bluuebunny/crossref_metadata_2025 huggingface dataset:
Simultaneous analysis of the enthalpy increment and heat capacity data measurements for updating the IVTANTHERMO database
Authors: Sineva M A , Morozov I V , Belov G V , Aristova N M , Lavrinenko Ya
Published: November 2019

An analysis of the enthalpy increment and heat capacity data measurements is required for developing thermodynamic databases such as the IVTANTHERMO database created in the Glushko Thermocenter of JIHT RAS. A new CondensedThermoFit code is developed which provides experts with a comprehensive set of analysis tools for working with data on the specific heat and enthalpy increments for substances in the condensed state. These tools include simultaneous approximation of these two types of data. The enthalpy increment data is treated using the Shomate method while the heat capacity data is fitted with a flexible and manually constructible function. Only polynomial-like fitting functions are implemented so far. The final results are ready for exporting into the database with a fixed form of the fitting function such as the IVTANTHERMO database. The code has a cross-platform design, extensible module structure and graphical user interface.
On importance of the multi-level chemical objects description in various problem domain models for information systems integration in inorganic materials science
Authors: Dudarev V A , Kiselyova N N
Published: November 2019

The paper proves the urgency of the integration of information systems (IS) on the properties of inorganic substances and materials (PISM). It is shown that consolidation is possible only on the basis of the problem domain formalization. The basic definitions are introduced and the formalization of the IS on PISM content is proposed on the basis of three models: verbal, set-theoretic and ontological.
Development of internet resources to assess the effectiveness of some GTP
Authors: Ochkov V F , Ustyuzhanin E E , Rykov S V , Shishakov V V , Znamensky B E , Tun Aung Thu Ya
Published: November 2019

The analysis of Internet resources is fulfilled. These resources contain such information as: (i) data on the thermal properties of substances, R = (ρ, h, s, …), (ii) numerical data on the efficiency and other energy criteria, Z, of power plants. Our analysis has shown some features of the resources. Currently the most of them have the form of text files. The second type of the resources represents a software in the form of “exe-file” and allows the client to calculate values of R using a mathematical formula (MF) at boundary conditions, Y = (P, T); the latter are the pressure and the temperature. In this case, the resource includes the program, which is closed to clients: there is no such option as “to copy MF formula” in the software. A group of researchers offers the software, which is designed to calculate R properties and has the form of the open interactive Internet resource (OS). A computational part of OS-resource includes: (i) MF formula, which associates the property R with the parameters Y = (P, T, …), (ii) Mathcad-program Code(R, Y) containing MF formula. The interactive part of the OS-resource is based on the computer science and Internet technology (IT). The report analyzes the methodological techniques and IT-tools, which have to be used to create OS-resource. We have considered OS-resources, which have a complex structure and are focused on the joint use of (i) the code designed to calculate the efficiency of power plants and (ii) OS-resources those allow to calculate R(Y) at specified points of the power plant cycle. We have discussed some results obtained on the basis of these resources.
Nanodiamond graphitization at heating and irradiation
Authors: Efremov V P , Zakatilova E I
Published: November 2019

In this work the graphitization and thermal stability of detonation nanodiamonds were studied. Received data showed that the temperature of graphitization of nanodiamond particles lies in wide range and the temperature of graphitization beginning depend on the particle size. It is established the influence of heating rate on the size of nanodiamond conglomerates. The analysis of literature shows that the graphitization processes take place at irradiation. Depending on the type and irradiation dose the point defects, amorphous and graphite phases can form in the diamond structure. Annealing of irradiation samples showed the defect structure restore to ideal lattice and the release of stored energy.
Precise measurements of thermodynamic parameters of low-boiling metallic liquids
Authors: Blagonravov L A , Modenov A A
Published: November 2019

In Blagonravov et al (2000 J. Non-Cryst. Solids 277 182) the results of the thermophysical properties study of caesium in the region of the anomalous behavior of these properties were presented. Interpretation of these anomalies is difficult due to the small size of the effects. At the site of the forced growth of the adiabatic thermal pressure coefficient (a.t.p.c.), the magnitude of the effect was 5% with a random error of 2%. In the proposed work, an attempt was made to increase the accuracy of measurements in order to obtain additional information on the behavior of thermodynamic derivatives in the region of their anomalous behavior. The measurement was made by the experimental facility in which the pressure change is carried out in a periodic mode. The software allows simultaneous averaging of the amplitude values of the pressure oscillations and the amplitudes of the temperature response oscillations with the subsequent determination of their ratio. Measurements of the thermodynamic derivative

(

d
T

d
P

)

s

of liquid caesium were carried out in the temperature range of 320–620 K. Random measurement error was 0.5–1%. The results obtained are analyzed in comparison with the similar results obtained in Blagonravov et al (2000 J. Non-Cryst. Solids 277 182).
Determination of melting point of n-alkanes by means of light scattering technique
Authors: Kuryakov V N , Ivanova D D
Published: November 2019

A modified droplet technique, an optical method, was used to determine the melting temperature of several n-alkanes. The authors prepared emulsions of n-alkanes in water by means of ultrasound dispersing without the use of surfactants. The average size of the paraffin cluster measured by dynamic light scattering had a radius of about 100 nm for all the samples. During heating, n-alkanes in the emulsion melt changing the optical properties of the emulsions. The sharp variation of light scattering intensity for a relatively small change in temperature corresponds to a phase transition of the n-alkane. Using the described principles, the authors determined the melting temperatures for n-alkanes from C19H40 (n-Nonadecane) to C28H58 (n-Octacosane). The obtained results are in good agreement with data of other works.
Numerical modeling of gasification and combustion of solid fuels in a solid fuel ramjet combustor
Authors: Razmyslov A V , Sultanov V G
Published: November 2019

In order to investigate features of processes inside a combustor of a solid fuel ramjet a numerical model was employed. The model is based on Reynolds-averaged Navier-Stokes equations along with turbulence and combustion models and considers solid fuel pyrolysis. Experimental data from an earlier work was used to validate the model. Dependencies of air mass flux on some combustor performance parameters were obtained for different solid fuels.
On vortices in the tube flow of ideal media
Authors: Denisenko V V , Fortova S V , Shepelev V V , Troshkin O V
Published: November 2019

Numerical simulation is presented, which models the evolution of the initial perturbation in axisymmetric subsonic flow of an ideal gas. The undisturbed flow is an axial flow perturbed by an azimuthal velocity, or a twist of the flow around the axis of symmetry. The twist leads to the establishment in the flow of an annular or ball vortex with increasing or decreasing radial axial velocity of the undisturbed flow, respectively.
Effect on the heat of hydration, setting times and mechanical resistance adding fly ash and blast furnace slag in commercial cement mixtures
Authors: Gutiérrez-Junco O J , Hernández Carrillo C G , Sarmiento Rojas J A
Published: November 2019

Commercial Portland cement is the most used construction material in the world, due its durability, versatility and economy generated in civil works, which follows a growth trend; however, a large amount of energy is required for its production, which generates a large amount of greenhouse gas emissions and air pollutants. Consequently, a large part of research has focused on mitigating these effects by partially replacing supplementary cementitious materials. Therefore, this research aims to evaluate the performance of commercial cement paste, partially replacing it with fly ash and blast furnace slag, characterized by scanning electron microscopy, X-ray fluorescence, surface area to establish variations of setting times and heat of hydration in hardening process. The results established that fly ash and blast furnace slag didn’t generate sufficient capacities to develop stable cementation reactions and therefore higher strengths, due to their compositions surface area and the high content of alternative cements present in the commercial Portland cement since its manufacture. Nevertheless, the fly ash and blast furnace slag are alternatives in mitigating the environmental effect generated by commercial cements.
Effect of exfoliation method on graphite oxide. A comparison between exfoliation by ball milling and sonication in different media
Authors: Casallas-Caicedo F M , Vera-López E , Agarwal A , Drozd V , Durigin A , Wang C
Published: November 2019

Graphene oxide and reduced graphene have been exfoliated from graphite oxide synthesized by Hummer’s method. In order to establish a comparison, the exfoliation process was performed using two different methods, high energy ball milling and sonication. Each one was studied in two different media, organic solvent N-methyl 2 pyrrolidone and deionized water, obtaining four different products. The quality of the graphene and graphene oxides was studied using Raman spectroscopy. Structural characterization was performed using X-ray diffraction technique. The presence of oxygen-containing functional groups was determined by Fourier transform infrared spectra, while the morphology was investigated by scanning electron microscopy and energy-dispersive spectroscopy. The aim of this work is present a process to obtain graphene and graphene oxide of high quality at lower cost and better environmental conditions.
A study of zirconium plasma flow generated by a vacuum arc evaporator
Authors: Parada-Becerra F F , Dugar-Zhabon V D , Garníca H , Tsygankov P A
Published: November 2019

In the industry of hard coatings, the vacuum arc evaporator is one of the commonly used devices due to its high productivity, reliability and ability to operate in a non-gaseous medium. Apart from this, the imposition of an external magnetic field allows to control the localization of the arc spots both on the simple and sectioned (i.e. made from different materials) cathode surfaces. Another important feature of the vacuum arc evaporators is their capability to generate multi-charged ions. Applying a high voltage negative bias to the substrate, there can be formed the coatings with high adhesion due to the implantation effect. This paper presents some results of the study of the plasma flows generated by an industrial vacuum arc evaporator with a sectioned disk cathode composed of a zirconium in its central part with a titanium ring surrounding it. The mode of evaporator functioning is such that the arc spot motion gets limited by the zirconium disk, which results in producing the zirconium plasma flow. The quantitative characteristics and the energy distribution function of ions have been measured by a multigrid probe with a retarding potential. It has been proved that the multiply charged ions make up a significant part of the flow. The relations between the detected ion components are found as 87.4% Zr
+, 10.6% Zr
2+, 1.5% Zr
3+ and 0.3% Zr
4+. The presence of multi-charged ions is also confirmed by optical spectrometry measurements.
Analysis of contamination level of gases generated during the surface cleaning process of metal sheets with low-pressure cold plasma
Authors: López L M , Fajardo J I , Carrasquero E J , Villavicencio I J , López C P
Published: November 2019

The research addresses an analysis of the level of contamination generated by the gases produced when applying low-pressure cold plasma in a cleaning process of metal sheets used in the manufacture of white goods. A mixture of argon and oxygen ionized gases at 50% was utilized to break down the lubricating oil molecules deposited on the surface of the sheet metal. A statistically significant number of samples were selected, with different volumes of oil on the surface, between 6 ml and 34 ml. The samples were later subjected to a plasma discharge with a time of 72 s, a gas pressure of 0.6 bar and 50% power to determine the correlation of the oil volume with the levels of gases generated by the discharge, maintaining the degree of surface cleanliness, as given by contact angle values between 67.5 and 79 degrees, constant. For the analysis of results a Pearson correlation was applied for each detected gas. An analysis was later conducted of the relationship between the degree of cleanliness of the metallic surface, as given by contact angles at 16, 36 and 53 degrees, with the levels of the gases generated by the plasma discharge, keeping the volume of the lubricating oil on the surface constant at 5 ml. For the analyses, statistical tests were carried out to find the correlation between the predictor variables and the dependent variable to establish a multivariate linear statistical model. The results allowed the behavior of the level of contamination to be determined, establishing that the volume of oil does not influence the level of the gases generated by the use of low-pressure cold plasma. The results obtained allow us to understand the relationship between the contact angle that represents the quality of surface cleaning of oil-impregnated sheet metal and the level of contamination generated in the process.
The effects of edges on the electronic localization properties of graphene
Authors: Espitia J S , Gutierrez W , Páez C J
Published: November 2019

In this numerically work, we study the effects of edges on the electronic properties of graphene lattices in the quantum Hall regime using a proposed quantity called participation ratio, that is employed to analyze the localization properties of edge states. We use the tight- binding model to include the effects of the magnetic field and disorder. The effect of the edges on the energy levels of the system is studied through Hofstadter’s butterfly-like spectrum. Using the participation ratio and analyzing the contributions of the armchair and zigzag edges separately, we find that there are energy regions where the wave functions are clearly more localized in a specific edge type. The zigzag preferential localization is a reminiscence of the case without magnetic field and the armchair localization which is dependent on the disorder and the strength of the magnetic field, comes from the presence of magnetic field in the system. The results obtained contribute to the understanding of the localization properties of graphene lattices with edges.
Tensile mechanical behavior of a polymeric composite reinforced with 4-axial carbon fiber woven
Authors: Villegas D F , Pedraza-Rosas S L , Toloza-Meza S A
Published: November 2019

During the last thirty years, there has been a growth in the study and analysis of composite materials for automotive and aerospace industry which require lightweight materials with demanding mechanical properties. textile reinforce composite materials have advantages with respect to laminated composite materials such as better formability and out-of-plane properties. Therefore, the purpose of this research is to determine the mechanical behavior for uniaxial testing of a carbon fiber of a composite material reinforced with a quadriaxial carbon fiber woven in order to decrease the anisotropy of the woven composite material. Five specimens for each of the different orientations at 0, 30, 45, and 90 degrees; In addition, six specimens of a plain woven (the most common on the market) were tested, two specimens per orientation at 0, 45 and 90 degrees, in order to contrast the behavior of these with the proposed tissue. It was obtained that the properties in the composite materials change according to the direction in which the fibers are oriented; therefore, the results showed that the quadriaxial tissue and the stress value are less than the plain tissue, by 39%, only in the zero degrees orientation, then the plaint woven has a greater number of fibers in that orientation, the orientation of ninety degrees is higher by 17%, and in the case of forty-five degrees orientation, the value is 82% higher. In the same way, when we study the orientations in there is no fiber, in the plain woven of the direction in which there is no fiber, is forty-five degrees’ orientation and in the proposed tissue it is the thirty-degree one 30 degrees and it can be seen that, in this case, in the behavior of the quadriaxial tissue is greater the stress value by 66%.
Estimation of injection parameters of a bio-based composite material from the rheological characterization
Authors: Fajardo J I , Paltán C , López L M
Published: November 2019

This research work presents an analysis of the injection molding process of a natural fiber-reinforced composite, from the characterization of its rheological properties by the technique of capillary rheometry. Two of the main parameters of injection molding were estimated: the injection pressure and the clamping force. The rheological coefficients obtained were used as inputs in analytical and finite element models, for the prediction of the injection parameters. The results were compared, and it was observed that there is good agreement between them. The percentage errors between the two estimation methods were less than 5% for injection pressure and less than 10% for the clamping force. Also, the behavior of the material using different natural reinforcing contents (compositions of 20%, 30% and 40% fiber with a coupling agent at 4% and 8%) and the effect of its rheological properties on both the injection pressure and clamping force were evaluated. The study is of particular interest given that from the rheological characterization, the experimental values were adjusted to the Cross-WLF viscosity model and the adjustment coefficients, which contain both the reinforcing and coupling agent effects, were fed into the two methods of estimation of the injection parameters. The methodology used and the results obtained allow the prediction of the main parameters of injection molding of new bio-based composites, facilitating their use on an industrial scale.
Graphite formation in abnormal glow discharge
Authors: Alvarez B , Sarmiento-Santos A , Hernández Y
Published: November 2019

Graphite is made up of flat sheets of carbon atoms that form a periodic system of hexagonal rings of six atoms. Along the perpendicular direction of the sheets it has a low electrical conductivity, whereas this is greater throughout them. The possibility of separating the constituent sheets of the graphite and obtaining individual layers of it has led to the current scientific and technological revolution. Graphite can be produced synthetically in the laboratory, with low energy consumption, through the plasma of the abnormal glow discharge in direct current. In this work the abnormal glow discharge graphite formation is reported. The glow was initiated throughout a gaseous atmosphere containing acetylene, utilizing direct current power. In plasma generated in this type of discharge the secondary electrons, coming from the cathode, transfer their kinetic energy to the neutral molecules of the hydrocarbon causing dissociation, ionization and excitation of them. These processes generate active species that react with each other and with the substrate, producing carbon deposits on it. Under controlled conditions of temperature, acetylene content and deposition time, carbon deposits, with the characteristic structure of graphite, in abnormal glow discharge can be obtained. For this purpose, the abnormal glow discharge was established in an atmosphere composed of a mixture of 20% acetylene, 60% argon and 20% hydrogen at low pressure, in a temperature range from 400 °C to 900 °C. Under these conditions, on a copper substrate, a time of 15 minutes was used to obtain the carbon deposits. These deposits were analyzed by infra-red spectroscopy, Raman spectroscopy and scanning electron microscopy, identifying the structure of the graphite and observing the morphology of the deposits on the copper substrate.
Acetylene polymerization in plasma of direct current
Authors: Alvarez B , Sarmiento-Santos A , Vera-López E
Published: November 2019

Plasma polymerization is a technique that allows obtaining polymer of any type of hydrocarbon, including the non-polymerizable by standard methods. This because of in the plasma state the activation energy can be reduced for the realization of reactions difficult to be presented under standard experimental conditions. For plasma polymerization only the implementation of different types of discharges in the radio frequency regime has been reported, leaving aside the application of direct current discharges for this process. The acetylene polymer consists of carbon chains with alternation of single and double covalent bonds. The formation of this polymer has been reported using radio frequency discharges in the abnormal regime. The paper reports the formation of polymer from acetylene using the abnormal glow discharge in the direct current regime, a novel process not yet reported in the literature. The deposition of the polymer is carried out at different times on a polycrystalline copper substrate previously treated in a glow discharge of argon and hydrogen. For the generation of this polymer an atmosphere of 60% Ar+35% H2+5% C2H2 at 2 torr pressure and a temperature of 600 °C is used. The structural and morphological analysis of the deposits is carried out by infrared spectroscopy and scanning electron microscopy, respectively.
Manufacture and evaluation of the tensile properties of a biodegradable composite material reinforced with Colombian coconut fibers
Authors: Arciniegas M , Delgado W , Lesmes S , Pertuz A
Published: November 2019

The mechanical properties of a biodegradable composite material made with Colombian coconut fibers were studied. The study was carried out considering a random distribution of fibers within the composite material for three fiber/matrix compositions (10, 20 and 30) in weight-to-weight percentage. Each of these was subjected to tensile tests to evaluate the effect of the fibers in each composition, taking into account the mechanical properties of ultimate tensile strength and elastic modulus that allow selecting the composition of greater rigidity and subsequently evaluating its properties under the effects of compression forces. The results obtained show that the more rigid composite material corresponds to the fiber/matrix 20 percent composition, which presented a tensile strength of 13.83 MPa and an elastic modulus of 924.46 MPa comparable with those reported in the literature. This composition is the most fragile with a percentage of elongation is 2.27% and with low tenacity to withstand impact efforts. Finally, the behavior of the more rigid material was compared with the mechanics of Ramberg-Osgood and Hollomon, the latter being the most adjusted allowing to predict the properties of this type of materials. The results obtained expand the uses of Colombian coconut fibers as a biodegradable composite.
Effect of wetting/drying and heating/cooling cycles on geomechanical behavior of mudrocks in the Lutitas de macanal formation
Authors: Chaparro C A , Jiménez O J , Espitia J M
Published: November 2019

The mudrocks are weatherable materials, an intrinsic condition of mineralogy and sedimentary formation. In the Eastern Cordillera of the Colombian Andes lies this rocky material, which implies the degradation of physical and mechanical properties in the face of environmental factors, such as changes in humidity and temperature that are intensively propitiated in the tropical climate of the region, factors not considered in the design of civil works. The present study determines an experimental procedure in laboratory to reproduce the effect of the cycles of wetting/drying and heating/cooling in conditions and periods similar to the original ones of the geomaterials, by means of the steam equilibrium technique and thermal change, the processes were carried out on rock cores extracted from the Lutitas de Macanal formation that emerges in the municipality of Pajarito, Boyacá, Rancheria sector, Colombia. The results quantitatively determined the degradation of Young’s module and the resistance to uniaxial compression with the applied treatments, having a greater effect on the heating/cooling cycles in a period equal to that of wetting/drying generating greater damage to the rock due to pronounced cracking.
Characterization of the metallic phase and the slag phase obtained during the inertization of the cathodes of spent alkaline batteries using liquid aluminum
Authors: Molina-Silva J , Vera-Serna P , Delvasto P
Published: November 2019

In this work, a reactive melting procedure was implemented for the inertization of the manganese-containing cathodes of spent alkaline batteries. The process consisted of adding the cathode powder mixed with borax on top of molten aluminum at 1000 °C. By means of an aluminothermic reaction, manganese oxides are reduced and incorporated into the alloy. The presence of borax in the reactive mixture was found to be fundamental to obtain the Al-Mn alloy. The characterization of the metal phase and the slag phase by scanning electron microscopy and X-ray diffraction showed that manganese is reduced to form manganese borides in the slag and Al-Mn intermetallics in the alloy. This process could make feasible to use aluminum casting shops as processors of spent alkaline batteries.
Ablation energy, water volume and ablation time: Gold nanoparticles obtained through by pulsed laser ablation in liquid
Authors: Hernández-Maya M , Rivera-Quintero P , Ospina R , Quintero-Orozco J H , García-Castro A C
Published: November 2019

It was studied the production of gold nanoparticles from a gold target by pulsed laser ablation in liquid medium. This technique allows replacing conventional methods of preparing nanoparticles without the need for precursors, where gold is used in its metallic state. Experimental tests were performed to determine the appropriate synthesis conditions to achieve small particle sizes. The variables studied were water volume, ablation time and ablation energy. Gold nanoparticles with spherical geometry, in metallic, and nanocrystalline state were obtained without the need to use precursors and stabilizers. Ablation energy is the most influential variable on the particle size, because it was observed that when is increased the ablation energy is generate greater particle sizes.
Compositional, thermal and morphological characterization of recycled and modified elastomers for inclusion in commercial cement mixtures
Authors: Mora-Rodríguez G K , Hernández Carrillo C G , Pineda-Triana Y
Published: November 2019

Elastomers are natural or synthetic polymers used in the automotive, mining, mold, assembly and other industries, due to their mechanical resistance in a wide temperature range from 60 °C to 320 °C; however, the waste generated is not disposed of properly, especially in the manufacture of tires, which generates environmental problems like inadequate final disposal, generation of toxic gases and public health problems; Therefore, in order to recycle these wastes, the present investigation modified elastomers superficially in order to produce strong adhesion with inorganic compounds like cement, through oxidation and sulfonation processes. For this purpose, NaOH and KMnO4 solutions were prepared at a concentration of 5% and then impregnated in saturated NaHSO3 solution. Subsequently, the modified elastomer was morphologically characterized by scanning electron microscope, thermogravimetrically by differential scanning calorimeter; compositionally by infrared spectroscopy, Raman spectroscopy, X-ray fluorescence, energy dispersive X-ray analysis and hydrophobic tests using contact angle techniques, in order to establish morphological and chemical compatibility with inorganic compounds. Results evidenced inclusion of functional groups OH, C = O and SO3, the reduction of carbon present in weak bonds and the presence of inorganic components such as potassium, sodium, manganese and sulfur were evident. The scanning electron microscope shows an increase in the roughness and contact surface of the elastomer as a function of the inclusion of polar functional groups by surface chemical treatment. These characteristics are to generate greater inclusion and compatibility of elastomers of an organic nature in inorganic compounds like cement matrices.
Synthesis and characterization of a hybrid perovskite to be applied as an absorbent layer in solar cell
Authors: Soracá-Pérez G Y , Gómez-Reyes D K , Gómez-Cuaspud J A , Vera-López E , Pineda-Triana Y
Published: November 2019

This study is based on the synthesis and characterization of a hybrid perovskite based on tin chloride and methylammonium (CH3NH3SnCl3) as an absorbent layer in solar cells. Preparation of the hybrid material was carried out using the wet method from a precursor of methylammonium chloride CH3NH3Cl and tin chloride (II) (SnCl2). The solid obtained was heated to a temperature of 60°C in order to obtain the final product. The hybrid material was then characterized by X-ray diffraction, Raman spectroscopy and scanning electron microscopy. The structural and morphological results showed the characteristic traits corresponding to the material. The formation of conglomerates with irregular spherical geometry and cubic forms associated with the precursor of tin chloride were also present. The application of this type of perovskite in solar cells is preferable due to its environmentally friendly impact, making it a promising material for photovoltaic technology.
Evaluation of the structural, thermal, rheological and morphological properties of polyethylene functionalized with a maleinized hyperbranched polyester
Authors: Ararat C A , Murillo E A
Published: November 2019

This experimental study was carried out with the aim of establishing and analyzing the thermal, structural, morphological, and rheological properties of a polyethylene functionalized with a maleinized hyperbranched polyester. This area of study has scarcely been reported. It is important to study the properties of this material, since it can be employed as functionalizing agent in blends of low density polyethylene and hydrophilic polymers. In addition, it also may be used as alternative for replacing the importation of polyethylene functionalized with maleic anhydride in our country. Therefore, in this experimental study, dicumyl peroxide was utilized to catalyze a functionalization reaction between low density polyethylene and maleinized hyperbranched polyester. In the experiment, dicumyl peroxide concentrations were maintained at 0.50 wt%, 1.0 wt%, 1.5 wt%, and 2.0 wt%. The resultant material after of the functionalization was characterized by various analytic methods including infrared analysis, contact angle, thermogravimetric analysis, X ray diffraction, rheological analysis and scanning electronic microscopy. The functionalization degree of the polyethylene functionalized with a maleinized hyperbranched increased with the dicumyl peroxide amount and in all cases it was higher than 8 weight percent.
Arduino data-logger and artificial neural network to data analysis
Authors: Contreras Contreras G F , Dulcé-Moreno H J , Ardila Melo R
Published: November 2019

This work takes thermodynamic modelling through computer science for incubation process at domestic birds, that has presented energy consumption significantly high than energy used in processes. Thus, a data analysis was applied upon variables of temperature and relative humidity for heating zones, trying to know how much energy supplied by source was used, as well as, voltage and current variables are measured in the same moment that temperature and relative humidity are acquired. Then, data analysis was done using artificial neural networks models with samples obtained from sensors, where real process is highly time- variant, fixing environment conditions at the moment required. Therefore, with this system has been obtained an air flow of 3.4375 10−2 m3/J using a anemometer respect to electrical energy supplied by fans, giving 9.4818 W of average power using ceramics resistances, and testing an adaptive controller where its variables are fitted using equations obtained from data analysis. In contrast, colombian farmers have decreased economic conditions to maintain them productions due to free trade agreements implemented lastly, indeed this system was developed using open- source software and hardware to avoid costs in acquisition by licensing politicians or periodic subscription to a specific product developed by companies.
Evaluation and analysis of structures with porch system in lightweight concrete by thermally expanded clay from San José de Cúcuta metropolitan area, Colombia
Authors: Palacios J D , Rojas J P , Cáceres J R
Published: November 2019

The increase in the world population has caused cities to grow vertically, increasing the amount of high-rise buildings, which is why there is a need to develop building materials with greater efficiency, that is, resistant and with less density to the conventional. The objective is to analyze the mechanical behavior of buildings with portico system when being designed with lightweight concrete mixtures made with thermally expanded clay from materials in the San José de Cúcuta metropolitan area, Colombia. Eight structural models were made using the finite element method with the Etabs® software, varying the building height and the concrete type that was used, in order to compare the properties and lightweight concrete characteristics contrasted with the conventional concrete. The modeled buildings were located on land with a capacity of 200 KPa and residential use. The San José de Cúcuta city is located on an area of high seismic threat according to the Colombian construction of resistant earthquake. It was determined that lightweight concrete manufactured with materials from the San José de Cúcuta metropolitan area, Colombia, is structural since it has a compressive strength at 28 days of 26 MPa on average and equilibrium density of 1646.16 Kg/m3 complying with the requirements minimums required by the Colombian regulation of resistant earthquake construction for a concrete to be considered light and structural. It was found that when using lightweight structural concrete in the design of joists and slabs, there is a 10% decrease in dead loads that reach the foundations of the structure, which implies a reduction in the dimensions of the foundations.
Thermal behavior evaluation of clays from algodonal formation and their impact on technological properties
Authors: Guerrero-Gómez G , Escobar-Mora N J , Nolasco-Serna C
Published: November 2019

It is presents the characterization of the clays from the algodonal formation and the mechanical properties of the products manufactured in brickyard “Hora”, located in Ocaña, Norte de Santander, Colombia.Tests of scanning electron microscopy, thermal gravimetric analysis, differential scanning calorimetry, initial rate of absorption, 24-hour immersion, compressive strength, and modulus of rupture were performed. The results indicate that the clay contains a considerable amount of silico-aluminate, while the products have low mechanical strength and high percentage of water absorption. The clays used present difficulty in the process of shaping and compacting the products. None of the samples comply with the values established in the standard and do not allow their use as non-structural masonry products for interior or exterior use.
Characterization of commercial luminescent powders
Authors: Paredes R A , Roa K L , Castro H F , Rodriguez G P
Published: November 2019

Luminescent powders have attracted the attention of scientists, boosting properties as specific as mechanoluminescence, thermoluminescence, and photoluminescence among other characteristics. The uses of these properties have grown exponentially from recreational uses in luminescent paints, toys, plasticines, and other industry-specific uses, such as crack sensors, flaw detectors, and radiation meters in medicine. These uses have grown proportionately with their more economical and efficient manufacturing methods and processes, generating more economical fluorescent pigments. This paper characterizes and compares a low-cost luminescent pigment with those reported by different authors, its chemical composition was characterized by X-ray energy dispersion spectrometry, X-ray fluorescence, and Raman spectroscopy. Its morphology was analyzed by scanning electron microscopy, and its particle size with a laser meter its structural condition with X-ray diffraction, the powder obtained was presented as a strontium alumínate doped with divalent europium and trivalent dysprosium (Al2O4: Eu2+, Dy3+) one of the most efficient powders around persistence and luminance intensity at present. The structure of the strontium aluminate was determined by the main peaks of the diffractogram showing a monoclinic system. The elemental composition helped to determine the doping of the strontium aluminate corroborating them with the obtained with Raman spectroscopy and the scanning electron microscopy images.
Comparison of segmentation tools for structural analysis of bone tissues by finite elements
Authors: Argüello D , Sánchez Acevedo H G , González-Estrada O A
Published: November 2019

Medical image segmentation is one of the bases of development in the field of personalized medicine, which allows the reconstruction of parts of the human body to produce virtual models by classifying pixels to create a surface or volume with similar properties. This work is focused on image segmentation through open-source software for bone structure analysis using the finite element method. According to this approach, the aim of this study is to investigate the sequential process, based on the features and requirements of the reconstruction software, to assess the segmentation tools and provide a comparative analysis. The methodology focuses on the software that has been documented for the anatomical reconstruction of organs and tissues, accounting for algorithms of manual, semi-automatic and automatic handling. Three segmentation packages are analyzed: 3D Slicer with a semi-automatic process called Region Growing, ITK-Snap with its interactive mechanism Active Contour segmentation mode, and, finally, In Vesalius with its automatic segmentation technique that identifies types of tissues and a simplified user-machine interface. A comparison is proposed based on the ease of the workflow, time for completion, the robustness of the tool, and precision of the semi-automatic and automatic methods, as opposed to the manual process, by statistic deviations and volume error obtained with Cloud Compare. The segmentation of a vertebra obtained from a DICOM© file in a computerized axial tomography was completed, and performance indicators were evaluated. The results showed that 3D Slicer - Grow from seeds is the best option to make the segmentation with a 9.59% of volume error and the fastest process among others.
Modeling a helium atom from a collision of an electron with an ionized helium atom
Authors: Alcalá Varilla L A , Pérez Pitalua D L , Torres Hoyos F
Published: November 2019

A method which is based on quantum scattering theory and, particularly, on the Jost functions, is presented for solving the bound states problem of helium atom. Within this approach, the energies of bound states of helium atom were obtained as the sum of energies of a hydrogen atom and the energies that one electron needs to bind to an ionized helium atom in a collision process. We calculated the ground state energy and the energies of the first excited states of helium atom, and obtained remarkable results, This method could then be used as basis to study atoms with more electrons.
Spatial autoresonance acceleration physical scheme based on magnetic rings system
Authors: Orozco E A , Dugar-Zhabon V D , López J E , López J
Published: November 2019

The spatial auto-resonant acceleration scheme consists in the acceleration of an electrons beam by the transverse electric field component of a standing microwave field and an external inhomogeneous magnetostatic field, whose longitudinal profile is fitted to maintain the electron cyclotron resonance condition along of its helical trajectories. In practice, the external magnetic profile can be generated by a system of current coils. In order to save energy and the possibility to reduce space, we study the option to replace the coils by a magnetic rings system of uniform axial magnetization. In this work, we present both, the results of the magnetostatic field generated by a magnets system, which is calculated from the magnetization currents using the Biot-Savart law, and the acceleration of an electrons beam in the spatial auto-resonant acceleration regime employing said magnetostatic field. The electron trajectory, its velocity and energy are obtained from the numerical solution of the relativistic Newton-Lorentz equation, showing that is possible to accelerate electrons injected with energies about of some electronvolts to values about of 250 keV.
Numerical simulation of fast ions guiding-center orbits in mega ampere spherical tokamak-reactor configuration
Authors: López J E , Orozco E A , Dugar-Zhabon V D , Cárdenas P A
Published: November 2019

Determining the charged particle trajectories in the inhomogeneous electric and magnetic fields is the common problem in the plasma physics. For the tokamak plasma, the orbits of the captured fast ions are affected both by the curvature and gradient of the magnetic field. In the present work, the fast ion trajectories and their guiding-centre orbits in a mega ampere spherical tokamak reactor are found with employing the numerical code, that was elaborated by our team, together with the leap-frog and Runge-Kutta techniques. The magnetic field is calculated by solving the Grad-Shafranov equation at the fixed boundaries on the non-homogeneous mesh grid. The obtained results show that the ions with the energies in the range 20 keV - 80 keV can describe the typical banana orbits as well as the passing trajectories in the poloidal plane. Finally, the numerical simulation scheme stability is tested.
Comparative thermal analysis of extruded ceramic products between multi perforated brick and modified bricks in cells distribution
Authors: Colmenares A P , Sánchez J , Díaz C X
Published: November 2019

The demand for cooling and heating systems to adapt spaces is a critical environmental problem due to the high energy consumption required for its operation. For this reason, the offer of products for architectural facades should consider constructive solutions that mitigate the heating of buildings. Thermal behavior of building materials is an elementary factor in the energy consumption of buildings. This paper presents the comparative thermal analysis of 4 ceramic product designs for masonry, of which, one represents the traditional multi perforated brick and the others, are proposed to prove whether shape affects the heat transfer processes. The research methodology is divided into 2 stages: product design and thermal validation by transfer and heat fluxes in the ANSYS R16 software using the finite element method. For the design process, modification of the internal cells and elimination of the thermal bridge was implemented. Simulations were configured under the highest values of solar radiation recorded in the city of San José de Cúcuta, Colombia to know the products performance in the most extreme conditions of the city. The results indicate that design varies energy performance of the product, since it reduces the temperature of the inner surface to 1.23 °C or increase it to 2.25 °C. The results show that the modification of cells distribution and elimination of thermal bridges are passive strategies for the reduction of heat transfer in the design of ceramic product for masonry. This research is a breakthrough for future research that develops constructive units focused on improving the quality of life of people from thermal comfort, energy efficiency and the use of local resources and technologies.
A numerical model of the behavior of the resistance to compression in prisms of solid masonry
Authors: Afanador García N , Farelo Alvarez K A , Calderon F
Published: November 2019

This research work presents an experimental and numerical analysis of three-dimensional behavior to the compression of masonry prisms with solid brick, in pieces built-in artisanal ovens used in the municipality of Ocaña, Colombia, with the objective to determining deterministically the resistance to uniaxial compression and determine numerical models for structural design purposes. The experimental methodology consisted of determining statistically for solid clay brick units, the initial rate of absorption, final absorption, rupture modulus and resistance to uniaxial compression, and in masonry prisms, to uniaxial compression resistance and modulus of elasticity. The behavior observed in the uniaxial compression test in masonry prisms were validated in a commercial code of finite element modeling. The efficiency of the model makes it possible to predict the uniaxial compressive strength of masonry prisms in solid bricks built in artisan ovens. Allowing to reduce the number of tests in the future and perform probabilistic analysis.
Implementation of research agendas in the training of engineers: Academic training with social sense
Authors: Bohórquez Chacón L F , Avendaño M A
Published: November 2019

The implementation of research intervention strategies is presented as the main theme of this longitudinal study, within the framework of the application of the research agenda of engineering programs. Classroom work, training practices, business practices, classroom projects, and research group projects are proposed as training scenarios. The strategies are actions that are applied in three productive processes of interest for the engineering, such as: (i) productive process of object systems (ii) primary biomass productive process and (iii) primary artisanal cosmetics production process. The objective is to show the results of the research agendas application as an academic process planning tool for form research competencies. Three cases have presented that show the knowledge construction and the research intervention traceability in different the engineer fields in his training process. The three production processes become application centers of an area of the engineer research interest, as is the supply chain optimization. In the results, the planning methods of the agenda highlight, with the collective construction of knowledge of the training process, the targeting of the area of research interest, the linking of actors, the articulation of research lines of the program, and the scope of the strategies of intervention and didactics by scenarios. The study shows training relevant processes in the economic, social and environmental fields, promoting collective learning opportunities and fostering innovation through inclusive industrialization.