Revista Facultad de Ingeniería Universidad de Antioquia

Preliminary

Revista Facultad de Ingeniería Universidad de Antioquia — Thu, 03 Nov 2022 00:00:00 -0500

Preliminary pages

Water quality trend analysis of Cheurfas II dam, Algeria

Salima Rezak, Farid Rahal, Abdellah Bahmani — Thu, 03 Nov 2022 00:00:00 -0500

The northwestern part of Algeria is characterized by a semi-arid climate which has created semi-permanent rivers and dams with low filling rates. It is important to preserve the water resource, which is becoming increasingly scarce. Additionally, it is worth indicating that the mobilized surface waters are continually under threat of significant organic pollution. Indeed, the dam of Cheurfas II, in the northwestern part of the country, is indicative of this situation. In order to establish a diagnosis of the state of the temporal evolution of water quality, time series of 11 variables indicating the presence of organic pollution in this dam were thus analyzed. The data collected were analyzed using the Mann-Kendall test to look for significant trends and the Webel-Ollech test to detect the presence of seasonality. The results obtained showed increasing trends in dry residues, organic matter, phosphates and dissolved oxygen. However, variables like BOD5, COD and NO-3 showed decreasing trends. As for the variables NH⁺₄, NO^-₂ and pH, they presented no trend. Finally, the water volume of the dam exhibited a significant increase. In addition, no seasonality was detected in the variables studied, with the exception of the PO43- time series and water volume. These findings indicate that the watershed of the dam received pollutants from different origins, in particular industrial pollutants. This makes water biodegradability difficult to achieve.

Development of a management model of support services in biotechnology companies

Thu, 03 Nov 2022 00:00:00 -0500

Support services are very significant for the correct performance of key processes; in the case of the biotechnology industry, this type of services is not frequently analyzed in their excellence performance. The purpose of this work is to suggest a model for the development of Support Services Management, which highlights the impacts over the level of customer satisfaction with the logistics system of biotechnology companies in the specific conditions of Cuba; however it can be applied to other contexts. For this, the basic elements of the management and service models are clarified as a theoretical basis for this research. As a methodology, experimentation and case studies are chosen, including the development of a production support service in the biotechnology industry. The level of customer satisfaction and the costs incurred are determined; In addition, the influence of the level of integration of support services on the results of the model is taken into account. The document provides the results of the model and its application in the biotechnology industry in Cuba, through a procedure designed for its implementation. This research satisfies the identified need to improve internal customer satisfaction based on quality and timely delivery of resources. At the same time, the costs of the logistics system are reduced or maintained, because the main cost must be in the key services.

New concrete masonry solid block with non-conventional geometry: Experimental characterization

María Fernanda Vargas, Julian Carrillo León — Thu, 03 Nov 2022 00:00:00 -0500

This paper presents and discusses the results of an experimental study aimed at characterizing the mechanical properties of an innovative and patented concrete masonry solid block with non-conventional geometry. The measured response in the new non-conventional block is compared with a conventional solid block. The experimental program was planned to verify whether the new block complies with the minimum values prescribed by the NSR-10 Colombian Code for being used as an unreinforced structural masonry block. The verification includes tests of water absorption and compressive strength of blocks, compressive strength of prisms, and flexural bond strength of standard beams. The similitudes or differences between the two types of blocks and prisms were evaluated using ANOVA tests. The results obtained demonstrated that both types of blocks comply with the requirements prescribed by NSR-10. Moreover, the flexural bond strength of the new block is roughly two times higher than that of the conventional block. The study results confirm that the new innovative block can be used for masonry structures.

A mechanical model to determine upheaval buckling of buried submarine pipelines

Thu, 03 Nov 2022 00:00:00 -0500

Thermal loads in submarine pipelines generate an axial compressive load that can force the pipeline to buckle, leading to failure if these loads are not considered in the design. Buried pipes are constraint to displacements in all directions, which leads to a high compressive load in the longitudinal axis and makes the pipes more vulnerable to buckling. If buried pipes under thermal loads do not buckle, a high-stresses state takes place when it is combined with high-pressure conditions. In this work, a simple mechanical model to determine the axial buckling load of a buried pipeline is proposed. The model is based on a simply supported beam subjected to a distributed transverse load representing the soil uplift resistance obtained from a referenced model, and an axial compressive load that represents the effective axial force and is computed according to the DNV-RP-F110. Additionally, the pipe–soil system is analyzed through a non-linear finite element model to compare the results with the analytical solution. The proposed simple mechanical model can capture the upheaval buckling behavior and provides results that are consistent with the numerical analysis, specifically for the two main parameters evaluated, namely, the initial pipe curvature and the magnitude of the transverse load.

Pipe bridge design optimisation through a comparative study of truss and girder arrangements

S. V. Sivapriya, S. Sadhana, N. Prathibha, S. Saranya — Thu, 03 Nov 2022 00:00:00 -0500

Pipe bridges are structures that play an indispensable role in chemical and oil plants. They support cable trays or pipe-carrying material. This study aims to identify the ideal configuration of a pipe bridge through the comparative study of girders with drop hanger and truss arrangements for three different spans. The most efficient arrangement for each span was suitably identified. Through the analysis carried out, it was then identified that the Girder arrangement is suitable for smaller spans such as 15 meters; while the truss arrangement was preferable for longer spans.

Optimal design and performance evaluation of tuned mass damper inerter in building structures

Daniel Caicedo Diaz, Luis Lara-Valencia, John Blandon — Thu, 03 Nov 2022 00:00:00 -0500

This paper concerns the numerical performance evaluation of multi-degree-of-freedom systems equipped with Tuned Mass Dampers-Inerter (TMDIs); a passive control device used for the mitigation of mechanical vibrations induced by dynamic loads. The inerter device is commonly used to increase the apparent mass of classics tuned mass dampers (TMDs), improving its seismic performance. To evaluate the TMDI action, three case studies are employed, determined from three real buildings of Medellin city from low, medium to high rise (30 meters, 97 meters, and 144 meters, respectively). Optimum design parameters are found using a metaheuristic optimization based on the differential evolution method, first, for the minimization of the horizontal peak displacements, and then, for the minimization of the root mean square (RMS) response of displacements. Besides, the case studies are assessed using eight seismic accelerations records representative of the literature. Finally, the seismic performance is evaluated on each case study considering different levels of inertance induced by the inerter device: 5%, 20%, and 50% with respect to the total mass of the building, for which it is observed a better dynamic behavior when TMDIs with lower values of inertance are implemented.

Design of a smart microgrid with small-scale hydro generation: a practical case study

Americo Vicente Teixeira Leite — Thu, 03 Nov 2022 00:00:00 -0500

Microgrids are local electric grids integrating distributed generation and consumption, energy storage and management and power control. They can be an alternative for the energy supply of a house, a building, a small village or a wider region. Small-scale hydropower, in the range of 5 kW, consists of distributed generation systems gaining increasing interest. These so-called pico-hydro systems are becoming popular since they can take advantage of the integration of low-power wind generators and photovoltaic (PV) inverters, which are widely available at competitive prices. Thus, pico-hydro systems are not only relevant for energy generation in off-grid systems in remote areas but also for new contexts where the utility grid is available. This paper presents the design of a smart microgrid with small-scale hydro generation. It is a practical case study with the integration of two grid-connected pico-hydro turbines: a low-head propeller turbine and a water wheel. The microgrid was designed and implemented in a small museum: Casa da Seda (House of Silk). The energy generation is based on the complementarity between hydro and PV. The microgrid can operate in both grid-connected and islanded modes and feeds the House of Silk loads. The connection of both pico-hydro turbines into the microgrid is based on the integration of wind generators and PV inverters.

Development of a flexible anode for lithium-ion batteries from electrospun carbon-magnetite composite microfibers

Thu, 03 Nov 2022 00:00:00 -0500

The development of a binder-free material is gaining ground as a flexible anode in lithium-ion batteries due to the higher specific capacity and possibilities of usage in portable appliances. In this work, magnetite nanoparticles (Fe₃O₄-NPs) were incorporated into carbon microfibers (CMFs) by electrospinning technique to improve the specific capacity of active material, retaining the high flexibility of the CMFs. The composite active material (CMFs-Fe₃O₄) was characterized by Raman spectroscopy, Thermogravimetric analyses (TGA), and transmission electron microscopy (TEM) to determine the composition, structure, and morphology of the composite. Electrochemical tests were done to evaluate the performance of the composite material as an anode in lithium-ion batteries. Fe₃O₄-NPs with particle sizes from 30 to 40 nm were incorporated into CMFs (800 nm), and the TEM images showed a homogeneous distribution of Fe₃O₄-NPs. The electrochemical tests evidenced that magnetite incorporation increases the specific capacity by 42% on the first cycle and 20% on the 50^th cycle. Similarly, the Coulombic efficiency increases by 20% in the composite material.

Potential ecological risk index for metals in a grazing area, Guasca, Cundinamarca

Thu, 03 Nov 2022 00:00:00 -0500

The presence of metals in soils used for primary economic activities can negatively impact the environment and public health. This research identified soil contamination by heavy metals (Lead, Copper, Zinc, and Manganese) by examining physical and chemical properties (Phosphorus, Potassium, organic carbon, cation exchange capacity, pH, texture, and bulk density) of the area during the dry and rainy seasons of 2017. Composite samplings of soil were carried out in both seasons, in order to obtain a representative value of the soil in certified laboratories. Thereafter, through interpolation by means of the Kriging method, a spatial scale of metal concentrations was conducted. This led to the conclusion that the study area has an acceptable environmental quality (5.8-6.9) for its current use of grazing. Likewise, the area presents a medium level (75.37), pursuant to the Potential Ecological Risk Index (RI) for the dry season, and a very high risk (195.04) during the rainy season. These estimates are directly related to lead concentrations, introduced to the soil of the area by human development activities and by contributions of parent material to the soil surface layers, through natural processes of weathering.

Indirect electrochemical degradation of acetaminophen: process performance, pollutant transformation, and matrix effects evaluation

Thu, 03 Nov 2022 00:00:00 -0500

Acetaminophen (ACE), a highly consumed pharmaceutical, was degraded in aqueous matrices by reactive chlorine species (RCS) electrogenerated using Ti/IrO₂ electrodes. Although this pollutant has been extensively treated by electrochemical techniques, little information is known about its degradation in fresh urine by electrogenerated RCS, and the understanding of its transformations using analyses of atomic charge. In this work, these two topics were discussed. Initially, the effect of current (10-40 mA) and supporting electrolyte (considering typical ions present in surface water and urine (Cl^- and SO₄^2-)) on the electrochemical system was evaluated. Then, the kinetics and primary transformations products involved in the elimination of ACE were described. It was found that, in distilled water, the process at 40 mA in NaCl presence led to 100 % of ACE degradation (10 min, 0.056 Ah L^-1). Theoretical analyses of atomic charge for ACE indicated that the amide group is the most susceptible to attacks by RCS such as HOCl. On the other hand, degradation of acetaminophen in synthetic fresh urine was slower (21% of degradation after 60 min of treatment) than in distilled water. This was attributed to the other substances in the urine matrix, which induce competition for the degrading RCS.

Thermal finite element analysis of complex heat sinks using open source tools and high-performance computing

Thu, 03 Nov 2022 00:00:00 -0500

The modeling of heat transfer phenomena in thermal systems has been extensively explored in industry and academia by using the finite element method (FEM) with commercial software. However, when the thermal problem introduces complexities in geometry and physics, the availability of licenses for high-performance computing could represent a limitation to achieving results in a reasonable time. Hence, finite element analysis (FEA) using open-source software (OSS) becomes a prominent candidate in this case. Therefore, multiple open-source tools are integrated into this work to solve the heat transfer equation, including conduction, convection, and radiation. Several geometrically complex heat sinks commonly used in the electronics industry are considered application examples. The performance of parallel computing is assessed in terms of processing time. The finite element solution engine is built by implementing the energy balance equations in their weak formulation in Firedrake, using its solver PETSc, the mesh generator GMSH and the post-processor Paraview, thus creating a fully OSS-based Python framework. Finally, the results are verified with commercial software for different case studies, and its potential to be extended to other fields of engineering is evident.

Subjects and authors index

Revista Facultad de Ingeniería Universidad de Antioquia — Thu, 03 Nov 2022 00:00:00 -0500

Editorial

Maryory A. Gómez-Botero — Thu, 03 Nov 2022 00:00:00 -0500

Continuous publication

The first two academic journals in the world were Le Journal des savants created in January, 1665 in France [1], followed by Philosophical transactions, founded later that year in March [2], in England. For the next 350 years, there were no significant changes in this form of scientific publishing, while in the last two decades, there have been many transformations caused by the development of the World Wide Web (WWW) in 1990 [3]. Only 3 years after the public presentation of the WWW in 1993, scientific journals began to be disseminated through the Internet.

Initially, scientific journals began to be edited with the aim of publishing summaries of printed books, and from the 19th century on, the scientific article became the most important means of communication of research results [4], multiplying continuously the number of existing scientific journals that were born on a regular basis, whether weekly, fortnightly, monthly, bimonthly.