bluuebunny/crossref_metadata_2025 huggingface dataset:
Clima y temperatura sub-superficial del mar en Bahía Culebra, Golfo de Papagayo, Costa Rica
Authors: Alfaro Eric J. , Cortés Jorge , Alvarado Juan José , Jiménez Carlos , León Alberto , Sánchez-Noguera Celeste , Nivia-Ruiz Jaime , Ruiz Eleazar
Published: July 2015

Bahía Culebra, Golfo de Papagayo, Costa Rica es una región de afloramiento estacional. Para determinar la relación entre el clima y la variabilidad de la temperatura sub-superficial, se analizaron los registros de la temperatura sub-superficial del mar de nueve estaciones localizadas en la Bahía. El análisis permitió caracterizar su ciclo anual y explorar su relación con fuentes de variabilidad climática que influencian el clima regional para el periodo 1998- 2010. Los resultados se contextualizaron usando además los datos de una estación meteorológica automática que funcionó en la bahía junto con el registro de la temperatura superficial del mar para una rejilla que cubre la región de 9-11°N, 85-87°W, para el periodo 1854-2011. Debido a la tendencia positiva encontrada en la región para la temperatura superficial del mar, se concluye que los resultados mostrados asociados a los ciclos anuales y diarios en Bahía Culebra deben ser interpretados bajo un escenario de cambio climático, asociado a un calentamiento ocurrido desde 1854, además coherente con lo observado globalmente, y que su variabilidad climática está influenciada no sólo por aquella ligada a la de El Niño-Oscilación del Sur, en el Pacífico Ecuatorial, sino también por influencias de tipo atmosférico relacionadas con la variabilidad en el Océano Atlántico, debido a que los eventos cálidos (fríos) en Bahía Culebra tienden a ocurrir en concordancia con anomalías positivas y negativas (negativas y positivas) de los índices Niño 3.4 y OAN, respectivamente
Atmospheric forcing of cool subsurface water events in Bahía Culebra, Gulf of Papagayo, Costa Rica
Authors: Alfaro Eric J. , Cortés Jorge
Published: July 2015

Bahía Culebra, localizada en el Golfo de Papagayo, al norte de la costa del Pacífico de Costa Rica, es un área de afloramiento estacional, en donde pueden ocurrir eventos de enfriamiento más intensos, principalmente durante algunas semanas del invierno boreal. Para estudiar estos eventos de enfriamiento extremo, se analizaron datos de nueve estaciones con registros de la temperatura subsuperficial del mar, desde 1998 hasta el 2010. A partir de estos registros, se identificaron cinco casos de estudio asociados a enfriamientos del mar en la región. Los descensos de la temperatura de estos eventos fueron de aproximadamente 8-9ºC y se asociaron al paso de empujes fríos en la región del Caribe y una fuerte magnitud del viento alisio sobre América Central. Este reforzamiento del flujo alisio favorece el desplazamiento del agua superficial hacia afuera de Bahía Culebra, cuyo eje principal se ubica en la dirección noreste-suroeste. Lo anterior favorece y provoca un enfriamiento de la temperatura del mar en la bahía, ya que el agua desplazada es reemplazada por aguas más frías provenientes de profundidades mayores.
Impact of upwelling events on the sea water carbonate chemistry and dissolved oxygen concentration in the Gulf of Papagayo (Culebra Bay), Costa Rica: Implications for coral reefs
Authors: Rixen Tim , Jiménez Carlos , Cortés Jorge
Published: July 2015

El Golfo de Papagayo, costa Pacífica de Costa Rica, es una de las tres regiones de afloramiento estacional de Mesoamérica. Las características físicas y químicas del agua que aflora no habían sido estudiadas. Durante 29 horas en Abril 2009, se estudiaron la temperatura superficial del mar (TSM), la concentración de oxígeno disuelto, salinidad, pH y la presión parcial de CO2 (pCO2), en la Marina Papagayo, Bahía Culebra. Con base en las mediciones de pH y pCO2 se calculó el estado de saturación de la aragonita (Ω) y otros parámetros del sistema de carbonatos como lo es el carbono orgánico disuelto (COD) y la alcalinidad total (AT). Los resultados indican que el arrastre por convección del agua sub-superficial durante los eventos de afloramiento aumenta la pCO2 y disminuye la TSM, la concentración de oxígeno disuelto y Ω. Aunque se asume que estas condiciones reducen el crecimiento coralino, las principales especies constructoras de arrecife en la región de Papagayo (Pocillopora spp. y Pavona clavus) tienen las mayores tasas de crecimiento en el Pacífico Tropical Oriental. Esto posiblemente implica que el efecto negativo del afloramiento es compensado por el crecimiento durante la época de no afloramiento.
Geología de Bahía Culebra, Guanacaste, Costa Rica
Authors: Herrera Zúñiga Pablo , Vargas Ana Enid
Published: July 2015

La geología de Bahía Culebra, Guanacaste, Costa Rica, está compuesta por rocas volcánicas de corteza oceánica; sedimentos marinos depositados en el talud, la plataforma continental y zonas someras cerca de la costa; secuencias de rocas piroclásticas intercaladas con sedimentos continentales y depósitos Cuaternarios recientes. En la base de la secuencia estratigráfica afloran los basaltos masivos, algunas veces en almohadilla, del Complejo de Nicoya con textura afanítica con fenocristales de olivino, augitas y plagioclasas. Dentro de la misma Formación se incluyen intrusivos de gabro masivos con piroxenos y plagiogranitos con fenocristales de plagioclasas y hornblenda. Seguidamente afloran las calizas de la Formación El Viejo constituida por colonias arrecifales e intercalaciones calcáreas. La Formación Montezuma compuesta por facies de arenisca media fosilífera, facies de arenisca media con laminación cruzada y facies rítmicas de areniscas y lutitas. Las Dacitas Carbonal están compuestas por lavas hexagonales y variaciones brechosas con clastos de pómez y minerales de alteración. La Formación Bagaces se constituye de varios eventos eruptivos con secuencias de ignimbritas y un depósito sedimentario posiblemente pluvial de arenas volcaniclásticas. En la parte superior de la secuencia estratigrafica se incluyen los depósitos producto de factores erosivos tales como coluvios, arenas de playa, sedimentos de zonas de manglar y aluviones.
Structural complexity and species composition of Potrero Grande and Santa Elena mangrove forests in Santa Rosa National Park, North Pacific of Costa Rica
Authors: Loría-Naranjo Margarita , Samper-Villarreal Jimena , Cortés Jorge
Published: July 2015

La mayoría de los manglares del Pacífico Norte de Costa Rica son de los más impactados en el país. Además, la información científica sobre la fisiología, ecología, estructura y geoquímica de estos manglares es limitada. Este estudio analizó la complejidad estructural y composición de especies de dos bosques de manglar del Pacífico Norte: Potrero Grande y Santa Elena. Las visitas al campo se realizaron entre mayo y junio del 2012. Se utilizó el método deCuadrantes Centrados en un Punto (PCQM) para estudiar la estructura del bosque. Se anotó las especies de mangle, altura, diámetro a la altura del pecho (DAP) y densidad del dosel en diez puntos a lo largo de cada transecto. Así mismo, se registró la fauna asociada y cobertura de macroalgas epífitas sobre las raíces de mangle. En cada punto se determinó la salinidad de agua intersticial. Se calculó la densidad, área basal, dominancia, valor de importancia e índice de complejidad. Rhizophora racemosa fue la especie con mayor dominancia relativa y valor de importancia para ambos sitios. Santa Elena es el manglar con el mayor índice de complejidad (IC=26.9), lo cual podría deberse a la alta densidad encontrada. Potrero Grande es considerado como uno de los manglares más desarrollados de la costa del Pacífico Norte de Costa Rica, dadas sus características estructurales (árboles con grandes alturas y DAP)y de composición de especies. La distribución conocida de Pelliciera rhizophorae en Costa Rica alcanzaba su límite norte en el manglar de Potrero Grande; sin embargo, este estudio extiende esta distribución más al norte, ya que se encontraron algunos individuos en Santa Elena. A diferencia de Potrero Grande, Santa Elena no cuenta con un sector marino protegido adyacente, esto ha resultado en la extracción de recursos y actividades turísticas incontroladas en la zona. Se recomienda la creación de un área de protección marina en la Bahía de Santa Elena para que sirva de zona de amortiguamiento al manglar.
Variación espacial y temporal de los organismos de un intermareal rocoso: Bahía Panamá, Pacífico Norte, Costa Rica
Authors: Sibaja-Cordero Jeffrey A. , García-Méndez Kimberly
Published: July 2015

The intertidal rocky shore of Bahía Panama, within Bahía Culebra in the North Pacific coast of Costa Rica, was sampled to study the biodiversity and the spatial patterns (three sites with differences in wave exposure, and five strata, from low to high tide levels) and temporal variation (a single date in 2007 and 2013) in different microhabitats (over and under rock surface, and crevices). The epibenthic organisms were sampled with quadrats of 25 x 25 cm in each stratum, and cryptic fauna was accounted by both visual census and manual collecting. The general pattern of vertical zonation of organisms at each site showed an increase in variety toward the infralittoral level, as well as in the composition of assemblages or partially in identity of taxa in each stratum. The sheltered section of the rocky coast, with shallow sand bottom (< 1 m), low wave action and greater sedimentation rate, had lower diversity, cover and abundance that increased towards the wave-exposed section, with more abrupt slope in the edge of rocky platform, lower turbidity, and deeper sand bottom (2-3 m). The horizontal change was more evident in epibenthic organisms, followed by the under rock surface inhabitants and finally in crevices. For the epibenthic organisms, a temporal change in assemblages (cover and abundance) was found between the 2007 and 2013, at each site and level (possibly by seasonal upwelling influence), but the spatial structure (vertical and horizontal) of the rocky shore seems the main cause of change in the composition of species. The spatial pattern of change in the biota (sheltered to exposed gradient) could be expected in similar shores of the Central American Pacific. Finally, the 157 species found (16 autotrophic taxa, 22 fishes, and 119 invertebrates) indicate the high biodiversity of this habitat in the tropics, and the importance of their conservation. Rev. Biol. Trop. 62 (Suppl. 4): 85-97. Epub 2014 Diciembre 01.
Docentes de inglés de primaria, secundaria y terciaria: Sus creencias pedagógicas sobre sus estudiantes
Authors: Díaz-Larenas Claudio , Alarcón-Hernández Paola , Martínez-Ilabaca Patricia , Roa-Ghiselini Iris , Sanhueza-Jara María Gabriela
Published: July 2015

Como agente reflexivo de su propia práctica, el profesorado construye creencias pedagógicas sobre el proceso de enseñanza y aprendizaje y, en particular, sobre el rol que sus estudiantes deben asumir en el aprendizaje de un idioma. Este estudio tiene como objetivo identificar las creencias pedagógicas de treinta docentes de inglés de primaria, secundaria y terciaria, en Chile, sobre el rol estudiantil en el proceso didáctico. Un cuestionario, una entrevista semi-estructurada, un diario auto-biográfico y cinco diarios de observación no-participante fueron utilizados para revelar las creencias pedagógicas de sus informantes. Los datos arrojados por los instrumentos fueron analizados con el programa cualitativo ATLASTI, que permitió el levantamiento de tres dimensiones y diez categorías, mediante el uso de la técnica del análisis de contenido semántico. Los resultados muestran que los tres grupos de profesorado declaran que estudiantes que aprenden una lengua extranjera deben tener características personales y académicas relacionadas con la motivación, la participación, la autonomía, entre otras; sin embargo, al interior del aula asumen un rol pasivo y reactivo frente al ambiente de enseñanza altamente estructurado que genera el personal docente. En conclusión, las creencias que cada docente sostiene se alimentan de la teoría y se corroboran o cuestionan en la práctica de aula, a modo de una relación bidireccional entre teoría y práctica, y viceversa.
Educación musical, desarrollo infantil y adolescente y enfoque de derechos humanos: Una reseña bibliográfica
Authors: Arguedas-Quesada Consuelo
Published: July 2015

El siguiente documento surge de la indagación bibliográfica que realiza la autora de este artículo, para llevar a cabo su investigación en la Maestría Profesional en Derechos Humanos de la Niñez y la Adolescencia, del Programa de Estudios de Posgrado en Trabajo Social de la Universidad de Costa Rica. Para tal efecto, hace una revisión sobre los estudios relacionados con la temática a nivel nacional e internacional al momento de la investigación que abarca los siguientes tópicos: práctica pedagógica musical, educación musical y currículo escolar, música y síndrome de Down, inteligencias múltiples y desarrollo integral, expresión artística y desarrollo humano, enfoque de derechos y expresión artística, y los derechos humanos de las personas con discapacidad. El objetivo del estudio tiene como propósito comparar y contrastar dichos temas, vinculándolos con los derechos humanos, la educación musical, y su práctica en personas en condiciones asociadas o no con la discapacidad. La finalidad es compartir estos hallazgos con personas interesadas en esta temática. Como parte de las conclusiones, la búsqueda muestra que en Costa Rica no existen trabajos de educación musical relacionados con derechos humanos de la niñez y la adolescencia y, en la mayoría de los trabajos, la música se plantea desde las inteligencias múltiples.
Reflexiones de los volcanólogos sobre su papel profesional en la gestión del riesgo volcánico en el contexto de América Latina
Authors: Ferrés Dolores , Escobar Rudiger P. , Bowman Luke
Published: July 2015

Las fortalezas y problemáticas comunes de los volcanólogos en los diversos roles que desempeñan como actores para la reducción del riesgo volcánico en América Latina fue debatida en el marco del taller “PASI 2011: Volcanes de conducto abierto”, celebrado en Costa Rica, con participación de profesionales de casi todos los países de la costa pacífia del continente y Argentina, el Reino Unido, Noruega y Suecia. Se trataron gran diversidad de temas, agrupados en cinco bloques, que permitieron defiir necesidades comunes en cinco ámbitos : 1) Carencia de recursos fiancieros, humanos y técnicos en los observatorios de la región; 2) Programas de cooperación gubernamental y no gubernamental entre organismos técnicos y académicos; 3) Necesidades de coordinación regional; 4) El rol de los volcanólogos como comunicadores y su interacción con otros actores de la gestión del riesgo y 5) El aporte de las ciencias sociales y la creación de grupos multidisciplinarios en el ámbito de los observatorios volcanológicos.
La margen pacífia del continente americano es un área altamente expuesta a la actividad volcánica, incluyendo algunas de las ciudades más importantes en el continente. Sin embargo, las instituciones encargadas de la observación y el monitoreo de la actividad y las amenazas volcánicas en muchos de los países de esta región, enfrentan serias limitaciones para desempeñar su labor. Para la mayoría de países latinoamericanos, el gran número de volcanes potencialmente activos y el reducido número de volcanólogos que trabajan en su monitoreo, constituyen una de las principales limitantes. La cooperación entre observatorios con universidades y centros de investigación, ha ayudado a cubrir esta necesidad al menos de forma parcial. Trascendiendo su papel científio y técnico como expertos en ciencias físicas o naturales, los volcanólogos también se han visto involucrados en tareas que requieren el desarrollo de otras habilidades, principalmente como comunicadores de información sobre el riesgo volcánico. Esto ha llevado a incrementar la colaboración multidisciplinaria con profesionales del área de las ciencias sociales. Sin embargo, existen aún grandes retos que deberán abordarse en un futuro próximo. Los aportes de la discusión sostenida en el taller pueden constituir un punto de partida para futuros foros y acciones orientados a la reducción del riesgo asociado con la actividad volcánica
Actividad histórica y análisis de la amenaza del volcán Turrialba, Costa Rica
Authors: González Gino , Mora-Amador Raúl , Ramírez Carlos , Rouwet Dmitri , Picado Cristian , Mora Rolando
Published: July 2015

Se conoce la actividad histórica del volcán Turrialba, gracias a los relatos de viajeros y noticias del siglo XIX. En 1864-1866, el Turrialba estuvo en un periodo eruptivo magmático, el cual se analizó en dos etapas: pre- eruptivo y eruptivo. La ceniza llegó a ~115 km de distancia, cubriendo un área de 3 400 km2. Se calculó por medio de un SIG cómo una erupción magmática similar a esta, podría afectar a la presente población e infraestructura, y se concluyó que la ceniza caería en los sectores de mayor población de Costa Rica, esto es importante como medida de prevención y análisis para la futura toma de decisiones.
En 2005, el volcán Turrialba incrementó la cantidad de sismos, emisión de gases y lluvia ácida, produciendo una mayor afectación en los sectores ubicados al S, SW y W del volcán. Luego de más de un siglo sin tener erupciones, el 5 de enero del 2010, comenzó un período eruptivo freático, con emisión de cenizas no juveniles, que llegaron hasta San José. Esta ceniza contiene cristobalita y hematita, los cuales son perjudiciales para la salud. Además, esta erupción formó una boca intracratérica de ~125 m x ~45 m de dirección NW-SE, con emisión de SO2 en estado de combustión, incandescencia y esporádicas salidas de ceniza. En junio del 2011, apareció una zona fumarólica a ~530 °C en el intracráter NW. El 11 de enero del 2012, apareció un flujo de azufre (175 m de largo), producto de un sobre calentamiento en el sistema, que resultó en un nuevo periodo de erupciones freáticas los días 12 y 18 de enero del 2012. Esta erupción formó otra boca en la pared externa E del cráter NW.
Las innovaciones pedagógicas y la gestión de la educación en la Escuela Nueva Laboratorio “Emma Gamboa” de la Universidad de Costa Rica y el Instituto Educativo Moderno
Authors: Brenes Montero Milena
Published: July 2015

El presente artículo pretende analizar el desarrollo de innovaciones pedagógicas desde la gestión en la Escuela Nueva Laboratorio “Emma Gamboa” de la Universidad de Costa Rica y en el Instituto Educativo Moderno, a partir de la identificación de los mecanismos para la implementación de estas innovaciones, la determinación de las estrategias desarrolladas por docentes en esta área y el establecimiento de las acciones de seguimiento, aplicadas desde la gestión, en el desarrollo de estas innovaciones. La investigación, de tipo descriptivo, se ejecutó entre los meses de octubre y diciembre del año 2013, con la participación de las dos directoras y el personal docente de ambos centros educativos, a quienes se les aplicó un cuestionario estructurado de acuerdo con las categorías de análisis definidas. Entre los principales hallazgos encontrados se señala que desde la fundación de ambas escuelas se procura la implementación de innovaciones pedagógicas, identificándose a su vez, áreas susceptibles de mejora, tanto en la implementación como la ejecución y el seguimiento de estas.
An adaptive Wavelet-Galerkin method for parabolic partial differentia equations
Authors: Vampa Victoria , Martín María T.
Published: July 2015

In this paper an Adaptive Wavelet-Galerkin method for the solution of parabolic partial differential equations modeling physical problems with different spatial and temporal scales is developed. A semi-implicit time difference scheme is applied and B-spline multiresolution structure on the interval is used. As in many cases these solutions are known to present localized sharp gradients, local error estimators are designed and an efficient adaptive strategy to choose the appropriate scale for each time is developed. Finally, experiments were performed to illustrate the applicability and efficiency of the proposed method.
Cognitive rhythms and evolutionary algorithms in university timetables scheduling
Authors: Castrillón Omar
Published: July 2015

The main purpose of this research is to design a methodology based on evolutionary algorithms to university timetable scheduling. This methodology will consider the students’ cognitive rhythms, which establish that teaching certain subjects in specific time intervals is much better than other techniques. This project takes place in three phases. First of all, there is a description of the different techniques used to solve this problem. Then, a new methodology based on cognitive rhythms and evolutionary algorithms is proposed, and finally, different methodologies are compared to determine the best. It is concluded that evolutionary algorithms are more efficient than other techniques in the university timetable scheduling. Future lines of research will determine the impact of these techniques within the students’ learning process.
Graphene-based Nanogenerator: Experiments, Theories and Applications
Authors: Li Weiping , Zhang Yupeng , Pan Chunxu
Published: July 2015

In addition to the piezoelectric nanogenerators and triboelectric nanogenerators, recently, the graphene-based nanogenerator has been widely concerned because of its simple assembly, flexibility and high structural stability. There are many interesting effects in graphene applied for nanogenenrators including anion adsorption in electrolyte solution, ion channels in graphene sheets network and the strain (band engineering) effect, etc. In this paper, we focus explicitly on the experimental results, mechanisms and applications of the graphene-based nanogenerator, and introduce our recent research on the graphene-based nanogenerator based on "modulation of the graphene strain-energy band effect". This nanogenerator is expected to have potential applications in active sensors and sustainable power source.
IMPACT MECHANISMS RESEARCH IN THE CONTACT NETWORK ON RAIL TRACK CIRCUITS
Authors: V. I. Shcheka
Published: July 2015

Purpose. Еlectromagnetic processes in «contact network-rails-earth»system should be researched for the purpose of electromagnetic compatibility rail circuits with traction power supply system providing and improving traffic safety on railway transport. Methodology. The methods of scientific analysis, mathematical modeling, experimental investigation, scale modeling have been applied to achieve this goal. Findings. Conducted theoretical and experimental investigations, indicate that electromagnetic processes in the «contact network-rails-earth» system in nearest zone in frequency range up to 1 MHz and it give us an opportunity to consider, that electromagnetic field of hindrance consists of two components: electric and magnetic. Each of them has its own mechanism to influence the rail circuits. In consequence of research the theoretical and experimental dependences of electromotive force induced in wire-receiver from the hindrance current frequency have been received. The frequency graph of relative error according to data «theory-experiment» has been received. The adequacy by Wilcoxon criterion of mathematical model to experimental data has been proved. Originality. The results of theoretical and experimental investigations of magnetic influence between two contours gives us a concurrence in frequency range up to 1000 Hz with average relative error 2, 33 %. With hindrance current frequency one can observe certain increasing the average relative error between calculated and measured values of electromotive force induced in the wire-receiver. Practical value. The adequacy by Wilcoxon criterion of mathematical model to experimental data has been proved on significance level 5 %. It gives an opportunity to use this mathematical apparatus for the investigation of electromagnetic processes in lines with plenty of wires and in «contact network-rails-earth»system in range up to 1000 Hz. The obtained results can be useful in designing, researching and providing electromagnetic compatibility of rail circuits with traction power supply system.
CALCULATED VOLUMES DETERMINATION OF WORK FOR MAIN-LINE AND INDUSTRIAL RAILWAY STATIONS
Authors: D. M. Kozachenko  , A. I. Verlan  , O. V. Horbova
Published: July 2015

Purpose.This article aims to improve the evaluation of irregularity of freight transport and calculated volumes determination of work for railway stations and sidings of industrial enterprises. Methodology. The methods of mathematical statistics are used as research methods for estimation of calculated volumes of traffic and loaded traffic, in particular, the methods of time series analysis; the methods of mathematical modeling are used to evaluate the calculated volumes of empty traffic. Findings. Calculated volumes of the main-line and industrial railway stations activity are determined according to the monthly and daily irregularity. Monthly irregularity is proposed to evaluate against the trend of the indicator over the last 3-5 years, constructed using the method of weighted moving average. The 30-day period in the previous year with the largest total amount of work is proposed to use as the calculation period for the assessment of daily irregularity. The computation size of empty traffic volumes is proposed to be determined on the basis of loaded traffic volumes with the probability matrix of cars usage for dual operations. The proposed method is verified by the work volume calculation for the year 2014 according to previous time periods. The test results showed that the proposed method as compared with traditional one provides higher stability of the results when changing time periods, used for analysis, as well as a more accurate assessment of the calculated volumes of work. Originality. Authors have improved determination methods for the calculated volumes of work to railway stations through the using time series analysis methods. Practical value. The proposed methodology allows assessing more accurately the prospective volumes of work and, through this, reduce the amount of capital expenditures associated with the development of stations and operating costs associated with their operation. The method can be used to improve the governing and methodological documents regulating the design and development of technological processes of the main-line and industrial railway stations.
FORMATION OF ESTIMATED CONDITIONS FOR LIFE CYCLE OF DEFORMATION WORK OF THE RAILWAY TRACK
Authors: Bondarenko I. O.
Published: July 2015

Purpose.The purpose of this research is to substantiate the technical limits of the railway track (under reliability status) for the formation the regulatory framework for reliability and functional safety of the railway track in Ukraine. Methodology.In order to achieve the goal of research analysis methods of the technical states of elements and trackforms that are typical of operation conditions of the railways in Ukraine were used. Findings.Technical states accordance of elements and trackforms to reliability status under existing regulations was defined. These conditions are based on the track assessments in accordance with the dimensional tape results. The status of each element of the track design affects its deformation work, but the rules are still absent that would connect state of track elements with the state of the track by estimation of the dimensional tape. The reasons on which the limits are not set were established. It was found out which researches are necessary to conduct for their installation. Originality. The classification of the reliability state of a railway track for permitted deviation at the track laying and maintenance was developed. The regulation importance the technical states of ballast section and subgrade for the developed classification was established. Practical value. Ukrzaliznytsia (UZ) is a founding member of the Council for Railway Transport of the Commonwealth. This body issued interstate standard State Standard 32192-2013 «Reliability of railway equipment. Basic concepts, terms and definitions». On this basis developed a new interstate standard «Security functional of railway equipment. Terms and definitions». At the same time UZ is a member of the cooperation of railways in International Union of Railway Transport where rules with reliable and safe operation of railways are established in all transport branches. This study will help implement these standards on the railways of Ukraine, improve the efficiency of the information in this sphere, providing mutual understanding and unity of presentation and perception of information, including contractual legal relations of economic agents with public authorities in international scientific and technical, trade and economic relations.
SPEED DEPENDENCE OF ACOUSTIC VIBRATION PROPAGATION FROM THE FERRITIC GRAIN SIZE IN LOW-CARBON STEEL
Authors: Vakulenko I. A. , Nadezhdin Yu. L. , Sokyrko V. A. , Hai Xu Xiao
Published: July 2015

Purpose. It is determining the nature of the ferrite grain size influence of low-carbon alloy steel on the speed propagation of acoustic vibrations. Methodology. The material for the research served a steel sheet of thickness 1.4 mm. Steel type H18T1 had a content of chemical elements within grade composition: 0, 12 % C, 17, 5 % Cr, 1 % Mn, 1, 1 % Ni, 0, 85 % Si, 0, 9 % Ti. The specified steel belongs to the semiferritic class of the accepted classification. The structural state of the metal for the study was obtained by cold plastic deformation by rolling at a reduction in the size range of 20-30 % and subsequent recrystallization annealing at 740 – 750 ° C. Different degrees of cold plastic deformation was obtained by pre-selection of the initial strip thickness so that after a desired amount of rolling reduction receives the same final thickness. The microstructure was observed under a light microscope, the ferrite grain size was determined using a quantitative metallographic technique. The using of X-ray structural analysis techniques allowed determining the level of second-order distortion of the crystal latitude of the ferrite. The speed propagation of acoustic vibrations was measured using a special device such as an ISP-12 with a working frequency of pulses 1.024 kHz. As the characteristic of strength used the hardness was evaluated by the Brinell’s method. Findings. With increasing of ferrite grain size the hardness of the steel is reduced. In the case of constant structural state of metal, reducing the size of the ferrite grains is accompanied by a natural increasing of the phase distortion. The dependence of the speed propagation of acoustic vibrations up and down the rolling direction of the ferrite grain size remained unchanged and reports directly proportional correlation. Originality. On the basis of studies to determine the direct impact of the proportional nature of the ferrite grain size on the rate of propagation of sound vibrations in the low-carbon alloy steel. The directly proportional nature of influence of ferrite grain size on the speed propagation of acoustic vibrations in low-carbon alloy steel on the basis of the conducted researches is defined. The paper is shown that at increasing in the size of the recrystallized ferrite grain the degree of influence the texture from the previous cold plastic deformation by rolling increases. Practical value. The received results on nature determination of influence of ferrite grain size on the speed propagation of acoustic vibrations can be the useful by development of techniques of non-destructive testing of metal materials quality. The special value the specified technique of measurement acquires in the conditions of line production of metal constructions.
INFLUENCE ANALYSES OF DESIGNED CHARACTERISTICS OF THE ELEVATOR TO THE PARAMETERS OF ITS DRIVE
Authors: V. M. Bohomaz
Published: July 2015

Purpose. A drive behaves to the basic elements of scoop band elevators. To determine the drive power calculations are carried out according to standard methods, which take plenty of time. It is necessary to conduct the analysis of influence of project characteristics on the parameters of high-speed drive in a scoop bent elevator and to build the improved algorithm of speed-up determination of its drive power on project descriptions, that will take into account the type of load, rise height, necessary productivity, standard parameters of scoops and tape. Methodology. Using parametric dependences of elevators drive power on its project characteristics, received by the author earlier, the improved algorithm of speed-up determination of elevators high-speed drive power with deep and shallow scoops at set type of load, productivity, rise height was offered. Findings. The algorithm of drive power speed-up determination of high-speed vertical elevators with deep and shallow scoops depending on project parameters was offered. The example of such algorithm application is considered for an elevator that is intended for transporting of cement. Analytical dependences of drive power of such elevator are determined on the productivity and rise height. Corresponding graphic dependences were built and character of drive power changes during the size changing of any project characteristics was determined. Originality. The improved algorithm of drive power elevator determination at the given project characteristics (type of load, rise height, productivity) that takes into account standard sizes, parameters of scoops and ribbons, was built at first time. Practical value. The use of an offered algorithm of calculation gives the possibility of relatively fast determination of reference value of high-speed elevators drive power with deep and shallow scoops, to build graphic dependences of drive power on the values of the productivity and rise height at the certain type of load, that assists the quality selection of his basic elements at certain project descriptions, such algorithm gives an opportunity to save time on calculations in the process of elevators planning.
EVALUATION OF DYNAMIC INDICATORS OF SIX-AXLE LOCOMOTIVE
Authors: S. V. Myamlin  , N. YU. Naumenko  , O. M. Markova  , H. M. Kovtun  , V. V. Maliy
Published: July 2015

Purpose. The paper is devoted to dynamic characteristics evaluation of the locomotive with prospective design and determination the feasibility of its use on the Ukrainian railways. Methodology. The methods of mathematical and computer modeling of the dynamics of railway vehicles, as well as methods for the numerical integration of systems of ordinary nonlinear differential equations were used to solve the problem. Findings. The calculated diagram of a locomotive on three-axle bogies was built to solve the problem, and it is a system of rigid bodies connected by various elements of rheology. The mathematical model of the locomotive movement, allowing studying its spatial vibrations at driving on straight and curved sections of the track with random irregularities in plan and profile was developed with use of this calculated diagram. At compiling the mathematical model took into account both geometric (nonlinearity profile of the wheel roll surface) and physical nonlinearity of the system (the work forces of dry friction, nonlinearity characteristics of interaction forces between wheels and rails). The multivariate calculations, which allowed assessing the dynamic qualities of the locomotive at its movement along straight and curved sections of the track, were realized with the use of computer modeling. The smoothness movement indicators of the locomotive in horizontal and vertical planes, frame strength, coefficients of vertical dynamics in the first and second stages of the suspension, the load factor of resistance against the derailment of the wheel from the rail were determined at the period of research. In addition, a comparison of the obtained results with similar characteristics is widely used on the Ukrainian railways in six-axle locomotive TE 116. The influence of speed and technical state of the track on the locomotive traffic safety was determined.Originality. A mathematical model of the spatial movement of a six-axle locomotive with prospective design, taking into account the peculiarities of its design was developed. Evaluation of dynamic characteristics at the carriage movement along a track of arbitrary shape was made. Practical value. The developed mathematical model of the six-axle locomotive movement can be used at conducting research on development of advanced locomotives designs.
Ultrasonografic changes in the axillary vein of patients with lymphedema after mastectomy
Authors: Abreu Junior Gilberto Ferreira de , Pitta Guilherme Benjamin Brandão , Araújo Marcelo , Castro Aldemar de Araújo , Azevedo Junior Walter Ferreira de , Miranda Junior Fausto
Published: July 2015

OBJECTIVE: To determine the prevalence of sonographic abnormalities (SA) in the axillary vein of patients with and without post-mastectomy lymphedema. METHODS: We studied a sample of 80 women, divided into two equal groups, with and without lymphedema, with B mode ultrasound, color and pulsed Doppler. The primary variable, SA, is defined as change in the venous diameter, parietal thickening, intraluminal images, compressibility, parietal collapse at inspiration and feature of the axillary venous flow on the operated side. Secondary variables were: stage of lymphedema, surgical technique, number of radio and chemotherapy sessions, limb volume, weight and age. The differences between the proportions in the groups were determined using the Chi-square test and / or Fisher's test. For continuous variables, we used the Mann-Whitney Test. To estimate the magnitude of the associations, we used the prevalence rate of SA in both groups as a measure of frequency, and as a measure of association, the prevalence ratio (PR) obtained as a function of relative risk (RR) and estimated by the test Mantel-Haenszel homogeneity test. We adopted the statistical significance level of 5% (p < 0.05). RESULTS: only the criterion "parietal thickening" was strongly associated with the lymphedema group (p = 0.001). The prevalence of SA was 55% in patients with lymphedema and 17.5% in the group without it, with difference in prevalence of 37.5%. CONCLUSION: the prevalence of SA was higher in patients undergoing mastectomy with lymphedema than in those without lymphedema.
Montreal classification of patient operated for Crohn's disease and identification of surgical recurrence predictors
Authors: Bechara Cristiane de Souza , Lacerda Filho Antonio , Ferrari Maria de Lourdes Abreu , Andrade Déborah Almeida Roquette , Luz Magda Maria Profeta da , Silva Rodrigo Gomes da
Published: July 2015

OBJECTIVE: to evaluate Crohn's disease recurrence and its possible predictors in patients undergoing surgical treatment. METHODS: We conducted a retrospective study with Crohn's disease (CD) patients undergoing surgical treatment between January 1992 and January 2012, and regularly monitored at the Bowel Clinic of the Hospital das Clínicas of the UFMG. RESULTS: we evaluated 125 patients, 50.4% female, with a mean age of 46.12 years, the majority (63.2%) diagnosed between 17 and 40 years of age. The ileum was involved in 58.4%, whereas stenotic behavior was observed in 44.8%, and penetrating, in 45.6%. We observed perianal disease in 26.4% of cases. The follow-up average was 152.40 months. Surgical relapse occurred in 29.6%, with a median time of 68 months from the first operation. CONCLUSION: The ileocolic location, penetrating behavior and perianal involvement (L3B3p) were associated with increased risk of surgical recurrence.
Influence of preoperative supplementation of omega-3 fatty acid in the healing of colonic anastomoses in malnourished rats receiving paclitaxel
Authors: Vizzotto Junior Alvo Orlando , Campos Antonio Carlos Ligocki , Mello Eneri Vieira de Souza Leite , Castilho Tiago Jacometo
Published: July 2015

OBJECTIVE: To evaluate the effect of preoperative supplementation of omega-3 fatty acids on the healing of colonic anastomoses in malnourished rats receiving paclitaxel. METHODS: we studied 160 male Wistar rats, divided in two groups: one subjected to malnutrition by pair feeding (M) for four weeks, and another that received food ad libitum (W). In the fourth week, the groups were further divided into two subgroups that received omega-3 or olive oil by gavage. The animals were submitted to colonic transection and end-to-end anastomosis. After the operation, each of the four groups was divided into two subgroups that received intraperitoneal isovolumetric solutions of saline or paclitaxel. RESULTS: mortality was 26.8% higher in the group of animals that received paclitaxel (p = 0.003). The complete rupture strength was greater in well-nourished-oil Paclitaxel group (WOP) compared with the the malnourished-oil Paclitaxel one (MOP). The collagen maturation index was higher in well-nourished-oil saline group (WOS) in relation to the malnutrition-oil-saline group (MOS), lower in malnourished-oil-saline group (MOS) in relation to malnourished-ômega3-saline one (M3S) and lower in the well-nourished-omega3-saline group (W3S) compared with the malnourished-omega3-saline (M3S). The blood vessel count was higher in the malnourished-oil-saline group (MOS) than in the malnourished-oil-paclitaxel group (MOP) and lower in the malnourished-oil-saline group (MOS) in relation to the malnourished-omega3-paclitaxel group (M3P). CONCLUSION: supplementation with omega-3 fatty acids was associated with a significant increase in the production of mature collagen in malnourished animals, with a reversal of the harmful effects caused by malnutrition associated with the use of paclitaxel on the rupture strength, and with a stimulus to neoangiogenesis in the group receiving paclitaxel.
Growth and Development of Purple Nutsedge Based on Days or Thermal Units
Authors: Lima R.S.O. , Machado E.C.R. , Silva A.P.P. , Marques B.S. , Gonçalves M.F. , Carvalho S.J.P.
Published: July 2015

This work was carried out with the objective of elaborating mathematical models to predict growth and development of purple nutsedge (Cyperus rotundus) based on days or accumulated thermal units (growing degree days). Thus, two independent trials were developed, the first with a decreasing photoperiod (March to July) and the second with an increasing photoperiod (August to November). In each trial, ten assessments of plant growth and development were performed, quantifying total dry matter and the species phenology. After that, phenology was fit to first degree equations, considering individual trials or their grouping. In the same way, the total dry matter was fit to logistic-type models. In all regressions four temporal scales possibilities were assessed for the x axis: accumulated days or growing degree days (GDD) with base temperatures (Tb) of 10, 12 and 15 oC. For both photoperiod conditions, growth and development of purple nutsedge were adequately fit to prediction mathematical models based on accumulated thermal units, highlighting Tb = 12 oC. Considering GDD calculated with Tb = 12 oC, purple nutsedge phenology may be predicted by y = 0.113x, while species growth may be predicted by y = 37.678/(1+(x/509.353)-7.047).
Evolution of Ryegrass Seed Banks Depending on Soil Tillage and Crops
Authors: Galvan J. , Rizzardi M.A. , Peruzzo S.T. , Ovejero R.F.
Published: July 2015

The seed bank is characterized by the amount of seeds and other viable reproductive structures in the soil and it is changed by the input and output of seeds, being classified by its permanence in the soil as transient or permanent. The tillage and crops used decisively influence this dynamic and more disturbed areas tend to have richer seed banks. The purpose of this study was to test different soil tillage and crop systems, aiming to reduce or eliminate the ryegrass in the area. The experiment was conducted from 2010 to 2012. In the first year, the effect of chemical tillage was assessed, compared to the area without tillage. From the second year on, in the area that received chemical tillage, the second experiment was installed, where it was assessed the effect of soil tillage and crop rotation in the ryegrass seed yield. The soil tillage treatment was chisel plow and non-chisel plow. The crop rotation was: fallow/soybean; wheat/soybean; black oat/maize. The samples of soil were taken three times a year and split in 0-5, 5-10, 10-15 and 15-20 cm. After sampling, the seeds were separated from the soil and sterilized. Afterwards, germination and tetrazolium test were conducted. In the same plots used for soil sampling, the emergence flow of ryegrass was assessed in the winter 2011 and 2012. In the first year it was observed that chemical tillage had considerably reduced the amount of ryegrass in the soil. The crop rotations used were more effective than soil tillage in reducing the seed banks in the soil. The rotation oat/maize and wheat/soybean, in only two years, practically zeroed the ryegrass seed banks in the area.
Variability and Genetic Structure in Populations of Arrabidaea bilabiata (Sprague) Sandwith in the Amazonas State
Authors: Souza L.S.A. , Silva J.F. , Lopes M.T.G. , Bentes J.L.S. , Valente M.S.F. , Costa Neto P.Q.
Published: July 2015

Weeds in pastures can intoxicate animals, and Arrabidaea bilabiata is the most important species for herbivores in floodplain areas in the Amazon Basin. Genetic diversity studies in natural populations may contribute to the better understanding of the range of toxicity and the genetic variability organization in this species. The objective of this study was to assess the variability and genetic structure in six populations of A. bilabiata sampled in floodplain areas in three municipalities of the Amazonas State, from the AFLP markers analysis. AFLP markers were efficient to characterize the genetic variability of the 65 individuals analyzed. From four combinations of oligonucleotides, a total of 309 AFLP fragments was obtained, where 304 (98.38%) were polymorphic. By the dendrogram and Bayesian cluster analysis, there was a formation of two isolated groups, the first one comprising individuals from Autazes municipality and the second one comprising individuals from Itacoatiara and Parintins. However, depending on the method to define the most probable cluster number, there was a separation of the six populations, according to their geographical origin. Mantel test confirmed that geographically closer populations are more akin, although low gene flow (0.538) is observed among the sampled populations. The molecular analysis of variance found that 49.29% of the genetic variability are among individuals inside populations and 50.71% among the populations analyzed. The results indicate the possibility that isolated A. bilabiata populations contain plants with different toxicity levels and suggest a strong adaptability of the species.
Glyphosate Effectiveness in the Control of Macrophytes Under a Greenhouse Condition
Authors: Cruz C. , Silva A.F. , Luna L.V. , Yamauchi A.K.F. , Garlich N. , Pitelli R.A.
Published: July 2015

The aim of this study was to assess the effectiveness of glyphosate, as Rodeo(r) formulation, to control Eichhornia crassipes, Pistia stratiotes, Salvinia molesta, Salvinia herzogii and Urochloa subquadripara, under greenhouse conditions. The doses assessed were (480, 960, 1440, 1920, 2400, 2880, 3360 and 3840 g ha-1 of glyphosate) with 0.5% of the Aterbane(r) BR surfactant and a control, with no herbicide application. All experiments were conducted in a completely randomized experimental design with ten replications. Applications were carried out by precision backpack sprayer at a CO2 constant pressure of 25 psi and spray solution consumption of 200 L ha-1. Product effectiveness was determined by assessing the growth inhibitions and phytotoxicity signals during the periods of 3, 7, 15, 21, 30 and 45 days after application (DAA). At 45 DAA, the highest glyphosate dose (3840 g ha-1) displayed 100% effectiveness for all four macrophyte species. Under greenhouse conditions, the glyphosate in formulation Rodeo(r) with 0.5% of Aterbarne(r) BR surfactant showed excellent effectiveness, inhibiting the growth of the floating aquatic macrophytes. This procedure can be included on the tillage plans for these species.