vol. 12 núm. 19 (2016)

Many scientists of the XVII century kept the results of their investigations secret in order to avoid others claiming them as their own. Thought leaders of the time, including Sir Isaac Newton, refrained from announcing many of their discoveries in fear of third parties claiming authorship on said findings.

Introduction: This article was created by the 2015research for the Electronics’ Engineering Degree of the University of Santa Catarina’s department (Brazil). Most systems that measure water and are used in residences can register the air flow that may be present in the distribution system. This problem is hard to measure, since it’s a combination of liquid and gas. The purpose of this article is to identify and quantify the sensibility of residential hydrometers to the air volume registered. Methodology: To accomplish it, an experimental hydraulic circuit was developed, and sensors were deployed to monitor the water entry and exit of the system, composed by two warehouses. One warehouse stored water for the circulation of the hydraulic drainage, while the other stored the total amount of water in the system. The water level in the storehouses is controlled with ultrasonic and potentiometer sensors. A spinner is used to estimate the total water volume that enters the system by measuring its volumetric flow. Results: The results show that the hydrometer is very sensible to the air flow and that it can measure up to 44% of air in the air/water combination. The difference in the estimated water volume in the spinner and in the hydrometer was of 3,7 liters. Conclusions: The hydrometer is especially sensible to air presence in the residential hydraulic pipelines under normal conditions of a nominal flow of approximately 1,5 m3 /h.

Introduction: this article was produced by the research project “Assessment of the environmental situation in educational institutions” developed in 2015 by the Industrial University of Santander and the University of Santander. The addressed research problem derives from the hurdle that current educational institutions must overcome when working with marginalized populations in creating environmental awareness and visualizing a future with sustainable educational institutions. Methodology: in order to perform the Environmental Impact Assessment (eia) in the case study educational institution, the conesa method and the measurement of the “ecological footprint” were applied. The resulting information was analyzed so that the educational institution would alleviate the environmental effects of daily actions of students, teachers and staff during the general course of operations. Results: a significant impact of social and cultural variables was made in the environment. Given the aforementioned, the findings indicated the need to promote good citizenship behaviors through play-like strategies that would allow the students to build social guidelines and create symbols associated with environmental conservation. Conclusion: the environmental perception of the case study educational institution was assessed through a statistical analysis that produced an unfavorable environmental perception. The biggest impact identified is associated to a high consumption of water, followed by the impact associated with high level noise.

Introduction: this article is the result of the research project “Factor identification of categorical type related to the structural condition of Bogota’s sewage pipelines stemming from concepts of information’s entropy” financed by the Mastery in Hydro-systems of the Pontifical University Javeriana and developed in 2014 and 2015. The objective was to identify the influence of factors of qualitative type (grid type, material of the associated road surface and material of the pipeline) on the structural grade obtained from CCTV  inspections in Bogota during 2007 and 2011. Methodology: the entropy’s concept of mutual information was studied to differentiate the following categorical variables: type of pipelines, type of road surface over the pipeline and materials of the pipeline. Results: obtained from the application of concepts like entropy and mutual information show that the structural classification is independent from the type of pipeline, since they present elevated values of joined entropy and imply a high degree of uncertainty in their relation. Conclusions: the categorical variables studied are important factors to account in an impairment model of sewage pipelines; they also provide decision-making to direct the inspection plans of sewage in the city.

Introduction: this article is the result of the research “Nutritional evaluation of fruits grown in Valle del Cauca, Colombia” conducted in 2014 by the University Santiago de Cali. Its purpose is to evaluate the Fe, Na, Mg and Cu minerals found in the pulp of sapodilla plum (Quararibea cordata) grown in Valle del Cauca. It uses flame atomic absorption spectrophotometry as the main method. Methodology: the quantification was performed by determining the lineal working range; concentration was low in each metal and meted the statistical tests of system linearity, like correlation coefficient and hypothesis for pending and intercepting when using a Student t-test with a confidence of 95% (including zero). Results: the obtained composition of minerals in the pulp of sapodilla plum was of 0,42 ± 0,03 mg Cu/100g pulp, 3,2 x 10-3 ± 0,04 mg Mg/100g pulp, 0,47 ± 0,09 mg Fe/100g pulp, and 0,03 ± 0,01 mg Na/100g pulp. The report includes low content of Mg and higher amounts of Fe and Cu. Conclusion: the analysis method of flame air-acetylene atomic absorption spectrophotometry for evaluating iron, magnesium, copper and sodium metals found in the pulp of sapodilla plum (Quararibea cordata) grown in the Valle del Cauca region guarantees the reliability of these results.

Introduction: this article is the result of the research “Controllers in simulation of investigation not associated to an institutional project” developed in 2012 by the Pontifical Bolivarian University in Medellin, Colombia. It describes the development of a temperature control system in a scaled prototype of a small cavity; analyzes the control method in simulation and demonstrates how to implement the algorithm in a microcontroller DSPIC using state space representation and power control per stage. Methodology: a static and dynamic analysis of the system is performed and the procedure is described to locate the parameters of the model. Results: they are presented graphically, using data obtained both in the simulation as in the physical implementation of the prototype. In the data is observed the behavior of the control system when confronted with changing temperature references and disturbances. Each of the improvements made to the control system enhances the expected answer, so that it reaches a stable state in approximately 4 minutes, when using the controller PID and the open control loop. Conclusions: the second order model selected for the system’s dynamic model has good precision and follows approximately the same form as the experimental dynamic curve. The controlled system takes about 4 minutes to reach a stable state when using the PID and the open control loop.

Introduction: these are findings of the research project “Evaluation of pollutant load in Combeima River, main supply source of Ibague’s urban aqueduct” developed by the Cooperative University of Colombia in Ibagué. Methodology: an exploratory research was conducted to evaluate the spatial behavior of murky river water and its conductivity in 2014; the quality samples were collected from unprocessed water in seven different points along the river. The research was performed during dry and rainy seasons, and analyzed during the covered period between 2008 and 2012. The dry and rainy seasons during that time were characterized by natural meteorological events known as El Niño and La Niña. Results: the highest monthly average values were recorded in May, period that matches the first rainy season and that evidences an average yearly increase. The conductivity had no variations during the course of a year. The findings include concentrations allowable for human consumption, in which the weather conditions did not had a significant impact, despite changing values of the murky water, to which it is not linked. Conclusion: the company IBAL S.A. E.S.P. proposed a medium-term solution to alleviate the effects of increased murky water during rainy seasons, via the study, design and construction of satellite water intakes at the sources that, given their volume and running conditions, may be beneficial as substitute systems during periods where it’s imperative to close the aqueduct’s water intake.

Introduction: this article is the result of the research “Design and construction of solar heaters with reusable material”. The research was conducted by the research seedbed sea, part of the research group of alternative power GIEAUD  of the District University Francisco José de Caldas, from November 3, 2014 to April 10, 2015. Methodology: the study describes mathematical analysis, selection of materials (both for the insulator and the tank body), simulation of hydrostatic behavior, construction processes based on the norm ASME, section VIII, test runs, and thermal assessment. Results: the solar collector (built by the students of the sea seedbed) and the tank built by the authors of this report were installed on the gymnasium’s terrace of the Technical Faculty of the District University Francisco José de Caldas. The tank was assessed to demonstrate its efficiency in conserving temperature levels and functioning as a solar heater. Conclusion: the experience acquired in creating and developing the tank and the assemblage of solar collectors confirms the convenience to pursue research on more elaborate methods that will allow the improvement of operations and usage of new materials in the design, manufacture and evaluation of solar heaters