Effects of thermal and mechanical treatments on montmorillonite homoionized with mono- and polyvalent cations: Insight into the surface and structural changes

Smectite is a family of clay minerals that have important applications. In the majority of these clay minerals, the hydrated interlayer cations play a crucial role on the properties of the clay. Moreover, many studies have revealed that both thermal and grinding treatments affect the MMT structure and that interlayer cations play an important role in the degradation of the structure, primarily after mechanical treatment. In this study, the effects of these treatments on MMTs homoionized with mono (Na+, Li+ or K+) or polyvalent (Ca2+ or Al3+) cations were analyzed by the combination of a set of techniques that can reveal the difference of bulk phenomena from those produced on the surface of the particles. The thermal and mechanical (in an oscillating mill) treatments affected the framework composition and structure of the MMT, and the thermal treatment caused less drastic changes that the mechanical one. The effect of the interlayer cations is primarily due to the oxidation state and, to the size of the cations, which also influenced the disappearance of aluminum in the MMT tetrahedral sheet. These treatments caused a decrease in the surface area and an increase in the particle agglomeration and the isoelectric point. Both treatments caused the leaching of the framework aluminum. Furthermore, the mechanical treatment induced structural defects, such as the breakup of the particles, which favored the dehydroxylation and the increase of the isoelectric points of the montmorillonites.ANPCyT 1360/2006DGICYT FEDER CTQ 2010-1487

La Economía Social y Solidaria: nuevas formas de generar valo

El siguiente trabajo pretende realizar un análisis en cifras de la situación de la Economía Social y Solidaria en España a través de su origen, de las entidades que forman parte, del apoyo legislativo que existe de las diferentes instituciones, tanto nacionales como autonómicas para con ello dar visibilidad a una nueva forma de entender la economía en la cual la parte central son las personas y el medioambiente para un desarrollo sostenible, con el consiguiente beneficio que aportan a aquellas personas en riesgo de exclusión social tanto de valor monetario como no monetario.Grado en Administración y Dirección de Empresa

LA INFLUENCIA DE LA DIVERSIFICACIÓN Y EXPERIENCIA INTERNACIONAL EN LA ESTRATEGIA MEDIOAMBIENTAL PROACTIVA DE LAS EMPRESAS

RESUMENEste trabajo tiene como objetivo analizar la influencia que la internacionalización puede tener sobre la adopción de una estrategia medioambiental más proactiva por parte de las empresas. Para conseguir este objetivo realizamos 103 entrevistas personales a los directores generales de empresas exportadoras españolas pertenecientes al sector de la alimentación. Nuestros resultados muestran que un alto grado de diversificación internacional favorece el desarrollo de una estrategia medioambiental más proactiva. Además, la experiencia internacional de las empresas contribuye también a la adquisición de capacidades medioambientales valiosas. Por tanto, la internacionalización permite a las empresas desarrollar una estrategia más avanzada en gestión medioambiental. Finalmente, recogemos una serie de implicaciones de carácter práctico para directivos y reguladores públicos.ABSTRACTWe analyze the influence of the firms' internationalization process of firms on the adoption of a proactive environmental strategy. Using direct interviews with the CEOs of 103 export Spanish firms from the food industry, we show that a high degree of international diversification encourages these firms to take advantage of different environmental competitive advantages from the different regions where they operate. In addition, firms' international experience contributes to acquiring valuable environmental capabilities. Thus, our results support that internationalization leads firms to develop an advanced posture to environmental issues and adopt a proactive environmental strategy. Our paper discusses implications for managers and policy-makers

Inhalable spray-dried chondroitin sulphate microparticles: effect of different solvents on particle properties and drug activity

Spray-drying stands as one of the most used techniques to produce inhalable microparticles, but several parameters from both the process and the used materials affect the properties of the resulting microparticles. In this work, we describe the production of drug-loaded chondroitin sulphate microparticles by spray-drying, testing the effect of using different solvents during the process. Full characterisation of the polymer and of the aerodynamic properties of the obtained microparticles are provided envisaging an application in inhalable tuberculosis therapy. The spray-dried microparticles successfully associated two first-line antitubercular drugs (isoniazid and rifabutin) with satisfactory production yield (up to 85%) and drug association efficiency (60%-95%). Ethanol and HCl were tested as co-solvents to aid the solubilisation of rifabutin and microparticles produced with the former generally revealed the best features, presenting a better ability to sustainably release rifabutin. Moreover, these presented aerodynamic properties compatible with deep lung deposition, with an aerodynamic diameter around 4 μm and fine particle fraction of approximately 44%. Finally, it was further demonstrated that the antitubercular activity of the drugs remained unchanged after encapsulation independently of the used solvent.UID/Multi/04326/2019; SFRH/BD/52426/2013; ED481B 2018/071info:eu-repo/semantics/publishedVersio

Structural studies of two Tinuvin® P analogs: 2-(2,4-Dimethylphenyl)- 2H-benzotriazole and 2-phenyl-2H-benzotriazole

2-(2,4-Dimethylphenyl)-2H-benzotriazole (1) has been synthesized in a three step procedure starting from 2,4-dimethyl-N-(2-nitrophenyl)benzamide via a 5-(2,4-dimethylphenyl)-1-(2-nitrophenyl)-1H-tetrazole intermediate. Its structure and those of Tinuvin® P and 2-phenyl-2H-benzotriazole (5) have been studied by multinuclear NMR (1H-, 13C- and 15N-) in solution and in the solid state. X-ray diffraction analysis of 1 and 5 allowed to us establish the molecular conformation around the single bond connecting the two aromatic systems, in agreement with the conclusions drawn from the NMR study. In the case of 1 ab initio geometry optimization was achieved at the Hartree-Fock HF/6-31G** and DFT B3LYP/6-31G ** levels. © 2007 by MDPI.Peer Reviewe

Balancing porosity and mechanical properties of titanium samples to favor cellular growth against bacteria

Two main problems limit the success of titanium implants: bacterial infection, which restricts their osseointegration capacity; and the stiffness mismatch between the implant and the host cortical bone, which promotes bone resorption and risk of fracture. Porosity incorporation may reduce this difference in stiffness but compromise biomechanical behavior. In this work, the relationship between the microstructure (content, size, and shape of pores) and the antibacterial and cellular behavior of samples fabricated by the space-holder technique (50 vol % NH4HCO3 and three ranges of particle sizes) is established. Results are discussed in terms of the best biomechanical properties and biofunctional activity balance (cell biocompatibility and antibacterial behavior). All substrates achieved suitable cell biocompatibility of premioblast and osteoblast in adhesion and proliferation processes. It is worth to highlighting that samples fabricated with the 100–200 μm space-holder present better mechanical behavior—in terms of stiffness, microhardness, and yield strength—which make them a very suitable material to replace cortical bone tissues. Those results exposed the relationship between the surface properties and the race of bacteria and mammalian cells for the surface with the aim to promote cellular growth over bacteria.University of Seville (Spain) VI Plan Propio de Investigación y Transferencia—US 2018, I.3A

Potential use of Sargassum muticum as source of plant biostimulants after three different drying methods

Seaweed derived biostimulants are gaining attention as an important tool in sustainable agriculture. This offers a unique opportunity to alleviate the environmental impact of Sargassum muticum (Ochrophyta, Phaeophyceae) as an invasive species by finding new applications for its biomass. In this sense, incorporating green extraction technologies is fundamental to ensure environmental-friendly goals. This research was initiated in an attempt to contribute to an integral valorization system of S. muticum biomass, exploring the biostimulant potential of the solubles obtained from pressed solids, through an autohydrolysis treatment. In addition, we compared the effect of three different liquid phase drying techniques (spray-drying, freeze-drying and convective air-drying). Low stress drying techniques as spray-drying showed better conservation of bioactive compounds and biostimulant potential. A bioassay with Nastrium officinale showed no phytotoxic effects despite high electric conductivity in most of the extracts and concentrations. Dried extracts showed mainly an amorphous structure but occasional crystal formation when spray-dried at low temperatures (T out  = 50 ºC) and after convective air drying (T = 40 ºC). Significant increases in root development were achieved at a concentration of 5 mg L −1 of spray-dried extracts and 50 mg L −1 in case of freeze-dried extracts. Munoo-Liisa vitality index showed best results with 50 mg L −1 of freeze-dried extracts. This study provides important information about the influence of different drying techniques on the physicochemical properties and biostimulant potential of S. muticum aqueous extracts and contributes to the integral valorization of its biomass.Agencia Estatal de Investigación | Ref. RYC2018-024454-IXunta de Galicia | Ref. ED431F 2020/01Xunta de Galicia | Ref. ED481D-2022/018Universidade de Vigo/CISU

Production of betalain-rich Opuntia ficus-indica peel flour microparticles using spray-dryer: A holist approach

This study aimed to obtain a betalain-rich extract (BRE) from Opuntia ficus-indica peels and protect them through a holistic approach involving microencapsulation via spray-drying. To enhance the stability of the microencapsulated betalains, an antioxidant-rich extract (ARE) obtained through hydrothermal extraction from the residual material remaining after the conventional extraction of betalains was used as a stabilizer during the spray-drying process. The antioxidant activity of the ARE was evaluated by measuring its IC50 value for 2,2-Diphenyl-1-picrylhydrazyl (DPPH) of 65.8 μg/mL, its Trolox equivalent antioxidant capacity (TEAC) of 60.4 gTrolox eq./100 g, and its reducing power of 16.6 g butylated hydroxytoluene (BHT) eq./100 g. Spray-drying parameters were optimized using a Box-Behnken design to enhance the total betalain content and minimize by-product formation. The results demonstrated that the addition of the ARE significantly improved the stability of betalains during spray-drying, leading to the formation of microparticles with high betalain content and enhanced stability. The optimal conditions (0.72% starch, 1.50% BRE and 0.25% ARE) resulted in microparticles with a maximum concentration of 6.74 ± 0.09 mgBetalains/g. The predictive model exhibited high accuracy in estimating experimental values. This research provides a natural and sustainable solution for food coloring by effectively utilizing discarded Opuntia ficus-indica peel. Moreover, it offers new scientific understanding on the production of betalain-rich microparticles as a possible substitute for food coloring, with considerable benefits in terms of sustainability and high antioxidant capacity.Agencia Estatal de Investigación | Ref. RYC2018-024454-IXunta de Galicia | Ref. ED431F 2020/01Xunta de Galicia | Ref. ED481D-2022/01

Analizadores de red de bajo coste

El uso masivo de dispositivos electrónicos, tanto en entornos domésticos como industriales, tiene un impacto directo e inmediato en la creciente y compleja red de distribución eléctrica a la que se conectan. De aquí la necesidad de analizar la calidad de la señal eléctrica y su energía asociada en la propia red e instalaciones afectadas. Por otra parte, la evolución exponencial de microcontroladores y micro PC´S y su aplicación al procesado de señales, convierte a estos dispositivos en candidatos excepcionales para cubrir la mencionada necesidad del análisis de la calidad eléctrica. Esta es justamente la propuesta que se hace en este trabajo. La detección de las perturbaciones eléctricas de mayor incidencia en la calidad de la señal de red se puede realizar de diferentes formas. En este caso, se propone el uso de una potente herramienta matemática como es la Transformada Wavelet (TW), con una contrastada aplicabilidad en este campo. Su traducción a nivel de programación mediante un complejo algoritmo es implementada en dispositivos de bajo coste, particularmente en Arduino y Raspberry Pi. A partir de este algoritmo es posible la detección, análisis y clasificación de distintas perturbaciones eléctricas de forma más intuitiva. Se ha diseñado un sistema capaz de adquirir y analizar la señal de la tensión eléctrica y monitorizar dichos resultados, demostrando la aptitud de estos sistemas de bajo coste para dicho análisis.The massive use of electronic devices, both in domestic and industrial environments, has a direct and immediate impact on the electrical network in which they are connected. This fact generates the need for a power quality analysis in the electrical distribution network and affected installations. On the other hand, the exponential evolution of microcontrollers and micro PC'S and their application to signal processing, makes these devices exceptional candidates to cover the aforementioned power quality analysis. This is precisely the proposal made in this work. The detection of electrical disturbances with greater incidence in power quality can be made in different ways. In this case, the use of a powerful mathematical tool such as the Wavelet Transform (WT), with a proven applicability in this field, is proposed. Its translation at the programming level through a complex algorithm is implemented in low cost devices, particularly in Arduino and Raspberry Pi. From this algorithm it is possible to detect, analyze and classify different electrical disturbances in a more intuitive way. A system capable of acquiring and analyzing the voltage signal, as well as monitoring the results, has been designed, showing the capacity of these low cost devices for such analysis.Plan Propio de la Universidad de Sevilla Proyecto: 2017/0000096

Opuntia ficus-indica seed pomace extracts with high UV-screening ability in a circular economy approach for body lotions with solar protection

Opuntia ficus-indica seed pomace, a by-product of seed oil extraction, was investigated due to its richness of phytochemical compounds and high antioxidant capacity. The pomace was subjected to hydrothermal extraction using water under subcritical conditions to solubilize various compounds. Different final heating temperatures 120 to 220 °C were applied, and the resulting filtered extracts were analyzed using HPLC and HPSEC to determine the monosaccharide profile and molecular weight of the oligomers. Notably, extractions performed at temperatures between 120 and 180 °C yielded extracts characterized by elevated levels of glucuronic acid and exhibited higher molecular weights. In contrast, extractions conducted at 200 and 220 °C were distinguished by their enriched xylose content and relatively low molecular weights, falling below 23.6 kDa. The extracts were tested for total phenolic compounds, as well as antioxidant activity using spectrophotometric methods such as TEAC, DPPH, and FRAP. Results showed that increasing temperature led to a corresponding increase in phenolic compounds (from 7.7 to 13.7 gGAE/100 g) and antioxidant activity, with the maximum observed at 200 °C. These phenolic compounds enriched extract were used to produce a body lotion with sun protection factor of 8, with rheological behavior similar to that of commercially available products but without the need for additional UV filters and antioxidants. The lotion was shown to be safe for topical use and did not cause skin irritation. This study highlights the potential of O. ficus-indica seed pomace as a valuable source of phytochemical compounds and demonstrates the feasibility of using hydrothermal extraction to produce eco-friendly commercially interesting compounds.Fundação para a Ciência e a Tecnologia | Ref. UIDB/50006/2020Fundação para a Ciência e a Tecnologia | Ref. UIDP/50006/2020Xunta de Galicia | Ref. ED481D-2022/018Xunta de Galicia | Ref. GRC-ED431C 2022/08Agencia Estatal de Investigación | Ref. TED2021-131555B-C22Agencia Estatal de Investigación | Ref. RYC2018-024454-IXunta de Galicia | Ref. ED431F 2020/0