bluuebunny/crossref_metadata_2025_split huggingface dataset:
AC Loss Analysis on Coated Conductors at different Sinusoidal Frequencies for Electric Propulsion Applications
Authors: Kumar Abhinav , Jeyan JV Muruga Lal , Agrawal Ashish 
Published: June 2020

Abstract
Superconducting magnets are one of the superior contenders in achieving the targets of electric aircraft industry successfully as they have very high power densities compared to other battery storage systems. Many aviation research agencies are looking at superconducting magnets as one of the alternate in replacing the conventional jet engines completely (electric aircrafts) or partially (hybrid aircrafts). National Aeronautics and Space Administration (NASA) and Air Force Research Laboratory (AFRL), USA has reported that high temperature superconducting magnets possesses higher specific energies (Wh/kg) and have infinite number of recharge cycles compared to other storage technologies employed for energy requirements. The other advantage of using such magnets is that there will be no hazardous disposals like batteries which lower the overall pollution. Superconducting magnets are DC operated systems however during charging or discharging transient behaviour of current results in the losses which would further ends up with heat generation. Heat generation during charging or discharging period would cause quenching of the superconductor due to sudden temperature rise.
In this work, electromagnetic analysis on superconducting magnet having capacity of 1 MJ has been performed where a 2D numerical model is developed using H-formulations in order to estimate the AC losses for a high temperature superconducting tape manufactured by SuperPower (SCS 12050) having 330 A critical current at 77 K. AC current having different load factors has been fed through the stacked tapes at 50 Hz, 60 Hz and 70 Hz frequency and AC losses have been evaluated. It has been found that at higher frequencies the AC losses are found to be larger than lower frequencies. Overcritical currents have been found in the current density distribution due to the application of E-J relationship for the homogeneous 2D numerical model.
Evaluating a new binder in the self-leveling mortar mixture
Authors: Guzman I , Porto A F , Cervantes G , Porto R I 
Published: June 2020

Abstract
The infrastructure of a country plays an important role in economic growth, contributing as a basis for other actors such as: production, transport and access to services that meet basic population needs. In this article we study the Sika-Colombia company dedicated to the construction material supplies, specifically self-leveling mortars, in relation to an improvement of physical properties (i.e. resistance and consistency) and production costs. The impact of new binder addition in a self-leveling mortar mixture Sika Grout 212 is analyzed experimentally. This approach is justified by the need to improve the granular skeleton of the study product, recover fluidity and maintain the resistance offered to customers. The research results conclude the physical and economic advantages of new binder adding to the mortar mixture as well as optimum composition.
Kinetic Study of Cyanide Degradation from Gold mining wastewater Using Photocatalysis
Authors: Correa-Turizo R.R. , Mestre-Martinez R.M. , Marrugo-Pautt I , Baldiris-Navarro I , Severiche Carlos 
Published: June 2020

Abstract
Highly toxic cyanides are among the most persistent chemical compounds in effluents, these chemicals are used in several industrial sectors and particularly in mining industry for the extraction of gold. Cyanides frequently appear at low levels in water, deteriorating its quality. In this paper a degradation of 55.76% and 62.99% was obtained using TiO2 catalyst and TiO2 doped with Cu heteropololybdate respectively in 360 min of reaction, applying photodegradation with a 125 watt mercury lamp source. Most of the trials showed that the degraded compound kinetics may be adjusted to a pseudo first order model.
Risk assessment of PCP lift system using a fishbone diagram and MICMAC method
Authors: Osorio-Tovar J. , Grimaldo-Guerrero J.W. 
Published: June 2020

Abstract
Hydrocarbons demand by industrialized and developed nations and the oil prices conditions last few years; many companies have turned again to fields that were not previously considered attractive to produce, to identify them as an alternative to meet that demand. This research shows the identification of a condition, which should be taken into account to produce a mature field by progressive cavity pumping (PCP) artificial lift system, an evaluation with the MICMAC method and the identification of the key variables to achieve the development in this practice. The results make possible to identify highest influence elements, which can guide intervention strategies and form the basis to formulate guidelines and policies for the PCP implementation. The results allow us to conclude that pressures and mechanical designs in field wells should be the guidelines for optimum production, the market rate improvement, and the reservoir productive life.
Prospective towards implementation of electric vehicles in Colombia
Authors: Gómez-Mesino E. , García-Quintero A.F. , Grimaldo-Guerrero J.W. 
Published: June 2020

Abstract
The effects of climate change have led to reduces fossil fuel in vehicle, developing new technologies such as the electric vehicles. The research presents an identification of barriers and inhibitors according to international experiences, an evaluation with the MICMAC method and the identification of key factors to achieve development of electric vehicles in Colombia. The results allow to identify the elements of high influence, which may guide intervention strategies and be the basis for the formulation of guidelines and policies. The results conclude that the business models for the purchase and sale of energy are the catalyst for the encouraging of the stakeholders, the improvement of the distribution network and the management of the electricity market.
Evaluation of trace-metal concentrations in water consumption of streams near Guajira (Colombia)
Authors: Garzon N. , Espinosa E , Sarmiento-Rubiano L. A. , Manzoli R R. , Canteroand R. , Castro-Suarez J. R 
Published: June 2020

Abstract
The spatial distribution of metals in the water for consumption in the different supply sources, natural sources, family storage tanks and deep wells were studied. 16 samples were made for different municipalities belonging to the department of La Guajira upper part. The water samples were analyzed in 2016 and analyzed physically and chemically and microbiologically. The results were compared with national standards and those established by the WHO. The results found show some traces of metals in some of the sampling sites. The concentrations of Calcium, Magnesium exceeded the concentrations established by the standards. The results reinforce the need for better control of the physicochemical and microbiological parameters of the water consumed by the population.
Design of a library using Matlab software for modeling and simulation of parabolic cylindrical solar collectors (CCP)
Authors: Sanchez S A , Quiroz M A , Sierra LR , Morales A D , Palencia J M 
Published: June 2020

Abstract
Much of the energy available to the earth comes from the sun, it is the largest source of radiation, emitting approximately 1353 W/m2 of energy into the Earth’s atmosphere, in the form of electromagnetic waves, with wavelengths (λ) between 0,3 and 3 μm. Within this spectrum we find the following radiations: Gamma (1%), Ultra violet (4%), Luminous (49%) and Infrared (46%). Only 51% of the solar radiation that enters the atmosphere reaches the earth’s surface. This radiation represents a main source for renewable energy, presenting great applicability in solar thermal energy and specifically in the use of parabolic cylindrical solar collectors; that take advantage of this radiation to raise the temperature of a fluid, located in a receiving tube. The great problem of these systems is to generate a good design, which allows to reach high temperatures and good yields, therefore, many investigations have generated multiple design software, which mitigates the margin of error, but generally this software are limited; With licenses, they are complex and do not specify all the features for processing. The main objective of this research is an open source library that allows obtaining the highest efficiency of parabolic cylindrical collectors, based on the theoretical references Duffie, Beckman and Kalogirou. For this, the Matlab software and the Soltrace tool were taken into account, in order to validate the sizing and optical, thermal, geometric and global performance. Within the results, the maximum concentration ratio of the parabola is checked, which is obtained when the edge angle is 90 °. A functional library can be generated, where multiple measurements and shapes of the parabola were simulated, obtaining the highest overall performance, when the focal length is equal to the maximum height of the parabola, obtaining a performance of 62.64%.
Parameter estimation of a second order system via nonlinear identification algorithm
Authors: Ordaz Patricio , Rodríguez-Guerrero Liliam , Santos Omar , Cuvas Carlos , Romero Hugo , Ordaz-Oliver Mario , López-Pérez Pablo 
Published: June 2020

Abstract
In this paper, a parameter estimation for a class of second order nonlinear system is presented. The considered system, can be represented in such way that it is linear respect its parameters. Since the system output is given, only, for the second integrator a state estimation of unmeasured state variables is reconstructed via nonlinear observer based on the terminal sliding mode observer. Therefore, the main contribution of this paper deals with a full order nonlinear observer algorithm design to enhance parameter identification of a nonlinear second order system. Finally, to illustrate the theoretical performance of the proposed identification algorithm, an experimental result of a mechanical system is presented.
NDT Non-Destructive Test for Quality Evaluation of Concrete specimens by Ultrasonic Pulse Velocity measurement
Authors: Pedreros L , Cárdenas F , Ramírez N , Forero E 
Published: June 2020

Abstract
Knowing the quality of concrete is very important, because this type of material is part of the design and implementation of most structures such as bridges, buildings, tunnels, among others, in this investigation non-destructive tests were carried out on test specimens of using ultrasound, which were designed and developed in the concrete laboratory at Santo Tomas University in Bogotá D.C. taking into account for its preparation a dosage of the estimated concrete mixture in order to obtain specimens with a compressive strength of 3500psi, 2500psi and 1500psi, in such a way, the specimens were allowed to cure for a period of 28 days, ensuring that they achieved their maximum compression strength.
As mentioned above, non-destructive ultrasound tests were applied in order to determine the quality of the manufactured concrete specimens, thus, an ultrasound system is proposed that makes it possible to pass an acoustic wave through a concrete specimen, this was proposed with the purpose of measuring the velocity with which the wave passes in the volume of this material, known as the ultrasonic pulse velocity. Therefore, the respective velocities for each of the concrete specimens were measured, thus finding a relationship between the ultrasonic pulse velocity and the compressive strength, which finally makes possible the evaluation of the manufactured concrete specimens.
Impact through digital marketing tools in social networks and web analytics in higher education institutions
Authors: Gómez Sierra C J 
Published: June 2020

Abstract
Any commercial activity that is implemented today must have the innovation and growth component. Under this premise, the education business cannot be left behind and that is why it is necessary to implement strategies and models to match and overcome the closest competition. This is where digital marketing appears as a profit strategy for the customer, displacing traditional marketing now almost disappeared.
There are different ways to develop good campaigns and digital marketing plans to obtain competitive advantages, among the most important we have: content marketing, inbound marketing, relational marketing, conversational marketing and permission marketing. In an academic business unit, such as a Higher Education Institution, it is essential to conduct a study of the behavior of social networks, know in which aspects it is very weak and be able to aggressively attack the target market. For this reason, the behavioral investigation of Facebook, Twitter, Instagram of the Antonio de Arévalo Unitecnar University Foundation, will be carried out with the following tools: Facebook statistics, Twitter statistics and Instagram statistics. The methodology implemented will be quantitative research, since all variables will be measured and analyzed to draw conclusions.
Development of an artificial vision system that allows non-destructive testing on flat concrete slabs for surface crack detection by processing of digital images in MATLAB
Authors: Romero-Tarazona BE , Rodriguez-Sandoval CL , Villabonai-Ascanio JG , Rincón-Quintero A D 
Published: June 2020

Abstract
A computing tool based on an intelligent algorithm generates new alternatives for an early crack detection on flat concrete slab in a surface testing. First, a system able to autonomously detect a surface crack, by means of a digital image processing system has been developed. This system carries on an effective selection of data by an algorism bound to a specialized MATLAB software that can assess in full detail the surface conditions of a concrete slab, and finding out any affected spot.
Elasticity modulus variation of the AISI SAE 1045 steel subjected to corrosion process by chloride using tension test destructive
Authors: Cárdenas-Arias C G , Rincón-Quintero A D , Santos-Jaimes A , Sandoval-Rodriguez C L , Rojas-Gomez D F , Ardila-Galvis S J 
Published: June 2020

Abstract
The study of materials corrosion effect is a great importance topic for the manufacturing industry and also for the customer that requires this. That is why a research study was conducted that aimed to determine the elasticity modulus variation of AISI SAE 1045 steel subjected to corrosion. To achieve this, thirty-five specimens were used, which were exposed to chlorides by immersion processes and salt spray chamber in three periods of time and then subjected to stress test destructive, following the guidelines established under ASTM G-1 standards, ASTM G-31 and ASTM E-8. Variation was found in the elastic behavior of steel and curves that differ from the theoretical ones raised in the documents.
Business architecture for the management of urban incidents: believes the TI government for the legal office of the Sinu University
Authors: Arrieta J C , Bonfante M C , Blanquicett L A , Murillo L F 
Published: June 2020

Abstract
Currently, business models integrated with the IT architecture become a strategic plan to improve services and be more competitive in a globalized world. This work describes how, from the model-based architecture (MDA), such as the CIM, you can obtain the BPMN language software requirements, obtain the PIM component models, then generate the application code and, subsequently, perform functional tests of the product. The legal office of the Sinu University is presented as a case study, in which an integrated and automated business architecture is proposed.
Discrete Events Simulation Method for Analyze Cycle Time: A Case Study in the Plastics Industry Sector
Authors: Troncoso A , Sanchez A , Gonzalez J 
Published: June 2020

Abstract
This work shows the potential of the Discrete-Event Simulation-DES-in a software modeling process applied to business decision making, using a descriptive methodology in a productive process of a manufacturing plastic bags company. The analysis identified the process characteristics and built a simulated model in Arena® software. Simulation shown variability in the process greater than 50% in the cycle time, which negatively affects the economic interests of the company, impacting opportunities to supply the market risking its position with other companies in the sector. The method implemented in the present work allows to know the critical points of the process, evaluate them and project a path to obtain the optimal or most viable solution, and propose modifications rising up the probability of success of any improvement plan. This makes any economic investment or locative change a desition-making quantitative supported.
Computational simulation of the temperature distribution of aerogel–based coated and uncoated multi–layer panels for thermal insulation
Authors: Ángel A , Suárez G , Niño J 
Published: June 2020

Abstract
A computational simulation is developed to study the temperature distribution of two types of multi–layer panels, one of which utilizes an aerogel–based coating. The simulation considers properties such as layer thickness, thermal conductivity, specific heat and density of the materials. From a set of materials, a multi–layer is geometrically modeled to perform the simulation. The results obtained indicate the temperature distribution across the different layers of materials and evidence the presence of the aerogel material with respect to the uncoated model. This research aims to visualize the effect of whether or not having a special coating can benefit the thermal distribution in the panel, hence, the thermal control within enclosures and architectural structures.
Vehicle Lateral Wander Measures Using Ultrasonic Sensors
Authors: Oconitrillo-Varela E , Hernández-Vega H , Aguiar-Moya J P 
Published: June 2020

Abstract
This paper evaluates the measurement of vehicle lateral wander using ultrasonic sensors. Measurements were made on different sections of the Costa Rican National Road Network. The recorded data allowed to determine the cumulative frequency distribution, lateral wander data and a confidence interval for the measurements. In some routes, where the sample size is greater than 70 vehicles, the distribution of the lateral wander data adjusted to a normal distribution. However, in several cases the data does not resemble a normal distribution curve, or other distributions reported in the literature. Finally, an Android app was developed to automate the data collection process using the ultrasonic sensor setup, simplifying the measurement process. From the cumulative frequency results, obtained with the ultrasonic sensors, it was determined that most vehicles travel between 50 and 150 cm from the edge of the road. In order to validate the data, the results obtained with the ultrasonic sensor setup were compared with the results obtained by image analysis of video recordings. These image analysis is possible due to pavement markings every five centimeters on the pavement from the lane edge. The results from video recordings and ultrasonic sensors show a high coefficient of correlation.
Region-specific nitrogen management indexes for sustainable cereal production in China
Authors: Tingyu Li , Weifeng Zhang , Hanbing Cao , Hao Ying , Qingsong Zhang , Siyang Ren , Zitong Liu , Yulong Yin , Wei Qin , Zhenling Cui , Xuejun Liu , Xiaotang Ju , Oenema Oene , de Vries Wim , Fusuo Zhang 
Published: June 2020

Abstract
Effective policy measures are required to control environmental problems caused by nitrogen (N) fertilizer use in intensive crop production systems in China. However, simply reducing the use of N fertilizer in all regions may be detrimental to food security. Here we reviewed N management policies and indicators, with a particular focus on European Union (EU), and designed an N index system for cereal crops in China. We suggest to use N surplus as an (environmental) evaluation index and N input as a guide to meet the dual challenge of food security and environmental sustainability, and propose crop and region-specific standards for these indexes. We inferred a mean critical N surplus of 75 kg N ha−1 for maize, 40 kg N ha−1 for wheat and 70 kg N ha−1 for rice. For N input, Maximum N (Max. N) and Minimum N (Min. N) input indices are proposed, to guide farming practices effectively. Max. N was based on the N demand of crops achieving their potential yield, in different regions, Min. N was based on the N demand of crops at their target yield, while associated N surpluses do not exceed the set critical values. To meet the dual challenge of food security and environmental sustainability, China needs to increase maize and wheat yields by 20%–40% (rice has achieved target yield) while reducing N input by 10%–20%. This requires an enormous increase in N use efficiency. The N management indexes proposed here can be used as benchmarks to monitor the progress at regional level. Max. N and Min. N may have to be updated regularly when potential and target yields, and thereby crop N demand, change. Also, critical N surpluses may have to change when insights in the impacts of these N surpluses change.
Impact of non-normal error distributions on the benchmarking and ranking of quantum machine learning models
Authors: Pernot Pascal , Huang Bing , Savin Andreas 
Published: June 2020

Abstract
Quantum machine learning models have been gaining significant traction within atomistic simulation communities. Conventionally, relative model performances are being assessed and compared using learning curves (prediction error vs. training set size). This article illustrates the limitations of using the Mean Absolute Error (MAE) for benchmarking, which is particularly relevant in the case of non-normal error distributions. We analyze more specifically the prediction error distribution of the kernel ridge regression with SLATM representation and L
2 distance metric (KRR-SLATM-L2) for effective atomization energies of QM7b molecules calculated at the level of theory CCSD(T)/cc-pVDZ. Error distributions of HF and MP2 at the same basis set referenced to CCSD(T) values were also assessed and compared to the KRR model. We show that the true performance of the KRR-SLATM-L2 method over the QM7b dataset is poorly assessed by the Mean Absolute Error, and can be notably improved after adaptation of the learning set.
Cost of an elaborate trait: a trade-off between attracting females and maintaining a clean ornament
Authors: McCullough Erin L , Chou Chun-Chia , Backwell Patricia R Y 
Published: June 2020

AbstractMany sexually selected ornaments and weapons are elaborations of an animal’s outer body surface, including long feathers, colorful skin, and rigid outgrowths. The time and energy required to keep these traits clean, attractive, and in good condition for signaling may represent an important but understudied cost of bearing a sexually selected trait. Male fiddler crabs possess an enlarged and brightly colored claw that is used both as a weapon to fight with rival males and also as an ornament to court females. Here, we demonstrate that males benefit from grooming because females prefer males with clean claws over dirty claws but also that the time spent grooming detracts from the amount of time available for courting females. Males, therefore, face a temporal trade-off between attracting the attention of females and maintaining a clean claw. Our study provides rare evidence of the importance of grooming for mediating sexual interactions in an invertebrate, indicating that sexual selection has likely shaped the evolution of self-maintenance behaviors across a broad range of taxa.