bluuebunny/crossref_metadata_2025_split huggingface dataset:
INFLUÊNCIA DO TIPO E DA CONCENTRAÇÃO DE QUEBRADORES DE GÉIS NO PROCESSO DE FRATURAMENTO HIDRÁULICO
Authors: Cavalcante Mayra Almeida , Chaves Sinthya Gadelha , Fagundes Fabio Pereira , Santana Fagundes Keila Regina 
Published: July 2017

Umas das técnicas mais utilizadas até hoje para auxiliar o aumento da produção de óleo e gás de reservatórios subterrâneos é o fraturamento hidráulico. Nesta técnica, um fluido viscoso é bombeado para o fundo do poço a uma pressão suficientemente elevada, visando à criação de uma fratura de alta condutividade na formação de interesse. O fluido de fraturamento (gel de fraturamento) transporta sólidos responsáveis pela sustentação da fratura (areia, bauxita ou cerâmica) os quais asseguram a existência de um canal efetivo e permanentemente aberto ao fluxo de hidrocarbonetos após o fim do bombeio. Normalmente, as soluções poliméricas são extensivamente utilizadas na preparação desses géis. Uma característica importante destes é ser facilmente quebrado no fim da operação, para que os seus resíduos não venham a tamponar os poros recém-criados. De acordo com a literatura, um gel completamente quebrado (Linear ou reticulado) é aquele cuja viscosidade é aproximadamente menor que 10 cP. Com isso, o objetivo deste trabalho consiste em avaliar a eficiência de diferentes tipos e concentrações (5%, 15%, 30%) dos “quebradores de gel” (Ácido Clorídrico, Persulfato de amônio e cloreto de cálcio) em função das propriedades reológicas do fluido de fraturamento. De acordo com os resultados obtidos podemos afirmar que o HCl 15% utilizado como quebrador, apesar de promover a quebra completa do gel acaba gerando alguns transtornos associados ao reservatório, podendo promover obstruções e acarretando um aumento no dano a formação. O cloreto de cálcio funcionou mais como um agente de precipitação do que propriamente como um quebrador. Assim, o persulfato de amônio, foi entre os quebradores estudados, o mais eficiente no processo de faturamento hidráulico tendo em vista os menores valores de viscosidade.
ESTUDO DE PREDIÇÃO DE PROJETOS DE RECUPERAÇÃO DE PETRÓLEO POR INJEÇÃO CONTINUA DE ÁGUA E GÁS: CAMPO DE EAST UNITY, BACIA DE MUGLAD
Authors: Pontes Amorim Nathália , Da Silva Nayra Vicente Souza , Almeida de Assis Debora Cristina 
Published: July 2017

O estudo e utilização da simulação numérica na Engenharia de Reservatórios advém da necessidade de se obter uma previsão do comportamento de um campo petrolífero ao longo de sua vida útil. Essa previsão é imprescindível para a tomada de decisão e determinação da melhor estratégia de produção, a qual extrairá a maior quantidade de óleo e alcançará um melhor desempenho do campo. Nesse contexto, o presente trabalho busca utilizar-se da simulação numérica de fluxo como ferramenta para prever e analisar a performance de diversos cenários de produção para um modelo de reservatório convencional de petróleo submetido a técnica de recuperação suplementar por injeção contínua de água e injeção contínua de gás. A injeção de água é uma técnica com domínio tecnológico conhecido e é amplamente utilizada na indústria de petróleo. A técnica de injeção de gás imiscível, assim como a injeção de água, possui o comportamento essencialmente mecânico de deslocar o óleo, não ocorrendo interação de ordem química entre o fluido injetado e o óleo. A simulação numérica de fluxo desse estudo foi realizada com o software em diferenças finitas, IMEX - Computer Modelling Group (CMG) e a análise dos resultados de cada cenário de injeção de água e de gás foi realizada a partir do estudo de variáveis, como o fator de recuperação do campo, produção acumulada de óleo e saturação de óleo. Para a definição do modelo físico, foram utilizadas as propriedades dos reservatórios observados no campo de East Unity, na Bacia de Muglad na África.
Design and Deployment of a Personalized News Service
Authors: Stefik Mark , Good Lance 
Published: July 2017

From 2008–2010 we built an experimental personalized news system where readers subscribed to organized channels of topical information that were curated by experts. AI technology was employed to present the right information efficiently to each reader and to reduce radically the workload of curators. The system went through three implementation cycles and processed more than 20 million news stories from about 12,000 Really Simple Syndication (RSS) feeds on more than 8000 topics organized by 160 curators for more than 600 registered readers. This article describes the approach, engineering, and AI technology of the system.
The Glass Infrastructure — Using Common Sense to Create a Dynamic, Place‐Based Social‐Information System
Authors: Havasi Catherine , Borovoy Richard , Kizelshteyn Boris , Ypodimatopoulos Polychronis , Ferguson Jon , Holtzman Henry , Lippman Andrew , Schultz Dan , Blackshaw Matthew , Elliott Greg 
Published: July 2017

Most organizations have a wealth of knowledge about themselves available online, but little for a visitor to interact with on‐site. At the MIT Media Lab, we have designed and deployed a novel intelligent signage system, the Glass Infrastructure (GI), that enables small groups of users to interact physically through a touch‐screen display with this data and to discover the latent connections between people, projects, and ideas. The displays are built on an adaptive, unsupervised model of the organization and its relationships developed using dimensionality reduction and commonsense knowledge that automatically classifies and organizes the information.The GI is currently in daily use at the lab. We discuss the AI model's development, the integration of AI into a human‐computer interaction (HCI) interface, and the use of the GI during the lab's peak visitor periods. We show that the GI is used repeatedly by lab visitors and provides a window into the workings of the organization.
Leveraging Multiple Artificial Intelligence Techniques to Improve the Responsiveness in Operations Planning: ASPEN for Orbital Express
Authors: Knight Russell , Chouinard Caroline , Jones Grailing , Tran Daniel 
Published: July 2017

The challenging timeline for DARPA's Orbital Express mission demanded a flexible, responsive, and (above all) safe approach to mission planning. Mission planning for space is challenging because of the mixture of goals and constraints. Every space mission tries to squeeze all of the capacity possible out of the spacecraft. For Orbital Express, this means performing as many experiments as possible, while still keeping the spacecraft safe. Keeping the spacecraft safe can be very challenging because we need to maintain the correct thermal environment (or batteries might freeze), we need to avoid pointing cameras and sensitive sensors at the sun, we need to keep the spacecraft batteries charged, and we need to keep the two spacecraft from colliding … made more difficult as only one of the spacecraft had thrusters.Because the mission was a technology demonstration, pertinent planning information was learned during actual mission execution. For example, we didn't know for certain how long it would take to transfer propellant from one spacecraft to the other, although this was a primary mission goal. The only way to find out was to perform the task and monitor how long it actually took. This information led to amendments to procedures, which led to changes in the mission plan. In general, we used the ASPEN planner scheduler to generate and validate the mission plans. ASPEN is a planning system that allows us to enter all of the spacecraft constraints, the resources, the communications windows, and our objectives. ASPEN then could automatically plan our day. We enhanced ASPEN to enable it to reason about uncertainty. We also developed a model generator that would read the text of a procedure and translate it into an ASPEN model. Note that a model is the input to ASPEN that describes constraints, resources, and activities. These technologies had a significant impact on the success of the Orbital Express mission. Finally, we formulated a technique for converting procedural information to declarative information by transforming procedures into models of hierarchical task networks (HTNs). The impact of this effort on the mission was a significant reduction in (1) the execution time of the mission, (2) the daily staff required to produce plans, and (3) planning errors. Not a single misconfigured command was sent during operations.
Alzheimer’s Disease: Dawn of a New Era?
Authors: Amirrad Farideh , Bousoik Emira , Shamloo Kiumars , Al-Shiyab Hassan , Nguyen Viet-Huong V. , Montazeri Aliabadi Hamidreza 
Published: July 2017

Alzheimer’s disease (AD) is an irreversible neurodegenerative disease characterized by a progressive decline in cognition and memory, leading to significant impairment in daily activities and ultimately death. It is the most common cause of dementia, the prevalence of which increases with age; however, age is not the only predisposing factor. The pathology of this cognitive impairing disease is still not completely understood, which has limited the development of valid therapeutic options. Recent years have witnessed a wide range of novel approaches to combat this disease, so that they greatly increased our understanding of the disease and of the unique drug development issues associated with this disease. In this paper, we provide a brief overview of the history, the clinical presentation and diagnosis, and we undertake a comprehensive review of the various approaches that have been brought to clinical trials in recent years, including immunotherapeutic approaches, tau-targeted strategies, neurotransmitter-based therapies, neurotropic and hematopoietic growth factors, and antioxidant therapies, trying to highlight the lessons learned from these approaches. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.
Kangaroo Mother Care 1: Alleviation of Physiological Problems in Premature Infants
Authors: Bear Rebecca J. , Mellor David J. 
Published: July 2017

ABSTRACTKangaroo mother care (KMC) involves placing the newborn infant into prolonged and continuous skin-to-skin contact with the mother as soon as possible after birth, exclusive breastfeeding, early discharge from the health facility, and supportive follow-up at home. Claimed benefits of KMC as an aid to the clinical mitigation of some detrimental features of prematurity need to be evidence based. This article, the first of two, provides an overview of the impact of prematurity on those features of neonates to which KMC may be directed. Specifically, the mitigation of some cardiorespiratory, neurophysiological, sensory, gastrointestinal, musculoskeletal, renal, metabolic, and immunological impacts are outlined. Relevant neurobehavioral, psychosocial, sociocultural, and economic perspectives are briefly reviewed in the companion article. These two articles provide scientific support for a wider upscaling of KMC education and its cautious use in physiologically stable preterm infants.
Effect of R Ratio on Performance of Injection-Pressure-Operated Gas Lift Valves
Authors: Decker (retired) K. L. 
Published: July 2017

Summary
An injection-pressure-operated (IPO) gas lift valve's closing force is supplied by a nitrogen charge, acting on the effective area of the bellows (Ab), or a spring force. Traditionally, the opening force is the production pressure acting on the area of the port (Ap) plus the injection pressure acting on the bellows effective area minus the area of the port (Ab − Ap). Traditionally, the ratio Ap/Ab is referred to as the R ratio, and has been considered constant for every valve of the same make, model, and port size. The actual R ratio is not a constant and neither is it equal to the published value. The published R ratios are embedded in all gas lift design programs, and are an integral part of the gas lift design process. This paper describes the consequences of using an assumed R ratio in a gas lift design that is not the same as the actual R ratio of the valve that will be installed in the well.
Phosphorus fractions and its summer flux from sediments of deep reservoirs located at a phosphate-rock watershed, Central China
Authors: Bao Yufei , Wang Yuchun , Hu Mingming , Wang Qiwen 
Published: July 2017

Abstract
Huangbai River, including four enchained reservoirs, is located in a phosphate-rock watershed in Yichang City, Central China. Previous studies showed that pollution levels due to activities of phosphate mining (PM) were extremely high and the water quality of reservoirs was severely affected by sedimentation. Yet, detailed knowledge of the sediment is lacking at that high phosphorus (P) concentration basin. Therefore, the different P fractions and its diffusion fluxes at the water-sediment interface of four deep reservoirs have been investigated for the first time to understand the internal P loading. The results indicated that the concentrations of total P , ranging from 9,631.5 to 581.6 mg kg−1, exhibited an apparent spatial trend from the upstream to the downstream reservoirs, which corresponded with the activities of P mining in this basin. The P-fraction concentrations obtained from the sites were mainly ranked in this order: P associated with calcium (Ca-Pi) &gt; organic P (Po) &gt; P bound to aluminum (Al), ferrum (Fe) and manganese (Mn) oxides and hydroxides (Fe/Al-Pi). The orthophosphate diffusion fluxes ranged from −0.40 ± 0.09 to 0.95 ± 0.14 mg m−2 d−1 which were positively related to P fraction concentrations while negatively related to oxidation–reduction potential and dissolved oxygen values. These results implied the dynamics role of internal P loading. The principle component analysis suggested that PM activities and internal P loading were the most reactive factors in this river system.
Influence of Shear Connection Distributions on the Behaviour of Continuous Steel-concrete Composite Beams
Authors: Zona Alessandro , Leoni Graziano , Dall’Asta Andrea 
Published: July 2017

Background:In this work the behaviour of continuous steel-concrete composite beams with different shear connection distributions obtained from two design methods,i.e. Eurocode 4 and a proposed alternative approach, is analysed.Objective:For this purpose a finite element model specifically developed for the nonlinear analysis of steel-concrete composite beams is adopted. This finite element model includes material nonlinearity of slab concrete, reinforcement steel, beam steel as well as slab-beam nonlinear partial interaction due to the deformable shear connection. The inclusion of the partial interaction in the composite beam model provides information on the slab-beam interface slip and shear force and enables to model the failure of the shear connectors.Results and Conclusion:In this way it is possible to analyse and quantify the effect of shear connector distributions on the global and local response of continuous steel-concrete composite beams, both under service load levels and at collapse. Particular attention is focused on the ductility requirements on the shear connectors when varying the connection design approach and distribution.
Frailty Screening Tools for Elderly Patients Incident to Dialysis
Authors: van Loon Ismay N. , Goto Namiko A. , Boereboom Franciscus T.J. , Bots Michiel L. , Verhaar Marianne C. , Hamaker Marije E. 
Published: July 2017

Background and objectives
A geriatric assessment is an appropriate method for identifying frail elderly patients. In CKD, it may contribute to optimize personalized care. However, a geriatric assessment is time consuming. The purpose of our study was to compare easy to apply frailty screening tools with the geriatric assessment in patients eligible for dialysis.

Design, setting, participants, & measurements
A total of 123 patients on incident dialysis ≥65 years old were included <3 weeks before to ≤2 weeks after dialysis initiation, and all underwent a geriatric assessment. Patients with impairment in two or more geriatric domains on the geriatric assessment were considered frail. The diagnostic abilities of six frailty screening tools were compared with the geriatric assessment: the Fried Frailty Index, the Groningen Frailty Indicator, Geriatric8, the Identification of Seniors at Risk, the Hospital Safety Program, and the clinical judgment of the nephrologist. Outcome measures were sensitivity, specificity, positive predictive value, and negative predictive value.

Results
In total, 75% of patients were frail according to the geriatric assessment. Sensitivity of frailty screening tools ranged from 48% (Fried Frailty Index) to 88% (Geriatric8). The discriminating features of the clinical judgment were comparable with the other screening tools. The Identification of Seniors at Risk screening tool had the best discriminating abilities, with a sensitivity of 74%, a specificity of 80%, a positive predictive value of 91%, and a negative predictive value of 52%. The negative predictive value was poor for all tools, which means that almost one half of the patients screened as fit (nonfrail) had two or more geriatric impairments on the geriatric assessment.

Conclusions
All frailty screening tools are able to detect geriatric impairment in elderly patients eligible for dialysis. However, all applied screening tools, including the judgment of the nephrologist, lack the discriminating abilities to adequately rule out frailty compared with a geriatric assessment.
Areas de actividad doméstica en Pueblo Viejo de Tucute (Puna de Jujuy)
Authors: Albeck María Ester 
Published: July 2017

La excavación y el análisis de los materiales arqueológicos del recinto 1 de Pueblo Viejo de Tucute, ubicado en la Puna de Jujuy, ha permitido definir diferentes áreas de actividad en el interior de la vivienda. La dispersión areal, asociación y estado de conservación de los materiales permiten proponer áreas preferenciales para el desarrollo de ciertas actividades domésticas como molienda, elaboración y consumo de comidas, almacenamiento y descanso.ABSTRACTThe excavation of house 1 in Pueblo Viejo de Tucute (Puna de Jujuy) and the further analysis of the archaeological finds show differents activity areas inside the dwelling. Preferential áreas for certain domestic activities like grinding, food elaboration and consumption, storage and resting places are proposed following the areal dispersion, association and conservation of the archaeological finds.
El fenómeno “pucara” visto desde la puna jujeña
Authors: Ruiz Marta , Albeck María Ester 
Published: July 2017

En los Andes Centro Sur el uso del término pucara es ambiguo, dado que se lo utiliza para denominar tanto fortalezas, poblados fortificados, asentamientos naturalmente inexpugnables o sitios estratégicos que controlan recursos o vías de circulación. Cronológicamente comprenden al menos dos momentos, preincaico e incaico. Se relaciona el surgimiento de este tipo de asentamientos con el contexto social y político de los inicios del Intermedio Tardío en los Andes Centro Sur. En la Puna de Jujuy es escasa la presencia de pucara al menos si lo referimos a algunas de las áreas aledañas (Quebrada de Humahuaca). Esto probablemente se pueda referir a particulares condiciones sociales o económicas en el Intermedio Tardío para esta parte de los Andes.ABSTRACTThe use of the term pucara is rather ambiguous in the South Central Andes. It is used for naming both fortresses, fortified villages, settlements with a very difficult access, or sites with a strategic location regarding resource controlor circulation. Some of these pucara belong to the Inca Period and other are earlier. The emergence of the pucara settlements is related to the political and social conditions in the begginning of the Late Intermediate Period in the South Central Andes. In the Puna de Jujuy the pucara are scarce, at least when we have in mind some nearby areas as the Quebrada de Humahuaca. This can probably be related to particular conditions in this part of the Andes during theLate Intermediate Period.
Aspectos rituales relacionados con el ganado en Santiago de Río Grande (II Región, Chile)
Authors: Lagos Reinaldo , Mendoza Emilio , Ampuero Nolberto , Hernández Nora 
Published: July 2017

Se transcribe una entrevista con Emilio Mendoza, comunero del pueblo Santiago de Río Grande (comuna de San Pedro de Atacama), relativa a aspectos rituales del ganado. Se describe la solidaridad social a nivel de las contribuciones comunitarias como aporte en la formación de rebaños para con los jóvenes que inician su vida marital; se hace referencia a las creencias que norman la iniciación de la vida pastoril y a las ceremonias relacionadas con la prosperidad ganadera. Además, se hace especial mención de las divinidades asociadas con el ganado de los rituales de huaqui y chuya y, de las ceremonias de tikavela y pitira.ABSTRACTWe transcribed the text of an interview with Emilio Mendoza, a resident of the pueblo Santiago de Rio Grande (San Pedro de Atacama) about the ritual relationships with livestock. We described the level of social solidarity by which the pueblo interacts in the formation of herds and animal husbandry practices. We make particular reference to the belief in these ceremonies of pastorial living and prosperous breeding. We also make special mention of divinities associated with the livestock, of the rituals of huaqui, chuya, and of the ceremonies of tikavela and pitira.
Apuntes sobre el tema de la identidad cultural en la Región de Tarapacá
Authors: González Cortez Héctor Segundo 
Published: July 2017

Este trabajo, redactado bajo la forma de un ensayo, recoge algunos de los componentes que el autor considera relevantes para abordar y problematizar el tema de la identidad cultural en la región deTarapacá. En primer término, se trata la relación entre identidad, historia y nacionalismo, enfatizando la manera en que la constitución de la nacionalidad chilena en un espacio de ocupación expulsa del imaginario cultural el período peruano y, además, por medio de políticas públicas abiertas o no declaradas, desde el Estado se imponen aquellos elementos culturales que, provenientes de la zona centro sur del país, se consideran representativos del deber ser nacional. En segundo lugar, se abordan algunas identidades de grupos particulares o ciertos componentes que todavía parecen influir en la definición de la identidad regional, además de otros que han aparecido más recientemente producto de los procesos de globalización de la cultura y la economía que afectan también a la región. Por último, a manera de conclusión, se tratan algunos elementos que, pese a su importancia pasada, están siendo o han sido relegados al abandono como constituyentes de identidad.ABSTRACTThis paper, drafted under the form of an essay, gathers some of the elements that the author considers relevant in approaching the research problem of the cultural identity issue in the Tarapacá region. The relationship between identity, history and nationalism is treated firstly, emphasizing the way in which the constitution of the Chilean nationality, from its occupation space, expels the cultural imaginary of the Peruvian period; and further more, cultural elements originated in the south central region of the country are imposed as genuine national representative symbols by means of public and not declared politics. Secondly, some identities of particular groups are considered, or some elements that still seem to influence the definition of regional identity with others that have emerged more recently, as a product of the globalization process of culture and economy that also affects the region. Finally and as a conclusion, some other important elements are referred to, even though they have been relegated to a second place and abandoned as constituent of identity.