bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of corrosive behavior of chromium silicon nitride under hydrodynamic conditions in aggressive environments
Authors: Villate J J , Vera E , Olaya J J 
Published: November 2019

Abstract
In order to analyze corrosion resistance and wear behavior, steel cylinders were coated with chromium silicon nitride via physical vapor deposition, using a reactive sputtering magnetron, with base and working pressures of 4*10−6 mbar and 8*10−3 mbar respectively. The diffraction patterns correspond to chromium nitride and the amorphous phase of silicon nitride, hardness of 6.52 GPa, thickness of 3 μm and chemical composition characterized by nitrogen, silicon and chromium. The corrosion behavior was determined with a rotating cylinder electrode, rotating at different speeds and connected to a Gamry potentiostat galvanostat, using the techniques of polarization resistance, electrochemical impedance spectroscopy and dynamic potentiation polarization. The tests were carried out in solutions composed of water, 1% of sodium chloride and silica sand, with temperatures of 25 °C and 45 °C. Limiting current density behavior was evidenced. The coating corrosion rate was reduced by up to two orders of magnitude compared to that found for steel samples and was affected by the system rotation speed, particle size and electrolyte temperature.
Durability considerations for mitigating corrosion caused by biogenic sulfuric acid in sewerage systems
Authors: Cortés M , Vera E 
Published: November 2019

Abstract
In sewerage systems, the corrosion process caused by microorganisms, has been studied. This affects the structural integrity of the concrete drainage pipes and the sewage treatment plants, This article is a review of research which focuses on the study of how to reduce the production of hydrogen sulfide, how to improve the resistance of concrete through the use of additives and the implementation of antimicrobial techniques to reduce bacterial growth, This review allowed us to find a way to improve the physical simulation of exposure to the corrosive medium through chemical tests, as well as the optimization and choice of the type of zeolite that would be incorporated into the mixture with which concrete pipes are normally manufactured. for sewers in Colombia improving their durability conditions.
Evaluation of mechanical wear in bismuth-titanium coatings synthesized by the sol-gel method and applied on 316 L stainless steel substrates
Authors: Garzón P , Bautista-Ruiz J , Chaparro A 
Published: November 2019

AbstractSteels are part of the basic equipment of most of the industrial framework, including very diverse sectors such as the oil, chemical and automotive industries. However, steels are susceptible to wear phenomena limiting their life in use and losing efficiency in the applications to which it is intended leading to a technological and economic problem. In mechanical systems, lubrication requires effective strategies to ensure that the increase in critical contact voltages does not cause material failure during operation. Although there are different ways to avoid the wear of steel parts, the development of material technology has allowed the manufacture of new alloys with anti-wear properties. Replacing steels with other higher cost materials is very unfeasible. For this reason, one of the alternatives of greatest interest to reduce wear is based on the surface modification of the metal through the use of coatings. The sol-gel method allows the manufacture of coatings on steel parts to reduce wear. The objective of this work was to manufacture, using sol-gel, bismuth-titanium coatings on 316 L stainless steel substrates in order to analyze the mechanical wear of the system and evaluate its wear rates and friction coefficients. The study focused on determining the effect of precursor concentration on performance as a film to reduce wear. It was determined that the friction coefficients show significant variations due to adhesive wear processes. With respect to wear, it is concluded that the coatings offer substrate protection by indicating wear rates lower than those reported for 316 L stainless steel substrates without coating.
Yttrium oxide evaluation as coating to reduce the corrosion velocity in industrial equipment working under combustion environments. Case study: Ferritic 9Cr-1Mo steel
Authors: Alviz-Meza A , De La Cruz W , Kafarov V , Ostos Y , Peña-Ballesteros D Y 
Published: November 2019

Abstract
The well-known scientific problem about global warming and less cost energy requirement, has been boosting to the petrochemical sector to implement eco-efficiency strategies by promoting the use of critical conditions throughout the traditional chain process of oil refining. In addition, many industrial combustion processes are developed using as energy source a mixture of natural and recovery gases, which added to high temperatures generate potential corrosion atmospheres. Thus, this research aims to try to reduce the pipeline degradation that take place in combustion environments by evaluating an yttrium oxide as coating for the ferritic 9Cr-1Mo steel. This coating was deposited on the substrate by plasma laser deposition, and several growth times were implemented to evaluate its thickness effect. On the other hand, in order to obtain the real combustion atmosphere, a flue gas model composition was selected, which was useful to calculate the theoretical oxidation products by simulation. Finally, those coatings were evaluated at 650 °C and testing times from 1 hour to 100 hours inside the calculated oxidation environment. The main results indicated that even with the tested coatings, the evaluated alloy had a severe corrosion velocity, but lower than without them.
Rotodynamic pump operating as a motor machine
Authors: Hernández E , Mantilla J C , Cordoba E 
Published: November 2019

Abstract
Rotodynamic pump is a commercial machine and very used in the factories so the use of centrifugal pumps or rotodynamic pump operating as turbines or motor machine offers a technically and economically viable alternative to traditional turbines, the selection and implementation of a pump that functions as a turbine is a subject that is still under development. In this investigation the process of selection and implementation of the centrifugal pump is performed where centrifugal pump works in reverse mode, as a turbine, and mechanical adaptations are made for proper operation. The hydraulic system consists mainly of a forced pipe and a tank at a height of 13.3 m. In the built equipment a maximum efficiency of 58% was obtained at 890 rpm and an electric power of 45 W with a consistent load of a 120 V and 70 W bulb. The results obtained in this case study are comparable with the results of conventional turbines.
Estimation of potential hydrogen production from palm kernel shell in Norte de Santander, Colombia
Authors: Acevedo J C , Solano S P , Durán J M , Posso F R , Arenas E 
Published: November 2019

Abstract
This work sought to estimate the economic and environmental potential of palm kernel shell for hydrogen production as energy vector in Norte de Santander, Colombia. A field research determined that the department generates monthly 14082 t of palm biomass of which 12501 of palm kernel shell remain available for their use. The proximate and ultimate analyses of the palm kernel shell report high heating value (19.53 MJ/kg) compared with other agro-industrial biomasses, high content of volatile material (69.82% w/w) and fixed carbon (21.68% w/w), promoters of chemical reactions in pyrolysis and gasification processes, respectively. In the Aspen Plus® simulation process of the palm kernel shell gasification at 900 °C and steam/biomass ratio of 1.5, a yield is obtained of hydrogen production of 40.7%, equivalent to a monthly production in Norte de Santander of 51.6 t. Using H2 in the generation of electric power permits producing 470.9 MWh/month that represent theoretical utilities of US$27734.5. In another scenario, 55848.8 gal/month of gasoline are substituted, equivalent to US$11708.6 through the sale of carbon credits. Regarding diesel, 45905.1 gal are replaced per month, which add US$9725.4 through the commercial transaction in the carbon market. It is concluded that using palm kernel shell as primary source to obtain H2, has, in principle, a favorable economic and environmental impact for sustainable development of the department of Norte de Santander, besides contributing to the knowledge base on the penetration of this vector in Colombia’s energy matrix; however, more detailed technical and economic studies are needed to conclude regarding the economic viability of this energy conversion process.
Synthesis of a chalcopyrite material, based on CuIn1−xGaXSe2(X = 0.3 y 0.5), for application as semiconductor layer, deposited by a low-cost technique
Authors: Castellanos Báez Y T , Torres-Barahona E A , Gómez-Cuaspud J A , Vera-López E , Pineda-Triana Y 
Published: November 2019

Abstract
The current work reports the synthesis and characterization of a photovoltaic material based on the CuIn1−xGaXSe2(X = 0.3 y 0.5) system, making use of the doctor blade method. For this purpose, homogeneous inks were obtained and worked under previous stoichiometry arrangement. The deposition process of thin films, were made in a heating plate on conventional glass substrates, previously washed and treated for this purpose. Once the layers of Cu, In, and Ga were deposited by chemical bath, a thermal treatment was performed at 550 °C for 30 min in a conditioned oven, in which the selenization process was performed. The obtained films were characterized by X-ray diffraction, Raman spectroscopy, solid-state impedance spectroscopy, UV spectroscopy and scanning electron microscopy techniques. The identification of the main crystalline phase could be corroborated, as well as the conductive and optoelectronic behavior of the solids in accordance with reported in literature. Simultaneously, it was checked that the method used allows obtaining layers of an optimum thickness, in order to be used as an absorbent layer in the design of solar devices.
Evaluation of semiconductor materials by hydrothermal synthesis
Authors: Pérez Bustos H G , Gómez-Cuaspud J A , Pineda-Triana Y , Vera-López E , Patarroyo-Mesa M 
Published: November 2019

AbstractThe present work describes the obtaining of semiconductor materials with kesterite structure by a hydrothermal methodology. The obtained kesterite has a structural modification of the conventional Cu2ZnSnS4structure with the insertion of titanium instead of tin, in order to obtain Cu2ZnTiS4. The precursors of this material, metallic salts of copper, zinc acetate, titanium butoxide and thiourea were added in a hermetic steel reactor, controlling time (24 hours, 48 hours and 72 hours) and temperature (200 °C — 300 °C). To evaluate the synthesis, the materials obtained were analysed by different characterization techniques (X-ray diffraction, scanning electron microscopy, solid state impedance). The results show that material with the conditions of synthesis 48 hours and 300 °C, exhibit the best textural and electrical results in terms of economy process. The X-ray diffraction analysis shows secondary phases, which can possibly be eliminated with a thermal treatment, since most of the secondary phases (such ZnS and Cu2S) can be eliminated by combustion in an inert atmosphere. The results showed that the increase in the temperature of synthesis decreases the formation of amorphous agglomerates, improving the morphology of the material. The characterization of the materials showed that the Cu2ZnSnS4phase is possible to obtain by hydrothermal synthesis.
Obtaining biogas for use during construction of residential buildings
Authors: Forero K K , Torrado K A , Gómez F R , Guarín O D , Ardila D F , Tiria L C 
Published: November 2019

Abstract
The present study examines the technical and economic feasibility of a biodigester to generate biogas from organic waste, such as human and food residues, generated during construction projects. Based on existing data and the scaling model selected, the quantity of such waste was estimated on a per-worker basis over a period of 30 days; yielding a daily average of 86 grams of food waste, 250 grams of stool, and 1.5 liters of urine. These estimates are scalable for the calculation of periods of greater or lesser duration. The data, variables, and calculations were analyzed using a technological tool developed for this study, such that other users or parties interested in the use of a biodigester for the management of organic wastes and biogas generation in construction projects can enter the relevant data for their project and generate scaling and cost data as an output. The use of a biodigester for construction projects is based on real-life experience in various sectors, for the most part in rural areas and domestic applications; while factors such as space, maintenance, and safety, among others, have hindered the use of this technology in the construction sector. Nevertheless, its implementation in new construction projects drives positive social, environmental, and economic impacts, as it reduces the volume of organic wastes for disposal, and substitutes for the use of fossil fuels. The latter results in a reduction of pollution, and improves the environment, with corresponding positive effects upon human health and wellbeing. It also represents an opportunity to reduce the cost of gas consumed during the construction process of residential buildings.
Design of a solar power system in San Agustin building Ocaña, Colombia
Authors: Arévalo J , Cabellos M I , Marquez R T 
Published: November 2019

Abstract
The purpose of this study is to design an autonomous solar system as an alternative to the electrical energy use of San Agustín building in the municipality of Ocaña, Colombia. The building has 8 floors of which the commercial and administrative zones consume 2447.2 Wh per month. Considering that electricity costs are high, the project focuses on lowering energy consumption in the billing. The research is carried out with the development of the phases of analysis, diagnosis, and design, in order to encourage the use of renewable energy in the building. The academic study is limited to providing the design of the autonomous system to the owners of the building to continue with the investment phase. The results are based on establishing the structural and energy parameters and validating the implementation of the solar power system taking into account electricity prices, which results in the use of 15 panels of 275 Watt and 7 panels of 325 Watt with a saving of approximately 1.500.000 Colombian pesos.
Biomethane production potential from selected agro-industrial waste in Colombia and perspectives of its use in vehicular transport
Authors: Posso F , Mantilla N 
Published: November 2019

Abstract
The proper disposal and management of the waste generated from the agro-industrial activity in Colombia constitute a problem with environmental, economic and social implications, such that its solution constitutes a matter of national interest. Thus, the objective of this work is to estimate the potential of biomethane production by biochemical conversion of selected agro-industrial waste and, its use is proposed in vehicular transport currently moved by natural gas. Methodologically, the study relies on official statistics of the national entities that report the volume of crops and waste generated yearly, Three crops were selected, applying criteria of abundance, geographic distribution, and energy properties: sugarcane, palm oil, and rice; the waste considered for each of them were sugarcane bagasse, empty fruit bunches of palm oil and rice straw. The conversion of said waste to energy vectors is by anaerobic digestion producing biogas, and from its purification, biomethane. The volume of biomethane obtained was 1,290x106 m3/year. This important value was compared with studies from other countries. The prospects for the final use of biomethane as vehicle fuel are promising. So, biomethane is a potentially attractive develop option in Colombia, which would make it necessary to carry out more specific and detailed studies include economic, environmental and social aspects that would positively impact the route to the sustainable development of the country.
Analysis for the implementation of a system for natural gas liquids removal and recovery at the gas processing plant El Centro in Santander, Colombia
Authors: Agón-León C , Sanabria-Cala J A , Conde-Rodríguez G R , Laverde-Cataño D , Peña-Ballesteros D Y , Estupiñan Durán H A 
Published: November 2019

Abstract
The present work carried out the analysis of seven natural gas liquids removal and recovery technologies, evaluating ten decision criteria to identify the technology with the highest technical and economic potential to be implemented at the gas plant “El Centro”, Colombia. The technical criteria evaluated took into account: the chemical composition of the natural gas processed; the flow, pressure and temperature of the system; the efficiency in the removal of natural gas liquids and the technology adaptability against fluctuations that may occur in the operating conditions. On the other hand, the economic criteria evaluated included the purchase of high–cost supplies and equipment, as well as space and maintenance requirements for their implementation. Based on the analysis, the triethylene glycol improved absorption process was established as the technology with the greatest potential to be implemented at the gas plant “El Centro”, Colombia, so it was evaluated in a pilot test where a reduction of 30 °F on the cricondentherm point was observed, associated to the removal of higher molecular weight hydrocarbons from the natural gas stream.
Internal inspection of the Lisama – El Centro gas pipeline using magnetic flux leakage technology in Santander, Colombia
Authors: Vargas-Gutiérrez D , Sanabria-Cala J A , Conde-Rodríguez G R , Laverde-Cataño D , Peña-Ballesteros D Y 
Published: November 2019

Abstract
The present work carried out the internal inspection of the pipeline that allows the natural gas transport from the “Compresora Lisama” to the gas plant “El Centro” in Santander, Colombia, establishing the current pipeline conditions and defining the actions that must be taken to maintain the safety of the process. The internal inspection was carried out using Magnetic Flux Leakage technology, which allowed identifying in a single run the different types of anomalies that may occur in the 8” diameter steel pipeline during natural gas transport. The anomalies identified during the internal inspection inherent to natural gas transport through water bodies and unstable soils of variable height corresponded to thickness losses, dents, and programmed anomalies with estimated repair factor greater than 1. These anomalies were grouped into a total of 41 sections of the “Lisama–El Centro” gas pipeline that require replacement to guarantee the correct operation of the “Compresora Lisama” and the gas plant “El Centro”, preventing unscheduled plant shutdowns that may lead to shortages in communities and companies that require daily the natural gas.
Methodology based on cross modal strain energy method to estimate the damage severity in a metallic structure
Authors: Sánchez-Acevedo H G , Rodríguez G H , González-Estrada O A 
Published: November 2019

Abstract
The studies related to the Structural Health Monitoring have been important to evaluate the operation condition of structures, and let reduce the maintenance costs. The modal strain energy method has been used for this goal. This method requires to compare the information of mechanical vibrations acquired from the structure vs the same structure in initial conditions, called structure in health condition. This work is focused on developing a methodology that differs from the traditional modal strain energy. The methodology allows us to identify and evaluate the damage severity using a severity indicator.The methodology has been implemented in an offshore structure. The results have been satisfactory for the damage quantification for single and multiple damages.
Observation of significant differences between electromagnetic and acoustic emissions during fracture processes: A study on rocks under compression loading
Authors: Clavijo J , Wang H , Sánchez S 
Published: November 2019

Abstract
Electromagnetic radiation (known as electromagnetic emissions) related to processes of loading and fracture in different types of materials (from metals to rocks) has been widely reported. The physical mechanisms behind these emissions are still under discussion, however, it is commonly accepted that they are created by some of the micro-cracks that appear in the sample during fracture processes. Nucleation and growing of micro-cracks generate mechanical waves (acoustic emissions), therefore, each electromagnetic emission should be linked with some acoustic event. Furthermore, it is expected that the electromagnetic and acoustic activities (number of emissions per second) have the same general characteristics. Contrary to what is usually reported, we find that there are significant differences between acoustic and electromagnetic emissions in loading processes on rocks. These differences were detected during the compression of a typical laboratory-scale sample of granite when it is compressed at a rate of around 20 kPa/s. We found two important discrepancies: i) There were at least 20 electromagnetic bursts (out of around 200) that were not coincident with any acoustic event. ii) The electromagnetic activity in general shows its maximum value when acoustic activity is very low. Both emissions just coincide at the moment of the final collapse. These results strongly suggest the existence of a non-fracture mechanism related to the origin of electromagnetic emissions. This could have important consequences for the field of non-destructive assessment of materials and even in the study of earthquake precursors and forecasting.
Bifurcation analysis of the threshold of a solid-state laser
Authors: Mesa F , Correa G , Cárdenas P 
Published: November 2019

Abstract
In this paper we describe the qualitative analysis of the dynamic model of a solid-state laser. Initially a brief description of the theory of dynamic systems is made, the part concerning the qualitative solutions of non-linear models, the obtaining of fixed points for second-order systems and the determination of the stability of these points. Later, the dynamic model of the solid-state laser is exposed, where all its inherent parameters and the behavior that follows will be described. Then, the qualitative analysis is developed where the model will be converted to dimensionless equivalent that contains two parameters that condense to all the others. The results obtained are verified with numerical analysis, there clarifies the veracity of the qualitative analysis in conjunction with the description of the behavior of the solid-state laser, to finish with the conclusions obtained from the whole development.
Bifurcation analysis field potential in isotropic materials defined by semi-spherical layers using finite elements
Authors: Ospina R , Correa G , Cardenas P 
Published: November 2019

Abstract
In this document, the finite element method is developed in three dimensions to find the potential field in a region composed of hemispherical shells defining subregions with different materials, the numerical solution is made by FlexPDE software version 7.12 and the general process to solve is shown Problems of three-dimensional differential equations using the Galerkin criterion to approximate functions by the linear combination of functions of form, thus, the differential problem is reduced to solve a set of algebraic equations to find the coefficients of the linear combination.