bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predicting Two-Phase Flow Regimes in Segments of a Gas/Condensate Well
Authors: Adeyemi Williams 
Published: December 2009

Abstract
As the prospect of producing gas reservoirs increases and economic uncertainties become greater, a good way of predicting the two-phase flow in a gas well is very important to know what to be expected and contingency plans to be adopted.
This paper presents a method of predicting the type of two-phase flow in segments of a well using a program written in FORTRAN, Bill-FlowTRAN.f95. The pressure drop across each segment was arithmetically calculated from the difference in the flowing bottomhole pressure across the segment, obtained using Cullender and Smith (Katz et al., 1957) method. Orkiszewski calculation procedures for two-phase flow and other correlations were then used to predict the two-phase flow in such a segment. The flow regimes covered are mist, transition and slug flow since bubble flow would likely not occur in a gas well.
Optimal Waterflood Management Under Geologic Uncertainty Using Rate Control: Theory and Field Applications
Authors: Alhuthali Ahmed H. 
Published: December 2009

Abstract
A robust and efficient approach for computing optimal injection and production rates is proposed to manage the waterflood front and maximize sweep efficiency. The work relies on equalizing the arrival times of the waterfront at all producers within selected sub-regions of a water flood project. The optimization approach proceeds smoothly toward the solution even if the initial conditions are far away because the arrival time optimization has favorable quasi-linear properties. The proposed approach also accounts for geologic uncertainty via a stochastic optimization framework using multiple realizations. Analytical forms for gradients and Hessian of the objective functions are derived, making the optimization computationally efficient for large-scale applications. In addition, optimization is performed under operational and facility constraints using a sequential quadratic programming approach.
The applicability of the approach is demonstrated using three field-scale examples. The first one is a benchmark case called ‘Brugge’ field, based on a North Sea Brent-type field. The production rate is optimized for this field as part of a closed-loop reservoir management process where the production history is matched prior to the production optimization. The optimization is performed over multiple realizations to account for geologic uncertainty. The second example is a CO2 pilot project area in the Goldsmith San Andres Unit (GSAU) in west Texas. The production rates are optimized for 31 wells while accounting for changing field condition such as shut-in and infill drilling. The third example is a super-giant middle-eastern field. The optimization is performed for a sub-region of this field which contains a large number of wells nearly 300 wells consisting of conventional vertical and horizontal wells and smart horizontal wells. The results clearly demonstrate the robustness and the efficiency of the proposed approach with considerable increase in cumulative oil production and a substantial decrease in the associated water production.
Determination of Facies From Seismic Data: A New and Improved Approach
Authors: Maria Belyanushkina 
Published: December 2009

Abstract
This paper describes a new computational method for facies mapping from seismic data and its application for analysis of new oil-prospective zones and projects for new exploration wells. In this paper the description of the algorithm and an opportunity of clustering of seismic data are presented. The developed algorithm allows execution of steady splitting into an automatically calculated number of clusters. In other words this algorithm enables obtaining identical results of clustering after reiteration of clustering procedure with the same parameters. A cluster's probability maps can be thus created. The evaluation procedure of the facies maps obtained can be done by means of this approach.
A system of tests was performed to check the new algorithm and to estimate its efficiency when the result of correct clustering is known in advance. Points were distributed randomly in spheres with the centers in corners of a multidimensional cube. Thus we can estimate the probability for correct calculation of the number of clusters.
Two sets of data were used: artificial (synthetic) data and real seismic data. For the synthetic data, as will be shown in the example, more reliable results were obtained when compared with the result of the well-known K-means algorithm. For real data the algorithm was applied to interesting areas for exploration of hydrocarbons deposits (traps) without using well information.
Investigation of the Mobilization of Residual Oil Using Micromodels
Authors: El Din Saad Ibrahim Ahmed Salah 
Published: December 2009

Abstract
The mobilization of residual oil was investigated in glass micromodels consisting of capillary networks with water-wet wettability as a function of capillary number (ratio of viscous to capillary forces). The micromodels used in this work had variable pore throat and pore body size distribution. Experimental results demonstrated that the entrapped residual oil blobs have a preferable orientation along the macroscopic flow direction of waterflooding. For substantial mobilization of the waterflood residual oil, the corresponding capillary number needs to be 100 times larger than that for the onset of mobilization of the largest blobs in place at the end of waterflooding. The reduced residual oil saturation with increasing capillary number obtained in this study is in qualitative and quantitative agreement with published capillary number curves for water-wet sandstones. A key feature of oil blob mobilization at high capillary number is the break-up of mobilized blobs to sub-pore size droplets as they flow through the pore network, some of which attach to the pore walls and thus making complete mobilization very difficult. It was concluded that class micromodels offer the potential to screen the best surfactant formulations for EOR application using residual oil mobilization experiments and for displacements of continuous oil in place.
Calculation of Permeabilities and Residual Saturations Using Invasion Percolation
Authors: Paredes Ricardo , Octavio Miguel 
Published: December 2009

Abstract
In this paper we describe computer simulations in two dimensions of two fluids flowing in a disordered porous media. In particular, we study the process of the displacement of a fluid by a second one in the limit of smallcapillary number. To simulate the dynamics of this process we use the invasion percolation model and represent the medium. by an array of pores with various size distributions. To assign disorder to the system, we model the presence of defects using percolating pore networks. The geometry of the disorder is characterized using concepts of the theory of fractals. The simulations yield percolating clusters of pores saturated with the invading fluid. The geometry of these clusters is characterized by its fractal dimension. This dimension depends on whether the displaced fluid is assumed to be completely incompressible or completely compressible, as well as on the fractal dimension of the porous medium. We also calculate the saturation of the fluids, which is found to be dependent on the geometry of the invader cluster and on the distribution of pore sizes. Using this invading clusters we employ a fast reduction algorithm, based on concepts of network theories, to calculate the effective permeability of the invader fluid with a variety of pore size distributions. We find that the particular size distribution and the geometry of the invading cluster determine the value of this permeability.

Introduction
In the last years, a series of new methods for studying disordered systems have shaken the investigations in porous media. The birth of new fractal geometries, which have struck a great part of natural sciences, also have begun to touch the field of reservoirs engineering. Though on a practical level, until now, fractal geometries haven't had the impact expected, on a conceptual level it has been possible to make researchers reorient their way of interpreting phenomena, from core to reservoir levels. On the other hand, stochastic type theories have also been revised with great interest by reservoir engineers. This type of theories have also been used from microscopic to reservoir scales. For example, many reservoir engineers have tought ingeostatistics as a fundamental tool in reservoir characterization.
Steam Stimulation Pilot Project in the Orinoco Belt, Zuata Area, Venezuela
Authors: Burkill Guy C.C. , Rondon Luis A. 
Published: December 2009

Abstract
Maraven has implemented a Pilot Project in the Zuata area of the Orinoco Belt to evaluate the following parameters in relation to a commercial development:Performance of slant wells drilled with angles of inclination up to 45degrees.Production mechanisms, particularly the possibility of reservoir compaction.Productivity of the area and well response to â??Huff and Puffâ?¿ steaminjection.Pumping efficiency as related to oil viscosity and well angle.
Twelve inclined wells (7 producers and 5 observers) have been drilled in a cluster configuration, using a slant rig with a well spacing at surface of 15metres and 300 metres in the reservoir.
The Case Against Mass E‐mails: Perverse Incentives and Low Quality Public Participation in U.S. Federal Rulemaking
Authors: Shulman Stuart W 
Published: December 2009

AbstractLarge‐scale e‐mail campaigns are a staple in the modern environmental movement. Interest groups increasingly use online mobilizations as a way to raise awareness, money, and membership. There are legitimate political, economic, and organizational reasons for doing so, but these gains may come at the expense of a more substantial and efficacious role for citizens who wish to use e‐mail to engage in public participation. This paper situates a close examination of the 1000 longest modified MoveOn. Org‐generated e‐mails sent to the Environmental Protection Agency (EPA) about its 2004 mercury rulemaking, in the broader context of online grassroots lobbying. The findings indicate that only a tiny portion of these public comments constitute potentially relevant new information for the EPA to consider. The vast majority of Move On comments are either exact duplicates of a two‐sentence form letter, or they are variants of a small number of broad claims about the inadequacy of the proposed rule. This paper argues that norms, rules, and tools will emerge to deal with the burden imposed by these communications. More broadly, it raises doubts about the notion that online public participation is a harbinger of a more deliberative and democratic era.
Early Adolescents' Use of Social Networking Sites to Maintain Friendship and Explore Identity: Implications for Policy
Authors: Clarke Barbie H 
Published: December 2009

AbstractThis paper considers 10‐14 year olds' adoption of digital technology, and the way in which the developmental tasks of early adolescence are played out within their everyday lives through their widespread interaction with digital media, considering both the social and the psychological processes that take place. It reflects on the concerns that have been expressed about children's use of digital social networking, but also looks at the benefits to children of using the media, and the implications for policymaking. The paper recognises that the widespread adoption of digital technology at this age is deeply embedded in the social context of early adolescents' lives. While the mental processes that take place and the developmental stages have not changed, it may be that digital technology is being used to process some of the tasks of early adolescence, especially in identity formation, the importance and the influence of peers, and the way that emotional support is given and received. An ethnographic study was carried out over two years in the homes of twenty‐eight children living in the south‐east of England. Research included over 30 hours of filmed observation, diaries, friendship maps, individual interviews, friendship focus groups and an online bulletin board. Early adolescence is viewed as a key stage in which emotional development can affect children's level of wellbeing, and friendship is especially important as they turn from their family to the outside world. In playing with identity, building relationships, maintaining friendships and turning to each other for encouragement and companionship, children gain ‘digital agency’. This process may be beneficial and an important source of support and comfort to the young adolescent who is experiencing transition both cognitively, physically, and through change of school. Policy decisions need to be based on a sound understanding of how children use digital technology, raising awareness of the benefits as well as the potential risks, encouraging peer communication and support, and informing parents and teachers of children's digital world.
An Economic Perspective on a U.S. National Broadband Plan
Authors: Hahn Robert , Wallsten Scott J. 
Published: December 2009

AbstractThis paper responds to the U.S. Federal Communications Commission's request for guidance in designing a national broadband plan. We argue that the U.S. market for Internet services is working well overall, as evidenced by nearly ubiquitous coverage, rapid adoption, large investments, and increasing speeds. Still, the market is not working well for all people in all places, and we offer a framework for considering policies intended to mitigate those issues. The core of the paper consists of nine recommendations. Two of our recommendations are general. First, the government should ensure that its interventions do more good than harm. Second, the government should define clear, measurable, goals that do not benefit particular firms, technologies, or regions. The remaining seven recommendations provide specific guidance for a U.S. broadband plan. They include: liberalizing spectrum, gathering and analyzing data on broadband demand, targeting resources to where they are most needed, defining broadband access to maximize social gain, designing mechanisms that will achieve the government's broadband goals at the lowest social cost, vigorous antitrust enforcement, and designing policies to facilitate rigorous evaluation.
The Internet and Public Policy
Authors: Margetts Helen Z 
Published: December 2009

AbstractThis article looks at the role of the Internet in policymaking, identifying potential policy effects of widespread use of the Internet by citizens, firms, governments and voluntary organizations. It considers how the Internet and Internet‐enabled social change might impact upon each of the four ‘tools’ of government policy — nodality, authority, treasure and organization — and how it might impact upon the mix of tools that policymakers select. It suggests a number of values normally associated with the Internet — innovation, trust, openness and equity — that might be expected to emerge in policy trends. It discusses the implications of Internet‐driven change for public policy research, pinpointing some key methodologies that will become increasingly important; generation of large‐scale transactional data; network analysis and experimental methods. The article argues that we cannot understand, analyse or make public policy without understanding the technological, social and economic shifts associated with the Internet — a task that the journal Policy & Internet is poised to undertake.
Rapunzel syndrome — a case report
Authors: Stojanovic Miroslava , Slavkovic Andjelka , Marjanovic Zoran , Stojanovic Miroslav , Zivanovic Dragoljub 
Published: December 2009

Abstract
Bezoars are collections of indigestible materials found in the gastrointestinal tract. Rapunzel syndrome is a rare complication of a gastric trichobezoar in which the mass of hair extends through the pylorus into the small bowel and can even reach the colon. A 12-year-old girl with severe pain and a feeling of “fullness” in the upper abdomen was admitted to Pediatric Surgery. Two days before admission, the patient presented with vague abdominal pain, vomiting with a little blood, and black stool. On physical examination she was pale and listless with patchy alopecia. Abdominal examination showed a mobile, palpable mass in the epigastrium. The initial hematocrit was 7,1%, and the erythrocyte count was 1,12×1012 cells per liter. Abdominal ultrasound and computed tomographic (CT) examinations confirmed the presence of a tumor-like formation in stomach. A giant bezoar with ulceration on the back wall of the stomach was verified by upper gastrointestinal endoscopy. Endoscopic extraction was not possible because of the size of the bezoar. Gastrotomy was performed to remove the bezoar that occupied most of the stomach, with a long tail that extended deeply into the duodenum (Rapunzel syndrome). The bezoar, 35 by 10 cm in diameter, was black and consisted of hair and synthetic fibers. Prompt diagnosis and treatment of trichobezoars are important to avoid a possible fatal outcome.
Molecular mechanisms of toxicity of simvastatin, widely used cholesterol-lowering drug. A review
Authors: Kaminsky Yury , Kosenko Elena 
Published: December 2009

Abstract
Statins are widely used and well tolerated cholesterol-lowering drugs, and when used for therapy purposes reduce morbidity and mortality from coronary heart disease. Simvastatin is one of nine known statins, specific inhibitors of hepatic enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase, the rate-limiting step of cholesterol biosynthesis, and is believed to reduce plasma cholesterol levels by decreasing the activity of this enzyme. Statin drugs represent the major improvement in the treatment of hypercholesterolemia that constitutes the main origin of atherosclerosis, leading to coronary heart disease. Although statins are generally safe, minor and severe adverse reactions are well known complications of statin use. Adverse events associated with simvastatin therapy are uncommon, but potentially serious. In this review some details about statins including their adverse effects in humans and animals, the effects of simvastatin on various intracellular and mitochondrial processes, and molecular mechanisms underlying simvastatin cytotoxicity are discussed.
“Does chronic kidney disease define a particular risk pattern of cerebral vessels modifications in patients with symptomatic ischemic cerebrovascular disease?”
Authors: Petrica Ligia , Petrica Maxim , Gheorghe Gluhovschi , Liviu Matcau , Florica Gadalean , Sorin Ursoniu , Catalin Jianu , Silvia Velciov , Flaviu Bob , Cristina Gluhovschi , Virginia Trandafirescu , Diana Matcau , Gheorghe Bozdog , Carmina Muresan 
Published: December 2009

Abstract
Cardiovascular complications, including stroke, may be attributed the highest rate of morbidity and mortality in patients with chronic kidney disease (CKD). The aim of our study was to evaluate the prevalence of CKD in patients with symptomatic ischaemic cerebrovascular disease and to establish of whether CKD may define a particular risk pattern of cerebral vessels modifications in this category of patients. The prevalence of CKD was evaluated in 590 consecutive patients with symptomatic ischaemic cerebrovascular disease admitted to a department of neurology. The types of stroke, the vascular territories, the vascular modifications and the haemodynamic changes (resistance index- RI) found by neurosonology (extracranial and transcranial Doppler ultrasound) were analysed in relation to classic and non-classic cerebrovascular risk factors, as well as to stages of CKD (defined by estimated glomerular filtration rate-eGFR-MDRD4 formula-K/DOQI 2002). The prevalence of CKD in the studied patients was 70.84%. Atherosclerosis in a diffuse pattern was detected in 79.7% of CKD patients, while carotid artery stenoses were found in 10% of cases, occlusions- 5.3%, stenoses + occlusions-1.2%, and multiple stenoses- 3.8% of cases. The RI evaluated in the internal carotid arteries correlated with fibrinogen(P<0.0001) and GFR(P<0.0001), while IR in the middle cerebral arteries correlated with fibrinogen(P<0.05), C-reactive protein(P<0.0001), and GFR(P<0.0001). There is a strong relation between symptomatic cerebrovascular disease and CKD, a fact demonstrated by the increased prevalence of CKD in these patients and by the severity of the cerebral vessels lesions.
Evaluation of fixed sources of variation and estimation of genetic parameters for incidence of bovine respiratory disease in preweaned calves and feedlot cattle12
Authors: Schneider M. J. , Tait R. G. , Ruble M. V. , Busby W. D. , Reecy J. M. 
Published: December 2009

ABSTRACTThe primary objective of this study was to estimate variance components and heritability of bovine respiratory disease (BRD) incidence in beef calves before weaning and during the finishing phase. The second objective was to investigate the impact of BRD incidence and treatment frequency on performance and carcass traits. Bovine respiratory disease is the biggest and most costly health challenge facing the cattle industry. The 2 populations used consisted of 1,519 preweaned calves and 3,277 head of feedlot cattle. The incidence rate of BRD in preweaned calves was 11.39%, and among treated cattle, 82.1% were treated once, 13.9% were treated twice, and 4.0% were treated 3 times or more. The incidence of BRD (P = 0.35) and the number of treatments (P = 0.77) had no significant effect on weaning BW. Heritability estimates of the entire preweaned population for BRD resistance and number of treatments were 0.11 ± 0.06 and 0.08 ± 0.05, respectively. The genetic correlation estimates for BRD incidence with weaning BW and birth BW were low (−0.02 ± 0.32 and 0.07 ± 0.27, respectively). The same estimate for the number of BRD treatments with weaning BW and birth BW was 0.25 ± 0.35 and 0.30 ± 0.27, respectively. The observed BRD incidence rate for feedlot cattle was observed at 9.43%. Incidence of BRD significantly (P &lt; 0.01) decreased overall and acclimation ADG by 0.06 ± 0.01 kg/d and 0.28 ± 0.03 kg/d, respectively. Carcass traits were also significantly (P &lt; 0.05) affected by BRD incidence; untreated cattle had a 9.1 ± 1.7-kg heavier HCW. Results were similar in the analysis of treatment frequency. The heritability estimate of BRD incidence and the number of treatments were 0.07 ± 0.04 and 0.02 ± 0.03, respectively. Estimates of genetic correlations of BRD incidence with production traits were −0.63 ± 0.22 for acclimation ADG, −0.04 ± 0.23 for on-test ADG, −0.31 ± 0.21 for overall ADG, −0.39 ± 0.21 for final BW, −0.22 ± 0.22 for HCW, −0.03 ± 0.22 for LM area, 0.24 ± 0.25 for fat, and −0.43 ± 0.20 for marbling score. Similar results for the number of treatments and production traits were −1.00 ± 0.68 for acclimation ADG, −0.04 ± 0.39 for on-test ADG, −0.47 ± 0.41 for overall ADG, −0.66 ± 0.40 for final BW, −0.58 ± 0.45 for HCW, −0.12 ± 0.38 for LM area, 0.42 ± 0.50 for fat, and −0.32 ± 0.37 for marbling score. Because of the high economic cost associated with BRD incidence, even these modest estimates for heritability of BRD resistance should be considered for incorporation into beef cattle breeding programs.