bluuebunny/crossref_metadata_2025_split huggingface dataset:
Removal of dyes from aqueous solutions by adsorbent prepared from coffee residues
Authors: López L , Ramirez A P , Giraldo S , Flórez E , Acelas N Y 
Published: November 2019

Abstract
This study reports the production of an adsorbent material derived from extracted coffee residues using phosphoric acid and zinc chloride as activating agents. The structural features of the materials were characterized using different analytical techniques. The BET surface areas were found between 3.81 m2.g−1 y 176.27 m2.g−1, while the FTIR analysis showed the formation of oxygenated functional groups, which are active in the adsorption process. These materials were evaluated as adsorbents for the removal of methylene blue from aqueous solution. Batch adsorption tests were performed at room temperature and the effects of contact time and, initial dye concentration was investigated. The equilibrium adsorption results were complied with Langmuir isotherm model and its maximum monolayer adsorption capacity was 15.92 mg.g−1. Adsorption kinetics studies indicated that the pseudo second order model yielded the best fit for the kinetic data. This typical dependence of methylene blue uptake on kinetic studies indicated the adsorption process to be both chemisorption and diffusion controlled. The experimental data obtained in the present study indicate that coffee residues are suitable candidates for use as adsorbents in the removal of cationic dyes.
Synthesis and characterization of a derivative of carbazole obtained from bromobenzyl alcohol
Authors: Cantillo R , Percino J , Murillo E A 
Published: November 2019

Abstract
Carbazole and their derivatives are compounds that have a great importance in the industry because their potential applications in solid-state lighting technologies. These materials have photorefractive and photoconductive properties, it is charge transporter (hole) and it is employed in organic light emission diodes. Therefore, with the aim of to contribute in the art state of this type of materials was done the synthesis of a carbazole-based material, from carbazole and bromobenzyl alcohol, employing as catalyzer sodium hydroxide and as solvent sulfoxide dimethyl. The material obtained was characterized by hydroxyl value, infrared analysis, nuclear magnetic resonance, thermogravimetric, X ray diffraction and ultraviolet- visible analyses. By infrared and proton nuclear magnetic resonance analyses was evidenced the formation of the carbazole-based material. The carbazole-based material presented fluorescent properties, since when was taken to ultraviolet lamp, this material emitted light. The thermal stability exhibited by this material may facilitate its use under conditions of high temperature. The results obtained in this study are very important since so many fluorescent materials such as organic light emission diodes are doing imported in Colombia. Therefore, the carbazole-based material may be an alternative for substitution of importations of this type of materials.
Removal of cadmium in wastewater through geopolymeric materials based on pumice.
Authors: Grillo J , Montaño A M , González C P , Barón G C 
Published: November 2019

Abstract
Heavy metal pollution in the effluent water due to industrial waste product of various economic activities is not adequately regulated in Colombia, this is because the agencies do little control track discharge and easily granting environmental licenses. As a result of this little regulation currently they do not have updated figures that provide real information on the amount of waste that ends up in the resort, causing health effects of living beings. In the tanning industry, in particular, there cadmium residual concentration higher than the maximum allowed by the Ministry of the environment. This work considers the use of a geopolymeric material based on pumice stone, to capture cadmium ions present in wastewater and thus reduce its concentration in the water resource in order to reduce the population’s exposure to diseases that are associated with accumulation of cadmium in the body. The synthesis of geopolymer began from the alkaline activation of pumice stone with commercial sodium silicate, the use of sand:pumice stone in a 1:1 ratio and 31 hours of reaction, these proportions were defined in a previously work by the authors. The morphological and crystallographic characterization of the sorbent geopolymeric material was performed by scanning electron microscopy and X-ray diffraction. To assess the sorption process, a study of the geopolymer’s contact time with a known solution of cadmium was performed. Cadmium concentration was determined using atomic absorption spectroscopy and the geopolymer was characterized after removal.
Carbon structures obtained from acetylene in a continuous current abnormal glow
Authors: Alvarez B , Sarmiento-Santos A , Hernández Y 
Published: November 2019

Abstract
Carbon is the great constituent of all organic matter and a key element of the compounds that make up the enormous and very complex discipline of organic chemistry. It was already known in antiquity to be obtained as a by-product of the incomplete combustion of organic materials. At present the properties of this atom constitutes a potential source for research due to its promising application in nanotechnology and new materials because of its unique mechanical, electrical and optical properties. Carbon has several structural configurations that are known as allotropes, these allotropes have the same basic component, but its molecular conformation is different. Other elements of the fourth column of the periodic table such as silicon, germanium and tin have characteristics similar to those of carbon, however, this is unique in the variety of its allotropes. The different allotropes of carbon can be produced, among other methods, by the chemical vapor deposition method, however, the energy cost of this type of growth is relatively high. Another technique that would allow to obtain deposits of carbon in the laboratory is the plasma of the glow discharge of direct current in abnormal regime, which also offers a wide range of applications in plasmo-chemistry and in the thermochemical treatment of materials. The application of the abnormal glow discharge in the deposition of synthetic materials is a recent technique that represents a decrease in the time and in the energy consumption of the process, because the heating is carried out directly by the bombardment of the ions and neutral atoms on the surface of the cathode where the sample is usually located. The technique of abnormal glow discharge was used in this work with the objective of studying the possibility of formation of carbon deposits, in a copper substrate, from an atmosphere of argon, hydrogen and acetylene. Thus, in the temperature of 600 °C, deposits of graphite, graphene and an acetylene polymer compound were obtained. These were identified by infra-red spectrometry and Raman spectrometry.
Synthesis of oxygenated compounds from methane, carbon dioxide and water in liquid phase using a plasma-catalytic system
Authors: Gelves J F , Dorkis L , Marquez M , Fourré E , Batiot-Dupeyrat C 
Published: November 2019

AbstractDirect synthesis of methanol and other oxygenated compounds (ethanol, propanol, acetaldehyde, formic acid, acetic acid and propanoic acid) was carried out through the partial oxidation of methane process using carbon dioxide (greenhouse gas) and water in liquid phase (water has only been used in the form of steam). The activation process was carried out with dielectric barrier discharge plasma (sinusoidal power) and in the presence of a catalyst. A Colombian natural zeolite, glass wool and a material composed of magnesium oxide and alumina were used in this scientific investigation as catalysts. Tests in the presence/absence of catalyst, presence/absence of liquid water and combinations of the previous tests were carried out in order to establish which conditions allow to obtain the highest conversion of reagents and selectivity to oxygenated compounds. It was evidenced that the glass wool allows to obtain the highest levels of reagent conversion, followed by the magnesium catalyst and finally the natural zeolite. Regarding selectivity, the natural zeolite showed to be efficient for the obtaining of oxygenated compounds. It was also established that the presence of liquid water in the reactor decreases the conversion of the reactants, but favors the formation of carbon monoxide, hydrogen and especially oxygenated compounds.
Mechanical characterization of the rachis fiber obtained from the African palm elaeis guineensis
Authors: Apoveda L C , Bohórquez O , González- Estrada O A , Pertuz A , Rueda Y 
Published: November 2019

AbstractIn the present work, experimental tests are carried out to determine the tensile strength of the fiber obtained from the African palm clusters. The tests were performed on a MTS BIONIX universal test machine under the ASTM standard, which characterizes the tensile strength and stiffness of the fiber in relation to its weight. Once the mechanical properties of the fiber are characterized, it is proposed to carry out studies as a reinforcement material in composite materials, reducing the amount of waste which generates health problems in this industry. Organic fibers have mechanical properties such as lightness, high mechanical strength and durability, for these reasons it has been used as a reinforcing element in polymeric matrices, being a potential replacement for some materials in the industry in general. By 2015, Colombia had 466000 hectares of African palm planted, highlighting the potential for acquiring this fiber in Colombia, to achieve positive results in the application of the fiber, a whole series of new industrial products can be developed with the social and economic impact that this represents.
Influence of mechanical milling on the hydrogen absorption properties of TiCrV – based alloys
Authors: Martinez-Amariz A , Peña Ballesteros D 
Published: November 2019

Abstract
The hydrogen economy is a concept focused on this element as a carrier of clean and cheap energy, one of the keys is the storage of this gas safely. In this sense, TiCrV-based alloys have great capacity to store hydrogen. In the present working studied the influence of the process of mechanical milling of high energy in the storage capacity of hydrogen of TiCr1.1 V0.9 alloy. The alloy was synthesized by arc fusion and manually crushed. The effects of mechanical milling were studied for periods of time of 1 hour and 3 hours at 300 revolutions per minute with a weight/weight ratio of the sample 10: 1. The x-ray diffraction analyzes revealed solid phase formation of body center cubic phase, characteristic of TiCrV base alloys, and formation of TiCr1.8H5.3 hydrides and TiH2 hydrides with orthorhombic structure and body center cubic, respectively. The hydrogen storage capacity of the TiCr1.1 V0.9 alloy decreased with the increase in grinding time. The reasons for the drop in hydrogen storage capacity are mainly two: contamination of the surface of the alloy powder and changes in the microstructure generated by the plastic deformation in the grinding process. However, an increase in absorption kinetics was observed at longer milling times because the surface area increases since the crystallite size decreases. This phenomenon can be explained by the catalytic effect produced by the decrease in the particle size of the samples. The differential scanning calorimetry analysis was able to determine that the TiCr1.8H5.3 hydride stored a greater amount of hydrogen and has a lower desorption temperature compared to the TiH2 hydride.
Analysis of the behavior of Tunja diatoms, before dispersive effect, acidity and suction
Authors: Jiménez O J , Abril W F 
Published: November 2019

Abstract
The present article analyzes some physical and chemical properties, which can influence the behavior of the diatoms present in the eastern part of the city of Tunja, by identifying and exploring three outcrops arranged in the territory, three characteristics to be evaluated and defined their respective laboratory tests were carried out in order to be able to estimate their behavior, analyzing parameters such as the dispersive effect using the pinhole test, acidity with hydrogen potential measurement and suction using the filter paper method. Prior to this, general characterization tests were developed, that is: Atterberg limits, specific gravity and hydrometer granulometry, carried out according to the respective regulations, the analysis of the results obtained and the pertinent recommendations are made in a particular way for each outcrop and in general form for the deposit of the city, defining the predominant values of the characteristics considered.
Localized states induced by variations in the curvature of the path of an electron in a closed nanoscopic loop
Authors: Torres J F , Morales N L , Espitia J S , Páez C J , Gutiérrez W 
Published: November 2019

Abstract
We analyzed the effect of the curvature of the path on the energy spectrum of an electron confined in a closed nanoscopic loop in the presence of magnetic and electric external fields has been studied. The system was modeled using the stationary Schrödinger equation in the framework of the approximation of effective mass and enveloping function, which was solved using the finite element method. The closed loop has been modeled theoretically as a flat waveguide, whose width is small compared to the length of the path. These geometries allowed putting in evidence the variation in the confinement potential of the electron due to changes in the curvature. The variation of the electronic spectrum and the electronic densities for some low-lying energy states were analyzed as a function of the intensity of a magnetic field applied in the direction of growth and an electric field applied in the structural plane. The results demonstrate, with clarity, the high sensitivity of the electronic spectrum of a closed nanoscopic loop in the presence of changes in the curvature of the path, which translates into high sensitivity in electronic, magnetic and optical properties.
Biofertilizing potential of a fertilizer based on cienego and native microorganisms in corn seeds
Authors: Diaz C E , Daza D , Arámbula C I 
Published: November 2019

Abstract
In the development of the productive process of stone aggregates, during the stage of washing and extraction of sludge from the decanter wells, a “cienego” sand is produced in an approximate quantity of 24.75 tons per day, of which only 10% per day is commercialized, the remaining 90% must be discarded, causing financial detriment, impact on the environment in terms of pollution by handling the product that is discarded, occupation of useful areas and landscape degradation, among other impacts negatively affecting the companies in the sector, and their environment. The objective of this research was to evaluate a fertilizer based on cienego and three native microorganisms (Azotobacter sp, 1 Azotobacter sp, 2 and Pseudomonas sp) in corn seeds. For this purpose, three native strains of diazotrophic bacteria were isolated from soil samples of oil palm crops in Tibú, located at Norte de Santander, Colombia, which were biochemically identified using traditional culture media. These isolates were inoculated into corn seeds in trays with sterile soil plus ciénego at 70/30 ratio respectively, and the plant growth-promoting effect was recorded every 4 days, by measuring morphological variables such as height, number of leaves, number of roots, length and germination rate. The results showed that Azotobacter sp, 2 treatment presented a higher production of roots, reached greater height (cm), number of leaves and germination rate in comparison to control treatment after 12 days of monitoring, besides directly influencing the percentage of organic matter in the substrate and elements such as calcium, potassium and phosphorus, allowing greater productivity and corn seed yield once these were germinated.
Performance, chemical composition and antibacterial activity of the essential oil of Ruta chalepensis and Origanum vulgare
Authors: Arámbula C I , Diaz C E , Garcia M I 
Published: November 2019

Abstract
The antibacterial effectiveness of Origanum vulgare and Ruta chalepensis essential oils cultivated in three municipalities of Norte de Santander, Colombia, on gram positive and gram-negative bacteria was determined in vitro. The oil extraction process was carried out at zoey perfumery company by the steam dragging method from 5 kg of vegetable material, the oil yield obtained compared with the vegetable material collected was calculated using mathematical formulas and its chemical composition was determined by mass spectrometry since is an analytical technique with great potential that allows to elucidate the structure and chemical properties of molecules. For the determination of the minimum inhibitory concentration and the minimum bactericidal concentration of the extracted oils, the mother solution of 2.5 g/mL was prepared and from this solution, the different dilutions at concentrations from 1000 mg/mL up to 15.62 mg/mL were made. A suspension equal to tube 0.5 of the McFarland scale of each of the microorganisms (Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853) was then prepared with sterile saline solution and inoculated in microplates with volumes of diluted solution, soy tripticasa broth and dimethyl sulfoxide, was then incubated at 37 °C for 18 hours and proceeded to inoculate in Müeller-Hinton agar to verify its minimum bactericidal concentration. The results show that the yield of Origanum vulgare essential oil was 0.8% and for Ruta chalepensis 0.1%. The chemical analysis of the oils revealed the major components of Origanum vulgare such as β-mircene 1.6%, ∝-terpinene 15.7%, 1.8-cineol 3.8%, yterpineno 2.6%, terpine-4-ol 1.1%, timol methyl ether 17.4%, timol 30.6%, carvacrol 8.1%, trans-β-caryophyllene 6.3%, ∝-humulene 1%, cariophylene oxide 3.1% and Ruta chalepensis as nonanone 37.1%, undecanone 39.4%, nonanyl acetate 2.2%, decanone 2.8%. The results obtained show that essential oil of Ruta chalepensis at concentration of 500 mg/mL stop growth of Escherichia coli and seudomonas aeruginosa and at a concentration of 1000 mg/mL stop growth of S. aureus while the essential oil of Origanum vulgare was the most effective for the inhibition of all the microorganisms evaluated, requiring a concentration of 15.62 mg/mL for Escherichia coli and Staphylococcus aureus and for Pseudomonas aeruginosa, a concentration of 125 mg/mL was necessary. It is concluded that according to the chemical composition, materials of vegetable origin such as Ruta chalepensis and Origanum vulgare essential oils can be taken for the elaboration of products with potential in artisanal cosmetics and even in pharmaceutical products.
Application of maturity method to estimate compressive strength of mass concrete
Authors: Gamba O , Peña G , Pineda Y 
Published: November 2019

Abstract
The correlation between the maturity index and the compressive strength of concrete is validated for mixtures with strengths of 2000, 2500, 3000 and 3500 PSI, which are the most used in the civil engineering field. Temperature probes DS18B20 connected by the 1-Wire protocol to the Raspberry Pi 3 card were used to census the data and calculate the maturity index. The concrete mixtures presented A/C ratios of 0.820, 0.748, 0.680 and 0.623, which are consistent with those used in the construction industry. Compressive strength tests were performed every 24 hours during a 28-day test scenario in order to understand the behavior of concrete throughout the curing process. From the values of mechanical resistance to compression obtained in the control ages of 7 and 14 days it is inferred that the concrete has a normal hardening, likewise when comparing the experimental results of the resistance to compression, with those found using the method of maturity, it was possible to identify that at early ages (less than 10 days) they present uncertainties greater than 10% while at ages greater than 10 days of curing this error does not exceed 5%. In general, it was evidenced that the assembly carried out with the Raspberry pi 3 card and DS18B20 probes reliably allowed the monitoring, recording and storage of temperature and time data during the entire curing process.
Metal hydrides with body-centered cubic structure: Advantages and challenges
Authors: Martinez-Amariz A , Peña Dario , Montes Vera E 
Published: November 2019

Abstract
Metal hydrides are considered an easy and safe way to store hydrogen. Storage is one of the keys to the large-scale implementation of the so-called hydrogen economy, which will undoubtedly revolutionize the new vision of sustainable development towards a more environmentally friendly world. This paper presents a general review of some alloys based on TiCrV and TiCrVZr showing their advantages and challenges that must be developed for their implementation. The capacity of absorption and desorption as a function of time is shown using a Sieverts type device, the structure is studied by means of X-ray diffraction as well as its morphology by means of scanning electron microscopy. This paper shows the advantages and disadvantages of alloy synthesis methods based on transition metals, it is observed that hydrogen capacity increases in the process of fusion synthesis and decreases in the process by mechanical grinding, however the capacity desorption is not optimal at room temperature.
Market analysis of the target population for the creation of waterproof paint to mitigate environmental impacts in Bucaramanga, Colombia
Authors: Tiria L C , Zamudio W H , Bellon D , Useche I E 
Published: November 2019

Abstract
In this study, a target population of hardware stores that sell paint in the city of Bucaramanga, Colombia was determined. Through a survey, we proceeded to investigate in business the different uses that give expanded polystyrene that generally serves as a product packaging element. A univariate and bivariate analysis of the variables used in this study was carried out with statistical package for the social sciences to make a diagnosis of the different uses of expanded polystyrene and its use in construction materials. Therefore, use the expanded polystyrene to reduce the volume in sanitary landfills through the creation of waterproofing paint. The gradual process of industrialization of the new paint based on expanded polystyrene EPS will allow mitigating the transit of these wastes to sanitary landfills to reduce environmental impact, will allow the emergence of a new production chain as a commitment to a social industry that will receive economic benefits for the improvement of the quality of life of the actors that will intervene in said productive chain. It has not been implemented because some scientists believe that the inputs required to mix expanded polystyrene are expensive and the industry would not be willing to take on. It is observable that the scientific community is also not interested in exploring limonene alternatives so that the criteria of a mixture with environmentally friendly expanded polystyrene are maintained.