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A new mechatronics laboratory for technology integration
(Springer-Verlag France, 2017-02-01) Velasquez-Lopez, Alejandro; Rodriguez-Garcia, Alberto; Universidad EAFIT. Departamento de Ingeniería Mecánica; Mecatrónica y Diseño de Máquinas
While teams and projects tend to be multi-domain, the infrastructure required to integrate and build prototypes lags behind to allow an efficient interaction and to offer multi-disciplinary facilities. Hence this paper presents an infrastructure approach developed in a Latin American academic context, where the concept of an Engineering Building is explained in order to support the demands of a 3rd Generation University. A deeper emphasis of this article is placed upon the development of a Technology Integration Laboratory in terms of functionality, capacity, adjacencies, furnishing and, physiologic and psicologic support. The layout design is based on the concepts of Mechatronics and Technical Systems while enhancing a teaching–learning-building process. After 5 years of operation the results obtained in terms of prototyping, filed patents and projects with the triad government-industry-academy are discussed. Our experience shows that such hands-on engineering facilities are worth having, especially within a virtual education growing trend, and that openness has influenced an increment of the Intellectual Property results. © 2015, Springer-Verlag France.
Adsorption of Cadmium Using Biochars Produced from Agro-Residues
(American Chemical Society, 2020-01-01) López J.E.; Builes S.; Heredia Salgado M.A.; Tarelho L.A.C.; Arroyave C.; Aristizábal A.; Chavez E.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
Biochars have been shown as promising materials for cadmium remediation. However, the different precursors and the pyrolysis process operating conditions can yield very different surface functional groups, and as a result, different cadmium sorption mechanisms can be observed in biochars. Herein we present the results of cadmium sorption on biochars produced from the pyrolysis of different agro-residues, namely, coffee husk, quinoa straw, and oil palm kernel shell. The adsorption isotherms were used to determine the influence of the biochar's physicochemical characteristics to their sorption behavior. The biochars prepared from quinoa residues showed much higher cadmium uptakes than the other biochars. The concentration of base cations was found to be a critical factor for cadmium sorption. Although the quinoa biochars presented large uptakes, it was found that base cations were supported on the biochars and could be removed by leaching. Results from this study suggest that concentration of base cations on biochars could be used as predictors of the biochar capabilities for the removal of cadmium in aqueous solution. Copyright © 2020 American Chemical Society.
Análisis de estructuras periódicas con descripción de fourier y redes neuronales
(IMPRENTA UNIV ANTIOQUIA, 2007-06-01) DIAZ, ADALBERTO GABRIEL; Universidad EAFIT. Departamento de Ingeniería de Producción; Ingeniería, Energía, Exergía y Sostenibilidad (IEXS)
Analysis of CO2 Adsorption in Amine-Functionalized Porous Silicas by Molecular Simulations
(American Chemical Society, 2015-06-01) BUILES, SANTIAGO; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
Analysis of CO2 adsorption in amine-functionalized porous silicas by molecular simulations
(American Chemical Society, 2015-06-01) Builes S.; López-Aranguren, P.; Fraile, J.; Vega, L.F.; Domingo, C.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
We present the results of a combined experimental-molecular simulations approach concerning the capacity for CO2 adsorption of aminosilica hybrid products synthesized using supercritical fluids. Two porous supports were examined for amine functionalization, an ordered mesoporous silica (MCM-41) and a disordered silica gel (SG40). The textural properties of the studied materials were analyzed by low-temperature N2 adsorption-desorption isotherms and compared to those of molecular simulations using the grand canonical Monte Carlo simulation method. The CO2 adsorption capacity of these materials was evaluated by recording CO2 adsorption isotherms up to 100 kPa. Molecular simulations of the CO2 adsorption behavior of selected samples were performed to gain a fundamental understanding of the effect of functionalization. This study shows that in the functionalized materials, the distance between nitrogen atoms of the grafted amines is a critical factor for the occurrence of CO2 chemisorption, providing some insight into key parameters for designing adsorbent materials for CO2 capture and separation. The relationship between the adsorption results with N2 and CO2 allow us to compare the potential applications of the materials in CO2 adsorption and separation processes. A correlation of the N2 adsorption at a given pressure with the CO2 adsorption at a different pressure allowed the prediction of which materials will perform well for these processes. The hybrid products with high amine density have desirable features required for industrial sorbents, such as an enhanced CO2 adsorption capacity and selectivity. © 2015 American Chemical Society.
Analysis of periodic structures with Fourier description and neuronal network
(IMPRENTA UNIV ANTIOQUIA, 2007-06-01) DIAZ, ADALBERTO GABRIEL; Universidad EAFIT. Departamento de Ingeniería de Producción; Ingeniería, Energía, Exergía y Sostenibilidad (IEXS)
This work is developed in a project of textile lattices inspection. The structure of a superficial texture is manifested with a behavior on the base of a model known as pattern which, is associated with a group of characteristics that define it as such. The identification process and classification of shortcomings in the texture consists on establishing a region of conformity in the coordinated space defined by the pattern's characteristics. The reduction process of this m-dimensional space, helps to its identification in an n-dimensional space, such that m > n, where the classification system actually depends on the characteristics of the new space, where the new characteristics truly contain the classification information. The space characteristics allow for the identification of the pattern as such in the place that is explored. The characteristic frequency corresponds to a reduction of the classification space, making it more generic in the area over the image. The classification system is modeled with neuronal networks algorithms and the complexity of the surfaces of decision is solved starting from the architecture and the algorithms of training of the neuronal net.
Approximation of the mechanical response of large lattice domains using homogenization and design of experiments
(Universitatea Politehnica Bucuresti, 2020-01-01) Montoya-Zapata D.; Acosta D.A.; Cortés C.; Pareja-Corcho J.; Moreno A.; Posada J.; Ruiz-Salguero O.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
Lattice-based workpieces contain patterned repetition of individuals of a basic topology (Schwarz, ortho-walls, gyroid, etc.) with each individual having distinct geometric grading. In the context of the design, analysis and manufacturing of lattice workpieces, the problem of rapidly assessing the mechanical behavior of large domains is relevant for pre-evaluation of designs. In this realm, two approaches can be identified: (1) numerical simulations which usually bring accuracy but limit the size of the domains that can be studied due to intractable data sizes, and (2) material homogenization strategies that sacrifice precision to favor efficiency and allow for simulations of large domains. Material homogenization synthesizes diluted material properties in a lattice, according to the volume occupancy factor of such a lattice. Preliminary publications show that material homogenization is reasonable in predicting displacements, but is not in predicting stresses (highly sensitive to local geometry). As a response to such shortcomings, this paper presents a methodology that systematically uses design of experiments (DOE) to produce simple mathematical expressions (meta-models) that relate the stress-strain behavior of the lattice domain and the displacements of the homogeneous domain. The implementation in this paper estimates the von Mises stress in large Schwarz primitive lattice domains under compressive loads. The results of our experiments show that (1) material homogenization can efficiently and accurately approximate the displacements field, even in complex lattice domains, and (2) material homogenization and DOE can produce rough estimations of the von Mises stress in large domains (more than 100 cells). The errors in the von Mises stress estimations reach 42% for domains of up to 24 cells. This result means that coarse stress-strain estimations may be possible in lattice domains by combining DOE and homogenized material properties. This option is not suitable for precise stress prediction in sensitive contexts wherein high accuracy is needed. Future work is required to refine the meta-models to improve the accuracies of the estimations. © 2020 by the authors.
Approximation of the Mechanical Response of Large Lattice Domains Using Homogenization and Design of Experiments
(Universitatea Politehnica Bucuresti, 2020-06-01) Montoya, D.; Acosta, D.; Cortes, C.; Pareja, J.; Moreno, Aitor; Posada, Jorge; Ruiz, O.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
Assessment of the optimized treatment of indigo-polluted industrial textile wastewater by a sequential electrocoagulation-activated carbon adsorption process
(Elsevier Ltd, 2020-01-01) GilPavas E.; Correa-Sanchez S.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
Wastewater collected from a local jean manufacturing plant was treated using an electrocoagulation process (EC) coupled with activated carbon (AC) adsorption. The process variables were optimized using multivariate regression coupled with nonlinear programming with nonlinear restrictions to achieve the lowest possible cost while keeping a high enough degradation rate for chemical oxygen demand (COD), color, and turbidity to fulfill the Colombian environmental regulation requirements. Under optimal conditions (pH = 5.4, s =2 mS/cm, j =14 mA/cm2, and t = 11 min) color, COD, and TOC removals of 95%, 63%, and 51%, respectively, were achieved. The biodegradability index also increased from 0.13 to 0.29, whereas toxicity tests showed a remaining toxicity of 45%. A kinetic study was conducted for the EC process. The activated carbon (AC) adsorption process was successfully used to completely remove toxicity, while further increasing color, COD, and TOC removals to 96%, 72%, and 61%, respectively. The conditions for the AC adsorption process (20 g/L of AC and 1 h) were determined by experimental adsorption isotherms and kinetic studies. The optimized EC/AC process led to an effluent satisfying the Colombian regulations and seems technologically viable with lower costs than other similar process that were reported in previous works. © 2020 Elsevier Ltd
Bifurcations and Sequences of Elements in Non-Smooth Systems Cycles
(2013-09-01) RUIZ, OSCAR EDUARDO; Arango, Iván Darío; Universidad EAFIT. Departamento de Ingeniería Mecánica; Mecatrónica y Diseño de Máquinas
Characteristic Point Sequences in Local and Global Bifurcation Analysis of Filippov Systems
(World Scientific and Engineering Academy and Society (WSEAS) Press, 2008-10-01) Arango, Iván Darío; Universidad EAFIT. Departamento de Ingeniería Mecánica; Mecatrónica y Diseño de Máquinas
Coagulation-flocculation sequential with Fenton or Photo-Fenton processes as an alternative for the industrial textile wastewater treatment
(Editorial Board, 2017-04-15) GilPavas, E.; Dobrosz-Gómez, I.; Gómez-García, M.Á.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
In this study, the industrial textile wastewater was treated using a chemical-based technique (coagulation-flocculation, C-F) sequential with an advanced oxidation process (AOP: Fenton or Photo-Fenton). During the C-F, Al2(SO4)3 was used as coagulant and its optimal dose was determined using the jar test. The following operational conditions of C-F, maximizing the organic matter removal, were determined: 700 mg/L of Al2(SO4)3 at pH = 9.96. Thus, the C-F allowed to remove 98% of turbidity, 48% of Chemical Oxygen Demand (COD), and let to increase in the BOD5/COD ratio from 0.137 to 0.212. Subsequently, the C-F effluent was treated using each of AOPs. Their performances were optimized by the Response Surface Methodology (RSM) coupled with a Box-Behnken experimental design (BBD). The following optimal conditions of both Fenton (Fe2+/H2O2) and Photo-Fenton (Fe2+/H2O2/UV) processes were found: Fe2+ concentration = 1 mM, H2O2 dose = 2 mL/L (19.6 mM), and pH = 3. The combination of C-F pre-treatment with the Fenton reagent, at optimized conditions, let to remove 74% of COD during 90 min of the process. The C-F sequential with Photo-Fenton process let to reach 87% of COD removal, in the same time. Moreover, the BOD5/COD ratio increased from 0.212 to 0.68 and from 0.212 to 0.74 using Fenton and Photo-Fenton processes, respectively. Thus, the enhancement of biodegradability with the physico-chemical treatment was proved. The depletion of H2O2 was monitored during kinetic study. Strategies for improving the reaction efficiency, based on the H2O2 evolution, were also tested. © 2017 Elsevier Ltd
Collaborative design model review in the AEC industry
(Springer-Verlag France, 2016-01-01) Carcamo, Juan Gonzalo; Trefftz Gomez, Helmuth; Acosta Maya, Diego Andres; Botero- B, Luis-F; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
The end result of this research is an application created using freely available tools applied to a case scenarioto perform review meetings by different specialists in real time.
Collaborative Networked Virtual Surgical Simulators (CNVSS) Implementing Hybrid Client-Server Architecture: Factors Affecting Collaborative Performance
(MIT PRESS, 2015-01-01) Diaz, Christian; Trefftz, Helmuth; Quintero, Lucia; Acosta, Diego A.; Srivastava, Sakti; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
Currently, surgical skills teaching in medical schools and hospitals is changing, requiring the development of new tools to focus on (i) the importance of the mentor's role, (ii) teamwork skills training, and (iii) remote training support. Collaborative Networked Virtual Surgical Simulators (CNVSS) allow collaborative training of surgical procedures where remotely located users with different surgical roles can take part in the training session. To provide successful training involving good collaborative performance, CNVSS should guarantee synchronicity in time of the surgical scene viewed by each user and a quick response time which are affected by factors such as users' machine capabilities and network conditions. To the best of our knowledge, the impact of these factors on the performance of CNVSS implementing hybrid client-server architecture has not been evaluated. In this paper the development of a CNVSS implementing a hybrid client-server architecture and two statistical designs of experiments (DOE) is described by using (i) a fractional factorial DOE and (ii) a central composite DOE, to determine the most influential factors and how these factors affect the collaboration in a CNVSS. From the results obtained, it was concluded that packet loss, bandwidth, and delay have a larger effect on the consistency of the shared virtual environment, whereas bandwidth, server machine capabilities, and delay and interaction between factors bandwidth and packet loss have a larger effect on the time difference and number of errors of the collaborative task.
Collaborative Networked Virtual Surgical Simulators (CNVSS): Factors Affecting Collaborative Performance
(MIT PRESS, 2013-01-01) Diaz, Christian; Trefftz, Helmuth; Quintero, Lucia; Acosta, Diego A.; Srivastava, Sakti; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
Stand-alone and networked surgical simulators based on virtual reality have been proposed as a means to train surgeons in specific surgical skills with or without expert guidance and supervision. However, a surgical operation usually involves a group of medical practitioners who cooperate as team members. To this end, CNVSS have been proposed for the collaborative training of surgical procedures in which users with different surgical roles can take part in the training session. To be successful, these simulators should guarantee synchronicity, which requires (1) consistent viewing of the surgical scene and (2) a quick response time. These two variables are affected by factors such as users' machine capabilities and network conditions. As far as we know, the impact of these factors on the performance of CNVSS has not been evaluated. In this paper, we describe the development of CNVSS and a statistical factorial design of experiments (DOE) to determine the most important factors affecting collaboration in CNVSS. From the results obtained, it was concluded that delay, jitter, packet loss percentage, and processor speed have a major impact on collaboration in CNVSS.
Combined electrocoagulation and electro-oxidation of industrial textile wastewater treatment in a continuous multi-stage reactor
(IWA PUBLISHING, 2017-11-01) GilPavas; E.; Arbeláez-Castaño; P.; Medina; J.; Acosta; D.A.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
A combined electrocoagulation (EC) and electrochemical oxidation (EO) industrial textile wastewater treatment potential is evaluated in this work. A fractional factorial design of experiment showed that EC current density, followed by pH, were the most significant factors. Conductivity and number of electrooxidation cells did not affect chemical oxygen demand degradation (DCOD). Aluminum and iron anodes performed similarly as sacrificial anodes. Current density, pH and conductivity were chosen for a Box-Behnken design of experiment to determine optimal conditions to achieve a high DCOD minimizing operating cost (OC). The optimum to achieve a 70% DCOD with an OC of USD 1.47/m(3) was: pH of 4, a conductivity of 3.7 mS/cm and a current density of 4.1 mA/cm(2). This study also shows the applicability of a combined EC/EO treatment process of a real complex industrial wastewater.
A Comparative Assessment of Emerging Solvents and Adsorbents for Mitigating CO2 Emissions From the Industrial Sector by Using Molecular Modeling Tools
(Frontiers Media S.A., 2020-01-01) Bahamon D.; Alkhatib I.I.I.; Alkhatib N.; Builes S.; Sinnokrot M.; Vega L.F.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
The possibilities offered by molecular modeling tools to obtain relevant data at process conditions, while also gaining molecular insights on the techniques used for CO2 capture and separation, are presented here using selected case studies. Two different technologies, absorption with amine-based systems and adsorption on porous materials, were explored, using the molecular-based equation of state, soft-Statistical Associating Fluid Theory (SAFT), and Grand Canonical Monte Carlo simulations, respectively. The aqueous monoethanolamine (MEA) system was set as the benchmark for absorption and compared to the performance of 8 alternative amine-based systems, while 16 adsorbents belonging to different families (zeolites, metal–organic frameworks, amorphous silicas, and activated carbons), bare or functionalized with alkylamines, were investigated for the separation of CO2 by adsorption. In addition to obtaining molecular information on the CO2 capture process, the models were further used to examine the CO2 capture performance in terms of cyclic working capacity and energy index as key performance indicators, allowing the identification of promising systems that can improve the current ones to be further evaluated for separation in non-power industries. Results show that for the same total amine mass concentration, non-aqueous amine solvents have a 5–10% reduction in cyclic working capacity, and a 10–30% decrease in the energy index compared to their aqueous counterparts due to their lower heat of vaporization and specific heat capacity. In addition, M-MOF-74, NaX, and NaY structures present the best results for adsorption in temperature swing adsorption (TSA) processes. Similar values of energy requirements to those of amine-based systems (2–2.5 MJ kg CO2–1) were obtained for some of the adsorbent; however, the disadvantage of the TSA process versus absorption should be considered. These results confirm the reliability of molecular modeling as an attractive and valuable screening tool for CO2 capture and separation processes. © Copyright © 2020 Bahamon, Alkhatib, Alkhatib, Builes, Sinnokrot and Vega.
Conceptual design of a Langmuir probe for cold plasma characterization employing statistical design of experiments
(IMPRENTA UNIV ANTIOQUIA, 2013-06-01) Camargo Suarez, Victor Hugo; Acosta Maya, Diego Andres; Jaramillo O, Juan Manuel; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
The characterization and control of plasma-assisted processes, has become increasingly urgent to adapt this kind technology to industrial contexts. This work presents the design and construction of a cold plasma characterization system by electrostatic means (Langmuir probe), based on concepts of plasma physics and tools of engineering, design of experiments and conceptual design. The result of this work is a functional prototype probe and some measurements on the reactor.
Continuation of Nonsmooth Bifurcations in Filippov Systems Using Singular Point Tracking
(2007-12-01) Arango, Iván Darío; Universidad EAFIT. Departamento de Ingeniería Mecánica; Mecatrónica y Diseño de Máquinas
Control of emissions in an internal combustion engine: first approach for sustainable design
(Springer-Verlag France, 2016-08-01) Amaya, A.F.D.; Torres, A.G.D.; Acosta, D.A.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
A mathematical model of emissions was developed in a Twingo D7F engine. The effects of variations in compression ratio, fuel/air equivalence ratio, spark advanced and combustion duration under pollutant emissions were studied. Analysis and data collection were performed in an engine bank using a data acquisition system integrated to an Interactive Engineering Environment. A control strategy was implemented to guarantee emissions reduction.

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