1,412 research outputs found

    Integration of catalytic wet peroxidation and membrane distillation processes for olive mill wastewater treatment and water recovery

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    The degradation of organic matter present in olive mill wastewater (OMW) and the recovery of water were studied by the integration of catalytic wet peroxidation (CWPO) and direct contact membrane distillation (DCMD) for the first time. The oxidation step was performed in a fixed–bed reactor (FBR) working in continuous mode (pH0 = 4.0 ± 0.2, 60 ◦C, Q = 0.75 mL/min, [H2O2]/[COD]feed = 2.3 ± 0.1 g H2O2/g O2). Samples of OMW diluted by 5– and 7.5–fold were used (OMW–5× and OMW–7.5×, respectively), corresponding to inlet chemical oxygen demand (COD) values of 3562 ± 68 and 2335 ± 54 mg/L, total phenolic content (TPh) of 177 ± 17 and 143 ± 7 mg GAeq/L, and total organic carbon (TOC) of 1258 ± 63 and 842 ± 45 mg/L, respectively. The FBR was loaded with 2.0 g of a Fe–activated carbon derived–catalyst, prepared by using olive stones as the precursor, in line with a circular economy model approach. The catalyst was selected based on the activity and stability towards polyphenolic synthetic solutions shown in previous works of the team, while actual OMW samples were used in this work. CWPO–treated samples of OMW allowed the operation of the DCMD unit at higher fluxes than with the analogous untreated ones, also showing higher rejections of organic matter from the feed solution upon DCMD, highlighting the beneficial effect of this novel configuration. Using a pre-treated sample of OMW–7.5× as feed solution (Q = 100 mL/min, Tpermeate ≈ 18 ◦C, Tfeed ≈ 66 ◦C), the produced permeate water stream presented several parameters well–below the legislated thresholds required for direct discharge for crops irrigation, including total suspended solids (TSS < 10 mg/L), TPh (<0.01 mg GAeq/L), biochemical oxygen demand (BOD5 < 40 mg/L), and dissolved Fe (<0.06 mg/L). Moreover, the resulting concentrated OMW–retentate streams could be recirculated to the FBR and maintain the same removal efficiencies obtained previously, despite the increased initial organic loadings of the retentate after DCMD.Portuguese Foundation for Science and Technology LA/P/0045/2020 UIDB/00511/2020 UIDP/00511/2020European Regional Development Funds (ERDF) through North Portugal Regional Operational Programme (NORTE 2020) NORTE-01-0145-FEDER000069NORTE 2020 under the PORTUGAL 2020 Partnership Agreement through ERDF NORTE-01-0145-FEDER000069MCIN/AEI/FEDER "Una manera de hacer Europa" RTI2018-099224B-I00Portuguese Foundation for Science and Technology BaseUIDB/50020/2020 UIDP/50020/2020Portuguese Foundation for Science and TechnologyEuropean Commission SFRH/BD/129235/2017National and the European Social Funds through the Human Capital Operational Programme (POCH) MCIN/AEI RYC-2019026634IEuropean Social Found (FSE) "El FSE invierte en tu futuro" RYC-2019026634

    Specific adsorbents for the treatment of OMW phenolic compounds by activation of bio-residues from the olive oil industry

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    A series of adsorbents was developed by physical (CO2) and chemical (KOH) activation of two bio-residues: olive stones (OS) and wood from olive tree pruning (OTP). The physicochemical properties of such materials were determined and correlated with their adsorptive performance in the removal of phenolic compounds of olive mill wastewater (OMW). Adsorption isotherms and kinetics of single phenolic acids, as well as the kinetics for competitive multi-compound adsorption, were fitted by applying different models, though Langmuir and pseudosecond order models fitted better the experimental results, respectively. The intraparticle diffusion model pointed out that mesoporosity reduces the influence of phenolic compounds' restrictions in the external film diffusion of the adsorbent particle-solution interphase, but adsorption capacity linearly increases with the micropore volume accessible to N-2 at -196 degrees C (and also with BET surface area), while diffusion into ultramicropores (<0.7 nm, determined by CO2-adsorption) is slow and presents minor influence on the total adsorption capacity. After saturation, thermal regeneration of spent adsorbents allows the removal of adsorbed products, enabling the reuse of samples whilst maintaining a significant performance.Portuguese Foundation for Science and Technology UIDB/00511/2020European Regional Development Funds (ERDF) through North Portugal Regional Operational Programme (NORTE 2020) NORTE-01-0247-FEDER-39789Project "HealthyWaters -Identification, Elimination, Social Awareness and Education of Water Chemical and Biological Micropollutants with Health and Environmental Implications" - NORTE 2020, under the PORTUGAL2020 Partnership Agreement NORTE-01-0145-FEDER-000069MCIN/AEI/FEDER "Una manera de hacer Europa" RTI2018-099224-B-I00Portuguese Foundation for Science and TechnologyEuropean Commission SFRH/BD/129235/2017National Fund through the Human Capital Operational Programme (POCH)European Social Fund through the Human Capital Operational Programme (POCH) MCIN/AEI RYC-2019-026634IEuropean Social Found (FSE) "El FSE invierte en tu futuro" RYC-2019-026634IUniversidad de Granada/CBU

    Expression of HLA-G in inflammatory bowel disease provides a potential way to distinguish between ulcerative colitis and Crohn's disease.

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    In addition to being involved in nutrient uptake, the epithelial mucosa constitute the first line of defense against microbial pathogens. A direct consequence of this physiological function is a very complex network of immunological interactions that lead to a strong control of the mucosal immune balance. The dysfunction of immunological tolerance is likely to be a cause of inflammatory bowel disease (IBD), ulcerative colitis (UC) and Crohn's disease (CD). HLA-G is a non-classical major histocompatibility complex (HLA) class I molecule, which is highly expressed by human cytotrophoblast cells. These cells play a role in immune tolerance by protecting trophoblasts from being killed by uterine NK cells. Because of the deregulation of immune system activity in IBD, as well as the immunoregulatory role of HLA-G, we have analyzed the expression of HLA-G in intestinal biopsies of patients with UC and CD. Our study shows that the differential expression of HLA-G provides a potential way to distinguish between UC and CD. Although the reason for this differential expression is unclear, it might involve a different mechanism of immune regulation. In addition, we demonstrate that in the lamina propria of the colon of patients with UC, IL-10 is strongly expressed. In conclusion, the presence of HLA-G on the surface of intestinal epithelial cell in patients with UC lends support to the notion that this molecule may serve as a regulator of mucosal immune responses to antigens of undefined origin. Thus, this different pattern of HLA-G expression may help to differentiate between the immunopathogenesis of CD and UC

    Cirugía de torus mandibular bilateral en mujer joven, Reporte de caso clínico.

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    Los torus o exóstosis orales son protuberancias óseas no patológicas que se observan en las superficies alveolares de los huesos de la mandíbula (Kumar Singh, A., et al. 2017). El torus mandibular es más raro y asienta por encima de la línea milohioidea, en los premolares; suele ser bilateral y simétrico (Donado, M., et al. 2013), Después de la exodoncia de los dientes inferiores y antes de la construcción de unas prótesis parciales o completas, puede que sea necesario extirpar los torus del maxilar inferior para facilitar la construcción de la prótesis (Hupp, R. J., et al. 2014)

    Formación y desarrollo de la competencia del docente como un proceso continuo de profesionalización: Modelo FoDeCD

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    The need to develop the competencies of educators during their formation is fundamental for their ultimate undertaking of academic responsibilities in a scientific and humanistic perspective. In order to be relevant in the XXI century, these competencies must advance through a continuous process of professionalization of teaching and a personological approach. In keeping with these principles, this paper proposes a model for the development of these competencies to integrate, in a dynamic way, investigation, and the professional, motivational and academic components. The proposed model conceives the teaching-learning process as a process of cooperation between educators and learners that encourages reflection, critical thinking and autonomy.La necesidad de desarrollar las competencias de los docentes en formación es un imperativo para que estos puedan asumir sus funciones académicas desde una posición científico-humanista. Para ser relevante en el siglo XXI, el desarrollo de competencias del docente debe ocurrir en un proceso continuo de profesionalización de la enseñanza y siguiendo un enfoque personológico. A tenor con estos principios, en este artículo se propone un modelo para el desarrollo de las competencias del docente en el que se integran, de forma dinámica, el componente investigativo, laboral, motivacional y académico. El modelo FoDeCD propuesto concibe la enseñanza-aprendizaje como un proceso de cooperación entre educadores y estudiantes que estimula en ellos la reflexión, el pensamiento crítico y la autonomía

    Advances in the phylogenetic study of the tribe Cinchoneae (Rubiaceae) with emphasis on the genus Cinchona and Ladenbergia

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    In its current circumscription, the Cinchoneae tribe includes 9 genera of neotropical distribution. Its species occur mostly in the Andes in South America, with few reaching Central America. Preliminary phylogenetic studies have suggested the monophyly of Cinchoneae but intrageneric relationships are still debatable. In this study, we sampled 8 genera of Cinchoneae (with ca 50% of species for Cinchona and Ladenbergia) and obtained multiple single-copy nuclear loci (ca 207 genes) by using the “Angiosperm353 universal probe set”, which was complemented with a taxonomic review of Cinchoneae. Phylogenetic inferences were realized with multispecies pseudo-coalescent (ASTRAL III) and gene concatenation analysis (ML). Our results strongly support the monophyly of the tribe and most of the genera, except for Ladenbergia. Furthermore, Ciliosemina, Ladenbergia, and Remijia formed a clade, although the position of Ciliosemina (= Remijia pedunculata) and Ladenbergia muzonensis is still elusive. The position of Ladenbergia muzonensis is intriguing due to its intermedíate floral morphology, which resembles both Remijia and Ladenbergia species. Additionally, our phylogeny also supports the recognition of a new species in Cinchona. Finally, our results show that sequencing data using the probe set designed for multiple gene capture is a useful tool for phylogenetic reconstructions in taxonomically complex groups

    Spatters and Spills: Spreading Dynamics for Partially Wetting Droplets

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    We present a solvable model inspired by dimensional analysis for the time-dependent spreading of droplets that partially wet a substrate, where the spreading eventually stops and the contact angle reaches a nonzero equilibrium value. We separately consider small droplets driven by capillarity and large droplets driven by gravity. To explore both regimes, we first measure the equilibrium radius vs a comprehensive range of droplet volumes for four household fluids, and we compare the results with predictions based on minimizing the sum of gravitational and interfacial energies. The agreement is good and gives a reliable measurement of an equilibrium contact angle that is consistent in both small and large droplet regimes. Next, we use energy considerations to develop equations of motion for the time dependence of the spreading, in both regimes, where the driving forces are balanced against viscous drag in the bulk of the droplet and by friction at the moving contact line. Our approach leads to explicit prediction of the functional form of the spreading dynamics. It successfully describes prior data for a small capillary-driven droplet, and it fits well to new data we obtain for large gravity-driven droplets with a wide range of volumes. While our prediction for the dynamics of small capillary-driven droplets assumes the case of thin nearly wetting droplets, with a small contact angle, this restriction is not otherwise invoked

    Spatters and Spills: Spreading Dynamics for Partially Wetting Droplets

    Get PDF
    We present a solvable model inspired by dimensional analysis for the time-dependent spreading of droplets that partially wet a substrate, where the spreading eventually stops and the contact angle reaches a nonzero equilibrium value. We separately consider small droplets driven by capillarity and large droplets driven by gravity. To explore both regimes, we first measure the equilibrium radius vs a comprehensive range of droplet volumes for four household fluids, and we compare the results with predictions based on minimizing the sum of gravitational and interfacial energies. The agreement is good and gives a reliable measurement of an equilibrium contact angle that is consistent in both small and large droplet regimes. Next, we use energy considerations to develop equations of motion for the time dependence of the spreading, in both regimes, where the driving forces are balanced against viscous drag in the bulk of the droplet and by friction at the moving contact line. Our approach leads to explicit prediction of the functional form of the spreading dynamics. It successfully describes prior data for a small capillary-driven droplet, and it fits well to new data we obtain for large gravity-driven droplets with a wide range of volumes. While our prediction for the dynamics of small capillary-driven droplets assumes the case of thin nearly wetting droplets, with a small contact angle, this restriction is not otherwise invoked
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