Universal Kinetic Model to Simulate Two-Step Biodiesel Production from Vegetable Oil

To date, to simulate biodiesel production, kinetic models from different authors have been provided, each one usually applied to the use of a specific vegetable oil and experimental conditions. Models, which may include esterification, besides transesterification simulation, were validated with their own experimental conditions and raw material. Moreover, information about the intermediate reaction steps, besides catalyst concentration variation, is either rare or nonexistent. Here, in this work, a universal mathematical model comprising the chemical kinetics of a two-step (esterification and transesterification) vegetable oil-based biodiesel reaction is proposed. The proposed model is universal, as it may simulate any vegetable oil biodiesel reaction from the literature. For this purpose, a mathematical model using the software MATLAB has been designed. Using the mathematical model, the estimation of mass variation with time, of both reactants and products, as well as glyceride conversion and homogeneous catalyst concentration variation (instead of only alcohol/catalyst solution) are allowed. Moreover, analysis of the influence of some important variables affecting the reaction kinetics of biodiesel production (e.g., catalyst concentration), along with comparison and model validation with data from different authors may be carried out. In addition, Supplementary material with a collection of 290 rate constants, derived from 55 different experiments using different vegetable oils and conditions is provided

Compatibility studies between an indirect injection diesel injector and biodiesel with different composition: Stationary tests

Compatibility between automotive materials and biodiesel is key for engine manufacturers, since failures occur in the medium term and may significantly reduce engine useful life. There are only few studies about compatibility between biodiesel and pure materials, but all agree there is biodiesel degradation and material corrosion beyond desirable values. This manuscript shows results about the compatibility behavior of an indirect injection diesel engine injector, with different types of biodiesel (from rapeseed, soybean, coconut and palm oil). Tests were carried out by static immersion of actual injector parts inside biodiesel, at room temperature, during 1100 h. To analyze elemental composition of each injector part and potential compatibility problems, scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) were used. Visual variations were detected in both biodiesel and metals, showing the need of a further quantification of both piece mass loss and biodiesel acid value increase. Metallic oxides on the surface were detected by X-ray photoelectron spectroscopy (XPS). After immersion tests, mass variation in alloying elements of each piece (behaving differently depending on their composition), besides biodiesel acid value differences, were found. In this sense, pieces with aluminum alloys showed the highest corrosion (mass loss) compared to those without aluminum in their structure, no matter the unsaturation degree and chain length of biodiesel. In sum, there were not conclusive results about the influence of biodiesel composition over injector materials. However, it was found that European biodiesel standard EN 14214 should include other parameters than just copper band corrosion, to determine material deterioration, provided that aluminum alloys and other metals react with biodiesel

Genetic Landscape of Nonobstructive Azoospermia and New Perspectives for the Clinic

We thank Alejandro Fernández Sevilla for his valuable help in the development of Figure 2 of this review. The authors were funded by the Spanish Ministry of Economy and Competitiveness through the Spanish National Plan for Scientific and Technical Research and Innovation (ref. SAF2016-78722-R) and the “Ramón y Cajal” program (ref. RYC-2014-16458).Nonobstructive azoospermia (NOA) represents the most severe expression of male infertility, involving around 1% of the male population and 10% of infertile men. This condition is characterised by the inability of the testis to produce sperm cells, and it is considered to have an important genetic component. During the last two decades, di erent genetic anomalies, including microdeletions of the Y chromosome, karyotype defects, and missense mutations in genes involved in the reproductive function, have been described as the primary cause of NOA in many infertile men. However, these alterations only explain around 25% of azoospermic cases, with the remaining patients showing an idiopathic origin. Recent studies clearly suggest that the so-called idiopathic NOA has a complex aetiology with a polygenic inheritance, which may alter the spermatogenic process. Although we are far from a complete understanding of the molecular mechanisms underlying NOA, the use of the new technologies for genetic analysis has enabled a considerable increase in knowledge during the last years. In this review, we will provide a comprehensive and updated overview of the genetic basis of NOA, with a special focus on the possible application of the recent insights in clinical practice.Funded by the Spanish Ministry of Economy and Competitiveness through the Spanish National Plan for Scientific and Technical Research and Innovation (ref. SAF2016-78722-R) and the “Ramón y Cajal” program (ref. RYC-2014-16458)

Señalización de seguridad y salud a través del humor de los Simpson

La familia Simpson hizo su primera aparición en 1987, en una serie creada por Matt Groening para la televisión americana, que ha tenido una difusión muy amplia alrededor de los cinco continentes, tanto en la pequeña y gran pantalla, como en otros soportes utilizados habitualmente por el marketing. Lo curioso es que las situaciones más divertidas que se producen tienen que ver con la seguridad laboral y familiar de todos los personajes. El propio autor de la serie creó 47 imágenes para dar a conocer algunas de las situaciones de riesgo, así como sus posibles consecuencias. A través de los diferentes personajes, se nos muestran los riesgos de un esfuerzo inadecuado, de un puesto no adaptado al trabajador, un incorrecto etiquetaje de productos químicos, distracciones, primeros auxilios, emergencias, espacios confinados, caídas, lesiones, uso de EPIs, riesgo eléctrico, formación en PRL, entre otras muchas situaciones relacionadas con la Seguridad y Salud Laboral. La prevención de riesgos laborales es un tema “serio” que afecta directamente al trabajador y su formación debe ser asimilada de la forma más asequible posible. La información aportada a base de humor resulta más fácil de captar y de retener. El objetivo general de esta comunicación es analizar la influencia que puede tener en los trabajadores la señalización en materia de seguridad y salud, a través del humor de la familia Simpson. Estudiando el caso concreto de una empresa del sector de la metalurgia, relacionada con la fabricación, suministro y mantenimiento de maquinaria de construcción. Encontramos estudios realizados en los que el humor ha sido usado en formación académica en alumnado de edades muy variadas, habiendo obtenido en la mayoría de los casos resultados positivos. No obstante, la disposición de un trabajador que considera su lugar de trabajo como algo serio y donde no es lo habitual recibir la información en clave de humor, no es la misma que la del alumnado dispuesto a recibir la formación en novedosos formatos, al intentar por parte del docente que su asimilación sea lo más asequible posible. La metodología empleada ha consistido en el diseño de seis modelos distintos de carteles de señalización de Seguridad y Salud obtenidos de la integración de los pictogramas establecidos por la normativa vigente y los carteles elaborados por el autor de la serie televisiva de la familia Simpson. Estos carteles se han expuesto en las instalaciones de la empresa colaboradora y con los cuestionarios que nos han facilitado sus trabajadores al final del proceso, hemos podido analizar los datos obtenidos a través del programa estadístico informático SPSS, realizando un análisis bivariado mediante tablas de contingencia de Chi-cuadrado de Pearson con el que se ha determinado la dependencia entre las variables categóricas de las que disponemos y su grado de significatividad

Sertoli cell-specific ablation of miR-17-92 cluster significantly alters whole testis transcriptome without apparent phenotypic effects

MicroRNAs are frequently organized into polycistronic clusters whose transcription is controlled by a single promoter. The miR-17-92 cluster is expressed in most embryonic and postnatal organs. It is a potent oncogene associated to several types of cancer and it is involved in several important developmental processes. In the testis, expression of the miR- 17-92 cluster in the germ cells is necessary to maintain normal spermatogenesis. This cluster is also expressed in Sertoli cells (the somatic cells of the seminiferous tubules), which require miRNAs for correct cell development and survival. To study the possible role of miR- 17-92 in Sertoli cell development and function and, in order to overcome the postnatal lethality of miR-17-92-/ mice, we conditionally deleted it in embryonic Sertoli cells shortly after the sex determination stage using an Amh-Cre allele. Mutant mice developed apparently normal testes and were fertile, but their testis transcriptomes contained hundreds of moderately deregulated genes, indicating that testis homeostasis is tightly controlled in mammals and that miR-17-92 expression in Sertoli cells contribute to maintain normal gene expression levels, but is unnecessary for testis development and function. Our results show that significant deregulation of hundreds of genes might have no functional consequences.This work was supported by grants from the Andalusian Government, Junta de Andalucía, BIO-109 to R. Jiménez and P11-CVI-7291 to M. Burgos and grants from the Spanish Ministry of Science and Innovation (CGL2011-23368 and CGL2015-67108-P) to R. Jiménez and F.J. Barrionuevo. The authors would like to thank the Spanish Ministry of Science and Innovation for the 'Ramón y Cajal' fellowship granted to F.D. Carmona (RYC-2014-16458) and the 'FPU' PhD fellowship granted to A. Hurtado

Influence of Dynamic Balance on Jumping-Based Asymmetries in Team Sport: A between-Sports Comparison in Basketball and Handball Athletes

The aims of the present study were to analyze mobility, dynamic balance and lower-limb strength and the prevalence of asymmetry according to the type of sport and assess the association between inter-limb asymmetry and sports performance. A total of 23 basketball and 25 handball players performed a test battery consisting of functional movements and a jump test. Inter-limb asymmetry was calculated using a standard percentage difference equation. A between-groups comparison analysis was carried out, and Pearson’s correlation coefficients (r) were calculated to establish a relationship between asymmetries and physical performance. The results found athletes in different sports to exhibit different performance in functional movements and the jump test, but no bilateral asymmetries. The reactive strength index (RSI) and stiffness asymmetries were significantly associated with the anterior reach Y-balance test (YBT) (r = -0.412; p < 0.01 and r = -0.359; p < 0.05, respectively), and the unilateral triple hop test (THTU) was negatively correlated to anterior reach, posterior lateral reach YBT and YBT composite YBT (r = -0.341 to -0.377; p < 0.05). These findings suggest that the asymmetries exhibited important dispersion not dependent upon the type of sport but on each individual and the applied test. In addition, asymmetry in anterior direction YBT showed the strongest association to the rest of the sports performance variables

Experimental and simulated study of 3D-printed couplings’ suitability for industrial application

This paper explores the possibility of applying reverse engineering to flexible coupling spare parts through additive manufacturing. Although couplings’ simplicity makes them go unnoticed, they connect elements that transmit power between two shafts, thus being an essential component for most of the machinery currently used in the industry. In this study, flexible couplings with different infill density (60% and 80%) were 3D printed by the fused filament fabrication technique. The original and the additive manufactured couplings were modelled to compare their compressive response and energy-absorbing characteristics, and experimental tests were performed to validate finite element analysis. To derive an optimal material distribution within coupling structure, a generative design approach was conducted through nTopology software. With this novel simulation-driven design, it is possible to reduce the weight of the redesigned part up to 15.8% by defining the wall thickness of the internal structure based on the results of finite element simulation, while maintaining its functionality. Moreover, an economic-environmental study was carried out. Results ensure that the 3D printed prototypes are suitable for replacing the original one under its current operating conditions. Additionally, the economic study shows that the redesigned couplings allow companies to save more than €2700 per coupling in relation to CO2 emission payments

Association of rhinitis with asthma prevalence and severity

Asthma; Comorbidities; Risk factorsAsma; Comorbilitats; Factors de riscAsma; Comorbilidades; Factores de riesgoAsthma and rhinitis often co-exist in the same patient. Although some authors observed a higher prevalence and/or greater severity of asthma in patients with rhinitis, this view is not homogeneous and the debate continues. The aim of our study is to describe the prevalence of rhinitis in children and adolescents and to analyse their relationship with the prevalence of asthma. A multicentre study was conducted using the methodology of the International Study of Asthma and Allergies in Childhood (ISAAC). The target population of the study was all those school children aged 6–7 and 13–14 years from 6 of the main health catchment areas of Galicia (1.9 million inhabitants). The schools required were randomly selected, and all children in the targeted age ranges were included. Multiple logistic regression was used to obtain adjusted prevalence odds ratios (OR) between asthma symptoms of the schoolchildren and rhinitis prevalence. The results were adjusted for parental smoking habits, maternal education level, cat and dog exposure, and obesity. A total of 21,420 valid questionnaires were finally obtained. Rhinitis was associated with a significant increase in the prevalence of asthma in both age groups. The highest OR were 11.375 for exercise induced asthma (EIA) for children with recent rhinoconjunctivitis and 9.807 for children with recent rhinitis in 6–7 years old group. The prevalence OR’s are higher in EIA and severe asthmatics. Rhinitis in children and adolescents is associated with a higher prevalence and severity of asthma.This work was funded by the Maria Jose Jove Foundation

Organosolv pulping of olive tree trimmings by use of ethylene glycol/soda/water mixtures

This paper reports on the influence of independent variables in the ethylene glycol/soda pulping of olive wood trimmings (165–1958C, 30–90 min, ethylene glycol concentration 5–15%, soda concentration 2.5–7.5% and liquid/ solid ratio 4–6), on the yield and Kappa index of the pulps and the strength properties (breaking length, burst index and tear index) of paper sheets. By using a central composite factorial design, equations that relate each dependent variable to the different independent variables were obtained which reproduced the experimental results for the dependent variables with errors less than 12%. Using a temperature of 1848C, ethylene glycol and soda concentrations of 15% and 7%, respectively, a liquid/solid ratio of 5:1 and a cooking time of 30 min results in yield, Kappa index, breaking length, burst index and tear index values that depart by 14.3%, 8.2%, 17.1%, 17.0% and 2.3%, respectively, from their optimum levels. These conditions result in substantial savings in power consumption and immobilised capital investments as they involve a lower temperature, a lower liquid/solid ratio, and a shorter time than the maximum values tested

Short-Peptide Supramolecular Hydrogels for In Situ Growth of Metal–Organic Framework-Peptide Biocomposites

The development of bio-MOFs or MOF biocomposites through the combination of MOFs with biopolymers offers the possibility of expanding the potential applications of MOFs, making use of more environmentally benign processes and reagents and giving rise to a new generation of greener and more bio-oriented composite materials. Now, with the increasing use of MOFs for biotechnological applications, the development of new protocols and materials to obtain novel bio-MOFs compatible with biomedical or biotechnological uses is needed. Herein, and as a proof of concept, we have explored the possibility of using short-peptide supramolecular hydrogels as media to promote the growth of MOF particles, giving rise to a new family of bio-MOFs. Short-peptide supramolecular hydrogels are very versatile materials that have shown excellent in vitro and in vivo biomedical applications such as tissue engineering and drug delivery vehicles, among others. These peptides self-assemble by noncovalent interactions, and, as such, these hydrogels are easily reversible, being more biocompatible and biodegradable. These peptides can self-assemble by a multitude of stimuli, such as changes in pH, temperature, solvent, adding salts, enzymatic activity, and so forth. In this work, we have taken advantage of this ability to promote peptide self-assembly with some of the components required to form MOF particles, giving rise to more homogeneous and well-integrated composite materials. Hydrogel formation has been triggered using Zn2+ salts, required to form ZIF-8, and formic acid, required to form MOF-808. Two different protocols for the in situ MOF growth have been developed. Finally, the MOF-808 composite hydrogel has been tested for the decontamination of water polluted with phosphate ions as well as for the catalytic degradation of toxic organophosphate methyl paraoxon in an unbuffered solution.Grants PID2020-118498GB-I00PID2020-113608RB-I00MCIN/AEI/10.13039/ 501100011033,Projects P18-FR-3533 and A-FQM-340-UGR20 by FEDER/Junta de Andaluci ́ a-Consejería de Transformación Económica, Industria, Conocimiento y Universidades (Spain)PPJIA2021.20 by Universidad de GranadaMarie Skłodowska-Curie Individual Fellowship (H2020-MSCA-IF-2019-EF-ST-888972-PSustMOF)European Union H2020 programme and EU FEDERGrant PRE2018-083773MCIN/ AEI/10.13039/501100011033ESF Investing in your future”, Spain