bluuebunny/crossref_metadata_2025 huggingface dataset:
Familiemoord gepleeg deur kinders: 'n Gevallestudie
Authors: Moen M , Bezuidenhout C
Published: March 2018

Die Suid-Afrikaanse samelewing word as gewelddadig beskou, met 'n gemiddelde nasionale moordsyfer wat beduidend hoër is as in die res van die wêreld. Die familie is ŉ kernsisteem binne die breëre gemeenskap en word tradisioneel as 'n veilige sisteem beskou. Die realiteit is egter dat 'n groot persentasie moorde in Suid-Afrika deur 'n kennis, familielid of lid van 'n huishouding gepleeg word. Die doel van die artikel was om die kind as 'n persoon wat familiemoord pleeg, beter te verstaan. 'n Kwalitatiewe navorsingsontwerp is gevolg en kwalitatiewe inhoudsontleding is vir data-analise gebruik. Die geval wat in hierdie artikel bespreek word om die tipiese kenmerke te illustreer van kinders wat familiemoord pleeg, het deel uitgemaak van ŉ PhD-studie in opvoedkundige sielkunde. Alhoewel elke geval van familiemoord tot ŉ mate uniek is, is daar wel kenmerke wat in die meerderheid gevalle voorkom en tot dieper insigte rakende die fenomeen kan bydra. Kenmerke wat dikwels voorkom, dui op ŉ swak (of geen) band met die primêre sorggewer. Geborge huislike omstandighede ontbreek oorwegend en die kind se emosionele behoeftes word grotendeels misken. Die akkumulatiewe stressors lei dikwels tot gevoelens en persepsies van verwerping. Verlies word nie altyd toereikend hanteer nie. Gesinswanfunksionering, wat mishandeling en ekstreme ouerskapstyle insluit, is opvallend. Akkumulatiewe stressors het dikwels gevoelens van angs en onderliggende aggressie tot gevolg. Die akkumulatiewe individuele en sistemiese gebeure vind oor jare plaas en lei daartoe dat die kind uiteindelik moord pleeg.
Before data acquisition -- Start MRI Project Spinoza REC v3
Authors: Beemsterboer Tinka , Snoek Lukas
Published: March 2018

Dear researcher, This protocol gives you the steps to start an MRI project at the Spinoza Centre Roeterseiland. If you haven't had contact with Steven Scholte or Tinka Beemsterboer, make sure to contact them before completing this protocol. You can reach us by email: Steven Scholte: h.s.scholte@uva.nl Tinka Beemsterboer: t.beemsterboer@uva.nl If you have any suggestions for improving the workflow, don't hesitate to add comments to the steps in the protocol. Hope to see you soon! Spinoza REC Team! Steven Scholte, Tinka Beemsterboer en Lukas Snoek
Obtención de parámetros óptimos en la clasificación de nubes de puntos LiDAR, a partir de sensores aerotransportados
Authors: Barragán Zaque William , Escobar Rey Lusette Karime , García Leidy
Published: March 2018

In the present work the information obtained from the data of two airborne topographic sensors LiDAR, Riegl VQ 580 and Leica ALS70 is used, obtaining cloud of points of the same zone. By performing a comparative iterative analysis, obtaining the optimal parameters of iteration angle, terrain, slope and iteration distance, used in the semiautomatic classification of points clouds and generate digital terrain models - DTM. In order to analyze the behavior of the point clouds and precision check, a control of dimensions was carried out and comparisons of the different digital terrain models were obtained, obtaining, therefore, this methodology.
Sistema de Pearson y modelos matemáticos aplicados a la hidrología
Authors: Ochoa Acevedo Yessica Paola , Esther Rivera María , Delgado Rodríguez Jesús Ramón
Published: March 2018

The application of mathematical models in the different areas of science focused on studying phenomena and events that occur on a surface today, has become a main tool, allowing to be efficient, providing successful solutions and with greater reliability. Environmental systems have been analyzed by mathematical modeling to understand the dynamics, spatial and temporal beha­vior of meteorological and hydrological variables and their impact on other processes and events. Pearson’s system of frequency curves has been widely used in areas such as economics, finance, military and engineering to analyze data series trajectories and to find the probabilistic behavior of an object or phenomenon in its dynamics based on its information historical. In general form found that the Black–sholes-Merton, Kolmogorov axioms, Frequency curves Pearson systems, Pearson-Wiener model, probability distributions, similarly the Fokker-Planck-Kolmogorov equa­tion, stochastic hydrological modeling, SIMGRO hydrological model, GRADEX method had been applied in the hydrological variable behavior, maximum flows estimation, ecosystem assessment how water resources regulators and hydrographics watershed management.
Análisis del flujo de pacientes en el servicio de urgencias del Hospital Universitario la Samaritana a través de simulación discreta
Authors: Hernández Chinchilla David , Camacho Oliveros Manuel Ángel , Duarte Forero Edgar Leonardo
Published: March 2018

The next article presents the development of an investigation project focused on the analysis of patients’ flow to the emergency room at Hospital Universitario la Samaritana in Bogotá, Colombia in order to propose strategies that allow raising the level of attention and the use of available resour­ces. First, a discrete simulation model was developed to describe the system and its key variables such as: arrival of patients, length of their stay, delays in attention and required ER staff. Within the context of this project, a methodology of segmentation was developed, based on the days of stay and the patient’s pathologies. After, scenarios and strategies were proposed to reduce the patient’s length of stay in the emergency room.
Biorefinación del fruto del Prosopis juliflora para producción de etanol. Evaluación de las etapas de acondicionamiento y pretratamiento
Authors: Morán Guillén Héctor Andrés , Faneite Noguera Alexis Manuel , Salones Chirino Glaycira del Valle , Gamez Gerdez Juan Vicente , Ferrer Ocando Alexis de Jesús
Published: March 2018

The fruits of Prosopis juliflora have the potential to be raw material in the production of bioethanol due to its high carbohydrate and fiber content, and its high productivity in arid localities. P. juliflora fruits were characterized chemically, its sun drying kinetics was modeled and 2 physicochemical pretreatments were evaluated. The fruits showed a moisture content of 12.51% on a wet basis (wb), 14.84% protein, 2.27% fat, 20.15% fiber, 58.49% Nitrogen Free Extract (NFE) and 4.25% of ash, on dry basis (db). The prediction sun drying of Faneite-Suárez model was the best, within the range of prevailing weather conditions. The acid pretreatment (6% of sulfuric acid, for 20 min, at 121 ° C) got the highest content of reducing sugars, 37.85%. The evaluated fruits can be used in the production of bioethanol through a technically feasible and sustainable processing route.
Valores medios y críticos, del consumo energético y de las variables meteorológicas, para el diseño de un sistema fotovoltaico y de respaldo, para la Universidad Libre - Seccional Socorro
Authors: Gómez Cardona Juan Pablo , López Sanmiguel Carolina , Almeira Ospina Juan Ernesto
Published: March 2018

La Universidad Libre - Seccional Socorro, through the research group GIAM-Z, took the initiative to design a photovoltaic generation system capable of supplying the energy consumed in the lighting of the classroom blocks, as well as a backup system that provide an autonomy of two hours. In order to have the necessary information to be able to calculate the specifications that the system should have, it was required to determine the mean and critical behavior of the weather conditions and the energy consumption. For this reason, a sampling was made throughout the day and year of the energy consumption, the speed and direction of the winds, the cloudiness, the solar trajectories and the solar radiation. In addition, data from energy consumption receipts were used, as well as meteorological data from IDEAM, NASA and the Majavita station.
Rutas y retos para la valorización de biogás
Authors: Navarro Puyuelo Andrea , Reyero Inés , Moral Ainara , Bimbela Fernando , Gandia Luis
Published: March 2018

The development of anaerobic digestion technologies for processing various residual streams (the organic fraction of landfill wastes, sewage sludge from wastewater treatment plants, pig and cow manure, etc.) has led to an increase in the production of biogas. Biogas is mainly composed of methane and carbon dioxide, though other minor compounds and impurities are present, hence different treatments must be applied for its purification and conditioning. Amidst the va­rious alternatives for its use and valorization, the most important are the following: direct use in the generation of heat and/or electric power, upgrading to biomethane, and syngas production (H2+CO), which is further used as raw material for producing liquid fuels and/or chemicals such as methanol. This work presents an overview on the different alternatives for biogas valorization, with special emphasis on catalytic reforming processes, such as dry and steam reforming, together with combined reforming routes including partial oxidation.
Assessment of compliance of prohibition of smoking (under section-4 of cigarettes and other tobacco products act) in Raipur city (C.G.), India: a cross sectional study
Authors: Kummar Jitendra Kumar , Jain Kamlesh , Verma Nirmal , Sinha Ashish , Bhawnani Dhiraj , Prashad Manish
Published: March 2018

Background: Use of tobacco has been proven to be one of the leading causes of preventable premature deaths and diseases across the globe. The global adult tobacco survey (GATS) India report 2009-10 estimates 34.6% of India’s adult population use tobacco in some form or other. The government of India has taken various initiatives for tobacco control by enacting comprehensive tobacco control legislation (Cigarette and Other Tobacco Products Act {COTPA}, 2003). The objective of the study was to assess the level of compliance of section 4 of COTPA in public places of Raipur.Methods: A cross sectional observational study was conducted in Raipur. The study was done around 480 public places for observing the compliance of section 4 of COTPA.Results: From the total 480 public places visited, 36.9% public places displayed “No Smoking” signage, out of 117 public places where “No Smoking” signage displayed only 11.3% were as per the COTPA specification. Only 12.3% of public places active smoking was observed during visit.Conclusions: This finding suggests a poor level of compliance of section 4 of COTPA in Raipur. Although the law has been drafted comprehensively, it is implemented only to certain extent.
Testimonialista Pedagogues: Testimonio Pedagogy in Critical Multicultural Education
Authors: El Ashmawi Yvonne Pilar , Hernandez Sanchez Ma. Eugenia , Flores Carmona Judith
Published: March 2018

Teacher educators employ a variety of approaches to multicultural education. This article describes how we have our students grapple with their positionalities, to socially locate themselves and then to question the how and why of what they learned by employing testimonio, a genre of qualitative research that has its epistemological roots in Chicana feminist thought, as pedagogy. We discuss how we use testimonio in our classes and how students can use the process of creating and sharing their testimonios to cultivate a multicultural education (MCE) perspective and begin crafting their own culturally relevant pedagogy.
A relação entre o Transtorno de Déficit de Atenção e Hiperatividade em adolescentes e a procura pelas drogas
Authors: Menestrina Laura Comiotto , Correa Camila Priscila , Reis Isabela Zini , Rangel Cyrino Luiz Arthur
Published: March 2018

Objetivos: Definir a adolescência, o Transtorno de Déficit de Atenção e Hiperatividade (TDAH), as drogas e a dependência química e verificar se este transtorno, em adolescentes, leva à procura pelas drogas. Fontes de dados: A abordagem metodológica adotada foi bibliográfica, com consulta às bases de dados CAPES, PCM, SciELO e PePSIC, entre 2000 a 2015. Síntese dos dados: Os artigos escolhidos abordam a correlação entre o TDAH em adolescentes e sua procura pelas drogas, levando a uma possível dependência química. Conclusão: Sendo a adolescência um período de complexas mudanças, hormonais e psicológicas, conforme os resultados obtidos denota-se que indivíduos com comorbidades associadas ao TDAH têm maior propensão a fazer uso de drogas na vida adulta, processo que se inicia em períodos anteriores do desenvolvimento. Isso reitera a necessidade de mais pesquisas e a promoção de políticas públicas de prevenção às drogas e maior aprofundamento e discussão em relação ao TDAH. Estes conhecimentos poderão ser aplicados na vida profissional em diversas áreas, na fisiologia, na psicologia do desenvolvimento, na psicofarmacologia, entre outras, cabendo ao psicólogo dominar o assunto para auxiliar seus pacientes, promovendo melhor qualidade de vida para os mesmos, debatendo o TDAH e sua correlação com o uso de drogas.
Editorial for Special Issue: Using Poetry and Poetic Inquiry as Political Response for Social Justice
Authors: Faulkner Sandra Lea
Published: March 2018

Editorial for special issue on Poetry and Social Justice
Elaboración de Chocolate con Espirulina (Spirulina Máxima) Endulzado con Stevia y Frutas Deshidratadas
Authors: El Salous Ahmed , Cadena Nadia , Mosquera Corina , Martínez Tatiana
Published: March 2018

The present research is based on elaborating a chocolate bar with spirulina sweetened with stevia and dehydrated fruits, generating an alternative of consumption for the people who like the innovation  of the chocolate.The treatments were mainly based on concentrations of cocoa dough (Arriba), dehydrated fruits (pineapple, banana, orange) and esperulin, obtaining as a product of the major sensory acceptance that treatment based on 69% cocoa dough, 20% Dehydrated fruit (pineapple and banana) and 5% spirulina. The Tukey's test was applied to the five percent of the probability in which it was possible to differentiate from the others treatments for its excellent attributes in brightness, sweet taste, fruit flavor and residual sweetness that it possessed.Nutritional results were given as protein with 15.47 g, dietary fiber 11.91 g in 100 grams serving. This indicates that it has a high content of protein, fiber and low concentrations of sucrose; because sugar comes from dehydrated fruits. The  microbiological parameters showed that the product complies with the Ecuadorian technical standard NTE INEN 621: 2010, giving evidence that it is fit for human consumption. Key words: Spirulina, dehydrated fruits, stevia, cocoa Arriba.
Bacterias del Ácido Láctico un Potencial para la Producción de Alimentos Probióticos Fermentados en la Industria Láctea de Panamá
Authors: Quintero Por: Melvys Jacqueline Vega
Published: March 2018

The lactic acid bacteria known by their initials (BAL) are microorganisms that in the absence of oxygen degrade carbohydrates like lactose (milk sugar), to synthesize lactic acid and energy, through a process known as lactic fermentation. In the dairy industry these microorganisms are used as lactic ferments or initiators of the lactic fermentation process for the manufacture of cheeses, yogurt, fermented milk and other products derived from milk. The type of bacterial species used as an initiator in the fermentation process is a determining factor in the nutritional quality and sensorial characteristics of the final product. The main objective of the investigation is to carry out an evaluation on the potential of sources and milk production in Panama, specifically in the Chiriquí Highlands. Regarding the scope of the research, its perspective is to continue research on the biological diversity of lactic acid bacteria present in dairy sources, for their isolation and use in the dairy industries. It is important to highlight the high production of cattle, sources and milk production in the Highlands, which represents a potential diversity of lactic acid bacteria.Keywords: Lactic acid bacteria, lactic fermentation, probiotic foods, genetic markers, phenotype.
Análisis de variables para el Departamento del Meta - Colombia Respecto de Algunos de sus Municipios
Authors: Fonseca Luis Joaquin Ducon , Garcia Juan Alejandro Chica
Published: March 2018

The present study corresponds to the analysis of a joint exercise between the Gobernación del Meta, COSMOS Corporation and the Autonomous University Corporation of Nariño, in which 1800 families were surveyed corresponding to 11 municipalities of the department and that focused on those whose lands were inferior to 3 ha, to ensure that a subsequent family agriculture program would be supported. The analysis corresponding to the application of the survey showed that some of the municipalities of the department have major economic deficiencies and that according to the commercial route of the same its economic characteristics are similar geometrically. Equally thanks to this exercise of analytical could find the municipality of greater economic prosperity.Keywords: food safety, state, economic prosperity.
Boussinesq Solitons as Propagators of Neural Signals
Authors: Vargas Edgar Villagran , C. Juan Ramón Collantes , Granados Máximo A. Agüero
Published: March 2018

We  consider  certain  approximation for determining the  equation  of motion  for nerve  signals by  using  the  model  of the  lipid  melting  of membranes.   The  nerve  pulses  are  found  to  display nonlinearity and  dispersion  during  the  melting  transition.  In this  simplified model the  nonlinear equation  early  proposed  by  Heimburg  and  coworkers  transformed to  the  well known  integrable Boussinesq  non linear  equation.   Under  specific values of the  parametric space this  system  shows the  existence  of singular  and  regular  soliton  like structures.   After  their  collisions  the  mutual creation  and annihilation (each other)  of nerve signals along the  nerve,  during  their  propagation, has been observed.Keywords: Boussinesq equation,  singular  solitons,  single neurons,  neural  code.
Relación Entre la Investigación y la Docencia Activa. Un Punto de Vista Cualitativo de Estudiantes de Ingeniería
Authors: Álvarez Aránzazu Berbey , Álvarez Humberto , Cedeño Jessica Guevara , Sanz Bobi Juan De Dios
Published: March 2018

This manuscript presents a qualitative analysis about the engineering students perspective of the insertion of research results in the teaching/learning process in the classroom, and if these didactic resources motivated or promoted a future scientific research career.Keywords: research, active learning teaching, engineering students, perception, qualitative study.
A Comparative Study on Fatigue Damage using a Wave Load Sequence Model
Authors: De Gracia Luis , Osawa Naoki , Tamaru Hitoi , Fukasawa Toichi
Published: March 2018

Despite that ships get the approval of classification societies and structural members are designed to survive random environmental conditions for twenty or twenty-five years, fatigue crack damage still occurs. Nowadays, the operation based on weather routing programs has become important, not only to avoid adverse sea conditions that can cause damage, time loss or significant speed reduction but also to improve the crew safety. In this paper, S-N based fatigue assessment of a welded joint in an ocean going is performed. It is assumed that the ship sails following a planned route and a route based on weather conditions. Short sea sequences are generated by a storm model called “4G Storm Model”, proposed by one of the co-authors (De Gracia et al., 2017). Stress histories are generated considering the stochastical nature of the wave direction variation. Cumulative fatigue damage is performed following a classification society rule. Based on these results, the effect of ship routing and headings model on the S-N fatigue assessment is discussed. Keywords: Weather routing, fatigue, cumulative damage, storm model, wave sequence model.
Estimación de Parámetros Para Cargas Contaminantes Conectadas a las Redes de Distribucción
Authors: Guerra Pedro Raúl De León
Published: March 2018

In this paper we propose a new algorithm for the estimation of the parameters of the harmonic loads connected to the electric distribution system. The new parameter estimation algorithm is based on the weighted least-squares technique. The estimation algorithm solves an optimization problem and minimizes a set of variables which must comply with a series of specifications or characteristics of the harmonic loads. The estimation algorithm is able to obtain a load model with good accuracy comparatively to current -model of the system, due to a good engineering estimation of the initial conditions. Finally the new estimation algorithm could be used for power quality studies and to measure the contribution of the harmonic contamination of the clients connected to the electrical distribution system.Keywords: Harmonics, parameter estimation, weighted least squares, models.
SARA: Videojuego Para el Aprendizaje Agrícola Soportado en Dinámica de Sistemas (DS)
Authors: Prada Urbano Eliécer Gómez
Published: March 2018

SARA is a videogame for the learning of agricultural production systems, in which the player simulates the decisions that would take in a greenhouse and concentrate them in a web portal for its subsequent follow-up, traceability and contrast of results in a way that favors the learning process. The game rules are supported in a simulation model elaborated with Systems Dynamics (SD).Keywords: Serious Videogame, Learning, Agriculture, Systems Dynamics, Web Information System, Knowledge Representation
Diseño de un Módulo Virtual Para el Aprendizaje de Ensamble y Configuración de Computadores en la Institución Educativa de Puerto Rico Meta
Authors: Moya Harrison Espitia , Hoyos Francisco Javier Cifuentes
Published: March 2018

In the “Institucion Educativa Urbana” in Puerto Rico Meta, there are important technological tools that are often missed that are granted by government subsidies; but with the creation of this educational module a process of technological revolution began in town.Students will have the ability to perform any assembly and installation of computer equipment showing a new job opportunity and improving the educational level with the use of information technology and communication and their minds away from the stark injustice and violence which subjected grabbed this town and its students.Innovation in education makes more striking the appropriation of concepts, and encourages students to explore many beyond what they can receive in a classroom making the experience an enriching element in the process of formation students; The application features a flash animation of how the process of assembling a pc, additionally with a video tutorial on installing and configuring multiple operating systems, an extensive glossary of terminology applied to computers and technology.Keywords: education, technological tools, appropriation of concepts, software.
Implementación del Emprendimiento en la Universidad Tecnológica de Panamá, y el Perfil del Emprendedor Universitario
Authors: Canto Mariela Salgado , Herrera Vicente
Published: March 2018

This paper describes the process of transformation formally implemented at the Universidad Tecnológica de Panamá (UTP), to create a platform for fostering and supporting entrepreneurship and the results of the research of the universities entrepreneurship research. The first part of the article presents the conceptual framework on the role that the University should play today, in the face of entrepreneurship.  We focus this part of the development of the article on the contributions of author Burton Clark, in his model of Entrepreneurial University and as implemented in the UTP, the common elements of entrepreneurial universities, which were identified by Clark as "transformation paths", which we have adapted and presented their development in a public university. The second part of the article seeks to analyze the profile of the university entrepreneur, that is to say, one wants to know the entrepreneurial intention, so it is important to analyze the attitudes and perceptions of the students of public and private universities in Panama. The results of the study show that there is a greater proportion of positive responses to entrepreneurship in students of private universities, that is to say, a higher positive attitude towards entrepreneurship. This is because they come from private schools, where its treated or discussed more, the aspect of entrepreneurship than in public schools. Globally we can see that there is a great positive entrepreneurial attitude in students, since universities today have several courses of entrepreneurship in the various university careers, something that did not happen 15 years ago. Keywords: Entrepreneur, entrepreneurial university, enterprising attitude, students.
Predicción de la Resistencia de las Conexiones Tipo Canal en Estructuras Compuestas de Acero y Hormigón
Authors: Quevedo Rafael Larrúa , Vergara Ramiro Vargas , Louzado Jennifer Espino
Published: March 2018

This article deals with channel connections in steel and concrete composite structures, with the main objective of obtaining a new formulation to determine the resistance of this widely used type of connection in the American region. Data from channel connections tests are collected from reliable experimental and numerical sources, and a valid database is created to make predictions by means of different combinations of artificial intelligence techniques, to obtain the most effective cases. Finally, a new formulation is proposed to calculate the resistance of channel connections in solid slab, applying statistical techniques to a database that incorporates experimental, numerical and artificial intelligence results, demonstrating its superiority with respect to the existing formulations in the international literature, by means of statistical measures appropriately applied to the studied case. The proposed methodology is novel and effective, and it can be expanded to other types of structural elements.  Keywords: composite structures, connections, resistance, prediction.
Organizational Best Practices for Transportation Projects Delivered Using Alternative Contracting Methods
Authors: Gransberg, PhD, PE Douglas D. , Del Puerto, PhD Carla Lopez , Tapia, PhD, PMP Ricardo M.
Published: March 2018

The use of Alternative Contracting Methods (ACM) to deliver US transportation projects has reached a point where a definitive set of best practices can be identified to leverage the lessons learned by early ACM adopters. The most pressing need is for guidance on how public agencies organize to implement ACMs in a budget-constrained environment where the possibility of increasing the number of public agency engineers is nil. This paper is based on mining the survey response data from 6 National Cooperative Highway Research Program (NCHRP) synthesis reports on ACM topics and proposes a framework for analyzing ACM practices deemed effective by peer-reviewed research to determine if each practice can be classified as a best practice. Importance index theory provides the analytical foundation for the framework and provides a ranking of candidate best practices in order of each practice’s importance and effectiveness. Nine effective ACM practices were identified and evaluated with only one, “appointing an agency ACM champion,” meeting the objective criteria for a best practice. The paper’s major contribution is to provide the suite of 1 best and 8 effective practices that can be employed when developing the organization for an agency that has decided to implement ACM project delivery.Keywords: Alternative contracting methods, best practices, organizational structure, index number theory.
Columnas Compuestas de Hormigón y Acero SRC, Sujetas a Flexocompresión Biaxial
Authors: Jaramillo Jorge Ricardo Vintimilla , Rodríguez Luis Tinerfe Hernández
Published: March 2018

The work presented is based on experimental and theoretical analysis of SRC composite columns subjected to biaxial bending and axial compression, where the specification of American and European code criteria are used to calculate de load bending strength. The computer program to calculate the interaction diagram of biaxial bending and axial compression with inclined neutral axis is made in the software Matlab by using the fiber method, besides, the strength of the specimen is calculated. Users can design new frame sections and check the exist sections. To obtain the displacements and load curve, to calculate load contours and determination of the interaction family curves of the modeled sections. The destructive performance of the round and rectangle composite columns are made in the structures laboratory of EPN to obtain the results such as the buckling displacement at strong, weak and longitudinal direction measured with LVDT´S. Subsequently, the theoretical and experimental analysis results are made to demonstrate the reliability of the numeric model.Keywords: Composite Columns, Concrete, Steel
Metal Biocorrosion of a Water Well: A Case Study
Authors: Calbo Vicente , Furlong Octavio Javier , Julián Silvia Viviana
Published: March 2018

Recently, in the city of La Rioja, the Microbiologically-Induced Corrosion (MIC) phenomenon has been confirmed. The last studied case corresponds to the water well of the La Rioja Regional Faculty of the National Technological University (UTN), where the water well facilities showed signs of this phenomenon.These microorganisms catalyze the iron (and magnesium) oxidation reactions, solubilizing or solubilizing and precipitating the metal. Confirming the existence of the MIC phenomenon is essential to mitigate or solve the problem.The laboratory work consisted in processing pipe and pump samples extracted after the well ceased to be used, at three initial temperatures and with different culture media, trying to cultivate, reproduce, and isolate and identify the different species.Thus, through culture methodology, the existence of a mixed flora featuring iron bacteria and sulfate-reducing bacteria was confirmed.Complementary Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray Spectroscopy (EDS) spectroscopy scans allowed to visualize the bacteria, the damage to the analyzed material, and the morphology of the bioprecipitation.This little-known phenomenon causes significant economic losses and should therefore be taken into account in the execution as well as the maintenance of wells. Keywords: Metal Corrosion, Microbiologically Induced Corrosion, Water Well, Bacteria.
Comunicación y transferencia en la co-gestión del hábitat local: el Proyecto "Hábitat 2"
Authors: Seijo Alexander González , Ranero Andrés Olivera , Pérez Pedro Seijo
Published: March 2018

El proyecto “Implementación de estrategias para la gestión local del hábitat a escala municipal” o “Hábitat 2”, surge con el objetivo de contribuir al mejoramiento de la calidad del hábitat de la población de diez municipios cubanos con cerca de medio millón de habitantes, con énfasis en la atención a grupos vulnerables y mujeres. Se pretende generar efectos que impactarán en la gestión pública de la vivienda y el hábitat; la eficiencia de la cadena productiva del hábitat; y la actualización de las políticas económicas y sociales del país en esta materia, en el periodo 2014-2019.Para el logro de los objetivos se ha desarrollado un sistema de co-gestión entre actores municipales y especialistas vinculados al tema que ha permitido el desarrollo de estrategias integrales de gestión del hábitat, el emplazamiento de maquinarias para la producción local de materiales de la construcción, ayudas a la movilidad, el acceso y almacenamiento de agua, la facilitacion de los trámites asociados a la vivienda y el hábitat de los ciudadanos, entre otras cuestiones. La gestión de la comunicacion y la transferencia tecnológica son procesos escenciales en el logro de estos resultados.Palabras claves: co-gestión, hábitat, transferencia tecnológica, comunicación.
Comparación y Efecto del Homogenizado en Billets de Aluminio AA 6063
Authors: Olmedo Bladimiro Hernán Navas , Moscoso Hernán Alberto Navas
Published: March 2018

The lack of comparative studies about the distribution of the main alloying elements along aluminum billet´s AA 6063 widely use in extrusion companies to produce aluminum profiles, It makes necessary to counterpoise the difference between homogenized billet produced in horizontal continuous casting machine and a billet produced in vertical semi-continuous casting process. Applying spectrometric tests to quantify the weight percent of main alloying elements, brings out its own nature of each production process on every billet. Nevertheless, helped out by a metallographic test reveals in one billet the negative effect of an inadequate process of homogenization after the heat treatment process T5 in the aluminum profiles that holds it back to reach an adequate Webster hardness related to quality assurance. It reflects that is not enough to have a billet with a uniform chemical composition but the importance of an adequate billet´s heat treatment in order to be use in the extrusion process.Keywords: AA 6063, Billet, Comparison, Homogenized
Development of a Practical Straightening Simulation for Welded Structures Using Inherent Strain Method
Authors: Hector Ruiz , Naoki Osawa , Hidekazu Murakawa , Hidekazu Murakawa , Sherif Rashed
Published: March 2018

Welding is the most widely used assembly method available to industries in the construction of metal structures, ships, and offshore platforms. However, this method always produces a certain amount of distortion that will not only degrade the performance but also increase the building cost of the structure, and it should be straightened. Murakawa [1] developed a thermal elastic plastic based and inherent strain based welding simulation FE code JWRIAN. Coarse shell FE models are usually used in the inherent strain based JWRIAN elastic analyses. This drastically reduces the manpower needed for modeling and computer resources needed for the calculation. However, it is not easy to perform straightening analysis using JWRIAN because gas heating’s inherent strain distributes over a range much smaller than element sizes of the shell model.RUIZ [2] modified JWRIAN’s code so that the inherent strain equivalent nodal forces along the heating line are calculated and applied in the elastic shell analysis. However, a discrepancy between 3-dimensional thermal-elastic-plastic analysis and elastic analysis was observed. This is mainly because of the nature of solid and shell elements. RUIZ [3] proposed a linearized inherent strain and applied it to both 3-d and 2d analysis, getting matching results between solid and shell element models. In this study, as a working example, a thin plate panel with an opening is considered utilizing the developed system at the same time a friendly user interface for staffs and workers on a production site is developed.  Keywords: Inherent strain, straightening, finite element method, Gauss-Legendre quadrature
Photoluminescence in Raman Scattering: Effects of HfO2 Template Layer on Ultrananocrystalline Diamond (UNCD) Films Grown on Stainless Steel Substrates
Authors: De Obaldia Elida , Tirado Pablo , Alcantar Jesús , Montes Jorge , Auciello Orlando
Published: March 2018

The growth of polycrystalline diamond films can play an important role in industry if they can be grown on industrially used materials like aluminum (Al) or stainless steel (SS).   A critical issue related to the growth of ultrananocrystalline diamond (UNCD) thin films on metals like SS, in a Hydrogen rich environment like the one present during growth of UNCD films, is the diffusion of Hydrogen (H) into the SS substrate, as it has been observed in prior research, which results in hydride formation in the SS that induce brittleness in the SS substrate.  Several interface layers have been proposed described to avoid the H diffusion into the SS. However, HfO2 has not been explored.  The work reported here was focused on investigating the growth of UNCD films on commercially available SS substrates by using an interface layer of HfO2, which was found to be a good diffusion barrier for H to inhibit penetration into the SS substrate. The samples where characterized with SEM and Raman spectroscopy.  A photoluminescence (PL) effect, observed in the Raman scattering analysis, is present in all the samples.  The PL effect may be due to the interaction of the UNCD / HfO2 interface. and the SS substrate rather than UNCD film alone.  The novel result from the experiments described here, is the fact that it is possible to grow UNCD films on unseeded HfO2 layers on SS substrates.Keywords: Poly-crystalline diamond, photoluminescence, UNCD, Stainless Steel, Hafnium Dioxide
Estudio de Materiales Nanoestructurados por Metalurgia de Polvos del Ternario Zn-Al-Ag
Authors: Hernández Nancy Badillo , Bustos Estela Sarmiento , Ocampo Arturo Molina , Casolco Said Robles
Published: March 2018

In this work one presents the study realized to the compound materials: a) Zn77.0-Al22.0-Ag1.0 (wt. %) [Ternary Alloy], b) Zn77.0-Al22.0-Ag-1.0 (wt. %) [Compound Material 1] reinforced with 5 % of NaCl, and c) Al77.0-Zn22.0-Ag1.0 (wt. %)/Si [compound Material 2], the materials were incorporated by means of the alloyed mechanic in a time of grinding of 7 hours. The microstructural characterization was realized by means of: a) Diffraction of beams-X (DRX), b) Scanning Electronic Microscopy (SEM) and c) Microhardness Vickers (HV). The aim of this work was to study the effect of the microstructure and the hardness of a materials composed bases zinc and his comparison with a ternary alloy. Materials were obtained nanostructure by sizes of crystal in the ternary alloy of 94nm, and for the compound materials 1 and 2, 116 and 121 nm respectively. The values of hardness obtained for three systems have direct relation with the size of crystal. The image obtained to SEM at 7 hours of grinding suggests that the ternary alloy presents in the morphology bigger agglomerated particles and the compound material 2 particles small flakes. The results suggest that porous materials were obtained in three studied systems. Keywords: Mechanical alloy, Metallurgy of powders, Nanocomposite, Reinforcement with particles.
Experimental Study of an Air-PCM Heat Exchanger: Melting in a Cylindrical Container
Authors: Del Rosario Maria De Los Ángeles Ortega , Bruneau Denis , Sébastian Patrick , Nadeau Jean-Pierre , Sommier Alain , Lopez Jêrome
Published: March 2018

This paper presents experimental results of an air-PCM heat exchanger, with an in-line arrangement of cylindrical containers. The objective is to highlight the physical phenomena occurring in a single container during the phase change. Temperature and airflow measures were carried out. These values were used to find the heat exchanges on the container. The experimental heat values were compared and validated with the theoretical heat stored obtained from the material properties. An only conduction 1D radial model is proposed to describe the melting front in the container.Keywords: phase change materials, thermal storage unit, cylinder, latent heat, radial conduction.
Análise de Sinais de Emissao Acústica e Estatística Counts na Detecção da Alteração Microestrutural na Retificação de Aço 1045
Authors: Alexandre Felipe Aparecido , Viera Martin Antonio Aulestia , Conceição Junior Pedro Oliveira , Simões Leonardo , Lopes Wenderson Nascimento , De Aguiar Paulo Roberto , Bianchi Eduardo Carlos , Da Silva Rosemar Batista
Published: March 2018

Grinding is a high-precision, high-value-added finishing process as it is usually the last stage of the manufacturing chain. However, unsatisfactory results may occur, mainly due to changes in the microstructure of the ground workpiece. Such changes are caused by the high temperatures involved in the process due to the grinding conditions in which the part was subjected. In this way, the main objective of this work is the monitoring of the grinding process in order to detect changes in the signal and to relate them with damage occurred in the ground workpiece. The tests were carried out on a surface grinding machine, aluminum oxide grinding wheel and ABNT 1045 steel parts. Metallography was performed on the parts for a more further analysis of their microstructure. The recording of signals was obtained at a sample rate of 2 MHz through an acoustic emission sensor (AE). A frequency study for the selection of the best frequency bands that characterize damage occurred in the ground workpiece. The event counts statistic was applied to the filtered signal in the chosen frequency bands. The results of this work show that the grinding conditions influence the signal and, therefore, its frequency spectrum.Keywords: Manufacturing process; automation, monitoring; grinding process; acoustic emission, damage detection
Estudio de un Sistema Informático que realice Intercambios Electrónicos de Datos para compartir Información controlada entre Entidades del Sector Marítimo Panameño
Authors: Palacios Nitzia Aleine Aguilar , Gonzalez Cap. Francisco
Published: March 2018

Este trabajo de investigación corresponde a un estudio para la propuesta de un sistema informático que realice intercambios electrónicos de datos (EDI) en procesos marítimos, principalmente refiriéndose a importaciones y exportaciones. La forma manual como se desarrollan los procesos en la actualidad genera grandes volúmenes de documentación física, que involucra procedimientos burocráticos, sellos y firmas cuya obtención generan tiempos de espera. Es de gran importancia erradicar la problemática expuesta, considerando que esta situación deja atrás a Panamá, impactando negativamente en sus relaciones comerciales con otros países.Considerando que el tiempo es un factor de relevancia en la productividad del sector, se debería reducir al máximo posible. Razón por la cual se propone la implementación de una plataforma digital capaz de compartir información controlada entre los actores involucrados.La Autoridad Marítima de Panamá (AMP) es la entidad idónea para dirigir mencionado sistema informático, donde los principales actores serían: puertos, navieras, importadores/exportadores, entidades gubernamentales (aduanas, AUPSA, migración, cuarentena, etc.), transportistas terrestres y agentes de carga. Compartir la información de una forma automatizada agilizaría el desarrollo de los procedimientos, garantizando un mejor manejo de la información.Al final del estudio el resultado obtenido es la comprobación de la hipótesis verdadera.Palabras claves: Procesos de import/export, Electronic data interchange (EDI), Ventanilla única, Port community systems, Integridad del sector marítimo.
Identificación y Caracterización de Infraestructuras Críticas en Panamá
Authors: Gómez Evidelia
Published: March 2018

Critical infrastructures are man-made systems, facilities that provide services necessary for the development of an increasingly demanding economy. The importance of clear identification and characterization allows us to analyze how they relate to each other and the level of dependence they have between them. The objective of this research is to provide a frame of reference for the study of Critical Infrastructures in Panama. For this purpose, the information of the international scientific community has been reviewed mainly due to the lack of studies related to the critical infrastructures of Panama, as well as public and private organizations that manage the operation of the main service systems in Panama.Keywords: dependence, critical infrastructures, systems
Identificación de Parámetros de Desempeño de un UAV a Través de Vuelos de Prueba
Authors: Castillo Oscar Daniel Garibaldi , Beltrán Ana
Published: March 2018

The design and implementation of a autonomous navigation and control system for UAV, mandates simulating the system before in-flight testing.  These simulations require a computational model of the aircraft, that can be obtained from the computation of aerodynamic parameters such as the drag polar. In this paper we present the identification of these parameters using two methods: one by flight testing techniques; the other by a combination of semi-empirical methods and computational fluid dynamics, dubbed the hybrid method. The hybrid method, which produces a parabolic polar drag, had the same qualitative trend compared to experiments. However, a detailed analysis of the parameters that shapes the polar drag, had significant differences, particularly in the parasite drag. This is probably due to propeller effects, low Reynolds Number and limitations of the piloting technique.Keywords: Drag polar, flight testing, parasite drag, UAV, VLM
Segmentación de Imágenes Basada en Entropía de Pixel
Authors: Caballero Rony , Berbey Aránzazu , Cogley Alberto
Published: March 2018

In this research, a new methodology for color image segmentation is proposed. In this approach, a pixel entropy derivative based rule is used. The algorithm is tested not only with good quality images, but also with some of them with light scattering and absortion problems.  Preliminary results shows good performance of this algorithm.Keywords: Image processing, segmentation, entropy, feedback.
Swarm Robotics as a Solution to Crops Inspection for Precision Agriculture
Authors: Carbone Carlos , Garibaldi Oscar , Kurt Zohre
Published: March 2018

This paper summarizes the concept of swarm robotics and its applicability to crop inspections. To increase the agricultural yield it is essential to monitor the crop health. Hence, precision agriculture is becoming a common practice for farmers providing a system that can inspect the state of the plants (Khosla and others, 2010). One of the rising technologies used for agricultural inspections is the use of unmaned air vehicles (UAVs) which are used to take aerial pictures of the farms so that the images could be processed to extract data about the state of the crops (Das et al., 2015). For this process both fixed wings and quadrotors UAVs are used with a preference over the quadrotor since it’s easier to operate and has a milder learning curve compared to fixed wings (Kolodny, 2017). UAVs require battery replacement especially when the environmental conditions result in longer inspection times (“Agriculture - Maximize Yields with Aerial Imaging,” n.d., “Matrice 100 - DJI Wiki,” n.d.). As a result, inspection systems for crops using commercial quadrotors are limited by the quadrotor´s maximum flight speed, maximum flight height, quadrotor´s battery time, crops area, wind conditions, etc. (“Mission Estimates,” n.d.).Keywords: Swarm Robotics, Precision Agriculture, Unmanned Air Vehicle, Quadrotor, inspection.
Métodos de Interpolación Basados en Funciones de Base Radial con Aplicaciones a la Reconstrucción de Imágenes
Authors: Combe Rodrigo , Arrocha Idulfo
Published: March 2018

This article presents the Radial Base Functions (RBFs) as a functional interpolation method for implicit surface reconstruction from points cloud.  These methods allow not only to improve inaccuracies resulting from scanners, but also possible discontinuities that occur in the point clouds.  The complexity of three-dimensional objects makes reconstruction difficult since devices such as scanners do not always faithfully reproduce the objects, which can lead to information gaps or an incomplete reconstruction. Interpolation methods based on RBFs allow to correct these errors.  Three-dimensional surface reconstruction has wide applications in biomedical engineering, in the design of industrial parts, among others.  With the algorithm, we developed we have been able to make reconstructions of both explicit and implicit functions, in two and three dimensions.Keywords:  Radial Basis Functions, Three-dimensional reconstruction, Interpolation Methods.