Bifurcation Analysis of an Exothermic Biocatalytic Reaction System

This paper focuses on the bifurcation analysis of an exothermic biocatalytic reaction system (EBRS). The objectives of the study were to provide a detailed dynamical systems analysis of an exothermic biocatalytic reaction and examine the long-term behaviours of the system using the techniques from phase portraits and bifurcation analysis. We investigated the combined influences of the proportional control constant and dilution rate on the dynamics of the model. Phase portraits relating to distinct outcomes of EBRS were computed to investigate the existence of different attractors in this system and its stability. Under a fixed dilution rate and different values of proportional control constant, there were four distinct outcomes in our model, which were stable steady states, bistability of two stable steady states, bistability between stable steady states and limit cycle and stable limit cycles. A bifurcation analysis (of codimensions one and two) was performed to examine how the overall dynamics change as chemically relevant parameters were varied. We observed that when the values of proportional control constant were high, the system would achieve stable steady states regardless of how fast the dilution rate was. With lower magnitudes of proportional constant control, bistability occurred and the outcomes of this system depended on the initial conditions. Compared to higher dilution rates scenario, reactions that occurred at lower dilution rates provided higher reaction yields for this EBRS operation; it was also observed that both scenarios produced stable steady-state outcomes with different concentrations. In conclusion, the dynamical system analysis of the model improves our understanding of the EBRS under consideration and these insights may be beneficial for optimising operating conditions of this chemical system.

Comparative analysis of income trends and perceived value of squad of the highest turnover European football clubs (2010-2019)

The purpose was to analyse the income variation of the 13 top clubs of Deloitte Football Money League Report (2019) as well as the variation of the perceived value of their squad, obtained from the website www.transfermarkt.es during 9 seasons. Friedman's two-way analysis by ranges of selected samples and Wilcoxon W tests were used to measure the evolution and relation among the clubs’ income and perceived value of players. The income of clubs was deflected according to inflation (CPI: 2016) and market value was adjusted to a 20 players squad. Market value and income have a significant positive variation from one year to the next (p = .000). We found differences between both variables only in the last 2 years on the period analysed (2011-2019). Market value has suffered an increase higher than expected. This fact should make football managers reflect on how to control constant inflation in the transfer market.

A New Model for Constant Fuel Utilization and Constant Fuel Flow in Fuel Cells

This paper presents a new model of fuel cells for two different modes of operation: constant fuel utilization control (constant stoichiometry condition) and constant fuel flow control (constant flow rate condition). The model solves the long-standing problem of mixing reversible and irreversible potentials (equilibrium and non-equilibrium states) in the Nernst voltage expression. Specifically, a Nernstian gain term is introduced for the constant fuel utilization condition, and it is shown that the Nernstian gain is an irreversibility in the computation of the output voltage of the fuel cell. A Nernstian loss term accounts for an irreversibility for the constant fuel flow operation. Simulation results are presented. The model has been validated against experimental data from the literature.

Conceptual Model for Evaluation of the Quality of Outsourcing Services

Increasing the effectivenss of outsourcing processes in military structures is part of their creation and use. The broadly popular perception of enhancing the effectivenss of a process as a whole is to increase its capabilities in some of its directions in order to make it more effective and to reduce costs. This is the reason for the focus on increasing the effectivenss of the outsourcing processes used in the Bulgarian Armed Forces. They should be considered not only as a transfer of certain services, but also as a process of management, control, constant monitoring and coordination with the modern, dynamic market that needs permanent optimisation in order to increase the effectivenss. This article studies and analyses the possibilities of evaluating the effectivenss of an outsourcing service and compiling a conceptual model for quality assessment

Contaminantes emitidos por los hornos colmena en empresas Cerámicas del Municipio del Zulia, Norte de Santander a través de la modelización de concentraciones

El sector de la arcilla es referente en la industria del Norte de Santander, con 87 empresas legalmente establecidas y una participación del 12,8% de Producto Interno Bruto (PIB). Elaboran productos en arcilla, para el sector de la construcción; como tabletas, ladrillos, tejas, bloques, entre otros, comercializados nacional o internacionalmente. En el proceso productivo, los hornos colmena utilizados emiten contaminantes a la atmósfera a través de las chimeneas. El Ministerio de Ambiente, Vivienda y Desarrollo Territorial estableció normas y estándares de emisión admisibles de contaminantes a la atmósfera para este tipo de industrias, así como el seguimiento y controla las fuentes fijas contaminantes con periodicidad de un año o menos si los resultados lo ameritan. Estos análisis son costosos y los realizan laboratorios especializados ubicados fuera del departamento. Se considera implementar métodos alternativos de control, a través de la formulación de un modelo matemático que estime las concentraciones de contaminantes emitidos por estos hornos en la fabricación de productos cerámicos del sector del Zulia Norte de Santander. Desarrollando una investigación cuantitativa, basada en la identificación y cuantificación de variables incidentes en el proceso de cocción y el análisis estadístico de históricos de los estudios de evaluación de emisiones atmosféricas en fuentes fijas, para establecer patrones de comportamiento; que a su vez se puede convertir en una herramienta de seguimiento y control continuo de contaminantes de los procesos de cocción desarrollados; situación que apunta a un conocimiento pertinente de los procesos y responsabilidades ante los estamentos nacionales. Palabras clave: Contaminación, Chimenea, Emisiones, Hornos colmena, Isocinéticos, Modelos AbstractThe sector of the clay is regarding in the Industry of Norte de Santander, with 87 companies established legally establisheds and an involvement of the 12, 8% of gross internal product (PIB). This produced products in clay, for the sector of the construction; like tablets, bricks, tiles, blocks, among others, commercializes national or internationally. In the productive process, the hive ovens use to emit contaminating’s to the atmosphere through of the chimneys, the ministry of environment , home and territorial development this established regulations and standards of transmission admissible of contaminating to the atmosphere for this kind of industries, as well as the monitoring and control to the permanent sources contaminating with periodicity of one year or less if the results the merit .These analysis are expensive and the this makes laboratories specialized located out of the state. Is considers implement methods alternatives of control, through of the formulation of a model mathematical that respect to the gathering of contaminating emits for this ovens in the manufacturing of ceramics products of the sector of Zulia from Norte de Santander . Developing an investigation quantitative, this is based in the identification and quantification of variables incidental in the process of boiling and the analysis statistical of historical of the studies of evaluation of transmissions atmospherics in permanent sources, for establish patterns of performance; what at the same time is can transform in an analytic tool of monitoring and control constant of contaminating of the process of boiling develops; Situation that indicate to an knowledge relevant of the process and responsibilities facing the stratum nationals.Key words: Contamination, Chimney, Hive ovens, Isokinetic, Models, Oven. ResumoO setor da argila está em causa na Indústria do Norte de Santander, com 87 empresas estabelecidas legalmente estabelecidas e um envolvimento dos 12, 8% do produto interno bruto (PIB). Isso produzia produtos em argila, para o setor da construção; como tablets, tijolos, telhas, blocos, entre outros, comercializa nacional ou internacionalmente. No processo produtivo, os fornos das colméias costumam emitir contaminantes para a atmosfera através das chaminés, do ministério do meio ambiente, do território e do desenvolvimento territorial, estabelecendo normas e padrões de transmissão admissíveis de contaminação para a atmosfera por esse tipo de indústrias, bem como como o monitoramento e controle das fontes permanentes contaminando com periodicidade de um ano ou menos se os resultados obtiverem o mérito. Essas análises são caras e isso torna os laboratórios especializados localizados fora do estado. Considera-se implementar métodos alternativos de controle, através da formulação de um modelo matemático que respeite ao recolhimento de emissores contaminantes para esses fornos na fabricação de produtos cerâmicos do setor de Zulia, do Norte de Santander. Desenvolvendo uma investigação quantitativa, esta baseia-se na identificação e quantificação de variáveis incidentais no processo de ebulição e a análise estatística de histórico dos estudos de avaliação de transmissões atmosféricas em fontes permanentes, por estabelecer padrões de desempenho; o que ao mesmo tempo é pode transformar em uma ferramenta analítica de monitoramento e controle constante de contaminação do processo de ebulição desenvolve; Situação que indica um conhecimento relevante do processo e responsabilidades frente aos estratos nacionais.Palavras-chave: Contaminação, Chaminé, Fornos de Colmeia, Isocinética, Modelos, Forno.

Development of a Fatigue Life Assessment and Prediction Framework for a Bimetallic-Welded Thick-Wall Component of a Steam Turbine

In this investigation, we have applied an integrated experimental-analytical framework for fatigue life assessment and prediction of a thick-wall component of a high-pressure (HP) steam turbine. Emphasis is placed on the development of an effective experimental and analytical procedure for life characterization on the basis of low cycle and high cycle fatigue (LCF/HCF) in order to improve the safety, reliability, and affordability of real world steam turbine operations. Stress-control constant amplitude fully reversed fatigue tests were performed in room temperature and 500°C to serve two purposes: (a) to obtain experimental stress-life (S-N) curves and (b) to assess the values of the parameters of the energy-based framework to predict the fatigue life. The experimental and the predicted S-N curves are compared with each other in case of both the room and the elevated temperature to examine the soundness of the present energy-based model to predict fatigue life. The present lifing model was found to be able to predict both the room and elevated temperature LCF/HCF life of the thick-wall component with excellent accuracy. Furthermore, the elevated temperature fatigue life is found to be lower than the room temperature fatigue life due to the lower fatigue toughness at elevated temperature.

Control of Industrial Drives through Multicell Impedance Source Inverter

In this paper, various power quality issues that occur while driving an industrial motor drive such as voltage sag, swell, interruptions are discussed. A solution for such issues is proposed drives during various conditions of power quality issues is discussed in detail and a comparison with traditional Z-source inverter is made. The results are validated for mathematically modelled using Multicell Z-source inverter. By controlling shoot-through duty cycle using various techniques such as Simple boost control, Maximum boost control, constant boost control these issues are addressed. Multicell Z-source inverter has come as a replacement for traditional Z-source inverter due to its less EMI noise; increased voltage level with increase in cell as well as reduced voltage stress makes it more advantages than traditional one. In this paper, control of industrial system of 3 kW induction drive in MATLAB/Simulink environment and the results are summarised.

Convergence Parameter Analysis for Different Metaheuristic Methods Control Constant Estimation and it’s Tradeoff Inference

This paper is an extension of our previous work, which discussed the difficulty in implementing different methods of resistance emulation techniques on the hardware due to its control constant estimation delay. In order to get rid of the delay this paper attempts to include the meta-heuristic methods for the control constants of the controller. To achieve the minimum Total Harmonic Disturbance (THD) in the AC side of the converter modern meta-heuristic methods are compared with the traditional methods. The convergence parameters, which are primary for the earlier estimation of the control constants, are compared with the measured parameters, tabulated and tradeoff inference is done among the methods. This kind of implementation does not need the mathematical model of the system under study for finding the control constants. The parameters considered for estimation are population size, maximum number of epochs, and global best solution of the control constants, best THD value and execution time. MatlabTM /Simulink based simulation is optimized with the M-file based optimization techniques like Particle Swarm Optimization (PSO), Genetic Algorithm (GA), Cuckoo Search Algorithm, Gravity Search Algorithm, Harmony Search Algorithm and Bat Algorithm.