bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characteristics Associated With Awareness, Perceptions, and Use of Electronic Nicotine Delivery Systems Among Young US Midwestern Adults
Authors: Choi Kelvin , Forster Jean 
Published: January 2013

Objectives. We assessed the characteristics associated with the awareness, perceptions, and use of electronic nicotine delivery systems (e-cigarettes) among young adults. Methods. We collected data in 2010–2011 from a cohort of 2624 US Midwestern adults aged 20 to 28 years. We assessed awareness and use of e-cigarettes, perceptions of them as a smoking cessation aid, and beliefs about their harmfulness and addictiveness relative to cigarettes and estimated their associations with demographic characteristics, smoking status, and peer smoking. Results. Overall, 69.9% of respondents were aware of e-cigarettes, 7.0% had ever used e-cigarettes, and 1.2% had used e-cigarettes in the past 30 days. Men, current and former smokers, and participants who had at least 1 close friend who smoked were more likely to be aware of and to have used e-cigarettes. Among those who were aware of e-cigarettes, 44.5% agreed e-cigarettes can help people quit smoking, 52.8% agreed e-cigarettes are less harmful than cigarettes, and 26.3% agreed e-cigarettes are less addictive than cigarettes. Conclusions. Health communication interventions to provide correct information about e-cigarettes and regulation of e-cigarette marketing may be effective in reducing young adults’ experimentation with e-cigarettes.
Trends in Mortality Risk by Education Level and Cause of Death Among US White Women From 1986 to 2006
Authors: Montez Jennifer Karas , Zajacova Anna 
Published: January 2013

Objectives. To elucidate why the inverse association between education level and mortality risk (the gradient) has increased markedly among White women since the mid-1980s, we identified causes of death for which the gradient increased. Methods. We used data from the 1986 to 2006 National Health Interview Survey Linked Mortality File on non-Hispanic White women aged 45 to 84 years (n = 230 692). We examined trends in the gradient by cause of death across 4 time periods and 4 education levels using age-standardized death rates. Results. During 1986 to 2002, the growing gradient for all-cause mortality reflected increasing mortality among low-educated women and declining mortality among college-educated women; during 2003 to 2006 it mainly reflected declining mortality among college-educated women. The gradient increased for heart disease, lung cancer, chronic lower respiratory disease, cerebrovascular disease, diabetes, and Alzheimer’s disease. Lung cancer and chronic lower respiratory disease explained 47% of the overall increase. Conclusions. Mortality disparities among White women widened across 1986 to 2006 partially because of causes of death for which smoking is a major risk factor. A comprehensive policy framework should address the social conditions that influence smoking among disadvantaged women.
Asylum Seekers, Violence and Health: A Systematic Review of Research in High-Income Host Countries
Authors: Kalt Anne , Hossain Mazeda , Kiss Ligia , Zimmerman Cathy 
Published: January 2013

We performed a systematic review of literature on violence and related health concerns among asylum seekers in high-income host countries. We extracted data from 23 peer-reviewed studies. Prevalence of torture, variably defined, was above 30% across all studies. Torture history in clinic populations correlated with hunger and posttraumatic stress disorder, although in small, nonrepresentative samples. One study observed that previous exposure to interpersonal violence interacted with longer immigration detention periods, resulting in higher depression scores. Limited evidence suggests that asylum seekers frequently experience violence and health problems, but large-scale studies are needed to inform policies and services for this vulnerable group often at the center of political debate.
The Burden of Influenza B: A Structured Literature Review
Authors: Paul Glezen W. , Schmier Jordana K. , Kuehn Carrie M. , Ryan Kellie J. , Oxford John 
Published: January 2013

We reviewed the epidemiology, clinical characteristics, disease severity, and economic burden of influenza B as reported in the peer-reviewed published literature. We used MEDLINE to perform a systematic literature review of peer-reviewed, English-language literature published between 1995 and 2010. Widely variable frequency data were reported. Clinical presentation of influenza B was similar to that of influenza A, although we observed conflicting reports. Influenza B–specific data on hospitalization rates, length of stay, and economic outcomes were limited but demonstrated that the burden of influenza B can be significant. The medical literature demonstrates that influenza B can pose a significant burden to the global population. The comprehensiveness and quality of reporting on influenza B, however, could be substantially improved. Few articles described complications. Additional data regarding the incidence, clinical burden, and economic impact of influenza B would augment our understanding of the disease and assist in vaccine development.
The Impact of Increasing Health Insurance Coverage on Disparities in Mortality: Health Care Reform in Colombia, 1998–2007
Authors: Arroyave Ivan , Cardona Doris , Burdorf Alex , Avendano Mauricio 
Published: January 2013

Objectives. We examined the impact of expanding health insurance coverage on socioeconomic disparities in total and cardiovascular disease mortality from 1998 to 2007 in Colombia. Methods. We used Poisson regression to analyze data from mortality registries (633 905 deaths) linked to population census data. We used the relative index of inequality to compare disparities in mortality by education between periods of moderate increase (1998–2002) and accelerated increase (2003–2007) in health insurance coverage. Results. Disparities in mortality by education widened over time. Among men, the relative index of inequality increased from 2.59 (95% confidence interval [CI] = 2.52, 2.67) in 1998–2002 to 3.07 (95% CI = 2.99, 3.15) in 2003–2007, and among women, from 2.86 (95% CI = 2.77, 2.95) to 3.12 (95% CI = 3.03, 3.21), respectively. Disparities increased yearly by 11% in men and 4% in women in 1998–2002, whereas they increased by 1% in men per year and remained stable among women in 2003–2007. Conclusions. Mortality disparities widened significantly less during the period of increased health insurance coverage than the period of no coverage change. Although expanding coverage did not eliminate disparities, it may contribute to curbing future widening of disparities.
What “Price” Means When Buying Food: Insights From a Multisite Qualitative Study With Black Americans
Authors: DiSantis Katherine Isselmann , Grier Sonya A. , Odoms-Young Angela , Baskin Monica L. , Carter-Edwards Lori , Young Deborah Rohm , Lassiter Vikki , Kumanyika Shiriki K. 
Published: January 2013

Objectives. We explored the role of price in the food purchasing patterns of Black adults and youths.Methods. We analyzed qualitative data from interviews and focus groups with socioeconomically diverse, primarily female, Black adults or parents (n = 75) and youths (n = 42) in 4 US cities. Interview protocols were locality specific, but all were designed to elicit broad discussion of food marketing variables. We performed a conventional qualitative content analysis by coding and analyzing data from each site to identify common salient themes.Results. Price emerged as a primary influence on food purchases across all sites. Other value considerations (e.g., convenience, food quality, healthfulness of product, and family preferences) were discussed, providing a more complex picture of how participants considered the price of a product.Conclusions. Food pricing strategies that encourage consumption of healthful foods may have high relevance for Black persons across income or education levels. Accounting for how price intersects with other value considerations may improve the effectiveness of these strategies.
Reservoir Simulation of Steam Fracturing in Early-Cycle Cyclic Steam Stimulation
Authors: Cokar Marya , Kallos Michael S. , Gates Ian D. 
Published: January 2013

Summary
In cyclic steam stimulation (CSS), steam is injected above the fracture pressure into the oil-sands reservoir. In early cycles, the injected steam fractures the reservoir, creating a relatively thin dilated zone that allows rapid distribution of heat within the reservoir without excessive displacement of oil from the neighborhood of the wellbore. Numerical reservoir-simulation models of CSS that deal with the fracturing process have difficulty simultaneously capturing flowing bottomhole-pressure (BHP) behavior and steam injection rate. In this research, coupled reservoir-simulation (flow and heat transfer) and geomechanics models are investigated to model dynamic fracturing during the first cycle of CSS in an oil-sands reservoir. In Alberta, Canada, in terms of volumetric production rate, CSS is the largest thermal recovery technology for bitumen production, with production rates equal to approximately 1.3 million B/D in 2008. The average recovery factor from CSS is between 25 and 28% at the economic end of the process. This implies that the majority of bitumen remains in the ground. Because the mobility of the bitumen depends strongly on temperature, the performance of CSS is intimately linked to steam conformance in the reservoir, which is largely established during steam fracturing of the reservoir in the early cycles of the process. Thus, a fundamental understanding of the flow and geomechanical aspects of early-cycle CSS is critical. A detailed thermal reservoir-simulation model, including dilation and dynamic fracturing, was developed, with the use of a commercially available thermal reservoir simulator, to understand their effects on BHP and injection rate. The results demonstrate that geomechanics must be included to accurately model CSS. The results also suggest that the reservoir dilates during steam injection as the result of increases in reservoir temperature, which lead to thermal dilation and higher pore pressure.
Surge-and-Swab Pressure Predictions for Yield-Power-Law Drilling Fluids
Authors: Crespo Freddy , Ahmed Ramadan , Enfis Majed , Saasen Arild , Amani Mahmood 
Published: January 2013

Summary
Surge and swab pressures have been known to cause formation fracture, lost circulation, and well-control problems. Accurate prediction of these pressures is crucially important in estimating the maximum tripping speeds to keep the wellbore pressure within specified limits of the pore and fracture pressures. It also plays a major role in running casings, particularly with narrow annular clearances. Existing surge/swab models are based on Bingham plastic (BP) and power-law (PL) fluid rheology models. However, in most cases, these models cannot adequately describe the flow behavior of drilling fluids.
This paper presents a new steady-state model that can account for fluid and formation compressibility and pipe elasticity. For the closed-ended pipe, the model is cast into a simplified model to predict pressure surge in a more convenient way. The steady-state laminar-flow equation is solved for narrow slot geometry to approximate the flow in a concentric annulus with inner-pipe axial movement considering yield-PL (YPL) fluid. The YPL rheology model is usually preferred because it provides a better description of the flow behavior of most drilling fluids. The analytical solution yields accurate predictions, though not in convenient forms. Thus, a numerical scheme has been developed to obtain the solutions. After conducting an extensive parametric study, regression techniques were applied primarily to develop a simplified model (i.e., dimensionless correlation).
The performance of the correlation has been tested by use of field and laboratory measurements. Comparisons of the model predictions with the measurements showed a satisfactory agreement. In most cases, the model makes better predictions in terms of closeness to the measurements because of the application of a more realistic rheology model. The correlation and model are useful for slimhole, deepwater, and extended-reach drilling applications.
Adaptation of the CPR Preconditioner for Efficient Solution of the Adjoint Equation
Authors: Han Choongyong , Wallis John , Sarma Pallav , Li Gary , Schrader Mark L. , Chen Wen 
Published: January 2013

Summary
It is well known that the adjoint approach is the most efficient approach for gradient calculation, and it can be used with gradient-based optimization techniques to solve various optimization problems, such as the production-optimization problem and the history-matching problem. The adjoint equation to be solved in the approach is a linear equation formed with the “transpose” of the Jacobian matrix from a fully implicit reservoir simulator. For a large and/or complex reservoir model, generalized preconditioners often prove impractical for solving the adjoint equation. Preconditioners specialized for reservoir simulation, such as constrained pressure residual (CPR), exploit properties of the Jacobian matrix to accelerate convergence, so they cannot be applied directly to the adjoint equation. To overcome this challenge, we have developed a new two-stage preconditioner for efficient solution of the adjoint equation by adaptation of the CPR preconditioner (named CPRA: CPR preconditioner for adjoint equation).
The CPRA preconditioner has been coupled with an algebraic multigrid (AMG) linear solver and implemented in Chevron's extended applications reservoir simulator (CHEARS®). The AMG solver is well known for its outstanding capability to solve the pressure equation of complex reservoir models; solving the linear system with the “transpose” of the pressure matrix is one of the two stages of construction of the CPRA preconditioner.
Through test cases, we have confirmed that the CPRA/AMG solver with generalized minimal residual (GMRES) acceleration solves the adjoint equation very efficiently with a reasonable number of linear-solver iterations. Adjoint simulations to calculate the gradients with the CPRA/AMG solver take approximately the same amount of time (at most) as do the corresponding CPR/AMG forward simulations. Accuracy of the solutions has also been confirmed by verifying the gradients against solutions with a direct solver. A production-optimization case study for a real field using the CPRA/AMG solver has further validated its accuracy, efficiency, and the capability to perform long-term optimization for large, complex reservoir models at low computational cost.
Accurate Resolution of Near-Well Effects in Upscaled Models Using Flow-Based Unstructured Local Grid Refinement
Authors: Karimi-Fard M.. , Durlofsky L.J.. J. 
Published: January 2013

Summary
We present a new approach for representing wells in coarse-scale reservoir simulation models. The technique is based on an expanded well model concept which provides a systematic procedure for the construction of the near-well grid. The method proceeds by first defining an underlying fine-scale model, in which the well and any key near-well features such as hydraulic fractures are fully resolved using an unstructured grid. In the (coarse) simulation model, the geometry of the grid in the expanded well region, and the associated "radial" transmissibilities, are determined from the solution of a fine-scale, single-phase, well-driven flow problem. The coarse-scale transmissibilities outside of the well region are computed using existing local upscaling techniques or by applying a new global upscaling procedure. Thus, through use of near-well flow-based gridding and generalized local grid refinement, this methodology efficiently incorporates the advantages of highly-resolved unstructured grid representations of wells into coarse models. The overall model provided by this technique is compatible with any reservoir simulator that allows general unstructured cell-to-cell connections (model capabilities, in terms of flow physics, are defined by the simulator).
The expanded well modeling approach is applied to challenging 3D problems involving injection and production in a low-permeability heterogeneous reservoir, tight-gas production by a hydraulically-fractured well, and production in a gas-condensate reservoir. In the first two cases, where it is possible to simulate the fine-grid unstructured model, results using the expanded well model closely match the reference solutions, while standard approaches lead to significant error. In the gas-condensate example, which involves a nine-component compositional model, the reference solution is not computed, but the solution using the expanded well model is shown to be physically reasonable while standard coarse-grid solutions show large variation under grid refinement.
A Novel Alkaline/Surfactant/Foam Enhanced Oil Recovery Process
Authors: Guo Hua , Zitha Pacelli L.J. , Faber Rien , Buijse Marten 
Published: January 2013

Summary
This article reports a laboratory study of a novel alkaline/surfactant/foam (ASF) process. The goal of the study was to investigate whether foaming a specially designed alkaline/surfactant (AS) formulation could meet the two key requirements for a good enhanced oil recovery (EOR) [i.e., lowering the interfacial tension (IFT) considerably and ensuring a good mobility control]. The study included phase-behavior tests, foam-column tests, and computed-tomography (CT)-scan-aided corefloods. It was found that the IFT of the designed AS and a selected crude oil drops by four orders of magnitude at the optimum salinity. The AS proved to be a good foaming agent in the column tests and corefloods in the absence of oil. The mobility reduction caused by the AS foam was hardly sensitive to salinity and increased with decreasing foam quality. CT-scanned corefloods demonstrated that AS foam, after a small AS preflush, recovered almost all the oil left after waterflooding. The oil-recovery mechanism by ASF combines the formation of an oil bank and the transport of emulsified oil by flowing lamellae. Further optimization of the ASF is needed to ensure that the oil is produced exclusively by the oil bank.
Interpreting Pressure and Flow-Rate Data From Permanent Downhole Gauges by Use of Data-Mining Approaches
Authors: Liu Yang , Horne Roland N. 
Published: January 2013

Summary
The permanent downhole gauge (PDG) is a promising tool for reservoir testing but has yet to reach its full potential. Generally, conventional well-testing methods are most able to use small sections of constant-flow-rate data. However, data mining, a newly developed technique in computer science, is a tool that can reveal the relationship among variables from large volumes of data. The application of data-mining algorithms to synthetic and field data has been successful in extracting the reservoir model from variable-flow-rate and pressure-transient data. In fact, because of uncertainty in flow-rate measurements, this technique is one of the few ways to make use of the flow-rate data that are now available with some modern PDG tools.
The application is conducted in two steps. First, the pressure and flow-rate data from the PDG are used to train a nonparametric data-mining algorithm. The reservoir model is obtained implicitly in the form of polynomials in a high-dimensional Hilbert space defined by kernel functions when the algorithm converges after being trained to the data. Next, a specific flow-rate input (for example, constant rate) is fed into the data-mining algorithm. The data-mining algorithm will make a pressure prediction subject to the input flow rate. Because the data-mining algorithm has already obtained the reservoir model, the pressure prediction is expected to be the reservoir response given the constant flow rate. Therefore, the proposed constant flow rate and the predicted pressure reveal the reservoir model underlying the variable PDG data, without needing to specify in advance which reservoir model is to be used. Three methods (Methods A, B, and C), differing by input vectors, kernel functions, and presence of breakpoints detection, are proposed in the paper.
Synthetic noisy data and real field data were used to test this approach. Methods B and C were able to satisfactorily recover the wellbore/reservoir model in most considered cases. Even in extreme cases when the flow-rate data are noisy and changing frequently, and in the absence of any shut-ins, the method was still able to extract the reservoir models.
Nikaitchuq Extended-Reach Drilling: Designing for Success on the North Slope of Alaska
Authors: Abahusayn Mishal , Foster Brandon , Brink Jason , Kuck Marc , Longo Joseph 
Published: January 2013

Summary
A 52-well heavy-oil field development that targeted shallow—a 3,400- to 4,000-ft true vertical depth (TVD)—sands on the North Slope of Alaska was initiated in 2008. Horizontal wells of 11,000- to 13,000-ft measured depth (MD) were drilled early in the program. These initial wells served as "data-gathering and technology-proving" opportunities leading up to the eventual 23,000-ft-MD wells. Key technical challenges include equivalent-circulating-density (ECD) and drag management.
ECD management became essential in the 8½-in. production-hole section of the longer wells. A relatively narrow (&lt;600 psi) mud-weight (MW) window necessitated changes to casing, drillstring, drilling fluids, and operational parameters. Lighter-weight production casing allowed the drilling of a larger production hole (8¾-in. vs. 8½-in.). A tapered drillstring, reduced mud rheology, and reduced flow rate all became a necessary part of the ECD-management solution.
Advanced drag-management techniques are required to install the 9⅝-in. production casing, 5½-in. production liner, and 4½ × 3½-in. intelligent inner-string completion. The 9⅝-in. casing is installed by use of the "buoyancy assist" method (i.e., "flotation") so it may be "pushed" and reamed in the hole beyond the point of negative weight. The lower completion consists of a 5½-in. slotted liner with swell packers. Centralizers on the liner were changed from nonrotating to fixed, which allowed breaking axial drag while reaming the liners to depth.
Extensive torque-and-drag modeling was used to plan intelligent inner-string completions on the injector wells, which included injection control devices, swell packers, and a fiber-optic distributed temperature sensor (DTS) to monitor injectivity.
This full-length paper discusses the technical challenges, well-design solutions, and operational practices that were trialed and implemented to enable extended-reach wells to be successfully drilled on the edge of the industry-experience envelope, with all wells meeting targeted objectives.