Evaluation of artificial neural network algorithms for predicting the effect of the urine flow rate on the power performance of microbial fuel cells

© 2020 The Authors Microbial fuel cell (MFC) power performance strongly depends on the biofilm growth, which in turn is affected by the feed flow rate. In this work, an artificial neural network (ANN) approach has been used to simulate the effect of the flow rate on the power output by ceramic MFCs fed with neat human urine. To this aim, three different second-order algorithms were used to train our network and then compared in terms of prediction accuracy and convergence time: Quasi-Newton, Levenberg-Marquardt, and Conjugate Gradient. The results showed that the three training algorithms were able to accurately simulate power production. Amongst all of them, the Levenberg-Marquardt was the one that presented the highest accuracy (R = 95%) and the fastest convergence (7.8 s). These results show that ANNs are useful and reliable tools for predicting energy harvesting from ceramic-MFCs under changeable flow rate conditions, which will facilitate the practical deployment of this technology

Modelling the energy harvesting from ceramic-based microbial fuel cells by using a fuzzy logic approach

© 2019 The Author(s) Microbial fuel cells (MFCs) is a promising technology that is able to simultaneously produce bioenergy and treat wastewater. Their potential large-scale application is still limited by the need of optimising their power density. The aim of this study is to simulate the absolute power output by ceramic-based MFCs fed with human urine by using a fuzzy inference system in order to maximise the energy harvesting. For this purpose, membrane thickness, anode area and external resistance, were varied by running a 27-parameter combination in triplicate with a total number of 81 assays performed. Performance indices such as R2 and variance account for (VAF) were employed in order to compare the accuracy of the fuzzy inference system designed with that obtained by using nonlinear multivariable regression. R2 and VAF were calculated as 94.85% and 94.41% for the fuzzy inference system and 79.72% and 65.19% for the nonlinear multivariable regression model, respectively. As a result, these indices revealed that the prediction of the absolute power output by ceramic-based MFCs of the fuzzy-based systems is more reliable than the nonlinear multivariable regression approach. The analysis of the response surface obtained by the fuzzy inference system determines that the maximum absolute power output by the air-breathing set-up studied is 450 μW when the anode area ranged from 160 to 200 cm2, the external loading is approximately 900 Ω and a membrane thickness of 1.6 mm, taking into account that the results also confirm that the latter parameter does not show a significant effect on the power output in the range of values studied

Aplicación de nanotubos de Ti/TiO2 en pilas de combustible microbianas

[ESP] En este trabajo se han elaborado y caracterizado electrodos formados por nanotubos de Ti/TiO2 (TiNT) para su posterior uso como material catódico en pilas de combustible microbianas (MFCs). Su evaluación se llevó a cabo en sistemas de doble cámara separados por una membrana intercambiadora de protones basada en el líquido iónico cloruro de metiltrioctil amonio. El proceso se llevó a cabo en discontinuo, a 25ºC y como sustrato se usó agua residual de base oleica con una carga orgánica de 400mg.L-1. La eficiencia de los materiales desarrollados se midió en términos de eliminación de demanda química de oxígeno (CODR 70%) y potencia generada (12.13mW.m-3). [ENG] In this work, Ti/TiO2 nanotubes (TiNT) electrodes were prepared, characterized and applied as cathode electrodes in double chamber microbial fuel cells (MFCs). The anode used was carbon rod/graphite granules and the separator was a homogeneous proton exchange membrane based on methyltrioctylammonium chloride. Industrial wastewater from a production factory of paraffin oil with a chemical oxygen demand initial value of 400mg.L-1(COD) was used as substrate. The analysis was performed in batch mode at 25°C and the efficiency of the microbial fuel cells was assessed in terms of soluble organic matter removal (70%) and capability of power generation (12.13mW.m-3).Centro Universitario de la Defensa. Escuela de Turismo de Cartagena. Escuela Técnica Superior de Ingeniería Industrial UPCT. Escuela Técnica Superior de Ingeniería de Telecomunicación (ETSIT). Escuela de Ingeniería de Caminos y Minas (EICM). Escuela de Arquitectura e Ingeniería de Edificación (ARQ&IDE). Parque Tecnológico de Fuente Álamo. Navantia. Campus Mare Nostrum. Estación Experimental Agroalimentaria Tomás Ferr

Understanding the interplay of carbon and nitrogen supply for ectoines production and metabolic overflow in high density cultures of Chromohalobacter salexigens

Background The halophilic bacterium Chromohalobacter salexigens has been proposed as promising cell factory for the production of the compatible solutes ectoine and hydroxyectoine. This bacterium has evolved metabolic adaptations to efficiently grow under high salt concentrations by accumulating ectoines as compatible solutes. However, metabolic overflow, which is a major drawback for the efficient conversion of biological feedstocks, occurs as a result of metabolic unbalances during growth and ectoines production. Optimal production of ectoines is conditioned by the interplay of carbon and nitrogen metabolisms. In this work, we set out to determine how nitrogen supply affects the production of ectoines. Results Chromohalobacter salexigens was challenged to grow in media with unbalanced carbon/nitrogen ratio. In C. salexigens, overflow metabolism and ectoines production are a function of medium composition. At low ammonium conditions, the growth rate decreased importantly, up to 80%. Shifts in overflow metabolism were observed when changing the C/N ratio in the culture medium. 13C-NMR analysis of ectoines labelling revealed a high metabolic rigidity, with almost constant flux ratios in all conditions assayed. Unbalanced C/N ratio led to pyruvate accumulation, especially upon N-limitation. Analysis of an ect − mutant demonstrated the link between metabolic overflow and ectoine biosynthesis. Under non ectoine synthesizing conditions, glucose uptake and metabolic overflow decreased importantly. Finally, in fed-batch cultures, biomass yield was affected by the feeding scheme chosen. High growth (up to 42.4 g L−1) and volumetric ectoine yields (up to 4.21 g L−1) were obtained by minimizing metabolite overflow and nutrient accumulation in high density cultures in a low nitrogen fed-batch culture. Moreover, the yield coefficient calculated for the transformation of glucose into biomass was 30% higher in fed-batch than in the batch culture, demonstrating that the metabolic efficiency of C. salexigens can be improved by careful design of culture feeding schemes. Conclusions Metabolic shifts observed at low ammonium concentrations were explained by a shift in the energy required for nitrogen assimilation. Carbon-limited fed-batch cultures with reduced ammonium supply were the best conditions for cultivation of C. salexigens, supporting high density growth and maintaining high ectoines production.España, Ministerio de Ciencia e Innovación BIO2011-29233-C02-01España, Ministerio de Economía y Competitividad BIO2014-54411-C2-1-

Evaluation of Ionic Liquids as In Situ Extraction Agents during the Alcoholic Fermentation of Carob Pod Extracts

Anhydrous ethanol is a promising alternative to gasoline in fuel engines. However, since ethanol forms an azeotrope with water, high-energy-consumption separation techniques such as azeotropic distillation, extractive distillation, and molecular sieves are needed to produce anhydrous ethanol. This work discusses the potential development of an integrated process for bioethanol production using ionic liquids and Ceratonia siliqua as a carbohydrate source for further fermentation of the aqueous extracts. A four-stage counter-current system was designed to improve the sugar extraction yield to values close to 99%. The alcoholic fermentation of the extracts showed ethanol concentrations of 95 g/L using the microorganism Saccharomyces cerevisae. The production of anhydrous ethanol through extractive distillation with ethylene glycol was simulated using CHEMCAD software, with an energy consumption of 13.23 MJ/Kg of anhydrous ethanol. Finally, several ionic liquids were analyzed and are proposed as potential solvents for the recovery of bioethanol for the design of an integrated extraction-fermentation-separation process, according to their ability to extract ethanol from aqueous solutions and their biocompatibility with the microorganism used in this study.This research was funded by the Fundación Séneca, grant number 20957/PI/18 and The Ministry of Economy and Competitiveness (MINECO) grant number RTI2018-099011-B-I00

Deep eutectic solvents for the extraction of fatty acids from microalgae biomass: Recovery of omega-3 eicosapentaenoic acid

Microalgae are a vast group of autotrophic microorganisms whose metabolic diversity makes them a natural source of valuable organic compounds such as lipids, carbohydrates, proteins, vitamins, and bioactive molecules. Several microalgae species contain notable amounts of polyunsaturated fatty acids, particularly eicosapentaenoic acid (EPA), which is an important alpha-linolenic acid derivative for human health. Conventional methods are considered effective at recovering total lipids from microalgae, however, they imply the use of large volumes of organic solvents such as methanol and chloroform, which are toxic and pose environmental risks. Thus, it is necessary to find new methods involving sustainable and green extracting phases. Deep eutectic solvents (DES) are renewable compounds often formed, but not exclusively, by quaternary ammonium salts and non-hydrated metal halides. Due to their availability, low cost, biodegradability, and environmental friendliness, DES are a promising alternative to organic solvents in extraction processes. This work assesses the efficiency of several DES phases for the extraction of fatty acids from the microalgae Nannochloropsis gaditana with a special interest in the recovery of EPA. The tested phases include mixtures containing choline chloride, lactic acid, ethylene glycol, and sodium acetate. Their performances were compared to those provided by conventional methods based on the use of organic solvents. Specifically, an in-situ transesterification process based on methanol with 10 %v/v of HCl was optimized in terms of temperature, time, and catalyst amount to be used as a reference. The results show that several of the tested eutectics such as choline chloride-ethylene glycol were capable of matching and even outperforming the best results obtained for EPA, with 104 % of extracted EPA methyl ester as the percentage of the mass obtained with HCl-methanol. The extraction capacity of DES was also improved by microalgae biomass pretreatment using ultrasonic and NaCl-based methods in a further stage. In the case of EPA extraction, and under optimal conditions, DES were capable of recovering over 18 % more quantity than the obtained with HCl-methanol. These results demonstrate that DES are effective at both recovering total fatty acids from pretreated biomass and at selectively recovering EPA using both unpretreated and pretreated biomass.The authors wish to acknowledge the financial support of the Ministry of Science, Innovation, and Universities (MICINN) ref. RTI2018-099011-B-I00 and the Seneca Foundation Science and Technology Agency of the Region of Murcia ref. 20957/PI/18. Dr. Sergio Sánchez Segado wishes to acknowledge The Ministry of Science, Innovation, and Universities of Spain its support through the “Beatriz Galindo” Fellowship BEAGAL18/00079

Estudio comparativo de la producción de biodiesel a partir de aceite de jatropha y karanja en metanol supercrítico

[ESP] El biodiesel es un combustible renovable que sirve de alternativa a los combustibles fósiles. Este trabajo ofrece un estudio comparativo de producción de biodiesel a partir de dos tipos de aceite no comestibles, jatropha y karanja, en un proceso en una sola etapa en metanol supercrítico y sin catalizador. Los resultados muestran que mientras es posible obtener un rendimiento a FAMEs superior al 99 % a 325 ºC a partir de aceite de jatropha, el rendimiento máximo a partir de karanja es inferior al 82 %, siendo estas diferencias atribuibles a la composición de ambos tipos de aceite. [ENG] Biodiesel is a renewable fuel that represents a real alternative to fossil fuels. The present work offers a comparative study of biodiesel production from two types of non-edible oil, jatropha and karanja, in a one-step batch process in supercritical methanol and in the absence of catalyst. The results show that a maximum FAME yield of over 99 % is achieved at 325 ºC when jatropha is used as oil source, while karanja oil poses some limitations with a maximum FAME yield of below 82 %. These differences can be explained by the composition of the oils used

Análisis del efecto de la temperatura en el biodiesel de segunda generación producido a partir de aceite de Jatropha curcas L.

[ESP] El agotamiento de los combustibles fósiles ha favorecido el desarrollo de nuevos métodos para la producción de energías renovables. En este trabajo se ha estudiado la descomposición térmica del biodiesel producido a partir de aceite no comestible de jatropha en metanol supercrítico. Los resultados obtenidos muestran que la descomposición térmica apareció a 350 ºC y 15 min, siendo máxima (24.16 %) a 350 ºC y 90 min. Además, se observó que las cadenas de ácido graso afectadas por la temperatura fueron las de tipo oleico y linoleico. Finalmente, se realizó una regresión lineal que permitió obtener una ecuación para predecir el efecto de la temperatura en el biodiesel producido. [ENG] The depletion of fossil fuels has encouraged the development of new methods for the production of renewable energies. In this work, the thermal decomposition of the biodiesel produced from non-edible jatropha oil in supercritical methanol was investigated. The results obtained show that thermal decomposition appeared at operating conditions of 350 ºC and 15 min, being maximum (24.16 %) at 350 ºC and 90 min. Moreover, it was observed that the fatty acid chains affected by temperature were those of oleic and linoleic acid type. Finally, a linear regression analysis was made, leading to a model that predicts the effect of the temperature on the biodiesel produced.Escuela Técnica Superior de Ingeniería de Telecomunicación (ETSIT), Escuela Técnica Superior de Ingeniería Agronómica (ETSIA), Escuela Técnica Superior de Ingeniería Industrial (ETSII), Escuela Técnica Superior de Arquitectura y Edificación (ETSAE), Escuela Técnica Superior de Ingeniería de Caminos, Canales y Puertos y de Ingeniería de Minas (ETSICCPIM), Facultad de Ciencias de la Empresa (FCCE), Parque Tecnológico de Fuente Álamo (PTFA), Vicerrectorado de Estudiantes y Extensión de la UPCT, Vicerrectorado de Investigación e Innovación de la UPCT, y Vicerrectorado de Internacionalización y Cooperación al Desarrollo de la UPCT

First line treatment with rituximab-Hyper-CVAD alternating with rituximab-Methotrexate-Cytarabine and followed by consolidation with 90Y-Ibritumomab-Tiuxetan in patients with mantle cell lymphoma. Results of a phase 2 pilot multicenter trial from the GELT

D. First line treatment with rituximab-Hyper-CVAD alternating with rituximab-Methotrexate-Cytarabine and followed by consolidation with 90Y-Ibritumomab-Tiuxetan in patients with mantle cell lymphoma. Results of a phase 2 pilot multicenter trial from th

Best Treatment Option for Patients With Refractory Aggressive B-Cell Lymphoma in the CAR-T Cell Era: Real-World Evidence From GELTAMO/GETH Spanish Groups

Real-world evidence comparing the efficacy of chimeric antigen receptor (CAR) T-cell therapy against that of the previous standard of care (SOC) for refractory large B-cell lymphoma (LBCL) is scarce. We retrospectively collected data from patients with LBCL according to SCHOLAR-1 criteria treated with commercial CAR T-cell therapy in Spain (204 patients included and 192 treated, 101 with axicabtagene ciloleucel [axi-cel], and 91 with tisagenlecleucel [tisa-cel]) and compared the results with a historical refractory population of patients (n = 81) obtained from the GELTAMO-IPI study. We observed superior efficacy for CAR-T therapy (for both axi-cel and tisa-cel) over pSOC, with longer progression-free survival (PFS) (median of 5.6 vs. 4-6 months, p <= 0.001) and overall survival (OS) (median of 15 vs. 8 months, p < 0.001), independently of other prognostic factors (HR: 0.59 (95% CI: 0.44-0.80); p < 0.001] for PFS, and 0.45 [(95% CI: 0.31-0.64)] for OS). Within the CAR-T cohort, axi-cel showed longer PFS (median of 7.3 versus 2.8 months, respectively, p = 0.027) and OS (58% versus 42% at 12 months, respectively, p = 0.048) than tisa-cel. These differences were maintained in the multivariable analysis. On the other hand, axi-cel was independently associated with a higher risk of severe cytokine release syndrome and neurotoxicity. Our results suggest that the efficacy of CAR-T cell therapy is superior to pSOC in the real-world setting. Furthermore, axi-cel could be superior in efficacy to tisa-cel, although more toxic, in this group of refractory patients according to SCHOLAR-1 criteria