bluuebunny/crossref_metadata_2025 huggingface dataset:
Using High Voltage Electrochemical Oxidation (HVEO) to obtain protective coatings, surface finishing on electronic materials
Authors:   Department of Electrical Engineering, Alex Ekwueme Federal University Ndufu Alike Ikwo, Nigeria, Nmadu D. , Eli-Chukwu N.C. ,   Department of Electrical Engineering, Alex Ekwueme Federal University Ndufu Alike Ikwo, Nigeria, Uma U. U. ,   Department of Electrical Engineering, Alex Ekwueme Federal University Ndufu Alike Ikwo, Nigeria, Ogah O. E. ,   Department of Electrical Engineering, Alex Ekwueme Federal University Ndufu Alike Ikwo, Nigeria, Parshuto A. A. ,   Physical-Technical Institute of The National Academy of Science of Belarus, Eheduru M. I. ,   Department of Electrical Engineering, Alex Ekwueme Federal University Ndufu Alike Ikwo, Nigeria, Ezichi S. I. ,   Department of Electrical Engineering, Alex Ekwueme Federal University Ndufu Alike Ikwo, Nigeria, Ogbonna-Mba C. N. ,   Department of Electrical Engineering, Alex Ekwueme Federal University Ndufu Alike Ikwo, Nigeria
Published: May 2022

Electronics and microelectronic components such as printed circuit board, capacitors, CPU heat sinks, hard drive, etc. commonly encounter harsh environmental conditions during their operational lifetime. To protect the electronics materials from conditions like corrosion, wear, humidity and contaminants, aluminium protective coating materials can be used. However, the behavior of materials in harsh environments and their effect on the reliability of electronics in industrial products has been studied only very little. Moreover, the changes in the parameters (current density, temperature and time) of commonly used aluminium under various conditions remain largely unknown. In this paper, High Voltage Electrochemical Oxidation (HVEO) was used to produce a high microhardness of 440HV and high surface thickness of up to 44µm oxide coatings on aluminum alloy AMg2 (analogues of 5052-H32 alloy) for electronic components protection. The process was carried out in electrolyte of tartaric acid and sulfuric acid as an electrolyte under constant duration for each sample and various anodizing temperatures and current densities. The samples used in the study were aluminum used for commercial electronics devices designed for use in harsh conditions.
Facile synthesis of Fe3O4/Sio2/Cu nanoparticles: investigation of physicochemical attributes of interaction in cationic micellar media and photo-antibacterial impact
Authors:   Department of Energy Science and Technology, Faculty of Science, TurkishGermen University, 106 34820, Istanbul, Turkey, Darroudi M. , Taj M. B. ,   Institute of Chemistry, Division of Inorganic Chemistry, The Islamia University Bahawalpur, Bahawalpur 63100, Pakistan
Published: May 2022

Solubilization of core-shell magnetic nanoparticles has gained new popularity as a versatile partitioning method with the recent growth in nanotechnology and related biotechnology applications. In this sense, Fe3O4/SiO2/Cu nanoparticles (NPs) were designed and characterized by various techniques such as Ultra-violet visible (UV-vis), Fourier transforms infrared (FTIR), X-ray diffractometry (XRD), scanning and transmission electron microscopy (SEM & TEM), energy dispersive X-ray (EDX) and thermogravimetric (TGA) analyses. The size determined by TEM analysis of Fe3O4/SiO2/Cu NPs was found in the range of 24 nm. The diffractometer results verified the impurity-free synthesis of the desired nanoparticles. Micellar solubilization and thermodynamics of micellization were determined correspondingly using a UV-Vis spectrophotometer and conductometer. The thermodynamics of micellization in terms of enthalpy, entropy and standard Gibb’s free energy was determined using electrical conductometry. The solubilization parameters viz. partition constant (Kc), binding constant (Kb), partition coefficient (Kx), and the corresponding Gibb’s free energies were estimated from the absorption spectroscopic analysis. The experimental outcomes and their computation revealed the rise in the critical micelle concentration of CTAB due to the incorporation of the nanoparticles with the micelles. Moreover, the photo-antibacterial activity of the nanoparticles in the bacteria culture environment showed effectiveness in comparison to the control group.
Synthesis and characterization of copper coatings on polyimide membranes (PIR 003)
Authors:   Department of Chemical and Materials Engineering, Pontifical Catholic University of Rio de Janeiro, RJ, Brasil, Velarde Loayza P. E. , Brocchi E. A. ,   Department of Chemical and Materials Engineering, Pontifical Catholic University of Rio de Janeiro, RJ, Brasil, de Siqueira R. N. C. ,   Department of Chemical and Materials Engineering, Pontifical Catholic University of Rio de Janeiro, RJ, Brasil
Published: May 2022

The formation of stable metallic/polymeric joints is a huge challenge in the materials sciences. Adhesion requires interphase that is able to specifically interact with the metallic phase. The primary amino groups exhibit copolymers as highly reactive to metal surfaces. This article will give a better understanding of the mechanisms of chemo-absorption by chemical functionalization of polyimides, as well as in the wet development of metallization of materials based on H2 reduction in polymers. And it will be evidenced by comparisons by measures of polymer/metal characterization.
Effect of antimony on characteristics of HgBa2CaCu2-xSbxO8+δ superconducting
Authors:   Dept. Radiology Techniques /College of Health and Medical Technology / Middle Technical University (MTU), Iraq, Radhi Jobayr M. , Mahdi S. H. ,   Department of Physics, College of Education for Pure Science (Ibn-ALHaitham)/University of Baghdad, Iraq, Salman E. M.T. ,   Department of Physics, College of Education for Pure Science (Ibn-ALHaitham)/University of Baghdad, Iraq, Jasim K. A. ,   Department of Physics, College of Education for Pure Science (Ibn-ALHaitham)/University of Baghdad, Iraq
Published: May 2022

In this work, HgBa2CaCu2-xSbxO8+δ compounds with (x = 0.2, 0.4, 0.6 and 0.8) have been prepared by the solid-state reaction method. Structural, morphological, and electrical properties were investigated using X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. Using the 4-probe technique to study the effect of antimony-substitution for Copper on the electrical properties of HgBa2CaCu2-xSbxO8+δ (Hg-1212) phase was investigated by measuring the resistivity as a function of temperature. Results indicate that the addition of antimony (Sb) increases the volume fraction of the phase and changes the superconducting transition temperature Tc of the superconductor to a normal state. The dielectric loss factor and ac conductivity have been investigated at room temperature. It was found that dielectric properties decreased with increasing electric field frequency. It was observed that the best value was 0.8 of the Sb content. Generally, with increasing antimony content, at lower frequencies, higher dielectric criteria are achieved, while at higher frequencies, lower dielectric criteria are achieved. On the other hand, the dissipation of the energy in the dielectric is directly proportional to the dielectric loss factor. Considering this, the increase in the values of ac conductivity is increasing with an increased frequency range to 5 MHz.
Shells as a Costume Element of the Turkic-Ugric Population of the Saltiv Culture (Based on Materials from the Krasna Hirka Biritual Burial Ground)
Authors:   PhD in History, Head of the Archaeology Department, The M.F. Sumtsov Kharkiv Historical museum, Aksionov Viktor
Published: May 2022

In eight burials (seven inhumations and one cremation) of the Krasna Hirka burial ground in Kharkiv region, there were found the pendants made of sea shells of the mollusk «Cypraea moneta» (burials Nos. 53, 176, 180, 191, 195, 311) (figs. 1: 2, 19, 20; 2: 15, 32; 3: 11; 4: 19; 5: 9) and pendants made of the valves of river mollusks («Unió pictorum» or «Anodonta») (burials Nos. 53, 185, 309) (figs. 2: 16, 33, 34; 6: 23—29). The pendants were present in the child’s burials (burials Nos. 53, 180, 185, 191, 195, 309) and young women of childbearing age (burials Nos. 176, 311). The location of shells jewelry in the burials indicates that they were sewn on clothes and headwear (burial No. 309), they were a part of removable breast ornaments (burial No. 176) (fig. 5: 15), a handbag decoration that was hung to the belt (burial Nos. 185, 191, 311) (figs. 2: 17; 3: 1; 4: 1), also they were woven together with glass beads, bronze bells and bronze spiral beads into the braids of buried people (burials Nos. 53, 180, 195) (fig. 2: 1). The arrangement of the pendants in the burial No. 309 allows asserting that three pendants adorned the child’s cap, being sewn at the area of the temples and on the crown (fig. 7: 2). By the location of the beads, bronze beads, bells and four more pendants of mollusks shells (fig. 7: 1), it can be seen that the collar of the child’s clothes in the neck area was decorated with monochrome beads and small beads sewn on, and four shell pendants that were sewn onto the child’s clothes in the chest area (fig. 7: 3). Polychrome beads (eye-shaped and striped), together with cast bronze bells and bronze beads, were threaded into the child’s braids (fig. 7: 4). In the investigated burials, the shell pendants resembled protective amulets. The connection of these jewelry with the water element, their shape and colour (white/ pearl) indicate that they are related to the cult of the Moon and are a symbol of the Great Goddess — the mother/ progenitor of all living beings and the giver of all life’s blessings.
New Materials for the Study of the Funeral Rite of the Przeworsk Culture in Western Buh Region
Authors:   Research Fellow of the Lviv Regional Council «History and Local Lore Museum», Sydorovych Volodymyr
Published: May 2022

Burial monuments are an important element of the spiritual culture of the Przeworsk population of the Western Buh region. The main type of burials was cremation in an urn or earthen pit. The cremation rite had dominated throughout its existence, but there are cases of inhumation burials. Borrowing from the Celts, the population of the Przeworsk culture buried weapons, ISSN 0235-3490 (Print), ISSN 2616-499X (Online). Археологія, 2022, № 1 143 jewelry, personal items and pottery. Almost all items were intentionally damaged. There are cases of intentional damage to small items: brooches, spurs, scissors, pins, needles, etc. One of these burial complexes was discovered by the so-called «black diggers» and transferred to the Lviv Regional Council «History and Local Lore Museum». The burial complex contained a ritually bent double-edged sword, a shield handle and a spearhead, which were connected to each other, an iron brooches and a ritually damaged shield boss. The four iron spurs were connected in pairs. The funeral rite and the items found in the burial have numerous analogies on the monuments of the Przeworsk culture in Poland and Western Ukraine. Among the total number of burials of the Przeworsk culture, burials with swords stand out. Obviously, the presence of a sword is an evidence of the high social status of its owner. The set of features of the material found in the burial allows us to confidently date it to the phase C1a—C2 of the Late Roman period (middle — end of the 3rd century AD). The advance of the bearers of the Przeworsk culture to the south and east in this chronological period was accompanied by local military conflicts. In any case, the Przeworsk population in the region of the Western Buh was an integral part of ethnic and cultural processes that lasted throughout the 3rd century. The formation of the source base of funerary monuments of the Przeworsk culture in the future will make it possible to identify certain regional features in topography, funeral inventory and ritual actions. Given that the study of monuments of this archaeological culture in Ukraine remains low.
Economic theoretical foundations of post-transformation reorientation of international business
Authors:   V. N. Karazin Kharkiv National University, Arkhiiereiev Sergey
Published: May 2022

The article considers economic and theoretical foundations of reorientation of international business in post-transformation economy and analyzes the multifactor character of this process. When considering geographical reorientation, the need for multi-vector changes is shown, which is not only reduced to East-West processes, but also to North-South ones. The analysis of structural reorientation lead to the conclusion that it is advisable to implement sectoral reorientation in favor of the industrial sector. The study of this process leads to the conclusion that the possibilities are exhausted of reindustrialization on the old industrial basis and there is an urgent need for neo-industrialization, similar to those taking place in the new industrial economies of East Asia. This, in turn, raises the question of the need for changes in the metabolism of knowledge characteristic for economy, when absorption of knowledge begins to play an equal, if not a more important role than its creation. The need to absorb knowledge raises other demands for the integration of production, when the reorientation of international business implies not just reintegration into world trade, but reintegration into world production. At the same time, the structure of the implementation of national output should be changed, and not only in connection with the increase in the share of part of output sold abroad compared to domestic ones, but also in connection with the expansion of progressive forms of export compared to traditional ones. These forms arise mainly through inclusion in global value chains, which significantly increases the opportunities for both export growth and value added in the country's economy as a whole. As a result of the analysis, the author concludes that the reorientation of international business is a complex multifactor phenomenon in which the indissoluble unity of institutional, subjective, object and process economic theoretical foundations is manifested.
Estimation of fugitive emissions in Ukraine’s gas industry taking into account 2019 Refinement to the 2006 IPCC Guidelines for national greenhouse gas inventories
Authors:   Institute of General Energy of the National Academy of Sciences of Ukraine, 172 Antonovycha str., Kyiv, 03150, Ukraine, Shcherbyna Ye.V.
Published: May 2022

The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 to assess the risks and possible consequences of anthropogenic climate change. The IPCC includes a task force on national inventories, which develops methodological documents for national greenhouse gas inventories. The report 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories was adopted and accepted during the 49th Session of the IPCC in May 2019. The development of 2019 Refinement is related to the improvement of existing and the emergence of new technologies in the world economy, which has led to the need to update emission parameters and take into account new sources of greenhouse gas emissions and removals. The purpose of the article is to study and apply changes in the methods of estimating fugitive emissions in Ukraine’s gas industry, taking into account 2019 Refinement to the 2006 IPCC Guidelines for national greenhouse gas inventories. The article examines the state of greenhouse gas emissions in the gas industry in 2019 according to the Ukraine’s Greenhouse Gas Inventory Report data. The formation methane and carbon dioxide fugitive emissions in the last National Inventory Report according to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories is analyzed. The changes in the methods for national inventories in the energy sector 2019 Refinement are compared to the 2006 IPCC Guidelines. The estimation methane and carbon dioxide fugitive emissions in Ukraine’s gas industry in 2019 according to 2019 Refinement is made (taking into account the new emission factors and a new subcategory of abandoned wells). The article provides a comparative analysis the results with fugitive emissions in the gas industry in 2019 according to data of National Inventory Report. A study of the results shows that the use of 2019 Refinement for future greenhouse gas inventories will reduce methane and carbon dioxide emissions. Keywords: gas industry, greenhouse gas emissions, methane, carbon dioxide, inventory
DETECCIÓN MOLECULAR DE BEGOMOVIRUS AISLADOS DE ARVENSES ASOCIADAS AL CULTIVO DE AJÍ (Capsicum spp.) EN EL VALLE DEL CAUCA, COLOMBIA
Authors: Lopez-Lopez Karina , Corredor-Rodríguez Andrea , Correa-Forero Adriana Melissa , Álvarez-Rubiano Laura Patricia , Suarez- Rodríguez Andrea , Vaca-Vaca Juan Carlos
Published: May 2022

Los virus Potato yellow mosaic virus (PYMV/Co), Passionfruit leaf distortion virus (PLDV), Pepper rugose mosaic virus (PRMV) y Rhynchosia golden mosaic Colombia virus (RhGMCV) son begomovirus de interés agrícola, aislados y caracterizados molecularmente en el Valle del Cauca. Sin embargo, en la actualidad no hay suficiente información sobre sus hospederos alternos. Dado que las arvenses cumplen un papel importante en la ecología y epidemiología viral, este estudio tuvo como objetivo detectar la presencia de estos begomovirus en arvenses asociadas al cultivo de ají en el Valle del Cauca, Colombia. Se recolectaron 121 plantas arvenses en zonas productoras de ají, localizadas en 7 municipios del Valle del Cauca, las cuales fueron identificadas a nivel taxonómico. A partir del ADN genómico purificado de estas plantas se evaluó la presencia de virus por PCR, usando cebadores universales para el género Begomovirus y específicos para PYMV/Co, PLDV, PRMV y RhGMCV. Se detectaron begomovirus en 15 de las especies de arvenses evaluadas. Esta es la primera vez que las especies Ipomoea tiliacea, Melothria pendula, Caperonia palustris, Desmodium tortuosum, Desmodium intortum, Ammannia coccinea, Panicum polygonatum, Capsicum rhomboideum, Eclipta prostrata y Synedrella nodiflora se reportan como hospederas de begomovirus en Colombia. Se detectaron los begomovirus RhGMCV, PYMV/Co, PRMV y PLDV en infecciones simples y mixtas. Estos resultados aportan nuevos datos sobre los hospederos alternos de begomovirus. Esta información servirá para implementar un plan de manejo integrado de enfermedades virales con el potencial para afectar negativamente el rendimiento del cultivo de ají, y otros cultivos en Colombia.
VARIABILIDAD DE LA ESTRUCTURA COMUNITARIA DE MACROINVERTEBRADOS ACUÁTICOS EN LAS SALINAS DE CHILCA, LIMA, PERÚ
Authors: Castillo Velásquez Rodolfo Mauricio , Huamantinco Araujo Ana Asunción
Published: May 2022

Las Salinas de Chilca están localizadas en el km 65 de la carretera Panamericana Sur, representadas por tres lagunas: La Milagrosa (laguna principal y pozas salinas), La Mellicera y La Encantada. El entorno de estas lagunas pertenece a la zona de vida Desierto Subtropical (d-ST). El objetivo del presente estudio fue determinar la influencia de las variables ambientales en los cambios de la estructura comunitaria de macroinvertebrados en las Salinas de Chilca, Lima, Perú. Se realizaron cuatro campañas de colecta desde enero hasta septiembre del 2018, estableciéndose doce estaciones de muestreo, tres estaciones por cada ambiente léntico. La muestra fue colectada a través de barridos con una red tipo D de 500 µm de apertura de malla en la orilla de cada laguna. Los parámetros fisicoquímicos del agua presentaron valores diferenciados en cada laguna y formaron una gradiente de salinidad descendente desde las pozas salinas (de valores hipersalinos) hacia la laguna La Encantada (de valores mesosalinos). Se recolectaron 42 géneros de macroinvertebrados, siendo los géneros más influyentes en los patrones comunitarios: Heleobia, Larsia, Trichocorixa, Ephydra y Artemia, estos organismos representaron el 83,85 % de la abundancia total. El gradiente ambiental generado por la salinidad determinó dos grupos muy diferenciados, un grupo de especies que no toleran valores elevados de salinidad (lagunas mesosalinas) de otro grupo de especies que soportan valores extremos de salinidad (lagunas hipersalinas); sin embargo, la depredación, alteraciones antrópicas, estructura del hábitat, entre otros factores, también estarían influyendo en los cambios de la estructura comunitaria.
DEPREDACIÓN EN NIDOS ARTIFICIALES DE AVES EN UN GRADIENTE DE INTERVENCIÓN ANTRÓPICA EN LA AMAZONIA COLOMBIANA
Authors: Londoño Duque Laura Victoria , Colorado Z. Gabriel J.
Published: May 2022

Las coberturas de los bosques naturales están cambiando por el avance de la frontera urbana, agrícola y ganadera, afectando la disponibilidad de refugios y recursos para la reproducción de algunas aves. A pesar del avance en el conocimiento del efecto de las intervenciones antrópicas sobre la biodiversidad, son limitadas las investigaciones que evidencien el efecto antrópico sobre la historia de vida de las aves, incluida la reproducción. Para describir el efecto antrópico sobre la depredación de nidos, se establecieron 108 nidos artificiales en un gradiente de intervención antrópica en la jurisdicción de Leticia, Amazonas, Colombia. De los 38 nidos que fueron depredados, 6 fueron en el sitio con menos intervención antrópica, 15 en el sitio de intervención intermedia y 17 en el sitio con mayor intervención. En particular, se evalúa cómo los cambios en la cobertura vegetal mediadas por las intervenciones antrópicas afectan la incubación de las aves, esperando que una mayor cobertura vegetal alrededor del nido, aumentara su probabilidad de éxito. Se encontró que las variables asociadas a la estructura de la vegetación cercana a los nidos (e.g. Cobertura a un metro alrededor del nido, Cobertura vegetal baja, Abertura de dosel), mostraron una relación significativa y positiva con el destino del nido. Esta investigación sugiere que procesos de urbanización (p. ej. Construcción de casas y carreteras) presentes en el contexto de la región amazónica, influyen en la pérdida de nidos artificiales de aves, y que cambios en la estructura de la vegetación mediados por la degradación de las coberturas naturales podrían jugar un papel fundamental en la depredación de nidos.
EL CRÁNEO DE Caiman crocodilus fuscus: VARIACIONES ALOMÉTRICAS Y ONTOGENÉTICAS
Authors: Falcón-Espitia Nelson Guillermo , Jerez Adriana
Published: May 2022

Las variaciones ontogenéticas en el cráneo ofrecen información del crecimiento y la ecología trófica en Crocodilia. Por lo tanto, analizamos las variaciones ontogenéticas de la forma y elementos óseos del cráneo en C. c. fuscus. Encontramos un efecto alométrico y cambios en la forma, ya que varía de un cráneo longirostrino en las crías a uno brevirostrino en subadultos y adultos. Se observó el ensanchamiento de la base del escamoso, del cuadratoyugal, del proceso lateral del pterigoides, del proceso retroarticular del articular y el desarrollo de una cresta dorsal en el surangular. Estos cambios, probablemente estarían relacionados con variaciones en la dieta durante la ontogenia, y tienen implicaciones ecológicas que deben ser consideradas en el estudio de la evolución y conservación de estas subespecies.
POTENTIAL DISTRIBUTION OF DOMESTICATED Sechium edule (CUCURBITACEAE) IN MEXICO
Authors: Barrera Guzmán Luis Ángel , Cadena Iñiguez Jorge , Legaria Solano Juan Porfirio , Sahagún Castellanos Jaime , Ramírez Ojeda Gabriela
Published: May 2022

Mexico is the centre of origin of the chayote (Sechium edule (Jacq.) Sw), an important plant in human consumption and in pharmaceuticals. The objective of this study was to determine the potential distribution of domesticated S. edule in Mexico using seven species distribution algorithms, to efficiently manage S. edule resources and help its conservation by identifying patterns of geographic distribution. Otherwise, areas of high suitability can be used to produce improved seed at a lower cost. 162 GBIF occurrence points and nine layers in raster format were used to evaluate seven algorithms of species distribution models. To evaluate the reliability and performance of the models, the statistics Area Under the Curve (AUC) and true skill statistic was used. Predominant climate types were Cwb (33.3 %) and Aw (17.9 %); predominant soil types were leptosol (33.3 %) and phaozem (16.7 %). The seven models showed areas of high suitability (> 0.75) in Chiapas, Guerrero, Oaxaca, Veracruz, Tabasco, Puebla and Hidalgo states. AUC values for the seven models were > 0.8 and their performance was adequate (0.4 > TSS < 0.7). Classification tree analysis was found to be the best algorithm measured by AUC (0.90); however, the seven models were adequate to explain S. edule distribution in Mexico. S. edule climatic adaptability also allows to be distributed towards the Yucatan Peninsula and western Mexico. The distribution of S. edule in Mexico, according to the studied algorithms, is limited to total annual precipitation and temperature seasonality.
TEORÍAS EVOLUTIVAS EN LOS CURSOS DE BOTÁNICA, GEOLOGÍA Y PALEONTOLOGÍA EN LA UNIVERSIDAD NACIONAL DE COLOMBIA 1868-1875
Authors: Marquínez Xavier , Usaquén-Martínez William , Muñoz-Durán Joao-Victor
Published: May 2022

La fundación de la Universidad Nacional de los Estados Unidos de Colombia en 1868 ocurrió casi una década después de la publicación del origen de las especies de Darwin (1859); en la Escuela de Ciencias Naturales se dictaron cursos que incluían temáticas de geografía de las plantas, geología y paleontología. ¿Seguirían estos cursos el paradigma de historia natural heredado de la expedición botánica del nuevo reino de granada, o se instalarían en la tradición biológica moderna, interpretando la naturaleza en el trasfondo de las teorías evolutivas que surgieron durante el siglo XIX? Esta investigación consultó fuentes históricas primarias y secundarias para determinar si entre 1868 y 1875, los cursos mencionados tenían un trasfondo esencialista-catastrofista, o evolucionista de estilo lamarckiano o darwiniano. El análisis permitió concluir que tuvieron como fuentes primarias textos franceses y españoles, de Decandolle y Orbigny, circunscritos a la escuela francesa principalmente esencialista y catastrofista. Aunque en los cursos se pudieron  discutir algunos temas referentes al origen de las especies, lo más probable es que estas discusiones no se realizaron en un contexto Darwiniano.
Estrategias contra el narcotráfico en Colombia en el marco del acuerdo de paz
Authors: Ibarra Padilla Adelaida María , Rojas Reyes Cristian
Published: May 2022

Uno de los puntos abordados en los diálogos de paz celebrados entre el gobierno de Colombia y la guerrilla de las Fuerzas Armadas Revolucionarias de Colombia (FARC-EP) fue el narcotráfico. Lo pactado respecto a este tema se resume en tres puntos: la sustitución de cultivos ilícitos por otros legales, el establecimiento de una política de salud pública frente al consumo y la lucha contra la producción y la comercialización de narcóticos. De acuerdo con los diferentes informes de las autoridades nacionales e internacionales, se evidencia que los cultivos, el tráfico y la comercialización de las drogas ilícitas en Colombia luego de la desmovilización de las FARC-EP no solo no han disminuido, sino que han aumentado. Este artículo analiza las estrategias implementadas por el Gobierno nacional contra el narcotráfico tras el acuerdo de paz y los factores que han impedido el control de esta problemática.
¿Qué hacer con el narcotráfico y las drogas ilícitas en Colombia? Elementos metodológicos para una política de Estado
Authors: Uprimny Y. Rodrigo
Published: May 2022

El autor, a partir de una reedición de trabajos previos, propone elementos metodológicos para lograr una política democrática que enfrente en forma más lúcida el narcotráfico en Colombia. El autor considera que es necesario distinguir tres problemas diversos pero interrelacionados: el impacto del narcotráfico en la violencia y la democracia colombianas, la discusión sobre el prohibicionismo y el grado de autonomía de Colombia frente al régimen internacional de control de sustancias psicoactivas. A partir de esas distinciones, el autor concluye que la política colombiana frente al narcotráfico debe buscar tanto alternativas a la prohibición (por ser la prohibición un régimen injusto e ineficaz) como alternativas dentro de la prohibición (pues este régimen se mantendrá en el mediano plazo, al menos para drogas como la marihuana o la cocaína).
Design, implementation, and testing of an energy consumption management system applied in Internet protocol data networks
Authors: Velez Varela Fernando , Marin Lozano Diego Fernando , Sarria Paja Miton Orlando
Published: May 2022

To model the power measurement conditions of an energy system, an initial reference should be made within the specification of a generic energy consumption (EC) model. This EC model is based on the energy state of a system comprising goods, networks, and services, which supports energy management capabilities. Therefore, a prototype tool to record power consumption (PC) at the device level is designed and implemented, thereby enabling devise use optimization. The core is to collect energy-related information in internet protocol networks that support the simple network management protocol, in addition to the standard proposed in RFC-7460, and the green information technology. The information obtained is related to the energy consumed by devices that support those technologies. Then, the information is processed to evaluate different PC characteristics of the network. This research impacts the knowledge gap of information system management, where the objective sought is to establish metrics and methodological schemes for obtaining data regarding measurable behaviors in the EC field
The epistemological obstacle in Electromagnetism
Authors: Torres-Sanchez Horacio
Published: May 2022

In the development of a historical analysis on the natural phenomenon of electromagnetism, recurrently a question appears on the subject:  why does it take researchers about 2300 years to decipher, understand and then dominate and apply the electromagnetic phenomenon for the benefit of the human being? To answer this question, the hypothesis about Bacon's “idols” and Bachelard's epistemological obstacle are presented. Both posed very correctly about the theory of knowledge: the limitations or impediments that affect the ability of individuals to build new knowledge. The fascinating interpretations, myths and legends, even the scientific understanding and its technological applications that changed life on earth, have been compiled and analyzed in this article, and in the Torres´s book [18]: “The enigma of Electromagnetism under the magnifying glass"
Numerical assessment of dissipation energy capacity in perforated plate steel dampers
Authors: Villalba Morales Jesús Daniel , Ferrer-Fuenmayor Samuel N.
Published: May 2022

The use of perforated metallic shear dampers in buildings has been an adequate strategy for reducing the magnitude of damages caused by earthquakes on primary elements. Furthermore, the amount of energy dissipated by the shear dampers is in turn affected by the geometrical shape of said perforations. Such process is carried out without knowing the most adequate shape or distribution of perforations in relation to an established amount of material.In this research, 5 different steel sheer damper setups will be compared in order to determine how this affects performance and to understand how damper perforation shape affects energy dissipation capacity. The latter is achieved through a performance analysis of dampers under a cyclic load using the finite element analysis software Abaqus. Likewise, the decrease in response to a seismic event of a plane frame will be measured using three different seismic motions for all the different setups used for the researched shear plates
Alkaline delignification of lignocellulosic biomass for the production of fermentable sugar syrups
Authors: Fuertez Córdoba John Marcelo , Acosta Pavas Juan Camilo , Ruiz Colorado Ángela Adriana
Published: May 2022

The objective of this study to analyze the effect of alkaline pretreatment on the structure, composition, and subsequent hydrolysis of agricultural wastes.  An increase in the content of reducing sugars after the pretreatment is achieved. Its effectiveness is confirmed, offering a practical procedure to produce alternative energy. Factors such as the calcium hydroxide concentration (0.1 and 0.5g Ca(OH)2/g-dry matter), liquid to solid ratio (12 and 28ml/g-dry matter), temperature (40 and 70°C), stirring rate (0 and 200rpm), an average particle size (0.45 and 1.015mm) were assessed using an experimental design. On average, kikuyo grass had the highest lignin removal (28.31%) while the African oil palm fiber had the lowest value (14.10%). The average particle size was a statistically significant factor for the pretreatment of African oil palm fiber, the stirring rate was an important factor during the pretreatment of kikuyo grass. The Ca(OH)2 concentration had a major effect on the pretreatment of sugarcane bagasse and coffee pulp waste.
Modification of the particle swarm optimization method through the intervention technique and its application for antenna design
Authors: Contreras Chacon Andry Carmelo , Tello Maita Josimar Dadi
Published: May 2022

In this research, a modification of the particle swarm optimization method was proposed, which is based on an intervention technique for the design of antennas. The proposed method was tested through its application on typical benchmark functions. Moreover, it was applied to the optimal design of a narrow band antenna and two ultra-wideband antennas through shape and hybrid optimization. The objective function was based on minimizing the S11 magnitude in the desired frequency range to improve impedance matching. The modified method had a better performance than the original particle swarm optimization in the typical benchmark functions, and the best results were obtained for the antenna optimization process. Therefore, this method is a good alternative to be applied in these processes because it allows obtaining a better quality of solution and reducing the number of evaluations of the objective function.
Behavior of pigs subjected to climate control system in the Semiarid Region of Pernambuco, Brazil
Authors: Farias Nicoly , Pandorfi Héliton , Coelho Barnabé Janice Maria , Guiselini Cristiane , Pontes de Almeida Gledson Luiz , Ribeiro de Holanda Mônica Calixto , Carneiro de Holanda Marco Aurélio , Da Silva Marcos Vinícius
Published: May 2022

The objective was to thermally characterize the facilities during the growth and finishing phases of pigs and to evaluate the influence of climate control systems on the expression of the behaviors of pigs. The experiment was conducted at the Federal Rural University of Pernambuco, Serra Talhada, PE, Brazil, during the spring of 2019. Twenty-seven pigs aged 63 days were used. The animals were submitted to pens without climate control system, with forced ventilation, and with an evaporative adiabatic cooling system. Dry bulb temperature (°C), relative air humidity (%), black globe temperature (°C), and swine behavioral responses were recorded, submitted to multivariate analysis, using the principal component technique. Pens with the evaporative adiabatic cooling system showed a significant reduction in air temperature and an increase in relative air humidity, during the two phases. Pigs submitted to evaporative cooling showed greater ingestive activity and lethargic behavior, typical of the studied phases
On the optimal reconfiguration of radial AC distribution networks using an MINLP formulation: A GAMS-based approach
Authors: Montoya Oscar Danilo , Gil González Walter Julián , Grisales-Noreña Luis Fernando , Giral Diego , Molina-Cabrera Alexander
Published: May 2022

This paper deals with the problem of the optimal reconfiguration of medium voltage distribution networks by proposing a mixed-integer nonlinear programming (MINLP) model. This optimization model has as objective function the minimization of the total power losses in all the branches of the network constrained by active and reactive power balance equations, voltage regulation bounds and device capabilities, among others. The proposed MINLP formulation works with branch-to-node incidence that allows representing the active and reactive power flow in branches as a function of the real and imaginary parts of the voltages and currents. The solution of the MINLP model is reached through the general algebraic modeling system widely know as GAMS package by presenting it in a tutorial form. This software allows implementing in compact form the proposed model and solve it via branch and bound methods. Two test feeders composed by 5 and 14 nodes permits demonstrating the fidelity of the proposed MINLP model regarding power losses minimization when compared with literature reports.
Methodology for Classifying the Structural State of Uninspected Pipes in Sewer Networks Based on Support Vector Machines
Authors: Hernandez Nathalie , Cañon Miguel , Torres Andrés
Published: May 2022

The nearly unmitigated growth of cities has placed ever-greater pressure on urban water systems regarding climate change, environmental pollution, resource limitations, and infrastructure aging. Therefore, the development of methods to classify and assess the structural state of urban drainage infrastructure becomes very important, given that they can be used as support tools for proactive management plans. This paper presents a method for predicting and classifying the structural state of uninspected sewer pipes using Support Vector Machines, based on the physical characteristics, age, and geographical location of the pipes. According to the results, the methodology: i) correctly classified more than 75% of uninspected pipes; (ii) identified pipes in critical structural states, with low importance prediction error for 69% of pipes; and (iii) provided a guide for establishing the number or percentage of pipes that require inspection or intervention.
Entre la “ayuda para la familia” y el “sueño del negocio propio”. Experiencias de emprendedurismo vinculadas a políticas sociales en contextos de pobreza urbana (Rosario, Argentina)
Authors: Vitali Sofia Magali
Published: May 2022

En este artículo analizo las experiencias productivas vinculadas al emprendedurismo de destinatarios/as de políticas de economía social en asentamientos irregulares de la ciudad de Rosario, Argentina.  Parto de un estudio etnográfico que combinó técnicas de entrevistas en profundidad, observación participante y análisis de narrativas biográficas que me permitieron restituir los sentidos, valores, prácticas y significaciones elaboradas por  las personas emprendeduristas. Presento las modalidades de implementación de las políticas sociales de la Secretaría de Economía Social de Rosario;  describo las características y estructuras productivas de los emprendimientos y finalmente me detengo en los sentidos y prácticas puestos en juego por las y los destinatarios de dichas políticas, en respuesta a las tensiones y reapropiaciones de las propuestas estatales.
De la máquina que se repara al dolor que habita lo corpóreo. Experiencias y significados del dolor en pacientes de un hospital de alta complejidad en Medellín, Colombia
Authors: Guevara-Farias Jairo Camilo , Botero Natalia , Ospina Juan Manuel , Yepes Carlos Enrique
Published: May 2022

Este trabajo indaga sobre los significados del dolor de pacientes sometidos a procesos de cirugía, anestesia y analgesia en un hospital de Medellín. A partir de 24 entrevistas semiestructuradas analizadas desde la teoría fundamentada, identificamos como problema central el cuerpo y su dualismo mecanicista, plasmado en técnicas corporales del saber biomédico en el manejo del dolor, desde la cuales los y las pacientes elaboran  metáforas sobre el sufrimiento y el dolor, su curso y significado. Concluimos que el cuerpo está escindido para el saber biomédico y para los pacientes, pero la experiencia con el dolor es total, integradora e inconmensurable y por tanto, los pacientes, sujetos sufrientes, la viven de forma distinta y en un lenguaje propio, diferente al del campo médico, que la codifica desde su propio saber.
Factores epidemiológicos y educativos asociados al nivel de conocimiento sobre prevención de cáncer gástrico en internos de medicina de Lima, Perú
Authors: Alva-Peña Juan Jair , Correa-López Lucy Elena , De la Cruz-Vargas Jhony Alberto
Published: May 2022

Introducción. El cáncer gástrico es uno de los cánceres más letales; por lo tanto, un alto nivel de conocimiento sobre su prevención es esencial en la formación de los futuros médicos.
Objetivo. Determinar los factores epidemiológicos y educativos asociados al nivel de conocimiento en prevención de cáncer gástrico en internos de medicina de una universidad en Lima, Perú.
Materiales y métodos. Estudio transversal analítico realizado en 319 internos de medicina matriculados en 2020 y 2021 en la Facultad de Medicina Humana de la Universidad Ricardo Palma. La información se recolectó utilizando encuestas. Además, el nivel socioeconómico y el nivel de conocimiento se midieron mediante la clasificación de Graffar y el test de conocimiento sobre prevención en cáncer gástrico, previamente validado en un centro de salud en Lima (Alfa de Cronbach: 0.84), respectivamente. Se realizó un análisis bivariado y uno multivariado con un modelo de regresión de Poisson, calculándose razones de prevalencia, con un intervalo de confianza (IC) de 95% y un nivel de significancia de p<0.05.
Resultados. El nivel de conocimientos fue alto en 53.92% de los internos. En el análisis multivariado, se observó una asociación significativa entre el nivel alto de conocimiento sobre prevención de cáncer gástrico y las siguientes variables: planear realizar una especialidad quirúrgica (RPa:1.43, IC95%:1.13-1.81; p=0.003) y tener nivel socioeconómico I-II (RPa:1.58, IC95%:1.26-1.99; p=0.000). Por otro lado, las variables sexo, edad, tener un familiar directo con cáncer, tener un familiar médico directo y asistencia a conferencias de cáncer no mostraron asociación significativa.
Conclusión. Planear realizar una especialidad quirúrgica y tener nivel socioeconómico I-II fueron las únicas variables asociadas con tener un nivel alto e conocimientos sobre prevención del cáncer gástrico, por lo que se recomienda que la Facultad de Medicina Humana desarrolle estrategias dirigidas a mejorar el nivel de conocimiento de los internos de medicina.
¿Tienen los artículos sobre COVID-19 más citaciones? Análisis bibliométrico en una revista biomédica de Latinoamérica
Authors: Arroyo-Hernández Hugo
Published: May 2022

Desde el inicio de la pandemia por la COVID-19 los editores de revistas científicas han implementado estrategias para agilizar sus procesos mediante la rápida gestión de los artículos sobre COVID-19 con la finalidad de divulgar los conocimientos de forma oportuna y generar evidencias para la toma de decisiones en salud, pero sin alterar el rigor del proceso de revisión por pares. 1,2 El impacto que alcanzan los artículos publicados en revistas científicas es medible por diversos parámetros. Sin embargo, son las citas que se reciben en otras publicaciones, como revistas, preprints, tesis, documentos técnicos, entre otros, uno de sus principales indicadores.
Consistencia interna, validez convergente, discriminante y de criterio del Start Back Screening Tool en una muestra colombiana
Authors: Alfonso Mora Margareth Lorena , Riveros Munevar Fernando , Castellanos-Garrido Adriana Lucía , Rengifo-Varona María Leonor , Corredor-Nieto Laura Paola , Guerra-Balic Miriam Elisa , Sánchez-Martín Ricardo
Published: May 2022

Introducción. El dolor lumbar (DL) es una causa frecuente de consulta y una de las principales causas de incapacidad laboral permanente. La estratificación del riesgo de discapacidad por DL permite desarrollar intervenciones terapéuticas específicas; sin embargo, dicha estratificación requiere instrumentos válidos y confiables.
Objetivo. Determinar la consistencia interna y la validez convergente, discriminante y de criterio del cuestionario Start Back Screening Tool (SBST) en una muestra colombiana.
Materiales y métodos. Estudio cuantitativo de validación de pruebas realizado en 68 pacientes adultos con DL que recibieron una intervención fisioterapéutica (10 sesiones) entre 2019 y 2020 en una clínica de Chía, Colombia. Los participantes diligenciaron el SBST, la escala numérica de clasificación del dolor (ENCD) y el cuestionario Roland Morris Disability (RMD) en tres momentos: pre-, post-intervención y luego de 6 semanas de seguimiento (sin tratamiento). La consistencia interna del SBST se determinó mediante los coeficientes Alfa de Cronbach, Omega, λ6 y Greatest lower bound (GLB). En cuanto a la validez de criterio y de constructo, se evaluaron las correlaciones entre el instrumento y la ENCD y el RMD mediante el coeficiente de correlación de Pearson. Finalmente, se realizó un ANOVA de medidas repetidas entre las medias de puntaje del SBST obtenidas en los tres momentos para estimar su validez discriminante.
Resultados. La consistencia interna del instrumento, según los diferentes coeficientes, varió entre aceptable y alta (Alfa= 0.634; Omega=0.648; λ6=0.664; GLB = 0.780). Se observaron correlaciones positivas entre el puntaje promedio en el SBST y los puntajes promedio en la ENCD (r=0.257; p=0.035) y la RMD (r=0.475; p<0.0010), así como diferencias significativas entre los puntajes promedio del SBST pre, post-intervención y seguimiento (ANOVA: F=33.722; p <0.001).
Conclusión. El SBST es un instrumento válido y confiable para el clasificar el nivel de riesgo de mal pronóstico en pacientes colombianos con DL.
COVID 19 in pregnant women and neonates: Clinical characteristics and laboratory and imaging findings. An overview of systematic reviews
Authors: Toapanta-Pinta Paola Cristina , Vasco-Toapanta Cristhian Santiago , Herrera-Tasiguano Alonso Ernesto , Verdesoto-Jácome Catalina Angélica , Páez-Pástor María José , Vasco-Morales Santiago
Published: May 2022

Introduction: SARS-CoV-2 infection in the perinatal period may be associated with an increased risk of morbidity and mortality in both the mother and the neonate.
Objective: To describe the clinical characteristics and, laboratory and imaging findings in pregnant women with COVID-19 and their newborns.
Materials and methods: We searched PubMed, Scopus, Web of Science, and Cochrane databases for systematic reviews published between February 1, 2020, and May 30, 2021, describing clinical characteristics and laboratory and imaging (chest) findings in pregnant women with COVID-19 and their newborns; there were no language restrictions. Data were reanalyzed by means of Bayesian meta-analysis using Markov Chain Monte Carlo methods. The study protocol is registered in PROSPERO under code CRD42020178329.
Results: Six systematic reviews were retrieved (for a total of 617 primary studies). A narrative synthesis of the proportions of signs, symptoms, and imaging and laboratory findings of both mothers and neonates was performed. The Odds ratios (OR) between pregnant women with and without COVID-19 were as follows: fetal well-being involvement: 1.9 (95%CI:1.09-3.63); stillbirth: 1.73 (95%CI:1.01-2.94); preterm birth: 1.77 (95%CI:1.25-2.61); maternal admission to the intensive care unit (ICU): 6.75 (95%CI:1-31.19). Regarding symptomatology, the following OR was obtained for myalgia between pregnant women and non-pregnant women with COVID-19: 0.67 (95% CI:0.51-0.93).
Conclusions: Cough, fever, dyspnea, and myalgia are the most common symptoms in pregnant women with COVID-19; in addition, there is a higher risk of admission to the ICU. Regarding complementary testing, the most frequent alterations are lymphopenia and the evidence of lesions in chest imaging studies. The presence of COVID-19 in pregnant women is associated with premature birth. It seems that SARS-CoV-2 infection in neonates is not serious and the risk of vertical transmission is low, since no data about congenital malformations attributable to the virus were found.