ◦C, which exhibited a suitable compromise between the N-doping level and developed mesoporosity that facilitates the access of the reactants to the catalytic sites. What is more, all the materials showed 100% selectivity for the hydrogenation of the nitro group to form the corresponding chloro-aniline.Financial support from the Ministry of Science and Innovation (Spain, PID2019-108453GB-C21) and Generalitat Valenciana (Spain, CIPROM/2021/022) is gratefully acknowledged

N-Doped Activated Carbons from Polypyrrole – Effect of Steam Activation Conditions

Polypyrrole (PPy) has been prepared by oxidative polymerization of pyrrole and used as a raw material for the preparation of N-doped activated carbons. Thus, PPy has been pyrolyzed at 900 °C and then activated with steam under different activation conditions (time and temperature). This has allowed for the preparation of activated carbons with different porosity development and nitrogen content, as well as distinctive distribution of nitrogen species. It has been observed that the presence of nitrogen functionalities favors water adsorption at low relative pressures but, at relative pressures higher than 0.5 it is determined by the porosity development.Financial support from Ministerio de Ciencia e Innovación (Spain, Project PID2019-108453GB-C21) is gratefully acknowledged. Open access funding enabled and organized by Projekt DEAL

Doped activated carbons obtained from nitrogen and sulfur-containing polymers as metal-free catalysts for application in nitroarenes hydrogenation

Activated carbons doped with nitrogen and/or sulfur have been obtained by pyrolysis followed of steam activation of a sulfur containing polymer (polythiophene) and two nitrogen-containing polymers (polyaniline and polypyrrole). These polymers were synthesized by oxidative chemical polymerization in aqueous media of their corresponding monomers. The influence of the steam activation on the textural properties and surface chemistry of the carbons has been evaluated and their catalytic activity has been determined in the hydrogenation reaction of 1-chloro-4-nitrobenzene. The degree of conversion in the reaction depends on the development of adequate porosity in the activated carbon (which is determined by the activation conditions) together with the presence of heteroatoms that act as active catalytic sites, with S showing considerably greater effectiveness than N. A compromise between an acceptable level of doping with sulfur and an adequate porosity is necessary, which has been achieved in a carbon obtained from polythiophene pyrolyzed at 900 °C and steam activated at 800 °C for 4 h, with a specific surface area of 742 m2/g and S content of 1.71 at%.Financial support from Spain Ministry of Science and Innovation (PID2019-108453GB-C21) is gratefully acknowledged

Carbothermally generated copper–molybdenum carbide supported on graphite for the CO2 hydrogenation to methanol

The carbothermal synthesis of monometallic and bimetallic molybdenum carbide and copper, supported on high surface area graphite (H), has been studied by in situ XRD, XPS, D2-TPD, TEM/STEM, TG-mass spectrometry, and N2 adsorption. The catalysts were prepared using H2 at 600 °C or 700 °C and tested in the hydrogenation of CO2 to methanol. Molybdenum carbide and oxycarbide phases were obtained, as well as hydride species, at 600 °C on both monometallic MoxC/H and bimetallic CuMoxC/H in a similar proportion. Upon increasing the temperature up to 700 °C, the formation of metallic Mo is favourable. Although this is observed on supported MoxC and CuMoxC, the bimetallic sample is less affected by the formation of the hydride, and molybdenum carbide is also observed upon treatment at 700 °C. With regards to the catalytic performance, supported monometallic copper was not active, but copper increased the activity and selectivity of the molybdenum carbide. The yield of methanol per catalyst's weight increases upon increasing the copper loading, indicating that a cooperation reaction takes place between the smallest Cu particles in contact with the molybdenum phase. The catalysts synthesized at 700 °C are less active and less selective to methanol favouring the reverse water gas shift under the studied conditions. Interestingly, the catalysts are stable under the reaction conditions, and the detected phases by XRD of the spent catalysts suggest that the hydride species favoured transformations involving MoOxCyHz ↔ β-Mo2C.A. B. Dongil acknowledges financial support from the Fundación General CSIC (Programa ComFuturo and iLink project No 20211 from CSIC (Spain)). Financial support from the Spanish Agencia Estatal de Investigación (AEI) and EU (FEDER) (projects MAT2016-80285-P, CTQ2017-89443-C3-1-R and CTQ2017-89443-C3-3-R) is also acknowledged

Candesartan exhibits low intrinsic permeation capacity and affects buccal tissue viability and integrity: An ex vivo study in porcine buccal mucosa

El candesartán es un bloqueante no peptídico de los receptores de angiotensina II que se une selectivamente al subtipo 1 de receptores de angiotensina II. Se administra por vía oral en su forma de éster (candesartán cilexetilo). Sin embargo, su escasa solubilidad acuosa hace que su biodisponibilidad sea baja, por lo que deben explorarse otras vías de administración. La mucosa bucal se ha estudiado ampliamente como vía alternativa para la administración de fármacos, ya que mejora la biodisponibilidad de los fármacos administrados por vía peroral. La mucosa bucal porcina se ha utilizado ampliamente como modelo ex vivo para estudiar la permeabilidad de diversos difusores; sin embargo, los estudios sobre candesartán son limitados. El objetivo de este estudio era evaluar el perfil de permeabilidad ex vivo del candesartán y sus efectos sobre la viabilidad y la integridad de la mucosa bucal porcina. Inicialmente, evaluamos la viabilidad, integridad y función de barrera del tejido bucal antes de realizar las pruebas de permeabilidad utilizando tejidos recién extirpados o tejidos tras 12 h de resección. En este caso, se utilizaron tres indicadores: penetración de cafeína, β-estradiol y FD-20; actividad metabólica de la mucosa, determinada mediante el ensayo de reducción de MTT; y tinción con hematoxilina y eosina. Nuestros resultados indicaron que la mucosa bucal porcina conservó su viabilidad, integridad y función de barrera antes del ensayo de permeación, permitiendo el paso de moléculas con una masa molecular inferior a 20 kDa, como la cafeína, pero no el β-estradiol y el FD-20. Además, analizamos la capacidad intrínseca del candesartán para difundirse a través de la mucosa bucal porcina fresca en dos condiciones de pH. La concentración de candesartán en la cámara receptora de la célula de difusión de Franz se cuantificó mediante cromatografía líquida de ultra alta resolución. En el ensayo de permeación, el candesartán mostró una baja capacidad de permeación intrínseca que afectó a la viabilidad e integridad del tejido bucal, lo que sugiere que el uso de la mucosa bucal como vía alternativa de administración requiere el desarrollo de una formulación farmacéutica que reduzca los efectos adversos sobre la mucosa y aumente la permeabilidad bucal del candesartán. © 2023Candesartan is a nonpeptide angiotensin II receptor blocker that selectively binds to angiotensin II receptor subtype 1. It is administered orally in its ester form (candesartan cilexetil). However, its poor aqueous solubility results in its low bioavailability; therefore, other routes of administration must be explored. The buccal mucosa has been extensively studied as an alternative route for drug delivery as it improves the bioavailability of drugs administered via the peroral route. Porcine buccal mucosa has been widely used as an ex vivo model to study the permeability of various diffusants; however, studies on candesartan are limited. This study aimed to evaluate the ex vivo permeation profile of candesartan and its effects on the viability and integrity of porcine buccal mucosa. Initially, we evaluated the viability, integrity, and barrier function of the buccal tissue before performing permeability tests using freshly excised tissues or tissues after 12 h of resection. Here, three indicators were used: caffeine, β-estradiol, and FD-20 penetration; mucosal metabolic activity, as determined using MTT reduction assay; and haematoxylin and eosin staining. Our results indicated that the porcine buccal mucosa preserved its viability, integrity, and barrier function before the permeation assay, allowing the passage of molecules with a molecular mass of less than 20 kDa, such as caffeine, but not β-estradiol and FD-20. Furthermore, we analyzed the intrinsic capacity of candesartan to diffuse through the fresh porcine buccal mucosa under two pH conditions. The concentration of candesartan in the receptor chamber of Franz diffusion cell was quantified using ultra-high liquid chromatography. In the permeation assay, candesartan exhibited a low intrinsic permeation capacity that impacted the buccal tissue viability and integrity, suggesting that using the buccal mucosa as an alternative route of administration requires developing a pharmaceutical formulation that reduces the adverse effects on mucosa and increasing the buccal permeability of candesartan. © 202

Effect of aquatic resistance interval training and dietary education program on physical and psychological health in older women: Randomized controlled trial

Due to demographic changes, the world’s population is progressively aging. The physiological deterioration of the older adult may lead to reduced balance capacity and increased risk of falls, among others, due to the prevalence of degenerative diseases. Physical exercise can be effective in reducing the risk of disease and slowing functional decline in older people. The aim of the research is to test the effects of aquatic resistance training and dietary education on health indicators, strength, balance, functional autonomy, perception of satisfaction with life. Thirty-four participants aged 69 ± 4 years were randomly assigned into two groups: experimental (aquatic resistance interval training) and control group (no intervention). The intervention consisted of resistance training in an aquatic environment carried out for 14 weeks (three sessions per week: 60 min each). All variables were analyzed twice; pre - post intervention. Aquatic resistance training has positive effects on strength (p < 0.001), functional self-sufficiency (p < 0.001) and aerobic capacity (p < 0.001), however, no significant differences were observed in the perception of satisfaction with life and balance. Research results suggest that older women who engage in regular, scheduled aquatic resistance training have greater autonomy in performing activities of daily living, agility, gait control, and body composition variables (lower fat compartment and greater muscle mass)

Reemplazo del protocolo SENT por LIN

Existen diversos protocolos de comunicación para interconectar dispositivos de control electrónico en un automóvil. La mayoría de las veces, más de un protocolo de comunicación convive dentro del mismo, cada uno muy diferente en términos de costos, velocidad, dependencias de hardware, etcétera. El propósito de este trabajo es comparar los protocolos de comunicación de bajo costo SENT y LIN, que se utilizan en la industria automotriz, y proporcionar información que ayudará a reemplazar o elegir el protocolo que mejor se adapte a sus necesidades, con la descripción de la forma en que operan, los formatos de trama y las topologías de red. La parte central del trabajo es la comparación teórica y práctica de los protocolos, para lo cual nos basamos en varias fuentes de dominio público, así como los estándares respectivos de cada protocolo (J2716_201001 para SENT y la especificación LIN 1.3) para obtener información valiosa, como las ventajas y desventajas de cada uno. Posteriormente, se obtuvieron varias métricas derivadas de la implementación de ambos protocolos en tarjetas de desarrollo DEMO9S12XEP100 con enfoque en el tiempo de transmisión, recepción y uso de la CPU y, finalmente, de acuerdo a las necesidades específicas del usuario, poder tomar la decisión de qué protocolo es óptimo para la aplicación del usuario.Consejo Nacional de Ciencia y Tecnologí

Conducting Polymer–TiO2 Hybrid Materials: Application in the Removal of Nitrates from Water

Materials able to produce the reduction of nitrate from water without the need of a metal catalyst and with avoiding the use of gaseous hydrogen have been developed by combining the synergistic properties of titania and two conducting polymers. Polymerization of aniline and pyrrol on titanium dioxide in the presence of two different oxidants/dopants (iron trichloride or potassium persulfate) has been evaluated. The resulting hybrid materials have good thermal stability imparted by the titania counterpart, and a considerable conductivity provided by the conducting polymers. The capability of the hybrid materials of reducing aqueous nitrate has been assessed and compared to the catalytic hydrogenation of nitrate using a platinum catalyst supported on these hybrid synthesized materials. The mechanism of nitrate abatement implies adsorption of nitrate on the polymer by ion exchange with the dopant anion, followed by the reduction of nitrate. The electron transfer from titania to the conducting polymer in the hybrid material favors the reductive ability of the polymer, in such a way that nitrate is selectively reduced with a very low production of undesirable side products. The obtained results show that the activity and selectivity of the catalytic reduction of nitrate with dihydrogen in the presence of a platinum catalyst supported on the hybrid materials are considerably lower than those of the metal-free nanocomposites.Financial support from Generalitat Valenciana, Spain (PROMETEOII/2014/004) and Ministry of Economy and Competitivity (MAT2016-80285-P) is gratefully acknowledged. E.S. acknowledges the Spanish MINECO and AEI/FEDER (ref CTQ2015-74494-JIN) and the University of Alicante (ref UATALENTO16-03)

Aceptación de aceite transgénico de distinto país de origen en la Región de La Araucanía, Chile

Considerando el rechazo de los consumidores hacia alimentos genéticamente modificados y que el país de origen es usado como indicador de calidad, se estudió la importancia relativa de la existencia de modificación genética (MG), origen y precio en la compra de aceite de girasol en Temuco, Chile, junto con la identificación y la caracterización de diferentes segmentos de mercado, mediante una encuesta a 400 personas. Utilizando análisis conjunto se determinó que la existencia de MG (36,0%) fue levemente más importante que el origen (33,3%) y el precio (30,7%) en la muestra total, con preferencia hacia el producto sin MG, de origen chileno y al menor precio. Mediante análisis de conglomerados jerárquicos se diferenciaron tres segmentos: el mayoritario (45,5%) dio elevada importancia a la existencia de MG y presentó un alto rechazo hacia el aceite transgénico; el segundo grupo (29,7%) asignó mayor relevancia al precio y acepta aceite argentino; el grupo minoritario (24,8%) otorgó mayor importancia al origen y acepta aceite español. Independientemente de lo anterior, los grupos mostraron mayor preferencia por el aceite chileno. La ausencia de MG en aceite es una condición deseable para una importante proporción de consumidores (45,5%), pero el resto se muestra relativamente indiferente hacia la existencia o ausencia de manipulación genética en este producto.Considerando el rechazo de los consumidores hacia alimentos genéticamente modificados y que el país de origen es usado como indicador de calidad, se estudió la importancia relativa de la existencia de modificación genética (MG), origen y precio en la compra de aceite de girasol en Temuco, Chile, junto con la identificación y la caracterización de diferentes segmentos de mercado, mediante una encuesta a 400 personas. Utilizando análisis conjunto se determinó que la existencia de MG (36,0%) fue levemente más importante que el origen (33,3%) y el precio (30,7%) en la muestra total, con preferencia hacia el producto sin MG, de origen chileno y al menor precio. Mediante análisis de conglomerados jerárquicos se diferenciaron tres segmentos: el mayoritario (45,5%) dio elevada importancia a la existencia de MG y presentó un alto rechazo hacia el aceite transgénico; el segundo grupo (29,7%) asignó mayor relevancia al precio y acepta aceite argentino; el grupo minoritario (24,8%) otorgó mayor importancia al origen y acepta aceite español. Independientemente de lo anterior, los grupos mostraron mayor preferencia por el aceite chileno. La ausencia de MG en aceite es una condición deseable para una importante proporción de consumidores (45,5%), pero el resto se muestra relativamente indiferente hacia la existencia o ausencia de manipulación genética en este producto

A novel converter topology for applications in smart grids: technical and economical evaluation

Technological advances in smart grids significantly contribute to an energy sustainability paradigm, assisting to diminish harms associated with global warming. Some of the key challenges in smart grids are linked with power electronics applications for renewable energy sources (RES), electric mobility (EM), energy storage systems (ESS) and power quality (PQ). These applications for smart grids have a common feature: the requirement to use the full-controlled grid-side power converters. Thereby, this paper aims to contribute with a technical and economical evaluation about a novel topology of the grid-side power converter for applications in smart grids. In terms of technical features, the proposed converter is classified as: (a) Bidirectional, allowing a bidirectional power flow with the electrical grid; (b) Symmetrical, allowing the operation with two distinct applications in the dc-side (e.g., RES, ESS, or EM); (c) Multilevel with nine levels, allowing high levels of PQ for the grid-side. With the objective to establish an accurate case-study, throughout the paper, the technical and economical evaluation is also performed based on the comparison between the proposed topology and the conventional ones. Considering an economical evaluation, the paper presents a cost estimation study concerning the implementation costs of the proposed topology, assuming realistic conditions of operation for applications in smart grids. Based on the entire evaluation for a real operating power range, the obtained results show the operational convenience of the topology in accordance with different applications in smart grids.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019. This work is financed by the ERDF – European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation ‐ COMPETE 2020 Programme, and by National Funds through the Portuguese funding agency, FCT‐Fundação para a Ciência e a Tecnologia, within project SAICTPAC/0004/2015‐ POCI‐01‐0145‐FEDER‐016434.Mr. Tiago Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by the Portuguese FCT agency. This work is part of the FCT project POCI-01-0145-FEDER-030283