bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of consistency assessment models for isolated horizontal curves in two-lane rural highways
Authors: Cárdenas-Aguilar Danilo , Echaveguren Tomás
Published: April 2016

This consistency assessment of highways’ geometrical design has the objective of providing safer roads. There are two types of models for consistency assessment: aggregated and disaggregated. The first one considers the difference between design and operating speed at the middle point of isolated horizontal curves. The second one considers the spatial variation of the operating speed profile along the horizontal curve. This paper compares the two types of consistency assessment models, using naturalistic speed and geometry data obtained in 34 horizontal curves of two-lane rural roads in Chile, using a 10 Hz GPS. Results obtained showed that in only 19 cases both methods are equivalent. This equivalence occurred only when operating speed profiles have the lowest spatial variance along the curves. If the operating speed profile has a high variance the consistency level obtained using both methods is different and the better option is combine it.
Numerical analysis of the influence of sample stiffness and plate shape in the Brazilian test
Authors: Álvarez Fernández Martina Inmaculada , González Nicieza Celestino , Prendes Gero Maria Belén , García-Menéndez José Ramón , Peñas Espinosa Juan Carlos , Suarez Dominguez Francisco José
Published: April 2016

Due to the heterogeneity of rocks, their tensile strength is around 10% of their compressive strength, which means that breakage is mainly caused by tensile stress. The measure of tensile stress is very difficult due to rock fragility, so it has usually been measured by indirect measurement methods , including the Brazilian test. However, recent works indicate that the tensile strength values obtained through the Brazilian test must be increased by almost 26%. To understand this divergence, indirect tensile tests have been monitored. The aim is to know the material deformation and load increase by means of stepwise regression. Stress fields in slightly deformed samples are analyzed and modeled (3D finite differences) with loads applied on flat and curved plates and different Young's modulus. Finally, the results are analyzed and compared with strength values reported using Timoshenko theory and Hondros' approximation.
New tuning rules for PID controllers based on IMC with minimum IAE for inverse response processes
Authors: Castrillón Hernández Fabio , Castellanos-Cárdenas Duby
Published: April 2016

In this paper new tuning rules for Proportional Integral Derivative (PID) are presented, which are based on Internal Model Control (IMC). This set of equations minimizes the performance index, in this case, the Integral Absolute Error (IAE). Furthermore, a correlation is proposed in order to calculate the tuning parameter of the method, where a holding oscillation response is obtained regarding changes in the set point. This value represents a stability limit for the IMC method. The overall development is then applied to an Inverse Response System of second order and with dead time.
Low-cost platform for the evaluation of single phase electromagnetic phenomena of power quality according to the IEEE 1159 standard
Authors: Diaz Rodriguez Jorge Luis , Pabón Fernández Luis David , Contreras Peña Jorge Luis
Published: April 2016

This paper presents the development of a data acquisition system and the evaluation of the electromagnetic phenomena associated with power quality according to the IEEE Standard 1159-1992 and applied to the particular case of single-phase electrical power systems. The evaluation software is implemented in the Labview® professional software using a NI 6009 USB board of the National Instrument® as acquisition device. The hardware implementation of the sensors was shown. Also the development of the algorithm and the design of a graphical user interface for viewing of the voltage and current waveforms, spectra, frequency and the power quality disturbances such as sags, swells, undervoltage, overvoltage, so on. Likewise, at the end a concise analysis of costs is presented to show that the developed system has a lower price to current solutions that are available in the market. Finally a study case was shown.
Self-assessment: A critical competence for Industrial Engineering
Authors: Verano-Tacoronte Domingo , Bolívar-Cruz Alicia , González-Betancor Sara M.
Published: April 2016

Assess one's own abilities realistically and critically is the key for a continuous adaptation to the changing labor market conditions. The university system must train the future engineers to rate their own performance accurately, reducing biases as self-benevolence. This paper analyzes, with a sample of students of Industrial Engineering, the accuracy of self-assessment in oral presentations, using a scoring rubric. The results of several statistical tests indicate that students are good assessors of others work, but benevolent with their own work. In addition, men evaluate themselves significantly higher than women do. Finally, self-assessment tend to compensate for others assessments, mainly in the case of students considered worse by teachers. These results point to the need of including self-assessment activities in an increasing number to improve students’ performance.
Numerical modelling of Alto Verde landslide using the material point method
Authors: Llano Serna Marcelo Alejandro , Muniz-de Farias Márcio , Martínez-Carvajal Hernán Eduardo
Published: April 2016

A huge landslide took place at Alto Verde residential complex at the end of 2008 in the city of Medellin, Colombia, claiming the lives of twelve people and destroying six houses. Landslides are characterized by large deformations in the soil mass. This study used the material point method (MPM), a particle-based method that takes advantage of a double Lagrangian-Eulerian discretization. This approach provides a robust framework that enables the numerical simulation of large strains, without mesh entanglement issues that are common with the Finite Element Method. The numerical model proposed here assumes simplifications of the geotechnical, morphological and structural buildings conditions on the site. Nevertheless, the final numerical deformed configuration described the geometric features observed in the field successfully. The result allows applications such as the design of barriers, risk assessment or determination of a minimum safe distance for a building from a slope susceptible to landslides.
Impact of working conditions on the quality of working life: Case manufacturing sector colombian Caribbean Region
Authors: Martinez-Buelvas Laura , Oviedo-Trespalacios Oscar , Luna-Amaya Carmenza
Published: April 2016

This paper investigate the impact of Working Conditions on Quality of Working Life of human talent of manufacturing sector in the Colombian Caribbean region. To analyze this process interviewed 518 employees in the sector. The experimental design used was not descriptive cross type; each participant was applied an interview with the instrument of Working Conditions and Quality of Working Life Tool (Wage and Subjective Conditions). Data were analyzed using correlation analysis and logistic regression models. The results showed that the thermal environment and safety standard at work positively affects the Quality of Working Life. These results show that the relationship between working conditions and CVL is based on competition and far from linear or simple relationship relating to the consideration of the presence or absence of working conditions. This has implications when formulating policies, programs and interventions to prevent the negative effects of working conditions and enhance the industrial safety within industrial companies.
Determination of the Rayleigh damping coefficients of steel bristles and clusters of bristles of gutter brushes
Authors: Vanegas Useche Libardo Vicente , Abdel Wahab Magd M , Parker Graham A
Published: April 2016

Street sweeping is an important service that is usually performed by lorry-type vehicles that have a gutter brush, which is comprised of clusters of steel bristles that sweep the debris found in the road gutter. Effective operation of this brush is important, as most of the debris on roads is located in the gutter. In order to model a gutter brush by means of finite element dynamic analyses, it is necessary to determine appropriate values of the Rayleigh damping coefficients of both individual bristles and clusters of bristles. This paper presents the methodology and results of experimental tests that have been conducted to determine these coefficients. The results obtained are useful when studying the performance of conventional and oscillatory street sweeper gutter brushes by means of dynamic finite element modeling.
Optimal estimating the project completion time and diagnosing the fault in the project
Authors: Hajali-Mohamad M. T. , Mosavi M. R. , Shahanaghi K.
Published: April 2016

The main objective of the project management team is to implement the project taking into consideration the Budget, schedule and constraints. In addition, project accomplishment, especially with large projects, requires the project to be correctly envisaged. Earned value (EV) management is a valuable technique for analyzing and controlling the performance of the project and predicting the total cost before its completion. Thus, fuzzy systems such as Adaptive Network based on the Fuzzy Inference System (ANFIS) and Parallel Structure based on the Fuzzy System (PSFS) are used to predict the project completion time. In this paper, the plan value diagram is used to predict the earn value diagram using three methods. These three methods are based on the PSFS and Neural Networks (NNs), which help with the implementation of the projects in organizations. The results of these three methods decreased the prediction error of the EV diagram by up to 2%.
Use of residual powder obtained from organic waste to partially replace cement in concrete
Authors: Soto Izquierdo Indara , Ramalho Marcio Antonio
Published: April 2016

The main objective of this research is to investigate the feasibility of using the residual powder obtained from organic waste to replace a part of Portland cement during concrete production. The chemical and physical properties of the organic residual powder were first investigated using scanning transmission electron microscopy (STEM) and energy dispersive X-ray spectroscopy (EDS). The replacement ratios of cement have also been studied for 0%, 5%, 10%, 15%, and 20% of the residual powder by weight. Moreover, we evaluated the compressive strength, specific gravity, water absorption, and voids content of the concrete specimens that were modified with different concentrations of the residual powder. Results indicate that 5% residual powder concentration resulted in better physical and mechanical properties of the modified concrete when compared with the reference concrete. At this concentration, the addition of residual powder act as fillers in concrete, reducing the amount of voids and causing a higher density in the material.
Fingerprint verification using computational geometry
Authors: Ramírez Flores Manuel , Aguilar Torres Gualberto , Gallegos García Gina , García Licona Miguel Ángel
Published: April 2016

This paper presents a robust minutiae based method for fingerprint verification. The proposed method uses Delaunay Triangulation to represent minutiae as nodes of a connected graph composed of triangles. The minimum angle over all triangulations is maximized, which gives local stability to the constructed structures against rotation and translation variations. Geometric thresholds and minutiae data were used to characterize the triangulations created from input and template fingerprint images. The effectiveness of the proposed method is confirmed through calculations of false acceptance rate (FAR), false rejected rate (FRR) and equal error rate (EER) over FVC2002 databases compared to the results of other approaches.
Non-destructive in situ analysis of garnet by combining scanning electron microscopy and X-ray diffraction techniques
Authors: Bonilla-Jaimes John Deiver , Henao-Martínez Jose Antonio , Mendoza-Luna Carolina , Castellanos-Alarcón Oscar Mauricio , Ríos-Reyes Carlos Alberto
Published: April 2016

Mediante el uso de la difracción de rayos-X de polvo (DRXP), microdifracción de rayos-X (mDXR) y microscopía electrónica de barrido, la caracterización estructural de minerales resulta ser mucho más fiable y precisa. La identificación y cuantificación elemental y composicional de los minerales mediante estas técnicas no destructivas, mejoran la calidad de los resultados y permiten realizar un análisis completo del material. Los datos obtenidos mediante estas técnicas revelaron la presencia de granate tipo espesartina, además de los elementos y compuestos trazas que conforman el material en general. El refinamiento estructural de la espesartina fue realizado mediante el método Rietveld a partir de los datos obtenidos por difracción convencional y con ayuda del software de análisis MDI RIQAS. Con los datos adquiridos por mDXR usando un detector de área, un menor tiempo de exposición (comparado con el requerido en detectores 0D y 1D) y sin la necesidad de la disminución del tamaño de partícula del mineral, fue posible la identificación de la espesartina y otros compuestos en menor concentración (mediciones "in situ"). Mediante la combinación de las técnicas de microscopía electrónica de barrido y microdifracción de rayos X, tanto de trabajo desde un punto de vista de la caracterización. El examen por difracción de micro-rayos X no requiere la separación física de la muestra. Usando esta información y las técnicas analíticas avanzadas anteriores, la identificación de granate puede ser mucho más fiable.
Crack growth in pyrographite under the conditions of radiation
Authors: Tamayo Meza Pedro Alejandro , Yermishkin Viacheslav Alexandrovich , Silva-Rivera Usiel Sandino , Leyva-Díaz Alejandro , Trejo-Escandón Josué Osmar , Sandoval-Pineda Juan Manuel , Flores-Herrera Luis
Published: April 2016

The damage induced by radiation in the pyrographite is accompanied by significant plastic deformation. Microcracks arise in the edges of the radiated areas that develop radially in the direction of the unaffected matrix. The peculiarities in the formation of the tension state of the radiated area and adjacent unaffected areas are analyzed in order to explain the reasons behind the growth of cracks. The analysis is carried out on graphite disks with constant thicknesses that are exposed to radiation with high-energy electrons in an HVTEM-JEOL 1000. A differential equation for specific load conditions is obtained from the analysis of equilibrium conditions of a disc-shaped element.
Conversion of an existing electrostatic precipitator casing to Pulse Jet Fabric filter in fossil power plants
Authors: Manzano-Agugliaro Francisco , Carrillo-Valle Javier
Published: April 2016

The combustion process of power generation plants originates particulates. There are different technologies to collecting particulate such as electrostatic precipitators (ESPs) or fabric filters. Currently, these ESPs take 25 or 35 years in service and if the performance expectations of their Plants are positives, improving investments required which can adapt to the new particulate emission limits becoming more stringent. This paper analyzes an alternative means great savings in investment costs; Conversion of the existing ESP casing to a Pulse Jet fabric filter. This study also presents a real case, implementing this conversion with good results in unit of 660 MW power plants of Italy.
Consumo de sustancias psicoactivas y comportamientos violentos en estudiantes de 11 a 18 años. Itagüí, Colombia
Authors: Chavarriaga Rios Marcia Cristina , Segura Cardona Angela Maria
Published: April 2016

Determinar la asociación entre el consumo de sustancias psicoactivas (SPA) y los comportamientos violentos en los escolarizados del municipio de Itagüí, 2011.

Método Estudio analítico transversal con una muestra probabilística de 646 estudiantes de las instituciones educativas. Los estudiantes diligenciaron de manera individual, anónima y voluntaria un cuestionario con preguntas sobre características socio demográficas, consumo de SPA y comportamientos violentos. Se realizó un análisis descriptivo para estas variables. Se estimaron razones de prevalencia (RP) y los intervalos de confianza del 95 % (IC95 %); se realizó un análisis multivariado para determinar asociación y estimación de riesgo.

Resultados 646 estudiantes contestaron satisfactoriamente la encuesta. La mediana de la edad fue 15 años (Rq3). El 45,6 % son hombres y el 54,3 % mujeres; el 59,3 % pertenecen a estrato socioeconómico bajo, el 38,9 % medio y el 0,8 % estrato alto; el 53,4 % manifestó haber consumido alguna SPA; el 46,9 % dice consumir bebidas alcohólicas durante el último año; el 15,3 %  marihuana. Todas las sustancias consumidas se asociaron y al ajustar variables, la mayoría representaron riesgo para el joven ser autor de comportamientos violentos.

Conclusiones El consumo de SPA, se asocia con los comportamientos violentos del joven y representa un factor de riesgo para serlo. la heroína, la cocaína y éxtasis representan mayor riesgo que las demás SPA analizadas. Al ajustar con las demás variables, el cigarrillo, los inhalables entre otras dejaron de ser FR.

Palabras Clave: Bebidas alcohólicas, violencia, estudiantes, estudios transversales, medidas de asociación, exposición, riesgo o desenlace.
Análisis preliminar de un cuestionario de evaluación de la percepción social de la contaminación atmosférica
Authors: Jiménez Benítez Mercedes , Ferrer Botero Alberto , Chaves Castaño Liliana , Navarro Carrascal Oscar Eduardo , Marín Fuentes Juan Gonzalo , Cárdenas Herrera Julián , Rodríguez Velásquez Sandra Cristina
Published: April 2016

Analizar las propiedades psicométricas y la organización estructural de un cuestionario diseñado para evaluar la percepción social de la contaminación del aire y de sus riesgos para la salud en el Valle de Aburrá, área geográfica donde se ha identificado una problemática ambiental asociada a la polución.

Métodos Estudio descriptivo en el que se diseñó y validó un cuestionario que recogía tres dimensiones de la percepción social de la contaminación del aire (socio-territorial, socio-cognitiva y comportamental) y algunas variables sociodemográficas. Tras el estudio piloto, las dimensiones de análisis fueron organizadas en 12 categorías, conformadas por 111 ítems con escalas tipo Likert de cuatro o cinco opciones de respuesta. El instrumento fue aplicado a una muestra no probabilística de 318 participantes, los cuales eran residentes de Medellín y del municipio de Girardota.

Resultados Tras el análisis factorial exploratorio (rotación varimax), el cuestionario se redujo a 68 ítems que evalúan siete dimensiones de la percepción social de la contaminación atmosférica y de sus riesgos para la salud. La varianza total explicada es del 75 % y la confiabilidad alpha de Cronbach de la prueba fue 0,9.

Discusión Las dimensiones encontradas permiten aproximarse a la organización estructural de la percepción social de la polución y de sus riesgos sanitarios en el contexto de estudio. Aunque algunas dimensiones socio-cognitivas y comportamentales fueron confirmadas, la dimensión socio-territorial y la implicación personal no se configuraron como componentes estructurales y requieren ser reelaboradas conceptualmente. Resulta necesario realizar un análisis estructural confirmatorio de las dimensiones del cuestionario.
Utilización de terapias complementarias y alternativas en niños con cáncer
Authors: Ibañez Claudia , Sanchez Ricardo , Suárez Amaranto
Published: April 2016

Determinar frecuencia, características y factores asociados al uso de terapias complementarias y alternativas en pacientes pediátricos en un departamento de oncología en Colombia.

Métodos Estudio transversal en el que se aplica una encuesta a 398 cuidadores de pacientes pediátricos con cáncer en el Instituto Nacional de Cancerología en Bogotá, Colombia. Se registró información sociodemográfica y clínica, se evaluó el tipo de terapia, mecanismos de acción propuestos y patrones de uso de los tratamientos. Con regresión logística se evaluaron factores asociados con el uso de estas terapias.

Resultados Todos los casos correspondieron a terapias complementarias usadas para efectuar curación o controlar síntomas de la enfermedad o del tratamiento. Un 81,9 % de los pacientes (IC95 %: 77,8% a 85,6 %) había recibido algún tipo de 81 diferentes modalidades utilizadas. Lo más utilizado fueron las terapias basadas biológicamente (especialmente jugos de frutos rojos). Quienes más frecuentemente usaron estas terapias fueron mujeres con mayor nivel educativo. El tiempo desde el diagnóstico y haber recibido tratamiento quirúrgico también se asociaron con el uso de estas terapias. El mecanismo de acción más frecuentemente atribuido fue el refuerzo inmunológico.

Conclusión Se encontró una alta prevalencia de uso de terapias complementarias en esta muestra. Los pediatras deberían explorar en los pacientes el uso de estas terapias dado el potencial de interacciones con tratamientos farmacológicos o efectos adversos.
Ross Macdonald: Un modelo para la dinámica del dengue en Cali, Colombia
Authors: Sepulveda Salcedo Lilian Sofia , Vasilieva Olga , Martínez Romero Hector Jairo , Arias Castro Judy Heliana
Published: April 2016

El dengue es una infección transmitida por mosquitos que se presenta en todas las regiones tropicales y subtropicales del planeta. En años recientes, la transmisión ha aumentado de manera predominante en zonas urbanas y semiurbanas y se ha convertido en un importante problema de salud pública. El Instituto Nacional de Salud, INS, ubicó a Cali como el municipio con más casos de dengue en Colombia. De acuerdo con el INS, en la ciudad de Cali, hasta la semana epidemiológica 18 (del 28 de abril al 4 de mayo de 2013), se han notificado 5.134 casos de dengue y 171 de dengue grave.

En este trabajo se presenta la descripción del modelo Ross-Macdonald, el análisis cualitativo de dicho modelo, y el análisis de sensibilidad del modelo a cambios en sus parámetros. Y base en el ajuste del modelo obtenido para los casos presentados en el 2010, se hacen y analizan simulaciones de posibles escenarios de brotes epidémicos en la ciudad de Cali.
Asociación entre estructuras craneofaciales de adolescentes y los trastornos temporomandibulares
Authors: Ramirez caro Silvia Neri , Espinosa de santillana Irene Aurora
Published: April 2016

Determinar la asociación entre las dimensiones de las estructuras craneofaciales de adolescentes y la presencia de TTM.

Material y Métodos Estudio de casos y controles. Se evaluaron 46 pacientes de 10 a 16 años de edad con sus respectivas radiografías laterales de cráneo (23 casos y 23 controles, pareados por edad y sexo). Se aplicaron los Criterios Diagnósticos para la Investigación de los TTM (CDI/TTM) para establecer los casos y los controles por investigador estandarizado.

Resultados La comparación entre casos y controles de las estructuras craneofaciales, no demostró diferencias significativas, sin embargo la altura facial inferior, el eje facial y el plano mandibular fueron ligeramente superiores en el grupo de los casos. En el análisis de ANOVA de dos vías, (diagnóstico y edad), la convexidad facial presentó diferencias entre los adolescentes varones con y sin Trastornos temporomandibulares (p=0,002).

Conclusión Las estructuras craneofaciales no se asocian con el diagnóstico de TTM en los adolescentes, sin embargo se presentan cambios en las relaciones maxilomandibulares, (ubicación anterior del maxilar con respecto a la mandíbula) que provocan un patrón esquelético Clase II y una forma alargada de la cara.
Cement-bentonite in comparison with other cemented materials
Authors: Alzayani Nuha J , Royal Alexander C D , Ghataora Gurmel S , Jefferson Ian
Published: April 2016

The deformation behaviour of cement-bentonite (CB) materials used in low-permeability cut-off walls is critical to the performance of these barriers on site. While a number of investigations have focused on the deformation behaviour of CB materials, it is suggested that insufficient knowledge has been generated to allow for the determination of the behaviour of a CB wall on site with confidence. This paper reviews the deformation behaviour of other cemented particulate systems commonly encountered in civil engineering, concrete, rock, clays and cemented soils, and compares it with CB response to determine if the greater research effort associated with these materials could be used to improve understanding of CB. It is concluded that a direct comparison of physical behaviour between these materials is problematic due to the differences observed. Furthermore, formation of microcracks before the peak strength in cemented materials (rocks, etc.) is an area that does not appear to have been studied previously with CB materials; yet it could have a significant impact on the ability of a CB barrier to retard groundwater migration. Therefore, additional research is required on CB behaviour, prior to the achievement of the peak strength, to determine whether microcracking in CB is a significant hazard.
Effects of Coffee Shop Servicescape on the Emotional Reaction and Behavioral Intention of Customers and the Moderating Effect of Background Music
Authors:   The Tourism Sciences Society Of Korea, Jung Mi-Wha , Son Eun Soo , Lee Jong-Ho
Published: April 2016

The purpose of this study was to find out the effects of Servicescape on the emotions and behavioral intention of coffee shop customers in the Busan area and their correlation with the moderating effect of coffee shop background music. As a result of empirical research, it was found that coffee shop Servicescape has a partial(positive or negative) influence on the emotional reaction of customers. It was also found that the emotional reaction of customers has an influence on behavioral intention. As a result of analysis on moderating effects of background music, it was found that servicescape has partial moderating effects on the emotional reaction of customers. This results because comfortability of seats which is a lower factor of servicescape provides moderating effects on positive emotional reactions of customers. Furthermore, the esthetics factor causes moderating effects on negative emotional reactions of customers. The practical implications of this research are that continuing investment is needed for those servicescape factors which can enhance positive emotions of customers. This will in turn give the greatest influence on the behavioral intention of customers such as the intention to re-visit and recommend the coffee shop. That improvement is needed for other service scape factors which provoke negative emotional reaction of customers. For background music which has partial moderating effects, it is suggested that musical variables such as genre and tempo should be adjusted appropriately.
The Effects of Self-congruity with Wine Brand on Brand Attitude and Brand Loyalty
Authors:   The Tourism Sciences Society Of Korea, Choi Hae-Sook , Cho Yong-hyun
Published: April 2016

As consumers, Korean people can afford to buy more bottles of wine than ever before, and they are now interested in and concerned about the quality as well as diversity among brands of wine. However, we should discuss this issue more before we talk about the popularization of wine market in Korea. The purpose of this study was to examine how the self-image congruity for wine brands influences the emotions of consumers and their resulted purchase behavior. Accordingly, a total of 497 effective questionnaires were obtained from wine consumers who live in the metropolitan area and SPSS 18.0 and AMOS 18.0 statistics programs were used to test latent hypotheses. The result of analyses showed that all three types of self-image congruity of wind brands had significant effects on consumption emotions. Likewise, Consumption emotions had significant influence on brand attitudes and brand loyalties. Furthermore, brand attitude had a significant effect on the brand loyalty of consumers. Based on these results, the thesis specifies a few suggestions and implications for wine dealers. There should be continuous consumer management and proper opportunities for wine tasting. Also brand story marketing utilizing SNS would be effective for consumers with social self-congruity.
Cognitive control and a sense of presence in virtual environments
Authors: Velichkovsky B.B. , Gusev A.N. , Vinogradova V.F. , Arbekova O.A.
Published: April 2016

User interaction with a virtual reality system may be accompanied with a sense of presence, the illusion of reality of virtual environment. The emergence of a sense of presence is determined by both technological and psychological factors. The authors show that a sense of presence may depend on the individual characteristics of cognitive control, i.e. the system of metacognition providing cognitive system setting on the solution of specific problems in context. It was found that the expression of a feeling of presence may depend on the efficiency of the control switch functions, interference suppression and updating of working memory. At the same time, the dependence of the severity of the sense of presence on the effectiveness of cognitive control differs in virtual environments with different levels of immersion.
CISSY: A station for preparation and surface/interface analysis of thin film materials and devices
Authors: Lauermann Iver , Steigert Alexander
Published: April 2016

The CISSY end station combines thin film deposition (sputtering, molecular beam epitaxy ambient-pressure methods) with surface and bulk-sensitive analysis (photo emission, x-ray emission, x-ray absorption) in the same UHV system, allowing fast and contamination–free transfer between deposition and analysis. It is mainly used for the fabrication and characterization of thin film devices and their components like thin film photovoltaic cells, water-splitting devices and other functional thin film materials.
Arbovirus en Latinoamérica
Authors: Arredondo-García JL , Méndez-Herrera A , Medina-Cortina H
Published: April 2016

Las enfermedades producidas por arbovirus son un problema muy grave a nivel mundial, debido a que su vigilancia y prevención implica también la vigilancia de sus vectores, lo que hace difícil su control y casi imposible evitar su expansión a cualquier país tropical o subtropical, e incluso algunas regiones templadas. A nivel mundial, el  dengue es la enfermedad por arbovirus más común con 40% de la población mundial viviendo en zonas de transmisión del virus del dengue. De las 390 millones de infecciones estimadas y 100 millones de casos anuales, una proporción pequeña de estos casos progresa a dengue grave. Aproximadamente uno de cada 2,000 casos de dengue causan la muerte; sin embargo, la tasa de letalidad de los pacientes con dengue grave se puede reducir de casi 10% a menos del 0.1% si se actúa rápidamente y con calidad en la atención clínica que reciben los pacientes. Esto, aunado a la reciente y rápida propagación del virus chikungunya y el brote de virus zika en países latinoamericanos, como México, hace necesaria la actualización médica y revisión de bibliografía respecto a la prevención, control y gestión de las infecciones causadas por arbovirus. Por lo tanto, presentamos una revisión de lo más reciente sobre enfermedades por arbovirus en América Latina.
Avulsión dental
Authors: De la Teja-Ángeles E , Villegas-García L , Rodríguez-Ramírez F , Durán- Gutiérrez LA
Published: April 2016

Los traumatismos dento-alveolares son la causa principal de urgencia estomatológica y representan un daño a la salud bucal con consecuencias estéticas, funcionales, psicológicas y económicas. Muchos de estos traumatismos se producen por accidentes automovilísticos, caídas, violencia o la práctica de deportes de contacto. La avulsión dental por un traumatismo dento-alveolar causa que el diente sea desalojado por completo de su alvéolo y el hueso alveolar; el cemento, el ligamento periodontal, la encía y la pulpa quedan lesionados.
En acción: mejorando el acceso a la atención óptima para todos los pacientes con inmunodeficiencias primarias Semana mundial de las Inmunodeficiencias Primarias
Authors: Espinosa Rosales Francisco , Condino-Neto Antonio , Franco José , Sorensen Ricardo
Published: April 2016

Las inmunodeficiencias primarias constituyen un grupo de más de 300 defectos innatos del sistema inmunitario, tanto en sus componentes hematopoyéticos como en los no-hematopoyéticos. Dichos defectos pueden presentarse con un amplio espectro de manifestaciones clínicas, ya sea con infecciones (comunes recurrentes, comunes graves, o raras y graves), autoinflamación, autoinmunidad, malignidad y/o alergia. Anteriormente clasificadas como “enfermedades raras”, las inmunodeficiencias primarias no son tan raras como se pensaba: hoy en día se estima que afectan a más de seis millones de personas alrededor del mundo, sin distinciones geográficas, de género o edad.
Razvoj metode za HPLC-analizo izbranih fenolnih spojin lesa
Authors: Poljanšek Ida , Vek Viljem , Oven Primož
Published: April 2016

The most suitable composition of mobile phase for the separation of simple phenolic compounds such as gallic acid, pyrocatechol, phloroglucinol, resorcinol, vanillin and related compound catechin by the high performance liquid chromatography was investigated. The most appropriate developing mobile system for the separation of these organic compounds was acetonitrile and 2% water solution of formic acid with gradient ratio from 2.98 to 25:75. The best separation of the six organic compounds was achieved using mobile phase with lower content of formic acid. HPLC is a method of choice for qualitative and quantitative analysis compounds in various types of samples in the broad field of forestry-wood-pulp-paper chain.
Lived Realities: Birthing experiences of Māori women under 20 years of age
Authors: Stevenson Kendall , Filoche Sara , Cram Fiona , Lawton Beverley
Published: April 2016

This paper explores the birthing experiences of 16 pregnant Māori women under 20 years of age who were involved in E Hine, a Kaupapa Māori (by Māori, for Māori) longitudinal qualitative research study of young Māori women's journeys through pregnancy and into motherhood that ran from 2010 to 2013. This study provided these young women with an opportunity to share their birthing experiences during kanohi-ki-te-kanohi (face-to-face) interviews. Interpretive phenomenological analysis guided the analysis of these interviews. Following analysis, four themes emerged: some tikanga Māori (Māori practices) are being practised today; whānau (family) support is critical for these young Māori mothers; current system issues impact negatively on birth experiences; and adaptation to motherhood varies. From these themes, positive practices were drawn out that can be applied to clinical practice to improve the birthing experiences of young Māori women. These practices include promoting positive communication between patient and providers, facilitating supportive whānau environments, and enhancing support services accessibility.
PRODUKSI MISELIUM Grifola frondosa (Dickson: Fries) Gray ISOLAT CIANJUR DAN BOBOT EKSTRAKNYA PADA MEDIUM MYPB DENGAN PENAMBAHAN BIJI BUNGA MATAHARI Helianthus annuus L.
Authors: Maulida Rizki , Ratnaningtyas Nuniek Ina , Priyanto Slamet
Published: April 2016

Grifola frondosa or maitake, not only can be used as a food ingredient but also as medicine. Other than nutrients, fruit body and mycelium of G. frondosa also contains bioactive compounds, such as terpenoids, alkaloids, flavonoids, and beta glucans extracellular polysaccharides (β-1,3 glucans and β-1,6 glucans). Extracellular polysaccharide harvested more often in mycelium form which is cultivated in liquid medium. Liquid medium which is commonly used for the growth of mycelium is MYPB (Malt Yeast Peptone Broth). Mycelium production on MYPB as a medium can be increased by adding additional ingredients, one of which is sunflower (Helianthus annuus L.). The treatment was the addition of sunflower seeds on medium MYPB. The main parameters were mycelium’s dry weight and the weight of raw extract of G. frondosa. Supporting parameters were final pH medium, extracellular polysaccharides (qualitatively), terpenoid, alkaloid, and flavonoid compounds in the raw extract of G. frondosa. The addition of 250 g/l sunflower seeds in the medium MYPB was the optimum treatment that can produce 1,379 g/100ml of mycelium and 0,299 g/100ml G. frondosa extracts.
Risk Perception in the Use of Non-Metallics
Authors: Waterton K. C.
Published: April 2016

The use of Non-Metallics Materials (elastomers, thermoplastics and thermosets, including composites) as either free standing engineering materials or barrier layers for protection of low alloy carbon steels is highly desirable. Their many attributes include high strength to weight ratio and excellent resistance to corrosive aqueous environments.

However, they may be permeable to, and absorb, gases and liquids; be vulnerable to physical and chemical change in contact with produced fluids and treatment chemicals, which might render their short term properties inadequate; be limited by the long term effects of time, temperature and applied load (creep) and subject to long term ageing effects by thermal oxidation and hydrolysis etc.

In order to best utilise their desirable characteristics, it is necessary to understand the strength and weaknesses of the non-metallic material solution offered. It is essential to understand the interactions between each material and the in-service environment, to identify the risks and mechanisms for failure and the threshold values for properties critical to successful performance. The parameters identified shall be thoroughly tested in a programme to qualify the system for service. By defining the limiting service conditions and the operating envelope the risk of premature failure may be mitigated.

The paper will consider the different approaches available to test and qualify non-metallic materials for oilfield service, including accelerated testing, illustrated by examples of recent testing programmes.
The Tales That Rust Can Tell: The Use of Corrosion Product Analyses In Corrosion Failure Investigations
Authors: Burns Michael G.
Published: April 2016

Premature corrosion failures are often due to unanticipated environmental conditions. Identifying those conditions after the fact can be a challenge. However, since each specific chemical compound in a corrosion deposit is formed in a specific range of thermodynamic conditions, an analysis of the corrosion deposit can often help determine the cause of the corrosion. This paper will describe the conditions under which various corrosion products of iron are formed, provide some case histories where a corrosion product analysis proved helpful, and discuss the limitations of this technique.
Innovative Strategy to Qualify Acid Systems for High-Temperature Wells Under Stringent Corrosion Acceptance Criteria
Authors: Choudhary Yogesh Kumar , Belakshe Ravikant , Mba Julius C. , Salgaonkar Lalit
Published: April 2016

In recent years, it has become even more challenging to qualify acid systems that satisfy stringent corrosion acceptance criteria. This paper describes a unique approach of combining the effect of cooldown and effective treatment design to perform scale removal treatments in high-temperature (HT) wells in the Norwegian sector of the North Sea. The method helps minimize the use of corrosion control additives and its associated cost without compromising the integrity of the well components.

Controlling corrosion is a key consideration in designing acid recipes for HT wells. Achieving sufficient cooldown can further help ensure that inhibition lasts for the entire treatment duration. In this work, temperature modelling software was used to determine the volume required to cool down the well from 135°C to a specific temperature. Static weight loss corrosion testing was used to design the inhibition chemistry on 13Cr-L80 alloy. A corrosion loss of ≤ 0.02 lbm/ft2 for the time tested with no pitting observed at 40x magnification was considered acceptable.

The corrosion tests were performed in both organic and inorganic acid mixtures with varying acid concentrations over a temperature range of 40 to 135°C for a period of 3 to 9 hours. This paper discusses the acid recipe composition, results of corrosion testing, and microscopic analysis to determine pitting. The simulation results of the temperature modelling show that wells can be easily cooled down to as low as 40°C by pumping a sufficient volume of preflush at a certain rate, and examples of such treatment designs are presented in this paper. The qualified acid system was used for carbonate scale removal in the Norwegian sector of the North Sea. The treatment post-job analysis showcases an improvement as a result of the acid treatment.

The approach presented serves as a cost-effective guide toward designing scale removal or acid stimulation treatments for HT wells. The details shared in this paper are aligned with the drive of the oil and gas industry toward using cost-effective solutions and environmentally acceptable chemicals.
Management of Microbiologically Influenced Corrosion in Risk Based Inspection Analysis
Authors: Skovhus Torben Lund , Andersen Erlend Stokstad , Hillier Elizabeth
Published: April 2016

Operating offshore oil and gas production facilities is often associated with high risk. In order to manage the risk, operators commonly use aids to support decision making in the establishment of a maintenance and inspection strategy. Risk Based Inspection (RBI) analysis is widely used in the offshore industry as a means to justify the inspection strategy adopted.

The RBI analysis is a decision-making technique that enables asset managers to identify the risk related to failure of their most critical systems and components, with an effect on safety, environmental and business related issues. Risk is a measure of possible loss or injury, and is expressed as the combination of the incident probability and its consequences. A component may have several associated risk levels depending on the different consequences of failure and the different probabilities of those failures occurring.

Microbiologically Influenced Corrosion (MIC) is a degradation mechanism that has received increased attention from corrosion engineers and asset operators in the past decades. In this paper, the most recent models that have been developed in order to assess the impact of MIC on asset integrity will be presented and discussed.

From a risk perspective, MIC is not satisfactorily assessed by the current models and the models lack a proper view of the MIC threat. Therefore, a review of known parameters that affect MIC is presented. The mapping and identification of parameters is based on the review of past models and an extensive up-to date literature study.

The parameters are discussed and subsequently combined in a novel procedure that allows assessment of MIC in a RBI analysis. The procedure is sub-divided into one screening step and a detailed assessment, which fits the recommended approach to assess risk in a RBI analysis.

To illustrate the practical application of the developed procedure a field case is presented.
Testing of H2S Inhibitors for Application in a MEOR Field Pilot in Germany
Authors: Klueglein N. , Mahler E. , Sonwa R. , Herold A. , Hatscher S. , Alkan H.
Published: April 2016

MEOR (microbial enhanced oil recovery) is known as low-cost and easy to apply EOR technology. It uses the fact that natural occuring microrganisms in the oil reservoir can be stimulated to create effects that may result in mobilizing oil and sweeping it to the production well. During bacterial stimulation, there is always the risk that the growth of sulfate-reducing microorganisms, specifically bacteria (SRB), which are present in many oil reservoirs, is also triggered and toxic and highly corrosive H2S could be produced. The paper reports an investigation of microbiological H2S production and its mitigation. The project is jointly run by Wintershall and BASF in the context of a MEOR project in a German oil field.

Different SRB inhibitors (one of them being nitrate) have been tested. The inhibitors have different modes of action regarding H2S inhibition, bacteriocidal activity and also show other side reactions. In growth experiments with original reservoir water, it was observed that some inhibitors can prevent H2S formation. It was concluded that very high nitrate concentrations (100 – 500 mM) are necessary for a long-term suppression of H2S up to 41 days. Furthermore, in cultures with nitrate, iron and calcite precipitations were observed as the result of chemical reactions induced by bacterial activity. Reactive flow simulations were performed using Toughreact to predict the impact of those precipitations on the permeability of the reservoir. In contrast to these findings, alternative inhibitors could successfully mitigate H2S production in long-term experiments without any complications. Based on this data and predictions, the use of an alternative SRB inhibitor is preferred over nitrate in the upcoming field pilot.
Rapid Screening of Low Carbon Steel Tubings Using an Oxygen-Free Sliding - CO2 Corrosion Test Rig
Authors: Trausmuth Andreas , Ripoll Manel Rodriguez , Zehethofer Gerald , Vogl Thomas , Badisch Ewald
Published: April 2016

Surface degradation in oil well tubings due to sliding contact against sucker rod couplings leads to component damage, decrease productivity by leakage and ultimately failure. Despite the detrimental effect of combined mechanical wear with CO2 corrosion has been known for long time, it is seldom considered when selecting and screening tubing materials. The present work proposes an experimental procedure for characterizing the sliding - CO2 corrosion behavior of low carbon steel tubings. Our approach provides a fast and reliable procedure to screen prospective tubing materials. The feasibility of the test rig to reproduce surface degradation under field conditions is illustrated by comparing two J55 tubing grades with different hardness and chromium content. The performance of the tubings is discussed by comparing the results of pure sliding, static corrosion and sliding - CO2 corrosion tests. The results show the damage interaction between mechanical wear and corrosion, thus highlighting their synergy. The role of mechanical properties and chromium content are discussed within this context and the damage mechanisms observed with our experimental simulation test rig are compared to those observed under real field applications.