bluuebunny/crossref_metadata_2025 huggingface dataset:
Star-Selection Principle: Another New Direction
Authors: Bal Prasenjit , Bhowmik Subrata
Published: July 2017

Generally selection principles deal with two collections of families of subsets. In this paper we have introduce some new star-selection principles termed as SS*C,1(A, B) and SS*C,fin(A, B) which deal with three collections of subsets or families of subsets of a set. As a initiation of a systemic study, some properties of the new selection principles are investigated which show them to be distinct from existing selection principles.
Slightly Regular and Vague Measures
Authors: Camacho Jr. James
Published: July 2017

Outer and inner measures of a measure μ are defined and used to prove results involving them on a lattice l and its complement l'. Most of the results concern slightly regular measures, and vague measures. Then outer and inner measures associated to two measures μ, ν are then used to prove results involving them on two lattices l1, and l2 where l1 ⊂ l2.
Making narrative connections? Exploring how late teens relate their own lives to the historically significant past
Authors: Duraisingh Elizabeth Dawes
Published: July 2017

This paper reports on a study that invited 187 16–18-year-old students in the United States to draw diagrams showing connections between their own lives and the past. Interviews were subsequently held with 26 study participants. The degree to which students made connections between
their own lives and the past, and the various ways in which they integrated personal and historical narratives, are discussed, with three examples explored in detail. The ways in which interviewed students talked about their diagrams point to the significance of individuals' understandings
of the nature of historical knowledge for how they use the past to orient their own lives.
History as a 'GPS': On the uses of historical narrative for French Canadian students' life orientation and identity
Authors: Lévesque Stéphane
Published: July 2017

This article presents the results of a study that analyses students' historical narratives of the nation in relation to historical consciousness and how their sense of self-identification with groups affects their narrative structure and orientation. This study was conducted with French
Canadian students registered in two high schools (n=58) and one university (n=18) in Ottawa, the federal capital of Canada. I found that a strong sense of identification leads young people to construct more engaging and militant stories of the collective past, with greater historical appropriation
(using the collective 'we') and a sense of continuity with past actualities. I then discuss the implications of this study for research on the narrative competence of historical consciousness and what history education might do in school to promote historical consciousness in Canada.
The Swedes and their history
Authors: Olofsson Hans , Samuelsson Johan , Stolare Martin , Wendell Joakim
Published: July 2017

The aim of this article is to analyse adolescents' views of Swedish history. A small number of adults were also included in the study. The analysis shows that, regardless of the age of the informants, Sweden is portrayed as an exception from the world through its legacy of a long peace
(in spite of a war-torn distant history) and through its enjoyment of progress, democracy and prosperity. We interpret this as a result of a history culture in which schools as well as other institutions produce a common, conflict-free history, which may be challenged in an emerging neonationalist
era.
Why national narratives are perpetuated: A literature review on new insights from history textbook research
Authors: Grever Maria , van der Vlies Tina
Published: July 2017

National narratives have often served to mobilize the masses for war by providing myths and distorted interpretations of the past, while conversely wars were major sources for producing national narratives. Because national history is very likely to remain a central topic in history
education, albeit in ways that differ from how the topic was used fifty years ago, it is important to gain a greater understanding of the underlying structures and mechanisms of these narratives in history textbooks. After outlining the historical interconnectedness of the emerging nation
states and history teaching, this review article explains the complexity of the history textbook as an educational resource. Next, we identify some current problems and challenges in history textbook research. We continue by discussing promising research trends related mainly to national narratives,
such as the analysis of images, the use of digital tools, and studies of the autonomy of textbook narratives and of history textbooks in relation to other media. Another recent reorientation is textbook research that uses a holistic approach. By this we mean studies that examine the
history textbook as a whole: composition, periodization, visual intertextuality and chapters that do not at first glance appear to focus on national history. These studies offer new insights and explanations for the perpetuation of national narratives in history textbooks.
“Travelling with the Traveller”: An Ethnographic Framework for the Study of Migrants’ Digital Inclusion’
Authors: Tsatsou Panayiota , Boursinou Maria-Nerina
Published: July 2017

This paper argues that researchers who study migrants’ digital inclusion need to shed light on migrants’ use of digital technologies within the time frame and context of ‘migration travel’ and while migrants are in transition to a new or safer place for resettlement. In support of this argument, the paper proposes a ‘travelling with the traveller’ research framework that applies an ethnographic methodology and aims at the researcher experiencing or even becoming an integral part of the migration travel. The paper presents this travelling with the traveller framework and discusses the implications of digital inclusion (or the absence of it) for migrants’ experience, to combat or alleviate of all sorts of adversities, volatile emotions, unanticipated problems and moments of uncertainty and crisis migrants so often encounter on the move from homeland to another land, from one life setting to another. Further, the paper presents the fieldwork processes and data collection techniques of the proposed travelling with the traveller framework, such as participant observation, informal and open-ended interviews, as well as the use of video and photographic footage.
Atención humanizada del parto. Diferencial según condición clínica y social de la materna
Authors: Cáceres-Manrique Flor De María , Nieves-Cuervo Giselly Mayerly
Published: July 2017

Objetivo: hacer una reflexión sobre el concepto de la atención humanizada del parto (AHP) y el desempeño diferencial del personal y las instituciones de salud según las condiciones clínicas y socioeconómicas de las maternas. Bajo la tesis de que la vivencia de la AHP es menos frecuente en gestantes adolescentes, de alto riego o de bajo nivel socioeconómico, se plantean una serie de preguntas que permiten al abordaje de los diferentes aspectos del AHP mediante una revisión de la literatura mundial que aborda este tema. Se encuentra que la AHP, no obstante estar definida y contenida en documentos y guías de atención de organizaciones internacionales y nacionales que proclaman su aplicación en toda gestante durante el control prenatal, el trabajo de parto y parto, no beneficia de igual manera a todas las mujeres. Se presentan estudios que aportan ejemplos en los cuales la vivencia de la AHP es menos frecuente en gestantes adolescentes, de alto riesgo o de bajo nivel socioeconómico. Estas desigualdades podrían configurar o agudizar inequidades, en detrimento de la salud de mujeres en desventaja, quienes deberían ser objeto de mayor cuidado dadas sus condiciones de vulnerabilidad.Conclusiones: la desigualdad en la vivencia de la AHP según edad, riesgo y nivel socioeconómico evidencia inequidad en la atención de salud a mu­jeres en condiciones de pobreza y marginación. Se requiere el compromiso de los profesionales de la salud y las instituciones para construir escenarios equitativos de AHP.
El parto: evento que exige la excelencia de la calidad en los servicios de salud
Authors: Gaitán-Duarte Hernando , Eslava-Schmalbach Javier
Published: July 2017

En este número de la revista se presenta un artículo de reflexión sobre las diferencias observadas en la calidad de la atención del parto que afectan de manera negativa a las gestantes con menos recursos económicos, las adolescentes y aquellas que presentan embarazos de alto riesgo.Se parte del hecho de que idealmente el trabajo del parto y el parto deben ser “una vivencia satisfactoria” que incluye, además de brindar las mejores prácticas basadas en la evidencia científica, “respetar la fisiología del parto; intervenir solo lo necesario; identificar, comprender y respetar los aspectos socioculturales de la gestante; brindarle apoyo emocional; darle poder de decisión, y garantizar su autonomía y privacidad”. Estos deberían ser los criterios para evaluar la calidad en la atención del parto, en un concepto humanista amplio, que lleva a tener en cuenta, no solo los criterios clásicos de calidad, sino también dominios relacionados con los derechos humanos, la cultura de la gestante y principios éticos fundamentales.
Prevalencia de corioamnionitis histológica en pacientes con trabajo de parto pretérmino espontáneo. Popayán, Colombia, 2014–2016
Authors: Arias-Peláez Carolina , Gallego-Betancourt Cristal Ximena , Mera-Ijaji Geovanni Alexander , Ortiz-Martínez Roberth Alirio , Chagüendo-García José Enrique
Published: July 2017

Objetivo: determinar la prevalencia de la co­rioamnionitis histológica en gestantes con trabajo de parto pretérmino espontáneo, evaluar posibles factores de riesgo y la asociación con signos clínicos y paraclínicos.Materiales y métodos: estudio descriptivo de prevalencia, con análisis secundario exploratorio en gestantes con embarazo menor a 37 semanas de gestación, con parto espontáneo, en quienes se dispuso de sus placentas para estudio histopatoló­gico, durante un periodo de 2 años, en un hospital de alta complejidad en Popayán, Colombia. Se ex­cluyeron partos pretérmino secundarios. Muestreo consecutivo, con tamaño muestral de 166 gestantes; se midieron variables sociodemográficas, clínicas, de laboratorio e imágenes diagnósticas, y resultado histopatológico de la placenta. En el análisis se es­timó la prevalencia de periodo de corioamnionitis histológica. Se obtuvo la razón de prevalencias como medida de asociación y el OR diagnóstico (ORD) con su respectivo intervalo de confianza al 95 %.Resultados: en un periodo de 2 años se analizaron 160 gestantes y sus placentas, 110 placentas fueron reportadas como positivas para corioamnionitis his­tológica con una prevalencia de 68,75 % (IC 95 %: 61,49-76,00), esta fue más prevalente en gestaciones menores de 34 semanas (RP = 1,48; IC 95 %: 1,20-1,83). En cuanto a la asociación de los síntomas y signos se encontró asociación significativa con la fiebre (ORD = 4,7; IC 95 %: 1,05-21,09), la taqui­cardia materna (ORD = 4,22; IC 95 %: 1,81-9,81), la taquicardia fetal (ORD = 3,74; IC 95 %: 1,23-11,35), movimientos respiratorios ausentes (ORD = 5,16; IC 95 %: 1,43-18,60), lago de líquido amniótico menor a 2 cm (ORD = 5,67; IC 95 %: 1,24-25,98), y presencia de neutrofilia (ORD = 2,97; IC 95 %: 1,44-6,12).Conclusiones: la prevalencia de corioamnionitis histológica es del 67% en los partos pretérmino y varió en función de la edad gestacional.
Tourism research, for what?
Authors: Korstanje Maximiliano
Published: July 2017

While tourism scholars have struggled over decades to establish tourism as a valid academic discipline, it’s no less true that social scientists have developed a negative image of our colleagues. This in fact happens because for social imaginary leisure and tourism are naïve activities, or practices enrooted in an alienatory nature. Paradoxically, many of founding parents of sociology of tourism was embraced this belief, the advance of modernity, as well as tourism, will disorganize the social ties. In this essay review, we place the French Tradition under the critical lens of scrutiny revealing alternatives in tourism epistemology between tourism as a profit-oriented industry and as a mechanism of discipline.
Una aproximación a la situación turística en la región de Bahía de Banderas, México
Authors: Medina Esparza Lorena Trinidad , Arnaiz Burne Stella Maris
Published: July 2017

El presente artículo analiza la situación turística actual que presenta la región de Bahía de Banderas, la cual comprende dos municipios del estado de Jalisco y uno del estado de Nayarit, México. El objetivo consistió en observar su contexto para determinar el posible escenario hacia el futuro del turismo en la mencionada región. Los resultados indican que no se ha procurado una visión futurista, puesto que sus recursos naturales y culturales han tenido un manejo inadecuado. Tal es el caso de Puerto Vallarta, considerado un destino maduro que necesita apremiantemente una renovación si desea continuar posicionado entre los tres destinos de playa principales en México. La propuesta consiste en la creación de parques temáticos y el trazo de rutas complementarias aprovechando el potencial de otros municipios que conforman la región, a fin de desarrollar estrategias diversificadas y personalizadas que solucionen algunos problemas de competitividad turística.
¿Es el ecoturismo una alternativa al turismo de aventura en el cantón El Chaco?
Authors: Polanco Daniela
Published: July 2017

El Chaco es uno de los cantones que han sobresalido en el turismo de aventura. Sin embargo, desde el año 2006, esta actividad no ha despuntado y el turismo ha quedado desligado del desarrollo local. El objetivo de la presente investigación es identificar la problemática del turismo de aventura en el cantón y proponer una línea de producto turístico de acuerdo con su potencialidad. Para los resultados se desarrolló una investigación teórico-metodológica centrada en entrevistas y cartografía social de la parroquia Gonzalo Díaz de Pineda y la cabecera cantonal El Chaco. Los principales resultados denotan que el turismo de aventura se ha ralentizado debido a la falta de organización, los costos elevados del equipamiento para el turismo de aventura y los impactos socioambientales por la construcción de la Hidroeléctrica Coca Codo Sinclair. Los resultados visibilizan la problemática y sustentan la propuesta de la práctica del ecoturismo como una nueva alternativa de desarrollo local.
Atraer visitantes a barrios antiguos. Creación y gestión de la ciudad turística-histórica de Plymouth, UK
Authors: Balbuena Vázquez Antonia Ma.
Published: July 2017

Plymouth es una ciudad de Reino Unido que se ha planteado el turismo como un medio de desarrollo. Para ello, ha creado una serie de estrategias dirigidas a fomentar este sector, convirtiendo así esta ciudad histórica en un lugar de consumo y venta. Esto ha traído como consecuencia una serie de impactos que le cuesta asumir ante la idea de convertirlo en un centro turístico-histórico. El autor aporta el estudio de este caso particular y nos hace un recorrido evolutivo e histórico de esta ciudad, ofreciéndonos una visión integral de los cambios que el turismo ha generado y los planes urbanísticos que se han trazado para lograr el objetivo de atraer turistas.
Cadena de valor turística y desarrollo local en el Amazonas: Implicaciones en el bienestar de la comunidad. Leticia (Colombia)
Authors: Pereiro Xerardo
Published: July 2017

Reseña crítica de un libro de la autoría de Germán Ignacio Ochoa Zuluaga sobre la cadena de valor turística y la distribución de beneficios del turismo en un contexto de la periferia colombiana. El trabajo de investigación base de esta publicación ha sido realizado en Leticia, zona fronteriza con Brasil y Perú.
El impacto del sistema tributario y el gasto social en la distribución del ingreso y la pobreza en América Latina: Argentina, Bolivia, Brasil, Chile, Colombia, Costa Rica, Ecuador, El Salvador, Guatemala, Honduras, México, Nicaragua, Perú, República Dominicana, Uruguay y Venezuela Una aplicación del marco metodológico del proyecto Compromiso con la Equidad (CEQ)
Authors: Lustig Nora
Published: July 2017

Este artículo presenta resultados sobre el impacto de la política fiscal en la desigualdad y la pobreza en dieciséis países de América Latina para alrededor del año 2010. Los países que más redistribuyen son Argentina, Brasil, Costa Rica y Uruguay, y los que menos, Guatemala, Honduras y Perú. A mayor gasto social, mayor redistribución pero países con un nivel de gasto social similar muestran diferentes niveles de redistribución lo cual sugiere que otros factores tales como la composición y focalización del gasto intervienen en determinar el efecto redistributivo más allá del tamaño. La política fiscal reduce la pobreza extrema en doce países.. Sin embargo, la incidencia de la pobreza después de impuestos, subsidios y transferencias monetarias es mayor que la incidencia para el ingreso de mercado en Bolivia, Guatemala, Honduras y Nicaragua, aun cuando la política fiscal reduce la desigualdad. Además, aun cuando la incidencia de la pobreza y la desigualdad se reducen, con la nueva medida de Empobrecimiento Fiscal se puede observar que en Brasil y México un tercio de la población pobre medida con el ingreso consumible fue empobrecida: es decir, pasó de pobre a ser más pobre o de no pobre a ser pobre. El gasto en educación pre-escolar y primaria es igualador y pro-pobre en todos los países. El gasto en educación secundaria es igualador en todos los países y también pro-pobre en algunos pero no en todos. El gasto en educación terciaria nunca es pro-pobre pero es igualador a excepción de Guatemala, donde es regresivo y desigualador y en Venezuela, donde su efecto redistributivo es cero. El gasto en salud siempre es igualador pero es pro-pobre solamente en Argentina, Brasil, Chile, Costa Rica, Ecuador, República Dominicana, Uruguay y Venezuela.
Debate sobre el Homo Economicus. El caso de los funcionarios de casilla
Authors: Barragán Robles Miroslava , Escalante Semerena Roberto , Domínguez Villalobos Lilia
Published: July 2017

Antecedentes: A partir de un caso empírico se estudia la decisión de las personas para participar voluntariamente como funcionarios de casilla el día de la jornada electoral en México. Al respecto, interesaba analizar si esa participación era motivada por un comportamiento prosocial, donde el ciudadano contribuía a la existencia de un bien público: la democracia. De ser el caso, se descartaría el comportamiento de Homo Economicus. Métodos: Ante la falta de información para hacer este estudio a nivel individual, se decidió hacerlo a nivel más agregado, a nivel municipal. Por medio de una regresión logística se exploró la probabilidad de que un municipio tuviera una alta tasa de aceptación para participar en la jornada electoral como funcionarios de casilla. Específicamente, se estudió en qué medida la variable dependiente se explica por variables asociadas a un comportamiento prosocial o a un comportamiento de Homo Economicus. Resultados: Los resultados muestran que, efectivamente, una parte de la participación es motivada por la responsabilidad ciudadana y el compromiso social, es decir, un comportamiento divergente del Homo Economicus. En tanto que la otra parte de la participación responde a incentivos no explícitos que estarían asociados al self-interest. Conclusiones: En este artículo se concluye que una parte de quienes aceptan la invitación para participar como funcionarios de casilla, lo hacen respondiendo a un comportamiento prosocial, pero para el resto no es posible descartar un comportamiento de Homo Economicus. Todo ello apunta a la necesidad de seguir trabajando para consolidar la calidad de la democracia mexicana.
Un modelo de inversión óptima para fondos soberanos: caso fondo mexicano del petróleo para la estabilización y el desarrollo
Authors: Sierra-Juárez Guillermo , Méndez García Daniela
Published: July 2017

Antecedentes: Los estudios referentes a la optimización de los recursos provenientes de la producción petrolera son un tema de fundamental importancia para México. La constitución de fondos de distintas características (como los fondos soberanos), los cuales sirvan para administrar y cubrir esta riqueza es una tarea primordial que ha emprendido el gobierno federal. Metodología: El objetivo del presente trabajo es proponer un modelo de optimización estocástica que pueda servir para el soporte y análisis de las políticas de decisión sobre los fondos constituidos provenientes del petróleo. Dicho modelo maximiza la utilidad de un inversionista sujeto a una restricción de riqueza integrada por una dotación petrolera y un activo financiero, con sus coberturas de opciones financieras y bonos utilizando la técnica HJB. Resultados: Después de aplicar la herramienta se hace una análisis sobre el cambio en los valores de las ponderaciones invertidas en cada uno de los activos al variar los parámetros. Conclusión: En general se puede decir que la cartera propuesta es de cobertura más que especulativa y los resultados obtenidos en el análisis de sensibilidad de los ponderadores de los activos son consistentes con la intuición esperado y la política pública.
Guest Column: SPE: Weathering the Downturn
Authors: Byrne Steve
Published: July 2017

Guest column

When oil prices began to fall rapidly in the last half of 2014, the impact was quickly felt in all of SPE’s programs. Our magazines were affected first by a reduction in advertising as companies reduced their marketing budgets. Training course attendance was next as companies cut back training and travel. Conference and workshop participation declined as travel was constrained, and technical programs for conferences were affected as authors were unable to present their papers. Participation in exhibitions held up for a while as many companies honored commitments that had already been made, but subsequent rebooking of exhibits declined. It quickly became apparent that all of SPE’s main programs were going to be suppressed as long as prices remained low and would likely trail the recovery of prices on the way out of the downturn.

Understanding that SPE could not continue to operate in a business-as-usual fashion, the Board of Directors and senior staff began examining the impact to SPE and options for adjusting operations to the downturn. SPE is very fortunate to have financial reserves to smooth the impacts of the economic fluctuations common to our industry. During the years of high prices, we were able to build a reserve fund and invest it to see us through harder times. As it became clear that the industry was facing a “lower for longer” situation, we recognized that we needed to adjust our operations to fit industry conditions.

When oil prices were high, SPE initiated a number of new member programs. One of our first steps was to examine these newer programs to determine whether they could be paused until conditions improved, or reduced in some manner to improve their economics. This effort quickly spread to longer-standing programs as well. Changes made to PetroBowl are an example of the type of action taken by the Board. The program had grown the number of teams involved, and SPE was covering the travel costs for many teams to attend the finals during ATCE. The costs had increased significantly. The Board modified the way in which regional teams are selected for the finals at ATCE and reduced the costs being borne by SPE for this popular program.
Major Alaskan Discoveries Promote Great Expectations
Authors: Rassenfoss Stephen
Published: July 2017

The Pikka Field discovered by Armstrong Oil & Gas is just 2 to 3 miles wide, about 30 miles long, could produce 1.2 billion barrels of oil, and is one of three major finds that have shattered assumptions about what is possible in the most explored parts of Alaska’s North Slope.

“The Armstrong discovery, and especially the size of that discovery, was stunning to everyone,” said David Houseknecht, a geologist for the US Geological Survey who has done multiple assessments of the potential in the area. “The thinking was the biggest oil pool we could imagine had 200 to 250 million barrels of recoverable oil. These discoveries coming in with more than a billion barrels or 300 million barrels, at least, really change things by an order of magnitude.”

The find by Armstrong in March may not be the biggest of the three. A discovery by Caelus Energy in Smith Bay called Tulimaniq could produce twice as much oil though the development challenges are also much greater. And Conoco Phillips’ Willow discovery could ultimately produce from 3.3 to 3.9 billion, and add more than 400,000 B/D of production in the next decade.

It is an impressive total, even when discounted for the fact that these are early estimates in a costly area for development in a period of struggling oil prices. In addition, what has been learned about identifying the subtle signs of oil trapped within two large formations—the Nanushuk and the Torok—could open up greater opportunities.

The recent finds could turn the Nanushuk from a minor reservoir into a “virtually unexplored play fairway covering at least 9000 to 15000 km2 that includes both onshore and shallow offshore areas,” said Houseknecht. He made the comment during a presentation at the recent annual meeting of the American Association of Petroleum Geologists in Houston, where even poster sessions on the North Slope drew crowds.

Those finds highlight advances in the tools used to look for oil pockets trapped in the earth, and unconventional techniques needed to maximize production from conventional reservoirs that are tighter than the free-flowing reservoirs found in the aging Prudhoe Bay field to the east.

“The bottom line is, because of 3D seismic and because of the completion practices used for unconventionals, we can now reasonably look at low-permeable Brookian [Nanushuk and Torok] reservoirs as viable,” he said.

One sign of the industry’s confidence was bidding at state and federal lease sales in December, where Conoco Phillips was the most aggressive bidder, picking up about 600,000 net acres, said Alison Wolters, a research analyst for Wood Mackenzie.
Custom-Designed Coiled Tubing Leads to Success in Extended-Reach Operations
Authors: Wilson Adam
Published: July 2017

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 184752, “Vaca Muerta Coiled-Tubing-Operations Success and the Development of Future Extended-Reach Operations,” by I.I. Galvan, Global Tubing; M.M. Nebiolo, R.D. Del Negro, and G.A. Landinez Gomez, YPF; C. Cerne, SPE, ThruTubing Solutions; and A. Sanchez, SPE, and G. Mallanao, Global Tubing, prepared for the 2017 SPE/ICoTA Coiled Tubing and Well Intervention Conference and  Exhibition, Houston, 21–22 March. The paper has not been peer reviewed.

Advanced horizontal drilling, multistage hydraulic fracturing, and other technologies have helped make the Vaca Muerta shale oil and gas resource economically viable. An option to exploit this resource better is to increase the length of the horizontal section of each well to add hydraulic-fracture stages. Anticipated high angles in deviated well sections, along with the extended horizontal length of the planned wells, formed an expectation that conventional coiled-tubing (CT) designs would not be able to service the new well designs. Using refined, custom-engineered CT-string designs appears to be an economic and efficient solution.

Project Overview

Increased diameter, strength, and reliability have made CT the preferred cost-effective well-intervention solution in the Vaca Muerta unconventional shale development; however, the maximum lateral reach the CT can achieve during operations is a limiting factor for well optimization.

Initially, 2-in. CT strings with a simple wall taper shape were an effective and reliable option to complete wells in the first development stage. However, the need for optimized design and even-larger-diameter CT with enhanced-wall-thickness configurations became apparent when an increase of the well lateral lengths was attempted.

CT-String Design Considerations

The CT-string designs followed a cooperative process between the operator, the CT service companies, tool providers, and the CT-manufacturing engineers. Tubing forces, buckling occurrence, and lockup depths were analyzed in detail to determine the optimal CT size and string design makeup to ensure the likelihood of reaching target depth (TD) in the planned extended-reach wells. Additionally, hydraulic analysis was performed to compare frictional pressure losses (CT, bottomhole-assembly, and annular) using the optimal flow rates for annular velocities adequate to support sufficient well cleaning. The results from the analysis were used to estimate fatigue accumulation in the CT strings, considering anticipated circulating pressures and surface-equipment (reel and gooseneck arch) dimensions.

The primary objective for the new CT-string design is to optimize lateral reach and available weight on bit for post-fracture mill-out operations.
What Vacuum-Insulated Tubings and Casings Bring to Thermal Wells
Authors: Carpenter Chris
Published: July 2017

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 182515, “What Vacuum-Insulated Tubings (or Vacuum-Insulated Casings) Bring to Thermal Wells,” by J. Damour and D. Johannson, Majus, prepared for the 2016 SPE Thermal Well Integrity and Design Symposium, Banff, Canada, 29 November–1 December. The paper has not been peer reviewed.

This paper describes both design and economic considerations that lead to the selection of vacuum-insulated tubing (VIT) or vacuum-insulated casing (VIC) for the completion of thermal wells. The results shared in this paper are some of the parameters considered during thermal-well design: temperature on the casing and the tubing, and heat loss. Knowing these parameters, well integrity can be studied and the overall efficiency of the process estimated.

Introduction

The most common thermal enhanced-recovery methods are cyclic steam stimulation, steamflooding, and steam-assisted gravity drainage, which is widely used in Canada. The role of these thermal-recovery methods is to convey heat into the reservoir, mainly by convection. The temperature of the oil increases and its viscosity decreases significantly in the reservoir. These methods can substantially increase the oil production of a field, increase the recovery factor, or unlock some heavy-oil assets.

Typical steam-injection temperature is between 250 and 310°C; in a few cases, it could be greater than 310°C. This high-temperature application requires adapting the design of the injector wells to avoid any mechanical failure of the well or to mitigate heat loss through the well. VIT or VIC are solutions to some of these issues.

VIT technologies have evolved significantly since their first application. Different materials are used as insulation material, and several designs are proposed by the industry to achieve the best thermal-performance-vs.-cost equation.

A model was developed to assess the temperature of the different components of a well—tubing, casing, cementation, and ground—and to provide the heat loss occurring during the steam injection. The results show that the wide range of VIT thermal performance provides a range of casing temperatures. Thus, the casing thermal expansion or thermal loads resulting from this temperature increase range significantly.
Formation of Majorana fermions in finite-size graphene strips
Authors: Kaladzhyan Vardan , Bena Cristina
Published: July 2017

We investigate the formation of Majorana fermions in finite-size
graphene strips with open boundary conditions in both directions, in the
presence of an in-plane magnetic field and in the proximity of a
superconducting substrate. We show that for long enough strips the
Majorana states can form in the presence of a Rashba-like spin-orbit
coupling, as well as in the presence of an inhomogeneous magnetic field.
We find that, unlike infinite graphene ribbons in which Majorana states
arise solely close to the bottom of the band and the Van Hove
singularities, for finite-size systems this can happen also at much
smaller doping values, close to the Dirac points, and depends strongly
on the type of the short edges of the systems (e.g. armchair vs.
zigzag), as well as on the width of the ribbons.
The response of nitrous oxide emissions to different operating conditions in activated sludge wastewater treatment plants in Southeastern Brazil
Authors: Ribeiro Renato P. , Bueno Rodrigo F. , Piveli Roque P. , Kligerman Débora C. , de Mello William Z. , Oliveira Jaime L. M.
Published: July 2017

The continuous measurements of N2O emissions from the aeration tanks of three activated sludge wastewater treatment plants (WWTPs) operated with biological nitrogen removal (BNR) and non-BNR were performed during the different operating conditions of several parameters, such as aeration, dissolved oxygen (DO) profiling and organic shock loading (with landfill leachate). The nitrification process is the main driving force behind N2O emission peaks. There are indications that the variation of the air flow rate influenced N2O emissions; high N2O emissions denote over-aeration conditions or incomplete nitrification, with accumulation of NO2− concentrations. Thus, continuous measurements of N2O emissions can provide information on aeration adequacy and the efficiency of complete nitrification, with major focus on DO control, in order to reduce N2O emissions. An additional concern is the observed propensity of WWTPs in developing countries to receive landfill leachates in their wastewater systems. This practice could have adverse effects on climate change, since wastewater treatment during periods of organic shock loading emitted significantly higher amounts of N2O than without organic shock loading. In short, non-BNR WWTPs are subject to high N2O emissions, in contrast to BNR WWTP with controlled nitrification and denitrification processes.
Drilling Mechanism Investigation on SiC Ceramic Using Diamond Bits
Authors: Gao Chao , Wu Guorong , Wang Sheng
Published: July 2017

Background:

SiC ceramic have been widely used in the fields of armor protection, but SiC ceramic is one of the difficult-to-machine material for its high hardness and low fracture toughness.

Objective:

This paper presents an investigation of drilling mechanism on SiC ceramic using diamond bits.

Method:

Based on the theory of indentation fracture mechanics model, cutting average load model and cutting average depth model for single particle were established, theory analysis of drilling mechanism was carried out; through scanning electron microscope (SEM) observation, experimental removal mechanism was discussed.

Results and Conclusions:

The results show that, brittle fracture is the dominant way for SiC ceramic’s removal mechanism, plastic deformation always exists during the drilling process. Brittle fracture includes cleavage fracture, transgranular fracture, intergranular fracture, material peeling off and grain boundary breakage; resintering and recrystallization happen under the joint action of grinding forces and grinding heat in the contact area, where plastic flow characteristics also appear; powdering removal is accompanied by the drilling process; cleavage fracture and transgranular fracture occur on intergranular pores and grain boundary; residual cracks are found in the drilling surface resulted by drilling stress and high temperature.
Sensitivity of WRF Cloud Microphysics to Simulations of a Convective Storm Over the Nepal Himalayas
Authors: Shrestha Rudra K. , Connolly Paul J. , Gallagher Martin W.
Published: July 2017

Background:

This paper investigates sensitivity of bulk microphysical parameterization (BMP) schemes within the Weather Research and Forecasting (WRF) model to simulate a convective storm that generally evolves during pre-monsoon season (March – May) across the foothills of the Himalayas.

Method:

Four mixed-phase BMP schemes (Morrison, Lin, WDM6, and WSM6), which are parameterized with an increasing complexity from single to double moments of particle distribution to represent cloud processes, are used with an explicit convection permitting grid resolution (3 km x 3 km). Experiments are set up to simulate a convective storm that occurred in the late afternoon of 18thMay 2011 and compared with i) Satellite-based tropical rainfall measuring mission (TRMM) 3B42 v7 data, and ii) Ground-based observations at Nagarkot (27.7°N, 85.5°E), Nepal.

Result:

Our results show that the simulated storm characteristics are not overly sensitive to the chosen BMP schemes. In general, all the BMP schemes produce similar rainfall characteristics and compares reasonably well with the observations across Siwalik Hills and Middle Mountains, which act as a topographic barrier to low level circulations and receive more rain. The schemes, however, show negative bias across central Nepal including the Kathmandu Valley, albeit the magnitude and spatial distribution of bias are different between the schemes. In contrast, upper level total water condensate and cloud fraction show a strong sensitivity to the BMP schemes.

Conclusion:

Overall, the Morrison scheme, in addition to warm clouds which also predict double moment distribution of all hydrometeors in the cold-cloud processes, a dominant cloud forming process in the Himalayas, accurately represents the mechanism and outperforms the simplified schemes based on root mean square error (RMSE) analysis.
Elementos da Nova Perspectiva sobre Paulo a partir de representantes clássicos
Authors: Wiese Werner
Published: July 2017

As cartas do apóstolo Paulo constituem um desafio. Sua recepção não foi consensual. Porém, a ocupação com elas cativou e impactou pessoas a ponto de se tornarem personagens cuja interpretação de Paulo se impôs e marcou decisivamente a história da teologia e igreja. Martim Lutero foi um exemplo clássico disso. Ocupando-se intensivamente com as cartas de Paulo aos Gálatas e Romanos, Lutero achou a chave hermenêutica para compreender a justiça de Deus como justifi cação do pecador somente pela fé em oposição às obras. Exceções e variações à parte, essa compreensão de justiça de Deus foi determinante para a exegese protestante posterior, e no “ocidente cristão” influenciou fortemente a compreensão do judaísmo como religião meramente legalista, à qual Paulo se opôs com veemência em suas cartas. Dos anos de 1960 em diante, surgiu uma nova leitura de Paulo e do judaísmo de seu tempo. Ela tornou-se conhecida como nova perspectiva sobre Paulo. Nela, questiona-se principalmente a exegese alemã. Isso causou reações materializadas em rica produção literária que não pode mais ser ignorada na pesquisa acadêmica sobre Paulo e o judaísmo. O presente artigo destaca, sobretudo, aspectos do debate da nova perspectiva sobre Paulo no contexto da exegese alemã. Para tal, os nomes de Stendahl, Sanders e Dunn são referência básica.
Martin Bucer e os judeus
Authors: Hasselhoff Görge K.
Published: July 2017

Tradicionalmente, a atitude em relação ao judaísmo de Martin Bucer, o reformador protestante de Estrasburgo, é julgada a partir de “Judenratschlag” (Conselho sobre os judeus) (1538), que ele escreveu junto com alguns pastores de Hesse a pedido do landgrave Felipe II. Este artigo faz uma aproximação diferente examinando as obras de Bucer de acordo com sua ordem cronológica. Sua atitude em relação à língua hebraica não era diferente daquela dos humanistas contemporâneos e, repetidamente, em seu comentário anonimamente publicado sobre os Salmos, utilizou a literatura exegética judaica pertinente.Com judeus contemporâneos como Josel de Rosheim ele mantinha uma relação pessoal amigável. Nesse contexto, é ainda mais surpreendente que ele seja o coautor do áspero livro “Judenratschlag”. A razão para isso poderia ser que Bucer era um teólogo tradicional que cresceu na tradição dominicana. Portanto seu conselho deveria ser visto como um conselho político com traços teológicos. No entanto, Bucer não era tão antijudaico e cheio de ódio judeu como seu companheiro reformador Martim Lutero.
Long-term influence of fixed lingual retainers on the development of gingival recession: A retrospective, longitudinal cohort study
Authors: Juloski Jovana , Glisic Branislav , Vandevska-Radunovic Vaska
Published: July 2017

Objective:

To investigate the long-term influence of fixed lingual retainers on the development of mandibular gingival recession and to compare the prevalence with untreated individuals.

Materials and Methods:

The material consisted of 144 subjects: 96 orthodontically treated patients followed for 5 years after therapy and 48 untreated age-matched subjects. The treated patients were divided in two groups: one receiving a fixed mandibular retainer (n = 48) and one receiving no form of retention in the mandible (n = 48). The presence or absence of gingival recession and calculus accumulation were scored before treatment (T0), after debonding (T1), and 5 years after debonding (T5) for each tooth in the mandibular intercanine region using plaster models and intraoral photographs. The chi-square test, one-way ANOVA, and Cochran's Q test were used to evaluate inter- and intragroup differences.

Results:

The prevalence of patients with recession increased gradually and significantly throughout the observation periods in all groups, but the intergroup differences at T5 were not significant. Significantly more calculus accumulation was observed at T5 in the retainer group compared with the group without retainers.

Conclusions:

Long-term presence of fixed lingual retainers does not seem to increase the development of mandibular gingival recession, but does increase calculus accumulation.
How accurate is Invisalign in nonextraction cases? Are predicted tooth positions achieved?
Authors: Grünheid Thorsten , Loh Charlene , Larson Brent E.
Published: July 2017

Objective:

To evaluate the accuracy of Invisalign technology in achieving predicted tooth positions with respect to tooth type and direction of tooth movement.

Materials and Methods:

The posttreatment models of 30 patients who had nonextraction Invisalign treatment were digitally superimposed on their corresponding virtual treatment plan models using best-fit surface-based registration. The differences between actual treatment outcome and predicted outcome were computed and tested for statistical significance for each tooth type in mesial-distal, facial-lingual, and occlusal-gingival directions, as well as for tip, torque, and rotation. Differences larger than 0.5 mm for linear measurements and 2° for angular measurements were considered clinically relevant.

Results:

Statistically significant differences (P < .05) between predicted and achieved tooth positions were found for all teeth except maxillary lateral incisors, canines, and first premolars. In general, anterior teeth were positioned more occlusally than predicted, rotation of rounded teeth was incomplete, and movement of posterior teeth in all dimensions was not fully achieved. However, except for excess posttreatment facial crown torque of maxillary second molars, these differences were not large enough to be clinically relevant.

Conclusions:

Although Invisalign is generally able to achieve predicted tooth positions with high accuracy in nonextraction cases, some of the actual outcomes may differ from the predicted outcomes. Knowledge of dimensions in which the final tooth position is less consistent with the predicted position enables clinicians to build necessary compensations into the virtual treatment plan.
Infecciones por Virus Zika en Colombia- 2015.
Authors: Jaramillo Tobón Antonio Carlos
Published: July 2017

El virus Zika se detectó en 1947 en Uganda, África, en un mico Macaccus Rhesus. Es parte de la familia Flaviviridae (género Flavivirus). En humanos la infección se demostró por serología en 1952 en Uganda y Tanzania; el virus se aisló en 1968 en Nigeria. La enfermedad consistía en fiebre de pocos grados, mialgias, artralgias, conjuntivitis serosa y un exantema morbiliforme parecido al del dengue clásico. Hasta 2006 hubo casos aislados en África y sudeste Asiático en viajeros. En 2007 en la Isla de Yap (Micronesia) se notificaron 185 casos y se identificó como posible vector al Aedes hensilii. En la Polinesia Francesa en 2013 hubo 10.000 casos y 70 fueron graves con complicaciones neurológicas y autoinmunes. Los vectores relacionados fueron Ae. aegypti y Ae. polynesiensis. En el 2014 hubo casos en Nueva Caledonia y en Islas Cook de Australia. En los siguientes siete años en viajeros en Thailandia, Camboya, Indonesia y Nueva Caledonia. No se informaron muertes. En América se había registrado casos en viajeros que se infectaron en África y las otras áreas ya mencionadas, con solo un caso autóctono en USA, por transmisión sexual. En febrero de 2014, hubo un caso confirmado en la isla de Pascua (Chile) y por lo menos otros 40 en Valparaíso; hubo nuevos casos hasta Junio en Pascua. Después de esto apareció la más grande epidemia registrada hasta ahora en la historia, en Brasil. Hasta la fecha se han detectado más de 84.931 casos (subrregistro más de 80 %), 40 muertes y una epidemia de microcefalia asociada a infecciones en embarazadas que se infectaron en los tres primeros meses. Ya hay casos en El Salvador, Guatemala, Guyana Francesa, Honduras, Martinica, México, Panamá, Puerto Rico, Paraguay, Surinam y Venezuela. En Colombia no se había informado casos hasta octubre de 2015, cuando el MSP confirmó nueve casos autóctonos en Cartagena (Bolívar), sin ninguna complicación. Hasta la semana epidemiológica 51 (diciembre 20-26, 2015), había un total de 736 casos confirmados en el Instituto Nacional de Salud (INS) y se había notificado 9.280 casos sospechosos. Procedían de 34/36 (94.44 %) de los Departamentos. No se han notificado muertes. Tampoco complicaciones, ni casos de microcefalia, aunque hubo 236 casos en embarazadas.
Cirugía de Ivor Lewis en el adenocarcinoma de la unión esofagogástrica, reporte de un caso
Authors: Castillo León Jhon Paul , Ordóñez Izquierdo María Del Cisne
Published: July 2017

El cáncer de esófago es el octavo tumor maligno más frecuente del mundo. En la mayoría de los pacientes el diagnóstico del tumor se realiza en estadios avanzados con elevada mortalidad. Se presenta el caso de un paciente masculino de 57 años que permanece asintomático, y en endoscopia digestiva de chequeo encuentran lesión ulcerada de 2 cm en unión esofagogástrica; la biopsia es positiva para malignidad (adenocarcinoma) por lo cual paciente es referido a cirugía oncológica para esofagectomía. El procedimiento realizado es Ivor Lewis (laparotomía + toracotomía derecha), y se complementa con ascenso gástrico para anastomosis esófago-gástrica, cirugía sin complicaciones. Lo silente y agresivo de esta patología debe tenerse en cuenta en pacientes añosos, con factores de riesgo, ya que no presenta sintomatología hasta que es demasiado tarde
POWER FREQUENCY OVERVOLTAGES GENERATED BY SOLAR PLANT INVERTERS
Authors: F.J. Pazos  , F.J. Pazos  , A. Barona  , J. Amantegui  , E. Azcona  , S. Fernández
Published: July 2017

A new kind of overvoltage, not covered by present standards, has been detected in solar plants when switching the inverters off. This power frequency overvoltage can be transmitted to the MV network, giving rise to damages to some pieces of low voltage electronic equipment. This phenomenon has been investigated in the field, testing several inverters in different solar plants, where the overvoltages, as well as the damages in revenue meters, have been reproduced and recorded. It has been proved that some inverter configurations are more prone to create severe overvoltages than other. In addition, some solutions have been tested and a laboratory test to reproduce the phenomenon is proposed