Ingeniería Química: Un espacio de integración y encuentro entre disciplinas

La Ingeniería Química, cuyo contenido es: concebir, calcular, diseñar, hacer construir y hacer funcionar las instalaciones donde efectuar a escala industrial transformaciones químicas y/o físicoquímicas para convertir materias primas en productos destinados al consumo de la sociedad, vive un momento particularmente interesante y complejo de su desarrollo caracterizado por profundos cambios tanto en la forma de diseñar nuevos procesos, como en la forma de realizar los cálculos que necesita esos desarrollos y, finalmente, en la manera de formar nuevos ingenieros. Una reconstrucción epistemológica de su desarrollo permite una compresión más clara de este momento y, sobre esta base, adoptar una posición constructiva en cualquiera de las direcciones antes planteadas. El presente trabajo está orientado en esa dirección y se interesa, en particular, por las consecuencias que este fenómeno tiene en materia educativ

New computational tools for chemical kinetics: the Cathedral Package

The advent of recent technological developments in software engineering has enabled the exploration of reaction mechanisms inside intricate reaction networks, thereby propelling the beginning of a new era in ab initio kinetics. While it is feasible to consider a substantial number of reactions, determining their rate constants with precision remains an arduous task, even for gas-phase processes. The difficulties are attributed not only to the inherent limitations in the calculation methodology but also to the manual labor and extensive chemical dynamics required, rendering these calculations inaccessible to the general public. As such, there is a pressing need for the development of automated codes and user-friendly interfaces to address this limitation. The present work focuses on the introduction of the Cathedral package, a unified computational code comprising the Q2DTor, TorsiFlex, and Pilgrim programs. This package serves to bridge the gap between theoretical studies in chemical kinetics and non-specialist users, making it more accessible and user-friendlyThe authors thank “Centro de Supercomputación de Galicia” (CESGA) for the use of their computational facilities. This work was partially supported by the Consellería de Cultura, Educación e Ordenación Universitaria (Centro singular de investigación de Galicia acreditación 2019-2022, ED431G 2019/03 and Grupo de referencia competitiva ED431C 2021/40) and the European Regional Development Fund (ERDF), and the Ministerio de Ciencia e Innovación through Grant PID2019-107307RB-I00. D.F.-C. thanks Xunta de Galicia for fnancial support through a postdoctoral grantS

A Combined Systematic-Stochastic Algorithm for the Conformational Search in Flexible Acyclic Molecules

We propose an algorithm that is a combination of systematic variation of the torsions and Monte Carlo (or stochastic) search. It starts with a trial geometry in internal coordinates and with a set of preconditioned torsional angles, i.e., torsional angles at which minima are expected according to the chemical knowledge. Firstly, the optimization of those preconditioned geometries is carried out at a low electronic structure level, generating an initial set of conformers. Secondly, random points in the torsional space are generated outside the “area of influence” of the previously optimized minima (i.e., outside a hypercube about each minima). These random points are used to build the trial structure, which is optimized by an electronic structure software. The optimized structure may correspond to a new conformer (which would be stored) or to an already existing one. Initial torsional angles (and also final ones if a new conformer is found) are stored to prevent visiting the same region of the torsional space twice. The stochastic search can be repeated as many times as desired. Finally, the low-level geometries are recovered and used as the starting point for the high-level optimizations. The algorithm has been employed in the calculation of multi-structural quasi harmonic and multi-structural torsional anharmonic partition functions for a series of alcohols ranging from n-propanol to n-heptanol. It was also tested for the amino acid L-serineFinancial support from the Consellería de Cultura, Educación e Ordenación Universitaria (Axuda para Consolidación e Estructuración de unidades de investigación competitivas do Sistema Universitario de Galicia, Xunta de Galicia ED431C 2017/17 & Centro singular de investigación de Galicia acreditación 2016-2019, ED431G/09) and the European Regional Development Fund (ERDF) is gratefully acknowledgedS

Tratamiento artroscópico quirúrgico de la disfunción de la ATM: estudio clínico prospectivo randomizado de la eficacia de la infiltración con plasma rico en factores de crecimiento plaquetario

La patología de la articulación temporomandibular (ATM) es muy frecuente, presenta una elevada prevalencia de entre el 20-­‐40% de la población general. Se considera que de estos pacientes el 80-­‐90% padece un trastorno interno (TI) de la ATM, que se define como una pérdida de coordinación estática y funcional entre el cóndilo mandibular y el disco articular, normalmente asociado a cambios degenerativos. Afecta fundamentalmente a mujeres en una proporción 9:1 y en cuanto a la edad, es más frecuente entre los 18-­‐45 años. Se relaciona con diversos factores causales como la hiperactividad muscular, el bruxismo, las parafunciones, entre otros. Los principales signos clínicos son el dolor normalmente agravado por la función y la limitación en la apertura. El diagnóstico se realiza con una adecuada anamnesis, exploración física y se confirma mediante una RNM. Los TI tienen un carácter evolutivo y el tratamiento conservador es eficaz en el 90% de los casos, dejando un 10% de pacientes refractarios a este tratamiento que precisan de otros tratamientos como la artroscopia. Desde hace años se asocia al procedimiento de artroscopia la infiltración de algunos productos como el ácido hialurónico (AH) o más recientemente, el plasma rico en factores de crecimiento plaquetarios (PRGF). La artroscopia en si misma aporta una serie de beneficios relacionados con el lavado constante de los mediadores de la inflamación, la eliminación de las áreas de sinovitis y reposición discal. El AH es el elemento principal del líquido sinovial, jugando un papel esencial en el mantenimiento de las propiedades viscoelásticas de la matriz de cartílago. El PRGF es un conjunto de sustancias polipeptídicas procedentes de las plaquetas y se conoce que juegan un importante papel en la diferenciación celular y en los procesos de reparación y cicatrización tisular. El presente estudio analítico, descriptivo, prospectivo y randomizado iniciado en 2008 pretende evaluar la repercusión en cuanto al dolor y la limitación de la apertura de pacientes diagnosticados de un TI asociado a cambios degenerativos tras un tratamiento de artroscopia con infiltración de PRGF utilizando el mismo procedimiento e infiltración de AH como grupo control

Automation in the simulation of processes with Aspen HYSYS: An academic approach

Aspen HYSYS is a typical tool used in some Master in Chemical Engineering courses at the University of Castilla-La Mancha like “Analysis and Optimization of Chemical Processes” and “Dynamic of Process: Regulation of Chemical Plants.” Automation is the process of linking commercial software to third-parties applications built in EXCEL-Visual Basic for Applications. The capability of automation as a powerful tool for simulating unprecedented complex processes suggests that it could be a relevant background complement to the classical one offered by a university. In this sense, a seminar about automation based on the study of two cases: a refrigeration process and a production one taken from literature, has been proposed at the University of Castilla-La Mancha. The analysis of the survey performed for the subject evaluation resulted to be very positive. Students consider the methodology of the course and the potentiality of automation for developing their research and professional skills appropriately. However, more examples are required to better understand the automation concept and its potential application to other situations. Finally, they declare that the concept of automation requires a lot of expertise and deep knowledge of programming and the correct application of numerical methods for solving complex problem

Niveles de felicidad en estudiantes del instituto de educación superior Daniel Alcides Carrión, 2017

La presente investigación es de tipo descriptivo, con un diseño no experimental y de corte transeccional descriptivo. La cual tuvo como objetivo determinar los niveles de felicidad en los estudiantes del Instituto de Educación Superior Daniel Alcides Carrión; así como también los niveles de los factores que conforman esta variable, los cuales son: sentido positivo de la vida, satisfacción con la vida, realización personal y alegría de vivir. Se trabajó con una muestra no probabilística intencional de 73 estudiantes del turno noche de los ciclos cuarto, quinto y sexto de las carreras de farmacia, enfermería y fisioterapia y rehabilitación del instituto mencionado. El instrumento empleado fue la Escala de Felicidad de Lima de Alarcón. Los resultados de los niveles de felicidad mostraron que los porcentajes en conjunto de los niveles bajo y muy bajo dan un 52%, lo que significa que más de la mitad de la muestra se encuentra en un nivel de felicidad por debajo del nivel promedio. En cuanto a los factores que conforman esta variable, se halló que para el sentido positivo de la vida, los niveles bajo y muy bajo conjuntamente dan un 49%; para la satisfacción con la vida, en su conjunto los niveles bajo y muy bajo dan un 59%; en cuanto a la realización personal, los niveles bajo y muy bajo dan un 42%; y para la alegría de vivir, se encuentra que un 42% de la muestra se ubica en el nivel medio.The present research is descriptive, with a non-experimental and cross-sectional descriptive design. That sought to determine the levels of happiness in students of the Institute of Higher Education Daniel Alcides Carrión; as well as the levels of the factors that form this variable, which are: positive sense of the life, satisfaction with the life, personal realization and happiness of living. The sample was intentional not probabilistic of 73 students of night shifts from the fourth, fifth and sixth semestre of pharmacy, nursing and physiotherapy and rehabilitation careers of the mentioned institute. The results of happiness levels showed that the combined percentages of the low and very low levels give 52%, which means that moren that half of the sample is in a level of happiness below the average level. As for the factors that form this variable, it was found that for the positive sense of life, the low and very low levels give 49%; for satisfaction with the life, as a whole the low and very lows levels give 59%; in terms of personal realization, the low and very low levels give 42%; and for the happiness of living, it is found that 42% of the sample is located in the middle leve

Two-dimensional plasmons in the random impedance network model of disordered thin-film nanocomposites

Random impedance networks are widely used as a model to describe plasmon resonances in disordered metal-dielectric nanocomposites. In order to study thin films, two-dimensional networks are often used despite the fact that such networks correspond to a two-dimensional electrodynamics [J.P. Clerc et al, J. Phys. A 29, 4781 (1996)]. In the present work, we propose a model of two-dimensional systems with three-dimensional Coulomb interaction and show that this model is equivalent to a planar network with long-range capacitive connections between sites. In a case of a metal film, we get a known dispersion $\omega \propto \sqrt{k}$ of plane-wave two-dimensional plasmons. In the framework of the proposed model, we study the evolution of resonances with decreasing of metal filling factor. In the subcritical region with metal filling $p$ lower than the percolation threshold $p_c$, we observe a gap with Lifshitz tails in the spectral density of states (DOS). In the supercritical region $p>p_c$, the DOS demonstrates a crossover between plane-wave two-dimensional plasmons and resonances associated with small clusters.Comment: 8 pages, 3 figures, revtex; references adde

Multiscale conceptual design of a scalable and sustainable process to dissolve and regenerate keratin from chicken feathers

A multiscale strategy was used to conceptually design and economically analyze a scalable and sustainable process for dissolving and regenerating keratin from chicken feathers by using a sodium acetate-urea deep eutectic solvent as the reacting media. In this study, the recovery and recycling of the solvent were also considered. Moreover, molecular modeling of the solvent, keratin and its derivatives, property estimation of the corresponding mixtures, and simulation of the different process alternatives proposed, including the equipment sizing, estimation of energy needs, and economic analysis were presented. A quasi-planar cluster governed by H-bond interactions resulted in the most stable configuration of the deep eutectic solvent. Molecular models having molecular weights higher than 1.400 g/mol were created to represent the keratin species, where the most abundant amino acids in the feathers were included and conveniently ordered in the chain. Property estimations performed with the conductor-like screening model-real solvent succeeded in describing the main features of the interactions between the keratin derivatives and the solvents used. The process analysis performed on several alternatives showed that the process is technically and economically viable at the industrial scale, the costs being strongly dependent on the excess of both the solvent used to dissolve keratin and the water added for its regeneration. Several options to improve the process and reduce the costs are discussedEuropeanUnion’s Horizon 2020 Researchand Innovation program undergrant agreement 72326

Surgical treatment of benign parapharyngeal space tumours : presentation of two clinical cases and revision of the literature

Parapharyngeal space (PPS) tumours, most of them benign, account for some 0.5% of tumours of the head and neck. The importance of these tumours lies mainly in two aspects: on the one hand, the difficulty of early diagnosis, due to the lack of symptoms in the initial stages and, on the other, the extreme complications of performing surgery in the parapharyngeal region. This article discusses two clinical cases of parapharyngeal space tumours: a 45 year old man and a 60 year old woman. We revise the scientific literature and analyse the diagnostic and therapeutic procedures used, placing special emphasis on describing the different surgical approaches to the parapharyngeal space: transcervical, transcervical-transparotid, transpalatal or transoral, transmandibular and orbitozygomatic, all of which, used alone or combined with others, allow for complete resection of these tumours with minimum morbidity